The document describes the development of a dual microchannel plate (MCP) framing camera for imaging high-energy x-rays above 50 keV. A dual MCP configuration is proposed to increase the sensitivity at high energies by using the first MCP as a low-gain photocathode and the second MCP as a high-gain electron multiplier. Testing of a dual MCP module showed a detective quantum efficiency of 4.5% for 59 keV x-rays, which is 3 times higher than a single thick MCP typically used in such cameras. The dual MCP configuration separates the photon absorption from electron multiplication to reduce statistical noise compared to a single thick MCP operated at high gain.
The document describes measurements of the spatial resolution of the Advanced Radiographic Capability X-ray Imaging System (AXIS) at energies relevant to Compton radiography. Experiments were conducted using x-ray sources at four energies between 20-100 keV. A resolution test mask was used and line spread functions were calculated from the images. The line spread functions varied with both energy and direction, and were modeled as the sum of three Gaussian components representing short, medium, and long-range effects. The results provide an initial characterization of the spatial resolution of the AXIS diagnostic for Compton radiography experiments.
You will find here all the elements presented by the CENAPT team ( Drs. Guido Pauli and Charlotte Simmler) and pertaining to the NMR workshop at the American Society of Pharmacognosy (ASP 2017, Portland Oregon).
These slides summarize the different steps related to the implementation of quantitative NMR for purity analysis.
ConorWilman_Manchester_Investigation of an effective low-cost THz TDS systemConor Wilman
The document summarizes an experiment to design a low-cost THz time-domain spectroscopy system using multimode laser diodes instead of expensive femtosecond lasers. Bowtie antennas were fabricated on low-temperature gallium arsenide and tested with laser diodes, but no THz signal was detected. Possible reasons for failure include low laser power, poor antenna quality, and lack of optimal equipment. The experiment provides a starting point for improving the system by using higher power lasers, better antenna design, and additional equipment in future attempts.
This document summarizes the development of gravitational wave detection and possible sources. It discusses James Weber's early experiments using aluminum bar detectors in the 1960s, which reported the first detections of gravitational waves. It also describes proposals to use laser interferometers and resonant bar detectors, which could achieve greater sensitivity. Finally, it outlines potential sources of gravitational waves including bursts from stellar collapses and mergers, and continuous waves from rapidly spinning neutron stars.
This document summarizes a student's radar imaging project on ionospheric plasma irregularities. It discusses using radar with an antenna array spaced 19.62-33.97 meters apart operating at 30 MHz to image the ionosphere and determine wind direction above 10km. Three imaging techniques are reviewed in literature: Fourier-based, Capon-based, and Maximum Entropy-based. The objective is to gather weather information in the ionosphere by detecting Doppler shifts from minor lobes during signal reception. MATLAB is used to simulate and design the antenna array and process signals.
Optical interferometery to detect sound waves as an analogue for gravitationa...Thomas Actn
This document describes an experiment using a Michelson interferometer to detect sound waves as an analogue for gravitational waves. A tuning fork resonating at 440Hz and a piezoelectric crystal were used to generate sound waves near one arm of the interferometer. An Arduino and oscilloscope measured the resulting interference patterns. The Arduino detected the tuning fork frequency accurately but the oscilloscope only detected around half the frequency due to its limited sampling. Multiple constituent frequencies were detected from hand claps, mimicking bursts from supernovae. While the setup could detect these 'fake' gravitational waves, its low sampling rate limited the detectable frequency window.
This summary provides the key points about an approach being investigated to enable all-optical switching and logic elements using the Zeno effect:
1) The approach aims to overcome challenges with existing all-optical switching technologies like the need for intense optical fields and high power dissipation.
2) It involves using a high quality factor microresonator containing an optical medium with high two-photon absorption to enhance nonlinear effects while minimizing losses via the Zeno effect.
3) Theoretical simulations and analysis indicate this approach could allow all-optical switching, logic, and memory functions with extremely low power dissipation if challenges like achieving high enough two-photon absorption rates are addressed.
Attosecond pulses produced by using HHG in gases, it is possible to make a few simple statements: attosecond pulses are unique tools for the investigation of ultrafast electronic processes in atoms, molecules, nano structures and solids. Impressive progress has been demonstrated from the technological point of view, with the possibility to routinely generate attosecond pulses in perfectly reproducible ways.
The document describes measurements of the spatial resolution of the Advanced Radiographic Capability X-ray Imaging System (AXIS) at energies relevant to Compton radiography. Experiments were conducted using x-ray sources at four energies between 20-100 keV. A resolution test mask was used and line spread functions were calculated from the images. The line spread functions varied with both energy and direction, and were modeled as the sum of three Gaussian components representing short, medium, and long-range effects. The results provide an initial characterization of the spatial resolution of the AXIS diagnostic for Compton radiography experiments.
You will find here all the elements presented by the CENAPT team ( Drs. Guido Pauli and Charlotte Simmler) and pertaining to the NMR workshop at the American Society of Pharmacognosy (ASP 2017, Portland Oregon).
These slides summarize the different steps related to the implementation of quantitative NMR for purity analysis.
ConorWilman_Manchester_Investigation of an effective low-cost THz TDS systemConor Wilman
The document summarizes an experiment to design a low-cost THz time-domain spectroscopy system using multimode laser diodes instead of expensive femtosecond lasers. Bowtie antennas were fabricated on low-temperature gallium arsenide and tested with laser diodes, but no THz signal was detected. Possible reasons for failure include low laser power, poor antenna quality, and lack of optimal equipment. The experiment provides a starting point for improving the system by using higher power lasers, better antenna design, and additional equipment in future attempts.
This document summarizes the development of gravitational wave detection and possible sources. It discusses James Weber's early experiments using aluminum bar detectors in the 1960s, which reported the first detections of gravitational waves. It also describes proposals to use laser interferometers and resonant bar detectors, which could achieve greater sensitivity. Finally, it outlines potential sources of gravitational waves including bursts from stellar collapses and mergers, and continuous waves from rapidly spinning neutron stars.
This document summarizes a student's radar imaging project on ionospheric plasma irregularities. It discusses using radar with an antenna array spaced 19.62-33.97 meters apart operating at 30 MHz to image the ionosphere and determine wind direction above 10km. Three imaging techniques are reviewed in literature: Fourier-based, Capon-based, and Maximum Entropy-based. The objective is to gather weather information in the ionosphere by detecting Doppler shifts from minor lobes during signal reception. MATLAB is used to simulate and design the antenna array and process signals.
Optical interferometery to detect sound waves as an analogue for gravitationa...Thomas Actn
This document describes an experiment using a Michelson interferometer to detect sound waves as an analogue for gravitational waves. A tuning fork resonating at 440Hz and a piezoelectric crystal were used to generate sound waves near one arm of the interferometer. An Arduino and oscilloscope measured the resulting interference patterns. The Arduino detected the tuning fork frequency accurately but the oscilloscope only detected around half the frequency due to its limited sampling. Multiple constituent frequencies were detected from hand claps, mimicking bursts from supernovae. While the setup could detect these 'fake' gravitational waves, its low sampling rate limited the detectable frequency window.
This summary provides the key points about an approach being investigated to enable all-optical switching and logic elements using the Zeno effect:
1) The approach aims to overcome challenges with existing all-optical switching technologies like the need for intense optical fields and high power dissipation.
2) It involves using a high quality factor microresonator containing an optical medium with high two-photon absorption to enhance nonlinear effects while minimizing losses via the Zeno effect.
3) Theoretical simulations and analysis indicate this approach could allow all-optical switching, logic, and memory functions with extremely low power dissipation if challenges like achieving high enough two-photon absorption rates are addressed.
Attosecond pulses produced by using HHG in gases, it is possible to make a few simple statements: attosecond pulses are unique tools for the investigation of ultrafast electronic processes in atoms, molecules, nano structures and solids. Impressive progress has been demonstrated from the technological point of view, with the possibility to routinely generate attosecond pulses in perfectly reproducible ways.
fr2.t03.5.2-micron IPDA Presentation at IGARSS-2011-Final-Revised-1.pptxgrssieee
This document describes the development of a high repetition rate, solid-state 2-micron pulsed laser for measuring carbon dioxide from airborne and space-based platforms. Key achievements include developing a double-pulsed, high energy 2-micron laser transmitter meeting requirements for profiling and column CO2 measurements. Ground tests demonstrated precision within 0.7% for column measurements. The laser design and performance meet requirements for direct detection pulsed integrated path differential absorption lidar for potential space-based carbon dioxide monitoring missions.
Construction of inexpensive Web-Cam based Optical Spectrometer usingSoares Fernando
This document describes the construction and use of an inexpensive webcam-based optical spectrometer for quantitative spectroscopic studies. Key points:
- An inexpensive spectrometer was built from readily available materials like DVDs, cardboard, tape and glue to enable students to measure electromagnetic spectra as a function of wavelength within 10s of nm resolution and accuracy.
- The spectrometer was calibrated using known emission lines from a helium source and the hydrogen emission spectrum was analyzed, matching theoretical predictions to within 0.04% error.
- The low-cost nature of this device makes it suitable for equipping large classes for hands-on spectroscopy experiments and studies in resource-limited educational settings.
Investigating the single and doubly periodic mapping in fully Dispersion mana...SachidanandChikkpeti
Implementation and comparison of classical and the
doubly periodic dispersion mapping for the 40gb/s single channel
long haul optical transmission system for on-off keying(OOK)
modulation, the system has been analyzed using in-line and
post-compensation scheme setting pre-compensation to zero with
maintaining system’s net residual dispersion to zero in the
nonlinear regime.
1) The document discusses ultrashort pulse (USP) laser interactions with matter, including microresonator-based optical frequency combs, high peak power laser processing of materials, and extreme ultraviolet comb spectroscopy.
2) It outlines several research initiatives exploring topics like dynamics of microresonator comb generation, laser ablation mechanisms with ultrashort pulses, and dual comb spectroscopy in the extreme ultraviolet.
3) The document also covers applications of USP lasers in metrology, material science, and particle acceleration, and research into relativistic laser-matter interactions generating bright x-ray sources.
Pablo Estevez: "Computational Intelligence Applied to Time Series Analysis" ieee_cis_cyprus
This document summarizes a presentation on analyzing astronomical time series data using information theoretic learning approaches. It discusses challenges with irregularly sampled and noisy light curve data from astronomical surveys. It proposes using correntropy, a generalized correlation measure, within a periodic kernel to create a Correntropy Kernelized Periodogram (CKP) for discriminating periodic vs non-periodic light curves and estimating periods of periodic curves. It applies this approach to real survey data from MACHO and EROS, achieving high classification accuracy and ability to process billions of light curves efficiently using GPU clusters.
Abstract
Terahertz sub-surface imaging offers an effective solution for surface and 3D imaging because of minimal
sample preparation requirements and its ability to “see” below the surface. Another important property is the ability
to inspect on a layer-by layer basis via a non-contact route, non-destructive route. Terahertz 3D imager designed
at Applied Research and Photonics (Harrisburg, PA) has been used to demonstrate reconstructive imaging with a
resolution of less than a nanometer. Gridding with inverse distance to power equations has been described for 3D
image formation. A continuous wave terahertz source derived from dendrimer dipole excitation has been used for
reflection mode scanning in the three orthogonal directions. Both 2D and 3D images are generated for the analysis
of silver iodide quantum dots’ size parameter. Layer by layer image analysis has been outlined. Graphical analysis
was used for particle size and layer thickness determinations. The demonstrated results of quantum dot particle
size checks well with those determined by TEM micrograph and powder X-ray diffraction analysis. The reported
non-contact measurement system is expected to be useful for characterizing 2D and 3D naomaterials as well as for process development and/or quality inspection at the production line.
Polarized gamma ray emission from the galactic black hole cygnus x-1Sérgio Sacani
Polarized gamma-ray emission was measured from the black hole binary system Cygnus X-1 using the INTEGRAL/IBIS telescope. Spectral modeling revealed two emission components: 250-400 keV emission consistent with Compton scattering and weakly polarized; 400 keV - 2 MeV emission from a power law component that is strongly polarized at 67%, likely from synchrotron emission in the jet. The polarization angle of 140° is significantly different than the radio jet angle, as seen in other jet sources.
Initial Calibration of CCD Images for the Dark Energy Survey- Deokgeun ParkDaniel Park
The document describes initial calibration of images from the Dark Energy Survey (DES) test run on the Cerro Tololo Inter-American Observatory 1-meter telescope in Chile. Standard star images taken in different atmospheric conditions (airmasses) were used to determine the relationship between measured and true star brightness. This relationship accounts for effects of atmosphere and allows calibration of images to determine true brightness of other stars, important for measuring galaxy redshifts and studying dark energy driving the expansion of the universe, the focus of the full DES study.
This document summarizes an analysis of X-ray data from the longest XMM-Newton observation of the galaxy ARK 564. The observation was 101,774 seconds in duration. Spectral analysis was performed using XSPEC software. The spectrum from 3-10 keV was initially fitted with an absorbed power law model. Adding a Gaussian component at 6.4 keV improved the fit, likely modeling iron K-alpha fluorescent emission. Below 3 keV, excess emission was observed indicating a soft X-ray excess from the source.
The document describes the DarkSide experiment which aims to directly detect dark matter particles using a liquid argon time projection chamber. It discusses the advantages of using argon as a target material and outlines the DarkSide collaboration and experimental program. The DarkSide-50 detector has begun data taking and aims to reach a dark matter-nucleon scattering sensitivity of 10-45 cm2. The IPHC and APC institutes are involved in the collaboration through developing Monte Carlo simulations and analyzing upcoming data to search for a dark matter signal.
Design of Rare Earth Ion Doped Polymer Waveguide LasersIJERA Editor
The laser performance of rare earth ion Nd3+-complex-doped polymer channel waveguides was investigated using a continuous-wave excitation at 800 nm. CW laser operation was achieved near 1060.2 nm and 878 nm in Nd3+-complex-doped polymer channel waveguides with output powers of up to 0.98 mW and 0.20 mW, respectively. The stability of the laser output was examined with CW excitation. To the best of our knowledge, this is the first report of a rare-earth-ion-doped polymer waveguide laser as well as a CW solid-state polymer laser.
Compressive Light Field Photography using Overcomplete Dictionaries and Optim...Ankit Thiranh
In this paper, a design is proposed for a compressive light field camera which will allow to recover light fields with higher resolution from a single image. Also, various other useful applications for light field atoms are discussed, including 4D light field compression and denoising.
Qualitative analysis of Fruits and Vegetables using Earth’s Field Nuclear Mag...IJERA Editor
Among the imaging techniques, magnetic resonance imaging (MRI) is a non-contact and a non-invasive technique to obtain images of the objects rich in water content and provides an excellent tool to study variation of contrast among the soft issues. It often utilizes a linear magnetic field gradient to obtain an image that combines the visualization of molecular structure and dynamics. It measures the characteristics of hydrogen nuclei of water and nuclei with similar chemical shifts, modified by chemical environment across the object. In the present work, MRI of fresh tomatoes has been recorded using Terranova-MRI for qualitative analysis. The technique is effective, powerful and reliable as an investigative tool in the quality analysis and diagnosis of infections in fruits and vegetables.
MODELING THE CHLOROPHYLL-A FROM SEA SURFACE REFLECTANCE IN WEST AFRICA BY DEE...ijaia
Deep learning provide successful applications in many fields. Recently, machines learning are involved for oceans remote sensing applications. In this study, we use and compare about eight (8) deep learning estimators for retrieval of a mainly pigment of phytoplankton. Depending on the water case and the multiple instruments simultaneously observing the earth on a variety of platforms, several algorithm are used to estimate the chlolophyll-a from marine reflectance.By using a long-term multi-sensor time-series of satellite ocean-colour data, as MODIS, SeaWifs, VIIRS, MERIS, etc…, we make a unique deep network model able to establish a relationship between sea surface reflectance and chlorophyll-a from any measurement satellite sensor over West Africa. These data fusion take into account the bias between case water and instruments.We construct several chlorophyll-a concentration prediction deep learning based models, compare them and therefore use the best for our study. Results obtained for accuracy training and test are quite good. The mean absolute error are very low and vary between 0,07 to 0,13 mg/m3 .
Parametric Time Domain Method for separation of Cloud and Drizzle for ARM Clo...Pratik Ramdasi
Presentation describes Parametric Time Domain Method (PTDM) to separate cloud and drizzle moments for the W-band ARM cloud radar located at Graciosa Island, Portugal.
Conferencia impartida por Sebastián Sánchez en los Viernes Científicos organizada por la Facultad de Ciencias Experimentales de la Universidad de Almería el 14 de enero de 2011.
The document characterizes an FPGA-based spectrometer prototype designed for use in heterodyne receivers at the Large Millimeter Telescope (LMT). Testing showed the spectrometer could successfully calibrate for offset, gain, and phase issues and reduce spurious tones in data. It was also found to be linear in nature and sufficiently follow the radiometer equation, with an Allan time of at least 400 seconds. The spectrometer uses a CASPER-designed ROACH2 board with a Xilinx FPGA and two analog to digital converter boards to process signals at sample rates up to 2.5 Giga samples per second across two channels.
The document discusses laser matter interaction and provides an overview of lasers. It defines what a laser is, the mechanism of stimulated emission that allows lasers to function, and the typical components of a laser. It also describes how lasers interact with and affect various materials, including semiconductors, solids, and gases. Several types of lasers are outlined such as diode lasers, gas lasers, fiber lasers, and crystal lasers.
This document summarizes a trial using MIMO radar to image the cross-section of an Antarctic ice shelf. A 12-element MIMO antenna array was used to collect data from the Ronne Ice Shelf. Signal processing was applied to produce a 2D depth profile image but it was degraded by grating lobes from the sparse antenna spacing. Further work is needed using a linear MIMO array with closer element spacing to improve angular resolution and produce a clearer cross-sectional radar image of the ice shelf structure.
Este documento trata sobre un curso de geometría en la Universidad Nacional Autónoma de México. La unidad 4 de geometría ll fue impartida en junio de 2016 por Castillo Nava Zeltzin Aline en la Facultad de Estudios Superiores Cuautitlán para el curso de diseño y comunicación visual.
Este documento contiene información sobre una unidad de geometría de la Facultad de Estudios Superiores Cuautitlán de la Universidad Nacional Autónoma de México. Cubre los temas 5 al 8 de la Unidad 4 del curso de Diseño y Comunicación Visual para la alumna Castillo Nava Zeltzin Aline en junio de 2016 e incluye bocetos y láminas.
fr2.t03.5.2-micron IPDA Presentation at IGARSS-2011-Final-Revised-1.pptxgrssieee
This document describes the development of a high repetition rate, solid-state 2-micron pulsed laser for measuring carbon dioxide from airborne and space-based platforms. Key achievements include developing a double-pulsed, high energy 2-micron laser transmitter meeting requirements for profiling and column CO2 measurements. Ground tests demonstrated precision within 0.7% for column measurements. The laser design and performance meet requirements for direct detection pulsed integrated path differential absorption lidar for potential space-based carbon dioxide monitoring missions.
Construction of inexpensive Web-Cam based Optical Spectrometer usingSoares Fernando
This document describes the construction and use of an inexpensive webcam-based optical spectrometer for quantitative spectroscopic studies. Key points:
- An inexpensive spectrometer was built from readily available materials like DVDs, cardboard, tape and glue to enable students to measure electromagnetic spectra as a function of wavelength within 10s of nm resolution and accuracy.
- The spectrometer was calibrated using known emission lines from a helium source and the hydrogen emission spectrum was analyzed, matching theoretical predictions to within 0.04% error.
- The low-cost nature of this device makes it suitable for equipping large classes for hands-on spectroscopy experiments and studies in resource-limited educational settings.
Investigating the single and doubly periodic mapping in fully Dispersion mana...SachidanandChikkpeti
Implementation and comparison of classical and the
doubly periodic dispersion mapping for the 40gb/s single channel
long haul optical transmission system for on-off keying(OOK)
modulation, the system has been analyzed using in-line and
post-compensation scheme setting pre-compensation to zero with
maintaining system’s net residual dispersion to zero in the
nonlinear regime.
1) The document discusses ultrashort pulse (USP) laser interactions with matter, including microresonator-based optical frequency combs, high peak power laser processing of materials, and extreme ultraviolet comb spectroscopy.
2) It outlines several research initiatives exploring topics like dynamics of microresonator comb generation, laser ablation mechanisms with ultrashort pulses, and dual comb spectroscopy in the extreme ultraviolet.
3) The document also covers applications of USP lasers in metrology, material science, and particle acceleration, and research into relativistic laser-matter interactions generating bright x-ray sources.
Pablo Estevez: "Computational Intelligence Applied to Time Series Analysis" ieee_cis_cyprus
This document summarizes a presentation on analyzing astronomical time series data using information theoretic learning approaches. It discusses challenges with irregularly sampled and noisy light curve data from astronomical surveys. It proposes using correntropy, a generalized correlation measure, within a periodic kernel to create a Correntropy Kernelized Periodogram (CKP) for discriminating periodic vs non-periodic light curves and estimating periods of periodic curves. It applies this approach to real survey data from MACHO and EROS, achieving high classification accuracy and ability to process billions of light curves efficiently using GPU clusters.
Abstract
Terahertz sub-surface imaging offers an effective solution for surface and 3D imaging because of minimal
sample preparation requirements and its ability to “see” below the surface. Another important property is the ability
to inspect on a layer-by layer basis via a non-contact route, non-destructive route. Terahertz 3D imager designed
at Applied Research and Photonics (Harrisburg, PA) has been used to demonstrate reconstructive imaging with a
resolution of less than a nanometer. Gridding with inverse distance to power equations has been described for 3D
image formation. A continuous wave terahertz source derived from dendrimer dipole excitation has been used for
reflection mode scanning in the three orthogonal directions. Both 2D and 3D images are generated for the analysis
of silver iodide quantum dots’ size parameter. Layer by layer image analysis has been outlined. Graphical analysis
was used for particle size and layer thickness determinations. The demonstrated results of quantum dot particle
size checks well with those determined by TEM micrograph and powder X-ray diffraction analysis. The reported
non-contact measurement system is expected to be useful for characterizing 2D and 3D naomaterials as well as for process development and/or quality inspection at the production line.
Polarized gamma ray emission from the galactic black hole cygnus x-1Sérgio Sacani
Polarized gamma-ray emission was measured from the black hole binary system Cygnus X-1 using the INTEGRAL/IBIS telescope. Spectral modeling revealed two emission components: 250-400 keV emission consistent with Compton scattering and weakly polarized; 400 keV - 2 MeV emission from a power law component that is strongly polarized at 67%, likely from synchrotron emission in the jet. The polarization angle of 140° is significantly different than the radio jet angle, as seen in other jet sources.
Initial Calibration of CCD Images for the Dark Energy Survey- Deokgeun ParkDaniel Park
The document describes initial calibration of images from the Dark Energy Survey (DES) test run on the Cerro Tololo Inter-American Observatory 1-meter telescope in Chile. Standard star images taken in different atmospheric conditions (airmasses) were used to determine the relationship between measured and true star brightness. This relationship accounts for effects of atmosphere and allows calibration of images to determine true brightness of other stars, important for measuring galaxy redshifts and studying dark energy driving the expansion of the universe, the focus of the full DES study.
This document summarizes an analysis of X-ray data from the longest XMM-Newton observation of the galaxy ARK 564. The observation was 101,774 seconds in duration. Spectral analysis was performed using XSPEC software. The spectrum from 3-10 keV was initially fitted with an absorbed power law model. Adding a Gaussian component at 6.4 keV improved the fit, likely modeling iron K-alpha fluorescent emission. Below 3 keV, excess emission was observed indicating a soft X-ray excess from the source.
The document describes the DarkSide experiment which aims to directly detect dark matter particles using a liquid argon time projection chamber. It discusses the advantages of using argon as a target material and outlines the DarkSide collaboration and experimental program. The DarkSide-50 detector has begun data taking and aims to reach a dark matter-nucleon scattering sensitivity of 10-45 cm2. The IPHC and APC institutes are involved in the collaboration through developing Monte Carlo simulations and analyzing upcoming data to search for a dark matter signal.
Design of Rare Earth Ion Doped Polymer Waveguide LasersIJERA Editor
The laser performance of rare earth ion Nd3+-complex-doped polymer channel waveguides was investigated using a continuous-wave excitation at 800 nm. CW laser operation was achieved near 1060.2 nm and 878 nm in Nd3+-complex-doped polymer channel waveguides with output powers of up to 0.98 mW and 0.20 mW, respectively. The stability of the laser output was examined with CW excitation. To the best of our knowledge, this is the first report of a rare-earth-ion-doped polymer waveguide laser as well as a CW solid-state polymer laser.
Compressive Light Field Photography using Overcomplete Dictionaries and Optim...Ankit Thiranh
In this paper, a design is proposed for a compressive light field camera which will allow to recover light fields with higher resolution from a single image. Also, various other useful applications for light field atoms are discussed, including 4D light field compression and denoising.
Qualitative analysis of Fruits and Vegetables using Earth’s Field Nuclear Mag...IJERA Editor
Among the imaging techniques, magnetic resonance imaging (MRI) is a non-contact and a non-invasive technique to obtain images of the objects rich in water content and provides an excellent tool to study variation of contrast among the soft issues. It often utilizes a linear magnetic field gradient to obtain an image that combines the visualization of molecular structure and dynamics. It measures the characteristics of hydrogen nuclei of water and nuclei with similar chemical shifts, modified by chemical environment across the object. In the present work, MRI of fresh tomatoes has been recorded using Terranova-MRI for qualitative analysis. The technique is effective, powerful and reliable as an investigative tool in the quality analysis and diagnosis of infections in fruits and vegetables.
MODELING THE CHLOROPHYLL-A FROM SEA SURFACE REFLECTANCE IN WEST AFRICA BY DEE...ijaia
Deep learning provide successful applications in many fields. Recently, machines learning are involved for oceans remote sensing applications. In this study, we use and compare about eight (8) deep learning estimators for retrieval of a mainly pigment of phytoplankton. Depending on the water case and the multiple instruments simultaneously observing the earth on a variety of platforms, several algorithm are used to estimate the chlolophyll-a from marine reflectance.By using a long-term multi-sensor time-series of satellite ocean-colour data, as MODIS, SeaWifs, VIIRS, MERIS, etc…, we make a unique deep network model able to establish a relationship between sea surface reflectance and chlorophyll-a from any measurement satellite sensor over West Africa. These data fusion take into account the bias between case water and instruments.We construct several chlorophyll-a concentration prediction deep learning based models, compare them and therefore use the best for our study. Results obtained for accuracy training and test are quite good. The mean absolute error are very low and vary between 0,07 to 0,13 mg/m3 .
Parametric Time Domain Method for separation of Cloud and Drizzle for ARM Clo...Pratik Ramdasi
Presentation describes Parametric Time Domain Method (PTDM) to separate cloud and drizzle moments for the W-band ARM cloud radar located at Graciosa Island, Portugal.
Conferencia impartida por Sebastián Sánchez en los Viernes Científicos organizada por la Facultad de Ciencias Experimentales de la Universidad de Almería el 14 de enero de 2011.
The document characterizes an FPGA-based spectrometer prototype designed for use in heterodyne receivers at the Large Millimeter Telescope (LMT). Testing showed the spectrometer could successfully calibrate for offset, gain, and phase issues and reduce spurious tones in data. It was also found to be linear in nature and sufficiently follow the radiometer equation, with an Allan time of at least 400 seconds. The spectrometer uses a CASPER-designed ROACH2 board with a Xilinx FPGA and two analog to digital converter boards to process signals at sample rates up to 2.5 Giga samples per second across two channels.
The document discusses laser matter interaction and provides an overview of lasers. It defines what a laser is, the mechanism of stimulated emission that allows lasers to function, and the typical components of a laser. It also describes how lasers interact with and affect various materials, including semiconductors, solids, and gases. Several types of lasers are outlined such as diode lasers, gas lasers, fiber lasers, and crystal lasers.
This document summarizes a trial using MIMO radar to image the cross-section of an Antarctic ice shelf. A 12-element MIMO antenna array was used to collect data from the Ronne Ice Shelf. Signal processing was applied to produce a 2D depth profile image but it was degraded by grating lobes from the sparse antenna spacing. Further work is needed using a linear MIMO array with closer element spacing to improve angular resolution and produce a clearer cross-sectional radar image of the ice shelf structure.
Este documento trata sobre un curso de geometría en la Universidad Nacional Autónoma de México. La unidad 4 de geometría ll fue impartida en junio de 2016 por Castillo Nava Zeltzin Aline en la Facultad de Estudios Superiores Cuautitlán para el curso de diseño y comunicación visual.
Este documento contiene información sobre una unidad de geometría de la Facultad de Estudios Superiores Cuautitlán de la Universidad Nacional Autónoma de México. Cubre los temas 5 al 8 de la Unidad 4 del curso de Diseño y Comunicación Visual para la alumna Castillo Nava Zeltzin Aline en junio de 2016 e incluye bocetos y láminas.
This document discusses various physics concepts related to energy transfer. It mentions work, entropy, conduction, radiation, convection, and circulation which are all different mechanisms or concepts through which energy can be transferred or transformed. Overall, the document seems to cover fundamental thermodynamics and heat transfer topics at a high level.
The document discusses organic growth versus acquired growth for insurance agencies. It emphasizes that agencies need to focus on building an organic growth engine through establishing a defined sales process before pursuing acquisitions. A sales process provides training, mentoring and career development for producers to foster sustainable growth. Acquiring revenue without a sales process in place can undermine growth as there is no plan to replace departing producers. The document also provides data on producer retention and career trajectories over time.
This document summarizes a research study that investigated applying polyacrylamide softeners to cotton and cotton/polyester fabrics to enhance surface smoothness and quality properties. The study prepared aqueous polyacrylamide softener solutions at various concentrations and applied them to fabrics using a pad-dry-cure method. The treated fabric swatches were evaluated for surface smoothness and yellowing effects. The results indicate that application of polyacrylamide softeners improved all smoothness and softness properties of the fabrics by enhancing surface adsorption. A thin layer of the applied softeners also reduced surface roughness and increased strength properties by forming a hydrophobic film on the fabric surfaces.
Account Right & Business Enterprises (AR & BE) is a business and financial consultancy firm that assists companies with challenges in their business operations and accounting. AR & BE takes a professional approach to proper record keeping, processes, internal controls, and accounting solutions for clients. The firm believes well-kept books are essential for a business's success and helps clients achieve smooth operations and solutions through experienced consultants. Services include setting up business processes and procedures, financial reporting, internal controls, software implementation, inventory taking, and outsourced accounting. The goal is to provide professional advice to clients and help improve their financial knowledge and compliance.
The GROWVista modular green roof system combines design flexibility with cost-effective installation. It uses recycled plastic modules with built-in water retention and drainage that can be planted with sedum mats, cuttings, or custom selections. The system is engineered for simple installation directly on a roof's waterproofing and allows for extensive, semi-intensive, or intensive green roof designs. Integrated accessories include walkway pavers, edge treatments, and irrigation components.
This document is a journal entry for a Principles of Business course taken online through SUNY Learning Network. The student discusses each chapter covered in Module 1, providing summaries of the key topics and relating them to her own experiences as a single mother and 20-year employee in the nuclear industry. She demonstrates an improved understanding of business concepts and how they apply to her job and everyday life after completing the course module.
This resume summary is for Alex Lumbard, an engineering technologist with experience in mechanical design, manufacturing, machining, and experimentation. He has over 5 years of experience in R&D at Lawrence Livermore National Laboratory where he designs electro/mechanical systems, machines parts, assembles systems, and troubleshoots experiments. He also has a Bachelor's degree in Industrial Technology and certifications in CNC machining.
This document discusses how technology can help insurance agencies improve their recruiting and sales processes. It outlines how customer relationship management platforms and automation can help track sales activities and identify opportunities for improvement, but that proper implementation and producer buy-in are needed for technology to effectively drive organic growth. Monitoring key metrics at each stage of the sales process and using technology to provide visibility into bottlenecks can help agencies close the gap between their revenue goals and actual results.
Optical Absoprtion of Thin Film SemiconductorsEnrico Castro
This document analyzes the optical properties of several thin film semiconductors. It characterizes the transmittance, reflectance, and absorption of CdS films deposited at different times, as well as Sb-S-Se films deposited at different temperatures. Key results include the absorption coefficient, transmission and reflection percentages in different wavelength regions, and estimates of photon flux and potential short circuit current density for each film based on their bandgaps. Optical properties were measured using UV-VIS spectroscopy to understand how effectively the materials could absorb light.
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di A. Lleres, O. Bartalini, V. Bellini, J. P. Bocquet, P. Calvat, M. Capogni, L. Casano, M. Castoldi, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, C. Gaulard, G. Gervino, F. Ghio, B. Girolami, A. Giusa, M. Guidal, E. Hourany, V. Kouznetsov, R. Kunne, A. Lapik, P. Levi Sandri, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, L. Nicoletti, C. Perrin, C. Randieri, D. Rebreyend, F. Renard, N. Rudnev, T. Russew, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge (2007)
Abstract
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Molecular transporter system for qubits generation
AXIS pop paper
1. Development of a dual MCP framing camera for high energy x-raysa)
N. Izumi, G. N. Hall, A. C. Carpenter, F. V. Allen, J. G. Cruz, B. Felker, D. Hargrove, J. Holder, J. D. Kilkenny, A.
Lumbard, R. Montesanti, N. E. Palmer, K. Piston, G. Stone, M. Thao, R. Vern, R. Zacharias, O. L. Landen, R.
Tommasini, D. K. Bradley, and P. M. Bell
Citation: Review of Scientific Instruments 85, 11D623 (2014); doi: 10.1063/1.4891712
View online: http://dx.doi.org/10.1063/1.4891712
View Table of Contents: http://scitation.aip.org/content/aip/journal/rsi/85/11?ver=pdfcov
Published by the AIP Publishing
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3. 11D623-2 Izumi et al. Rev. Sci. Instrum. 85, 11D623 (2014)
and the number of collisions in the MCP pore is large, the
PHD can be approximated by a negative exponential,9
dP(ξ)
dξ avalanche
=
1
ξ
exp −
ξ
ξ
, (5)
where ξ and ξ are the gain and the average value of the gain.
Another source of PHD broadening is the depth depen-
dent gain. The electron multiplication for a detection event
that has taken place at a depth x from the MCP surface is
ξ(x) = ξ0
L−x
L , (6)
where ξ0 is the nominal gain of the surface event (x = 0),
and L is the thickness of the MCP. The PHD determined by
this depth dependence is10
dP(ξ)
dξ
=
L
0
dP
dx
×
dP(ξ, x)
dξ avalanche
dx
=
L
0
μ
1 − e−μL
exp(−μx)
1
ξ0
(1−x / L)
× exp −
ξ
ξ0
(1−x / L)
dx, (7)
where μ is the linear absorption coefficient of the MCP. For
hard x-rays (μL 1) this equation can be simplified:
dP(ξ)
dξ
=
1
ξ ln( ξ0 )
exp −
ξ
ξ0
− exp(−ξ) . (8)
Fig. 1 shows the PHD calculated by Eq. (7) (L: 460 μm, μ:
0.385 mm−1
at 59 keV). When ξ0 is high, the effect of the
depth dependent gain is dominant and the PHD shows a long
tail with ξ−1
dependence.
We evaluate the noise factor as
NF( ξ0 ) =
∞
0 ξ2 dP(ξ)
dξ
dξ
∞
0 ξ dP(ξ)
dξ
dξ
2
≈
ξ0 + 1
ξ0 − 1
ln( ξ0 ) (9)
and it has minimum = 2 when the MCP is operated near unity
gain: ξ0 ∼ 1. Fig. 2 shows a comparison of Eq. (9) and the
experiment. The estimated nominal gain (the first-order mo-
ment of Eq. (7)) is also plotted. To produce a strong enough
signal in a harsh neutron induced background environment,11
a MCP based x-ray detector has to be operated with the nomi-
nal gain about 103
( ξ0 ∼ 104
). Therefore, the expected noise
factor of cameras with a single MCP configuration is 8–9.
FIG. 1. Expected PHD calculated by Eq. (7).
FIG. 2. Comparison of the experimentally obtained noise factor and Eq. (9).
The surface gain of the data was estimated from a test sheet provided by the
manufacturer.
Therefore, the SNRo obtainable with the conventional single
MCP configuration is smaller by factor 3 than that of an ideal
detector which has a narrow PHD for high energy x-rays.
In order to obtain enough DQE with the nominal gain
∼103
, we propose to stack two MCPs. The first low-gain MCP
works as thick x-ray photocathode with low NF. The second
MCP amplifies the electron stream. To validate the advantages
of this concept, we assembled a test module and measured the
QE and the PHD of the single and dual MCP setup.
IV. EXPERIMENT
Fig. 3 shows the experimental setup we have used to
test the proposed configuration. The MCP was irradiated by
59 keV x-rays emitted by a 241
Am (10 μCi) radioactive
source, 48.5 mm from the surface of the MCP. The low energy
emission lines from the source (13.9, 26.3, 33.2, and
43.4 keV) were filtered by an aluminum filter (3.88 mm thick)
which also acted as the vacuum window. X-ray photons are
converted to electrons in the MCPs. After multiplication in the
MCPs, the electrons are accelerated to 3 keV and hit the P46
phosphor (Y3Al5O12:Ce). The optical output from the phos-
phor was detected by the photo-multiplier tube (PMT: Hama-
matsu R329-02, bias: 1.1 kV).
The PMT signal was amplified by a charge sensitive am-
plifier (ORTEC 113), shaped (ORTEC 460) and recorded by a
multi-channel analyzer (MCA: ORTEC TRUM PCI 8K). The
dynamic range of the pulse height recording system is limited
to about 100. To extend the dynamic range, we performed the
measurements twice with different gain setting (0.15–40 pC
and 1.2–400 pC range) and spliced the respective spectra at
20 pC. Background counts from the PMT, the MCP, and the
Am 241 MCP
Low gain
Phosphor / FOP
Al filter
MCP
High gain
PMT
FIG. 3. Experimental setup.
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4. 11D623-3 Izumi et al. Rev. Sci. Instrum. 85, 11D623 (2014)
FIG. 4. Experimentally obtained pulse height distribution: (a) single MCP
460 μm thick and (b) dual MCP 460 μm + 460 μm.
direct x-ray excitation on phosphor were measured separately
and subtracted from the raw data.
Fig. 4(a) shows the PHD obtained with single MCP
(thickness L: 460 μm, pore diameter d: 10 μm). When the
MCP is operated in low gain, the PHD is close to a decaying
exponential and the standard deviation of the PHD is close to
the mean value. When we increase the MCP gain by applying
higher bias voltage, the depth dependent gain effect becomes
significant. We also measured the PHD of a 800 μm thick sin-
gle MCP. Fig. 5(a) shows the QE and DQE of the single MCP
configuration as a function of the bias voltage. The observed
DQE departs from the QE behavior at high gain values due
to the depth dependent gain effect. When the nominal MCP
gain is 103
(the nominal PMT signal ∼18 pC/event), the ob-
served DQE was 1.4% (2.6%) for 460 μm (800 μm) thick
plate.
Fig. 4(b) shows the result of the dual plate configuration
(stack of two L/d = 46 plates). We changed the bias volt-
age given to the 1st MCP (V1) from 0 to 570 V, while the
2nd MCP (V2) was operated with 600 V bias. The voltage
given to the gap between two plates (Vg) was 100 V. When V1
= 0 V, the events are dominated by x-ray detection on the 2nd
MCP and the observed PHD was almost identical to that of the
single plate with 600 V bias. When the V1 ≥ 300 V, increase
of the count rate was observed below 0.3 pC. We believe this
is false count due to multiple counting of the large x-ray de-
tection events caused by slow decay component of the P46
phosphor. Therefore, the PHD below 0.3 pC was ignored for
calculation of the QE and the DQE. When the 1st plate was
operated near the turn on voltage (V1 ∼ 400 V), the PHD in-
creased starting from a few pC without affecting the high gain
tail. When the gain was set higher than unity, the PHD started
FIG. 5. Measured QE and DQE of the single MCP: (a) single MCP and
(b) dual MCP.
showing ξ−1
dependence. Fig. 5(b) shows the QE and DQE
for the dual MCP configuration. The DQEs were compared
for 1st MCP thicknesses of 460 μm and 800 μm (L/d: 46 and
80, respectively). The highest DQE (4.5%) is obtained when
the 800-μm-thick plate with V1 = 625 V. When the nominal
MCP gain is 103
, the observed DQE is 3.2% and 4.3% for the
460-μm-thick and 800-μm-thick, 1st MCP, respectively.
V. DISCUSSION
By using the dual MCP configuration, the noise factor
of the system was reduced and the DQE was successfully in-
creased by a factor ∼3 compared to commonly used 460 μm
thick single MCP configuration. However, reduced QE was
experienced when the gain of the 1st MCP was set to low val-
ues. We believe this is due to the termination of the electron
stream on the first collisions with the pore wall (causing a zero
multiplication). If that is the case, the QE may be improved by
reducing the L/d ratio of the 1st MCP because it is possible to
accelerate the electrons to a higher energy per collision while
keeping low overall multiplication gain.6
ACKNOWLEDGMENTS
This work was performed under the auspices of the U.S.
Department of Energy by Lawrence Livermore National Lab-
oratory under Contract No. DE-AC52-07NA27344.
1J. D. Kilkenny, Laser Part. Beams 9, 49 (1991).
2R. Tommasini et al., Phys. Plasmas 18, 056309 (2011).
3G. N. Hall et al., “AXIS: An instrument for imaging Compton radiographs
using ARC on the NIF,” Rev. Sci. Instrum. (these proceedings).
4J. E. Bateman et al., Nucl. Instrum. Methods 144, 537 (1977).
5G. Zanella and R. Zannoni, Nucl. Instrum. Methods Phys. Res. A 359, 474
(1995).
6A. J. Guest, Acta Electron. 14, 49 (1971).
7G. Zanella and R. Zannoni, Nucl. Instrum Methods Phys. Res. A 406, 93
(1998).
8S. E. Moran et al., Proc. SPIE 3173, 430–457 (1997).
9J. L. Wiza, Nucl. Instrum. Methods 162, 587 (1979).
10K. W. Dolan and J. Chang, Proc. SPIE 0106, 178–188 (1977).
11N. Izumi et al., Rev. Sci. Instrum. 81, 10E515 (2010); C. Hagmann et al.,
ibid. 81, 10E514 (2010).
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2016 19:55:24