This document summarizes an experimental study that measured the nonlinear optical properties of 2,3-
Diaminopyridine solution using z-scan techniques with continuous wave laser illumination. The study found
that the solution exhibited negative nonlinear refraction with a refractive index on the order of 10-8 cm2/W and
nonlinear absorption with a coefficient on the order of 10-3 cm/W. Diffraction ring patterns were also observed
due to nonlinear refraction effects. The nonlinear properties increased with higher concentration, intensity, and
wavelength. The results suggest 2,3-Diaminopyridine could be a new nonlinear optical material.
This document summarizes research on measuring the third-order nonlinear optical properties of Bismarck Brown Y dye using Z-scan technique with a continuous-wave laser. Key findings include:
- The nonlinear refractive index (n2) was measured to be on the order of 10-7 cm2/Watt and the nonlinear absorption coefficient (β) was measured to be on the order of 10-3 cm/Watt.
- The third-order nonlinear susceptibility (χ(3)) was calculated from the n2 and β values using equations in the document.
- Optical limiting behavior was observed, with transmission decreasing and leveling off above a threshold input power of around 4.5
AOS is an industry leader in diffractive optics design & manufacturing. We offer the best lens design, metrology, and extensive fabrication of diffractive optical elements with high precision and diffraction efficiency. Visit Us
Best therapy for small superficial treatment areasRosannah Smith
The document compares electron therapy and low energy photon therapy for small superficial treatments. Film dosimetry experiments show that electron therapy results in underdosing of the central treatment area and overdosing of surrounding healthy tissue for fields smaller than 3 cm due to the wide penumbra. In contrast, photon therapy provides a more uniform dose across the majority of the treatment area with a much narrower penumbra, avoiding misdosing. Therefore, photons are concluded to provide a safer and more effective option than electrons for small superficial treatments.
Computationally Efficient Methods for Sonar Image Denoising using Fractional ...CSCJournals
Sonar images produced due to the coherent nature of scattering phenomenon inherit a multiplicative component called speckle and contain almost homogeneous as well as textured regions with relatively rare edges. Speckle removal is a pre-processing step required in applications like the detection and classification of objects in the sonar image. In this paper computationally efficient Fractional Integral Mask algorithms to remove the speckle noise from sonar images is proposed. Riemann- Liouville definition of fractional calculus is used to create Fractional integral masks in eight directions. The use of a mask incorporated with the significant coefficients from the eight directional masks and a single convolution operation required in such case helps in obtaining the computational efficiency. The sonar image heterogeneous patch classification is based on a new proposed naive homogeneity index which depends on the texture strength of the patches and despeckling filters can be adjusted to these patches. The application of the mask convolution only to the selected patches again reduce the computational complexity. The non-homomorphic approach used in the proposed method avoids the undesired bias occurring in the traditional homomorphic approach. Experiments show that the mask size required directly depends on the fractional order. Mask size can be reduced for lower fractional orders thus ensuring the computation complexity reduction for lower orders. Experimental results substantiate the effectiveness of the despeckling method. The different non reference image performance evaluation criterion are used to evaluate the proposed method.
This document summarizes a measurement of a photon beam profile. The beam profile was measured at multiple depths in a water phantom using an ionization chamber. The results showed that the beam flatness improved with increasing depth due to increased scatter and decreasing photon energy off-axis. Specifically, the beam profile was measured at depths of 5cm, 10cm, and 20cm for a 10x10cm beam, with the flatness increasing the deeper the measurement.
This document summarizes an experiment that uses four laser beams to trap thousands of sub-micron polystyrene particles in water, forming an optically induced crystal. Bragg scattering patterns from the crystal agree with the calculated lattice structure and polarization dependence. By observing the decay and rise of Bragg scattering intensity when turning the lattice on and off, the researchers study the Brownian motion dynamics of particles in the periodic potential, finding agreement with simulations based on the Langevin equation.
Optimization of Aberrated Coherent Optical SystemsIOSR Journals
This document summarizes research on optimizing the image quality of aberrated coherent optical systems through apodization. It studies how apodization filters can be used to reduce edge effects like ringing, gradient, and shifting caused by aberrations like defocus, coma, and spherical aberration. The results show that at certain apodization parameter values and aberration combinations, the image quality is improved with minimum edge shifting and improved edge gradient. Specifically, an apodization parameter of 0.75 eliminated edge ringing for various aberration combinations studied. Thus, apodization can help mitigate the degrading effects of one aberration through the introduction of other aberrations.
11.the optical constants of highly absorbing films using the spectral reflect...Alexander Decker
This document summarizes a study that determined the optical constants of thin films of rhodium metal using spectral reflectance measurements. The researchers measured the reflectance of rhodium films of varying thicknesses using a double beam spectrophotometer. They then used Kramers-Kronig relations to calculate the phase angle from the reflectance data and determine the real refractive index and extinction coefficient. Their method provides accurate optical constants without needing transmission measurements. They found the refractive index and extinction coefficient were nearly equal for thin films and that their method compared well to values from other interference-based techniques.
This document summarizes research on measuring the third-order nonlinear optical properties of Bismarck Brown Y dye using Z-scan technique with a continuous-wave laser. Key findings include:
- The nonlinear refractive index (n2) was measured to be on the order of 10-7 cm2/Watt and the nonlinear absorption coefficient (β) was measured to be on the order of 10-3 cm/Watt.
- The third-order nonlinear susceptibility (χ(3)) was calculated from the n2 and β values using equations in the document.
- Optical limiting behavior was observed, with transmission decreasing and leveling off above a threshold input power of around 4.5
AOS is an industry leader in diffractive optics design & manufacturing. We offer the best lens design, metrology, and extensive fabrication of diffractive optical elements with high precision and diffraction efficiency. Visit Us
Best therapy for small superficial treatment areasRosannah Smith
The document compares electron therapy and low energy photon therapy for small superficial treatments. Film dosimetry experiments show that electron therapy results in underdosing of the central treatment area and overdosing of surrounding healthy tissue for fields smaller than 3 cm due to the wide penumbra. In contrast, photon therapy provides a more uniform dose across the majority of the treatment area with a much narrower penumbra, avoiding misdosing. Therefore, photons are concluded to provide a safer and more effective option than electrons for small superficial treatments.
Computationally Efficient Methods for Sonar Image Denoising using Fractional ...CSCJournals
Sonar images produced due to the coherent nature of scattering phenomenon inherit a multiplicative component called speckle and contain almost homogeneous as well as textured regions with relatively rare edges. Speckle removal is a pre-processing step required in applications like the detection and classification of objects in the sonar image. In this paper computationally efficient Fractional Integral Mask algorithms to remove the speckle noise from sonar images is proposed. Riemann- Liouville definition of fractional calculus is used to create Fractional integral masks in eight directions. The use of a mask incorporated with the significant coefficients from the eight directional masks and a single convolution operation required in such case helps in obtaining the computational efficiency. The sonar image heterogeneous patch classification is based on a new proposed naive homogeneity index which depends on the texture strength of the patches and despeckling filters can be adjusted to these patches. The application of the mask convolution only to the selected patches again reduce the computational complexity. The non-homomorphic approach used in the proposed method avoids the undesired bias occurring in the traditional homomorphic approach. Experiments show that the mask size required directly depends on the fractional order. Mask size can be reduced for lower fractional orders thus ensuring the computation complexity reduction for lower orders. Experimental results substantiate the effectiveness of the despeckling method. The different non reference image performance evaluation criterion are used to evaluate the proposed method.
This document summarizes a measurement of a photon beam profile. The beam profile was measured at multiple depths in a water phantom using an ionization chamber. The results showed that the beam flatness improved with increasing depth due to increased scatter and decreasing photon energy off-axis. Specifically, the beam profile was measured at depths of 5cm, 10cm, and 20cm for a 10x10cm beam, with the flatness increasing the deeper the measurement.
This document summarizes an experiment that uses four laser beams to trap thousands of sub-micron polystyrene particles in water, forming an optically induced crystal. Bragg scattering patterns from the crystal agree with the calculated lattice structure and polarization dependence. By observing the decay and rise of Bragg scattering intensity when turning the lattice on and off, the researchers study the Brownian motion dynamics of particles in the periodic potential, finding agreement with simulations based on the Langevin equation.
Optimization of Aberrated Coherent Optical SystemsIOSR Journals
This document summarizes research on optimizing the image quality of aberrated coherent optical systems through apodization. It studies how apodization filters can be used to reduce edge effects like ringing, gradient, and shifting caused by aberrations like defocus, coma, and spherical aberration. The results show that at certain apodization parameter values and aberration combinations, the image quality is improved with minimum edge shifting and improved edge gradient. Specifically, an apodization parameter of 0.75 eliminated edge ringing for various aberration combinations studied. Thus, apodization can help mitigate the degrading effects of one aberration through the introduction of other aberrations.
11.the optical constants of highly absorbing films using the spectral reflect...Alexander Decker
This document summarizes a study that determined the optical constants of thin films of rhodium metal using spectral reflectance measurements. The researchers measured the reflectance of rhodium films of varying thicknesses using a double beam spectrophotometer. They then used Kramers-Kronig relations to calculate the phase angle from the reflectance data and determine the real refractive index and extinction coefficient. Their method provides accurate optical constants without needing transmission measurements. They found the refractive index and extinction coefficient were nearly equal for thin films and that their method compared well to values from other interference-based techniques.
MEASUREMENT OF SCATTERING LOSSES OF LASER COMPONENTS BY TOTAL INTEGRATED SCAT...Simona Liukaityte
This document summarizes research on measuring scattering losses of laser components using the Total Integrated Scattering (TIS) method with different beam diameters. The study found that using smaller beam diameters (less than 0.4mm required by standards) increased the resolution of surface maps but also increased measurement durations and scattering loss values. Smaller beams made smaller defects and damages more visible. Beam diameters from 0.2mm to 1.12mm produced scattering loss measurements that varied within ±10% and are suitable for measurements.
Dosimetric Evaluation of High Energy Electron Beams Applied in RadiotherapyAYMAN G. STOHY
Electron-beam therapy: is used to treat superficial tumors at a standard 100 cm source-to-surface distance (SSD). Characteristics of electron beams from an Elekta PreciseTM linear accelerator are presented at a nominal SSD of 100 cm. However, certain clinical situations require the use of an extended SSD. The effects of extended source-to-surface distance (SSD) on the electron beam dose profiles were evaluated for various electron beam energies 6, 8, 10,12 and 15 MeV and the accuracy of various output correction methods was analyzed on an Elekta PreciseTM linear accelerator using a radiation field analyzer (RFA). Effective SSDs was evaluated for field sizes ranging from 6×6, 10×10, 14×14 and 20×20 cm2 for various energies.
Aim of the work
1.Investigate the physical properties of electron beams
at different beam energies.
2.Evaluate the accuracy of dose calculated by
Treatment Planning System (TPS) and measured for
different field configurations.
ELECTRICAL AND STRUCTURAL PROPERTIES OF ZnSe THIN FILMS BY ELECTRODEPOSITION ...IKHIOYA IMOSOBOMEH LUCKY
The document summarizes research on producing zinc selenide (ZnSe) thin films through an electrodeposition technique. X-ray diffraction analysis showed the films had a cubic structure and preferred orientation along the (111) plane. Optical analysis found the band gap energy was between 2.1-2.3 eV. Electrical measurements showed the films had high resistivity, making ZnSe suitable as a buffer layer in thin film technologies. Overall, the research aimed to characterize ZnSe thin films produced through an inexpensive electrodeposition method for potential optoelectronic and photovoltaic device applications.
This document summarizes an MPhys project report on optical coherence tomography using a Fourier domain method. The student, Riccardo William Monfardini, built an OCT apparatus and used it to measure the thickness of a microscope cover glass, determined to be 154.33±4.70μm. The report describes the theory behind OCT, including Fourier domain techniques, and details the student's method of using the apparatus to indirectly measure the glass thickness.
Comparison of Denoising Filters on Greyscale TEM Image for Different NoiseIOSR Journals
This document compares five different filters for removing noise from transmission electron microscopy (TEM) images: Wiener filter using discrete wavelet transform, hybrid median filter, bilateral filter, dual vectorial ROF filter, and fuzzy histogram equalization. Four types of noise are added to TEM images at varying levels: Gaussian noise, speckle noise, salt and pepper noise, and Poisson noise. The filters are applied to the noisy images and evaluated based on mean, mean square error, signal-to-noise ratio, and peak signal-to-noise ratio. Simulation results show that the dual vectorial ROF filter performs the best according to the evaluation metrics for each type of noise.
Performance Comparison of Various Filters and Wavelet Transform for Image De-...IOSR Journals
This document compares different filtering and wavelet transform approaches for image de-noising. It adds three types of noise (Gaussian, salt and pepper, speckle) to an image and uses median, Wiener, Gaussian, average filters and wavelet transform to remove the noise. It evaluates the performance of each approach using peak signal-to-noise ratio and root mean square error. The results show that wavelet transform performs best for removing Gaussian and speckle noise, while median filtering works best for salt and pepper noise removal. Overall, wavelet transform is concluded to be very effective for de-noising all types of noise.
Particle Size Analysis by Laser Diffraction Method. AshviniTanpure
For Determination of Particle Size various method are used. here I mentioned the Laser Light scattering for determining the Particle Size. Mainly two type of laser scattering are used,
1. Static laser light scattering.
2. Dynamic laser light scattering.
detail about there principle we see in the slide .
.
.
.
If in any point you didn't understood ,you can contact with me.
hope it useful to you.
Thank You.
Image Denoising is an important part of diverse image processing and computer vision problems. The
important property of a good image denoising model is that it should completely remove noise as far as
possible as well as preserve edges. One of the most powerful and perspective approaches in this area is
image denoising using discrete wavelet transform (DWT). In this paper, comparison of various Wavelets at
different decomposition levels has been done. As number of levels increased, Peak Signal to Noise Ratio
(PSNR) of image gets decreased whereas Mean Absolute Error (MAE) and Mean Square Error (MSE) get
increased . A comparison of filters and various wavelet based methods has also been carried out to denoise
the image. The simulation results reveal that wavelet based Bayes shrinkage method outperforms other
methods.
This document summarizes a 3-step method for segmenting skin lesions in images:
1. Preprocess by converting the color image to an intensity image, enhancing boundaries while suppressing internal details.
2. Segment the image by thresholding intensities, finding approximate lesion boundaries.
3. Refine the boundaries using edge information, initializing a curve at the boundary and fitting it to nearby edges.
Radiation indicator ink. 1. photogravure ink (vip)Mozierlan Li
This document summarizes the development of a radiation indicator ink that changes color based on absorbed radiation dose.
The ink was developed to allow quick and simple assessment of radiation doses used for sterilizing medical supplies. It contains diethylaminoazobenzene, which changes the ink color from yellow to orange, red, and purple as the radiation dose increases from 10 to 50 kGy.
Testing found the ink color change corresponds directly to radiation dose, regardless of dose rate from 1.41 to 33.4 kGy/h. Electron beam irradiation also produced consistent results. The ink provides a convenient way to check sterilization doses for large quantities of supplies.
This document discusses the physical properties of textile fibers and methods used to investigate fiber structure. It begins by explaining that the arrangement and bonding of atoms determines a material's properties. Fibers are defined as having flexibility, fineness, and a high length-to-thickness ratio. Methods used to investigate fiber structure include infrared spectroscopy, X-ray diffraction, optical microscopy, and nuclear magnetic resonance. Infrared spectroscopy identifies functional groups while X-ray diffraction provides information on crystalline structure and orientation. These methods allow characterization of fiber composition, molecular structure, and degree of crystallinity.
Effect of zinc on structural and some optical properties of cd s thin filmsAlexander Decker
This document summarizes research on the structural and optical properties of cadmium sulfide (CdS) thin films doped with varying concentrations of zinc (Zn). X-ray diffraction analysis showed that all films had a hexagonal structure and were polycrystalline. Grain size decreased with increasing Zn concentration, while surface roughness decreased based on atomic force microscopy. Optical analysis found that transmittance increased with Zn concentration, as did the optical band gap. Increasing the Zn dopant concentration improved some structural and optical properties of the CdS thin films.
Preparation and characterization of nimesulide loaded cellulose acetate hydro...Jing Zang
This document summarizes a study that prepared nimesulide-loaded cellulose acetate hydrogen phthalate nanoparticles using the salting out technique. The effect of drug concentration and polymer concentration on nanoparticle size, shape, and uniformity was investigated. Increasing the polymer concentration decreased nanoparticle size and improved uniformity. Drug concentration did not affect size. Nanoparticles were characterized using SEM, zeta potential analysis, and photon correlation spectroscopy. The mean nanoparticle size was 548.2 nm with a zeta potential of -19.8 mV, indicating stability.
Analysis of the_optical_density_profile_of_otolith_of_icefishryszardtraczyk
The document analyzes optical density profiles of otoliths from two fish species, Ps. georgianus and Ch. gunnarii, using computer measurement and harmonic analysis to investigate daily and other increments. For Ps. georgianus, the average width of daily larval otolith increments was 9.41 * 10-4 mm, while for juvenile Ch. gunnarii it was 0.0024 mm. Cyclical increments in larval Ps. georgianus otoliths followed a sine wave pattern.
This document describes an experiment to determine the width of a sheet of paper using wedge interference phenomenon. A sheet of paper is placed between two glass plates, forming an air wedge. Monochromatic light is shone through the wedge, and interference fringes are observed in the microscope. The distance between fringes is measured and used to calculate the width of the paper based on the wedge angle and refractive index differences.
The Indices of Refraction of Molecular-Beam Epitaxy–Grown BexZn1–xTe Ternary ...Oleg Maksimov
This document discusses a study that uses a combination of prism-coupling, reflectivity, and ellipsometric techniques to determine the indices of refraction (n) of molecular-beam epitaxy grown BexZn1-xTe thin films. Initially, prism-coupling measurements were used to obtain discrete n values and film thicknesses at specific wavelengths. Reflectivity data was then analyzed using the prism-coupling results to determine n dispersion below the bandgap. Ellipsometry was finally used to model n dispersion both below and above the bandgap, guided by the prior thickness and below-bandgap n data from the other techniques. The combination of these three methods allowed for accurate determination of n over a wide wavelength
International journal of applied sciences and innovation vol 2015 - no 2 - ...sophiabelthome
The document summarizes research on the physical properties of tin sulfide (Sn2S3) nanocrystalline thin films deposited via spray pyrolysis. Key findings include:
1) X-ray diffraction analysis revealed the films had a nanocrystalline structure with a grain size of 130 angstroms.
2) Optical analysis found the films had direct and indirect energy band gaps of 2 eV and 0.74 eV respectively.
3) Using models to analyze dispersion and dielectric properties, the films were found to have ionic characteristics.
This document discusses central axis depth doses in water for both SSD and SAD techniques. For SSD technique:
- Percentage depth dose (PDD) curves measure attenuation at different depths and are affected by beam quality, field size, and SSD.
- Buildup region occurs as secondary electrons deposit energy downstream, increasing dose with depth until maximum.
- Depth dose maximum (zmax) depends on beam energy and field size.
- PDD increases with larger field sizes due to increased scatter radiation.
- PDD increases with longer SSD due to the inverse square law of radiation intensity.
This document summarizes a research paper that compares different image filtering methods for reducing noise, including an adaptive bilateral filter, median filter, and Butterworth filter. The paper applies these filters to images with added Gaussian white noise and compares the results based on visual quality, mean squared error (MSE), and peak signal-to-noise ratio (PSNR). It finds that the adaptive bilateral filter produces the best results with the lowest MSE and highest PSNR, indicating it most effectively removes noise while preserving image details and sharpness.
Spectroscopic reflectance is a powerful method for thickness and n&k measurement of the translucent film. MProbe system makes this measurement easy and reliable
http://www.semiconsoft.com/wp/mprobe20desktop/
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document discusses the nonlinear optical properties of copper nanoparticles prepared by pulse laser ablation in different solutions. Copper nanoparticles were synthesized in distilled water, deionized water, and a mixture of ethylene glycol and deionized water using a nanosecond pulsed Nd:YAG laser. Characterization using UV-visible spectroscopy and SEM showed the nanoparticles had surface plasmon resonance peaks between 590-676 nm and diameters ranging from 13.16-21.25 nm depending on the solution. Z-scan measurements determined the nonlinear refractive index and nonlinear absorption coefficient of the copper nanoparticle suspensions.
MEASUREMENT OF SCATTERING LOSSES OF LASER COMPONENTS BY TOTAL INTEGRATED SCAT...Simona Liukaityte
This document summarizes research on measuring scattering losses of laser components using the Total Integrated Scattering (TIS) method with different beam diameters. The study found that using smaller beam diameters (less than 0.4mm required by standards) increased the resolution of surface maps but also increased measurement durations and scattering loss values. Smaller beams made smaller defects and damages more visible. Beam diameters from 0.2mm to 1.12mm produced scattering loss measurements that varied within ±10% and are suitable for measurements.
Dosimetric Evaluation of High Energy Electron Beams Applied in RadiotherapyAYMAN G. STOHY
Electron-beam therapy: is used to treat superficial tumors at a standard 100 cm source-to-surface distance (SSD). Characteristics of electron beams from an Elekta PreciseTM linear accelerator are presented at a nominal SSD of 100 cm. However, certain clinical situations require the use of an extended SSD. The effects of extended source-to-surface distance (SSD) on the electron beam dose profiles were evaluated for various electron beam energies 6, 8, 10,12 and 15 MeV and the accuracy of various output correction methods was analyzed on an Elekta PreciseTM linear accelerator using a radiation field analyzer (RFA). Effective SSDs was evaluated for field sizes ranging from 6×6, 10×10, 14×14 and 20×20 cm2 for various energies.
Aim of the work
1.Investigate the physical properties of electron beams
at different beam energies.
2.Evaluate the accuracy of dose calculated by
Treatment Planning System (TPS) and measured for
different field configurations.
ELECTRICAL AND STRUCTURAL PROPERTIES OF ZnSe THIN FILMS BY ELECTRODEPOSITION ...IKHIOYA IMOSOBOMEH LUCKY
The document summarizes research on producing zinc selenide (ZnSe) thin films through an electrodeposition technique. X-ray diffraction analysis showed the films had a cubic structure and preferred orientation along the (111) plane. Optical analysis found the band gap energy was between 2.1-2.3 eV. Electrical measurements showed the films had high resistivity, making ZnSe suitable as a buffer layer in thin film technologies. Overall, the research aimed to characterize ZnSe thin films produced through an inexpensive electrodeposition method for potential optoelectronic and photovoltaic device applications.
This document summarizes an MPhys project report on optical coherence tomography using a Fourier domain method. The student, Riccardo William Monfardini, built an OCT apparatus and used it to measure the thickness of a microscope cover glass, determined to be 154.33±4.70μm. The report describes the theory behind OCT, including Fourier domain techniques, and details the student's method of using the apparatus to indirectly measure the glass thickness.
Comparison of Denoising Filters on Greyscale TEM Image for Different NoiseIOSR Journals
This document compares five different filters for removing noise from transmission electron microscopy (TEM) images: Wiener filter using discrete wavelet transform, hybrid median filter, bilateral filter, dual vectorial ROF filter, and fuzzy histogram equalization. Four types of noise are added to TEM images at varying levels: Gaussian noise, speckle noise, salt and pepper noise, and Poisson noise. The filters are applied to the noisy images and evaluated based on mean, mean square error, signal-to-noise ratio, and peak signal-to-noise ratio. Simulation results show that the dual vectorial ROF filter performs the best according to the evaluation metrics for each type of noise.
Performance Comparison of Various Filters and Wavelet Transform for Image De-...IOSR Journals
This document compares different filtering and wavelet transform approaches for image de-noising. It adds three types of noise (Gaussian, salt and pepper, speckle) to an image and uses median, Wiener, Gaussian, average filters and wavelet transform to remove the noise. It evaluates the performance of each approach using peak signal-to-noise ratio and root mean square error. The results show that wavelet transform performs best for removing Gaussian and speckle noise, while median filtering works best for salt and pepper noise removal. Overall, wavelet transform is concluded to be very effective for de-noising all types of noise.
Particle Size Analysis by Laser Diffraction Method. AshviniTanpure
For Determination of Particle Size various method are used. here I mentioned the Laser Light scattering for determining the Particle Size. Mainly two type of laser scattering are used,
1. Static laser light scattering.
2. Dynamic laser light scattering.
detail about there principle we see in the slide .
.
.
.
If in any point you didn't understood ,you can contact with me.
hope it useful to you.
Thank You.
Image Denoising is an important part of diverse image processing and computer vision problems. The
important property of a good image denoising model is that it should completely remove noise as far as
possible as well as preserve edges. One of the most powerful and perspective approaches in this area is
image denoising using discrete wavelet transform (DWT). In this paper, comparison of various Wavelets at
different decomposition levels has been done. As number of levels increased, Peak Signal to Noise Ratio
(PSNR) of image gets decreased whereas Mean Absolute Error (MAE) and Mean Square Error (MSE) get
increased . A comparison of filters and various wavelet based methods has also been carried out to denoise
the image. The simulation results reveal that wavelet based Bayes shrinkage method outperforms other
methods.
This document summarizes a 3-step method for segmenting skin lesions in images:
1. Preprocess by converting the color image to an intensity image, enhancing boundaries while suppressing internal details.
2. Segment the image by thresholding intensities, finding approximate lesion boundaries.
3. Refine the boundaries using edge information, initializing a curve at the boundary and fitting it to nearby edges.
Radiation indicator ink. 1. photogravure ink (vip)Mozierlan Li
This document summarizes the development of a radiation indicator ink that changes color based on absorbed radiation dose.
The ink was developed to allow quick and simple assessment of radiation doses used for sterilizing medical supplies. It contains diethylaminoazobenzene, which changes the ink color from yellow to orange, red, and purple as the radiation dose increases from 10 to 50 kGy.
Testing found the ink color change corresponds directly to radiation dose, regardless of dose rate from 1.41 to 33.4 kGy/h. Electron beam irradiation also produced consistent results. The ink provides a convenient way to check sterilization doses for large quantities of supplies.
This document discusses the physical properties of textile fibers and methods used to investigate fiber structure. It begins by explaining that the arrangement and bonding of atoms determines a material's properties. Fibers are defined as having flexibility, fineness, and a high length-to-thickness ratio. Methods used to investigate fiber structure include infrared spectroscopy, X-ray diffraction, optical microscopy, and nuclear magnetic resonance. Infrared spectroscopy identifies functional groups while X-ray diffraction provides information on crystalline structure and orientation. These methods allow characterization of fiber composition, molecular structure, and degree of crystallinity.
Effect of zinc on structural and some optical properties of cd s thin filmsAlexander Decker
This document summarizes research on the structural and optical properties of cadmium sulfide (CdS) thin films doped with varying concentrations of zinc (Zn). X-ray diffraction analysis showed that all films had a hexagonal structure and were polycrystalline. Grain size decreased with increasing Zn concentration, while surface roughness decreased based on atomic force microscopy. Optical analysis found that transmittance increased with Zn concentration, as did the optical band gap. Increasing the Zn dopant concentration improved some structural and optical properties of the CdS thin films.
Preparation and characterization of nimesulide loaded cellulose acetate hydro...Jing Zang
This document summarizes a study that prepared nimesulide-loaded cellulose acetate hydrogen phthalate nanoparticles using the salting out technique. The effect of drug concentration and polymer concentration on nanoparticle size, shape, and uniformity was investigated. Increasing the polymer concentration decreased nanoparticle size and improved uniformity. Drug concentration did not affect size. Nanoparticles were characterized using SEM, zeta potential analysis, and photon correlation spectroscopy. The mean nanoparticle size was 548.2 nm with a zeta potential of -19.8 mV, indicating stability.
Analysis of the_optical_density_profile_of_otolith_of_icefishryszardtraczyk
The document analyzes optical density profiles of otoliths from two fish species, Ps. georgianus and Ch. gunnarii, using computer measurement and harmonic analysis to investigate daily and other increments. For Ps. georgianus, the average width of daily larval otolith increments was 9.41 * 10-4 mm, while for juvenile Ch. gunnarii it was 0.0024 mm. Cyclical increments in larval Ps. georgianus otoliths followed a sine wave pattern.
This document describes an experiment to determine the width of a sheet of paper using wedge interference phenomenon. A sheet of paper is placed between two glass plates, forming an air wedge. Monochromatic light is shone through the wedge, and interference fringes are observed in the microscope. The distance between fringes is measured and used to calculate the width of the paper based on the wedge angle and refractive index differences.
The Indices of Refraction of Molecular-Beam Epitaxy–Grown BexZn1–xTe Ternary ...Oleg Maksimov
This document discusses a study that uses a combination of prism-coupling, reflectivity, and ellipsometric techniques to determine the indices of refraction (n) of molecular-beam epitaxy grown BexZn1-xTe thin films. Initially, prism-coupling measurements were used to obtain discrete n values and film thicknesses at specific wavelengths. Reflectivity data was then analyzed using the prism-coupling results to determine n dispersion below the bandgap. Ellipsometry was finally used to model n dispersion both below and above the bandgap, guided by the prior thickness and below-bandgap n data from the other techniques. The combination of these three methods allowed for accurate determination of n over a wide wavelength
International journal of applied sciences and innovation vol 2015 - no 2 - ...sophiabelthome
The document summarizes research on the physical properties of tin sulfide (Sn2S3) nanocrystalline thin films deposited via spray pyrolysis. Key findings include:
1) X-ray diffraction analysis revealed the films had a nanocrystalline structure with a grain size of 130 angstroms.
2) Optical analysis found the films had direct and indirect energy band gaps of 2 eV and 0.74 eV respectively.
3) Using models to analyze dispersion and dielectric properties, the films were found to have ionic characteristics.
This document discusses central axis depth doses in water for both SSD and SAD techniques. For SSD technique:
- Percentage depth dose (PDD) curves measure attenuation at different depths and are affected by beam quality, field size, and SSD.
- Buildup region occurs as secondary electrons deposit energy downstream, increasing dose with depth until maximum.
- Depth dose maximum (zmax) depends on beam energy and field size.
- PDD increases with larger field sizes due to increased scatter radiation.
- PDD increases with longer SSD due to the inverse square law of radiation intensity.
This document summarizes a research paper that compares different image filtering methods for reducing noise, including an adaptive bilateral filter, median filter, and Butterworth filter. The paper applies these filters to images with added Gaussian white noise and compares the results based on visual quality, mean squared error (MSE), and peak signal-to-noise ratio (PSNR). It finds that the adaptive bilateral filter produces the best results with the lowest MSE and highest PSNR, indicating it most effectively removes noise while preserving image details and sharpness.
Spectroscopic reflectance is a powerful method for thickness and n&k measurement of the translucent film. MProbe system makes this measurement easy and reliable
http://www.semiconsoft.com/wp/mprobe20desktop/
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document discusses the nonlinear optical properties of copper nanoparticles prepared by pulse laser ablation in different solutions. Copper nanoparticles were synthesized in distilled water, deionized water, and a mixture of ethylene glycol and deionized water using a nanosecond pulsed Nd:YAG laser. Characterization using UV-visible spectroscopy and SEM showed the nanoparticles had surface plasmon resonance peaks between 590-676 nm and diameters ranging from 13.16-21.25 nm depending on the solution. Z-scan measurements determined the nonlinear refractive index and nonlinear absorption coefficient of the copper nanoparticle suspensions.
ELECTRICAL AND STRUCTURAL PROPERTIES OF ZnSe THIN FILMS BY ELECTRODEPOSITION ...IKHIOYA IMOSOBOMEH LUCKY
The document summarizes research on producing zinc selenide (ZnSe) thin films through an electrodeposition technique. X-ray diffraction analysis showed the films had a cubic structure and preferred orientation along the (111) plane. Optical analysis found the band gap was between 2.1-2.3 eV and the films had high transmittance in the visible-near infrared range, making ZnSe suitable as a glazing material. Electrical analysis measured the resistivity of the films to be in the range of 104-1012 Ωm, indicating ZnSe is suitable as a buffer layer in thin film technologies.
S IGNAL A ND I MAGE P ROCESSING OF O PTICAL C OHERENCE T OMOGRAPHY AT 1310 NM...sipij
OCT is a recently developed optical interferometric
technique for non-invasive diagnostic medical imag
ing
in vivo; the most sensitive optical imaging modalit
y.OCT finds its application in ophthalmology, blood
flow
estimation and cancer diagnosis along with many non
biomedical applications. The main advantage of
OCT is its high resolution which is in
μ
m range and depth of penetration in mm range. Unlik
e other
techniques like X rays and CT scan, OCT does not co
mprise any x ray source and therefore no radiations
are involved. This research work discusses the basi
cs of spectral domain OCT (SD-OCT), experimental
setup, data acquisition and signal processing invol
ved in OCT systems. Simulation of OCT involving
modelling and signal processing, carried out on Lab
VIEW platform has been discussed. Using the
experimental setup, some of the non biomedical samp
les have been scanned. The signal processing and
image processing of the scanned data was carried ou
t in MATLAB and Lab VIEW, some of the results thus
obtained have been discussed in the end
About The Importance Of The Definition Of Reflectance Quantities-Results Of C...Jim Webb
1) The document discusses the importance of properly defining reflectance quantities used in remote sensing studies. It notes inconsistencies in how terms like "albedo" have been used in different studies.
2) It summarizes definitions of key reflectance terms like BRDF, BRF, DHR, HDRF, and provides examples of measurable versus conceptual quantities.
3) Case studies are presented comparing modeling results for directional versus hemispherical reflectance quantities for a black spruce forest canopy and snow cover, as well as MISR satellite data products, to demonstrate differences between these reflectance definitions.
Study the effect of thin film thickness on the optical features of (IR5 laser...TELKOMNIKA JOURNAL
The document studies the effect of thin film thickness and number of laser pulses on the linear and non-linear optical properties of thin film samples composed of IR5 laser dye, CdSe nanoparticles, and polypropylene polymer. Linear properties such as transmittance, absorbance, absorption coefficient, and refractive index were calculated for films of varying thickness and number of laser pulses. Non-linear properties including non-linear refractive index, non-linear phase shift, and non-linear absorption coefficient were determined from Z-scan measurements for films of different thickness. The results show that thicker films eliminate non-linear effects between layers, while CdSe nanoparticles cause absorption shifting to longer wavelengths. Film thickness and number of laser pulses influence non-
- The document describes an experiment to determine the wavelength of mercury light using a transmission grating. Observations were recorded of the diffraction angles of different colors of light in the first and second order spectra. Calculations were done to determine the wavelengths, which were found to have percentage errors of 7-16% compared to standard values. Precautions included ensuring proper setup of the spectrometer and keeping the grating normal to the incident light.
Numerical ray tracing through a modified cladding fiber optic segment sensorsRadhi Chyad
1) The document investigates light transmission through an optical fiber with a modified cladding segment using 3D geometric optics modeling.
2) It analyzes how the intensity of transmitted light is affected by the refractive index and length of the modified cladding segment.
3) The modeling shows that if the modified cladding has a higher refractive index than the core, light transmission is very low due to partial reflection and losses. But if the modified cladding has a lower refractive index, transmission reaches saturation after a short segment length, making it suitable for sensor applications.
Low optical limiting and nonlinear optical properties of vanadyl phthalocyani...Alexander Decker
This document summarizes research on the nonlinear optical and optical limiting properties of vanadyl phthalocyanine (VOPc) using a continuous wave laser. VOPc was prepared and characterized. Its third-order nonlinear optical properties were evaluated using the Z-scan technique, which observed a concentration dependent nonlinear refractive index. Low power optical limiting was also observed based on nonlinear refraction, indicating VOPc's potential as an optical limiting material.
Application of Seismic Reflection Surveys to Detect Massive Sulphide Deposits...iosrjce
Seismic reflection techniques, the most widely used geophysical method for hydrocarbon exploration
has the capability to delineate and provide better images of regional structure for exploration of mineral
deposits in any geological settings. Previous tests on detection and imaging of massive sulphide ores using
seismic reflection techniques have been done mostly in crystalline environments. Application of seismic
reflection techniques for imaging sedimentary hosted massive sulphide is relatively new and the few experiments
carried out are at local scale (<500m). In this study, we analyze the feasibility of such regional exploration by
modelling three massive sulphide ore and norite lenses scenario using 2D seismic survey with relatively sparse
source-receiver geometry to image these deposits within 1.5km depth range. Results from the modelling
experiment demonstrate that 2-Dimensional seismic reflections survey can be used to detect massive sulphides
at any scale. The test further indicates that geologic setting and acquisition parameters are very important for
the detection of these ore bodies. Overall, the outcomes of the results support our started objective which is to
demonstrate that seismic reflection surveys can be used to detect the presence of sediment hosted massive
sulphides at regional scale
Near infrared (NIR) spectroscopy involves using infrared light to analyze samples. It works by passing infrared light through a sample and measuring how much light is absorbed at different wavelengths. This absorption data reveals details about the molecular structure of the sample. A basic NIR spectroscopy device consists of a light source, monochromator to separate wavelengths, and detector to record signals. Calibration using samples of known composition is required to develop models relating spectral data to reference measurements. NIR spectroscopy offers advantages over traditional methods like being nondestructive, requiring minimal sample preparation, and allowing simultaneous analysis of multiple components.
Nephelometry and turbidimetry are techniques used to measure light scattering in solutions containing insoluble particles. Nephelometry measures the intensity of scattered light at an angle, usually 90 degrees, to the incident light beam. Turbidimetry measures the intensity of transmitted light through the solution at 180 degrees. The amount of scattered or transmitted light is proportional to the concentration of particles in solution. These techniques can be used to analyze factors like water clarity or determine concentrations of substances like sulfates, ammonia, and phosphorus.
1. The document discusses potential methods for realizing an all-plasmonic chip, including plasmonic photolithography and active plasmonic elements.
2. It describes a plasmonic waveguide ring resonator, which can selectively transmit wavelengths and could be used as a passive element.
3. It also discusses techniques for sub-wavelength photolithography like plasmonic lithography using localized surface plasmons, which has advantages over other methods like being low-cost and compatible with current fabrication processes.
The Birefringent Property of an Optical Resinfor the Study of a Stress Field ...ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Nephelometry and turbidimetry are analytical techniques that measure light scattering in solutions. Nephelometry measures scattered light intensity, while turbidimetry measures transmitted light intensity decrease. Both techniques can be used to determine analyte concentration and are applied in areas like water quality testing, food and beverage analysis, and clinical chemistry. The document discusses the principles, instrumentation, factors affecting measurement, and applications of nephelometry and turbidimetry.
The document discusses light scattering and the techniques of turbidimetry and nephelometry. It explains that turbidimetry measures light transmitted through a solution, while nephelometry measures scattered light, usually at a 90 degree angle. Key applications of these techniques include determining concentrations of particles in solutions and qualities like water clarity. Factors like particle size, wavelength, and concentration affect light scattering and the measurements.
Study of Rotation Measurements with a Passive Resonant Gyroscope Based on Hol...ijtsrd
We present rotation measurements performed with a passive resonant optical fibre gyroscope. The fibre used to realize the resonant cavity was a Kagome Hollow Core Fiber. Measurements were performed in two types of configurations. In the first configuration, the counter propagating beams resonate on the same cavity mode. This leads to observation of lock in that prevents measuring rotation rates below roughly 1° s. In the second configuration, the counter propagating beams resonate on two different cavity modes. This leads to rotation rates measurements below 0.1° s that are currently limited by some drifts. We will describe in the conference possible sources of drifts and the solutions we consider to circumvent them. Dr. Vinay Kumar Chaudhary "Study of Rotation Measurements with a Passive Resonant Gyroscope Based on Hollow Core Fiber" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26390.pdfPaper URL: https://www.ijtsrd.com/physics/other/26390/study-of-rotation-measurements-with-a-passive-resonant-gyroscope-based-on-hollow-core-fiber/dr-vinay-kumar-chaudhary
Application Of Biochemical Tools And Techniques.Ashley Carter
This document discusses various biochemical tools and techniques used in analysis. It describes several types of microscopy like light microscopy, fluorescence microscopy and electron microscopy. It also explains various spectroscopy techniques such as colorimetry, UV-visible spectroscopy and infrared spectroscopy. Additionally, it covers different types of chromatography and electrophoresis techniques used in biochemistry like paper chromatography, gel electrophoresis and SDS-PAGE.
The optical constants of highly absorbing films using the spectral reflectanc...Alexander Decker
This document summarizes a study that determined the optical constants of thin rhodium films using spectral reflectance measurements. The study used Kramers-Kronig relations to calculate the phase angle from reflectance measurements. This allowed determining the real refractive index. The extinction coefficient was then estimated using equations relating reflectance, refractive index, and film thickness. The determined optical constants compared well to values from an interference method. The method provides an accurate way to determine optical constants of highly absorbing thin films using normal incidence reflectance measurements alone.
This document proposes methods for generating electricity from speed breakers. It discusses 5 classifications of speed breaker power generators that use different mechanisms: 1) a chain drive mechanism, 2) a rack and pinion system, 3) direct use of the load through a reciprocating device, 4) a translator and stator topology, and 5) a pressure lever mechanism. The document also outlines the advantages of using speed breakers for power generation such as low cost and maintenance and being a renewable source. Some challenges are also noted such as selecting a suitable generator and dealing with rain damage.
Cassava waste water was used as an admixture to replace distilled water in ratios of 5%, 10%, 15%, and 20% for producing sandcrete blocks. 60 sandcrete blocks of size 450mm x 150mm x 225mm were produced with different admixture ratios and a control with 0% admixture. The blocks were cured for 7, 14, 21, and 28 days and then tested for moisture content, specific gravity, water absorption, and compressive strength. Test results showed that blocks with 20% cassava waste water admixture met the minimum compressive strength requirement of 3.30 N/mm2 set by Nigerian standards, indicating the potential of cassava waste water to improve sandcrete block quality and
The document presents a theorem on random fixed points in metric spaces. It begins with introductions to fixed point theory, random fixed point theory, and relevant definitions. The main result is Theorem 3.1, which proves that if a self-mapping E on a complete metric space X satisfies certain contraction conditions involving parameters between 0 and 1, then E has a unique fixed point. The proof constructs a Cauchy sequence that converges to the unique fixed point. The document contributes to the study of random equations and random fixed point theory, which has applications in nonlinear analysis, probability theory, and other fields.
1. The document discusses applying multi-curve reconstruction technology to seismic inversion to improve accuracy and reliability. It focuses on reconstructing SP and RMN curves from well logs that are affected by various distortions.
2. The process of reconstructing the curves involves removing baseline drift, standardizing values, applying linear filtering, and fitting the curves. This removes interference and retains valid lithological information.
3. Reconstructing high quality curves improves the resolution and credibility of seismic inversion results. The method is shown to effectively predict sand distribution with little error.
This document compares the performance of a Minimum-Mean-Square-Error (MMSE) adaptive receiver and a conventional Rake receiver for receiving Ultra-Wideband (UWB) signals over a multipath fading channel. It first describes the UWB pulse shapes and channel model used, including the 6th derivative of the Gaussian pulse and the IEEE 802.15.3a modified Saleh-Valenzuela channel model. It then discusses the Direct-Sequence and Time-Hopping transmission and multiple access schemes for UWB. The document presents the receiver structures for the MMSE adaptive receiver and Rake receiver and compares their performance using MATLAB simulations.
This document summarizes a study on establishing logging interpretation models for reservoir parameters like porosity, permeability, oil saturation, and gas saturation in the Gaotaizi Reservoir of the L Oilfield. Models were developed using core data from 4 wells and include:
1) A porosity model relating acoustic travel time to porosity with an error of 0.92%
2) A permeability model relating permeability to porosity with an error of 0.31%
3) An oil saturation model using resistivity data with empirically determined parameters
4) A method to determine original gas saturation from mercury injection data.
Application of the models improved interpretation precision and allowed recalculation of oil and gas reserves for the
This document discusses predicting spam videos on social media platforms using machine learning. It proposes using attributes like number of likes, comments, and view count to classify videos as spam or not spam. A predictive algorithm is developed that uses threshold values for attributes and natural language processing of comments to classify videos. Testing of the algorithm on a dataset achieved a spam prediction precision of 93.6%. Issues with small datasets decreasing accuracy are also discussed, along with continuing work to address this issue.
1) The study experimentally evaluated the compatibility relationship between polymer solutions and oil layers through core flooding tests with different permeability cores.
2) The results showed that injection rate decreased with increasing polymer concentration and molecular weight, and increased with permeability.
3) Based on the results, boundaries for injection capability were established and a compatibility chart was proposed to guide polymer solution selection for different sedimentary microfacies in the field based on permeability and pore size.
1. The document discusses the identification of lithologic traps in the D3 Member of the Gaonan Region using seismic attribute analysis, acoustic impedance inversion, and sedimentary microfacies analysis.
2. Several lithologic traps were identified in the I and II oil groups of the D3 Member, with the largest trap located between wells G46 and G146X1 covering an area of about 2.35 km2.
3. Impedance inversion, seismic attribute analysis, and sedimentary microfacies characterization using 3D seismic data helped determine the location and development of effective lithologic traps in the thin sandstone-shale interbeds of the target stratum.
This document examines using coal ash as a partial replacement for cement in concrete. Coal ash was substituted for cement at rates of 5%, 10%, and 15% by weight. Testing found that concrete with a 5% substitution of coal ash exhibited only a slight decrease in compressive strength of 2% at 28 days while gaining improved workability. Higher substitution rates of 10% and 15% coal ash led to greater decreases in compressive and tensile strength. The study concludes that a 5% substitution of coal ash for cement provides benefits of reduced cost and improved workability with minimal strength impacts, representing an effective use of a waste material that addresses sustainability.
Accounting professional judgment involves handling accounting events and compiling financial reports according to regulations and standards. However, professional judgment is sometimes manipulated to distort accounting information. The document discusses three ways manipulation occurs: 1) abandoning accounting principles, 2) optional changes to accounting policies, and 3) abuse of accounting estimates. The causes of manipulation include distorted motivations from corporate governance issues and catering to various stakeholder interests. Strengthening supervision and improving the accounting system are proposed to manage manipulation of professional judgment.
The document discusses research on the distribution of oil and water in the eastern block of the Chao202-2 area in China. It establishes standards for identifying oil, poor oil, dry, and water layers using well logging data. Analysis shows structural reservoirs are dominant and fault and sand body configuration control oil-water distribution. Oil-water distribution varies between fault blocks from "up oil, bottom water" to "up water, bottom oil" depending on structure and sand body development.
The document describes an intelligent fault diagnosis system for reciprocating pumps that uses pressure and flow signals as inputs. It consists of hardware for data acquisition and a software system for signal processing, feature extraction, and fault diagnosis using wavelet neural networks. The system was able to accurately diagnose three main fault types - seal ring faults, valve damage, and spring faults - based on differences observed in the pressure curves. Testing on over 12 samples of each fault type achieved a correct diagnosis rate of over 94%. The system provides a fast and effective means of remotely monitoring reciprocating pumps and identifying faults.
This document discusses the application of meta-learning algorithms in banking sector data mining for fraud detection. It proposes using Classification and Regression Tree (CART), AdaBoost, LogitBoost, Bagging and Dagging algorithms for classification of banking transaction data. The experimental results show that Bagging algorithm has the best performance with the lowest misclassification rate, making it effective for banking fraud detection through data mining. Data mining can help banks detect patterns for applications like credit scoring, payment default prediction, fraud detection and risk management by analyzing customer transaction history and loan details.
This document presents a numerical solution for unsteady heat and mass transfer flow past an infinite vertical plate with variable thermal conductivity, taking into account Dufour number and heat source effects. The governing equations are non-linear and coupled, and were solved numerically using an implicit finite difference scheme. Various parameters, including Dufour number and heat source, were found to influence the velocity, temperature, and concentration profiles. Skin friction, Nusselt number, and Sherwood number were also calculated.
The document discusses methods for obtaining a background image using depth information from a depth camera to more accurately extract foreground objects. It finds that accumulating depth images and taking the median value at each pixel provides the most accurate background image. The accuracy of three methods - average, median, and mode - are evaluated using simulated depth data of a captured plane. The median method provides the best results, followed by average, while mode performs worst. More accumulated images provide a more accurate background image across all methods.
This document presents a mathematical model for determining the minimum overtaking sight distance (OSDm) required for an ascending vehicle to safely pass another slower vehicle on a single lane highway with an incline. It defines sight distance, stopping sight distance, perception-reaction time and derives equations to calculate the reaction distance (d1), overtaking distance (d2), vehicle travel distance during overtaking (d3), and total minimum OSDm based on vehicle characteristics, road geometry, and coefficients of friction. The safe overtaking zone is defined as 3 times the minimum OSDm. The model accounts for effects of slope angle and aims to satisfy laws of mechanics for overtaking maneuvers on inclined two-way single lane highways.
This document discusses a novel technique for better analysis of ice properties using Kalman filtering. It summarizes previous research on sea ice segmentation using SAR imagery and dual polarization techniques. It proposes using an automated SAR algorithm along with Kalman filtering to more accurately detect sea ice properties from RADARSAT1 and RADARSAT2 imagery data. The document reviews techniques for image segmentation, dual polarization, PMA detection, and related work on sea ice classification using statistical ice properties, edge preserving region models, and object extraction methods.
This document summarizes a study on the bioaccumulation of heavy metals in bass fish (Morone Saxatilis) caught at Rodoni Cape in the Adriatic Sea in Albania. Samples of bass fish were collected from five sites and analyzed for mercury, lead, and cadmium levels in their muscles. The concentrations of heavy metals varied between fish and sites but were below international limits for human consumption. While the fish were found to be safe for eating, the study recommends continuous monitoring of metal levels in fish from the area due to various factors that can influence metal uptake over time.
This document discusses optimal maintenance policies for repairable systems with linearly increasing hazard rates. It considers a system with a constant repair rate and predetermined availability requirement. There are two maintenance policies: corrective maintenance only, and preventive maintenance at set time intervals. The goal is to determine the preventive maintenance interval that guarantees the availability requirement at minimum cost. Equations are developed to calculate the availability under each policy and the optimal preventive maintenance interval based on both availability and cost. A numerical example is provided to demonstrate the decision process in determining the optimal policy.
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
This presentation delves into the journey of Albumentations.ai, a highly successful open-source library for data augmentation.
Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
GraphSummit Singapore | The Art of the Possible with Graph - Q2 2024Neo4j
Neha Bajwa, Vice President of Product Marketing, Neo4j
Join us as we explore breakthrough innovations enabled by interconnected data and AI. Discover firsthand how organizations use relationships in data to uncover contextual insights and solve our most pressing challenges – from optimizing supply chains, detecting fraud, and improving customer experiences to accelerating drug discoveries.
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
Communications Mining Series - Zero to Hero - Session 1
E04542733
1. IOSR Journal of Engineering (IOSRJEN) www.iosrjen.org
ISSN (e): 2250-3021, ISSN (p): 2278-8719
Vol. 04, Issue 05 (May. 2014), ||V4|| PP 27-33
International organization of Scientific Research 27 | P a g e
Self diffraction and nonlinear optical properties for 2, 3-
Diaminopyridine under cw illumination
Abdulameer Imran1
, Hussain A. Badran2*
, Qusay M. Ali Hassan 3
1,2,3
(Physics Department , Education College for pure sciences, Basrah University, Basrah, Iraq)
Abstract: - The nonlinear absorption and refraction indices for 2,3-Diaminopyridine solution were measured
using open-and closed- aperture z-scan techniques, with continuous wave (cw) irradiation. Furthermore,
diffraction rings pattern as a result of nonlinear refraction was observed. The effect of concentration, wavelength
and laser intensity on the nonlinear absorption, nonlinear refraction and diffraction rings are studied
experimentally. It is found that the nonlinear refraction and absorption indexes in order of 10-8
cm2
/W and10-3
cm/W, respectively. We suggested an opportunity to form a new nonlinear-optical media for nonlinear optical
application.
Keywords: - nonlinear refractive index, nonlinear materials, Z-scan, self- diffraction.
I. INTRODUCTION
Nonlinear optics (NLO) is a branch of optics that is associated with the changes in the optical
properties of material when it interacts with light. Nonlinear optical materials have been explored greatly for
their various applications in all-optical switches, opto-electronic devices, 3-D optical memory devices, optical
modulation, tele-communications, human eyes and optical sensors protection, etc., and future applications in
biological and medical sciences [1-6]. Continuous wave lasers ranging from mW to kW are widely used in
many applications[7]. Wide range of materials including liquid crystals, porphyrins, dyes, semiconductor
nanoparticles, thin films, phthalocyanines and crystals are known to be optically nonlinear under cw laser
illumination [8-16].
Several techniques developed to measure the nonlinear optical properties such as nonlinear
interferometry, degenerate four-wave mixing, nearly degenerate three-wave mixing, ellipse [17,18]. rotation and
beam-distortion are sensitive but usually require complex experimental apparatuses The Z-scan technique is a
popular and powerful method for the measurements of the optical nonlinearity because of its sensitivity,
simplicity and ability to determinate the signs and magnitudes of optical nonlinearity. This method allows the
simultaneous measurement of both nonlinear refractive index and nonlinear absorption coefficient. Basically,
the method consists of translating a sample through the focus of a Gaussian beam and monitoring the changes in
the far field intensity pattern. Because of the light-induced lens-like effect, the sample has the tendency to
recollimating or defocusing the incident beam, depending on its z position with respect to the focal plane. By
properly monitoring the transmittance change through a small aperture placed at the far-field position (closed
aperture), one is able to determine the amplitude of the phase shift. By moving the sample through the focus and
without placing an aperture at the detector (open aperture), one can measure the intensity dependent absorption
as a change of transmittance through the sample.
In this study, we report the experimental investigation of third-order optical nonlinearity of 2,3-
Diaminopyridine by using the single beam Z-scan technique. We also investigated the self-diffraction for the
sample under cw laser illumination. The experiment is performed for different concentrations, wavelengths and
incident beam intensities. The sample is found to exhibit a negative and large optical nonlinearity.
II. EXPERIMENTAL
The sample and DMSO are purchased from Aldrich Chemical Company and were used without any
purification. The chemical structure and molecular formula of 2,3-Diaminopyridine are shown in Fig.1. A UV–
visible spectroscopy has been used to characterize the 2,3-Diaminopyridine in solvent DMSO in the spectral
range (350–900 nm). The absorbance (A) of the sample measured using Cecil Reflected-Scan CE 3055
reflectance spectrometer. These measured were performed at room temperature. Fig.1 shows the spectral
distribution of absorbance of samples with different concentrations. We can see from the Fig. 1 that the
absorbance of the sample increases with increasing the concentration this due to increase number of molecular
per unit volume, so the absorbance will be increased.
2. Self diffraction and nonlinear optical properties for 2,3-Diaminopyridine under cw illumination
International organization of Scientific Research 28 | P a g e
Fig. 1. UV-Visible absorption spectrum of 2,3-Diaminopyridine with different concentrations. Inset shows the
chemical structure of 2,3-Diaminopyridine .
The nonlinear absorption and nonlinear refraction of the sample were measured by using the open-and
closed-aperture Z-scan technique. The schematic diagram of Z-scan experiment is shown in Fig.2. A cw laser
beam from solid state laser SDL at 473 nm wavelength with an average power of 4.6 mW was used as a source
of light in our experiment. The output of the laser beam had a Gaussian intensity profile. The Gaussian laser
beam was focused by using a lens of focal length 5 cm, into the sample solution contained in a 1 mm quartz
cuvette. The resulting beam waist radius at the focus was 22.19 µm and the diffraction length, ZR was found to
be 3.2 mm. The sample was moved along a z-axis by a motorized translational stage. The transmission of the
beam through an aperture placed in the far field is measured using photo detector fed to the digital power meter
(Field master Gs-coherent). For an open aperture Z-scan, a lens was used to collect the entire laser beam
transmitted through the sample with the aperture replaced. The sample thickness of 1 mm was less than the
Rayleigh length and hence it could be treated as a ‘thin medium’. The measurements were done at room
temperature.
Fig.2. Schematic diagram of experimental arrangement for the Z-scan measurement
III. RESULTS AND DISCUSSION
3-1 THE ABSORPTION COEFFICIENT (Α)
The spectrum of the optical absorption was computed from the absorbance data. The absorption coefficient ( )
has been obtained directly from the absorbance against wavelength curves using the relation [19]:
dA/303.2 ………………………………………….(1)
Where d is the sample thickness and A is the absorbance.
The values of absorption coefficient at wavelength 473 nm for 2,3-Diaminopyridine with different
concentrations have been calculated using Eq.1 and they are given in Table 1.
3.2 Nonlinear optical properties
The third order nonlinear optical properties of the sample is studied by conducting the Z-scan
experiment. The model described in [20] was used to determine the magnitude of nonlinear absorption
coefficient β and the nonlinear refractive index n2 of the 2,3-Diaminopyridine in solvent DMSO.
The magnitude and sign of nonlinear absorption coefficient, β, of the 2,3-Diaminopyridine was determined
through open aperture Z-scan. Fig.3 shows the Z-scan data fo 2,3-Diaminopyridine in solvent DMSO at four
different concentration 2,6,8 and 10 mM at incident intensity I0 = 0.595 kW/cm2
. It can be seen from Fig. 4 that
the normalized transmittance decreases when sample moves nearer to the focal point. This is an indication of
nonlinear absorption. The nonlinear absorption also increases considerably with the concentration.
3. Self diffraction and nonlinear optical properties for 2,3-Diaminopyridine under cw illumination
International organization of Scientific Research 29 | P a g e
Fig. 3. Open aperture Z-scan data for different concentrations.
The nonlinear absorption coefficient ,, can be calculated using the equation [21].
effLI
T
22
…………………………………… (1)
Where ΔT is one-valley transmission, I is the intensity of the laser beam at focus and Leff =[1-exp(-αL)] /α is the
effective thickness of the samples, L is the thickness of the sample.
The closed aperture Z-scan experiments were performed by placing the aperture in front of the detector,
which allowed us to determine the sign and magnitude of the nonlinear refractive index,n2, of sample. The
sensitivity to nonlinear refraction is entirely due to aperture, and absence of aperture completely eliminates the
effect. Fig. 4 illustrates the closed aperture Z-scan profiles of the samples. The normalized closed aperture Z-
scan curve exhibits a pre-focal transmittance maximum (peak) followed by a post-focal transmittance minimum
(valley) signature for the samples. This peak-valley signature indicates the self-defocusing property and it is
represented by negative nonlinear refractive index n2. The sign of the nonlinear index of refraction n2 of a
sample is thus immediately clear from the shape of graph.
Fig. 4. Closed-aperture Z-scan data for different concentrations.
Self-focusing and self-defocusing were also observed with naked eye. Fig. 6 shows the variation of the spot size
at the far-field as a function of the sample position relative to the focal plane for sample. The first photograph
(Fig. 6(a)) was taken well before (-z) where the nonlinear effect is not present because of low intensity in this
region. Similar spot size and shape was observed long after (+z) (Fig. 6(d)). Fig.6 (b) was taken at the pre-focal
transmittance maximum and Fig. 6(c) was taken at the post-focal transmittance minimum. The above implies
that self- focusing and self-defocusing can be easily observed with a low-power cw laser. This can be used as a
quick check for nonlinear behavior of materials before proceeding with the experiment.
4. Self diffraction and nonlinear optical properties for 2,3-Diaminopyridine under cw illumination
International organization of Scientific Research 30 | P a g e
Fig.5. Photographs show the variation of the spot size as a function of the sample position relative to the lens
focal point. (a) Before focus, where no nonlinear effects are present. (b) Pre-focus transmittance maximum. (c)
Post-focus transmittance minimum (d) After focus, where no nonlinear effects are present.
Since closed aperture data obtained from Z-scan will contain both nonlinear refraction and nonlinear
absorption components, it is necessary to separate the nonlinear absorption components from the nonlinear
refraction so as to extract pure nonlinear refraction. In order to differentiate nonlinear refraction from nonlinear
absorption, the division method is followed [20]. Fig.6 gives the pure nonlinear refraction curve obtained by
dividing closed aperture data by the corresponding open aperture data. The physical origin of nonlinear
refraction can be electronic, molecular, electrostrictive or thermal in nature. The nonlinear response is related to
thermally induced nonlinear effects because the cw laser normally produces heating effect and the defocusing
nonlinearity is due to the laser heating process.
Fig. 6. Pure Z-scan data for different concentrations.
The difference in peak- valley normalized transmittance ΔTP-V can be defined as the difference between the
normalized peak and valley transmittances TP-TV. The variation of ΔTP-V quantity as a function of ΔØo is given
by[20],
ΔTP-V = 0.406 (1-S)0.25
ΔØo ……………………………………….. (2)
Where ΔØo is the on-axis phase shift and S=1-exp(-2 r0
2
/ωo
2
) is the aperture linear transmittance with ro
denoting the aperture radius and ωo denoting the beam radius at the aperture in the linear regime. The nonlinear
refractive index, n2, is given by
IL
n
eff
2
2
……………………………………….. (3)
where λ is the laser wavelength.
The estimated values of nonlinear absorption coefficient and nonlinear refractive index of sample
solution for different concentrations are given in Table 1.
Table 1: Nonlinear optical parameters for 2,3-Diaminopyridine in the solvent DSMO.
Con. (mM) (cm-1
) x 10-3
(cm/W) n Leff (mm)
2n x10-8
(cm2
/W)
2 0.599 0.539 1.53 1.183 0.097 7.037
6 1.258 1.479 4.818 3.349 0.093 19.925
8 1.589 1.179 6.595 4.094 0.092 24.360
10 1.909 2.333 8.761 5.271 0.091 31.361
Fig. 7 shows the Z-scan data for 10 mM concentration of sample solution at different incident beam
intensities. The output laser intensities used were 0.219, 0.413 and 0.595 kW/cm2
respectively. The values of
nonlinear absorption coefficient and nonlinear refractive index for sample solution calculated from the Fig. 7a
5. Self diffraction and nonlinear optical properties for 2,3-Diaminopyridine under cw illumination
International organization of Scientific Research 31 | P a g e
and c and are listed in the Table 2. As expected, the nonlinear features increase when the beam intensity
increases.
Fig.7. Z-scan curves of the 10 mM solution of 2,3-Diaminopyridine for different incident intensities.
Table 2: Nonlinear optical parameters for different incident intensities.
Intensity (kW/cm2
) x 10-3
(cm/W) 2n x10-8
(cm2
/W)
0.220 0.797 28.510
0.414 4.523 29.898
0.595 8.761 31.361
A study has been made to investigate the influence of the wavelength on the nonlinear absorption
coefficient β and nonlinear refractive index for the sample by using the set-up shown in Fig.2. Fig. 8 shows the
Z-scan data for open aperture, closed aperture and dividing closed aperture measured at 473and 532 nm
wavelengths for a sample solution with 14 mM concentration. The Z-scan curves are different for 473 and 532
nm wavelengths as can be seen in Fig.8. The nonlinear absorption coefficient β and nonlinear refractive index of
the sample for 473 and 532 nm wavelengths are 33.6x10-3
cm/W, 34.816x10-8
cm2
/W and 1.073x10-3
cm/W,
8.588x10-8
cm2
/W, respectively. The deference in amplitude of the Z-scan curves for the two wavelengths can
be due to the deference in absorption coefficient at the two wavelengths, where the absorption coefficient α for
the sample at 473 nm is 2.3562 cm-1
,while the absorption coefficient α at 532 nm is 1.2541 cm-1
. The output
laser intensities used is 0.595 kW/cm2
for 473 and 532 nm wavelengths.
Fig.8. Z-scan curves of the 14 mM solution of 2,3-Diaminopyridine for different wavelengths.
3.3 Self-diffraction pattern
The experimental set-up for the demonstration of self-diffraction of the laser beam by 2,3-
Diaminopyridine under cw laser illumination is very similar to the standard Z-scan geometry and the same
parameters were used as for the Z-scan experimental set-up. The cuvette containing the nonlinear medium is
placed just after the focal point. To observation beam patterns out of the sample we replaced the aperture with
an screen 50 cm away from the focal point and were recorded by a digital camera. As the laser power was
gradually increased, diffraction rings were observed on the screen when the laser power exceeds a certain value
threshold value. The number of rings increases with the increase of laser power. This indicates that they were
intensity dependent. A typical pattern of the diffraction rings for incident intensity 1.39, 2.31 and 3.52 kW/cm2
is shown in Fig. 9. We assumed that thermally induced refractive index change is responsible for the observed
diffraction. When the Gaussion beam illuminates the film, the medium absorbs the light and its temperature
rises. The rises of temperature results in the change of local refractive index and thus induces the self-
diffraction.
6. Self diffraction and nonlinear optical properties for 2,3-Diaminopyridine under cw illumination
International organization of Scientific Research 32 | P a g e
Fig.9. Self-diffraction patterns for different incident intensity: (a) 1. 39, (b) 2. 31 and (c) 3.52 kW/cm2
.
The diffraction rings also appear when the sample is illuminated by laser of 473 nm, but there is some
difference between the two conditions: (1) the threshold values of the illumination powers for self-diffraction
rings are unequal. The threshold value at 473 nm (Pth = 1.58 mW) is lower than that at 532 nm (Pth = 5.3 mW),
which is consistent with the absorption property of sample in this region ; (2) the number of rings varies for
different wavelengths under the same intensity. The number of rings at 473 nm is more than that at 532 nm for
the same intensity, where the number of rings at 473 nm is 11, while the number of rings at 532 nm is 5 . Fig.10
shows the diffraction rings patterns for the sample at 532 nm and 743 nm wavelength for incident intensity
9.05kW/cm2
.
Fig.10. Self-diffraction patterns for different wavelengths: (a) 473 nm (b) 532 nm.
Fig. 11 shows diffraction rings pattern taken for samples with 14,16,18 and 20 mM concentrations. We
can see from the Fig. 11 the number of self diffracted rings increases with increasing concentration of the
samples. Also the threshold values of the sample with different concentrations for self-diffraction rings are
unequal, the threshold values of the sample at 14, 16, 18 and 20 mM concentration are 1.66, 2.35, 3.07 and 3.35
mW respectively. The increasing of the number of diffraction rings with increasing the concentration are due to
the increase in aggregation of the sample molecules at the point of focus at higher concentrations. The
diffusivity extends to a larger region thereby causing more interference to take place leading to an increased
number of rings. For pure DMSO no diffraction patterns were seen. It has been verified that the pure DMSO
does not exhibit either self defocusing or self diffraction effects at the power levels used in the experiment.
Fig. 11. Self-diffraction patterns at four different concentrations: (a)14 mM, (b)16 mM, (c) 18mM, and (d)
20mM.
IV. CONCLUSION
We have measured the nonlinear refraction index coefficient, n2, and the nonlinear absorption
coefficient, β, for solution of sample using the Z-scan technique with 473 nm SDL laser. The closed aperture Z-
scan experiments for sample shows peak–valley characteristic and it is concluded that thermal self defocusing is
the most probable mechanism of nonlinearities in this sample and sign of nonlinear refraction is negative.
Moreover, the induced self-diffraction patterns were observed for different concentrations, wavelengths and
laser intensities. We think that the sample dissolved in DMSO will be a significant candidate for possible
applications in nonlinear optical devices.
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