This document describes the design of a system to control the frequency at which laser diodes are modulated for analyzing samples using photothermal techniques. The system uses an amplitude modulated laser diode with swept frequency. It was developed considering the electrical characteristics of different laser diodes. A driver circuit was created to enable both amplitude modulation and frequency sweeping of the laser diodes without reducing their optical power. Testing on a piezoelectric sensor showed the stability of the driver and different frequency responses for different laser diodes, demonstrating the ability to analyze samples using photothermal techniques.
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.
14 A Profibus-based Control System for Nuclear Physics Applications - The 6th...Cristian Randieri PhD
A Profibus-based Control System for Nuclear Physics Applications - The 6th World Multi-Conference on Systemics, Cybernetics and Informatics SCI 2002, July 2002, Orlando, Florida
di O. Mirabella, V. Bellini, C. Randieri, C. Spitale
Abstract
In this paper we present the results of implementation of a remote control system based on ProFiBus technologies used for the remote control of experimental nuclear physics apparata. Remote control makes experiment handling more flexible, eliminating any problems originating from the need for direct access to the systems being controlled. In the paper we describe two different applications. The first application of the ProFiBus is the remote control of a multidetector (made up of a bidimensional array of CsI scintillators) used to detect light nuclear particles, as protons and/or light ions. In the second application, we present an implementation of the control of a vacuum system suitable for a special chamber used for the development and testing of particle detectors operating in vacuum conditions.
Nuclear Magnetic Resonance (NMR) is a RF technique that is able to detect any compound by sensing the excited resonance signals from atomic nuclei having non-zero spin. NQR is similar to NMR but the only difference is NMR needs a DC magnetic field and due to this its application in the field is limited. A FPGA based NQR spectrometer is designed using a single FPGA chip to perform the digital tasks required for NQR spectrometer. Design of Probe for NMR/NQR spectrometer is researched. Parallel tuned and series tuned Probes are discussed and simulated.14N NQR from NaNO2 is observed from spectrometer designed with parallel tuned probe.
The Time and Frequency Laboratory of the Hellenic Institute of Metrology (EIM)eimgreece
1. Continuous and reliable local representation of Universal Coordinated Time - UTC(EIM).
2. Contribution to Temps Atomique International (TAI).
3. Reliable and continuous distribution of reference frequencies.
4. Traceability to the international standards.
5. Broadcast of standard time and frequency signals inside and outside EIM facilities.
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.
14 A Profibus-based Control System for Nuclear Physics Applications - The 6th...Cristian Randieri PhD
A Profibus-based Control System for Nuclear Physics Applications - The 6th World Multi-Conference on Systemics, Cybernetics and Informatics SCI 2002, July 2002, Orlando, Florida
di O. Mirabella, V. Bellini, C. Randieri, C. Spitale
Abstract
In this paper we present the results of implementation of a remote control system based on ProFiBus technologies used for the remote control of experimental nuclear physics apparata. Remote control makes experiment handling more flexible, eliminating any problems originating from the need for direct access to the systems being controlled. In the paper we describe two different applications. The first application of the ProFiBus is the remote control of a multidetector (made up of a bidimensional array of CsI scintillators) used to detect light nuclear particles, as protons and/or light ions. In the second application, we present an implementation of the control of a vacuum system suitable for a special chamber used for the development and testing of particle detectors operating in vacuum conditions.
Nuclear Magnetic Resonance (NMR) is a RF technique that is able to detect any compound by sensing the excited resonance signals from atomic nuclei having non-zero spin. NQR is similar to NMR but the only difference is NMR needs a DC magnetic field and due to this its application in the field is limited. A FPGA based NQR spectrometer is designed using a single FPGA chip to perform the digital tasks required for NQR spectrometer. Design of Probe for NMR/NQR spectrometer is researched. Parallel tuned and series tuned Probes are discussed and simulated.14N NQR from NaNO2 is observed from spectrometer designed with parallel tuned probe.
The Time and Frequency Laboratory of the Hellenic Institute of Metrology (EIM)eimgreece
1. Continuous and reliable local representation of Universal Coordinated Time - UTC(EIM).
2. Contribution to Temps Atomique International (TAI).
3. Reliable and continuous distribution of reference frequencies.
4. Traceability to the international standards.
5. Broadcast of standard time and frequency signals inside and outside EIM facilities.
Ion Beam Analytical Technique PIXE for Pollution Study at Dhaka Van de Graaff...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Photosynthesis active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar
radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of
photosynthesis.
Experimental Testing of a Real-Time Implementation of a PMU-Based Wide-Area D...Power System Operation
The modern power grid is being used under operating conditions of increasing stress, giving
rise to grid stability issues. One of these stability issues is the phenomenon of inter-area oscillations.
Simulations have demonstrated the advantages of Wide-area Measurement Signals (WAMS)-based Oscillation Damping Controls in achieving improved electromechanical mode damping compared to traditional,
local signal-based Power System Stabilizers (PSS). This work takes an existing Phasor-based oscillation
damping (POD) algorithm and uses it to implement a proof-of-concept, wide-area, real-time controller
on National Instruments hardware. The developed prototype is tested in a real-time Hardware-in-theloop setup (RT-HIL) using OPAL-RT’s eMEGASIM real-time simulation platform and synchrophasor data
from actual Phasor Measurement Units (PMUs). The prototype and experiments provide insight into the
feasibility and real-world limitations of wide-area controls. Further, it is demonstrated how the proposed
control architecture has applications independent of the controlled power system device. Challenges faced,
the solutions implemented together with the present prototype’s limitations are also discussed.
Detection air pollution based on infrared image processingTELKOMNIKA JOURNAL
This paper proposes a method of detecting air pollution in a region using image processing techniques. The image used is the infrared image that obtained using a modified digital camera by mounting the SRS filter. Image processing technique used is to utilize wavelet transformation. Pollutants are detected based on the average number of white pixels that appear on the image. This white pixel appears due to the reflection of the wavelength of the pollutant that hits the sensor on the camera. From the results of the proposed method detection is known that the highest pollution occurs in 12.00 which is the busiest traffic time and the lowest pollution occurred in 08.00 where the traffic passing through the area has not been crowded.
Ion Beam Analytical Technique PIXE for Pollution Study at Dhaka Van de Graaff...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Photosynthesis active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar
radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of
photosynthesis.
Experimental Testing of a Real-Time Implementation of a PMU-Based Wide-Area D...Power System Operation
The modern power grid is being used under operating conditions of increasing stress, giving
rise to grid stability issues. One of these stability issues is the phenomenon of inter-area oscillations.
Simulations have demonstrated the advantages of Wide-area Measurement Signals (WAMS)-based Oscillation Damping Controls in achieving improved electromechanical mode damping compared to traditional,
local signal-based Power System Stabilizers (PSS). This work takes an existing Phasor-based oscillation
damping (POD) algorithm and uses it to implement a proof-of-concept, wide-area, real-time controller
on National Instruments hardware. The developed prototype is tested in a real-time Hardware-in-theloop setup (RT-HIL) using OPAL-RT’s eMEGASIM real-time simulation platform and synchrophasor data
from actual Phasor Measurement Units (PMUs). The prototype and experiments provide insight into the
feasibility and real-world limitations of wide-area controls. Further, it is demonstrated how the proposed
control architecture has applications independent of the controlled power system device. Challenges faced,
the solutions implemented together with the present prototype’s limitations are also discussed.
Detection air pollution based on infrared image processingTELKOMNIKA JOURNAL
This paper proposes a method of detecting air pollution in a region using image processing techniques. The image used is the infrared image that obtained using a modified digital camera by mounting the SRS filter. Image processing technique used is to utilize wavelet transformation. Pollutants are detected based on the average number of white pixels that appear on the image. This white pixel appears due to the reflection of the wavelength of the pollutant that hits the sensor on the camera. From the results of the proposed method detection is known that the highest pollution occurs in 12.00 which is the busiest traffic time and the lowest pollution occurred in 08.00 where the traffic passing through the area has not been crowded.
Characterization of Liquid Waste in Isotope production and Research Facilitiesiosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Several algorithms have been offered to track the Maximum Power Point when we have one maximum power point. Moreover, fuzzy control and neural was utilized to track the Maximum Power Point when we have multi-peaks power points. In this paper, we will propose an improved Maximum Power Point tracking method for the photovoltaic system utilizing a modified PSO algorithm. The main advantage of the method is the decreasing of the steady state oscillation (to practically zero) once the Maximum Power Point is located. moreover, the proposed method has the ability to track the Maximum Power Point for the extreme environmental condition that cause the presence of maximum multi-power points, for example, partial shading condition and large fluctuations of insolation. To evaluate the effectiveness of the proposed method, MATLAB simulations are carried out under very challenging circumstance, namely step changes in irradiance, step changes in load, and partial shading of the Photovoltaic array. Finally, its performance is compared with the perturbation and observation” and fuzzy logic results for the single peak, and the neural-fuzzy control results for the multi-peaks.
Experimental Study for the Different Methods of Generating Millimeter WavesIJERA Editor
In this paper a analytical comparison and experimental implementation of different methods used in generating a low phase noise millimeter wave signals is presented. Four techniques were experimented and compared, Multiplication, phase lock loop (PLL), Injection locking (IL), and Injection locking with phase lock loop (ILPLL). The comparison and experimental results of a laboratory discussed.
In this paper, an adaptive control system is employed in a novel implementation technique of feedforward linearization system for optical analog communication systems’ laser transmitter. The adaptive control system applies the Newton trust-region dogleg algorithm, which is a numerical optimization algorithm, to automatically tune the adjustment parameters in the feedforward loops to optimize the feedforward system performance and adapt to process variations. At the end of the paper, significant reductions of over 20 dBm in the third-order intermodulation distortion products have been achieved for operating frequencies from 5.0 to 5.8 GHz.
IEEE International Conference PresentationAnmol Dwivedi
IEEE INTERNATIONAL CONFERENCE -
Paper Title "Real-Time Implementation of Phasor Measurement Unit Using NI CompactRIO".
Code Available on: https://github.com/anmold-07/Synchrophasor-Estimation
Design and Development of a Shortwave near Infrared Spectroscopy using NIR LE...IJECEIAES
Near infrared (NIR) spectroscopic technology has been getting more attention in various fields. The development of a low cost NIR spectroscopy is crucial to reduce the financial barriers so that more NIR spectroscopic applications will be investigated and developed by means of the NIR spectroscopic technology. This study proposes an alternative to measure shortwave NIR spectrum using one collimating lens, two slits, one NIR transmission grating, one linear array sensor, and one microcontroller. Five high precision narrow bands NIR light emitting diodes (LEDs) were used to calibrate the proposed spectroscopy. The effects of the proposed two slits design, the distance between the grating and linear array sensor, and three different regression models were investigated. The accuracy of the proposed design was cross-validated using leave-one-out cross-validation. Results show that the proposed two slits design was able to eliminate unwanted signals substantially, and the cross-validation was able to estimate the best model with root mean squared error of cross-validation of 3.8932nm. Findings indicate that the cross-validation approach is a good approach to estimate the final model without over-fitting, and the proposed shortwave NIR spectroscopy was able to estimate the peak value of the acquired spectrum from NIR LEDs with RMSE of 1.1616nm.
A first response microcontroller basedIJCI JOURNAL
This paper presents the microcontroller based advanced technique to design and development of a portable
radiation survey meter to measure low level gamma radiation using NAI(T1) scintillation detector. A
scintillation detector was used as radiation detector and a microcontroller PIC16F876 was used to control
the function of the developed system. The microcontroller generated square wave frequency at specified
pulse width to produce high voltage (+1200V) and regulates it. The high voltage was required to activate
the scintillation detector. Preamplifier and amplifier were designed to make the detector signal for the
further amplification. Microcontroller senses the pulses from the amplifier output and processes data by
software and displays the results. The microcontroller was programmed using a high level programming
language ‘C’ with PCWH compiler.
In photovoltaic (PV) systems, maximum power point tracking (MPPT) techniques are used to track the maximum power from the PV array under the change in irradiance and temperature conditions. The perturb and observe (P&O) is one of the most widely used MPPT techniques in recent times due to its simple implementation and improved performance. However, the P&O has limitations such as oscillation around the MPP during which time the P&O algorithm will become confused due to rapidly changing atmospheric conditions. To overcome the above limitation, this paper uses the fuzzy logic controller (FLC) to track the maximum power from the PV system under different irradiance, integrates it with a DC-DC boost converter as a tracker. The result of the FLC performance is compared with the traditional P&O method and shows the MPPT algorithm based on FLC ensures continuous tracking of the maximum power within a short period compared with the traditional P&O method. Besides that, the proposed method (FLC) has a faster dynamic response and low oscillations at the operating point around the MPP under steady-state conditions and dynamic change in irradiance.
A Novel Approach for Precise Motion Artefact Detection in Photoplethysmograph...AM Publications
PPG signal is a useful tool for quick and critical diagnosis related to cardiovascular output via wearable or portable devices. Its drawback is unreliable during non-stationary states due to occurrences of frequency overlap of the desired and motion artifact signals. The accelerometer is usually used to reflect the motion artifact when the adaptive noise cancellation technique is implemented to address this obstacle, but it failed to predict the value of real induced noise accurately. In this work, we investigate a new concept that is capable of providing the entire motion artifact separately by recruiting twin photodetectors to formulate the influential signals. The main function of photo-detector (MPD) is to generate the corrupted PPG signal. While the second photo-detector (CPD) that covered up from the light effect, will be used to reflect the corruption effect that exists in both sources simultaneously by counting the generated dark photocurrent (GDPC). To validate the GDPC approach, experiments were executed to analyze the response of two methods during steady and motion state. Results showed resemblance responses for both methods regarding the’ amplitude fluctuations and high positive correlations in the time domain. Furthermore, the FFT peak plots in frequency domain indicated the potential of CPD to reflect all fundamental frequencies caused by motion, unlike the acceleration approach. Therefore, the proposed concept is a sure-fire method to obtain precise measurements at a lower cost.
This paper presents a maximum power point (MPP) tracking method based on a hybrid combination between the fuzzy logic controller (FLC) and the conventional Perturb-and-Observe (P&O) method. The proposed algorithm utilizes the FLC to initialize P&O algorithm with an initial duty cycle. MATLAB/Simulink models consisting of, the photovoltaic system, boost converter and controllers, are built to evaluate the performance of the proposed algorithm. To accurately illustrate the performance of the proposed algorithm, comparisons with standalone FLC and P&O are carried out. The performance of the proposed algorithm is investigated difficult weather conditions including sudden changes and partial shading. The results showed that the proposed algorithm successfully reaches MPP in all scenarios.
In order to maximize the electric energy production of a photovoltaic generator (PVG), the maximum power point tracking (MPPT) methods are usually used in photovoltaic systems. The principle of these techniques is to operate the PVG to the maximum power point (MPP), which depends on the environmental factors, such as solar irradiance and ambient temperature, ensuring the optimal power transfer between PVG and load. In this paper, we present the implementation of two digital MPPT commands using the Arduino Mega type. The two proposed MPPT controls are based on the algorithm of perturb and observe (P&O), the first one with fixed perturbation step and the second one with two perturbations step varying with some conditions. The experimental results show that the P&O algorithm with variable step perturbation gives good results compared to the P&O algorithm with fixed perturbation step in terms of the time response and the oscillations around the MPP.
Adaptive maximum power point tracking using neural networks for a photovoltai...Mellah Hacene
Adaptive Maximum Power Point Tracking Using Neural Networks for a Photovoltaic Systems According Grid
Electrical Engineering & Electromechanics, (5), 57–66, 2021. https://doi.org/10.20998/2074-272X.2021.5.08
Design of Microcontroller Based Multi-Frequency Ultrasonic Pulser ReceiverIJERA Editor
Ultrasonic technique is widely accepted as a characterizing tool because of its non destructive nature. Great
technical advancement in ultrasonic apparatuses over the last few years has permitted their increased use. In the
present work, an attempt has been made to develop an ultrasonic pulser receiver for pulse echo technique which
gives pulsed RF of desired frequency on selection from PC without shifting to another oscillator. A
microcontroller (ATMega16) controlled oscillator generates required frequencies on receiving a command. A
pulse repetition frequency (PRF) is generated by microcontroller in such a way to give fixed number of RF
cycles for each selected frequency. The receiver section receives the echoes from the same transducer, rectifies
and amplifies it and is projected to oscilloscope for further study. The designed multi frequency ultrasonic pulser
receiver system has been tested in standard liquids for velocity measurements.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Essentials of Automations: Optimizing FME Workflows with Parameters
B041221317
1. IOSR Journal of Engineering (IOSRJEN) www.iosrjen.org
ISSN (e): 2250-3021, ISSN (p): 2278-8719
Vol. 04, Issue 12 (December 2014), ||V2|| PP 13-17
International organization of Scientific Research 13 | P a g e
Amplitude Modulation Laser Diode with swept Frequency
analysis of samples
Ríos Medellín Manuel Alfonso1
, Jaime Hugo Puebla Lomas2
José Luis Hernández Aguilar3
Abstract: This paper presents the design of a system with the ability to control the frequency with which they
are stimulated laser diodes used to analyze samples in any physical states. It is common that the modulation of
the laser diode is performed in amplitude, this for the analysis of samples using photothermal techniques. Our
system was developed considering the electrical characteristics of each of the laser diodes such as current
operating power, wavelength and operating voltage. We developed a kind of driver, with it is possible the
amplitude modulation of the, but at the same time performing a frequency sweep of this, this without neglecting
the optical power of each of the laser diodes used, and to ensure that the beam from each diode is suitable for
this application. We take the design´s driver of the bipolar transistor configuration that allows the current
flowing through the base of the transistor is that encourages each of the laser diodes, this applied separately to
each diode used.
Keywords: Amplitude, Frequency, Laser, Modulation Photothermal.
I. INTRODUCTION
The photothermal techniques allow analyzing various transport phenomena of temperature, charge and
mass. Can be analyzed vibrations in solids, liquids and gases. Moreover they are useful in the study of
photochemical reactions and phase transitions.
Another major advantage of photothermal techniques is that this phenomenon can be detected in many
different ways. Depending on the detection system, the name given to the technique. When we use microphones
or piezoelectric talk about photoacoustic techniques , if we use pyroelectric detectors we mean
photopyroelectric techniques , when using beam test for sensing the temperature through the change of local
refractive index, we have the mirage effect , temperature thermoreflective and the thermal lens. One of the most
promising methods is using remote sensing and is known as infrared photothermal radiometry.
The infrared radiometry allows studying the optical and thermal properties of the materials, without
requiring contact with the samples and in principle any sanding or polishing treatment for the samples is not
necessary. In the infrared radiometry is incident light beam on a material, this as consequently emits infrared
radiation and is recorded by an infrared detector, suited to the emitted wavelength. There are basically two
experimental configurations known transmission and reflection. Also you can work in two ways using pulsed or
modulated radiation.
Using these techniques, involves among other things, the modulation of a radiation source to which the
sample is exposed for its characterization [1]. In most cases is chosen powerful lamps which are modulated by
external devices. This set provides a more robust experiment, besides the price increase. Finding sources of
modulated radiation involving a lower cost and also remain practical is the aim of this work. A laser diode with
an appropriate modulation may be a viable substitute for such sources.
It will use a TTL signal, which will be generated by a PIC16F876 microcontroller medium scale.
Making use of a driver enabling positive Laser Diode modulation to obtain the desired modulation results in a
wide range of frequencies from its feed stream. It is important to note that this project is part of another system
which is responsible for collecting the information through a photoacoustic chamber, which will be built-in
microphone for obtaining data [2]. Later, this information will be amplified by a lock-in amplifiers, whose
function is to amplify signals of very low amplitude, so that through a Graphical User Interface (GUI) will be
displayed below the graphs (Amplitude vs Frequency and Phase vs Frequency) of the material response to the
heat emitted by the beam of the Laser Diode.
Finally the photothermal prototype multipurpose analyzer presented in this paper consists of four
modules:
The first module is the pyroelectric detection system for photothermal analyzer. The second module is
the prototype of Lock-in Amplifier for photothermal analyzer. The third module is the photoacoustic detection
system for photothermal analyzer. The last module that is discussed in this article is the prototype lighting
system photothermal analyzer. This can be better understood by observing Figure 1.
2. Paper preparation guidelines for IOSR Journal of Engineering
International organization of Scientific Research 14 | P a g e
Figure 1. Basic configuration of the photoacoustic experiment.
II. DEVELOPMENT
To implement a light source is necessary to take various considerations. One is the type of sample is to
characterize; because this determines, among other things, the necessary power source to generate photoacoustic
signals optimal [3]. Also relevant is the experiment setup, sometimes space is limited, and a fix is looking to
small.
For this work, different materials among these the experiment was conducted in a piezoelectric sensor
were considered. For phase control and conditioning of our system. The circuit shown in Figure 2 shows the
layout of the control stage which is responsible for manipulating the driver which is used primarily for
2N2222A transistor amplitude modulation of each laser diode, and in conjunction with the PIC16F876
microcontroller laser diode selection is made.
The sweep frequency of the system, consisted in the selection of different laser diode wavelength
making the change to a frequency set in the JAVA program, this was feasible when selecting the button to
change the type of sample to be analyzed, and primarily for each type of laser diode to the same driver
amplitude modulation of said laser diode is used.
Figure 2. Prototype used for testing electronic
III. DESIGN AND CONSTRUCTION OF PROTOTYPE
In our project employ near-infrared laser diodes are shown in Table 1.
Table 1. List of laser diodes used for the tests of temperature change of a piezoelectric material.
Name Long. Wave Potency Volt.
Laser Module D9mm 405nm 5mW 5VDC
Laser Module D8mm 532nm 10 mW 3VDC
Laser Module D4mm 635nm 5mW 3VDC
Laser Module D4mm 650nm 5mW 3VDC
Laser Module D6mm 780nm 5mW 3VDC
As the design and construction of the Electronic Prototype was developed according to the following
parameters;
3. Paper preparation guidelines for IOSR Journal of Engineering
International organization of Scientific Research 15 | P a g e
1. Power Laser Diode
2. Operating Temperature.
3. Wavelength.
4. Operating current.
5. Operating Voltage.
Each of these parameters is considered suitable for the amplitude modulation and frequency sweep
applied to the laser diode described in Table 1.
In the case of controlling the optical power only enough to consider the following conditions; the
current flowing through the laser diode is controlled by voltage source and driver configuration which is
presented in Figure 3.
Figure 3. Configuring the Driver for photothermal applications.
Note that for controlling the power source industrial voltage is used, in order to reduce the noise that
occurs in the prototype and foremost be in the future if it is necessary to control the optical power enough to
implement a photodiode combined system which allows monitoring the optical energy being necessary for
photothermal applications, particularly when used a photothermal microscope [4].
This situation is of great interest for those areas where the analysis of nanofluids is attractive for
photothermal applications mentioned and controlling the optical power of each laser diode can see some
interesting results, nondestructive testing and materials developed samples.
IV. SWEEP FREQUENCY OF LASER DIODES
In this case software developed in the object-oriented (Java), which aims to make a sweep frequency of
each of the laser diodes used language was used as mentioned. View the interface in Figure 4.
Figure 4. Interface for frequency scanning Laser Diode.
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International organization of Scientific Research 16 | P a g e
V. RESULTS AND TESTING SYSTEM
The tests were performed using a piezoelectric sensor, with the aid of this see the stability of the driver
developed, see Figures 5 and 6.
Figure 5. Exponential piezoelectric materials response
Figure 6. Amplitude and phase versus frequency of the diode laser.
Also we can see the graphics that were doing the tests in the laboratory, see Figures 7 and 8.
Figure 7. Response amplitude and phase vs. frequency, piezoelectric sensor. 635nm Diode.
5. Paper preparation guidelines for IOSR Journal of Engineering
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Figure 8. Response in amplitude and phase vs. frequency, piezoelectric sensor. 850nm Diode.
In the example we can see the frequency response of both the amplitude and phase for each laser diode,
and its response is different, which means that the material responds differently as the case of photothermal
technique [5].
VI. Conclusions
Implementing an NPN silicon transistor for modulation of a laser diode with complex arrangements can
replace gas lasers or lamps coupled to other devices to sample radiation in photoacoustic techniques. Reducing
cost and the need for this type of space experiments. Additionally the versatility of the prototype greatly
improves the results in-live and in-situ, modular samples would not be possible to obtain results of these outside
its fixed location.
With this we can say that the developed system is versatile because it does not require being in the
place where you will find all the equipment to get the results of the photothermal techniques employed. So the
obtained system satisfies the characteristics of a computer system with the ability to perform the analysis of
samples of different materials in liquid, solid and gaseous states. Also its mechanical design allows you to adjust
and select the Laser Diode to use, thanks to the programming of a microcontroller (PIC16F876) and in turn
control the frequency sweep, to know the result of different materials radiate varying frequency.
References
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