Optical Doppler tomography based on a field programmable gate array

DEFF Research Database (Denmark)

Larsen, Henning Engelbrecht; Nilsson, Ronnie Thorup; Thrane, Lars

2008-01-01

We report the design of and results obtained by using a field programmable gate array (FPGA) to digitally process optical Doppler tomography signals. The processor fits into the analog signal path in an existing optical coherence tomography setup. We demonstrate both Doppler frequency and envelope...... extraction using the Hilbert transform, all in a single FPGA. An FPGA implementation has certain advantages over general purpose digital signal processor (DSP) due to the fact that the processing elements operate in parallel as opposed to the DSP. which is primarily a sequential processor....

Examination of cotton fibers and common contaminants using an infrared microscope and a focal-plane array detector

Science.gov (United States)

The chemical imaging of cotton fibers and common contaminants in fibers is presented. Chemical imaging was performed with an infrared microscope equipped with a Focal-Plane Array (FPA) detector. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In a...

Implementing a Microcontroller Watchdog with a Field-Programmable Gate Array (FPGA)

Science.gov (United States)

Straka, Bartholomew

2013-01-01

Reliability is crucial to safety. Redundancy of important system components greatly enhances reliability and hence safety. Field-Programmable Gate Arrays (FPGAs) are useful for monitoring systems and handling the logic necessary to keep them running with minimal interruption when individual components fail. A complete microcontroller watchdog with logic for failure handling can be implemented in a hardware description language (HDL.). HDL-based designs are vendor-independent and can be used on many FPGAs with low overhead.

NEPP Update of Independent Single Event Upset Field Programmable Gate Array Testing

Science.gov (United States)

Berg, Melanie; Label, Kenneth; Campola, Michael; Pellish, Jonathan

2017-01-01

This presentation provides a NASA Electronic Parts and Packaging (NEPP) Program update of independent Single Event Upset (SEU) Field Programmable Gate Array (FPGA) testing including FPGA test guidelines, Microsemi RTG4 heavy-ion results, Xilinx Kintex-UltraScale heavy-ion results, Xilinx UltraScale+ single event effect (SEE) test plans, development of a new methodology for characterizing SEU system response, and NEPP involvement with FPGA security and trust.

Apertureless near-field/far-field CW two-photon microscope for biological and material imaging and spectroscopic applications.

Science.gov (United States)

Nowak, Derek B; Lawrence, A J; Sánchez, Erik J

2010-12-10

We present the development of a versatile spectroscopic imaging tool to allow for imaging with single-molecule sensitivity and high spatial resolution. The microscope allows for near-field and subdiffraction-limited far-field imaging by integrating a shear-force microscope on top of a custom inverted microscope design. The instrument has the ability to image in ambient conditions with optical resolutions on the order of tens of nanometers in the near field. A single low-cost computer controls the microscope with a field programmable gate array data acquisition card. High spatial resolution imaging is achieved with an inexpensive CW multiphoton excitation source, using an apertureless probe and simplified optical pathways. The high-resolution, combined with high collection efficiency and single-molecule sensitive optical capabilities of the microscope, are demonstrated with a low-cost CW laser source as well as a mode-locked laser source.

Fiber laser-microscope system for femtosecond photodisruption of biological samples.

Science.gov (United States)

Yavaş, Seydi; Erdogan, Mutlu; Gürel, Kutan; Ilday, F Ömer; Eldeniz, Y Burak; Tazebay, Uygar H

2012-03-01

We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells.

Development of a fast time-to-digital converter (TDC) using a programmable gate array

International Nuclear Information System (INIS)

Mine, Shun-ichi; Tokushuku, Katsuo; Yamada, Sakue.

1994-09-01

A fast time-to-digital converter with a 5 ns step was designed and tested by utilizing a user-programmable gate array. The stabilities against temperature and supply voltage variation were measured. A module was built with this TDC, and was successfully used in the first-level trigger system of the ZEUS detector to reject proton-beam induced background events. (author)

Modeling and Simulation of a Non-Coherent Frequency Shift Keying Transceiver Using a Field Programmable Gate Array (FPGA)

National Research Council Canada - National Science Library

Voskakis, Konstantinos

2008-01-01

...) receiver-transmitter in a Field Programmable Gate Array (FPGA). After introducing the theory behind the Non- Coherent BFSK demodulation implemented at the receiver, the design of transmitter and receiver is illustrated...

Field programmable gate array-assigned complex-valued computation and its limits

Energy Technology Data Exchange (ETDEWEB)

Bernard-Schwarz, Maria, E-mail: maria.bernardschwarz@ni.com [National Instruments, Ganghoferstrasse 70b, 80339 Munich (Germany); Institute of Applied Physics, TU Wien, Wiedner Hauptstrasse 8, 1040 Wien (Austria); Zwick, Wolfgang; Klier, Jochen [National Instruments, Ganghoferstrasse 70b, 80339 Munich (Germany); Wenzel, Lothar [National Instruments, 11500 N MOPac Expy, Austin, Texas 78759 (United States); Gröschl, Martin [Institute of Applied Physics, TU Wien, Wiedner Hauptstrasse 8, 1040 Wien (Austria)

2014-09-15

We discuss how leveraging Field Programmable Gate Array (FPGA) technology as part of a high performance computing platform reduces latency to meet the demanding real time constraints of a quantum optics simulation. Implementations of complex-valued operations using fixed point numeric on a Virtex-5 FPGA compare favorably to more conventional solutions on a central processing unit. Our investigation explores the performance of multiple fixed point options along with a traditional 64 bits floating point version. With this information, the lowest execution times can be estimated. Relative error is examined to ensure simulation accuracy is maintained.

A software framework for pipelined arithmetic algorithms in field programmable gate arrays

Science.gov (United States)

Kim, J. B.; Won, E.

2018-03-01

Pipelined algorithms implemented in field programmable gate arrays are extensively used for hardware triggers in the modern experimental high energy physics field and the complexity of such algorithms increases rapidly. For development of such hardware triggers, algorithms are developed in C++, ported to hardware description language for synthesizing firmware, and then ported back to C++ for simulating the firmware response down to the single bit level. We present a C++ software framework which automatically simulates and generates hardware description language code for pipelined arithmetic algorithms.

Configuration and debug of field programmable gate arrays using MATLAB[reg)/SIMULINK[reg

International Nuclear Information System (INIS)

Grout, I; Ryan, J; O'Shea, T

2005-01-01

Increasingly, the need to seamlessly link high-level behavioural descriptions of electronic hardware for modelling and simulation purposes to the final application hardware highlights the gap between the high-level behavioural descriptions of the required circuit functionality (considering here digital logic) in commonly used mathematical modelling tools, and the hardware description languages such as VHDL and Verilog-HDL. In this paper, the linking of a MATLAB[reg] model for digital algorithm for implementation on a programmable logic device for design synthesis from the MATLAB[reg] model into VHDL is discussed. This VHDL model is itself synthesised and downloaded to the target Field Programmable Gate Array, for normal operation and also for design debug purposes. To demonstrate this, a circuit architecture mapped from a SIMULINK[reg] model is presented. The rationale is for a seamless interface between the initial algorithm development and the target hardware, enabling the hardware to be debugged and compared to the simulated model from a single interface for use with by a non-expert in the programmable logic and hardware description language use

Multiple constant multiplication optimizations for field programmable gate arrays

CERN Document Server

Kumm, Martin

2016-01-01

This work covers field programmable gate array (FPGA)-specific optimizations of circuits computing the multiplication of a variable by several constants, commonly denoted as multiple constant multiplication (MCM). These optimizations focus on low resource usage but high performance. They comprise the use of fast carry-chains in adder-based constant multiplications including ternary (3-input) adders as well as the integration of look-up table-based constant multipliers and embedded multipliers to get the optimal mapping to modern FPGAs. The proposed methods can be used for the efficient implementation of digital filters, discrete transforms and many other circuits in the domain of digital signal processing, communication and image processing. Contents Heuristic and ILP-Based Optimal Solutions for the Pipelined Multiple Constant Multiplication Problem Methods to Integrate Embedded Multipliers, LUT-Based Constant Multipliers and Ternary (3-Input) Adders An Optimized Multiple Constant Multiplication Architecture ...

Active Micro structured Optical Arrays of Grazing Incidence Reflectors

International Nuclear Information System (INIS)

Willingale, R.; Feldman, Ch.; Michette, A.; Hart, D.; McFaul, Ch; Morrison, G.R.; Pfauntsch, S.; Powell, A.K.; Sahraei, Sh.; Shand, M.T.; Button, T.; Rodriguez-Sanmartin, D.; Zhang, D.; Dunare, C.; Parkes, W.; Stevenson, T.; Folkard, M.; Vojnovic, B.; Vojnovic, B.

2011-01-01

The UK Smart X-Ray Optics (SXO) programme is developing active/adaptive optics for terrestrial applications. One of the technologies proposed is micro structured optical arrays (MOAs), which focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels. Although such arrays are similar in concept to poly capillary and microchannel plate optics, they can be bent and adjusted using piezoelectric actuators providing control over the focusing and inherent aberrations. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays, and the channels of appropriate aspect ratios can be made using deep silicon etching. An exemplar application will be in the micro probing of biological cells and tissue samples using Ti Ka radiation (4.5?keV) in studies related to radiation-induced cancers. This paper discusses the optical design, modelling, and manufacture of such optics

Field-Programmable Gate Array-based fluxgate magnetometer with digital integration

Science.gov (United States)

Butta, Mattia; Janosek, Michal; Ripka, Pavel

2010-05-01

In this paper, a digital magnetometer based on printed circuit board fluxgate is presented. The fluxgate is pulse excited and the signal is extracted by gate integration. We investigate the possibility to perform integration on very narrow gates (typically 500 ns) by using digital techniques. The magnetometer is based on field-programmable gate array (FPGA) card: we will show all the advantages and disadvantages, given by digitalization of fluxgate output voltage by means of analog-to-digital converter on FPGA card, as well as digitalization performed by external digitizer. Due to very narrow gate, it is shown that a magnetometer entirely based on a FPGA card is preferable, because it avoids noise due to trigger instability. Both open loop and feedback operative mode are described and achieved results are presented.

Real-time field programmable gate array architecture for computer vision

Science.gov (United States)

Arias-Estrada, Miguel; Torres-Huitzil, Cesar

2001-01-01

This paper presents an architecture for real-time generic convolution of a mask and an image. The architecture is intended for fast low-level image processing. The field programmable gate array (FPGA)-based architecture takes advantage of the availability of registers in FPGAs to implement an efficient and compact module to process the convolutions. The architecture is designed to minimize the number of accesses to the image memory and it is based on parallel modules with internal pipeline operation in order to improve its performance. The architecture is prototyped in a FPGA, but it can be implemented on dedicated very- large-scale-integrated devices to reach higher clock frequencies. Complexity issues, FPGA resources utilization, FPGA limitations, and real-time performance are discussed. Some results are presented and discussed.

Three-channel phase meters based on the AD8302 and field programmable gate arrays for heterodyne millimeter wave interferometer

Czech Academy of Sciences Publication Activity Database

Varavin, A.V.; Ermak, G.P.; Vasiliev, A.S.; Fateev, A.V.; Varavin, Mykyta; Žáček, František; Zajac, Jaromír

2016-01-01

Roč. 75, č. 11 (2016), s. 1009-1025 ISSN 0040-2508 Institutional support: RVO:61389021 Keywords : AD8302 * Interferometer * Millimeter wave * Phase meter * Programmable gate array * Tokamak Subject RIV: BL - Plasma and Gas Discharge Physics

Firmware-only implementation of Time-to-Digital Converter (TDC) in Field-Programmable Gate Array (FPGA)

International Nuclear Information System (INIS)

Jinyuan Wu; Zonghan Shi; Irena Y Wang

2003-01-01

A Time-to-Digital Converter (TDC) implemented in general purpose field-programmable gate array (FPGA) for the Fermilab CKM experiment will be presented. The TDC uses a delay chain and register array structure to produce lower bits in addition to higher bits from a clock counter. Lacking the direct controls custom chips, the FPGA implementation of the delay chain and register array structure had to address two major problems: (1) the logic elements used for the delay chain and register array structure must be placed and routed by the FPGA compiler in a predictable manner, to assure uniformity of the TDC binning and short-term stability. (2) The delay variation due to temperature and power supply voltage must be compensated for to assure long-term stability. They used the chain structures in the existing FPGAs that the venders designed for general purpose such as carry algorithm or logic expansion to solve the first problem. To compensate for delay variations, they studied several digital compensation strategies that can be implemented in the same FPGA device. Some bench-top test results will also be presented in this document

An automatic evaluation method for the surface profile of a microlens array using an optical interferometric microscope

International Nuclear Information System (INIS)

Lin, Chern-Sheng; Loh, Guo-Hao; Fu, Shu-Hsien; Chang, Hsun-Kai; Yang, Shih-Wei; Yeh, Mau-Shiun

2010-01-01

In this paper, an automatic evaluation method for the surface profile of a microlens array using an optical interferometric microscope is presented. For inspecting the microlens array, an XY-table is used to position it. With a He–Ne laser beam and optical fiber as a probing light, the measured image is sent to the computer to analyze the surface profile. By binary image slicing and area recognition, this study located the center of each ring and determined the substrate of the microlens array image through the background of the entire microlens array interference image. The maximum and minimum values of every segment brightness curve were determined corresponding to the change in the segment phase angle from 0° to 180°. According to the ratio of the actual ring area and the ideal ring area, the area ratio method was adopted to find the phase-angle variation of the interference ring. Based on the ratio of actual ring brightness and the ideal ring brightness, the brightness ratio method was used to determine the phase-angle variation of the interference ring fringe. The area ratio method and brightness ratio method are interchangeable in precisely determining the phase angles of the innermost and outermost rings of the interference fringe and obtaining different microlens surface altitudes of respective pixels in the segment, to greatly increase the microlens array surface profile inspection accuracy and quality

A control system based on field programmable gate array for papermaking sewage treatment

International Nuclear Information System (INIS)

Zhang, Zi Sheng; Xie, Chang; Xiong, Yan Qing; Liu, Zhi Qiang; Li, Qing

2013-01-01

A sewage treatment control system is designed to improve the efficiency of papermaking wastewater treatment system. The automation control system is based on Field Programmable Gate Array (FPGA), coded with Very-High-Speed Integrate Circuit Hardware Description Language (VHDL), compiled and simulated with Quartus. In order to ensure the stability of the data used in FPGA, the data is collected through temperature sensors, water level sensor and online PH measurement system. The automatic control system is more sensitive, and both the treatment efficiency and processing power are increased. This work provides a new method for sewage treatment control.

Infrared microscope inspection apparatus

Science.gov (United States)

Forman, Steven E.; Caunt, James W.

1985-02-26

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

Design and analysis of a dual mode CMOS field programmable analog array

International Nuclear Information System (INIS)

Cheng Xiaoyan; Yang Haigang; Yin Tao; Wu Qisong; Zhang Hongfeng; Liu Fei

2014-01-01

This paper presents a novel field-programmable analog array (FPAA) architecture featuring a dual mode including discrete-time (DT) and continuous-time (CT) operation modes, along with a highly routable connection boxes (CBs) based interconnection lattice. The dual mode circuit for the FPAA is capable of achieving targeted optimal performance in different applications. The architecture utilizes routing switches in a CB not only for the signal interconnection purpose but also for control of the electrical charge transfer required in switched-capacitor circuits. This way, the performance of the circuit in either mode shall not be hampered with adding of programmability. The proposed FPAA is designed and implemented in a 0.18 μm standard CMOS process with a 3.3 V supply voltage. The result from post-layout simulation shows that a maximum bandwidth of 265 MHz through the interconnection network is achieved. The measured results from demonstrated examples show that the maximum signal bandwidth of up to 2 MHz in CT mode is obtained with the spurious free dynamic range of 54 dB, while the signal processing precision in DT mode reaches 96.4%. (semiconductor integrated circuits)

Radiation-Hardened Circuitry Using Mask-Programmable Analog Arrays. Final Report

Energy Technology Data Exchange (ETDEWEB)

Britton, Jr., Charles L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ericson, Milton Nance [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bobrek, Miljko [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Blalock, Benjamin [Univ. of Tennessee, Knoxville, TN (United States)

2015-12-01

As the recent accident at Fukushima Daiichi so vividly demonstrated, telerobotic technologies capable of withstanding high radiation environments need to be readily available to enable operations, repair, and recovery under severe accident scenarios where human entry is extremely dangerous or not possible. Telerobotic technologies that enable remote operation in high dose rate environments have undergone revolutionary improvement over the past few decades. However, much of this technology cannot be employed in nuclear power environments due the radiation sensitivity of the electronics and the organic insulator materials currently in use. This is the final report of the activities involving the NEET 2 project Radiation Hardened Circuitry Using Mask-Programmable Analog Arrays. We present a detailed functional block diagram of the proposed data acquisition system, the thought process leading to technical decisions, the implemented system, and the tested results from the systems. This system will be capable of monitoring at least three parameters of importance to nuclear reactor monitoring: temperature, radiation level, and pressure.

A high throughput array microscope for the mechanical characterization of biomaterials

Science.gov (United States)

Cribb, Jeremy; Osborne, Lukas D.; Hsiao, Joe Ping-Lin; Vicci, Leandra; Meshram, Alok; O'Brien, E. Tim; Spero, Richard Chasen; Taylor, Russell; Superfine, Richard

2015-02-01

In the last decade, the emergence of high throughput screening has enabled the development of novel drug therapies and elucidated many complex cellular processes. Concurrently, the mechanobiology community has developed tools and methods to show that the dysregulation of biophysical properties and the biochemical mechanisms controlling those properties contribute significantly to many human diseases. Despite these advances, a complete understanding of the connection between biomechanics and disease will require advances in instrumentation that enable parallelized, high throughput assays capable of probing complex signaling pathways, studying biology in physiologically relevant conditions, and capturing specimen and mechanical heterogeneity. Traditional biophysical instruments are unable to meet this need. To address the challenge of large-scale, parallelized biophysical measurements, we have developed an automated array high-throughput microscope system that utilizes passive microbead diffusion to characterize mechanical properties of biomaterials. The instrument is capable of acquiring data on twelve-channels simultaneously, where each channel in the system can independently drive two-channel fluorescence imaging at up to 50 frames per second. We employ this system to measure the concentration-dependent apparent viscosity of hyaluronan, an essential polymer found in connective tissue and whose expression has been implicated in cancer progression.

Field-programmable lab-on-a-chip based on microelectrode dot array architecture.

Science.gov (United States)

Wang, Gary; Teng, Daniel; Lai, Yi-Tse; Lu, Yi-Wen; Ho, Yingchieh; Lee, Chen-Yi

2014-09-01

The fundamentals of electrowetting-on-dielectric (EWOD) digital microfluidics are very strong: advantageous capability in the manipulation of fluids, small test volumes, precise dynamic control and detection, and microscale systems. These advantages are very important for future biochip developments, but the development of EWOD microfluidics has been hindered by the absence of: integrated detector technology, standard commercial components, on-chip sample preparation, standard manufacturing technology and end-to-end system integration. A field-programmable lab-on-a-chip (FPLOC) system based on microelectrode dot array (MEDA) architecture is presented in this research. The MEDA architecture proposes a standard EWOD microfluidic component called 'microelectrode cell', which can be dynamically configured into microfluidic components to perform microfluidic operations of the biochip. A proof-of-concept prototype FPLOC, containing a 30 × 30 MEDA, was developed by using generic integrated circuits computer aided design tools, and it was manufactured with standard low-voltage complementary metal-oxide-semiconductor technology, which allows smooth on-chip integration of microfluidics and microelectronics. By integrating 900 droplet detection circuits into microelectrode cells, the FPLOC has achieved large-scale integration of microfluidics and microelectronics. Compared to the full-custom and bottom-up design methods, the FPLOC provides hierarchical top-down design approach, field-programmability and dynamic manipulations of droplets for advanced microfluidic operations.

Field programmable gate array reliability analysis using the dynamic flow graph methodology

Energy Technology Data Exchange (ETDEWEB)

McNelles, Phillip; Lu, Lixuan [Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology (UOIT), Ontario (Canada)

2016-10-15

Field programmable gate array (FPGA)-based systems are thought to be a practical option to replace certain obsolete instrumentation and control systems in nuclear power plants. An FPGA is a type of integrated circuit, which is programmed after being manufactured. FPGAs have some advantages over other electronic technologies, such as analog circuits, microprocessors, and Programmable Logic Controllers (PLCs), for nuclear instrumentation and control, and safety system applications. However, safety-related issues for FPGA-based systems remain to be verified. Owing to this, modeling FPGA-based systems for safety assessment has now become an important point of research. One potential methodology is the dynamic flowgraph methodology (DFM). It has been used for modeling software/hardware interactions in modern control systems. In this paper, FPGA logic was analyzed using DFM. Four aspects of FPGAs are investigated: the 'IEEE 1164 standard', registers (D flip-flops), configurable logic blocks, and an FPGA-based signal compensator. The ModelSim simulations confirmed that DFM was able to accurately model those four FPGA properties, proving that DFM has the potential to be used in the modeling of FPGA-based systems. Furthermore, advantages of DFM over traditional reliability analysis methods and FPGA simulators are presented, along with a discussion of potential issues with using DFM for FPGA-based system modeling.

Confocal scanning microscope for nuclear photoemulsion

International Nuclear Information System (INIS)

Batusov, Yu.A.; Kovalev, Yu.S.; Soroko, L.M.

2005-01-01

The application of the confocal scanning microscope to the objects in the nuclear photoemulsion is described. An array of 27 microtomograms of single silver grain is shown. The cross sections of the same particle track of diameter 1 μm, detected by means of the confocal scanning microscope with open and annular apertures, are presented. It was shown that the confocal scanning microscope opens indeed new opportunities for the nuclear photoemulsion technique to get previously inaccessible information for physics of the short-living particles

Radiation-hardened optically reconfigurable gate array exploiting holographic memory characteristics

Science.gov (United States)

Seto, Daisaku; Watanabe, Minoru

2015-09-01

In this paper, we present a proposal for a radiation-hardened optically reconfigurable gate array (ORGA). The ORGA is a type of field programmable gate array (FPGA). The ORGA configuration can be executed by the exploitation of holographic memory characteristics even if 20% of the configuration data are damaged. Moreover, the optoelectronic technology enables the high-speed reconfiguration of the programmable gate array. Such a high-speed reconfiguration can increase the radiation tolerance of its programmable gate array to 9.3 × 104 times higher than that of current FPGAs. Through experimentation, this study clarified the configuration dependability using the impulse-noise emulation and high-speed configuration capabilities of the ORGA with corrupt configuration contexts. Moreover, the radiation tolerance of the programmable gate array was confirmed theoretically through probabilistic calculation.

Enhanced depth-of-field of an integral imaging microscope using a bifocal holographic optical element-micro lens array.

Science.gov (United States)

Kwon, Ki-Chul; Lim, Young-Tae; Shin, Chang-Won; Erdenebat, Munkh-Uchral; Hwang, Jae-Moon; Kim, Nam

2017-08-15

We propose and implement an integral imaging microscope with extended depth-of-field (DoF) using a bifocal holographic micro lens array (MLA). The properties of the two MLAs are switched via peristrophic multiplexing, where different properties of the MLA are recorded onto the single holographic optical element (HOE). The recorded MLA properties are perpendicular to each other: after the first mode is recorded, the HOE is rotated by 90° clockwise, and the second mode is recorded. The experimental results confirm that the DoF of the integral imaging microscopy system is extended successfully by using the bifocal MLA.

LC-lens array with light field algorithm for 3D biomedical applications

Science.gov (United States)

Huang, Yi-Pai; Hsieh, Po-Yuan; Hassanfiroozi, Amir; Martinez, Manuel; Javidi, Bahram; Chu, Chao-Yu; Hsuan, Yun; Chu, Wen-Chun

2016-03-01

In this paper, liquid crystal lens (LC-lens) array was utilized in 3D bio-medical applications including 3D endoscope and light field microscope. Comparing with conventional plastic lens array, which was usually placed in 3D endoscope or light field microscope system to record image disparity, our LC-lens array has higher flexibility of electrically changing its focal length. By using LC-lens array, the working distance and image quality of 3D endoscope and microscope could be enhanced. Furthermore, the 2D/3D switching ability could be achieved if we turn off/on the electrical power on LClens array. In 3D endoscope case, a hexagonal micro LC-lens array with 350um diameter was placed at the front end of a 1mm diameter endoscope. With applying electric field on LC-lens array, the 3D specimen would be recorded as from seven micro-cameras with different disparity. We could calculate 3D construction of specimen with those micro images. In the other hand, if we turn off the electric field on LC-lens array, the conventional high resolution 2D endoscope image would be recorded. In light field microscope case, the LC-lens array was placed in front of the CMOS sensor. The main purpose of LC-lens array is to extend the refocusing distance of light field microscope, which is usually very narrow in focused light field microscope system, by montaging many light field images sequentially focusing on different depth. With adjusting focal length of LC-lens array from 2.4mm to 2.9mm, the refocusing distance was extended from 1mm to 11.3mm. Moreover, we could use a LC wedge to electrically shift the optics axis and increase the resolution of light field.

Segmented Routing for Speed-Performance and Routability in Field-Programmable Gate Arrays

Directory of Open Access Journals (Sweden)

Stephen Brown

1996-01-01

Full Text Available This paper addresses several issues involved for routing in Field-Programmable Gate Arrays (FPGAs that have both horizontal and vertical routing channels, with wire segments of various lengths. Routing is studied by using CAD routing tools to map a set of benchmark circuits into FPGAs, and measuring the effects that various parameters of the CAD tools have on the implementation of the circuits. A two-stage routing strategy of global followed by detailed routing is used, and the effects of both of these CAD stages are discussed, with emphasis on detailed routing. We present a new detailed routing algorithm designed specifically for the types of routing structures found in the most recent generation of FPGAs, and show that the new algorithm achieves significantly better results than previously published FPGA routers with respect to the speed-performance of implemented circuits.

Examining the Real Merits of the Virtual Microscope

Science.gov (United States)

Hennessy, Ronan; Meere, Pat; Ho, Timsie; Menuge, Julian; Tyrrell, Shane; Kamber, Balz; Higgs, Bettie; Kelley, Simon

2017-04-01

The Geoscience e-Laboratory (GeoLAB) project is a cooperative digital petrological microscopy technology enhanced learning (TEL) resource development project involving the four main university geoscience teaching centres in Ireland. Collaborating with the Open University (UK), a new digital library of petrographic thin sections has been added to the Virtual Microscope for Earth Sciences (VMfES) online repository. The collection was compiled with a view to introducing high-quality samples to teaching programmes in a manner that hitherto was limited by sample and microscope availability and cost and the temporal limits of laboratory access. The project has proceeded to explore the pedagogical implications of using the Virtual Microscope in teaching programmes. Online assessments and self-guided exercises developed using applications such as Google Forms have been introduced into programmes at each centre, and complimented by tutorial and interactive videos designed to support self-guided learning. The GeoLab project is reporting on the pedagogical implications of providing students with unimpeded access to high-quality petrographic learning resources during the term of semester and in advance of student assessments. Additionally, the project is collating data on the perceptions of both teachers and learners to using online learning media in mineralogy and petrology programmes, and if there are benefits therein to the more traditional styles of petrology and microscopy teaching and learning.

Note: The design of thin gap chamber simulation signal source based on field programmable gate array

International Nuclear Information System (INIS)

Hu, Kun; Wang, Xu; Li, Feng; Jin, Ge; Lu, Houbing; Liang, Futian

2015-01-01

The Thin Gap Chamber (TGC) is an important part of ATLAS detector and LHC accelerator. Targeting the feature of the output signal of TGC detector, we have designed a simulation signal source. The core of the design is based on field programmable gate array, randomly outputting 256-channel simulation signals. The signal is generated by true random number generator. The source of randomness originates from the timing jitter in ring oscillators. The experimental results show that the random number is uniform in histogram, and the whole system has high reliability

Temperature-sensitive junction transformations for mid-wavelength HgCdTe photovoltaic infrared detector arrays by laser beam induced current microscope

Energy Technology Data Exchange (ETDEWEB)

Qiu, Weicheng [College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Hu, Weida, E-mail: wdhu@mail.sitp.ac.cn; Lin, Tie; Yin, Fei; Zhang, Bo; Chen, Xiaoshuang; Lu, Wei [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Cheng, Xiang' ai, E-mail: xiang-ai-cheng@126.com; Wang, Rui [College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)

2014-11-10

In this paper, we report on the disappearance of the photosensitive area extension effect and the unusual temperature dependence of junction transformation for mid-wavelength, n-on-p HgCdTe photovoltaic infrared detector arrays. The n-type region is formed by B{sup +} ion implantation on Hg-vacancy-doped p-type HgCdTe. Junction transformations under different temperatures are visually captured by a laser beam induced current microscope. A physical model of temperature dependence on junction transformation is proposed and demonstrated by using numerical simulations. It is shown that Hg-interstitial diffusion and temperature activated defects jointly lead to the p-n junction transformation dependence on temperature, and the weaker mixed conduction compared with long-wavelength HgCdTe photodiode contributes to the disappearance of the photosensitive area extension effect in mid-wavelength HgCdTe infrared detector arrays.

Solid state optical microscope

Science.gov (United States)

Young, Ian T.

1983-01-01

A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

The impact of software and CAE tools on SEU in field programmable gate arrays

International Nuclear Information System (INIS)

Katz, R.; Wang, J.; McCollum, J.; Cronquist, B.

1999-01-01

Field programmable gate array (FPGA) devices, heavily used in spacecraft electronics, have grown substantially in size over the past few years, causing designers to work at a higher conceptual level, with computer aided engineering (CAE) tools synthesizing and optimizing the logic from a description. It is shown that the use of commercial-off-the-shelf (COTS) CAE tools can produce unreliable circuit designs when the device is used in a radiation environment and a flip-flop is upset. At a lower level, software can be used to improve the SEU performance of a flip-flop, exploiting the configurable nature of FPGA technology and on-chip delay, parasitic resistive, and capacitive circuit elements

Nine-channel mid-power bipolar pulse generator based on a field programmable gate array

Energy Technology Data Exchange (ETDEWEB)

Haylock, Ben, E-mail: benjamin.haylock2@griffithuni.edu.au; Lenzini, Francesco; Kasture, Sachin; Fisher, Paul; Lobino, Mirko [Centre for Quantum Dynamics, Griffith University, Brisbane (Australia); Queensland Micro and Nanotechnology Centre, Griffith University, Brisbane (Australia); Streed, Erik W. [Centre for Quantum Dynamics, Griffith University, Brisbane (Australia); Institute for Glycomics, Griffith University, Gold Coast (Australia)

2016-05-15

Many channel arbitrary pulse sequence generation is required for the electro-optic reconfiguration of optical waveguide networks in Lithium Niobate. Here we describe a scalable solution to the requirement for mid-power bipolar parallel outputs, based on pulse patterns generated by an externally clocked field programmable gate array. Positive and negative pulses can be generated at repetition rates up to 80 MHz with pulse width adjustable in increments of 1.6 ns across nine independent outputs. Each channel can provide 1.5 W of RF power and can be synchronised with the operation of other components in an optical network such as light sources and detectors through an external clock with adjustable delay.

Field Programmable Gate Array Reliability Analysis Guidelines for Launch Vehicle Reliability Block Diagrams

Science.gov (United States)

Al Hassan, Mohammad; Britton, Paul; Hatfield, Glen Spencer; Novack, Steven D.

2017-01-01

Field Programmable Gate Arrays (FPGAs) integrated circuits (IC) are one of the key electronic components in today's sophisticated launch and space vehicle complex avionic systems, largely due to their superb reprogrammable and reconfigurable capabilities combined with relatively low non-recurring engineering costs (NRE) and short design cycle. Consequently, FPGAs are prevalent ICs in communication protocols and control signal commands. This paper will identify reliability concerns and high level guidelines to estimate FPGA total failure rates in a launch vehicle application. The paper will discuss hardware, hardware description language, and radiation induced failures. The hardware contribution of the approach accounts for physical failures of the IC. The hardware description language portion will discuss the high level FPGA programming languages and software/code reliability growth. The radiation portion will discuss FPGA susceptibility to space environment radiation.

A flexible 32-channel time-to-digital converter implemented in a Xilinx Zynq-7000 field programmable gate array

International Nuclear Information System (INIS)

Wang, Yonggang; Kuang, Jie; Liu, Chong; Cao, Qiang; Li, Deng

2017-01-01

A high performance multi-channel time-to-digital converter (TDC) is implemented in a Xilinx Zynq-7000 field programmable gate array (FPGA). It can be flexibly configured as either 32 TDC channels with 9.9 ps time-interval RMS precision, 16 TDC channels with 6.9 ps RMS precision, or 8 TDC channels with 5.8 ps RMS precision. All TDCs have a 380 M Samples/second measurement throughput and a 2.63 ns measurement dead time. The performance consistency and temperature dependence of TDC channels are also evaluated. Because Zynq-7000 FPGA family integrates a feature-rich dual-core ARM based processing system and 28 nm Xilinx programmable logic in a single device, the realization of high performance TDCs on it will make the platform more widely used in time-measuring related applications.

A flexible 32-channel time-to-digital converter implemented in a Xilinx Zynq-7000 field programmable gate array

Energy Technology Data Exchange (ETDEWEB)

Wang, Yonggang, E-mail: wangyg@ustc.edu.cn; Kuang, Jie; Liu, Chong; Cao, Qiang; Li, Deng

2017-03-01

A high performance multi-channel time-to-digital converter (TDC) is implemented in a Xilinx Zynq-7000 field programmable gate array (FPGA). It can be flexibly configured as either 32 TDC channels with 9.9 ps time-interval RMS precision, 16 TDC channels with 6.9 ps RMS precision, or 8 TDC channels with 5.8 ps RMS precision. All TDCs have a 380 M Samples/second measurement throughput and a 2.63 ns measurement dead time. The performance consistency and temperature dependence of TDC channels are also evaluated. Because Zynq-7000 FPGA family integrates a feature-rich dual-core ARM based processing system and 28 nm Xilinx programmable logic in a single device, the realization of high performance TDCs on it will make the platform more widely used in time-measuring related applications.

Field-programmable gate array based controller for multi spot light-addressable potentiometric sensors with integrated signal correction mode

Energy Technology Data Exchange (ETDEWEB)

Werner, Carl Frederik; Schusser, Sebastian; Spelthahn, Heiko [Aachen University of Applied Sciences, Juelich Campus, Institute of Nano- and Biotechnologies, Heinrich-Mussmann-Strasse 1, 52428 Juelich (Germany); Institute of Bio- and Nanosystems (IBN-2), Research Centre Juelich GmbH, 52425 Juelich (Germany); Wagner, Torsten; Yoshinobu, Tatsuo [Tohoku University, Department of Electronic Engineering, 6-6-05 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Schoening, Michael J., E-mail: schoening@fh-aachen.de [Aachen University of Applied Sciences, Juelich Campus, Institute of Nano- and Biotechnologies, Heinrich-Mussmann-Strasse 1, 52428 Juelich (Germany); Institute of Bio- and Nanosystems (IBN-2), Research Centre Juelich GmbH, 52425 Juelich (Germany)

2011-11-01

Highlights: > Flexible up-scalable design of a light-addressable potentiometric sensor set-up. > Utilisation of a field-programmable gate array to address LAPS measurement spots. > Measurements in amplitude-mode and phase-mode for different pH solutions. > Amplitude, phase and frequency behaviour of LAPS for single and multiple light stimulus. > Signal calibration method by brightness control to compensated systematic errors. - Abstract: A light-addressable potentiometric sensor (LAPS) can measure the concentration of one or several analytes at the sensor surface simultaneously in a spatially resolved manner. A modulated light pointer stimulates the semiconductor structure at the area of interest and a responding photocurrent can be read out. By simultaneous stimulation of several areas with light pointers of different modulation frequencies, the read out can be performed at the same time. With the new proposed controller electronic based on a field-programmable gate array (FPGA), it is possible to control the modulation frequencies, phase shifts, and light brightness of multiple light pointers independently and simultaneously. Thus, it is possible to investigate the frequency response of the sensor, and to examine the analyte concentration by the determination of the surface potential with the help of current/voltage curves and phase/voltage curves. Additionally, the ability to individually change the light intensities of each light pointer is used to perform signal correction.

A Fastbus module for trigger applications based on a digital signal processor and on programmable gate arrays

International Nuclear Information System (INIS)

Battaiotto, P.; Colavita, A.; Fratnik, F.; Lanceri, L.; Udine Univ.

1991-01-01

The new generation of DSP microprocessors based on RISC and Harvard-like architectures can conveniently take the place of specially built processors in fast trigger circuits for high-energy physics experiments. Presently available programmable gate arrays are well matched to them in speed and contribute to simplify the design of trigger circuits. Using these components, we designed and constructed a Fastbus module. We describe an application for the total-energy trigger of DELPHI, performing the readout of digitized calorimeter trigger data and some simple computations in less than 3 μs. (orig.)

Design and Implementation of Video Shot Detection on Field Programmable Gate Arrays

Directory of Open Access Journals (Sweden)

Jharna Majumdar

2012-09-01

Full Text Available Video has become an interactive medium of communication in everyday life. The sheer volume of video makes it extremely difficult to browse through and find the required data. Hence extraction of key frames from the video which represents the abstract of the entire video becomes necessary. The aim of the video shot detection is to find the position of the shot boundaries, so that key frames can be selected from each shot for subsequent processing such as video summarization, indexing etc. For most of the surveillance applications like video summery, face recognition etc., the hardware (real time implementation of these algorithms becomes necessary. Here in this paper we present the architecture for simultaneous accessing of consecutive frames, which are then used for the implementation of various Video Shot Detection algorithms. We also present the real time implementation of three video shot detection algorithms using the above mentioned architecture on FPGA (Field Programmable Gate Arrays.

Programmable architecture for quantum computing

NARCIS (Netherlands)

Chen, J.; Wang, L.; Charbon, E.; Wang, B.

2013-01-01

A programmable architecture called “quantum FPGA (field-programmable gate array)” (QFPGA) is presented for quantum computing, which is a hybrid model combining the advantages of the qubus system and the measurement-based quantum computation. There are two kinds of buses in QFPGA, the local bus and

Application of Field Programmable Gate Arrays in Instrumentation and Control Systems of Nuclear Power Plants

International Nuclear Information System (INIS)

2016-01-01

Field programmable gate arrays (FPGAs) are gaining increased attention worldwide for application in nuclear power plant (NPP) instrumentation and control (I&C) systems, particularly for safety and safety related applications, but also for non-safety ones. NPP operators and equipment suppliers see potential advantages of FPGA based digital I&C systems as compared to microprocessor based applications. This is because FPGA based systems can be made simpler, more testable and less reliant on complex software (e.g. operating systems), and are easier to qualify for safety and safety related applications. This publication results from IAEA consultancy meetings covering the various aspects, including design, qualification, implementation, licensing, and operation, of FPGA based I&C systems in NPPs

Field Programmable Gate Array Failure Rate Estimation Guidelines for Launch Vehicle Fault Tree Models

Science.gov (United States)

Al Hassan, Mohammad; Novack, Steven D.; Hatfield, Glen S.; Britton, Paul

2017-01-01

Today's launch vehicles complex electronic and avionic systems heavily utilize the Field Programmable Gate Array (FPGA) integrated circuit (IC). FPGAs are prevalent ICs in communication protocols such as MIL-STD-1553B, and in control signal commands such as in solenoid/servo valves actuations. This paper will demonstrate guidelines to estimate FPGA failure rates for a launch vehicle, the guidelines will account for hardware, firmware, and radiation induced failures. The hardware contribution of the approach accounts for physical failures of the IC, FPGA memory and clock. The firmware portion will provide guidelines on the high level FPGA programming language and ways to account for software/code reliability growth. The radiation portion will provide guidelines on environment susceptibility as well as guidelines on tailoring other launch vehicle programs historical data to a specific launch vehicle.

Miniaturized integration of a fluorescence microscope

Science.gov (United States)

Ghosh, Kunal K.; Burns, Laurie D.; Cocker, Eric D.; Nimmerjahn, Axel; Ziv, Yaniv; Gamal, Abbas El; Schnitzer, Mark J.

2013-01-01

The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals towards relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including semiconductor light source and sensor. This device enables high-speed cellular-level imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens. PMID:21909102

Compact field programmable gate array-based pulse-sequencer and radio-frequency generator for experiments with trapped atoms

Energy Technology Data Exchange (ETDEWEB)

Pruttivarasin, Thaned, E-mail: thaned.pruttivarasin@riken.jp [Quantum Metrology Laboratory, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Katori, Hidetoshi [Quantum Metrology Laboratory, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Innovative Space-Time Project, ERATO, JST, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2015-11-15

We present a compact field-programmable gate array (FPGA) based pulse sequencer and radio-frequency (RF) generator suitable for experiments with cold trapped ions and atoms. The unit is capable of outputting a pulse sequence with at least 32 transistor-transistor logic (TTL) channels with a timing resolution of 40 ns and contains a built-in 100 MHz frequency counter for counting electrical pulses from a photo-multiplier tube. There are 16 independent direct-digital-synthesizers RF sources with fast (rise-time of ∼60 ns) amplitude switching and sub-mHz frequency tuning from 0 to 800 MHz.

Gas Sensors Characterization and Multilayer Perceptron (MLP) Hardware Implementation for Gas Identification Using a Field Programmable Gate Array (FPGA)

Science.gov (United States)

Benrekia, Fayçal; Attari, Mokhtar; Bouhedda, Mounir

2013-01-01

This paper develops a primitive gas recognition system for discriminating between industrial gas species. The system under investigation consists of an array of eight micro-hotplate-based SnO2 thin film gas sensors with different selectivity patterns. The output signals are processed through a signal conditioning and analyzing system. These signals feed a decision-making classifier, which is obtained via a Field Programmable Gate Array (FPGA) with Very High-Speed Integrated Circuit Hardware Description Language. The classifier relies on a multilayer neural network based on a back propagation algorithm with one hidden layer of four neurons and eight neurons at the input and five neurons at the output. The neural network designed after implementation consists of twenty thousand gates. The achieved experimental results seem to show the effectiveness of the proposed classifier, which can discriminate between five industrial gases. PMID:23529119

Optical programmable metamaterials

Science.gov (United States)

Gong, Cheng; Zhang, Nan; Dai, Zijie; Liu, Weiwei

2018-02-01

We suggest and demonstrate the concept of optical programmable metamaterials which can configure the device's electromagnetic parameters by the programmable optical stimuli. In such metamaterials, the optical stimuli produced by a FPGA controlled light emitting diode array can switch or combine the resonance modes which are coupled in. As an example, an optical programmable metamaterial terahertz absorber is proposed. Each cell of the absorber integrates four meta-rings (asymmetric 1/4 rings) with photo-resistors connecting the critical gaps. The principle and design of the metamaterials are illustrated and the simulation results demonstrate the functionalities for programming the metamaterial absorber to change its bandwidth and resonance frequency.

Single event upset susceptibilities of latchup immune CMOS process programmable gate arrays

Science.gov (United States)

Koga, R.; Crain, W. R.; Crawford, K. B.; Hansel, S. J.; Lau, D. D.; Tsubota, T. K.

Single event upsets (SEU) and latchup susceptibilities of complementary metal oxide semiconductor programmable gate arrays (CMOS PPGA's) were measured at the Lawrence Berkeley Laboratory 88-in. cyclotron facility with Xe (603 MeV), Cu (290 MeV), and Ar (180 MeV) ion beams. The PPGA devices tested were those which may be used in space. Most of the SEU measurements were taken with a newly constructed tester called the Bus Access Storage and Comparison System (BASACS) operating via a Macintosh II computer. When BASACS finds that an output does not match a prerecorded pattern, the state of all outputs, position in the test cycle, and other necessary information is transmitted and stored in the Macintosh. The upset rate was kept between 1 and 3 per second. After a sufficient number of errors are stored, the test is stopped and the total fluence of particles and total errors are recorded. The device power supply current was closely monitored to check for occurrence of latchup. Results of the tests are presented, indicating that some of the PPGA's are good candidates for selected space applications.

Design of readout drivers for ATLAS pixel detectors using field programmable gate arrays

CERN Document Server

Sivasubramaniyan, Sriram

Microstrip detectors are an integral patt of high energy physics research . Special protocols are used to transmit the data from these detectors . To readout the data from such detectors specialized instrumentation have to be designed . To achieve this task, creative and innovative high speed algorithms were designed simulated and implemented in Field Programmable gate arrays, using CAD/CAE tools. The simulation results indicated that these algorithms would be able to perform all the required tasks quickly and efficiently. This thesis describes the design of data acquisition system called the Readout Drivers (ROD) . It focuses on the ROD data path for ATLAS Pixel detectors. The data path will be an integrated part of Readout Drivers setup to decode the data from the silicon micro strip detectors and pixel detectors. This research also includes the design of Readout Driver controller. This Module is used to control the operation of the ROD. This module is responsible for the operation of the Pixel decoders bas...

Development of measurement system for radiation effect on static random access memory based field programmable gate array

International Nuclear Information System (INIS)

Yao Zhibin; He Baoping; Zhang Fengqi; Guo Hongxia; Luo Yinhong; Wang Yuanming; Zhang Keying

2009-01-01

Based on the detailed investigation in field programmable gate array(FPGA) radiation effects theory, a measurement system for radiation effects on static random access memory(SRAM)-based FPGA was developed. The testing principle of internal memory, function and power current was introduced. The hardware and software implement means of system were presented. Some important parameters for radiation effects on SRAM-based FPGA, such as configuration RAM upset section, block RAM upset section, function fault section and single event latchup section can be gained with this system. The transmission distance of the system can be over 50 m and the maximum number of tested gates can reach one million. (authors)

Optical diffraction tomography microscopy with transport of intensity equation using a light-emitting diode array

Science.gov (United States)

Li, Jiaji; Chen, Qian; Zhang, Jialin; Zhang, Zhao; Zhang, Yan; Zuo, Chao

2017-08-01

Optical diffraction tomography (ODT) is an effective label-free technique for quantitatively refractive index imaging, which enables long-term monitoring of the internal three-dimensional (3D) structures and molecular composition of biological cells with minimal perturbation. However, existing optical tomographic methods generally rely on interferometric configuration for phase measurement and sophisticated mechanical systems for sample rotation or beam scanning. Thereby, the measurement is suspect to phase error coming from the coherent speckle, environmental vibrations, and mechanical error during data acquisition process. To overcome these limitations, we present a new ODT technique based on non-interferometric phase retrieval and programmable illumination emitting from a light-emitting diode (LED) array. The experimental system is built based on a traditional bright field microscope, with the light source replaced by a programmable LED array, which provides angle-variable quasi-monochromatic illumination with an angular coverage of ±37 degrees in both x and y directions (corresponding to an illumination numerical aperture of ∼0.6). Transport of intensity equation (TIE) is utilized to recover the phase at different illumination angles, and the refractive index distribution is reconstructed based on the ODT framework under first Rytov approximation. The missing-cone problem in ODT is addressed by using the iterative non-negative constraint algorithm, and the misalignment of the LED array is further numerically corrected to improve the accuracy of refractive index quantification. Experiments on polystyrene beads and thick biological specimens show that the proposed approach allows accurate refractive index reconstruction while greatly reduced the system complexity and environmental sensitivity compared to conventional interferometric ODT approaches.

Computational diffraction tomographic microscopy with transport of intensity equation using a light-emitting diode array

Science.gov (United States)

Li, Jiaji; Chen, Qian; Zhang, Jialin; Zuo, Chao

2017-10-01

Optical diffraction tomography (ODT) is an effective label-free technique for quantitatively refractive index imaging, which enables long-term monitoring of the internal three-dimensional (3D) structures and molecular composition of biological cells with minimal perturbation. However, existing optical tomographic methods generally rely on interferometric configuration for phase measurement and sophisticated mechanical systems for sample rotation or beam scanning. Thereby, the measurement is suspect to phase error coming from the coherent speckle, environmental vibrations, and mechanical error during data acquisition process. To overcome these limitations, we present a new ODT technique based on non-interferometric phase retrieval and programmable illumination emitting from a light-emitting diode (LED) array. The experimental system is built based on a traditional bright field microscope, with the light source replaced by a programmable LED array, which provides angle-variable quasi-monochromatic illumination with an angular coverage of +/-37 degrees in both x and y directions (corresponding to an illumination numerical aperture of ˜ 0.6). Transport of intensity equation (TIE) is utilized to recover the phase at different illumination angles, and the refractive index distribution is reconstructed based on the ODT framework under first Rytov approximation. The missing-cone problem in ODT is addressed by using the iterative non-negative constraint algorithm, and the misalignment of the LED array is further numerically corrected to improve the accuracy of refractive index quantification. Experiments on polystyrene beads and thick biological specimens show that the proposed approach allows accurate refractive index reconstruction while greatly reduced the system complexity and environmental sensitivity compared to conventional interferometric ODT approaches.

Protein Functionalized Nanodiamond Arrays

Directory of Open Access Journals (Sweden)

Liu YL

2010-01-01

Full Text Available Abstract Various nanoscale elements are currently being explored for bio-applications, such as in bio-images, bio-detection, and bio-sensors. Among them, nanodiamonds possess remarkable features such as low bio-cytotoxicity, good optical property in fluorescent and Raman spectra, and good photostability for bio-applications. In this work, we devise techniques to position functionalized nanodiamonds on self-assembled monolayer (SAMs arrays adsorbed on silicon and ITO substrates surface using electron beam lithography techniques. The nanodiamond arrays were functionalized with lysozyme to target a certain biomolecule or protein specifically. The optical properties of the nanodiamond-protein complex arrays were characterized by a high throughput confocal microscope. The synthesized nanodiamond-lysozyme complex arrays were found to still retain their functionality in interacting with E. coli.

Balanced into array : genome-wide array analysis in 54 patients with an apparently balanced de novo chromosome rearrangement and a meta-analysis

NARCIS (Netherlands)

Feenstra, Ilse; Hanemaaijer, Nicolien; Sikkema-Raddatz, Birgit; Yntema, Helger; Dijkhuizen, Trijnie; Lugtenberg, Dorien; Verheij, Joke; Green, Andrew; Hordijk, Roel; Reardon, William; de Vries, Bert; Brunner, Han; Bongers, Ernie; de Leeuw, Nicole; van Ravenswaaij-Arts, Conny

2011-01-01

High-resolution genome-wide array analysis enables detailed screening for cryptic and submicroscopic imbalances of microscopically balanced de novo rearrangements in patients with developmental delay and/or congenital abnormalities. In this report, we added the results of genome-wide array analysis

Combined reflection and transmission microscope for telemedicine applications in field settings.

Science.gov (United States)

Biener, Gabriel; Greenbaum, Alon; Isikman, Serhan O; Lee, Kelvin; Tseng, Derek; Ozcan, Aydogan

2011-08-21

We demonstrate a field-portable upright and inverted microscope that can image specimens in both reflection and transmission modes. This compact and cost-effective dual-mode microscope weighs only ∼135 grams (image of the specimen onto an opto-electronic sensor-array that is positioned above the beam-splitter cube. In addition to this, the illumination beam is also partially transmitted through the same specimen, which then casts lensfree in-line holograms of the same objects onto a second opto-electronic sensor-array that is positioned underneath the beam-splitter cube. By rapid digital reconstruction of the acquired lensfree holograms, transmission images (both phase and amplitude) of the same specimen are also created. We tested the performance of this field-portable microscope by imaging various micro-particles, blood smears as well as a histopathology slide corresponding to skin tissue. Being compact, light-weight and cost-effective, this combined reflection and transmission microscope might especially be useful for telemedicine applications in resource limited settings. This journal is © The Royal Society of Chemistry 2011

Field-programmable gate array implementation of an all-digital IEEE 802.15.4-compliant transceiver

Science.gov (United States)

Cornetta, Gianluca; Touhafi, Abdellah; Santos, David J.; Vázquez, José M.

2010-12-01

An architecture for a low-cost, low-complexity digital transceiver is presented in this article. The proposed architecture targets the IEEE 802.15.4 standard for short-range wireless personal area networks and has been implemented as a synthesisable VHDL register transfer level description. The system has been evaluated and tested using a Xilinx 90 nm Virtex-4 field-programmable gate array as the target technology. Bit error rate (BER) and error vector magnitude (EVM) have been used as the figures of merit for modem performance. Simulations show that the recommended minimum BER is achieved at E b/N 0 = 8.7 dB, whereas the EVM is 19.5%. The implemented device occupies 10% of the target FPGA and has a normalised maximum power consumption of 44 mW in transmit mode and 53 mW in receiver mode.

Oriented Mn-doped CuO nanowire arrays

International Nuclear Information System (INIS)

Han, Dongqiang; Wu, Zhaofeng; Wang, Zhihe; Yang, Shaoguang

2016-01-01

Using anodic aluminum oxide membranes as the nanoreactors and controller, oriented nanowire arrays of the diluted magnetic semiconductor Mn-doped CuO have been successfully fabricated using Mn(NO_3)_2 · 4H_2O and Cu(NO_3)_2 · 3H_2O as the starting materials. X-ray diffraction measurements showed that the as-prepared oriented nanowire arrays are of high purity. Scanning electron microscope and transmission electron microscope studies showed the nanowires are oriented, continuous and uniform with a diameter and length of about 170 nm and several tens of micrometers, respectively, and thus of a high aspect ratio. Low-temperature magnetic measurements showed the ferromagnetic property of the oriented Mn-doped CuO nanowire arrays with the critical temperature at around 80 K, which will endow them with great potential applications in spintronics in the future. (paper)

A programmable artificial retina

International Nuclear Information System (INIS)

Bernard, T.M.; Zavidovique, B.Y.; Devos, F.J.

1993-01-01

An artificial retina is a device that intimately associates an imager with processing facilities on a monolithic circuit. Yet, except for simple environments and applications, analog hardware will not suffice to process and compact the raw image flow from the photosensitive array. To solve this output problem, an on-chip array of bare Boolean processors with halftoning facilities might be used, providing versatility from programmability. By setting the pixel memory size to 3 b, the authors have demonstrated both the technological practicality and the computational efficiency of this programmable Boolean retina concept. Using semi-static shifting structures together with some interaction circuitry, a minimal retina Boolean processor can be built with less than 30 transistors and controlled by as few as 6 global clock signals. The successful design, integration, and test of such a 65x76 Boolean retina on a 50-mm 2 CMOS 2-μm circuit are presented

A digital optical phase-locked loop for diode lasers based on field programmable gate array

Science.gov (United States)

Xu, Zhouxiang; Zhang, Xian; Huang, Kaikai; Lu, Xuanhui

2012-09-01

We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad2 and transition time of 100 μs under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.

Nucleic acid programmable protein array a just-in-time multiplexed protein expression and purification platform.

Science.gov (United States)

Qiu, Ji; LaBaer, Joshua

2011-01-01

Systematic study of proteins requires the availability of thousands of proteins in functional format. However, traditional recombinant protein expression and purification methods have many drawbacks for such study at the proteome level. We have developed an innovative in situ protein expression and capture system, namely NAPPA (nucleic acid programmable protein array), where C-terminal tagged proteins are expressed using an in vitro expression system and efficiently captured/purified by antitag antibodies coprinted at each spot. The NAPPA technology presented in this chapter enable researchers to produce and display fresh proteins just in time in a multiplexed high-throughput fashion and utilize them for various downstream biochemical researches of interest. This platform could revolutionize the field of functional proteomics with it ability to produce thousands of spatially separated proteins in high density with narrow dynamic rand of protein concentrations, reproducibly and functionally. Copyright © 2011 Elsevier Inc. All rights reserved.

In situ synthesis of protein arrays.

Science.gov (United States)

He, Mingyue; Stoevesandt, Oda; Taussig, Michael J

2008-02-01

In situ or on-chip protein array methods use cell free expression systems to produce proteins directly onto an immobilising surface from co-distributed or pre-arrayed DNA or RNA, enabling protein arrays to be created on demand. These methods address three issues in protein array technology: (i) efficient protein expression and availability, (ii) functional protein immobilisation and purification in a single step and (iii) protein on-chip stability over time. By simultaneously expressing and immobilising many proteins in parallel on the chip surface, the laborious and often costly processes of DNA cloning, expression and separate protein purification are avoided. Recently employed methods reviewed are PISA (protein in situ array) and NAPPA (nucleic acid programmable protein array) from DNA and puromycin-mediated immobilisation from mRNA.

Design of a Tritium-in-air-monitor using field programmable gate arrays

International Nuclear Information System (INIS)

McNelles, Phillip; Lu, Lixuan

2015-01-01

Field Programmable Gate Arrays (FPGAs) have recently garnered significant interest for certain applications within the nuclear field. Some applications of these devices include Instrumentation and Control (I and C) systems, pulse measurement systems, particle detectors and health physics purposes. In CANada Deuterium Uranium (CANDU) nuclear power plants, the use of heavy water (D2O) as the moderator leads to the increased production of Tritium, which poses a health risk and must be monitored by Tritium-In-Air Monitors (TAMs). Traditional TAMs are mostly designed using microprocessors. More recent studies show that FPGAs could be a potential alternative to implement the electronic logic used in radiation detectors, such as the TAM, more effectively. In this paper, an FPGA-based TAM is designed and constructed in a laboratory setting using an FPGA-based cRIO system. New functionalities, such as the detection of Carbon-14 and the addition of noble gas compensation are incorporated into a new FPGA-based TAM. Additionally, all of the standard functions included in the original microprocessor-based TAM, such as tritium detection, gamma compensation, pump and air flow control, and background and thermal drift corrections were also implemented. The effectiveness of the new design is demonstrated through simulations as well as laboratory testing on the prototype system. (author)

A new data acquisition and imaging system for nuclear microscopy based on a Field Programmable Gate Array card

International Nuclear Information System (INIS)

Bettiol, A.A.; Udalagama, C.; Watt, F.

2009-01-01

The introduction of the new Field Programmable Gate Array (FPGA) cards by National Instruments has made it possible for the first time to develop reconfigurable custom data acquisition hardware easily with the LabVIEW programming environment. Data acquisition issues such as precise timing for scanning and operating system latencies can now be easily overcome using this new technology because the data acquisition software is embedded in the FPGA chip on the card. In this paper we present the first results of the new data acquisition system developed at the Centre for Ion Beam Applications (CIBA), National University of Singapore using the new National Instruments cards in conjunction with rack mountable Wilkinson type ADCs.

A new computerized moving stage for optical microscopes

Science.gov (United States)

Hatiboglu, Can Ulas; Akin, Serhat

2004-06-01

Measurements of microscope stage movements in the x and y directions are of importance for some stereological methods. Traditionally, the length of stage movements is measured with differing precision and accuracy using a suitable motorized stage, a microscope and software. Such equipment is generally expensive and not readily available in many laboratories. One other challenging problem is the adaptability to available microscope systems which weakens the possibility of the equipment to be used with any kind of light microscope. This paper describes a simple and cheap programmable moving stage that can be used with the available microscopes in the market. The movements of the stage are controlled by two servo-motors and a controller chip via a Java-based image processing software. With the developed motorized stage and a microscope equipped with a CCD camera, the software allows complete coverage of the specimens with minimum overlap, eliminating the optical strain associated with counting hundreds of images through an eyepiece, in a quick and precise fashion. The uses and the accuracy of the developed stage are demonstrated using thin sections obtained from a limestone core plug.

Efficient processing of two-dimensional arrays with C or C++

Science.gov (United States)

Donato, David I.

2017-07-20

Because fast and efficient serial processing of raster-graphic images and other two-dimensional arrays is a requirement in land-change modeling and other applications, the effects of 10 factors on the runtimes for processing two-dimensional arrays with C and C++ are evaluated in a comparative factorial study. This study’s factors include the choice among three C or C++ source-code techniques for array processing; the choice of Microsoft Windows 7 or a Linux operating system; the choice of 4-byte or 8-byte array elements and indexes; and the choice of 32-bit or 64-bit memory addressing. This study demonstrates how programmer choices can reduce runtimes by 75 percent or more, even after compiler optimizations. Ten points of practical advice for faster processing of two-dimensional arrays are offered to C and C++ programmers. Further study and the development of a C and C++ software test suite are recommended.Key words: array processing, C, C++, compiler, computational speed, land-change modeling, raster-graphic image, two-dimensional array, software efficiency

Implementation of data acquisition interface using on-board field-programmable gate array (FPGA) universal serial bus (USB) link

International Nuclear Information System (INIS)

Nolida Yussup; Maslina Mohd Ibrahim; Lojius Lombigit; Nur Aira Abdul Rahman; Muhammad Rawi Mohamed Zin

2013-01-01

Full-text: Typically a system consists of hardware as the controller and software which is installed in the personal computer (PC). In the effective nuclear detection, the hardware involves the detection setup and the electronics used, with the software consisting of analysis tools and graphical display on PC. A data acquisition interface is necessary to enable the communication between the controller hardware and PC. Nowadays, Universal Serial Bus (USB) has become a standard connection method for computer peripherals and has replaced many varieties of serial and parallel ports. However the implementation of USB is complex. This paper describes the implementation of data acquisition interface between a field-programmable gate array (FPGA) board and a PC by exploiting the USB link of the FPGA board. The USB link is based on an FTDI chip which allows direct access of input and output to the Joint Test Action Group (JTAG) signals from a USB host and a complex programmable logic device (CPLD) with a 24 MHz clock input to the USB link. The implementation and results of using the USB link of FPGA board as the data interfacing are discussed. (author)

Implementation of data acquisition interface using on-board field-programmable gate array (FPGA) universal serial bus (USB) link

International Nuclear Information System (INIS)

Yussup, N.; Ibrahim, M. M.; Lombigit, L.; Rahman, N. A. A.; Zin, M. R. M.

2014-01-01

Typically a system consists of hardware as the controller and software which is installed in the personal computer (PC). In the effective nuclear detection, the hardware involves the detection setup and the electronics used, with the software consisting of analysis tools and graphical display on PC. A data acquisition interface is necessary to enable the communication between the controller hardware and PC. Nowadays, Universal Serial Bus (USB) has become a standard connection method for computer peripherals and has replaced many varieties of serial and parallel ports. However the implementation of USB is complex. This paper describes the implementation of data acquisition interface between a field-programmable gate array (FPGA) board and a PC by exploiting the USB link of the FPGA board. The USB link is based on an FTDI chip which allows direct access of input and output to the Joint Test Action Group (JTAG) signals from a USB host and a complex programmable logic device (CPLD) with a 24 MHz clock input to the USB link. The implementation and results of using the USB link of FPGA board as the data interfacing are discussed

Development and simulation of soft morphological operators for a field programmable gate array

Science.gov (United States)

Tickle, Andrew J.; Harvey, Paul K.; Smith, Jeremy S.; Wu, Q. Henry

2013-04-01

In image processing applications, soft mathematical morphology (MM) can be employed for both binary and grayscale systems and is derived from set theory. Soft MM techniques have improved behavior over standard morphological operations in noisy environments, as they can preserve small details within an image. This makes them suitable for use in image processing applications on portable field programmable gate arrays for tasks such as robotics and security. We explain how the systems were developed using Altera's DSP Builder in order to provide optimized code for the many different devices currently on the market. Also included is how the circuits can be inserted and combined with previously developed work in order to increase their functionality. The testing procedures involved loading different images into these systems and analyzing the outputs against MATLAB-generated validation images. A set of soft morphological operations are described, which can then be applied to various tasks and easily modified in size via altering the line buffer settings inside the system to accommodate a range of image attributes ranging from image sizes such as 320×240 pixels for basic webcam imagery up to high quality 4000×4000 pixel images for military applications.

A digital optical phase-locked loop for diode lasers based on field programmable gate array

Energy Technology Data Exchange (ETDEWEB)

Xu Zhouxiang; Zhang Xian; Huang Kaikai; Lu Xuanhui [Physics Department, Zhejiang University, Hangzhou, 310027 (China)

2012-09-15

We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad{sup 2} and transition time of 100 {mu}s under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.

A field programmable gate array unit for the diagnosis and control of neoclassical tearing modes on MAST

Energy Technology Data Exchange (ETDEWEB)

O' Gorman, T.; Gibson, K. J.; Snape, J. A. [York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom); Naylor, G.; Huang, B.; McArdle, G. J.; Scannell, R.; Shibaev, S.; Thomas-Davies, N. [EURATOM/CCFE Fusion Association, Culham Science Centre, Oxfordshire OX14 3DB (United Kingdom)

2012-10-15

A real-time system has been developed to trigger both the MAST Thomson scattering (TS) system and the plasma control system on the phase and amplitude of neoclassical tearing modes (NTMs), extending the capabilities of the original system. This triggering system determines the phase and amplitude of a given NTM using magnetic coils at different toroidal locations. Real-time processing of the raw magnetic data occurs on a low cost field programmable gate array (FPGA) based unit which permits triggering of the TS lasers on specific amplitudes and phases of NTM evolution. The MAST plasma control system can receive a separate trigger from the FPGA unit that initiates a vertical shift of the MAST magnetic axis. Such shifts have fully removed m/n= 2/1 NTMs instabilities on a number of MAST discharges.

Evaluation of the Leon3 soft-core processor within a Xilinx radiation-hardened field-programmable gate array.

Energy Technology Data Exchange (ETDEWEB)

Learn, Mark Walter

2012-01-01

The purpose of this document is to summarize the work done to evaluate the performance of the Leon3 soft-core processor in a radiation environment while instantiated in a radiation-hardened static random-access memory based field-programmable gate array. This evaluation will look at the differences between two soft-core processors: the open-source Leon3 core and the fault-tolerant Leon3 core. Radiation testing of these two cores was conducted at the Texas A&M University Cyclotron facility and Lawrence Berkeley National Laboratory. The results of these tests are included within the report along with designs intended to improve the mitigation of the open-source Leon3. The test setup used for evaluating both versions of the Leon3 is also included within this document.

Layered growth of aligned carbon nanotube arrays by pyrolysis

International Nuclear Information System (INIS)

Zhang Hongrui; Liang Erjun; Ding Pei; Chao Mingju

2003-01-01

Based on the study of reaction temperature and duration of the growth of aligned carbon nanotube arrays, layered aligned multi-wall carbon nanotube (MWNT) films grown directly around a reaction quartz tube in an Ar/H 2 atmosphere by pyrolysis of ferrocene in xylene in a suitable reaction furnace with the help of cobalt powder. The scanning electron microscope and transmission electron microscope images indicated that the obtained arrays were composed of many separated layers with MWNTs. The reaction temperature significantly influenced the alignment of the MWNTs, and an appropriate reaction temperature range for growth was 800-900 deg. C. The diameter of the carbon nanotube increased from 46 to 75 nm with the growth temperature. Besides temperature, the reaction duration influenced the length of the well-aligned carbon nanotubes. There was no significant relation between the growth time and the diameter of the carbon nanotubes in the array

Development of a protection system for research reactor based in Field Programmable Gate Array - FPGA; Desenvolvimento de sistema de protecao para reator nuclear de pesquisa baseado em Field Programmable Gate Array - FPGA

Energy Technology Data Exchange (ETDEWEB)

Martins, Roque Hudson da Silva

2016-07-01

This study presents a implementation purpose of a protection system for research nuclear reactors by using a programed device FPGA (Field Programmable Gate Array). As well as logic protection method involved on an automatic shutdown (TRIP) of a reactor, that ensure the security on such systems. These new control and operation mechanics are developed to guarantee that the security limits of a power plant are not exceeded, these mechanics can work isolated or in groups to safe guard the security levels. For this implementation to be completed, there will be presented the main aspects and concepts referred to protection systems, mostly about research nuclear reactors, with some applications terms exposed. The system proposed at this paper was developed following the VHDL (Very High Speed Integrated Circuits) hardware describing language, and the Modelsim software from Altera Software to program the automatic turning off routines, and hypothetical simulations for such. The results show that for every software application for supporting nuclear reactors, like security devices, they have to meet the IEC 60880 criteria. This paper have great importance, seeing that nuclear reactor security systems, are a basic element for ensure the reactor security. (author)

Field programmable gate array-based real-time optical Doppler tomography system for in vivo imaging of cardiac dynamics in the chick embryo

DEFF Research Database (Denmark)

Thrane, Lars; Larsen, Henning Engelbrecht; Norozi, Kambiz

2009-01-01

efficient and compact implementation by combining the conversion to an analytic signal with a pulse shaping function without the need for extra resources as compared to the Hilbert transform method. The conversion of the analytic signal to amplitude and phase is done by use of the coordinate rotation......We demonstrate a field programmable gate-array-based real-time optical Doppler tomography system. A complex-valued bandpass filter is used for the first time in optical coherence tomography signal processing to create the analytic signal. This method simplifies the filter design, and allows...

Innovative Columnar Type of Grid Array SJ BIST HALT Method, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Ridgetop will develop a superior method for testing and qualifying columnar type of grid arrays such as field programmable gate arrays (FPGAs) packaged in column...

A prototype of programmable associative memory for track finding

International Nuclear Information System (INIS)

Bardi, A.; Belforte, S.; Dell'Orso, M.

1999-01-01

The authors present a device, based on the concept of associative memory for pattern recognition, dedicated to on-line track finding in high-energy physics experiments. A large pattern bank, describing all possible tracks, can be organized into Field Programmable Gate Arrays where all patterns are compared in parallel to data coming from the detector during readout. Patterns, recognized among 2 66 possible combinations, are output in a few 30 MHz clock cycles. Programmability results in a flexible, simple architecture and it allows them to keep up smoothly with technology improvements. A 64 PAM array has been assembled on a prototype VME board and fully tested up to 30 MHz

Development of field programmable gate array-based reactor trip functions using systems engineering approach

Energy Technology Data Exchange (ETDEWEB)

Jung, Jae Cheon; Ahmed, Ibrahim [Nuclear Power Plant Engineering, KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2016-08-15

Design engineering process for field programmable gate array (FPGA)-based reactor trip functions are developed in this work. The process discussed in this work is based on the systems engineering approach. The overall design process is effectively implemented by combining with design and implementation processes. It transforms its overall development process from traditional V-model to Y-model. This approach gives the benefit of concurrent engineering of design work with software implementation. As a result, it reduces development time and effort. The design engineering process consisted of five activities, which are performed and discussed: needs/systems analysis; requirement analysis; functional analysis; design synthesis; and design verification and validation. Those activities are used to develop FPGA-based reactor bistable trip functions that trigger reactor trip when the process input value exceeds the setpoint. To implement design synthesis effectively, a model-based design technique is implied. The finite-state machine with data path structural modeling technique together with very high speed integrated circuit hardware description language and the Aldec Active-HDL tool are used to design, model, and verify the reactor bistable trip functions for nuclear power plants.

Design of acoustic logging signal source of imitation based on field programmable gate array

Science.gov (United States)

Zhang, K.; Ju, X. D.; Lu, J. Q.; Men, B. Y.

2014-08-01

An acoustic logging signal source of imitation is designed and realized, based on the Field Programmable Gate Array (FPGA), to improve the efficiency of examining and repairing acoustic logging tools during research and field application, and to inspect and verify acoustic receiving circuits and corresponding algorithms. The design of this signal source contains hardware design and software design,and the hardware design uses an FPGA as the control core. Four signals are made first by reading the Random Access Memory (RAM) data which are inside the FPGA, then dealing with the data by digital to analog conversion, amplification, smoothing and so on. Software design uses VHDL, a kind of hardware description language, to program the FPGA. Experiments illustrate that the ratio of signal to noise for the signal source is high, the waveforms are stable, and also its functions of amplitude adjustment, frequency adjustment and delay adjustment are in accord with the characteristics of real acoustic logging waveforms. These adjustments can be used to imitate influences on sonic logging received waveforms caused by many kinds of factors such as spacing and span of acoustic tools, sonic speeds of different layers and fluids, and acoustic attenuations of different cementation planes.

Full image-processing pipeline in field-programmable gate array for a small endoscopic camera

Science.gov (United States)

Mostafa, Sheikh Shanawaz; Sousa, L. Natércia; Ferreira, Nuno Fábio; Sousa, Ricardo M.; Santos, Joao; Wäny, Martin; Morgado-Dias, F.

2017-01-01

Endoscopy is an imaging procedure used for diagnosis as well as for some surgical purposes. The camera used for the endoscopy should be small and able to produce a good quality image or video, to reduce discomfort of the patients, and to increase the efficiency of the medical team. To achieve these fundamental goals, a small endoscopy camera with a footprint of 1 mm×1 mm×1.65 mm is used. Due to the physical properties of the sensors and human vision system limitations, different image-processing algorithms, such as noise reduction, demosaicking, and gamma correction, among others, are needed to faithfully reproduce the image or video. A full image-processing pipeline is implemented using a field-programmable gate array (FPGA) to accomplish a high frame rate of 60 fps with minimum processing delay. Along with this, a viewer has also been developed to display and control the image-processing pipeline. The control and data transfer are done by a USB 3.0 end point in the computer. The full developed system achieves real-time processing of the image and fits in a Xilinx Spartan-6LX150 FPGA.

Case for a field-programmable gate array multicore hybrid machine for an image-processing application

Science.gov (United States)

Rakvic, Ryan N.; Ives, Robert W.; Lira, Javier; Molina, Carlos

2011-01-01

General purpose computer designers have recently begun adding cores to their processors in order to increase performance. For example, Intel has adopted a homogeneous quad-core processor as a base for general purpose computing. PlayStation3 (PS3) game consoles contain a multicore heterogeneous processor known as the Cell, which is designed to perform complex image processing algorithms at a high level. Can modern image-processing algorithms utilize these additional cores? On the other hand, modern advancements in configurable hardware, most notably field-programmable gate arrays (FPGAs) have created an interesting question for general purpose computer designers. Is there a reason to combine FPGAs with multicore processors to create an FPGA multicore hybrid general purpose computer? Iris matching, a repeatedly executed portion of a modern iris-recognition algorithm, is parallelized on an Intel-based homogeneous multicore Xeon system, a heterogeneous multicore Cell system, and an FPGA multicore hybrid system. Surprisingly, the cheaper PS3 slightly outperforms the Intel-based multicore on a core-for-core basis. However, both multicore systems are beaten by the FPGA multicore hybrid system by >50%.

Development and applications of a computer-aided phased array assembly for ultrasonic testing

International Nuclear Information System (INIS)

Schenk, G.; Montag, H.J.; Wuestenberg, H.; Erhard, A.

1985-01-01

The use of modern electronic equipment for programmable signal delay increasingly allows transit-time controlled phased arrays to be applied in non-destructive, ultrasonic materials testing. A phased-array assembly is described permitting fast variation of incident angle of acoustic wave and of sonic beam focus, together with numerical evaluation of measured data. Phased arrays can be optimized by adding programmable electronic equipment so that the quality of conventional designs can be achieved. Applications of the new technical improvement are explained, referring to stress corrosion cracking, turbine testing, echo tomography of welded joints. (orig./HP) [de

Design techniques for a stable operation of cryogenic field-programmable gate arrays

Science.gov (United States)

Homulle, Harald; Visser, Stefan; Patra, Bishnu; Charbon, Edoardo

2018-01-01

In this paper, we show how a deep-submicron field-programmable gate array (FPGA) can be operated more stably at extremely low temperatures through special firmware design techniques. Stability at low temperatures is limited through long power supply wires and reduced performance of various printed circuit board components commonly employed at room temperature. Extensive characterization of these components shows that the majority of decoupling capacitor types and voltage regulators are not well behaved at cryogenic temperatures, asking for an ad hoc solution to stabilize the FPGA supply voltage, especially for sensitive applications. Therefore, we have designed a firmware that enforces a constant power consumption, so as to stabilize the supply voltage in the interior of the FPGA. The FPGA is powered with a supply at several meters distance, causing significant resistive voltage drop and thus fluctuations on the local supply voltage. To achieve the stabilization, the variation in digital logic speed, which directly corresponds to changes in supply voltage, is constantly measured and corrected for through a tunable oscillator farm, implemented on the FPGA. The impact of the stabilization technique is demonstrated together with a reconfigurable analog-to-digital converter (ADC), completely implemented in the FPGA fabric and operating at 15 K. The ADC performance can be improved by at most 1.5 bits (effective number of bits) thanks to the more stable supply voltage. The method is versatile and robust, enabling seamless porting to other FPGA families and configurations.

A Field Programmable Gate Array-Based Reconfigurable Smart-Sensor Network for Wireless Monitoring of New Generation Computer Numerically Controlled Machines

Directory of Open Access Journals (Sweden)

Ion Stiharu

2010-08-01

Full Text Available Computer numerically controlled (CNC machines have evolved to adapt to increasing technological and industrial requirements. To cover these needs, new generation machines have to perform monitoring strategies by incorporating multiple sensors. Since in most of applications the online Processing of the variables is essential, the use of smart sensors is necessary. The contribution of this work is the development of a wireless network platform of reconfigurable smart sensors for CNC machine applications complying with the measurement requirements of new generation CNC machines. Four different smart sensors are put under test in the network and their corresponding signal processing techniques are implemented in a Field Programmable Gate Array (FPGA-based sensor node.

A Field Programmable Gate Array-Based Reconfigurable Smart-Sensor Network for Wireless Monitoring of New Generation Computer Numerically Controlled Machines

Science.gov (United States)

Moreno-Tapia, Sandra Veronica; Vera-Salas, Luis Alberto; Osornio-Rios, Roque Alfredo; Dominguez-Gonzalez, Aurelio; Stiharu, Ion; de Jesus Romero-Troncoso, Rene

2010-01-01

Computer numerically controlled (CNC) machines have evolved to adapt to increasing technological and industrial requirements. To cover these needs, new generation machines have to perform monitoring strategies by incorporating multiple sensors. Since in most of applications the online Processing of the variables is essential, the use of smart sensors is necessary. The contribution of this work is the development of a wireless network platform of reconfigurable smart sensors for CNC machine applications complying with the measurement requirements of new generation CNC machines. Four different smart sensors are put under test in the network and their corresponding signal processing techniques are implemented in a Field Programmable Gate Array (FPGA)-based sensor node. PMID:22163602

Virtual pinhole confocal microscope

Energy Technology Data Exchange (ETDEWEB)

George, J.S.; Rector, D.M.; Ranken, D.M. [Los Alamos National Lab., NM (United States). Biophysics Group; Peterson, B. [SciLearn Inc. (United States); Kesteron, J. [VayTech Inc. (United States)

1999-06-01

Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

Programmable delay unit incorporating a semi-custom integrated circuit

International Nuclear Information System (INIS)

Linstadt, E.

1985-04-01

The synchronization of SLC accelerator control and monitoring functions is realized by a CAMAC module, the PDU II (Programmable Delay Unit II, SLAC 253-002), which includes a semi-custom gate array integrated circuit. The PDU II distributes 16 channels of independently programmable delayed pulses to other modules within the same CAMAC crate. The delays are programmable in increments of 8.4 ns. Functional descriptions of both the module and the semi-custom integrated circuit used to generate the output pulses are given

Low temperature growth and properties of ZnO nanorod arrays

International Nuclear Information System (INIS)

Wu, Xiang; Zheng, Yufeng; Chen, Huibo; Gong, Lihong; Qu, Fengyu

2011-01-01

In this paper, well aligned ZnO nanorod arrays were synthesized by a simple hydrothermal route at a low temperature. The diameters of the as-synthesized products were 20–60 nm and the lengths were as much as several micrometers. The surfaces and tops of the nanorods were smooth. The as-grown nanorod arrays were investigated by x-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), photoluminescence (PL) spectroscopy and contact angle (CA) analysis. The as-grown nanorods were single crystalline structures with a wurtzite phase, and grew along the [0001] direction. The PL spectrum with only one strong peak at 383 nm shows good intrinsic emission

Use of Field Programmable Gate Array Technology in Future Space Avionics

Science.gov (United States)

Ferguson, Roscoe C.; Tate, Robert

2005-01-01

Fulfilling NASA's new vision for space exploration requires the development of sustainable, flexible and fault tolerant spacecraft control systems. The traditional development paradigm consists of the purchase or fabrication of hardware boards with fixed processor and/or Digital Signal Processing (DSP) components interconnected via a standardized bus system. This is followed by the purchase and/or development of software. This paradigm has several disadvantages for the development of systems to support NASA's new vision. Building a system to be fault tolerant increases the complexity and decreases the performance of included software. Standard bus design and conventional implementation produces natural bottlenecks. Configuring hardware components in systems containing common processors and DSPs is difficult initially and expensive or impossible to change later. The existence of Hardware Description Languages (HDLs), the recent increase in performance, density and radiation tolerance of Field Programmable Gate Arrays (FPGAs), and Intellectual Property (IP) Cores provides the technology for reprogrammable Systems on a Chip (SOC). This technology supports a paradigm better suited for NASA's vision. Hardware and software production are melded for more effective development; they can both evolve together over time. Designers incorporating this technology into future avionics can benefit from its flexibility. Systems can be designed with improved fault isolation and tolerance using hardware instead of software. Also, these designs can be protected from obsolescence problems where maintenance is compromised via component and vendor availability.To investigate the flexibility of this technology, the core of the Central Processing Unit and Input/Output Processor of the Space Shuttle AP101S Computer were prototyped in Verilog HDL and synthesized into an Altera Stratix FPGA.

PATTERN RECOGNITION STUDIES OF HALOGENATED ORGANIC COMPOUNDS USING CONDUCTING POLYMER SENSOR ARRAYS. (R825323)

Science.gov (United States)

Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...

Field-programmable beam reconfiguring based on digitally-controlled coding metasurface

Science.gov (United States)

Wan, Xiang; Qi, Mei Qing; Chen, Tian Yi; Cui, Tie Jun

2016-02-01

Digital phase shifters have been applied in traditional phased array antennas to realize beam steering. However, the phase shifter deals with the phase of the induced current; hence, it has to be in the path of each element of the antenna array, making the phased array antennas very expensive. Metamaterials and/or metasurfaces enable the direct modulation of electromagnetic waves by designing subwavelength structures, which opens a new way to control the beam scanning. Here, we present a direct digital mechanism to control the scattered electromagnetic waves using coding metasurface, in which each unit cell loads a pin diode to produce binary coding states of “1” and “0”. Through data lines, the instant communications are established between the coding metasurface and the internal memory of field-programmable gate arrays (FPGA). Thus, we realize the digital modulation of electromagnetic waves, from which we present the field-programmable reflective antenna with good measurement performance. The proposed mechanism and functional device have great application potential in new-concept radar and communication systems.

Enhancing Learning Effectiveness in Digital Design Courses through the Use of Programmable Logic Boards

Science.gov (United States)

Zhu, Yi; Weng, T.; Cheng, Chung-Kuan

2009-01-01

Incorporating programmable logic devices (PLD) in digital design courses has become increasingly popular. The advantages of using PLDs, such as complex programmable logic devices (CPLDs) and field programmable gate arrays (FPGA), have been discussed before. However, previous studies have focused on the experiences from the point of view of the…

Design of acoustic logging signal source of imitation based on field programmable gate array

International Nuclear Information System (INIS)

Zhang, K; Ju, X D; Lu, J Q; Men, B Y

2014-01-01

An acoustic logging signal source of imitation is designed and realized, based on the Field Programmable Gate Array (FPGA), to improve the efficiency of examining and repairing acoustic logging tools during research and field application, and to inspect and verify acoustic receiving circuits and corresponding algorithms. The design of this signal source contains hardware design and software design,and the hardware design uses an FPGA as the control core. Four signals are made first by reading the Random Access Memory (RAM) data which are inside the FPGA, then dealing with the data by digital to analog conversion, amplification, smoothing and so on. Software design uses VHDL, a kind of hardware description language, to program the FPGA. Experiments illustrate that the ratio of signal to noise for the signal source is high, the waveforms are stable, and also its functions of amplitude adjustment, frequency adjustment and delay adjustment are in accord with the characteristics of real acoustic logging waveforms. These adjustments can be used to imitate influences on sonic logging received waveforms caused by many kinds of factors such as spacing and span of acoustic tools, sonic speeds of different layers and fluids, and acoustic attenuations of different cementation planes. (paper)

Scanning probe lithography for fabrication of Ti metal nanodot arrays

International Nuclear Information System (INIS)

Jung, B.; Jo, W.; Gwon, M.J.; Lee, E.; Kim, D.-W.

2010-01-01

We report fabrication of Ti metal nanodot arrays by scanning probe microscopic indentation. A thin poly-methylmethacrylate (PMMA) layer was spin-coated on Si substrates with thickness of 70 nm. Nanometer-size pore arrays were formed by indenting the PMMA layer using a cantilever of a scanning probe microscope. Protuberances with irregular boundaries appeared during the indentation process. Control of approach and pulling-out speed during indentation was able to dispose of the protrusions. Ti metal films were deposited on the patterned PMMA layers by a radio-frequency sputtering method and subsequently lifted off to obtain metal nanodot arrays. The fabricated metal nanodot arrays have 200 nm of diameter and 500 nm of interdistance, which corresponds to a density of 4x10 8 /cm 2 . Scanning probe-based measurement of current-voltage (I-V) behaviors for a single Ti metal nanodot showed asymmetric characteristics. Applying external bias is likely to induce oxidation of Ti metal, since the conductance decreased and volume change of the dots was observed. I-V behaviors of Ti metal nanodots by conventional e-beam lithography were also characterized for comparison.

Resonance spectra of diabolo optical antenna arrays

Directory of Open Access Journals (Sweden)

Hong Guo

2015-10-01

Full Text Available A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

Design and implementation of a reconfigurable mixed-signal SoC based on field programmable analog arrays

Science.gov (United States)

Liu, Lintao; Gao, Yuhan; Deng, Jun

2017-11-01

This work presents a reconfigurable mixed-signal system-on-chip (SoC), which integrates switched-capacitor-based field programmable analog arrays (FPAA), analog-to-digital converter (ADC), digital-to-analog converter, digital down converter , digital up converter, 32-bit reduced instruction-set computer central processing unit (CPU) and other digital IPs on a single chip with 0.18 μm CMOS technology. The FPAA intellectual property could be reconfigured as different function circuits, such as gain amplifier, divider, sine generator, and so on. This single-chip integrated mixed-signal system is a complete modern signal processing system, occupying a die area of 7 × 8 mm 2 and consuming 719 mW with a clock frequency of 150 MHz for CPU and 200 MHz for ADC/DAC. This SoC chip can help customers to shorten design cycles, save board area, reduce the system power consumption and depress the system integration risk, which would afford a big prospect of application for wireless communication. Project supported by the National High Technology and Development Program of China (No. 2012AA012303).

A counting-weighted calibration method for a field-programmable-gate-array-based time-to-digital converter

International Nuclear Information System (INIS)

Chen, Yuan-Ho

2017-01-01

In this work, we propose a counting-weighted calibration method for field-programmable-gate-array (FPGA)-based time-to-digital converter (TDC) to provide non-linearity calibration for use in positron emission tomography (PET) scanners. To deal with the non-linearity in FPGA, we developed a counting-weighted delay line (CWD) to count the delay time of the delay cells in the TDC in order to reduce the differential non-linearity (DNL) values based on code density counts. The performance of the proposed CWD-TDC with regard to linearity far exceeds that of TDC with a traditional tapped delay line (TDL) architecture, without the need for nonlinearity calibration. When implemented in a Xilinx Vertix-5 FPGA device, the proposed CWD-TDC achieved time resolution of 60 ps with integral non-linearity (INL) and DNL of [−0.54, 0.24] and [−0.66, 0.65] least-significant-bit (LSB), respectively. This is a clear indication of the suitability of the proposed FPGA-based CWD-TDC for use in PET scanners.

Using field programmable gate array hardware for the performance improvement of ultrasonic wave propagation imaging system

Energy Technology Data Exchange (ETDEWEB)

Shan, Jaffry Syed [Hamdard University, Karachi (Pakistan); Abbas, Syed Haider; Lee, Jung Ryul [Dept. of Aerospace Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kang, Dong Hoon [Advanced Materials Research Team, Korea Railroad Research Institute, Uiwang (Korea, Republic of)

2015-12-15

Recently, wave propagation imaging based on laser scanning-generated elastic waves has been intensively used for nondestructive inspection. However, the proficiency of the conventional software based system reduces when the scan area is large since the processing time increases significantly due to unavoidable processor multitasking, where computing resources are shared with multiple processes. Hence, the field programmable gate array (FPGA) was introduced for a wave propagation imaging method in order to obtain extreme processing time reduction. An FPGA board was used for the design, implementing post-processing ultrasonic wave propagation imaging (UWPI). The results were compared with the conventional system and considerable improvement was observed, with at least 78% (scanning of 100x100mm{sup 2} with 0.5 mm interval) to 87.5% (scanning of 200x200mm{sup 2} with 0.5 mm interval) less processing time, strengthening the claim for the research. This new concept to implement FPGA technology into the UPI system will act as a break-through technology for full-scale automatic inspection.

Using field programmable gate array hardware for the performance improvement of ultrasonic wave propagation imaging system

International Nuclear Information System (INIS)

Shan, Jaffry Syed; Abbas, Syed Haider; Lee, Jung Ryul; Kang, Dong Hoon

2015-01-01

Recently, wave propagation imaging based on laser scanning-generated elastic waves has been intensively used for nondestructive inspection. However, the proficiency of the conventional software based system reduces when the scan area is large since the processing time increases significantly due to unavoidable processor multitasking, where computing resources are shared with multiple processes. Hence, the field programmable gate array (FPGA) was introduced for a wave propagation imaging method in order to obtain extreme processing time reduction. An FPGA board was used for the design, implementing post-processing ultrasonic wave propagation imaging (UWPI). The results were compared with the conventional system and considerable improvement was observed, with at least 78% (scanning of 100x100mm 2 with 0.5 mm interval) to 87.5% (scanning of 200x200mm 2 with 0.5 mm interval) less processing time, strengthening the claim for the research. This new concept to implement FPGA technology into the UPI system will act as a break-through technology for full-scale automatic inspection

A counting-weighted calibration method for a field-programmable-gate-array-based time-to-digital converter

Energy Technology Data Exchange (ETDEWEB)

Chen, Yuan-Ho, E-mail: chenyh@mail.cgu.edu.tw [Department of Electronic Engineering, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China); Center for Reliability Sciences and Technologies, Chang Gung University, Tao-Yuan 333, Taiwan (China)

2017-05-11

In this work, we propose a counting-weighted calibration method for field-programmable-gate-array (FPGA)-based time-to-digital converter (TDC) to provide non-linearity calibration for use in positron emission tomography (PET) scanners. To deal with the non-linearity in FPGA, we developed a counting-weighted delay line (CWD) to count the delay time of the delay cells in the TDC in order to reduce the differential non-linearity (DNL) values based on code density counts. The performance of the proposed CWD-TDC with regard to linearity far exceeds that of TDC with a traditional tapped delay line (TDL) architecture, without the need for nonlinearity calibration. When implemented in a Xilinx Vertix-5 FPGA device, the proposed CWD-TDC achieved time resolution of 60 ps with integral non-linearity (INL) and DNL of [−0.54, 0.24] and [−0.66, 0.65] least-significant-bit (LSB), respectively. This is a clear indication of the suitability of the proposed FPGA-based CWD-TDC for use in PET scanners.

Development of a protection system for research reactor based in Field Programmable Gate Array - FPGA

International Nuclear Information System (INIS)

Martins, Roque Hudson da Silva

2016-01-01

This study presents a implementation purpose of a protection system for research nuclear reactors by using a programed device FPGA (Field Programmable Gate Array). As well as logic protection method involved on an automatic shutdown (TRIP) of a reactor, that ensure the security on such systems. These new control and operation mechanics are developed to guarantee that the security limits of a power plant are not exceeded, these mechanics can work isolated or in groups to safe guard the security levels. For this implementation to be completed, there will be presented the main aspects and concepts referred to protection systems, mostly about research nuclear reactors, with some applications terms exposed. The system proposed at this paper was developed following the VHDL (Very High Speed Integrated Circuits) hardware describing language, and the Modelsim software from Altera Software to program the automatic turning off routines, and hypothetical simulations for such. The results show that for every software application for supporting nuclear reactors, like security devices, they have to meet the IEC 60880 criteria. This paper have great importance, seeing that nuclear reactor security systems, are a basic element for ensure the reactor security. (author)

Dual-mode optical microscope based on single-pixel imaging

Science.gov (United States)

Rodríguez, A. D.; Clemente, P.; Tajahuerce, E.; Lancis, J.

2016-07-01

We demonstrate an inverted microscope that can image specimens in both reflection and transmission modes simultaneously with a single light source. The microscope utilizes a digital micromirror device (DMD) for patterned illumination altogether with two single-pixel photosensors for efficient light detection. The system, a scan-less device with no moving parts, works by sequential projection of a set of binary intensity patterns onto the sample that are codified onto a modified commercial DMD. Data to be displayed are geometrically transformed before written into a memory cell to cancel optical artifacts coming from the diamond-like shaped structure of the micromirror array. The 24-bit color depth of the display is fully exploited to increase the frame rate by a factor of 24, which makes the technique practicable for real samples. Our commercial DMD-based LED-illumination is cost effective and can be easily coupled as an add-on module for already existing inverted microscopes. The reflection and transmission information provided by our dual microscope complement each other and can be useful for imaging non-uniform samples and to prevent self-shadowing effects.

Radiation-Hardened Circuitry Using Mask-Programmable Analog Arrays. Report 3

Energy Technology Data Exchange (ETDEWEB)

Britton, Jr, Charles L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shelton, Jacob H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ericson, Milton Nance [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Blalock, Benjamin [Univ. of Tennessee, Knoxville, TN (United States)

2015-03-01

As the recent accident at Fukushima Daiichi so vividly demonstrated, telerobotic technologies capable of withstanding high radiation environments need to be readily available to enable operations, repair, and recovery under severe accident scenarios when human entry is extremely dangerous or not possible. Telerobotic technologies that enable remote operation in high dose rate environments have undergone revolutionary improvement over the past few decades. However, much of this technology cannot be employed in nuclear power environments because of the radiation sensitivity of the electronics and the organic insulator materials currently in use. This is a report of the activities involving Task 3 of the Nuclear Energy Enabling Technologies (NEET) 2 project Radiation Hardened Circuitry Using Mask-Programmable Analog Arrays [1]. Evaluation of the performance of the system for both pre- and post-irradiation as well as operation at elevated temperature will be performed. Detailed performance of the system will be documented to ensure the design meets requirements prior to any extended evaluation. A suite of tests will be developed which will allow evaluation before and after irradiation and during temperature. Selection of the radiation exposure facilities will be determined in the early phase of the project. Radiation exposure will consist of total integrated dose (TID) up to 200 kRad or above with several intermediate doses during test. Dose rates will be in various ranges determined by the facility that will be used with a target of 30 kRad/hr. Many samples of the pre-commercial devices to be used will have been tested in previous projects to doses of at least 300 kRad and temperatures up to 125C. The complete systems will therefore be tested for performance at intermediate doses. Extended temperature testing will be performed up to the limit of the commercial sensors. The test suite performed at each test point will consist of operational testing of the three basic

A programmable delay unit incorporating a semi-custom integrated circuit

International Nuclear Information System (INIS)

Linstadt, E.

1985-01-01

The synchronization of SLC accelerator control and monitoring functions is realized by a CAMAC module, the PDU II (Programmable Delay Unit II, SLAC 253-002), which includes a semi-custom gate array integrated circuit. The PDU II distributes 16 channels of independently programmable delayed pulses to other modules within the same CAMAC crate. The delays are programmable in increments of 8.4 ns. Functional descriptions of both the module and the semi-custom integrated circuit used to generate the output pulses are given

Field Emission of ITO-Coated Vertically Aligned Nanowire Array.

KAUST Repository

Lee, Changhwa

2010-04-29

An indium tin oxide (ITO)-coated vertically aligned nanowire array is fabricated, and the field emission characteristics of the nanowire array are investigated. An array of vertically aligned nanowires is considered an ideal structure for a field emitter because of its parallel orientation to the applied electric field. In this letter, a vertically aligned nanowire array is fabricated by modified conventional UV lithography and coated with 0.1-μm-thick ITO. The turn-on electric field intensity is about 2.0 V/μm, and the field enhancement factor, β, is approximately 3,078 when the gap for field emission is 0.6 μm, as measured with a nanomanipulator in a scanning electron microscope.

Field Emission of ITO-Coated Vertically Aligned Nanowire Array.

KAUST Repository

Lee, Changhwa; Lee, Seokwoo; Lee, Seung S

2010-01-01

An indium tin oxide (ITO)-coated vertically aligned nanowire array is fabricated, and the field emission characteristics of the nanowire array are investigated. An array of vertically aligned nanowires is considered an ideal structure for a field emitter because of its parallel orientation to the applied electric field. In this letter, a vertically aligned nanowire array is fabricated by modified conventional UV lithography and coated with 0.1-μm-thick ITO. The turn-on electric field intensity is about 2.0 V/μm, and the field enhancement factor, β, is approximately 3,078 when the gap for field emission is 0.6 μm, as measured with a nanomanipulator in a scanning electron microscope.

Atomic Force Microscope for Imaging and Spectroscopy

Science.gov (United States)

Pike, W. T.; Hecht, M. H.; Anderson, M. S.; Akiyama, T.; Gautsch, S.; deRooij, N. F.; Staufer, U.; Niedermann, Ph.; Howald, L.; Mueller, D.

2000-01-01

We have developed, built, and tested an atomic force microscope (AFM) for extraterrestrial applications incorporating a micromachined tip array to allow for probe replacement. It is part of a microscopy station originally intended for NASA's 2001 Mars lander to identify the size, distribution, and shape of Martian dust and soil particles. As well as imaging topographically down to nanometer resolution, this instrument can be used to reveal chemical information and perform infrared and Raman spectroscopy at unprecedented resolution.

Spatiotemporal polarization modulation microscopy with a microretarder array

Science.gov (United States)

Ding, Changqin; Ulcickas, James R. W.; Simpson, Garth J.

2018-02-01

A patterned microretarder array positioned in the rear conjugate plane of a microscope enables rapid polarizationdependent nonlinear optical microscopy. The pattern introduced to the array results in periodic modulation of the polarization-state of the incident light as a function of position within the field of view with no moving parts or active control. Introduction of a single stationary optical element and a fixed polarizer into the beam of a nonlinear optical microscope enabled nonlinear optical tensor recovery, which informs on local structure and orientation. Excellent agreement was observed between the measured and predicted second harmonic generation (SHG) of z-cut quartz, selected as a test system with well-established nonlinear optical properties. Subsequent studies of spatially varying samples further support the general applicability of this relatively simple strategy for detailed polarization analysis in both conventional and nonlinear optical imaging of structurally diverse samples.

Methodology for Assessing the Degree of Internationalization of Business Academic Study Programmes

OpenAIRE

Dan-Cristian Dabija; Cătălin Postelnicu; Nicolae Al. Pop

2014-01-01

The purpose of this paper is to develop a methodology for assessing the degree of internationalization of undergraduate, Master’s and doctoral business programmes with the aid of complex indicators designed to capture the vast array of characteristics displayed by these programmes and contribute to their promotion in the international academic competition. The methodology should include both general indicators applicable to any study programme and some indicators that are specifically develop...

A multi-modal stereo microscope based on a spatial light modulator.

Science.gov (United States)

Lee, M P; Gibson, G M; Bowman, R; Bernet, S; Ritsch-Marte, M; Phillips, D B; Padgett, M J

2013-07-15

Spatial Light Modulators (SLMs) can emulate the classic microscopy techniques, including differential interference (DIC) contrast and (spiral) phase contrast. Their programmability entails the benefit of flexibility or the option to multiplex images, for single-shot quantitative imaging or for simultaneous multi-plane imaging (depth-of-field multiplexing). We report the development of a microscope sharing many of the previously demonstrated capabilities, within a holographic implementation of a stereo microscope. Furthermore, we use the SLM to combine stereo microscopy with a refocusing filter and with a darkfield filter. The instrument is built around a custom inverted microscope and equipped with an SLM which gives various imaging modes laterally displaced on the same camera chip. In addition, there is a wide angle camera for visualisation of a larger region of the sample.

Symmetric and Programmable Multi-Chip Module for Low-Power Prototyping System

OpenAIRE

Yen, Mao-Hsu; Chen, Sao-Jie; Lan, Sanko H.

2001-01-01

The advantages of a Multi-Chip Module (MCM) product are its low-power and small-size. But the design of an MCM system usually requires weeks of engineering effort, thus we need a generic MCM substrate with programmable interconnections to accelerate system prototyping. In this paper, we propose a Symmetric and Programmable MCM (SPMCM) substrate for this purpose. This SPMCM substrate consists of a symmetrical array of slots for bare-chip attachment and Field Programmable Interco...

[Hardware Implementation of Numerical Simulation Function of Hodgkin-Huxley Model Neurons Action Potential Based on Field Programmable Gate Array].

Science.gov (United States)

Wang, Jinlong; Lu, Mai; Hu, Yanwen; Chen, Xiaoqiang; Pan, Qiangqiang

2015-12-01

Neuron is the basic unit of the biological neural system. The Hodgkin-Huxley (HH) model is one of the most realistic neuron models on the electrophysiological characteristic description of neuron. Hardware implementation of neuron could provide new research ideas to clinical treatment of spinal cord injury, bionics and artificial intelligence. Based on the HH model neuron and the DSP Builder technology, in the present study, a single HH model neuron hardware implementation was completed in Field Programmable Gate Array (FPGA). The neuron implemented in FPGA was stimulated by different types of current, the action potential response characteristics were analyzed, and the correlation coefficient between numerical simulation result and hardware implementation result were calculated. The results showed that neuronal action potential response of FPGA was highly consistent with numerical simulation result. This work lays the foundation for hardware implementation of neural network.

A programmable associative memory for track finding

International Nuclear Information System (INIS)

Bardi, A.; Belforte, S.; Donati, S.; Galeotti, S.; Giannetti, P.; Morsani, F.; Passuello, D.; Spinella, F.; Cerri, A.; Punzi, G.; Ristori, L.; Dell'Orso, M.; Meschi, E.; Leger, A.; Speer, T.; Wu, X.

1998-01-01

We present a device, based on the concept of associative memory for pattern recognition, dedicated to on-line track finding in high-energy physics experiments. A large pattern bank, describing all possible tracks, can be organized into field programmable gate arrays where all patterns are compared in parallel to data coming from the detector during readout. Patterns, recognized among 2 66 possible combinations, are output in a few 30 MHz clock cycles. Programmability results in a flexible, simple architecture and it allows to keep up smoothly with technology improvements. (orig.)

A programmable systolic array correlator as a trigger processor for electron pairs in rich (ring image Cherenkov) counters

Science.gov (United States)

Männer, R.

1989-12-01

This paper describes a systolic array processor for a ring image Cherenkov counter which is capable of identifying pairs of electron circles with a known radius and a certain minimum distance within 15 μs. The processor is a very flexible and fast device. It consists of 128 x 128 processing elements (PEs), where one PE is assigned to each pixel of the image. All PEs run synchronously at 40 MHz. The identification of electron circles is done by correlating the detector image with the proper circle circumference. Circle centers are found by peak detection in the correlation result. A second correlation with a circle disc allows circles of closed electron pairs to be rejected. The trigger decision is generated if a pseudo adder detects at least two remaining circles. The device is controlled by a freely programmable sequencer. A VLSI chip containing 8 x 8 PEs is being developed using a VENUS design system and will be produced in 2μ CMOS technology.

A programmable systolic array correlator as a trigger processor for electron pairs in RICH (ring image Cherenkov) counters

International Nuclear Information System (INIS)

Maenner, R.

1989-01-01

This paper describes a systolic array processor for a ring image Cherenkov counter which is capable of identifying pairs of electron circles with a known radius and a certain minimum distance within 15 μs. The processor is a very flexible and fast device. It consists of 128x128 processing elements (PEs), where one PE is assigned to each pixel of the image. All PEs run synchronously at 40 MHz. The identification of electron circles is done by correlating the detector image with the proper circle circumference. Circle centers are found by peak detection in the correlation result. A second correlation with a circle disc allows circles of closed electron pairs to be rejected. The trigger decision is generated if a pseudo adder detects at least two remaining circles. The device is controlled by a freely programmable sequencer. A VLSI chip containing 8x8 PEs is being developed using a VENUS design system and will be produced in 2μ CMOS technology. (orig.)

Improved Scanners for Microscopic Hyperspectral Imaging

Science.gov (United States)

Mao, Chengye

2009-01-01

Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version

Formation of array microstructures on silicon by multibeam interfered femtosecond laser pulses

International Nuclear Information System (INIS)

Zhao Quanzhong; Qiu Jianrong; Zhao Chongjun; Jiang Xiongwei; Zhu Congshan

2005-01-01

We report on an optical interference method to fabricate array microstructures on the surface of silicon wafers by means of five-beam interference of femtosecond laser pulses. Optical microscope and scanning electron microscope observations revealed microstructures with micrometer-order were fabricated. The diffraction characteristics of the fabricated structures were evaluated. The present technique allows one-step realization of functional optoelectronic devices on silicon surface

Microscopic characterisation of TIG-deposition and -welding

International Nuclear Information System (INIS)

Groot, P.

1992-11-01

In the framework of the European Fusion Technology Programme austenitic RVS AISI 316LN is considered as candidate material for the First Wall. In this report, among others, tungsten-arc (TIG) welding connections are investigated as a part of the ECN project 1.653. It concerns respectively; the deposition of TIG-electrode-material and the welding connection. The connections are fabricated by the Danish Welding Institute Svejsecentrals in Broendby. This study is supposed to give a welding qualification by microscopic characterisation of a TIG-deposition and a TIG-weld. 3 refs., 33 figs., 5 tabs

Real-time image processing and control interface for remote operation of a microscope

Science.gov (United States)

Leng, Hesong; Wilder, Joseph

1999-08-01

A real-time image processing and control interface for remote operation of a microscope is presented in this paper. The system has achieved real-time color image display for 640 X 480 pixel images. Multi-resolution image representation can be provided for efficient transmission through the network. Through the control interface the computer can communicate with the programmable microscope via the RS232 serial ports. By choosing one of three scanning patterns, a sequence of images can be saved as BMP or PGM files to record information on an entire microscope slide. The system will be used by medical and graduate students at the University of Medicine and Dentistry of New Jersey for distance learning. It can be used in many network-based telepathology applications.

A stereo-compound hybrid microscope for combined intracellular and optical recording of invertebrate neural network activity.

Science.gov (United States)

Frost, William N; Wang, Jean; Brandon, Christopher J

2007-05-15

Optical recording studies of invertebrate neural networks with voltage-sensitive dyes seldom employ conventional intracellular electrodes. This may in part be due to the traditional reliance on compound microscopes for such work. While such microscopes have high light-gathering power, they do not provide depth of field, making working with sharp electrodes difficult. Here we describe a hybrid microscope design, with switchable compound and stereo objectives, that eases the use of conventional intracellular electrodes in optical recording experiments. We use it, in combination with a voltage-sensitive dye and photodiode array, to identify neurons participating in the swim motor program of the marine mollusk Tritonia. This microscope design should be applicable to optical recording studies in many preparations.

Full-frame, programmable hyperspectral imager

Science.gov (United States)

Love, Steven P.; Graff, David L.

2017-07-25

A programmable, many-band spectral imager based on addressable spatial light modulators (ASLMs), such as micro-mirror-, micro-shutter- or liquid-crystal arrays, is described. Capable of collecting at once, without scanning, a complete two-dimensional spatial image with ASLM spectral processing applied simultaneously to the entire image, the invention employs optical assemblies wherein light from all image points is forced to impinge at the same angle onto the dispersing element, eliminating interplay between spatial position and wavelength. This is achieved, as examples, using telecentric optics to image light at the required constant angle, or with micro-optical array structures, such as micro-lens- or capillary arrays, that aim the light on a pixel-by-pixel basis. Light of a given wavelength then emerges from the disperser at the same angle for all image points, is collected at a unique location for simultaneous manipulation by the ASLM, then recombined with other wavelengths to form a final spectrally-processed image.

Neuron array with plastic synapses and programmable dendrites.

Science.gov (United States)

Ramakrishnan, Shubha; Wunderlich, Richard; Hasler, Jennifer; George, Suma

2013-10-01

We describe a novel neuromorphic chip architecture that models neurons for efficient computation. Traditional architectures of neuron array chips consist of large scale systems that are interfaced with AER for implementing intra- or inter-chip connectivity. We present a chip that uses AER for inter-chip communication but uses fast, reconfigurable FPGA-style routing with local memory for intra-chip connectivity. We model neurons with biologically realistic channel models, synapses and dendrites. This chip is suitable for small-scale network simulations and can also be used for sequence detection, utilizing directional selectivity properties of dendrites, ultimately for use in word recognition.

Thermoelastic expansion vs. piezoelectricity for high-frequency, 2-D arrays.

Science.gov (United States)

Buma, Takashi; Spisar, Monica; O'Donnell, Matthew

2003-08-01

Optical generation using the thermoelastic effect has traditionally suffered from low conversion efficiency. We previously demonstrated increased efficiency of nearly 20 dB with an optical absorbing layer consisting of a mixture of polydimethylsiloxane (PDMS) and carbon black spin coated onto a glass microscope slide. In this paper we show that the radiated power from a black PDMS film is comparable to a 20 MHz piezoelectric two-dimensional (2-D) array element. Furthermore, we predict that a thermoelastic array element can produce similar acoustic power levels compared to ideal piezoelectric 2-D array elements at frequencies in the 100 MHz regime. We believe these results show that thermoelastic generation of ultrasound is a promising alternative to piezoelectricity for high-frequency, 2-D arrays.

GaN Nanowire Arrays for High-Output Nanogenerators

KAUST Repository

Huang, Chi-Te

2010-04-07

Three-fold symmetrically distributed GaN nanowire (NW) arrays have been epitaxially grown on GaN/sapphire substrates. The GaN NW possesses a triangular cross section enclosed by (0001), (2112), and (2112) planes, and the angle between the GaN NW and the substrate surface is ∼62°. The GaN NW arrays produce negative output voltage pulses when scanned by a conductive atomic force microscope in contact mode. The average of piezoelectric output voltage was about -20 mV, while 5-10% of the NWs had piezoelectric output voltages exceeding -(0.15-0.35) V. The GaN NW arrays are highly stable and highly tolerate to moisture in the atmosphere. The GaN NW arrays demonstrate an outstanding potential to be utilized for piezoelectric energy generation with a performance probably better than that of ZnO NWs. © 2010 American Chemical Society.

Dynamic array of dark optical traps

DEFF Research Database (Denmark)

Daria, V.R.; Rodrigo, P.J.; Glückstad, J.

2004-01-01

A dynamic array of dark optical traps is generated for simultaneous trapping and arbitrary manipulation of multiple low-index microstructures. The dynamic intensity patterns forming the dark optical trap arrays are generated using a nearly loss-less phase-to-intensity conversion of a phase......-encoded coherent light source. Two-dimensional input phase distributions corresponding to the trapping patterns are encoded using a computer-programmable spatial light modulator, enabling each trap to be shaped and moved arbitrarily within the plane of observation. We demonstrate the generation of multiple dark...... optical traps for simultaneous manipulation of hollow "air-filled" glass microspheres suspended in an aqueous medium. (C) 2004 American Institute of Physics....

Failure mode taxonomy for assessing the reliability of Field Programmable Gate Array based Instrumentation and Control systems

International Nuclear Information System (INIS)

McNelles, Phillip; Zeng, Zhao Chang; Renganathan, Guna; Chirila, Marius; Lu, Lixuan

2017-01-01

Highlights: • The use FPGAs in I&C systems in Nuclear Power Plants is an important issue (IAEA). • OECD-NEA published a failure mode taxonomy for software-based digital I&C systems. • This paper extends the OECD-NEA taxonomy to model FPGA-based systems. • FPGA failure modes, failure effects, uncovering methods are categorized/described. • Provides an example of modelling an FPGA-Based RTS/ESFAS using the FPGA taxonomy. - Abstract: Field Programmable Gate Arrays (FPGAs) are a form of programmable digital hardware configured to perform digital logic functions. This configuration (programming) is performed using Hardware Description Language (HDL), making FPGAs a form of HDL Programmed Device (HPD). In the nuclear field, FPGAs have seen use in upgrades and replacements of obsolete Instrumentation and Control (I&C) systems. This paper expands upon previous work that resulted in extensive FPGA failure mode data, to allow for the application of the OECD-NEA failure modes taxonomy. The OECD-NEA taxonomy presented a method to model digital (software-based) I&C systems, based on the hardware and software failure modes, failure uncovering effects and levels of abstraction, using a Reactor Trip System/Engineering Safety Feature Actuation System (RTS/ESFAS) as an example system. To create the FPGA taxonomy, this paper presents an additional “sub-component” level of abstraction, to demonstrate the effect of the FPGA failure modes and failure categories on an FPGA-based system. The proposed FPGA taxonomy is based on the FPGA failure modes, failure categories, failure effects and uncovering situations. The FPGA taxonomy is applied to the RTS/ESFAS test system, to demonstrate the effects of the anticipated FPGA failure modes on a digital I&C system, and to provide a modelling example for this proposed taxonomy.

Design of Circularly-Polarised, Crossed Drooping Dipole, Phased Array Antenna Using Genetic Algorithm Optimisation

DEFF Research Database (Denmark)

Larsen, Niels Vesterdal

2007-01-01

A printed drooping dipole array is designed and constructed. The design is based on a genetic algorithm optimisation procedure used in conjunction with the software programme AWAS. By optimising the array G/T for specific combinations of scan angles and frequencies an optimum design is obtained...

Passive anti-frosting surfaces using microscopic ice arrays

Science.gov (United States)

Ahmadi, Farzad; Nath, Saurabh; Iliff, Grady; Boreyko, Jonathan

2017-11-01

Despite exceptional advances in surface chemistry and micro/nanofabrication, no engineered surface has been able to passively suppress the in-plane growth of frost occurring in humid, subfreezing environments. Motivated by this, and inspired by the fact that ice itself can evaporate nearby liquid water droplets, we present a passive anti-frosting surface in which the majority of the surface remains dry indefinitely. We fabricated an aluminum surface exhibiting an array of small metallic fins, where a wicking micro-groove was laser-cut along the top of each fin to produce elevated water ``stripes'' that freeze into ice. As the saturation vapor pressure of ice is less than that of supercooled liquid water, the ice stripes serve as overlapping humidity sinks that siphon all nearby moisture from the air and prevent condensation and frost from forming anywhere else on the surface. Our experimental results show that regions between stripes remain dry even after 24 hours of operation under humid and supercooled conditions. We believe that the presented anti-frosting technology has the potential to help solve the world's multi-billion dollar frosting problem that adversely affects transportation, power generation, and HVAC systems.

21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproductive microscopes and microscope... Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a) Identification. Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are...

Theory and implementation of a very high throughput true random number generator in field programmable gate array

Energy Technology Data Exchange (ETDEWEB)

Wang, Yonggang, E-mail: wangyg@ustc.edu.cn; Hui, Cong; Liu, Chong; Xu, Chao [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)

2016-04-15

The contribution of this paper is proposing a new entropy extraction mechanism based on sampling phase jitter in ring oscillators to make a high throughput true random number generator in a field programmable gate array (FPGA) practical. Starting from experimental observation and analysis of the entropy source in FPGA, a multi-phase sampling method is exploited to harvest the clock jitter with a maximum entropy and fast sampling speed. This parametrized design is implemented in a Xilinx Artix-7 FPGA, where the carry chains in the FPGA are explored to realize the precise phase shifting. The generator circuit is simple and resource-saving, so that multiple generation channels can run in parallel to scale the output throughput for specific applications. The prototype integrates 64 circuit units in the FPGA to provide a total output throughput of 7.68 Gbps, which meets the requirement of current high-speed quantum key distribution systems. The randomness evaluation, as well as its robustness to ambient temperature, confirms that the new method in a purely digital fashion can provide high-speed high-quality random bit sequences for a variety of embedded applications.

Accelerating object detection via a visual-feature-directed search cascade: algorithm and field programmable gate array implementation

Science.gov (United States)

Kyrkou, Christos; Theocharides, Theocharis

2016-07-01

Object detection is a major step in several computer vision applications and a requirement for most smart camera systems. Recent advances in hardware acceleration for real-time object detection feature extensive use of reconfigurable hardware [field programmable gate arrays (FPGAs)], and relevant research has produced quite fascinating results, in both the accuracy of the detection algorithms as well as the performance in terms of frames per second (fps) for use in embedded smart camera systems. Detecting objects in images, however, is a daunting task and often involves hardware-inefficient steps, both in terms of the datapath design and in terms of input/output and memory access patterns. We present how a visual-feature-directed search cascade composed of motion detection, depth computation, and edge detection, can have a significant impact in reducing the data that needs to be examined by the classification engine for the presence of an object of interest. Experimental results on a Spartan 6 FPGA platform for face detection indicate data search reduction of up to 95%, which results in the system being able to process up to 50 1024×768 pixels images per second with a significantly reduced number of false positives.

Microlens array processor with programmable weight mask and direct optical input

Science.gov (United States)

Schmid, Volker R.; Lueder, Ernst H.; Bader, Gerhard; Maier, Gert; Siegordner, Jochen

1999-03-01

We present an optical feature extraction system with a microlens array processor. The system is suitable for online implementation of a variety of transforms such as the Walsh transform and DCT. Operating with incoherent light, our processor accepts direct optical input. Employing a sandwich- like architecture, we obtain a very compact design of the optical system. The key elements of the microlens array processor are a square array of 15 X 15 spherical microlenses on acrylic substrate and a spatial light modulator as transmissive mask. The light distribution behind the mask is imaged onto the pixels of a customized a-Si image sensor with adjustable gain. We obtain one output sample for each microlens image and its corresponding weight mask area as summation of the transmitted intensity within one sensor pixel. The resulting architecture is very compact and robust like a conventional camera lens while incorporating a high degree of parallelism. We successfully demonstrate a Walsh transform into the spatial frequency domain as well as the implementation of a discrete cosine transform with digitized gray values. We provide results showing the transformation performance for both synthetic image patterns and images of natural texture samples. The extracted frequency features are suitable for neural classification of the input image. Other transforms and correlations can be implemented in real-time allowing adaptive optical signal processing.

Fabrication and characterization of nano-gas sensor arrays

International Nuclear Information System (INIS)

Hassan, H. S.; Kashyout, A. B.; Morsi, I.; Nasser, A. A. A.; Raafat, A.

2015-01-01

A novel structures of Nanomaterials gas sensors array constructed using ZnO, and ZnO doped with Al via sol-gel technique. Two structure arrays are developed; the first one is a double sensor array based on doping with percentages of 1% and 5%. The second is a quadrature sensor array based on several doping ratios concentrations (0%, 1%, 5% and 10%). The morphological structures of prepared ZnO were revealed using scanning electron microscope (SEM). X-ray diffraction (XRD) patterns reveal a highly crystallized wurtzite structure and used for identifying phase structure and chemical state of both ZnO and ZnO doped with Al under different preparation conditions and different doping ratios. Chemical composition of Al-doped ZnO nanopowders was performed using energy dispersive x-ray (EDS) analysis. The electrical characteristics of the sensor are determined by measuring the two terminal sensor’s output resistance for O 2 , H 2 and CO 2 gases as a function of temperature

Fabrication and characterization of nano-gas sensor arrays

Energy Technology Data Exchange (ETDEWEB)

Hassan, H. S., E-mail: hassan.shokry@gmail.com; Kashyout, A. B., E-mail: hady8@yahoo.com [Electronic Materials Researches Department, Advanced Technology and New Materials Research Institute, City of Scientific Researches and technological applications, New Borg El-Arab City, Alexandria (Egypt); Morsi, I., E-mail: drimanmorsi@yahoo.com; Nasser, A. A. A., E-mail: menem-1954@yahoo.com; Raafat, A., E-mail: abrs-218@yahoo.com [Arab Academy for Science and Technology, and Maritime Transport, Alexandria, 21936 (Egypt)

2015-03-30

A novel structures of Nanomaterials gas sensors array constructed using ZnO, and ZnO doped with Al via sol-gel technique. Two structure arrays are developed; the first one is a double sensor array based on doping with percentages of 1% and 5%. The second is a quadrature sensor array based on several doping ratios concentrations (0%, 1%, 5% and 10%). The morphological structures of prepared ZnO were revealed using scanning electron microscope (SEM). X-ray diffraction (XRD) patterns reveal a highly crystallized wurtzite structure and used for identifying phase structure and chemical state of both ZnO and ZnO doped with Al under different preparation conditions and different doping ratios. Chemical composition of Al-doped ZnO nanopowders was performed using energy dispersive x-ray (EDS) analysis. The electrical characteristics of the sensor are determined by measuring the two terminal sensor’s output resistance for O{sub 2}, H{sub 2} and CO{sub 2} gases as a function of temperature.

Directional absorption by phased arrays of plasmonic nanoantennae probed with time-reversed Fourier microscopy

International Nuclear Information System (INIS)

Lozano, Gabriel; Barten, Tommy; Grzela, Grzegorz; Rivas, Jaime Gómez

2014-01-01

We demonstrate that an ordered array of aluminum nanopyramids, behaving as a phased array of optical antennae, strongly modifies light absorption in thin layers of dye molecules. Photoluminescence measurements as a function of the illumination angle are performed using a time-reversed Fourier microscope. This technique enables a variable-angle plane-wave illumination of nanostructures in a microscope-based setup. Our measurements reveal an enhancement of the light conversion in certain directions of illumination, which indicate the efficient diffractive coupling between the free space radiation and the surface plasmons. Numerical simulations confirm that surface modes supported by the periodic array enhance the intensity of the pump field in the space between particles, where the dye molecules are located, yielding a directional plasmonic-mediated enhancement of the optical absorption. This combined experimental and numerical characterization of the angular dependence of light absorption in nanostructures can be beneficial for the design and optimization of devices in which the harvesting of light plays a major role. (paper)

MOS solid-state detector arrays for x-ray imaging

International Nuclear Information System (INIS)

Koppel, L.N.

1977-01-01

Two types of MOS detector arrays were used to sense directly patterns of soft x-rays, in the Lawrence Livermore Laboratory experimental laser-fusion program. A linear self-scanning photodiode array (SSPA) is used in a wave-length-dispersive spectrometer. A frame transfer charge-coupled device (CCD) facilitates the use of an x-ray microscope. Measurements and calculations of the x-ray sensitivity of these devices are presented. Their linearity and dynamic range are discussed, as well as data recovery systems for each detector. Experiences in using these devices to detect pulses of x-rays in laser-fusion experiments are described

Adaptation of commercial microscopes for advanced imaging applications

Science.gov (United States)

Brideau, Craig; Poon, Kelvin; Stys, Peter

2015-03-01

Today's commercially available microscopes offer a wide array of options to accommodate common imaging experiments. Occasionally, an experimental goal will require an unusual light source, filter, or even irregular sample that is not compatible with existing equipment. In these situations the ability to modify an existing microscopy platform with custom accessories can greatly extend its utility and allow for experiments not possible with stock equipment. Light source conditioning/manipulation such as polarization, beam diameter or even custom source filtering can easily be added with bulk components. Custom and after-market detectors can be added to external ports using optical construction hardware and adapters. This paper will present various examples of modifications carried out on commercial microscopes to address both atypical imaging modalities and research needs. Violet and near-ultraviolet source adaptation, custom detection filtering, and laser beam conditioning and control modifications will be demonstrated. The availability of basic `building block' parts will be discussed with respect to user safety, construction strategies, and ease of use.

Cooled CCDs for recording data from electron microscopes

CERN Document Server

Faruqi, A R

2000-01-01

A cooled-CCD camera based on a low-noise scientific grade device is described in this paper used for recording images in a 120 kV electron microscope. The primary use of the camera is for recording electron diffraction patterns from two-dimensionally ordered arrays of proteins at liquid-nitrogen temperatures leading to structure determination at atomic or near-atomic resolution. The traditional method for recording data in the microscope is with electron sensitive film but electronic detection methods offer the following advantages over film methods: the data is immediately available in a digital format which can be displayed on a monitor screen for visual inspection whereas a film record needs to be developed and digitised, a lengthy process taking at least several hours, prior to inspection; the dynamic range of CCD detectors is about two orders of magnitude greater with better linearity. The accuracy of measurements is also higher for CCDs, particularly for weak signals due to inherent fog levels in film. ...

A Compute Environment of ABC95 Array Computer Based on Multi-FPGA Chip

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

ABC95 array computer is a multi-function network's computer based on FPGA technology, The multi-function network supports processors conflict-free access data from memory and supports processors access data from processors based on enhanced MESH network.ABC95 instruction's system includes control instructions, scalar instructions, vectors instructions.Mostly net-work instructions are introduced.A programming environment of ABC95 array computer assemble language is designed.A programming environment of ABC95 array computer for VC++ is advanced.It includes load function of ABC95 array computer program and data, store function, run function and so on.Specially, The data type of ABC95 array computer conflict-free access is defined.The results show that these technologies can develop programmer of ABC95 array computer effectively.

A programmable CCD driver circuit for multiphase CCD operation

International Nuclear Information System (INIS)

Ewin, A.J.; Reed, K.V.

1989-01-01

A programmable CCD driver circuit was designed to drive CCD's in multiphased modes. The purpose of the drive electronics was to operate developmental CCD imaging arrays for NASA's Moderate Resolution Imaging Spectrometer - Tiltable (MODIS-T). Five prototype arrays were designed. Valid's Graphics Editor (GED) was used to design the driver. With this driver design, any of the five arrays can be readout. Designing the driver with GED allowed functional simulation, timing verification, and certain packaging analyses to be done on the design before fabrication. The driver verified its function with the master clock running up to 10 MHz. This suggests a maximum rate of 400 Kpixels/sec. Timing and packaging parameters were verified. the design uses 54 TTL component chips

Fringe pattern demodulation using the one-dimensional continuous wavelet transform: field-programmable gate array implementation.

Science.gov (United States)

Abid, Abdulbasit

2013-03-01

This paper presents a thorough discussion of the proposed field-programmable gate array (FPGA) implementation for fringe pattern demodulation using the one-dimensional continuous wavelet transform (1D-CWT) algorithm. This algorithm is also known as wavelet transform profilometry. Initially, the 1D-CWT is programmed using the C programming language and compiled into VHDL using the ImpulseC tool. This VHDL code is implemented on the Altera Cyclone IV GX EP4CGX150DF31C7 FPGA. A fringe pattern image with a size of 512×512 pixels is presented to the FPGA, which processes the image using the 1D-CWT algorithm. The FPGA requires approximately 100 ms to process the image and produce a wrapped phase map. For performance comparison purposes, the 1D-CWT algorithm is programmed using the C language. The C code is then compiled using the Intel compiler version 13.0. The compiled code is run on a Dell Precision state-of-the-art workstation. The time required to process the fringe pattern image is approximately 1 s. In order to further reduce the execution time, the 1D-CWT is reprogramed using Intel Integrated Primitive Performance (IPP) Library Version 7.1. The execution time was reduced to approximately 650 ms. This confirms that at least sixfold speedup was gained using FPGA implementation over a state-of-the-art workstation that executes heavily optimized implementation of the 1D-CWT algorithm.

Living Matter Observations with a Novel Hyperspectral Supercontinuum Confocal Microscope for VIS to Near-IR Reflectance Spectroscopy

Directory of Open Access Journals (Sweden)

Francesca R. Bertani

2013-10-01

Full Text Available A broad range hyper-spectroscopic microscope fed by a supercontinuum laser source and equipped with an almost achromatic optical layout is illustrated with detailed explanations of the design, implementation and data. The real novelty of this instrument, a confocal spectroscopic microscope capable of recording high resolution reflectance data in the VIS-IR spectral range from about 500 nm to 2.5 μm wavelengths, is the possibility of acquiring spectral data at every physical point as defined by lateral coordinates, X and Y, as well as at a depth coordinate, Z, as obtained by the confocal optical sectioning advantage. With this apparatus we collect each single scanning point as a whole spectrum by combining two linear spectral detector arrays, one CCD for the visible range, and one InGaAs infrared array, simultaneously available at the sensor output channel of the home made instrument. This microscope has been developed for biomedical analysis of human skin and other similar applications. Results are shown illustrating the technical performances of the instrument and the capability in extracting information about the composition and the structure of different parts or compartments in biological samples as well as in solid statematter. A complete spectroscopic fingerprinting of samples at microscopic level is shown possible by using statistical analysis on raw data or analytical reflectance models based on Abelés matrix transfer methods.

The anodization synthesis of copper oxide nanosheet arrays and their photoelectrochemical properties

Energy Technology Data Exchange (ETDEWEB)

Shu, Xia [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zheng, Hongmei [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China); Xu, Guangqing, E-mail: gqxu1979@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China); Zhao, Jiebo [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Cui, Lihua [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); School of Materials Science and Engineering, Beifang University of Nationalities, Yinchuan 750021 (China); Cui, Jiewu; Qin, Yongqiang; Wang, Yan [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zhang, Yong [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China); Wu, Yucheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China)

2017-08-01

Graphical abstract: Current-time and potential-time curves of the copper foil anodization process, CV of copper substrate in anodization solution and SEM morphologies of anodization products on Cu substrates obtained at different time. - Highlights: • Copper oxides nanosheet arrays were achieved via anodization method. • The growth mechanisms of the copper anodization process were studied. • Photoelectrochemical performances of copper oxides NSAs were studied. - Abstract: We studied the growth of copper oxide nanosheet arrays on copper foil via a simple anodization method. The structures, morphologies, and elemental compositions of the specimens were characterized with an X-ray diffractometer, scanning electron microscope, high resolution transmission electron microscope, and X-ray photoelectron spectrometer. The copper oxide (Cu{sub 2}O and CuO) nanosheet arrays were comprised of 30-nm-thick nanosheets that stand vertically on the Cu substrate. The anodizing parameters, such as the current density, temperature, and polyethylene glycol concentration, were optimized to obtain the regular nanosheet arrays. The optical absorption properties of the anodized products were evaluated using a diffuse reflectance spectrometer, and broad and strong optical absorption bands arising from the UV to visible region were observed. The photoelectrochemical performance of the nanosheet arrays was measured with chronoamperometry and cyclic voltammetry on an electrochemical workstation equipped with a Xe lamp (wavelength >400 nm). A negative photocurrent was obtained due to the p-type semiconductor of the copper oxides. The copper oxide nanosheet arrays achieve the highest photocurrent of 0.4 mA/cm{sup 2} at the current density of 1.0 A/dm{sup 2}, temperature of 70 °C, and polyethylene glycol concentration of 0.5 g/L.

CCD and IR array controllers

Science.gov (United States)

Leach, Robert W.; Low, Frank J.

2000-08-01

A family of controllers has bene developed that is powerful and flexible enough to operate a wide range of CCD and IR focal plane arrays in a variety of ground-based applications. These include fast readout of small CCD and IR arrays for adaptive optics applications, slow readout of large CCD and IR mosaics, and single CCD and IR array operation at low background/low noise regimes as well as high background/high speed regimes. The CCD and IR controllers have a common digital core based on user- programmable digital signal processors that are used to generate the array clocking and signal processing signals customized for each application. A fiber optic link passes image data and commands to VME or PCI interface boards resident in a host computer to the controller. CCD signal processing is done with a dual slope integrator operating at speeds of up to one Megapixel per second per channel. Signal processing of IR arrays is done either with a dual channel video processor or a four channel video processor that has built-in image memory and a coadder to 32-bit precision for operating high background arrays. Recent developments underway include the implementation of a fast fiber optic data link operating at a speed of 12.5 Megapixels per second for fast image transfer from the controller to the host computer, and supporting image acquisition software and device drivers for the PCI interface board for the Sun Solaris, Linux and Windows 2000 operating systems.

Characterization of SPAD Array for Multifocal High-Content Screening Applications

Directory of Open Access Journals (Sweden)

Anthony Tsikouras

2016-10-01

Full Text Available Current instruments used to detect specific protein-protein interactions in live cells for applications in high-content screening (HCS are limited by the time required to measure the lifetime. Here, a 32 × 1 single-photon avalanche diode (SPAD array was explored as a detector for fluorescence lifetime imaging (FLIM in HCS. Device parameters and characterization results were interpreted in the context of the application to determine if the SPAD array could satisfy the requirements of HCS-FLIM. Fluorescence lifetime measurements were performed using a known fluorescence standard; and the recovered fluorescence lifetime matched literature reported values. The design of a theoretical 32 × 32 SPAD array was also considered as a detector for a multi-point confocal scanning microscope.

A Soft Computing Approach to Crack Detection and Impact Source Identification with Field-Programmable Gate Array Implementation

Directory of Open Access Journals (Sweden)

Arati M. Dixit

2013-01-01

Full Text Available The real-time nondestructive testing (NDT for crack detection and impact source identification (CDISI has attracted the researchers from diverse areas. This is apparent from the current work in the literature. CDISI has usually been performed by visual assessment of waveforms generated by a standard data acquisition system. In this paper we suggest an automation of CDISI for metal armor plates using a soft computing approach by developing a fuzzy inference system to effectively deal with this problem. It is also advantageous to develop a chip that can contribute towards real time CDISI. The objective of this paper is to report on efforts to develop an automated CDISI procedure and to formulate a technique such that the proposed method can be easily implemented on a chip. The CDISI fuzzy inference system is developed using MATLAB’s fuzzy logic toolbox. A VLSI circuit for CDISI is developed on basis of fuzzy logic model using Verilog, a hardware description language (HDL. The Xilinx ISE WebPACK9.1i is used for design, synthesis, implementation, and verification. The CDISI field-programmable gate array (FPGA implementation is done using Xilinx’s Spartan 3 FPGA. SynaptiCAD’s Verilog Simulators—VeriLogger PRO and ModelSim—are used as the software simulation and debug environment.

Final Report, Center for Programming Models for Scalable Parallel Computing: Co-Array Fortran, Grant Number DE-FC02-01ER25505

Energy Technology Data Exchange (ETDEWEB)

Robert W. Numrich

2008-04-22

The major accomplishment of this project is the production of CafLib, an 'object-oriented' parallel numerical library written in Co-Array Fortran. CafLib contains distributed objects such as block vectors and block matrices along with procedures, attached to each object, that perform basic linear algebra operations such as matrix multiplication, matrix transpose and LU decomposition. It also contains constructors and destructors for each object that hide the details of data decomposition from the programmer, and it contains collective operations that allow the programmer to calculate global reductions, such as global sums, global minima and global maxima, as well as vector and matrix norms of several kinds. CafLib is designed to be extensible in such a way that programmers can define distributed grid and field objects, based on vector and matrix objects from the library, for finite difference algorithms to solve partial differential equations. A very important extra benefit that resulted from the project is the inclusion of the co-array programming model in the next Fortran standard called Fortran 2008. It is the first parallel programming model ever included as a standard part of the language. Co-arrays will be a supported feature in all Fortran compilers, and the portability provided by standardization will encourage a large number of programmers to adopt it for new parallel application development. The combination of object-oriented programming in Fortran 2003 with co-arrays in Fortran 2008 provides a very powerful programming model for high-performance scientific computing. Additional benefits from the project, beyond the original goal, include a programto provide access to the co-array model through access to the Cray compiler as a resource for teaching and research. Several academics, for the first time, included the co-array model as a topic in their courses on parallel computing. A separate collaborative project with LANL and PNNL showed how to

Astroparticle physics: the new ASPERA-2 programme

CERN Multimedia

2009-01-01

On 7 July the ASPERA-2 programme funded by the European Commission was officially launched in Hamburg with the goal of creating a sustainable structure for the coordination of astroparticle physics in Europe. CERN, which is a participant in the programme, could play an important role in this respect. Artist’s impression of the CTA (Cherenkov Telescope Array). The CTA is one of the "Magnificent Seven", the seven large astroparticle physics infrastructures planned for the coming years. It is the next-generation facility destined to succeed the H.E.S.S. telescope in Namibia and the MAGIC telescope in the Canary Islands. (Credit ASPERA/G.Toma/A.Saftoiu). Following the success of ASPERA-1, the European network for astroparticle physics (see box), funding agency representatives gathered in Hamburg on 7 July 2009 for the official launch of ASPERA-2, a new three-year programme funded by the European Commission. Today the strategic roles of ...

Dynamic Adaptive Neural Network Arrays: A Neuromorphic Architecture

Energy Technology Data Exchange (ETDEWEB)

Disney, Adam [University of Tennessee (UT); Reynolds, John [University of Tennessee (UT)

2015-01-01

Dynamic Adaptive Neural Network Array (DANNA) is a neuromorphic hardware implementation. It differs from most other neuromorphic projects in that it allows for programmability of structure, and it is trained or designed using evolutionary optimization. This paper describes the DANNA structure, how DANNA is trained using evolutionary optimization, and an application of DANNA to a very simple classification task.

Laser-based microstructuring of materials surfaces using low-cost microlens arrays

Science.gov (United States)

Nieto, Daniel; Vara, G.; Diez, J. A.; O`Connor, Gerard M.; Arines, Justo; Gómez-Reino, C.; Flores-Arias, M.

2012-03-01

Since frictional interactions in microscopically small components are becoming increasingly important for the development of new products for all modern technology, we present a laser-based technique for micro-patterning surfaces of materials using low-cost microlens arrays. The microlens used were fabricated on soda-lime glass using a laser direct-write technique, followed by a thermal treatment into an oven. By combining laser direct-write and the thermal treatment it was possible to obtain high quality elements using a low cost infrared laser widely implemented in industry which makes this technique attractive in comparison with other more expensive methods. The main advantage of using microlens arrays for micropatterning surfaces is the possibility of fabricating a large number of identical structures simultaneously, leading to a highly efficient process. In order to study the capabilities of the microlens fabricated for microstructuring materials, identical structures and arrays of holes were fabricated over a variety of materials, such us, stainless steel, polymer and ceramic. The minimum diameter of the individual microstructure generated at surface is 5 μm. Different nanosecond lasers operating at Infrared, Green and UV were used. The topography and morphology of the elements obtained were determined using a confocal microscope SENSOFAR 2300 Plμ.

Pancam and microscopic imager observations of dust on the Spirit Rovers

DEFF Research Database (Denmark)

Vaughan....[], Alicia F.; Johnson, Jeffrey R.; Walter, Goetz

2010-01-01

This work describes dust deposits on the Spirit Rover over 2000 sols through examination of Pancam and Microscopic Imager observations of specific locations on the rover body, including portions of the solar array, Pancam and Mini-TES calibration targets, and the magnets. This data set reveals...... the three "cleaning events" experienced by Spirit to date, the spectral properties of dust, and the tendency of dust particles to form aggregates 100 um and larger...

Ion-assisted functional monolayer coating of nanorod arrays in hydrogen plasmas

International Nuclear Information System (INIS)

Tam, E.; Levchenko, I.; Ostrikov, K.; Keidar, M.; Xu, S.

2007-01-01

Uniformity of postprocessing of large-area, dense nanostructure arrays is currently one of the greatest challenges in nanoscience and nanofabrication. One of the major issues is to achieve a high level of control in specie fluxes to specific surface areas of the nanostructures. As suggested by the numerical experiments in this work, this goal can be achieved by manipulating microscopic ion fluxes by varying the plasma sheath and nanorod array parameters. The dynamics of ion-assisted deposition of functional monolayer coatings onto two-dimensional carbon nanorod arrays in a hydrogen plasma is simulated by using a multiscale hybrid numerical simulation. The numerical results show evidence of a strong correlation between the aspect ratios and nanopattern positioning of the nanorods, plasma sheath width, and densities and distributions of microscopic ion fluxes. When the spacing between the nanorods and/or their aspect ratios are larger, and/or the plasma sheath is wider, the density of microscopic ion current flowing to each of the individual nanorods increases, thus reducing the time required to apply a functional monolayer coating down to 11 s for a 7-μm-wide sheath, and to 5 s for a 50-μm-wide sheath. The computed monolayer coating development time is consistent with previous experimental reports on plasma-assisted functionalization of related carbon nanostructures [B. N. Khare et al., Appl. Phys. Lett. 81, 5237 (2002)]. The results are generic in that they can be applied to a broader range of plasma-based processes and nanostructures, and contribute to the development of deterministic strategies of postprocessing and functionalization of various nanoarrays for nanoelectronic, biomedical, and other emerging applications

The Advanced Gamma-ray Imaging System (AGIS): Real Time Stereoscopic Array Trigger

Science.gov (United States)

Byrum, K.; Anderson, J.; Buckley, J.; Cundiff, T.; Dawson, J.; Drake, G.; Duke, C.; Haberichter, B.; Krawzcynski, H.; Krennrich, F.; Madhavan, A.; Schroedter, M.; Smith, A.

2009-05-01

Future large arrays of Imaging Atmospheric Cherenkov telescopes (IACTs) such as AGIS and CTA are conceived to comprise of 50 - 100 individual telescopes each having a camera with 10**3 to 10**4 pixels. To maximize the capabilities of such IACT arrays with a low energy threshold, a wide field of view and a low background rate, a sophisticated array trigger is required. We describe the design of a stereoscopic array trigger that calculates image parameters and then correlates them across a subset of telescopes. Fast Field Programmable Gate Array technology allows to use lookup tables at the array trigger level to form a real-time pattern recognition trigger tht capitalizes on the multiple view points of the shower at different shower core distances. A proof of principle system is currently under construction. It is based on 400 MHz FPGAs and the goal is for camera trigger rates of up to 10 MHz and a tunable cosmic-ray background suppression at the array level.

Characterization of electron microscopes with binary pseudo-random multilayer test samples

Science.gov (United States)

Yashchuk, Valeriy V.; Conley, Raymond; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; McKinney, Wayne R.; Takacs, Peter Z.; Voronov, Dmitriy L.

2011-09-01

Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested [1,2] and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [5]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi 2/Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.

Characterization of electron microscopes with binary pseudo-random multilayer test samples

International Nuclear Information System (INIS)

Yashchuk, Valeriy V.; Conley, Raymond; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; McKinney, Wayne R.; Takacs, Peter Z.; Voronov, Dmitriy L.

2011-01-01

Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [5]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi 2 /Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.

Design of a neutron penumbral-aperture microscope with 10-μm resolution

International Nuclear Information System (INIS)

Ress, D.; Lerche, R.A.; Ellis, R.J.; Lane, S.M.

1990-05-01

We are currently designing a 10-μm resolution neutron penumbral-aperture microscope to diagnose high-convergence targets at the Nova laser facility. To achieve such high resolution, the new microscope will require substantial improvements in three areas. First, we have designed thick penumbral apertures with extremely sharp cutoffs over a useful (∼100 μm) field of view; fabrication of such apertures appears feasible using gold electroplating techniques. Second, the limited field of view and required close proximity of the aperture to the target (2 cm) necessitates a durable mounting and alignment system with +25 μm accuracy. Finally, a neutron detector containing 160,000 scintillator elements is required; readout and optimization of this large array are outstanding issues. 5 refs., 3 figs

The Advanced Gamma-ray Imaging System (AGIS): Topological Array Trigger

Science.gov (United States)

Smith, Andrew W.

2010-03-01

AGIS is a concept for the next-generation ground-based gamma-ray observatory. It will be an array of 36 imaging atmospheric Cherenkov telescopes (IACTs) sensitive in the energy range from 50 GeV to 200 TeV. The required improvements in sensitivity, angular resolution, and reliability of operation relative to the present generation instruments imposes demanding technological and cost requirements on the design of the telescopes and on the triggering and readout systems for AGIS. To maximize the capabilities of large arrays of IACTs with a low energy threshold, a wide field of view and a low background rate, a sophisticated array trigger is required. We outline the status of the development of a stereoscopic array trigger that calculates image parameters and correlates them across a subset of telescopes. Field Programmable Gate Arrays (FPGAs) implement the real-time pattern recognition to suppress cosmic rays and night-sky background events. A proof of principle system is being developed to run at camera trigger rates up to 10MHz and array-level rates up to 10kHz.

Binary pseudo-random patterned structures for modulation transfer function calibration and resolution characterization of a full-field transmission soft x-ray microscope

Energy Technology Data Exchange (ETDEWEB)

Yashchuk, V. V., E-mail: VVYashchuk@lbl.gov; Chan, E. R.; Lacey, I. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fischer, P. J. [Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, University of California Santa Cruz, Santa Cruz, California 94056 (United States); Conley, R. [Advance Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973 (United States); McKinney, W. R. [Diablo Valley College, 321 Golf Club Road, Pleasant Hill, California 94523 (United States); Artemiev, N. A. [KLA-Tencor Corp., 1 Technology Drive, Milpitas, California 95035 (United States); Bouet, N. [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973 (United States); Cabrini, S. [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Calafiore, G.; Peroz, C.; Babin, S. [aBeam Technologies, Inc., Hayward, California 94541 (United States)

2015-12-15

We present a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) one-dimensional sequences and two-dimensional arrays as an effective method for spectral characterization in the spatial frequency domain of a broad variety of metrology instrumentation, including interferometric microscopes, scatterometers, phase shifting Fizeau interferometers, scanning and transmission electron microscopes, and at this time, x-ray microscopes. The inherent power spectral density of BPR gratings and arrays, which has a deterministic white-noise-like character, allows a direct determination of the MTF with a uniform sensitivity over the entire spatial frequency range and field of view of an instrument. We demonstrate the MTF calibration and resolution characterization over the full field of a transmission soft x-ray microscope using a BPR multilayer (ML) test sample with 2.8 nm fundamental layer thickness. We show that beyond providing a direct measurement of the microscope’s MTF, tests with the BPRML sample can be used to fine tune the instrument’s focal distance. Our results confirm the universality of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters.

Binary pseudo-random patterned structures for modulation transfer function calibration and resolution characterization of a full-field transmission soft x-ray microscope

International Nuclear Information System (INIS)

Yashchuk, V. V.; Chan, E. R.; Lacey, I.; Fischer, P. J.; Conley, R.; McKinney, W. R.; Artemiev, N. A.; Bouet, N.; Cabrini, S.; Calafiore, G.; Peroz, C.; Babin, S.

2015-01-01

We present a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) one-dimensional sequences and two-dimensional arrays as an effective method for spectral characterization in the spatial frequency domain of a broad variety of metrology instrumentation, including interferometric microscopes, scatterometers, phase shifting Fizeau interferometers, scanning and transmission electron microscopes, and at this time, x-ray microscopes. The inherent power spectral density of BPR gratings and arrays, which has a deterministic white-noise-like character, allows a direct determination of the MTF with a uniform sensitivity over the entire spatial frequency range and field of view of an instrument. We demonstrate the MTF calibration and resolution characterization over the full field of a transmission soft x-ray microscope using a BPR multilayer (ML) test sample with 2.8 nm fundamental layer thickness. We show that beyond providing a direct measurement of the microscope’s MTF, tests with the BPRML sample can be used to fine tune the instrument’s focal distance. Our results confirm the universality of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters

Javascript Library for Developing Interactive Micro-Level Animations for Teaching and Learning Algorithms on One-Dimensional Arrays

Science.gov (United States)

Végh, Ladislav

2016-01-01

The first data structure that first-year undergraduate students learn during the programming and algorithms courses is the one-dimensional array. For novice programmers, it might be hard to understand different algorithms on arrays (e.g. searching, mirroring, sorting algorithms), because the algorithms dynamically change the values of elements. In…

AECL research programmes in materials science

International Nuclear Information System (INIS)

Cox, B.; Eastwood, T.A.; Mitchell, I.V.; Dutton, R.

1980-10-01

The high capacity factors achieved by CANDU nuclear power reactors can be attributed in part to the careful attention which has been paid in the concept and design phases to the selection of materials. Improved tolerance of these materials to the hostile conditions of a reactor core depends upon our understanding of such phenomena as radiation damage, corrosion and cracking. This report is an introduction to some of the fundamental and underlying research programmes that have evolved at the AECL laboratories in response to this need. The interactions of energetic atomic particles with solids on a microscopic scale are considered, first under the general heading of radiation effects, followed by sections on energy loss processes, ion channeling, and crystal lattice defects. The latter section leads into the important programmes on deformation processes (creep and growth) in zirconium. The final section discusses the extensive work on the oxidation and environmental cracking of zirconium alloys. (auth)

Nanoscale coupling of photons to vibrational excitation of Ag nanoparticle 2D array studied by scanning tunneling microscope light emission spectroscopy.

Science.gov (United States)

Katano, Satoshi; Toma, Koji; Toma, Mana; Tamada, Kaoru; Uehara, Yoichi

2010-11-28

Scanning tunneling microscope light emission (STM-LE) spectroscopy has been utilized to elucidate the luminescence phenomena of Ag nanoparticles capped with myristate (myristate-capped AgNP) and 2-methyl-1-propanethiolate (C(4)S-capped AgNP) on the dodecanethiol-precovered Au substrate. The STM imaging revealed that myristate-capped AgNPs form an ordered hexagonal array whereas C(4)S-capped AgNPs show imperfect ordering, indicating that a shorter alkyl chain of C(4)S-capped AgNP is not sufficient to form rigid interdigitation. It should be noted that such a nanoparticle ordering affects the luminescence properties of the Ag nanoparticle. We found that the STM-LE is only detected from the Ag nanoparticles forming the two-dimensional superlattice. This indicates that the STM-LE of the Ag nanoparticle is radiated via the collective excitation of the local surface plasmon resonance (LSPR) spread over the Ag nanoparticles. Note that the STM-LE spectra of the Ag nanoparticles exhibit spike-like peaks superimposed on the broad light emission peak. Using Raman spectroscopy, we concluded that the spike-like structure appearing in the STM-LE spectra is associated with the vibrational excitation of the molecule embedded between Ag nanoparticles.

Soft x-ray microscope using Fourier transform holography

International Nuclear Information System (INIS)

McNulty, I.; Kirz, J.; Jacobsen, C.; Anderson, E.; Howells, M.R.; Rarback, H.

1989-01-01

A Fourier transform holographic microscope with an anticipated resolution of better than 100 nm has been built. Extensive testing of the apparatus has begun. Preliminary results include the recording of interference fringes using 3.6 nm x-rays. The microscope employs a charge-coupled device (CCD) detector array of 576 x 384 elements. The system is illuminated by soft x-rays from a high brightness undulator. The reference point source is formed by a Fresnel zone plate with a finest outer zone width of 50 nm. Sufficient temporal coherence for hologram formation is obtained by a spherical grating monochromator. The x-ray hologram intensities at the recording plane are to be collected, digitized and reconstructed by computer. Data acquisition is under CAMAC control, while image display and off-line processing takes place on a VAX graphics workstation. Computational models of Fourier transform hologram synthesis, and reconstruction in the presence of noise, have demonstrated the feasibility of numerical methods in two dimensions, and that three-dimensional information is potentially recoverable. 13 refs., 3 figs

Digitally programmable microfluidic automaton for multiscale combinatorial mixing and sample processing†

Science.gov (United States)

Jensen, Erik C.; Stockton, Amanda M.; Chiesl, Thomas N.; Kim, Jungkyu; Bera, Abhisek; Mathies, Richard A.

2013-01-01

A digitally programmable microfluidic Automaton consisting of a 2-dimensional array of pneumatically actuated microvalves is programmed to perform new multiscale mixing and sample processing operations. Large (µL-scale) volume processing operations are enabled by precise metering of multiple reagents within individual nL-scale valves followed by serial repetitive transfer to programmed locations in the array. A novel process exploiting new combining valve concepts is developed for continuous rapid and complete mixing of reagents in less than 800 ms. Mixing, transfer, storage, and rinsing operations are implemented combinatorially to achieve complex assay automation protocols. The practical utility of this technology is demonstrated by performing automated serial dilution for quantitative analysis as well as the first demonstration of on-chip fluorescent derivatization of biomarker targets (carboxylic acids) for microchip capillary electrophoresis on the Mars Organic Analyzer. A language is developed to describe how unit operations are combined to form a microfluidic program. Finally, this technology is used to develop a novel microfluidic 6-sample processor for combinatorial mixing of large sets (>26 unique combinations) of reagents. The digitally programmable microfluidic Automaton is a versatile programmable sample processor for a wide range of process volumes, for multiple samples, and for different types of analyses. PMID:23172232

Transmission positron microscopes

International Nuclear Information System (INIS)

Doyama, Masao; Kogure, Yoshiaki; Inoue, Miyoshi; Kurihara, Toshikazu; Yoshiie, Toshimasa; Oshima, Ryuichiro; Matsuya, Miyuki

2006-01-01

Immediate and near-future plans for transmission positron microscopes being built at KEK, Tsukuba, Japan, are described. The characteristic feature of this project is remolding a commercial electron microscope to a positron microscope. A point source of electrons kept at a negative high voltage is changed to a point source of positrons kept at a high positive voltage. Positional resolution of transmission microscopes should be theoretically the same as electron microscopes. Positron microscopes utilizing trapping of positrons have always positional ambiguity due to the diffusion of positrons

A FPGA-based signal processing unit for a GEM array detector

International Nuclear Information System (INIS)

Yen, W.W.; Chou, H.P.

2013-06-01

in the present study, a signal processing unit for a GEM one-dimensional array detector is presented to measure the trajectory of photoelectrons produced by cosmic X-rays. The present GEM array detector system has 16 signal channels. The front-end unit provides timing signals from trigger units and energy signals from charge sensitive amplifies. The prototype of the processing unit is implemented using commercial field programmable gate array circuit boards. The FPGA based system is linked to a personal computer for testing and data analysis. Tests using simulated signals indicated that the FPGA-based signal processing unit has a good linearity and is flexible for parameter adjustment for various experimental conditions (authors)

Anodic Fabrication of Ti-Ni-O Nanotube Arrays on Shape Memory Alloy

Directory of Open Access Journals (Sweden)

Qiang Liu

2014-04-01

Full Text Available Surface modification with oxide nanostructures is one of the efficient ways to improve physical or biomedical properties of shape memory alloys. This work reports a fabrication of highly ordered Ti-Ni-O nanotube arrays on Ti-Ni alloy substrates through pulse anodization in glycerol-based electrolytes. The effects of anodization parameters and the annealing process on the microstructures and surface morphology of Ti-Ni-O were studied using scanning electron microscope and Raman spectroscopy. The electrolyte type greatly affected the formation of nanotube arrays. A formation of anatase phase was found with the Ti-Ni-O nanotube arrays annealed at 450 °C. The oxide nanotubes could be crystallized to rutile phase after annealing treatment at 650 °C. The Ti-Ni-O nanotube arrays demonstrated an excellent thermal stability by keeping their nanotubular structures up to 650 °C.

High-speed multi-frame dynamic transmission electron microscope image acquisition system with arbitrary timing

Science.gov (United States)

Reed, Bryan W.; DeHope, William J.; Huete, Glenn; LaGrange, Thomas B.; Shuttlesworth, Richard M.

2016-02-23

An electron microscope is disclosed which has a laser-driven photocathode and an arbitrary waveform generator (AWG) laser system ("laser"). The laser produces a train of temporally-shaped laser pulses each being of a programmable pulse duration, and directs the laser pulses to the laser-driven photocathode to produce a train of electron pulses. An image sensor is used along with a deflector subsystem. The deflector subsystem is arranged downstream of the target but upstream of the image sensor, and has a plurality of plates. A control system having a digital sequencer controls the laser and a plurality of switching components, synchronized with the laser, to independently control excitation of each one of the deflector plates. This allows each electron pulse to be directed to a different portion of the image sensor, as well as to enable programmable pulse durations and programmable inter-pulse spacings.

Programmable trigger for electron pairs in ring image Cherenkov counters

International Nuclear Information System (INIS)

Glab, J.; Baur, R.; Manner, R.

1990-01-01

This paper describes a programmable trigger processor for the recognition of Cherenkov rings in a RICH counter. It identifies open electron pairs and suppresses close conversion and Dalitz pairs within 20 μs. More generally, the system can be used for correlating pixel images with pattern masks in order to locate all relatively well defined patterns of a certain type. The trigger processor consists of a systolic processor array of 160 x 176, i.e., 28,160 identical processing elements (PEs) that filter out open electron pairs, and a pseudo adder array that determines whether there was at least one such pair. The processor array is assembled of 20 x 22 VLSI chips containing 8 x 8 PEs each. The semi-custom chip has been developed in 2 μ CMOS standard cell technology

A 45 ps time digitizer with a two-phase clock and dual-edge two-stage interpolation in a field programmable gate array device

Science.gov (United States)

Szplet, R.; Kalisz, J.; Jachna, Z.

2009-02-01

We present a time digitizer having 45 ps resolution, integrated in a field programmable gate array (FPGA) device. The time interval measurement is based on the two-stage interpolation method. A dual-edge two-phase interpolator is driven by the on-chip synthesized 250 MHz clock with precise phase adjustment. An improved dual-edge double synchronizer was developed to control the main counter. The nonlinearity of the digitizer's transfer characteristic is identified and utilized by the dedicated hardware code processor for the on-the-fly correction of the output data. Application of presented ideas has resulted in the measurement uncertainty of the digitizer below 70 ps RMS over the time interval ranging from 0 to 1 s. The use of the two-stage interpolation and a fast FIFO memory has allowed us to obtain the maximum measurement rate of five million measurements per second.

A 45 ps time digitizer with a two-phase clock and dual-edge two-stage interpolation in a field programmable gate array device

International Nuclear Information System (INIS)

Szplet, R; Kalisz, J; Jachna, Z

2009-01-01

We present a time digitizer having 45 ps resolution, integrated in a field programmable gate array (FPGA) device. The time interval measurement is based on the two-stage interpolation method. A dual-edge two-phase interpolator is driven by the on-chip synthesized 250 MHz clock with precise phase adjustment. An improved dual-edge double synchronizer was developed to control the main counter. The nonlinearity of the digitizer's transfer characteristic is identified and utilized by the dedicated hardware code processor for the on-the-fly correction of the output data. Application of presented ideas has resulted in the measurement uncertainty of the digitizer below 70 ps RMS over the time interval ranging from 0 to 1 s. The use of the two-stage interpolation and a fast FIFO memory has allowed us to obtain the maximum measurement rate of five million measurements per second

Digitally Programmable High-Q Voltage Mode Universal Filter

Directory of Open Access Journals (Sweden)

D. Singh

2013-12-01

Full Text Available A new low-voltage low-power CMOS current feedback amplifier (CFA is presented in this paper. This is used to realize a novel digitally programmable CFA (DPCFA using transistor arrays and MOS switches. The proposed realizations nearly allow rail-to-rail swing capability at all the ports. Class-AB output stage ensures low power dissipation and high current drive capability. The proposed CFA/ DPCFA operates at supply voltage of ±0.75 V and exhibits bandwidth better than 95 MHz. An application of the DPCFA to realize a novel voltage mode high-Q digitally programmable universal filter (UF is given. Performances of all the proposed circuits are verified by PSPICE simulation using TSMC 0.25μm technology parameters.

Virtual vitreoretinal surgery: validation of a training programme.

Science.gov (United States)

Vergmann, Anna Stage; Vestergaard, Anders Højslet; Grauslund, Jakob

2017-02-01

To test the validity of the eyesi surgical simulator as an assessment tool in a virtual reality vitreoretinal training programme. In collaboration with an experienced vitreoretinal surgeon, a virtual vitreoretinal training programme was composed on the eyesi surgical simulator, software version 2.9.2 (VRmagic GmbH, Manheim, Germany). It was completed twice by three groups: 20 medical students, ten residents of ophthalmology and five trained vitreoretinal surgeons. The programme contained six training modules: navigation level 2 (Nav2), forceps training level 5 (ForT5), bimanual training level 3 (BimT3), laser coagulation level 3 (LasC3), posterior hyaloid level 3 (PostH3) and internal limiting membrane peeling level 3 (ILMP3). The scores in each module were assessed from two to five different factors (tissue treatment, efficiency, target achievement, instrument handling and microscope handling), and it was possible to achieve 100 points in each module. At the final training session, the highest overall median score was found for the vitreoretinal surgeons (vitreoretinal surgeons: 434 points, residents: 394.5 points, medical students: 272.5 points, p training programme with validity for the eyesi surgical simulator as an assessment tool for overall score and for four of six vitreoretinal modules. These findings could potentially make the programme a useful tool in the training of future vitreoretinal surgeons. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

A synchronous serial bus for multidimensional array acoustic logging tool

Science.gov (United States)

Men, Baiyong; Ju, Xiaodong; Lu, Junqiang; Qiao, Wenxiao

2016-12-01

In high-temperature and spatial borehole applications, a distributed structure is employed in a multidimensional array acoustic logging tool (MDALT) based on a phased array technique for electronic systems. However, new challenges, such as synchronous multichannel data acquisition, multinode real-time control and bulk data transmission in a limited interval, have emerged. To address these challenges, we developed a synchronous serial bus (SSB) in this study. SSB works in a half-duplex mode via a master-slave architecture. It also consists of a single master, several slaves, a differential clock line and a differential data line. The clock line is simplex, whereas the data line is half-duplex and synchronous to the clock line. A reliable communication between the master and the slaves with real-time adjustment of synchronisation is achieved by rationally designing the frame format and protocol of communication and by introducing a scramble code and a Hamming error-correcting code. The control logic of the master and the slaves is realized in field programmable gate array (FPGA) or complex programmable logic device (CPLD). The clock speed of SSB is 10 MHz, the effective data rate of the bulk data transmission is over 99%, and the synchronous errors amongst the slaves are less than 10 ns. Room-temperature test, high-temperature test (175 °C) and field test demonstrate that the proposed SSB is qualified for MDALT.

EUROGAM: A high efficiency escape suppressed spectrometer array

Energy Technology Data Exchange (ETDEWEB)

Nolan, P J [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.

1992-08-01

EUROGAM is a UK-France collaboration to develop and build a high efficiency escape suppressed spectrometer array. The project has involved the development of both germanium (Ge) and bismuth germanate (BGO) detectors to produce crystals which are both bigger and have a more complex geometry. As a major investment for the future, the collaboration has developed a new electronics and data acquisition system based on the VXI and VME standards. The array will start its experimental programme in mid 1992 at the Nuclear Structure Facility at Daresbury, U.K. At this stage it will have a total photopeak efficiency (for 1.33 MeV gamma-rays) of {approx} 4.5%. This will give an improvement in sensitivity (relative to presently operating arrays) of a factor of about 10. When EUROGAM moves to France in mid 1993 its photopeak efficiency will have increased to about 8.5% which will result in an increase in sensitivity of a further factor of about 10. In this article I will concentrate on the array which will operate at Daresbury in 1992 and only briefly cover the developments which will take place for the full array before it is used in France in 1993. (author). 13 refs., 2 tabs., 10 figs.

EUROGAM: A high efficiency escape suppressed spectrometer array

International Nuclear Information System (INIS)

Nolan, P.J.

1992-01-01

EUROGAM is a UK-France collaboration to develop and build a high efficiency escape suppressed spectrometer array. The project has involved the development of both germanium (Ge) and bismuth germanate (BGO) detectors to produce crystals which are both bigger and have a more complex geometry. As a major investment for the future, the collaboration has developed a new electronics and data acquisition system based on the VXI and VME standards. The array will start its experimental programme in mid 1992 at the Nuclear Structure Facility at Daresbury, U.K. At this stage it will have a total photopeak efficiency (for 1.33 MeV gamma-rays) of ∼ 4.5%. This will give an improvement in sensitivity (relative to presently operating arrays) of a factor of about 10. When EUROGAM moves to France in mid 1993 its photopeak efficiency will have increased to about 8.5% which will result in an increase in sensitivity of a further factor of about 10. In this article I will concentrate on the array which will operate at Daresbury in 1992 and only briefly cover the developments which will take place for the full array before it is used in France in 1993. (author). 13 refs., 2 tabs., 10 figs

The Fermilab Advanced Computer Program multi-array processor system (ACPMAPS): A site oriented supercomputer for theoretical physics

International Nuclear Information System (INIS)

Nash, T.; Areti, H.; Atac, R.

1988-08-01

The ACP Multi-Array Processor System (ACPMAPS) is a highly cost effective, local memory parallel computer designed for floating point intensive grid based problems. The processing nodes of the system are single board array processors based on the FORTRAN and C programmable Weitek XL chip set. The nodes are connected by a network of very high bandwidth 16 port crossbar switches. The architecture is designed to achieve the highest possible cost effectiveness while maintaining a high level of programmability. The primary application of the machine at Fermilab will be lattice gauge theory. The hardware is supported by a transparent site oriented software system called CANOPY which shields theorist users from the underlying node structure. 4 refs., 2 figs

Field programmable gate array based hardware implementation of a gradient filter for edge detection in colour images with subpixel precision

International Nuclear Information System (INIS)

Schellhorn, M; Rosenberger, M; Correns, M; Blau, M; Goepfert, A; Rueckwardt, M; Linss, G

2010-01-01

Within the field of industrial image processing the use of colour cameras becomes ever more common. Increasingly the established black and white cameras are replaced by economical single-chip colour cameras with Bayer pattern. The use of the additional colour information is particularly important for recognition or inspection. Become interesting however also for the geometric metrology, if measuring tasks can be solved more robust or more exactly. However only few suitable algorithms are available, in order to detect edges with the necessary precision. All attempts require however additional computation expenditure. On the basis of a new filter for edge detection in colour images with subpixel precision, the implementation on a pre-processing hardware platform is presented. Hardware implemented filters offer the advantage that they can be used easily with existing measuring software, since after the filtering a single channel image is present, which unites the information of all colour channels. Advanced field programmable gate arrays represent an ideal platform for the parallel processing of multiple channels. The effective implementation presupposes however a high programming expenditure. On the example of the colour filter implementation, arising problems are analyzed and the chosen solution method is presented.

Magnetomicrofluidics Circuits for Organizing Bioparticle Arrays

Science.gov (United States)

Abedini-Nassab, Roozbeh

Single-cell analysis (SCA) tools have important applications in the analysis of phenotypic heterogeneity, which is difficult or impossible to analyze in bulk cell culture or patient samples. SCA tools thus have a myriad of applications ranging from better credentialing of drug therapies to the analysis of rare latent cells harboring HIV infection or in Cancer. However, existing SCA systems usually lack the required combination of programmability, flexibility, and scalability necessary to enable the study of cell behaviors and cell-cell interactions at the scales sufficient to analyze extremely rare events. To advance the field, I have developed a novel, programmable, and massively-parallel SCA tool which is based on the principles of computer circuits. By integrating these magnetic circuits with microfluidics channels, I developed a platform that can organize a large number of single particles into an array in a controlled manner. My magnetophoretic circuits use passive elements constructed in patterned magnetic thin films to move cells along programmed tracks with an external rotating magnetic field. Cell motion along these tracks is analogous to the motion of charges in an electrical conductor, following a rule similar to Ohm's law. I have also developed asymmetric conductors, similar to electrical diodes, and storage sites for cells that behave similarly to electrical capacitors. I have also developed magnetophoretic circuits which use an overlaid pattern of microwires to switch single cells between different tracks. This switching mechanism, analogous to the operation of electronic transistors, is achieved by establishing a semiconducting gap in the magnetic pattern which can be changed from an insulating state to a conducting state by application of electrical current to an overlaid electrode. I performed an extensive study on the operation of transistors to optimize their geometry and minimize the required gate currents. By combining these elements into

Dynamic Phases in Driven Vortex Lattices in Superconductors with Periodic Pinning Arrays.

Science.gov (United States)

Reichhardt, C.; Olson, C. J.; Nori, F.

1997-03-01

In an extensive series of simulations of driven vortices interacting with periodic pinning arrays, an extremely rich variety of novel plastic flow phases, very distinct from those observed in random arrays, are found as a function of applied driving force. We show that signatures of the transitions between these different dynamical phases appear as pronounced jumps and dips in the I-V curves, coinciding with marked changes in the microscopic structure and flow behavior of the vortex lattice. When the number of vortices is greater than the number of pinning sites, we observe up to six distinct dynamical phases, including a pinned phase, a flow of interstitial vortices between pinned vortices, a disordered flow, a 1D flow along the pinning rows, and a homogeneous flow. By varying a wide range of microscopic pinning parameters, including pinning strength, size, density, and degree of ordering, as well as varying temperature and commensurability, we obtain a series of dynamic phase diagrams. nori>A short video will also be presented to highlight these different dynamic phases.

Field application of smart SHM using field programmable gate array technology to monitor an RC bridge in New Mexico

International Nuclear Information System (INIS)

Azarbayejani, M; Jalalpour, M; Reda Taha, M M; El-Osery, A I

2011-01-01

In this paper, an innovative field application of a structural health monitoring (SHM) system using field programmable gate array (FPGA) technology and wireless communication is presented. The new SHM system was installed to monitor a reinforced concrete (RC) bridge on Interstate 40 (I-40) in Tucumcari, New Mexico. This newly installed system allows continuous remote monitoring of this bridge using solar power. Details of the SHM component design and installation are discussed. The integration of FPGA and solar power technologies make it possible to remotely monitor infrastructure with limited access to power. Furthermore, the use of FPGA technology enables smart monitoring where data communication takes place on-need (when damage warning signs are met) and on-demand for periodic monitoring of the bridge. Such a system enables a significant cut in communication cost and power demands which are two challenges during SHM operation. Finally, a three-dimensional finite element (FE) model of the bridge was developed and calibrated using a static loading field test. This model is then used for simulating damage occurrence on the bridge. Using the proposed automation process for SHM will reduce human intervention significantly and can save millions of dollars currently spent on prescheduled inspection of critical infrastructure worldwide

Field application of smart SHM using field programmable gate array technology to monitor an RC bridge in New Mexico

Science.gov (United States)

Azarbayejani, M.; Jalalpour, M.; El-Osery, A. I.; Reda Taha, M. M.

2011-08-01

In this paper, an innovative field application of a structural health monitoring (SHM) system using field programmable gate array (FPGA) technology and wireless communication is presented. The new SHM system was installed to monitor a reinforced concrete (RC) bridge on Interstate 40 (I-40) in Tucumcari, New Mexico. This newly installed system allows continuous remote monitoring of this bridge using solar power. Details of the SHM component design and installation are discussed. The integration of FPGA and solar power technologies make it possible to remotely monitor infrastructure with limited access to power. Furthermore, the use of FPGA technology enables smart monitoring where data communication takes place on-need (when damage warning signs are met) and on-demand for periodic monitoring of the bridge. Such a system enables a significant cut in communication cost and power demands which are two challenges during SHM operation. Finally, a three-dimensional finite element (FE) model of the bridge was developed and calibrated using a static loading field test. This model is then used for simulating damage occurrence on the bridge. Using the proposed automation process for SHM will reduce human intervention significantly and can save millions of dollars currently spent on prescheduled inspection of critical infrastructure worldwide.

Microscopic and Macroscopic Structures of Carbon Nanotubes Produced by Pyrolysis of Iron Phthalocyanine

International Nuclear Information System (INIS)

Huang Shaoming; Dai Liming

2002-01-01

By pyrolysis of iron phthalocyanine (FePc), either in a patterned or non-patterned fashion, under an Ar/H 2 atmosphere, we have demonstrated the large-scale production of aligned carbon nanotubes perpendicular to the substrate surface useful for building devices with three-dimensional structures. Depending on the particular pyrolytic conditions used, carbon nanotubes with a wide range of microscopic structures having curved, helical, coiled, branched, and tube-within-tube shapes have also been prepared by the pyrolysis of FePc. This, coupled with several microfabrication methods (photolithography, soft-lithography, self-assembling, micro-contact transfer, etc.), has enabled us to produce carbon nanotube arrays of various macroscopic architectures including polyhedral, flower-like, dendritic, circular, multilayered, and micropatterned geometries. In this article, we summarize our work on the preparation of FePc-generated carbon nanotubes with the large variety of microscopic and macroscopic structures and give a brief overview on the perspectives of making carbon nanotubes with tailor-made microscopic/macroscopic structures, and hence well-defined physicochemical properties, for specific applications

Characteristics of N-doped TiO{sub 2} nanotube arrays by N{sub 2}-plasma for visible light-driven photocatalysis

Energy Technology Data Exchange (ETDEWEB)

Liu Xu [College of Chemical Engineering, Sichuan University, Chengdu 610065 (China); Liu Zhongqing, E-mail: 301zql@vip.sina.com [College of Chemical Engineering, Sichuan University, Chengdu 610065 (China); Zheng Jian; Yan Xin; Li Dandan; Chen Si [College of Chemical Engineering, Sichuan University, Chengdu 610065 (China); Chu Wei, E-mail: chuwei1965_scu@yahoo.com [College of Chemical Engineering, Sichuan University, Chengdu 610065 (China)

2011-10-13

Highlights: > A new pathway is provided to prepare N-doped TiO2 nanotube arrays using N{sub 2}-plasma treatment. > N{sub 2}-plasma treatment did not wreck the structure of nanotube arrays. > Nitrogen doping promoted the phase transition to rutile phase at low annealing temperatures > Nitrogen doping narrow band gap of TiO{sub 2} and improve the photocatalytic activity of samples. - Abstract: N-doped TiO{sub 2} nanotube arrays were prepared by electrochemical anode oxidation of Ti foil followed by treatment with N{sub 2}-plasma and subsequent annealed under Ar atmosphere. The morphologies, composition and optical properties of N-doped TiO{sub 2} nanotube arrays were characterized using field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction spectrometer (XRD), Photoluminescence (PL) and UV-vis diffusion reflection spectroscopy (UV-vis DRS). Methylene blue (MB) solution was utilized as the degradation model to evaluate the photocatalytic activity of the samples under visible light irradiation. The results suggested N{sub 2}-plasma treatment created doping of nitrogen onto the surface of photoelectrodes successfully and the N-doped TiO{sub 2} nanotube arrays display a significantly enhancement of the photocatalytic activity comparing with the pure TiO{sub 2} nanotube arrays under the visible light irradiation.

Développement de circuits logiques programmables résistants aux alas logiques en technologie CMOS submicrométrique

CERN Document Server

Bonacini, Sandro; Kloukinas, Kostas

2007-01-01

The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Most of the microelectronics components developed for the first generation of LHC experiments have been designed with very precise experiment-specific goals and are hardly adaptable to other applications. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust programmable components for application in High Energy Physics (HEP) experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 micron CMOS technology. The FPGA under development is instead a 32x32 logic block array, equivalent to ~25k gates, in 0.13 micron CMOS. This wor...

Soft x-ray spectro microscope

International Nuclear Information System (INIS)

Campuzano, J.C.; Jennings, G.; Beaulaigue, L.; Rodricks, B.G.; Brizard, C.

1990-01-01

This paper reports on the development of an x-ray photoelectron microscope that provides spatial as well as chemical information on the nature of the sample. Photons from the Aladdin Synchrotron at the Synchrotron Radiation Center in Stoughton, WI are monochromatized by an extended-range Grasshopper monochromator covering the range 40 to 1500 eV with energy resolution varying between 10 and 200 MeV. The monochromatized radiation generates photoelectrons in the sample, which are energy-analyzed with a resolving power E|ΔE > 5 x 10 4 and imaged by a multichannel plate array. The visible image is transferred to a computer by a virtual-phase charge-coupled device camera with a dynamic range of 4096:1. Preliminary coarse measurements indicate a spatial resolution of the instrument of better than 1μm, although a limit of 600 Angstrom is possible. The instrument provides chemical shift-resolved images of low-lying core levels in a variety of samples

Arraycount, an algorithm for automatic cell counting in microwell arrays

OpenAIRE

Kachouie, Nezamoddin N.; Kang, Lifeng; Khademhosseini, Ali

2009-01-01

Microscale technologies have emerged as a powerful tool for studying and manipulating biological systems and miniaturizing experiments. However, the lack of software complementing these techniques has made it difficult to apply them for many high-throughput experiments. This work establishes Arraycount, an approach to automatically count cells in microwell arrays. The procedure consists of fluorescent microscope imaging of cells that are seeded in microwells of a microarray system and then an...

Design verification enhancement of field programmable gate array-based safety-critical I&C system of nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Ibrahim [Department of Nuclear Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of); Jung, Jaecheon, E-mail: jcjung@kings.ac.kr [Department of Nuclear Power Plant Engineering, KEPCO International Nuclear Graduate School, 658-91 Haemaji-ro, Seosang-myeon, Ulju-gun, Ulsan 45014 (Korea, Republic of); Heo, Gyunyoung [Department of Nuclear Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of)

2017-06-15

Highlights: • An enhanced, systematic and integrated design verification approach is proposed for V&V of FPGA-based I&C system of NPP. • RPS bistable fixed setpoint trip algorithm is designed, analyzed, verified and discussed using the proposed approaches. • The application of integrated verification approach simultaneously verified the entire design modules. • The applicability of the proposed V&V facilitated the design verification processes. - Abstract: Safety-critical instrumentation and control (I&C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. However, safety analysis for FPGA-based I&C systems, and verification and validation (V&V) assessments still remain important issues to be resolved, which are now become a global research point of interests. In this work, we proposed a systematic design and verification strategies from start to ready-to-use in form of model-based approaches for FPGA-based reactor protection system (RPS) that can lead to the enhancement of the design verification and validation processes. The proposed methodology stages are requirement analysis, enhanced functional flow block diagram (EFFBD) models, finite state machine with data path (FSMD) models, hardware description language (HDL) code development, and design verifications. The design verification stage includes unit test – Very high speed integrated circuit Hardware Description Language (VHDL) test and modified condition decision coverage (MC/DC) test, module test – MATLAB/Simulink Co-simulation test, and integration test – FPGA hardware test beds. To prove the adequacy of the proposed

Design verification enhancement of field programmable gate array-based safety-critical I&C system of nuclear power plant

International Nuclear Information System (INIS)

Ahmed, Ibrahim; Jung, Jaecheon; Heo, Gyunyoung

2017-01-01

Highlights: • An enhanced, systematic and integrated design verification approach is proposed for V&V of FPGA-based I&C system of NPP. • RPS bistable fixed setpoint trip algorithm is designed, analyzed, verified and discussed using the proposed approaches. • The application of integrated verification approach simultaneously verified the entire design modules. • The applicability of the proposed V&V facilitated the design verification processes. - Abstract: Safety-critical instrumentation and control (I&C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. However, safety analysis for FPGA-based I&C systems, and verification and validation (V&V) assessments still remain important issues to be resolved, which are now become a global research point of interests. In this work, we proposed a systematic design and verification strategies from start to ready-to-use in form of model-based approaches for FPGA-based reactor protection system (RPS) that can lead to the enhancement of the design verification and validation processes. The proposed methodology stages are requirement analysis, enhanced functional flow block diagram (EFFBD) models, finite state machine with data path (FSMD) models, hardware description language (HDL) code development, and design verifications. The design verification stage includes unit test – Very high speed integrated circuit Hardware Description Language (VHDL) test and modified condition decision coverage (MC/DC) test, module test – MATLAB/Simulink Co-simulation test, and integration test – FPGA hardware test beds. To prove the adequacy of the proposed

Optical simulation of quantum algorithms using programmable liquid-crystal displays

International Nuclear Information System (INIS)

Puentes, Graciana; La Mela, Cecilia; Ledesma, Silvia; Iemmi, Claudio; Paz, Juan Pablo; Saraceno, Marcos

2004-01-01

We present a scheme to perform an all optical simulation of quantum algorithms and maps. The main components are lenses to efficiently implement the Fourier transform and programmable liquid-crystal displays to introduce space dependent phase changes on a classical optical beam. We show how to simulate Deutsch-Jozsa and Grover's quantum algorithms using essentially the same optical array programmed in two different ways

An integrated circuit with transmit beamforming flip-chip bonded to a 2-D CMUT array for 3-D ultrasound imaging.

Science.gov (United States)

Wygant, Ira O; Jamal, Nafis S; Lee, Hyunjoo J; Nikoozadeh, Amin; Oralkan, Omer; Karaman, Mustafa; Khuri-Yakub, Butrus T

2009-10-01

State-of-the-art 3-D medical ultrasound imaging requires transmitting and receiving ultrasound using a 2-D array of ultrasound transducers with hundreds or thousands of elements. A tight combination of the transducer array with integrated circuitry eliminates bulky cables connecting the elements of the transducer array to a separate system of electronics. Furthermore, preamplifiers located close to the array can lead to improved receive sensitivity. A combined IC and transducer array can lead to a portable, high-performance, and inexpensive 3-D ultrasound imaging system. This paper presents an IC flip-chip bonded to a 16 x 16-element capacitive micromachined ultrasonic transducer (CMUT) array for 3-D ultrasound imaging. The IC includes a transmit beamformer that generates 25-V unipolar pulses with programmable focusing delays to 224 of the 256 transducer elements. One-shot circuits allow adjustment of the pulse widths for different ultrasound transducer center frequencies. For receiving reflected ultrasound signals, the IC uses the 32-elements along the array diagonals. The IC provides each receiving element with a low-noise 25-MHz-bandwidth transimpedance amplifier. Using a field-programmable gate array (FPGA) clocked at 100 MHz to operate the IC, the IC generated properly timed transmit pulses with 5-ns accuracy. With the IC flip-chip bonded to a CMUT array, we show that the IC can produce steered and focused ultrasound beams. We present 2-D and 3-D images of a wire phantom and 2-D orthogonal cross-sectional images (Bscans) of a latex heart phantom.

Integrated Miniature Arrays of Optical Biomolecule Detectors

Science.gov (United States)

Iltchenko, Vladimir; Maleki, Lute; Lin, Ying; Le, Thanh

2009-01-01

Integrated miniature planar arrays of optical sensors for detecting specific biochemicals in extremely small quantities have been proposed. An array of this type would have an area of about 1 cm2. Each element of the array would include an optical microresonator that would have a high value of the resonance quality factor (Q . 107). The surface of each microresonator would be derivatized to make it bind molecules of a species of interest, and such binding would introduce a measurable change in the optical properties of the microresonator. Because each microresonator could be derivatized for detection of a specific biochemical different from those of the other microresonators, it would be possible to detect multiple specific biochemicals by simultaneous or sequential interrogation of all the elements in the array. Moreover, the derivatization would make it unnecessary to prepare samples by chemical tagging. Such interrogation would be effected by means of a grid of row and column polymer-based optical waveguides that would be integral parts of a chip on which the array would be fabricated. The row and column polymer-based optical waveguides would intersect at the elements of the array (see figure). At each intersection, the row and column waveguides would be optically coupled to one of the microresonators. The polymer-based waveguides would be connected via optical fibers to external light sources and photodetectors. One set of waveguides and fibers (e.g., the row waveguides and fibers) would couple light from the sources to the resonators; the other set of waveguides and fibers (e.g., the column waveguides and fibers) would couple light from the microresonators to the photodetectors. Each microresonator could be addressed individually by row and column for measurement of its optical transmission. Optionally, the chip could be fabricated so that each microresonator would lie inside a microwell, into which a microscopic liquid sample could be dispensed.

A Complementary Resistive Switch-based Crossbar Array Adder

OpenAIRE

Siemon, A.; Menzel, S.; Waser, R.; Linn, E.

2014-01-01

Redox-based resistive switching devices (ReRAM) are an emerging class of non-volatile storage elements suited for nanoscale memory applications. In terms of logic operations, ReRAM devices were suggested to be used as programmable interconnects, large-scale look-up tables or for sequential logic operations. However, without additional selector devices these approaches are not suited for use in large scale nanocrossbar memory arrays, which is the preferred architecture for ReRAM devices due to...

Dependable Design Flow for Protection Systems using Programmable Logic Devices

CERN Document Server

Kwiatkowski, M

2011-01-01

Programmable Logic Devices (PLD) such as Field Programmable Gate Arrays (FPGA) are becoming more prevalent in protection and safety-related electronic systems. When employing such programmable logic devices, extra care and attention needs to be taken. The final synthesis result, used to generate the bit-stream to program the device, must be shown to meet the design’s requirements. This paper describes how to maximize confidence using techniques such as Formal Methods, exhaustive Hardware Description Language (HDL) code simulation and hardware testing. An example is given for one of the critical functions of the Safe Machine Parameters (SMP) system, used in the protection of the Large Hadron Collider (LHC) at CERN. CERN is also working towards an adaptation of the IEC- 61508 lifecycle designed for Machine Protection Systems (MPS), and the High Energy Physics environment, implementation of a protection function in FPGA code is only one small step of this lifecycle. The ultimate aim of this project is to cre...

Integrated strain array for cellular mechanobiology studies

International Nuclear Information System (INIS)

Simmons, C S; Sim, J Y; Baechtold, P; Chung, C; Borghi, N; Pruitt, B L; Gonzalez, A

2011-01-01

We have developed an integrated strain array for cell culture enabling high-throughput mechano-transduction studies. Biocompatible cell culture chambers were integrated with an acrylic pneumatic compartment and microprocessor-based control system. Each element of the array consists of a deformable membrane supported by a cylindrical pillar within a well. For user-prescribed waveforms, the annular region of the deformable membrane is pulled into the well around the pillar under vacuum, causing the pillar-supported region with cultured cells to be stretched biaxially. The optically clear device and pillar-based mechanism of operation enables imaging on standard laboratory microscopes. Straightforward fabrication utilizes off-the-shelf components, soft lithography techniques in polydimethylsiloxane and laser ablation of acrylic sheets. Proof of compatibility with basic biological assays and standard imaging equipment were accomplished by straining C2C12 skeletal myoblasts on the device for 6 h. At higher strains, cells and actin stress fibers realign with a circumferential preference

Universal programmable quantum circuit schemes to emulate an operator

Energy Technology Data Exchange (ETDEWEB)

Daskin, Anmer; Grama, Ananth; Kollias, Giorgos [Department of Computer Science, Purdue University, West Lafayette, Indiana 47907 (United States); Kais, Sabre [Department of Chemistry, Department of Physics and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Qatar Environment and Energy Research Institute, Doha (Qatar)

2012-12-21

Unlike fixed designs, programmable circuit designs support an infinite number of operators. The functionality of a programmable circuit can be altered by simply changing the angle values of the rotation gates in the circuit. Here, we present a new quantum circuit design technique resulting in two general programmable circuit schemes. The circuit schemes can be used to simulate any given operator by setting the angle values in the circuit. This provides a fixed circuit design whose angles are determined from the elements of the given matrix-which can be non-unitary-in an efficient way. We also give both the classical and quantum complexity analysis for these circuits and show that the circuits require a few classical computations. For the electronic structure simulation on a quantum computer, one has to perform the following steps: prepare the initial wave function of the system; present the evolution operator U=e{sup -iHt} for a given atomic and molecular Hamiltonian H in terms of quantum gates array and apply the phase estimation algorithm to find the energy eigenvalues. Thus, in the circuit model of quantum computing for quantum chemistry, a crucial step is presenting the evolution operator for the atomic and molecular Hamiltonians in terms of quantum gate arrays. Since the presented circuit designs are independent from the matrix decomposition techniques and the global optimization processes used to find quantum circuits for a given operator, high accuracy simulations can be done for the unitary propagators of molecular Hamiltonians on quantum computers. As an example, we show how to build the circuit design for the hydrogen molecule.

Universal programmable quantum circuit schemes to emulate an operator

International Nuclear Information System (INIS)

Daskin, Anmer; Grama, Ananth; Kollias, Giorgos; Kais, Sabre

2012-01-01

Unlike fixed designs, programmable circuit designs support an infinite number of operators. The functionality of a programmable circuit can be altered by simply changing the angle values of the rotation gates in the circuit. Here, we present a new quantum circuit design technique resulting in two general programmable circuit schemes. The circuit schemes can be used to simulate any given operator by setting the angle values in the circuit. This provides a fixed circuit design whose angles are determined from the elements of the given matrix–which can be non-unitary–in an efficient way. We also give both the classical and quantum complexity analysis for these circuits and show that the circuits require a few classical computations. For the electronic structure simulation on a quantum computer, one has to perform the following steps: prepare the initial wave function of the system; present the evolution operator U=e −iHt for a given atomic and molecular Hamiltonian H in terms of quantum gates array and apply the phase estimation algorithm to find the energy eigenvalues. Thus, in the circuit model of quantum computing for quantum chemistry, a crucial step is presenting the evolution operator for the atomic and molecular Hamiltonians in terms of quantum gate arrays. Since the presented circuit designs are independent from the matrix decomposition techniques and the global optimization processes used to find quantum circuits for a given operator, high accuracy simulations can be done for the unitary propagators of molecular Hamiltonians on quantum computers. As an example, we show how to build the circuit design for the hydrogen molecule.

Comparative study of image contrast in scanning electron microscope and helium ion microscope.

Science.gov (United States)

O'Connell, R; Chen, Y; Zhang, H; Zhou, Y; Fox, D; Maguire, P; Wang, J J; Rodenburg, C

2017-12-01

Images of Ga + -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga + density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Graphical Environment Tools for Application to Gamma-Ray Energy Tracking Arrays

Energy Technology Data Exchange (ETDEWEB)

Todd, Richard A. [RIS Corp.; Radford, David C. [ORNL Physics Div.

2013-12-30

Highly segmented, position-sensitive germanium detector systems are being developed for nuclear physics research where traditional electronic signal processing with mixed analog and digital function blocks would be enormously complex and costly. Future systems will be constructed using pipelined processing of high-speed digitized signals as is done in the telecommunications industry. Techniques which provide rapid algorithm and system development for future systems are desirable. This project has used digital signal processing concepts and existing graphical system design tools to develop a set of re-usable modular functions and libraries targeted for the nuclear physics community. Researchers working with complex nuclear detector arrays such as the Gamma-Ray Energy Tracking Array (GRETA) have been able to construct advanced data processing algorithms for implementation in field programmable gate arrays (FPGAs) through application of these library functions using intuitive graphical interfaces.

First test model of the optical microscope which images the whole vertical particle tracks without any depth scanning

International Nuclear Information System (INIS)

Soroko, L.M.

2001-01-01

The first test model of the optical microscope which produces the in focus image of the whole vertical particle track without depth scanning is described. The in focus image of the object consisting of the linear array of the point-like elements was obtained. A comparison with primary out of focus image of such an object has been made

Smart-phone based computational microscopy using multi-frame contact imaging on a fiber-optic array.

Science.gov (United States)

Navruz, Isa; Coskun, Ahmet F; Wong, Justin; Mohammad, Saqib; Tseng, Derek; Nagi, Richie; Phillips, Stephen; Ozcan, Aydogan

2013-10-21

We demonstrate a cellphone based contact microscopy platform, termed Contact Scope, which can image highly dense or connected samples in transmission mode. Weighing approximately 76 grams, this portable and compact microscope is installed on the existing camera unit of a cellphone using an opto-mechanical add-on, where planar samples of interest are placed in contact with the top facet of a tapered fiber-optic array. This glass-based tapered fiber array has ~9 fold higher density of fiber optic cables on its top facet compared to the bottom one and is illuminated by an incoherent light source, e.g., a simple light-emitting-diode (LED). The transmitted light pattern through the object is then sampled by this array of fiber optic cables, delivering a transmission image of the sample onto the other side of the taper, with ~3× magnification in each direction. This magnified image of the object, located at the bottom facet of the fiber array, is then projected onto the CMOS image sensor of the cellphone using two lenses. While keeping the sample and the cellphone camera at a fixed position, the fiber-optic array is then manually rotated with discrete angular increments of e.g., 1-2 degrees. At each angular position of the fiber-optic array, contact images are captured using the cellphone camera, creating a sequence of transmission images for the same sample. These multi-frame images are digitally fused together based on a shift-and-add algorithm through a custom-developed Android application running on the smart-phone, providing the final microscopic image of the sample, visualized through the screen of the phone. This final computation step improves the resolution and also removes spatial artefacts that arise due to non-uniform sampling of the transmission intensity at the fiber optic array surface. We validated the performance of this cellphone based Contact Scope by imaging resolution test charts and blood smears.

Increasing feasibility of the field-programmable gate array implementation of an iterative image registration using a kernel-warping algorithm

Science.gov (United States)

Nguyen, An Hung; Guillemette, Thomas; Lambert, Andrew J.; Pickering, Mark R.; Garratt, Matthew A.

2017-09-01

Image registration is a fundamental image processing technique. It is used to spatially align two or more images that have been captured at different times, from different sensors, or from different viewpoints. There have been many algorithms proposed for this task. The most common of these being the well-known Lucas-Kanade (LK) and Horn-Schunck approaches. However, the main limitation of these approaches is the computational complexity required to implement the large number of iterations necessary for successful alignment of the images. Previously, a multi-pass image interpolation algorithm (MP-I2A) was developed to considerably reduce the number of iterations required for successful registration compared with the LK algorithm. This paper develops a kernel-warping algorithm (KWA), a modified version of the MP-I2A, which requires fewer iterations to successfully register two images and less memory space for the field-programmable gate array (FPGA) implementation than the MP-I2A. These reductions increase feasibility of the implementation of the proposed algorithm on FPGAs with very limited memory space and other hardware resources. A two-FPGA system rather than single FPGA system is successfully developed to implement the KWA in order to compensate insufficiency of hardware resources supported by one FPGA, and increase parallel processing ability and scalability of the system.

Highly Uniform Epitaxial ZnO Nanorod Arrays for Nanopiezotronics

Directory of Open Access Journals (Sweden)

Nagata T

2009-01-01

Full Text Available Abstract Highly uniform and c-axis-aligned ZnO nanorod arrays were fabricated in predefined patterns by a low temperature homoepitaxial aqueous chemical method. The nucleation seed patterns were realized in polymer and in metal thin films, resulting in, all-ZnO and bottom-contacted structures, respectively. Both of them show excellent geometrical uniformity: the cross-sectional uniformity according to the scanning electron micrographs across the array is lower than 2%. The diameter of the hexagonal prism-shaped nanorods can be set in the range of 90–170 nm while their typical length achievable is 0.5–2.3 μm. The effect of the surface polarity was also examined, however, no significant difference was found between the arrays grown on Zn-terminated and on O-terminated face of the ZnO single crystal. The transmission electron microscopy observation revealed the single crystalline nature of the nanorods. The current–voltage characteristics taken on an individual nanorod contacted by a Au-coated atomic force microscope tip reflected Schottky-type behavior. The geometrical uniformity, the designable pattern, and the electrical properties make the presented nanorod arrays ideal candidates to be used in ZnO-based DC nanogenerator and in next-generation integrated piezoelectric nano-electromechanical systems (NEMS.

Ferromagnetic resonance investigation in permalloy magnetic antidot arrays on alumina nanoporous membranes

Energy Technology Data Exchange (ETDEWEB)

Rodríguez-Suárez, R.L., E-mail: rrodriguez@fis.puc.cl [Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860 Casilla 306, Santiago (Chile); Palma, J.L.; Burgos, E.O. [Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Michea, S. [Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860 Casilla 306, Santiago (Chile); Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Escrig, J.; Denardin, J.C. [Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Aliaga, C. [Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago (Chile)

2014-01-15

The magnetic properties of Ni{sub 80}Fe{sub 20} antidot arrays with hole diameters of 18 and 70 nm fabricated by a template-assisted method were investigated using the ferromagnetic resonance technique. Tuning the antidot arrays by changing the hole diameter enables control on the angular dependence of the ferromagnetic resonance field. The scanning electron microscope images reveal a quite regular hexagonal arrangement of the pores, however the angular dependence of the resonance field do not exhibit the six-fold symmetry expected for this symmetry. Micromagnetic simulations performed on a perfect hexagonal lattice, when compared with those made on our real system taken from the scanning microscope images, reveal that the presence of defects in the antidot lattice affects the ferromagnetic resonance field symmetry. - Highlights: • We use the FMR technique to investigate the magnetic properties of Py antidots. • We studied the effect of pore diameter on FMR angular measurement. • FMR field does not exhibit the six-fold symmetry. • For all angular positions there are two resonance modes always present. • Micromagnetic simulations agree with the experimental results with defects.

Quantum dots coupled ZnO nanowire-array panels and their photocatalytic activities.

Science.gov (United States)

Liao, Yulong; Que, Wenxiu; Zhang, Jin; Zhong, Peng; Yuan, Yuan; Qiu, Xinku; Shen, Fengyu

2013-02-01

Fabrication and characterization of a heterojunction structured by CdS quantum dots@ZnO nanowire-array panels were presented. Firstly, ZnO nanowire-array panels were prepared by using a chemical bath deposition approach where wurtzite ZnO nanowires with a diameter of about 100 nm and 3 microm in length grew perpendicularly to glass substrate. Secondly, CdS quantum dots were deposited onto the surface of the ZnO nanowire-arrays by using successive ion layer absorption and reaction method, and the CdS shell/ZnO core heterojunction were thus obtained. Field emission scanning electron microscopy and transmission electron microscope were employed to characterize the morphological properties of the as-obtained CdS quantum dots@ZnO nanowire-array panels. X-ray diffraction was adopted to characterize the crystalline properties of the as-obtained CdS quantum dots@ZnO nanowire-array panels. Methyl orange was taken as a model compound to confirm the photocatalytic activities of the CdS shell/ZnO core heterojunction. Results indicate that CdS with narrow band gap not only acts as a visible-light sensitizer but also is responsible for an effective charge separation.

A transmission positron microscope and a scanning positron microscope being built at KEK, Japan

International Nuclear Information System (INIS)

Doyama, M.; Inoue, M.; Kogure, Y.; Kurihara, T.; Yagishita, A.; Shidara, T.; Nakahara, K.; Hayashi, Y.; Yoshiie, T.

2001-01-01

This paper reports the plans of positron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan improving used electron microscopes. The kinetic energies of positron produced by accelerators or by nuclear decays have not a unique value but show a spread over in a wide range. Positron beam will be guided near electron microscopes, a transmission electron microscope (JEM100S) and a scanning electron microscope (JSM25S). Positrons are slowed down by a tungsten foil, accelerated and focused on a nickel sheet. The monochromatic focused beam will be injected into an electron microscope. The focusing of positrons and electrons is achieved by magnetic system of the electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (orig.)

Many - body simulations using an array processor

International Nuclear Information System (INIS)

Rapaport, D.C.

1985-01-01

Simulations of microscopic models of water and polypeptides using molecular dynamics and Monte Carlo techniques have been carried out with the aid of an FPS array processor. The computational techniques are discussed, with emphasis on the development and optimization of the software to take account of the special features of the processor. The computing requirements of these simulations exceed what could be reasonably carried out on a normal 'scientific' computer. While the FPS processor is highly suited to the kinds of models described, several other computationally intensive problems in statistical mechanics are outlined for which alternative processor architectures are more appropriate

Dynamic focusing of phased arrays for nondestructive testing: characterization and application

International Nuclear Information System (INIS)

Lamarre, A.; Mainguy, F.

1999-01-01

Recent developments in Phased Array hardware developed by R/D TECH for nondestructive testing now allow dynamic focusing on reception. This new option, borrowed from medical technology, enables a programmable, real-time array response on reception by modifying the delay line, the gain, and the activation of each element as a function of time. This technology is presented as a new powerful tool, which can extend the depth-of-field, reduce the beam spread and increase the overall signal-to-noise ratio. Implementation of dynamic focusing in Phased Array systems will present many advantages such as an increase of the Pulse Rate Frequency (PRF). The technology implies a lot of significant possibilities, but also an extensive beam characterization. Some results are presented to quantify the advantages and drawbacks of the technique in comparison with standard phased array zone focusing and conventional UT. Results are clearly demonstrating the effect of dynamic focusing on the depth-of-field, the beam spread, the signal-to-noise ratio, and the acquisition rate, both with linear and annular arrays. Therefore this technique is suitable for applications where long soundpaths and small beam divergence are required as boresonic, billet, and blade root inspections. (author)

Modelling of critical functions of nuclear reactors using Fild Programmable Gate Array; Modelagem de funcoes criticas de reatores nucleares utilizando Fild Programmable Gate Array

Energy Technology Data Exchange (ETDEWEB)

Teixeira, Pamela Iara Nolasco

2016-07-01

This paper proposes the development of a method using FPGA for critical security functions of a nuclear reactor. It was implemented two critical safety functions in VHDL, which is a way to describe, through a program, the behavior of a circuit or digital component. Two critical security functions, FCS Core Cooling, responsible for cooling the reactor core in the charts of the plant and also in the event of accidents involving loss of coolant and FCS Heat Transfer, responsible for cooling the reactor core in the event an accident with loss of coolant were implemented. In this Dissertation it was chosen the use of FPGA, because - due to the effects of aging, obsolescence issues, environmental degradation and mechanical failures - nuclear power plants need to replace their older systems by new ones based on digital technology. The technologies obtained using a system described in hardware language can be implemented in a programmable device, having the advantage of changing the code at any time. (author)

A BLUEPRINT FOR IMPLEMENTING GRAND CHALLENGE SCHOLARS’ PROGRAMME: A CASE STUDY OF TAYLOR’S UNIVERSITY

Directory of Open Access Journals (Sweden)

MUSHTAK AL-ATABI

2013-04-01

Full Text Available The National Academy for Engineering announced 14 Grand Challenges for the 21st Century engineers to address in order to ensure a sustainable future for the generations to come. These grand challenges are in four broad areas, namely, energy and environment, health, security and learning and computation. This paper reports on a Grand Challenges Scholars’ Programme that is developed to prepare the engineering students to be able to address the grand challenges using the CDIO framework and focusing on five components; research experience, interdisciplinary curriculum, entrepreneurship, global dimension and service learning. The programme is voluntary and the candidates are expected to commit additional learning time. The programme was launched with 16 participants who are expected to graduate in 2016. A preliminary assessment of the programs shows that the participants found the programme useful in developing an array of CDIO skills. The School intends to continue offering this programme with the intention of integrating it with a holistic education approach.

Real-time monitoring of cellular dynamics using a microfluidic cell culture system with integrated electrode array and potentiostat

DEFF Research Database (Denmark)

Zor, Kinga; Vergani, M.; Heiskanen, Arto

2011-01-01

A versatile microfluidic, multichamber cell culture and analysis system with an integrated electrode array and potentiostat suitable for electrochemical detection and microscopic imaging is presented in this paper. The system, which allows on-line electrode cleaning and modification, was develope...

Development of Single-Event Upset hardened programmable logic devices in deep submicron CMOS; Developpement de circuits logiques programmables resistants aux aleas logiques en technologie CMOS submicrometrique

Energy Technology Data Exchange (ETDEWEB)

Bonacini, S

2007-11-15

The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust (Single Event Upset) programmable components for application in high energy physics experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 {mu}m CMOS technology. The FPGA under development is a 32*32 logic block array, equivalent to {approx} 25 k gates, in 0.13 {mu}m CMOS. The irradiation test results obtained in the CMOS 0.25 {mu}m technology demonstrate good robustness of the circuit up to an LET (Linear Energy Transfer) of 79.6 cm{sup 2}*MeV/mg, which make it suitable for the target environment. The CMOS 0.13 {mu}m circuit has showed robustness to an LET of 37.4 cm{sup 2}*MeV/mg in the static test mode and has increased sensitivity in the dynamic test mode. This work focused also on the research for an SEU-robust register in both the mentioned technologies. The SEU-robust register is employed as a user data flip-flop in the FPGA and PLD designs and as a configuration cell as well in the FPGA design.

Multisite two-photon imaging of neurons on multielectrode arrays

Science.gov (United States)

Potter, Steve M.; Lukina, Natalia; Longmuir, Kenneth J.; Wu, Yan

2001-04-01

We wish to understand how neural systems store, recall, and process information. We are using cultured networks of cortical neurons grown on microelectrode arrays as a model system for studying the emergent properties of ensembles of living neurons. We have developed a 2-way communication interface between the cultured network and a computer- generated animal, the Neurally Controlled Animat. Neural activity is used to control the behavior of the Animat, and 2- photon time-lapse imaging is carried out in order to observe the morphological changes that might underlie changes in neural processing. The 2-photon microscope is ideal for repeated imaging over hours or days, with submicron resolution and little photodamage. We have designed a computer-controlled microscope stage that allows imaging several locations in sequence, in order to collect more image data. For the latest progress, see: http://www.caltech.edu/~pinelab/PotterGroup.htm.

Automatic analysis of digitized TV-images by a computer-driven optical microscope

International Nuclear Information System (INIS)

Rosa, G.; Di Bartolomeo, A.; Grella, G.; Romano, G.

1997-01-01

New methods of image analysis and three-dimensional pattern recognition were developed in order to perform the automatic scan of nuclear emulsion pellicles. An optical microscope, with a motorized stage, was equipped with a CCD camera and an image digitizer, and interfaced to a personal computer. Selected software routines inspired the design of a dedicated hardware processor. Fast operation, high efficiency and accuracy were achieved. First applications to high-energy physics experiments are reported. Further improvements are in progress, based on a high-resolution fast CCD camera and on programmable digital signal processors. Applications to other research fields are envisaged. (orig.)

Architectural design and analysis of a programmable image processor

International Nuclear Information System (INIS)

Siyal, M.Y.; Chowdhry, B.S.; Rajput, A.Q.K.

2003-01-01

In this paper we present an architectural design and analysis of a programmable image processor, nicknamed Snake. The processor was designed with a high degree of parallelism to speed up a range of image processing operations. Data parallelism found in array processors has been included into the architecture of the proposed processor. The implementation of commonly used image processing algorithms and their performance evaluation are also discussed. The performance of Snake is also compared with other types of processor architectures. (author)

ATMAD: robust image analysis for Automatic Tissue MicroArray De-arraying.

Science.gov (United States)

Nguyen, Hoai Nam; Paveau, Vincent; Cauchois, Cyril; Kervrann, Charles

2018-04-19

Over the last two decades, an innovative technology called Tissue Microarray (TMA), which combines multi-tissue and DNA microarray concepts, has been widely used in the field of histology. It consists of a collection of several (up to 1000 or more) tissue samples that are assembled onto a single support - typically a glass slide - according to a design grid (array) layout, in order to allow multiplex analysis by treating numerous samples under identical and standardized conditions. However, during the TMA manufacturing process, the sample positions can be highly distorted from the design grid due to the imprecision when assembling tissue samples and the deformation of the embedding waxes. Consequently, these distortions may lead to severe errors of (histological) assay results when the sample identities are mismatched between the design and its manufactured output. The development of a robust method for de-arraying TMA, which localizes and matches TMA samples with their design grid, is therefore crucial to overcome the bottleneck of this prominent technology. In this paper, we propose an Automatic, fast and robust TMA De-arraying (ATMAD) approach dedicated to images acquired with brightfield and fluorescence microscopes (or scanners). First, tissue samples are localized in the large image by applying a locally adaptive thresholding on the isotropic wavelet transform of the input TMA image. To reduce false detections, a parametric shape model is considered for segmenting ellipse-shaped objects at each detected position. Segmented objects that do not meet the size and the roundness criteria are discarded from the list of tissue samples before being matched with the design grid. Sample matching is performed by estimating the TMA grid deformation under the thin-plate model. Finally, thanks to the estimated deformation, the true tissue samples that were preliminary rejected in the early image processing step are recognized by running a second segmentation step. We

Cryogenic immersion microscope

Science.gov (United States)

Le Gros, Mark; Larabell, Carolyn A.

2010-12-14

A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

Binary Pseudo-Random Gratings and Arrays for Calibration of Modulation Transfer Functions of Surface Profilometers

Energy Technology Data Exchange (ETDEWEB)

Barber, Samuel K.; Anderson, Erik D.; Cambie, Rossana; McKinney, Wayne R.; Takacs, Peter Z.; Stover, John C.; Voronov, Dmitriy L.; Yashchuk, Valeriy V.

2009-09-11

A technique for precise measurement of the modulation transfer function (MTF), suitable for characterization of a broad class of surface profilometers, is investigated in detail. The technique suggested in [Proc. SPIE 7077-7, (2007), Opt. Eng. 47(7), 073602-1-5 (2008)]is based on use of binary pseudo-random (BPR) gratings and arrays as standard MTF test surfaces. Unlike most conventional test surfaces, BPR gratings and arrays possess white-noise-like inherent power spectral densities (PSD), allowing the direct determination of the one- and two-dimensional MTF, respectively, with a sensitivity uniform over the entire spatial frequency range of a profiler. In the cited work, a one dimensional realization of the suggested method based on use of BPR gratings has been demonstrated. Here, a high-confidence of the MTF calibration technique is demonstrated via cross comparison measurements of a number of two dimensional BPR arrays using two different interferometric microscopes and a scatterometer. We also present the results of application of the experimentally determined MTF correction to the measurement taken with the MicromapTM-570 interferometric microscope of the surface roughness of a super-polished test mirror. In this particular case, without accounting for the instrumental MTF, the surface rms roughness over half of the instrumental spatial frequency bandwidth would be underestimated by a factor of approximately 1.4.

Methodology for Assessing the Degree of Internationalization of Business Academic Study Programmes

Directory of Open Access Journals (Sweden)

Dan-Cristian Dabija

2014-08-01

Full Text Available The purpose of this paper is to develop a methodology for assessing the degree of internationalization of undergraduate, Master’s and doctoral business programmes with the aid of complex indicators designed to capture the vast array of characteristics displayed by these programmes and contribute to their promotion in the international academic competition. The methodology should include both general indicators applicable to any study programme and some indicators that are specifically developed for business study programmes. No consensus exists in the internationalization literature and practice over the actual scope and the indicators to be considered in the implementation of such a study. Researchers rather propose methods for assessing and prioritizing universities and/or faculties and lay down a lot of criteria according to which rankings are developed. These rankings are mainly focused on the level of internationalization of socioeconomic and engineering study programmes. Being aware of the limits of theory and practice, the authors develop a scoring model that measures the degree of internationalization of business education curricula according to stringent criteria. The research originality lies in the attempt to describe the avenues of a new methodology for measuring and assessing realistically the economic study programmes so that these may be better positioned on the educational market and become more attractive to the future candidates. Based on a synergistic approach to indicators, the model may contribute to creating competitive advantage in relation to other programmes from the same university or from partner institutions.

Image processing with cellular nonlinear networks implemented on field-programmable gate arrays for real-time applications in nuclear fusion

International Nuclear Information System (INIS)

Palazzo, S.; Vagliasindi, G.; Arena, P.; Murari, A.; Mazon, D.; De Maack, A.

2010-01-01

In the past years cameras have become increasingly common tools in scientific applications. They are now quite systematically used in magnetic confinement fusion, to the point that infrared imaging is starting to be used systematically for real-time machine protection in major devices. However, in order to guarantee that the control system can always react rapidly in case of critical situations, the time required for the processing of the images must be as predictable as possible. The approach described in this paper combines the new computational paradigm of cellular nonlinear networks (CNNs) with field-programmable gate arrays and has been tested in an application for the detection of hot spots on the plasma facing components in JET. The developed system is able to perform real-time hot spot recognition, by processing the image stream captured by JET wide angle infrared camera, with the guarantee that computational time is constant and deterministic. The statistical results obtained from a quite extensive set of examples show that this solution approximates very well an ad hoc serial software algorithm, with no false or missed alarms and an almost perfect overlapping of alarm intervals. The computational time can be reduced to a millisecond time scale for 8 bit 496x560-sized images. Moreover, in our implementation, the computational time, besides being deterministic, is practically independent of the number of iterations performed by the CNN - unlike software CNN implementations.

Field-Programmable Logic Devices with Optical Input Output

Science.gov (United States)

Szymanski, Ted H.; Saint-Laurent, Martin; Tyan, Victor; Au, Albert; Supmonchai, Boonchuay

2000-02-01

A field-programmable logic device (FPLD) with optical I O is described. FPLD s with optical I O can have their functionality specified in the field by means of downloading a control-bit stream and can be used in a wide range of applications, such as optical signal processing, optical image processing, and optical interconnects. Our device implements six state-of-the-art dynamically programmable logic arrays (PLA s) on a 2 mm 2 mm die. The devices were fabricated through the Lucent Technologies Advanced Research Projects Agency Consortium for Optical and Optoelectronic Technologies in Computing (Lucent ARPA COOP) workshop by use of 0.5- m complementary metal-oxide semiconductor self-electro-optic device technology and were delivered in 1998. All devices are fully functional: The electronic data paths have been verified at 200 MHz, and optical tests are pending. The device has been programmed to implement a two-stage optical switching network with six 4 4 crossbar switches, which can realize more than 190 10 6 unique programmable input output permutations. The same device scaled to a 2 cm 2 cm substrate could support as many as 4000 optical I O and 1 Tbit s of optical I O bandwidth and offer fully programmable digital functionality with approximately 110,000 programmable logic gates. The proposed optoelectronic FPLD is also ideally suited to realizing dense, statically reconfigurable crossbar switches. We describe an attractive application area for such devices: a rearrangeable three-stage optical switch for a wide-area-network backbone, switching 1000 traffic streams at the OC-48 data rate and supporting several terabits of traffic.

STM-SQUID probe microscope

International Nuclear Information System (INIS)

Hayashi, Tadayuki; Tachiki, Minoru; Itozaki, Hideo

2007-01-01

We have developed a STM-SQUID probe microscope. A high T C SQUID probe microscope was combined with a scanning tunneling microscope for investigation of samples at room temperature in air. A high permeability probe needle was used as a magnetic flux guide to improve the spatial resolution. The probe with tip radius of less than 100 nm was prepared by microelectropolishing. The probe was also used as a scanning tunneling microscope tip. Topography of the sample surface could be measured by the scanning tunneling microscope with high spatial resolution prior to observation by SQUID microscopy. The SQUID probe microscope image could be observed while keeping the distance from the sample surface to the probe tip constant. We observed a topographic image and a magnetic image of Ni fine pattern and also a magnetically recorded hard disk. Furthermore we have investigated a sample vibration method of the static magnetic field emanating from a sample with the aim of achieving a higher signal-to-noise (S/N) ratio

Photon scanning tunneling microscope in combination with a force microscope

NARCIS (Netherlands)

Moers, M.H.P.; Moers, M.H.P.; Tack, R.G.; van Hulst, N.F.; Bölger, B.; Bölger, B.

1994-01-01

The simultaneous operation of a photon scanning tunneling microscope with an atomic force microscope is presented. The use of standard atomic force silicon nitride cantilevers as near-field optical probes offers the possibility to combine the two methods. Vertical forces and torsion are detected

Application of Pfortran and Co-Array Fortran in the Parallelization of the GROMOS96 Molecular Dynamics Module

Directory of Open Access Journals (Sweden)

Piotr Bała

2001-01-01

Full Text Available After at least a decade of parallel tool development, parallelization of scientific applications remains a significant undertaking. Typically parallelization is a specialized activity supported only partially by the programming tool set, with the programmer involved with parallel issues in addition to sequential ones. The details of concern range from algorithm design down to low-level data movement details. The aim of parallel programming tools is to automate the latter without sacrificing performance and portability, allowing the programmer to focus on algorithm specification and development. We present our use of two similar parallelization tools, Pfortran and Cray's Co-Array Fortran, in the parallelization of the GROMOS96 molecular dynamics module. Our parallelization started from the GROMOS96 distribution's shared-memory implementation of the replicated algorithm, but used little of that existing parallel structure. Consequently, our parallelization was close to starting with the sequential version. We found the intuitive extensions to Pfortran and Co-Array Fortran helpful in the rapid parallelization of the project. We present performance figures for both the Pfortran and Co-Array Fortran parallelizations showing linear speedup within the range expected by these parallelization methods.

Visible light photoelectrocatalysis with salicylic acid-modified TiO2 nanotube array electrode for p-nitrophenol degradation

International Nuclear Information System (INIS)

Wang Xin; Zhao Huimin; Quan Xie; Zhao Yazhi; Chen Shuo

2009-01-01

This research focused on immersion method synthesis of visible light active salicylic acid (SA)-modified TiO 2 nanotube array electrode and its photoelectrocatalytic (PEC) activity. The SA-modified TiO 2 nanotube array electrode was synthesized by immersing in SA solution with an anodized TiO 2 nanotube array electrode. Scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), UV-vis diffuse reflectance spectrum (DRS), and Surface photovoltage (SPV) were used to characterize this electrode. It was found that SA-modified TiO 2 nanotube array electrode absorbed well into visible region and exhibited enhanced visible light PEC activity on the degradation of p-nitrophenol (PNP). The degradation efficiencies increased from 63 to 100% under UV light, and 79-100% under visible light (λ > 400 nm), compared with TiO 2 nanotube array electrode. The enhanced PEC activity of SA-modified TiO 2 nanotube array electrode was attributed to the amount of surface hydroxyl groups introduced by SA-modification and the extension of absorption wavelength range.

Scanning Color Laser Microscope

Science.gov (United States)

Awamura, D.; Ode, T.; Yonezawa, M.

1988-01-01

A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

Array capabilities and future arrays

International Nuclear Information System (INIS)

Radford, D.

1993-01-01

Early results from the new third-generation instruments GAMMASPHERE and EUROGAM are confirming the expectation that such arrays will have a revolutionary effect on the field of high-spin nuclear structure. When completed, GAMMASHPERE will have a resolving power am order of magnitude greater that of the best second-generation arrays. When combined with other instruments such as particle-detector arrays and fragment mass analysers, the capabilites of the arrays for the study of more exotic nuclei will be further enhanced. In order to better understand the limitations of these instruments, and to design improved future detector systems, it is important to have some intelligible and reliable calculation for the relative resolving power of different instrument designs. The derivation of such a figure of merit will be briefly presented, and the relative sensitivities of arrays currently proposed or under construction presented. The design of TRIGAM, a new third-generation array proposed for Chalk River, will also be discussed. It is instructive to consider how far arrays of Compton-suppressed Ge detectors could be taken. For example, it will be shown that an idealised open-quote perfectclose quotes third-generation array of 1000 detectors has a sensitivity an order of magnitude higher again than that of GAMMASPHERE. Less conventional options for new arrays will also be explored

Vrancea seismic source analysis using a small-aperture array

International Nuclear Information System (INIS)

Popescu, E.; Popa, M.; Radulian, M.; Placinta, A.O.

2005-01-01

A small-aperture seismic array (BURAR) was installed in 1999 in the northern part of the Romanian territory (Bucovina area). Since then, the array has been in operation under a joint cooperation programme between Romania and USA. The array consists of 10 stations installed in boreholes (nine short period instruments and one broadband instrument) with enough high sensitivity to properly detect earthquakes generated in Vrancea subcrustal domain (at about 250 km epicentral distance) with magnitude M w below 3. Our main purpose is to investigate and calibrate the source parameters of the Vrancea intermediate-depth earthquakes using specific techniques provided by the BURAR array data. Forty earthquakes with magnitudes between 2.9 and 6.0 were selected, including the recent events of September 27, 2004 (45.70 angle N, 26.45 angle E, h = 166 km, M w = 4.7), October 27, 2004 (45.84 angle N, 26.63 angle E, h = 105 km, M w = 6.0) and May 14, 2005 (45.66 angle N, 26.52 angle E, h = 146 km, M w = 5.1), which are the best ever recorded earthquakes on the Romanian territory: Empirical Green's function deconvolution and spectral ratio methods are applied for pairs of collocated events with similar focal mechanism. Stability tests are performed for the retrieved source time function using the array elements. Empirical scaling and calibration relationships are also determined. Our study shows the capability of the BURAR array to determine the source parameters of the Vrancea intermediate-depth earthquakes as a stand alone station and proves that the recordings of this array alone provides reliable and useful tools to efficiently constrain the source parameters and consequently source scaling properties. (authors)

High Performance Systolic Array Core Architecture Design for DNA Sequencer

Directory of Open Access Journals (Sweden)

Saiful Nurdin Dayana

2018-01-01

Full Text Available This paper presents a high performance systolic array (SA core architecture design for Deoxyribonucleic Acid (DNA sequencer. The core implements the affine gap penalty score Smith-Waterman (SW algorithm. This time-consuming local alignment algorithm guarantees optimal alignment between DNA sequences, but it requires quadratic computation time when performed on standard desktop computers. The use of linear SA decreases the time complexity from quadratic to linear. In addition, with the exponential growth of DNA databases, the SA architecture is used to overcome the timing issue. In this work, the SW algorithm has been captured using Verilog Hardware Description Language (HDL and simulated using Xilinx ISIM simulator. The proposed design has been implemented in Xilinx Virtex -6 Field Programmable Gate Array (FPGA and improved in the core area by 90% reduction.

A facile method to fabricate close-packed concave microlens array on cylindrical glass

International Nuclear Information System (INIS)

Deng, Zefang; Chen, Feng; Yang, Qing; Liu, Hewei; Bian, Hao; Du, Guangqing; Hu, Yang; Si, Jinhai; Meng, Xiangwei; Hou, Xun

2012-01-01

This work presents a facile method to fabricate concave microlens arrays (MLAs) with controllable shape and high fill factor on cylindrical silica glass by a femtosecond laser-enhanced chemical wet etching process. The hexagonal and rectangular MLAs are flexibly fabricated on the silica glass cylinder with a diameter of 3 mm. The morphological characteristics of MLAs are measured by a scanning electron microscope and a laser scanning confocal microscope. The measurements show that the good uniformity and high packing density MLA structures are generated. It has also been demonstrated that the shape and size of the concave structures could be easily tuned by changing laser power and the arrangement of laser exposure spots. The convex MLAs replicated by the polymer casting method experience excellent image quality. (paper)

The FPGA Pixel Array Detector

International Nuclear Information System (INIS)

Hromalik, Marianne S.; Green, Katherine S.; Philipp, Hugh T.; Tate, Mark W.; Gruner, Sol M.

2013-01-01

A proposed design for a reconfigurable x-ray Pixel Array Detector (PAD) is described. It operates by integrating a high-end commercial field programmable gate array (FPGA) into a 3-layer device along with a high-resistivity diode detection layer and a custom, application-specific integrated circuit (ASIC) layer. The ASIC layer contains an energy-discriminating photon-counting front end with photon hits streamed directly to the FPGA via a massively parallel, high-speed data connection. FPGA resources can be allocated to perform user defined tasks on the pixel data streams, including the implementation of a direct time autocorrelation function (ACF) with time resolution down to 100 ns. Using the FPGA at the front end to calculate the ACF reduces the required data transfer rate by several orders of magnitude when compared to a fast framing detector. The FPGA-ASIC high-speed interface, as well as the in-FPGA implementation of a real-time ACF for x-ray photon correlation spectroscopy experiments has been designed and simulated. A 16×16 pixel prototype of the ASIC has been fabricated and is being tested. -- Highlights: ► We describe the novelty and need for the FPGA Pixel Array Detector. ► We describe the specifications and design of the Diode, ASIC and FPGA layers. ► We highlight the Autocorrelation Function (ACF) for speckle as an example application. ► Simulated FPGA output calculates the ACF for different input bitstreams to 100 ns. ► Reduced data transfer rate by 640× and sped up real-time ACF by 100× other methods.

Virtual reality microscope versus conventional microscope regarding time to diagnosis: an experimental study.

Science.gov (United States)

Randell, Rebecca; Ruddle, Roy A; Mello-Thoms, Claudia; Thomas, Rhys G; Quirke, Phil; Treanor, Darren

2013-01-01

  To create and evaluate a virtual reality (VR) microscope that is as efficient as the conventional microscope, seeking to support the introduction of digital slides into routine practice.   A VR microscope was designed and implemented by combining ultra-high-resolution displays with VR technology, techniques for fast interaction, and high usability. It was evaluated using a mixed factorial experimental design with technology and task as within-participant variables and grade of histopathologist as a between-participant variable. Time to diagnosis was similar for the conventional and VR microscopes. However, there was a significant difference in the mean magnification used between the two technologies, with participants working at a higher level of magnification on the VR microscope.   The results suggest that, with the right technology, efficient use of digital pathology for routine practice is a realistic possibility. Further work is required to explore what magnification is required on the VR microscope for histopathologists to identify diagnostic features, and the effect on this of the digital slide production process. © 2012 Blackwell Publishing Limited.

The head-mounted microscope.

Science.gov (United States)

Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

2012-04-01

Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Pancam and Microscopic Imager observations of dust on the Spirit Rover: Cleaning events, spectral properties, and aggregates

Science.gov (United States)

Vaughan, Alicia F.; Johnson, Jeffrey R.; Herkenhoff, Kenneth E.; Sullivan, Robert; Landis, Geoffrey A.; Goetz, Walter; Madsen, Morten B.

2010-01-01

This work describes dust deposits on the Spirit Rover over 2000 sols through examination of Pancam and Microscopic Imager observations of specific locations on the rover body, including portions of the solar array, Pancam and Mini-TES calibration targets, and the magnets. This data set reveals the three "cleaning events" experienced by Spirit to date, the spectral properties of dust, and the tendency of dust particles to form aggregates 100 um and larger.

The Homemade Microscope.

Science.gov (United States)

Baker, Roger C., Jr.

1991-01-01

Directions for the building of a pocket microscope that will make visible the details of insect structure and living bacteria are described. Background information on the history of microscopes and lenses is provided. The procedures for producing various types of lenses are included. (KR)

Direct microneedle array fabrication off a photomask to deliver collagen through skin.

Science.gov (United States)

Kochhar, Jaspreet Singh; Anbalagan, Parthiban; Shelar, Sandeep Balu; Neo, Jun Kai; Iliescu, Ciprian; Kang, Lifeng

2014-07-01

To fabricate microneedle arrays directly off a photomask using a simple photolithographical approach and evaluate their potential for delivering collagen. A simple photolithographical approach was developed by using photomask consisting of embedded micro-lenses that govern microneedle geometry in a mould free process. Microneedle length was controlled by use of simple glass scaffolds as well as addition of backing layer. The fabricated arrays were tested for their mechanical properties by using a force gauge as well as insertion into human skin with trypan blue staining. Microneedle arrays were then evaluated for the delivery of fluorescent collagen, which was evaluated using a confocal laser scanning microscope. Microneedles with sharp tips ranging between 41.5 ± 8.4 μm and 71.6 ± 13.7 μm as well as of two different lengths of 1336 ± 193 μm and 957 ± 171 μm were fabricated by using the photomasks. The microneedles were robust and resisted fracture forces up to 25 N. They were also shown to penetrate cadaver human skin samples with ease; especially microneedle arrays with shorter length of 957 μm penetrated up to 72% of needles. The needles were shown to enhance permeation of collagen through cadaver rat skin, as compared to passive diffusion of collagen. A simple and mould free approach of fabricating polymeric microneedle array is proposed. The fabricated microneedle arrays enhance collagen permeation through skin.

Study of the diffraction in the microscope: Annular condenser

International Nuclear Information System (INIS)

Ciocci, L; Echarri, R M; Simon, J M

2011-01-01

In this work we study the diffraction in the microscope when an annular condenser is used to illuminate the object. We calculate the point spread function (PSF) for a pinhole in an opaque screen illuminated with an annular condenser, consisting in an 1D array of incoherent point sources. We compare it with the PSF for a self-luminous point object, finding that the central disk of the diffraction pattern is narrower and the first intensity minimum is deeper for illuminated objects. We also analyze the resolution of the system by means of the intensity profile produced by two points objects, finding that two self luminous point objects are better resolved than two illuminated objects at the same distance. This suggests that the correlation introduced in the object diminishes the resolution in the former case.

Nonlinear viscous vortex motion in two-dimensional Josephson-junction arrays

International Nuclear Information System (INIS)

Hagenaars, T.J.; Tiesinga, P.H.E.; van Himbergen, J.E.; Jose, J.V.

1994-01-01

When a vortex in a two-dimensional Josephson-junction array is driven by a constant external current it may move as a particle in a viscous medium. Here we study the nature of this viscous motion. We model the junctions in a square array as resistively and capacitively shunted Josephson junctions and carry out numerical calculations of the current-voltage characteristics. We find that the current-voltage characteristics in the damped regime are well described by a model with a nonlinear viscous force of the form F D =η(y)y=[A/(1+By]y, where y is the vortex velocity, η(y) is the velocity-dependent viscosity, and A and B are constants for a fixed value of the Stewart-McCumber parameter. This result is found to apply also for triangular lattices in the overdamped regime. Further qualitative understanding of the nature of the nonlinear friction on the vortex motion is obtained from a graphic analysis of the microscopic vortex dynamics in the array. The consequences of having this type of nonlinear friction law are discussed and compared to previous theoretical and experimental studies

Proper alignment of the microscope.

Science.gov (United States)

Rottenfusser, Rudi

2013-01-01

The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. Copyright © 2013 Elsevier Inc. All rights

Wolter x-ray microscope calibration

International Nuclear Information System (INIS)

Gerassimenko, M.

1986-06-01

A 22 x Wolter microscope was calibrated after several months of operation in the Lawrence Livermore National laboratory (LLNL) Inertial Confinement Fusion program. Placing a point x-ray source at the microscope focus, I recorded the image plane spectrum, as well as the direct spectrum, and from the ratio of these two spectra derived an accurate estimate of the microscope solid angle in the 1 to 4 keV range. The solid angle was also calculated using the microscope geometry and composition. Comparison of this calculated value with the solid angle that was actually measured suggests contamination of the microscope surface

Wolter x-ray microscope calibration

International Nuclear Information System (INIS)

Gerassimenko, M.

1986-01-01

A 22 x Wolter microscope was calibrated after several months of operation in the Lawrence Livermore National Laboratory (LLNL) Inertial Confinement Fusion program. Placing a point x-ray source at the microscope focus, I recorded the image plane spectrum, as well as the direct spectrum, and from the ratio of these two spectra derived an accurate estimate of the microscope solid angle in the 1-4 keV range. The solid angle was also calculated using the microscope geometry and composition. Comparison of this calculated value with the solid angle that was actually measured suggests contamination of the microscope surface

Mailing microscope slides

Science.gov (United States)

Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

High reproducibility and sensitivity of bifacial copper nanowire array for detection of glucose

Directory of Open Access Journals (Sweden)

Hanqing Zhang

2017-06-01

Full Text Available The ordered bifacial copper nanowire array (Cu BNWA was synthesized by a template assisted electrochemical deposition method. The morphology and structure of the as-prepared samples were investigated by field emission scanning electron microscope (FESEM and X-ray diffraction (XRD. The results show that the ordered Cu nanowire array with uniform geometrical dimensions covered both side of the Cu substrate. When used as the electrode for glucose detection, the minimum detectable concentration of glucose can be reached as low as 0.2 mM. Impressively, the sample still showed high sensitivity and stability for glucose detection after two months placement in ambient environment. These excellent performances of the Cu BNWA make it a promising non-enzyme glucose detection sensor for various applications.

Sample mounting and transfer for coupling an ultrahigh vacuum variable temperature beetle scanning tunneling microscope with conventional surface probes

International Nuclear Information System (INIS)

Nafisi, Kourosh; Ranau, Werner; Hemminger, John C.

2001-01-01

We present a new ultrahigh vacuum (UHV) chamber for surface analysis and microscopy at controlled, variable temperatures. The new instrument allows surface analysis with Auger electron spectroscopy, low energy electron diffraction, quadrupole mass spectrometer, argon ion sputtering gun, and a variable temperature scanning tunneling microscope (VT-STM). In this system, we introduce a novel procedure for transferring a sample off a conventional UHV manipulator and onto a scanning tunneling microscope in the conventional ''beetle'' geometry, without disconnecting the heating or thermocouple wires. The microscope, a modified version of the Besocke beetle microscope, is mounted on a 2.75 in. outer diameter UHV flange and is directly attached to the base of the chamber. The sample is attached to a tripod sample holder that is held by the main manipulator. Under UHV conditions the tripod sample holder can be removed from the main manipulator and placed onto the STM. The VT-STM has the capability of acquiring images between the temperature range of 180--500 K. The performance of the chamber is demonstrated here by producing an ordered array of island vacancy defects on a Pt(111) surface and obtaining STM images of these defects

An Optofluidic Lens Array Microchip for High Resolution Stereo Microscopy

Directory of Open Access Journals (Sweden)

Mayurachat Ning Gulari

2014-08-01

Full Text Available We report the development of an add-on, chip-based, optical module—termed the Microfluidic-based Oil-immersion Lenses (μOIL chip—which transforms any stereo microscope into a high-resolution, large field of view imaging platform. The μOIL chip consists of an array of ball mini-lenses that are assembled onto a microfluidic silicon chip. The mini-lenses are made out of high refractive index material (sapphire and they are half immersed in oil. Those two key features enable submicron resolution and a maximum numerical aperture of ~1.2. The μOIL chip is reusable and easy to operate as it can be placed directly on top of any biological sample. It improves the resolution of a stereo microscope by an order of magnitude without compromising the field of view; therefore, we believe it could become a versatile tool for use in various research studies and clinical applications.

Femtosecond photoelectron point projection microscope

International Nuclear Information System (INIS)

Quinonez, Erik; Handali, Jonathan; Barwick, Brett

2013-01-01

By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect

FPGA-Based Communications Receivers for Smart Antenna Array Embedded Systems

Directory of Open Access Journals (Sweden)

Millar James

2006-01-01

Full Text Available Field-programmable gate arrays (FPGAs are drawing ever increasing interest from designers of embedded wireless communications systems. They outpace digital signal processors (DSPs, through hardware execution of a wide range of parallelizable communications transceiver algorithms, at a fraction of the design and implementation effort and cost required for application-specific integrated circuits (ASICs. In our study, we employ an Altera Stratix FPGA development board, along with the DSP Builder software tool which acts as a high-level interface to the powerful Quartus II environment. We compare single- and multibranch FPGA-based receiver designs in terms of error rate performance and power consumption. We exploit FPGA operational flexibility and algorithm parallelism to design eigenmode-monitoring receivers that can adapt to variations in wireless channel statistics, for high-performing, inexpensive, smart antenna array embedded systems.

FPGA-Based Communications Receivers for Smart Antenna Array Embedded Systems

Directory of Open Access Journals (Sweden)

James Millar

2006-10-01

Full Text Available Field-programmable gate arrays (FPGAs are drawing ever increasing interest from designers of embedded wireless communications systems. They outpace digital signal processors (DSPs, through hardware execution of a wide range of parallelizable communications transceiver algorithms, at a fraction of the design and implementation effort and cost required for application-specific integrated circuits (ASICs. In our study, we employ an Altera Stratix FPGA development board, along with the DSP Builder software tool which acts as a high-level interface to the powerful Quartus II environment. We compare single- and multibranch FPGA-based receiver designs in terms of error rate performance and power consumption. We exploit FPGA operational flexibility and algorithm parallelism to design eigenmode-monitoring receivers that can adapt to variations in wireless channel statistics, for high-performing, inexpensive, smart antenna array embedded systems.

Development of Single-Event Upset hardened programmable logic devices in deep submicron CMOS

International Nuclear Information System (INIS)

Bonacini, S.

2007-11-01

The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust (Single Event Upset) programmable components for application in high energy physics experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 μm CMOS technology. The FPGA under development is a 32*32 logic block array, equivalent to ∼ 25 k gates, in 0.13 μm CMOS. The irradiation test results obtained in the CMOS 0.25 μm technology demonstrate good robustness of the circuit up to an LET (Linear Energy Transfer) of 79.6 cm 2 *MeV/mg, which make it suitable for the target environment. The CMOS 0.13 μm circuit has showed robustness to an LET of 37.4 cm 2 *MeV/mg in the static test mode and has increased sensitivity in the dynamic test mode. This work focused also on the research for an SEU-robust register in both the mentioned technologies. The SEU-robust register is employed as a user data flip-flop in the FPGA and PLD designs and as a configuration cell as well in the FPGA design

A High-Voltage SOI CMOS Exciter Chip for a Programmable Fluidic Processor System.

Science.gov (United States)

Current, K W; Yuk, K; McConaghy, C; Gascoyne, P R C; Schwartz, J A; Vykoukal, J V; Andrews, C

2007-06-01

A high-voltage (HV) integrated circuit has been demonstrated to transport fluidic droplet samples on programmable paths across the array of driving electrodes on its hydrophobically coated surface. This exciter chip is the engine for dielectrophoresis (DEP)-based micro-fluidic lab-on-a-chip systems, creating field excitations that inject and move fluidic droplets onto and about the manipulation surface. The architecture of this chip is expandable to arrays of N X N identical HV electrode driver circuits and electrodes. The exciter chip is programmable in several senses. The routes of multiple droplets may be set arbitrarily within the bounds of the electrode array. The electrode excitation waveform voltage amplitude, phase, and frequency may be adjusted based on the system configuration and the signal required to manipulate a particular fluid droplet composition. The voltage amplitude of the electrode excitation waveform can be set from the minimum logic level up to the maximum limit of the breakdown voltage of the fabrication technology. The frequency of the electrode excitation waveform can also be set independently of its voltage, up to a maximum depending upon the type of droplets that must be driven. The exciter chip can be coated and its oxide surface used as the droplet manipulation surface or it can be used with a top-mounted, enclosed fluidic chamber consisting of a variety of materials. The HV capability of the exciter chip allows the generated DEP forces to penetrate into the enclosed chamber region and an adjustable voltage amplitude can accommodate a variety of chamber floor thicknesses. This demonstration exciter chip has a 32 x 32 array of nominally 100 V electrode drivers that are individually programmable at each time point in the procedure to either of two phases: 0deg and 180deg with respect to the reference clock. For this demonstration chip, while operating the electrodes with a 100-V peak-to-peak periodic waveform, the maximum HV electrode

Tapping mode imaging and measurements with an inverted atomic force microscope.

Science.gov (United States)

Chan, Sandra S F; Green, John-Bruce D

2006-07-18

This report demonstrates the successful use of the inverted atomic force microscope (i-AFM) for tapping mode AFM imaging of cantilever-supported samples. i-AFM is a mode of AFM operation in which a sample supported on a tipless cantilever is imaged by one of many tips in a microfabricated tip array. Tapping mode is an intermittent contact mode whereby the cantilever is oscillated at or near its resonance frequency, and the amplitude and/or phase are used to image the sample. In the process of demonstrating that tapping mode images could be obtained in the i-AFM design, it was observed that the amplitude of the cantilever oscillation decreased markedly as the cantilever and tip array were approached. The source of this damping of the cantilever oscillations was identified to be the well-known "squeeze film damping", and the extent of damping was a direct consequence of the relatively shorter tip heights for the tip arrays, as compared to those of commercially available tapping mode cantilevers with integrated tips. The functional form for the distance dependence of the damping coefficient is in excellent agreement with previously published models for squeeze film damping, and the values for the fitting parameters make physical sense. Although the severe damping reduces the cantilever free amplitude substantially, we found that we were still able to access the low-amplitude regime of oscillation necessary for attractive tapping mode imaging of fragile molecules.

Microwave metamaterials—from passive to digital and programmable controls of electromagnetic waves

Science.gov (United States)

Cui, Tie Jun

2017-08-01

Since 2004, my group at Southeast University has been carrying out research into microwave metamaterials, which are classified into three catagories: metamaterials based on the effective medium model, plasmonic metamaterials for spoof surface plasmon polaritons (SPPs), and coding and programmable metamaterials. For effective-medium metamaterials, we have developed a general theory to accurately describe effective permittivity and permeability in semi-analytical forms, from which we have designed and realized a three dimensional (3D) wideband ground-plane invisibility cloak, a free-space electrostatic invisibility cloak, an electromagnetic black hole, optical/radar illusions, and radially anisotropic zero-index metamaterial for omni-directional radiation and a nearly perfect power combination of source array, etc. We have also considered the engineering applications of microwave metamaterials, such as a broadband and low-loss 3D transformation-optics lens for wide-angle scanning, a 3D planar gradient-index lens for high-gain radiations, and a random metasurface for reducing radar cross sections. In the area of plasmonic metamaterials, we proposed an ultrathin, narrow, and flexible corrugated metallic strip to guide SPPs with a small bending loss and radiation loss, from which we designed and realized a series of SPP passive devices (e.g. power divider, coupler, filter, and resonator) and active devices (e.g. amplifier and duplexer). We also showed a significant feature of the ultrathin SPP waveguide in overcoming the challenge of signal integrity in traditional integrated circuits, which will help build a high-performance SPP wireless communication system. In the area of coding and programmable metamaterials, we proposed a new measure to describe a metamaterial from the viewpoint of information theory. We have illustrated theoretically and experimentally that coding metamaterials composed of digital units can be controlled by coding sequences, leading to different

Integration of a high-NA light microscope in a scanning electron microscope.

Science.gov (United States)

Zonnevylle, A C; Van Tol, R F C; Liv, N; Narvaez, A C; Effting, A P J; Kruit, P; Hoogenboom, J P

2013-10-01

We present an integrated light-electron microscope in which an inverted high-NA objective lens is positioned inside a scanning electron microscope (SEM). The SEM objective lens and the light objective lens have a common axis and focal plane, allowing high-resolution optical microscopy and scanning electron microscopy on the same area of a sample simultaneously. Components for light illumination and detection can be mounted outside the vacuum, enabling flexibility in the construction of the light microscope. The light objective lens can be positioned underneath the SEM objective lens during operation for sub-10 μm alignment of the fields of view of the light and electron microscopes. We demonstrate in situ epifluorescence microscopy in the SEM with a numerical aperture of 1.4 using vacuum-compatible immersion oil. For a 40-nm-diameter fluorescent polymer nanoparticle, an intensity profile with a FWHM of 380 nm is measured whereas the SEM performance is uncompromised. The integrated instrument may offer new possibilities for correlative light and electron microscopy in the life sciences as well as in physics and chemistry. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

Antibacterial activity of single crystalline silver-doped anatase TiO{sub 2} nanowire arrays

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiangyu, E-mail: zhangxiangyu@tyut.edu.cn; Li, Meng; He, Xiaojing; Hang, Ruiqiang; Huang, Xiaobo; Wang, Yueyue; Yao, Xiaohong; Tang, Bin, E-mail: tangbin@tyut.edu.cn

2016-05-30

Graphical abstract: The silver-doped TiO{sub 2} nanowire arrays on titanium foil substrate were synthesized via a two-step process. It includes: deposition of AgTi films on titanium foil by magnetron sputtering; preparation of AgNW arrays on AgTi films via alkali (NaOH) hydrothermal treatment and ion-exchange with HCl, followed by calcinations. - Highlights: • Ag-doped TiO{sub 2} nanowire arrays have been prepared by a duplex-treatment. • The duplex-treatment consisted of magnetron sputtering and hydrothermal growth. • Ag-doped nanowire arrays show excellent antibacterial activity against E. coli. - Abstract: Well-ordered, one-dimensional silver-doped anatase TiO{sub 2} nanowire (AgNW) arrays have been prepared through a hydrothermal growth process on the sputtering-deposited AgTi layers. Electron microscope analyses reveal that the as-synthesized AgNW arrays exhibit a single crystalline phase with highly uniform morphologies, diameters ranging from 85 to 95 nm, and lengths of about 11 μm. Silver is found to be doped into TiO{sub 2} nanowire evenly and mainly exists in the zerovalent state. The AgNW arrays show excellent efficient antibacterial activity against Escherichia coli (E. coli), and all of the bacteria can be killed within 1 h. Additionally, the AgNW arrays can still kill E. coli after immersion for 60 days, suggesting the long-term antibacterial property. The technique reported here is environmental friendly for formation of silver-containing nanostructure without using any toxic organic solvents.

Programmable dispersion on a photonic integrated circuit for classical and quantum applications.

Science.gov (United States)

Notaros, Jelena; Mower, Jacob; Heuck, Mikkel; Lupo, Cosmo; Harris, Nicholas C; Steinbrecher, Gregory R; Bunandar, Darius; Baehr-Jones, Tom; Hochberg, Michael; Lloyd, Seth; Englund, Dirk

2017-09-04

We demonstrate a large-scale tunable-coupling ring resonator array, suitable for high-dimensional classical and quantum transforms, in a CMOS-compatible silicon photonics platform. The device consists of a waveguide coupled to 15 ring-based dispersive elements with programmable linewidths and resonance frequencies. The ability to control both quality factor and frequency of each ring provides an unprecedented 30 degrees of freedom in dispersion control on a single spatial channel. This programmable dispersion control system has a range of applications, including mode-locked lasers, quantum key distribution, and photon-pair generation. We also propose a novel application enabled by this circuit - high-speed quantum communications using temporal-mode-based quantum data locking - and discuss the utility of the system for performing the high-dimensional unitary optical transformations necessary for a quantum data locking demonstration.

Robotic autopositioning of the operating microscope.

Science.gov (United States)

Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

2014-06-01

Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

Microshutter Array Development for the Multi-Object Spectrograph for the New Generation Space Telescope, and Its Ground-based Demonstrator

Science.gov (United States)

Woodgate, Bruce E.; Moseley, Harvey; Fettig, Rainer; Kutyrev, Alexander; Ge, Jian; Fisher, Richard R. (Technical Monitor)

2001-01-01

The 6.5-m NASA/ESA/Canada New Generation Space Telescope to be operated at the L2 Lagrangian point will require a multi-object spectrograph (MOS) operating from 1 to 5 microns. Up to 3000 targets will be selected for simultaneous spectroscopy using a programmable cryogenic (approx. 35K) aperture array, consisting of a mosaic of arrays of micromirrors or microshutters. We describe the current status of the GSFC microshutter array development. The 100 micron square shutters are opened magnetically and latched open or closed electrostatically. Selection will be by two crossed one-dimensional addressing circuits. We will demonstrate the use of a 512 x 512 unit array on a ground-based IR MOS which will cover 0.6 to 5 microns, and operate rapidly to include spectroscopy of gamma ray burst afterglows.

FPGAs for software programmers

CERN Document Server

Hannig, Frank; Ziener, Daniel

2016-01-01

This book makes powerful Field Programmable Gate Array (FPGA) and reconfigurable technology accessible to software engineers by covering different state-of-the-art high-level synthesis approaches (e.g., OpenCL and several C-to-gates compilers). It introduces FPGA technology, its programming model, and how various applications can be implemented on FPGAs without going through low-level hardware design phases. Readers will get a realistic sense for problems that are suited for FPGAs and how to implement them from a software designer’s point of view. The authors demonstrate that FPGAs and their programming model reflect the needs of stream processing problems much better than traditional CPU or GPU architectures, making them well-suited for a wide variety of systems, from embedded systems performing sensor processing to large setups for Big Data number crunching. This book serves as an invaluable tool for software designers and FPGA design engineers who are interested in high design productivity through behavi...

Nanocrystalline TiO{sub 2} micropillar arrays grafted on conductive glass supports: microscopic and spectroscopic studies

Energy Technology Data Exchange (ETDEWEB)

Cesano, Federico, E-mail: federico.cesano@unito.it; Agostini, Giovanni, E-mail: giovanni.agostini@esrf.fr; Scarano, Domenica

2015-09-01

Vertically oriented TiO{sub 2} micropillar arrays were obtained on Fluorine-doped Tin Oxide (FTO) conductive glasses by adopting a facile and cost-effective method. The process consists in the spray-coating with a polymer film containing an organo-metallic precursor (Ti isopropoxyde), followed by scratching the film surface by means of a sandpaper and an oxidative treatment. The role played by the scratching step in the formation of vertically oriented TiO{sub 2} micropillars, as well as the nanostructured scaffold nature consequent upon the oxidation, will be highlighted. The morphology, structure and optical properties of samples, were investigated by combining electron and atomic force microscopies with X-ray diffraction and UV–vis spectroscopy. Due to the robust texture of highly crystalline and cemented anatase and rutile nanoparticles and to the porous nature of TiO{sub 2} pillars covering FTO glasses, this system may find application in energy, photochemistry and photodegradation fields. - Highlights: • TiO{sub 2}-based polymer films are deposited on a conductive glass by spray coating. • The polymer film is scratched by a sandpaper. • Quasi-regular arrays of TiO{sub 2} micropillars are obtained via thermal oxidation. • Nanostructured TiO{sub 2} pillars are robust, porous and well adhering to the conductive glass.

Microscopic approach to polaritons

DEFF Research Database (Denmark)

Skettrup, Torben

1981-01-01

contrary to experimental experience. In order to remove this absurdity the semiclassical approach must be abandoned and the electromagnetic field quantized. A simple microscopic polariton model is then derived. From this the wave function for the interacting exciton-photon complex is obtained...... of light of the crystal. The introduction of damping smears out the excitonic spectra. The wave function of the polariton, however, turns out to be very independent of damping up to large damping values. Finally, this simplified microscopic polariton model is compared with the exact solutions obtained...... for the macroscopic polariton model by Hopfield. It is seen that standing photon and exciton waves must be included in an exact microscopic polariton model. However, it is concluded that for practical purposes, only the propagating waves are of importance and the simple microscopic polariton wave function derived...

Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope

DEFF Research Database (Denmark)

Jensen, Carsten P.

Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope......Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope...

Martian Microscope

Science.gov (United States)

2004-01-01

The microscopic imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th sol of the rover's journey. The microscopic imager is located on the rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red.

The Scanning Optical Microscope.

Science.gov (United States)

Sheppard, C. J. R.

1978-01-01

Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

Large micro-mirror arrays: key components in future space instruments for Universe and Earth Observation

Directory of Open Access Journals (Sweden)

Zamkotsian Frederic

2015-01-01

Full Text Available In future space missions for Universe and Earth Observation, scientific return could be optimized using MOEMS devices. Micro-mirror arrays are used for designing new generation of instruments, multi-object spectrographs in Universe Observation and programmable wide field spectrographs in Earth Observation. Mock-ups have been designed and built for both applications and they show very promising results.

Atomic force microscope with integrated optical microscope for biological applications

OpenAIRE

Putman, Constant A.J.; Putman, C.A.J.; van der Werf, Kees; de Grooth, B.G.; van Hulst, N.F.; Segerink, Franciscus B.; Greve, Jan

1992-01-01

Since atomic force microscopy (AFM) is capable of imaging nonconducting surfaces, the technique holds great promises for high‐resolution imaging of biological specimens. A disadvantage of most AFMs is the fact that the relatively large sample surface has to be scanned multiple times to pinpoint a specific biological object of interest. Here an AFM is presented which has an incorporated inverted optical microscope. The optical image from the optical microscope is not obscured by the cantilever...

Foldscope: origami-based paper microscope.

Directory of Open Access Journals (Sweden)

James S Cybulski

Full Text Available Here we describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education.

Regulatory issues on using programmable logic device in nuclear power plants

International Nuclear Information System (INIS)

Park, G. Y.; Yu, Y. J.; Kim, H. T.; Kwon, Y. I.; Park, H. S.; Jeong, C. H.

2012-01-01

For replacing obsolete analog equipment in nuclear power plant, the Programmable Logic Devices (PLDs) using Hardware Description Language (HDL) have been widely adopted in digitalized Instrumentation and Control (I and C) systems because of its flexibility. For safety reviews on Nuclear Power Plants (NPPs,) qualifying digitalized safety I and C system using PLDs is an important issue. As an effort to provide regulatory position on using PLDs in safety I and C system, there is a research project to provide the regulatory positions against emerging issues involved with digitalisation of I and C system including using PLDs. Therefore, this paper addresses the important considerations for using PLDs in safety I and C systems such as diversity, independence and qualification, etc. In this point, this study focuses on technical reports for Field Programmable Gate Array (FPGA) from EPRI,. U.S. NRC, and relevant technical standards

Regulatory issues on using programmable logic device in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Park, G. Y.; Yu, Y. J.; Kim, H. T.; Kwon, Y. I.; Park, H. S.; Jeong, C. H. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2012-10-15

For replacing obsolete analog equipment in nuclear power plant, the Programmable Logic Devices (PLDs) using Hardware Description Language (HDL) have been widely adopted in digitalized Instrumentation and Control (I and C) systems because of its flexibility. For safety reviews on Nuclear Power Plants (NPPs,) qualifying digitalized safety I and C system using PLDs is an important issue. As an effort to provide regulatory position on using PLDs in safety I and C system, there is a research project to provide the regulatory positions against emerging issues involved with digitalisation of I and C system including using PLDs. Therefore, this paper addresses the important considerations for using PLDs in safety I and C systems such as diversity, independence and qualification, etc. In this point, this study focuses on technical reports for Field Programmable Gate Array (FPGA) from EPRI,. U.S. NRC, and relevant technical standards.

FPscope: a field-portable high-resolution microscope using a cellphone lens.

Science.gov (United States)

Dong, Siyuan; Guo, Kaikai; Nanda, Pariksheet; Shiradkar, Radhika; Zheng, Guoan

2014-10-01

The large consumer market has made cellphone lens modules available at low-cost and in high-quality. In a conventional cellphone camera, the lens module is used to demagnify the scene onto the image plane of the camera, where image sensor is located. In this work, we report a 3D-printed high-resolution Fourier ptychographic microscope, termed FPscope, which uses a cellphone lens in a reverse manner. In our platform, we replace the image sensor with sample specimens, and use the cellphone lens to project the magnified image to the detector. To supersede the diffraction limit of the lens module, we use an LED array to illuminate the sample from different incident angles and synthesize the acquired images using the Fourier ptychographic algorithm. As a demonstration, we use the reported platform to acquire high-resolution images of resolution target and biological specimens, with a maximum synthetic numerical aperture (NA) of 0.5. We also show that, the depth-of-focus of the reported platform is about 0.1 mm, orders of magnitude longer than that of a conventional microscope objective with a similar NA. The reported platform may enable healthcare accesses in low-resource settings. It can also be used to demonstrate the concept of computational optics for educational purposes.

Infrared up-conversion microscope

DEFF Research Database (Denmark)

2014-01-01

There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...

Compact, Light-weight and Cost-effective Microscope based on Lensless Incoherent Holography for Telemedicine Applications

Science.gov (United States)

Mudanyali, Onur; Tseng, Derek; Oh, Chulwoo; Isikman, Serhan O.; Sencan, Ikbal; Bishara, Waheb; Oztoprak, Cetin; Seo, Sungkyu; Khademhosseini, Bahar; Ozcan, Aydogan

2010-01-01

Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing ~46 grams with dimensions smaller than 4.2cm × 4.2cm × 5.8cm that achieves sub-cellular resolution over a large field of view of ~24 mm2. This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings. PMID:20401422

Programmable level-1 trigger with 3D-Flow processor array

International Nuclear Information System (INIS)

Crosetto, D.

1994-01-01

The 3D-Flow parallel processing system is a new concept in processor architecture, system architecture, and assembly architecture. Compared to the electronics used in present systems, this approach reduces the cost and complexity of the hardware and allows easy assembly, disassembly, incremental upgrading, and maintenance of different interconnection topologies. The 3D-Flow parallel-processing system benefits high energy physics (HEP) by allowing: (1) common less costly hardware to be used in different experiments. (2) new uses of existing installations. (3) tuning of trigger based on the first analyzed data, and (4) selection of desired events directly from raw data. The goal of this parallel-processing architecture is to acquire multiple data in parallel (up to 100 million frames per second) and to process them at high speed, accomplishing digital filtering on the input data, pattern recognition (particle identification), data moving, and data formatting. The main features of the system are its programmability, scalability, high-speed communication, and low cost. The compactness of the 3D-Flow parallel-processing system in concert with the processor architecture allows processor interconnections to be mapped into the geometry of sensors (detectors in HEP) without large interconnection signal delay, enabling real-time pattern recognition. The overall 3D-Flow project has passed a major design review at Fermilab (Reviewers included experts in computers, triggering, system assembly, and electronics)

Material versatility using replica molding for large-scale fabrication of high aspect-ratio, high density arrays of nano-pillars

International Nuclear Information System (INIS)

Li, Y; Menon, C; Ng, H W; Gates, B D

2014-01-01

Arrays of high aspect-ratio (AR) nano-pillars have attracted a lot of interest for various applications, such as for use in solar cells, surface acoustic sensors, tissue engineering, bio-inspired adhesives and anti-reflective surfaces. Each application may require a different structural material, which can vary in the required chemical composition and mechanical properties. In this paper, a low cost fabrication procedure is proposed for large scale, high AR and high density arrays of nano-pillars. The proposed method enables the replication of a master with high fidelity, using the subsequent replica molds multiple times, and preparing arrays of nano-pillars in a variety of different materials. As an example applied to bio-inspired dry adhesion, polymeric arrays of nano-pillars are prepared in this work. Thermoset and thermoplastic nano-pillar arrays are examined using an atomic force microscope to assess their adhesion strength and its uniformity. Results indicate the proposed method is robust and can be used to reliably prepare nano-structures with a high AR. (paper)

Structural control of ultra-fine CoPt nanodot arrays via electrodeposition process

Energy Technology Data Exchange (ETDEWEB)

Wodarz, Siggi [Department of Applied Chemistry, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Hasegawa, Takashi; Ishio, Shunji [Department of Materials Science, Akita University, Akita City 010-8502 (Japan); Homma, Takayuki, E-mail: t.homma@waseda.jp [Department of Applied Chemistry, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

2017-05-15

CoPt nanodot arrays were fabricated by combining electrodeposition and electron beam lithography (EBL) for the use of bit-patterned media (BPM). To achieve precise control of deposition uniformity and coercivity of the CoPt nanodot arrays, their crystal structure and magnetic properties were controlled by controlling the diffusion state of metal ions from the initial deposition stage with the application of bath agitation. Following bath agitation, the composition gradient of the CoPt alloy with thickness was mitigated to have a near-ideal alloy composition of Co:Pt =80:20, which induces epitaxial-like growth from Ru substrate, thus resulting in the improvement of the crystal orientation of the hcp (002) structure from its initial deposition stages. Furthermore, the cross-sectional transmission electron microscope (TEM) analysis of the nanodots deposited with bath agitation showed CoPt growth along its c-axis oriented in the perpendicular direction, having uniform lattice fringes on the hcp (002) plane from the Ru underlayer interface, which is a significant factor to induce perpendicular magnetic anisotropy. Magnetic characterization of the CoPt nanodot arrays showed increase in the perpendicular coercivity and squareness of the hysteresis loops from 2.0 kOe and 0.64 (without agitation) to 4.0 kOe and 0.87 with bath agitation. Based on the detailed characterization of nanodot arrays, the precise crystal structure control of the nanodot arrays with ultra-high recording density by electrochemical process was successfully demonstrated. - Highlights: • Ultra-fine CoPt nanodot arrays were fabricated by electrodeposition. • Crystallinity of hcp (002) was improved with uniform composition formation. • Uniform formation of hcp lattices leads to an increase in the coercivity.

Scanning tunnelling microscope fabrication of phosphorus array in silicon for a nuclear spin quantum computer

International Nuclear Information System (INIS)

O'Brien, J.L.; Schofield, S.R.; Simmons, M.Y.; Clark, R.G.; Dzurak, A.S.; Prawer, S.; Adrienko, I.; Cimino, A.

2000-01-01

Full text: In the vigorous worldwide effort to experimentally build a quantum computer, recent intense interest has focussed on solid state approaches for their promise of scalability. Particular attention has been given to silicon-based proposals that can readily be integrated into conventional computing technology. For example the Kane design uses the well isolated nuclear spin of phosphorous donor nuclei (I=1/2) as the qubits embedded in isotopically pure 28 Si (I=0). We demonstrate the ability to fabricate a precise array of P atoms on a clean Si surface with atomic-scale resolution compatible with the fabrication of the Kane quantum computer

Telescope Array Control System Based on Wireless Touch Screen Platform

Science.gov (United States)

Fu, Xia-nan; Huang, Lei; Wei, Jian-yan

2017-10-01

Ground-based Wide Angle Cameras (GMAC) are the ground-based observational facility for the SVOM (Space Variable Object Monitor) astronomical satellite of Sino-French cooperation, and Mini-GWAC is the pathfinder and supplement of GWAC. In the context of the Mini-GWAC telescope array, this paper introduces the design and implementation of a kind of telescope array control system based on the wireless touch screen platform. We describe the development and implementation of the system in detail in terms of control system principle, system hardware structure, software design, experiment, and test etc. The system uses a touch-control PC which is based on the Windows CE system as the upper computer, while the wireless transceiver module and PLC (Programmable Logic Controller) are taken as the system kernel. It has the advantages of low cost, reliable data transmission, and simple operation. And the control system has been applied to the Mini-GWAC successfully.

Molecular Dynamics Simulation of High Density DNA Arrays

Directory of Open Access Journals (Sweden)

Rudolf Podgornik

2018-01-01

Full Text Available Densely packed DNA arrays exhibit hexagonal and orthorhombic local packings, as well as a weakly first order transition between them. While we have some understanding of the interactions between DNA molecules in aqueous ionic solutions, the structural details of its ordered phases and the mechanism governing the respective phase transitions between them remains less well understood. Since at high DNA densities, i.e., small interaxial spacings, one can neither neglect the atomic details of the interacting macromolecular surfaces nor the atomic details of the intervening ionic solution, the atomistic resolution is a sine qua non to properly describe and analyze the interactions between DNA molecules. In fact, in order to properly understand the details of the observed osmotic equation of state, one needs to implement multiple levels of organization, spanning the range from the molecular order of DNA itself, the possible ordering of counterions, and then all the way to the induced molecular ordering of the aqueous solvent, all coupled together by electrostatic, steric, thermal and direct hydrogen-bonding interactions. Multiscale simulations therefore appear as singularly suited to connect the microscopic details of this system with its macroscopic thermodynamic behavior. We review the details of the simulation of dense atomistically resolved DNA arrays with different packing symmetries and the ensuing osmotic equation of state obtained by enclosing a DNA array in a monovalent salt and multivalent (spermidine counterions within a solvent permeable membrane, mimicking the behavior of DNA arrays subjected to external osmotic stress. By varying the DNA density, the local packing symmetry, and the counterion type, we are able to analyze the osmotic equation of state together with the full structural characterization of the DNA subphase, the counterion distribution and the solvent structural order in terms of its different order parameters and

Programme

OpenAIRE

Hobday, E, fl. 1905, artist

2003-01-01

A photograph of an illustrated programme listing dances. The illustration shows a snake charmer playing to a snake while another man watches. Buildings and trees can be seen behind a wall in the distance. In the lower right-hand corner of the programme is the signature 'E. Hobday'. The programme is almost certainly related to the Punjab Ball, Lahore. It is placed next to the Punjab Ball Menu in the album and the Menu is also illustrated by 'E. Hobday'.

Focal plane array with modular pixel array components for scalability

Science.gov (United States)

Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

2014-12-09

A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

Gigapixel imaging with microlens arrays

Science.gov (United States)

Orth, Antony; Schonbrun, Ethan

2016-03-01

A crucial part of the drug discovery process involves imaging the response of thousands of cell cultures to candidate drugs. Quantitative parameters from these "high content screens", such as protein expression and cell morphology, are extracted from fluorescence and brightfield micrographs. Due to the sheer number of cells that need to imaged for adequate statistics, the imaging time itself is a major bottleneck. Automated microscopes image small fields-of-view (FOVs) serially, which are then stitched together to form gigapixel-scale mosaics. We have developed a microscopy architecture that reduces mechanical overhead of traditional large field-of-view by parallelizing the image capture process. Instead of a single objective lens imaging FOVs one by one, we employ a microlens array for continuous photon capture, resulting in a 3-fold throughput increase. In this contribution, we present the design and imaging results of this microscopy architecture in three different contrast modes: multichannel fluorescence, hyperspectral fluorescence and brightfield.

A template-free sol-gel technique for controlled growth of ZnO nanorod arrays

International Nuclear Information System (INIS)

Huang, N.; Zhu, M.W.; Gao, L.J.; Gong, J.; Sun, C.; Jiang, X.

2011-01-01

The growth of ZnO nanorod arrays via a template-free sol-gel process was investigated. The nanorod is single-crystalline wurtzite structure with [0 0 0 1] growth direction determined by the transmission electron microscope. The aligned ZnO arrays were obtained directly on the glass substrates by adjusting the temperatures and the withdrawal speeds, without seed-layer or template assistant. A thicker oriented ZnO nanorod arrays was obtained at proper experimental conditions by adding dip-coating layers. Room temperature photoluminescence spectrum exhibits an intensive UV emission with a weak broad green emission as well as a blue double-peak emission located at 451 and 468 nm, respectively. Further investigation results show that the difference in the alignment of nanorods ascribes to the different orientations of the nanoparticles-packed film formed prior to nanorods on the substrate. Well ordered ZnO nanorods are formed from this film with good c-axis orientation. Our study is expected to pave a way for direct growth of oriented nanorods by low-cost solution approaches.

Exploiting first-class arrays in Fortran for accelerator programming

International Nuclear Information System (INIS)

Rasmussen, Craig E.; Weseloh, Wayne N.; Robey, Robert W.; Sottile, Matthew J.; Quinlan, Daniel; Overbey, Jeffrey

2010-01-01

Emerging architectures for high performance computing often are well suited to a data parallel programming model. This paper presents a simple programming methodology based on existing languages and compiler tools that allows programmers to take advantage of these systems. We will work with the array features of Fortran 90 to show how this infrequently exploited, standardized language feature is easily transformed to lower level accelerator code. Our transformations are based on a mapping from Fortran 90 to C++ code with OpenCL extensions. The sheer complexity of programming for clusters of many or multi-core processors with tens of millions threads of execution make the simplicity of the data parallel model attractive. Furthermore, the increasing complexity of todays applications (especially when convolved with the increasing complexity of the hardware) and the need for portability across hardware architectures make a higher-level and simpler programming model like data parallel attractive. The goal of this work has been to exploit source-to-source transformations that allow programmers to develop and maintain programs at a high-level of abstraction, without coding to a specific hardware architecture. Furthermore these transformations allow multiple hardware architectures to be targeted without changing the high-level source. It also removes the necessity for application programmers to understand details of the accelerator architecture or to know OpenCL.

Timed arrays wideband and time varying antenna arrays

CERN Document Server

Haupt, Randy L

2015-01-01

Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

Microwave Microscope

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

Photon-Counting Arrays for Time-Resolved Imaging

Directory of Open Access Journals (Sweden)

I. Michel Antolovic

2016-06-01

Full Text Available The paper presents a camera comprising 512 × 128 pixels capable of single-photon detection and gating with a maximum frame rate of 156 kfps. The photon capture is performed through a gated single-photon avalanche diode that generates a digital pulse upon photon detection and through a digital one-bit counter. Gray levels are obtained through multiple counting and accumulation, while time-resolved imaging is achieved through a 4-ns gating window controlled with subnanosecond accuracy by a field-programmable gate array. The sensor, which is equipped with microlenses to enhance its effective fill factor, was electro-optically characterized in terms of sensitivity and uniformity. Several examples of capture of fast events are shown to demonstrate the suitability of the approach.

Crispv programme

International Nuclear Information System (INIS)

Marinkovicj, N.

CRISPV (Criticality and Spectrum code) is a multigroup neutron spectrum code for homogeneous reactor cores and is actually a somewhat modified version of the original CRISP programme. It is a combination of DATAPREP-II and BIGG-II programmes. It is assumed that the reactor cell is a cylindrical fuel rod in the light or heavy water moderator. DATEPREP-II CODE forms the multigroup data for homogeneous reactor and prepares the input parameters for the BIGG-II code. It has its own nuclear data library on a separate tape in binary mode. BIGG-II code is a multigroup neutron spectrum and criticality code for a homogenized medium. It has as well its own separate data library. In the CRISPV programme the overlay structure enables automatic handling of data calculated in the DATAPREP-II programme and needed in the BIGG-II core. Both programmes are written in FORTRAN for CDC 3600. Using the programme is very efficient and simple

A Student-Built Scanning Tunneling Microscope

Science.gov (United States)

Ekkens, Tom

2015-01-01

Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

A fluorescence scanning electron microscope

International Nuclear Information System (INIS)

Kanemaru, Takaaki; Hirata, Kazuho; Takasu, Shin-ichi; Isobe, Shin-ichiro; Mizuki, Keiji; Mataka, Shuntaro; Nakamura, Kei-ichiro

2009-01-01

Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM) and an electron microscope (EM). In the current study, a scanning electron microscope (SEM) (JEOL JXA8600 M) was combined with a fluorescence digital camera microscope unit and this hybrid instrument was named a fluorescence SEM (FL-SEM). In the labeling of FL-SEM samples, both Fluolid, which is an organic EL dye, and Alexa Fluor, were employed. We successfully demonstrated that the FL-SEM is a simple and practical tool for correlative fluorescence and electron microscopy.

ArrayBridge: Interweaving declarative array processing with high-performance computing

Energy Technology Data Exchange (ETDEWEB)

Xing, Haoyuan [The Ohio State Univ., Columbus, OH (United States); Floratos, Sofoklis [The Ohio State Univ., Columbus, OH (United States); Blanas, Spyros [The Ohio State Univ., Columbus, OH (United States); Byna, Suren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Prabhat, Prabhat [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Kesheng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Paul [Paradigm4, Inc., Waltham, MA (United States)

2017-05-04

Scientists are increasingly turning to datacenter-scale computers to produce and analyze massive arrays. Despite decades of database research that extols the virtues of declarative query processing, scientists still write, debug and parallelize imperative HPC kernels even for the most mundane queries. This impedance mismatch has been partly attributed to the cumbersome data loading process; in response, the database community has proposed in situ mechanisms to access data in scientific file formats. Scientists, however, desire more than a passive access method that reads arrays from files. This paper describes ArrayBridge, a bi-directional array view mechanism for scientific file formats, that aims to make declarative array manipulations interoperable with imperative file-centric analyses. Our prototype implementation of ArrayBridge uses HDF5 as the underlying array storage library and seamlessly integrates into the SciDB open-source array database system. In addition to fast querying over external array objects, ArrayBridge produces arrays in the HDF5 file format just as easily as it can read from it. ArrayBridge also supports time travel queries from imperative kernels through the unmodified HDF5 API, and automatically deduplicates between array versions for space efficiency. Our extensive performance evaluation in NERSC, a large-scale scientific computing facility, shows that ArrayBridge exhibits statistically indistinguishable performance and I/O scalability to the native SciDB storage engine.

National programme: Finland

International Nuclear Information System (INIS)

Forsten, J.

1986-01-01

Finland's programmes in the field of reactor pressure components are presented in this paper. The following information on each of these programmes is given: the brief description of the programme; the programme's schedule and duration; the name of the project manager

Transmission electron microscope CCD camera

Science.gov (United States)

Downing, Kenneth H.

1999-01-01

In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

A compact scanning soft X-ray microscope

International Nuclear Information System (INIS)

Trail, J.A.

1989-01-01

Soft x-ray microscopes operating at wavelengths between 2.3 nm and 4.4 nm are capable of imaging wet biological cells with a resolution many times that of a visible light microscope. Several such soft x-ray microscopes have been constructed. However, with the exception of contact microscopes, all use synchrotrons as the source of soft x-ray radiation and Fresnel zone plates as the focusing optics. These synchrotron based microscopes are very successful but have the disadvantage of limited access. This dissertation reviews the construction and performance of a compact scanning soft x-ray microscope whose size and accessibility is comparable to that of an electron microscope. The microscope uses a high-brightness laser-produced plasma as the soft x-ray source and normal incidence multilayer-coated mirrors in a Schwarzschild configuration as the focusing optics. The microscope operates at a wavelength of 14 nm, has a spatial resolution of 0.5 μm, and has a soft x-ray photon flux through the focus of 10 4 -10 5 s -1 when operated with only 170 mW of average laser power. The complete system, including the laser, fits on a single 4' x 8' optical table. The significant components of the compact microscope are the laser-produced plasma (LPP) source, the multilayer coatings, and the Schwarzschild objective. These components are reviewed, both with regard to their particular use in the current microscope and with regard to extending the microscope performance to higher resolution, higher speed, and operation at shorter wavelengths. Measurements of soft x-ray emission and debris emission from our present LPP source are presented and considerations given for an optimal LPP source. The LPP source was also used as a broadband soft x-ray source for measurement of normal incidence multilayer mirror reflectance in the 10-25 nm spectral region

Modelling of critical functions of nuclear reactors using Fild Programmable Gate Array

International Nuclear Information System (INIS)

Teixeira, Pamela Iara Nolasco

2016-01-01

This paper proposes the development of a method using FPGA for critical security functions of a nuclear reactor. It was implemented two critical safety functions in VHDL, which is a way to describe, through a program, the behavior of a circuit or digital component. Two critical security functions, FCS Core Cooling, responsible for cooling the reactor core in the charts of the plant and also in the event of accidents involving loss of coolant and FCS Heat Transfer, responsible for cooling the reactor core in the event an accident with loss of coolant were implemented. In this Dissertation it was chosen the use of FPGA, because - due to the effects of aging, obsolescence issues, environmental degradation and mechanical failures - nuclear power plants need to replace their older systems by new ones based on digital technology. The technologies obtained using a system described in hardware language can be implemented in a programmable device, having the advantage of changing the code at any time. (author)

A quadruple-scanning-probe force microscope for electrical property measurements of microscopic materials

International Nuclear Information System (INIS)

Higuchi, Seiji; Kubo, Osamu; Kuramochi, Hiromi; Aono, Masakazu; Nakayama, Tomonobu

2011-01-01

Four-terminal electrical measurement is realized on a microscopic structure in air, without a lithographic process, using a home-built quadruple-scanning-probe force microscope (QSPFM). The QSPFM has four probes whose positions are individually controlled by obtaining images of a sample in the manner of atomic force microscopy (AFM), and uses the probes as contacting electrodes for electrical measurements. A specially arranged tuning fork probe (TFP) is used as a self-detection force sensor to operate each probe in a frequency modulation AFM mode, resulting in simultaneous imaging of the same microscopic feature on an insulator using the four TFPs. Four-terminal electrical measurement is then demonstrated in air by placing each probe electrode in contact with a graphene flake exfoliated on a silicon dioxide film, and the sheet resistance of the flake is measured by the van der Pauw method. The present work shows that the QSPFM has the potential to measure the intrinsic electrical properties of a wide range of microscopic materials in situ without electrode fabrication.

Mechanical control of the plasmon coupling with Au nanoparticle arrays fixed on the elastomeric film via chemical bond

Science.gov (United States)

Bedogni, Elena; Kaneko, Satoshi; Fujii, Shintaro; Kiguchi, Manabu

2017-03-01

We have fabricated Au nanoparticle arrays on the flexible poly(dimethylsiloxane) (PDMS) film. The nanoparticles were bound to the film via a covalent bond by a ligand exchange reaction. Thanks to the strong chemical bonding, highly stable and uniformly dispersed Au nanoparticle arrays were fixed on the PDMS film. The Au nanoparticle arrays were characterized by the UV-vis, scanning electron microscope (SEM) and surface enhanced Raman scattering (SERS). The UV-vis and SEM measurements showed the uniformity of the surface-dispersed Au nanoparticles, and SERS measurement confirmed the chemistry of the PDMS film. Reflecting the high stability and the uniformity of the Au nanoparticle arrays, the plasmon wavelength of the Au nanoparticles reversely changed with modulation of the interparticle distance, which was induced by the stretching of the PDMS film. The plasmon wavelength linearly decreased from 664 to 591 nm by stretching of 60%. The plasmon wavelength shift can be explained by the change in the strength of the plasmon coupling which is mechanically controlled by the mechanical strain.

Vortex dynamics in two-dimensional Josephson junction arrays with asymmetrically bimodulated potential

International Nuclear Information System (INIS)

Nie, Qing-Miao; Zhang, Sha-Sha; Chen, Qing-Hu; Zhou, Wei

2012-01-01

On the basis of resistively-shunted junction dynamics, we study vortex dynamics in two-dimensional Josephson junction arrays with asymmetrically single and bimodulated periodic pinning potential for the full range of vortex density f. The ratchet effect occurring at a certain range of temperature, current, and f, is observed in our simulation. We explain the microscopic behavior behind this effect by analyzing the vortex distribution and interaction. The reversal of the ratchet effect can be observed at several f values for a small driven current. This effect is stronger when the asymmetric potential is simultaneously introduced in two directions. -- Highlights: ► The ratchet effect in Josephson junction arrays strongly depends on vortex density. ► The reversed ratchet effect can be observed at several f for a small current. ► The interaction between vortices can explain the reversed ratchet effect. ► The ratchet effect is enhanced by injecting the bimodulated asymmetric potential.

The Digital Microscope and Its Image Processing Utility

Directory of Open Access Journals (Sweden)

Tri Wahyu Supardi

2011-12-01

Full Text Available Many institutions, including high schools, own a large number of analog or ordinary microscopes. These microscopes are used to observe small objects. Unfortunately, object observations on the ordinary microscope require precision and visual acuity of the user. This paper discusses the development of a high-resolution digital microscope from an analog microscope, including the image processing utility, which allows the digital microscope users to capture, store and process the digital images of the object being observed. The proposed microscope is constructed from hardware components that can be easily found in Indonesia. The image processing software is capable of performing brightness adjustment, contrast enhancement, histogram equalization, scaling and cropping. The proposed digital microscope has a maximum magnification of 1600x, and image resolution can be varied from 320x240 pixels up to 2592x1944 pixels. The microscope was tested with various objects with a variety of magnification, and image processing was carried out on the image of the object. The results showed that the digital microscope and its image processing system were capable of enhancing the observed object and other operations in accordance with the user need. The digital microscope has eliminated the need for direct observation by human eye as with the traditional microscope.

The fabrication of ordered arrays of exchange biased Ni/FeF2 nanostructures

International Nuclear Information System (INIS)

Kovylina, M; Labarta, A; Batlle, X; Erekhinsky, M; Schuller, I K; Morales, R

2010-01-01

The fabrication of ordered arrays of exchange biased Ni/FeF 2 nanostructures by focused ion beam lithography is reported. High quality nano-elements, with controlled removal depth and no significant re-deposition, were carved using small ion beam currents (30 pA), moderate dwell times (1 μs) and repeated passages over the same area. Two types of nanostructures were fabricated: square arrays of circular dots with diameters from 125 ± 8 to 500 ± 12 nm and periodicities ranging from 200 ± 8 to 1000 ± 12 nm, and square arrays of square antidots (207 ± 8 nm in edge length) with periodicities ranging from 300 ± 8 to 1200 ± 12 nm. The arrays were characterized using scanning ion and electron microscopy, and atomic force microscopy. The effect of the patterning on the exchange bias field (i.e., the shift in the hysteresis loop of ferromagnetic Ni due to proximity to antiferromagnetic FeF 2 ) was studied using magneto-transport measurements. These high quality nanostructures offer a unique method to address some of the open questions regarding the microscopic origin of exchange bias. This is not only of major relevance in the fabrication and miniaturization of magnetic devices but it is also one of the important proximity phenomena in nanoscience and materials science.

Scanning Microscopes Using X Rays and Microchannels

Science.gov (United States)

Wang, Yu

2003-01-01

Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, Miniature Microscope Without Lenses (NPO-20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43; and Reflective Variants of Miniature Microscope Without Lenses (NPO-20610), NASA Tech Briefs, Vol. 26, No. 9 (September 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the

Programmable Input Mode Instrumentation Amplifier Using Multiple Output Current Conveyors

Directory of Open Access Journals (Sweden)

Pankiewicz Bogdan

2017-03-01

Full Text Available In this paper a programmable input mode instrumentation amplifier (IA utilising second generation, multiple output current conveyors and transmission gates is presented. Its main advantage is the ability to choose a voltage or current mode of inputs by setting the voltage of two configuration nodes. The presented IA is prepared as an integrated circuit block to be used alone or as a sub-block in a microcontroller or in a field programmable gate array (FPGA, which shall condition analogue signals to be next converted by an analogue-to-digital converter (ADC. IA is designed in AMS 0.35 µm CMOS technology and the power supply is 3.3 V; the power consumption is approximately 9.1 mW. A linear input range in the voltage mode reaches ± 1.68 V or ± 250 µA in current mode. A passband of the IA is above 11 MHz. The amplifier works in class A, so its current supply is almost constant and does not cause noise disturbing nearby working precision analogue circuits.

Mobile microscope complex GIB-1

International Nuclear Information System (INIS)

Belyakov, A.V.; Gorbachev, A.N.

2002-01-01

To study microstructure in operating pipelines of power units a mobile microscope system is developed and successfully used. The system includes a portable microscope, a monitor, power supply and a portable computer. The monitor is used for surveying images from a video camera mounted on the microscope. The magnification on visual examination constitutes x 100 and x 500. Diameters of pipelines examined should not be less than 130 mm. Surface preparation for microstructural studies includes routine mechanical rough grinding and polishing with subsequent etching [ru

The deuteron microscopic optical potential

International Nuclear Information System (INIS)

Lu Congshan; Zhang Jingshang; Shen Qingbiao

1991-01-01

The two particle Green's function is introduced. When the direct interaction between two nucleons is neglected, the first and second order mass operators of two particles are the sum of those for each particle. The nucleon microscopic optical potential is calculated by applying nuclear matter approximation and effective Skyrme interaction. Then the deuteron microscopic optical potential (DMOP) is calculated by using fold formula. For improvement of the theory, the two particle polarization diagram contribution to the imaginary part of the deuteron microscopic optical potential is studied

A Memory-Based Programmable Logic Device Using Look-Up Table Cascade with Synchronous Static Random Access Memories

Science.gov (United States)

Nakamura, Kazuyuki; Sasao, Tsutomu; Matsuura, Munehiro; Tanaka, Katsumasa; Yoshizumi, Kenichi; Nakahara, Hiroki; Iguchi, Yukihiro

2006-04-01

A large-scale memory-technology-based programmable logic device (PLD) using a look-up table (LUT) cascade is developed in the 0.35-μm standard complementary metal oxide semiconductor (CMOS) logic process. Eight 64 K-bit synchronous SRAMs are connected to form an LUT cascade with a few additional circuits. The features of the LUT cascade include: 1) a flexible cascade connection structure, 2) multi phase pseudo asynchronous operations with synchronous static random access memory (SRAM) cores, and 3) LUT-bypass redundancy. This chip operates at 33 MHz in 8-LUT cascades at 122 mW. Benchmark results show that it achieves a comparable performance to field programmable gate array (FPGAs).

Small-size low-temperature scanning tunnel microscope

International Nuclear Information System (INIS)

Al'tfeder, I.B.; Khajkin, M.S.

1989-01-01

A small-size scanning tunnel microscope, designed for operation in transport helium-filled Dewar flasks is described. The microscope design contains a device moving the pin to the tested sample surface and a piezoelectric fine positioning device. High vibration protection of the microscope is provided by its suspension using silk threads. The small-size scanning tunnel microscope provides for atomic resolution

Hollow silicon microneedle array based trans-epidermal antiemetic patch for efficient management of chemotherapy induced nausea and vomiting

Science.gov (United States)

Kharbikar, Bhushan N.; Kumar S., Harish; Kr., Sindhu; Srivastava, Rohit

2015-12-01

Chemotherapy Induced Nausea and Vomiting (CINV) is a serious health concern in the treatment of cancer patients. Conventional routes for administering anti-emetics (i.e. oral and parenteral) have several drawbacks such as painful injections, poor patient compliance, dependence on skilled personnel, non-affordability to majority of population (parenteral), lack of programmability and suboptimal bioavailability (oral). Hence, we have developed a trans-epidermal antiemetic drug delivery patch using out-of-plane hollow silicon microneedle array. Microneedles are pointed micron-scale structures that pierce the epidermal layer of skin to reach dermal blood vessels and can directly release the drug in their vicinity. They are painless by virtue of avoiding significant contact with dermal sensory nerve endings. This alternate approach gives same pharmacodynamic effects as par- enteral route at a sparse drug-dose requirement, hence negligible side-effects and improved patient compliance. Microneedle design attributes were derived by systematic study of human skin anatomy, natural micron-size structures like wasp-sting and cactus-spine and multi-physics simulations. We used deep reactive ion etching with Bosch process and optimized recipe of gases to fabricate high-aspect-ratio hollow silicon microneedle array. Finally, microneedle array and polydimethylsiloxane drug reservoir were assembled to make finished anti-emetic patch. We assessed microneedles mechanical stability, physico-chemical properties and performed in-vitro, ex- vivo and in-vivo studies. These studies established functional efficacy of the device in trans-epidermal delivery of anti-emetics, its programmability, ease of use and biosafety. Thus, out-of-plane hollow silicon microneedle array trans-epidermal antiemetic patch is a promising strategy for painless and effective management of CINV at low cost in mainstream healthcare.

Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications

Science.gov (United States)

Mayes, Sam A.; Leavesley, Silas J.; Rich, Thomas C.

2016-04-01

Current microscopic and endoscopic technologies for cancer screening utilize white-light illumination sources. Hyper-spectral imaging has been shown to improve sensitivity while retaining specificity when compared to white-light imaging in both microscopy and in vivo imaging. However, hyperspectral imaging methods have historically suffered from slow acquisition times due to the narrow bandwidth of spectral filters. Often minutes are required to gather a full image stack. We have developed a novel approach called excitation-scanning hyperspectral imaging that provides 2-3 orders of magnitude increased signal strength. This reduces acquisition times significantly, allowing for live video acquisition. Here, we describe a preliminary prototype excitation-scanning hyperspectral imaging system that can be coupled with endoscopes or microscopes for hyperspectral imaging of tissues and cells. Our system is comprised of three subsystems: illumination, transmission, and imaging. The illumination subsystem employs light-emitting diode arrays to illuminate at different wavelengths. The transmission subsystem utilizes a unique geometry of optics and a liquid light guide. Software controls allow us to interface with and control the subsystems and components. Digital and analog signals are used to coordinate wavelength intensity, cycling and camera triggering. Testing of the system shows it can cycle 16 wavelengths at as fast as 1 ms per cycle. Additionally, more than 18% of the light transmits through the system. Our setup should allow for hyperspectral imaging of tissue and cells in real time.

CCDiode: an optimal detector for laser confocal microscopes

Science.gov (United States)

Pawley, James B.; Blouke, Morley M.; Janesick, James R.

1996-04-01

The laser confocal microscope (LCM) is now an established research tool in biology and materials science. In biological applications, it is usually employed to detect the location of fluorescent market molecules and, under these conditions, signal levels from bright areas are often digitizer. To maintain the desired +/- 3 e noise level at the relatively high data rate of 1 MHz, our new device utilizes 64 separate readout amplifier/digitizer systems, operating in sequence. The resulting detector is more compact, efficient and reliable than the PMT it replaces but as its sensitive area is smaller than that of a PMT, it will require auxiliary optics when used with any LCM having a large (mm) pinhole. As the signal light is parallel, a simple lens mounted axially and with the CCDiode at its focus would suffice. Future versions may use 3 X 3 or 5 X 5 arrays of sensors to `track' the confocal spot as it is deflected by inhomogeneities of the specimen, change its effective size or shape or detect system misalignment.

Development of an ultrasound microscope combined with optical microscope for multiparametric characterization of a single cell.

Science.gov (United States)

Arakawa, Mototaka; Shikama, Joe; Yoshida, Koki; Nagaoka, Ryo; Kobayashi, Kazuto; Saijo, Yoshifumi

2015-09-01

Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound microscope system combined with optical microscope for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 × 80 μm with up to 200 × 200 sampling points. An inverted optical microscope was incorporated in the design of the system, allowing for simultaneous optical observations of cultured cells. Two-dimensional mapping of multiple ultrasound parameters, such as sound speed, attenuation, and acoustic impedance, as well as the thickness, density, and bulk modulus of specimen/cell under investigation, etc., was realized by the system. Sound speed and thickness of a 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound microscope system combined with optical microscope further enhances our understanding of cellular biomechanics.

Programmable CCD imaging system for synchrotron radiation studies

International Nuclear Information System (INIS)

Rodricks, B.; Brizard, C.

1992-01-01

A real-time imaging system for x-ray detection has been developed. The CAMAC-based system has a Charge Coupled Device (CCD) as its active detection element. The electronics consist of a CAMAC-crate-based dedicated microprocessor coupled to arbitrary waveform generators, programmable timing, and ADC modules. The hardware flexibility achievable through this system enables one to use virtually any commercially available CCD. A dedicated CAMAC-based display driver allows for real-time imaging on a high-resolution color monitor. An optional front end consisting of a fiber-optic taper and a focusing optical lens system coupled to a phosphor screen allows for large area imaging. Further, programming flexibility, in which the detector can be used in different read-out modes, enables it to be exploited for time-resolved experiments. In one mode, sections of the CCD can be read-out with millisecond time-resolution and, in another, the use of the CCD as a storage device is exploited resulting in microsecond time-resolution. Three different CCDs with radically different read-out timings and waveforms have been tested: the TI 4849, a 39Ox584 pixel array; TC 215, a 1024x1O24 pixel array; and the TH 7883, a 576x384 pixel array. The TC 215 and TI 4849 are single-phase CCDs manufactured by Texas Instruments, and the TH 7883 is a four-phase device manufactured by Thomson-CSF. The CCD characterized for uniformity, charge transfer efficiency (CTE), linearity, and sensitivity is the TC215

A programmable systolic trigger processor for FERA bus data

International Nuclear Information System (INIS)

Appelquist, G.; Hovander, B.; Sellden, B.; Bohm, C.

1992-09-01

A generic CAMAC based trigger processor module for fast processing of large amounts of ADC data, has been designed. This module has been realised using complex programmable gate arrays (LCAs from XILINX). The gate arrays have been connected to memories and multipliers in such a way that different gate array configurations can cover a wide range of module applications. Using this module, it is possible to construct complex trigger processors. The module uses both the fast ECL FERA bus and the CAMAC bus for inputs and outputs. The latter, however, is primarily used for set-up and control but may also be used for data output. Large numbers of ADCs can be served by a hierarchical arrangement of trigger processor modules, processing ADC data with pipe-line arithmetics producing the final result at the apex of the pyramid. The trigger decision will be transmitted to the data acquisition system via a logic signal while numeric results may be extracted by the CAMAC controller. The trigger processor was originally developed for the proposed neutral particle search experiment at CERN, NUMASS. There it was designed to serve as a second level trigger processor. It was required to correct all ADC raw data for efficiency and pedestal, calculate the total calorimeter energy, obtain the optimal time of flight data and calculate the particle mass. A suitable mass cut would then deliver the trigger decision. More complex triggers were also considered. (au)

A Digitally Programmable Differential Integrator with Enlarged Time Constant

Directory of Open Access Journals (Sweden)

S. K. Debroy

1994-12-01

Full Text Available A new Operational Amplifier (OA-RC integrator network is described. The novelties of the design are used of single grounded capacitor, ideal integration function realization with dual-input capability and design flexibility for extremely large time constant involving an enlargement factor (K using product of resistor ratios. The aspect of the digital control of K through a programmable resistor array (PRA controlled by a microprocessor has also been implemented. The effect of the OA-poles has been analyzed which indicates degradation of the integrator-Q at higher frequencies. An appropriate Q-compensation design scheme exhibiting 1 : |A|2 order of Q-improvement has been proposed with supporting experimental observations.

Scanless nonlinear optical microscope for image reconstruction and space-time correlation analysis

Science.gov (United States)

Ceffa, N. G.; Radaelli, F.; Pozzi, P.; Collini, M.; Sironi, L.; D'alfonso, L.; Chirico, G.

2017-06-01

Optical Microscopy has been applied to life science from its birth and reached widespread application due to its major advantages: limited perturbation of the biological tissue and the easy accessibility of the light sources. However, as the spatial and time resolution requirements and the time stability of the microscopes increase, researchers are struggling against some of its limitations: limited transparency and the refractivity of the living tissue to light and the field perturbations induced by the path in the tissue. We have developed a compact stand-alone, completely scan-less, optical setup that allows to acquire non-linear excitation images and to measure the sample dynamics simultaneously on an ensemble of arbitrary chosen regions of interests. The image is obtained by shining a square array of spots on the sample obtained by a spatial light modulator and by shifting it (10 ms refresh time) on the sample. The final image is computed from the superposition of (100-1000) images. Filtering procedures can be applied to the raw images of the excitation array before building the image. We discuss results that show how this setup can be used for the correction of wave front aberrations induced by turbid samples (such as living tissues) and for the computation of space-time cross-correlations in complex networks.

Mechanically modulated dewetting by atomic force microscope for micro- and nano- droplet array fabrication.

Science.gov (United States)

Wang, Feifei; Li, Pan; Wang, Dong; Li, Longhai; Xie, Shuangxi; Liu, Lianqing; Wang, Yuechao; Li, Wen Jung

2014-10-06

Organizing a material into well-defined patterns during the dewetting process provides an attractive micro-/nano-fabrication method without using a conventional lithographic process, and hence, offers potential applications in organic electronics, optics systems, and memory devices. We report here how the mechanical modification of polymer surface by an Atomic Force Microscope (AFM) can be used to guide thin film dewetting evolution and break the intrinsic spatial correlation of spontaneous instability. An AFM is used to implement the mechanical modification of progressively narrow grids to investigate the influence of pattern size on the modulation of ultrathin polystyrene films dewetting evolution. For films with different initial thicknesses, when grid size is close to or below the characteristic wavelength of instability, the spinodal dewetting is suppressed, and film rupture is restricted to the cutting trench. We will show in this paper it is possible to generate only one droplet per gridded area on a thin film subsequent to nucleation dominated dewetting on a non-patterned substrate. Furthermore, when the grid periodicity exceeds the spinodal length, the number of droplets in predefined areas gradually approaches that associated with unconfined dewetting.

Design of a transmission electron positron microscope

International Nuclear Information System (INIS)

Doyama, Masao; Inoue, M.; Kogure, Y.; Hayashi, Y.; Yoshii, T.; Kurihara, T.; Tsuno, K.

2003-01-01

This paper reports the plans and design of positron-electron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan. A used electron microscope is altered. The kinetic energies of positrons produced by accelerators or by nuclear decays are not a unique value but show a spread over in a wide range. Positron beam is guided to a transmission electron microscope (JEM100SX). Positrons are moderated by a tungsten foil, are accelerated and are focused on a nickel sheet. The monochromatic focused beam is injected into an electron microscope. The focusing and aberration of positrons are the same as electrons in a magnetic system which are used in commercial electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (author)

Site-controlled quantum dots fabricated using an atomic-force microscope assisted technique

Directory of Open Access Journals (Sweden)

Sakuma Y

2006-01-01

Full Text Available AbstractAn atomic-force microscope assisted technique is developed to control the position and size of self-assembled semiconductor quantum dots (QDs. Presently, the site precision is as good as ± 1.5 nm and the size fluctuation is within ± 5% with the minimum controllable lateral diameter of 20 nm. With the ability of producing tightly packed and differently sized QDs, sophisticated QD arrays can be controllably fabricated for the application in quantum computing. The optical quality of such site-controlled QDs is found comparable to some conventionally self-assembled semiconductor QDs. The single dot photoluminescence of site-controlled InAs/InP QDs is studied in detail, presenting the prospect to utilize them in quantum communication as precisely controlled single photon emitters working at telecommunication bands.

Occupational concerns associated with regular use of microscope.

Science.gov (United States)

Jain, Garima; Shetty, Pushparaja

2014-08-01

Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. a questionnaire based survey done on 50 professionals and technicians who used microscope regularly in pathology, microbiology, hematology and cytology laboratories. Sixty two percent of subjects declared that they were suffering from musculoskeletal problems, most common locations being neck and back. Maximum prevalence of musculoskeletal problems was noted in those using microscope for 11-15 years and for more than 30 h/week. Sixty two percent of subjects were aware of workplace ergonomics. Fifty six percent of microscope users took regular short breaks for stretching exercises and 58% took visual breaks every 15-30 min in between microscope use sessions. As many as 94% subjects reported some form of visual problem. Fourty four percent of microscope users felt stressed with long working hours on microscope. The most common occupational concerns of microscope users were musculoskeletal problems of neck and back regions, eye fatigue, aggravation of ametropia, headache, stress due to long working hours and anxiety during or after microscope use. There is an immediate need for increasing awareness about the various occupational hazards and their irreversible effects to prevent them.

Design for an IO block array in a tile-based FPGA

International Nuclear Information System (INIS)

Ding Guangxin; Chen Lingdou; Liu Zhongli

2009-01-01

A design for an IO block array in a tile-based FPGA is presented. Corresponding with the characteristics of the FPGA, each IO cell is composed of a signal path, local routing pool and configurable input/output buffers. Shared programmable registers in the signal path can be configured for the function of JTAG, without specific boundary scan registers/latches, saving layout area. The local routing pool increases the flexibility of routing and the routability of the whole FPGA. An auxiliary power supply is adopted to increase the performance of the IO buffers at different configured IO standards. The organization of the IO block array is described in an architecture description file, from which the array layout can be accomplished through use of an automated layout assembly tool. This design strategy facilitates the design of FPGAs with different capacities or architectures in an FPGA family series. The bond-out schemes of the same FPGA chip in different packages are also considered. The layout is based on SMIC 0.13 μm logic 1P8M salicide 1.2/2.5 V CMOS technology. Our performance is comparable with commercial SRAM-based FPGAs which use a similar process. (semiconductor integrated circuits)

Microscopic Polyangiitis

Science.gov (United States)

... body, specifically the feet, lower legs and, in bed-ridden patients, the buttocks. The skin findings of cutaneous ... that are in contact with the lungs’ microscopic air sacs – the condition may quickly pose a threat ...

Electron microscope studies

International Nuclear Information System (INIS)

Crewe, A.V.; Kapp, O.H.

1992-01-01

This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations

Electron microscope studies

Energy Technology Data Exchange (ETDEWEB)

Crewe, A.V.; Kapp, O.H.

1992-07-01

This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

Silicon Micromachined Microlens Array for THz Antennas

Science.gov (United States)

Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, IImran; Gill, John J.; Jung-Kubiak, Cecile D.; Llombart, Nuria

2013-01-01

5 5 silicon microlens array was developed using a silicon micromachining technique for a silicon-based THz antenna array. The feature of the silicon micromachining technique enables one to microfabricate an unlimited number of microlens arrays at one time with good uniformity on a silicon wafer. This technique will resolve one of the key issues in building a THz camera, which is to integrate antennas in a detector array. The conventional approach of building single-pixel receivers and stacking them to form a multi-pixel receiver is not suited at THz because a single-pixel receiver already has difficulty fitting into mass, volume, and power budgets, especially in space applications. In this proposed technique, one has controllability on both diameter and curvature of a silicon microlens. First of all, the diameter of microlens depends on how thick photoresist one could coat and pattern. So far, the diameter of a 6- mm photoresist microlens with 400 m in height has been successfully microfabricated. Based on current researchers experiences, a diameter larger than 1-cm photoresist microlens array would be feasible. In order to control the curvature of the microlens, the following process variables could be used: 1. Amount of photoresist: It determines the curvature of the photoresist microlens. Since the photoresist lens is transferred onto the silicon substrate, it will directly control the curvature of the silicon microlens. 2. Etching selectivity between photoresist and silicon: The photoresist microlens is formed by thermal reflow. In order to transfer the exact photoresist curvature onto silicon, there needs to be etching selectivity of 1:1 between silicon and photoresist. However, by varying the etching selectivity, one could control the curvature of the silicon microlens. The figure shows the microfabricated silicon microlens 5 x5 array. The diameter of the microlens located in the center is about 2.5 mm. The measured 3-D profile of the microlens surface has a

Magnetic structure of cross-shaped permalloy arrays embedded in silicon wafers

International Nuclear Information System (INIS)

Machida, Kenji; Tezuka, Tomoyuki; Yamamoto, Takahiro; Ishibashi, Takayuki; Morishita, Yoshitaka; Koukitu, Akinori; Sato, Katsuaki

2005-01-01

This paper describes the observed magnetic structure and the micromagnetic simulation of cross-shaped, permalloy (Ni 80 Fe 20 ) arrays embedded in silicon wafers. The nano-scale-width, cross-shaped patterns were fabricated using the damascene technique, electron beam lithography, and chemical mechanical polishing. The magnetic poles were observed as two pairs of bright and dark spots at the ends of the crossed-bars using a magnetic force microscope. The force gradient distributions were simulated based on micromagnetic calculations and tip's stray field calculations using the integral equation method. This process of calculation successfully explains the appearance of the poles and complicated spin structure at the crossing region

Occupational concerns associated with regular use of microscope

Directory of Open Access Journals (Sweden)

Garima Jain

2014-08-01

Full Text Available Objectives: Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. Material and Methods: A questionnaire based survey done on 50 professionals and technicians who used microscope regularly in pathology, microbiology, hematology and cytology laboratories. Results: Sixty two percent of subjects declared that they were suffering from musculoskeletal problems, most common locations being neck and back. Maximum prevalence of musculoskeletal problems was noted in those using microscope for 11–15 years and for more than 30 h/week. Sixty two percent of subjects were aware of workplace ergonomics. Fifty six percent of microscope users took regular short breaks for stretching exercises and 58% took visual breaks every 15–30 min in between microscope use sessions. As many as 94% subjects reported some form of visual problem. Fourty four percent of microscope users felt stressed with long working hours on microscope. Conclusions: The most common occupational concerns of microscope users were musculoskeletal problems of neck and back regions, eye fatigue, aggravation of ametropia, headache, stress due to long working hours and anxiety during or after microscope use. There is an immediate need for increasing awareness about the various occupational hazards and their irreversible effects to prevent them.

Evaluation of a completely robotized neurosurgical operating microscope.

Science.gov (United States)

Kantelhardt, Sven R; Finke, Markus; Schweikard, Achim; Giese, Alf

2013-01-01

Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted with an optical coherence tomography-scanning module. The robotized microscope was tested on model systems. It could be freely positioned, without forcing the surgeon to take the hands from the instruments or avert the eyes from the oculars. Positioning error was about 1 mm, and vibration faded in 1 second. Tracking of microscope movements, combined with an autofocus function, allowed determination of the focus position within the 3-dimensional space. This constituted a second loop of navigation independent from conventional infrared reflector-based techniques. In the robot mode, automated optical coherence tomography scanning of large surface areas was feasible. The prototype of a robotized optical coherence tomography-integrated operating microscope combines the advantages of a conventional manually controlled operating microscope with a remote-controlled positioning aid and a self-navigating microscope system that performs automated positioning tasks such as surface scans. This demonstrates that, in the future, operating microscopes may be used to acquire intraoperative spatial data, volume changes, and structural data of brain or brain tumor tissue.

Microchamber arrays with an integrated long luminescence lifetime pH sensor.

Science.gov (United States)

Poehler, Elisabeth; Pfeiffer, Simon A; Herm, Marc; Gaebler, Michael; Busse, Benedikt; Nagl, Stefan

2016-04-01

A pH probe with a microsecond luminescence lifetime was obtained via covalent coupling of 6-carboxynaphthofluorescein (CNF) moieties to ruthenium-tris-(1,10-phenanthroline)(2+). The probe was covalently attached to amino-modified poly-(2-hydroxyethyl)methacrylate (pHEMA) and showed a pH-dependent FRET with luminescence lifetimes of 681 to 1260 ns and a working range from ca. pH 6.5 to 9.0 with a pKa of 7.79 ± 0.14. The pH sensor matrix was integrated via spin coating as ca. 1- to 2-μm-thick layer into "CytoCapture" cell culture dishes of 6 mm in diameter. These contained a microcavity array of square-shaped regions of 40 μm length and width and 15 μm depth that was homogeneously coated with the pH sensor matrix. The sensor layer showed fast response times in both directions. A microscopic setup was developed that enabled imaging of the pH inside the microchamber arrays over many hours. As a proof of principle, we monitored the pH of Escherichia coli cell cultures grown in the microchamber arrays. The integrated sensor matrix allowed pH monitoring spatially resolved in every microchamber, and the differences in cell growth between individual chambers could be resolved and quantified.

Ag nanoparticles-decorated ZnO nanorod array on a mechanical flexible substrate with enhanced optical and antimicrobial properties

Science.gov (United States)

Chen, Yi; Tse, Wai Hei; Chen, Longyan; Zhang, Jin

2015-03-01

Heteronanostructured zinc oxide nanorod (ZnO NR) array are vertically grown on polydimethylsiloxane (PDMS) through a hydrothermal method followed by an in situ deposition of silver nanoparticles (Ag NPs) through a photoreduction process. The Ag-ZnO heterostructured nanorods on PDMS are measured with an average diameter of 160 nm and an average length of 2 μm. ZnO NRs measured by high-resolution transmission electron microscope (HRTEM) shows highly crystalline with a lattice fringe of 0.255 nm, which corresponds to the (0002) planes in ZnO crystal lattice. The average diameter of the Ag NPs in situ deposited on the ZnO NRs is estimated at 22 ± 2 nm. As compared to the bare ZnO NRs, the heterostructured Ag-ZnO nanorod array shows enhanced ultraviolet (UV) absorption at 440 nm, and significant emission in the visible region (λem = 542 nm). In addition, the antimicrobial efficiency of Ag-ZnO heterostructured nanorod array shows obvious improvement as compared to bare ZnO nanorod array. The cytotoxicity of ZnO nanorod array with and without Ag NPs was studied by using 3 T3 mouse fibroblast cell line. No significant toxic effect is imposed on the cells.

The emergence of community health worker programmes in the late apartheid era in South Africa: An historical analysis.

Science.gov (United States)

van Ginneken, Nadja; Lewin, Simon; Berridge, Virginia

2010-09-01

There is re-emerging interest in community health workers (CHWs) as part of wider policies regarding task-shifting within human resources for health. This paper examines the history of CHW programmes established in South Africa in the later apartheid years (1970s-1994) - a time of innovative initiatives. After 1994, the new democratic government embraced primary healthcare (PHC), however CHW initiatives were not included in their health plan and most of these programmes subsequently collapsed. Since then a wide array of disease-focused CHW projects have emerged, particularly within HIV care. Thirteen oral history interviews and eight witness seminars were conducted in South Africa in April 2008 with founders and CHWs from these earlier programmes. These data were triangulated with written primary sources and analysed using thematic content analysis. The study suggests that 1970s-1990s CHW programmes were seen as innovative, responsive, comprehensive and empowering for staff and communities, a focus which respondents felt was lost within current programmes. The growth of these earlier projects was underpinned by the struggle against apartheid. Respondents felt that the more technical focus of current CHW programmes under-utilise a valuable human resource which previously had a much wider social and health impact. These prior experiences and lessons learned could usefully inform policy-making frameworks for CHWs in South Africa today. Copyright 2010 Elsevier Ltd. All rights reserved.

The Current Status of Microscopical Hair Comparisons

Directory of Open Access Journals (Sweden)

Walter F. Rowe

2001-01-01

Full Text Available Although the microscopical comparison of human hairs has been accepted in courts of law for over a century, recent advances in DNA technology have called this type of forensic examination into question. In a number of cases, post-conviction DNA testing has exonerated defendants who were convicted in part on the results of microscopical hair comparisons. A federal judge has held a Daubert hearing on the microscopical comparison of human hairs and has concluded that this type of examination does not meet the criteria for admission of scientific evidence in federal courts. A review of the available scientific literature on microscopical hair comparisons (including studies conducted by the Royal Canadian Mounted Police and the Federal Bureau of Investigation leads to three conclusions: (1 microscopical comparisons of human hairs can yield scientifically defensible conclusions that can contribute to criminal investigations and criminal prosecutions, (2 the reliability of microscopical hair comparisons is strongly affected by the training of the forensic hair examiner, (3 forensic hair examiners cannot offer estimates of the probability of a match of a questioned hair with a hair from a randomly selected person. In order for microscopical hair examinations to survive challenges under the U.S. Supreme Court’s Daubert decision, hair microscopists must be better trained and undergo frequent proficiency testing. More research on the error rates of microscopical hair comparisons should be undertaken, and guidelines for the permissible interpretations of such comparisons should be established. Until these issues have been addressed and satisfactorily resolved, microscopical hair comparisons should be regarded by law enforcement agencies and courts of law as merely presumptive in nature, and all microscopical hair comparisons should be confirmed by nuclear DNA profiling or mitochondrial DNA sequencing.

Developments of FPGA-based digital back-ends for low frequency antenna arrays at Medicina radio telescopes

Science.gov (United States)

Naldi, G.; Bartolini, M.; Mattana, A.; Pupillo, G.; Hickish, J.; Foster, G.; Bianchi, G.; Lingua, A.; Monari, J.; Montebugnoli, S.; Perini, F.; Rusticelli, S.; Schiaffino, M.; Virone, G.; Zarb Adami, K.

In radio astronomy Field Programmable Gate Array (FPGA) technology is largely used for the implementation of digital signal processing techniques applied to antenna arrays. This is mainly due to the good trade-off among computing resources, power consumption and cost offered by FPGA chip compared to other technologies like ASIC, GPU and CPU. In the last years several digital backend systems based on such devices have been developed at the Medicina radio astronomical station (INAF-IRA, Bologna, Italy). Instruments like FX correlator, direct imager, beamformer, multi-beam system have been successfully designed and realized on CASPER (Collaboration for Astronomy Signal Processing and Electronics Research, https://casper.berkeley.edu) processing boards. In this paper we present the gained experience in this kind of applications.

The need for theory evaluation in global citizenship programmes: The case of the GCSA programme.

Science.gov (United States)

Goodier, Sarah; Field, Carren; Goodman, Suki

2018-02-01

Many education programmes lack a documented programme theory. This is a problem for programme planners and evaluators as the ability to measure programme success is grounded in the plausibility of the programme's underlying causal logic. Where the programme theory has not been documented, conducting a theory evaluation offers a foundational evaluation step as it gives an indication of whether the theory behind a programme is sound. This paper presents a case of a theory evaluation of a Global Citizenship programme at a top-ranking university in South Africa, subsequently called the GCSA Programme. This evaluation highlights the need for documented programme theory in global citizenship-type programmes for future programme development. An articulated programme theory produced for the GCSA Programme, analysed against the available social science literature, indicated it is comparable to other such programmes in terms of its overarching framework. What the research found is that most other global citizenship programmes do not have an articulated programme theory. These programmes also do not explicitly link their specific activities to their intended outcomes, making demonstrating impact impossible. In conclusion, we argue that taking a theory-based approach can strengthen and enable outcome evaluations in global citizenship programmes. Copyright © 2017. Published by Elsevier Ltd.

IMIS: An intelligence microscope imaging system

Science.gov (United States)

Caputo, Michael; Hunter, Norwood; Taylor, Gerald

1994-01-01

Until recently microscope users in space relied on traditional microscopy techniques that required manual operation of the microscope and recording of observations in the form of written notes, drawings, or photographs. This method was time consuming and required the return of film and drawings from space for analysis. No real-time data analysis was possible. Advances in digital and video technologies along with recent developments in article intelligence will allow future space microscopists to have a choice of three additional modes of microscopy: remote coaching, remote control, and automation. Remote coaching requires manual operations of the microscope with instructions given by two-way audio/video transmission during critical phases of the experiment. When using the remote mode of microscopy, the Principal Investigator controls the microscope from the ground. The automated mode employs artificial intelligence to control microscope functions and is the only mode that can be operated in the other three modes as well. The purpose of this presentation is to discuss the advantages and disadvantages of the four modes of of microscopy and how the IMIS, a proposed intelligent microscope imaging system, can be used as a model for developing and testing concepts, operating procedures, and equipment design of specifications required to provide a comprehensive microscopy/imaging capability onboard Space Station Freedom.

Microscopic Analysis of Activated Sludge. Training Manual.

Science.gov (United States)

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Course topics include: sampling techniques, sample handling, laboratory analysis, identification of organisms, data interpretation, and use of the compound microscope.…

Thimble microscope system

Science.gov (United States)

Kamal, Tahseen; Rubinstein, Jaden; Watkins, Rachel; Cen, Zijian; Kong, Gary; Lee, W. M.

2016-12-01

Wearable computing devices, e.g. Google Glass, Smart watch, embodies the new human design frontier, where technology interfaces seamlessly with human gestures. During examination of any subject in the field (clinic, surgery, agriculture, field survey, water collection), our sensory peripherals (touch and vision) often go hand-in-hand. The sensitivity and maneuverability of the human fingers are guided with tight distribution of biological nerve cells, which perform fine motor manipulation over a range of complex surfaces that is often out of sight. Our sight (or naked vision), on the other hand, is generally restricted to line of sight that is ill-suited to view around corner. Hence, conventional imaging methods are often resort to complex light guide designs (periscope, endoscopes etc) to navigate over obstructed surfaces. Using modular design strategies, we constructed a prototype miniature microscope system that is incorporated onto a wearable fixture (thimble). This unique platform allows users to maneuver around a sample and take high resolution microscopic images. In this paper, we provide an exposition of methods to achieve a thimble microscopy; microscope lens fabrication, thimble design, integration of miniature camera and liquid crystal display.

Atomic force microscope featuring an integrated optical microscope

NARCIS (Netherlands)

Putman, C.A.J.; Putman, Constant A.J.; de Grooth, B.G.; van Hulst, N.F.; Greve, Jan

1992-01-01

The atomic force microscope (AFM) is used to image the surface of both conductors and nonconductors. Biological specimens constitute a large group of nonconductors. A disadvantage of most AFM's is the fact that relatively large areas of the sample surface have to be scanned to pinpoint a biological

Programme documentation to control programme for Solar-tracker; Programdokumentation til styringsprogram til Solar-tracker

Energy Technology Data Exchange (ETDEWEB)

Rudbeck, C.

1995-07-01

The report contains the programme documentation partly for a programme to control of a tracking system and partly a programme, which uses this programme to make measurements of transmittance for covering layer. Both the transmittance measurement programme and the programme is built in Borland Pascal v7.0, and is compiled in Real mode for the use on a processor of the 80X86-family. The source code for the programme for transmittance measurements and the programmes (the positioning routines) are described in Appendix B. (EHS)

Spin microscope based on optically detected magnetic resonance

Science.gov (United States)

Berman, Gennady P.; Chernobrod, Boris M.

2007-12-11

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Wafer-level radiometric performance testing of uncooled microbolometer arrays

Science.gov (United States)

Dufour, Denis G.; Topart, Patrice; Tremblay, Bruno; Julien, Christian; Martin, Louis; Vachon, Carl

2014-03-01

A turn-key semi-automated test system was constructed to perform on-wafer testing of microbolometer arrays. The system allows for testing of several performance characteristics of ROIC-fabricated microbolometer arrays including NETD, SiTF, ROIC functionality, noise and matrix operability, both before and after microbolometer fabrication. The system accepts wafers up to 8 inches in diameter and performs automated wafer die mapping using a microscope camera. Once wafer mapping is completed, a custom-designed quick insertion 8-12 μm AR-coated Germanium viewport is placed and the chamber is pumped down to below 10-5 Torr, allowing for the evaluation of package-level focal plane array (FPA) performance. The probe card is electrically connected to an INO IRXCAM camera core, a versatile system that can be adapted to many types of ROICs using custom-built interface printed circuit boards (PCBs). We currently have the capability for testing 384x288, 35 μm pixel size and 160x120, 52 μm pixel size FPAs. For accurate NETD measurements, the system is designed to provide an F/1 view of two rail-mounted blackbodies seen through the Germanium window by the die under test. A master control computer automates the alignment of the probe card to the dies, the positioning of the blackbodies, FPA image frame acquisition using IRXCAM, as well as data analysis and storage. Radiometric measurement precision has been validated by packaging dies measured by the automated probing system and re-measuring the SiTF and Noise using INO's pre-existing benchtop system.

SNP Arrays

Directory of Open Access Journals (Sweden)

Jari Louhelainen

2016-10-01

Full Text Available The papers published in this Special Issue “SNP arrays” (Single Nucleotide Polymorphism Arrays focus on several perspectives associated with arrays of this type. The range of papers vary from a case report to reviews, thereby targeting wider audiences working in this field. The research focus of SNP arrays is often human cancers but this Issue expands that focus to include areas such as rare conditions, animal breeding and bioinformatics tools. Given the limited scope, the spectrum of papers is nothing short of remarkable and even from a technical point of view these papers will contribute to the field at a general level. Three of the papers published in this Special Issue focus on the use of various SNP array approaches in the analysis of three different cancer types. Two of the papers concentrate on two very different rare conditions, applying the SNP arrays slightly differently. Finally, two other papers evaluate the use of the SNP arrays in the context of genetic analysis of livestock. The findings reported in these papers help to close gaps in the current literature and also to give guidelines for future applications of SNP arrays.

Design and commissioning of an aberration-corrected ultrafast spin-polarized low energy electron microscope with multiple electron sources.

Science.gov (United States)

Wan, Weishi; Yu, Lei; Zhu, Lin; Yang, Xiaodong; Wei, Zheng; Liu, Jefferson Zhe; Feng, Jun; Kunze, Kai; Schaff, Oliver; Tromp, Ruud; Tang, Wen-Xin

2017-03-01

We describe the design and commissioning of a novel aberration-corrected low energy electron microscope (AC-LEEM). A third magnetic prism array (MPA) is added to the standard AC-LEEM with two prism arrays, allowing the incorporation of an ultrafast spin-polarized electron source alongside the standard cold field emission electron source, without degrading spatial resolution. The high degree of symmetries of the AC-LEEM are utilized while we design the electron optics of the ultrafast spin-polarized electron source, so as to minimize the deleterious effect of time broadening, while maintaining full control of electron spin. A spatial resolution of 2nm and temporal resolution of 10ps (ps) are expected in the future time resolved aberration-corrected spin-polarized LEEM (TR-AC-SPLEEM). The commissioning of the three-prism AC-LEEM has been successfully finished with the cold field emission source, with a spatial resolution below 2nm. Copyright © 2017 Elsevier B.V. All rights reserved.

21 CFR 864.3600 - Microscopes and accessories.

Science.gov (United States)

2010-04-01

... enlarge images of specimens, preparations, and cultures for medical purposes. Variations of microscopes... light. (3) Inverted stage microscopes, which permit examination of tissue cultures or other biological... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microscopes and accessories. 864.3600 Section 864...

A novel method to design sparse linear arrays for ultrasonic phased array.

Science.gov (United States)

Yang, Ping; Chen, Bin; Shi, Ke-Ren

2006-12-22

In ultrasonic phased array testing, a sparse array can increase the resolution by enlarging the aperture without adding system complexity. Designing a sparse array involves choosing the best or a better configuration from a large number of candidate arrays. We firstly designed sparse arrays by using a genetic algorithm, but found that the arrays have poor performance and poor consistency. So, a method based on the Minimum Redundancy Linear Array was then adopted. Some elements are determined by the minimum-redundancy array firstly in order to ensure spatial resolution and then a genetic algorithm is used to optimize the remaining elements. Sparse arrays designed by this method have much better performance and consistency compared to the arrays designed only by a genetic algorithm. Both simulation and experiment confirm the effectiveness.

Axiomatic electrodynamics and microscopic mechanics

International Nuclear Information System (INIS)

Yussouff, M.

1981-04-01

A new approach to theoretical physics, along with the basic formulation of a new MICROSCOPIC MECHANICS for the motion of small charged particles is described in this set of lecture notes. Starting with the classical (Newtonian) mechanics and classical fields, the important but well known properties of Classical Electromagnetic field are discussed up to section 4. The next nection describes the usual radiation damping theory and its difficulties. It is argued that the usual treatment of radiation damping is not valid for small space and time intervals and the true description of motion requires a new type of mechanics - the MICROSCOPIC MECHANICS: Section 6 and 7 are devoted to showing that not only the new microscopic mechanics goes over to Newtonian mechanics in the proper limit, but also it is closely connected with Quantum Mechanics. All the known results of the Schroedinger theory can be reproduced by microscopic mechanics which also gives a clear physical picture. It removes Einstein's famous objections against Quantum Theory and provides a clear distinction between classical and Quantum behavior. Seven Axioms (three on Classical Mechanics, two for Maxwell's theory, one for Relativity and a new Axiom on Radiation damping) are shown to combine Classical Mechanics, Maxwellian Electrodynamics, Relativity and Schroedinger's Quantum Theory within a single theoretical framework under Microscopic Mechanics which awaits further development at the present time. (orig.)

Microscopic Theory of Fission

International Nuclear Information System (INIS)

Younes, W; Gogny, D

2008-01-01

In recent years, the microscopic method has been applied to the notoriously difficult problem of nuclear fission with unprecedented success. In this paper, we discuss some of the achievements and promise of the microscopic method, as embodied in the Hartree-Fock method using the Gogny finite-range effective interaction, and beyond-mean-field extensions to the theory. The nascent program to describe induced fission observables using this approach at the Lawrence Livermore National Laboratory is presented

Microscopic description of magnetized plasma: quasiparticle concept

International Nuclear Information System (INIS)

Sosenko, P.P.; Decyk, V.K.

1993-01-01

A quasiparticle concept is developed systematically, from first principles, within the context of microscopic description of magnetized plasma. It is argued that the zeroth velocity-gyroangle harmonic of the microscopic particle distribution function under the gyrokinetic change of variables can be taken as a microscopic quasi-particle density in a reduced phase space. The nature of quasiparticles is discussed and equations of their motion are derived within both exact and reduced microscopic descriptions. The reduced one employs explicitly the separation of interesting time scales. (orig.)

Preparation and characterization of SiO2:Sm3+ nanotube arrays with 1.06 μm laser antireflective property

International Nuclear Information System (INIS)

Tan, Wei-min; Huang, Ning; Wang, Li-jun; Song, Tian-shun; Lu, Chun-hua; Wang, Liu-fang; Zhang, Jun-zhi

2013-01-01

SiO 2 : Sm 3+ nanotube arrays with excellent antireflective property at 1.06 μm were synthesized by a template-assisted sol–gel process. The molecular structure, morphology and optical properties of the fabricated SiO 2 :Sm 3+ nanotube arrays were investigated by a Fourier transform infrared spectroscope (FTIR), a Scanning electron microscope (SEM), and a spectro-fluorometer, respectively. The experimental results demonstrate that the SiO 2 :Sm 3+ nanotube arrays were formed via the AAO membrane during the sol–gel process. The remarkable antireflective characteristic of about 0.166% at 1.06 μm was attributed to the drastic decrease of effective refraction index which enhances the matching effect between air and substrate. As well as the absorption performance of Sm3+ at 1.06 μm which consumes the energies of incident light. - Graphical abstract: Directional aligned SiO 2 :Sm 3+ nanotube arrays were synthesized in AAO template by sol–gel process, and the antiflective performance of arrays is prominent comparing to the blank AAO template. Highlights: ► SiO 2 :Sm 3+ nanotube arrays are synthesized by a template-assisted sol–gel process. ► SiO 2 :Sm 3+ nanotube arrays have remarkable antireflective properties at 1.06 μm. ► The subwavelength structure results in a decrease of effective refraction index. ► The absorption performance of Sm 3+ at 1.06 μm consume the energies of incident light

Fractal assembly of micrometre-scale DNA origami arrays with arbitrary patterns

Science.gov (United States)

Tikhomirov, Grigory; Petersen, Philip; Qian, Lulu

2017-12-01

Self-assembled DNA nanostructures enable nanometre-precise patterning that can be used to create programmable molecular machines and arrays of functional materials. DNA origami is particularly versatile in this context because each DNA strand in the origami nanostructure occupies a unique position and can serve as a uniquely addressable pixel. However, the scale of such structures has been limited to about 0.05 square micrometres, hindering applications that demand a larger layout and integration with more conventional patterning methods. Hierarchical multistage assembly of simple sets of tiles can in principle overcome this limitation, but so far has not been sufficiently robust to enable successful implementation of larger structures using DNA origami tiles. Here we show that by using simple local assembly rules that are modified and applied recursively throughout a hierarchical, multistage assembly process, a small and constant set of unique DNA strands can be used to create DNA origami arrays of increasing size and with arbitrary patterns. We illustrate this method, which we term ‘fractal assembly’, by producing DNA origami arrays with sizes of up to 0.5 square micrometres and with up to 8,704 pixels, allowing us to render images such as the Mona Lisa and a rooster. We find that self-assembly of the tiles into arrays is unaffected by changes in surface patterns on the tiles, and that the yield of the fractal assembly process corresponds to about 0.95m - 1 for arrays containing m tiles. When used in conjunction with a software tool that we developed that converts an arbitrary pattern into DNA sequences and experimental protocols, our assembly method is readily accessible and will facilitate the construction of sophisticated materials and devices with sizes similar to that of a bacterium using DNA nanostructures.

The optics of microscope image formation.

Science.gov (United States)

Wolf, David E

2013-01-01

Although geometric optics gives a good understanding of how the microscope works, it fails in one critical area, which is explaining the origin of microscope resolution. To accomplish this, one must consider the microscope from the viewpoint of physical optics. This chapter describes the theory of the microscope-relating resolution to the highest spatial frequency that a microscope can collect. The chapter illustrates how Huygens' principle or construction can be used to explain the propagation of a plane wave. It is shown that this limit increases with increasing numerical aperture (NA). As a corollary to this, resolution increases with decreasing wavelength because of how NA depends on wavelength. The resolution is higher for blue light than red light. Resolution is dependent on contrast, and the higher the contrast, the higher the resolution. This last point relates to issues of signal-to-noise and dynamic range. The use of video and new digital cameras has necessitated redefining classical limits such as those of Rayleigh's criterion. Copyright © 2007 Elsevier Inc. All rights reserved.

Science 101: How Does an Electron Microscope Work?

Science.gov (United States)

Robertson, Bill

2013-01-01

Contrary to popular opinion, electron microscopes are not used to look at electrons. They are used to look for structure in things that are too small to observe with an optical microscope, or to obtain images that are magnified much more than is obtainable with an optical microscope. To understand how electron microscopes work, it will help to go…

Microscopic cross sections: An utopia?

Energy Technology Data Exchange (ETDEWEB)

Hilaire, S. [CEA Bruyeres-le-Chatel, DIF 91 (France); Koning, A.J. [Nuclear Research and Consultancy Group, PO Box 25, 1755 ZG Petten (Netherlands); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

2010-07-01

The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

Microscopic cross sections: An utopia?

International Nuclear Information System (INIS)

Hilaire, S.; Koning, A.J.; Goriely, S.

2010-01-01

The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations.While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

Scalable Direct Writing of Lanthanide-Doped KMnF3 Perovskite Nanowires into Aligned Arrays with Polarized Up-Conversion Emission.

Science.gov (United States)

Shi, Shuo; Sun, Ling-Dong; Xue, Ying-Xian; Dong, Hao; Wu, Ke; Guo, Shi-Chen; Wu, Bo-Tao; Yan, Chun-Hua

2018-05-09

The use of one-dimensional nano- and microstructured semiconductor and lanthanide materials is attractive for polarized-light-emission studies. Up-conversion emission from single-nanorod or anisotropic nanoparticles with a degree of polarization has also been discussed. However, microscale arrays of nanoparticles, especially well-aligned one-dimensional nanostructures as well as their up-conversion polarization characterization, have not been investigated yet. Herein, we present a novel and facile paradigm for preparing highly aligned arrays of lanthanide-doped KMnF 3 (KMnF 3 :Ln) perovskite nanowires, which are good candidates for polarized up-conversion emission studies. These perovskite nanowires, with a width of 10 nm and length of a few micrometers, are formed through the oriented attachment of KMnF 3 :Ln nanocubes along the [001] direction. By the employment of KMnF 3 :Ln nanowire gel as nanoink, a direct-writing method is developed to obtain diverse types of aligned patterns from the nanoscale to the wafer scale. Up-conversion emissions from the highly aligned nanowire arrays are polarized along the array direction with a polarization degree up to 60%. Taking advantage of microscopic nanowire arrays, these polarized up-conversion emissions should offer potential applications in light or information transportation.

Laser apparatus and method for microscopic and spectroscopic analysis and processing of biological cells

Science.gov (United States)

Gourley, P.L.; Gourley, M.F.

1997-03-04

An apparatus and method are disclosed for microscopic and spectroscopic analysis and processing of biological cells. The apparatus comprises a laser having an analysis region within the laser cavity for containing one or more biological cells to be analyzed. The presence of a cell within the analysis region in superposition with an activated portion of a gain medium of the laser acts to encode information about the cell upon the laser beam, the cell information being recoverable by an analysis means that preferably includes an array photodetector such as a CCD camera and a spectrometer. The apparatus and method may be used to analyze biomedical cells including blood cells and the like, and may include processing means for manipulating, sorting, or eradicating cells after analysis. 20 figs.

Handy Microscopic Close-Range Videogrammetry

Science.gov (United States)

Esmaeili, F.; Ebadi, H.

2017-09-01

The modeling of small-scale objects is used in different applications such as medicine, industry, and cultural heritage. The capability of modeling small-scale objects using imaging with the help of hand USB digital microscopes and use of videogrammetry techniques has been implemented and evaluated in this paper. Use of this equipment and convergent imaging of the environment for modeling, provides an appropriate set of images for generation of three-dimensional models. The results of the measurements made with the help of a microscope micrometer calibration ruler have demonstrated that self-calibration of a hand camera-microscope set can help obtain a three-dimensional detail extraction precision of about 0.1 millimeters on small-scale environments.

Microscope and method of use

Science.gov (United States)

Bongianni, Wayne L.

1984-01-01

A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers.

Microscopic collective models of nuclei

International Nuclear Information System (INIS)

Lovas, Rezsoe

1985-01-01

Microscopic Rosensteel-Rowe theory of the nuclear collective motion is described. The theoretical insufficiency of the usual microscopic establishment of the collective model is pointed. The new model treating exactly the degrees of freedom separates the coordinates describing the collective motion and the internal coordinates by a consistent way. Group theoretical methods analyzing the symmetry properties of the total Hamiltonian are used defining the collective subspaces transforming as irreducible representations of the group formed by the collective operators. Recent calculations show that although the results of the usual collective model are approximately correct and similar to those of the new microscopic collective model, the underlying philosophy of the old model is essentially erroneous. (D.Gy.)

Microscope sterility during spine surgery.

Science.gov (United States)

Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

2012-04-01

Prospective study. Assess the contamination rates of sterile microscope drapes after spine surgery. The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection. This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002). Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact

Calibration and Stokes Imaging with Full Embedded Element Primary Beam Model for the Murchison Widefield Array

Science.gov (United States)

Sokolowski, M.; Colegate, T.; Sutinjo, A. T.; Ung, D.; Wayth, R.; Hurley-Walker, N.; Lenc, E.; Pindor, B.; Morgan, J.; Kaplan, D. L.; Bell, M. E.; Callingham, J. R.; Dwarakanath, K. S.; For, Bi-Qing; Gaensler, B. M.; Hancock, P. J.; Hindson, L.; Johnston-Hollitt, M.; Kapińska, A. D.; McKinley, B.; Offringa, A. R.; Procopio, P.; Staveley-Smith, L.; Wu, C.; Zheng, Q.

2017-11-01

The Murchison Widefield Array (MWA), located in Western Australia, is one of the low-frequency precursors of the international Square Kilometre Array (SKA) project. In addition to pursuing its own ambitious science programme, it is also a testbed for wide range of future SKA activities ranging from hardware, software to data analysis. The key science programmes for the MWA and SKA require very high dynamic ranges, which challenges calibration and imaging systems. Correct calibration of the instrument and accurate measurements of source flux densities and polarisations require precise characterisation of the telescope's primary beam. Recent results from the MWA GaLactic Extragalactic All-sky Murchison Widefield Array (GLEAM) survey show that the previously implemented Average Embedded Element (AEE) model still leaves residual polarisations errors of up to 10-20% in Stokes Q. We present a new simulation-based Full Embedded Element (FEE) model which is the most rigorous realisation yet of the MWA's primary beam model. It enables efficient calculation of the MWA beam response in arbitrary directions without necessity of spatial interpolation. In the new model, every dipole in the MWA tile (4 × 4 bow-tie dipoles) is simulated separately, taking into account all mutual coupling, ground screen, and soil effects, and therefore accounts for the different properties of the individual dipoles within a tile. We have applied the FEE beam model to GLEAM observations at 200-231 MHz and used false Stokes parameter leakage as a metric to compare the models. We have determined that the FEE model reduced the magnitude and declination-dependent behaviour of false polarisation in Stokes Q and V while retaining low levels of false polarisation in Stokes U.

A method for the quantitative metallographic analysis of nuclear fuels (Programme QMA)

International Nuclear Information System (INIS)

Moreno, A.; Sari, C.

1978-01-01

A method is described for the quantitative analysis of features such as voids, cracks, phases, inclusions and grains distributed on random plane sections of fuel materials. An electronic image analyzer, Quantimet, attached to a MM6 Leitz microscope was used to measure size, area, perimeter and shape of features dispersed in a matrix. The apparatus is driven by a computer which calculates the size, area and perimeter distribution, form factors and orientation of the features as well as the inclusion content of the matrix expressed in weight per cent. A computer programme, QMA, executes the spatial correction of the measured two-dimensional sections and delivers the true distribution of feature sizes in a three-dimensional system

Analytical Electron Microscope

Data.gov (United States)

Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

The International Baccalaureate (IB programme: An international gateway to higher education and beyond

Directory of Open Access Journals (Sweden)

Susan E. Saxton

2014-09-01

Full Text Available The aim of this article is to present the International Baccalaureate (IB Programme and briefly outline its core components, followed by a review of what authoritative reports identify as skills for the future, esteemed by universities and the job market. There is a striking match between these skills and IB outcomes; thus, DP graduates perform well in higher education and add to the reputation of those institutions. After a review of the literature, the authors found the IB Diploma Programme has been studied in many countries by both consultants and educational agencies, and also by a wide array of universities themselves; however, there are fewer qualitative studies concerning the degree to which IB graduates display attitudes, values, and behaviours in line with the IB Learner Profile. This is why the authors stress the claims made are supported by examples of significant research, noting that there is a dearth of qualitative longitudinal studies to sufficiently substantiate the affective domain claims that currently rely more on anecdotal evidence. The authors conclude by pointing out more research is needed in order to substantiate anecdotal evidence regarding future employment success for IB Diploma Programme graduates.  DOI: 10.18870/hlrc.v4i3.123

Piezoelectric Nanogenerator Using p-Type ZnO Nanowire Arrays

KAUST Repository

Lu, Ming-Pei

2009-03-11

Using phosphorus-doped ZnO nanowire (NW) arrays grown on silicon substrate, energy conversion using the p-type ZnO NWs has been demonstrated for the first time. The p-type ZnO NWs produce positive output voltage pulses when scanned by a conductive atomic force microscope (AFM) in contact mode. The output voltage pulse is generated when the tip contacts the stretched side (positive piezoelectric potential side) of the NW. In contrast, the n-type ZnO NW produces negative output voltage when scanned by the AFM tip, and the output voltage pulse is generated when the tip contacts the compressed side (negative potential side) of the NW. In reference to theoretical simulation, these experimentally observed phenomena have been systematically explained based on the mechanism proposed for a nanogenerator. © 2009 American Chemical Society.

Column Grid Array Rework for High Reliability

Science.gov (United States)

Mehta, Atul C.; Bodie, Charles C.

2008-01-01

Due to requirements for reduced size and weight, use of grid array packages in space applications has become common place. To meet the requirement of high reliability and high number of I/Os, ceramic column grid array packages (CCGA) were selected for major electronic components used in next MARS Rover mission (specifically high density Field Programmable Gate Arrays). ABSTRACT The probability of removal and replacement of these devices on the actual flight printed wiring board assemblies is deemed to be very high because of last minute discoveries in final test which will dictate changes in the firmware. The questions and challenges presented to the manufacturing organizations engaged in the production of high reliability electronic assemblies are, Is the reliability of the PWBA adversely affected by rework (removal and replacement) of the CGA package? and How many times can we rework the same board without destroying a pad or degrading the lifetime of the assembly? To answer these questions, the most complex printed wiring board assembly used by the project was chosen to be used as the test vehicle, the PWB was modified to provide a daisy chain pattern, and a number of bare PWB s were acquired to this modified design. Non-functional 624 pin CGA packages with internal daisy chained matching the pattern on the PWB were procured. The combination of the modified PWB and the daisy chained packages enables continuity measurements of every soldered contact during subsequent testing and thermal cycling. Several test vehicles boards were assembled, reworked and then thermal cycled to assess the reliability of the solder joints and board material including pads and traces near the CGA. The details of rework process and results of thermal cycling are presented in this paper.

Using machine-learning to optimize phase contrast in a low-cost cellphone microscope

Science.gov (United States)

Wartmann, Rolf; Schadwinkel, Harald; Heintzmann, Rainer

2018-01-01

Cellphones equipped with high-quality cameras and powerful CPUs as well as GPUs are widespread. This opens new prospects to use such existing computational and imaging resources to perform medical diagnosis in developing countries at a very low cost. Many relevant samples, like biological cells or waterborn parasites, are almost fully transparent. As they do not exhibit absorption, but alter the light’s phase only, they are almost invisible in brightfield microscopy. Expensive equipment and procedures for microscopic contrasting or sample staining often are not available. Dedicated illumination approaches, tailored to the sample under investigation help to boost the contrast. This is achieved by a programmable illumination source, which also allows to measure the phase gradient using the differential phase contrast (DPC) [1, 2] or even the quantitative phase using the derived qDPC approach [3]. By applying machine-learning techniques, such as a convolutional neural network (CNN), it is possible to learn a relationship between samples to be examined and its optimal light source shapes, in order to increase e.g. phase contrast, from a given dataset to enable real-time applications. For the experimental setup, we developed a 3D-printed smartphone microscope for less than 100 $ using off-the-shelf components only such as a low-cost video projector. The fully automated system assures true Koehler illumination with an LCD as the condenser aperture and a reversed smartphone lens as the microscope objective. We show that the effect of a varied light source shape, using the pre-trained CNN, does not only improve the phase contrast, but also the impression of an improvement in optical resolution without adding any special optics, as demonstrated by measurements. PMID:29494620

Auditing emergency management programmes: Measuring leading indicators of programme performance.

Science.gov (United States)

Tomsic, Heather

Emergency Management Programmes benefit from review and measurement against established criteria. By measuring current vs required programme elements for their actual currency, completeness and effectiveness, the resulting timely reports of achievements and documentation of identified gaps can effectively be used to rationally support prioritised improvement. Audits, with their detailed, triangulated and objectively weighted processes, are the ultimate approach in terms of programme content measurement. Although Emergency Management is often presented as a wholly separate operational mechanism, distinct and functionally different from the organisation's usual management structure, this characterisation is only completely accurate while managing an emergency itself. Otherwise, an organisation's Emergency Management Programme is embedded within that organisation and dependent upon it. Therefore, the organisation's culture and structure of management, accountability and measurement must be engaged for the programme to exist, much less improve. A wise and successful Emergency Management Coordinator does not let the separate and distinct nature of managing an emergency obscure their realisation of the need for an organisation to understand and manage all of the other programme components as part of its regular business practices. This includes its measurement. Not all organisations are sufficiently large or capable of supporting the use of an audit. This paper proposes that alternate, less formal, yet effective mechanisms can be explored, as long as they reflect and support organisational management norms, including a process of relatively informal measurement focused on the organisation's own perception of key Emergency Management Programme performance indicators.

Designs for a quantum electron microscope.

Science.gov (United States)

Kruit, P; Hobbs, R G; Kim, C-S; Yang, Y; Manfrinato, V R; Hammer, J; Thomas, S; Weber, P; Klopfer, B; Kohstall, C; Juffmann, T; Kasevich, M A; Hommelhoff, P; Berggren, K K

2016-05-01

One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This 'quantum weirdness' could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or "quantum electron microscope". A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Coupling in reflector arrays

DEFF Research Database (Denmark)

Appel-Hansen, Jørgen

1968-01-01

In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present communic......In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present...

Ag nanoparticles-decorated ZnO nanorod array on a mechanical flexible substrate with enhanced optical and antimicrobial properties

OpenAIRE

Chen, Yi; Tse, Wai Hei; Chen, Longyan; Zhang, Jin

2015-01-01

Heteronanostructured zinc oxide nanorod (ZnO NR) array are vertically grown on polydimethylsiloxane (PDMS) through a hydrothermal method followed by an in situ deposition of silver nanoparticles (Ag NPs) through a photoreduction process. The Ag-ZnO heterostructured nanorods on PDMS are measured with an average diameter of 160?nm and an average length of 2??m. ZnO NRs measured by high-resolution transmission electron microscope (HRTEM) shows highly crystalline with a lattice fringe of 0.255?nm...

Occupational concerns associated with regular use of microscope

OpenAIRE

Garima Jain; Pushparaja Shetty

2014-01-01

Objectives: Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. Material and Methods: A questionnaire...

Microscopic nuclear structure with sub-nucleonic degrees of freedom

International Nuclear Information System (INIS)

Sauer, P.U.

1986-01-01

The paper reviews microscopic theories of nuclear structure. The subject is discussed under the topic headings: microscopic nuclear structure with nucleons only; microscopic nuclear structure with nucleons, isobars and mesons; and microscopic nuclear structure with nucleons, mesons and dibaryons. (U.K.)

Literature survey on microscopic friction modeling

NARCIS (Netherlands)

Hol, J.

2010-01-01

To better understand contact and friction conditions, experimental and theoretical studies have been performed in order to take microscopic dependencies into account. Friction is developed on microscopic level by adhesion between contacting asperities, the ploughing effect between asperities and the

Cloth-based hybridization array system for expanded identification of the animal species origin of derived materials in feeds.

Science.gov (United States)

Murphy, Johanna; Armour, Jennifer; Blais, Burton W

2007-12-01

A cloth-based hybridization array system (CHAS) previously developed for the detection of animal species for which prohibited materials have been specified (cattle, sheep, goat, elk, and deer) has been expanded to include the detection of animal species for which there are no prohibitions (pig and horse) in Canadian and American animal feeds. Animal species were identified by amplification of mitochondrial DNA sequences by PCR and subsequent hybridization of the amplicons with an array of species-specific oligonucleotide capture probes immobilized on a polyester cloth support, followed by an immunoenzymatic assay of the bound PCR products. The CHAS permitted sensitive and specific detection of meat meals from different animal species blended in a grain-based feed and should provide a useful adjunct to microscopic examination for the identification of prohibited materials in animal feeds.

Microscopic approach to nuclear anharmonicities

International Nuclear Information System (INIS)

Matsuo, Masayuki; Shimizu, Yoshifumi; Matsuyanagi, Kenichi

1985-01-01

Present status of microscopic study of nuclear anharmonicity phenomena is reviewed from the viewpoint of the time-dependent Hartree-Bogoliubov approach. Both classical- and quantum-mechanical aspects of this approach are discussed. The Bohr-Mottelson-type collective Hamiltonian for anharmonic gamma vibrations is microscopically derived by means of the self-consistent-collective-coordinate method, and applied to the problem of two-phonon states of 168 Er. (orig.)

Determination of the parameters of a microscopic object from a complex response of a differential microscope

International Nuclear Information System (INIS)

Baranov, D V; Egorov, Alexander A; Zolotov, Evgenii M; Svidzinsky, K K

1998-01-01

An analysis of the amplitude and phase of a complex response of a heterodyne differential microscope was used to demonstrate experimentally the feasibility of determination of the parameters of a composite microscopic object representing a combination of a step with a groove. (laser applications and other topics in quantum electronics)

Microscopic appearance analysis of raw material used for the production of sintered UO2 by scanning electron microscope

International Nuclear Information System (INIS)

Liu feiming

1992-01-01

The paper describes the microscopic appearance of UO 2 , U 3 O 8 , ADU and AUC powders used for the production of sintered UO 2 slug of nuclear fuel component of PWR. The characteristic analysis of the microscopic appearance observed by scanning electron microscope shows that the quality and finished product rate of sintered UO 2 depend on the appearance characteristic of the active Uo 2 powder, such as grade size and its distribution, spherulitized extent, surface condition and heap model etc.. The addition of U 3 O 8 to the UO 2 powder improves significantly the quality and the finished product rate. The mechanism of this effect is discussed on the basis of the microscopic appearance characteristic for two kinds of powder

Fabrication of doped TiO2 nanotube array films with enhanced photo-catalytic activity

Science.gov (United States)

Peighambardoust, Naeimeh-Sadat; Khameneh-asl, Shahin; Khademi, Adib

2018-01-01

In the present work, we investigate the N and Fe-doped TiO2 nanotube array film prepared by treating TiO2 nanotube array film with ammonia solution and anodizing in Fe(NO3)3 solution respectively. This method avoided the use of hazardous ammonia gas, or laborious ion implantation process. N and Fe-doped TiO2 nanotube arrays (TiO2 NTs) were prepared by electrochemical anodization process in 0.5 wt % HF aqueous solution. The anodization was performed at the conditions of 20 V and 20 min, Followed by a wet immersion in NH3.H2O (1M) for N-doping for 2 hr and annealing post-treatment at 450 °C. The morphology and structure of the nanotube films were characterized by field emission scanning electron microscope (FESEM) and EDX. UV-vis. illumination test were done to observe photo-enhanced catalysis. The effect of different annealing temperature on the structure and photo-absorption property of the TiO2-TNTs was investigated. The results showed that N-TNTs nanotubes exhibited higher photocatalytic activity compared whit the Fe-doped and pure TNTs, because doping N promoted the separation of the photogenerated electrons and holes.

Scanning tunnel microscope with large vision field compatible with a scanning electron microscope

International Nuclear Information System (INIS)

Volodin, A.P.; Stepanyan, G.A.; Khajkin, M.S.; Ehdel'man, V.S.

1989-01-01

A scanning tunnel microscope (STM) with the 20μm vision field and 1nm resolution, designed to be compatible with a scanning electron microscope (SEM), is described. The sample scanning area is chosen within the 3x10mm limits with a 0.1-1μm step. The STM needle is moved automatically toward the sample surface from the maximum distance of 10mm until the tunneling current appears. Bimorphous elements of the KP-1 piezocorrector are used in the STM design. The device is installed on a table of SEM object holders

Concurrent array-based queue

Science.gov (United States)

Heidelberger, Philip; Steinmacher-Burow, Burkhard

2015-01-06

According to one embodiment, a method for implementing an array-based queue in memory of a memory system that includes a controller includes configuring, in the memory, metadata of the array-based queue. The configuring comprises defining, in metadata, an array start location in the memory for the array-based queue, defining, in the metadata, an array size for the array-based queue, defining, in the metadata, a queue top for the array-based queue and defining, in the metadata, a queue bottom for the array-based queue. The method also includes the controller serving a request for an operation on the queue, the request providing the location in the memory of the metadata of the queue.

Programmable Array Logic Design

International Nuclear Information System (INIS)

Demon Handoyo; Djen Djen Djainal

2007-01-01

Good digital circuit design that part of a complex system, often becoming a separate problem. To produce finishing design according to wanted performance is often given on to considerations which each other confuse, hence thereby analyse optimization become important in this case. To realization is made design logic program, the first are determined global diagram block, then are decided contents of these block diagram, and then determined its interconnection in the form of logic expression, continued with election of component. These steps are done to be obtained the design with low price, easy in its interconnection, minimal volume, low power and certainty god work. (author)

Development of multi-channel gated integrator and PXI-DAQ system for nuclear detector arrays

International Nuclear Information System (INIS)

Kong Jie; Su Hong; Chen Zhiqiang; Dong Chengfu; Qian Yi; Gao Shanshan; Zhou Chaoyang; Lu Wan; Ye Ruiping; Ma Junbing

2010-01-01

A multi-channel gated integrator and PXI based data acquisition system have been developed for nuclear detector arrays with hundreds of detector units. The multi-channel gated integrator can be controlled by a programmable GI controller. The PXI-DAQ system consists of NI PXI-1033 chassis with several PXI-DAQ cards. The system software has a user-friendly GUI which is written in C language using LabWindows/CVI under Windows XP operating system. The performance of the PXI-DAQ system is very reliable and capable of handling event rate up to 40 kHz.

Automated Microscopy: Macro Language Controlling a Confocal Microscope and its External Illumination: Adaptation for Photosynthetic Organisms.

Science.gov (United States)

Steinbach, Gábor; Kaňa, Radek

2016-04-01

Photosynthesis research employs several biophysical methods, including the detection of fluorescence. Even though fluorescence is a key method to detect photosynthetic efficiency, it has not been applied/adapted to single-cell confocal microscopy measurements to examine photosynthetic microorganisms. Experiments with photosynthetic cells may require automation to perform a large number of measurements with different parameters, especially concerning light conditions. However, commercial microscopes support custom protocols (through Time Controller offered by Olympus or Experiment Designer offered by Zeiss) that are often unable to provide special set-ups and connection to external devices (e.g., for irradiation). Our new system combining an Arduino microcontroller with the Cell⊕Finder software was developed for controlling Olympus FV1000 and FV1200 confocal microscopes and the attached hardware modules. Our software/hardware solution offers (1) a text file-based macro language to control the imaging functions of the microscope; (2) programmable control of several external hardware devices (light sources, thermal controllers, actuators) during imaging via the Arduino microcontroller; (3) the Cell⊕Finder software with ergonomic user environment, a fast selection method for the biologically important cells and precise positioning feature that reduces unwanted bleaching of the cells by the scanning laser. Cell⊕Finder can be downloaded from http://www.alga.cz/cellfinder. The system was applied to study changes in fluorescence intensity in Synechocystis sp. PCC6803 cells under long-term illumination. Thus, we were able to describe the kinetics of phycobilisome decoupling. Microscopy data showed that phycobilisome decoupling appears slowly after long-term (>1 h) exposure to high light.

Optical modeling of Fresnel zoneplate microscopes

International Nuclear Information System (INIS)

Naulleau, Patrick P.; Mochi, Iacopo; Goldberg, Kenneth A.

2011-01-01

Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community.

Color Laser Microscope

Science.gov (United States)

Awamura, D.; Ode, T.; Yonezawa, M.

1987-04-01

A color laser microscope utilizing a new color laser imaging system has been developed for the visual inspection of semiconductors. The light source, produced by three lasers (Red; He-Ne, Green; Ar, Blue; He-Cd), is deflected horizontally by an AOD (Acoustic Optical Deflector) and vertically by a vibration mirror. The laser beam is focused in a small spot which is scanned over the sample at high speed. The light reflected back from the sample is reformed to contain linear information by returning to the original vibration mirror. The linear light is guided to the CCD image sensor where it is converted into a video signal. Individual CCD image sensors are used for each of the three R, G, or B color image signals. The confocal optical system with its laser light source yields a color TV monitor image with no flaring and a much sharper resolution than that of the conventional optical microscope. The AOD makes possible a high speed laser scan and a NTSC or PAL TV video signal is produced in real time without any video memory. Since the light source is composed of R, G, and B laser beams, color separation superior to that of white light illumination is achieved. Because of the photometric linearity of the image detector, the R, G, and B outputs of the system are most suitably used for hue analysis. The CCD linear image sensors in the optical system produce no geometrical distortion, and good color registration is available principally. The output signal can be used for high accuracy line width measuring. The many features of the color laser microscope make it ideally suited for the visual inspection of semiconductor processing. A number of these systems have already been installed in such a capacity. The Color Laser Microscope can also be a very useful tool for the fields of material engineering and biotechnology.

Free and open-source automated 3-D microscope.

Science.gov (United States)

Wijnen, Bas; Petersen, Emily E; Hunt, Emily J; Pearce, Joshua M

2016-11-01

Open-source technology not only has facilitated the expansion of the greater research community, but by lowering costs it has encouraged innovation and customizable design. The field of automated microscopy has continued to be a challenge in accessibility due the expense and inflexible, noninterchangeable stages. This paper presents a low-cost, open-source microscope 3-D stage. A RepRap 3-D printer was converted to an optical microscope equipped with a customized, 3-D printed holder for a USB microscope. Precision measurements were determined to have an average error of 10 μm at the maximum speed and 27 μm at the minimum recorded speed. Accuracy tests yielded an error of 0.15%. The machine is a true 3-D stage and thus able to operate with USB microscopes or conventional desktop microscopes. It is larger than all commercial alternatives, and is thus capable of high-depth images over unprecedented areas and complex geometries. The repeatability is below 2-D microscope stages, but testing shows that it is adequate for the majority of scientific applications. The open-source microscope stage costs less than 3-9% of the closest proprietary commercial stages. This extreme affordability vastly improves accessibility for 3-D microscopy throughout the world. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Microbe observation and cultivation array (MOCA) for cultivating and analyzing environmental microbiota.

Science.gov (United States)

Gao, Weimin; Navarroli, Dena; Naimark, Jared; Zhang, Weiwen; Chao, Shih-Hui; Meldrum, Deirdre R

2013-01-09

The use of culture-independent nucleic acid techniques, such as ribosomal RNA gene cloning library analysis, has unveiled the tremendous microbial diversity that exists in natural environments. In sharp contrast to this great achievement is the current difficulty in cultivating the majority of bacterial species or phylotypes revealed by molecular approaches. Although recent new technologies such as metagenomics and metatranscriptomics can provide more functionality information about the microbial communities, it is still important to develop the capacity to isolate and cultivate individual microbial species or strains in order to gain a better understanding of microbial physiology and to apply isolates for various biotechnological applications. We have developed a new system to cultivate bacteria in an array of droplets. The key component of the system is the microbe observation and cultivation array (MOCA), which consists of a Petri dish that contains an array of droplets as cultivation chambers. MOCA exploits the dominance of surface tension in small amounts of liquid to spontaneously trap cells in well-defined droplets on hydrophilic patterns. During cultivation, the growth of the bacterial cells across the droplet array can be monitored using an automated microscope, which can produce a real-time record of the growth. When bacterial cells grow to a visible microcolony level in the system, they can be transferred using a micropipette for further cultivation or analysis. MOCA is a flexible system that is easy to set up, and provides the sensitivity to monitor growth of single bacterial cells. It is a cost-efficient technical platform for bioassay screening and for cultivation and isolation of bacteria from natural environments.

On thermodynamic and microscopic reversibility

International Nuclear Information System (INIS)

Crooks, Gavin E

2011-01-01

The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa

Microscopic to macroscopic depletion model development for FORMOSA-P

International Nuclear Information System (INIS)

Noh, J.M.; Turinsky, P.J.; Sarsour, H.N.

1996-01-01

Microscopic depletion has been gaining popularity with regard to employment in reactor core nodal calculations, mainly attributed to the superiority of microscopic depletion in treating spectral history effects during depletion. Another trend is the employment of loading pattern optimization computer codes in support of reload core design. Use of such optimization codes has significantly reduced design efforts to optimize reload core loading patterns associated with increasingly complicated lattice designs. A microscopic depletion model has been developed for the FORMOSA-P pressurized water reactor (PWR) loading pattern optimization code. This was done for both fidelity improvements and to make FORMOSA-P compatible with microscopic-based nuclear design methods. Needless to say, microscopic depletion requires more computational effort compared with macroscopic depletion. This implies that microscopic depletion may be computationally restrictive if employed during the loading pattern optimization calculation because many loading patterns are examined during the course of an optimization search. Therefore, the microscopic depletion model developed here uses combined models of microscopic and macroscopic depletion. This is done by first performing microscopic depletions for a subset of possible loading patterns from which 'collapsed' macroscopic cross sections are obtained. The collapsed macroscopic cross sections inherently incorporate spectral history effects. Subsequently, the optimization calculations are done using the collapsed macroscopic cross sections. Using this approach allows maintenance of microscopic depletion level accuracy without substantial additional computing resources

Development of confocal laser microscope system for examination of microscopic characteristics of radiophotoluminescence glass dosemeters

International Nuclear Information System (INIS)

Maki, D.; Ishii, T.; Sato, F.; Kato, Y.; Yamamoto, T.; Iida, T.

2011-01-01

A confocal laser microscope system was developed for the measurement of radiophotoluminescence (RPL) photons emitted from a minute alpha-ray-irradiated area in an RPL glass dosemeter. The system was composed mainly of an inverted-type microscope, an ultraviolet laser, an XY movable stage and photon-counting circuits. The photon-counting circuits were effective in the reduction of the background noise level in the measurement of RPL photons. The performance of this microscope system was examined by the observation of standard RPL glass samples irradiated using 241 Am alpha rays. The spatial resolution of this system was ∼3 μm, and with regard to the sensitivity of this system, a hit of more than four to five alpha rays in unit area produced enough amount of RPL photons to construct the image. (authors)

Development of confocal laser microscope system for examination of microscopic characteristics of radiophotoluminescence glass dosemeters.

Science.gov (United States)

Maki, Daisuke; Ishii, Tetsuya; Sato, Fuminobu; Kato, Yushi; Yamamoto, Takayoshi; Iida, Toshiyuki

2011-03-01

A confocal laser microscope system was developed for the measurement of radiophotoluminescence (RPL) photons emitted from a minute alpha-ray-irradiated area in an RPL glass dosemeter. The system was composed mainly of an inverted-type microscope, an ultraviolet laser, an XY movable stage and photon-counting circuits. The photon-counting circuits were effective in the reduction of the background noise level in the measurement of RPL photons. The performance of this microscope system was examined by the observation of standard RPL glass samples irradiated using (241)Am alpha rays. The spatial resolution of this system was ∼ 3 μm, and with regard to the sensitivity of this system, a hit of more than four to five alpha rays in unit area produced enough amount of RPL photons to construct the image.

Neuromorphic Data Microscope

Energy Technology Data Exchange (ETDEWEB)

Naegle, John H.; Suppona, Roger A.; Aimone, James Bradley; James, Conrad D.; Follett, David R.; Townsend, Duncan C.M.; Follett, Pamela L.; Karpman, Gabe D.

2017-08-01

In 2016, Lewis Rhodes Labs, (LRL), shipped the first commercially viable Neuromorphic Processing Unit, (NPU), branded as a Neuromorphic Data Microscope (NDM). This product leverages architectural mechanisms derived from the sensory cortex of the human brain to efficiently implement pattern matching. LRL and Sandia National Labs have optimized this product for streaming analytics, and demonstrated a 1,000x power per operation reduction in an FPGA format. When reduced to an ASIC, the efficiency will improve to 1,000,000x. Additionally, the neuromorphic nature of the device gives it powerful computational attributes that are counterintuitive to those schooled in traditional von Neumann architectures. The Neuromorphic Data Microscope is the first of a broad class of brain-inspired, time domain processors that will profoundly alter the functionality and economics of data processing.

Mesooptical microscope as a tomographical device

International Nuclear Information System (INIS)

Soroko, L.M.

1989-01-01

It is shown that there are at least four regions which are common for the mesooptical microscopes, on the one hand, and for the reconstructed tomography, on the other hand. The following characteristics of the mesooptical microscope show the tomographical properties: the structure of the output data concerning the orientation and the position in space of the straight-line objects going at small angles with the perpendicular to the given tomographic plane, the behaviour of the two-dimensional fourier-transform of the straight-line object in the course of the rotation of this object with respect to the specified axis in space, the scanning algorithm of the nuclear emulsion volume by the fence-like illuminated region in the mesooptical microscope for searching for particle tracks going parallel to the optical axis of the microscope, and, finally, the fact that the mesooptical images of the straight-line particle tracks with a common vertex in the nuclear emulsion lie on the sinogram. 12 refs.; 16 figs

Using the scanning electron microscope and energy dispersive x-ray spectrometer to do mineral identification and compositional point counting on unconsolidated marine sediments

International Nuclear Information System (INIS)

Robson, S.H.

1982-01-01

This paper describes a rapid and accurate method of point-counting sands and silt-size in unconsolidated open-ocean sediments. As traditional techniques for this operation cannot be employed on the fine-grained material which frequently forms the bulk of deep sea marine sediments, an alternative method has been sought. The method described makes use of equipment known as QUANTEX-RAY comprising a computerised data acquisition and reduction system designed for use in X-ray energy spectrometry and used in conjunction with a scanning electron microscope (SEM). Grains that cannot be identified by their visual morphology in the scanning electron microscope are analysed by X-ray spectrometry. Spectra are acquired in 200 seconds or less and processed by a sequence of software routines under semi-automatic control producing a listing of oxide concentrations as the final result. Each user must customize the control programme and operating conditions to suit his requirements

Operation of a scanning near field optical microscope in reflection in combination with a scanning force microscope

NARCIS (Netherlands)

van Hulst, N.F.; Moers, M.H.P.; Moers, M.H.P.; Noordman, O.F.J.; Noordman, O.F.J.; Faulkner, T.; Segerink, Franciscus B.; van der Werf, Kees; de Grooth, B.G.; Bölger, B.; Bölger, B.

1992-01-01

Images obtained with a scanning near field optical microscope (SNOM) operating in reflection are presented. We have obtained the first results with a SiN tip as optical probe. The instrument is simultaneously operated as a scanning force microscope (SFM). Moreover, the instrument incorporates an

Chromosome structure investigated with the atomic force microscope

NARCIS (Netherlands)

de Grooth, B.G.; Putman, C.A.J.; Putman, Constant A.; van der Werf, Kees; van Hulst, N.F.; van Oort, G.; van Oort, Geeske; Greve, Jan; Manne, Srinivas

1992-01-01

We have developed an atomic force microscope (AFM) with an integrated optical microscope. The optical microscope consists of an inverted epi-illumination system that yields images in reflection or fluorescence of the sample. With this system it is possible to quickly locate an object of interest. A

Fusion technology programme

International Nuclear Information System (INIS)

Finken, D.

1984-04-01

KfK participates to the Fusion Technology Programme of the European Community. Most of the work in progress addresses the Next European Torus (NET) and the long term technology aspects as defined in the 82/86 programme. A minor part serves to preparation of future contributions and to design studies on fusion concepts in a wider perspective. The Fusion Technology Programme of Euratom covers mainly aspects of nuclear engineering. Plasma engineering, heating, refueling and vacuum technology are at present part of the Physics Programme. In view of NET, integration of the different areas of work will be mandatory. KfK is therefore prepared to address technical aspects beyond the actual scope of the physics experiments. The technology tasks are reported project wise under title and code of the Euratom programme. Most of the projects described here are shared with other European fusion laboratories as indicated in the table annexed to this report. (orig./GG)

X-ray microscope with a Wolter mirror

International Nuclear Information System (INIS)

Watanabe, Norio; Aoki, Sadao

2003-01-01

A Wolter mirror as an objective of an X-ray microscope is described. In comparison with other optical elements, a Wolter mirror has several advantages, such as a large numerical aperture and no chromatic aberration. Recent developments of fabrication process enabled us to make a Wolter mirror objective for X-rays. The fabrication process and the applications to a soft X-ray microscope and an X-ray fluorescence microscope are described. (author)

Development and applications of the positron microscope

International Nuclear Information System (INIS)

1991-01-01

Progress on the positron microscope during the past year has been steady, and we currently project that initial microscope images can be collected during mid to late summer of 1992. Work during the year has mainly been divided among four areas of effort: hardware construction; power supply and control system development; radioactive source fabrication; and planning of initial experimental projects. Details of progress in these areas will be given below. An initial optical design of the microscope was completed during 1990, but during the past year, significant improvements have been made to this design, and several limiting cases of microscope performance have been evaluated. The results of these evaluations have been extremely encouraging, giving us strong indications that the optical performance of the microscope will be better than originally anticipated. In particular, we should be able to explore ultimate performance capabilities of positron microscopy using our currently planned optical system, with improvements only in the image detector system, and the positron-source/moderator configuration. We should be able to study imaging reemission microscopy with resolutions approaching 10 Angstrom and be able to produce beam spots for rastered microscope work with diameters below the 1000 Angstrom diffusion limit. Because of these exciting new possibilities, we have decided to upgrade several microscope subsystems to levels consistent with ultimate performance earlier in our construction schedule than we had previously intended. In particular, alignment facilities in the optical system, vibration isolation, and power supply and control system flexibility have all been upgraded in their design over the past year

21 CFR 878.4700 - Surgical microscope and accessories.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical microscope and accessories. 878.4700 Section 878.4700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... microscope and accessories. (a) Identification. A surgical microscope and accessories is an AC-powered device...

The 'Kristallin' programme: investigations, results, future procedure

International Nuclear Information System (INIS)

Gautschi, A.

1995-01-01

The synthesis of the geological investigations carried out to date as part of the 'Kristallin' programme has indicated that potentially suitable crystalline rock at an appropriate depth can be found in two regions of Northern Switzerland. The most promising siting options are in Canton Aargau, in a strip of land a few kilometers wide to the south of the Rhine river (Area West: Kaisten-Leuggern-Boettstein). A second-priority option is in Canton Schaffhausen (Area East: Siblingen). For the next phase of investigations into the possibility of locating a repository for high-level and long-lived intermediate-level waste in a crystalline formation, it is planned to carry out a 3D seismic survey in the Boettstein-Leuggern region and to drill an array of inclined boreholes at the former deep borehole site at Leuggern (or Boettstein). These two boreholes have already revealed the presence of large sections of low-permeability crystalline basement. (author) 12 figs

Finnish bioenergy research programme

Energy Technology Data Exchange (ETDEWEB)

Asplund, D. [VTT Energy, Jyvaeskylae (Finland)

1996-12-31

Finland is a leading country in the use of biofuels and has excellent opportunities to increase the use of biofuels by up to 25-30 %. The Finnish Government has set an objective for the promotion of bioenergy. The aim is to increase the use of bioenergy by about 25 % from the present level by 2005, and the increment corresponds to 1.5 million tonnes of oil equivalent (toe) per year. The R and D work has been considered as an important factor to achieve this ambitious goal. Energy research was organised into a series of research programmes in 1988 in accordance with the proposal of Finnish Energy Research Committee. The object of the research programmes is to enhance research activities and to bundle individual projects together into larger research packages. The common target of the Finnish energy research programmes is to proceed from basic and applied research to product development and pilot operation, and after that to the first commercial applications, e.g. demonstrations. As the organisation of energy research to programmes has led to good results, the Finnish Ministry of Trade and Industry decided to go on with this practice by launching new six-year programmes in 1993-1998. One of these programmes is the Bioenergy Research Programme and the co-ordination of this programme is carried out by VTT Energy. Besides VTT Energy the Finnish Forest Research Institute, Work Efficiency Institute, Metsaeteho and University of Joensuu are participating in the programme 7 refs.

Finnish bioenergy research programme

Energy Technology Data Exchange (ETDEWEB)

Asplund, D [VTT Energy, Jyvaeskylae (Finland)

1997-12-31

Finland is a leading country in the use of biofuels and has excellent opportunities to increase the use of biofuels by up to 25-30 %. The Finnish Government has set an objective for the promotion of bioenergy. The aim is to increase the use of bioenergy by about 25 % from the present level by 2005, and the increment corresponds to 1.5 million tonnes of oil equivalent (toe) per year. The R and D work has been considered as an important factor to achieve this ambitious goal. Energy research was organised into a series of research programmes in 1988 in accordance with the proposal of Finnish Energy Research Committee. The object of the research programmes is to enhance research activities and to bundle individual projects together into larger research packages. The common target of the Finnish energy research programmes is to proceed from basic and applied research to product development and pilot operation, and after that to the first commercial applications, e.g. demonstrations. As the organisation of energy research to programmes has led to good results, the Finnish Ministry of Trade and Industry decided to go on with this practice by launching new six-year programmes in 1993-1998. One of these programmes is the Bioenergy Research Programme and the co-ordination of this programme is carried out by VTT Energy. Besides VTT Energy the Finnish Forest Research Institute, Work Efficiency Institute, Metsaeteho and University of Joensuu are participating in the programme 7 refs.

Multi-compartment microscopic diffusion imaging

OpenAIRE

Kaden, Enrico; Kelm, Nathaniel D.; Carson, Robert P.; Does, Mark D.; Alexander, Daniel C.

2016-01-01

This paper introduces a multi-compartment model for microscopic diffusion anisotropy imaging. The aim is to estimate microscopic features specific to the intra- and extra-neurite compartments in nervous tissue unconfounded by the effects of fibre crossings and orientation dispersion, which are ubiquitous in the brain. The proposed MRI method is based on the Spherical Mean Technique (SMT), which factors out the neurite orientation distribution and thus provides direct estimates of the microsco...

A pragmatic guide to multiphoton microscope design

Science.gov (United States)

Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

2016-01-01

Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

A frameless stereotaxic operating microscope for neurosurgery

International Nuclear Information System (INIS)

Friets, E.M.; Strohbehn, J.W.; Hatch, J.F.; Roberts, D.W.

1989-01-01

A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given

A frameless stereotaxic operating microscope for neurosurgery.

Science.gov (United States)

Friets, E M; Strohbehn, J W; Hatch, J F; Roberts, D W

1989-06-01

A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given.

Microscopic enteritis: Bucharest consensus.

Science.gov (United States)

Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

2015-03-07

Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5(th) International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy.

Note: Design of FPGA based system identification module with application to atomic force microscopy

Science.gov (United States)

Ghosal, Sayan; Pradhan, Sourav; Salapaka, Murti

2018-05-01

The science of system identification is widely utilized in modeling input-output relationships of diverse systems. In this article, we report field programmable gate array (FPGA) based implementation of a real-time system identification algorithm which employs forgetting factors and bias compensation techniques. The FPGA module is employed to estimate the mechanical properties of surfaces of materials at the nano-scale with an atomic force microscope (AFM). The FPGA module is user friendly which can be interfaced with commercially available AFMs. Extensive simulation and experimental results validate the design.

A fortran programme for determining frequency responses for linear systems with time delays

International Nuclear Information System (INIS)

Milsom, P.R.

1966-11-01

In this report a digital computer programme for evaluating frequency responses is described. In its standard form the programme is capable of determining the gain and phase of up to 35 variables over a range of up to 30 frequencies for a system described by up to 65 equations. The equations must be either first order differential or algebraic and either type may include time delayed terms. Up to 50 such terms are permissible throughout the equation set. Provision is made for up to 10 inputs and up to 50 differentiated input terms are permitted throughout the equation set. However, it is possible for the user to increase a maximum dimension, albeit at the expense of another array dimension. In punching the data from the equations the user has no sorting or arranging of coefficients to do, and the equations may be in any order. The specifying of other input information, such as frequency range, the inputs to be perturbed and the variables for which frequency responses are required, is also very straightforward. (author)

Microscopic modelling of doped manganites

International Nuclear Information System (INIS)

Weisse, Alexander; Fehske, Holger

2004-01-01

Colossal magneto-resistance manganites are characterized by a complex interplay of charge, spin, orbital and lattice degrees of freedom. Formulating microscopic models for these compounds aims at meeting two conflicting objectives: sufficient simplification without excessive restrictions on the phase space. We give a detailed introduction to the electronic structure of manganites and derive a microscopic model for their low-energy physics. Focusing on short-range electron-lattice and spin-orbital correlations we supplement the modelling with numerical simulations

Deuteron microscopic optical model potential

International Nuclear Information System (INIS)

Guo Hairui; Han Yinlu; Shen Qingbiao; Xu Yongli

2010-01-01

A deuteron microscopic optical model potential is obtained by the Green function method through nuclear-matter approximation and local-density approximation based on the effective Skyrme interaction. The microscopic optical model potential is used to calculate the deuteron reaction cross sections and the elastic scattering angular distributions for some target nuclei in the mass range 6≤A≤208 with incident deuteron energies up to 200 MeV. The calculated results are compared with the experimental data.

Bolsa Família (Family Grant Programme: an analysis of Brazilian income transfer programme

Directory of Open Access Journals (Sweden)

Luciana Mourão

2012-06-01

Full Text Available Income transfer programmes are common in various countries and play an important role in combating poverty. This article presents a review of the results of the Bolsa Família (Family Grant Programme, implemented in Brazil by the government of Lula da Silva in 2004. Over the last seven years many evaluations of the programme have been conducted, allowing an overview of its results and its strong and weak points to be mapped. Five central aspects relating to the programme are discussed in article five: (1 programme access, (2 hunger fighting results, (3 programme financial impacts, (4 conditioning factors of education and health, (5 supplementary programs and social mobility. The results of scientific research were presented for each of these aspects, and any of these believed to be convergent or divergent were discussed. As a general result it was concluded that the programme has generated significant results for the country, but there are still some issues that need to be reviewed, such as conditioning factors and the integrated management of the programme.

The Winfrith DSN programme

Energy Technology Data Exchange (ETDEWEB)

Francescon, S [General Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

1963-05-15

The programme, which is written in the Fortran language, solves the Carlson discrete S{sub n} approximation to the Boltzmann transport equation in cylindrical geometry. This report describes the input and output facilities of the WINFRITH DSN programme and the associated editing programme WED. (author)

The Winfrith DSN programme

International Nuclear Information System (INIS)

Francescon, S.

1963-05-01

The programme, which is written in the Fortran language, solves the Carlson discrete S n approximation to the Boltzmann transport equation in cylindrical geometry. This report describes the input and output facilities of the WINFRITH DSN programme and the associated editing programme WED. (author)

UNESCO's Ethics Education Programme.

NARCIS (Netherlands)

Have, H.A.M.J. ten

2008-01-01

Unesco initiated the Ethics Education Programme in 2004 at the request of member states to reinforce and increase the capacities in the area of ethics teaching. The programme is focused on providing detailed information about existing teaching programmes. It also develops and promotes teaching

Qualification, monitoring, and integration into a production environment of the world's first fully programmable illuminator

Science.gov (United States)

McIntyre, Gregory; Corliss, Daniel; Groenendijk, Remco; Carpaij, Rene; van Niftrik, Ton; Landie, Guillaume; Tamura, Takao; Pepin, Thomas; Waddell, James; Woods, Jerry; Robinson, Chris; Tian, Kehan; Johnson, Richard; Halle, Scott; Kim, Ryoung-Han; Mclellan, Erin; Kato, Hirokazu; Scaduto, Anthony; Maier, Carl; Colburn, Matt

2011-04-01

This paper will describe the development, qualification, monitoring, and integration into a production environment of the world's first fully programmable illuminator for optical lithography. FlexRay TM, a programmable illuminator based on a MEMs multi-mirror array that was developed for TWINSCAN XT:19x0i and TWINSCAN NXT series ASML immersion scanners, was first installed in January 2010 at Albany Nanotech, with subsequent tools installed in IBM's East Fishkill Manufacturing facility. After a brief overview of the concept and benefits of FlexRay, this paper will provide a comprehensive assessment of its reliability and imaging performance. A CD-based pupil qualification (CDPQ) procedure will be introduced and shown to be an efficient and effective way to monitor pupil performance. Various CDPQ and in-resist measurement results will be described, offering convincing evidence that FlexRay reliably generates high-quality pupils and is well suited for high volume manufacturing at lithography's leading edge.

Photocatalytic activity of self-assembled porous TiO2 nano-columns array fabricated by oblique angle sputter deposition

Science.gov (United States)

Shi, Pengjun; Li, Xibo; Zhang, Qiuju; Yi, Zao; Luo, Jiangshan

2018-04-01

A well-separated and oriented TiO2 nano-columns arrays with porous structure were fabricated by the oblique angle sputter deposition technique and subsequently annealing at 450 °C in Ar/O2 mixed atmosphere. The deposited substrate was firstly modified by a template of self-assembled close-packed arrays of 500 nm-diameter silica (SiO2) spheres. Scanning electronic microscopic (SEM) images show that the porous columnar nanostructure is formed as a result of the geometric shadowing effect and surface diffusion of the adatoms in oblique angle deposition (OAD). X-ray diffraction (XRD) measurements reveal that the physically OAD film with annealing treatment are generally mixed phase of rutile and anatase TiO2 polymorphic forms. The morphology induced absorbance and band gap tuning by different substrates was demonstrated by the UV–vis spectroscopy. The well-separated one-dimensional (1D) nano-columns array with specific large porous surface area is beneficial for charge separation in photocatalytic degradation. Compared with compact thin film, such self-assembled porous TiO2 nano-columns array fabricated by oblique angle sputter deposition performed an enhanced visible light induced photocatalytic activity by decomposing methyl orange (MO) solution. The well-designed periodic array-structured porous TiO2 films by using modified patterned substrates has been demonstrated significantly increased absorption edge in the UV-visible light region with a narrower optical band gap, which are expected to be favorable for application in photovoltaic, lithium-ion insertion and photocatalytic, etc.

Sub-nanosecond time-resolved near-field scanning magneto-optical microscope.

Science.gov (United States)

Rudge, J; Xu, H; Kolthammer, J; Hong, Y K; Choi, B C

2015-02-01

We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of microscope, the magnetic field pulse induced gyrotropic vortex dynamics occurring in 1 μm diameter, 20 nm thick CoFeB circular disks has been investigated. The microscope provides sub-wavelength resolution magnetic images of the gyrotropic motion of the vortex core at a resonance frequency of ∼240 MHz.

[Remote Slit Lamp Microscope Consultation System Based on Web].

Science.gov (United States)

Chen, Junfa; Zhuo, Yong; Liu, Zuguo; Chen, Yanping

2015-11-01

To realize the remote operation of the slit lamp microscope for department of ophthalmology consultation, and visual display the real-time status of remote slit lamp microscope, a remote slit lamp microscope consultation system based on B/S structure is designed and implemented. Through framing the slit lamp microscope on the website system, the realtime acquisition and transmission of remote control and image data is realized. The three dimensional model of the slit lamp microscope is established and rendered on the web by using WebGL technology. The practical application results can well show the real-time interactive of the remote consultation system.

The INTEGRAL Core Observing Programme

DEFF Research Database (Denmark)

Winkler, C.; Gehrels, N.; Lund, Niels

1999-01-01

The Core Programme of the INTEGRAL mission is defined as the portion of the scientific programme covering the guaranteed time observations for the INTEGRAL Science Working Team. This paper describes the current status of the Core Programme preparations and summarizes the key elements...... of the observing programme....

Cyclotron-Resonance-Maser Arrays

International Nuclear Information System (INIS)

Kesar, A.; Lei, L.; Dikhtyar, V.; Korol, M.; Jerby, E.

1999-01-01

The cyclotron-resonance-maser (CRM) array [1] is a radiation source which consists of CRM elements coupled together under a common magnetic field. Each CRM-element employs a low-energy electron-beam which performs a cyclotron interaction with the local electromagnetic wave. These waves can be coupled together among the CRM elements, hence the interaction is coherently synchronized in the entire array. The implementation of the CRM-array approach may alleviate several technological difficulties which impede the development of single-beam gyro-devices. Furthermore, it proposes new features, such as the phased-array antenna incorporated in the CRM-array itself. The CRM-array studies may lead to the development of compact, high-power radiation sources operating at low-voltages. This paper introduces new conceptual schemes of CRM-arrays, and presents the progress in related theoretical and experimental studies in our laboratory. These include a multi-mode analysis of a CRM-array, and a first operation of this device with five carbon-fiber cathodes

A variable-temperature nanostencil compatible with a low-temperature scanning tunneling microscope/atomic force microscope

International Nuclear Information System (INIS)

Steurer, Wolfram; Gross, Leo; Schlittler, Reto R.; Meyer, Gerhard

2014-01-01

We describe a nanostencil lithography tool capable of operating at variable temperatures down to 30 K. The setup is compatible with a combined low-temperature scanning tunneling microscope/atomic force microscope located within the same ultra-high-vacuum apparatus. The lateral movement capability of the mask allows the patterning of complex structures. To demonstrate operational functionality of the tool and estimate temperature drift and blurring, we fabricated LiF and NaCl nanostructures on Cu(111) at 77 K

A variable-temperature nanostencil compatible with a low-temperature scanning tunneling microscope/atomic force microscope

Energy Technology Data Exchange (ETDEWEB)

Steurer, Wolfram, E-mail: wst@zurich.ibm.com; Gross, Leo; Schlittler, Reto R.; Meyer, Gerhard [IBM Research-Zurich, 8803 Rüschlikon (Switzerland)

2014-02-15

We describe a nanostencil lithography tool capable of operating at variable temperatures down to 30 K. The setup is compatible with a combined low-temperature scanning tunneling microscope/atomic force microscope located within the same ultra-high-vacuum apparatus. The lateral movement capability of the mask allows the patterning of complex structures. To demonstrate operational functionality of the tool and estimate temperature drift and blurring, we fabricated LiF and NaCl nanostructures on Cu(111) at 77 K.

A variable-temperature nanostencil compatible with a low-temperature scanning tunneling microscope/atomic force microscope.

Science.gov (United States)

Steurer, Wolfram; Gross, Leo; Schlittler, Reto R; Meyer, Gerhard

2014-02-01

We describe a nanostencil lithography tool capable of operating at variable temperatures down to 30 K. The setup is compatible with a combined low-temperature scanning tunneling microscope/atomic force microscope located within the same ultra-high-vacuum apparatus. The lateral movement capability of the mask allows the patterning of complex structures. To demonstrate operational functionality of the tool and estimate temperature drift and blurring, we fabricated LiF and NaCl nanostructures on Cu(111) at 77 K.

A microscopic model of triangular arbitrage

Science.gov (United States)

Aiba, Yukihiro; Hatano, Naomichi

2006-11-01

We introduce a microscopic model which describes the dynamics of each dealer in multiple foreign exchange markets, taking account of the triangular arbitrage transaction. The model reproduces the interaction among the markets well. We explore the relation between the parameters of the present microscopic model and the spring constant of a macroscopic model that we proposed previously.

Quantum theory and microscopic mechanics. I

International Nuclear Information System (INIS)

Yussouff, M.

1984-08-01

The need for theoretical descriptions and experimental observations on 'small' individual systems is emphasized. It is shown that the mathematical basis for microscopic mechanics is very simple in one dimension. The square well problem is discussed to clarify general points about stationary states and the continuity of (p'/p) across potential boundaries in the applications of microscopic mechanics. (author)

Electron Microscope Center Opens at Berkeley.

Science.gov (United States)

Robinson, Arthur L.

1981-01-01

A 1.5-MeV High Voltage Electron Microscope has been installed at the Lawrence Berkeley Laboratory which will help materials scientists and biologists study samples in more true-to-life situations. A 1-MeV Atomic Resolution Microscope will be installed at the same location in two years which will allow scientists to distinguish atoms. (DS)

Towards vortex imaging with scanning tunneling microscope

International Nuclear Information System (INIS)

Fuchs, Dan T.

1994-02-01

A low temperature, Besocke beetle type scanning tunneling microscope, with a scan range of 10 by 10 microns was built. The scanning tunneling microscope was calibrates for various temperatures and tested on several samples. Gold monolayers evaporated at 400 deg C were resolved and their dynamic behavior observed. Atomic resolution images of graphite were obtained. The scanning tunneling microscope was designed for future applications of vortex imaging in superconductors. The special design considerations for this application are discussed and the physics underlying it reviewed. (author)

Degree-of-Freedom Strengthened Cascade Array for DOD-DOA Estimation in MIMO Array Systems.

Science.gov (United States)

Yao, Bobin; Dong, Zhi; Zhang, Weile; Wang, Wei; Wu, Qisheng

2018-05-14

In spatial spectrum estimation, difference co-array can provide extra degrees-of-freedom (DOFs) for promoting parameter identifiability and parameter estimation accuracy. For the sake of acquiring as more DOFs as possible with a given number of physical sensors, we herein design a novel sensor array geometry named cascade array. This structure is generated by systematically connecting a uniform linear array (ULA) and a non-uniform linear array, and can provide more DOFs than some exist array structures but less than the upper-bound indicated by minimum redundant array (MRA). We further apply this cascade array into multiple input multiple output (MIMO) array systems, and propose a novel joint direction of departure (DOD) and direction of arrival (DOA) estimation algorithm, which is based on a reduced-dimensional weighted subspace fitting technique. The algorithm is angle auto-paired and computationally efficient. Theoretical analysis and numerical simulations prove the advantages and effectiveness of the proposed array structure and the related algorithm.

Unresolved transition array based water window soft x-ray source by laser-produced high-Z plasma

International Nuclear Information System (INIS)

Higashiguchi, Takeshi; Dunne, Padraig; O'Sullivan, Gerry

2013-01-01

We demonstrate a table-top broadband emission water window source based on laser-produced high-Z plasmas. resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs) in the 2 to 4 nm region, extending below the carbon K edge (4.37 nm). Arrays resulting from n=4-n=4 transitions are overlaid with n=4-n=5 emission and shift to shorter wavelength with increasing atomic number. An outline of a microscope design for single-shot live cell imaging is proposed based on a bismuth plasma UTA source, coupled to multilayer mirror optics. At power densities available from 'table-top' solid-state lasers, comparison of emission from a number of targets has shown that 3d-4f UTA in zirconium plasmas have highest overall brightness and in an imaging system based on reflective multilayer mirrors, may, depending on bandwidth, have superior performance than either line or broader-band sources. (author)

Nanoscale phosphorus atom arrays created using STM for the fabrication of a silicon based quantum computer.

Energy Technology Data Exchange (ETDEWEB)

O' Brien, J. L. (Jeremy L.); Schofield, S. R. (Steven R.); Simmons, M. Y. (Michelle Y.); Clark, R. G. (Robert G.); Dzurak, A. S. (Andrew S.); Curson, N. J. (Neil J.); Kane, B. E. (Bruce E.); McAlpine, N. S. (Neal S.); Hawley, M. E. (Marilyn E.); Brown, G. W. (Geoffrey W.)

2001-01-01

Quantum computers offer the promise of formidable computational power for certain tasks. Of the various possible physical implementations of such a device, silicon based architectures are attractive for their scalability and ease of integration with existing silicon technology. These designs use either the electron or nuclear spin state of single donor atoms to store quantum information. Here we describe a strategy to fabricate an array of single phosphorus atoms in silicon for the construction of such a silicon based quantum computer. We demonstrate the controlled placement of single phosphorus bearing molecules on a silicon surface. This has been achieved by patterning a hydrogen mono-layer 'resist' with a scanning tunneling microscope (STM) tip and exposing the patterned surface to phosphine (PH3) molecules. We also describe preliminary studies into a process to incorporate these surface phosphorus atoms into the silicon crystal at the array sites. Keywords: Quantum computing, nanotechriology scanning turincling microscopy, hydrogen lithography

Scanning electron microscope

International Nuclear Information System (INIS)

Anon.

1980-01-01

The principle underlying the design of the scanning electron microscope (SEM), the design and functioning of SEM are described. Its applications in the areas of microcircuitry and materials science are outlined. The development of SEM in India is reviewed. (M.G.B.)

A review of array radars

Science.gov (United States)

Brookner, E.

1981-10-01

Achievements in the area of array radars are illustrated by such activities as the operational deployment of the large high-power, high-range-resolution Cobra Dane; the operational deployment of two all-solid-state high-power, large UHF Pave Paws radars; and the development of the SAM multifunction Patriot radar. This paper reviews the following topics: array radars steered in azimuth and elevation by phase shifting (phase-phase steered arrays); arrays steered + or - 60 deg, limited scan arrays, hemispherical coverage, and omnidirectional coverage arrays; array radars steering electronically in only one dimension, either by frequency or by phase steering; and array radar antennas which use no electronic scanning but instead use array antennas for achieving low antenna sidelobes.

Quantification of tephritid fruit fly dispersal. Guidelines for a sterile release programme

International Nuclear Information System (INIS)

Baker, P.S.; Chan, A.S.T.

1991-01-01

The dispersal of sterile Anastrepha ludens and Ceratitis capitata was studied in a mango and coffee plantation in Chiapas, S. Mexico. Flies were released at the centre of a rectangular array of McPhail and Jackson traps. There were small though significant downwind movements in very light winds (below 1 m/s). Fly distributions were significantly correlated in the x-y plane on several days and these orientations were also related to wind direction. Released flies disappeared quickly, more than 90 % were caught within 5 days of release. Methodology for the presentation and analysis of data is discussed in relation to the needs of a practical sterile release programme. Recommendations are made for routine studies of fly dispersal

An electron microscope for the aberration-corrected era

Energy Technology Data Exchange (ETDEWEB)

Krivanek, O.L. [Nion Co., 1102 8th Street, Kirkland, WA 98033 (United States)], E-mail: krivanek.ondrej@gmail.com; Corbin, G.J.; Dellby, N.; Elston, B.F.; Keyse, R.J.; Murfitt, M.F.; Own, C.S.; Szilagyi, Z.S.; Woodruff, J.W. [Nion Co., 1102 8th Street, Kirkland, WA 98033 (United States)

2008-02-15

Improved resolution made possible by aberration correction has greatly increased the demands on the performance of all parts of high-end electron microscopes. In order to meet these demands, we have designed and built an entirely new scanning transmission electron microscope (STEM). The microscope includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors. The microscope features many innovations, such as a modular column assembled from building blocks that can be stacked in almost any order, in situ storage and cleaning facilities for up to five samples, computer-controlled loading of samples into the column, and self-diagnosing electronics. The microscope construction is described, and examples of its capabilities are shown.

An electron microscope for the aberration-corrected era

International Nuclear Information System (INIS)

Krivanek, O.L.; Corbin, G.J.; Dellby, N.; Elston, B.F.; Keyse, R.J.; Murfitt, M.F.; Own, C.S.; Szilagyi, Z.S.; Woodruff, J.W.

2008-01-01

Improved resolution made possible by aberration correction has greatly increased the demands on the performance of all parts of high-end electron microscopes. In order to meet these demands, we have designed and built an entirely new scanning transmission electron microscope (STEM). The microscope includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors. The microscope features many innovations, such as a modular column assembled from building blocks that can be stacked in almost any order, in situ storage and cleaning facilities for up to five samples, computer-controlled loading of samples into the column, and self-diagnosing electronics. The microscope construction is described, and examples of its capabilities are shown

The Wind Energy programme - SFOE Research Programme 2000 - 2003; Programm Wind. Konzept BFE-Forschungsprogramm 'Wind' 2000 - 2003

Energy Technology Data Exchange (ETDEWEB)

Horbaty, R.

2001-07-01

This document, issued by the Swiss Federal Office of Energy (SFOE) describes the concept behind the Swiss wind energy programme. The first part of the report discusses the origins and development of the wind energy programme in Switzerland, discussing the importance of wind energy and policy matters associated with its promotion. The experience gained during the previous research programmes is reviewed. The degree to which targets were reached, promotional activities, the central government's own wind energy activities and the results of a programme evaluation are discussed. Lists of projects that have been realised and activities that have been carried out are presented and positive and negative influences on development are noted. A second part is dedicated to the goals of the wind energy programme in terms of target figures for the year 2010 and the strategies chosen to reach these goals, including pilot and demonstration projects (P and D) and promotional activities. Details of the P and D programme including lists of wind-power projects to be supported, the priorities that have been set and information and further education that is to be provided, are given. New activities in the wind power area such as the development of new type of wind turbine especially suited to alpine conditions are discussed. The role of the Swiss Association for Wind Energy 'Suisse Eole' as a network-partner in the wind energy programme is discussed. An appendix provides details of wind energy projects in Switzerland, market partners and customers. The results of a survey made of wind energy activities at Swiss institutes of higher education are presented.

Optically Programmable Field Programmable Gate Arrays (FPGA) Systems

National Research Council Canada - National Science Library

Mumbru, Jose

2004-01-01

... holograms for these modules. The first chapter makes the case that a direct interface between an optical memory and a chip integrating detectors and logic circuitry can better utilize the high parallelism inherent in holographic modules...

The EUROBALL array

International Nuclear Information System (INIS)

Rossi Alvarez, C.

1998-01-01

The quality of the multidetector array EUROBALL is described, with emphasis on the history and formal organization of the related European collaboration. The detector layout is presented together with the electronics and Data Acquisition capabilities. The status of the instrument, its performances and the main features of some recently developed ancillary detectors will also be described. The EUROBALL array is operational in Legnaro National Laboratory (Italy) since April 1997 and is expected to run up to November 1998. The array represents a significant improvement in detector efficiency and sensitivity with respect to the previous generation of multidetector arrays

Design Methodology of an Equalizer for Unipolar Non Return to Zero Binary Signals in the Presence of Additive White Gaussian Noise Using a Time Delay Neural Network on a Field Programmable Gate Array

Science.gov (United States)

Pérez Suárez, Santiago T.; Travieso González, Carlos M.; Alonso Hernández, Jesús B.

2013-01-01

This article presents a design methodology for designing an artificial neural network as an equalizer for a binary signal. Firstly, the system is modelled in floating point format using Matlab. Afterward, the design is described for a Field Programmable Gate Array (FPGA) using fixed point format. The FPGA design is based on the System Generator from Xilinx, which is a design tool over Simulink of Matlab. System Generator allows one to design in a fast and flexible way. It uses low level details of the circuits and the functionality of the system can be fully tested. System Generator can be used to check the architecture and to analyse the effect of the number of bits on the system performance. Finally the System Generator design is compiled for the Xilinx Integrated System Environment (ISE) and the system is described using a hardware description language. In ISE the circuits are managed with high level details and physical performances are obtained. In the Conclusions section, some modifications are proposed to improve the methodology and to ensure portability across FPGA manufacturers.

Design Methodology of an Equalizer for Unipolar Non Return to Zero Binary Signals in the Presence of Additive White Gaussian Noise Using a Time Delay Neural Network on a Field Programmable Gate Array

Directory of Open Access Journals (Sweden)

Santiago T. Pérez Suárez

2013-12-01

Full Text Available This article presents a design methodology for designing an artificial neural network as an equalizer for a binary signal. Firstly, the system is modelled in floating point format using Matlab. Afterward, the design is described for a Field Programmable Gate Array (FPGA using fixed point format. The FPGA design is based on the System Generator from Xilinx, which is a design tool over Simulink of Matlab. System Generator allows one to design in a fast and flexible way. It uses low level details of the circuits and the functionality of the system can be fully tested. System Generator can be used to check the architecture and to analyse the effect of the number of bits on the system performance. Finally the System Generator design is compiled for the Xilinx Integrated System Environment (ISE and the system is described using a hardware description language. In ISE the circuits are managed with high level details and physical performances are obtained. In the Conclusions section, some modifications are proposed to improve the methodology and to ensure portability across FPGA manufacturers.

Electron beam excitation assisted optical microscope with ultra-high resolution.

Science.gov (United States)

Inami, Wataru; Nakajima, Kentaro; Miyakawa, Atsuo; Kawata, Yoshimasa

2010-06-07

We propose electron beam excitation assisted optical microscope, and demonstrated its resolution higher than 50 nm. In the microscope, a light source in a few nanometers size is excited by focused electron beam in a luminescent film. The microscope makes it possible to observe dynamic behavior of living biological specimens in various surroundings, such as air or liquids. Scan speed of the nanometric light source is faster than that in conventional near-field scanning optical microscopes. The microscope enables to observe optical constants such as absorption, refractive index, polarization, and their dynamic behavior on a nanometric scale. The microscope opens new microscopy applications in nano-technology and nano-science.

Ghana's nuclear programme

International Nuclear Information System (INIS)

Ahafia, Albert K.

1988-01-01

The Paper gives the purpose of Ghana's Nuclear Programme and describes some specific research activities and peaceful applications of atomic energy in agriculture, medicine and industry. A discussion of some of the problem facing the programme concludes the Paper. (author)

Installation of the MAXIMUM microscope at the ALS

International Nuclear Information System (INIS)

Ng, W.; Perera, R.C.C.; Underwood, J.H.; Singh, S.; Solak, H.; Cerrina, F.

1995-10-01

The MAXIMUM scanning x-ray microscope, developed at the Synchrotron Radiation Center (SRC) at the University of Wisconsin, Madison was implemented on the Advanced Light Source in August of 1995. The microscope's initial operation at SRC successfully demonstrated the use of multilayer coated Schwarzschild objective for focusing 130 eV x-rays to a spot size of better than 0.1 micron with an electron energy resolution of 250meV. The performance of the microscope was severely limited, because of the relatively low brightness of SRC, which limits the available flux at the focus of the microscope. The high brightness of the ALS is expected to increase the usable flux at the sample by a factor of 1,000. The authors will report on the installation of the microscope on bending magnet beamline 6.3.2 at the ALS and the initial measurement of optical performance on the new source, and preliminary experiments with surface chemistry of HF etched Si will be described

A high resolution ion microscope for cold atoms

International Nuclear Information System (INIS)

Stecker, Markus; Schefzyk, Hannah; Fortágh, József; Günther, Andreas

2017-01-01

We report on an ion-optical system that serves as a microscope for ultracold ground state and Rydberg atoms. The system is designed to achieve a magnification of up to 1000 and a spatial resolution in the 100 nm range, thereby surpassing many standard imaging techniques for cold atoms. The microscope consists of four electrostatic lenses and a microchannel plate in conjunction with a delay line detector in order to achieve single particle sensitivity with high temporal and spatial resolution. We describe the design process of the microscope including ion-optical simulations of the imaging system and characterize aberrations and the resolution limit. Furthermore, we present the experimental realization of the microscope in a cold atom setup and investigate its performance by patterned ionization with a structure size down to 2.7 μ m. The microscope meets the requirements for studying various many-body effects, ranging from correlations in cold quantum gases up to Rydberg molecule formation. (paper)

Microscopic cross-section measurements by thermal neutron activation

International Nuclear Information System (INIS)

Avila L, J.

1987-08-01

Microscopic cross sections measured by thermal neutron activation using RP-0 reactor at the Peruvian Nuclear Energy Institute. The method consists in measuring microscopic cross section ratios through activated samples, requiring being corrected in thermal and epithermal energetic range by Westcott formalism. Furthermore, the comptage ratios measured for each photopeak to its decay fraction should be normalized from interrelation between both processes above, activation microscopic cross sections are obtained

Two-probe atomic-force microscope manipulator and its applications

Science.gov (United States)

Zhukov, A. A.; Stolyarov, V. S.; Kononenko, O. V.

2017-06-01

We report on a manipulator based on a two-probe atomic force microscope (AFM) with an individual feedback system for each probe. This manipulator works under an upright optical microscope with 3 mm focal distance. The design of the microscope helps us tomanipulate nanowires using the microscope probes as a two-prong fork. The AFM feedback is realized based on the dynamic full-time contact mode. The applications of the manipulator and advantages of its two-probe design are presented.

Two-probe atomic-force microscope manipulator and its applications.

Science.gov (United States)

Zhukov, A A; Stolyarov, V S; Kononenko, O V

2017-06-01

We report on a manipulator based on a two-probe atomic force microscope (AFM) with an individual feedback system for each probe. This manipulator works under an upright optical microscope with 3 mm focal distance. The design of the microscope helps us tomanipulate nanowires using the microscope probes as a two-prong fork. The AFM feedback is realized based on the dynamic full-time contact mode. The applications of the manipulator and advantages of its two-probe design are presented.

A Spaceborne Synthetic Aperture Radar Partial Fixed-Point Imaging System Using a Field- Programmable Gate Array-Application-Specific Integrated Circuit Hybrid Heterogeneous Parallel Acceleration Technique.

Science.gov (United States)

Yang, Chen; Li, Bingyi; Chen, Liang; Wei, Chunpeng; Xie, Yizhuang; Chen, He; Yu, Wenyue

2017-06-24

With the development of satellite load technology and very large scale integrated (VLSI) circuit technology, onboard real-time synthetic aperture radar (SAR) imaging systems have become a solution for allowing rapid response to disasters. A key goal of the onboard SAR imaging system design is to achieve high real-time processing performance with severe size, weight, and power consumption constraints. In this paper, we analyse the computational burden of the commonly used chirp scaling (CS) SAR imaging algorithm. To reduce the system hardware cost, we propose a partial fixed-point processing scheme. The fast Fourier transform (FFT), which is the most computation-sensitive operation in the CS algorithm, is processed with fixed-point, while other operations are processed with single precision floating-point. With the proposed fixed-point processing error propagation model, the fixed-point processing word length is determined. The fidelity and accuracy relative to conventional ground-based software processors is verified by evaluating both the point target imaging quality and the actual scene imaging quality. As a proof of concept, a field- programmable gate array-application-specific integrated circuit (FPGA-ASIC) hybrid heterogeneous parallel accelerating architecture is designed and realized. The customized fixed-point FFT is implemented using the 130 nm complementary metal oxide semiconductor (CMOS) technology as a co-processor of the Xilinx xc6vlx760t FPGA. A single processing board requires 12 s and consumes 21 W to focus a 50-km swath width, 5-m resolution stripmap SAR raw data with a granularity of 16,384 × 16,384.

Designs for a quantum electron microscope

Energy Technology Data Exchange (ETDEWEB)

Kruit, P., E-mail: p.kruit@tudelft.nl [Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands); Hobbs, R.G.; Kim, C-S.; Yang, Y.; Manfrinato, V.R. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Hammer, J.; Thomas, S.; Weber, P. [Department of Physics, Friedrich Alexander University Erlangen-Nürnberg (FAU), Staudtstrasse 1, d-91058 Erlangen (Germany); Klopfer, B.; Kohstall, C.; Juffmann, T.; Kasevich, M.A. [Department of Physics, Stanford University, Stanford, California 94305 (United States); Hommelhoff, P. [Department of Physics, Friedrich Alexander University Erlangen-Nürnberg (FAU), Staudtstrasse 1, d-91058 Erlangen (Germany); Berggren, K.K. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2016-05-15

One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This ‘quantum weirdness’ could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or “quantum electron microscope”. A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. - Highlights: • Quantum electron microscopy has the potential of reducing radiation damage. • QEM requires a fraction of the electron wave to pass through the sample

Designs for a quantum electron microscope

International Nuclear Information System (INIS)

Kruit, P.; Hobbs, R.G.; Kim, C-S.; Yang, Y.; Manfrinato, V.R.; Hammer, J.; Thomas, S.; Weber, P.; Klopfer, B.; Kohstall, C.; Juffmann, T.; Kasevich, M.A.; Hommelhoff, P.; Berggren, K.K.

2016-01-01

One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This ‘quantum weirdness’ could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or “quantum electron microscope”. A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. - Highlights: • Quantum electron microscopy has the potential of reducing radiation damage. • QEM requires a fraction of the electron wave to pass through the sample

Field-portable pixel super-resolution colour microscope.

Directory of Open Access Journals (Sweden)

Alon Greenbaum

Full Text Available Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm(2. This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate 'rainbow' like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings.

Operating scheme for the light-emitting diode array of a volumetric display that exhibits multiple full-color dynamic images

Science.gov (United States)

Hirayama, Ryuji; Shiraki, Atsushi; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2017-07-01

We designed and developed a control circuit for a three-dimensional (3-D) light-emitting diode (LED) array to be used in volumetric displays exhibiting full-color dynamic 3-D images. The circuit was implemented on a field-programmable gate array; therefore, pulse-width modulation, which requires high-speed processing, could be operated in real time. We experimentally evaluated the developed system by measuring the luminance of an LED with varying input and confirmed that the system works appropriately. In addition, we demonstrated that the volumetric display exhibits different full-color dynamic two-dimensional images in two orthogonal directions. Each of the exhibited images could be obtained only from the prescribed viewpoint. Such directional characteristics of the system are beneficial for applications, including digital signage, security systems, art, and amusement.

General programmable Level-1 trigger with 3D-Flow assembly system for calorimeters of different sizes and event rates

International Nuclear Information System (INIS)

Crosetto, D.

1992-12-01

Experience demonstrates that fine tuning on the trigger of an experiment is often achieved only after running the experiment and analyzing the first data acquired. It is desirable that identification and, consequently, selection of interesting events be made on a more refined identification of particles. Use of an innovative parallel-processing system architecture together with an instruction set allows identification of objects (particles) among the data coming from a calorimeter in a programmable manner, utilizing the information related to their shape in two- or three-dimensional form, rather than applying only a programmable threshold proportional to their energy. The architecture is flexible, allowing execution of simple algorithms as well as complex pattern recognition algorithms. It is scalable in the sense that the same hardware can be used for small or large calorimeters having a slow or fast event rate. The simple printed circuit board (accommodating 16 x 3D-Flow processors) on a 4 in. x 4 in. board described herein uses the same hardware to build a large Level-1 programmable trigger (by interconnecting many boards in a matrix array) and is capable of implementing simple or complex pattern recognition algorithms at different event input rates (by cascading boards one on top of another). With the same hardware one can build low-cost, programmable Level-1 triggers for a small and low-event-rate calorimeter, or high-performance, programmable Level-1 triggers for a large calorimeter capable of sustaining up to 60 million events per second

Storage array reflection considerations

International Nuclear Information System (INIS)

Haire, M.J.; Jordan, W.C.; Taylor, R.G.

1997-01-01

The assumptions used for reflection conditions of single containers are fairly well established and consistently applied throughout the industry in nuclear criticality safety evaluations. Containers are usually considered to be either fully water reflected (i.e., surrounded by 6 to 12 in. of water) for safety calculations or reflected by 1 in. of water for nominal (structural material and air) conditions. Tables and figures are usually available for performing comparative evaluations of containers under various loading conditions. Reflection considerations used for evaluating the safety of storage arrays of fissile material are not as well established. When evaluating arrays, it has become more common for analysts to use calculations to demonstrate the safety of the array configuration. In performing these calculations, the analyst has considerable freedom concerning the assumptions made for modeling the reflection of the array. Considerations are given for the physical layout of the array with little or no discussion (or demonstration) of what conditions are bounded by the assumed reflection conditions. For example, an array may be generically evaluated by placing it in a corner of a room in which the opposing walls are far away. Typically, it is believed that complete flooding of the room is incredible, so the array is evaluated for various levels of water mist interspersed among array containers. This paper discusses some assumptions that are made regarding storage array reflection

Cascading Constrained 2-D Arrays using Periodic Merging Arrays

DEFF Research Database (Denmark)

Forchhammer, Søren; Laursen, Torben Vaarby

2003-01-01

We consider a method for designing 2-D constrained codes by cascading finite width arrays using predefined finite width periodic merging arrays. This provides a constructive lower bound on the capacity of the 2-D constrained code. Examples include symmetric RLL and density constrained codes...

Plasmonic photonic crystals realized through DNA-programmable assembly.

Science.gov (United States)

Park, Daniel J; Zhang, Chuan; Ku, Jessie C; Zhou, Yu; Schatz, George C; Mirkin, Chad A

2015-01-27

Three-dimensional dielectric photonic crystals have well-established enhanced light-matter interactions via high Q factors. Their plasmonic counterparts based on arrays of nanoparticles, however, have not been experimentally well explored owing to a lack of available synthetic routes for preparing them. However, such structures should facilitate these interactions based on the small mode volumes associated with plasmonic polarization. Herein we report strong light-plasmon interactions within 3D plasmonic photonic crystals that have lattice constants and nanoparticle diameters that can be independently controlled in the deep subwavelength size regime by using a DNA-programmable assembly technique. The strong coupling within such crystals is probed with backscattering spectra, and the mode splitting (0.10 and 0.24 eV) is defined based on dispersion diagrams. Numerical simulations predict that the crystal photonic modes (Fabry-Perot modes) can be enhanced by coating the crystals with a silver layer, achieving moderate Q factors (∼10(2)) over the visible and near-infrared spectrum.

Microscope on Mars

Science.gov (United States)

2004-01-01

This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

Quantitative methods for the analysis of electron microscope images

DEFF Research Database (Denmark)

Skands, Peter Ulrik Vallø

1996-01-01

The topic of this thesis is an general introduction to quantitative methods for the analysis of digital microscope images. The images presented are primarily been acquired from Scanning Electron Microscopes (SEM) and interfermeter microscopes (IFM). The topic is approached though several examples...... foundation of the thesis fall in the areas of: 1) Mathematical Morphology; 2) Distance transforms and applications; and 3) Fractal geometry. Image analysis opens in general the possibility of a quantitative and statistical well founded measurement of digital microscope images. Herein lies also the conditions...

Testing of focal plane arrays

International Nuclear Information System (INIS)

Merriam, J.D.

1988-01-01

Problems associated with the testing of focal plane arrays are briefly examined with reference to the instrumentation and measurement procedures. In particular, the approach and instrumentation used as the Naval Ocean Systems Center is presented. Most of the measurements are made with flooded illumination on the focal plane array. The array is treated as an ensemble of individual pixels, data being taken on each pixel and array averages and standard deviations computed for the entire array. Data maps are generated, showing the pixel data in the proper spatial position on the array and the array statistics

Adaptive optical microscope for brain imaging in vivo

Science.gov (United States)

Wang, Kai

2017-04-01

The optical heterogeneity of biological tissue imposes a major limitation to acquire detailed structural and functional information deep in the biological specimens using conventional microscopes. To restore optimal imaging performance, we developed an adaptive optical microscope based on direct wavefront sensing technique. This microscope can reliably measure and correct biological samples induced aberration. We demonstrated its performance and application in structural and functional brain imaging in various animal models, including fruit fly, zebrafish and mouse.

FUSION technology programme 2003-2006

International Nuclear Information System (INIS)

Karttunen, S.; Rantamaeki, K.

2007-01-01

This report summarises the results of the FUSION technology programme during the period between 2003-2006. FUSION is a continuation of the previous FFusion and FFusion2 technology programmes that took place from 1993 to 2002. The FUSION technology programme was fully integrated into the European Fusion Programme in the sixth Framework Programme (Euratom), through the bilateral Contract of Association between Euratom and Tekes and the multilateral European Fusion Development Agreement (EFDA). The Association Euratom-Tekes was established in 1995. At the moment, there are 26 Euratom Fusion associations working together as an European Research Area. There are four research areas in the FUSION technology programme: (1) fusion physics and plasma engineering, (2) vessel/in-vessel materials, joints and components, (3) in-vessel remote handling systems, and (4) system studies. The FUSION team consists of research groups from the Technical Research Centre of Finland (VTT), the Helsinki, Tampere and Lappeenranta Universities of Technology and the University of Helsinki. The co-ordinating unit is VTT. A key element of the FUSION programme is the close collaboration between VTT, the universities and the industry, which has resulted in dynamic and sufficiently large research teams to tackle challenging research and development projects. The distribution of work between research institutes and industry has also been clear. Industrial activities related to the FUSION programme are co-ordinated through the 'Big Science' Project by Finpro and Prizztech. The total expenditure of the FUSION technology programme for 2003-2006 amounted to euro 14,9 million in research work at VTT and the universities with an additional euro 3,5 million for projects by the Finnish companies including the industry co-ordination. The funding of the FUSION programme and related industrial projects was mainly provided by Tekes (37%), Euratom (38%) and the participating institutes and industry (24%). The

Overmathematisation in game theory : pitting the Nash Equilibrium Refinement Programme against the Epistemic Programme

NARCIS (Netherlands)

de Bruin, Boudewijn

The paper argues that the Nash Equilibrium Refinement Programme was less successful than its competitor, the Epistemic Programme (Interactive Epistemology). The prime criterion of success is the extent to which the programmes were able to reach the key objective guiding non-cooperative game theory

Dynamic wedge, electron energy and beam profile Q.A. using an ionization chamber linear array

International Nuclear Information System (INIS)

Kenny, M.B.; Todd, S.P.

1996-01-01

Since the introduction of multi-modal linacs the quality assurance workload of a Physical Sciences department has increased dramatically. The advent of dynamic wedges has further complicated matters because of the need to invent accurate methods to perform Q.A. in a reasonable time. We have been using an ionization chamber linear array, the Thebes 7000 TM by Victoreen, Inc., for some years to measure X-ray and electron beam profiles. Two years ago we developed software to perform Q.A. on our dynamic wedges using the array and more recently included a routine to check electron beam energies using the method described by Rosenow, U.F. et al., Med. Phys. 18(1) 19-25. The integrated beam and profile management system has enabled us to maintain a comprehensive quality assurance programme on all our linaccs. Both our efficiency and accuracy have increased to the point where we are able to keep up with the greater number of tests required without an increase in staff or hours spent in quality assurance. In changing the processor from the Z80 of the Thebes console to the 486 of the PC we have also noticed a marked increase in the calibration stability of the array. (author)

Sol-gel auto-combustion synthesis of hydroxyapatite nanotubes array in porous alumina template

International Nuclear Information System (INIS)

Yuan Yuan; Liu Changsheng; Zhang Yuan; Shan Xiaoqian

2008-01-01

In this paper, an array of highly ordered hydroxyapatite (HAP) nanotubes was synthesized by sol-gel auto-combustion method with porous anodic aluminum oxide (AAO) template for the first time. Based on thermogravimetry (DTA/TG), Fourier transform infrared (FTIR) and X-ray diffraction (XRD), the dried gel, derived from the sol solution with Ca(NO 3 ) 2 .4H 2 O and PO(CH 3 O) 3 as precursors and ethylene glycol as the polymeric matrix, exhibited a typical self-propagating combustion behavior at low temperature, directly resulting in hexagonal crystalline HAP materials. The resultant HAP arrays fabricated from the above sol-gel in the AAO template were uniformly distributed, highly ordered nanotubes with uniform length and diameter according to the observations of scanning electron microscopy (SEM) and transmission electron microscope (TEM). The electron diffraction (ED), XRD and X-ray photoelectron spectroscopy (XPS) survey proved the formation of HAP phase with polycrystalline structure in the AAO template. Based on these results, a potential mechanism of 'an auto-combustion from dried gel to nanoparticles and a subsequent in situ reaction from nanoparticles to nanotubes' was proposed

Multi-mode sensor processing on a dynamically reconfigurable massively parallel processor array

Science.gov (United States)

Chen, Paul; Butts, Mike; Budlong, Brad; Wasson, Paul

2008-04-01

This paper introduces a novel computing architecture that can be reconfigured in real time to adapt on demand to multi-mode sensor platforms' dynamic computational and functional requirements. This 1 teraOPS reconfigurable Massively Parallel Processor Array (MPPA) has 336 32-bit processors. The programmable 32-bit communication fabric provides streamlined inter-processor connections with deterministically high performance. Software programmability, scalability, ease of use, and fast reconfiguration time (ranging from microseconds to milliseconds) are the most significant advantages over FPGAs and DSPs. This paper introduces the MPPA architecture, its programming model, and methods of reconfigurability. An MPPA platform for reconfigurable computing is based on a structural object programming model. Objects are software programs running concurrently on hundreds of 32-bit RISC processors and memories. They exchange data and control through a network of self-synchronizing channels. A common application design pattern on this platform, called a work farm, is a parallel set of worker objects, with one input and one output stream. Statically configured work farms with homogeneous and heterogeneous sets of workers have been used in video compression and decompression, network processing, and graphics applications.

Investigating Dissolution and Precipitation Phenomena with a Smartphone Microscope

Science.gov (United States)

Lumetta, Gregg J.; Arcia, Edgar

2016-01-01

A novel smartphone microscope can be used to observe the dissolution and crystallization of sodium chloride at a microscopic level. Observation of these seemingly simple phenomena through the microscope at 100× magnification can actually reveal some surprising behavior. These experiments offer the opportunity to discuss some basic concepts such as…

Phased-array radars

Science.gov (United States)

Brookner, E.

1985-02-01

The operating principles, technology, and applications of phased-array radars are reviewed and illustrated with diagrams and photographs. Consideration is given to the antenna elements, circuitry for time delays, phase shifters, pulse coding and compression, and hybrid radars combining phased arrays with lenses to alter the beam characteristics. The capabilities and typical hardware of phased arrays are shown using the US military systems COBRA DANE and PAVE PAWS as examples.

FFUSION research programme 1993-1998. Final report of the Finnish fusion research programme

Energy Technology Data Exchange (ETDEWEB)

Karttunen, S.; Heikkinen, J.; Korhonen, R. [VTT Energy, Espoo (Finland)] [and others

1998-12-31

This report summarizes the results of the Fusion Energy Research Programme, FFUSION, during the period 1993-1998. After the planning phase the programme started in 1994, and later in March 1995 the FFUSION Programme was integrated into the EU Fusion Programme and the Association Euratom-Tekes was established. Research areas in the FFUSION Programme are (1) fusion physics and plasma engineering, (2) fusion reactor materials and (3) remote handling systems. In all research areas industry is involved. Recently, a project on environmental aspects of fusion and other future energy systems started as a part of the socio-economic research (SERF) in the Euratom Fusion Programme. A crucial component of the FFUSION programme is the close collaboration between VTT Research Institutes, universities and Finnish industry. This collaboration has guaranteed dynamic and versatile research teams, which are large enough to tackle challenging research and development projects. Regarding industrial fusion R and D activities, the major step was the membership of Imatran Voima Oy in the EFET Consortium (European Fusion Engineering and Technology), which further strengthened the position of industry in the engineering design activities of ITER. The number of FFUSION research projects was 66. In addition, there were 32 industrial R and D projects. The total cost of the FFUSION Programme in 1993-1998 amounted to FIM 54 million in research at VTT and universities and an additional FIM 21 million for R and D in Finnish industry. The main part of the funding was provided by Tekes, 36%. Since 1995, yearly Euratom funding has exceeded 25%. The FFUSION research teams have played an active role in the European Programme, receiving excellent recognition from the European partners. Theoretical and computational fusion physics has been at a high scientific level and the group collaborates with the leading experimental laboratories in Europe. Fusion technology is focused on reactor materials, joining

FFUSION research programme 1993-1998. Final report of the Finnish fusion research programme

International Nuclear Information System (INIS)