Hydrogen maser clocks in space for solid-Earth research and time-transfer applications: Experiment overview and evaluation of Russian miniature sapphire loaded cavity

NASA Astrophysics Data System (ADS)

Busca, G.; Bernier, L. G.; Silvestrin, P.; Feltham, S.; Gaygerov, B. A.; Tatarenkov, V. M.

1994-05-01

The Observatoire Cantonal de Neuchatel (ON) is developing for ESTEC a compact H-maser for space use based upon a miniature sapphire loaded microwave cavity, a technique pioneered at VNIIFTRI. Various contacts between West-European parties, headed by ESA, and the Russian parties, headed by ESA, led to the proposal for flying two H-masers on Meteor 3M, a Russian meteorology satellite in low polar orbit. The experiment will include two masers, one provided by ON and the other by VNIIFTRI. T/F transfer and precise positioning will be performed by both a microwave link, using PRARE equipment, and an optical link, using LASSO-like equipment. The main objectives of the experiment are precise orbit determination and point positioning for geodetic/geophysical research, ultra-accurate time comparison and dissemination as well as in-orbit demonstration of operation and performance of H-masers. Within the scope of a preliminary space H-maser development phase performed for ESTEC at ON in preparation to the joint experiment, a Russian miniature sapphire loaded microwave cavity, on loan from VNIIFTRI, was evaluated in a full-size EFOS hydrogen maser built by ON. The experimental evaluation confirmed the theoretical expectation that with a hydrogen storage volume of only 0.65 liter an atomic quality factor of 1.5 x 10(exp 9) can be obtained for a -105 dBm output power. This represents a theoretical Allan deviation of 1.7 x 10(exp -15) averaged on a 1000 s time interval. From a full-size design to a compact one, therefore, the sacrifice in performance due to the reduction of the storage volume is very small.

Hydrogen maser clocks in space for solid-Earth research and time-transfer applications: Experiment overview and evaluation of Russian miniature sapphire loaded cavity

NASA Technical Reports Server (NTRS)

Busca, G.; Bernier, L. G.; Silvestrin, P.; Feltham, S.; Gaygerov, B. A.; Tatarenkov, V. M.

1994-01-01

The Observatoire Cantonal de Neuchatel (ON) is developing for ESTEC a compact H-maser for space use based upon a miniature sapphire loaded microwave cavity, a technique pioneered at VNIIFTRI. Various contacts between West-European parties, headed by ESA, and the Russian parties, headed by ESA, led to the proposal for flying two H-masers on Meteor 3M, a Russian meteorology satellite in low polar orbit. The experiment will include two masers, one provided by ON and the other by VNIIFTRI. T/F transfer and precise positioning will be performed by both a microwave link, using PRARE equipment, and an optical link, using LASSO-like equipment. The main objectives of the experiment are precise orbit determination and point positioning for geodetic/geophysical research, ultra-accurate time comparison and dissemination as well as in-orbit demonstration of operation and performance of H-masers. Within the scope of a preliminary space H-maser development phase performed for ESTEC at ON in preparation to the joint experiment, a Russian miniature sapphire loaded microwave cavity, on loan from VNIIFTRI, was evaluated in a full-size EFOS hydrogen maser built by ON. The experimental evaluation confirmed the theoretical expectation that with a hydrogen storage volume of only 0.65 liter an atomic quality factor of 1.5 x 10(exp 9) can be obtained for a -105 dBm output power. This represents a theoretical Allan deviation of 1.7 x 10(exp -15) averaged on a 1000 s time interval. From a full-size design to a compact one, therefore, the sacrifice in performance due to the reduction of the storage volume is very small.

Miniaturized optical wavelength sensors

NASA Astrophysics Data System (ADS)

Kung, Helen Ling-Ning

Recently semiconductor processing technology has been applied to the miniaturization of optical wavelength sensors. Compact sensors enable new applications such as integrated diode-laser wavelength monitors and frequency lockers, portable chemical and biological detection, and portable and adaptive hyperspectral imaging arrays. Small sensing systems have trade-offs between resolution, operating range, throughput, multiplexing and complexity. We have developed a new wavelength sensing architecture that balances these parameters for applications involving hyperspectral imaging spectrometer arrays. In this thesis we discuss and demonstrate two new wavelength-sensing architectures whose single-pixel designs can easily be extended into spectrometer arrays. The first class of devices is based on sampling a standing wave. These devices are based on measuring the wavelength-dependent period of optical standing waves formed by the interference of forward and reflected waves at a mirror. We fabricated two different devices based on this principle. The first device is a wavelength monitor, which measures the wavelength and power of a monochromatic source. The second device is a spectrometer that can also act as a selective spectral coherence sensor. The spectrometer contains a large displacement piston-motion MEMS mirror and a thin GaAs photodiode flip-chip bonded to a quartz substrate. The performance of this spectrometer is similar to that of a Michelson in resolution, operating range, throughput and multiplexing but with the added advantages of fewer components and one-dimensional architecture. The second class of devices is based on the Talbot self-imaging effect. The Talbot effect occurs when a periodic object is illuminated with a spatially coherent wave. Periodically spaced self-images are formed behind the object. The spacing of the self-images is proportional to wavelength of the incident light. We discuss and demonstrate how this effect can be used for spectroscopy. In the conclusion we compare these two new miniaturized spectrometer architectures to existing miniaturized spectrometers. We believe that the combination of miniaturized wavelength sensors and smart processing should facilitate the development real-time, adaptive and portable sensing systems.

Reducing Unsteady Loads on a Piggyback Miniature Submarine

NASA Technical Reports Server (NTRS)

Lin, John

2009-01-01

A small, simple fixture has been found to be highly effective in reducing destructive unsteady hydrodynamic loads on a miniature submarine that is attached in piggyback fashion to the top of a larger, nuclear-powered, host submarine. The fixture, denoted compact ramp, can be installed with minimal structural modification, and the use of it does not entail any change in submarine operations.

Compact and Light-Weight Solar Spaceflight Instrument Designs Utilizing Newly Developed Miniature Free-Standing Zone Plates: EUV Radiometer and Limb-Scanning Monochromator

NASA Astrophysics Data System (ADS)

Seely, J. F.; McMullin, D. R.; Bremer, J.; Chang, C.; Sakdinawat, A.; Jones, A. R.; Vest, R.

2014-12-01

Two solar instrument designs are presented that utilize newly developed miniature free-standing zone plates having interconnected Au opaque bars and no support membrane resulting in excellent long-term stability in space. Both instruments are based on a zone plate having 4 mm outer diameter and 1 to 2 degree field of view. The zone plate collects EUV radiation and focuses a narrow bandpass through a pinhole aperture and onto a silicon photodiode detector. As a miniature radiometer, EUV irradiance is accurately determined from the zone plate efficiency and the photodiode responsivity that are calibrated at the NIST SURF synchrotron facility. The EUV radiometer is pointed to the Sun and measures the absolute solar EUV irradiance in high time cadence suitable for solar physics and space weather applications. As a limb-scanning instrument in low earth orbit, a miniature zone-plate monochromator measures the extinction of solar EUV radiation by scattering through the upper atmosphere which is a measure of the variability of the ionosphere. Both instruments are compact and light-weight and are attractive for CubeSats and other missions where resources are extremely limited.

Diagnostics and Optimization of a Miniature High Frequency Pulse Tube Cryocooler

NASA Astrophysics Data System (ADS)

Garaway, I.; Veprik, A.; Radebaugh, R.

2010-04-01

A miniature, high energy density, pulse tube cryocooler with an inertance tube and reservoir has been developed, tested, diagnosed and optimized to provide appropriate cooling for size-limited cryogenic applications demanding fast cool down. This cryocooler, originally designed using REGEN 3.2 for 80 K, an operating frequency of 150 Hz and an average pressure of 5.0 MPa, has regenerator dimensions of 4.4 mm inside diameter and 27 mm length and is filled with ♯635 mesh stainless steel screen. Various design features, such as the use of compact heat exchangers and a miniature linear compressor, resulted in a remarkably compact pulse tube cryocooler. In this report, we present the preliminary test results and the subsequent diagnostic and optimization sequence performed to improve the overall design and operation of the complete cryocooler. These experimentally determined optimal parameters, though slightly different from those proposed in the initial numerical model, yielded 530 mW of gross cooling power at 120 K with an input electrical power of only 25 W. This study highlights the need to further establish our understanding of miniature, high frequency, regenerative cryocoolers, not only as a collection of independent subcomponents, but as one single working unit. It has also led to a list of additional improvements that may yet be made to even further improve the operating characteristics of such a complete miniature cryocooler.

Design and Analysis of a Compact Precision Positioning Platform Integrating Strain Gauges and the Piezoactuator

PubMed Central

Huang, Hu; Zhao, Hongwei; Yang, Zhaojun; Fan, Zunqiang; Wan, Shunguang; Shi, Chengli; Ma, Zhichao

2012-01-01

Miniaturization precision positioning platforms are needed for in situ nanomechanical test applications. This paper proposes a compact precision positioning platform integrating strain gauges and the piezoactuator. Effects of geometric parameters of two parallel plates on Von Mises stress distribution as well as static and dynamic characteristics of the platform were studied by the finite element method. Results of the calibration experiment indicate that the strain gauge sensor has good linearity and its sensitivity is about 0.0468 mV/μm. A closed-loop control system was established to solve the problem of nonlinearity of the platform. Experimental results demonstrate that for the displacement control process, both the displacement increasing portion and the decreasing portion have good linearity, verifying that the control system is available. The developed platform has a compact structure but can realize displacement measurement with the embedded strain gauges, which is useful for the closed-loop control and structure miniaturization of piezo devices. It has potential applications in nanoindentation and nanoscratch tests, especially in the field of in situ nanomechanical testing which requires compact structures. PMID:23012566

Compact Miniaturized Antenna for 210 MHz RFID

NASA Technical Reports Server (NTRS)

Lee, Richard Q.; Chun, Kue

2008-01-01

This paper describes the design and simulation of a miniaturized square-ring antenna. The miniaturized antenna, with overall dimensions of approximately one tenth of a wavelength (0.1 ), was designed to operate at around 210 MHz, and was intended for radio-frequency identification (RFID) application. One unique feature of the design is the use of a parasitic element to improve the performance and impedance matching of the antenna. The use of parasitic elements to enhance the gain and bandwidth of patch antennas has been demonstrated and reported in the literature, but such use has never been applied to miniaturized antennas. In this work, we will present simulation results and discuss design parameters and their impact on the antenna performance.

Relativistic jets in SS 433

NASA Astrophysics Data System (ADS)

Margon, B.

1982-01-01

A variety of recent optical, radio, and X-ray observations have confirmed the hypothesis that the peculiar star SS 433 is ejecting two narrow, opposed, highly collimated jets of matter at one-quarter the speed of light. This unique behavior is probably driven by mass exchange between a relatively normal star and a compact companion, either a neutron star or a black hole. However, numerous details regarding the energetics, radiation, acceleration, and collimation of the jets remain to be understood. This phenomenon may well be a miniature example of similar collimated ejection of gas by active extragalactic objects such as quasars and radio galaxies.

Development of solid tunable optics for ultra-miniature imaging systems

NASA Astrophysics Data System (ADS)

Yongchao, Zou

This thesis focuses on the optimal design, fabrication and testing of solid tunable optics and exploring their applications in miniature imaging systems. It starts with the numerical modelling of such lenses, followed by the optimum design method and alignment tolerance analysis. A miniature solid tunable lens driven by a piezo actuator is then developed. To solve the problem of limited maximum optical power and tuning range in conventional lens designs, a novel multi-element solid tunable lens is proposed and developed. Inspired by the Alvarez principle, a novel miniature solid tunable dual-focus lens, which is designed using freeform surfaces and driven by one micro-electro-mechanical-systems (MEMS) rotary actuator, is demonstrated. To explore the applications of these miniature solid tunable lenses, a miniature adjustable-focus endoscope and one compact adjustable-focus camera module are developed. The adjustable-focus capability of these two miniature imaging systems is fully proved by electrically focusing targets placed at different positions.

A Laser Interferometric Miniature Seismometer

DTIC Science & Technology

2010-09-01

A LASER INTERFEROMETRIC MINIATURE SEISMOMETER Dustin W. Carr, Patrick C. Baldwin, Shawn A. Knapp-Kleinsorge, Howard Milburn, and David Robinson...Symphony Acoustics, Inc. Sponsored by the National Nuclear Security Administration Award No. DE-FG02-08ER85108.001 ABSTRACT The threat of...performance, compact device can enable rapid deployment of large-scale arrays , which can in turn be used to provide higher-quality data during times of

Automated novel high-accuracy miniaturized positioning system for use in analytical instrumentation

NASA Astrophysics Data System (ADS)

Siomos, Konstadinos; Kaliakatsos, John; Apostolakis, Manolis; Lianakis, John; Duenow, Peter

1996-01-01

The development of three-dimensional automotive devices (micro-robots) for applications in analytical instrumentation, clinical chemical diagnostics and advanced laser optics, depends strongly on the ability of such a device: firstly to be positioned with high accuracy, reliability, and automatically, by means of user friendly interface techniques; secondly to be compact; and thirdly to operate under vacuum conditions, free of most of the problems connected with conventional micropositioners using stepping-motor gear techniques. The objective of this paper is to develop and construct a mechanically compact computer-based micropositioning system for coordinated motion in the X-Y-Z directions with: (1) a positioning accuracy of less than 1 micrometer, (the accuracy of the end-position of the system is controlled by a hard/software assembly using a self-constructed optical encoder); (2) a heat-free propulsion mechanism for vacuum operation; and (3) synchronized X-Y motion.

Objective-lens-free Fiber-based Position Detection with Nanometer Resolution in a Fiber Optical Trapping System.

PubMed

Ti, Chaoyang; Ho-Thanh, Minh-Tri; Wen, Qi; Liu, Yuxiang

2017-10-13

Position detection with high accuracy is crucial for force calibration of optical trapping systems. Most existing position detection methods require high-numerical-aperture objective lenses, which are bulky, expensive, and difficult to miniaturize. Here, we report an affordable objective-lens-free, fiber-based position detection scheme with 2 nm spatial resolution and 150 MHz bandwidth. This fiber based detection mechanism enables simultaneous trapping and force measurements in a compact fiber optical tweezers system. In addition, we achieved more reliable signal acquisition with less distortion compared with objective based position detection methods, thanks to the light guiding in optical fibers and small distance between the fiber tips and trapped particle. As a demonstration of the fiber based detection, we used the fiber optical tweezers to apply a force on a cell membrane and simultaneously measure the cellular response.

Technology Development of Miniaturized Far-Infrared Sources for Biomolecular Spectroscopy

NASA Technical Reports Server (NTRS)

Kono, Junichiro

2003-01-01

The objective of this project was to develop a purely solid-state based, thus miniaturized, far-infrared (FIR) (also known as terahertz (THz)) wave source using III-V semiconductor nanostructures for biomolecular detection and sensing. Many biomolecules, such as DNA and proteins, have distinct spectroscopic features in the FIR wavelength range as a result of vibration-rotation-tunneling motions and various inter- and intra-molecule collective motions. Spectroscopic characterization of such molecules requires narrow linewidth, sufficiently high power, tunable (in wavelength), and coherent FIR sources. Unfortunately, the FIR frequency is one of the least technologically developed ranges in the electromagnetic spectrum. Currently available FIR sources based on non-solid state technology are bulky, inefficient, and very often incoherent. In this project we investigated antimonide based compound semiconductor (ABCS) nanostructures as the active medium to generate FIR radiation. The final goal of this project was to demonstrate a semiconductor THz source integrated with a pumping diode laser module to achieve a compact system for biomolecular applications.

2D stepping drive for hyperspectral systems

NASA Astrophysics Data System (ADS)

Endrödy, Csaba; Mehner, Hannes; Grewe, Adrian; Sinzinger, Stefan; Hoffmann, Martin

2015-07-01

We present the design, fabrication and characterization of a compact 2D stepping microdrive for pinhole array positioning. The miniaturized solution enables a highly integrated compact hyperspectral imaging system. Based on the geometry of the pinhole array, an inch-worm drive with electrostatic actuators was designed resulting in a compact (1 cm2) positioning system featuring a step size of about 15 µm in a 170 µm displacement range. The high payload (20 mg) as required for the pinhole array and the compact system design exceed the known electrostatic inch-worm-based microdrives.

Miniaturized LTCC elliptic-function lowpass filters with side stopbands

DOE PAGES

Hsieh, Lung -Hwa; Dai, Steve Xunhu

2015-05-28

A compact, high-selectivity, and wide stopband lowpass filter is highly demanded in wireless communication systems to suppress adjacent harmonics and unwanted signals. In this letter, a new miniaturized lowpass filter with elliptic-function frequency response is introduced. The filter is fabricated in multilayer low temperature cofired ceramics. The size of the miniaturized filter is 5.5 × 3.9 × 1.72 mm3. As a result, the measured insertion loss of the filter is better than 0.37 dB from DC to 1.28 GHz and the measured stopband of the filter is great than 22 dB from 2.3 to 7.5 GHz.

Miniature Magnet for Electron Spin Resonance Experiments

ERIC Educational Resources Information Center

Rupp, L. W.; And Others

1976-01-01

Describes commercially available permanent magnets that have been incorporated in a compact and inexpensive structure providing both field sweep and modulation suitable for electron spin resonance at microwave frequencies. (MLH)

X-ray astronomy in the laboratory with a miniature compact object produced by laser-driven implosion

NASA Astrophysics Data System (ADS)

Fujioka, Shinsuke; Takabe, Hideaki; Yamamoto, Norimasa; Salzmann, David; Wang, Feilu; Nishimura, Hiroaki; Li, Yutong; Dong, Quanli; Wang, Shoujun; Zhang, Yi; Rhee, Yong-Joo; Lee, Yong-Woo; Han, Jae-Min; Tanabe, Minoru; Fujiwara, Takashi; Nakabayashi, Yuto; Zhao, Gang; Zhang, Jie; Mima, Kunioki

2009-11-01

X-ray spectroscopy is an important tool for understanding the extreme photoionization processes that drive the behaviour of non-thermal equilibrium plasmas in compact astrophysical objects such as black holes. Even so, the distance of these objects from the Earth and the inability to control or accurately ascertain the conditions that govern their behaviour makes it difficult to interpret the origin of the features in astronomical X-ray measurements. Here, we describe an experiment that uses the implosion driven by a 3TW, 4kJ laser system to produce a 0.5keV blackbody radiator that mimics the conditions that exist in the neighbourhood of a black hole. The X-ray spectra emitted from photoionized silicon plasmas resemble those observed from the binary stars Cygnus X-3 (refs 7, 8) and Vela X-1 (refs 9, 10 11) with the Chandra X-ray satellite. As well as demonstrating the ability to create extreme radiation fields in a laboratory plasma, our theoretical interpretation of these laboratory spectra contrasts starkly with the generally accepted explanation for the origin of similar features in astronomical observations. Our experimental approach offers a powerful means to test and validate the computer codes used in X-ray astronomy.

A compact, portable, re-configurable, and automated system for on-demand pharmaceutical tablet manufacturing.

PubMed

Azad, Mohammad A; Osorio, Juan G; Brancazio, David; Hammersmith, Gregory; Klee, David M; Rapp, Kersten; Myerson, Allan

2018-03-25

Due to the complex nature of the pharmaceutical supply chain, the industry faces several major challenges when it comes to ensuring an adequate supply of quality drug products. These challenges are not only the causes of supply chain disruptions and financial loss, but can also prevent underserved and remote areas from receiving life-saving drugs. As a preliminary demonstration to mitigate all these challenges, at MIT we have developed active pharmaceutical ingredients manufacturing in a miniature platform. However, manufacturing of final oral solid dosage as tablets from drug substances had not been demonstrated. In this study, a compact, portable, re-configurable, and automated tablet manufacturing system, roughly the size of a North American household oven, [72.4 cm (length) × 53.3 cm (width) × 134.6 cm (height)] was designed, built and demonstrated. This miniature system is able to manufacture on-demand tablets from drug crystals on a scale of hundreds to thousands per day. Ibuprofen and Diazepam, each having different drug loading, were manufactured using this miniature system and meet U.S. Pharmacopeia standards. We foresee this flexible, miniature, plug-and-play pharmaceutical solids dosage manufacturing system advancing on-demand ready-to-use pharmaceuticals enabling future treatment of human diseases at the point-of-care. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of a miniature Stirling cryocooler for LWIR small satellite applications

NASA Astrophysics Data System (ADS)

Kirkconnell, C. S.; Hon, R. C.; Perella, M. D.; Crittenden, T. M.; Ghiaasiaan, S. M.

2017-05-01

The optimum small satellite (SmallSat) cryocooler system must be extremely compact and lightweight, achieved in this paper by operating a linear cryocooler at a frequency of approximately 300 Hz. Operation at this frequency, which is well in excess of the 100-150 Hz reported in recent papers on related efforts, requires an evolution beyond the traditional Oxford-class, flexure-based methods of setting the mechanical resonance. A novel approach that optimizes the electromagnetic design and the mechanical design together to simultaneously achieve the required dynamic and thermodynamic performances is described. Since highly miniaturized pulse tube coolers are fundamentally ill-suited for the sub-80K temperature range of interest because the boundary layer losses inside the pulse tube become dominant at the associated very small pulse tube size, a moving displacer Stirling cryocooler architecture is used. Compact compressor mechanisms developed on a previous program are reused for this design, and they have been adapted to yield an extremely compact Stirling warm end motor mechanism. Supporting thermodynamic and electromagnetic analysis results are reported.

Miniature Surface Plasmon Polariton Amplitude Modulator by Beat Frequency and Polarization Control

PubMed Central

Chang, Cheng-Wei; Lin, Chu-En; Yu, Chih-Jen; Yeh, Ting-Tso; Yen, Ta-Jen

2016-01-01

The miniaturization of modulators keeps pace for the compact devices in optical applications. Here, we present a miniature surface plasmon polariton amplitude modulator (SPPAM) by directing and interfering surface plasmon polaritons on a nanofabricated chip. Our results show that this SPPAM enables two kinds of modulations. The first kind of modulation is controlled by encoding angular-frequency difference from a Zeeman laser, with a beat frequency of 1.66 MHz; the second of modulation is validated by periodically varying the polarization states from a polarization generator, with rotation frequencies of 0.5–10 k Hz. In addition, the normalized extinction ratio of our plasmonic structure reaches 100. Such miniaturized beat-frequency and polarization-controlled amplitude modulators open an avenue for the exploration of ultrasensitive nanosensors, nanocircuits, and other integrated nanophotonic devices. PMID:27558516

A compact fiber-optic SHG scanning endomicroscope and its application to visualize cervical remodeling during pregnancy

PubMed Central

Zhang, Yuying; Akins, Meredith L.; Murari, Kartikeya; Xi, Jiefeng; Li, Ming-Jun; Luby-Phelps, Katherine; Mahendroo, Mala; Li, Xingde

2012-01-01

We report the development of an all-fiber-optic scanning endomicroscope capable of high-resolution second harmonic generation (SHG) imaging of biological tissues and demonstrate its utility for monitoring the remodeling of cervical collagen during gestation in mice. The endomicroscope has an overall 2.0 mm diameter and consists of a single customized double-clad fiber, a compact rapid two-dimensional beam scanner, and a miniature compound objective lens for excitation beam delivery, scanning, focusing, and efficient SHG signal collection. Endomicroscopic SHG images of murine cervical tissue sections at different stages of normal pregnancy reveal progressive, quantifiable changes in cervical collagen morphology with resolution similar to that of bench-top SHG microscopy. SHG endomicroscopic imaging of ex vivo murine and human cervical tissues through intact epithelium has also been performed. Our findings demonstrate the feasibility of SHG endomicroscopy technology for staging normal pregnancy, and suggest its potential application as a minimally invasive tool for clinical assessment of abnormal cervical remodeling associated with preterm birth. PMID:22826263

Miniature integrated-optical wavelength analyzer chip

NASA Astrophysics Data System (ADS)

Kunz, R. E.; Dübendorfer, J.

1995-11-01

A novel integrated-optical chip suitable for realizing compact miniature wavelength analyzers with high linear dispersion is presented. The chip performs the complete task of converting the spectrum of an input beam into a corresponding spatial irradiance distribution without the need for an imaging function. We demonstrate the feasibility of this approach experimentally by monitoring the changes in the mode spectrum of a laser diode on varying its case temperature. Comparing the results with simultaneous measurements by a commercial spectrometer yielded a rms wavelength deviation of 0.01 nm.

Microcombustor-thermoelectric power generator for 10-50 watt applications

NASA Astrophysics Data System (ADS)

Marshall, Daniel S.; Cho, Steve T.

2010-04-01

Fuel-based portable power systems, including combustion and fuel cell systems, take advantage of the 80x higher energy density of fuel over lithium battery technologies and offer the potential for much higher energy density power sources - especially for long-duration applications, such as unattended sensors. Miniaturization of fuel-based systems poses significant challenges, including processing of fuel in small channels, catalyst poisoning, and coke and soot formation. Recent advances in micro-miniature combustors in the 200Watt thermal range have enabled the development of small power sources that use the chemical energy of heavy fuel to drive thermal-to-electric converters for portable applications. CUBE Technology has developed compact Micro-Furnace combustors that efficiently deliver high-quality heat to optimized thermal-to-electric power converters, such as advanced thermoelectric power modules and Stirling motors, for portable power generation at the 10-50Watt scale. Key innovations include a compact gas-gas recuperator, innovative heavy fuel processing, coke- & soot-free operation, and combustor optimization for low balance-of-plant power use while operating at full throttle. This combustor enables the development of robust, high energy density, miniature power sources for portable applications.

Miniature and Molecularly Specific Optical Screening Technologies for Breast Cancer

DTIC Science & Technology

2006-10-01

modeling of the heat dissipation effects of compact LEDs on tissue samples, selection of multiwavelength compact light sources, calculating bandwidth...Opto Technology also designs custom chip on board assemblies with single and multiple wavelengths of UV , Visible and IR LED die (365 – 940 nm...reflectance with high signal to noise for optical properties typical of tissue in the UV -VIS. We have furthermore investigated the potential use of LEDs as

Low-Shock Pyrotechnic Actuator

NASA Technical Reports Server (NTRS)

Lucy, M. H.

1984-01-01

Miniature 1-ampere, 1-watt pyrotechnic actuator enclosed in flexible metal bellows. Bellows confines outgassing products, and pyrotechnic shock reduction achieved by action of bellows, gas cushion within device, and minimum use of pyrotechnic material. Actuator inexpensive, compact, and lightweight.

Development of a miniature multiple reference optical coherence tomography imaging device

NASA Astrophysics Data System (ADS)

McNamara, Paul M.; O'Riordan, Colm; Collins, Seán.; O'Brien, Peter; Wilson, Carol; Hogan, Josh; Leahy, Martin J.

2016-03-01

Multiple reference optical coherence tomography (MR-OCT) is a new technology ideally suited to low-cost, compact OCT imaging. This modality is an extension of time-domain OCT with the addition of a partial mirror in front of the reference mirror. This enables extended, simultaneous depth scanning with the relatively short sweep of a miniature voice coil motor on which the scanning mirror is mounted. Applications of this technology include biometric security, ophthalmology, personal health monitoring and non-destructive testing. This work details early-stage development of the first iteration of a miniature MR-OCT device. This device utilizes a fiber-coupled input from an off-board superluminescent diode (SLD). Typical dimensions of the module are 40 × 57 mm, but future designs are expected to be more compact. Off-the-shelf miniature optical components, voice coil motors and photodetectors are used, with the complexity of design depending on specific applications. The photonic module can be configured as either polarized or non-polarized and can include balanced detection. The photodetectors are directly connected to a printed circuit board under the module containing a transimpedance amplifier with complimentary outputs. The results shown in this work are from the non-polarized device. Assembly of the photonic modules requires extensive planning. In choosing the optical components, Zemax simulations are performed to model the beam characteristics. The physical layout is modeled using Solidworks and each component is placed and aligned via a well-designed alignment procedure involving an active-alignment pick-and-place assembly system.

A miniature continuous adiabatic demagnetization refrigerator with compact shielded superconducting magnets

NASA Astrophysics Data System (ADS)

Duval, Jean-Marc; Cain, Benjamin M.; Timbie, Peter T.

2004-10-01

Cryogenic detectors for astrophysics depend on cryocoolers capable of achieving temperatures below ~ 100 mK. In order to provide continuous cooling at 50 mK for space or laboratory applications, we are designing a miniature adiabatic demagnetization refrigerator (MADR) anchored at a reservoir at 5 K. Continuous cooling is obtained by the use of several paramagnetic pills placed in series with heat switches. All operations are fully electronic and this technology can be adapted fairly easily for a wide range of temperatures and cooling powers. We are focusing on reducing the size and mass of the cooler. For that purpose we have developed and tested magnetoresistive heat switches based on single crystals of tungsten. Several superconducting magnets are required for this cooler and we have designed and manufactured compact magnets. A special focus has been put on the reduction of parasitic magnetic fields in the cold stage, while minimizing the mass of the shields. A prototype continuous MADR, using magnetoresistive heat switches, small paramagnetic pills and compact magnets has been tested. A design of MADR that will provide ~ 5 uW of continuous cooling down to 50 mK is described.

Low energy CMOS for space applications

NASA Technical Reports Server (NTRS)

Panwar, Ramesh; Alkalaj, Leon

1992-01-01

The current focus of NASA's space flight programs reflects a new thrust towards smaller, less costly, and more frequent space missions, when compared to missions such as Galileo, Magellan, or Cassini. Recently, the concept of a microspacecraft was proposed. In this concept, a small, compact spacecraft that weighs tens of kilograms performs focused scientific objectives such as imaging. Similarly, a Mars Lander micro-rover project is under study that will allow miniature robots weighing less than seven kilograms to explore the Martian surface. To bring the microspacecraft and microrover ideas to fruition, one will have to leverage compact 3D multi-chip module-based multiprocessors (MCM) technologies. Low energy CMOS will become increasingly important because of the thermodynamic considerations in cooling compact 3D MCM implementations and also from considerations of the power budget for space applications. In this paper, we show how the operating voltage is related to the threshold voltage of the CMOS transistors for accomplishing a task in VLSI with minimal energy. We also derive expressions for the noise margins at the optimal operating point. We then look at a low voltage CMOS (LVCMOS) technology developed at Stanford University which improves the power consumption over conventional CMOS by a couple of orders of magnitude and consider the suitability of the technology for space applications by characterizing its SEU immunity.

Frequency locking of compact laser-diode modules at 633 nm

NASA Astrophysics Data System (ADS)

Nölleke, Christian; Leisching, Patrick; Blume, Gunnar; Jedrzejczyk, Daniel; Pohl, Johannes; Feise, David; Sahm, Alexander; Paschke, Katrin

2018-02-01

This work reports on a compact diode-laser module emitting at 633 nm. The emission frequency can be tuned with temperature and current, while optical feedback of an internal DBR grating ensures single-mode operation. The laser diode is integrated into a micro-fabricated package, which includes optics for beam shaping, a miniaturized optical isolator, and a vapor cell as frequency reference. The achieved absolute frequency stability is below 10-8 , while the output power can be more than 10 mW. This compact absolute frequency-stabilized laser system can replace gas lasers and may be integrated in future quantum technology devices.

Highly miniaturized FEEP propulsion system (NanoFEEP) for attitude and orbit control of CubeSats

NASA Astrophysics Data System (ADS)

Bock, Daniel; Tajmar, Martin

2018-03-01

A highly miniaturized Field Emission Electric Propulsion (FEEP) system is currently under development at TU Dresden, called NanoFEEP [1]. The highly miniaturized thruster heads are very compact and have a volume of less than 3 cm3 and a weight of less than 6 g each. One thruster is able to generate continuous thrust of up to 8 μN with short term peaks of up to 22 μN. The very compact design and low power consumption (heating power demand between 50 and 150 mW) are achieved by using Gallium as metal propellant with its low melting point of approximately 30 °C. This makes it possible to implement an electric propulsion system consisting of four thruster heads, two neutralizers and the necessary electronics on a 1U CubeSat with its strong limitation in space, weight and available power. Even formation flying of 1U CubeSats using an electric propulsion system is possible with this system, which is shown by the example of a currently planned cooperation project between Wuerzburg University, Zentrum fuer Telematik and TU Dresden. It is planned to use the NanoFEEP electric propulsion system on the UWE (University Wuerzburg Experimental) 1U CubeSat platform [2] to demonstrate orbit and two axis attitude control with our electric propulsion system NanoFEEP. We present the latest performance characteristics of the NanoFEEP thrusters and the highly miniaturized electronics. Additionally, the concept and the current status of a novel cold neutralizer chip using Carbon Nano Tubes (CNTs) is presented.

Gas-cell atomic clocks for space: new results and alternative schemes

NASA Astrophysics Data System (ADS)

Affolderbach, C.; Breschi, E.; Schori, C.; Mileti, G.

2017-11-01

We present our development activities on compact Rubidium gas-cell atomic frequency standards, for use in space-borne and ground-based applications. We experimentally demonstrate a high-performance laser optically-pumped Rb clock for space applications such as telecommunications, science missions, and satellite navigation systems (e.g. GALILEO). Using a stabilised laser source and optimized gas cells, we reach clock stabilities as low as 1.5·10-12 τ-1/2 up to 103 s and 4·10-14 at 104 s. The results demonstrate the feasibility of a laser-pumped Rb clock reaching < 1·10-12 τ-1/2 in a compact device (<2 liters, 2 kg, 20 W), given optimization of the implemented techniques. A second activity concerns more radically miniaturized gas-cell clocks, aiming for low power consumption and a total volume around 1 cm3 , at the expense of relaxed frequency stability. Here miniaturized "chip-scale" vapour cells and use of coherent laser interrogation techniques are at the heart of the investigations.

a Compact, Rf-Driven Pulsed Ion Source for Intense Neutron Generation

NASA Astrophysics Data System (ADS)

Perkins, L. T.; Celata, C. M.; Lee, Y.; Leung, K. N.; Picard, D. S.; Vilaithong, R.; Williams, M. D.; Wutte, D.

1997-05-01

Lawrence Berkeley National Laboratory is currently developing a compact, sealed-accelerator-tube neutron generator capable of producing a neutron flux in the range of 109 to 1010 D-T neutrons per second. The ion source, a miniaturized variation of earlier 2 MHz radio-frequency (rf)-driven multicusp ion sources, is designed to fit within a #197# 5 cm diameter borehole. Typical operating parameters include repetition rates up to 100 pps, with pulse widths between 10 and 80 us and source pressures as low as #197# 5 mTorr. In this configuration, peak extractable hydrogen current exceeding 35 mA from a 2 mm diameter aperture together with H1+ yields over 94% have been achieved. The required rf impedance matching network has been miniaturized to #197# 5 cm diameter. The accelerator column is a triode design using the IGUN ion optics codes and allows for electron suppression. Results from the testing of the integrated matching network-ion source-accelerator system will be presented.

Miniaturized compact water-cooled pitot-pressure probe for flow-field surveys in hypersonic wind tunnels

NASA Technical Reports Server (NTRS)

Ashby, George C.

1988-01-01

An experimental investigation of the design of pitot probes for flowfield surveys in hypersonic wind tunnels is reported. The results show that a pitot-pressure probe can be miniaturized for minimum interference effects by locating the transducer in the probe support body and water-cooling it so that the pressure-settling time and transducer temperature are compatible with hypersonic tunnel operation and flow conditions. Flowfield surveys around a two-to-one elliptical cone model in a 20-inch Mach 6 wind tunnel using such a probe show that probe interference effects are essentially eliminated.

A Magnetically Suspended Wheel for a Miniature Gyro Made Using Planar Fabrication Technologies

NASA Technical Reports Server (NTRS)

Dauwalter, Charles R.

1996-01-01

The technical feasibility of a magnetically suspended rotating wheel for miniature gyro applications was investigated under a NASA SBIR contract. A concept for a configuration for a system of compact, lightweight magnetic actuators capable of generating the necessary suspension forces and fabrication using millimachining planar fabrication technologies was developed. Both capacitive and electromagnetic position sensing concepts were developed for implementing a closed loop control system for supporting the wheel. A finite difference technique, implemented in a spreadsheet environment, for analyzing the force characteristics of the actuator was used and the results verified with Finite Element Analysis.

Design of a miniaturized integrated spectrometer for spectral tissue sensing

NASA Astrophysics Data System (ADS)

Belay, Gebirie Yizengaw; Hoving, Willem; Ottevaere, Heidi; van der Put, Arthur; Weltjens, Wim; Thienpont, Hugo

2016-04-01

Minimally-invasive image-guided procedures become increasingly used by physicians to obtain real-time characterization feedback from the tissue at the tip of their interventional device (needle, catheter, endoscopic or laparoscopic probes, etc…) which can significantly improve the outcome of diagnosis and treatment, and ultimately reduce cost of the medical treatment. Spectral tissue sensing using compact photonic probes has the potential to be a valuable tool for screening and diagnostic purposes, e.g. for discriminating between healthy and tumorous tissue. However, this technique requires a low-cost broadband miniature spectrometer so that it is commercially viable for screening at point-of-care locations such as physicians' offices and outpatient centers. Our goal is therefore to develop a miniaturized spectrometer based on diffractive optics that combines the functionalities of a visible/near-infrared (VIS/NIR) and shortwave-infrared (SWIR) spectrometer in one very compact housing. A second goal is that the hardware can be produced in high volume at low cost without expensive time consuming alignment and calibration steps. We have designed a miniaturized spectrometer which operates both in the visible/near-infrared and shortwave-infrared wavelength regions ranging from 400 nm to 1700 nm. The visible/near-infrared part of the spectrometer is designed for wavelengths from 400 nm to 800 nm whereas the shortwave-infrared segment ranges from 850 nm to 1700 nm. The spectrometer has a resolution of 6 nm in the visible/near-infrared wavelength region and 10 nm in the shortwave-infrared. The minimum SNR of the spectrometer for the intended application is about 151 in the VIS/NIR range and 6000 for SWIR. In this paper, the modelling and design, and power budget analysis of the miniaturized spectrometer are presented. Our work opens a door for future affordable micro- spectrometers which can be integrated with smartphones and tablets, and used for point-of-care applications. As next steps in the development, we will manufacture the different optical components and experimentally characterize the spectrometer device in more detail.

Application and Miniaturization of Linear and Nonlinear Raman Microscopy for Biomedical Imaging

NASA Astrophysics Data System (ADS)

Mittal, Richa

Current diagnostics for several disorders rely on surgical biopsy or evaluation of ex vivo bodily fluids, which have numerous drawbacks. We evaluated the potential for vibrational techniques (both linear and nonlinear Raman) as a reliable and noninvasive diagnostic tool. Raman spectroscopy is an optical technique for molecular analysis that has been used extensively in various biomedical applications. Based on demonstrated capabilities of Raman spectroscopy we evaluated the potential of the technique for providing a noninvasive diagnosis of mucopolysaccharidosis (MPS). These studies show that Raman spectroscopy can detect subtle changes in tissue biochemistry. In applications where sub-micrometer visualization of tissue compositional change is required, a transition from spectroscopy to high quality imaging is necessary. Nonlinear vibrational microscopy is sensitive to the same molecular vibrations as linear Raman, but features fast imaging capabilities. Coherent Raman scattering when combined with other nonlinear optical (NLO) techniques (like two-photon excited fluorescence and second harmonic generation) forms a collection of advanced optical techniques that provide noninvasive chemical contrast at submicron resolution. This capability to examine tissues without external molecular agents is driving the NLO approach towards clinical applications. However, the unique imaging capabilities of NLO microscopy are accompanied by complex instrument requirements. Clinical examination requires portable imaging systems for rapid inspection of tissues. Optical components utilized in NLO microscopy would then need substantial miniaturization and optimization to enable in vivo use. The challenges in designing compact microscope objective lenses and laser beam scanning mechanisms are discussed. The development of multimodal NLO probes for imaging oral cavity tissue is presented. Our prototype has been examined for ex vivo tissue imaging based on intrinsic fluorescence and SHG contrast. These studies show a potential for multiphoton compact probes to be used for real time imaging in the clinic.

Biotelemetry system for ambulatory patients

NASA Technical Reports Server (NTRS)

Fryer, T. B.

1978-01-01

Compact transmitter for multichannel telemetry of medical data is carried in patient's belt. Pulse-code modulation (PCM), is used for high-quality signal, and low-power CMOS integrated circuits make miniaturization possible. Transmitter is useful for electro-encephalograms (EEG) and electro-cardiograms (EKG) and other biomedical patient-monitoring situations.

Optical surface contouring for non-destructive inspection of turbomachinery

NASA Astrophysics Data System (ADS)

Modarress, Dariush; Schaack, David F.

1994-03-01

Detection of stress cracks and other surface defects during maintenance and in-service inspection of propulsion system components, including turbine blades and combustion compartments, is presently performed visually. There is a need for a non-contact, miniaturized, and fully fieldable instrument that may be used as an automated inspection tool for inspection of aircraft engines. During this SBIR Phase 1 program, the feasibility of a ruggedized optical probe for automatic and nondestructive inspection of complex shaped objects will be established. Through a careful analysis of the measurement requirements, geometrical and optical constraints, and consideration of issues such as manufacturability, compactness, simplicity, and cost, one or more conceptual optical designs will be developed. The proposed concept will be further developed and a prototype will be fabricated during Phase 2.

Optical surface contouring for non-destructive inspection of turbomachinery

NASA Technical Reports Server (NTRS)

Modarress, Dariush; Schaack, David F.

1994-01-01

Detection of stress cracks and other surface defects during maintenance and in-service inspection of propulsion system components, including turbine blades and combustion compartments, is presently performed visually. There is a need for a non-contact, miniaturized, and fully fieldable instrument that may be used as an automated inspection tool for inspection of aircraft engines. During this SBIR Phase 1 program, the feasibility of a ruggedized optical probe for automatic and nondestructive inspection of complex shaped objects will be established. Through a careful analysis of the measurement requirements, geometrical and optical constraints, and consideration of issues such as manufacturability, compactness, simplicity, and cost, one or more conceptual optical designs will be developed. The proposed concept will be further developed and a prototype will be fabricated during Phase 2.

Two Views of Islam: Ceramic Tile Design and Miniatures.

ERIC Educational Resources Information Center

Macaulay, Sara Grove

2001-01-01

Describes an art project focusing on Islamic art that consists of two parts: (1) ceramic tile design; and (2) Islamic miniatures. Provides background information on Islamic art and step-by-step instructions for designing the Islamic tile and miniature. Includes learning objectives and resources on Islamic tile miniatures. (CMK)

Ultra-compact coherent receiver with serial interface for pluggable transceiver.

PubMed

Itoh, Toshihiro; Nakajima, Fumito; Ohno, Tetsuichiro; Yamanaka, Shogo; Soma, Shunichi; Saida, Takashi; Nosaka, Hideyuki; Murata, Koichi

2014-09-22

An ultra-compact integrated coherent receiver with a volume of 1.3 cc using a quad-channel transimpedance amplifier (TIA)-IC chip with a serial peripheral interface (SPI) is demonstrated for the first time. The TIA with the SPI and photodiode (PD) bias circuits, a miniature dual polarization optical hybrid, an octal-PD and small optical coupling system enabled the realization of the compact receiver. Measured transmission performance with 32 Gbaud dual-polarization quadrature phase shift keying signal is equivalent to that of the conventional multi-source agreement-based integrated coherent receiver with dual channel TIA-ICs. By comparing the bit-error rate (BER) performance with that under continuous SPI access, we also confirmed that there is no BER degradation caused by SPI interface access. Such an ultra-compact receiver is promising for realizing a new generation of pluggable transceivers.

Efficient 3M PBS enhancing miniature projection optics

NASA Astrophysics Data System (ADS)

Yun, Zhisheng; Nevitt, Timothy; Willett, Stephen; Mortenson, Dave; Le, John; McDowell, Erin; Kent, Susan; Wong, Timothy; Beniot, Gilles J.; Ouderkirk, Andrew

2016-09-01

Over the past decade, 3M has developed a number of mobile projectors, with a goal towards providing the world's smallest, most efficient projection systems. Compact size and efficiency are required characteristics for projection systems used in mobile devices and more lately, in augmented reality systems. In this paper we summarize the main generations of 3M light engine optical designs. We present the optical architectures of four light engines, including the rationale behind the illumination designs and the projection systems. In particular, we describe various configurations relating to the 3M polarizing beam splitter (PBS) which is key to enhanced efficiency of the miniature projection systems.

A miniature fuel reformer system for portable power sources

NASA Astrophysics Data System (ADS)

Dolanc, Gregor; Belavič, Darko; Hrovat, Marko; Hočevar, Stanko; Pohar, Andrej; Petrovčič, Janko; Musizza, Bojan

2014-12-01

A miniature methanol reformer system has been designed and built to technology readiness level exceeding a laboratory prototype. It is intended to feed fuel cells with electric power up to 100 W and contains a complete setup of the technological elements: catalytic reforming and PROX reactors, a combustor, evaporators, actuation and sensing elements, and a control unit. The system is engineered not only for performance and quality of the reformate, but also for its lightweight and compact design, seamless integration of elements, low internal electric consumption, and safety. In the paper, the design of the system is presented by focussing on its miniaturisation, integration, and process control.

Design and modeling of a prototype fiber scanning CARS endoscope

NASA Astrophysics Data System (ADS)

Veilleux, Isra"l.; Doucet, Michel; Coté, Patrice; Verreault, Sonia; Fortin, Michel; Paradis, Patrick; Leclair, Sébastien; Da Costa, Ralph S.; Wilson, Brian C.; Seibel, Eric; Mermut, Ozzy; Cormier, Jean-François

2010-02-01

An endoscope capable of Coherent Anti-Stokes Raman scattering (CARS) imaging would be of significant clinical value for improving early detection of endoluminal cancers. However, developing this technology is challenging for many reasons. First, nonlinear imaging techniques such as CARS are single point measurements thus requiring fast scanning in a small footprint if video rate is to be achieved. Moreover, the intrinsic nonlinearity of this modality imposes several technical constraints and limitations, mainly related to pulse and beam distortions that occur within the optical fiber and the focusing objective. Here, we describe the design and report modeling results of a new CARS endoscope. The miniature microscope objective design and its anticipated performance are presented, along with its compatibility with a new spiral scanningfiber imaging technology developed at the University of Washington. This technology has ideal attributes for clinical use, with its small footprint, adjustable field-of-view and high spatial-resolution. This compact hybrid fiber-based endoscopic CARS imaging design is anticipated to have a wide clinical applicability.

Miniature Compressive Ultra-spectral Imaging System Utilizing a Single Liquid Crystal Phase Retarder

NASA Astrophysics Data System (ADS)

August, Isaac; Oiknine, Yaniv; Abuleil, Marwan; Abdulhalim, Ibrahim; Stern, Adrian

2016-03-01

Spectroscopic imaging has been proved to be an effective tool for many applications in a variety of fields, such as biology, medicine, agriculture, remote sensing and industrial process inspection. However, due to the demand for high spectral and spatial resolution it became extremely challenging to design and implement such systems in a miniaturized and cost effective manner. Using a Compressive Sensing (CS) setup based on a single variable Liquid Crystal (LC) retarder and a sensor array, we present an innovative Miniature Ultra-Spectral Imaging (MUSI) system. The LC retarder acts as a compact wide band spectral modulator. Within the framework of CS, a sequence of spectrally modulated images is used to recover ultra-spectral image cubes. Using the presented compressive MUSI system, we demonstrate the reconstruction of gigapixel spatio-spectral image cubes from spectral scanning shots numbering an order of magnitude less than would be required using conventional systems.

Experimental research on a modular miniaturization nanoindentation device

NASA Astrophysics Data System (ADS)

Huang, Hu; Zhao, Hongwei; Mi, Jie; Yang, Jie; Wan, Shunguang; Yang, Zhaojun; Yan, Jiwang; Ma, Zhichao; Geng, Chunyang

2011-09-01

Nanoindentation technology is developing toward the in situ test which requires miniaturization of indentation instruments. This paper presents a miniaturization nanoindentation device based on the modular idea. It mainly consists of macro-adjusting mechanism, x-y precise positioning platform, z axis precise driving unit, and the load-depth measuring unit. The device can be assembled with different forms and has minimum dimensions of 200 mm × 135 mm × 200 mm. The load resolution is about 0.1 mN and the displacement resolution is about 10 nm. A new calibration method named the reference-mapping method is proposed to calibrate the developed device. Output performance tests and indentation experiments indicate the feasibility of the developed device and calibration method. This paper gives an example that combining piezoelectric actuators with flexure hinge to realize nanoindentation tests. Integrating a smaller displacement sensor, a more compact nanoindentation device can be designed in the future.

Miniature Compressive Ultra-spectral Imaging System Utilizing a Single Liquid Crystal Phase Retarder.

PubMed

August, Isaac; Oiknine, Yaniv; AbuLeil, Marwan; Abdulhalim, Ibrahim; Stern, Adrian

2016-03-23

Spectroscopic imaging has been proved to be an effective tool for many applications in a variety of fields, such as biology, medicine, agriculture, remote sensing and industrial process inspection. However, due to the demand for high spectral and spatial resolution it became extremely challenging to design and implement such systems in a miniaturized and cost effective manner. Using a Compressive Sensing (CS) setup based on a single variable Liquid Crystal (LC) retarder and a sensor array, we present an innovative Miniature Ultra-Spectral Imaging (MUSI) system. The LC retarder acts as a compact wide band spectral modulator. Within the framework of CS, a sequence of spectrally modulated images is used to recover ultra-spectral image cubes. Using the presented compressive MUSI system, we demonstrate the reconstruction of gigapixel spatio-spectral image cubes from spectral scanning shots numbering an order of magnitude less than would be required using conventional systems.

Development, characterization and application of compact spectrometers based on MEMS with in-plane capacitive drives

NASA Astrophysics Data System (ADS)

Kenda, A.; Kraft, M.; Tortschanoff, A.; Scherf, Werner; Sandner, T.; Schenk, Harald; Luettjohann, Stephan; Simon, A.

2014-05-01

With a trend towards the use of spectroscopic systems in various fields of science and industry, there is an increasing demand for compact spectrometers. For UV/VIS to the shortwave near-infrared spectral range, compact hand-held polychromator type devices are widely used and have replaced larger conventional instruments in many applications. Still, for longer wavelengths this type of compact spectrometers is lacking suitable and affordable detector arrays. In perennial development Carinthian Tech Research AG together with the Fraunhofer Institute for Photonic Microsystems endeavor to close this gap by developing spectrometer systems based on photonic MEMS. Here, we review on two different spectrometer developments, a scanning grating spectrometer working in the NIR and a FT-spectrometer accessing the mid-IR range up to 14 μm. Both systems are using photonic MEMS devices actuated by in-plane comb drive structures. This principle allows for high mechanical amplitudes at low driving voltages but results in gratings respectively mirrors oscillating harmonically. Both systems feature special MEMS structures as well as aspects in terms of system integration which shall tease out the best possible overall performance on the basis of this technology. However, the advantages of MEMS as enabling technology for high scanning speed, miniaturization, energy efficiency, etc. are pointed out. Whereas the scanning grating spectrometer has already evolved to a product for the point of sale analysis of traditional Chinese medicine products, the purpose of the FT-spectrometer as presented is to demonstrate what is achievable in terms of performance. Current developments topics address MEMS packaging issues towards long term stability, further miniaturization and usability.

Compact Microscope Imaging System With Intelligent Controls Improved

NASA Technical Reports Server (NTRS)

McDowell, Mark

2004-01-01

The Compact Microscope Imaging System (CMIS) with intelligent controls is a diagnostic microscope analysis tool with intelligent controls for use in space, industrial, medical, and security applications. This compact miniature microscope, which can perform tasks usually reserved for conventional microscopes, has unique advantages in the fields of microscopy, biomedical research, inline process inspection, and space science. Its unique approach integrates a machine vision technique with an instrumentation and control technique that provides intelligence via the use of adaptive neural networks. The CMIS system was developed at the NASA Glenn Research Center specifically for interface detection used for colloid hard spheres experiments; biological cell detection for patch clamping, cell movement, and tracking; and detection of anode and cathode defects for laboratory samples using microscope technology.

Compact, Single-Stage MMIC InP HEMT Amplifier

NASA Technical Reports Server (NTRS)

Pukala, David; Samoska, Lorene; Fung, King Man; Gaier, Todd; Deal, W. R.; Mei, Gerry; Radisic, Vesna; Lai, Richard

2008-01-01

A monolithic micro - wave integrated-circuit (MMIC) singlestage amplifier containing an InP-based high-electron-mobility transistor (HEMT) plus coplanar-waveguide (CPW) transmission lines for impedance matching and input and output coupling, all in a highly miniaturized layout as needed for high performance at operating frequencies of hundreds of gigahertz is described.

Use of microstrip patch antennas in grain permittivity measurement

USGS Publications Warehouse

El Sabbagh, M.A.; Ramahi, O.M.; Trabelsi, S.; Nelson, S.O.; Khan, L.

2003-01-01

In this paper, a compact size free-space setup is proposed for the measurement of complex permittivity of granular materials. The horn antennas in the conventional setup are replaced by microstrip patch antennas which is a step toward system miniaturization. The experimental results obtained are in good agreement with those obtained with horn antennas.

Compact DFB laser modules with integrated isolator at 935 nm

NASA Astrophysics Data System (ADS)

Reggentin, M.; Thiem, H.; Tsianos, G.; Malach, M.; Hofmann, J.; Plocke, T.; Kneier, M.; Richter, L.

2018-02-01

New developments in industrial applications and applications under rough environmental conditions within the field of spectroscopy and quantum technology in the 935 nm wavelength regime demand new compact, stable and robust laser systems. Beside a stable laser source the integration of a compact optical isolator is necessary to reduce size and power consumption for the whole laser system. The integration of a suitable optical isolator suppresses back reflections from the following optical system efficiently. However, the miniaturization of the optics inside the package leads to high optical power density levels that make a more detailed analysis of the components and their laser damage threshold necessary. We present test results on compact stable DFB laser sources (butterfly style packages) with newly integrated optical isolators operating around 935 nm. The presented data includes performance and lifetime tests for the laser diodes as well as package components. Overall performance data of the packaged laser diodes will be shown as well.

Microelectrode for energy and current control of nanotip field electron emitters

NASA Astrophysics Data System (ADS)

Lüneburg, S.; Müller, M.; Paarmann, A.; Ernstorfer, R.

2013-11-01

Emerging experiments and applications in electron microscopy, holography, and diffraction benefit from miniaturized electron guns for compact experimental setups. We present a highly compact microelectrode integrated field emitter that consists of a tungsten nanotip coated with a few micrometers thick polyimide film followed by a several nanometers thick gold film, both positioned behind the exposed emitter apex by approximately 10-30 μm. The control of the electric field strength at the nanometer scale tip apex allows suppression, extraction, and energy tuning of field-emitted electrons. The performance of the microelectrode is demonstrated experimentally and supported by numerical simulations.

Miniature Stirling cryocoolers at Thales Cryogenics: qualification results and integration solutions

NASA Astrophysics Data System (ADS)

Arts, R.; Martin, J.-Y.; Willems, D.; Seguineau, C.; de Jonge, G.; Van Acker, S.; Mullié, J.; Le Bordays, J.; Benschop, T.

2016-05-01

During the 2015 SPIE-DSS conference, Thales Cryogenics presented new miniature cryocoolers for high operating temperatures. In this paper, an update is given regarding the qualification programme performed on these new products. Integration aspects are discussed, including an in-depth examination of the influence of the dewar cold finger on sizing and performance of the cryocooler. The UP8197 will be placed in the reference frame of the Thales product range of high-reliability linear cryocoolers, while the rotary solution will be considered as the most compact solution in the Thales portfolio. Compatibility of the cryocoolers design with new and existing 1/4" dewar designs is examined, and potential future developments are presented.

Flexible implementation of front-end bioelectric signal amplifier using FPAA for telemedicine system.

PubMed

Chan, U Fai; Chan, Wai Wong; Pun, Sio Hang; Vai, Mang I; Mak, Peng Un

2007-01-01

Traditional/Current electronic circuits for Telemedicine have significant performance on certain bioelectric signal detection. However, it is rarely seen that can handle multiple signals without changing of hardware. This paper introduces a general front-end amplifier for various bioelectric signals based on Field Programmable Analogy Array (FPAA) Technology. Employing FPAA technology, the implemented amplifier can be adapted for various bioelectric signals without alternating the circuitry while its compact size (core parts < 2 cm2) provides an alternative solution for miniaturized Telemedicine system and Wearable Devices. The proposed design implementation has demonstrated, through successfully ECG and EMG signal extractions, a quick way to miniaturize analog biomedical circuit in a convenient and cost effective way.

Miniature spectrally selective dosimeter

NASA Technical Reports Server (NTRS)

Adams, R. R.; Macconochie, I. O.; Poole, B. D., Jr. (Inventor)

1980-01-01

A miniature spectrally selective dosimeter capable of measuring selected bandwidths of radiation exposure on small mobile areas is described. This is achieved by the combination of photovoltaic detectors, electrochemical integrators (E-cells) and filters in a small compact case which can be easily attached in close proximity to and substantially parallel to the surface being measured. In one embodiment two photovoltaic detectors, two E-cells, and three filters are packaged in a small case with attaching means consisting of a safety pin. In another embodiment, two detectors, one E-cell, three filters are packaged in a small case with attaching means consisting of a clip to clip over a side piece of an eye glass frame.

Compact Optical Correlators

NASA Astrophysics Data System (ADS)

Gregory, Don A.; Kirsch, James C.

1989-02-01

In the past 15 years, a dozen or so designs have been proposed for compact optical correlators. Of these, maybe one-third of them have actually been built and only a few of those tested. This paper will give an overview of some of the systems that have been built as well as mention some promising early and current designs that have not been built. The term compact, as used in the title of this paper, will be applied very loosely; to mean smaller than a laboratory size optical table. To date, only one correlator has been built and tested that actually can be called miniature. This softball size correlator was built by the Perkin-Elmer Corporation for the U. S. Army Missile Command at Redstone Arsenal, Alabama. More will be said about this correlator in following sections.

Ultra-compact high-performance MCT MWIR engine

NASA Astrophysics Data System (ADS)

Lutz, H.; Breiter, R.; Eich, D.; Figgemeier, H.; Oelmaier, R.; Rutzinger, S.; Schenk, H.; Wendler, J.

2017-02-01

Size, weight and power (SWaP) reduction is highly desired by applications such as sights for the dismounted soldier or small gimbals for UAVs. But why have high performance and small size of IR systems inevitably exclude each other? Namely, recent development progress in the fields of miniature cryocoolers, short dewars and high operating temperature (HOT) FPAs combined with pitch size reduction opens the door for very compact MWIR-modules while keeping high electro-optical performance. Now, AIM has realized first prototypes of an ultra-compact high-performance MWIR engine in a total volume of only 18cl (60mm length x 60mm height x 50mm width). Impressive SWaP characteristics are completed by a total weight below 400g and a power consumption < 4W in basic imaging mode. The engine consists of a XGA-format (1024x768) MCT detector array with 10μm pitch and a low power consuming ROIC. It is cooled down to a typical operating temperature of 160K by the miniature linear cryocooler SX020. The dewar uses a short coldfinger and is designed to reduce the heat load as much as possible. The cooler drive electronics is implemented in the CCE layout in order to reduce the required space of the printed boards and to save power. Uncorrected 14bit video data is provided via Camera Link. Optionally, a small image processing board can be stacked on top of the CCE to gain access to basic functions such as BPR, 2- point NUC and dynamic reduction. This paper will present the design, functionalities and performance data of the ultra-compact MCT MWIR engine operated at HOT.

Extracorporeal Respiratory Support With a Miniature Integrated Pediatric Pump-Lung Device in an Acute Ovine Respiratory Failure Model.

PubMed

Wei, Xufeng; Sanchez, Pablo G; Liu, Yang; Claire Watkins, A; Li, Tieluo; Griffith, Bartley P; Wu, Zhongjun J

2016-11-01

Respiratory failure is one of the major causes of mortality and morbidity all over the world. Therapeutic options to treat respiratory failure remain limited. The objective of this study was to evaluate the gas transfer performance of a newly developed miniature portable integrated pediatric pump-lung device (PediPL) with small membrane surface for respiratory support in an acute ovine respiratory failure model. The respiratory failure was created in six adult sheep using intravenous anesthesia and reduced mechanical ventilation at 2 breaths/min. The PediPL device was surgically implanted and evaluated for respiratory support in a venovenous configuration between the right atrium and pulmonary artery. The hemodynamics and respiratory status of the animals during support with the device gas transfer performance of the PediPL were studied for 4 h. The animals exhibited respiratory failure 30 min after mechanical ventilation was reduced to 2 breaths/min, indicated by low oxygen partial pressure, low oxygen saturation, and elevated carbon dioxide in arterial blood. The failure was reversed by establishing respiratory support with the PediPL after 30 min. The rates of O 2 transfer and CO 2 removal of the PediPL were 86.8 and 139.1 mL/min, respectively. The results demonstrated that the PediPL (miniature integrated pump-oxygenator) has the potential to provide respiratory support as a novel treatment for both hypoxia and hypercarbia. The compact size of the PediPL could allow portability and potentially be used in many emergency settings to rescue patients suffering acute lung injury. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Mini and micro spectrometers pave the way to on-field advanced analytics

NASA Astrophysics Data System (ADS)

Bouyé, Clémentine; Kolb, Hugo; d'Humières, Benoît.

2016-03-01

First introduced in the 1990's, miniature optical spectrometers were compact, portable devices brought on the market by the desire to move from time-consuming lab-based analyses to on-field and in situ measurements. This goal of getting spectroscopy into the hands of non-specialists is driving current technical and application developments, the ultimate goal being, in a far future, the integration of a spectrometer into a smartphone or any other smart device (tablet, watch, …). In this article, we present the results of our study on the evolution of the compact spectrometers market towards widespread industrial use and consumer applications. Presently, the main market of compact spectrometers remains academic labs. However, they have been adopted on some industrial applications such as optical source characterization (mainly laser and LEDs). In a near future, manufacturers of compact spectrometers target the following industrial applications: agriculture crop monitoring, food process control or pharmaceuticals quality control. Next steps will be to get closer to the consumer market with point-of-care applications such as glucose detection for diabetics, for example. To reach these objectives, technological breakthroughs will be necessary. Recent progresses have already allowed the release of micro-spectrometers. They take advantage of new micro-technologies such as MEMS (MicroElectroMechanical Systems), MOEMS (Micro-Opto-Electro-Mechanical Systems), micro-mirrors arrays to reduce cost and size while allowing good performance and high volume manufacturability. Integrated photonics is being investigated for future developments. It will also require new business models and new market approaches. Indeed, spreading spectroscopy to more industrial and consumer applications will require spectrometers manufacturers to get closer to the end-users and develop application-oriented products.

Miniaturized Fourier-plane fiber scanner for OCT endoscopy

NASA Astrophysics Data System (ADS)

Vilches, Sergio; Kretschmer, Simon; Ataman, Çağlar; Zappe, Hans

2017-10-01

A forward-looking endoscopic optical coherence tomography (OCT) probe featuring a Fourier-plane fiber scanner is designed, manufactured and characterized. In contrast to common image-plane fiber scanners, the Fourier-plane scanner is a telecentric arrangement that eliminates vignetting and spatial resolution variations across the image plane. To scan the OCT beam in a spiral pattern, a tubular piezoelectric actuator is used to resonate an optical fiber bearing a collimating GRIN lens at its tip. The free-end of the GRIN lens sits at the back focal plane of an objective lens, such that its rotation replicates the beam angles in the collimated region of a classical telecentric 4f optical system. Such an optical arrangement inherently has a low numerical aperture combined with a relatively large field-of-view, rendering it particularly useful for endoscopic OCT imaging. Furthermore, the optical train of the Fourier-plane scanner is shorter than that of a comparable image-plane scanner by one focal length of the objective lens, significantly shortening the final arrangement. As a result, enclosed within a 3D printed housing of 2.5 mm outer diameter and 15 mm total length, the developed probe is the most compact forward-looking endoscopic OCT imager to date. Due to its compact form factor and compatibility with real-time OCT imaging, the developed probe is also ideal for use in the working channel of flexible endoscopes as a potential optical biopsy tool.

Multi-aperture microoptical system for close-up imaging

NASA Astrophysics Data System (ADS)

Berlich, René; Brückner, Andreas; Leitel, Robert; Oberdörster, Alexander; Wippermann, Frank; Bräuer, Andreas

2014-09-01

Modern applications in biomedical imaging, machine vision and security engineering require close-up optical systems with high resolution. Combined with the need for miniaturization and fast image acquisition of extended object fields, the design and fabrication of respective devices is extremely challenging. Standard commercial imaging solutions rely on bulky setups or depend on scanning techniques in order to meet the stringent requirements. Recently, our group has proposed a novel, multi-aperture approach based on parallel image transfer in order to overcome these constraints. It exploits state of the art microoptical manufacturing techniques on wafer level in order to create a compact, cost-effective system with a large field of view. However, initial prototypes have so far been subject to various limitations regarding their manufacturing, reliability and applicability. In this work, we demonstrate the optical design and fabrication of an advanced system, which overcomes these restrictions. In particular, a revised optical design facilitates a more efficient and economical fabrication process and inherently improves system reliability. An additional customized front side illumination module provides homogeneous white light illumination over the entire field of view while maintaining a high degree of compactness. Moreover, the complete imaging assembly is mounted on a positioning system. In combination with an extended working range, this allows for adjustment of the system's focus location. The final optical design is capable of capturing an object field of 36x24 mm2 with a resolution of 150 cycles/mm. Finally, we present experimental results of the respective prototype that demonstrate its enhanced capabilities.

Miniature Robotic Spacecraft for Inspecting Other Spacecraft

NASA Technical Reports Server (NTRS)

Fredrickson, Steven; Abbott, Larry; Duran, Steve; Goode, Robert; Howard, Nathan; Jochim, David; Rickman, Steve; Straube, Tim; Studak, Bill; Wagenknecht, Jennifer;

Miniature Fuel Processors for Portable Fuel Cell Power Supplies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holladay, Jamie D.; Jones, Evan O.; Palo, Daniel R.

2003-06-02

Miniature and micro-scale fuel processors are discussed. The enabling technologies for these devices are the novel catalysts and the micro-technology-based designs. The novel catalyst allows for methanol reforming at high gas hourly space velocities of 50,000 hr-1 or higher, while maintaining a carbon monoxide levels at 1% or less. The micro-technology-based designs enable the devices to be extremely compact and lightweight. The miniature fuel processors can nominally provide between 25-50 watts equivalent of hydrogen which is ample for soldier or personal portable power supplies. The integrated processors have a volume less than 50 cm3, a mass less than 150 grams,more » and thermal efficiencies of up to 83%. With reasonable assumptions on fuel cell efficiencies, anode gas and water management, parasitic power loss, etc., the energy density was estimated at 1700 Whr/kg. The miniature processors have been demonstrated with a carbon monoxide clean-up method and a fuel cell stack. The micro-scale fuel processors have been designed to provide up to 0.3 watt equivalent of power with efficiencies over 20%. They have a volume of less than 0.25 cm3 and a mass of less than 1 gram.« less

Biocompatible ionic liquid-biopolymer electrolyte-enabled thin and compact magnesium-air batteries.

PubMed

Jia, Xiaoteng; Yang, Yang; Wang, Caiyun; Zhao, Chen; Vijayaraghavan, R; MacFarlane, Douglas R; Forsyth, Maria; Wallace, Gordon G

2014-12-10

With the surge of interest in miniaturized implanted medical devices (IMDs), implantable power sources with small dimensions and biocompatibility are in high demand. Implanted battery/supercapacitor devices are commonly packaged within a case that occupies a large volume, making miniaturization difficult. In this study, we demonstrate a polymer electrolyte-enabled biocompatible magnesium-air battery device with a total thickness of approximately 300 μm. It consists of a biocompatible polypyrrole-para(toluene sulfonic acid) cathode and a bioresorbable magnesium alloy anode. The biocompatible electrolyte used is made of choline nitrate (ionic liquid) embedded in a biopolymer, chitosan. This polymer electrolyte is mechanically robust and offers a high ionic conductivity of 8.9 × 10(-3) S cm(-1). The assembled battery delivers a maximum volumetric power density of 3.9 W L(-1), which is sufficient to drive some types of IMDs, such as cardiac pacemakers or biomonitoring systems. This miniaturized, biocompatible magnesium-air battery may pave the way to a future generation of implantable power sources.

Monolithic crystalline cladding microstructures for efficient light guiding and beam manipulation in passive and active regimes.

PubMed

Jia, Yuechen; Cheng, Chen; Vázquez de Aldana, Javier R; Castillo, Gabriel R; Rabes, Blanca del Rosal; Tan, Yang; Jaque, Daniel; Chen, Feng

2014-08-07

Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump of miniaturized waveguiding active structures offers a low-cost but intriguing solution for compact light-emitting devices. In this work, we demonstrate a novel family of three dimensional (3D) photonic microstructures monolithically integrated in a Nd:YAG laser crystal wafer. They are produced by the femtosecond laser writing, capable of simultaneous light waveguiding and beam manipulation. In these guiding systems, tailoring of laser modes by both passive/active beam splitting and ring-shaped transformation are achieved by an appropriate design of refractive index patterns. Integration of graphene thin-layer as saturable absorber in the 3D laser structures allows for efficient passive Q-switching of tailored laser radiations which may enable miniature waveguiding lasers for broader applications. Our results pave a way to construct complex integrated passive and active laser circuits in dielectric crystals by using femtosecond laser written monolithic photonic chips.

A Compact Magnetic Field-Based Obstacle Detection and Avoidance System for Miniature Spherical Robots.

PubMed

Wu, Fang; Vibhute, Akash; Soh, Gim Song; Wood, Kristin L; Foong, Shaohui

2017-05-28

Due to their efficient locomotion and natural tolerance to hazardous environments, spherical robots have wide applications in security surveillance, exploration of unknown territory and emergency response. Numerous studies have been conducted on the driving mechanism, motion planning and trajectory tracking methods of spherical robots, yet very limited studies have been conducted regarding the obstacle avoidance capability of spherical robots. Most of the existing spherical robots rely on the "hit and run" technique, which has been argued to be a reasonable strategy because spherical robots have an inherent ability to recover from collisions. Without protruding components, they will not become stuck and can simply roll back after running into bstacles. However, for small scale spherical robots that contain sensitive surveillance sensors and cannot afford to utilize heavy protective shells, the absence of obstacle avoidance solutions would leave the robot at the mercy of potentially dangerous obstacles. In this paper, a compact magnetic field-based obstacle detection and avoidance system has been developed for miniature spherical robots. It utilizes a passive magnetic field so that the system is both compact and power efficient. The proposed system can detect not only the presence, but also the approaching direction of a ferromagnetic obstacle, therefore, an intelligent avoidance behavior can be generated by adapting the trajectory tracking method with the detection information. Design optimization is conducted to enhance the obstacle detection performance and detailed avoidance strategies are devised. Experimental results are also presented for validation purposes.

Miniature Wide-Angle Lens for Small-Pixel Electronic Camera

NASA Technical Reports Server (NTRS)

Mouroulils, Pantazis; Blazejewski, Edward

2009-01-01

A proposed wideangle lens is shown that would be especially well suited for an electronic camera in which the focal plane is occupied by an image sensor that has small pixels. The design of the lens is intended to satisfy requirements for compactness, high image quality, and reasonably low cost, while addressing issues peculiar to the operation of small-pixel image sensors. Hence, this design is expected to enable the development of a new generation of compact, high-performance electronic cameras. The lens example shown has a 60 degree field of view and a relative aperture (f-number) of 3.2. The main issues affecting the design are also shown.

Microelectrode for energy and current control of nanotip field electron emitters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lüneburg, S.; Müller, M., E-mail: m.mueller@fhi-berlin.mpg.de; Paarmann, A., E-mail: alexander.paarmann@fhi-berlin.mpg.de

2013-11-18

Emerging experiments and applications in electron microscopy, holography, and diffraction benefit from miniaturized electron guns for compact experimental setups. We present a highly compact microelectrode integrated field emitter that consists of a tungsten nanotip coated with a few micrometers thick polyimide film followed by a several nanometers thick gold film, both positioned behind the exposed emitter apex by approximately 10–30 μm. The control of the electric field strength at the nanometer scale tip apex allows suppression, extraction, and energy tuning of field-emitted electrons. The performance of the microelectrode is demonstrated experimentally and supported by numerical simulations.

Pure-iron/iron-based-alloy hybrid soft magnetic powder cores compacted at ultra-high pressure

NASA Astrophysics Data System (ADS)

Saito, Tatsuya; Tsuruta, Hijiri; Watanabe, Asako; Ishimine, Tomoyuki; Ueno, Tomoyuki

2018-04-01

We developed Fe/FeSiAl soft magnetic powder cores (SMCs) for realizing the miniaturization and high efficiency of an electromagnetic conversion coil in the high-frequency range (˜20 kHz). We found that Fe/FeSiAl SMCs can be formed with a higher density under higher compaction pressure than pure-iron SMCs. These SMCs delivered a saturation magnetic flux density of 1.7 T and iron loss (W1/20k) of 158 kW/m3. The proposed SMCs exhibited similar excellent characteristics even in block shapes, which are closer to the product shapes.

Compact piezoelectric micromotor with a single bulk lead zirconate titanate stator

NASA Astrophysics Data System (ADS)

Yan, Liang; Lan, Hua; Jiao, Zongxia; Chen, Chin-Yin; Chen, I.-Ming

2013-04-01

The advance of micro/nanotechnology promotes the development of micromotors in recent years. In this article, a compact piezoelectric ultrasonic micromotor with a single bulk lead zirconate titanate stator is proposed. A traveling wave is generated by superposition of bending modes with 90° phase difference excited by d15 inverse piezoelectric effects. The operating principle simplifies the system structure significantly, and provides a miniaturization solution. A research prototype with the size of 0.75× 0.75×1.55 mm is developed. It can produce start-up torque of 0.27μNmand maximum speed of 2760 r/min at 14RMS.

Miniaturized multiwavelength digital holography sensor for extensive in-machine tool measurement

NASA Astrophysics Data System (ADS)

Seyler, Tobias; Fratz, Markus; Beckmann, Tobias; Bertz, Alexander; Carl, Daniel

2017-06-01

In this paper we present a miniaturized digital holographic sensor (HoloCut) for operation inside a machine tool. With state-of-the-art 3D measurement systems, short-range structures such as tool marks cannot be resolved inside a machine tool chamber. Up to now, measurements had to be conducted outside the machine tool and thus processing data are generated offline. The sensor presented here uses digital multiwavelength holography to get 3D-shape-information of the machined sample. By using three wavelengths, we get a large artificial wavelength with a large unambiguous measurement range of 0.5mm and achieve micron repeatability even in the presence of laser speckles on rough surfaces. In addition, a digital refocusing algorithm based on phase noise is implemented to extend the measurement range beyond the limits of the artificial wavelength and geometrical depth-of-focus. With complex wave field propagation, the focus plane can be shifted after the camera images have been taken and a sharp image with extended depth of focus is constructed consequently. With 20mm x 20mm field of view the sensor enables measurement of both macro- and micro-structure (such as tool marks) with an axial resolution of 1 µm, lateral resolution of 7 µm and consequently allows processing data to be generated online which in turn qualifies it as a machine tool control. To make HoloCut compact enough for operation inside a machining center, the beams are arranged in two planes: The beams are split into reference beam and object beam in the bottom plane and combined onto the camera in the top plane later on. Using a mechanical standard interface according to DIN 69893 and having a very compact size of 235mm x 140mm x 215mm (WxHxD) and a weight of 7.5 kg, HoloCut can be easily integrated into different machine tools and extends no more in height than a typical processing tool.

Miniature Two-Axis Joystick Controller

NASA Technical Reports Server (NTRS)

Hollow, R.

1983-01-01

Novel movable-button-actuated self-centering controller uses optoelectronics to produce X and Y signals for aircraft control. In addition to be extremely compact, device puts our voltages having high signal-to-noise ratio, especially at critical center position where in many controllers this ratio is poorest. Combination of new saddle-shaped button and positive centering gives "feel" and "breakout" met with pilot approval.

AlGaN Ultraviolet Detectors for Dual-Band UV Detection

NASA Technical Reports Server (NTRS)

Miko, Laddawan; Franz, David; Stahle, Carl M.; Yan, Feng; Guan, Bing

2010-01-01

This innovation comprises technology that has the ability to measure at least two ultraviolet (UV) bands using one detector without relying on any external optical filters. This allows users to build a miniature UVA and UVB monitor, as well as to develop compact, multicolor imaging technologies for flame temperature sensing, air-quality control, and terrestrial/counter-camouflage/biosensing applications.

Development of a Miniature Pulse Tube Cryocooler of 2.5W at 65K for Telecommunication Applications

NASA Astrophysics Data System (ADS)

Matsumoto, Noboru; Yasukawa, Yukio; Ohshima, Keishi; Takeuchi, Takayuki; Matsushita, Tomoyuki; Mizoguchi, Yoshinori

The Fuji Electric Group has established main technologies with high reliability for use in Stirling cryocoolers for space satellite systems. For commercial applications, we also have developed and started selling a miniature pulse tube cryocooler from 2W to 3W at 70K with 100W electric power input. In the development of a new compressor, we introduce a moving magnet to a driving system to achieve greater compactness and higher efficiency in place of the moving coil that had about 70% efficiency. In addition, we adopted a coaxial pulse tube as an expander for compactness. This development is aimed at cooling a high-temperature superconductive (HTS) device in a wireless telecommunication system. The compressor requires total compression work of 75W with 90% efficiency for longer than 50,000 hours. Preliminary tests of each part of a moving magnet linear motor and a coaxial pulse tube have been completed. In the next phase, we have made a first-stage prototype compressor used by the new linear motor, and we have tested the new machine. Here we describe each test and combination test results of the cryocooler.

Progress Toward a Compact, Highly Stable Ion Clock

NASA Technical Reports Server (NTRS)

Prestage, John; Chung, Sang

2009-01-01

There was an update on the subject of two previous NASA Tech Briefs articles: Compact, Highly Stable Ion Clock (NPO-43075), Vol. 32, No. 5 (May 2008), page 63; and Neon as a Buffer Gas for a Mercury-Ion Clock (NPO-42919), Vol. 32, No. 7 (July 2008), page 62. To recapitulate: A developmental miniature mercury-ion clock has stability comparable to that of a hydrogen-maser clock. The ion-handling components are housed in a sealed vacuum tube, wherein a getter pump maintains the partial vacuum, and the evacuated tube is backfilled with mercury vapor in a neon buffer gas. There was progress in the development of the clock, with emphasis on the design, fabrication, pump-down, and bake-out of the vacuum tube (based on established practice in the travelingwave- tube-amplifier industry) and the ability of the tube to retain a vacuum after a year of operation. Other developments include some aspects of the operation of mercury-vapor source (a small appendage oven containing HgO) so as to maintain the optimum low concentration of mercury vapor, and further efforts to miniaturize the vacuum and optical subsystems to fit within a volume of 2 L.

OSMOSIS: a new joint laboratory between SOFRADIR and ONERA for the development of advanced DDCA with integrated optics

NASA Astrophysics Data System (ADS)

Druart, Guillaume; Matallah, Noura; Guerineau, Nicolas; Magli, Serge; Chambon, Mathieu; Jenouvrier, Pierre; Mallet, Eric; Reibel, Yann

2014-06-01

Today, both military and civilian applications require miniaturized optical systems in order to give an imagery function to vehicles with small payload capacity. After the development of megapixel focal plane arrays (FPA) with micro-sized pixels, this miniaturization will become feasible with the integration of optical functions in the detector area. In the field of cooled infrared imaging systems, the detector area is the Detector-Dewar-Cooler Assembly (DDCA). SOFRADIR and ONERA have launched a new research and innovation partnership, called OSMOSIS, to develop disruptive technologies for DDCA to improve the performance and compactness of optronic systems. With this collaboration, we will break down the technological barriers of DDCA, a sealed and cooled environment dedicated to the infrared detectors, to explore Dewar-level integration of optics. This technological breakthrough will bring more compact multipurpose thermal imaging products, as well as new thermal capabilities such as 3D imagery or multispectral imagery. Previous developments will be recalled (SOIE and FISBI cameras) and new developments will be presented. In particular, we will focus on a dual-band MWIR-LWIR camera and a multichannel camera.

A visually guided collision warning system with a neuromorphic architecture.

PubMed

Okuno, Hirotsugu; Yagi, Tetsuya

2008-12-01

We have designed a visually guided collision warning system with a neuromorphic architecture, employing an algorithm inspired by the visual nervous system of locusts. The system was implemented with mixed analog-digital integrated circuits consisting of an analog resistive network and field-programmable gate array (FPGA) circuits. The resistive network processes the interaction between the laterally spreading excitatory and inhibitory signals instantaneously, which is essential for real-time computation of collision avoidance with a low power consumption and a compact hardware. The system responded selectively to approaching objects of simulated movie images at close range. The system was, however, confronted with serious noise problems due to the vibratory ego-motion, when it was installed in a mobile miniature car. To overcome this problem, we developed the algorithm, which is also installable in FPGA circuits, in order for the system to respond robustly during the ego-motion.

Chip-on-the-tip ultra-compact flexible endoscopic epifluorescence video-microscope for in-vivo imaging in medical and biomedical fields

NASA Astrophysics Data System (ADS)

Matz, Gregor; Messerschmidt, Bernhard; Göbel, Werner; Filser, Severin; Betz, Christian; Kunze, Marcel; Flaemig, Sven; Ehrhardt, André; Irion, Klaus-Martin; Herms, Jochen; Gross, Herbert

2017-02-01

We demonstrate a flexible stand-alone, minimally invasive video-endomicroscope with an outer diameter of 1.6 mm and a length of the rigid tip of 6.7 mm that enables surgeons and biologists to image hardly accessible regions in-vivo in epifluorescence mode. The 60 mg light device improves state-of-the-art objectives by a double deflection approach using a side-fire fiber in combination with spherical microlenses, GRIN-lenses with a specific adapted gradient index profile and an extremely miniaturized chip-on-the-tip camera to achieve an excellent imaging quality. A high NA of 0.7 enables the observation of subcellular features within the entire field of view with a diameter of 183 μm, assure a bright and high-contrast image and promise a good overview during the intervention. Ex-vivo measurements of biological samples confirmed the functionality of the probe.

High-reliable linear cryocoolers and miniaturization developments at Thales Cryogenics

NASA Astrophysics Data System (ADS)

van der Weijden, H.; Benschop, A.; v. D. Groep, W.; Willems, D.; Mullie, J.

2010-04-01

Thales Cryogenics (TCBV) has an extensive background in delivering long life cryogenic coolers for military, civil and space programs. This cooler range is based on two main compressor concepts: close tolerance contact seals (UP) and flexure bearing (LSF/LPT) coolers. Main difference between these products is the Mean Time To Failure (MTTF). In this paper an overview of lifetime parameters will be listed versus the impact in the different cooler types. Also test results from both the installed base and the Thales Cryogenics test lab will be presented. New developments at Thales Cryogenics regarding compact long lifetime coolers will be outlined. In addition new developments for miniature linear cooler drive electronics with high temperature stability and power density will be described.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Liang; Au-Yeung, Ka Yan; Yang, Min

Damping of low frequency vibration by lightweight and compact devices has been a serious challenge in various areas of engineering science. Here we report the experimental realization of a type of miniature low frequency vibration dampers based on decorated membrane resonators. At frequency around 150 Hz, two dampers, each with outer dimensions of 28 mm in diameter and 5 mm in height, and a total mass of 1.78 g which is less than 0.6% of the host structure (a nearly free-standing aluminum beam), can reduce its vibrational amplitude by a factor of 1400, or limit its maximum resonance quality factormore » to 18. Furthermore, the conceptual design of the dampers lays the foundation and demonstrates the potential of further miniaturization of low frequency dampers.« less

Miniature objective lens for array digital pathology: design improvement based on clinical evaluation

NASA Astrophysics Data System (ADS)

McCall, Brian; Pierce, Mark; Graviss, Edward A.; Richards-Kortum, Rebecca R.; Tkaczyk, Tomasz S.

2016-03-01

A miniature objective designed for digital detection of Mycobacterium tuberculosis (MTB) was evaluated for diagnostic accuracy. The objective was designed for array microscopy, but fabricated and evaluated at this stage of development as a single objective. The counts and diagnoses of patient samples were directly compared for digital detection and standard microscopy. The results were found to be correlated and highly concordant. The evaluation of this lens by direct comparison to standard fluorescence sputum smear microscopy presented unique challenges and led to some new insights in the role played by the system parameters of the microscope. The design parameters and how they were developed are reviewed in light of these results. New system parameters are proposed with the goal of easing the challenges of evaluating the miniature objective and maintaining the optical performance that produced the agreeable results presented without over-optimizing. A new design is presented that meets and exceeds these criteria.

Compact system with handheld microfabricated optoelectronic probe for needle-based tissue sensing applications

NASA Astrophysics Data System (ADS)

Lee, Seung Yup; Na, Kyounghwan; Pakela, Julia M.; Scheiman, James M.; Yoon, Euisik; Mycek, Mary-Ann

2017-02-01

We present the design, development, and bench-top verification of an innovative compact clinical system including a miniaturized handheld optoelectronic sensor. The integrated sensor was microfabricated with die-level light-emitting diodes and photodiodes and fits into a 19G hollow needle (internal diameter: 0.75 mm) for optical sensing applications in solid tissues. Bench-top studies on tissue-simulating phantoms have verified system performance relative to a fiberoptic based tissue spectroscopy system. With dramatically reduced system size and cost, the technology affords spatially configurable designs for optoelectronic light sources and detectors, thereby enabling customized sensing configurations that would be impossible to achieve with needle-based fiber-optic probes.

Uncovering the identities of compact objects in high-mass X-ray binaries and gamma-ray binaries by astrometric measurements

NASA Astrophysics Data System (ADS)

Yamaguchi, M. S.; Yano, T.; Gouda, N.

2018-03-01

We develop a method for identifying a compact object in binary systems with astrometric measurements and apply it to some binaries. Compact objects in some high-mass X-ray binaries and gamma-ray binaries are unknown, which is responsible for the fact that emission mechanisms in such systems have not yet confirmed. The accurate estimate of the mass of the compact object allows us to identify the compact object in such systems. Astrometric measurements are expected to enable us to estimate the masses of the compact objects in the binary systems via a determination of a binary orbit. We aim to evaluate the possibility of the identification of the compact objects for some binary systems. We then calculate probabilities that the compact object is correctly identified with astrometric observation (= confidence level) by taking into account a dependence of the orbital shape on orbital parameters and distributions of masses of white dwarfs, neutron stars and black holes. We find that the astrometric measurements with the precision of 70 μas for γ Cas allow us to identify the compact object at 99 per cent confidence level if the compact object is a white dwarf with 0.6 M⊙. In addition, we can identify the compact object with the precision of 10 μas at 97 per cent or larger confidence level for LS I +61° 303 and 99 per cent or larger for HESS J0632+057. These results imply that the astrometric measurements with the 10 μas precision level can realize the identification of compact objects for γ Cas, LS I +61° 303, and HESS J0632+057.

Concepts for compact mid-IR spectroscopy in photochemistry

NASA Astrophysics Data System (ADS)

Cu-Nguyen, Phuong-Ha; Wang, Ziyu; Zappe, Hans

2016-11-01

Mid-infrared (IR) spectroscopy, typically 3 to 5 µm, is often the technology of choice to monitor the interaction between and concentration of molecules during photochemical reactions. However, classical mid-IR spectrometers are bulky, complex and expensive, making them unsuitable for use in the miniaturized microreactors increasingly being employed for chemical synthesis. We present here the concept for an ultra-miniaturized mid-IR spectrometer directly integrated onto a chemical microreactor to monitor the chemical reaction. The spectrometer is based on micro-machined Fabry-Perot resonator filters realized using pairs of Bragg mirrors to achieve a high spectral resolution. The fabrication of the optical filters is outlined and the measurement of transmittance spectra in the mid-IR range show a good agreement with theory and are thus promising candidates for a fully integrated system.

A miniaturized HTS microwave receiver front-end subsystem for radar and communication applications

NASA Astrophysics Data System (ADS)

Bian, Yongbo; Guo, Jin; Gao, Changzheng; Li, Chunguang; Li, Hong; Wang, Jia; Cui, Bin; He, Xiaofeng; Li, Chao; Li, Na; Li, Guoqiang; Zhang, Qiang; Zhang, Xueqiang; Meng, Jibao; He, Yusheng

2010-08-01

This paper presents a miniaturized high performance high temperature superconducting (HTS) microwave receiver front-end subsystem, which uses a mini stirling cryocooler to cool a high selective HTS filter and a low noise amplifier (LNA). The HTS filter was miniaturized by using specially designed compact resonators and fabricating with double-sided YBCO films on LAO substrate which has a relatively high permittivity. The LNA was specially designed to work at cryogenic temperature with noise figure of 0.27 dB at 71 K. The mini cryocooler, which is widely used in infrared detectors, has a smaller size (60 mm × 80 mm × 100 mm) and a lighter weight (340 g) than the stirling cryocoolers commonly used in other HTS filter subsystem. The whole front-end subsystem, including a HTS filter, a LNA, a cryocooler and the vacuum chamber, has a size of only φ120 mm × 175 mm and a weight of only 3.3 kg. The microwave devices inside the subsystem are working at 71.8 K with a consumed cooling power of 0.325 W. The center frequency of this subsystem is 925.2 MHz and the bandwidth is 2.7 MHz (which is a fractional bandwidth of 0.2%), with the gain of 19.75 dB at center frequency and the return loss better than -18.11 dB in the pass band. The stop band rejection is more than 60 dB and the skirt slope is exceeding 120 dB MHz -1. The noise figure of this subsystem is less than 0.8 dB. This front-end subsystem can be used in radars and communication systems conveniently due to it’s compact size and light weight.

A handheld laser-induced fluorescence detector for multiple applications.

PubMed

Fang, Xiao-Xia; Li, Han-Yang; Fang, Pan; Pan, Jian-Zhang; Fang, Qun

2016-04-01

In this paper, we present a compact handheld laser-induced fluorescence (LIF) detector based on a 450 nm laser diode and quasi-confocal optical configuration with a total size of 9.1 × 6.2 × 4.1 cm(3). Since there are few reports on the use of 450 nm laser diode in LIF detection, especially in miniaturized LIF detector, we systematically investigated various optical arrangements suitable for the requirements of 450 nm laser diode and system miniaturization, including focusing lens, filter combination, and pinhole, as well as Raman effect of water at 450 nm excitation wavelength. As the result, the handheld LIF detector integrates the light source (450 nm laser diode), optical circuit module (including a 450 nm band-pass filter, a dichroic mirror, a collimating lens, a 525 nm band-pass filter, and a 1.0mm aperture), optical detector (miniaturized photomultiplier tube), as well as electronic module (including signal recording, processing and displaying units). This detector is capable of working independently with a cost of ca. $2000 for the whole instrument. The detection limit of the instrument for sodium fluorescein solution is 0.42 nM (S/N=3). The broad applicability of the present system was demonstrated in capillary electrophoresis separation of fluorescein isothiocyanate (FITC) labeled amino acids and in flow cytometry of tumor cells as an on-line LIF detector, as well as in droplet array chip analysis as a LIF scanner. We expect such a compact LIF detector could be applied in flow analysis systems as an on-line detector, and in field analysis and biosensor analysis as a portable universal LIF detector. Copyright © 2015 Elsevier B.V. All rights reserved.

Design and fabrication of a miniature objective consisting of high refractive index zinc sulfide lenses for laser surgery

PubMed Central

Shadfan, Adam; Pawlowski, Michal; Wang, Ye; Subramanian, Kaushik; Gabay, Ilan; Ben-Yakar, Adela; Tkaczyk, Tomasz

2016-01-01

A miniature laser ablation probe relying on an optical fiber to deliver light requires a high coupling efficiency objective with sufficient magnification in order to provide adequate power and field for surgery. A diffraction-limited optical design is presented that utilizes high refractive index zinc sulfide to meet specifications while reducing the miniature objective down to two lenses. The design has a hypercentric conjugate plane on the fiber side and is telecentric on the tissue end. Two versions of the objective were built on a diamond lathe—a traditional cylindrical design and a custom-tapered mount. Both received an antireflective coating. The objectives performed as designed in terms of observable resolution and field of view as measured by imaging a 1951 USAF resolution target. The slanted edge technique was used to find Strehl ratios of 0.75 and 0.78, respectively, indicating nearly diffraction-limited performance. Finally, preliminary ablation experiments indicated threshold fluence of gold film was comparable to similar reported probes. PMID:28579656

Design and fabrication of a miniature objective consisting of high refractive index zinc sulfide lenses for laser surgery

NASA Astrophysics Data System (ADS)

Shadfan, Adam; Pawlowski, Michal; Wang, Ye; Subramanian, Kaushik; Gabay, Ilan; Ben-Yakar, Adela; Tkaczyk, Tomasz

2016-02-01

A miniature laser ablation probe relying on an optical fiber to deliver light requires a high coupling efficiency objective with sufficient magnification in order to provide adequate power and field for surgery. A diffraction-limited optical design is presented that utilizes high refractive index zinc sulfide to meet specifications while reducing the miniature objective down to two lenses. The design has a hypercentric conjugate plane on the fiber side and is telecentric on the tissue end. Two versions of the objective were built on a diamond lathe-a traditional cylindrical design and a custom-tapered mount. Both received an antireflective coating. The objectives performed as designed in terms of observable resolution and field of view as measured by imaging a 1951 USAF resolution target. The slanted edge technique was used to find Strehl ratios of 0.75 and 0.78, respectively, indicating nearly diffraction-limited performance. Finally, preliminary ablation experiments indicated threshold fluence of gold film was comparable to similar reported probes.

Miniaturized spectrometer for stand-off chemical detection

NASA Astrophysics Data System (ADS)

Henning, Patrick F.; Chadha, Suneet; Damren, Richard; Rowe, Rebecca C.; Stevenson, Chuck; Curtiss, Lawrence E.; DiGiuseppe, Thomas G.

2002-02-01

Advanced autonomous detection of both chemical warfare agents and toxic industrial chemicals has long been of major military concern and is becoming an increasingly realistic need. Foster-Miller has successfully designed and demonstrated a high spectral throughput monolithic wedge spectrometer capable of providing early, stand-off detection of chemical threats. Recent breakthrough innovations in IR source technologies, high D* multispectral array detectors, and IR waveguide materials has allowed for the development of a robust, miniature, monolithic infrared spectrometer. Foster-Miller recently demonstrated a high resolution spectrometer operating in the 8 to 12 micron region for chemical agent detection. Results will be presented demonstrating the feasibility of adapting the wedge spectrometer to operate as an upward looking ground sensor for stand-off chemical detection. Our miniaturized spectrometer forms the basis for deploying low cost, lightweight sensors which may be used for reconnaissance missions or delivered to remote locations for unattended operation. The ability of perform passive stand-off infrared chemical agent and chemical emissions detection with a low cost, compact device that can operate autonomously in remote environments has broad applications in both the military and commercial marketplace.

A self-sustained, complete and miniaturized methanol fuel processor for proton exchange membrane fuel cell

NASA Astrophysics Data System (ADS)

Yang, Mei; Jiao, Fengjun; Li, Shulian; Li, Hengqiang; Chen, Guangwen

2015-08-01

A self-sustained, complete and miniaturized methanol fuel processor has been developed based on modular integration and microreactor technology. The fuel processor is comprised of one methanol oxidative reformer, one methanol combustor and one two-stage CO preferential oxidation unit. Microchannel heat exchanger is employed to recover heat from hot stream, miniaturize system size and thus achieve high energy utilization efficiency. By optimized thermal management and proper operation parameter control, the fuel processor can start up in 10 min at room temperature without external heating. A self-sustained state is achieved with H2 production rate of 0.99 Nm3 h-1 and extremely low CO content below 25 ppm. This amount of H2 is sufficient to supply a 1 kWe proton exchange membrane fuel cell. The corresponding thermal efficiency of whole processor is higher than 86%. The size and weight of the assembled reactors integrated with microchannel heat exchangers are 1.4 L and 5.3 kg, respectively, demonstrating a very compact construction of the fuel processor.

Monolithic crystalline cladding microstructures for efficient light guiding and beam manipulation in passive and active regimes

PubMed Central

Jia, Yuechen; Cheng, Chen; Vázquez de Aldana, Javier R.; Castillo, Gabriel R.; Rabes, Blanca del Rosal; Tan, Yang; Jaque, Daniel; Chen, Feng

2014-01-01

Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump of miniaturized waveguiding active structures offers a low-cost but intriguing solution for compact light-emitting devices. In this work, we demonstrate a novel family of three dimensional (3D) photonic microstructures monolithically integrated in a Nd:YAG laser crystal wafer. They are produced by the femtosecond laser writing, capable of simultaneous light waveguiding and beam manipulation. In these guiding systems, tailoring of laser modes by both passive/active beam splitting and ring-shaped transformation are achieved by an appropriate design of refractive index patterns. Integration of graphene thin-layer as saturable absorber in the 3D laser structures allows for efficient passive Q-switching of tailored laser radiations which may enable miniature waveguiding lasers for broader applications. Our results pave a way to construct complex integrated passive and active laser circuits in dielectric crystals by using femtosecond laser written monolithic photonic chips. PMID:25100561

Experimental investigation on the miniature mixed refrigerant cooler driven by a mini-compressor

NASA Astrophysics Data System (ADS)

Chen, Gaofei; Gong, Maoqiong; Wu, Yinong

2018-05-01

Three miniature Joule-Thomson cryogenic coolers and a testing set up were built to investigate the cooling performance in this work. Shell-and-tube heat exchanger and plate fin heat exchangers with rectangular micro channels were designed to achieve high specific surface area. The main processing technology of micro mixed refrigerant cooler (MMRC) was described. The design and fabrication processing of the plate fin heat exchangers were also described. The new developed micro plate-fin type heat exchanger shows high compactness with the specific heat surface larger than 1.0x104 m2/m3. The results of experimental investigations on miniature mixed refrigerant J-T cryogenic coolers driven by a Mini-Compressor were discussed. The performance evaluation and comparison of the three coolers was made to find out the features for each type of cooler. Expressions of refrigeration coefficient and exergy efficiency were pointed out. No-load temperature of about 112 K, and the cooling power of 4.0W at 118K with the input power of 120W is achieved. The exergy efficiency of the SJTC is 5.14%.

RMs1: qualification results of the rotary miniature Stirling cryocooler at Thales Cryogenics

NASA Astrophysics Data System (ADS)

Martin, Jean-Yves; Seguineau, Cédric; Van-Acker, Sébastien; Sacau, Mikel; Le Bordays, Julien; Etchanchu, Thierry; Vasse, Christophe; Abadie, Christian; Laplagne, Gilles; Benschop, Tonny

2017-05-01

The trend for miniaturized Integrated Dewar and Cooler Assemblies (IDCA) has been confirmed over the past few years with several mentions of a new generation of IR detector working at High Operating Temperature (HOT). This key technology enables the use of cryocooler with reduced needs of cryogenics power. As a consequence, miniaturized IDCA are the combination of a HOT IR detector coupled with a low-size, low-weight and low-power (SWaP) cryocooler. Thales Cryogenics has developed his own line of SWaP products. Qualification results on linear solution where shown last year. The current paper focuses on the latest results obtained on RMs1 prototypes, the new rotary SWaP cryocooler from Thales Cryogenics. Cryogenic performances and induced vibrations are presented. In a second part, progress is discussed on compactness and weight on one side, and on power consumption on the other side. It shows how the trade-off made between weight and power consumption could lead to an optimized solution at system level. At least, an update is made on the qualification status.

Design and evaluation of a miniature laser speckle imaging device to assess gingival health

PubMed Central

Regan, Caitlin; White, Sean M.; Yang, Bruce Y.; Takesh, Thair; Ho, Jessica; Wink, Cherie; Wilder-Smith, Petra; Choi, Bernard

2016-01-01

Abstract. Current methods used to assess gingivitis are qualitative and subjective. We hypothesized that gingival perfusion measurements could provide a quantitative metric of disease severity. We constructed a compact laser speckle imaging (LSI) system that could be mounted in custom-made oral molds. Rigid fixation of the LSI system in the oral cavity enabled measurement of blood flow in the gingiva. In vitro validation performed in controlled flow phantoms demonstrated that the compact LSI system had comparable accuracy and linearity compared to a conventional bench-top LSI setup. In vivo validation demonstrated that the compact LSI system was capable of measuring expected blood flow dynamics during a standard postocclusive reactive hyperemia and that the compact LSI system could be used to measure gingival blood flow repeatedly without significant variation in measured blood flow values (p<0.05). Finally, compact LSI system measurements were collected from the interdental papilla of nine subjects and compared to a clinical assessment of gingival bleeding on probing. A statistically significant correlation (ρ=0.53; p<0.005) was found between these variables, indicating that quantitative gingival perfusion measurements performed using our system may aid in the diagnosis and prognosis of periodontal disease. PMID:27787545

Design and evaluation of a miniature laser speckle imaging device to assess gingival health

NASA Astrophysics Data System (ADS)

Regan, Caitlin; White, Sean M.; Yang, Bruce Y.; Takesh, Thair; Ho, Jessica; Wink, Cherie; Wilder-Smith, Petra; Choi, Bernard

2016-10-01

Current methods used to assess gingivitis are qualitative and subjective. We hypothesized that gingival perfusion measurements could provide a quantitative metric of disease severity. We constructed a compact laser speckle imaging (LSI) system that could be mounted in custom-made oral molds. Rigid fixation of the LSI system in the oral cavity enabled measurement of blood flow in the gingiva. In vitro validation performed in controlled flow phantoms demonstrated that the compact LSI system had comparable accuracy and linearity compared to a conventional bench-top LSI setup. In vivo validation demonstrated that the compact LSI system was capable of measuring expected blood flow dynamics during a standard postocclusive reactive hyperemia and that the compact LSI system could be used to measure gingival blood flow repeatedly without significant variation in measured blood flow values (p<0.05). Finally, compact LSI system measurements were collected from the interdental papilla of nine subjects and compared to a clinical assessment of gingival bleeding on probing. A statistically significant correlation (ρ=0.53 p<0.005) was found between these variables, indicating that quantitative gingival perfusion measurements performed using our system may aid in the diagnosis and prognosis of periodontal disease.

Compact Two-step Laser Time-of-Flight Mass Spectrometer for in Situ Analyses of Aromatic Organics on Planetary Missions

NASA Technical Reports Server (NTRS)

Getty, Stephanie; Brickerhoff, William; Cornish, Timothy; Ecelberger, Scott; Floyd, Melissa

2012-01-01

RATIONALE A miniature time-of-flight mass spectrometer has been adapted to demonstrate two-step laser desorption-ionization (LOI) in a compact instrument package for enhanced organics detection. Two-step LDI decouples the desorption and ionization processes, relative to traditional laser ionization-desorption, in order to produce low-fragmentation conditions for complex organic analytes. Tuning UV ionization laser energy allowed control ofthe degree of fragmentation, which may enable better identification of constituent species. METHODS A reflectron time-of-flight mass spectrometer prototype measuring 20 cm in length was adapted to a two-laser configuration, with IR (1064 nm) desorption followed by UV (266 nm) postionization. A relatively low ion extraction voltage of 5 kV was applied at the sample inlet. Instrument capabilities and performance were demonstrated with analysis of a model polycyclic aromatic hydrocarbon, representing a class of compounds important to the fields of Earth and planetary science. RESULTS L2MS analysis of a model PAH standard, pyrene, has been demonstrated, including parent mass identification and the onset o(tunable fragmentation as a function of ionizing laser energy. Mass resolution m/llm = 380 at full width at half-maximum was achieved which is notable for gas-phase ionization of desorbed neutrals in a highly-compact mass analyzer. CONCLUSIONS Achieving two-step laser mass spectrometry (L2MS) in a highly-miniature instrument enables a powerful approach to the detection and characterization of aromatic organics in remote terrestrial and planetary applications. Tunable detection of parent and fragment ions with high mass resolution, diagnostic of molecular structure, is possible on such a compact L2MS instrument. Selectivity of L2MS against low-mass inorganic salt interferences is a key advantage when working with unprocessed, natural samples, and a mechanism for the observed selectivity is presented.

Microminiature rotary Stirling cryocooler for compact, lightweight, and low-power thermal imaging systems

NASA Astrophysics Data System (ADS)

Filis, Avishai; Bar Haim, Zvi; Pundak, Nachman; Broyde, Ramon

2009-05-01

Novel compact and low power consuming cooled infrared thermal imagers as used in gyro-stabilized payloads of miniature unmanned aerial vehicles, Thermal small arms sights and tactical night vision goggles often rely on integral rotary micro-miniature closed cycle Stirling cryogenic engines. Development of EPI Antimonides technology and optimization of MCT technology allowed decreasing in order of magnitudes the level of dark current in infrared detectors thus enabling an increase in the optimal focal plane temperature in excess of 95K while keeping the same radiometric performances as achieved at 77K using regular technologies. Maintaining focal plane temperature in the range of 95K to 110K instead of 77K improves the efficiency of Stirling thermodynamic cycle thus enlarging cooling power and enabling the development of a mini micro cooler similar to RICOR's K562S model which is three times smaller, lighter and more compact than a standard tactical cryocooler like RICOR's K508 model. This cooler also features a new type of ball bearings and internal components which were optimized to fit tight bulk constraints and maintain the required life span, while keeping a low level of vibration and noise signature. Further, the functions of management the brushless DC motor and temperature stabilization are delivered by the newly developed high performance sensorless digital controller. By reducing Dewar Detector thermal losses and increasing the focal plane temperature, longer life time operation is expected as was proved with RICOR's K508 model. Resulting from this development, the RICOR K562S model cryogenic engine consumes 1.2 - 3.0 WDC while operating in the closed loop mode and maintaining the typical focal plane arrays at 200-100K. This makes it compatible with very compact battery packages allowing further reduction of the overall thermal imager weight thus making it comparable with the compatible uncooled infrared thermal imager relying on a microbolometer detector in terms of power consumption and bulk.

Design optimization of a compact photonic crystal microcavity based on slow light and dispersion engineering for the miniaturization of integrated mode-locked lasers

NASA Astrophysics Data System (ADS)

Kemiche, Malik; Lhuillier, Jérémy; Callard, Ségolène; Monat, Christelle

2018-01-01

We exploit slow light (high ng) modes in planar photonic crystals in order to design a compact cavity, which provides an attractive path towards the miniaturization of near-infrared integrated fast pulsed lasers. By applying dispersion engineering techniques, we can design structures with a low dispersion, as needed by mode-locking operation. Our basic InP SiO2 heterostructure is robust and well suited to integrated laser applications. We show that an optimized 30 μm long cavity design yields 9 frequency-equidistant modes with a FSR of 178 GHz within a 11.5 nm bandwidth, which could potentially sustain the generation of optical pulses shorter than 700 fs. In addition, the numerically calculated quality factors of these modes are all above 10,000, making them suitable for reaching laser operation. Thanks to the use of a high group index (28), this cavity design is almost one order of magnitude shorter than standard rib-waveguide based mode-locked lasers. The use of slow light modes in planar photonic crystal based cavities thus relaxes the usual constraints that tightly link the device size and the quality (peak power, repetition rate) of the pulsed laser signal.

Small Scaffolds, Big Potential: Developing Miniature Proteins as Therapeutic Agents.

PubMed

Holub, Justin M

2017-09-01

Preclinical Research Miniature proteins are a class of oligopeptide characterized by their short sequence lengths and ability to adopt well-folded, three-dimensional structures. Because of their biomimetic nature and synthetic tractability, miniature proteins have been used to study a range of biochemical processes including fast protein folding, signal transduction, catalysis and molecular transport. Recently, miniature proteins have been gaining traction as potential therapeutic agents because their small size and ability to fold into defined tertiary structures facilitates their development as protein-based drugs. This research overview discusses emerging developments involving the use of miniature proteins as scaffolds to design novel therapeutics for the treatment and study of human disease. Specifically, this review will explore strategies to: (i) stabilize miniature protein tertiary structure; (ii) optimize biomolecular recognition by grafting functional epitopes onto miniature protein scaffolds; and (iii) enhance cytosolic delivery of miniature proteins through the use of cationic motifs that facilitate endosomal escape. These objectives are discussed not only to address challenges in developing effective miniature protein-based drugs, but also to highlight the tremendous potential miniature proteins hold for combating and understanding human disease. Drug Dev Res 78 : 268-282, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Stopband-Extended and Size-Miniaturized Low-Pass Filter Based on Interdigital Capacitor Loaded Hairpin Resonator with Four Transmission Zeros

NASA Astrophysics Data System (ADS)

Wu, Jia-Jia; Li, Lin

2018-04-01

In this paper, a compact low-pass filter (LPF) with wide stopband is proposed based on interdigital capacitor loaded hairpin resonator. The structure composed of an upper high-impedance transmission line, a middle interdigital capacitor, and a pair of inter-coupled symmetrical stepped-impedance stubs. Detailed investigation into this structure based on even-odd mode approach reveals that up to four transmission zeros can be generated and reallocated by choosing the proper circuit parameters. And owing to the aid of transmission zeros, the fabricated quasi-elliptic LPFs experimentally demonstrate a wide 20dB stopband from 1.4fc to 5.1fc using a compact size of only 0.005 λg2.

Development of a compact, rf-driven, pulsed ion source for neutron generation

NASA Astrophysics Data System (ADS)

Perkins, L. T.; Celata, C.; Lee, Y.; Leung, K. N.; Picard, D. S.; Vilaithong, R.; Williams, M. D.; Wutte, D.

1997-02-01

Lawrence Berkeley National Laboratory is currently developing a compact, sealed-accelerator-tube neutron generator capable of producing a neutron flux in the range of 109 to 1010 D-T neutrons per second. The ion source, a miniaturized variation of earlier radio-frequency (rf)-driven multicusp ion sources, is designed to fit within a ˜5 cm diameter borehole. Typical operating parameters include repetition rates up to 100 pps, with pulse widths between 10 and 80 μs (limited only by the available rf power supply) and source pressures as low as ˜5 mTorr. In this configuration, peak extractable hydrogen current densities exceeding 1180 mA/cm2 with H1+ yields over 94% having been achieved.

New SOFRADIR 10μm pixel pitch infrared products

NASA Astrophysics Data System (ADS)

Lefoul, X.; Pere-Laperne, N.; Augey, T.; Rubaldo, L.; Aufranc, Sébastien; Decaens, G.; Ricard, N.; Mazaleyrat, E.; Billon-Lanfrey, D.; Gravrand, Olivier; Bisotto, Sylvette

2014-10-01

Recent advances in miniaturization of IR imaging technology have led to a growing market for mini thermal-imaging sensors. In that respect, Sofradir development on smaller pixel pitch has made much more compact products available to the users. When this competitive advantage is mixed with smaller coolers, made possible by HOT technology, we achieved valuable reductions in the size, weight and power of the overall package. At the same time, we are moving towards a global offer based on digital interfaces that provides our customers simplifications at the IR system design process while freeing up more space. This paper discusses recent developments on hot and small pixel pitch technologies as well as efforts made on compact packaging solution developed by SOFRADIR in collaboration with CEA-LETI.

Far field focusing for a microwave patch antenna with composite substrate

NASA Astrophysics Data System (ADS)

Wan, Jian; Rybin, Oleg; Shulga, Sergey

2018-03-01

Modeling for a compact microwave antenna structure on base of a miniaturized rectangular patch antenna with composite substrate and magnetic superstrates is made in this study by using FDTD simulations. The resonant frequency of the antenna structure is supposed to be 15 GHz. The design of the antenna with composite substrate and without superstrate is made up by using the microwave miniaturization concept for rectangular patch antennas created by first author of this study. The optimal distance between the superstrate and antenna surface is found by using Fabry-Perot cavity theory as maximum values of power directivity and efficiency of the antenna is achieved. The comparative analysis with regard to some far and near field parameters of the above antenna structures and the antenna with dielectric substrate having same value of the relative permittivity is performed.

Recent advances in design and fabrication of on-chip micro-supercapacitors

NASA Astrophysics Data System (ADS)

Beidaghi, Majid; Wang, Chunlei

2012-06-01

Recent development in miniaturized electronic devices has increased the demand for power sources that are sufficiently compact and can potentially be integrated on a chip with other electronic components. Miniaturized electrochemical capacitors (EC) or micro-supercapacitors have great potential to complement or replace batteries and electrolytic capacitors in a variety of applications. Recently, we have developed several types of micro-supercapacitors with different structural designs and active materials. Carbon-Microelectromechanical Systems (C-MEMS) with three dimensional (3D) interdigital structures are employed both as electrode material for electric double layer capacitor (EDLC) or as three dimensional (3D) current collectors of pseudo-capacitive materials. More recently, we have also developed microsupercapacitor based on hybrid graphene and carbon nanotube interdigital structures. In this paper, the recent advances in design and fabrication of on-chip micro-supercapacitors are reviewed.

Investigation of the vibration and EMC characteristics of miniature Stirling electric coolers for space applications

NASA Astrophysics Data System (ADS)

Kondratjev, V.; Gostilo, V.; Owens, anb A.

2017-08-01

We present the results of an investigation into the detrimental effects that electromechanical coolers can have on the spectral performance of compact, large volume HPGe spectrometers for space applications. Both mechanical vibration and electromagnetic pickup effects were considered, as well as a comparative assessment between three miniature Stirling cycle coolers—two Ricor model K508 coolers and one Thales model RM3 cooler. In spite of the limited number of coolers tested, the following conclusions can be made. There are significant differences in the vibration characteristics not only between the various types of cooler but also between coolers of the same type. It was also found that compared to the noise induced by mechanical vibrations, electromagnetic interference emanating from the embedded controllers does not significantly impact the energy resolution of detectors.

An ultra-compact and low-power oven-controlled crystal oscillator design for precision timing applications.

PubMed

Lim, Jaehyun; Kim, Hyunsoo; Jackson, Thomas; Choi, Kyusun; Kenny, David

2010-09-01

A novel design for a chip-scale miniature oven-controlled crystal oscillator (OCXO) is presented. In this design, all the main components of an OCXO--consisting of an oscillator, a temperature sensor, a heater, and temperature-control circuitry--are integrated on a single CMOS chip. The OCXO package size can be reduced significantly with this design, because the resonator does not require a separate package and most of the circuitry is integrated on a single CMOS chip. Other characteristics such as power consumption and warm-up time are also improved. Two different types of quartz resonators, an AT-cut tab mesa-type quartz crystal and a frame enclosed resonator, allow miniaturization of the OCXO structure. Neither of these quartz resonator types requires a separate package inside the oven structure; therefore, they can each be directly integrated with the custom-designed CMOS chip. The miniature OCXO achieves a frequency stability of +/- 0.35 ppm with an AT-cut tab mesa-type quartz crystal in the temperature range of 0 °C to 60 °C. The maximum power consumption of this miniature OCXO is 1.2 W at start-up and 303 mW at steady state. The warm-up time to reach the steady state is 190 s. These results using the proposed design are better than or the same as high-frequency commercial OCXOs.

A Miniature Laser Desorption/Ionization Time-of-Flight Mass Spectrometer for in Situ Analysis of Mars Surface Composition and Identification of Hazard in Advance of Future Manned Exploration

NASA Technical Reports Server (NTRS)

Getty, S. A.; Brinckerhoff, W. B.; Arevalo, R. D.; Floyd, M. M.; Li, X.; Cornish, T.; Ecelberger, S. A.

2012-01-01

Future landed missions to Mars will be guided by two strategic directions: (1) sample return to Earth, for comprehensive compositional analyses, as recommended by the 2011 NRC Planetary Decadal Survey; and (2) preparation for human exploration in the 2030s and beyond, as laid out by US space policy. The resultant mission architecture will likely require high-fidelity in situ chemical/organic sample analyses within an extremely constrained resource envelope. Both science goals (e.g., MEPAG Goal 1, return sample selection, etc.) as well as identification of any potential toxic and biological hazards to humans, must be addressed. Over the past several years of instrument development, we have found that the adaptable, compact, and highly capable technique of laser desorption/ionization time-of-flight mass spectrometry (LD-TOF-MS) has significant potential to contribute substantially to these dual objectives. This concept thus addresses Challenge Area 1: instrumentation and Investigation Approaches.

Ice-Penetrating Robot for Scientific Exploration

NASA Technical Reports Server (NTRS)

Zimmerman, Wayne; Carsey, Frank; French, Lloyd

2007-01-01

The cryo-hydro integrated robotic penetrator system (CHIRPS) is a partially developed instrumentation system that includes a probe designed to deeply penetrate the European ice sheet in a search for signs of life. The CHIRPS could also be used on Earth for similar exploration of the polar ice caps especially at Lake Vostok in Antarctica. The CHIRPS probe advances downward by a combination of simple melting of ice (typically for upper, non-compacted layers of an ice sheet) or by a combination of melting of ice and pumping of meltwater (typically, for deeper, compacted layers). The heat and electric power for melting, pumping, and operating all of the onboard instrumentation and electronic circuitry are supplied by radioisotope power sources (RPSs) and thermoelectric converters energized by the RPSs. The instrumentation and electronic circuitry includes miniature guidance and control sensors and an advanced autonomous control system that has fault-management capabilities. The CHIRPS probe is about 1 m long and 15 cm in diameter. The RPSs generate a total thermal power of 1.8 kW. Initially, as this power melts the surrounding ice, a meltwater jacket about 1 mm thick forms around the probe. The center of gravity of the probe is well forward (down), so that the probe is vertically stabilized like a pendulum. Heat is circulated to the nose by means of miniature pumps and heat pipes. The probe melts ice to advance in a step-wise manner: Heat is applied to the nose to open up a melt void, then heat is applied to the side to allow the probe to slip down into the melt void. The melt void behind the probe is allowed to re-freeze. Four quadrant heaters on the nose and another four quadrant heaters on the rear (upper) surface of the probe are individually controllable for steering: Turning on two adjacent nose heaters on the nose and two adjacent heaters on the opposite side at the rear causes melt voids to form on opposing sides, such that the probe descends at an angle from vertical. This steering capability can be used to avoid debris trapped in the ice or to maneuver closer to a trapped object of scientific interest.

Advances in Miniaturized Instruments for Genomics

PubMed Central

2014-01-01

In recent years, a lot of demonstrations of the miniaturized instruments were reported for genomic applications. They provided the advantages of miniaturization, automation, sensitivity, and specificity for the development of point-of-care diagnostics. The aim of this paper is to report on recent developments on miniaturized instruments for genomic applications. Based on the mature development of microfabrication, microfluidic systems have been demonstrated for various genomic detections. Since one of the objectives of miniaturized instruments is for the development of point-of-care device, impedimetric detection is found to be a promising technique for this purpose. An in-depth discussion of the impedimetric circuits and systems will be included to provide total consideration of the miniaturized instruments and their potential application towards real-time portable imaging in the “-omics” era. The current excellent demonstrations suggest a solid foundation for the development of practical and widespread point-of-care genomic diagnostic devices. PMID:25114919

A compact, continuous-wave terahertz source based on a quantum-cascade laser and a miniature cryocooler.

PubMed

Richter, H; Greiner-Bär, M; Pavlov, S G; Semenov, A D; Wienold, M; Schrottke, L; Giehler, M; Hey, R; Grahn, H T; Hübers, H-W

2010-05-10

We report on the development of a compact, easy-to-use terahertz radiation source, which combines a quantum-cascade laser (QCL) operating at 3.1 THz with a compact, low-input-power Stirling cooler. The QCL, which is based on a two-miniband design, has been developed for high output and low electrical pump power. The amount of generated heat complies with the nominal cooling capacity of the Stirling cooler of 7 W at 65 K with 240 W of electrical input power. Special care has been taken to achieve a good thermal coupling between the QCL and the cold finger of the cooler. The whole system weighs less than 15 kg including the cooler and power supplies. The maximum output power is 8 mW at 3.1 THz. With an appropriate optical beam shaping, the emission profile of the laser is fundamental Gaussian. The applicability of the system is demonstrated by imaging and molecular-spectroscopy experiments. (c) 2010 Optical Society of America.

A Compact, Broadband Antenna for Planetary Surface-to-Surface Wireless Communications

NASA Technical Reports Server (NTRS)

Barr, Philip; Zaman, Afroz; Miranda, Felix

2006-01-01

The Compact Microstrip Monopole Antenna (CMMA) is a novel antenna design that combines a microstrip patch antenna with a three-dimensional structure to attain a highly directive, broadband, compact antenna. A Tri-Lobed Patch (TLP) was designed to minimize the patch's area while reducing the antenna's operating frequency. A Grounding Wall (GW) connects the patch to the ground plane and a Vertical Enclosure Wall (VEW) extends up away from portions of the patch's perimeter. This VEW supplies the antenna with a higher directivity in the radial direction as well as reduces the operating frequency. The CMMA was designed to operate at 2.23 GHz, but experimental results have shown this antenna resonates at 2.05 GHz which is on the order of approximately Lambda(sub o)/11.6 with respect to the antenna's largest dimension, with a directivity and bandwidth of 6.0 dBi, and 130 MHz (6.3 percent), respectively. This miniature, radially emitting antenna makes the CMMA attractive for planetary-based surface-to-surface communications.

Application of a compact diode pumped solid-state laser source for quantitative laser-induced breakdown spectroscopy analysis of steel

NASA Astrophysics Data System (ADS)

Tortschanoff, Andreas; Baumgart, Marcus; Kroupa, Gerhard

2017-12-01

Laser-induced breakdown spectroscopy (LIBS) technology holds the potential for onsite real-time measurements of steel products. However, for a mobile and robust LIBS measurement system, an adequate small and ruggedized laser source is a key requirement. In this contribution, we present tests with our compact high-power laser source, which, initially, was developed for ignition applications. The CTR HiPoLas® laser is a robust diode pumped solid-state laser with a passive Q-switch with dimensions of less than 10 cm3. The laser generates 2.5-ns pulses with 30 mJ at a maximum continuous repetition rate of about 30 Hz. Feasibility of LIBS experiments with the laser source was experimentally verified with steel samples. The results show that the laser with its current optical output parameters is very well-suited for LIBS measurements. We believe that the miniaturized laser presented here will enable very compact and robust portable high-performance LIBS systems.

Serum C-reactive protein concentrations in healthy Miniature Schnauzer dogs.

PubMed

Wong, Valerie M; Kidney, Beverly A; Snead, Elisabeth C R; Myers, Sherry L; Jackson, Marion L

2011-09-01

C-reactive protein (CRP) is a sensitive marker for inflammation in people and dogs. In people, an association between CRP concentration and atherosclerosis has been reported. Atherosclerosis is rare in dogs, but the Miniature Schnauzer breed may be at increased risk for developing this vascular disease. It is not known if CRP concentrations in Miniature Schnauzer dogs differ from those in other dog breeds. Our objectives were to validate an automated human CRP assay for measuring CRP in dogs and compare CRP concentrations in healthy Miniature Schnauzer dogs with those in non-Miniature Schnauzer breeds. Sera from 37 non-Miniature Schnauzer dogs with inflammatory disease were pooled and used to validate a human CRP immunoturbidimetric assay for measuring canine CRP. Blood was collected from 20 healthy Miniature Schnauzer dogs and 41 healthy dogs of other breeds. Median serum CRP concentration of healthy Miniature Schnauzer dogs was compared with that of healthy non-Miniature Schnauzer dogs. The human CRP assay measured CRP reliably with linearity between 0 and 20 mg/L. CRP concentration for healthy Miniature Schnauzer dogs (median 4.0 mg/L, minimum-maximum 0-18.2 mg/L) was significantly higher than for the healthy non-Miniature Schnauzer dogs (median 0.1 mg/L, minimum-maximum 0-10.7 mg/L); 17 of the 20 Miniature Schnauzer dogs had values that overlapped with those of the non-Miniature Schnauzer dogs. Median CRP concentration of Miniature Schnauzer dogs was slightly higher than that of other breeds of dogs. A relationship between higher CRP concentration in Miniature Schnauzer dogs and idiopathic hyperlipidemia, pancreatitis, and possible increased risk for atherosclerosis remains to be determined. ©2011 American Society for Veterinary Clinical Pathology.

Improving the spectral resolution of flat-field concave grating miniature spectrometers by dividing a wide spectral band into two narrow ones.

PubMed

Zhou, Qian; Pang, Jinchao; Li, Xinghui; Ni, Kai; Tian, Rui

2015-11-10

In this study, a new flat-field concave grating miniature spectrometer is proposed with improved resolution across a wide spectral band. A mirror is added to a conventional concave grating spectrometer and placed near the existing detector array, allowing a wide spectral band to be divided into two adjacent subspectral bands. One of these bands is directly detected by the detector, and the other is indirectly analyzed by the same detector after being reflected by the mirror. These two subspectral bands share the same entrance slit, concave grating, and detector, which allows for a compact size, while maintaining an improved spectral resolution across the entire spectral band. The positions of the mirror and other parameters of the spectrometer are designed by a computer procedure and the optical design software ZEMAX. Simulation results show that the resolution of this kind of flat-field concave grating miniature spectrometer is better than 1.6 nm across a spectral band of 700 nm. Experiments based on three laser sources reveal that the measured resolutions are comparable to the simulated ones, with a maximum relative error between them of less than 19%.

A Cascaded Self-Similar Rat-Race Hybrid Coupler Architecture and its Compact Ka-Band Implementation

DTIC Science & Technology

2017-03-01

real-estate and limit the system-level performance, including bandwidth, gain, and energy - efficiency. These many challenges are positioning passive...and are used in numerous RF/mm-wave systems for radar and wireless communications. Although a Marchand balun covers a large bandwidth, it is...requires multiple λ/4 transmission lines (t-lines), making its on-chip designs very costly even for RF/mm-wave bands. Reported miniaturized rat-race

Miniature and micro spectrometers market: who is going to catch the value?

NASA Astrophysics Data System (ADS)

Bouyé, Clémentine; d'Humières, Benoît

2017-02-01

The market of miniature and micro spectrometers is evolving fast. The technology is getting ever smaller and cheaper while keeping high performances. The market is attracting new players: spin-offs from major research institutes, large companies outside the classic spectroscopy market, software providers with innovative analytical solutions, … The goal of this involvement is to bring spectroscopy closer to the end-users and provide spectrometers able to operate on-field or in-line. The high potential of compact spectrometers is recognized for a wide variety of applications: chemistry, pharmaceutics, agro-food, agriculture, forensics, healthcare, consumer applications, … But its emergence as a large volume market faces a major bottleneck. Each application implies specific processes and analyses and specific parameters to control, i.e. a specific interpretation of the raw spectra in order to provide information usable by nonphotonic experts. Who is going to pay for that adaptation effort? Are there ways for reducing the adaptation costs, by means of selflearning algorithms and/or flexible and easily adaptable sensors? In other words, who is going to catch the value? In this article, we will investigate the potential of each major industrial application market and provide market data. We will also wonder, what are the strengths and weaknesses of the different players - spectrometer manufacturers, algorithms developers, full-systems providers, … - to catch the value of the compact spectrometer market.

NASA Tech Briefs, December 2009

NASA Technical Reports Server (NTRS)

2009-01-01

Topics include: A Deep Space Network Portable Radio Science Receiver; Detecting Phase Boundaries in Hard-Sphere Suspensions; Low-Complexity Lossless and Near-Lossless Data Compression Technique for Multispectral Imagery; Very-Long-Distance Remote Hearing and Vibrometry; Using GPS to Detect Imminent Tsunamis; Stream Flow Prediction by Remote Sensing and Genetic Programming; Pilotless Frame Synchronization Using LDPC Code Constraints; Radiometer on a Chip; Measuring Luminescence Lifetime With Help of a DSP; Modulation Based on Probability Density Functions; Ku Telemetry Modulator for Suborbital Vehicles; Photonic Links for High-Performance Arraying of Antennas; Reconfigurable, Bi-Directional Flexfet Level Shifter for Low-Power, Rad-Hard Integration; Hardware-Efficient Monitoring of I/O Signals; Video System for Viewing From a Remote or Windowless Cockpit; Spacesuit Data Display and Management System; IEEE 1394 Hub With Fault Containment; Compact, Miniature MMIC Receiver Modules for an MMIC Array Spectrograph; Waveguide Transition for Submillimeter-Wave MMICs; Magnetic-Field-Tunable Superconducting Rectifier; Bonded Invar Clip Removal Using Foil Heaters; Fabricating Radial Groove Gratings Using Projection Photolithography; Gratings Fabricated on Flat Surfaces and Reproduced on Non-Flat Substrates; Method for Measuring the Volume-Scattering Function of Water; Method of Heating a Foam-Based Catalyst Bed; Small Deflection Energy Analyzer for Energy and Angular Distributions; Polymeric Bladder for Storing Liquid Oxygen; Pyrotechnic Simulator/Stray-Voltage Detector; Inventions Utilizing Microfluidics and Colloidal Particles; RuO2 Thermometer for Ultra-Low Temperatures; Ultra-Compact, High-Resolution LADAR System for 3D Imaging; Dual-Channel Multi-Purpose Telescope; Objective Lens Optimized for Wavefront Delivery, Pupil Imaging, and Pupil Ghosting; CMOS Camera Array With Onboard Memory; Quickly Approximating the Distance Between Two Objects; Processing Images of Craters for Spacecraft Navigation; Adaptive Morphological Feature-Based Object Classifier for a Color Imaging System; Rover Slip Validation and Prediction Algorithm; Safety and Quality Training Simulator; Supply-Chain Optimization Template; Algorithm for Computing Particle/Surface Interactions; Cryogenic Pupil Alignment Test Architecture for Aberrated Pupil Images; and Thermal Transport Model for Heat Sink Design.

Compact soft x-ray multichord camera: Design and initial operation

NASA Astrophysics Data System (ADS)

Franz, P.; Gadani, G.; Pasqualotto, R.; Marrelli, L.; Martin, P.; Spizzo, G.; Brunsell, P.; Chapman, B. E.; Paganucci, F.; Rossetti, P.; Xiao, C.

2003-03-01

A compact and low cost diagnostic for spatially resolved measurements of soft x-ray or total radiation emission has been designed and realized to be flexibly applied to different plasma physics experiments. Its reduced size (outer diameter=35 mm) makes it suited to a variety of devices. The line integrated emissivity (brightness) has been measured along up to 20 lines of sight, using an array of miniaturized silicon photodiodes. Preliminary prototypes of the diagnostic have been installed in the Madison Symmetric Torus reversed field pinch (RFP) device at University of Wisconsin and in the EXTRAP T2 RFP device at the Royal Institute of Technology in Stockholm. Application of the diagnostic to a gas-fed (argon, helium) magnetoplasma dynamic thruster (MPDT) with an external magnetic field will also be discussed.

Double-clad photonic crystal fiber coupler for compact nonlinear optical microscopy imaging.

PubMed

Fu, Ling; Gu, Min

2006-05-15

A 1 x 2 double-clad photonic crystal fiber coupler is fabricated by the fused tapered method, showing a low excess loss of 1.1 dB and a splitting ratio of 97/3 over the entire visible and near-infrared wavelength range. In addition to the property of splitting the laser power, the double-clad feature of the coupler facilitates the separation of a near-infrared single-mode beam from a visible multimode beam, which is ideal for nonlinear optical microscopy imaging. In conjunction with a gradient-index lens, this coupler is used to construct a miniaturized microscope based on two-photon fluorescence and second-harmonic generation. Three-dimensional nonlinear optical images demonstrate potential applications of the coupler to compact all-fiber and nonlinear optical microscopy and endoscopy.

An efficient miniature 120 Hz pulse tube cryocooler using high porosity regenerator material

NASA Astrophysics Data System (ADS)

Yu, Huiqin; Wu, Yinong; Ding, Lei; Jiang, Zhenhua; Liu, Shaoshuai

2017-12-01

A 1.22 kg coaxial miniature pulse tube cryocooler (MPTC) has been fabricated and tested in our laboratory to provide cooling for cryogenic applications demanding compactness, low mass and rapid cooling rate. The geometrical parameters of regenerator, pulse tube and phase shifter are optimized. The investigation demonstrates that using higher mesh number and thinner wire diameter of stainless steel screen (SSS) can promote the coefficient of performance (COP) when the MPTC operates at 120 Hz. In this study, the 604 mesh SSS with 17 μm diameter of mesh wire is constructed as filler of regenerator. The experimental results show the MPTC operating at 120 Hz achieves a no-load temperature of 53.5 K with 3.8 MPa charging pressure, and gets a cooling power of 2 W at 80 K with 55 W input electric power which has a relative Carnot efficiency of 9.68%.

Guided post-acceleration of laser-driven ions by a miniature modular structure

PubMed Central

Kar, Satyabrata; Ahmed, Hamad; Prasad, Rajendra; Cerchez, Mirela; Brauckmann, Stephanie; Aurand, Bastian; Cantono, Giada; Hadjisolomou, Prokopis; Lewis, Ciaran L. S.; Macchi, Andrea; Nersisyan, Gagik; Robinson, Alexander P. L.; Schroer, Anna M.; Swantusch, Marco; Zepf, Matt; Willi, Oswald; Borghesi, Marco

2016-01-01

All-optical approaches to particle acceleration are currently attracting a significant research effort internationally. Although characterized by exceptional transverse and longitudinal emittance, laser-driven ion beams currently have limitations in terms of peak ion energy, bandwidth of the energy spectrum and beam divergence. Here we introduce the concept of a versatile, miniature linear accelerating module, which, by employing laser-excited electromagnetic pulses directed along a helical path surrounding the laser-accelerated ion beams, addresses these shortcomings simultaneously. In a proof-of-principle experiment on a university-scale system, we demonstrate post-acceleration of laser-driven protons from a flat foil at a rate of 0.5 GeV m−1, already beyond what can be sustained by conventional accelerator technologies, with dynamic beam collimation and energy selection. These results open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications. PMID:27089200

Mathematical Simulation for Integrated Linear Fresnel Spectrometer Chip

NASA Technical Reports Server (NTRS)

Park, Yeonjoon; Yoon, Hargoon; Lee, Uhn; King, Glen C.; Choi, Sang H.

2012-01-01

A miniaturized solid-state optical spectrometer chip was designed with a linear gradient-gap Fresnel grating which was mounted perpendicularly to a sensor array surface and simulated for its performance and functionality. Unlike common spectrometers which are based on Fraunhoffer diffraction with a regular periodic line grating, the new linear gradient grating Fresnel spectrometer chip can be miniaturized to a much smaller form-factor into the Fresnel regime exceeding the limit of conventional spectrometers. This mathematical calculation shows that building a tiny motionless multi-pixel microspectrometer chip which is smaller than 1 cubic millimter of optical path volume is possible. The new Fresnel spectrometer chip is proportional to the energy scale (hc/lambda), while the conventional spectrometers are proportional to the wavelength scale (lambda). We report the theoretical optical working principle and new data collection algorithm of the new Fresnel spectrometer to build a compact integrated optical chip.

Compact Micromachined Bandpass Filters for Infrared Planetary Spectroscopy

NASA Technical Reports Server (NTRS)

Brown, Ari D.; Aslam, Shahid; Chervenak, James A.; Huang, Wei-Chung; Merrell, Willie; Quijada, Manuel

2011-01-01

The thermal instrument strawman payload of the Jupiter Europa Orbiter on the Europa Jupiter Science Mission will map out thermal anomalies, the structure, and atmospheric conditions of Europa and Jupiter within the 7-100 micron spectral range. One key requirement for the payload is that the mass cannot exceed 3.7 kg. Consequently, a new generation of light-weight miniaturized spectrometers needs to be developed. On the path toward developing these spectrometers is development of ancillary miniaturized spectroscopic components. In this paper, we present a strategy for making radiation hard and low mass FIR band pass metal mesh filters. Our strategy involves using MEMS-based fabrication techniques, which will permit the quasi-optical filter structures to be made with micron-scale precision. This will enable us to achieve tight control over both the pass band of the filter and the micromachined silicon support structure architecture, which will facilitate integration of the filters for a variety of applications.

Miniature Fourier transform spectrometer with a dual closed-loop controlled electrothermal micromirror.

PubMed

Han, Fengtian; Wang, Wei; Zhang, Xiaoyang; Xie, Huikai

2016-10-03

A large piston-displacement electrothermal micromirror with closed-loop control of both piston scan and tilting of the mirror plate is demonstrated for use in a miniature Fourier transform spectrometer. Constant scan velocity in an ultra large piston scan range has been demonstrated by the proposed closed-loop piston control scheme which can be easily implemented without considerably increasing system complexity. The experimental results show that the usable linear scan range generated by the micromirror has been extended up to 505 μm. The measured spectral resolution in a compact spectrometer reaches 20 cm^-1, or 0.57 nm at 532 nm wavelength. Compared to other presented systems, this microspectrometer will benefit from the closed-loop thermal actuator approach utilizing both the piston servo and tilt control to provide more consistent spectral response, improved spectral resolution and enhanced robustness to disturbances.

A compact LWIR imaging spectrometer with a variable gap Fabry-Perot interferometer

NASA Astrophysics Data System (ADS)

Zhang, Fang; Gao, Jiaobo; Wang, Nan; Zhao, Yujie; Zhang, Lei; Gao, Shan

2017-02-01

Fourier transform spectroscopy is a widely employed method for obtaining spectra, with applications ranging from the desktop to remote sensing. The long wave infrared (LWIR) interferometric spectral imaging system is always with huge volume and large weight. In order to miniaturize and light the instrument, a new method of LWIR spectral imaging system based on a variable gap Fabry-Perot (FP) interferometer is researched. With the system working principle analyzed, theoretically, it is researched that how to make certain the primary parameter, such as, the reflectivity of the two interferometric cavity surfaces, field of view (FOV) and f-number of the imaging lens. A prototype is developed and a good experimental result of CO2 laser is obtained. The research shows that besides high throughput and high spectral resolution, the advantage of miniaturization is also simultaneously achieved in this method.

Testing the Binary Black Hole Nature of a Compact Binary Coalescence

NASA Astrophysics Data System (ADS)

Krishnendu, N. V.; Arun, K. G.; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

Testing the Binary Black Hole Nature of a Compact Binary Coalescence.

PubMed

Krishnendu, N V; Arun, K G; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

Design, assembly, and optical bench testing of a high-numerical-aperture miniature injection-molded objective for fiber-optic confocal reflectance microscopy.

PubMed

Chidley, Matthew D; Carlson, Kristen D; Richards-Kortum, Rebecca R; Descour, Michael R

2006-04-10

The design, analysis, assembly methods, and optical-bench test results for a miniature injection-molded plastic objective lens used in a fiber-optic confocal reflectance microscope are presented. The five-lens plastic objective was tested as a stand-alone optical system before its integration into a confocal microscope for in vivo imaging of cells and tissue. Changing the spacing and rotation of the individual optical elements can compensate for fabrication inaccuracies and improve performance. The system performance of the miniature objective lens is measured by use of an industry-accepted slanted-edge modulation transfer function (MTF) metric. An estimated Strehl ratio of 0.61 and a MTF value of 0.66 at the fiber-optic bundle Nyquist frequency have been obtained. The optical bench testing system is configured to permit interactive optical alignment during testing to optimize performance. These results are part of an effort to demonstrate the manufacturability of low-cost, high-performance biomedical optics for high-resolution in vivo imaging. Disposable endoscopic microscope objectives could help in vivo confocal microscopy technology mature to permit wide-scale clinical screening and detection of early cancers and precancerous lesions.

Multi-Evaporator Miniature Loop Heat Pipe for Small Spacecraft Thermal Control. Part 1; New Technologies and Validation Approach

NASA Technical Reports Server (NTRS)

Ku, Jentung; Ottenstein, Laura; Douglas, Donya; Hoang, Triem

2010-01-01

Under NASA s New Millennium Program Space Technology 8 (ST 8) Project, four experiments Thermal Loop, Dependable Microprocessor, SAILMAST, and UltraFlex - were conducted to advance the maturity of individual technologies from proof of concept to prototype demonstration in a relevant environment , i.e. from a technology readiness level (TRL) of 3 to a level of 6. This paper presents the new technologies and validation approach of the Thermal Loop experiment. The Thermal Loop is an advanced thermal control system consisting of a miniature loop heat pipe (MLHP) with multiple evaporators and multiple condensers designed for future small system applications requiring low mass, low power, and compactness. The MLHP retains all features of state-of-the-art loop heat pipes (LHPs) and offers additional advantages to enhance the functionality, performance, versatility, and reliability of the system. Details of the thermal loop concept, technical advances, benefits, objectives, level 1 requirements, and performance characteristics are described. Also included in the paper are descriptions of the test articles and mathematical modeling used for the technology validation. An MLHP breadboard was built and tested in the laboratory and thermal vacuum environments for TRL 4 and TRL 5 validations, and an MLHP proto-flight unit was built and tested in a thermal vacuum chamber for the TRL 6 validation. In addition, an analytical model was developed to simulate the steady state and transient behaviors of the MLHP during various validation tests. Capabilities and limitations of the analytical model are also addressed.

180-GHz I-Q Second Harmonic Resistive Mixer MMIC

NASA Technical Reports Server (NTRS)

Kangaslahti, Pekka P.; Lai, Richard; Mei, Xiaobing

2010-01-01

An indium phosphide MMIC (monolithic microwave integrated circuit) mixer was developed, processed, and tested in the NGC 35-nm-gate-length HEMT (high electron mobility transistor) process. This innovation is very compact in size and operates with very low LO power. Because it is a resistive mixer, this innovation does not require DC power. This is an enabling technology for the miniature receiver modules for the GeoSTAR instrument, which is the only viable option for the NRC decadal study mission PATH.

Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues.

PubMed

Sung, Kung-Bin; Liang, Chen; Descour, Michael; Collier, Tom; Follen, Michele; Richards-Kortum, Rebecca

2002-10-01

We have built a fiber-optic confocal reflectance microscope capable of imaging human tissues in near real time. Miniaturization of the objective lens and the mechanical components for positioning and axially scanning the objective enables the device to be used in inner organs of the human body. The lateral resolution is 2 micrometers and axial resolution is 10 micrometers. Confocal images of fixed tissue biopsies and the human lip in vivo have been obtained at 15 frames/s without any fluorescent stains. Both cell morphology and tissue architecture can be appreciated from images obtained with this microscope.

NASA Tech Briefs, July 2008

NASA Technical Reports Server (NTRS)

2008-01-01

Topics covered include: Torque Sensor Based on Tunnel-Diode Oscillator; Shaft-Angle Sensor Based on Tunnel-Diode Oscillator; Ground Facility for Vicarious Calibration of Skyborne Sensors; Optical Pressure-Temperature Sensor for a Combustion Chamber; Impact-Locator Sensor Panels; Low-Loss Waveguides for Terahertz Frequencies; MEMS/ECD Method for Making Bi(2-x)Sb(x)Te3 Thermoelectric Devices; Low-Temperature Supercapacitors; Making a Back-Illuminated Imager with Back-Side Contact and Alignment Markers; Compact, Single-Stage MMIC InP HEMT Amplifier; Nb(x)Ti(1-x)N Superconducting-Nanowire Single-Photon Detectors; Improved Sand-Compaction Method for Lost-Foam Metal Casting; Improved Probe for Evaluating Compaction of Mold Sand; Polymer-Based Composite Catholytes for Li Thin-Film Cells; Using ALD To Bond CNTs to Substrates and Matrices; Alternating-Composition Layered Ceramic Barrier Coatings; Variable-Structure Control of a Model Glider Airplane; Axial Halbach Magnetic Bearings; Compact, Non-Pneumatic Rock-Powder Samplers; Biochips Containing Arrays of Carbon-Nanotube Electrodes; Nb(x)Ti(1-x)N Superconducting-Nanowire Single-Photon Detectors; Neon as a Buffer Gas for a Mercury-Ion Clock; Miniature Incandescent Lamps as Fiber-Optic Light Sources; Bidirectional Pressure-Regulator System; and Prism Window for Optical Alignment. Single-Grid-Pair Fourier Telescope for Imaging in Hard-X Rays and gamma Rays Range-Gated Metrology with Compact Optical Head Lossless, Multi-Spectral Data Compressor for Improved Compression for Pushbroom-Typetruments.

Development of a linear compressor for compact 2 K Gifford- McMahon cryocoolers

NASA Astrophysics Data System (ADS)

Hiratsuka, Y.

2015-12-01

Recently, a new, compact Gifford-McMahon (GM) cryocooler for cooling superconducting single photon detectors (SSPD) has been developed at Sumitomo Heavy Industries, Ltd. (SHI) [1, 2]. The objective is to reduce the total height of the expander by 33% relative to the existing RDK-101 GM expander and to reduce the total volume of the compressor unit by 50% relative to the existing CNA-11 compressor. In addition, considering the targeted cooling application, we set the design temperature targets of the first and the second stages to 1 W and 20 mW of heat load at 60 K and 2.3 K, respectively. Although optimization of the internal components is one way to miniaturize the volume of the compressor unit, major design changes are required because the volume of the adsorber and the oil separator is almost the same as the volume of the compressor capsule. Thus, one approach is to develop a non-lubricated compressor, such as a valved linear compressor. An experimental unit of a valved linear compressor was designed and built, and preliminary experiments were conducted. Under no-load condition, a low temperature of 2.19 K has been achieved. With 1 W and 14 mW heat load, the temperature is 48 K at the first stage and 2.3 K at the second stage, with an input power of about 1.2 KW. The detailed experimental results will be discussed in this paper.

High performance infrared fast cooled detectors for missile applications

NASA Astrophysics Data System (ADS)

Reibel, Yann; Espuno, Laurent; Taalat, Rachid; Sultan, Ahmad; Cassaigne, Pierre; Matallah, Noura

2016-05-01

SOFRADIR was selected in the late 90's for the production of 320×256 MW detectors for major European missile programs. This experience has established our company as a key player in the field of missile programs. SOFRADIR has since developed a vast portfolio of lightweight, compact and high performance JT-based solutions for missiles. ALTAN is a 384x288 Mid Wave infrared detector with 15μm pixel pitch, and is offered in a miniature ultra-fast Joule- Thomson cooled Dewar. Since Sofradir offers both Indium Antimonide (InSb) and Mercury Cadmium Telluride technologies (MCT), we are able to deliver the detectors best suited to customers' needs. In this paper we are discussing different figures of merit for very compact and innovative JT-cooled detectors and are highlighting the challenges for infrared detection technologies.

SpiderSpec: a low-cost compact colorimeter with IoT functionality

NASA Astrophysics Data System (ADS)

Mignani, Anna G.; Mencaglia, Andrea A.; Baldi, Massimo; Ciaccheri, Leonardo

2015-07-01

A miniaturized device for colorimetry is presented that utilizes a LED array for illumination and a compact spectrometer for detection. It can be battery-powered, operated locally as a stand-alone device, or connected via wi-fi to the internet. It has potentials to be remotely operated by means of a tablet or a smartphone. In practice, it consists of a low-cost hardware configuration that is adaptable via software to the user's most varied requests, as a spectroscopic platform appropriate for a variety of applications. The hardware and software modules can be designed with different performances, complexities and costs, with the aim of making the colorimeter a device for Internet-of-Things use. It will be suitable for a selected range of consumer applications, as well as for targeted industrial, environmental, and food applications.

Camera-based micro interferometer for distance sensing

NASA Astrophysics Data System (ADS)

Will, Matthias; Schädel, Martin; Ortlepp, Thomas

2017-12-01

Interference of light provides a high precision, non-contact and fast method for measurement method for distances. Therefore this technology dominates in high precision systems. However, in the field of compact sensors capacitive, resistive or inductive methods dominates. The reason is, that the interferometric system has to be precise adjusted and needs a high mechanical stability. As a result, we have usual high-priced complex systems not suitable in the field of compact sensors. To overcome these we developed a new concept for a very small interferometric sensing setup. We combine a miniaturized laser unit, a low cost pixel detector and machine vision routines to realize a demonstrator for a Michelson type micro interferometer. We demonstrate a low cost sensor smaller 1cm3 including all electronics and demonstrate distance sensing up to 30 cm and resolution in nm range.

Distribution of compact object mergers around galaxies

NASA Astrophysics Data System (ADS)

Bulik, T.; Belczyński, K.; Zbijewski, W.

1999-09-01

Compact object mergers are one of the favoured models of gamma ray bursts (GRB). Using a binary population synthesis code we calculate properties of the population of compact object binaries; e.g. lifetimes and velocities. We then propagate them in galactic potentials and find their distribution in relation to the host.

Comprehensive helicopter rotor instrumentation - A retrofit approach using miniature transducers

NASA Technical Reports Server (NTRS)

Jacklin, Stephen A.; Mort, Ray; Morrison, Dwayne

1992-01-01

This paper reports an approach used to retrofit a set of full-scale main rotor blades with 290 miniature pressure transducers, 46 strain gages, and 24 miniature accelerometers. Normally, in order to avoid disturbing the aerodynamics of the rotor flow field, the pressure instrumentation must be integrally built into the body of the rotor blades. However, using a method developed with NASA, miniature pressure transducers are mounted to the blade exterior surface without degrading the quality of the blade aerodynamics. Moreover, it is estimated that this approach reduced costs by more than 50 percent over building a set of pressure instrumented blades. The aerodynamic measurement objectives are presented as are instrumentation design considerations, type of instrumentation used, assembly process, and the installed instrumentation characteristics.

Scalable NMR spectroscopy with semiconductor chips

PubMed Central

Ha, Dongwan; Paulsen, Jeffrey; Sun, Nan; Song, Yi-Qiao; Ham, Donhee

2014-01-01

State-of-the-art NMR spectrometers using superconducting magnets have enabled, with their ultrafine spectral resolution, the determination of the structure of large molecules such as proteins, which is one of the most profound applications of modern NMR spectroscopy. Many chemical and biotechnological applications, however, involve only small-to-medium size molecules, for which the ultrafine resolution of the bulky, expensive, and high-maintenance NMR spectrometers is not required. For these applications, there is a critical need for portable, affordable, and low-maintenance NMR spectrometers to enable in-field, on-demand, or online applications (e.g., quality control, chemical reaction monitoring) and co-use of NMR with other analytical methods (e.g., chromatography, electrophoresis). As a critical step toward NMR spectrometer miniaturization, small permanent magnets with high field homogeneity have been developed. In contrast, NMR spectrometer electronics capable of modern multidimensional spectroscopy have thus far remained bulky. Complementing the magnet miniaturization, here we integrate the NMR spectrometer electronics into 4-mm2 silicon chips. Furthermore, we perform various multidimensional NMR spectroscopies by operating these spectrometer electronics chips together with a compact permanent magnet. This combination of the spectrometer-electronics-on-a-chip with a permanent magnet represents a useful step toward miniaturization of the overall NMR spectrometer into a portable platform. PMID:25092330

Miniaturized pulsed laser source for time-domain diffuse optics routes to wearable devices

NASA Astrophysics Data System (ADS)

Di Sieno, Laura; Nissinen, Jan; Hallman, Lauri; Martinenghi, Edoardo; Contini, Davide; Pifferi, Antonio; Kostamovaara, Juha; Mora, Alberto Dalla

2017-08-01

We validate a miniaturized pulsed laser source for use in time-domain (TD) diffuse optics, following rigorous and shared protocols for performance assessment of this class of devices. This compact source (12×6 mm2) has been previously developed for range finding applications and is able to provide short, high energy (˜100 ps, ˜0.5 nJ) optical pulses at up to 1 MHz repetition rate. Here, we start with a basic level laser characterization with an analysis of suitability of this laser for the diffuse optics application. Then, we present a TD optical system using this source and its performances in both recovering optical properties of tissue-mimicking homogeneous phantoms and in detecting localized absorption perturbations. Finally, as a proof of concept of in vivo application, we demonstrate that the system is able to detect hemodynamic changes occurring in the arm of healthy volunteers during a venous occlusion. Squeezing the laser source in a small footprint removes a key technological bottleneck that has hampered so far the realization of a miniaturized TD diffuse optics system, able to compete with already assessed continuous-wave devices in terms of size and cost, but with wider performance potentialities, as demonstrated by research over the last two decades.

Compact and broadband antenna based on a step-shaped metasurface.

PubMed

Li, Ximing; Yang, Jingjing; Feng, Yun; Yang, Meixia; Huang, Ming

2017-08-07

A metasurface (MS) is highly useful for improving the performance of patch antennae and reducing their size due to their inherent and unique electromagnetic properties. In this paper, a compact and broadband antenna based on a step-shaped metasurface (SMS) at an operating frequency of 4.3 GHz is presented, which is fed by a planar monopole and enabled by selecting an SMS with high selectivity. The SMS consists of an array of metallic step-shaped unit cells underneath the monopole, which provide footprint miniaturization and bandwidth expansion. Numerical results show that the SMS-based antenna with a maximum size of 0.42λ02 (where λ 0 is the operating wavelength in free space) exhibits a 22.3% impedance bandwidth (S11 < -10 dB) and a high gain of more than 7.15 dBi within the passband. Experimental results at microwave frequencies verify the performance of the proposed antenna, demonstrating substantial consistency with the simulation results. The compact and broadband antenna therefore predicts numerous potential applications within modern wireless communication systems.

Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system

NASA Astrophysics Data System (ADS)

Gao, Shengkui; Mondal, Suman B.; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

2015-01-01

Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use.

Evaluation of the Effect of Source Geometry on the Output of Miniature X-ray Tube for Electronic Brachytherapy through Simulation

PubMed Central

Barati, B.; Zabihzadeh, M.; Tahmasebi Birgani, M.J.; Chegini, N.; Fatahiasl, J.; Mirr, I.

2018-01-01

Objective: The use of miniature X-ray source in electronic brachytherapy is on the rise so there is an urgent need to acquire more knowledge on X-ray spectrum production and distribution by a dose. The aim of this research was to investigate the influence of target thickness and geometry at the source of miniature X-ray tube on tube output. Method: Five sources were simulated based on problems each with a specific geometric structure and conditions using MCNPX code. Tallies proportional to the output were used to calculate the results for the influence of source geometry on output. Results: The results of this work include the size of the optimal thickness of 5 miniature sources, energy spectrum of the sources per 50 kev and also the axial and transverse dose of simulated sources were calculated based on these thicknesses. The miniature source geometric was affected on the output x-ray tube. Conclusion: The result of this study demonstrates that hemispherical-conical, hemispherical and truncated-conical miniature sources were determined as the most suitable tools. PMID:29732338

Differential Expression of Programmed Cell Death on the Follicular Development in Normal and Miniature Pig Ovary

PubMed Central

Kim, Sang Hwan; Min, Kwan Sik; Kim, Nam Hyung; Yoon, Jong Taek

2012-01-01

Follicles are important in oocyte maturation. Successful estrous cycle requires remodeling of follicular cells, and proper execution of programmed cell death is crucial for normal follicular development. The objectives of the present study were to understand programmed cell death during follicle development, to analyze the differential follicle development patterns, and to assess the patterns of apoptosis and autophagy expression during follicle development in normal and miniature pigs. Through the analysis of differential patterns of programmed cell death during follicular development in porcine, MAP1LC3A, B and other autophagy-associated genes (ATG5, mTOR, Beclin-1) were found to increase in normal pigs, while it decreased in miniature pigs. However, for the apoptosis-associated genes, progression of genes during follicular development increased in miniature pigs, while it decreased in normal pigs. Thus, results show that normal and miniature pigs showed distinct patterns of follicular remodeling manifesting that programmed cell death largely depends on the types of pathway during follicular development (Type II or autophagy for normal pigs and Type I or apoptosis for miniature pigs). PMID:23056260

Mars Miniature Science Instruments

NASA Technical Reports Server (NTRS)

Kim, Soon Sam; Hayati, Samad; Lavery, David; McBrid, Karen

2006-01-01

For robotic Mars missions, all the science information is gathered through on-board miniature instruments that have been developed through many years of R&D. Compared to laboratory counterparts, the rover instruments require miniaturization, such as low mass (1-2 kg), low power (> 10 W) and compact (1-2 liter), yet with comparable sensitivity. Since early 1990's, NASA recognized the need for the miniature instruments and launched several instrument R&D programs, e.g., PIDDP (Planetary Instrument Definition and Development). However, until 1998, most of the instrument R&D programs supported only up to a breadboard level (TRL 3, 4) and there is a need to carry such instruments to flight qualifiable status (TU 5, 6) to respond to flight AOs (Announcement of Opportunity). Most of flight AOs have only limited time and financial resources, and can not afford such instrument development processes. To bridge the gap between instrument R&D programs and the flight instrument needs, NASA's Mars Technology Program (MTP) created advanced instrumentation program, Mars Instrument Development Project (MIDP). MIDP candidate instruments are selected through NASA Research Announcement (NRA) process [l]. For example, MIDP 161998-2000) selected and developed 10 instruments, MIDP II (2003-2005) 16 instruments, and MIDP III (2004-2006) II instruments.Working with PIs, JPL has been managing the MIDP tasks since September 1998. All the instruments being developed under MIDP have been selected through a highly competitive NRA process, and employ state-of-the-art technology. So far, four MIDP funded instruments have been selected by two Mars missions (these instruments have further been discussed in this paper).

Ring-patterned plasmonic photonic crystal thermal light source for miniaturized near-infrared spectrometers

NASA Astrophysics Data System (ADS)

Labib, Shady R.; Elsayed, Ahmed A.; Sabry, Yasser M.; Khalil, Diaa

2018-02-01

There is a growing number of spectroscopy applications in the near-infrared (NIR) range including gas sensing, food analysis, pharmaceutical and industrial applications that requires highly efficient, more compact and low-cost miniaturized spectrometers. One of the key components for such systems is the wideband light source that can be fabricated using Silicon technology and hence integrated with other components on the same chip. In this work, we report a ring-patterned plasmonic photonic crystal (PC) thermal light source for miniaturized near-infrared spectrometers. The design is based on silicon and tuned to achieve wavelength selectivity in the emitted spectrum. The design is optimized by using Rigorous Coupled-Wave Analysis (RCWA) simulation, which is used to compute the power reflectance and transmittance that are used to predict the emissivity of the structure. The design consists of a PC of silicon rings coated with platinum. The period of the structure is about 2 μm and the silicon is highly-doped with n-type doping level in the order of 1019-1020 cm-3 to enhance the free-carrier absorption. The ring etching depth, diameter and shell thickness are optimized to increase its emissivity within a specific wavelength range of interest. The simulation results show an emissivity exceeding 0.9 in the NIR range up to 2.5 μm, while the emissivity is decreased significantly for longer wavelengths suppressing the emission out of the range of interest, and hence increasing the efficiency for the source. The reported results open the door for black body radiation engineering in integrated silicon sources for spectrometer miniaturization.

Miniature fiber optic loop subcomponent for compact sensors and dense routing

NASA Astrophysics Data System (ADS)

Gillham, Frederick J.; Stowe, David W.; Ouellette, Thomas R.; Pryshlak, Adrian P.

1999-05-01

Fiber optic data links and embedded sensors, such as Fabry- Perot and Mach-Zehnders, are important elements in smart structure architectures. Unfortunately, one problem with optical fiber is the inherent limit through which fibers and cables can be looped. A revolutionary, patented technology has been developed which overcomes this problem. Based on processing the fiber into low loss miniature bends, it permits routing the fiber to difficult areas, and minimizing the size of sensors and components. The minimum bend diameter for singlemode fiber is typically over two inches in diameter, to avoid light attenuation and limit stresses which could prematurely break the fiber. With the new miniature bend technology, bend diameters as small as 1 mm are readily achieved. One embodiment is a sub-component with standard singlemode fiber formed into a 180 degree bend and packaged in a glass tube only 1.5 mm OD X 8 mm long, Figure 1. Measured insertion loss is less than 0.2 dB from 1260 nm to 1680 nm. A final processing step which anneals the fiber into the eventual curvature, reduces the internal stress, thereby resulting in long life expectancy with robust immunity to external loading. This paper addresses the optical and physical performance of the sub-component. Particular attention is paid to attenuation spectra, polarization dependent loss, reflectance, thermal cycle, damp heat, and shock tests. Applications are presented which employs the bend technology. Concatenating right angle bends into a 'wire harness' demonstrates the ability to route fiber through a smart engine or satellite structure. Miniature optical coils are proposed for sensors and expansion joints.

A compact, inexpensive infrared laser system for continuous-wave optical stimulation of the rat prostate cavernous nerves

NASA Astrophysics Data System (ADS)

Perkins, William C.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

2014-03-01

Optical nerve stimulation (ONS) has been commonly performed in the laboratory using high-power, pulsed, infrared (IR) lasers including Holmium:YAG, diode, and Thulium fiber lasers. However, the relatively high cost of these lasers in comparison with conventional electrical nerve stimulation (ENS) equipment may represent a significant barrier to widespread adoption of ONS. Optical stimulation of the prostate cavernous nerves (CN's) has recently been reported using lower cost, continuous-wave (CW), all-fiber-based diode lasers. This preliminary study describes further miniaturization and cost reduction of the ONS system in the form of a compact, lightweight, cordless, and inexpensive IR laser. A 140-mW, 1560-nm diode laser was integrated with a green aiming beam and delivery optics into a compact ONS system. Surface and subsurface ONS was performed in a total of 5 rats, in vivo, with measurement of an intracavernous pressure (ICP) response during CW laser irradiation for 30 s with a spot diameter of 0.7 mm. Short-term, CW ONS of the prostate CN's is feasible using a compact, inexpensive, batterypowered IR laser diode system. This ONS system may represent an alternative to ENS for laboratory studies, and with further development, a handheld option for ONS in the clinic to identify and preserve the CN's during prostate cancer surgery.

Miniature Release Mechanism or Diminutive Assembly for Nanosatellite Deployables (DANY)

NASA Technical Reports Server (NTRS)

Santos Soto, Luis H. (Inventor); Hesh, Scott V. (Inventor); Hudeck, John D. (Inventor)

2017-01-01

Miniature release mechanisms constrain objects, such as deployables during the launch of space vehicles, such as small satellites and nanosatellites, and enable the release of the objects once a desired destination is reached by the space vehicle. Constraint and release of the objects are achieved by providing a secure threaded interface that may be released by the release mechanisms. The release mechanisms include a housing structure; a release block can include a threaded interface; one or more retracting pins; one or more release springs; a breakable link, such as a plastic link; a cable harness clamp; and a circuit board. The release mechanism can be 0.1875 inches (approximately 4.8 mm) thick.

Dark field imaging system for size characterization of magnetic micromarkers

NASA Astrophysics Data System (ADS)

Malec, A.; Haiden, C.; Kokkinis, G.; Keplinger, F.; Giouroudi, I.

2017-05-01

In this paper we demonstrate a dark field video imaging system for the detection and size characterization of individual magnetic micromarkers suspended in liquid and the detection of pathogens utilizing magnetically labelled E.coli. The system follows dynamic processes and interactions of moving micro/nano objects close to or below the optical resolution limit, and is especially suitable for small sample volumes ( 10 μl). The developed detection method can be used to obtain clinical information about liquid contents when an additional biological protocol is provided, i.e., binding of microorganisms (e.g. E.coli) to specific magnetic markers. Some of the major advantages of our method are the increased sizing precision in the micro- and nano-range as well as the setup's simplicity making it a perfect candidate for miniaturized devices. Measurements can thus be carried out in a quick, inexpensive, and compact manner. A minor limitation is that the concentration range of micromarkers in a liquid sample needs to be adjusted in such a manner that the number of individual particles in the microscope's field of view is sufficient.

Blur spot limitations in distal endoscope sensors

NASA Astrophysics Data System (ADS)

Yaron, Avi; Shechterman, Mark; Horesh, Nadav

2006-02-01

In years past, the picture quality of electronic video systems was limited by the image sensor. In the present, the resolution of miniature image sensors, as in medical endoscopy, is typically superior to the resolution of the optical system. This "excess resolution" is utilized by Visionsense to create stereoscopic vision. Visionsense has developed a single chip stereoscopic camera that multiplexes the horizontal dimension of the image sensor into two (left and right) images, compensates the blur phenomena, and provides additional depth resolution without sacrificing planar resolution. The camera is based on a dual-pupil imaging objective and an image sensor coated by an array of microlenses (a plenoptic camera). The camera has the advantage of being compact, providing simultaneous acquisition of left and right images, and offering resolution comparable to a dual chip stereoscopic camera with low to medium resolution imaging lenses. A stereoscopic vision system provides an improved 3-dimensional perspective of intra-operative sites that is crucial for advanced minimally invasive surgery and contributes to surgeon performance. An additional advantage of single chip stereo sensors is improvement of tolerance to electronic signal noise.

Evaluation of a miniature microscope objective designed for fluorescence array microscopy detection of Mycobacterium tuberculosis.

PubMed

McCall, Brian; Olsen, Randall J; Nelles, Nicole J; Williams, Dawn L; Jackson, Kevin; Richards-Kortum, Rebecca; Graviss, Edward A; Tkaczyk, Tomasz S

2014-03-01

A prototype miniature objective that was designed for a point-of-care diagnostic array microscope for detection of Mycobacterium tuberculosis and previously fabricated and presented in a proof of concept is evaluated for its effectiveness in detecting acid-fast bacteria. To evaluate the ability of the microscope to resolve submicron features and details in the image of acid-fast microorganisms stained with a fluorescent dye, and to evaluate the accuracy of clinical diagnoses made with digital images acquired with the objective. The lens prescription data for the microscope design are presented. A test platform is built by combining parts of a standard microscope, a prototype objective, and a digital single-lens reflex camera. Counts of acid-fast bacteria made with the prototype objective are compared to counts obtained with a standard microscope over matched fields of view. Two sets of 20 smears, positive and negative, are diagnosed by 2 pathologists as sputum smear positive or sputum smear negative, using both a standard clinical microscope and the prototype objective under evaluation. The results are compared to a reference diagnosis of the same sample. More bacteria are counted in matched fields of view in digital images taken with the prototype objective than with the standard clinical microscope. All diagnostic results are found to be highly concordant. An array microscope built with this miniature lens design will be able to detect M tuberculosis with high sensitivity and specificity.

A miniature disposable radio (MiDR) for unattended ground sensor systems (UGSS) and munitions

NASA Astrophysics Data System (ADS)

Wells, Jeffrey S.; Wurth, Timothy J.

2004-09-01

Unattended and tactical sensors are used by the U.S. Army"s Future Combat Systems (FCS) and Objective Force Warrior (OFW) to detect and identify enemy targets on the battlefield. The radios being developed as part of the Networked Sensors for the Objective Force (NSOF) are too costly and too large to deploy in missions requiring throw-away hardware. A low-cost miniature radio is required to satisfy the communication needs for unmanned sensor and munitions systems that are deployed in a disposable manner. A low cost miniature disposable communications suite is leveraged using the commercial off-the-shelf market and employing a miniature universal frequency conversion architecture. Employing the technology of universal frequency architecture in a commercially available communication unit delivers a robust disposable transceiver that can operate at virtually any frequency. A low-cost RF communication radio has applicability in the commercial, homeland defense, military, and other government markets. Specific uses include perimeter monitoring, infrastructure defense, unattended ground sensors, tactical sensors, and border patrol. This paper describes a low-cost radio architecture to meet the requirements of throw-away radios that can be easily modified or tuned to virtually any operating frequency required for the specific mission.

A miniature Marine Aerosol Reference Tank (miniMART) as a compact breaking wave analogue

NASA Astrophysics Data System (ADS)

Stokes, M. Dale; Deane, Grant; Collins, Douglas B.; Cappa, Christopher; Bertram, Timothy; Dommer, Abigail; Schill, Steven; Forestieri, Sara; Survilo, Mathew

2016-09-01

In order to understand the processes governing the production of marine aerosols, repeatable, controlled methods for their generation are required. A new system, the miniature Marine Aerosol Reference Tank (miniMART), has been designed after the success of the original MART system, to approximate a small oceanic spilling breaker by producing an evolving bubble plume and surface foam patch. The smaller tank utilizes an intermittently plunging jet of water produced by a rotating water wheel, into an approximately 6 L reservoir to simulate bubble plume and foam formation and generate aerosols. This system produces bubble plumes characteristic of small whitecaps without the large external pump inherent in the original MART design. Without the pump it is possible to easily culture delicate planktonic and microbial communities in the bulk water during experiments while continuously producing aerosols for study. However, due to the reduced volume and smaller plunging jet, the absolute numbers of particles generated are approximately an order of magnitude less than in the original MART design.

Scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage

NASA Astrophysics Data System (ADS)

El-Kady, Maher F.; Kaner, Richard B.

2013-02-01

The rapid development of miniaturized electronic devices has increased the demand for compact on-chip energy storage. Microscale supercapacitors have great potential to complement or replace batteries and electrolytic capacitors in a variety of applications. However, conventional micro-fabrication techniques have proven to be cumbersome in building cost-effective micro-devices, thus limiting their widespread application. Here we demonstrate a scalable fabrication of graphene micro-supercapacitors over large areas by direct laser writing on graphite oxide films using a standard LightScribe DVD burner. More than 100 micro-supercapacitors can be produced on a single disc in 30 min or less. The devices are built on flexible substrates for flexible electronics and on-chip uses that can be integrated with MEMS or CMOS in a single chip. Remarkably, miniaturizing the devices to the microscale results in enhanced charge-storage capacity and rate capability. These micro-supercapacitors demonstrate a power density of ~200 W cm-3, which is among the highest values achieved for any supercapacitor.

State-of-The-Art and Applications of 3D Imaging Sensors in Industry, Cultural Heritage, Medicine, and Criminal Investigation

PubMed Central

Sansoni, Giovanna; Trebeschi, Marco; Docchio, Franco

2009-01-01

3D imaging sensors for the acquisition of three dimensional (3D) shapes have created, in recent years, a considerable degree of interest for a number of applications. The miniaturization and integration of the optical and electronic components used to build them have played a crucial role in the achievement of compactness, robustness and flexibility of the sensors. Today, several 3D sensors are available on the market, even in combination with other sensors in a “sensor fusion” approach. An importance equal to that of physical miniaturization has the portability of the measurements, via suitable interfaces, into software environments designed for their elaboration, e.g., CAD-CAM systems, virtual renders, and rapid prototyping tools. In this paper, following an overview of the state-of-art of 3D imaging sensors, a number of significant examples of their use are presented, with particular reference to industry, heritage, medicine, and criminal investigation applications. PMID:22389618

State-of-The-Art and Applications of 3D Imaging Sensors in Industry, Cultural Heritage, Medicine, and Criminal Investigation.

PubMed

Sansoni, Giovanna; Trebeschi, Marco; Docchio, Franco

2009-01-01

3D imaging sensors for the acquisition of three dimensional (3D) shapes have created, in recent years, a considerable degree of interest for a number of applications. The miniaturization and integration of the optical and electronic components used to build them have played a crucial role in the achievement of compactness, robustness and flexibility of the sensors. Today, several 3D sensors are available on the market, even in combination with other sensors in a "sensor fusion" approach. An importance equal to that of physical miniaturization has the portability of the measurements, via suitable interfaces, into software environments designed for their elaboration, e.g., CAD-CAM systems, virtual renders, and rapid prototyping tools. In this paper, following an overview of the state-of-art of 3D imaging sensors, a number of significant examples of their use are presented, with particular reference to industry, heritage, medicine, and criminal investigation applications.

Biodiesel sensing using silicon-on-insulator technologies

NASA Astrophysics Data System (ADS)

Casas Bedoya, Alvaro; Ling, Meng Y.; Brouckaert, Joost; Yebo, Nebiyu A.; Van Thourhout, Dries; Baets, Roel G.

2009-05-01

By measuring the transmission of Biodiesel/Diesel mixtures in the near- and far-infrared wavelength ranges, it is possible to predict the blend level with a high accuracy. Conventional photospectrometers are typically large and expensive and have a performance that often exceeds the requirements for most applications. For automotive applications for example, what counts is size, robustness and most important cost. As a result the miniaturization of the spectrometer can be seen as an attractive implementation of a Biodiesel sensor. Using Silicon-on-Insulator (SOI) this spectrometer miniaturization can be achieved. Due to the large refractive index contrast of the SOI material system, photonic devices can be made very compact. Moreover, they can be manufactured on high-quality SOI substrates using waferscale CMOS fabrication tools, making them cheap for the market. In this paper, we show that it is possible to determine Biodiesel blend levels using an SOI spectrometer-on-a-chip. We demonstrate absorption measurements using spiral shaped waveguides and we also present the spectrometer design for on-chip Biodiesel blend level measurements.

Tunable microwave bandpass filter integrated power divider based on the high anisotropy electro-optic nematic liquid crystal.

PubMed

Liu, Yupeng; Liu, Yang; Li, Haiyan; Jiang, Di; Cao, Weiping; Chen, Hui; Xia, Lei; Xu, Ruimin

2016-07-01

A novel, compact microwave tunable bandpass filter integrated power divider, based on the high anisotropy electro-optic nematic liquid crystal, is proposed in this letter. Liquid crystal, as the electro-optic material, is placed between top inverted microstrip line and the metal plate. The proposed structure can realize continuous tunable bandpass response and miniaturization. The proposed design concept is validated by the good performance of simulation results and experimental results. The electro-optic material has shown great potential for microwave application.

Ultra-Compact Motor Controller

NASA Technical Reports Server (NTRS)

Townsend, William T.; Cromwell, Adam; Hauptman, Traveler; Pratt, Gill Andrews

2012-01-01

This invention is an electronically commutated brushless motor contro ller that incorporates Hall-array sensing in a small, 42-gram packag e that provides 4096 absolute counts per motor revolution position s ensing. The unit is the size of a miniature hockey puck, and is a 44 -pin male connector that provides many I/O channels, including CANbus , RS-232 communications, general-purpose analog and digital I/O (GPI O), analog and digital Hall inputs, DC power input (18-90 VDC, 0-l0 A), three-phase motor outputs, and a strain gauge amplifier.

Emphysema diagnosis using X-ray dark-field imaging at a laser-driven compact synchrotron light source

PubMed Central

Schleede, Simone; Meinel, Felix G.; Bech, Martin; Herzen, Julia; Achterhold, Klaus; Potdevin, Guillaume; Malecki, Andreas; Adam-Neumair, Silvia; Thieme, Sven F.; Bamberg, Fabian; Nikolaou, Konstantin; Bohla, Alexander; Yildirim, Ali Ö.; Loewen, Roderick; Gifford, Martin; Ruth, Ronald; Eickelberg, Oliver; Reiser, Maximilian; Pfeiffer, Franz

2012-01-01

In early stages of various pulmonary diseases, such as emphysema and fibrosis, the change in X-ray attenuation is not detectable with absorption-based radiography. To monitor the morphological changes that the alveoli network undergoes in the progression of these diseases, we propose using the dark-field signal, which is related to small-angle scattering in the sample. Combined with the absorption-based image, the dark-field signal enables better discrimination between healthy and emphysematous lung tissue in a mouse model. All measurements have been performed at 36 keV using a monochromatic laser-driven miniature synchrotron X-ray source (Compact Light Source). In this paper we present grating-based dark-field images of emphysematous vs. healthy lung tissue, where the strong dependence of the dark-field signal on mean alveolar size leads to improved diagnosis of emphysema in lung radiographs. PMID:23074250

Toward a compact fibered squeezing parametric source.

PubMed

Brieussel, Alexandre; Ott, Konstantin; Joos, Maxime; Treps, Nicolas; Fabre, Claude

2018-03-15

In this work, we investigate three different compact fibered systems generating vacuum squeezing that involve optical cavities limited by the end surface of a fiber and by a curved mirror and containing a thin parametric crystal. These systems have the advantage to couple squeezed states directly to a fiber, allowing the user to benefit from the flexibility of fibers in the use of squeezing. Three types of fibers are investigated: standard single-mode fibers, photonic-crystal large-mode-area single-mode fibers, and short multimode fibers taped to a single-mode fiber. The observed squeezing is modest (-0.56  dB, -0.9  dB, -1  dB), but these experiments open the way for miniaturized squeezing devices that could be a very interesting advantage in scaling up quantum systems for quantum processing, opening new perspectives in the domain of integrated quantum optics.

Getting small: new 10μm pixel pitch cooled infrared products

NASA Astrophysics Data System (ADS)

Reibel, Y.; Pere-Laperne, N.; Augey, T.; Rubaldo, L.; Decaens, G.; Bourqui, M.-L.; Manissadjian, A.; Billon-Lanfrey, D.; Bisotto, S.; Gravrand, O.; Destefanis, G.; Druart, G.; Guerineau, N.

2014-06-01

Recent advances in miniaturization of IR imaging technology have led to a burgeoning market for mini thermalimaging sensors. Seen in this context our development on smaller pixel pitch has opened the door to very compact products. When this competitive advantage is mixed with smaller coolers, thanks to HOT technology, we achieve valuable reductions in size, weight and power of the overall package. In the same time, we are moving towards a global offer based on digital interfaces that provides our customers lower power consumption and simplification on the IR system design process while freeing up more space. Additionally, we are also investigating new wafer level camera solution taking advantage of the progress in micro-optics. This paper discusses recent developments on hot and small pixel pitch technologies as well as efforts made on compact packaging solution developed by SOFRADIR in collaboration with CEA-LETI and ONERA.

Miniature Extreme Ultraviolet Solar Radiometers

NASA Astrophysics Data System (ADS)

McMullin, D. R.; Seely, J. F.; Bremer, J.; Jones, A. R.; Vest, R.; Sakdinawat, A.

2015-12-01

Free-standing zone plates for use in EUV solar radiometers have been fabricated using electron beam lithography and calibrated at the NIST SURF synchrotron facility. The radiometers that we are developing use zone plates (ZPs) to focus the total solar irradiance in narrow EUV spectral bands and measure it with negligible sensitivity to field angle and polarization, and with greater accuracy and greater long-term stability than radiometers that have alternative architectures. These radiometers are easy to accommodate on spacecraft due to their small size, low mass, low power requirements, low data rates, and modest pointing requirements. A proto-type instrument will be presented with performance characteristics and spacecraft resource requirements for hosting these new instruments. The compact size of the optical train make these zone plates attractive for small CubeSats. The robustness of the compact design makes these radiometers available for a large variety of applications.

Prevalence of the AMHR2 mutation in Miniature Schnauzers and genetic investigation of a Belgian Malinois with persistent Müllerian duct syndrome.

PubMed

Smit, M M; Ekenstedt, K J; Minor, K M; Lim, C K; Leegwater, Paj; Furrow, E

2018-04-01

Persistent Müllerian duct syndrome (PMDS) is a sex-limited disorder in which males develop portions of the female reproductive tract. Important consequences of PMDS are cryptorchidism and its sequelae of infertility and increased risk of testicular cancer. Anti-Müllerian hormone (AMH) and its receptor (AMHR2) induce the regression of the Müllerian ducts in male embryos. In Miniature Schnauzer dogs, the genetic basis has been identified as an autosomal recessive nonsense mutation in AMHR2, but the allele frequency of the mutation is unknown. Thus, the primary objective of this study was to estimate the prevalence of the AMHR2 mutation in North American Miniature Schnauzers, in order to ascertain the value of genetic testing in this breed. An additional objective was to determine whether mutations in AMH or AMHR2 were responsible for PMDS in a Belgian Malinois; this would aid development of a genetic test for the Belgian Malinois breed. Genomic DNA from 216 Miniature Schnauzers (including one known PMDS case) was genotyped for the AMHR2 mutation, and DNA from a single PMDS-affected Belgian Malinois was sequenced for all coding exons of AMH and AMHR2. The Miniature Schnauzer cohort had an AMHR2 mutation allele frequency of 0.16 and a carrier genotypic frequency of 0.27. The genetic basis for PMDS in the Belgian Malinois was not determined, as no coding or splicing mutations were identified in either AMH or AMHR2. These findings support a benefit to AMHR2 mutation testing Miniature Schnauzers used for breeding or with cryptorchidism. © 2017 Blackwell Verlag GmbH.

Microtube strip heat exchanger

NASA Astrophysics Data System (ADS)

Doty, F. D.

1992-07-01

The purpose of this contract has been to explore the limits of miniaturization of heat exchangers with the goals of (1) improving the theoretical understanding of laminar heat exchangers, (2) evaluating various manufacturing difficulties, and (3) identifying major applications for the technology. A low-cost, ultra-compact heat exchanger could have an enormous impact on industry in the areas of cryocoolers and energy conversion. Compact cryocoolers based on the reverse Brayton cycle (RBC) would become practical with the availability of compact heat exchangers. Many experts believe that hardware advances in personal computer technology will rapidly slow down in four to six years unless lowcost, portable cryocoolers suitable for the desktop supercomputer can be developed. Compact refrigeration systems would permit dramatic advances in high-performance computer work stations with 'conventional' microprocessors operating at 150 K, and especially with low-cost cryocoolers below 77 K. NASA has also expressed strong interest in our MTS exchanger for space-based RBC cryocoolers for sensor cooling. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas exchangers. These laminar-flow, microtube exchangers exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to mass production techniques, but considerable process development remains. The reduction in materials usage and the improved heat exchanger performance promise to be of enormous significance in advanced engine designs and in cryogenics.

NASA Tech Briefs, January 2003

NASA Technical Reports Server (NTRS)

2003-01-01

Topics covered include: Optoelectronic Tool Adds Scale Marks to Photographic Images; Compact Interconnection Networks Based on Quantum Dots; Laterally Coupled Quantum-Dot Distributed-Feedback Lasers; Bit-Serial Adder Based on Quantum Dots; Stabilized Fiber-Optic Distribution of Reference Frequency; Delay/Doppler-Mapping GPS-Reflection Remote-Sensing System; Ladar System Identifies Obstacles Partly Hidden by Grass; Survivable Failure Data Recorders for Spacecraft; Fiber-Optic Ammonia Sensors; Silicon Membrane Mirrors with Electrostatic Shape Actuators; Nanoscale Hot-Wire Probes for Boundary-Layer Flows; Theodolite with CCD Camera for Safe Measurement of Laser-Beam Pointing; Efficient Coupling of Lasers to Telescopes with Obscuration; Aligning Three Off-Axis Mirrors with Help of a DOE; Calibrating Laser Gas Measurements by Use of Natural CO2; Laser Ranging Simulation Program; Micro-Ball-Lens Optical Switch Driven by SMA Actuator; Evaluation of Charge Storage and Decay in Spacecraft Insulators; Alkaline Capacitors Based on Nitride Nanoparticles; Low-EC-Content Electrolytes for Low-Temperature Li-Ion Cells; Software for a GPS-Reflection Remote-Sensing System; Software for Building Models of 3D Objects via the Internet; "Virtual Cockpit Window" for a Windowless Aerospacecraft; CLARAty Functional-Layer Software; Java Library for Input and Output of Image Data and Metadata; Software for Estimating Costs of Testing Rocket Engines; Energy-Absorbing, Lightweight Wheels; Viscoelastic Vibration Dampers for Turbomachine Blades; Soft Landing of Spacecraft on Energy-Absorbing Self-Deployable Cushions; Pneumatically Actuated Miniature Peristaltic Vacuum Pumps; Miniature Gas-Turbine Power Generator; Pressure-Sensor Assembly Technique; Wafer-Level Membrane-Transfer Process for Fabricating MEMS; A Reactive-Ion Etch for Patterning Piezoelectric Thin Film; Wavelet-Based Real-Time Diagnosis of Complex Systems; Quantum Search in Hilbert Space; Analytic Method for Computing Instrument Pointing Jitter; and Semiselective Optoelectronic Sensors for Monitoring Microbes.

Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

DOEpatents

Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

1996-10-22

An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

DOEpatents

Majewski, Stanislaw; Kross, Brian J.; Zorn, Carl J.; Majewski, Lukasz A.

1996-01-01

An optimized examination system and method based on the Reverse Geometry X-Ray.RTM. (RGX.RTM.) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging.

On the validity and robustness of the scale error phenomenon in early childhood.

PubMed

DeLoache, Judy S; LoBue, Vanessa; Vanderborght, Mieke; Chiong, Cynthia

2013-02-01

Scale errors is a term referring to very young children's serious efforts to perform actions on miniature replica objects that are impossible due to great differences in the size of the child's body and the size of the target objects. We report three studies providing further documentation of scale errors and investigating the validity and robustness of the phenomenon. In the first, we establish that 2-year-olds' behavior in response to prompts to "pretend" with miniature replica objects differs dramatically from scale errors. The second and third studies address the robustness of the phenomenon and its relative imperviousness to attempts to influence the rate of scale errors. Copyright © 2012 Elsevier Inc. All rights reserved.

Miniaturized CARS microendoscope probe design for label-free intraoperative imaging

NASA Astrophysics Data System (ADS)

Chen, Xu; Wang, Xi; Xu, Xiaoyun; Cheng, Jie; Liu, Zhengfan; Weng, Sheng; Thrall, Michael J.; Goh, Alvin C.; McCormick, Daniel T.; Wong, Kelvin; Wong, Stephen T. C.

2014-03-01

A Coherent Anti-Stokes Raman Scattering (CARS) microendoscope probe for early stage label-free prostate cancer diagnosis at single cell resolution is presented. The handheld CARS microendoscope probe includes a customized micro-electromechanical systems (MEMS) scanning mirror as well as miniature optical and mechanical components. In our design, the excitation laser (pump and stokes beams) from the fiber is collimated, reflected by the reflecting mirror, and transmitted via a 2D MEMS scanning mirror and a micro-objective system onto the sample; emission in the epi-direction is returned through the micro-objective lens, MEMS and reflecting mirror, and collimation system, and finally the emission signal is collected by a photomultiplier tube (PMT). The exit pupil diameter of the collimator system is designed to match the diameter of the MEMS mirror and the entrance pupil diameter of the micro-objective system. The back aperture diameter of the micro-objective system is designed according to the largest MEMS scanning angle and the distance between the MEMS mirror and the back aperture. To increase the numerical aperture (NA) of the micro-objective system in order to enhance the signal collection efficiency, the back aperture diameter of the micro-objective system is enlarged with an upfront achromatic wide angle Keplerian telescope beam expander. The integration of a miniaturized micro-optics probe with optical fiber CARS microscopy opens up the possibility of in vivo molecular imaging for cancer diagnosis and surgical intervention.

Novel short-pulse laser diode source for high-resolution 3D flash lidar

NASA Astrophysics Data System (ADS)

Canal, Celine; Laugustin, Arnaud; Kohl, Andreas; Rabot, Olivier

2017-06-01

Imaging based on laser illumination is present in various fields of applications such as medicine, security, defense, civil engineering and in the automotive sector. In this last domain, research and development to bring autonomous vehicles on the roads has been intensified the recent years. Among the various technologies currently studied, automotive lidars are a fast-growing one due to their accuracy to detect a wide range of objects at distances up to a few hundreds of meters in various weather conditions. First commercialized devices for ADAS were laser scanners. Since then, new architectures have recently appeared such as solid-state lidar and flash lidar that offer a higher compactness, robustness and a cost reduction. Flash lidars are based on time-of-flight measurements, with the particularity that they do not require beam scanners because only one short laser pulse with a large divergence is used to enlighten the whole scene. Depth of encountered objects can then be recovered from measurement of echoed light at once, hence enabling real-time 3D mapping of the environment. This paper will bring into the picture a cutting edge laser diode source that can deliver millijoule pulses as short as 12 ns, which makes them highly suitable for integration in flash lidars. They provide a 100-kW peak power highly divergent beam in a footprint of 4x5 cm2 (including both the laser diode and driver) and with a 30-% electrical-to-optical efficiency, making them suitable for integration in environments in which compactness and power consumption are a priority. Their emission in the range of 800-1000 nm is considered to be eye safe when taking into account the high divergence of the output beam. An overview of architecture of these state-of-the-art pulsed laser diode sources will be given together with some solutions for their integration in 3D mapping systems. Future work leads will be discussed for miniaturization of the laser diode and drastic cost reduction.

Development of a Miniaturized and Portable Methane Analyzer for Natural Gas Leak Walking Surveys

NASA Astrophysics Data System (ADS)

Huang, Y. W.; Leen, J. B.; Gupta, M.; Baer, D. S.

2016-12-01

Traditional natural gas leak walking surveys have been conducted with devices that are based on technologies such as flame ionization detector (FID), IR-based spectrometer and IR camera. The sensitivity is typically on the ppm level. The low sensitivity means the device cannot pick up leaks far from it, and more time is spent surveying the area before pinpointing the leak location. A miniaturized methane analyzer has been developed to significantly improve the sensitivity of the device used in walking surveys to detect natural gas leaks at greater distance. ABB/LGR's patented Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) is utilized to offer rugged and highly sensitive methane detection in a portable package. The miniaturized package weighs 13.5 lb, with a 4-hour rechargeable battery inside. The precision of the analyzer for methane is 2 ppb at 1 second. The analyzer operates at 10 Hz and its flow response time is 3 seconds for measurements through a 1-meter long sampling wand to registering on the data stream. The data can be viewed in real-time on a tablet or a smartphone. The compact and simplified package of the methane analyzer allows for more efficient walking surveys. It also allows for other applications that require low-power, low-weight and a portable package. We present data from walking surveys to demonstrate its ability to detect methane leaks.

Miniature high-performance infrared spectrometer for space applications

NASA Astrophysics Data System (ADS)

Kruzelecky, Roman V.; Haddad, Emile; Wong, Brian; Lafrance, Denis; Jamroz, Wes; Ghosh, Asoke K.; Zheng, Wanping; Phong, Linh

2004-06-01

Infrared spectroscopy probes the characteristic vibrational and rotational modes of chemical bonds in molecules to provide information about both the chemical composition and the bonding configuration of a sample. The significant advantage of the Infrared spectral technique is that it can be used with minimal consumables to simultaneously detect a large variety of chemical and biochemical species with high chemical specificity. To date, relatively large Fourier Transform (FT-IR) spectrometers employing variations of the Michelson interferometer have been successfully employed in space for various IR spectroscopy applications. However, FT-IR systems are mechanically complex, bulky (> 15 kg), and require considerable processing. This paper discusses the use of advanced integrated optics and smart optical coding techniques to significantly extend the performance of miniature IR spectrometers by several orders of magnitude in sensitivity. This can provide the next-generation of compact, high-performance IR spectrometers with monolithically integrated optical systems for robust optical alignment. The entire module can weigh under 3 kg to minimize the mass penalty for space applications. Miniaturized IR spectrometers are versatile and very convenient for small and micro satellite based missions. They can be dedicated to the monitoring of the CO2 in an Earth Observation mission, to Mars exobiology exploration, as well as to vital life support in manned space system; such as the cabin air quality and the quality of the recycled water supply.

Miniature high-performance infrared spectrometer for space applications

NASA Astrophysics Data System (ADS)

Kruzelecky, Roman V.; Haddad, Emile; Wong, Brian; Lafrance, Denis; Jamroz, Wes; Ghosh, Asoke K.; Zheng, Wanping; Phong, Linh

2017-11-01

Infrared spectroscopy probes the characteristic vibrational and rotational modes of chemical bonds in molecules to provide information about both the chemical composition and the bonding configuration of a sample. The significant advantage of the Infrared spectral technique is that it can be used with minimal consumables to simultaneously detect a large variety of chemical and biochemical species with high chemical specificity. To date, relatively large Fourier Transform (FT-IR) spectrometers employing variations of the Michelson interferometer have been successfully employed in space for various IR spectroscopy applications. However, FT-IR systems are mechanically complex, bulky (> 15 kg), and require considerable processing. This paper discusses the use of advanced integrated optics and smart optical coding techniques to significantly extend the performance of miniature IR spectrometers by several orders of magnitude in sensitivity. This can provide the next generation of compact, high-performance IR spectrometers with monolithically integrated optical systems for robust optical alignment. The entire module can weigh under 3 kg to minimize the mass penalty for space applications. Miniaturized IR spectrometers are versatile and very convenient for small and micro satellite based missions. They can be dedicated to the monitoring of the CO2 in an Earth Observation mission, to Mars exobiology exploration, as well as to vital life support in manned space system; such as the cabin air quality and the quality of the recycled water supply.

Miniaturized pulsed laser source for time-domain diffuse optics routes to wearable devices.

PubMed

Di Sieno, Laura; Nissinen, Jan; Hallman, Lauri; Martinenghi, Edoardo; Contini, Davide; Pifferi, Antonio; Kostamovaara, Juha; Mora, Alberto Dalla

2017-08-01

We validate a miniaturized pulsed laser source for use in time-domain (TD) diffuse optics, following rigorous and shared protocols for performance assessment of this class of devices. This compact source (12×6  mm2) has been previously developed for range finding applications and is able to provide short, high energy (∼100  ps, ∼0.5  nJ) optical pulses at up to 1 MHz repetition rate. Here, we start with a basic level laser characterization with an analysis of suitability of this laser for the diffuse optics application. Then, we present a TD optical system using this source and its performances in both recovering optical properties of tissue-mimicking homogeneous phantoms and in detecting localized absorption perturbations. Finally, as a proof of concept of in vivo application, we demonstrate that the system is able to detect hemodynamic changes occurring in the arm of healthy volunteers during a venous occlusion. Squeezing the laser source in a small footprint removes a key technological bottleneck that has hampered so far the realization of a miniaturized TD diffuse optics system, able to compete with already assessed continuous-wave devices in terms of size and cost, but with wider performance potentialities, as demonstrated by research over the last two decades. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Flow Injection Photochemical Vapor Generation Coupled with Miniaturized Solution-Cathode Glow Discharge Atomic Emission Spectrometry for Determination and Speciation Analysis of Mercury.

PubMed

Mo, Jiamei; Li, Qing; Guo, Xiaohong; Zhang, Guoxia; Wang, Zheng

2017-10-03

A novel, compact, and green method was developed for the determination and speciation analysis of mercury, based on flow injection photochemical vapor generation (PVG) coupled with miniaturized solution cathode glow discharge-atomic emission spectroscopy (SCGD-AES). The SCGD was generated between a miniature hollow titanium tube and a solution emerging from a glass capillary. Cold mercury vapor (Hg(0)) was generated by PVG and subsequently delivered to the SCGD for excitation, and finally the emission signals were recorded by a miniaturized spectrograph. The detection limits (DLs) of Hg(II) and methylmercury (MeHg) were both determined to be 0.2 μg L -1 . Moreover, mercury speciation analysis could also be performed by using different wavelengths and powers from the UV lamp and irradiation times. Both Hg(II) and MeHg can be converted to Hg(0) for the determination of total mercury (T-Hg) with 8 W/254 nm UV lamp and 60 s irradiation time; while only Hg(II) can be reduced to Hg(0) and determined selectively with 4 W/365 nm UV lamp and 20 s irradiation time. Then, the concentration of MeHg can be calculated by subtracting the Hg(II) from the T-Hg. Because of its similar sensitivity and DL at 8 W/254 nm, the simpler and less toxic Hg(II) was used successfully as a primary standard for the quantification of T-Hg. The novel PVG-SCGD-AES system provides not only a 365-fold improvement in the DL for Hg(II) but also a nonchromatographic method for the speciation analysis of mercury. After validating its accuracy, this method was successfully used for mercury speciation analysis of water and biological samples.

A novel all-fiber optic flow cytometer technology for Point-of Care and Remote Environments

NASA Astrophysics Data System (ADS)

Mermut, Ozzy

Traditional flow cytometry designs tend to be bulky systems with a complex optical-fluidic sub-system and often require trained personnel for operation. This makes them difficult to readily translate to remote site testing applications. A new compact and portable fiber-optic flow cell (FOFC) technology has been developed at INO. We designed and engineered a specialty optical fiber through which a square hole is transversally bored by laser micromachining. A capillary is fitted into that hole to flow analyte within the fiber square cross-section for detection and counting. With demonstrated performance benchmarks potentially comparable to commercial flow cytometers, our FOFC provides several advantages compared to classic free-space con-figurations, e.g., sheathless flow, low cost, reduced number of optical components, no need for alignment (occurring in the fabrication process only), ease-of-use, miniaturization, portability, and robustness. This sheathless configuration, based on a fiber optic flow module, renders this cytometer amenable to space-grade microgravity environments. We present our recent results for an all-fiber approach to achieve a miniature FOFC to translate flow cytometry from bench to a portable, point-of-care device for deployment in remote settings. Our unique fiber approach provides the capability to illuminate a large surface with a uniform intensity distri-bution, independently of the initial shape originating from the light source, and without loss of optical power. The CVs and sensitivities are measured and compared to industry benchmarks. Finally, integration of LEDs enable several advantages in cost, compactness, and wavelength availability.

Towards the determination of isoprene in human breath using substrate-integrated hollow waveguide mid-infrared sensors.

PubMed

Perez-Guaita, David; Kokoric, Vjekoslav; Wilk, Andreas; Garrigues, Salvador; Mizaikoff, Boris

2014-06-01

Selected volatile organic compounds (VOCs) in breath may be considered biomarkers if they are indicative of distinct diseases or disease states. Given the inherent molecular selectivity of vibrational spectroscopy, infrared sensing technologies appear ideally suitable for the determination of endogenous VOCs in breath. The aim of this study was to determine that mid-infrared (MIR; 3-20 µm) gas phase sensing is capable of determining isoprene in exhaled breath as an exemplary medically relevant VOC by hyphenating novel substrate-integrated hollow waveguides (iHWG) with a likewise miniaturized preconcentration system. A compact preconcentrator column for sampling isoprene from exhaled breath was coupled to an iHWG serving simultaneously as highly miniaturized gas cell and light conduit in combination with a compact Fourier transform infrared spectrometer. A gas mixing system enabled extensive system calibration using isoprene standards. After system optimization, a calibration function obtaining a limit of quantification of 106 ppb was achieved. According to the literature, the obtained sensitivity is sufficient for quantifying middle to high isoprene concentrations occurring in exhaled breath. Finally, a volunteer breath sample was analysed proving comparable values of isoprene in a real-world scenario. Despite its fundamental utility, the proposed methodology contains some limitations in terms of sensitivity and temporal resolution in comparison with the readily available measurement techniques that should be addressed during future optimization of the system. Nonetheless, this study presents the first determination of endogenous VOCs in breath via advanced hollow waveguide MIR sensor technology, clearly demonstrating its potential for the analysis of volatile biomarkers in exhaled breath.

In vivo fiber-optic confocal reflectance microscope with an injection-molded plastic miniature objective lens.

PubMed

Carlson, Kristen; Chidley, Matthew; Sung, Kung-Bin; Descour, Michael; Gillenwater, Ann; Follen, Michele; Richards-Kortum, Rebecca

2005-04-01

For in vivo optical diagnostic technologies to be distributed to the developed and developing worlds, optical imaging systems must be constructed of inexpensive components. We present a fiber-optic confocal reflectance microscope with a cost-effective injection-molded plastic miniature objective lens for in vivo imaging of human tissues in near real time. The measured lateral resolution is less than 2.2 microm, and the measured axial resolution is 10 microm. Confocal images of ex vivo cervical tissue biopsies and in vivo human lip taken at 15 frames/s demonstrate the microscope's capability of imaging cell morphology and tissue architecture.

A compact high-voltage pulse generator based on pulse transformer with closed magnetic core.

PubMed

Zhang, Yu; Liu, Jinliang; Cheng, Xinbing; Bai, Guoqiang; Zhang, Hongbo; Feng, Jiahuai; Liang, Bo

2010-03-01

A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 microF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 ohm matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 ohms, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.

Laser Opto-Electronic Correlator for Robotic Vision Automated Pattern Recognition

NASA Technical Reports Server (NTRS)

Marzwell, Neville

1995-01-01

A compact laser opto-electronic correlator for pattern recognition has been designed, fabricated, and tested. Specifically it is a translation sensitivity adjustable compact optical correlator (TSACOC) utilizing convergent laser beams for the holographic filter. Its properties and performance, including the location of the correlation peak and the effects of lateral and longitudinal displacements for both filters and input images, are systematically analyzed based on the nonparaxial approximation for the reference beam. The theoretical analyses have been verified in experiments. In applying the TSACOC to important practical problems including fingerprint identification, we have found that the tolerance of the system to the input lateral displacement can be conveniently increased by changing a geometric factor of the system. The system can be compactly packaged using the miniature laser diode sources and can be used in space by the National Aeronautics and Space Administration (NASA) and ground commercial applications which include robotic vision, and industrial inspection of automated quality control operations. The personnel of Standard International will work closely with the Jet Propulsion Laboratory (JPL) to transfer the technology to the commercial market. Prototype systems will be fabricated to test the market and perfect the product. Large production will follow after successful results are achieved.

Compact Video Microscope Imaging System Implemented in Colloid Studies

NASA Technical Reports Server (NTRS)

McDowell, Mark

2002-01-01

Long description Photographs showing fiber-optic light source, microscope and charge-coupled discharge (CCD) camera head connected to camera body, CCD camera body feeding data to image acquisition board in PC, and Cartesian robot controlled via PC board. The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. CMIS can be used in situ with a minimum amount of user intervention. This system can scan, find areas of interest in, focus on, and acquire images automatically. Many multiple-cell experiments require microscopy for in situ observations; this is feasible only with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control. The software also has a user-friendly interface, which can be used independently of the hardware for further post-experiment analysis. CMIS has been successfully developed in the SML Laboratory at the NASA Glenn Research Center and adapted for use for colloid studies and is available for telescience experiments. The main innovations this year are an improved interface, optimized algorithms, and the ability to control conventional full-sized microscopes in addition to compact microscopes. The CMIS software-hardware interface is being integrated into our SML Analysis package, which will be a robust general-purpose image-processing package that can handle over 100 space and industrial applications.

Low-cost compact MEMS scanning ladar system for robotic applications

NASA Astrophysics Data System (ADS)

Moss, Robert; Yuan, Ping; Bai, Xiaogang; Quesada, Emilio; Sudharsanan, Rengarajan; Stann, Barry L.; Dammann, John F.; Giza, Mark M.; Lawler, William B.

2012-06-01

Future robots and autonomous vehicles require compact low-cost Laser Detection and Ranging (LADAR) systems for autonomous navigation. Army Research Laboratory (ARL) had recently demonstrated a brass-board short-range eye-safe MEMS scanning LADAR system for robotic applications. Boeing Spectrolab is doing a tech-transfer (CRADA) of this system and has built a compact MEMS scanning LADAR system with additional improvements in receiver sensitivity, laser system, and data processing system. Improved system sensitivity, low-cost, miniaturization, and low power consumption are the main goals for the commercialization of this LADAR system. The receiver sensitivity has been improved by 2x using large-area InGaAs PIN detectors with low-noise amplifiers. The FPGA code has been updated to extend the range to 50 meters and detect up to 3 targets per pixel. Range accuracy has been improved through the implementation of an optical T-Zero input line. A compact commercially available erbium fiber laser operating at 1550 nm wavelength is used as a transmitter, thus reducing the size of the LADAR system considerably from the ARL brassboard system. The computer interface has been consolidated to allow image data and configuration data (configuration settings and system status) to pass through a single Ethernet port. In this presentation we will discuss the system architecture and future improvements to receiver sensitivity using avalanche photodiodes.

Construction of a Chemical Sensor/Instrumentation Package Using Fiber Optic and Miniaturization Technology

NASA Technical Reports Server (NTRS)

Newton, R. L.

1999-01-01

The objective of this research was to construct a chemical sensor/instrumentation package that was smaller in weight and volume than conventional instrumentation. This reduction in weight and volume is needed to assist in further reducing the cost of launching payloads into space. To accomplish this, fiber optic sensors, miniaturized spectrometers, and wireless modems were employed. The system was evaluated using iodine as a calibration analyte.

Miniature X-Ray Solar Spectrometer: A Science-Oriented, University 3U CubeSat

NASA Technical Reports Server (NTRS)

Mason, James P.; Woods, Thomas N.; Caspi, Amir; Chamberlin, Phillip C.; Moore, Christopher; Jones, Andrew; Kohnert, Rick; Li, Xinlin; Palo, Scott; Solomon, Stanley C.

2016-01-01

The miniature x-ray solar spectrometer is a three-unit CubeSat developed at the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. Over 40 students contributed to the project with professional mentorship and technical contributions from professors in the Aerospace Engineering Sciences Department at University of Colorado, Boulder and from Laboratory for Atmospheric and Space Physics scientists and engineers. The scientific objective of the miniature x-ray solar spectrometer is to study processes in the dynamic sun, from quiet sun to solar flares, and to further understand how these changes in the sun influence the Earth's atmosphere by providing unique spectral measurements of solar soft x-rays. The enabling technology providing the advanced solar soft x-ray spectral measurements is the Amptek X123, a commercial off-the-shelf silicon drift detector. The Amptek X123 has a low mass (approx. 324 g after modification), modest power consumption (approx. 2.50 W), and small volume (6.86 x 9.91 x 2.54 cm), making it ideal for a CubeSat. This paper provides an overview of the miniature x-ray solar spectrometer mission: the science objectives, project history, subsystems, and lessons learned, which can be useful for the small-satellite community.

A Survey of Compact Star Clusters in the South-West Field of the M 31 Disk

NASA Astrophysics Data System (ADS)

Kodaira, Keiichi; Vansevičius, Vladas; Bridzius, Audrius; Komiyama, Yutaka; Miyazaki, Satoshi; Stonkute, Rima; Šablevičiutė, Ieva; Narbutis, Donatas

2004-12-01

A survey for compact clusters with a dimension of 10pc order was conducted in an area of about 500 square arc-minutes of the south-west part of the M31 disk, making use of the high-resolution capability of Suprime-Cam. Photometry in the B, V, and R broad-bands, and in the R* medium-band centered around Hα with varying apertures was carried out for about 1200 targets, which are related to about 300 compact objects detected in the survey. The results for 101 prominent compact objects are presented as photometric catalogues and morphological atlases, separately for samples with and without strong Hα emission. Many of the compact objects, which were previously suspected to be globular cluster candidates, are judged to be open clusters based upon their internal structures of sub-arc-second order. The majority of the 49 listed compact non-emission objects, which are restricted to be brighter than MV ˜ -5, have colors of 0 < B - V < 1.0, indicating their nature of massive evolved clusters. In contrast, only about 10% of the 52 listed compact emission objects are brighter than MiV ˜ -5, probably reflecting the short period of the emission phase and the substantial effects of the circum-stellar extinction. The detection of a few candidates of background galaxies is also reported.

Miniaturized Cassegrainian concentrator concept demonstration

NASA Technical Reports Server (NTRS)

Patterson, R. E.; Rauschenbach, H. S.

1982-01-01

High concentration ratio photovoltaic systems for space applications have generally been considered impractical because of perceived difficulties in controlling solar cell temperatures to reasonably low values. A miniaturized concentrator system is now under development which surmounts this objection by providing acceptable solar cell temperatures using purely passive cell cooling methods. An array of identical miniaturized, rigid Cassegrainian optical systems having a low f-number with resulting short dimensions along their optical axes are rigidly mounted into a frame to form a relatively thin concentrator solar array panel. A number of such panels, approximately 1.5 centimeters thick, are wired as an array and are folded against one another for launch in a stowed configuration. Deployment on orbit is similar to the deployment of conventional planar honeycomb panel arrays or flexible blanket arrays. The miniaturized concept was conceived and studied in the 1978-80 time frame. Progress in the feasibility demonstration to date is reported.

Miniature Laser Tracker

DOEpatents

Vann, Charles S.

2003-09-09

This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

Lower bound on the compactness of isotropic ultracompact objects

NASA Astrophysics Data System (ADS)

Hod, Shahar

2018-04-01

Horizonless spacetimes describing spatially regular ultracompact objects which, like black-hole spacetimes, possess closed null circular geodesics (light rings) have recently attracted much attention from physicists and mathematicians. In the present paper we raise the following physically intriguing question: how compact is an ultracompact object? Using analytical techniques, we prove that ultracompact isotropic matter configurations with light rings are characterized by the dimensionless lower bound maxr{2 m (r )/r }>7 /12 on their global compactness parameter.

Gravitational-wave signatures of exotic compact objects and of quantum corrections at the horizon scale

NASA Astrophysics Data System (ADS)

Cardoso, Vitor; Hopper, Seth; Macedo, Caio F. B.; Palenzuela, Carlos; Pani, Paolo

2016-10-01

Gravitational waves from binary coalescences provide one of the cleanest signatures of the nature of compact objects. It has been recently argued that the postmerger ringdown waveform of exotic ultracompact objects is initially identical to that of a black hole, and that putative corrections at the horizon scale will appear as secondary pulses after the main burst of radiation. Here we extend this analysis in three important directions: (i) we show that this result applies to a large class of exotic compact objects with a photon sphere for generic orbits in the test-particle limit; (ii) we investigate the late-time ringdown in more detail, showing that it is universally characterized by a modulated and distorted train of "echoes"of the modes of vibration associated with the photon sphere; (iii) we study for the first time equal-mass, head-on collisions of two ultracompact boson stars and compare their gravitational-wave signal to that produced by a pair of black holes. If the initial objects are compact enough as to mimic a binary black-hole collision up to the merger, the final object exceeds the maximum mass for boson stars and collapses to a black hole. This suggests that—in some configurations—the coalescence of compact boson stars might be almost indistinguishable from that of black holes. On the other hand, generic configurations display peculiar signatures that can be searched for in gravitational-wave data as smoking guns of exotic compact objects.

Miniature Heat Transport System for Nanosatellite Technology

NASA Technical Reports Server (NTRS)

Douglas, Donya M,

1999-01-01

The scientific understanding of key physical processes between the Sun and the Earth require simultaneous measurements from many vantage points in space. Nano-satellite technologies will enable a class of constellation missions for the NASA Space Science Sun-Earth Connections. This recent emphasis on the implementation of smaller satellites leads to a requirement for development of smaller subsystems in several areas. Key technologies under development include: advanced miniaturized chemical propulsion; miniaturized sensors; highly integrated, compact electronics; autonomous onboard and ground operations; miniatures low power tracking techniques for orbit determination; onboard RF communications capable of transmitting data to the ground from far distances; lightweight efficient solar array panels; lightweight, high output battery cells; lightweight yet strong composite materials for the nano-spacecraft and deployer-ship structures. These newer smaller systems may have higher power densities and higher thermal transport requirements than seen on previous small satellites. Furthermore, the small satellites may also have a requirement to maintain thermal control through extended earth shadows, possibly up to 8 hours long. Older thermal control technology, such as heaters, thermostats, and heat pipes, may not be sufficient to meet the requirements of these new systems. Conversely, a miniature two-phase heat transport system (Mini-HTS) such as a Capillary Pumped Loop (CPL) or Loop Heat Pipe (LBP) is a viable alternative. A Mini-HTS can provide fine temperature control, thermal diode action, and a highly efficient means of heat transfer. The Mini-HTS would have power capabilities in the range of tens of watts or less and provide thermal control over typical spacecraft ranges. The Mini-HTS would allow the internal portion of the spacecraft to be thermally isolated from the external radiator, thus protecting the internal components from extreme cold temperatures during an eclipse. The Mini-HTS would transport the beat from these components to a radiator during their operational modes, and it would be shutdown during non-operational or eclipse modes. Shutdown of the Mini-HTS would be accomplished with small heaters and has been successfully demonstrated on numerous occasions, both in the lab and on flight experiments. Efforts are now underway to miniaturize two-phase heat transport systems for the Nanosatellite project, with potential application to other small satellite programs. 'ne goal of this project is to design, build, and test miniature heat transport systems (MHTS) that would demonstrate the feasibility of a small Capillary Pumped Loop (CPL) or Loop Heat Pipe (LBP).

Radiation dosimetry with fiber Bragg gratings

NASA Astrophysics Data System (ADS)

Avino, S.; D'Avino, V.; Giorgini, A.; Pacelli, R.; Liuzzi, R.; Cella, L.; Gagliardi, G.; De Natale, P.

2014-05-01

The measurement and monitoring of radiation dose delivered in patient tissues is a critical aspect in radiation therapy. Various dosimeters have proven effective in measuring radiations at low doses. However, there is a growing demand for new dosimeters based on small, non-invasive and high resolution devices. Here we report on a miniature dosimeter based on an optical fiber cavity. We demonstrate an ultimate detection limit of 160 mGy with an effective interaction region of 6 x 10-4 mm3. Due to its reliability, compactness and biomedical dose level sensitivity, our system shows itself suitable for applications in radiation therapy dosimetry.

Development of a miniature fan motor

NASA Astrophysics Data System (ADS)

Wang, Chien-Chang; Yao, Yeong-Der; Liang, Kun-Yi; Huang, Chung-Chun; Chang, Yu-Choung

2012-04-01

A novel compact axial flux fan motor was developed. Such a micromotor could be a potential candidate for using as the cooling solution for the next generation mobile devices, for example, smart phones and pico-projectors. The key parameters of the motor, such as back electromotive force, cogging torque, and axial preload are predicted using finite element method. In addition, new approaches are proposed to measure these items, and the corresponding experimental results are in good agreement with the simulated one. Moreover, the undesired vibration harmonic is successfully suppressed, and the fan motor represents a high static pressure and air flow rate.

Nanosatellite Power System Considerations

NASA Technical Reports Server (NTRS)

Robyn, M.; Thaller, L.; Scott, D.

1995-01-01

The capability to build complex electronic functions into compact packages is opening the path to miniature satellites on the order of 1 kg mass, 10 cm across, packed with the computing processors, motion controllers, measurement sensors, and communications hardware necessary for operation. Power generation will be from short strings of silicon or gallium arsenide-based solar photovoltaic cells with the array power maximized by a peak power tracker (PPT). Energy storage will utilize a low voltage battery with nickel cadmium or lithium ion cells as the most likely selections for rechargeables and lithium (MnO2-Li) primary batteries for one shot short missions.

Development of integrated optical tracking sensor by planar optics

NASA Astrophysics Data System (ADS)

Kawano, Hiroyuki; Sasagawa, Tomohiro; Nishimae, Junichi; Sato, Yukio

1999-03-01

A compact and light weight optical tracking sensor for a large capacity flexible disk drive is demonstrated. The size of the optical element is no larger than 5.4 mm in length X 3.6 mm in width X 1.2 mm in height and the weight is only 18 mg. The application of the planar optical technique makes it possible to integrate all passive optical elements onto one transparent substrate. These features are useful for high- speed access, easy optical alignment, mass production, and miniaturization. The design and optical characteristics of the optical tracking sensor are described.

Miniaturized Pi (Π) - Slit monopole antenna for 2.4/5.2/5.8 applications

NASA Astrophysics Data System (ADS)

Chandan, Bharti, Gagandeep; Bharti, Pradutt Kumar; Rai, B. S.

2018-04-01

In present paper, two - shaped slots are inserted in a rectangular patch of a monopole antenna for dual band operation. The antenna design is very simple, compact and light weight with overall dimension 29×38×0.8 mm3. Prototype of the proposed antenna is constructed and tested to verify its usefulness for 2.4/5.2/5.8 ghz wlan/wimax applications. It has been observed that both simulated and measured results have good agreement and measured peak gain and radiation pattern are suitable as per the need of application.

Parameterization of Shape and Compactness in Object-based Image Classification Using Quickbird-2 Imagery

NASA Astrophysics Data System (ADS)

Tonbul, H.; Kavzoglu, T.

2016-12-01

In recent years, object based image analysis (OBIA) has spread out and become a widely accepted technique for the analysis of remotely sensed data. OBIA deals with grouping pixels into homogenous objects based on spectral, spatial and textural features of contiguous pixels in an image. The first stage of OBIA, named as image segmentation, is the most prominent part of object recognition. In this study, multiresolution segmentation, which is a region-based approach, was employed to construct image objects. In the application of multi-resolution, three parameters, namely shape, compactness and scale must be set by the analyst. Segmentation quality remarkably influences the fidelity of the thematic maps and accordingly the classification accuracy. Therefore, it is of great importance to search and set optimal values for the segmentation parameters. In the literature, main focus has been on the definition of scale parameter, assuming that the effect of shape and compactness parameters is limited in terms of achieved classification accuracy. The aim of this study is to deeply analyze the influence of shape/compactness parameters by varying their values while using the optimal scale parameter determined by the use of Estimation of Scale Parameter (ESP-2) approach. A pansharpened Qickbird-2 image covering Trabzon, Turkey was employed to investigate the objectives of the study. For this purpose, six different combinations of shape/compactness were utilized to make deductions on the behavior of shape and compactness parameters and optimal setting for all parameters as a whole. Objects were assigned to classes using nearest neighbor classifier in all segmentation observations and equal number of pixels was randomly selected to calculate accuracy metrics. The highest overall accuracy (92.3%) was achieved by setting the shape/compactness criteria to 0.3/0.3. The results of this study indicate that shape/compactness parameters can have significant effect on classification accuracy with 4% change in overall accuracy. Also, statistical significance of differences in accuracy was tested using the McNemar's test and found that the difference between poor and optimal setting of shape/compactness parameters was statistically significant, suggesting a search for optimal parameterization instead of default setting.

Miniature objective lens with variable focus for confocal endomicroscopy

PubMed Central

Kim, Minkyu; Kang, DongKyun; Wu, Tao; Tabatabaei, Nima; Carruth, Robert W.; Martinez, Ramses V; Whitesides, George M.; Nakajima, Yoshikazu; Tearney, Guillermo J.

2014-01-01

Spectrally encoded confocal microscopy (SECM) is a reflectance confocal microscopy technology that can rapidly image large areas of luminal organs at microscopic resolution. One of the main challenges for large-area SECM imaging in vivo is maintaining the same imaging depth within the tissue when patient motion and tissue surface irregularity are present. In this paper, we report the development of a miniature vari-focal objective lens that can be used in an SECM endoscopic probe to conduct adaptive focusing and to maintain the same imaging depth during in vivo imaging. The vari-focal objective lens is composed of an aspheric singlet with an NA of 0.5, a miniature water chamber, and a thin elastic membrane. The water volume within the chamber was changed to control curvature of the elastic membrane, which subsequently altered the position of the SECM focus. The vari-focal objective lens has a diameter of 5 mm and thickness of 4 mm. A vari-focal range of 240 μm was achieved while maintaining lateral resolution better than 2.6 μm and axial resolution better than 26 μm. Volumetric SECM images of swine esophageal tissues were obtained over the vari-focal range of 260 μm. SECM images clearly visualized cellular features of the swine esophagus at all focal depths, including basal cell nuclei, papillae, and lamina propria. PMID:25574443

Topology-preserving quantum deformation with non-numerical parameter

NASA Astrophysics Data System (ADS)

Aukhadiev, Marat; Grigoryan, Suren; Lipacheva, Ekaterina

2013-11-01

We introduce a class of compact quantum semigroups, that we call semigroup deformations of compact Abelian qroups. These objects arise from reduced semigroup -algebras, the generalization of the Toeplitz algebra. We study quantum subgroups, quantum projective spaces and quantum quotient groups for such objects, and show that the group is contained as a compact quantum subgroup in the deformation of itself. The connection with the weak Hopf algebra notion is described. We give a grading on the -algebra of the compact quantum semigroups constructed.

Miniaturized Lab System for Future Cold Atom Experiments in Microgravity

NASA Astrophysics Data System (ADS)

Kulas, Sascha; Vogt, Christian; Resch, Andreas; Hartwig, Jonas; Ganske, Sven; Matthias, Jonas; Schlippert, Dennis; Wendrich, Thijs; Ertmer, Wolfgang; Maria Rasel, Ernst; Damjanic, Marcin; Weßels, Peter; Kohfeldt, Anja; Luvsandamdin, Erdenetsetseg; Schiemangk, Max; Grzeschik, Christoph; Krutzik, Markus; Wicht, Andreas; Peters, Achim; Herrmann, Sven; Lämmerzahl, Claus

2017-02-01

We present the technical realization of a compact system for performing experiments with cold 87Rb and 39K atoms in microgravity in the future. The whole system fits into a capsule to be used in the drop tower Bremen. One of the advantages of a microgravity environment is long time evolution of atomic clouds which yields higher sensitivities in atom interferometer measurements. We give a full description of the system containing an experimental chamber with ultra-high vacuum conditions, miniaturized laser systems, a high-power thulium-doped fiber laser, the electronics and the power management. In a two-stage magneto-optical trap atoms should be cooled to the low μK regime. The thulium-doped fiber laser will create an optical dipole trap which will allow further cooling to sub- μK temperatures. The presented system fulfills the demanding requirements on size and power management for cold atom experiments on a microgravity platform, especially with respect to the use of an optical dipole trap. A first test in microgravity, including the creation of a cold Rb ensemble, shows the functionality of the system.

Widely tunable Fabry-Perot filter based MWIR and LWIR microspectrometers

NASA Astrophysics Data System (ADS)

Ebermann, Martin; Neumann, Norbert; Hiller, Karla; Gittler, Elvira; Meinig, Marco; Kurth, Steffen

2012-06-01

As is generally known, miniature infrared spectrometers have great potential, e. g. for process and environmental analytics or in medical applications. Many efforts are being made to shrink conventional spectrometers, such as FTIR or grating based devices. A more rigorous approach for miniaturization is the use of MEMS technologies. Based on an established design for the MWIR new MEMS Fabry-Perot filters and sensors with expanded spectral ranges in the LWIR have been developed. The range 5.5 - 8 μm is particularly suited for the analysis of liquids. A dual-band sensor, which can be simultaneously tuned from 4 - 5 μm and 8 - 11 μm for the measurement of anesthetics and carbon dioxide has also been developed. A new material system is used to reduce internal stress in the reflector layer stack. Good results in terms of finesse (<= 60) and transmittance (<= 80 %) could be demonstrated. The hybrid integration of the filter in a pyroelectric detector results in very compact, robust and cost effective microspectrometers. FP filters with two moveable reflectors instead of only one reduce significantly the acceleration sensitivity and actuation voltage.

Thermo-mechanical actuator-based miniature tagging module for localization in capsule endoscopy

NASA Astrophysics Data System (ADS)

Chandrappan, Jayakrishnan; Ruiqi, Lim; Su, Nandar; Yen Yi, Germaine Hoe; Vaidyanathan, Kripesh

2011-04-01

Capsule endoscopy is a frontline medical diagnostic tool for the gastro intestinal tract disorders. During diagnosis, efficient localization techniques are essential to specify a pathological area that may require further diagnosis or treatment. This paper presents the development of a miniature tagging module that relies on a novel concept to label the region of interest and has the potential to integrate with a capsule endoscope. The tagging module is a compact thermo-mechanical actuator loaded with a biocompatible micro tag. A low power microheater attached to the module serves as the thermal igniter for the mechanical actuator. At optimum temperature, the actuator releases the micro tag instantly and penetrates the mucosa layer of a GI tract, region of interest. Ex vivo animal trials are conducted to verify the feasibility of the tagging module concept. X-ray imaging is used to detect the location of the micro tag embedded in the GI tract wall. The method is successful, and radiopaque micro tags can provide valuable pre-operative position information on the infected area to facilitate further clinical procedures.

Miniature star tracker for small remote sensing satellites

NASA Astrophysics Data System (ADS)

Cassidy, Lawrence W.; Schlom, Leslie

1995-01-01

Designers of future remote sensing spacecraft, including platforms for Mission to Planet Earth and small satellites, will be driven to provide spacecraft designs that maximize data return and minimize hardware and operating costs. The attitude determination subsystems of these spacecraft must likewise provide maximum capability and versatility at an affordable price. Hughes Danbury Optical Systems (HDOS) has developed the Model HD-1003 Miniature Star Tracker which combines high accuracy, high reliability and growth margin for `all-stellar' capability in a compact, radiation tolerant design that meets these future spacecraft needs and whose cost is competitive with horizon sensors and digital fine sum sensors. Begun in 1991, our HD-1003 development program has now entered the hardware qualification phase. This paper acquaints spacecraft designers with the design and performance capabilities of the HD- 1003 tracker. We highlight the tracker's unique features which include: (1) Very small size (165 cu. in.). (2) Low weight (7 lbs). (3) Multi-star tracking (6 stars simultaneously). (4) Eighteen arc-sec (3-sigma) accuracy. (5) Growth margin for `all-stellar' attitude reference.

M32 analogs? A population of massive ultra-compact dwarf and compact elliptical galaxies in intermediate-redshift clusters

DOE PAGES

Zhang, Yuanyuan; Bell, Eric F.

2017-01-13

Here, we report the discovery of relatively massive, M32-like ultra compact dwarf (UCD) and compact elliptical (CE) galaxy candidates inmore » $$0.2\\lt z\\lt 0.6$$ massive galaxy clusters imaged by the Cluster Lensing And Supernova survey with Hubble (CLASH) survey. Examining the nearly unresolved objects in the survey, we identify a sample of compact objects concentrated around the cluster central galaxies with colors similar to cluster red sequence galaxies. Their colors and magnitudes suggest stellar masses around $${10}^{9}{M}_{\\odot }$$. More than half of these galaxies have half-light radii smaller than 200 pc, falling into the category of massive UCDs and CEs, with properties similar to M32. The properties are consistent with a tidal stripping origin, but we cannot rule out the possibility that they are early-formed compact objects trapped in massive dark matter halos. The 17 CLASH clusters studied in this work on average contain 2.7 of these objects in their central 0.3 Mpc and 0.6 in their central 50 kpc. Our study demonstrates the possibility of statistically characterizing UCDs/CEs with a large set of uniform imaging survey data.« less

M32 analogs? A population of massive ultra-compact dwarf and compact elliptical galaxies in intermediate-redshift clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yuanyuan; Bell, Eric F.

Here, we report the discovery of relatively massive, M32-like ultra compact dwarf (UCD) and compact elliptical (CE) galaxy candidates inmore » $$0.2\\lt z\\lt 0.6$$ massive galaxy clusters imaged by the Cluster Lensing And Supernova survey with Hubble (CLASH) survey. Examining the nearly unresolved objects in the survey, we identify a sample of compact objects concentrated around the cluster central galaxies with colors similar to cluster red sequence galaxies. Their colors and magnitudes suggest stellar masses around $${10}^{9}{M}_{\\odot }$$. More than half of these galaxies have half-light radii smaller than 200 pc, falling into the category of massive UCDs and CEs, with properties similar to M32. The properties are consistent with a tidal stripping origin, but we cannot rule out the possibility that they are early-formed compact objects trapped in massive dark matter halos. The 17 CLASH clusters studied in this work on average contain 2.7 of these objects in their central 0.3 Mpc and 0.6 in their central 50 kpc. Our study demonstrates the possibility of statistically characterizing UCDs/CEs with a large set of uniform imaging survey data.« less

Turbo-Brayton cryocooler technology for low-temperature space applications

NASA Astrophysics Data System (ADS)

Zagarola, Mark V.; Breedlove, Jeffrey F.; McCormick, John A.; Swift, Walter L.

2003-03-01

High performance, low temperature cryocoolers are being developed for future space-borne telescopes and instruments. To meet mission objectives, these coolers must be compact, lightweight, have low input power, operate reliably for 5-10 years, and produce no disturbances that would affect the pointing accuracy of the instruments. This paper describes progress in the development of turbo-Brayton cryocoolers addressing cooling in the 5 K to 20 K temperature range for loads of up to 300 mW. The key components for these cryocoolers are the miniature, high-speed turbomachines and the high performance recuperative heat exchangers. The turbomachines use gas-bearings to support the low mass, high speed rotors, resulting in negligible vibration and long life. Precision fabrication techniques are used to produce the necessary micro-scale geometric features that provide for high cycle efficiencies at these reduced sizes. Turbo-Brayton cryocoolers for higher temperatures and loads have been successfully developed for space applications. For efficient operation at low temperatures and capacities, advances in the core technologies have been pursued. Performance test results of a new, low poer compressor will be presented, and early cryogenic test results on a low temperature expansion turbine will be discussed. Projections for several low temperature cooler configurations are summarized.

Ultrahigh-rate supercapacitors based on eletrochemically reduced graphene oxide for ac line-filtering.

PubMed

Sheng, Kaixuan; Sun, Yiqing; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

2012-01-01

The recent boom in multifunction portable electronic equipments requires the development of compact and miniaturized electronic circuits with high efficiencies, low costs and long lasting time. For the operation of most line-powered electronics, alternating current (ac) line-filters are used to attenuate the leftover ac ripples on direct current (dc) voltage busses. Today, aluminum electrolytic capacitors (AECs) are widely applied for this purpose. However, they are usually the largest components in electronic circuits. Replacing AECs by more compact capacitors will have an immense impact on future electronic devices. Here, we report a double-layer capacitor based on three-dimensional (3D) interpenetrating graphene electrodes fabricated by electrochemical reduction of graphene oxide (ErGO-DLC). At 120-hertz, the ErGO-DLC exhibited a phase angle of -84 degrees, a specific capacitance of 283 microfaradays per centimeter square and a resistor-capacitor (RC) time constant of 1.35 milliseconds, making it capable of replacing AECs for the application of 120-hertz filtering.

Ultrahigh-rate supercapacitors based on eletrochemically reduced graphene oxide for ac line-filtering

NASA Astrophysics Data System (ADS)

Sheng, Kaixuan; Sun, Yiqing; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

2012-02-01

The recent boom in multifunction portable electronic equipments requires the development of compact and miniaturized electronic circuits with high efficiencies, low costs and long lasting time. For the operation of most line-powered electronics, alternating current (ac) line-filters are used to attenuate the leftover ac ripples on direct current (dc) voltage busses. Today, aluminum electrolytic capacitors (AECs) are widely applied for this purpose. However, they are usually the largest components in electronic circuits. Replacing AECs by more compact capacitors will have an immense impact on future electronic devices. Here, we report a double-layer capacitor based on three-dimensional (3D) interpenetrating graphene electrodes fabricated by electrochemical reduction of graphene oxide (ErGO-DLC). At 120-hertz, the ErGO-DLC exhibited a phase angle of -84 degrees, a specific capacitance of 283 microfaradays per centimeter square and a resistor-capacitor (RC) time constant of 1.35 milliseconds, making it capable of replacing AECs for the application of 120-hertz filtering.

Ultrahigh-rate supercapacitors based on eletrochemically reduced graphene oxide for ac line-filtering

PubMed Central

Sheng, Kaixuan; Sun, Yiqing; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

2012-01-01

The recent boom in multifunction portable electronic equipments requires the development of compact and miniaturized electronic circuits with high efficiencies, low costs and long lasting time. For the operation of most line-powered electronics, alternating current (ac) line-filters are used to attenuate the leftover ac ripples on direct current (dc) voltage busses. Today, aluminum electrolytic capacitors (AECs) are widely applied for this purpose. However, they are usually the largest components in electronic circuits. Replacing AECs by more compact capacitors will have an immense impact on future electronic devices. Here, we report a double-layer capacitor based on three-dimensional (3D) interpenetrating graphene electrodes fabricated by electrochemical reduction of graphene oxide (ErGO-DLC). At 120-hertz, the ErGO-DLC exhibited a phase angle of −84 degrees, a specific capacitance of 283 microfaradays per centimeter square and a resistor-capacitor (RC) time constant of 1.35 milliseconds, making it capable of replacing AECs for the application of 120-hertz filtering. PMID:22355759

Compact, multi-exposure speckle contrast optical spectroscopy (SCOS) device for measuring deep tissue blood flow

PubMed Central

Dragojević, Tanja; Hollmann, Joseph L.; Tamborini, Davide; Portaluppi, Davide; Buttafava, Mauro; Culver, Joseph P.; Villa, Federica; Durduran, Turgut

2017-01-01

Speckle contrast optical spectroscopy (SCOS) measures absolute blood flow in deep tissue, by taking advantage of multi-distance (previously reported in the literature) or multi-exposure (reported here) approach. This method promises to use inexpensive detectors to obtain good signal-to-noise ratio, but it has not yet been implemented in a suitable manner for a mass production. Here we present a new, compact, low power consumption, 32 by 2 single photon avalanche diode (SPAD) array that has no readout noise, low dead time and has high sensitivity in low light conditions, such as in vivo measurements. To demonstrate the capability to measure blood flow in deep tissue, healthy volunteers were measured, showing no significant differences from the diffuse correlation spectroscopy. In the future, this array can be miniaturized to a low-cost, robust, battery operated wireless device paving the way for measuring blood flow in a wide-range of applications from sport injury recovery and training to, on-field concussion detection to wearables. PMID:29359106

An integrated compact airborne multispectral imaging system using embedded computer

NASA Astrophysics Data System (ADS)

Zhang, Yuedong; Wang, Li; Zhang, Xuguo

2015-08-01

An integrated compact airborne multispectral imaging system using embedded computer based control system was developed for small aircraft multispectral imaging application. The multispectral imaging system integrates CMOS camera, filter wheel with eight filters, two-axis stabilized platform, miniature POS (position and orientation system) and embedded computer. The embedded computer has excellent universality and expansibility, and has advantages in volume and weight for airborne platform, so it can meet the requirements of control system of the integrated airborne multispectral imaging system. The embedded computer controls the camera parameters setting, filter wheel and stabilized platform working, image and POS data acquisition, and stores the image and data. The airborne multispectral imaging system can connect peripheral device use the ports of the embedded computer, so the system operation and the stored image data management are easy. This airborne multispectral imaging system has advantages of small volume, multi-function, and good expansibility. The imaging experiment results show that this system has potential for multispectral remote sensing in applications such as resource investigation and environmental monitoring.

A Compact Microwave Microfluidic Sensor Using a Re-Entrant Cavity.

PubMed

Hamzah, Hayder; Abduljabar, Ali; Lees, Jonathan; Porch, Adrian

2018-03-19

A miniaturized 2.4 GHz re-entrant cavity has been designed, manufactured and tested as a sensor for microfluidic compositional analysis. It has been fully evaluated experimentally with water and common solvents, namely methanol, ethanol, and chloroform, with excellent agreement with the expected behaviour predicted by the Debye model. The sensor's performance has also been assessed for analysis of segmented flow using water and oil. The samples' interaction with the electric field in the gap region has been maximized by aligning the sample tube parallel to the electric field in this region, and the small width of the gap (typically 1 mm) result in a highly localised complex permittivity measurement. The re-entrant cavity has simple mechanical geometry, small size, high quality factor, and due to the high concentration of electric field in the gap region, a very small mode volume. These factors combine to result in a highly sensitive, compact sensor for both pure liquids and liquid mixtures in capillary or microfluidic environments.

Assessment of a miniature four-roll mill and a cross-slot microchannel for high-strain-rate stagnation point flows

NASA Astrophysics Data System (ADS)

Akbaridoust, Farzan; Philip, Jimmy; Marusic, Ivan

2018-04-01

Stagnation point flows have been widely used to study the deformation and break-up of objects in two-dimensional pure straining flows. Here, we report a systematic study of the characterisation of stagnation point flows in two devices, a miniature Taylor’s four-roll mill and a cross-slot microchannel. The aim of the study is to find the best platform suitable for investigating the effect of strain rate on the mechanical properties of waterborne microorganisms. Using micro-PIV, the velocity field and the strain rates in both devices were measured at different flow rates and compared with an ideal hyperbolic stagnation point flow. The cross-slot microchannel was found to be a better experimental device than the miniature four-roll mill for the purpose of confining micron-sized objects in a controlled stagnation point flow. This is mainly due to the difficulty of maintaining a fixed location for the stagnation point within one micron in the miniature four-roll mill and achieving high strain rates beyond 10 s-1 . However, with no moving parts, the cross-slot microchannel was found to maintain a steady flow, with the stagnation point varying less than one micron at a cross-junction of 400× 400~μm2 , and was able to reach uniform strain rates up to 140 s-1 .

NASA Tech Briefs, February 2004

NASA Technical Reports Server (NTRS)

2004-01-01

Topics include: Simulation Testing of Embedded Flight Software; Improved Indentation Test for Measuring Nonlinear Elasticity; Ultraviolet-Absorption Spectroscopic Biofilm Monitor; Electronic Tongue for Quantitation of Contaminants in Water; Radar for Measuring Soil Moisture Under Vegetation; Modular Wireless Data-Acquisition and Control System; Microwave System for Detecting Ice on Aircraft; Routing Algorithm Exploits Spatial Relations; Two-Finger EKG Method of Detecting Evasive Responses; Updated System-Availability and Resource-Allocation Program; Routines for Computing Pressure Drops in Venturis; Software for Fault-Tolerant Matrix Multiplication; Reproducible Growth of High-Quality Cubic-SiC Layers; Nonlinear Thermoelastic Model for SMAs and SMA Hybrid Composites; Liquid-Crystal Thermosets, a New Generation of High-Performance Liquid-Crystal Polymers; Formulations for Stronger Solid Oxide Fuel-Cell Electrolytes; Simulation of Hazards and Poses for a Rocker-Bogie Rover; Autonomous Formation Flight; Expandable Purge Chambers Would Protect Cryogenic Fittings; Wavy-Planform Helicopter Blades Make Less Noise; Miniature Robotic Spacecraft for Inspecting Other Spacecraft; Miniature Ring-Shaped Peristaltic Pump; Compact Plasma Accelerator; Improved Electrohydraulic Linear Actuators; A Software Architecture for Semiautonomous Robot Control; Fabrication of Channels for Nanobiotechnological Devices; Improved Thin, Flexible Heat Pipes; Miniature Radioisotope Thermoelectric Power Cubes; Permanent Sequestration of Emitted Gases in the Form of Clathrate Hydrates; Electrochemical, H2O2-Boosted Catalytic Oxidation System; Electrokinetic In Situ Treatment of Metal-Contaminated Soil; Pumping Liquid Oxygen by Use of Pulsed Magnetic Fields; Magnetocaloric Pumping of Liquid Oxygen; Tailoring Ion-Thruster Grid Apertures for Greater Efficiency; and Lidar for Guidance of a Spacecraft or Exploratory Robot.

Comparison of Uncalibrated Rgbvi with Spectrometer-Based Ndvi Derived from Uav Sensing Systems on Field Scale

NASA Astrophysics Data System (ADS)

Bareth, G.; Bolten, A.; Gnyp, M. L.; Reusch, S.; Jasper, J.

2016-06-01

The development of UAV-based sensing systems for agronomic applications serves the improvement of crop management. The latter is in the focus of precision agriculture which intends to optimize yield, fertilizer input, and crop protection. Besides, in some cropping systems vehicle-based sensing devices are less suitable because fields cannot be entered from certain growing stages onwards. This is true for rice, maize, sorghum, and many more crops. Consequently, UAV-based sensing approaches fill a niche of very high resolution data acquisition on the field scale in space and time. While mounting RGB digital compact cameras to low-weight UAVs (< 5 kg) is well established, the miniaturization of sensors in the last years also enables hyperspectral data acquisition from those platforms. From both, RGB and hyperspectral data, vegetation indices (VIs) are computed to estimate crop growth parameters. In this contribution, we compare two different sensing approaches from a low-weight UAV platform (< 5 kg) for monitoring a nitrogen field experiment of winter wheat and a corresponding farmers' field in Western Germany. (i) A standard digital compact camera was flown to acquire RGB images which are used to compute the RGBVI and (ii) NDVI is computed from a newly modified version of the Yara N-Sensor. The latter is a well-established tractor-based hyperspectral sensor for crop management and is available on the market since a decade. It was modified for this study to fit the requirements of UAV-based data acquisition. Consequently, we focus on three objectives in this contribution: (1) to evaluate the potential of the uncalibrated RGBVI for monitoring nitrogen status in winter wheat, (2) investigate the UAV-based performance of the modified Yara N-Sensor, and (3) compare the results of the two different UAV-based sensing approaches for winter wheat.

Micro-optical artificial compound eyes.

PubMed

Duparré, J W; Wippermann, F C

2006-03-01

Natural compound eyes combine small eye volumes with a large field of view at the cost of comparatively low spatial resolution. For small invertebrates such as flies or moths, compound eyes are the perfectly adapted solution to obtaining sufficient visual information about their environment without overloading their brains with the necessary image processing. However, to date little effort has been made to adopt this principle in optics. Classical imaging always had its archetype in natural single aperture eyes which, for example, human vision is based on. But a high-resolution image is not always required. Often the focus is on very compact, robust and cheap vision systems. The main question is consequently: what is the better approach for extremely miniaturized imaging systems-just scaling of classical lens designs or being inspired by alternative imaging principles evolved by nature in the case of small insects? In this paper, it is shown that such optical systems can be achieved using state-of-the-art micro-optics technology. This enables the generation of highly precise and uniform microlens arrays and their accurate alignment to the subsequent optics-, spacing- and optoelectronics structures. The results are thin, simple and monolithic imaging devices with a high accuracy of photolithography. Two different artificial compound eye concepts for compact vision systems have been investigated in detail: the artificial apposition compound eye and the cluster eye. Novel optical design methods and characterization tools were developed to allow the layout and experimental testing of the planar micro-optical imaging systems, which were fabricated for the first time by micro-optics technology. The artificial apposition compound eye can be considered as a simple imaging optical sensor while the cluster eye is capable of becoming a valid alternative to classical bulk objectives but is much more complex than the first system.

New Evidence for a Black Hole in the Compact Binary Cygnus X-3

NASA Technical Reports Server (NTRS)

Shrader, Chris R.; Titarchuk, Lev; Shaposhnikov, Nikolai

2010-01-01

The bright and highly variable X-ray and radio source known as Cygnus X-3 was among the first X-ray sources discovered, yet it remains in many ways an enigma. Its known to consist of a massive. Wolf-Rayet primary in an extremely tight orbit with a compact object. Yet one of the most basic of pa.ranietern the mass of the compact object - is not known. Nor is it even clear whether its is a neutron star or a black hole. In this Paper we present our analysis of the broad-band high-energy continua covering a substantial range in luminosity and spectral morphology. We apply these results to a recently identified scaling relationship which has been demonstrated to provide reliable estimates of the compact object mass in a number of accretion powered binaries. This analysis leads us to conclude that the compact object in Cygnus X-3 has a mass greater than 4.2 solar mass thus clearly indicative of a black hole and as such resolving a longstanding issue. The full range of uncertainty in our analysis and from using a. range of recently published distance estimates constrains the compact object mass to lie between 4.2 solar mass and 14.4 solar mass. Our favored estimate, based on a 9.0 kpc distance estimate is approx. l0 solar mass, with the. error margin of 3.2 solar masses. This result may thus pose challenges to shared-envelope evolutionary models of compact binaries. as well as establishing Cygnus X-3 as the first confirmed accretion-powered galactic gamma: ray source.

A simple physical model for X-ray burst sources

NASA Technical Reports Server (NTRS)

Joss, P. C.; Rappaport, S.

1977-01-01

In connection with information considered by Illarianov and Sunyaev (1975) and van den Heuvel (1975), a simple physical model for an X-ray burst source in the galactic disk is proposed. The model includes an unevolved OB star with a relatively weak stellar wind and a compact object in a close binary system. For some reason, the stellar wind from the OB star is unable to accrete steadily on to the compact object. When the stellar wind is sufficiently weak, the compact object accretes irregularly, leading to X-ray bursts.

A New Compact Double-Negative Miniaturized Metamaterial for Wideband Operation.

PubMed

Hasan, Md Mehedi; Faruque, Mohammad Rashed Iqbal; Islam, Sikder Sunbeam; Islam, Mohammad Tariqul

2016-10-13

The aim of this paper is to introduce a compact double-negative (DNG) metamaterial that exhibits a negative refractive index (NRI) bandwidth of more than 3.6 GHz considering the frequency from 2 to 14 GHz. In this framework, two arms of the designed unit cell are split in a way that forms a Modified-Z-shape structure of the FR-4 substrate material. The finite integration technique (FIT)-based Computer Simulation Technology (CST) Microwave Studio is applied for computation, and the experimental setup for measuring the performance is performed inside two waveguide ports. Therefore, the measured data complies well with the simulated data of the unit cell at 0-degree and 90-degree rotation angles. The designed unit cell shows a negative refractive index from 3.482 to 7.096 GHz (bandwidth of 3.61 GHz), 7.876 to 10.047 GHz (bandwidth of 2.171 GHz), and 11.594 to 14 GHz (bandwidth of 2.406 GHz) in the microwave spectra. The design also exhibits almost the same wide negative refractive index bandwidth in the major region of the C-band and X-band if it is rotated 90 degrees. However, the novelty of the proposed structure lies in its effective medium ratio of more than 4, wide bandwidth, and compact size.

A New Compact Double-Negative Miniaturized Metamaterial for Wideband Operation

PubMed Central

Hasan, Md. Mehedi; Faruque, Mohammad Rashed Iqbal; Islam, Sikder Sunbeam; Islam, Mohammad Tariqul

2016-01-01

The aim of this paper is to introduce a compact double-negative (DNG) metamaterial that exhibits a negative refractive index (NRI) bandwidth of more than 3.6 GHz considering the frequency from 2 to 14 GHz. In this framework, two arms of the designed unit cell are split in a way that forms a Modified-Z-shape structure of the FR-4 substrate material. The finite integration technique (FIT)-based Computer Simulation Technology (CST) Microwave Studio is applied for computation, and the experimental setup for measuring the performance is performed inside two waveguide ports. Therefore, the measured data complies well with the simulated data of the unit cell at 0-degree and 90-degree rotation angles. The designed unit cell shows a negative refractive index from 3.482 to 7.096 GHz (bandwidth of 3.61 GHz), 7.876 to 10.047 GHz (bandwidth of 2.171 GHz), and 11.594 to 14 GHz (bandwidth of 2.406 GHz) in the microwave spectra. The design also exhibits almost the same wide negative refractive index bandwidth in the major region of the C-band and X-band if it is rotated 90 degrees. However, the novelty of the proposed structure lies in its effective medium ratio of more than 4, wide bandwidth, and compact size. PMID:28773951

Cryocoolers developments at Thales Cryogenics enabling compact remote sensing

NASA Astrophysics Data System (ADS)

Benschop, A.; van de Groep, W.; Mullié, J.; Willems, D.; Clesca, O.; Griot, R.; Martin, J.-Y.

2010-10-01

Thales Cryogenics (TCBV) has an extensive background in developing and delivering long-life cryogenic coolers for military, civil and space programs. This cooler range is based on three main compressor concepts: rotary compressors (RM), linear close tolerance contact seals (UP), and linear flexure bearing (LSF/LPT) compressors. The main differences - next to the different conceptual designs - between these products are their masses and Mean Time To Failure (MTTF) and the availability prediction of a single unit. New developments at Thales Cryogenics enabling compact long lifetime coolers - with an MTTF up to 50.000 hrs - will be outlined. In addition new developments for miniature cooler drive electronics with high temperature stability and power density will be described. These new cooler developments could be of particular interest for space missions where lower costs and mass are identified as important selection criteria. The developed compressors are originally connected to Stirling cold fingers that can directly be interfaced to different sizes of available dewars. Next to linear coolers, Thales Cryogenics has compact rotary coolers in its product portfolio. Though having a higher exported vibration level and a more limited MTTF of around 8.000 to 10.000 hours, their compactness and high efficiency could provide a good alternative for compact cooling of sensors in specific space missions. In this paper an overview of lifetime parameters will be listed versus the impact in the different cooler types. Tests results from both the installed base and the Thales Cryogenics test lab will be presented as well. Next to this differences in operational use for the different types of coolers as well as the outlook for further developments will be discussed.

Miniature traveling wave tube and method of making

NASA Technical Reports Server (NTRS)

Kosmahl, Henry G. (Inventor)

1989-01-01

It is an object of the invention to provide a miniature traveling wave tube which will have most of the advantages of solid state circuitry but with higher efficiency and without being highly sensitive to temperature and various types of electromagnetic radiation and subatomic particles as are solid state devices. The traveling wave tube which is about 2.5 cm in length includes a slow wave circuit (SWS) comprising apertured fins with a top cover which is insulated from the fins by strips or rungs of electrically insulating, dielectric material. Another object of the invention is to construct a SWS of extremely small size by employing various grooving or etching methods and by providing insulating strips or rungs by various deposition and masking techniques.

Deep Tissue Photoacoustic Imaging Using a Miniaturized 2-D Capacitive Micromachined Ultrasonic Transducer Array

PubMed Central

Kothapalli, Sri-Rajasekhar; Ma, Te-Jen; Vaithilingam, Srikant; Oralkan, Ömer

2014-01-01

In this paper, we demonstrate 3-D photoacoustic imaging (PAI) of light absorbing objects embedded as deep as 5 cm inside strong optically scattering phantoms using a miniaturized (4 mm × 4 mm × 500 µm), 2-D capacitive micromachined ultrasonic transducer (CMUT) array of 16 × 16 elements with a center frequency of 5.5 MHz. Two-dimensional tomographic images and 3-D volumetric images of the objects placed at different depths are presented. In addition, we studied the sensitivity of CMUT-based PAI to the concentration of indocyanine green dye at 5 cm depth inside the phantom. Under optimized experimental conditions, the objects at 5 cm depth can be imaged with SNR of about 35 dB and a spatial resolution of approximately 500 µm. Results demonstrate that CMUTs with integrated front-end amplifier circuits are an attractive choice for achieving relatively high depth sensitivity for PAI. PMID:22249594

Study on a New Combination Method and High Efficiency Outer Rotor Type Permanent Magnet Motors

NASA Astrophysics Data System (ADS)

Enomoto, Yuji; Kitamura, Masashi; Motegi, Yasuaki; Andoh, Takashi; Ochiai, Makoto; Abukawa, Toshimi

The segment stator core, high space factor coil, and high efficiency magnet are indispensable technologies in the development of compact and a high efficiency motors. But adoption of the segment stator core and high space factor coil has not progressed in the field of outer rotor type motors, for the reason that the inner components cannot be laser welded together. Therefore, we have examined a segment stator core combination technology for the purposes of getting a large increase in efficiency and realizing miniaturization. We have also developed a characteristic estimation method which provides the most suitable performance for segment stator core motors.

An automated miniaturized Haploscope for testing binocular visual function

NASA Technical Reports Server (NTRS)

Decker, T. A.; Williams, R. E.; Kuether, C. L.; Wyman-Cornsweet, D.

1976-01-01

A computer-controlled binocular vision testing device has been developed as one part of a system designed for NASA to test the vision of astronauts during spaceflight. The device, called the Mark III Haploscope, utilizes semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phorias, fixation disparity and accommodation/convergence relationships. All tests are self-administered, yield quantitative data and may be used repeatedly without subject memorization. Future applications of this programmable, compact device include its use as a clinical instrument to perform routine eye examinations or vision screening, and as a research tool to examine the effects of environment or work-cycle upon visual function.

Compact optical filter for dual-wavelength fluorescence-spectrometry based on enhanced transmission through metallic nano-slit array

NASA Astrophysics Data System (ADS)

Hu, X.; Zhan, L.; Xia, Y.

2009-03-01

A novel optical filter based on enhanced transmission through metallic nano-slit is proposed for dual-wavelength fluorescence-spectrometry. A special structure, sampled-period slit array, is utilized to meet the requirement of dual-wavelength transmission in this system. Structure parameters on the transmission property are analyzed by means of Fourier transformation. With the features both to enhance the fluorescence generation and to enhance light transmission, in addition with the feasibility for miniaturization, integration on one chip, and mass production, the proposed filters are promising for the realization of dual-wavelength fluorescence-spectrometry in micro-total-analysis-system.

Tool and process for miniature explosive joining of tubes

NASA Technical Reports Server (NTRS)

Bement, Laurence J. (Inventor); Bailey, James W. (Inventor)

1987-01-01

A tool and process to be used in the explosive joining of tubes is disclosed. The tool consists of an initiator, a tool form, and a ribbon explosive. The assembled tool is a compact, storable, and safe device suitable for explosive joining of small, lightweight tubes down to 0.20 inch in diameter. The invention is inserted into either another tube or a tube plate. A shim or standoff between the two surfaces to be welded is necessary. Initiation of the explosive inside the tube results in a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding wherein electron-sharing linkups are formed.

Design of inside cut von koch fractal UWB MIMO antenna

NASA Astrophysics Data System (ADS)

Tharani, V.; Shanmuga Priya, N.; Rajesh, A.

2017-11-01

An Inside Cut Hexagonal Von Koch fractal MIMO antenna is designed for UWB applications and its characteristics behaviour are studied. Self-comparative and space filling properties of Koch fractal structure are utilized in the antenna design which leads to the desired miniaturization and wideband characteristics. The hexagonal shaped Von Koch Fractal antenna with Defected Ground Structure (DGS) is designed on FR4 substrate with a compact size of 30mm x 20mm x 1.6mm. The antenna achieves a maximum of -44dB and -51dB at 7.1GHz for 1-element and 2-element case respectively.

GPS free navigation inspired by insects through monocular camera and inertial sensors

NASA Astrophysics Data System (ADS)

Liu, Yi; Liu, J. G.; Cao, H.; Huang, Y.

2015-12-01

Navigation without GPS and other knowledge of environment have been studied for many decades. Advance technology have made sensors more compact and subtle that can be easily integrated into micro and hand-hold device. Recently researchers found that bee and fruit fly have an effectively and efficiently navigation mechanism through optical flow information and process only with their miniature brain. We present a navigation system inspired by the study of insects through a calibrated camera and other inertial sensors. The system utilizes SLAM theory and can be worked in many GPS denied environment. Simulation and experimental results are presented for validation and quantification.

Managing SRS competition in a miniature visible Nd:YVO4/BaWO4 Raman laser.

PubMed

Li, Xiaoli; Lee, Andrew J; Huo, Yujing; Zhang, Huaijin; Wang, Jiyang; Piper, James A; Pask, Helen M; Spence, David J

2012-08-13

We demonstrate the operation of a compact and efficient continuous wave (CW) self-Raman laser utilizing a Nd:YVO4 gain crystal and BaWO4 Raman crystal, generating yellow emission at 590 nm. We investigate the competition that occurs between Stokes lines in the Nd:YVO4 and BaWO4 crystals, and within the BaWO4 crystal itself. Through careful consideration of crystal length and orientation, we are able to suppress competition between Stokes lines, and generate pure yellow emission at 590 nm with output power of 194 mW for just 3.8 W pump power.

Inherited retinal dysplasia and persistent hyperplastic primary vitreous in Miniature Schnauzer dogs.

PubMed

Grahn, Bruce H; Storey, Eric S; McMillan, Catherine

2004-01-01

The objectives of this study were to define the clinical syndrome of retinal dysplasia and persistent primary vitreous in Miniature Schnauzer dogs and determine the etiology. We examined 106 Miniature Schnauzers using a biomicroscope and indirect ophthalmoscope. The anterior and posterior segments of affected dogs were photographed. Four enucleated eyes were examined using routine light microscopy and scanning electron microscopy. A pedigree was constructed and related dogs were test-bred to define the mode of inheritance of this syndrome. Congenital retinal dysplasia was confirmed in 24 of 106 related Miniature Schnauzer dogs. Physical and postmortem examinations revealed that congenital abnormalities were limited to the eyes. Biomicroscopic, indirect ophthalmoscopic, and neuro-ophthalmic examinations confirmed that some of these dogs were blind secondary to bilateral retinal dysplasia and detachment (nonattachment) (n = 13), and the remainder had generalized retinal dysplasia (n = 11). Fifteen of these dogs were also diagnosed with unilateral (n = 9) or bilateral (n = 6) persistent hyperplastic primary vitreous. Nutritional, infectious, or toxic etiologies were not evident on physical, postmortem, light microscopic, or transmitting and scanning electron microscopic examination of four affected Miniature Schnauzers. We examined the pedigree and determined that an autosomal recessive mode of inheritance was most likely. Three test-bred litters including those from affected parents, carrier and affected parents, and carrier parents confirmed this mode of inheritance. This study confirms that retinal dysplasia and persistent hyperplastic primary vitreous is a congenital abnormality that is inherited as an autosomal recessive condition in Miniature Schnauzers.

Effect of postactivation treatment with latrunculin A on in vitro and in vivo development of cloned embryos derived from kidney fibroblasts of an aged Clawn miniature boar.

PubMed

Himaki, Takehiro; Mizobe, Yamato; Tsuda, Kenichirou; Suetomo, Masashi; Yamakuchi, Hiroshi; Miyoshi, Kazuchika; Takao, Sonshin; Yoshida, Mitsutoshi

2012-01-01

The objective of this study was to examine the effect of postactivation treatment with latrunculin A (LatA), an actin polymerization inhibitor, on in vitro and in vivo development of somatic cell nuclear transfer (SCNT) embryos derived from kidney fibroblasts of an aged Clawn miniature boar (12 years old). After electric activation, SCNT embryos were treated with 0, 0.5 or 1 μM LatA and cultured in vitro. The rate of blastocyst formation was significantly higher (P<0.05) in SCNT embryos treated with 0.5 μM LatA (38%) than those in control (14%). When cloned embryos treated with 0.5 μM LatA were transferred into the oviducts of two recipient miniature gilts to assess their development in vivo, both recipients became pregnant; one maintained pregnancy to term, and a live piglet (weighing 220 g) was delivered by Caesarean section. The results of this study indicated that the postactivation treatment with LatA was effective in improving in vitro developmental capacity of SCNT miniature pig embryos derived from kidney fibroblasts of an aged animal and that miniature pig cloned embryos treated with LatA had the ability to develop to term.

Miniature injection-molded optics for fiber-optic, in vivo confocal microscopy

NASA Astrophysics Data System (ADS)

Chidley, Matthew D.; Liang, Chen; Descour, Michael R.; Sung, Kung-Bin; Richards-Kortum, Rebecca R.; Gillenwater, Ann

2002-12-01

In collaboration with the Department of Biomedical Engineering at the University of Texas at Austin and the UT MD Anderson Cancer Center, a laser scanning fiber confocal reflectance microscope (FCRM) system has been designed and tested for in vivo detection of cervical and oral pre-cancers. This system along with specially developed diagnosis algorithms and techniques can achieve an unprecedented specificity and sensitivity for the diagnosis of pre-cancers in epithelial tissue. The FCRM imaging system consists of an NdYAG laser (1064 nm), scanning mirrors/optics, precision pinhole, detector, and an endoscopic probe (the objective). The objective is connected to the rest of the imaging system via a fiber bundle. The fiber bundle allows the rest of the system to be remotely positioned in a convenient location. Only the objective comes into contact with the patient. It is our intent that inexpensive mass-produced disposable endoscopic probes would be produced for large clinical trials. This paper touches on the general design process of developing a miniature, high numerical aperture, injection-molded (IM) objective. These IM optical designs are evaluated and modified based on manufacturing and application constraints. Based on these driving criteria, one specific optical design was chosen and a detailed tolerance analysis was conducted. The tolerance analysis was custom built to create a realistic statistical analysis for integrated IM lens elements that can be stacked one on top of another using micro-spheres resting in tiny circular grooves. These configurations allow each lens element to be rotated and possibly help compensate for predicted manufacturing errors. This research was supported by a grant from the National Institutes of Health (RO1 CA82880). Special thanks go to Applied Image Group/Optics for the numerous fabrication meetings concerning the miniature IM objective.

Central Compact Objects in Kes 79 and RCW 103 as `Hidden' Magnetars with Crustal Activity

NASA Astrophysics Data System (ADS)

Popov, S. B.; Kaurov, A. A.; Kaminker, A. D.

2015-05-01

We propose that observations of `hidden' magnetars in central compact objects can be used to probe crustal activity of neutron stars with large internal magnetic fields. Estimates based on calculations by Perna & Pons, Pons & Rea and Kaminker et al. suggest that central compact objects, which are proposed to be `hidden' magnetars, must demonstrate flux variations on the time scale of months-years. However, the most prominent candidate for the `hidden' magnetars - CXO J1852.6+0040 in Kes 79 - shows constant (within error bars) flux. This can be interpreted by lower variable crustal activity than in typical magnetars. Alternatively, CXO J1852.6+0040 can be in a high state of variable activity during the whole period of observations. Then we consider the source 1E161348 - 5055 in RCW103 as another candidate. Employing a simple 2D-modelling we argue that properties of the source can be explained by the crustal activity of the magnetar type. Thus, this object may be supplemented for the three known candidates for the `hidden' magnetars among central compact objects discussed in literature.

REVIEWS OF TOPICAL PROBLEMS: Small-scale structure of dark matter and microlensing

NASA Astrophysics Data System (ADS)

Gurevich, Aleksandr V.; Zybin, Kirill P.; Sirota, V. A.

1997-09-01

It has been revealed using microlensing that a considerable part, possibly more than half, of the dark matter in the halo of our Galaxy consists of objects with a mass spectrum ranging from 0.05 to 0.8 of the solar mass. What is the nature of these objects? There exist two hypotheses. According to one, these are Jupiter type planets or small stars (brown and white dwarfs) consisting of normal baryonic matter. According to the other, these are non-compact objects, i.e., small-scale formations in non-baryonic dark matter. Here, a theory is proposed describing the possibility of the existence of non-compact objects in the halo of our Galaxy, their structure and formation from non-baryonic matter. The theory of microlensing on compact and non-compact objects is considered in detail. The results of microlensing observations are described and compared with theory. Possible astrophysical manifestations of the presence of small-scale structure are pointed out. The field is being extensively studied and is of fundamental interest for cosmology and astrophysics.

Fundamentals of Nanoscale Polymer–Protein Interactions and Potential Contributions to Solid-State Nanobioarrays

PubMed Central

2015-01-01

Protein adsorption onto polymer surfaces is a very complex, ubiquitous, and integrated process, impacting essential areas of food processing and packaging, health devices, diagnostic tools, and medical products. The nature of protein–surface interactions is becoming much more complicated with continuous efforts toward miniaturization, especially for the development of highly compact protein detection and diagnostic devices. A large body of literature reports on protein adsorption from the perspective of ensemble-averaged behavior on macroscopic, chemically homogeneous, polymeric surfaces. However, protein–surface interactions governing the nanoscale size regime may not be effectively inferred from their macroscopic and microscopic characteristics. Recently, research efforts have been made to produce periodically arranged, nanoscopic protein patterns on diblock copolymer surfaces solely through self-assembly. Intriguing protein adsorption phenomena are directly probed on the individual biomolecule level for a fundamental understanding of protein adsorption on nanoscale surfaces exhibiting varying degrees of chemical heterogeneity. Insight gained from protein assembly on diblock copolymers can be effectively used to control the surface density, conformation, orientation, and biofunctionality of prebound proteins in highly miniaturized applications, now approaching the nanoscale. This feature article will highlight recent experimental and theoretical advances made on these fronts while focusing on single-biomolecule-level investigations of protein adsorption behavior combined with surface chemical heterogeneity on the length scale commensurate with a single protein. This article will also address advantages and challenges of the self-assembly-driven patterning technology used to produce protein nanoarrays and its implications for ultrahigh density, functional, and quantifiable protein detection in a highly miniaturized format. PMID:24456577

A flow-batch analyzer with piston propulsion applied to automatic preparation of calibration solutions for Mn determination in mineral waters by ET AAS.

PubMed

Almeida, Luciano F; Vale, Maria G R; Dessuy, Morgana B; Silva, Márcia M; Lima, Renato S; Santos, Vagner B; Diniz, Paulo H D; Araújo, Mário C U

2007-10-31

The increasing development of miniaturized flow systems and the continuous monitoring of chemical processes require dramatically simplified and cheap flow schemes and instrumentation with large potential for miniaturization and consequent portability. For these purposes, the development of systems based on flow and batch technologies may be a good alternative. Flow-batch analyzers (FBA) have been successfully applied to implement analytical procedures, such as: titrations, sample pre-treatment, analyte addition and screening analysis. In spite of its favourable characteristics, the previously proposed FBA uses peristaltic pumps to propel the fluids and this kind of propulsion presents high cost and large dimension, making unfeasible its miniaturization and portability. To overcome these drawbacks, a low cost, robust, compact and non-propelled by peristaltic pump FBA is proposed. It makes use of a lab-made piston coupled to a mixing chamber and a step motor controlled by a microcomputer. The piston-propelled FBA (PFBA) was applied for automatic preparation of calibration solutions for manganese determination in mineral waters by electrothermal atomic-absorption spectrometry (ET AAS). Comparing the results obtained with two sets of calibration curves (five by manual and five by PFBA preparations), no significant statistical differences at a 95% confidence level were observed by applying the paired t-test. The standard deviation of manual and PFBA procedures were always smaller than 0.2 and 0.1mugL(-1), respectively. By using PFBA it was possible to prepare about 80 calibration solutions per hour.

Miniature Sensor Probe for O2, CO2, and H2O Monitoring in Portable Life Support Systems

NASA Technical Reports Server (NTRS)

Delgado, Jesus; Chambers, Antja

2013-01-01

A miniature sensor probe, composed of four sensors which monitor the partial pressure of O2, CO2, H2O, and temperature, designed to operate in the portable life support system (PLSS), has been demonstrated. The probe provides an important advantage over existing technology in that it is able to operate reliably while wet. These luminescence-based fiber optic sensors consist of an indicator chemistry immobilized in a polymeric film, whose emission lifetime undergoes a strong change upon a reversible interaction with the target gas. Each sensor includes chemistry specifically sensitive to one target parameter. All four sensors are based on indicator chemistries that include luminescent dyes from the same chemical family, and therefore exhibit similar photochemical properties, which allow performing measurements of all the sensors by a single, compact, low-power optoelectronic unit remotely connected to the sensors by an electromagnetic interference-proof optical fiber cable. For space systems, using these miniature sensor elements with remote optoelectronics provides unmatched design flexibility for measurements in highly constrained volume systems such as the PLSS. A 10 mm diameter and 15 mm length prototype multiparameter probe was designed, fabricated, tested, and demonstrated over a wide operational range of gas concentration, humidity, and temperature relevant to operation in the PLSS. The sensors were evaluated for measurement range, precision, accuracy, and response time in temperatures ranging from 50 aF-150 aF and relative humidity from dry to 100% RH. Operation of the sensors in water condensation conditions was demonstrated wherein the sensors not only tolerated liquid water but actually operated while wet.

A family for miniature, easily reconfigurable particle sensors for space plasma measurements

NASA Astrophysics Data System (ADS)

Wieser, M.; Barabash, S.

2016-12-01

Over the last 15 years the Swedish Institute of Space Physics developed a line of miniaturized ion mass analyzers for space plasma studies with masses of 400-600 g and highly compact and dense design to minimize the volume. The sensors cover an energy range from few eV up to 15 keV and reach an angular coverage up to hemispherical and mass resolution up to 7, depending on application. The experience with this line of sensors demonstrates that a sensor mass of 400-600 g is a limit in the trade-off between scientifically valuable performance and the sensor mass. The Solar Wind Monitor (SWIM), part of the Sub-keV Atom Reflecting Analyzer (SARA) on board of the Indian Chandrayaan-1 mission to the Moon, was the first sensor in the line. A number of instruments derived from SWIM were built, each using the same basic architecture but adapted for the needs of the corresponding mission: the Miniature Ion Precipitation Analyzer (MIPA) on the European Space Agency's BepiColombo mission to Mercury, the Detector for Ions at Mars (DIM) for the Russian Phobos-Grunt mission and the Yinghuo Plasma Package Ion sensor (YPPi) for the Chinese Yinghuo-1 spacecraft (both to Mars), the Prisma Ion Mass Analyzer (PRIMA) for the Swedish PRISMA spacecraft to Earth orbit, the eXtra Small Analyzer of Neutrals (XASN) for the Russian Luna-Glob lander, and the Laboratory Ion Scattering Analyzer (LISA) used for laboratory studies. We review architecture, design, performance, and fields of application of the instruments in this family and give and outlook in future developments.

Thermal Vacuum Testing of a Proto-flight Miniature Loop Heat Pipe with Two Evaporators and Two Condensers

NASA Technical Reports Server (NTRS)

Ku, Jentung; Ottenstein, Laura

2011-01-01

This paper describes thermal vacuum testing of a proto-flight miniature loop heat pipe (MLHP) with two evaporators and two condensers designed for future small systems applications requiring low mass, low power and compactness. Each evaporator contains a wick with an outer diameter of 6.35 mm, and each has its own integral compensation chamber (CC). Miniaturization of the loop components reduces the volume and mass of the thermal system. Multiple evaporators provide flexibility for placement of instruments that need to be maintained at the same temperature, and facilitate heat load sharing among instruments, reducing the auxiliary heater power requirement. A flow regulator is used to regulate heat dissipations between the two condensers, allowing flexible placement of radiators on the spacecraft. A thermoelectric converter (TEC) is attached to each CC for control of the operating temperature and enhancement of start-up success. Tests performed include start-up, power cycle, sink temperature cycle, high power and low power operation, heat load sharing, and operating temperature control. The proto-flight MLHP demonstrated excellent performance in the thermal vacuum test. The loop started successfully and operated stably under various evaporator heat loads and condenser sink temperatures. The TECs were able to maintain the loop operating temperature within b1K of the desired set point temperature at all power levels and all sink temperatures. The un-powered evaporator would automatically share heat from the other powered evaporator. The flow regulator was able to regulate the heat dissipation among the radiators and prevent vapor from flowing into the liquid line.

Fundamentals of nanoscale polymer-protein interactions and potential contributions to solid-state nanobioarrays.

PubMed

Hahm, Jong-in

2014-08-26

Protein adsorption onto polymer surfaces is a very complex, ubiquitous, and integrated process, impacting essential areas of food processing and packaging, health devices, diagnostic tools, and medical products. The nature of protein-surface interactions is becoming much more complicated with continuous efforts toward miniaturization, especially for the development of highly compact protein detection and diagnostic devices. A large body of literature reports on protein adsorption from the perspective of ensemble-averaged behavior on macroscopic, chemically homogeneous, polymeric surfaces. However, protein-surface interactions governing the nanoscale size regime may not be effectively inferred from their macroscopic and microscopic characteristics. Recently, research efforts have been made to produce periodically arranged, nanoscopic protein patterns on diblock copolymer surfaces solely through self-assembly. Intriguing protein adsorption phenomena are directly probed on the individual biomolecule level for a fundamental understanding of protein adsorption on nanoscale surfaces exhibiting varying degrees of chemical heterogeneity. Insight gained from protein assembly on diblock copolymers can be effectively used to control the surface density, conformation, orientation, and biofunctionality of prebound proteins in highly miniaturized applications, now approaching the nanoscale. This feature article will highlight recent experimental and theoretical advances made on these fronts while focusing on single-biomolecule-level investigations of protein adsorption behavior combined with surface chemical heterogeneity on the length scale commensurate with a single protein. This article will also address advantages and challenges of the self-assembly-driven patterning technology used to produce protein nanoarrays and its implications for ultrahigh density, functional, and quantifiable protein detection in a highly miniaturized format.

Corrugated paraffin nanocomposite films as large stroke thermal actuators and self-activating thermal interfaces.

PubMed

Copic, Davor; Hart, A John

2015-04-22

High performance active materials are of rapidly growing interest for applications including soft robotics, microfluidic systems, and morphing composites. In particular, paraffin wax has been used to actuate miniature pumps, solenoid valves, and composite fibers, yet its deployment is typically limited by the need for external volume constraint. We demonstrate that compact, high-performance paraffin actuators can be made by confining paraffin within vertically aligned carbon nanotube (CNT) films. This large-stroke vertical actuation is enabled by strong capillary interaction between paraffin and CNTs and by engineering the CNT morphology by mechanical compression before capillary-driven infiltration of the molten paraffin. The maximum actuation strain of the corrugated CNT-paraffin films (∼0.02-0.2) is comparable to natural muscle, yet the maximum stress is limited to ∼10 kPa by collapse of the CNT network. We also show how a CNT-paraffin film can serve as a self-activating thermal interface that closes a gap when it is heated. These new CNT-paraffin film actuators could be produced by large-area CNT growth, infiltration, and lamination methods, and are attractive for use in miniature systems due to their self-contained design.

Single-mode laser studies: Design and performance of a fixed-wave length source and coupling of lasers to thin-film optical waveguides

NASA Technical Reports Server (NTRS)

Ladany, I.; Hammer, J. M.

1980-01-01

A module developed for the generation of a stable single wavelength to be used for a fiber optic multiplexing scheme is described. The laser is driven with RZ pulses, and the temperature is stabilized thermoelectrically. The unit is capable of maintaining a fixed wavelength within about 6 A as the pulse duty cycle is changed between 0 and 100 percent. This is considered the most severe case, and much tighter tolerances are obtainable for constant input power coding schemes. Using a constricted double heterostructure laser, a wavelength shift of 0.083 A mA is obtained due to laser self-heating by a dc driving current. The thermoelectric unit is capable of maintaining a constant laser heat-sink temperature within 0.02 C. In addition, miniature lenses and couplers are described which allow efficient coupling of single wavelength modes of junction lasers to thin film optical waveguides. The design of the miniature cylinder lenses and the prism coupling techniques allow 2 mW of single wavelength mode junction laser light to b coupled into thin film waveguides using compact assemblies. Selective grating couplers are also studied.

Study on Miniaturized UHF Antennas for Partial Discharge Detection in High-Voltage Electrical Equipment.

PubMed

Liu, Jingcun; Zhang, Guogang; Dong, Jinlong; Wang, Jianhua

2015-11-20

Detecting partial discharge (PD) is an effective way to evaluate the condition of high-voltage electrical equipment insulation. The UHF detection method has attracted attention due to its high sensitivity, strong interference resistance, and ability to locate PDs. In this paper, a miniaturized equiangular spiral antenna (ESA) for UHF detection that uses a printed circuit board is proposed. I-shaped, L-shaped, and C-shaped microstrip baluns were designed to match the impedance between the ESA and coaxial cable and were verified by a vector network analyzer. For comparison, three other types of UHF antenna were also designed: A microstrip patch antenna, a microstrip slot antenna, and a printed dipole antenna. Their antenna factors were calibrated in a uniform electric field of different frequencies modulated in a gigahertz transverse electromagnetic cell. We performed comparison experiments on PD signal detection using an artificial defect model based on the international IEC 60270 standard. We also conducted time-delay test experiments on the ESA sensor to locate a PD source. It was found that the proposed ESA sensor meets PD signal detection requirements. The sensor's compact size makes it suitable for internal installation in high-voltage electrical equipment.

Study on Miniaturized UHF Antennas for Partial Discharge Detection in High-Voltage Electrical Equipment

PubMed Central

Liu, Jingcun; Zhang, Guogang; Dong, Jinlong; Wang, Jianhua

2015-01-01

Detecting partial discharge (PD) is an effective way to evaluate the condition of high-voltage electrical equipment insulation. The UHF detection method has attracted attention due to its high sensitivity, strong interference resistance, and ability to locate PDs. In this paper, a miniaturized equiangular spiral antenna (ESA) for UHF detection that uses a printed circuit board is proposed. I-shaped, L-shaped, and C-shaped microstrip baluns were designed to match the impedance between the ESA and coaxial cable and were verified by a vector network analyzer. For comparison, three other types of UHF antenna were also designed: A microstrip patch antenna, a microstrip slot antenna, and a printed dipole antenna. Their antenna factors were calibrated in a uniform electric field of different frequencies modulated in a gigahertz transverse electromagnetic cell. We performed comparison experiments on PD signal detection using an artificial defect model based on the international IEC 60270 standard. We also conducted time-delay test experiments on the ESA sensor to locate a PD source. It was found that the proposed ESA sensor meets PD signal detection requirements. The sensor’s compact size makes it suitable for internal installation in high-voltage electrical equipment. PMID:26610506

Performance of a Miniature Pulse Tube Cryocooler

NASA Astrophysics Data System (ADS)

Matsumoto, N.; Yasukawa, Y.; Ohshima, K.; Minematsu, S.; Takeuchi, T.; Yoshizawa, K.; Matsushita, T.; Mizoguchi, Y.

2006-04-01

Fuji Electric Group has developed a miniature pulse tube cryocooler (PTC) of U-shaped configuration with a specific cooling capacity of 2W at 70K and requiring 100W of electrical input power. The emphasis has been on compactness, light weight, high performance, high reliability and low cost. This PTC is for commercial applications: for example, semiconductivity and high temperature superconductivity (HTS) devices used in wireless telecommunication systems and imaging sensors. The dimensions of the PTC have been reduced to 246mm wide by 232mm high and a weight of 8.5kg as integral configurations. The linear compressor motor uses two sets of moving coils to drive twin pistons supported by flexure bearings in a dual opposed configuration. The phase shifter, consisting of an inertance tube and reservoir tank, has been optimized. We produced and tested a prototype reduced-cost PTC. The prototype has a cooling capacity greater than 2.5W at 70K with 100W of electrical input power. The vibration of the cold head is less than 2 micrometers (peak to peak) when the hot-end side flange of the expander is fixed. This paper describes in detail its performance including inclination and vibration.

Miniaturized Ion and Neutral Mass Spectrometer for CubeSat Atmospheric Measurements

NASA Technical Reports Server (NTRS)

Rodriguez, M.; Paschalidis, N.; Jones, S.; Sittler, E.; Chornay, D.; Uribe, P.; Cameron, T.

2016-01-01

To increase the number of single point in-situ measurements of thermosphere and exosphere ion and neutral composition and density, miniaturized instrumentation is in high demand to take advantage of the increasing platform opportunities available in the smallsat/cubesat industry. The INMS (Ion-Neutral Mass Spectrometer) addresses this need by providing simultaneous measurements of both the neutral and ion environment, essentially providing two instruments in one compact model. The 1.3U volume, 570 gram, 1.8W nominal power INMS instrument makes implementation into cubesat designs (3U and above) practical and feasible. With high dynamic range (0.1-500eV), mass dynamic range of 1-40amu, sharp time resolution (0.1s), and mass resolution of MdM16, the INMS instrument addresses the atmospheric science needs that otherwise would have required larger more expensive instrumentation. INMS-v1 (version 1) launched on Exocube (CalPoly 3U cubesat) in 2015 and INMS-v2 (version 2) is scheduled to launch on Dellingr (GSFC 6U cubesat) in 2017. New versions of INMS are currently being developed to increase and add measurement capabilities, while maintaining its smallsat/cubesat form.

Lab-on-a-chip modules for detection of highly pathogenic bacteria: from sample preparation to detection

NASA Astrophysics Data System (ADS)

Julich, S.; Kopinč, R.; Hlawatsch, N.; Moche, C.; Lapanje, A.; Gärtner, C.; Tomaso, H.

2014-05-01

Lab-on-a-chip systems are innovative tools for the detection and identification of microbial pathogens in human and veterinary medicine. The major advantages are small sample volume and a compact design. Several fluidic modules have been developed to transform analytical procedures into miniaturized scale including sampling, sample preparation, target enrichment, and detection procedures. We present evaluation data for single modules that will be integrated in a chip system for the detection of pathogens. A microfluidic chip for purification of nucleic acids was established for cell lysis using magnetic beads. This assay was evaluated with spiked environmental aerosol and swab samples. Bacillus thuringiensis was used as simulant for Bacillus anthracis, which is closely related but non-pathogenic for humans. Stationary PCR and a flow-through PCR chip module were investigated for specific detection of six highly pathogenic bacteria. The conventional PCR assays could be transferred into miniaturized scale using the same temperature/time profile. We could demonstrate that the microfluidic chip modules are suitable for the respective purposes and are promising tools for the detection of bacterial pathogens. Future developments will focus on the integration of these separate modules to an entire lab-on-a-chip system.

Wide-angle lens for miniature capsule endoscope

NASA Astrophysics Data System (ADS)

Ou-Yang, Mang; Chen, Yung-Lin; Lee, Hsin-Hung; LU, Shih-chieh; Wu, Hsien-Ming

2006-02-01

In recent years, using the capsule endoscope to inspect the pathological change of digestive system and intestine had a great break-through on the medical engineering. However, there are some problems needs to overcome. One is that, the field of view was not wide enough, and the other is that the image quality was not enough well. The drawbacks made medical professionals to examine digestive diseases unclearly and ambiguously. In order to solve these problems, the paper designed a novel miniature lenses which has a wide angle of field of view and a good quality of imaging. The lenses employed in the capsule endoscope consisted of a piece of plastic aspherical lens and a piece of glass lens and compacted in the 9.8mm (W) *9.8mm (L) *10.7mm (H) size. Taking the white LED light source and the 10μm pixel size of 256*256 CMOS sensor under considerations, the field of view of the lenses could be achieved to 86 degrees, and the MTF to 37% at 50lp/mm of space frequency. The experimental data proves that the design is consistent with the finished prototype.

Arbitrary-ratio power splitter based on nonlinear multimode interference coupler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tajaldini, Mehdi; Young Researchers and Elite Club, Baft Branch, Islamic Azad University, Baft; Jafri, Mohd Zubir Mat

2015-04-24

We propose an ultra-compact multimode interference (MMI) power splitter based on nonlinear effects from simulations using nonlinear modal propagation analysis (NMPA) cooperation with finite difference Method (FDM) to access free choice of splitting ratio. Conventional multimode interference power splitter could only obtain a few discrete ratios. The power splitting ratio may be adjusted continuously while the input set power is varying by a tunable laser. In fact, using an ultra- compact MMI with a simple structure that is launched by a tunable nonlinear input fulfills the problem of arbitrary-ratio in integrated photonics circuits. Silicon on insulator (SOI) is used asmore » the offered material due to the high contrast refractive index and Centro symmetric properties. The high-resolution images at the end of the multimode waveguide in the simulated power splitter have a high power balance, whereas access to a free choice of splitting ratio is not possible under the linear regime in the proposed length range except changes in the dimension for any ratio. The compact dimensions and ideal performance of the device are established according to optimized parameters. The proposed regime can be extended to the design of M×N arbitrary power splitters ratio for programmable logic devices in all optical digital signal processing. The results of this study indicate that nonlinear modal propagation analysis solves the miniaturization problem for all-optical devices based on MMI couplers to achieve multiple functions in a compact planar integrated circuit and also overcomes the limitations of previously proposed methods for nonlinear MMI.« less

Continued Development of Compact Multi-gas Monitor for Life Support Systems Control in Space

NASA Technical Reports Server (NTRS)

Delgado-Alonso, Jesús; Phillips, Straun; Chullen, Cinda; Quinn, Gregory

2016-01-01

Miniature optic gas sensors (MOGS) based on luminescent materials have shown great potential as alternatives to Near-Infrared-based gas sensor systems for the advanced space suit portable life support system (PLSS). The unique capability of MOGS for carbon dioxide and oxygen monitoring under wet conditions has been reported, as has the fast recovery of MOGS humidity sensors after long periods of being wet. Lower volume and power requirements are also potential advantages of MOGS over both traditional and advanced Non-Dispersive Infrared (NDIR) gas sensors, which have shown so far longer life than luminescent sensors. This paper presents the most recent results in the development and analytical validation of a compact multi-gas sensor unit based on luminescent sensors for the PLSS. Results of extensive testing are presented, including studies conducted at Intelligent Optical Systems laboratories, a United Technology Corporation Aerospace Systems (UTAS) laboratory, and a Johnson Space Center laboratory. The potential of this sensor technology for gas monitoring in PLSSs and other life support systems and the advantages and limitations found through detailed sensor validation are discussed.

Frequency scaling with miniature COmpact MIcrowave and Coaxial ion sources

NASA Astrophysics Data System (ADS)

Sortais, Pascal; André, Thomas; Angot, Julien; Bouat, Sophie; Jacob, Josua; Lamy, Thierry; Sole, Patrick

2014-02-01

We will present recent basic developments about possible extension of the COMIC (for COmpact MIcrowave and Coaxial) devices up to 5.8 GHz in place of the present 2.45 GHz operation [P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81, 02B314 (2010)]. New applications associating multiple COMIC devices for thin film deposition will be described and we will explain why an increase of the current density delivered by each individual ion source could lead to the increase of the deposition rate. For this purpose, we will present results of about two devices working at 5.8 GHz. The first one is a tiny ion source, the world smallest microwave ion source, exactly similar to COMIC but operating at 5.8 GHz with a quarter wave cavity structure and a few watts microwave power consumption. We will show that the frequency scaling effect is effective inside such small machines. The second one is a more ambitious ion source designed around a three quarter wave structure that works with a few tens of watts at 5.8 GHz.

A compact centrifugal blood pump for extracorporeal circulation: design and performance.

PubMed

Tanaka, S; Yamamoto, S; Yamakoshi, K; Kamiya, A

1987-08-01

A new compact centrifugal blood pump driven by a miniature DC servomotor has been designed for use for short-term extra corporeal and cardiac-assisted circulation. The impeller of the pump was connected directly to the motor by using a simple-gear coupling. The shaft for the impeller was sealed from blood by both a V-ring and a seal bearing. Either pulsatile or nonpusatile flow was produced by controlling the current supply to the motor. The pump characteristics and the degree of hemolysis were evaluated with regard to the configuration of the impeller with a 38-mm outer diameter in vitro tests; the impeller having the blade angles at the inlet of 20 deg and at the outlet of 50 deg was the most appropriate as a blood pump. The performance in an operation, hemolysis and thrombus formation in the pump were assessed by a left ventricular bypass experiment in dogs. It was suggested by this study that this prototype pump appears promising for use not only in animal experiments but also in clinical application.

Development of an ultra-compact mid-infrared attenuated total reflectance spectrophotometer

NASA Astrophysics Data System (ADS)

Kim, Dong Soo; Lee, Tae-Ro; Yoon, Gilwon

2014-07-01

Mid-infrared spectroscopy has been an important tool widely used for qualitative analysis in various fields. However, portable or personal use is size and cost prohibitive for either Fourier transform infrared or attenuated total reflectance (ATR) spectrophotometers. In this study, we developed an ultra-compact ATR spectrophotometer whose frequency band was 5.5-11.0 μm. We used miniature components, such as a light source fabricated by semiconductor technology, a linear variable filter, and a pyro-electric array detector. There were no moving parts. Optimal design based on two light sources, a zippered configuration of the array detector and ATR optics could produce absorption spectra that might be used for qualitative analysis. A microprocessor synchronized the pulsed light sources and detector, and all the signals were processed digitally. The size was 13.5×8.5×3.5 cm3 and the weight was 300 grams. Due to its low cost, our spectrophotometer can replace many online monitoring devices. Another application could be for a u-healthcare system installed in the bathroom or attached to a smartphone for monitoring substances in body fluids.

A compact, multichannel, and low noise arbitrary waveform generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Govorkov, S.; Ivanov, B. I.; Novosibirsk State Technical University, K.Marx-Ave. 20, Novosibirsk 630092

2014-05-15

A new type of high functionality, fast, compact, and easy programmable arbitrary waveform generator for low noise physical measurements is presented. The generator provides 7 fast differential waveform channels with a maximum bandwidth up to 200 MHz frequency. There are 6 fast pulse generators on the generator board with 78 ps time resolution in both duration and delay, 3 of them with amplitude control. The arbitrary waveform generator is additionally equipped with two auxiliary slow 16 bit analog-to-digital converters and four 16 bit digital-to-analog converters for low frequency applications. Electromagnetic shields are introduced to the power supply, digital, and analogmore » compartments and with a proper filter design perform more than 110 dB digital noise isolation to the output signals. All the output channels of the board have 50 Ω SubMiniature version A termination. The generator board is suitable for use as a part of a high sensitive physical equipment, e.g., fast read out and manipulation of nuclear magnetic resonance or superconducting quantum systems and any other application, which requires electromagnetic interference free fast pulse and arbitrary waveform generation.« less

Robust and compact entanglement generation from diode-laser-pumped four-wave mixing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrie, B. J.; Yang, Y.; Eaton, M.

Four-wave-mixing processes are now routinely used to demonstrate multi-spatial-mode Einstein- Podolsky-Rosen entanglement and intensity difference squeezing. Recently, diode-laser-pumped four-wave mixing processes have been shown to provide an affordable, compact, and stable source for intensity difference squeezing, but it was unknown if excess phase noise present in power amplifier pump configurations would be an impediment to achieving quadrature entanglement. Here, we demonstrate the operating regimes under which these systems are capable of producing entanglement and under which excess phase noise produced by the amplifier contaminates the output state. We show that Einstein-Podolsky-Rosen entanglement in two mode squeezed states can be generatedmore » by a four-wave-mixing source deriving both the pump field and the local oscillators from a tapered-amplifier diode-laser. In conclusion, this robust continuous variable entanglement source is highly scalable and amenable to miniaturization, making it a critical step toward the development of integrated quantum sensors and scalable quantum information processors, such as spatial comb cluster states.« less

Robust and compact entanglement generation from diode-laser-pumped four-wave mixing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrie, B. J., E-mail: lawriebj@ornl.gov; Pooser, R. C.; Yang, Y.

Four-wave-mixing processes are now routinely used to demonstrate multi-spatial-mode Einstein-Podolsky-Rosen entanglement and intensity difference squeezing. Diode-laser-pumped four-wave mixing processes have recently been shown to provide an affordable, compact, and stable source for intensity difference squeezing, but it was unknown if excess phase noise present in power amplifier pump configurations would be an impediment to achieving quadrature entanglement. Here, we demonstrate the operating regimes under which these systems are capable of producing entanglement and under which excess phase noise produced by the amplifier contaminates the output state. We show that Einstein-Podolsky-Rosen entanglement in two mode squeezed states can be generated bymore » a four-wave-mixing source deriving both the pump field and the local oscillators from a tapered-amplifier diode-laser. This robust continuous variable entanglement source is highly scalable and amenable to miniaturization, making it a critical step toward the development of integrated quantum sensors and scalable quantum information processors, such as spatial comb cluster states.« less

Continued Development of Compact Multi-Gas Monitor for Life Support Systems Control in Space

NASA Technical Reports Server (NTRS)

Delgado, Jesus; Phillips, Straun; Chullen, Cinda

2015-01-01

Miniature optic gas sensors (MOGS) based on luminescent materials have shown great potential as alternatives to NIR-based gas sensor systems for the Portable Life Support System (PLSS). The unique capability of MOGS for carbon dioxide and oxygen monitoring under wet conditions has been reported, as has the fast recovery of MOGS humidity sensors after long periods of being wet. Lower volume and power requirements are also potential advantages of MOGS over both traditional and advanced Non-Dispersive Infrared (NDIR) gas sensors, which have shown so far longer life than luminescent sensors. In this paper we present the most recent results in the development and analytical validation of a compact multi-gas sensor unit based on luminescent sensors for the PLSS. Results of extensive testing are presented, including studies conducted at Intelligent Optical Systems laboratories, a United Technology Corporation Aerospace Systems (UTAS) laboratory, and a Johnson Space Center laboratory. The potential of this sensor technology for gas monitoring in PLSSs and other life support systems and the advantages and limitations found through detailed sensor validation are discussed.

Creating compact and microscale features in paper-based devices by laser cutting.

PubMed

Mahmud, Md Almostasim; Blondeel, Eric J M; Kaddoura, Moufeed; MacDonald, Brendan D

2016-11-14

In this work we describe a fabrication method to create compact and microscale features in paper-based microfluidic devices using a CO 2 laser cutting/engraving machine. Using this method we are able to produce the smallest features with the narrowest barriers yet reported for paper-based microfluidic devices. The method uses foil backed paper as the base material and yields inexpensive paper-based devices capable of using small fluid sample volumes and thus small reagent volumes, which is also suitable for mass production. The laser parameters (power and laser head speed) were adjusted to minimize the width of hydrophobic barriers and we were able to create barriers with a width of 39 ± 15 μm that were capable of preventing cross-barrier bleeding. We generated channels with a width of 128 ± 30 μm, which we found to be the physical limit for small features in the chromatography paper we used. We demonstrate how miniaturizing of paper-based microfluidic devices enables eight tests on a single bioassay device using only 2 μL of sample fluid volume.

Robust and compact entanglement generation from diode-laser-pumped four-wave mixing

DOE PAGES

Lawrie, B. J.; Yang, Y.; Eaton, M.; ...

2016-04-11

Four-wave-mixing processes are now routinely used to demonstrate multi-spatial-mode Einstein- Podolsky-Rosen entanglement and intensity difference squeezing. Recently, diode-laser-pumped four-wave mixing processes have been shown to provide an affordable, compact, and stable source for intensity difference squeezing, but it was unknown if excess phase noise present in power amplifier pump configurations would be an impediment to achieving quadrature entanglement. Here, we demonstrate the operating regimes under which these systems are capable of producing entanglement and under which excess phase noise produced by the amplifier contaminates the output state. We show that Einstein-Podolsky-Rosen entanglement in two mode squeezed states can be generatedmore » by a four-wave-mixing source deriving both the pump field and the local oscillators from a tapered-amplifier diode-laser. In conclusion, this robust continuous variable entanglement source is highly scalable and amenable to miniaturization, making it a critical step toward the development of integrated quantum sensors and scalable quantum information processors, such as spatial comb cluster states.« less

Continued Development of Compact Multi-Gas Monitor for Life Support Systems Control in Space

NASA Technical Reports Server (NTRS)

Delgado-Alonso, Jesus; Phillips, Straun; Berry, David; DiCarmine, Paul; Chullen, Cinda; Quinn, Gregory

2016-01-01

Miniature optical gas sensors based on luminescent materials have shown great potential as alternatives to NIR-based gas sensor systems for the Portable Life Support System (PLSS). The unique capability of luminescent sensors for carbon dioxide and oxygen monitoring under wet conditions has been reported, as has the fast recovery of humidity sensors after long periods of being wet. Lower volume and power requirements are also potential advantages over both traditional and advanced non-dispersive infrared (NDIR) gas sensors, which have so far shown longer life than luminescent sensors. In this paper we present the most recent results in the development and analytical validation of a compact multi-gas sensor unit based on luminescent sensors for the PLSS. Results of extensive testing are presented, including studies conducted in Intelligent Optical Systems laboratories, a United Technologies Corporation Aerospace Systems (UTC) laboratory, and a Johnson Space Center laboratory. The potential of this sensor technology for gas monitoring in PLSSs and other life support systems, and the advantages and limitations found through detailed sensor validation are discussed.

Rapid test for the detection of hazardous microbiological material

NASA Astrophysics Data System (ADS)

Mordmueller, Mario; Bohling, Christian; John, Andreas; Schade, Wolfgang

2009-09-01

After attacks with anthrax pathogens have been committed since 2001 all over the world the fast detection and determination of biological samples has attracted interest. A very promising method for a rapid test is Laser Induced Breakdown Spectroscopy (LIBS). LIBS is an optical method which uses time-resolved or time-integrated spectral analysis of optical plasma emission after pulsed laser excitation. Even though LIBS is well established for the determination of metals and other inorganic materials the analysis of microbiological organisms is difficult due to their very similar stoichiometric composition. To analyze similar LIBS-spectra computer assisted chemometrics is a very useful approach. In this paper we report on first results of developing a compact and fully automated rapid test for the detection of hazardous microbiological material. Experiments have been carried out with two setups: A bulky one which is composed of standard laboratory components and a compact one consisting of miniaturized industrial components. Both setups work at an excitation wavelength of λ=1064nm (Nd:YAG). Data analysis is done by Principal Component Analysis (PCA) with an adjacent neural network for fully automated sample identification.

Relativistic compact stars with charged anisotropic matter

NASA Astrophysics Data System (ADS)

Maurya, S. K.; Banerjee, Ayan; Channuie, Phongpichit

2018-05-01

In this article, we perform a detailed theoretical analysis of new exact solutions with anisotropic fluid distribution of matter for compact objects subject to hydrostatic equilibrium. We present a family solution to the Einstein-Maxwell equations describing a spherically symmetric, static distribution of a fluid with pressure anisotropy. We implement an embedding class one condition to obtain a relation between the metric functions. We generalize the properties of a spherical star with hydrostatic equilibrium using the generalised Tolman-Oppenheimer-Volkoff (TOV) equation. We match the interior solution to an exterior Reissner-Nordström one, and study the energy conditions, speed of sound, and mass-radius relation of the star. We also show that the obtained solutions are compatible with observational data for the compact object Her X-1. Regarding our results, the physical behaviour of the present model may serve for the modeling of ultra compact objects.

Gravitationally Focused Dark Matter around Compact Stars

NASA Astrophysics Data System (ADS)

Bromley, Benjamin C.

2011-12-01

If dark matter self-annihilates then it may produce an observable signal when its density is high. The details depend on the intrinsic properties of dark matter and how it clusters in space. For example, the density profile of some dark matter candidates may rise steeply enough toward the Galactic Center that self-annihilation may produce detectable γ-ray emission. Here, we discuss the possibility that an annihilation signal arises near a compact object (e.g., neutron star or black hole) even when the density of dark matter in the neighborhood of the object is uniform. Gravitational focusing produces a local enhancement of density with a profile that falls off approximately as the inverse square-root of distance from the compact star. While geometric dilution may overwhelm the annihilation signal from this local enhancement, magnetic fields tied to the compact object can increase the signal's contrast relative to the background.

Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) Instrument Improvements

NASA Technical Reports Server (NTRS)

Dunagan, Stephen E.; Redemann, Jens; Chang, Cecilia; Dahlgren, Robert; Fahey, Lauren; Flynn, Connor; Johnson, Roy; Kacenelenbogen, Meloe; Leblanc, Samuel; Liss, Jordan;

Low-cost, compact, and robust gas abundance sensor package

NASA Astrophysics Data System (ADS)

Tran, Dat; Nehmetallah, George; Gorius, Nicolas; Ferguson, Frank T.; Esper, Jaime; Johnson, Natasha M.; Aslam, Shahid; Nixon, Conor

2018-05-01

Gas Abundance Sensor Package (GASP) is a stand-alone scientific instrument that has the capability to measure the concentration of target gases based on a non-dispersive infrared sensor system along with atmospheric reference parameters. The main objective of this work is to develop a GASP system which takes advantage of available technologies and off-the-shelf components to provide a cost-effective solution for localized sampling of gas concentrations. GASP will enable scientists to study the atmosphere and will identify the conditions of the target's planetary local environment. Moreover, due to a recent trend of miniaturization of electronic components and thermopiles detectors, a small size and robust instrument with a reduction in power consumption is developed in this work. This allows GASP to be easily integrated into a variety of small space vehicles such as CubeSats or small satellite system, especially the Micro-Reentry Capsule (MIRCA) prototype vehicle. This prototype is one of the most advanced concepts of small satellites that has the capability to survive the rapid dive into the atmosphere of a planet. In this paper, a fully-operational instrument system will be developed and tested in the laboratory environment as well as flight preparation for a field test of the instrument suite will be described.

MIMA, a miniaturized Fourier infrared spectrometer for Mars ground exploration: Part I. Concept and expected performance

NASA Astrophysics Data System (ADS)

Bellucci, G.; Saggin, B.; Fonti, S.; Biondi, D.; Cerulli, P.; De Luca, M.; Altieri, F.; Mattana, A.; Alberti, E.; Marzo, G.; Zasova, L.

2007-10-01

The Mars Infrared MApper (MIMA) is a FT-IR miniaturised spectrometer which is being developed for ESA ExoMars Pasteur mission. The Martian Infrared MApper Fourier Spectrometer is designed to provide remote measurements of mineralogy and atmosphere of the scene surrounding a Martian rover and guide it to key targets for detailed in situ measurements by other rover experiments. Among the main scientific objectives of the MIMA instrument are to assist the rover in rock/soils selection for further in-situ investigation and to identify rocks and soils on the Martian surface which provide evidence of past/present biological activity. The instrument is also designed to measure the water vapour abundance and vertical distribution and its diurnal and seasonal variation, dust opacity, optical properties, composition, diurnal and seasonal variation. The instrument is a double pendulum interferometer providing spectra in the 2 - 25 μm wavelength domain with a resolving power of 1000 at 2 μm and 80 at 25 μm. The radiometric performances are SNR > 40 in the near infrared and a NEDe = 0.002 in the thermal region. The instrument design is very compact, with a total mass of 1kg and an average power consumption of 5 W.

Compact Microscope Imaging System Developed

NASA Technical Reports Server (NTRS)

McDowell, Mark

2001-01-01

The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. The CMIS can be used in situ with a minimum amount of user intervention. This system, which was developed at the NASA Glenn Research Center, can scan, find areas of interest, focus, and acquire images automatically. Large numbers of multiple cell experiments require microscopy for in situ observations; this is only feasible with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control capabilities. The software also has a user-friendly interface that can be used independently of the hardware for post-experiment analysis. CMIS has potential commercial uses in the automated online inspection of precision parts, medical imaging, security industry (examination of currency in automated teller machines and fingerprint identification in secure entry locks), environmental industry (automated examination of soil/water samples), biomedical field (automated blood/cell analysis), and microscopy community. CMIS will improve research in several ways: It will expand the capabilities of MSD experiments utilizing microscope technology. It may be used in lunar and Martian experiments (Rover Robot). Because of its reduced size, it will enable experiments that were not feasible previously. It may be incorporated into existing shuttle orbiter and space station experiments, including glove-box-sized experiments as well as ground-based experiments.

Shaping of Looped Miniaturized Chalcogenide Fiber Sensing Heads for Mid-Infrared Sensing

PubMed Central

Houizot, Patrick; Anne, Marie-Laure; Boussard-Plédel, Catherine; Loréal, Olivier; Tariel, Hugues; Lucas, Jacques; Bureau, Bruno

2014-01-01

Chalcogenide glass fibers are promising photonic tools to develop Fiber Evanescent Wave Spectroscopy (FEWS) optical sensors working in the mid-infrared region. Numerous pioneering works have already been carried out showing their efficiency, especially for bio-medical applications. Nevertheless, this technology remains confined to academic studies at the laboratory scale because chalcogenide glass fibers are difficult to shape to produce reliable, sensitive and compact sensors. In this paper, a new method for designing and fabricating a compact and robust sensing head with a selenide glass fiber is described. Compact looped sensing heads with diameter equal to 2 mm were thus shaped. This represents an outstanding achievement considering the brittleness of such uncoated fibers. FEWS experiments were implemented using alcoholic solutions as target samples showing that the sensitivity is higher than with the routinely used classical fiber. It is also shown that the best compromise in term of sensitivity is to fabricate a sensing head including two full loops. From a mechanical point of view, the breaking loads of the loop shaped head are also much higher than with classical fiber. Finally, this achievement paves the way for the use of mid-infrared technology during in situ and even in vivo medical operations. Indeed, is is now possible to slide a chalcogenide glass fiber in the operating channel of a standard 2.8 mm diameter catheter. PMID:25264953

On the number of light rings in curved spacetimes of ultra-compact objects

NASA Astrophysics Data System (ADS)

Hod, Shahar

2018-01-01

In a very interesting paper, Cunha, Berti, and Herdeiro have recently claimed that ultra-compact objects, self-gravitating horizonless solutions of the Einstein field equations which have a light ring, must possess at least two (and, in general, an even number of) light rings, of which the inner one is stable. In the present compact paper we explicitly prove that, while this intriguing theorem is generally true, there is an important exception in the presence of degenerate light rings which, in the spherically symmetric static case, are characterized by the simple dimensionless relation 8 πrγ2 (ρ +pT) = 1 [here rγ is the radius of the light ring and { ρ ,pT } are respectively the energy density and tangential pressure of the matter fields]. Ultra-compact objects which belong to this unique family can have an odd number of light rings. As a concrete example, we show that spherically symmetric constant density stars with dimensionless compactness M / R = 1 / 3 possess only one light ring which, interestingly, is shown to be unstable.

Development of a Novel Brayton-Cycle Cryocooler and Key Component Technologies

NASA Astrophysics Data System (ADS)

Nieczkoski, S. J.; Mohling, R. A.

2004-06-01

Brayton-cycle cryocoolers are being developed to provide efficient cooling in the 6 K to 70 K temperature range. The cryocoolers are being developed for use in space and in terrestrial applications where combinations of long lifetime, high efficiency, compactness, low mass, low vibration, flexible interfacing, load variability, and reliability are essential. The key enabling technologies for these systems are a mesoscale expander and an advanced oil-free scroll compressor. Both these components are nearing completion of their prototype development phase. The emphasis on the component and system development has been on invoking fabrication processes and techniques that can be evolved to further reduction in scale tending toward cryocooler miniaturization.

Converting a Monopole Emission into a Dipole Using a Subwavelength Structure

NASA Astrophysics Data System (ADS)

Fan, Xu-Dong; Zhu, Yi-Fan; Liang, Bin; Cheng, Jian-chun; Zhang, Likun

2018-03-01

High-efficiency emission of multipoles is unachievable by a source much smaller than the wavelength, preventing compact acoustic devices for generating directional sound beams. Here, we present a primary scheme towards solving this problem by numerically and experimentally enclosing a monopole sound source in a structure with a dimension of around 1 /10 sound wavelength to emit a dipolar field. The radiated sound power is found to be more than twice that of a bare dipole. Our study of efficient emission of directional low-frequency sound from a monopole source in a subwavelength space may have applications such as focused ultrasound for imaging, directional underwater sound beams, miniaturized sonar, etc.

Simplified Identification of mRNA or DNA in Whole Cells

NASA Technical Reports Server (NTRS)

Almeida, Eduardo; Kadambi, Geeta

2007-01-01

A recently invented method of detecting a selected messenger ribonucleic acid (mRNA) or deoxyribonucleic acid (DNA) sequence offers two important advantages over prior such methods: it is simpler and can be implemented by means of compact equipment. The simplification and miniaturization achieved by this invention are such that this method is suitable for use outside laboratories, in field settings in which space and power supplies may be limited. The present method is based partly on hybridization of nucleic acid, which is a powerful technique for detection of specific complementary nucleic acid sequences and is increasingly being used for detection of changes in gene expression in microarrays containing thousands of gene probes.

Compact beam splitters with deep gratings for miniature photonic integrated circuits: design and implementation aspects.

PubMed

Chen, Chin-Hui; Klamkin, Jonathan; Nicholes, Steven C; Johansson, Leif A; Bowers, John E; Coldren, Larry A

2009-09-01

We present an extensive study of an ultracompact grating-based beam splitter suitable for photonic integrated circuits (PICs) that have stringent density requirements. The 10 microm long beam splitter exhibits equal splitting, low insertion loss, and also provides a high extinction ratio in an integrated coherent balanced receiver. We further present the design strategies for avoiding mode distortion in the beam splitter and discuss optimization of the widths of the detectors to improve insertion loss and extinction ratio of the coherent receiver circuit. In our study, we show that the grating-based beam splitter is a competitive technology having low fabrication complexity for ultracompact PICs.

Scattering from Artificial Piezoelectriclike Meta-Atoms and Molecules

NASA Astrophysics Data System (ADS)

Goltcman, Leonid; Hadad, Yakir

2018-01-01

Inspired by natural piezoelectricity, we introduce hybrid-wave electromechanical meta-atoms and metamolecules that consist of coupled electrical and mechanical oscillators with similar resonance frequencies. We explore the linearized electromechanical scattering process and demonstrate that by exploiting the hybrid-wave interaction one may enable functionalities that are forbidden otherwise. For example, we study a dimer metamolecule that is highly directional for electromagnetic waves, although it is electrically deep subwavelength. This unique behavior is a consequence of the fact that, while the metamolecule is electrically small, it is acoustically large. This idea opens vistas for a plethora of exciting dynamics and phenomena in electromagnetics and acoustics, with implications for miniaturized sensors, superresolution imaging, compact nonreciprocal antennas, and more.

Integrated intelligent sensor for the textile industry

NASA Astrophysics Data System (ADS)

Peltie, Philippe; David, Dominique

1996-08-01

A new sensor has been developed for pantyhose inspection. Unlike a first complete inspection machine devoted to post- manufacturing control of the whole panty, this sensor will be directly integrated on currently existing manufacturing machines, and will combine advantages of miniaturization is to design an intelligent, compact and very cheap product, which should be integrated without requiring any modifications of host machines. The sensor part was designed to achieve closed acquisition, and various solutions have been explored to maintain adequate depth of field. The illumination source will be integrated in the device. The processing part will include correction facilities and electronic processing. Finally, high-level information will be output in order to interface directly with the manufacturing machine automate.

Laser Frequency Stabilization for Coherent Lidar Applications using Novel All-Fiber Gas Reference Cell Fabrication Technique

NASA Technical Reports Server (NTRS)

Meras, Patrick, Jr.; Poberezhskiy, Ilya Y.; Chang, Daniel H.; Levin, Jason; Spiers, Gary D.

2008-01-01

Compact hollow-core photonic crystal fiber (HC-PCF)gas frequency reference cell was constructed using a novel packaging technique that relies on torch-sealing a quartz filling tube connected to a mechanical splice between regular and hollow-core fibers. The use of this gas cell for laser frequency stabilization was demonstrated by locking a tunable diode laser to the center of the P9 line from the (nu)1+(nu)3 band of acetylene with RMS frequency error of 2.06 MHz over 2 hours. This effort was performed in support of a task to miniaturize the laser frequency stabilization subsystem of JPL/LMCT Laser Absorption Spectrometer (LAS) instrument.

Hybrid integration of VCSELs onto a silicon photonic platform for biosensing application

NASA Astrophysics Data System (ADS)

Lu, Huihui; Lee, Jun Su; Zhao, Yan; Cardile, Paolo; Daly, Aidan; Carroll, Lee; O'Brien, Peter

2017-02-01

This paper presents a technology of hybrid integration vertical cavity surface emitting lasers (VCSELs) directly on silicon photonics chip. By controlling the reflow of the solder balls used for electrical and mechanical bonding, the VCSELs were bonded at 10 degree to achieve the optimum angle-of-incidence to the planar grating coupler through vision based flip-chip techniques. The 1 dB discrepancy between optical loss values of flip-chip passive assembly and active alignment confirmed that the general purpose of the flip-chip design concept is achieved. This hybrid approach of integrating a miniaturized light source on chip opens the possibly of highly compact sensor system, which enable future portable and wearable diagnostics devices.

Generating and Separating Twisted Light by gradient-rotation Split-Ring Antenna Metasurfaces.

PubMed

Zeng, Jinwei; Li, Ling; Yang, Xiaodong; Gao, Jie

2016-05-11

Nanoscale compact optical vortex generators promise substantially significant prospects in modern optics and photonics, leading to many advances in sensing, imaging, quantum communication, and optical manipulation. However, conventional vortex generators often suffer from bulky size, low vortex mode purity in the converted beam, or limited operation bandwidth. Here, we design and demonstrate gradient-rotation split-ring antenna metasurfaces as unique spin-to-orbital angular momentum beam converters to simultaneously generate and separate pure optical vortices in a broad wavelength range. Our proposed design has the potential for realizing miniaturized on-chip OAM-multiplexers, as well as enabling new types of metasurface devices for the manipulation of complex structured light beams.

r-Process Nucleosynthesis in the Early Universe Through Fast Mergers of Compact Binaries in Triple Systems

NASA Astrophysics Data System (ADS)

Bonetti, Matteo; Perego, Albino; Capelo, Pedro R.; Dotti, Massimo; Miller, M. Coleman

2018-05-01

Surface abundance observations of halo stars hint at the occurrence of r-process nucleosynthesis at low metallicity ([Fe/H] < -3), possibly within the first 108 yr after the formation of the first stars. Possible loci of early-Universe r-process nucleosynthesis are the ejecta of either black hole-neutron star or neutron star-neutron star binary mergers. Here, we study the effect of the inclination-eccentricity oscillations raised by a tertiary (e.g. a star) on the coalescence time-scale of the inner compact object binaries. Our results are highly sensitive to the assumed initial distribution of the inner binary semi-major axes. Distributions with mostly wide compact object binaries are most affected by the third object, resulting in a strong increase (by more than a factor of 2) in the fraction of fast coalescences. If instead the distribution preferentially populates very close compact binaries, general relativistic precession prevents the third body from increasing the inner binary eccentricity to very high values. In this last case, the fraction of coalescing binaries is increased much less by tertiaries, but the fraction of binaries that would coalesce within 108 yr even without a third object is already high. Our results provide additional support to the compact-binary merger scenario for r-process nucleosynthesis.

Central Hypothyroidism in Miniature Schnauzers.

PubMed

Voorbij, Annemarie M W Y; Leegwater, Peter A J; Buijtels, Jenny J C W M; Daminet, Sylvie; Kooistra, Hans S

2016-01-01

Primary hypothyroidism is a common endocrinopathy in dogs. In contrast, central hypothyroidism is rare in this species. The objective of this article is to describe the occurrence and clinical presentation of central hypothyroidism in Miniature Schnauzers. Additionally, the possible role of the thyroid-stimulating hormone (TSH)-releasing hormone receptor (TRHR) gene and the TSHβ (TSHB) gene was investigated. Miniature Schnauzers with proven central hypothyroidism, based on scintigraphy, and the results of a 3-day-TSH-stimulation test, or a TSH-releasing hormone (TRH)-stimulation test or both, presented to the Department of Clinical Sciences of Companion Animals at Utrecht University or the Department of Medicine and Clinical Biology of Small Animals at Ghent University from 2008 to 2012. Retrospective study. Pituitary function tests, thyroid scintigraphy, and computed tomography (CT) of the pituitary area were performed. Gene fragments of affected dogs and controls were amplified by polymerase chain reaction (PCR). Subsequently, the deoxyribonucleic acid (DNA) sequences of the products were analyzed. Central hypothyroidism was diagnosed in 7 Miniature Schnauzers. Three dogs had disproportionate dwarfism and at least one of them had a combined deficiency of TSH and prolactin. No disease-causing mutations were found in the TSHB gene and the exons of the TRHR gene of these Schnauzers. Central hypothyroidism could be underdiagnosed in Miniature Schnauzers with hypothyroidism, especially in those of normal stature. The fact that this rare disorder occurred in 7 dogs from the same breed suggests that central hypothyroidism could have a genetic background in Miniature Schnauzers. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Accretion torques in X-ray pulsars

NASA Technical Reports Server (NTRS)

Rappaport, S.; Joss, P. C.

1977-01-01

An analysis of the accretion process in an X-ray pulsar, whereby angular momentum is transferred to the star and its rotation period is changed, is presented, and an expression for the fractional rate of change of the pulse period in terms of X-ray luminosity and other star parameters is derived. It is shown that observed characteristic spin-up time scales for seven X-ray pulsars strongly support the view that in every source (1) the pulse period reflects the rotation period of a compact object, (2) the accretion is mediated by a disk surrounding the compact object and rotating in the same sense, and (3) the compact object is a neutron star rather than a white dwarf.

REVIEWS OF TOPICAL PROBLEMS: Axisymmetric stationary flows in compact astrophysical objects

NASA Astrophysics Data System (ADS)

Beskin, Vasilii S.

1997-07-01

A review is presented of the analytical results available for a large class of axisymmetric stationary flows in the vicinity of compact astrophysical objects. The determination of the two-dimensional structure of the poloidal magnetic field (hydrodynamic flow field) faces severe difficulties, due to the complexity of the trans-field equation for stationary axisymmetric flows. However, an approach exists which enables direct problems to be solved even within the balance law framework. This possibility arises when an exact solution to the equation is available and flows close to it are investigated. As a result, with the use of simple model problems, the basic features of supersonic flows past real compact objects are determined.

The feasibility of miniaturizing the versatile portable speech prosthesis: A market survey of commercial products

NASA Technical Reports Server (NTRS)

Walklet, T.

1981-01-01

The feasibility of a miniature versatile portable speech prosthesis (VPSP) was analyzed and information on its potential users and on other similar devices was collected. The VPSP is a device that incorporates speech synthesis technology. The objective is to provide sufficient information to decide whether there is valuable technology to contribute to the miniaturization of the VPSP. The needs of potential users are identified, the development status of technologies similar or related to those used in the VPSP are evaluated. The VPSP, a computer based speech synthesis system fits on a wheelchair. The purpose was to produce a device that provides communication assistance in educational, vocational, and social situations to speech impaired individuals. It is expected that the VPSP can be a valuable aid for persons who are also motor impaired, which explains the placement of the system on a wheelchair.

Miniaturized Environmental Monitoring Instrumentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

C. B. Freidhoff

1997-09-01

The objective of the Mass Spectrograph on a Chip (MSOC) program is the development of a miniature, multi-species gas sensor fabricated using silicon micromachining technology which will be orders of magnitude smaller and lower power consumption than a conventional mass spectrometer. The sensing and discrimination of this gas sensor are based on an ionic mass spectrograph, using magnetic and/or electrostatic fields. The fields cause a spatial separation of the ions according to their respective mass-to-charge ratio. The fabrication of this device involves the combination of microelectronics with micromechanically built sensors and, ultimately, vacuum pumps. The prototype of a chemical sensormore » would revolutionize the method of performing environmental monitoring for both commercial and government applications. The portable unit decided upon was the miniaturized gas chromatograph with a mass spectrometer detector, referred to as a GC/MS in the analytical marketplace.« less

Formation of Compact Ellipticals in the merging star cluster scenario

NASA Astrophysics Data System (ADS)

Urrutia Zapata, Fernanda Cecilia; Theory and star formation group

2018-01-01

In the last years, extended old stellar clusters have been observed. They are like globular clusters (GCs) but with larger sizes(a limit of Re=10 pc is currently seen as reasonable). These extended objects (EOs) cover a huge range of mass. Objects at the low mass end with masses comparable to normal globular clusters are called extended clusters or faint fuzzies Larsen & Brodie (2000) and objects at the high-mass end are called ultra compact dwarf galaxies (UCDs). Ultra compact dwarf galaxies are compact object with luminositys above the brigtest known GCs. UCDs are more compact than typical dwarf galaxies but with comparable luminosities. Usually, a lower mass limit of 2 × 10^6 Solar masses is applied.Fellhauer & Kroupa (2002a,b) demostrated that object like ECs, FFs and UCDs can be the remnants of the merger of star clusters complexes, this scenario is called the Merging Star Cluster Scenario. Amore concise study was performed by Bruens et al. (2009, 2011).Our work tries to explain the formation of compact elliptical(cE). These objects are a comparatively rare class of spheroidal galaxies, possessing very small Re and high central surface brightnesses (Faber 1973). cEs have the same parameters as extended objects but they are slightly larger than 100 pc and the luminosities are in the range of -11 to -12 Mag.The standard formation sceanrio of these systems proposes a galaxy origin. CEs are the result of tidal stripping and truncation of nucleated larger systems. Or they could be a natural extension of the class of elliptical galaxies to lower luminosities and smaller sizes.We want to propose a completely new formation scenario for cEs. In our project we try to model cEs in a similar way that UCDs using the merging star cluster scenario extended to much higher masses and sizes. We think that in the early Universe we might have produced sufficiently strong star bursts to form cluster complexes which merge into cEs. So far it is observationally unknown if cEs are dark matter dominated objects. If our scenario is true, then they would be dark matter free very extended and massive "star clusters".

Classifying and Finding Nearby Compact Stellar Systems

NASA Astrophysics Data System (ADS)

Colebaugh, Alexander; Cunningham, Devin; Dixon, Christopher; Romanowsky, Aaron; Striegel, Stephanie

2018-01-01

Compact stellar systems (CSSs) such as compact ellipticals (cEs) and ultracompact dwarfs (UCDs) are relatively rare and poorly understood types of galaxies. To build a more complete picture of these objects, we create search queries using the Sloan Digital Sky Survey, to inventory CSSs in the nearby universe and to explore their properties. We develop an objective set of criteria for classifying cEs, and use these to construct a large, novel catalog of cEs both during and after formation. We also investigate the numbers of cEs and UCDs around nearby giant galaxies.

Predicting gravitational lensing by stellar remnants

NASA Astrophysics Data System (ADS)

Harding, Alexander J.; Stefano, R. Di; Lépine, S.; Urama, J.; Pham, D.; Baker, C.

2018-03-01

Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this paper, we describe the prospects for predicting lensing events generated by the local population of compact objects, consisting of 250 neutron stars, five black holes, and ≈35 000 white dwarfs. By focusing on a population of nearby compact objects with measured proper motions and known distances from us, we can measure their masses by studying the characteristics of any lensing event they generate. Here, we concentrate on shifts in the position of a background source due to lensing by a foreground compact object. With Hubble Space Telescope, JWST, and Gaia, measurable centroid shifts caused by lensing are relatively frequent occurrences. We find that 30-50 detectable events per decade are expected for white dwarfs. Because relatively few neutron stars and black holes have measured distances and proper motions, it is more difficult to compute realistic rates for them. However, we show that at least one isolated neutron star has likely produced detectable events during the past several decades. This work is particularly relevant to the upcoming data releases by the Gaia mission and also to data that will be collected by JWST. Monitoring predicted microlensing events will not only help to determine the masses of compact objects, but will also potentially discover dim companions to these stellar remnants, including orbiting exoplanets.

Social Embodiment of Technical Devices: Eyeglasses over the Centuries and According to Their Uses

ERIC Educational Resources Information Center

Veyrat, Nicolas; Blanco, Eric; Trompette, Pascale

2008-01-01

This article is an attempt to prepare the ground for the analysis and theorization of the connection between the body and technical devices emerging from miniaturized wearable technologies. The research object is a secular and common "body object," namely, eyeglasses. The article reviews the social history of this artifact and analyzes its…

Design and experimental evaluation of compact radial-inflow turbines

NASA Technical Reports Server (NTRS)

Fredmonski, A. J.; Huber, F. W.; Roelke, R. J.; Simonyi, S.

1991-01-01

The application of a multistage 3D Euler solver to the aerodynamic design of two compact radial-inflow turbines is presented, along with experimental results evaluating and validating the designs. The objectives of the program were to design, fabricate, and rig test compact radial-inflow turbines with equal or better efficiency relative to conventional designs, while having 40 percent less rotor length than current traditionally-sized radial turbines. The approach to achieving these objectives was to apply a calibrated 3D multistage Euler code to accurately predict and control the high rotor flow passage velocities and high aerodynamic loadings resulting from the reduction in rotor length. A comparison of the advanced compact designs to current state-of-the-art configurations is presented.

Results of ultra compact plasma focus operating in repetitive burst-mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shukla, R.; Shyam, A.; Verma, R.

2014-07-01

The results of a miniature plasma focus are being presented in this paper which is operated with energy less than or equal to 150 Joules. The miniature plasma focus is driven by a small capacitor bank and the peak current delivered in the focus is 75kA. The deuterium gas is filled with a pressure range of 5-7 mbar inside the plasma focus chamber. The quartz glass is used for generating initial surface breakdown at 4-5 kV discharge which is a typical value for low-voltage plasma focus discharges. The repetitive operation of the device is achieved by a combination of amore » simple and high power (5 kW) power supply with the synchronized triggering of the capacitor bank at the time of isolation between supply and the capacitor bank. As the plasma focus chamber volume is very low, in order to achieve reduced after-shot contamination effects, the gas pressure inside the plasma focus is maintained by continuous pumping which is disallowed at the time of shorts rather having a sealed type plasma focus assembly. The results of such scheme are also discussed in the paper. The diameter of cathode is 25mm and anode diameter is 8-12 mm and both of them are made of stainless steel. The length of anode and gas pressure is adjusted in such a way that the pinching occurs at the time of occurrence of the peak of current. It enhances the neutron emission from the device. The time-of-flight diagnostic is used to distinguish neutron and X-ray emission from the plasma focus. The device can serve the purpose of being a portable and compact repetitive neutron source for various applications as the flux of the radiation is comparable with the bigger devices of same type. The modeling results of plasma focus are also compared with experimental results to give a broader picture of the device. (author)« less

Performance modelling of miniaturized flash-imaging lidars for future mars exploration missions

NASA Astrophysics Data System (ADS)

Mitev, V.; Pollini, A.; Haesler, J.; Pereira do Carmo, João.

2017-11-01

Future planetary exploration missions require the support of 3D vision in the GN&C during key spacecraft's proximity phases, namely: i) spacecraft precision and soft Landing on the planet's surface; ii) Rendezvous and Docking (RVD) between a Sample Canister (SC) and an orbiter spacecraft; iii) Rover Navigation (RN) on planetary surface. The imaging LiDARs are among the best candidate for such tasks [1-3]. The combination of measurement requirements and environmental conditions seems to find its optimum in the flash 3D LiDAR architecture. Here we present key steps is the evaluation of novelty light detectors and MOEMS (Micro-Opto- Electro-Mechanical Systems) technologies with respect to LiDAR system performance and miniaturization. The objectives of the project MILS (Miniaturized Imaging LiDAR System, Phase 1) concentrated on the evaluation of novel detection and scanning technologies for the miniaturization of 3D LiDARs intended for planetary mission. Preliminary designs for an elegant breadboard (EBB) for the three tasks stated above (Landing, RVD and RN) were proposed, based on results obtained with a numerical model developed in the project and providing the performances evaluation of imaging LiDARs.

Miniaturized blood sampling techniques to benefit reduction in mice and refinement in nonhuman primates: applications to bioanalysis in toxicity studies with antibody-drug conjugates.

PubMed

Caron, Alexis; Lelong, Christine; Pascual, Marie-Hélène; Benning, Véronique

2015-03-01

Minimizing the number of animals in regulatory toxicity studies while achieving study objectives to support the development of future medicines contributes to good scientific and ethical practices. Recent advances in technology have enabled the development of miniaturized blood sampling methods (including microsampling and dried blood spots) applicable to toxicokinetic determinations of small-molecule drugs. Implementation of miniaturized blood sampling methods in the context of biotherapeutic drugs is desirable because a limitation to this type of medicine remains the total blood volume needed from a single animal to support toxicokinetic determinations of several analytes (parent drug, metabolites[s], antidrug antibodies, and so forth). We describe here the technical details, applicability, and relevance of new miniaturized blood sampling procedures in mice and nonhuman primates in the context of the toxicologic evaluation of biotherapeutic drugs consisting of antibody-drug conjugates developed for oncology indications. These examples illustrate how these techniques can benefit the reduction of animal usage in mouse toxicity studies by decreasing the number of animals dedicated to toxicokinetic determinations and the refinement of practices in nonhuman primate toxicity studies by decreasing the blood volume repeatedly drawn for toxicokinetic determinations.

Miniaturized Blood Sampling Techniques to Benefit Reduction in Mice and Refinement in Nonhuman Primates: Applications to Bioanalysis in Toxicity Studies with Antibody–Drug Conjugates

PubMed Central

Caron, Alexis; Lelong, Christine; Pascual, Marie-Hélène; Benning, Véronique

2015-01-01

Minimizing the number of animals in regulatory toxicity studies while achieving study objectives to support the development of future medicines contributes to good scientific and ethical practices. Recent advances in technology have enabled the development of miniaturized blood sampling methods (including microsampling and dried blood spots) applicable to toxicokinetic determinations of small-molecule drugs. Implementation of miniaturized blood sampling methods in the context of biotherapeutic drugs is desirable because a limitation to this type of medicine remains the total blood volume needed from a single animal to support toxicokinetic determinations of several analytes (parent drug, metabolites[s], antidrug antibodies, and so forth). We describe here the technical details, applicability, and relevance of new miniaturized blood sampling procedures in mice and nonhuman primates in the context of the toxicologic evaluation of biotherapeutic drugs consisting of antibody–drug conjugates developed for oncology indications. These examples illustrate how these techniques can benefit the reduction of animal usage in mouse toxicity studies by decreasing the number of animals dedicated to toxicokinetic determinations and the refinement of practices in nonhuman primate toxicity studies by decreasing the blood volume repeatedly drawn for toxicokinetic determinations. PMID:25836960

Lensless high-resolution on-chip optofluidic microscopes for Caenorhabditis elegans and cell imaging

PubMed Central

Cui, Xiquan; Lee, Lap Man; Heng, Xin; Zhong, Weiwei; Sternberg, Paul W.; Psaltis, Demetri; Yang, Changhuei

2008-01-01

Low-cost and high-resolution on-chip microscopes are vital for reducing cost and improving efficiency for modern biomedicine and bioscience. Despite the needs, the conventional microscope design has proven difficult to miniaturize. Here, we report the implementation and application of two high-resolution (≈0.9 μm for the first and ≈0.8 μm for the second), lensless, and fully on-chip microscopes based on the optofluidic microscopy (OFM) method. These systems abandon the conventional microscope design, which requires expensive lenses and large space to magnify images, and instead utilizes microfluidic flow to deliver specimens across array(s) of micrometer-size apertures defined on a metal-coated CMOS sensor to generate direct projection images. The first system utilizes a gravity-driven microfluidic flow for sample scanning and is suited for imaging elongate objects, such as Caenorhabditis elegans; and the second system employs an electrokinetic drive for flow control and is suited for imaging cells and other spherical/ellipsoidal objects. As a demonstration of the OFM for bioscience research, we show that the prototypes can be used to perform automated phenotype characterization of different Caenorhabditis elegans mutant strains, and to image spores and single cellular entities. The optofluidic microscope design, readily fabricable with existing semiconductor and microfluidic technologies, offers low-cost and highly compact imaging solutions. More functionalities, such as on-chip phase and fluorescence imaging, can also be readily adapted into OFM systems. We anticipate that the OFM can significantly address a range of biomedical and bioscience needs, and engender new microscope applications. PMID:18663227

Digital hydraulic drive for microfluidics and miniaturized cell culture devices based on shape memory alloy actuators

NASA Astrophysics Data System (ADS)

Tsai, Cheng-Han; Wu, Xuanye; Kuan, Da-Han; Zimmermann, Stefan; Zengerle, Roland; Koltay, Peter

2018-08-01

In order to culture and analyze individual living cells, microfluidic cultivation and manipulation of cells become an increasingly important topic. Such microfluidic systems allow for exploring the phenotypic differences between thousands of genetically identical cells or pharmacological tests in parallel, which is impossible to achieve by traditional macroscopic cell culture methods. Therefore, plenty of microfluidic systems and devices have been developed for cell biological studies like cell culture, cell sorting, and cell lysis in the past. However, these microfluidic systems are still limited by the external pressure sources which most of the time are large in size and have to be connected by fluidic tubing leading to complex and delicate systems. In order to provide a miniaturized, more robust actuation system a novel, compact and low power consumption digital hydraulic drive (DHD) has been developed that is intended for use in portable and automated microfluidic systems for various applications. The DHD considered in this work consists of a shape memory alloy (SMA) actuator and a pneumatic cylinder. The switching time of the digital modes (pressure ON versus OFF) can be adjusted from 1 s to min. Thus, the DHDs might have many applications for driving microfluidic devices. In this work, different implementations of DHDs are presented and their performance is characterized by experiments. In particular, it will be shown that DHDs can be used for microfluidic large-scale integration (mLSI) valve control (256 valves in parallel) as well as potentially for droplet-based microfluidic systems. As further application example, high-throughput mixing of cell cultures (96 wells in parallel) is demonstrated employing the DHD to drive a so-called ‘functional lid’ (FL), to enable a miniaturized micro bioreactor in a regular 96-well micro well plate.

Totally implantable total artificial heart and ventricular assist device with multipurpose miniature electromechanical energy system.

PubMed

Takatani, S; Orime, Y; Tasai, K; Ohara, Y; Naito, K; Mizuguchi, K; Makinouchi, K; Damm, G; Glueck, J; Ling, J

1994-01-01

A multipurpose miniature electromechanical energy system has been developed to yield a compact, efficient, durable, and biocompatible total artificial heart (TAH) and ventricular assist device (VAD). Associated controller-driver electronics were recently miniaturized and converted into hybrid circuits. The hybrid controller consists of a microprocessor and controller, motor driver, Hall sensor, and commutation circuit hybrids. The sizing study demonstrated that all these components can be incorporated in the pumping unit of the TAH and VAD, particularly in the centerpiece of the TAH and the motor housing of the VAD. Both TAH and VAD pumping units will start when their power line is connected to either the internal power pack or the external battery unit. As a redundant driving and diagnostic port, an emergency port was newly added and will be placed in subcutaneous location. In case of system failure, the skin will be cut down, and an external motor drive or a pneumatic driver will be connected to this port to run the TAH. This will minimize the circulatory arrest time. Overall efficiency of the TAH without the transcutaneous energy transmission system was 14-18% to deliver pump outputs of 4-9 L/min against the right and left afterload pressures of 25 and 100 mm Hg. The internal power requirement ranged from 6 to 13 W. The rechargeable batteries such as NiCd or NiMH with 1 AH capacity can run the TAH for 30-45 min. The external power requirement, when TETS efficiency of 75% was assumed, ranged from 8 to 18 W. The accelerated endurance test in the 42 degrees C saline bath demonstrated stable performance over 4 months. Long-term endurance and chronic animal studies will continue toward a system with 5 years durability by the year 2000.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, S; Young, C; Mizaikoff, B

Fundamental vibrational and rotational modes associated with most inorganic and organic molecules are spectroscopically accessible within the mid-infrared (MIR; 3-20 {micro}m) regime of the electromagnetic spectrum. The interaction between MIR photons and organic molecules provides particularly sharp transitions, which - despite the wide variety of organic molecules - provide unique MIR absorption spectra reflecting the molecularly characteristic arrangement of chemical bonds within the probed molecules via the frequency position of the associated vibrational and rotational transitions. Given the inherent molecular selectivity and achievable sensitivity, MIR spectroscopy provides an ideal platform for optical sensing applications. Despite this potential, early MIR sensingmore » applications were limited to localized applications due to the size of the involved instrumentation, and limited availability of appropriately compact MIR optical components including light sources, detectors, waveguides, and spectrometers. During the last decades, engineering advances in photonics and optical engineering have facilitated the translation of benchtop-style MIR spectroscopy into miniaturized optical sensing schemes providing a footprint compatible with portable instrumentation requirements for field deployable analytical tools. In this trend article, we will discuss recent advances and future strategies for miniaturizing MIR sensor technology. The Beer-Lambert law implies that achievable limit of detection (LOD) for any optical sensor system improves by increasing the interaction length between photons and target analyte species such as e.g., folding the optical path multiple times as in multi-pass gas phase sensing; however, this governing paradigm naturally leads to an increase in system dimensions. Hence, miniaturization of optical sensing system requires scaling down of each optical component, yet improving the performance of each optical element within a smaller form factor for overall at least maintaining, or ideally improving the achievable sensitivity.« less

Miniaturization of Planar Horn Motors

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Ostlund, Patrick N.; Chang, Zensheu; Bao, Xiaoqi; Bar-Cohen, Yoseph; Widholm, Scott E.; Badescu, Mircea

2012-01-01

There is a great need for compact, efficient motors for driving various mechanisms including robots or mobility platforms. A study is currently underway to develop a new type of piezoelectric actuators with significantly more strength, low mass, small footprint, and efficiency. The actuators/motors utilize piezoelectric actuated horns which have a very high power density and high electromechanical conversion efficiency. The horns are fabricated using our recently developed novel pre-stress flexures that make them thermally stable and increases their coupling efficiency. The monolithic design and integrated flexures that pre-stresses the piezoelectric stack eliminates the use of stress bolt. This design allows embedding solid-state motors and actuators in any structure so that the only macroscopically moving parts are the rotor or the linear translator. The developed actuator uses a stack/horn actuation and has a Barth motor configuration, which potentially generates very large torque and speeds that do not require gearing. Finite element modeling and design tools were investigated to determine the requirements and operation parameters and the results were used to design and fabricate a motor. This new design offers a highly promising actuation mechanism that can potentially be miniaturized and integrated into systems and structures. It can be configured in many shapes to operate as multi-degrees of freedom and multi-dimensional motors/actuators including unidirectional, bidirectional, 2D and 3D. In this manuscript, we are reporting the experimental measurements from a bench top design and the results from the efforts to miniaturize the design using 2x2x2 mm piezoelectric stacks integrated into thin plates that are of the order of3 x 3x 0.2 cm.

A case for ZnO nanowire field emitter arrays in advanced x-ray source applications

NASA Astrophysics Data System (ADS)

Robinson, Vance S.; Bergkvist, Magnus; Chen, Daokun; Chen, Jun; Huang, Mengbing

2016-09-01

Reviewing current efforts in X-ray source miniaturization reveals a broad spectrum of applications: Portable and/or remote nondestructive evaluation, high throughput protein crystallography, invasive radiotherapy, monitoring fluid flow and particulate generation in situ, and portable radiography devices for battle-front or large scale disaster triage scenarios. For the most part, all of these applications are being addressed with a top-down approach aimed at improving portability, weight and size. That is, the existing system or a critical sub-component is shrunk in some manner in order to miniaturize the overall package. In parallel to top-down x-ray source miniaturization, more recent efforts leverage field emission and semiconductor device fabrication techniques to achieve small scale x-ray sources via a bottom-up approach where phenomena effective at a micro/nanoscale are coordinated for macro-scale effect. The bottom-up approach holds potential to address all the applications previously mentioned but its entitlement extends into new applications with much more ground-breaking potential. One such bottom-up application is the distributed x-ray source platform. In the medical space, using an array of microscale x-ray sources instead of a single source promises significant reductions in patient dose as well as smaller feature detectability and fewer image artifacts. Cold cathode field emitters are ideal for this application because they can be gated electrostatically or via photonic excitation, they do not generate excessive heat like other common electron emitters, they have higher brightness and they are relatively compact. This document describes how ZnO nanowire field emitter arrays are well suited for distributed x-ray source applications because they hold promise in each of the following critical areas: emission stability, simple scalable fabrication, performance, radiation resistance and photonic coupling.

Miniaturized radioisotope solid state power sources

NASA Astrophysics Data System (ADS)

Fleurial, J.-P.; Snyder, G. J.; Patel, J.; Herman, J. A.; Caillat, T.; Nesmith, B.; Kolawa, E. A.

2000-01-01

Electrical power requirements for the next generation of deep space missions cover a wide range from the kilowatt to the milliwatt. Several of these missions call for the development of compact, low weight, long life, rugged power sources capable of delivering a few milliwatts up to a couple of watts while operating in harsh environments. Advanced solid state thermoelectric microdevices combined with radioisotope heat sources and energy storage devices such as capacitors are ideally suited for these applications. By making use of macroscopic film technology, microgenrators operating across relatively small temperature differences can be conceptualized for a variety of high heat flux or low heat flux heat source configurations. Moreover, by shrinking the size of the thermoelements and increasing their number to several thousands in a single structure, these devices can generate high voltages even at low power outputs that are more compatible with electronic components. Because the miniaturization of state-of-the-art thermoelectric module technology based on Bi2Te3 alloys is limited due to mechanical and manufacturing constraints, we are developing novel microdevices using integrated-circuit type fabrication processes, electrochemical deposition techniques and high thermal conductivity substrate materials. One power source concept is based on several thermoelectric microgenerator modules that are tightly integrated with a 1.1W Radioisotope Heater Unit. Such a system could deliver up to 50mW of electrical power in a small lightweight package of approximately 50 to 60g and 30cm3. An even higher degree of miniaturization and high specific power values (mW/mm3) can be obtained when considering the potential use of radioisotope materials for an alpha-voltaic or a hybrid thermoelectric/alpha-voltaic power source. Some of the technical challenges associated with these concepts are discussed in this paper. .

Low Gas Fractions Connect Compact Star-forming Galaxies to Their z ~ 2 Quiescent Descendants

NASA Astrophysics Data System (ADS)

Spilker, Justin S.; Bezanson, Rachel; Marrone, Daniel P.; Weiner, Benjamin J.; Whitaker, Katherine E.; Williams, Christina C.

2016-11-01

Early quiescent galaxies at z˜ 2 are known to be remarkably compact compared to their nearby counterparts. Possible progenitors of these systems include galaxies that are structurally similar, but are still rapidly forming stars. Here, we present Karl G. Jansky Very Large Array (VLA) observations of the CO(1-0) line toward three such compact, star-forming galaxies (SFGs) at z˜ 2.3, significantly detecting one. The VLA observations indicate baryonic gas fractions ≳ 5 times lower and gas depletion timescales ≳ 10 times shorter than normal, extended massive SFGs at these redshifts. At their current star formation rates, all three objects will deplete their gas reservoirs within 100 Myr. These objects are among the most gas-poor objects observed at z\\gt 2, and are outliers from standard gas scaling relations, a result that remains true regardless of assumptions about the CO-H2 conversion factor. Our observations are consistent with the idea that compact, SFGs are in a rapid state of transition to quiescence in tandem with the buildup of the z˜ 2 quenched population. In the detected compact galaxy, we see no evidence of rotation or that the CO-emitting gas is spatially extended relative to the stellar light. This casts doubt on recent suggestions that the gas in these compact galaxies is rotating and significantly extended compared to the stars. Instead, we suggest that, at least for this object, the gas is centrally concentrated, and only traces a small fraction of the total galaxy dynamical mass.

Novel Design of Tunable Microlens with Lowered Driving Voltage and Iris with Conformal Antireflective Surface

NASA Astrophysics Data System (ADS)

Almoallem, Yousuf Dawood

Miniaturizing camera systems as required in many new compact devices places a severe restriction on the device size and power consumption. In modern life nowadays, a daily used compact devices like mobile phones and tablets must have some essential components such as single or multiple tiny cameras, as a component of micro-optical systems. In fact, for most of the current miniaturized cameras, optical power is varied based on the traditional situation where the distances between the lenses are mechanically varied relying on old-fashioned voice coil motors or equivalent mechanical drivers. Spatial and power consumption could be scaled down drastically with much faster response time when the revolutionary alternative liquid tunable microlens is utilized after acquiring a good understanding of microfluidics. The influence of interfacial tension as a key metric in controlling microfluidics systems (e.g. liquid microlens) has drawn considerable attention in biomedical, industrial, military fields over the past decade. Tunable microlenses overcome aforementioned concerns of miniaturizing optical systems and present a viable solution by tuning the focal length of lenses via, for example, variation in the lens curvature. Here, a novel tunable dielectrophoretic (DEP)-based tunable lens is presented. Out of many other mechanisms of tuning the lenses, the dielectric mechanism is especially promising since having the capability to achieve a faster response and overcome the electrolysis issue. Nonetheless, DEP usually requires high driving voltage levels. The proposed design is operating with a lowered voltage level and is based on a tunable dielectric liquid lens with a double-sided electrode design, unlike in the conventional scheme with a single-sided electrode design. The design methodology, geometrical analysis, device fabrication, simulation, and testing are demonstrated. Furthermore, the design, simulation, fabrication and characterization of a black-silicon (BSi) based iris is discussed. Reducing undesirable light stray reflections from surfaces is desired in many 3D optical elements, such as supporting optomechanical mounts, irises, optical filters, solar cells, and photolithography underlying layers. BSi (as antireflective nanostructures) provides a potential economic solution which is highly absorptive across the visible spectrum to replace many currently used yet expensive coating materials. Si nanowires (SiNW) were formed using a metal-assisted chemical (MAC) etching process to get a conformal antireflective property on the iris 3D structure including sharp tips and sidewalls. A significant reduction in undesirable light stray reflections was achieved as a result of successful implementation of the conformal antireflective surface on all facets of fabricated irises to eliminate undesirable light stray reflections.

Small pixel pitch MCT IR-modules

NASA Astrophysics Data System (ADS)

Lutz, H.; Breiter, R.; Eich, D.; Figgemeier, H.; Fries, P.; Rutzinger, S.; Wendler, J.

2016-05-01

It is only some years ago, since VGA format detectors in 15μm pitch, manufactured with AIM's MCT n-on-p LPE standard technology, have been introduced to replace TV/4 format detector arrays as a system upgrade. In recent years a rapid increase in the demand for higher resolution, while preserving high thermal resolution, compactness and low power budget is observed. To satisfy these needs AIM has realized first prototypes of MWIR XGA format (1024x768) detector arrays in 10μm pitch. They fit in the same compact dewar as 640x512, 15μm pitch detector arrays. Therefore, they are best suited for system upgrade purposes to benefit from higher spatial resolution and keep cost on system level low. By combining pitch size reduction with recent development progress in the fields of miniature cryocoolers, short dewars and high operating temperatures the way ahead to ultra-compact high performance MWIR-modules is prepared. For cost reduction MBE grown MCT on commercially available GaAs substrates is introduced at AIM. Recently, 640x512, 15μm pitch FPAs, grown with MBE have successfully passed long-term high temperature storage tests as a crucial step towards serial production readiness level for use in future products. Pitch size reduction is not limited to arrays sensitive in the MWIR, but is of great interest for high performance LWIR or 3rd Gen solutions. Some applications such as rotorcraft pilotage require superior spatial resolution in a compact design to master severe weather conditions or degraded visual environment such as brown-out. For these applications AIM is developing both LWIR as well as dual band detector arrays in HD-format (1280x720) with 12μm pitch. This paper will present latest results in the development of detector arrays with small pitch sizes of 10μm and 12μm at AIM, together with their usage to realize compact cooled IR-modules.

Methodologies to determine forces on bones and muscles of body segments during exercise, employing compact sensors suitable for use in crowded space vehicles

NASA Technical Reports Server (NTRS)

Figueroa, Fernando

1995-01-01

Work under this grant was carried out by the author and by a graduate research assistant. An instrumented bicycle ergometer was implemented focusing on the stated objective: to estimate the forces exerted by each muscle of the feet, calf, and thigh of an individual while bicycling. The sensors used were light and compact. These were probes to measure muscle EMG activity, miniature accelerometers, miniature load sensors, and small encoders to measure angular positions of the pedal. A methodology was developed and implemented to completely describe the kinematics of the limbs using data from the sensors. This work has been published as a Master's Thesis by the Graduate student supported by the grant. The instrumented ergometer along with the sensors and instrumentation were tested during a KC-135 Zero-Gravity flight in July, 1994. A complete description of the system and the tests performed have been published as a report submitted to NASA Johnson Space Center. The data collected during the KC-135 flight is currently being processed so that a kinematic description of the bicycling experiment will be soon determined. A methodology to estimate the muscle forces has been formulated based on previous work. The methodology involves the use of optimization concepts so that the individual muscle forces that represent variables in dynamic equations of motion may be estimated. Optimization of a criteria (goal) function such as minimization of energy will be used along with constraint equations defined by rigid body equations of motion. Use of optimization principles is necessary, because the equations of motion alone constitute an indeterminate system of equations with respect to the large amount of muscle forces which constitute the variables in these equations. The number of variables is reduced somewhat by using forces measured by the load cells installed on the pedal. These load cells measure pressure and shear forces on the foot. The author and his collaborators at NASA and at the University of Alabama, Tuscaloosa, are continuing the work of reducing the experimental data from the KC-135 flight, and the implementation of the optimization methods to estimate muscle forces. As soon as results from these efforts are available, they will be published in reputable journals. Results of this work will impact studies addressing bone density loss and development of countermeasures to minimize bone loss in zero gravity conditions. By analyzing muscle forces on Earth and in Space during exercise, scientists could eventually formulate new exercises and machines to help maintain bone density. On Earth, this work will impact studies concerning arthritis, and will provide the means to study possible exercise countermeasures to minimize arthritis problems.

Constraining black holes with light boson hair and boson stars using epicyclic frequencies and quasiperiodic oscillations

NASA Astrophysics Data System (ADS)

Franchini, Nicola; Pani, Paolo; Maselli, Andrea; Gualtieri, Leonardo; Herdeiro, Carlos A. R.; Radu, Eugen; Ferrari, Valeria

2017-06-01

Light bosonic fields are ubiquitous in extensions of the Standard Model. Even when minimally coupled to gravity, these fields might evade the assumptions of the black-hole no-hair theorems and give rise to spinning black holes which can be drastically different from the Kerr metric. Furthermore, they allow for self-gravitating compact solitons, known as (scalar or Proca) boson stars. The quasiperiodic oscillations (QPOs) observed in the x-ray flux emitted by accreting compact objects carry information about the strong-field region, thus providing a powerful tool to constrain deviations from Kerr's geometry and to search for exotic compact objects. By using the relativistic precession model as a proxy to interpret the QPOs in terms of geodesic frequencies, we investigate how the QPO frequencies could be used to test the no-hair theorem and the existence of light bosonic fields near accreting compact objects. We show that a detection of two QPO triplets with current sensitivity can already constrain these models and that the future eXTP mission or a LOFT-like mission can set very stringent constraints on black holes with bosonic hair and on (scalar or Proca) boson stars. The peculiar geodesic structure of compact scalar/Proca boson stars implies that these objects can easily be ruled out as alternative models for x-ray source GRO J1655-40.

Discovery of Compact Quiescent Galaxies at Intermediate Redshifts in DEEP2

NASA Astrophysics Data System (ADS)

Blancato, Kirsten; Chilingarian, Igor; Damjanov, Ivana; Moran, Sean; Katkov, Ivan

2015-01-01

Compact quiescent galaxies in the redshift range 0.6 < z < 1.1 are the missing link needed to complete the evolutionary histories of these objects from the high redshift z ≥ 2 Universe to the local z ~ 0 Universe. We identify the first intermediate redshift compact quiescent galaxies by searching a sample of 1,089 objects in the DEEP2 Redshift Survey that have multi-band photometry, spectral fitting, and readily available structural parameters. We find 27 compact quiescent candidates between z = 0.6 and z = 1.1 where each candidate galaxy has archival Hubble Space Telescope (HST) imaging and is visually confirmed to be early-type. The candidates have half-light radii ranging from 0.83 < Re,c < 7.14 kpc (median Re,c = 1.77 kpc) and virial masses ranging from 2.2E10 < Mdyn < 5.6E11 Msun (median Mdyn = 7.7E10 Msun). Of our 27 compact quiescent candidates, 13 are truly compact with sizes at most half of the size of their z ~ 0 counterparts of the same mass. In addition to their structural properties bridging the gap between their high and low redshift counterparts, our sample of intermediate redshift quiescent galaxies span a large range of ages but is drawn from two distinct epochs of galaxy formation: formation at z > 2 which suggests these objects may be the relics of the observed high redshift compact galaxies and formation at z ≤ 2 which suggests there is an additional population of more recently formed massive compact galaxies. This work is supported in part by the NSF REU and DOD ASSURE programs under NSF grant no. 1262851 and by the Smithsonian Institution.

Some topics in the magnetohydrodynamics of accreting magnetic compact objects

NASA Technical Reports Server (NTRS)

Aly, J. J.

1986-01-01

Magnetic compact objects (neutron stars or white dwarfs) are currently thought to be present in many accreting systems that are releasing large amounts of energy. The magnetic field of the compact star may interact strongly with the accretion flow and play an essential role in the physics of these systems. Some magnetohydrodynamic (MHD) problems that are likely to be relevant in building up self-consistent models of the interaction between the accreting plasma and the star's magnetosphere are addressed in this series of lectures. The basic principles of MHD are first introduced and some important MHD mechanisms (Rayleigh-Taylor and Kelvin-Helmholtz instabilities; reconnection) are discussed, with particular reference to their role in allowing the infalling matter to penetrate the magnetosphere and mix with the field. The structure of a force-free magnetosphere and the possibility of quasistatic momentum and energy transfer between regions linked by field-aligned currents are then studied in some detail. Finally, the structure of axisymmetric accretion flows onto magnetic compact objects is considered.

Spherical torus fusion reactor

DOEpatents

Martin Peng, Y.K.M.

1985-10-03

The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.

Quark Phase Transition in Compact Objects and Multimessenger Astronomy: Neutrino Signals, Supernovae and Gamma-Ray Bursts

NASA Astrophysics Data System (ADS)

Sokolov, V. V.; Vlasyuk, V. V.; Petkov, V. B.

2016-06-01

The International Workshop on Quark Phase Transition in Compact Objects and Multimessenger Astronomy: Neutrino Signals, Supernovae and Gamma-Ray Bursts (October, 7-14, 2015) was dedicated to Quantum ChromoDynamics (QCD) Phase Transitions and observational signals of these transitions related to formation of compact astrophysical objects. The aim of this workshop was to bring together researchers working on the problems of behavior of matter under critical conditions achievable in such astrophysical objects as "strange" or "hybrid" stars and in laboratories at heavy-ion collisions to discuss fundamental issues and recent developments. Topics included both observations (radio, optical and X-ray astronomy, gamma ray bursts, gravitational waves, neutrino detection, heavy-ion collisions, etc.) and theory (supernova simulations, proto-neutron and neutron stars, equation of state of dense matter, neutron star cooling, unstable modes, nucleosynthesis, explosive transitions, quark-gluon plasma).

Pharmaceutical Raw Material Identification Using Miniature Near-Infrared (MicroNIR) Spectroscopy and Supervised Pattern Recognition Using Support Vector Machine

PubMed Central

Hsiung, Chang; Pederson, Christopher G.; Zou, Peng; Smith, Valton; von Gunten, Marc; O’Brien, Nada A.

2016-01-01

Near-infrared spectroscopy as a rapid and non-destructive analytical technique offers great advantages for pharmaceutical raw material identification (RMID) to fulfill the quality and safety requirements in pharmaceutical industry. In this study, we demonstrated the use of portable miniature near-infrared (MicroNIR) spectrometers for NIR-based pharmaceutical RMID and solved two challenges in this area, model transferability and large-scale classification, with the aid of support vector machine (SVM) modeling. We used a set of 19 pharmaceutical compounds including various active pharmaceutical ingredients (APIs) and excipients and six MicroNIR spectrometers to test model transferability. For the test of large-scale classification, we used another set of 253 pharmaceutical compounds comprised of both chemically and physically different APIs and excipients. We compared SVM with conventional chemometric modeling techniques, including soft independent modeling of class analogy, partial least squares discriminant analysis, linear discriminant analysis, and quadratic discriminant analysis. Support vector machine modeling using a linear kernel, especially when combined with a hierarchical scheme, exhibited excellent performance in both model transferability and large-scale classification. Hence, ultra-compact, portable and robust MicroNIR spectrometers coupled with SVM modeling can make on-site and in situ pharmaceutical RMID for large-volume applications highly achievable. PMID:27029624

Miniaturized INtrinsic DISsolution Screening (MINDISS) assay for preformulation.

PubMed

Alsenz, Jochem; Haenel, Elisabeth; Anedda, Aline; Du Castel, Pauline; Cirelli, Giorgio

2016-05-25

This study describes a novel Miniaturized INtrinsic DISsolution Screening (MINDISS) assay for measuring disk intrinsic dissolution rates (DIDR). In MINDISS, compacted mini disks of drugs (2-5mg/disk) are prepared in custom made holders with a surface area of 3mm(2). Disks are immersed, pellet side down, into 0.35ml of appropriate dissolution media per well in 96-well microtiter plates, media are stirred and disk-holders are transferred to new wells after defined periods of time. After filtration, drug concentration in dissolution media is quantified by Ultra Performance Liquid Chromatography (UPLC) and solid state property of the disk is characterized by Raman spectroscopy. MINDISS was identified as an easy-to-use tool for rapid, parallel determination of DIDR of compounds that requires only small amounts of compound and of dissolution medium. Results obtained with marketed drugs in MINDISS correlate well with large scale DIDR methods and indicate that MINDISS can be used for (1) rank-ordering of compounds by intrinsic dissolution in late phase discovery and early development, (2) comparison of polymorphic forms and salts, (3) screening and selection of appropriate dissolution media, and (4) characterization of the intestinal release behavior of compounds along the gastro intestinal tract by changing biorelevant media during experiments. Copyright © 2015 Elsevier B.V. All rights reserved.

Handheld 2-channel impedimetric cell counting system with embedded real-time processing

NASA Astrophysics Data System (ADS)

Rottigni, A.; Carminati, M.; Ferrari, G.; Vahey, M. D.; Voldman, J.; Sampietro, M.

2011-05-01

Lab-on-a-chip systems have been attracting a growing attention for the perspective of miniaturization and portability of bio-chemical assays. Here we present a the design and characterization of a miniaturized, USB-powered, self-contained, 2-channel instrument for impedance sensing, suitable for label-free tracking and real-time detection of cells flowing in microfluidic channels. This original circuit features a signal generator based on a direct digital synthesizer, a transimpedance amplifier, an integrated square-wave lock-in coupled to a Σ▵ ADC converter, and a digital processing platform. Real-time automatic peak detection on two channels is implemented in a FPGA. System functionality has been tested with an electronic resistance modulator to simulate 1% impedance variation produced by cells, reaching a time resolution of 50μs (enabling a count rate of 2000 events/s) with an applied voltage as low as 200mV. Biological experiments have been carried out counting yeast cells. Statistical analysis of events is in agreement with the expected amplitude and time distributions. 2-channel yeast counting has been performed with concomitant dielectrophoretic cell separation, showing that this novel and ultra compact sensing system, thanks to the selectivity of the lock-in detector, is compatible with other AC electrical fields applied to the device.

Scalable Fabrication of Photochemically Reduced Graphene-Based Monolithic Micro-Supercapacitors with Superior Energy and Power Densities.

PubMed

Wang, Sen; Wu, Zhong-Shuai; Zheng, Shuanghao; Zhou, Feng; Sun, Chenglin; Cheng, Hui-Ming; Bao, Xinhe

2017-04-25

Micro-supercapacitors (MSCs) hold great promise as highly competitive miniaturized power sources satisfying the increased demand of smart integrated electronics. However, single-step scalable fabrication of MSCs with both high energy and power densities is still challenging. Here we demonstrate the scalable fabrication of graphene-based monolithic MSCs with diverse planar geometries and capable of superior integration by photochemical reduction of graphene oxide/TiO 2 nanoparticle hybrid films. The resulting MSCs exhibit high volumetric capacitance of 233.0 F cm -3 , exceptional flexibility, and remarkable capacity of modular serial and parallel integration in aqueous gel electrolyte. Furthermore, by precisely engineering the interface of electrode with electrolyte, these monolithic MSCs can operate well in a hydrophobic electrolyte of ionic liquid (3.0 V) at a high scan rate of 200 V s -1 , two orders of magnitude higher than those of conventional supercapacitors. More notably, the MSCs show landmark volumetric power density of 312 W cm -3 and energy density of 7.7 mWh cm -3 , both of which are among the highest values attained for carbon-based MSCs. Therefore, such monolithic MSC devices based on photochemically reduced, compact graphene films possess enormous potential for numerous miniaturized, flexible electronic applications.

Micro/Nano Fabricated Solid-State Thermoelectric Generator Devices for Integrated High Voltage Power Sources

NASA Astrophysics Data System (ADS)

Fleurial, J.-P.; Ryan, M. A.; Snyder, G. J.; Huang, C.-K.; Whitacre, J. F.; Patel, J.; Lim, J.; Borshchevsky, A.

2002-01-01

Deep space missions have a strong need for compact, high power density, reliable and long life electrical power generation and storage under extreme temperature conditions. Except for electrochemical batteries and solar cells, there are currently no available miniaturized power sources. Conventional power generators devices become inefficient in extreme environments (such as encountered in Mars, Venus or outer planet missions) and rechargeable energy storage devices can only be operated in a narrow temperature range thereby limiting mission duration. The planned development of much smaller spacecrafts incorporating a variety of micro/nanodevices and miniature vehicles will require novel, reliable power technologies. It is also expected that such micro power sources could have a wide range of terrestrial applications, in particular when the limited lifetime and environmental limitations of batteries are key factors. Advanced solid-state thermoelectric combined with radioisotope or waste heat sources and low profile energy storage devices are ideally suited for these applications. The Jet Propulsion Laboratory has been actively pursuing the development of thermoelectric micro/nanodevices that can be fabricated using a combination of electrochemical deposition and integrated circuit processing techniques. Some of the technical challenges associated with these micro/nanodevice concepts, their expected level of performance and experimental fabrication and testing results to date are presented and discussed.

Miniature self-contained vacuum compatible electronic imaging microscope

DOEpatents

Naulleau, Patrick P.; Batson, Phillip J.; Denham, Paul E.; Jones, Michael S.

2001-01-01

A vacuum compatible CCD-based microscopic camera with an integrated illuminator. The camera can provide video or still feed from the microscope contained within a vacuum chamber. Activation of an optional integral illuminator can provide light to illuminate the microscope subject. The microscope camera comprises a housing with a objective port, modified objective, beam-splitter, CCD camera, and LED illuminator.

Optimal Cooling of High Purity Germanium Spectrometers for Missions to Planets and Moons

NASA Astrophysics Data System (ADS)

Chernenko, A.; Kostenko, V.; Konev, S.; Rybkin, B.; Paschin, A.; Prokopenko, I.

2004-04-01

Gamma-ray spectrometers based on high purity germanium (HPGe) detectors are ultimately sensitive instruments for composition studies of surfaces of planets and moons. However, they require deep cooling well below 120K for the entire duration of space mission, and this challenges the feasibility of such instruments in the era of small and cost-efficient missions. In this paper we summarise our experience in the field of the theoretical and experimental studies of optimal cryogenic cooling of gamma-ray spectrometers based on HPGe detectors in order to find out how efficient, light and compact these instruments could be, provided such technologies like cryogenic heat pipe diodes (HPDs), efficient thermal insulation and efficient miniature cryocoolers are used.

Gravitational Influences on the Growth of Polydiacetylene Films by Ultraviolet Solution Polymerization

NASA Technical Reports Server (NTRS)

Frazier, Donald O.

2000-01-01

Technically, the field of integrated optics using organic/polymer materials as a new means of information processing, has emerged as of vital importance to optical computers, optical switching, optical communications, the defense industry, etc. The goal is to replace conventional electronic integrated circuits and wires by equivalent miniaturized optical integrated circuits and fibers, offering larger bandwidths, more compactness and reliability, immunity to electromagnetic interference and less cost. From the Code E perspective, this research area represents an opportunity to marry "front-line" education in science and technology with national scientific and technological interests while maximizing human resources utilization. This can be achieved by the development of untapped resources for scientific research - such as minorities, women, and universities traditionally uninvolved in scientific research.

Fluidics cube for biosensor miniaturization

NASA Technical Reports Server (NTRS)

Dodson, J. M.; Feldstein, M. J.; Leatzow, D. M.; Flack, L. K.; Golden, J. P.; Ligler, F. S.

2001-01-01

To create a small, portable, fully automated biosensor, a compact means of fluid handling is required. We designed, manufactured, and tested a "fluidics cube" for such a purpose. This cube, made of thermoplastic, contains reservoirs and channels for liquid samples and reagents and operates without the use of any internal valves or meters; it is a passive fluid circuit that relies on pressure relief vents to control fluid movement. We demonstrate the ability of pressure relief vents to control fluid movement and show how to simply manufacture or modify the cube. Combined with the planar array biosensor developed at the Naval Research Laboratory, it brings us one step closer to realizing our goal of a handheld biosensor capable of analyzing multiple samples for multiple analytes.

Miniature X-band GaAs MMIC analog and bi-phase modulators for spaceborne communications applications

NASA Technical Reports Server (NTRS)

Mysoor, Narayan R.; Ali, Fazal

1992-01-01

The design concepts, analyses, and the development of GaAs monolithic microwave integrated circuit (MMIC) linear-phase and digital modulators for the next generation of spaceborne communications systems are summarized. The design approach uses a very compact lumped-element, quadrature hybrid, and MESFET-varactors to provide low-loss and well-controlled phase performance for deep-space transponder (DST) applications. The measured results of the MESFET-diode show a capacitance range of 2:1 under reverse bias, and a Q of 38 at 10 GHz. Three cascaded sections of hybrid-coupled reflection phase shifters have been modeled and simulations performed to provide an X-band (8415 +/- 50 MHz) DST phase modulator with +/-2.5 radians of peak phase deviation.

Recent advances and progress in photonic crystal-based gas sensors

NASA Astrophysics Data System (ADS)

Goyal, Amit Kumar; Sankar Dutta, Hemant; Pal, Suchandan

2017-05-01

This review covers the recent progress made in the photonic crystal-based sensing technology for gas sensing applications. Photonic crystal-based sensing has tremendous potential because of its obvious advantages in sensitivity, stability, miniaturisation, portability, online use, remote monitoring etc. Several 1D and 2D photonic crystal structures including photonic crystal waveguides and cavities for gas sensing applications have been discussed in this review. For each kind of photonic crystal structure, the novelty, measurement principle and their respective gas sensing properties are presented. The reported works and the corresponding results predict the possibility to realize a commercially viable miniaturized and highly sensitive photonic crystal-based optical gas sensor having flexibility in the structure of ultra-compact size with excellent sensing properties.

Evolution of the accretion structure of the compact object in the symbiotic binary BF Cygni during outburst in 2009-2014

NASA Astrophysics Data System (ADS)

Tomov, N. A.; Tomova, M. T.; Bisikalo, D. V.

2017-12-01

The eclipsing symbiotic binary BF Cyg has had five orbital minima during its last optical outburst after 2006. The second minimum is much shallower than the first one and after that the minimum get deeper again. We determined the parameters of the accretion structure surrounding the compact object in two minima and traced its evolution until 2014. Moreover, we analysed the continuum of the system in the region of the UBVRCIC photometric bands to derive the parameters of its components at two times orbital maximum and calculated the mass-loss rate of the compact object. The results obtained allow us to conclude about the mechanism of fading of the optical light of the system until 2014. These results show that the optical flux of the outbursted compact object decreases because of "contraction" of its observed photosphere (pseudophotosphere) which, on its side, is due to increase of the velocity of its stellar wind, and the optical flux of the circumbinary nebula decreases mainly because of reduction of its mean density, which, on its side, is due to destruction of the accretion structure.

The Next Generation Virgo Cluster Survey. XII. Stellar Populations and Kinematics of Compact, Low-mass Early-type Galaxies from Gemini GMOS-IFU Spectroscopy

NASA Astrophysics Data System (ADS)

Guérou, Adrien; Emsellem, Eric; McDermid, Richard M.; Côté, Patrick; Ferrarese, Laura; Blakeslee, John P.; Durrell, Patrick R.; MacArthur, Lauren A.; Peng, Eric W.; Cuillandre, Jean-Charles; Gwyn, Stephen

2015-05-01

We present Gemini Multi Object Spectrograph integral-field unit (GMOS-IFU) data of eight compact, low-mass early-type galaxies (ETGs) in the Virgo cluster. We analyze their stellar kinematics and stellar population and present two-dimensional maps of these properties covering the central 5″ × 7″ region. We find a large variety of kinematics, from nonrotating to highly rotating objects, often associated with underlying disky isophotes revealed by deep images from the Next Generation Virgo Cluster Survey. In half of our objects, we find a centrally concentrated younger and more metal-rich stellar population. We analyze the specific stellar angular momentum through the λR parameter and find six fast rotators and two slow rotators, one having a thin counterrotating disk. We compare the local galaxy density and stellar populations of our objects with those of 39 more extended low-mass Virgo ETGs from the SMAKCED survey and 260 massive (M > 1010 {{M}⊙ }) ETGs from the ATLAS3D sample. The compact low-mass ETGs in our sample are located in high-density regions, often close to a massive galaxy, and have, on average, older and more metal-rich stellar populations than less compact low-mass galaxies. We find that the stellar population parameters follow lines of constant velocity dispersion in the mass-size plane, smoothly extending the comparable trends found for massive ETGs. Our study supports a scenario where low-mass compact ETGs have experienced long-lived interactions with their environment, including ram-pressure stripping and gravitational tidal forces, that may be responsible for their compact nature.

Low Gas Fractions Connect Compact Star-Forming Galaxies to their z~2 Quiescent Descendants

NASA Astrophysics Data System (ADS)

Spilker, Justin; Bezanson, Rachel; Marrone, Daniel P.; Weiner, Benjamin J.; Whitaker, Katherine E.; Williams, Christina C.

2017-01-01

Early quiescent galaxies at z ~ 2 are known to be remarkably compact compared to their nearby counterparts. Possible progenitors of these systems include galaxies that are structurally similar, but are still rapidly forming stars. I will present Karl G. Jansky Very Large Array (VLA) observations of the CO(1-0) line towards three such compact, star-forming galaxies at z ~ 2.3, significantly detecting one. The VLA observations indicate baryonic gas fractions 5 times lower and gas depletion times 10 times shorter than normal, extended massive star-forming galaxies at these redshifts. At their current star formation rates, all three objects will deplete their gas reservoirs within 100Myr. These objects are among the most gas-poor objects observed at z > 2 and are outliers from standard gas scaling relations, a result which remains true regardless of assumptions about the CO-H2 conversion factor. Our observations are consistent with the idea that compact, star-forming galaxies are in a rapid state of transition to quiescence in tandem with the build-up of the z ~ 2 quenched population. In the detected compact galaxy, we see no evidence of rotation or that the CO-emitting gas is spatially extended relative to the stellar light. This casts doubt on recent suggestions that the gas in these compact galaxies is rotating and significantly extended compared to the stars. Instead, we suggest that, at least for this object, the gas is centrally concentrated, and only traces a small fraction of the total galaxy dynamical mass. I will conclude by discussing my ongoing efforts to characterize the gas and star forming properties of this unusual population of galaxies.

WR 148 and the not so compact companion

NASA Astrophysics Data System (ADS)

Munoz, Melissa; Moffat, Anthony J.; Hill, Grant M.; Shenar, Tomer; Richardson, Noel D.; Pablo, Herbert; St-Louis, Nicole; Ramiaramanantsoa, Tahina

2017-11-01

The objective is to determine the nature of the unseen companion of the single-lined spectroscopic binary, WR 148 (= WN7h+?). The absence of companion lines supports a compact companion (cc) scenario. The lack of hard X-rays favours a non-compact companion scenario. Is WR 148 a commonplace WR+OB binary or a rare WR+cc binary?

Asphaltic mixture compaction and density validation : research brief.

DOT National Transportation Integrated Search

2017-02-01

Research Objectives: : Evaluate HMA longitudinal joint type, method and compaction data to produce specification recommendations to ensure the highest density at longitudinal joints : Evaluate thin lift overlay HMA and provide recommendations...

Optical Microfibre Based Photonic Components and Their Applications in Label-Free Biosensing

PubMed Central

Wang, Pengfei; Bo, Lin; Semenova, Yuliya; Farrell, Gerald; Brambilla, Gilberto

2015-01-01

Optical microfibre photonic components offer a variety of enabling properties, including large evanescent fields, flexibility, configurability, high confinement, robustness and compactness. These unique features have been exploited in a range of applications such as telecommunication, sensing, optical manipulation and high Q resonators. Optical microfibre biosensors, as a class of fibre optic biosensors which rely on small geometries to expose the evanescent field to interact with samples, have been widely investigated. Due to their unique properties, such as fast response, functionalization, strong confinement, configurability, flexibility, compact size, low cost, robustness, ease of miniaturization, large evanescent field and label-free operation, optical microfibres based biosensors seem a promising alternative to traditional immunological methods for biomolecule measurements. Unlabeled DNA and protein targets can be detected by monitoring the changes of various optical transduction mechanisms, such as refractive index, absorption and surface plasmon resonance, since a target molecule is capable of binding to an immobilized optical microfibre. In this review, we critically summarize accomplishments of past optical microfibre label-free biosensors, identify areas for future research and provide a detailed account of the studies conducted to date for biomolecules detection using optical microfibres. PMID:26287252

Compact, cost-effective and field-portable microscope prototype based on MISHELF microscopy

NASA Astrophysics Data System (ADS)

Sanz, Martín; Picazo-Bueno, José Ángel; Granero, Luis; García, Javier; Micó, Vicente

2017-02-01

We report on a reduced cost, portable and compact prototype design of lensless holographic microscope with an illumination/detection scheme based on wavelength multiplexing, working with single hologram acquisition and using a fast convergence algorithm for image processing. All together, MISHELF (initials coming from Multi-Illumination Single-Holographic-Exposure Lensless Fresnel) microscopy allows the recording of three Fresnel domain diffraction patterns in a single camera snap-shot incoming from illuminating the sample with three coherent lights at once. Previous implementations have proposed an illumination/detection procedure based on a tuned (illumination wavelengths centered at the maximum sensitivity of the camera detection channels) configuration but here we report on a detuned (non-centered ones) scheme resulting in prototype miniaturization and cost reduction. Thus, MISHELF microscopy in combination with a novel and fast iterative algorithm allows high-resolution (μm range) phase-retrieved (twin image elimination) quantitative phase imaging of dynamic events (video rate recording speed). The performance of this microscope prototype is validated through experiments using both amplitude (USAF resolution test) and complex (live swine sperm cells and flowing microbeads) samples. The proposed method becomes in an alternative instrument improving some capabilities of existing lensless microscopes.

A PDA-based flexible telecommunication system for telemedicine applications.

PubMed

Nazeran, Homer; Setty, Sunil; Haltiwanger, Emily; Gonzalez, Virgilio

2004-01-01

Technology has been used to deliver health care at a distance for many years. Telemedicine is a rapidly growing area and recently there are studies devoted to prehospital care of patients in emergency cases. In this work we have developed a compact, reliable, and low cost PDA-based telecommunication device for telemedicine applications to transmit audio, still images, and vital signs from a remote site to a fixed station such as a clinic or a hospital in real time. This was achieved based on a client-server architecture. A Pocket PC, a miniature camera, and a hands-free microphone were used at the client site and a desktop computer running the Windows XP operating system was used as a server. The server was located at a fixed station. The system was implemented on TCP/IP and HTTP protocol. Field tests have shown that the system can reliably transmit still images, audio, and sample vital signs from a simulated remote site to a fixed station either via a wired or wireless network in real time. The Pocket PC was used at the client site because of its compact size, low cost and processing capabilities.

All-optical universal logic gates on nonlinear multimode interference coupler using tunable input intensity

NASA Astrophysics Data System (ADS)

Tajaldini, Mehdi; Jafri, Mohd Zubir Mat

2015-04-01

The theory of Nonlinear Modal Propagation Analysis Method (NMPA) have shown significant features of nonlinear multimode interference (MMI) coupler with compact dimension and when launched near the threshold of nonlinearity. Moreover, NMPA have the potential to allow studying the nonlinear MMI based the modal interference to explorer the phenomenon that what happen due to the natural of multimode region. Proposal of all-optical switch based NMPA has approved its capability to achieving the all-optical gates. All-optical gates have attracted increasing attention due to their practical utility in all-optical signal processing networks and systems. Nonlinear multimode interference devices could apply as universal all-optical gates due to significant features that NMPA introduce them. In this Paper, we present a novel Ultra-compact MMI coupler based on NMPA method in low intensity compared to last reports either as a novel design method and potential application for optical NAND, NOR as universal gates on single structure for Boolean logic signal processing devices and optimize their application via studding the contrast ratio between ON and OFF as a function of output width. We have applied NMPA for several applications so that the miniaturization in low nonlinear intensities is their main purpose.

THz and Sub-THz Capabilities of a Table-Top Radiation Source Driven by an RF Thermionic Electron Gun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smirnov, Alexei V.; Agustsson, R.; Boucher, S.

Design features and experimental results are presented for a sub-mm wave source [1] based on APS RF thermionic electron gun. The setup includes compact alpha-magnet, quadrupoles, sub-mm-wave radiators, and THz optics. The sub-THz radiator is a planar, oversized structure with gratings. Source upgrade for generation frequencies above 1 THz is discussed. The THz radiator will use a short-period undulator having 1 T field amplitude, ~20 cm length, and integrated with a low-loss oversized waveguide. Both radiators are integrated with a miniature horn antenna and a small ~90°-degree in-vacuum bending magnet. The electron beamline is designed to operate different modes includingmore » conversion to a flat beam interacting efficiently with the radiator. The source can be used for cancer diagnostics, surface defectoscopy, and non-destructive testing. Sub-THz experiment demonstrated a good potential of a robust, table-top system for generation of a narrow bandwidth THz radiation. This setup can be considered as a prototype of a compact, laser-free, flexible source capable of generation of long trains of Sub-THz and THz pulses with repetition rates not available with laser-driven sources.« less

Optical Microfibre Based Photonic Components and Their Applications in Label-Free Biosensing.

PubMed

Wang, Pengfei; Bo, Lin; Semenova, Yuliya; Farrell, Gerald; Brambilla, Gilberto

2015-07-22

Optical microfibre photonic components offer a variety of enabling properties, including large evanescent fields, flexibility, configurability, high confinement, robustness and compactness. These unique features have been exploited in a range of applications such as telecommunication, sensing, optical manipulation and high Q resonators. Optical microfibre biosensors, as a class of fibre optic biosensors which rely on small geometries to expose the evanescent field to interact with samples, have been widely investigated. Due to their unique properties, such as fast response, functionalization, strong confinement, configurability, flexibility, compact size, low cost, robustness, ease of miniaturization, large evanescent field and label-free operation, optical microfibres based biosensors seem a promising alternative to traditional immunological methods for biomolecule measurements. Unlabeled DNA and protein targets can be detected by monitoring the changes of various optical transduction mechanisms, such as refractive index, absorption and surface plasmon resonance, since a target molecule is capable of binding to an immobilized optical microfibre. In this review, we critically summarize accomplishments of past optical microfibre label-free biosensors, identify areas for future research and provide a detailed account of the studies conducted to date for biomolecules detection using optical microfibres.

Low voltage operation of plasma focus.

PubMed

Shukla, Rohit; Sharma, S K; Banerjee, P; Das, R; Deb, P; Prabahar, T; Das, B K; Adhikary, B; Shyam, A

2010-08-01

Plasma foci of compact sizes and operating with low energies (from tens of joules to few hundred joules) have found application in recent years and have attracted plasma-physics scientists and engineers for research in this direction. We are presenting a low energy and miniature plasma focus which operates from a capacitor bank of 8.4 muF capacity, charged at 4.2-4.3 kV and delivering approximately 52 kA peak current at approximately 60 nH calculated circuit inductance. The total circuit inductance includes the plasma focus inductance. The reported plasma focus operates at the lowest voltage among all reported plasma foci so far. Moreover the cost of capacitor bank used for plasma focus is nearly 20 U.S. dollars making it very cheap. At low voltage operation of plasma focus, the initial breakdown mechanism becomes important for operation of plasma focus. The quartz glass tube is used as insulator and breakdown initiation is done on its surface. The total energy of the plasma focus is approximately 75 J. The plasma focus system is made compact and the switching of capacitor bank energy is done by manual operating switch. The focus is operated with hydrogen and deuterium filled at 1-2 mbar.

Compact, cost-effective and field-portable microscope prototype based on MISHELF microscopy

PubMed Central

Sanz, Martín; Picazo-Bueno, José Ángel; Granero, Luis; García, Javier; Micó, Vicente

2017-01-01

We report on a reduced cost, portable and compact prototype design of lensless holographic microscope with an illumination/detection scheme based on wavelength multiplexing, working with single hologram acquisition and using a fast convergence algorithm for image processing. All together, MISHELF (initials coming from Multi-Illumination Single-Holographic-Exposure Lensless Fresnel) microscopy allows the recording of three Fresnel domain diffraction patterns in a single camera snap-shot incoming from illuminating the sample with three coherent lights at once. Previous implementations have proposed an illumination/detection procedure based on a tuned (illumination wavelengths centered at the maximum sensitivity of the camera detection channels) configuration but here we report on a detuned (non-centered ones) scheme resulting in prototype miniaturization and cost reduction. Thus, MISHELF microscopy in combination with a novel and fast iterative algorithm allows high-resolution (μm range) phase-retrieved (twin image elimination) quantitative phase imaging of dynamic events (video rate recording speed). The performance of this microscope prototype is validated through experiments using both amplitude (USAF resolution test) and complex (live swine sperm cells and flowing microbeads) samples. The proposed method becomes in an alternative instrument improving some capabilities of existing lensless microscopes. PMID:28233829

Quasiperiodic Oscillations in X-ray Binaries

NASA Astrophysics Data System (ADS)

van der Klis, M.; Murdin, P.

2000-11-01

The term quasiperiodic oscillation (QPO) is used in high-energy astrophysics for any type of non-periodic variability that is constrained to a relatively narrow range of variability frequencies. X-RAY BINARIES are systems in which a `compact object', either a BLACK HOLE or a NEUTRON STAR, orbits a normal star and captures matter from it. The matter spirals down to the compact object and heats up ...

Low cost, high performance, self-aligning miniature optical systems

PubMed Central

Kester, Robert T.; Christenson, Todd; Kortum, Rebecca Richards; Tkaczyk, Tomasz S.

2009-01-01

The most expensive aspects in producing high quality miniature optical systems are the component costs and long assembly process. A new approach for fabricating these systems that reduces both aspects through the implementation of self-aligning LIGA (German acronym for lithographie, galvanoformung, abformung, or x-ray lithography, electroplating, and molding) optomechanics with high volume plastic injection molded and off-the-shelf glass optics is presented. This zero alignment strategy has been incorporated into a miniature high numerical aperture (NA = 1.0W) microscope objective for a fiber confocal reflectance microscope. Tight alignment tolerances of less than 10 μm are maintained for all components that reside inside of a small 9 gauge diameter hypodermic tubing. A prototype system has been tested using the slanted edge modulation transfer function technique and demonstrated to have a Strehl ratio of 0.71. This universal technology is now being developed for smaller, needle-sized imaging systems and other portable point-of-care diagnostic instruments. PMID:19543344

Challenges in miniaturized automotive long-range lidar system design

NASA Astrophysics Data System (ADS)

Fersch, Thomas; Weigel, Robert; Koelpin, Alexander

2017-05-01

This paper discusses the current technical limitations posed on endeavors to miniaturize lidar systems for use in automotive applications and how to possibly extend those limits. The focus is set on long-range scanning direct time of flight LiDAR systems using APD photodetectors. Miniaturization evokes severe problems in ensuring absolute laser safety while maintaining the systems' performance in terms of maximum range, signal-to-noise ratio, detection probability, pixel density, or frame rate. Based on hypothetical but realistic specifications for an exemplary system the complete lidar signal path is calculated. The maximum range of the system is used as a general performance indicator. It is determined with the minimum signal-to-noise ratio required to detect an object. Various system parameters are varied to find their impact on the system's range. The reduction of the laser's pulse width and the right choice for the transimpedance amplifier's amplification have shown to be practicable measures to double the system's range.

Role of pressure anisotropy on relativistic compact stars

NASA Astrophysics Data System (ADS)

Maurya, S. K.; Banerjee, Ayan; Hansraj, Sudan

2018-02-01

We investigate a compact spherically symmetric relativistic body with anisotropic particle pressure profiles. The distribution possesses characteristics relevant to modeling compact stars within the framework of general relativity. For this purpose, we consider a spatial metric potential of Korkina and Orlyanskii [Ukr. Phys. J. 36, 885 (1991)] type in order to solve the Einstein field equations. An additional prescription we make is that the pressure anisotropy parameter takes the functional form proposed by Lake [Phys. Rev. D 67, 104015 (2003), 10.1103/PhysRevD.67.104015]. Specifying these two geometric quantities allows for further analysis to be carried out in determining unknown constants and obtaining a limit of the mass-radius diagram, which adequately describes compact strange star candidates like Her X-1 and SMC X-1. Using the anisotropic Tolman-Oppenheimer-Volkoff equations, we explore the hydrostatic equilibrium and the stability of such compact objects. Then, we investigate other physical features of this model, such as the energy conditions, speeds of sound, and compactness of the star, in detail and show that our results satisfy all the required elementary conditions for a physically acceptable stellar model. The results obtained are useful in analyzing the stability of other anisotropic compact objects like white dwarfs, neutron stars, and gravastars.

Probing Planckian Corrections at the Horizon Scale with LISA Binaries

NASA Astrophysics Data System (ADS)

Maselli, Andrea; Pani, Paolo; Cardoso, Vitor; Abdelsalhin, Tiziano; Gualtieri, Leonardo; Ferrari, Valeria

2018-02-01

Several quantum-gravity models of compact objects predict microscopic or even Planckian corrections at the horizon scale. We explore the possibility of measuring two model-independent, smoking-gun effects of these corrections in the gravitational waveform of a compact binary, namely, the absence of tidal heating and the presence of tidal deformability. For events detectable by the future space-based interferometer LISA, we show that the effect of tidal heating dominates and allows one to constrain putative corrections down to the Planck scale. The measurement of the tidal Love numbers with LISA is more challenging but, in optimistic scenarios, it allows us to constrain the compactness of a supermassive exotic compact object down to the Planck scale. Our analysis suggests that highly spinning, supermassive binaries at 1-20 Gpc provide unparalleled tests of quantum-gravity effects at the horizon scale.

Probing Planckian Corrections at the Horizon Scale with LISA Binaries.

PubMed

Maselli, Andrea; Pani, Paolo; Cardoso, Vitor; Abdelsalhin, Tiziano; Gualtieri, Leonardo; Ferrari, Valeria

2018-02-23

Several quantum-gravity models of compact objects predict microscopic or even Planckian corrections at the horizon scale. We explore the possibility of measuring two model-independent, smoking-gun effects of these corrections in the gravitational waveform of a compact binary, namely, the absence of tidal heating and the presence of tidal deformability. For events detectable by the future space-based interferometer LISA, we show that the effect of tidal heating dominates and allows one to constrain putative corrections down to the Planck scale. The measurement of the tidal Love numbers with LISA is more challenging but, in optimistic scenarios, it allows us to constrain the compactness of a supermassive exotic compact object down to the Planck scale. Our analysis suggests that highly spinning, supermassive binaries at 1-20 Gpc provide unparalleled tests of quantum-gravity effects at the horizon scale.

78 FR 50104 - Notice of Inventory Completion: U.S. Department of the Interior, National Park Service, San Juan...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... individuals were identified. The 60 associated funerary objects are 1 splinter awl made from deer bone, 1 tip... flakes, 47 non-human skeletal fragments and non-human teeth, and 2 bags of non-human bone. In the Federal... identified. The 34 associated funerary objects are 28 non-human bone fragments, 1 miniature bone club, and 5...

Gamma-ray evidence for a stellar-mass black hole near the Galactic center

NASA Technical Reports Server (NTRS)

Ramaty, Reuven; Lingenfelter, Richard E.

1989-01-01

An analysis of the time variability of the observed 511-keV line emission from the direction of the Galactic center and the correlation of its variations in the continuum emission above 511 keV from the same direction suggest the existence of a compact object at or near the Galactic center. A possible mechanism of the observed positron annihilation is consistent with a compact interaction region of the order of 10 to the 8th cm. A black hole of several hundred solar masses is favored as a candidate for this compact object; arguments in support of this suggestion are presented.

Performance analysis of a miniature Joule-Thomson cryocooler with and without the distributed J-T effect

NASA Astrophysics Data System (ADS)

Damle, Rashmin; Atrey, Milind

2015-12-01

Cryogenic temperatures are obtained with Joule-Thomson (J-T) cryocoolers in an easier way as compared to other cooling techniques. Miniature J-T cryocoolers are often employed for cooling of infrared sensors, cryoprobes, biological samples, etc. A typical miniature J-T cryocooler consists of a storage reservoir/compressor providing the high pressure gas, a finned tube recuperative heat exchanger, an expansion valve/orifice, and the cold end. The recuperative heat exchanger is indispensable for attaining cryogenic temperatures. The geometrical parameters and the operating conditions of the heat exchanger drastically affect the cryocooler performance in terms of cool down time and cooling effect. In the literature, the numerical models for the finned recuperative heat exchanger have neglected the distributed J-T effect. The distributed J-T effect accounts for the changes in enthalpy of the fluid due to changes of pressure in addition to those due to changes of temperature. The objective of this work is to explore the distributed J-T effect and study the performance of a miniature J-T cryocooler with and without the distributed J-T effect. A one dimensional transient model is employed for the numerical analysis of the cryocooler. Cases with different operating conditions are worked out with argon and nitrogen as working fluids.

An open source, wireless capable miniature microscope system

NASA Astrophysics Data System (ADS)

Liberti, William A., III; Perkins, L. Nathan; Leman, Daniel P.; Gardner, Timothy J.

2017-08-01

Objective. Fluorescence imaging through head-mounted microscopes in freely behaving animals is becoming a standard method to study neural circuit function. Flexible, open-source designs are needed to spur evolution of the method. Approach. We describe a miniature microscope for single-photon fluorescence imaging in freely behaving animals. The device is made from 3D printed parts and off-the-shelf components. These microscopes weigh less than 1.8 g, can be configured to image a variety of fluorophores, and can be used wirelessly or in conjunction with active commutators. Microscope control software, based in Swift for macOS, provides low-latency image processing capabilities for closed-loop, or BMI, experiments. Main results. Miniature microscopes were deployed in the songbird premotor region HVC (used as a proper name), in singing zebra finches. Individual neurons yield temporally precise patterns of calcium activity that are consistent over repeated renditions of song. Several cells were tracked over timescales of weeks and months, providing an opportunity to study learning related changes in HVC. Significance. 3D printed miniature microscopes, composed completely of consumer grade components, are a cost-effective, modular option for head-mounting imaging. These easily constructed and customizable tools provide access to cell-type specific neural ensembles over timescales of weeks.

Autonomous, agile micro-satellites and supporting technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Breitfeller, E; Dittman, M D; Gaughan, R J

1999-07-19

This paper updates the on-going effort at Lawrence Livermore National Laboratory to develop autonomous, agile micro-satellites (MicroSats). The objective of this development effort is to develop MicroSats weighing only a few tens of kilograms, that are able to autonomously perform precision maneuvers and can be used telerobotically in a variety of mission modes. The required capabilities include satellite rendezvous, inspection, proximity-operations, docking, and servicing. The MicroSat carries an integrated proximity-operations sensor-suite incorporating advanced avionics. A new self-pressurizing propulsion system utilizing a miniaturized pump and non-toxic mono-propellant hydrogen peroxide was successfully tested. This system can provide a nominal 25 kg MicroSatmore » with 200-300 m/s delta-v including a warm-gas attitude control system. The avionics is based on the latest PowerPC processor using a CompactPCI bus architecture, which is modular, high-performance and processor-independent. This leverages commercial-off-the-shelf (COTS) technologies and minimizes the effects of future changes in processors. The MicroSat software development environment uses the Vx-Works real-time operating system (RTOS) that provides a rapid development environment for integration of new software modules, allowing early integration and test. We will summarize results of recent integrated ground flight testing of our latest non-toxic pumped propulsion MicroSat testbed vehicle operated on our unique dynamic air-rail.« less

An economical fluorescence detector for lab-on-a-chip devices with a light emitting photodiode and a low-cost avalanche photodiode.

PubMed

Wu, Jing; Liu, Xianhu; Wang, Lili; Dong, Lijun; Pu, Qiaosheng

2012-01-21

An economical fluorescence detector was developed with an LED as the exciting source and a low-cost avalanche photodiode (APD) module as a photon sensor. The detector was arranged in an epifluorescence configuration using a microscope objective (20× or 40×) and a dichroic mirror. The low-cost APD was biased by a direct current (DC) high voltage power supply at 121 V, which is much lower than that normally used for a PMT. Both DC and square wave (SW) supplies were used to power the LED and different data treatment protocols, such as simple average for DC mode, software based lock-in amplification and time specific average for SW mode, were tested to maximize the signal-to-noise ratio. Using an LED at a DC mode with simple data averaging, a limit of detection of 0.2 nmol L(-1) for sodium fluorescein was attained, which is among the lowest ever achieved with an LED as an excitation source. The detector was successfully used in both capillary and chip electrophoresis. The most significant advantages of the detector are the compact size and low cost of its parts. The aim of the work is to prove that widely available, low-cost components for civilian use can be successfully used for miniaturized analytical devices.

Analytical characterization of a new mobile X-ray fluorescence and X-ray diffraction instrument combined with a pigment identification case study

NASA Astrophysics Data System (ADS)

Van de Voorde, Lien; Vekemans, Bart; Verhaeven, Eddy; Tack, Pieter; De Wolf, Robin; Garrevoet, Jan; Vandenabeele, Peter; Vincze, Laszlo

2015-08-01

A new, commercially available, mobile system combining X-ray diffraction and X-ray fluorescence has been evaluated which enables both elemental analysis and phase identification simultaneously. The instrument makes use of a copper or molybdenum based miniature X-ray tube and a silicon-Pin diode energy-dispersive detector to count the photons originating from the samples. The X-ray tube and detector are both mounted on an X-ray diffraction protractor in a Bragg-Brentano θ:θ geometry. The mobile instrument is one of the lightest and most compact instruments of its kind (3.5 kg) and it is thus very useful for in situ purposes such as the direct (non-destructive) analysis of cultural heritage objects which need to be analyzed on site without any displacement. The supplied software allows both the operation of the instrument for data collection and in-depth data analysis using the International Centre for Diffraction Data database. This paper focuses on the characterization of the instrument, combined with a case study on pigment identification and an illustrative example for the analysis of lead alloyed printing letters. The results show that this commercially available light-weight instrument is able to identify the main crystalline phases non-destructively, present in a variety of samples, with a high degree of flexibility regarding sample size and position.

Building MapObjects attribute field in cadastral database based on the method of Jackson system development

NASA Astrophysics Data System (ADS)

Chen, Zhu-an; Zhang, Li-ting; Liu, Lu

2009-10-01

ESRI's GIS components MapObjects are applied in many cadastral information system because of its miniaturization and flexibility. Some cadastral information was saved in cadastral database directly by MapObjects's Shape file format in this cadastral information system. However, MapObjects didn't provide the function of building attribute field for map layer's attribute data file in cadastral database and user cann't save the result of analysis. This present paper designed and realized the function of building attribute field in MapObjects based on the method of Jackson's system development.

Note: A manifold ranking based saliency detection method for camera.

PubMed

Zhang, Libo; Sun, Yihan; Luo, Tiejian; Rahman, Mohammad Muntasir

2016-09-01

Research focused on salient object region in natural scenes has attracted a lot in computer vision and has widely been used in many applications like object detection and segmentation. However, an accurate focusing on the salient region, while taking photographs of the real-world scenery, is still a challenging task. In order to deal with the problem, this paper presents a novel approach based on human visual system, which works better with the usage of both background prior and compactness prior. In the proposed method, we eliminate the unsuitable boundary with a fixed threshold to optimize the image boundary selection which can provide more precise estimations. Then, the object detection, which is optimized with compactness prior, is obtained by ranking with background queries. Salient objects are generally grouped together into connected areas that have compact spatial distributions. The experimental results on three public datasets demonstrate that the precision and robustness of the proposed algorithm have been improved obviously.

Micro axial tomography: A miniaturized, versatile stage device to overcome resolution anisotropy in fluorescence light microscopy

NASA Astrophysics Data System (ADS)

Staier, Florian; Eipel, Heinz; Matula, Petr; Evsikov, Alexei V.; Kozubek, Michal; Cremer, Christoph; Hausmann, Michael

2011-09-01

With the development of novel fluorescence techniques, high resolution light microscopy has become a challenging technique for investigations of the three-dimensional (3D) micro-cosmos in cells and sub-cellular components. So far, all fluorescence microscopes applied for 3D imaging in biosciences show a spatially anisotropic point spread function resulting in an anisotropic optical resolution or point localization precision. To overcome this shortcoming, micro axial tomography was suggested which allows object tilting on the microscopic stage and leads to an improvement in localization precision and spatial resolution. Here, we present a miniaturized device which can be implemented in a motor driven microscope stage. The footprint of this device corresponds to a standard microscope slide. A special glass fiber can manually be adjusted in the object space of the microscope lens. A stepwise fiber rotation can be controlled by a miniaturized stepping motor incorporated into the device. By means of a special mounting device, test particles were fixed onto glass fibers, optically localized with high precision, and automatically rotated to obtain views from different perspective angles under which distances of corresponding pairs of objects were determined. From these angle dependent distance values, the real 3D distance was calculated with a precision in the ten nanometer range (corresponding here to an optical resolution of 10-30 nm) using standard microscopic equipment. As a proof of concept, the spindle apparatus of a mature mouse oocyte was imaged during metaphase II meiotic arrest under different perspectives. Only very few images registered under different rotation angles are sufficient for full 3D reconstruction. The results indicate the principal advantage of the micro axial tomography approach for many microscopic setups therein and also those of improved resolutions as obtained by high precision localization determination.

Development of a miniature scanning electron microscope for in-flight analysis of comet dust

NASA Technical Reports Server (NTRS)

Conley, J. M.; Bradley, J. G.; Giffin, C. E.; Albee, A. L.; Tomassian, A. D.

1983-01-01

A description is presented of an instrument which was developed with the original goal of being flown on the International Comet Mission, scheduled for a 1985 launch. The Scanning Electron Microscope and Particle Analyzer (SEMPA) electron miniprobe is a miniaturized electrostatically focused electron microscope and energy dispersive X-ray analyzer for in-flight analysis of comet dust particles. It was designed to be flown on board a comet rendezvous spacecraft. Other potential applications are related to asteroid rendezvous and planetary lander missions. According to the development objectives, SEMPA miniprobe is to have the capability for imaging and elemental analysis of particles in the size range of 0.25 microns and larger.

New Ultra-Compact Dwarf Galaxies in Clusters

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-02-01

How do ultra-compact dwarf galaxies (UCDs) galaxies that are especially small and dense form and evolve? Scientists have recently examined distant galaxy clusters, searching for more UCDs to help us answer this question.Origins of DwarfsIn recent years we have discovered a growing sample of small, very dense galaxies. Galaxies that are tens to hundreds of light-years across, with masses between a million and a billion solar masses, fall into category of ultra-compact dwarfs (UCDs).An example of an unresolved compact object from the authors survey that is likely an ultra-compact dwarf galaxy. [Adapted from Zhang Bell 2017]How do these dense and compact galaxies form? Two possibilities are commonly suggested:An initially larger galaxy was tidally stripped during interactions with other galaxies in a cluster, leaving behind only its small, dense core as a UCD.UCDs formed as compact galaxies at very early cosmic times. The ones living in a massive dark matter halo may have been able to remain compact over time, evolving into the objectswe see today.To better understand which of these formation scenarios applies to which galaxies, we need a larger sample size! Our census of UCDs is fairly limited and because theyare small and dim, most of the ones weve discovered are in the nearby universe. To build a good sample, we need to find UCDs at higher redshifts as well.A New SampleIn a recent study, two scientists from University of Michigan have demonstrated how we might find more UCDs. Yuanyuan Zhang (also affiliated with Fermilab) and Eric Bell used the Cluster Lensing and Supernova Survey with Hubble (CLASH) to search 17 galaxy clusters at intermediate redshifts of 0.2 z 0.6, looking for unresolved objects that might be UCDs.The mass and size distributions of the UCD candidates reported in this study, in the context of previously known nuclear star clusters, globular clusters (GCs), UCDs, compact elliptical galaxies (cEs), and dwarf galaxies. [Zhang Bell 2017]Zhang and Bell discovered a sample of compact objects grouped around the central galaxies of the clusters that are consistent with ultra-compact galaxies. The inferred sizes (many around 600 light-years in radius) and masses (roughly one billion solar masses) of these objects suggest that this sample may contain some of the densest UCDs discovered to date.The properties of this new set of UCD candidates arent enough to distinguish between formation scenarios yet, but the authors argue that if we find more such galaxies, we will be able to use the statistics of their spatial and color distributions to determine how they were formed.Zhang and Bell estimate that the 17 CLASH clusters studied in this work each contain an average of 2.7 of these objects in the central million light-years of the cluster. The authors work here suggests that searching wide-field survey data for similar discoveries is a plausible way to increase our sample of UCDs. This will allow us to statistically characterize these dense, compact galaxies and better understand their origins.CitationYuanyuan Zhang and Eric F. Bell 2017 ApJL 835 L2. doi:10.3847/2041-8213/835/1/L2

Ambiguity-free completion of the equations of motion of compact binary systems at the fourth post-Newtonian order

NASA Astrophysics Data System (ADS)

Marchand, Tanguy; Bernard, Laura; Blanchet, Luc; Faye, Guillaume

2018-02-01

We present the first complete (i.e., ambiguity-free) derivation of the equations of motion of two nonspinning compact objects up to the 4PN (post-Newtonian) order, based on the Fokker action of point particles in harmonic coordinates. The last ambiguity parameter is determined from first principle, by resorting to a matching between the near-zone and far-zone fields, and a consistent computation of the 4PN tail effect in d dimensions. Dimensional regularization is used throughout for treating IR divergences appearing at 4PN order, as well as UV divergences due to the modeling of the compact objects as point particles.

Effect of irradiation temperature and strain rate on the mechanical properties of V-4Cr-4Ti irradiated to low doses in fission reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zinkle, S.J.; Snead, L.L.; Rowcliffe, A.F.

Tensile tests performed on irradiated V-(3-6%)Cr-(3-6%)Ti alloys indicate that pronounced hardening and loss of strain hardening capacity occurs for doses of 0.1--20 dpa at irradiation temperatures below {approximately}330 C. The amount of radiation hardening decreases rapidly for irradiation temperatures above 400 C, with a concomitant increase in strain hardening capacity. Low-dose (0.1--0.5 dpa) irradiation shifts the dynamic strain aging regime to higher temperatures and lower strain rates compared to unirradiated specimens. Very low fracture toughness values were observed in miniature disk compact specimens irradiated at 200--320 C to {approximately}1.5--15 dpa and tested at 200 C.

A phased antenna array for surface plasmons

PubMed Central

Dikken, Dirk Jan W.; Korterik, Jeroen P.; Segerink, Frans B.; Herek, Jennifer L.; Prangsma, Jord C.

2016-01-01

Surface plasmon polaritons are electromagnetic waves that propagate tightly bound to metal surfaces. The concentration of the electromagnetic field at the surface as well as the short wavelength of surface plasmons enable sensitive detection methods and miniaturization of optics. We present an optical frequency plasmonic analog to the phased antenna array as it is well known in radar technology and radio astronomy. Individual holes in a thick gold film act as dipolar emitters of surface plasmon polaritons whose phase is controlled individually using a digital spatial light modulator. We show experimentally, using a phase sensitive near-field microscope, that this optical system allows accurate directional emission of surface waves. This compact and flexible method allows for dynamically shaping the propagation of plasmons and holds promise for nanophotonic applications employing propagating surface plasmons. PMID:27121099

Note: Repetitive operation of the capacitor bank of the low-voltage miniature plasma focus at 50 Hz.

PubMed

Shukla, Rohit; Shyam, Anurag

2013-10-01

We have already reported the low-voltage operation of a plasma focus describing the operation of plasma focus at 4.2 kV which proposes possibility of making a repetitive system using compact driving source. Another recent article describes that the same capacitor-bank can drive the plasma focus for a measured ~5 × 10(4) neutrons per shot at 5 kV and 59 kA current. In the present work, repetitive operation of the capacitor-bank of plasma focus is done and that too is being reported at a very high repetition rate of 50 Hz using very simple scheme of charging and triggering the bank. The bank is continuously discharged to burst duration of 20 s in this configuration admeasuring a thousand shots.

IMPS, A Static-Optics Application of Full-Stokes Spectropolarimetry to Search for Extraterrestrial Biosignatures

NASA Astrophysics Data System (ADS)

Telesco, C. M.; Sparks, W. B.; Zhao, B.; Varosi, F.; Schofield, S.; Germer, T. A.; Kolokolova, L.; Parenteau, M. N.; Cooper, G.; Grundy, W. M.; Guzmán, R.; Pantin, E.

2016-12-01

Optical spectropolarimetry holds great promise in the search for extraterrestrial life. In particular, the detection of circular polarization can indicate chirality, a signature of biological significance. We describe an on-going effort to implement the full-Stokes (I, Q, U, V), static-optics concept for optical spectropolarimetry described by Sparks et al. [App. Optics, 51, 5495 (2012)]. Our early breadboard embodiments of the concept demonstrate its simplicity and indicate its potential for space missions in which a compact design with no moving parts is crucial to achieve the mission goals. We describe the instrument, called the Integrated Miniature Polarimeter and Spectrograph (IMPS), and consider one example for its deployment: a mission to land on an outer solar system body such as Europa.

Feasibility and safety of minimized cardiopulmonary bypass in major aortic surgery

PubMed Central

Momin, Aziz U.; Sharabiani, Mansour T. A.; Kidher, Emadin; Najefi, Ali; Mulholland, John W.; Reeves, Barnaby C.; Angelini, Gianni D.; Anderson, Jon R.

2013-01-01

OBJECTIVES Conventional cardiopulmonary bypass causes haemodilution and is a trigger of systemic inflammatory reactions, coagulopathy and organ failure. Miniaturized cardiopulmonary bypass has been proposed as a way to reduce these deleterious effects of conventional cardiopulmonary bypass and to promote a more physiological state. The use of miniaturized cardiopulmonary bypass has been reported in low-risk patients undergoing valve and coronary artery bypass graft (CABG) surgery. However, little is known about its application in major aortic surgery. METHODS From February 2007 to September 2010, 49 patients underwent major aortic surgery using the Hammersmith miniaturized cardiopulmonary bypass (ECCO, Sorin). Data were extracted from medical records to characterize preoperative comorbidities (EuroSCORE), perioperative complications and the use of blood products. The same data were collected and described for 328 consecutive patients having similar surgery with conventional cardiopulmonary bypass at the Bristol Heart Institute, our twinned centre, during the same period. RESULTS The miniaturized cardiopulmonary bypass group had a median EuroSCORE of 8 [inter-quartile range (IQR): 5–11], 13% had preoperative renal dysfunction and 20% of operations were classified as emergency or salvage. Thirty-day mortalities were 6.4; and 69, 67 and 74% had ≥1 unit of red cells, fresh frozen plasma (FFP) and platelets transfused, respectively. Eight percent of patients experienced a renal complication, and 8% a neurological complication. The conventional cardiopulmonary bypass group was similar, with a EuroSCORE of 8 (IQR: 6–10); 30-day mortalities were 9.4; and 68, 62 and 74% had ≥1 unit of red cells, FFP and platelets transfused, respectively. The proportions experiencing renal and neurological complications were 14 and 5%. CONCLUSIONS Our experience suggests that miniaturized cardiopulmonary bypass is safe and feasible for use in major aortic cardiac surgery. A randomized trial is needed to evaluate miniaturized cardiopulmonary bypass formally. PMID:23814138

Color Constancy in Two-Dimensional and Three-Dimensional Scenes: Effects of Viewing Methods and Surface Texture.

PubMed

Morimoto, Takuma; Mizokami, Yoko; Yaguchi, Hirohisa; Buck, Steven L

2017-01-01

There has been debate about how and why color constancy may be better in three-dimensional (3-D) scenes than in two-dimensional (2-D) scenes. Although some studies have shown better color constancy for 3-D conditions, the role of specific cues remains unclear. In this study, we compared color constancy for a 3-D miniature room (a real scene consisting of actual objects) and 2-D still images of that room presented on a monitor using three viewing methods: binocular viewing, monocular viewing, and head movement. We found that color constancy was better for the 3-D room; however, color constancy for the 2-D image improved when the viewing method caused the scene to be perceived more like a 3-D scene. Separate measurements of the perceptual 3-D effect of each viewing method also supported these results. An additional experiment comparing a miniature room and its image with and without texture suggested that surface texture of scene objects contributes to color constancy.

A new direction for dark matter research: intermediate-mass compact halo objects

NASA Astrophysics Data System (ADS)

Chapline, George F.; Frampton, Paul H.

2016-11-01

The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been argued that MACHOs with masses > 15Msolar may have been prolifically produced at the onset of the big bang. Although a variety of astrophysical signatures for primordial MACHOs with masses in this range have been discussed in the literature, we favor a strategy that uses the potential for magnification of stars outside our galaxy due to gravitational microlensing of these stars by MACHOs in the halo of our galaxy. We point out that the effect of the motion of the Earth on the shape of the micro-lensing brightening curves provides a promising approach to testing over the course of next several years the hypothesis that dark matter consists of massive compact objects.

Evaluation of a compact tinnitus therapy by electrophysiological tinnitus decompensation measures.

PubMed

Low, Yin Fen; Argstatter, Heike; Bolay, Hans Volker; Strauss, Daniel J

2008-01-01

Large-scale neural correlates of the tinnitus decompensation have been identified by using wavelet phase stability criteria of single sweep sequences of auditory late responses (ALRs). Our previous work showed that the synchronization stability in ALR sequences might be used for objective quantification of the tinnitus decompensation and attention which link to Jastreboff tinnitus model. In this study, we intend to provide an objective evaluation for quantifying the effect of music therapy in tinnitus patients. We examined neural correlates of the attentional mechanism in single sweep sequences of ALRs in chronic tinnitus patients who underwent compact therapy course by using the maximum entropy auditory paradigm. Results by our measure showed that the extent of differentiation between attended and unattended conditions improved significantly after the therapy. It is concluded that the wavelet phase synchronization stability of ALRs single sweeps can be used for the objective evaluation of tinnitus therapies, in this case the compact tinnitus music therapy.

Comparison of Laboratory and Field Density of Asphalt Mixtures

DOT National Transportation Integrated Search

1991-01-01

The objective of this paper is to investigate the relationships between the measured density of the mixture obtained in the mix design, during quality control of the mixture (laboratory compaction of field produced mix), after initial compaction (cor...

Ultra Compact Optical Pickup with Integrated Optical System

NASA Astrophysics Data System (ADS)

Nakata, Hideki; Nagata, Takayuki; Tomita, Hironori

2006-08-01

Smaller and thinner optical pickups are needed for portable audio-visual (AV) products and notebook personal computers (PCs). We have newly developed an ultra compact recordable optical pickup for Mini Disc (MD) that measures less than 4 mm from the disc surface to the bottom of the optical pickup, making the optical system markedly compact. We have integrated all the optical components into an objective lens actuator moving unit, while fully satisfying recording and playback performance requirements. In this paper, we propose an ultra compact optical pickup applicable to portable MD recorders.

An intraventricular axial flow blood pump integrated with a bearing purge system.

PubMed

Yamazaki, K; Kormos, R; Mori, T; Umezu, M; Kameneva, M; Antaki, J; Outa, E; Litwak, P; Kerrigan, J; Tomczak, J

1995-01-01

The future development of implantable axial flow blood pumps must address two major issues: mechanically induced hemolysis and shaft seal reliability. The recent revisions to our miniature intraventricular axial flow left ventricular assist device (LVAD) were aimed particularly at addressing these concerns. To improve hemocompatibility, a new impeller has been designed according to the following criteria: 1) gradual pressure rise along the blade chord; 2) minimized local fluid acceleration to prevent cavitation; 3) minimum surface roughness; and 4) radius edges. Subsequent in vitro hemolysis tests conducted with bovine and ovine blood have demonstrated very low hemolysis (normalized index of hemolysis = 0.0051 +/- 0.0047 g/100 L) with this new impeller design. To address the need for a reliable seal, we have developed a purged seal system consisting of a miniature lip seal and ceramic pressure groove journal bearing that also acts as a purge pump. Several spiral grooves formed on the bearing surface provide viscous pumping of the purge fluid, generating more than 3,000 mmHg at 10,000 rpm. This purge flow flushes the lip seal and prevents blood backflow into the bearing. We have found this purge pump to offer several advantages because it is simple, compact, durable, does not require separate actuation, and offers a wide range of flow, depending upon the groove design. In vivo animal tests demonstrated the potential of the purged seal system.

Development of a miniaturized deformable mirror controller

NASA Astrophysics Data System (ADS)

Bendek, Eduardo; Lynch, Dana; Pluzhnik, Eugene; Belikov, Ruslan; Klamm, Benjamin; Hyde, Elizabeth; Mumm, Katherine

2016-07-01

High-Performance Adaptive Optics systems are rapidly spreading as useful applications in the fields of astronomy, ophthalmology, and telecommunications. This technology is critical to enable coronagraphic direct imaging of exoplanets utilized in ground-based telescopes and future space missions such as WFIRST, EXO-C, HabEx, and LUVOIR. We have developed a miniaturized Deformable Mirror controller to enable active optics on small space imaging mission. The system is based on the Boston Micromachines Corporation Kilo-DM, which is one of the most widespread DMs on the market. The system has three main components: The Deformable Mirror, the Driving Electronics, and the Mechanical and Heat management. The system is designed to be extremely compact and have lowpower consumption to enable its use not only on exoplanet missions, but also in a wide-range of applications that require precision optical systems, such as direct line-of-sight laser communications, and guidance systems. The controller is capable of handling 1,024 actuators with 220V maximum dynamic range, 16bit resolution, and 14bit accuracy, and operating at up to 1kHz frequency. The system fits in a 10x10x5cm volume, weighs less than 0.5kg, and consumes less than 8W. We have developed a turnkey solution reducing the risk for currently planned as well as future missions, lowering their cost by significantly reducing volume, weight and power consumption of the wavefront control hardware.

Rotary Motors Actuated by Traveling Ultrasonic Flexural Waves

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph; Bao, Xiaoqi; Grandia, Willem

1999-01-01

Efficient miniature actuators that are compact and consume low power are needed to drive space and planetary mechanisms in future NASA missions. Ultrasonic rotary motors have the potential to meet this NASA need and they are developed as actuators for miniature telerobotic applications. These motors have emerged in commercial products but they need to be adapted for operation at the harsh space environments that include cryogenic temperatures and vacuum and also require effective analytical tools for the design of efficient motors. A finite element analytical model was developed to examine the excitation of flexural plate wave traveling in a piezoelectrically actuated rotary motor. The model uses 3D finite element and equivalent circuit models that are applied to predict the excitation frequency and modal response of the stator. This model incorporates the details of the stator including the teeth, piezoelectric ceramic, geometry, bonding layer, etc. The theoretical predictions were corroborated experimentally for the stator. In parallel, efforts have been made to determine the thermal and vacuum performance of these motors. Experiments have shown that the motor can sustain at least 230 temperature cycles from 0 C to -90 C at 7 Torr pressure significant performance change. Also, in an earlier study the motor lasted over 334 hours at -150 C and vacuum. To explore telerobotic applications for USMs a robotic arm was constructed with such motors.

Miniature Raman spectrometer development

NASA Astrophysics Data System (ADS)

Bonvallet, Joseph; Auz, Bryan; Rodriguez, John; Olmstead, Ty

2018-02-01

The development of techniques to rapidly identify samples ranging from, molecule and particle imaging to detection of high explosive materials, has surged in recent years. Due to this growing want, Raman spectroscopy gives a molecular fingerprint, with no sample preparation, and can be done remotely. These systems can be small, compact, lightweight, and with a user interface that allows for easy use and sample identification. Ocean Optics Inc. has developed several systems that would meet all these end user requirements. This talk will describe the development of different Ocean Optics Inc miniature Raman spectrometers. The spectrometer on a phone (SOAP) system was designed using commercial off the shelf (COTS) components, in a rapid product development cycle. The footprint of the system measures 40x40x14 mm (LxWxH) and was coupled directly to the cell phone detector camera optics. However, it gets roughly only 40 cm-1 resolution. The Accuman system is the largest (290x220X100 mm) of the three, but uses our QEPro spectrometer and get 7-11 cm-1 resolution. Finally, the HRS-30 measuring 165x85x40 mm is a combination of the other two systems. This system uses a modified EMBED spectrometer and gets 7-12 cm-1 resolution. Each of these units uses a peak matching algorithm that then correlates the results to the pre-loaded and customizable spectral libraries.

Monolithic integrated optic fiber Bragg grating sensor interrogator

NASA Astrophysics Data System (ADS)

Mendoza, Edgar A.; Esterkin, Yan; Kempen, Cornelia; Sun, Songjian

2010-04-01

Fiber Bragg gratings (FBGs) are a mature sensing technology that has gained rapid acceptance in civil, aerospace, chemical and petrochemical, medicine, aviation and automotive industries. Fiber Bragg grating sensors can be use for a variety of measurements including strain, stress, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion distributed at multiple locations within the structure using a single fiber element. The most prominent advantages of FBGs are: small size and light weight, multiple FBG transducers on a single fiber, and immunity to radio frequency interference. A major disadvantage of FBG technology is that conventional state-of-the-art fiber Bragg grating interrogation systems are typically bulky, heavy, and costly bench top instruments that are assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the need for a compact FBG interrogation system, this paper describes recent progress towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-TransceiverTM) system based on multi-channel monolithic integrated optic sensor microchip technology. The integrated optic microchip technology enables the monolithic integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogators systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm small form factor (SFF) package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation.

An Environmental Friendly Procedure for Photometric Determination of Hypochlorite in Tap Water Employing a Miniaturized Multicommuted Flow Analysis Setup

PubMed Central

Borges, Sivanildo S.; Reis, Boaventura F.

2011-01-01

A photometric procedure for the determination of ClO− in tap water employing a miniaturized multicommuted flow analysis setup and an LED-based photometer is described. The analytical procedure was implemented using leucocrystal violet (LCV; 4,4′,4′′-methylidynetris (N,N-dimethylaniline), C25H31N3) as a chromogenic reagent. Solenoid micropumps employed for solutions propelling were assembled together with the photometer in order to compose a compact unit of small dimensions. After control variables optimization, the system was applied for the determination of ClO− in samples of tap water, and aiming accuracy assessment samples were also analyzed using an independent method. Applying the paired t-test between results obtained using both methods, no significant difference at the 95% confidence level was observed. Other useful features include low reagent consumption, 2.4 μg of LCV per determination, a linear response ranging from 0.02 up to 2.0 mg L−1  ClO−, a relative standard deviation of 1.0% (n = 11) for samples containing 0.2 mg L−1  ClO−, a detection limit of 6.0 μg L−1  ClO−, a sampling throughput of 84 determinations per hour, and a waste generation of 432 μL per determination. PMID:21747732

Auxiliary total artificial heart: A compact electromechanical artificial heart working simultaneously with the natural heart.

PubMed

Andrade, A; Nicolosi, D; Lucchi, J; Biscegli, J; Arruda, A C; Ohashi, Y; Mueller, J; Tayama, E; Glueck, J; Nosé, Y

1999-09-01

Leading international institutions are designing and developing various types of ventricular assist devices (VAD) and total artificial hearts (TAH). Some of the commercially available pulsatile VADs are not readily implantable into the thoracic cavity of smaller size patients because of size limitation. The majority of the TAH dimensions requires the removal of the patients' native heart. A miniaturized artificial heart, the auxiliary total artificial heart (ATAH), is being developed in these authors' laboratories. This device is an electromechanically driven ATAH using a brushless direct current (DC) motor fixed in a center metallic piece. This pusher plate-type ATAH control is based on Frank-Starling's law. The beating frequency is regulated through the change of the left preload, assisting the native heart in obtaining adequate blood flow. With the miniaturization of this pump, the average sized patient can have the surgical implantation procedure in the right thoracic cavity without removing the native heart. The left and right stroke volumes are 35 and 32 ml, respectively. In vitro tests were conducted, and the performance curves demonstrate that the ATAH produces 5 L/min of cardiac output at 180 bpm (10 mmHg of left inlet mean pressure and 100 mm Hg of left outlet mean pressure). Taking into account that this ATAH is working along with the native heart, this output is more than satisfactory for such a device.

Role of size on the relative importance of fluid dynamic losses in linear cryocoolers

NASA Astrophysics Data System (ADS)

Kirkconnell, Carl; Ghavami, Ali; Ghiaasiaan, S. Mostafa; Perrella, Matthew

2017-12-01

Thermodynamic modeling results for a novel small satellite (SmallSat) Stirling Cryocooler, capable of delivering over 200 mW net cooling power at 80 K for less than 6 W DC input power, are used in this paper as the basis for related pulse tube computational fluid dynamics (CFD) analysis. Industry and government requirements for SmallSat infrared sensors are driving the development of ever-more miniaturized cryocooler systems. Such cryocoolers must be extremely compact and lightweight, a challenge met by this research team through operating a Stirling cryocooler at a frequency of approximately 300 Hz. The primary advantage of operating at such a high frequency is that the required compression and expansion swept volumes are reduced relative to linear coolers operating at lower frequencies, which evidently reduces the size of the motor mechanisms and the thermodynamic components. In the case of a pulse tube cryocooler, this includes a reduction in diameter of the pulse tube itself. This unfortunately leads to high boundary layer losses, as the presented results demonstrate. Using a Stirling approach with a mechanical moving expander piston eliminates this small pulse tube loss mechanism, but other challenges are introduced, such as maintaining very tight clearance gaps between moving and stationary elements. This paper focuses on CFD modelling results for a highly miniaturized pulse tube cooler.

In-line optical fiber metallic mirror reflector for monolithic common path optical coherence tomography probes.

PubMed

Singh, Kanwarpal; Reddy, Rohith; Sharma, Gargi; Verma, Yogesh; Gardecki, Joseph A; Tearney, Guillermo

2018-03-01

Endoscopic optical coherence tomography probes suffer from various artifacts due to dispersion imbalance and polarization mismatch between reference and sample arm light. Such artifacts can be minimized using a common path approach. In this work, we demonstrate a miniaturized common path probe for optical coherence tomography using an inline fiber mirror. A common path optical fiber probe suitable for performing high-resolution endoscopic optical coherence tomography imaging was developed. To achieve common path functionality, an inline fiber mirror was fabricated using a thin gold layer. A commercially available swept source engine was used to test the designed probe in a cadaver human coronary artery ex vivo. We achieved a sensitivity of 104 dB for this probe using a swept source optical coherence tomography system. To test the probe, images of a cadaver human coronary artery were obtained, demonstrating the quality that is comparable to those obtained by OCT systems with separate reference arms. Additionally, we demonstrate recovery of ranging depth by use of a Michelson interferometer in the detection path. We developed a miniaturized monolithic inline fiber mirror-based common path probe for optical coherence tomography. Owing to its simplicity, our design will be helpful in endoscopic applications that require high-resolution probes in a compact form factor while reducing system complexity. Lasers Surg. Med. 50:230-235, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effect of antistripping additives on the compaction of bituminous concrete.

DOT National Transportation Integrated Search

1981-01-01

The objective of this investigation was to determine the effect of antistripping additives on the compaction of bituminous concrete. To do this, the densities obtained on test sections with and without additive were compared. Comparisons of nuclear d...

WisDOT asphaltic mixture new specifications implementation : field compaction and density.

DOT National Transportation Integrated Search

2016-06-01

The main research objectives of this study were to evaluate HMA Longitudinal Joint type, method and compaction data to produce specification recommendations that will ensure the highest density longitudinal joint, as well as evaluate and produce a sp...

A recipe for echoes from exotic compact objects

NASA Astrophysics Data System (ADS)

Mark, Zachary; Zimmerman, Aaron; Du, Song Ming; Chen, Yanbei

2017-10-01

Gravitational wave astronomy provides an unprecedented opportunity to test the nature of black holes and search for exotic, compact alternatives. Recent studies have shown that exotic compact objects (ECOs) can ring down in a manner similar to black holes, but can also produce a sequence of distinct pulses resembling the initial ringdown. These "echoes" would provide definite evidence for the existence of ECOs. In this work we study the generation of these echoes in a generic, parametrized model for the ECO, using Green's functions. We show how to reprocess radiation in the near-horizon region of a Schwarzschild black hole into the asymptotic radiation from the corresponding source in an ECO spacetime. Our methods allow us to understand the connection between distinct echoes and ringing at the resonant frequencies of the compact object. We find that the quasinormal mode ringing in the black hole spacetime plays a central role in determining the shape of the first few echoes. We use this observation to develop a simple template for echo waveforms. This template preforms well over a variety of ECO parameters, and with improvements may prove useful in the analysis of gravitational waves.

Clinical Investigation Program: Annual Progress Report

DTIC Science & Technology

1992-09-30

Academy of Surgical Research, Chicago, Illinois; Yucatan Miniature Swine as a Model System for the Studyt of Vocal Fold Vibratory Function; 6th Annual...34(14)e". (15) Study Objective: Compare two enteral formulas in respect to nutritional aspects. (16) Technical Approach: Protocol will take place in

Let's Talk

ERIC Educational Resources Information Center

Woodard, Carol; Haskins, Guy; Schaefer, Grace; Smolen, Linda

2004-01-01

This article presents the Let's Talk project as a different approach to oral language development. This approach was based on observations of classrooms in the Netherlands where children talked at large tables while playing with miniature figures representing people and objects they were familiar with in their daily lives. It was also influenced…

Initial Parameters of Neutron Stars

NASA Astrophysics Data System (ADS)

Popov, S. B.; Turolla, R.

2012-12-01

A subpopulation of neutron stars (NSs), known as central compact objects (CCOs) in supernova remnants, are suspected to be low-field objects basing on P - ṗ measurements for three of them. The birth rate of low-field NSs is probably comparable with the birth rate of normal radio pulsars. However, among compact objects in High-Mass X-ray Binaries (HMXBs) we do not see robust candidates for low-field NSs. We propose that this contradiction can be solved if magnetic fields of CCOs was buried due to strong fall-back, and then the field emerges on the time scale 104 -105 yrs.

Zero curvature-surface driven small objects

NASA Astrophysics Data System (ADS)

Dou, Xiaoxiao; Li, Shanpeng; Liu, Jianlin

2017-08-01

In this study, we investigate the spontaneous migration of small objects driven by surface tension on a catenoid, formed by a layer of soap constrained by two rings. Although the average curvature of the catenoid is zero at each point, the small objects always migrate to the position near the ring. The force and energy analyses have been performed to uncover the mechanism, and it is found that the small objects distort the local shape of the liquid film, thus making the whole system energetically favorable. These findings provide some inspiration to design microfluidics, aquatic robotics, and miniature boats.

Studies of compact objects with Einstein - Review and prospects

NASA Technical Reports Server (NTRS)

Grindlay, Jonathan E.

1990-01-01

X-ray images and spectra of a wide range of systems containing compact objects were obtained with the Einstein X-ray Observatory. Accreting white dwarfs, neutron stars and black holes were observed in binary systems in the Galaxy, and new constraints were derived for their formation, nature and evolution. Massive black holes were studied in active galactic nuclei, and X-ray spectra (and evolution) of AGN have led to a new model for the diffuse X-ray background.

A Miniature Forward-imaging B-scan Optical Coherence Tomography Probe to Guide Real-time Laser Ablation

PubMed Central

Li, Zhuoyan; Shen, Jin H.; Kozub, John A.; Prasad, Ratna; Lu, Pengcheng; Joos, Karen M.

2014-01-01

Background and Objective Investigations have shown that pulsed lasers tuned to 6.1 μm in wavelength are capable of ablating ocular and neural tissue with minimal collateral damage. This study investigated whether a miniature B-scan forward-imaging optical coherence tomography (OCT) probe can be combined with the laser to provide real-time visual feedback during laser incisions. Study Design/Methods and Materials A miniature 25-gauge B-scan forward-imaging OCT probe was developed and combined with a 250 μm hollow-glass waveguide to permit delivery of 6.1 μm laser energy. A gelatin mixture and both porcine corneal and retinal tissues were simultaneously imaged and lased (6.1 μm, 10 Hz, 0.4-0.7 mJ) through air. The ablation studies were observed and recorded in real time. The crater dimensions were measured using OCT imaging software (Bioptigen, Durham, NC). Histological analysis was performed on the ocular tissues. Results The combined miniature forward-imaging OCT and mid-infrared laser-delivery probe successfully imaged real-time tissue ablation in gelatin, corneal tissue, and retinal tissue. Application of a constant number of 60 pulses at 0.5 mJ/pulse to the gelatin resulted in a mean crater depth of 123 ± 15 μm. For the corneal tissue, there was a significant correlation between the number of pulses used and depth of the lased hole (Pearson correlation coefficient = 0.82; P = 0.0002). Histological analysis of the cornea and retina tissues showed discrete holes with minimal thermal damage. Conclusions A combined miniature OCT and laser -delivery probe can monitor real-time tissue laser ablation. With additional testing and improvements, this novel instrument has the future possibility of effectively guiding surgeries by simultaneously imaging and ablating tissue. PMID:24648326

The NICMOS Cooling SYSTEM-5 Years of Successful On-Orbit Operation

NASA Astrophysics Data System (ADS)

Swift, W. L.; Dolan, F. X.; Zagarola, M. V.

2008-03-01

The NICMOS Cooling System consists of a closed-loop turbo-Brayton cryocooler coupled with a cryogenic circulator that provides refrigeration to the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope (HST). The cryocooler heat is rejected to space through a capillary pumped loop connected to radiators mounted on the side of the telescope. The system was deployed and integrated with NICMOS by astronauts during STS-109 (Space Shuttle Columbia) in March 2002. It has operated nearly continuously without performance degradation since that time, maintaining NICMOS detectors at a constant temperature of 77 K. Miniature, high-speed turbomachines are used in the cryocooler and the circulator loop to provide vibration-free, long-life operation. A small centrifugal compressor and miniature turboalternator are key elements of the closed loop cryocooler. A miniature cryogenic centrifugal circulator in a separate pressurized neon loop transports heat from the NICMOS instrument to the cryocooler interface heat exchanger. This paper describes the development of the system, key operational features, ground and orbital tests prior to its deployment, and operational results during its five-year operational history on orbit.

Well behaved anisotropic compact star models in general relativity

NASA Astrophysics Data System (ADS)

Jasim, M. K.; Maurya, S. K.; Gupta, Y. K.; Dayanandan, B.

2016-11-01

Anisotropic compact star models have been constructed by assuming a particular form of a metric function e^{λ}. We solved the Einstein field equations for determining the metric function e^{ν}. For this purpose we have assumed a physically valid expression of radial pressure (pr). The obtained anisotropic compact star model is representing the realistic compact objects such as PSR 1937 +21. We have done an extensive study about physical parameters for anisotropic models and found that these parameters are well behaved throughout inside the star. Along with these we have also determined the equation of state for compact star which gives the radial pressure is purely the function of density i.e. pr=f(ρ).

Optical/Infrared properties of Be stars in X-ray Binary systems

NASA Astrophysics Data System (ADS)

Naik, Sachindra

2018-04-01

Be/X-ray binaries, consisting of a Be star and a compact object (neutron star), form the largest subclass of High Mass X-ray Binaries. The orbit of the compact object around the Be star is wide and highly eccentric. Neutron stars in the Be/X-ray binaries are generally quiescent in X-ray emission. Transient X-ray outbursts seen in these objects are thought to be due to the interaction between the compact object and the circumstellar disk of the Be star at the periastron passage. Optical/infrared observations of the companion Be star during these outbursts show that the increase in the X-ray intensity of the neutron star is coupled with the decrease in the optical/infrared flux of the companion star. Apart from the change in optical/infrared flux, dramatic changes in the Be star emission line profiles are also seen during X-ray outbursts. Observational evidences of changes in the emission line profiles and optical/infrared continuum flux along with associated X-ray outbursts from the neutron stars in several Be/X-ray binaries are presented in this paper.

A Complete Cubesat Magnetometer System Project

NASA Technical Reports Server (NTRS)

Zesta, Eftyhia

2014-01-01

The objective of this work is to provide the center with a fully tested, flexible, low cost, miniaturized science magnetometer system applicable to small satellite programs, like Cubesats, and to rides of opportunity that do not lend themselves to the high integration costs a science magnetometer on a boom necessitates.

Magnetic quadrupoles lens for hot spot proton imaging in inertial confinement fusion

NASA Astrophysics Data System (ADS)

Teng, J.; Gu, Y. Q.; Chen, J.; Zhu, B.; Zhang, B.; Zhang, T. K.; Tan, F.; Hong, W.; Zhang, B. H.; Wang, X. Q.

2016-08-01

Imaging of DD-produced protons from an implosion hot spot region by miniature permanent magnetic quadrupole (PMQ) lens is proposed. Corresponding object-image relation is deduced and an adjust method for this imaging system is discussed. Ideal point-to-point imaging demands a monoenergetic proton source; nevertheless, we proved that the blur of image induced by proton energy spread is a second order effect therefore controllable. A proton imaging system based on miniature PMQ lens is designed for 2.8 MeV DD-protons and the adjust method in case of proton energy shift is proposed. The spatial resolution of this system is better than 10 μm when proton yield is above 109 and the spectra width is within 10%.

The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery.

PubMed

Yuruk, Koray; Bezemer, Rick; Euser, Mariska; Milstein, Dan M J; de Geus, Hilde H R; Scholten, Evert W; de Mol, Bas A J M; Ince, Can

2012-09-01

OBJECTIVES To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery using conventional extracorporeal circulation systems has been associated with significantly reduced microcirculatory perfusion, but it remains unknown whether this could be prevented by an mECC system. Here, we aimed to test the hypothesis that microcirculatory perfusion decreases with the use of a conventional extracorporeal circulation system and would be preserved with the use of an miniaturized extracorporeal circulation system. METHODS Microcirculatory density and perfusion were assessed using sublingual side stream dark-field imaging in patients undergoing on-pump coronary artery bypass graft (CABG) surgery before, during and after the use of either a conventional extracorporeal circulation system (n = 10) or a miniaturized extracorporeal circulation system (n = 10). In addition, plasma neutrophil gelatinase-associated lipocalin and creatinine levels and creatinine clearance were assessed up to 5 days post-surgery to monitor renal function. RESULTS At the end of the CPB, one patient in the miniaturized extracorporeal circulation-treated group and five patients in the conventional extracorporeal circulation-treated group received one bag of packed red blood cells (300 ml). During the CPB, the haematocrit and haemoglobin levels were slightly higher in the miniaturized extracorporeal circulation-treated patients compared with the conventional extracorporeal circulation-treated patients (27.7 ± 3.3 vs 24.7 ± 2.0%; P = 0.03; and 6.42 ± 0.75 vs 5.41 ± 0.64 mmol/l; P < 0.01). The density of perfused vessels with a diameter <25 µm (i.e. perfused vessel density) decreased slightly in the conventional extracorporeal circulation-treated group from 16.4 ± 3.8 to 12.8 ± 3.3 mm/mm(2) (P < 0.01) and remained stable in the miniaturized extracorporeal circulation-treated group (16.3 ± 2.7 and 15.2 ± 2.9 mm/mm(2) before and during the pump, respectively). Plasma neutrophil gelatinase-associated lipocalin levels were increased following the use of extracorporeal circulation in both groups, and no differences were observed between the groups. Plasma creatinine levels and creatinine clearance were not affected by CABG surgery or CPB. CONCLUSIONS The results from this relatively small study suggest that the use of the miniaturized extracorporeal circulation system is associated with a statistically significant (but clinically insignificant) reduction in haemodilution and microcirculatory hypoperfusion compared with the use of the conventional extracorporeal circulation system.

Towards establishing compact imaging spectrometer standards

USGS Publications Warehouse

Slonecker, E. Terrence; Allen, David W.; Resmini, Ronald G.

2016-01-01

Remote sensing science is currently undergoing a tremendous expansion in the area of hyperspectral imaging (HSI) technology. Spurred largely by the explosive growth of Unmanned Aerial Vehicles (UAV), sometimes called Unmanned Aircraft Systems (UAS), or drones, HSI capabilities that once required access to one of only a handful of very specialized and expensive sensor systems are now miniaturized and widely available commercially. Small compact imaging spectrometers (CIS) now on the market offer a number of hyperspectral imaging capabilities in terms of spectral range and sampling. The potential uses of HSI/CIS on UAVs/UASs seem limitless. However, the rapid expansion of unmanned aircraft and small hyperspectral sensor capabilities has created a number of questions related to technological, legal, and operational capabilities. Lightweight sensor systems suitable for UAV platforms are being advertised in the trade literature at an ever-expanding rate with no standardization of system performance specifications or terms of reference. To address this issue, both the U.S. Geological Survey and the National Institute of Standards and Technology are eveloping draft standards to meet these issues. This paper presents the outline of a combined USGS/NIST cooperative strategy to develop and test a characterization methodology to meet the needs of a new and expanding UAV/CIS/HSI user community.

Design and expected performance of a compact and continuous nuclear demagnetization refrigerator for sub-mK applications

NASA Astrophysics Data System (ADS)

Toda, Ryo; Murakawa, Satoshi; Fukuyama, Hiroshi

2018-03-01

Sub-mK temperatures are achievable by a copper nuclear demagnetization refrigerator (NDR). Recently, research demands for such an ultra-low temperature environment are increasing not only in condensed matter physics but also in astrophysics. A standard NDR requires a specially designed room, a high-field superconducting magnet, and a high-power dilution refrigerator (DR). And it is a one-shot cooling apparatus. To reduce these requirements, we are developing a compact and continuous NDR with two PrNi5 nuclear stages which occupies only a small space next to an appropriate pre-cooling stage such as DR. PrNi5 has a large magnetic-field enhancement on Pr3+ nuclei due to the strong hyperfine coupling. This enables us to enclose each stage in a miniature superconducting magnet and to locate two such sets in close proximity by surrounding them with high-permeability magnetic shields. The two stages are thermally connected in series to the pre-cooling stage by two Zn superconducting heat switches. A numerical analysis taking account of thermal resistances of all parts and an eddy current heating shows that the lowest sample temperature of 0.8 mK can be maintained continuously under a 10 nW ambient heat leak.

A compact membrane-driven diamond anvil cell and cryostat system for nuclear resonant scattering at high pressure and low temperature

DOE PAGES

Zhao, J. Y.; Bi, W.; Sinogeikin, S.; ...

2017-12-13

In order to study the vibrational and thermal dynamic properties of materials using the nuclear resonant inelastic X-ray scattering (NRIXS) and the hyperfine interactions and magnetic properties using the synchrotron Mössbauer spectroscopy (SMS) at simultaneously high pressure (multi-Mbar) and low temperature (T< 10 K), a new miniature panoramic diamond anvil cell (mini-pDAC) as well as a special gas membrane driven mechanism have been developed and implemented at 3ID, Advanced Photon Source. The gas membrane system allows in situ pressure tuning of the mini- pDAC at low temperature. The mini-pDAC fits into a specially designed compact liquid helium flow cryostat systemmore » to achieve low temperature, where liquid helium flows through the holder of the mini-pDAC to cool the sample more efficiently. The sample temperature as low as 9 K has been achieved. Through the membrane, the sample pressure as high as 1.4 Mbar has been generated from this mini-pDAC. The instrument has been routinely used at 3ID for NRIXS and SMS studies. In this paper, technical details of the mini-pDAC, membrane engaging mechanism and the cryostat system are described, and some experimental results are discussed.« less

A compact membrane-driven diamond anvil cell and cryostat system for nuclear resonant scattering at high pressure and low temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, J. Y.; Bi, W.; Sinogeikin, S.

In order to study the vibrational and thermal dynamic properties of materials using the nuclear resonant inelastic X-ray scattering (NRIXS) and the hyperfine interactions and magnetic properties using the synchrotron Mössbauer spectroscopy (SMS) at simultaneously high pressure (multi-Mbar) and low temperature (T< 10 K), a new miniature panoramic diamond anvil cell (mini-pDAC) as well as a special gas membrane driven mechanism have been developed and implemented at 3ID, Advanced Photon Source. The gas membrane system allows in situ pressure tuning of the mini- pDAC at low temperature. The mini-pDAC fits into a specially designed compact liquid helium flow cryostat systemmore » to achieve low temperature, where liquid helium flows through the holder of the mini-pDAC to cool the sample more efficiently. The sample temperature as low as 9 K has been achieved. Through the membrane, the sample pressure as high as 1.4 Mbar has been generated from this mini-pDAC. The instrument has been routinely used at 3ID for NRIXS and SMS studies. In this paper, technical details of the mini-pDAC, membrane engaging mechanism and the cryostat system are described, and some experimental results are discussed.« less

Estimating gravitational radiation from super-emitting compact binary systems

NASA Astrophysics Data System (ADS)

Hanna, Chad; Johnson, Matthew C.; Lehner, Luis

2017-06-01

Binary black hole mergers are among the most violent events in the Universe, leading to extreme warping of spacetime and copious emission of gravitational radiation. Even though black holes are the most compact objects they are not necessarily the most efficient emitters of gravitational radiation in binary systems. The final black hole resulting from a binary black hole merger retains a significant fraction of the premerger orbital energy and angular momentum. A nonvacuum system can in principle shed more of this energy than a black hole merger of equivalent mass. We study these super-emitters through a toy model that accounts for the possibility that the merger creates a compact object that retains a long-lived time-varying quadrupole moment. This toy model may capture the merger of (low mass) neutron stars, but it may also be used to consider more exotic compact binaries. We hope that this toy model can serve as a guide to more rigorous numerical investigations into these systems.

Growing Magnetic Fields in Central Compact Objects

NASA Astrophysics Data System (ADS)

Bernal, C. G.; Page, D.

2011-10-01

We study the effects of growth models of magnetic fields in Central Compact Objects (CCOs). Such a field evolution is not a new idea (Blandford, Applegate, & Hernquist 1983) but the evolutionary implications not have been followed up completely (Michel 1994). We discussed the new class of neutron stars which belong to five main types that have mainly been recognized in the last ten years. The possibility that a rapid weakly magnetized pulsar might have formed in SN1987A is commented.

Massive Compact Halo Objects from the relics of the cosmic quark-hadron transition

NASA Astrophysics Data System (ADS)

Banerjee, Shibaji; Bhattacharyya, Abhijit; Ghosh, Sanjay K.; Raha, Sibaji; Sinha, Bikash; Toki, Hiroshi

2003-03-01

The existence of compact gravitational lenses, with masses around 0.5 Msolar, has been reported in the halo of the Milky Way. The nature of these dark lenses is as yet obscure, particularly because these objects have masses well above the threshold for nuclear fusion. In this work, we show that they find a natural explanation as being the evolutionary product of the metastable false vacuum domains (the so-called strange quark nuggets) formed in a first order cosmic quark-hadron transition.

Hollow glass microsphere-structured Fabry-Perot interferometric sensor for highly sensitive temperature measurement

NASA Astrophysics Data System (ADS)

Cheng, Junna; Zhou, Ciming; Fan, Dian; Ou, Yiwen

2017-04-01

We propose and demonstrate a miniature Fabry-Perot (F-P) interferometric sensor based on a hollow glass microsphere (HGM) for highly sensitive temperature measurement. The sensor head is fabricated by sticking a HGM on the end face of a single-mode fiber, and it consists of a short air F-P cavity between the front and the rear surfaces of the HGM. A sensor with 135.7280-μm cavity length was tested for temperature measurement from -5 °C to 50 °C. The obtained sensitivity reached up to 24.5 pm/°C and the variation rate of the HGM- F-P's cavity length was2.1 nm/°C. The advantages of compact size, easy fabrication and low cost make the sensor suitable for highly sensitive temperature sensing.

Optical and Electronic NOx Sensors for Applications in Mechatronics

PubMed Central

Di Franco, Cinzia; Elia, Angela; Spagnolo, Vincenzo; Scamarcio, Gaetano; Lugarà, Pietro Mario; Ieva, Eliana; Cioffi, Nicola; Torsi, Luisa; Bruno, Giovanni; Losurdo, Maria; Garcia, Michael A.; Wolter, Scott D.; Brown, April; Ricco, Mario

2009-01-01

Current production and emerging NOx sensors based on optical and nanomaterials technologies are reviewed. In view of their potential applications in mechatronics, we compared the performance of: i) Quantum cascade lasers (QCL) based photoacoustic (PA) systems; ii) gold nanoparticles as catalytically active materials in field-effect transistor (FET) sensors, and iii) functionalized III-V semiconductor based devices. QCL-based PA sensors for NOx show a detection limit in the sub part-per-million range and are characterized by high selectivity and compact set-up. Electrochemically synthesized gold-nanoparticle FET sensors are able to monitor NOx in a concentration range from 50 to 200 parts per million and are suitable for miniaturization. Porphyrin-functionalized III-V semiconductor materials can be used for the fabrication of a reliable NOx sensor platform characterized by high conductivity, corrosion resistance, and strong surface state coupling. PMID:22412315

Metasurface optics for full-color computational imaging.

PubMed

Colburn, Shane; Zhan, Alan; Majumdar, Arka

2018-02-01

Conventional imaging systems comprise large and expensive optical components that successively mitigate aberrations. Metasurface optics offers a route to miniaturize imaging systems by replacing bulky components with flat and compact implementations. The diffractive nature of these devices, however, induces severe chromatic aberrations, and current multiwavelength and narrowband achromatic metasurfaces cannot support full visible spectrum imaging (400 to 700 nm). We combine principles of both computational imaging and metasurface optics to build a system with a single metalens of numerical aperture ~0.45, which generates in-focus images under white light illumination. Our metalens exhibits a spectrally invariant point spread function that enables computational reconstruction of captured images with a single digital filter. This work connects computational imaging and metasurface optics and demonstrates the capabilities of combining these disciplines by simultaneously reducing aberrations and downsizing imaging systems using simpler optics.

Low-cost and miniaturized 100-Gb/s (2 × 50 Gb/s) PAM-4 TO-packaged ROSA for data center networks.

PubMed

Kang, Sae-Kyoung; Huh, Joon Young; Lee, Jie Hyun; Lee, Joon Ki

2018-03-05

We design and implement a cost-effective and compact 100-Gb/s (2 × 50 Gb/s) PAM-4 receiver optical sub-assembly (ROSA) by using a TO-can package instead of an expensive box-type package. It consists of an optical demultiplexer, two PIN-PDs and a 2-channel linear transimpedance amplifier. The components are passively aligned and assembled using alignment marks engraved on each part. With a real-time PAM-4 DSP chip, we measured the back-to-back receiver sensitivities of the 100-Gb/s ROSA based on TO-56 to be less than -13.2 dBm for both channels at a bit error rate of 2.4e-4. The crosstalk penalty due to the adjacent channel interference was observed around 0.1 dB.

Fiber optic in vivo imaging in the mammalian nervous system

PubMed Central

Mehta, Amit D; Jung, Juergen C; Flusberg, Benjamin A; Schnitzer, Mark J

2010-01-01

The compact size, mechanical flexibility, and growing functionality of optical fiber and fiber optic devices are enabling several new modalities for imaging the mammalian nervous system in vivo. Fluorescence microendoscopy is a minimally invasive fiber modality that provides cellular resolution in deep brain areas. Diffuse optical tomography is a non-invasive modality that uses assemblies of fiber optic emitters and detectors on the cranium for volumetric imaging of brain activation. Optical coherence tomography is a sensitive interferometric imaging technique that can be implemented in a variety of fiber based formats and that might allow intrinsic optical detection of brain activity at a high resolution. Miniaturized fiber optic microscopy permits cellular level imaging in the brains of behaving animals. Together, these modalities will enable new uses of imaging in the intact nervous system for both research and clinical applications. PMID:15464896

Monolithic integration of a plasmonic sensor with CMOS technology

NASA Astrophysics Data System (ADS)

Shakoor, Abdul; Cheah, Boon C.; Hao, Danni; Al-Rawhani, Mohammed; Nagy, Bence; Grant, James; Dale, Carl; Keegan, Neil; McNeil, Calum; Cumming, David R. S.

2017-02-01

Monolithic integration of nanophotonic sensors with CMOS detectors can transform the laboratory based nanophotonic sensors into practical devices with a range of applications in everyday life. In this work, by monolithically integrating an array of gold nanodiscs with the CMOS photodiode we have developed a compact and miniaturized nanophotonic sensor system having direct electrical read out. Doing so eliminates the need of expensive and bulky laboratory based optical spectrum analyzers used currently for measurements of nanophotonic sensor chips. The experimental optical sensitivity of the gold nanodiscs is measured to be 275 nm/RIU which translates to an electrical sensitivity of 5.4 V/RIU. This integration of nanophotonic sensors with the CMOS electronics has the potential to revolutionize personalized medical diagnostics similar to the way in which the CMOS technology has revolutionized the electronics industry.

Multimode quantum interference of photons in multiport integrated devices

PubMed Central

Peruzzo, Alberto; Laing, Anthony; Politi, Alberto; Rudolph, Terry; O'Brien, Jeremy L.

2011-01-01

Photonics is a leading approach in realizing future quantum technologies and recently, optical waveguide circuits on silicon chips have demonstrated high levels of miniaturization and performance. Multimode interference (MMI) devices promise a straightforward implementation of compact and robust multiport circuits. Here, we show quantum interference in a 2×2 MMI coupler with visibility of V=95.6±0.9%. We further demonstrate the operation of a 4×4 port MMI device with photon pairs, which exhibits complex quantum interference behaviour. We have developed a new technique to fully characterize such multiport devices, which removes the need for phase-sensitive measurements and may find applications for a wide range of photonic devices. Our results show that MMI devices can operate in the quantum regime with high fidelity and promise substantial simplification and concatenation of photonic quantum circuits. PMID:21364563

Compact RGBY light sources with high luminance for laser display applications

NASA Astrophysics Data System (ADS)

Paschke, Katrin; Blume, Gunnar; Werner, Nils; Müller, André; Sumpf, Bernd; Pohl, Johannes; Feise, David; Ressel, Peter; Sahm, Alexander; Bege, Roland; Hofmann, Julian; Jedrzejczyk, Daniel; Tränkle, Günther

2018-02-01

Watt-class visible laser light with a high luminance can be created with high-power GaAs-based lasers either directly in the red spectral region or using single-pass second harmonic generation (SHG) for the colors in the blue-yellow spectral region. The concepts and results of red- and near infrared-emitting distributed Bragg reflector tapered lasers and master oscillator power amplifier systems as well as their application for SHG bench-top experiments and miniaturized modules are presented. Examples of these high-luminance light sources aiming at different applications such as flying spot display or holographic 3D cinema are discussed in more detail. The semiconductor material allows an easy adaptation of the wavelength allowing techniques such as six-primary color 3D projection or color space enhancement by adding a fourth yellow color.

Hands-Free Transcranial Color Doppler Probe

NASA Technical Reports Server (NTRS)

Chin, Robert; Madala, Srihdar; Sattler, Graham

2012-01-01

Current transcranial color Doppler (TCD) transducer probes are bulky and difficult to move in tiny increments to search and optimize TCD signals. This invention provides miniature motions of a TCD transducer probe to optimize TCD signals. The mechanical probe uses spherical bearing in guiding and locating the tilting crystal face. The lateral motion of the crystal face as it tilts across the full range of motion was achieved by minimizing the distance between the pivot location and the crystal face. The smallest commonly available metal spherical bearing was used with an outer diameter of 12 mm, a 3-mm tall retaining ring, and 5-mm overall height. Small geared motors were used that would provide sufficient power in a very compact package. After confirming the validity of the basic positioning concept, optimization design loops were completed to yield the final design.

Integrated Magneto-Electrochemical Sensor for Exosome Analysis.

PubMed

Jeong, Sangmoo; Park, Jongmin; Pathania, Divya; Castro, Cesar M; Weissleder, Ralph; Lee, Hakho

2016-02-23

Extracellular vesicles, including exosomes, are nanoscale membrane particles that carry molecular information on parental cells. They are being pursued as biomarkers of cancers that are difficult to detect or serially follow. Here we present a compact sensor technology for rapid, on-site exosome screening. The sensor is based on an integrated magneto-electrochemical assay: exosomes are immunomagnetically captured from patient samples and profiled through electrochemical reaction. By combining magnetic enrichment and enzymatic amplification, the approach enables (i) highly sensitive, cell-specific exosome detection and (ii) sensor miniaturization and scale-up for high-throughput measurements. As a proof-of-concept, we implemented a portable, eight-channel device and applied it to screen extracellular vesicles in plasma samples from ovarian cancer patients. The sensor allowed for the simultaneous profiling of multiple protein markers within an hour, outperforming conventional methods in assay sensitivity and speed.

Integrated Magneto-Electrochemical Sensor for Exosome Analysis

PubMed Central

Jeong, Sangmoo; Park, Jongmin; Pathania, Divya; Castro, Cesar M.; Weissleder, Ralph; Lee, Hakho

2016-01-01

Extracellular vesicles, including exosomes, are nanoscale vesicles that carry molecular information of parental cells. They are being pursued as biomarkers of cancers that are difficult to detect or serially follow. Here we present a compact sensor technology for rapid, on-site exosome screening. The sensor is based on an integrated magnetic-electrochemical assay: exosomes are immunomagnetically captured from patient samples, and profiled through electrochemical reaction. By combining magnetic enrichment and enzymatic amplification, the approach enables i) highly sensitive, cell-specific exosome detection, and ii) sensor miniaturization and scale-up for high throughput measurements. As a proof-of-concept, we implemented a portable, eight-channel device, and applied it to screen extracellular vesicles in plasma samples from ovarian cancer patients. The sensor allowed for the profiling of multiple protein markers simultaneously within an hour, outperforming conventional methods in assay sensitivity and speed. PMID:26808216

Report of the workshop on intelligent compaction for soils and HMA.

DOT National Transportation Integrated Search

2008-04-01

This document summarizes the discussion and findings of a workshop on intelligent compaction for soils and hot-mix asphalt held in West Des Moines, Iowa, on April 2-4, 2008. The objective of the meeting was to provide a collaborative exchange of idea...

Phase II, Compact AMS System for Biological Tracer Detection Final Report CRADA No. TSV-1533-96

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, T. A.; Hamm, R. W.

2017-11-01

The objective of this collaboration between LLNL and AccSys Technology, Inc. of Pleasanton, California was to build and demonstrate a low cost, compact tritium (3H) Accelerator Mass Spectrometer (AMS) system matched to the requirements of biomedical research.

A new direction for dark matter research: intermediate-mass compact halo objects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapline, George F.; Frampton, Paul H., E-mail: george.chapline@gmail.com, E-mail: paul.h.frampton@gmail.com

2016-11-01

The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been argued that MACHOs with masses > 15 M {sub ⊙} may have been prolifically produced at the onset of the big bang. Although a variety of astrophysical signatures for primordial MACHOs with masses in this range have been discussed in the literature, we favor a strategy that uses the potential for magnification of stars outside our galaxy due to gravitational microlensing of thesemore » stars by MACHOs in the halo of our galaxy. We point out that the effect of the motion of the Earth on the shape of the micro-lensing brightening curves provides a promising approach to testing over the course of next several years the hypothesis that dark matter consists of massive compact objects.« less

High-energy radiation from the relativistic jet of Cygnus X-3

NASA Astrophysics Data System (ADS)

Cerutti, B.; Dubus, G.; Henri, G.

2010-12-01

Cygnus X-3 is an accreting high-mass X-ray binary composed of a Wolf-Rayet star and an unknown compact object, possibly a black hole. The gamma-ray space telescope Fermi found definitive evidence that high-energy emission is produced in this system. We propose a scenario to explain the GeV gamma-ray emission in Cygnus X-3. In this model, energetic electron-positron pairs are accelerated at a specific location in the relativistic jet, possibly related to a recollimation shock, and upscatter the stellar photons to high energies. The comparison with Fermi observations shows that the jet should be inclined close to the line of sight and pairs should not be located within the system. Energetically speaking, a massive compact object is favored. We report also on our investigations of the gamma-ray absorption of GeV photons with the radiation emitted by a standard accretion disk in Cygnus X-3. This study shows that the gamma-ray source should not lie too close to the compact object.

A compact small-beam XRF instrument for in-situ analysis of objects of historical and/or artistic value

NASA Astrophysics Data System (ADS)

Vittiglio, G.; Janssens, K.; Vekemans, B.; Adams, F.; Oost, A.

1999-11-01

The analytical characteristics, possibilities and limitations of a compact and easily transportable small-beam XRF instrument are described. The instrument consists of a compact, mini-focus Mo X-ray tube that is collimated to produce a sub-mm beam and a peltier-cooled PIN diode detector. Relative MDLs in highly scattering matrices are situated in the 10-100-ppm range; for metallic matrices featuring strong matrix lines, the MDLs of the instrument are approximately a factor 2 higher. Since only a small irradiation area is required, a simple micro-polishing technique that may be performed in situ in combination with the measurements is shown to be effective for the determination of the bulk composition of corroded bronze objects. As an example, a series of Egyptian bronze objects date from XXII nd Egyptian Dynasty (ca. 1090 BC) to the Roman era (30 BC to 640 AD) was analyzed in order to contribute to the very limited database on Cu-alloy compositions from this period.

An atlas of H-alpha-emitting regions in M33: A systematic search for SS433 star candidates

NASA Technical Reports Server (NTRS)

Calzetti, Daniela; Kinney, Anne L.; Ford, Holland; Doggett, Jesse; Long, Knox S.

1995-01-01

We report finding charts and accurate positions for 432 compact H-alpha emitting regions in the Local Group galaxy M 33 (NGC 598), in an effort to isolate candidates for an SS433-like stellar system. The objects were extracted from narrow band images, centered in the rest-frame H-alpha (lambda 6563 A) and in the red continuum at 6100 A. The atlas is complete down to V approximately equal to 20 and includes 279 compact HII regions and 153 line emitting point-like sources. The point-like sources undoubtedly include a variety of objects: very small HII regions, early type stars with intense stellar winds, and Wolf-Rayet stars, but should also contain objects with the characteristics of SS433. This extensive survey of compact H-alpha regions in M 33 is a first step towards the identification of peculiar stellar systems like SS433 in external galaxies.

METHOD FOR PRODUCING CEMENTED CARBIDE ARTICLES

DOEpatents

Onstott, E.I.; Cremer, G.D.

1959-07-14

A method is described for making molded materials of intricate shape where the materials consist of mixtures of one or more hard metal carbides or oxides and matrix metals or binder metals thereof. In one embodiment of the invention 90% of finely comminuted tungsten carbide powder together with finely comminuted cobalt bonding agent is incorporated at 60 deg C into a slurry with methyl alcohol containing 1.5% paraffin, 3% camphor, 3.5% naphthalene, and 1.8% toluene. The compact is formed by the steps of placing the slurry in a mold at least one surface of which is porous to the fluid organic system, compacting the slurry, removing a portion of the mold from contact with the formed object and heating the formed object to remove the remaining organic matter and to sinter the compact.

Relativistic model for anisotropic strange stars

NASA Astrophysics Data System (ADS)

Deb, Debabrata; Chowdhury, Sourav Roy; Ray, Saibal; Rahaman, Farook; Guha, B. K.

2017-12-01

In this article, we attempt to find a singularity free solution of Einstein's field equations for compact stellar objects, precisely strange (quark) stars, considering Schwarzschild metric as the exterior spacetime. To this end, we consider that the stellar object is spherically symmetric, static and anisotropic in nature and follows the density profile given by Mak and Harko (2002) , which satisfies all the physical conditions. To investigate different properties of the ultra-dense strange stars we have employed the MIT bag model for the quark matter. Our investigation displays an interesting feature that the anisotropy of compact stars increases with the radial coordinate and attains its maximum value at the surface which seems an inherent property for the singularity free anisotropic compact stellar objects. In this connection we also perform several tests for physical features of the proposed model and show that these are reasonably acceptable within certain range. Further, we find that the model is consistent with the energy conditions and the compact stellar structure is stable with the validity of the TOV equation and Herrera cracking concept. For the masses below the maximum mass point in mass vs radius curve the typical behavior achieved within the framework of general relativity. We have calculated the maximum mass and radius of the strange stars for the three finite values of bag constant Bg.

Report of the workshop on intelligent compaction for soils and HMA : executive summary.

DOT National Transportation Integrated Search

2008-04-01

This document summarizes the discussion and findings of a workshop on intelligent compaction for soils and hot-mix asphalt held in West Des Moines, Iowa, on April 2-4, 2008. The objective of the meeting was to provide a collaborative exchange of idea...

Flight Test Results for the NICMOS Cryocooler

NASA Technical Reports Server (NTRS)

Dolan, F. X.; McCormick, J. A.; Nellis, G. F.; Sixsmith, H.; Swift, W. L.

1999-01-01

In October 1998 a mechanical cryocooler and cryogenic circulator loop were flown on NASA's STS-95 as part of the Hubble Orbital System Test (HOST). The system will be installed on the Hubble Space Telescope (HST) during Service Mission #3 in 2000 and will provide cooling to the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). It will extend the useful life of that instrument by 5 to 10 years. This was the first successful space demonstration of a turbobrayton cryocooler. The cooler is a single stage reverse Brayton type, using low-vibration high-speed miniature turbomachines for the compression and expansion functions. A miniature centrifugal cryogenic circulator is used to deliver refrigerated neon to the instrument. During the mission, the cooler operated without anomalies for approximately 185 hours over a range of conditions to verify its mechanical, thermodynamic and control functions. The cryocooler satisfied all mission objectives including maximum cooldown to near-design operating conditions, warm and cold starts and stops, operation at near-design temperatures, and demonstration of long-term temperature stability. This paper presents a description of the cooler and its operation during the HOST flight.

Monte-Carlo Simulation for Accuracy Assessment of a Single Camera Navigation System

NASA Astrophysics Data System (ADS)

Bethmann, F.; Luhmann, T.

2012-07-01

The paper describes a simulation-based optimization of an optical tracking system that is used as a 6DOF navigation system for neurosurgery. Compared to classical system used in clinical navigation, the presented system has two unique properties: firstly, the system will be miniaturized and integrated into an operating microscope for neurosurgery; secondly, due to miniaturization a single camera approach has been designed. Single camera techniques for 6DOF measurements show a special sensitivity against weak geometric configurations between camera and object. In addition, the achievable accuracy potential depends significantly on the geometric properties of the tracked objects (locators). Besides quality and stability of the targets used on the locator, their geometric configuration is of major importance. In the following the development and investigation of a simulation program is presented which allows for the assessment and optimization of the system with respect to accuracy. Different system parameters can be altered as well as different scenarios indicating the operational use of the system. Measurement deviations are estimated based on the Monte-Carlo method. Practical measurements validate the correctness of the numerical simulation results.

Color Constancy in Two-Dimensional and Three-Dimensional Scenes: Effects of Viewing Methods and Surface Texture

PubMed Central

Morimoto, Takuma; Mizokami, Yoko; Yaguchi, Hirohisa; Buck, Steven L.

2017-01-01

There has been debate about how and why color constancy may be better in three-dimensional (3-D) scenes than in two-dimensional (2-D) scenes. Although some studies have shown better color constancy for 3-D conditions, the role of specific cues remains unclear. In this study, we compared color constancy for a 3-D miniature room (a real scene consisting of actual objects) and 2-D still images of that room presented on a monitor using three viewing methods: binocular viewing, monocular viewing, and head movement. We found that color constancy was better for the 3-D room; however, color constancy for the 2-D image improved when the viewing method caused the scene to be perceived more like a 3-D scene. Separate measurements of the perceptual 3-D effect of each viewing method also supported these results. An additional experiment comparing a miniature room and its image with and without texture suggested that surface texture of scene objects contributes to color constancy. PMID:29238513

Hot super-dense compact object with particular EoS

NASA Astrophysics Data System (ADS)

Tito, E. P.; Pavlov, V. I.

2018-03-01

We show the possibility of existence of a self-gravitating spherically-symmetric equilibrium configuration for a neutral matter with neutron-like density, small mass M ≪ M_{⊙}, and small radius R ≪ R_{⊙}. We incorporate the effects of both the special and general theories of relativity. Such object may be formed in a cosmic cataclysm, perhaps an exotic one. Since the base equations of hydrostatic equilibrium are completed by the equation of state (EoS) for the matter of the object, we offer a novel, interpolating experimental data from high-energy physics, EoS which permits the existence of such compact system of finite radius. This EoS model possesses a critical state characterized by density ρc and temperature Tc. For such an object, we derive a radial distribution for the super-dense matter in "liquid" phase using Tolman-Oppenheimer-Volkoff equations for hydrostatic equilibrium. We demonstrate that a stable configuration is indeed possible (only) for temperatures smaller than the critical one. We derive the mass-radius relation (adjusted for relativistic corrections) for such small (M ≪ M_{⊙}) super-dense compact objects. The results are within the constraints established by both heavy-ion collision experiments and theoretical studies of neutron-rich matter.

MONICA: A Compact, Portable Dual Gamma Camera System for Mouse Whole-Body Imaging

PubMed Central

Xi, Wenze; Seidel, Jurgen; Karkareka, John W.; Pohida, Thomas J.; Milenic, Diane E.; Proffitt, James; Majewski, Stan; Weisenberger, Andrew G.; Green, Michael V.; Choyke, Peter L.

2009-01-01

Introduction We describe a compact, portable dual-gamma camera system (named “MONICA” for MObile Nuclear Imaging CAmeras) for visualizing and analyzing the whole-body biodistribution of putative diagnostic and therapeutic single photon emitting radiotracers in animals the size of mice. Methods Two identical, miniature pixelated NaI(Tl) gamma cameras were fabricated and installed “looking up” through the tabletop of a compact portable cart. Mice are placed directly on the tabletop for imaging. Camera imaging performance was evaluated with phantoms and field performance was evaluated in a weeklong In-111 imaging study performed in a mouse tumor xenograft model. Results Tc-99m performance measurements, using a photopeak energy window of 140 keV ± 10%, yielded the following results: spatial resolution (FWHM at 1-cm), 2.2-mm; sensitivity, 149 cps/MBq (5.5 cps/μCi); energy resolution (FWHM), 10.8%; count rate linearity (count rate vs. activity), r2 = 0.99 for 0–185 MBq (0–5 mCi) in the field-of-view (FOV); spatial uniformity, < 3% count rate variation across the FOV. Tumor and whole-body distributions of the In-111 agent were well visualized in all animals in 5-minute images acquired throughout the 168-hour study period. Conclusion Performance measurements indicate that MONICA is well suited to whole-body single photon mouse imaging. The field study suggests that inter-device communications and user-oriented interfaces included in the MONICA design facilitate use of the system in practice. We believe that MONICA may be particularly useful early in the (cancer) drug development cycle where basic whole-body biodistribution data can direct future development of the agent under study and where logistical factors, e.g. limited imaging space, portability, and, potentially, cost are important. PMID:20346864

Toward the realization of a compact chemical sensor platform using quantum cascade lasers

NASA Astrophysics Data System (ADS)

Holthoff, Ellen L.; Marcus, Logan S.; Pellegrino, Paul M.

2015-05-01

The Army is investigating several spectroscopic techniques (e.g., infrared spectroscopy) that could allow for an adaptable sensor platform. Traditionally, chemical sensing platforms have been hampered by the opposing concerns of increasing sensor capability while maintaining a minimal package size. Current sensors, although reasonably sized, are geared to more classical chemical threats, and the ability to expand their capabilities to a broader range of emerging threats is uncertain. Recently, photoacoustic spectroscopy, employed in a sensor format, has shown enormous potential to address these ever-changing threats, while maintaining a compact sensor design. In order to realize the advantage of photoacoustic sensor miniaturization, light sources of comparable size are required. Recent research has employed quantum cascade lasers (QCLs) in combination with MEMS-scale photoacoustic cell designs. The continuous tuning capability of QCLs over a broad wavelength range in the mid-infrared spectral region greatly expands the number of compounds that can be identified. Results have demonstrated that utilizing a tunable QCL with a MEMS-scale photoacoustic cell produces favorable detection limits (ppb levels) for chemical targets (e.g., dimethyl methyl phosphonate (DMMP), vinyl acetate, 1,4-dioxane). Although our chemical sensing research has benefitted from the broad tuning capabilities of QCLs, the limitations of these sources must be considered. Current commercially available tunable systems are still expensive and obviously geared more toward laboratory operation, not fielding. Although the laser element itself is quite small, the packaging, power supply, and controller remain logistical burdens. Additionally, operational features such as continuous wave (CW) modulation and laser output powers while maintaining wide tunability are not yet ideal for a variety of sensing applications. In this paper, we will discuss our continuing evaluation of QCL technology as it matures in relation to our ultimate goal of a universal compact chemical sensor platform.

A Compact Ion and Neutral Mass Spectrometer for Measuring Atmospheric Composition with Preliminary Results from the Dellingr Mission

NASA Astrophysics Data System (ADS)

Jones, S.; Paschalidis, N.; Rodriguez, M.; Sittler, E. C., Jr.; Chornay, D. J.; Uribe, P.; Cameron, T.

2017-12-01

A compact Ion and Neutral Mass Spectrometer (INMS) has been developed for GSFC's Dellingr mission, using the 6U CubeSat platform. Dellingr is expected to deploy into ISS orbit in October 2017 to measure the dynamics of the ionosphere-thermosphere-mesosphere and to determine the steady state background atmospheric conditions at this altitude. The INMS makes in situ measurements of ionized and neutral H, He, N, O, N2, O2 densities with M/dM of approximately 10-12 for thermal particles. The INMS is based on particle acceleration, electronically gated time of flight (TOF), electrostatic analyzer, and CEM detectors. The compact instrument has a dual symmetric configuration with ion and neutral sensor heads on opposite sides of the shared electronics. The neutral front-end includes thermionic ionization and ion-blocking grids. The electronics include fast preamplifiers, electric gating, and TOF measurements and processing, C&DH digital electronics for commands, data storage and back-end I/O, and HVPS for detector and sensor biases. The data package includes 400 bins of mass spectra per ion and neutral sensor and key housekeeping and calibration data, in a single time tagged data frame of 14kbits uncompressed. The nominal data sampling is 1 sec corresponding to 7.5km spatial resolution in LEO orbits. This miniaturized instrument occupies a 1.1U volume, weighs only 570g and nominally operates at 1.2W. This presentation will include preliminary flight data of ions and neutrals from the Dellingr mission and outlines improvements incorporated into the design for the Dellingr (Oct 2017), ExoCube2 (Dec 2017) and petitSat (2020) CubeSat missions.

Hands-Free Transcranial Color Doppler Probe

NASA Technical Reports Server (NTRS)

Chin, Robert; Madala, Srihdar; Sattler, Graham

2012-01-01

Current transcranial color Doppler (TCD) transducer probes are bulky and difficult to move in tiny increments to search and optimize TCD signals. This invention provides miniature motions of a TCD transducer probe to optimize TCD signals. The mechanical probe uses a spherical bearing in guiding and locating the tilting crystal face. The lateral motion of the crystal face as it tilts across the full range of motion was achieved by minimizing the distance between the pivot location and the crystal face. The smallest commonly available metal spherical bearing was used with an outer diameter of 12 mm, a 3-mm tall retaining ring, and 5-mm overall height. Small geared motors were used that would provide sufficient power in a very compact package. After confirming the validity of the basic positioning concept, optimization design loops were completed to yield the final design. A parallel motor configuration was used to minimize the amount of space wasted inside the probe case while minimizing the overall case dimensions. The distance from the front edge of the crystal to the edge of the case was also minimized to allow positioning of the probe very close to the ear on the temporal lobe. The mechanical probe is able to achieve a +/-20deg tip and tilt with smooth repeatable action in a very compact package. The enclosed probe is about 7 cm long, 4 cm wide, and 1.8 cm tall. The device is compact, hands-free, and can be adjusted via an innovative touchscreen. Positioning of the probe to the head is performed via conventional transducer gels and pillows. This device is amendable to having advanced software, which could intelligently focus and optimize the TCD signal.

Development of a 150-GHz MMIC Module Prototype for Large-Scale CMB Radiation

NASA Technical Reports Server (NTRS)

Kangaslahti, Pekka P.; Samoska, Lorene A.; Gaier, Todd C.; Soria, Mary M.; Lau, Judy M.; Sieth, Matthew M.; VanWinkle, Daniel; Tantawi, Sami

2011-01-01

HEMT-based receiver arrays with excellent noise and scalability are already starting to be manufactured at 100 GHz, but the advances in technology should make it possible to develop receiver modules with even greater operation frequency up to 200 GHz. A prototype heterodyne amplifier module has been developed for operation from 140 to 170 GHz using monolithic millimeter-wave integrated circuit (MMIC) low-noise InP high electron mobility transistor (HEMT) amplifiers. The compact, scalable module is centered on the 150-GHz atmospheric window using components known to operate well at these frequencies. Arrays equipped with hundreds of these modules can be optimized for many different astrophysical measurement techniques, including spectroscopy and interferometry. This module is a heterodyne receiver module that is extremely compact, and makes use of 35-nm InP HEMT technology, and which has been shown to have excellent noise temperatures when cooled cryogenically to 30 K. This reduction in system noise over prior art has been demonstrated in commercial mixers (uncooled) at frequencies of 160-180 GHz. The module is expected to achieve a system noise temperature of 60 K when cooled. An MMIC amplifier module has been designed to demonstrate the feasibility of expanding heterodyne amplifier technology to the 140 to 170-GHz frequency range for astronomical observations. The miniaturization of many standard components and the refinement of RF interconnect technology have cleared the way to mass-production of heterodyne amplifier receivers, making it a feasible technology for many large-population arrays. This work furthers the recent research efforts in compact coherent receiver modules, including the development of the Q/U Imaging ExperimenT (QUIET) modules centered at 40 and 90 GHz, and the production of heterodyne module prototypes at 90 GHz.

Testing strong-field gravity with tidal Love numbers

NASA Astrophysics Data System (ADS)

Cardoso, Vitor; Franzin, Edgardo; Maselli, Andrea; Pani, Paolo; Raposo, Guilherme

2017-04-01

The tidal Love numbers (TLNs) encode the deformability of a self-gravitating object immersed in a tidal environment and depend significantly both on the object's internal structure and on the dynamics of the gravitational field. An intriguing result in classical general relativity is the vanishing of the TLNs of black holes. We extend this result in three ways, aiming at testing the nature of compact objects: (i) we compute the TLNs of exotic compact objects, including different families of boson stars, gravastars, wormholes, and other toy models for quantum corrections at the horizon scale. In the black-hole limit, we find a universal logarithmic dependence of the TLNs on the location of the surface. (ii) We compute the TLNs of black holes beyond vacuum general relativity, including Einstein-Maxwell, Brans-Dicke, and Chern-Simons gravity. (iii) We assess the ability of present and future gravitational-wave detectors to measure the TLNs of these objects, including the first analysis of TLNs with LISA. Both LIGO, ET, and LISA can impose interesting constraints on boson stars, while LISA is able to probe even extremely compact objects. We argue that the TLNs provide a smoking gun of new physics at the horizon scale and that future gravitational-wave measurements of the TLNs in a binary inspiral provide a novel way to test black holes and general relativity in the strong-field regime.

Inheritance of congenital cataracts and microphthalmia in the Miniature Schnauzer.

PubMed

Gelatt, K N; Samuelson, D A; Bauer, J E; Das, N D; Wolf, E D; Barrie, K P; Andresen, T L

1983-06-01

Congenital cataracts and microphthalmia in the Miniature Schnauzer were inherited as an autosomal recessive trait. Eighteen matings of affected X affected Miniature Schnauzers resulted in 87 offspring with congenital cataracts and microphthalmia (49 males/38 females). Two matings of congenital cataractous and microphthalmic Miniature Schnauzers (2 females) X a normal Miniature Schnauzer (1 male) yielded 11 clinically normal Miniature Schnauzers (7 males/4 females). Eighteen matings of congenital cataractous and microphthalmic Miniature Schnauzers (6 males) X carrier Miniature Schnauzers (9 females) produced 81 offspring; 39 exhibited congenital cataracts and microphthalmia (20 males/19 females) and 42 had clinically normal eyes (17 males/25 females).

Laser light scattering instrument advanced technology development

NASA Technical Reports Server (NTRS)

Wallace, J. F.

1993-01-01

The objective of this advanced technology development (ATD) project has been to provide sturdy, miniaturized laser light scattering (LLS) instrumentation for use in microgravity experiments. To do this, we assessed user requirements, explored the capabilities of existing and prospective laser light scattering hardware, and both coordinated and participated in the hardware and software advances needed for a flight hardware instrument. We have successfully breadboarded and evaluated an engineering version of a single-angle glove-box instrument which uses solid state detectors and lasers, along with fiber optics, for beam delivery and detection. Additionally, we have provided the specifications and written verification procedures necessary for procuring a miniature multi-angle LLS instrument which will be used by the flight hardware project which resulted from this work and from this project's interaction with the laser light scattering community.

Do massive compact objects without event horizon exist in infinite derivative gravity?

NASA Astrophysics Data System (ADS)

Koshelev, Alexey S.; Mazumdar, Anupam

2017-10-01

Einstein's general theory of relativity is plagued by cosmological and black-hole type singularities Recently, it has been shown that infinite derivative, ghost free, gravity can yield nonsingular cosmological and mini-black hole solutions. In particular, the theory possesses a mass-gap determined by the scale of new physics. This paper provides a plausible argument, not a no-go theorem, based on the Area-law of gravitational entropy that within infinite derivative, ghost free, gravity nonsingular compact objects in the static limit need not have horizons.

Manifestations of dynamo driven large-scale magnetic field in accretion disks of compact objects

NASA Technical Reports Server (NTRS)

Chagelishvili, G. D.; Chanishvili, R. G.; Lominadze, J. G.; Sokhadze, Z. A.

1991-01-01

A turbulent dynamo nonlinear theory of turbulence was developed that shows that in the compact objects of accretion disks, the generated large-scale magnetic field (when the generation takes place) has a practically toroidal configuration. Its energy density can be much higher than turbulent pulsations energy density, and it becomes comparable with the thermal energy density of the medium. On this basis, the manifestations to which the large-scale magnetic field can lead at the accretion onto black holes and gravimagnetic rotators, respectively, are presented.

Handheld spectrometers: the state of the art

NASA Astrophysics Data System (ADS)

Crocombe, Richard A.

2013-05-01

"Small" spectrometers fall into three broad classes: small versions of laboratory instruments, providing data, subsequently processed on a PC; dedicated analyzers, providing actionable information to an individual operator; and process analyzers, providing quantitative or semi-quantitative information to a process controller. The emphasis of this paper is on handheld dedicated analyzers. Many spectrometers have historically been large, possible fragile, expensive and complicated to use. The challenge over the last dozen years, as instruments have moved into the field, has been to make spectrometers smaller, affordable, rugged, easy-to-use, but most of all capable of delivering actionable results. Actionable results can dramatically improve the efficiency of a testing process and transform the way business is done. There are several keys to this handheld spectrometer revolution. Consumer electronics has given us powerful mobile platforms, compact batteries, clearly visible displays, new user interfaces, etc., while telecomm has revolutionized miniature optics, sources and detectors. While these technologies enable miniature spectrometers themselves, actionable information has demanded the development of rugged algorithms for material confirmation, unknown identification, mixture analysis and detection of suspicious materials in unknown matrices. These algorithms are far more sophisticated than the `correlation' or `dot-product' methods commonly used in benchtop instruments. Finally, continuing consumer electronics advances now enable many more technologies to be incorporated into handheld spectrometers, including Bluetooth, wireless, WiFi, GPS, cameras and bar code readers, and the continued size shrinkage of spectrometer `engines' leads to the prospect of dual technology or `hyphenated' handheld instruments.

Development of miniature, high frequency pulse tube cryocoolers

NASA Astrophysics Data System (ADS)

Radebaugh, Ray; Garaway, Isaac; Veprik, Alexander M.

2010-04-01

Because acoustic power density is proportional to frequency, the size of pulse tube cryocoolers for a given refrigeration power can be reduced by operating them at higher frequencies. A frequency of about 60 Hz had been considered the maximum frequency that could be used while maintaining high efficiency. Recently, we have shown through modeling that by decreasing the volume and hydraulic diameter of the regenerator and increasing the average pressure, it is possible to maintain high efficiency even for frequencies of several hundred hertz. Subsequent experimental results have demonstrated high efficiencies for frequencies of 100 to 140 Hz. The very high power density achieved at higher pressures and higher frequencies leads to very short cooldown times and very compact devices. The use of even higher frequencies requires the development of special compressors designed for such conditions and the development of regenerator matrices with hydraulic diameters less than about 30 Μm. To demonstrate the advantages of higher frequency operation, we discuss here the development of a miniature pulse tube cryocooler designed to operate at 80 K with a frequency of 150 Hz and an average pressure of 5.0 MPa. The regenerator diameter and length are 4.4 mm and 27 mm, respectively. The lowest temperature achieved to date has been 97 K, but a net refrigeration power of 530 mW was achieved at 120 K. Acoustic mismatches with existing compressors significantly limit the efficiency, but necessary modifications to improve the acoustic impedance match between the compressor and the cold head are discussed briefly.

Multi-Evaporator Miniature Loop Heat Pipe for Small Spacecraft Thermal Control. Part 2; Validation Results

NASA Technical Reports Server (NTRS)

Ku, Jentung; Ottenstein, Laura; Douglas, Donya; Hoang, Triem

2010-01-01

Under NASA s New Millennium Program Space Technology 8 (ST 8) Project, Goddard Space Fight Center has conducted a Thermal Loop experiment to advance the maturity of the Thermal Loop technology from proof of concept to prototype demonstration in a relevant environment , i.e. from a technology readiness level (TRL) of 3 to a level of 6. The thermal Loop is an advanced thermal control system consisting of a miniature loop heat pipe (MLHP) with multiple evaporators and multiple condensers designed for future small system applications requiring low mass, low power, and compactness. The MLHP retains all features of state-of-the-art loop heat pipes (LHPs) and offers additional advantages to enhance the functionality, performance, versatility, and reliability of the system. An MLHP breadboard was built and tested in the laboratory and thermal vacuum environments for the TRL 4 and TRL 5 validations, respectively, and an MLHP proto-flight unit was built and tested in a thermal vacuum chamber for the TRL 6 validation. In addition, an analytical model was developed to simulate the steady state and transient behaviors of the MLHP during various validation tests. The MLHP demonstrated excellent performance during experimental tests and the analytical model predictions agreed very well with experimental data. All success criteria at various TRLs were met. Hence, the Thermal Loop technology has reached a TRL of 6. This paper presents the validation results, both experimental and analytical, of such a technology development effort.

Recent advancements in system design for miniaturized MEMS-based laser projectors

NASA Astrophysics Data System (ADS)

Scholles, M.; Frommhagen, K.; Gerwig, Ch.; Knobbe, J.; Lakner, H.; Schlebusch, D.; Schwarzenberg, M.; Vogel, U.

2008-02-01

Laser projection systems that use the flying spot principle and which are based on a single MEMS micro scanning mirrors are a very promising way to build ultra-compact projectors that may fit into mobile devices. First demonstrators that show the feasibility of this approach and the applicability of the micro scanning mirror developed by Fraunhofer IPMS for these systems have already been presented. However, a number of items still have to be resolved until miniaturized laser projectors are ready for the market. This contribution describes progress on several different items, each of them of major importance for laser projection systems. First of all, the overall performance of the system has been increased from VGA resolution to SVGA (800×600 pixels) with easy connection to a PC via DVI interface or by using the projector as embedded system with direct camera interface. Secondly, the degree of integration of the electronics has been enhanced by design of an application specific analog front end IC for the micro scanning mirror. It has been fabricated in a special high voltage technology and does not only allow to generate driving signals for the scanning mirror with amplitudes of up to 200V but also integrates position detection of the mirror by several methods. Thirdly, first results concerning Speckle reduction have been achieved, which is necessary for generation of images with high quality. Other aspects include laser modulation and solutions regarding projection on tilted screens which is possible because of the unlimited depth of focus.

Proposal of ultra-compact NAND/NOR/XNOR all-optical logic gates based on a nonlinear 3x1 multimode interference

NASA Astrophysics Data System (ADS)

Tajaldini, Mehdi; Mat Jafri, M. Z.

2014-05-01

We present a highly miniaturized multimode interference (MMI) coupler based on nonlinear modal propagation analysis (NMPA) method as a novel design method and potential application for optical NAND, NOR and XNOR logic gates for Boolean logic signal processing devices. Crystalline polydiacetylene is used to allow the appearances of nonlinear effects in low input intensities and ultra- short length to control the MMI coupler as an active device to access light switching due to its high nonlinear susceptibility. We consider a 10x33 μm2 MMI structure with three inputs and one output. Notably, the access facets are single-mode waveguides with sub-micron width. The center input contributes to control the induced light propagation in MMI by intensity variation whereas others could be launched by particular intensity when they are ON and 0 in OFF. Output intensity is analyzed in various sets of inputs to show the capability of Boolean logic gates, the contrast between ON and OFF is calculated on mentioned gates to present the efficiency. Good operation in low intensity and highly miniaturized MMI coupler is observed. Furthermore, nonlinear effects could be realized through the modal interferences. The issue of high insertion loss is addressed with a 3×3 upgraded coupler. Furthermore, the main significant aspect of this paper is simulating an MMI coupler that is launched by three nonlinear inputs, simultaneously, whereas last presents have never studied more than one input in nonlinear regimes.

Targeted sections in either XY or XZ plane with dual-axes confocal endomicroscope (Conference Presentation)

NASA Astrophysics Data System (ADS)

Li, Gaoming; Li, Haijun; Duan, Xiyu; Zhou, Quan; Zhou, Juan; Oldham, Kenn R.; Wang, Thomas D.

2017-02-01

We demonstrate a dual axes confocal architecture, which can be used to collect horizontal(XY-plane) or vertical cross-sectional(XZ-plane) images for tissue. This scanner head is 5.5mm in outer diameter(OD), and integrates a 3D MEMS scanner with a compact chip size of 3.2×2.9mm2. To realize the miniaturization, there are some obstacles of the small size of 3D MEMS scanner, MEMS wire bundle, the air pressure effect for MEMS motion, the processing of parabolic mirror, and optical alignment to come over. In our probe, separation mechanical structure for optical alignment was adopted and a step shape MEMS holder was designed to deal with the difficult of MEMS wire bundle. Peptides have been demonstrated tremendous potential for in vivo use to detect colonic dysplasia. This class of in vivo molecular probe can be labeled with near-infrared (NIR) dyes for visualizing the full depth of the epithelium in small animals. To confirm our probe performance, we take use of USAF 1951 resolution target to test its lateral and axial resolution. It has lateral and axial resolution of 2.49um and 4.98um, respectively. When we collect the fluorescence imaging of colon, it shows that the field of view are 1000um×1000um (horizontal) and 1000um×430um (vertical). The horizontal and vertical cross-sectional images of fresh mouse colonic mucosa demonstrate imaging performance with this miniature instrument.

A stand-alone compact EUV microscope based on gas-puff target source.

PubMed

Torrisi, Alfio; Wachulak, Przemyslaw; Węgrzyński, Łukasz; Fok, Tomasz; Bartnik, Andrzej; Parkman, Tomáš; Vondrová, Šárka; Turňová, Jana; Jankiewicz, Bartłomiej J; Bartosewicz, Bartosz; Fiedorowicz, Henryk

2017-02-01

We report on a very compact desk-top transmission extreme ultraviolet (EUV) microscope based on a laser-plasma source with a double stream gas-puff target, capable of acquiring magnified images of objects with a spatial (half-pitch) resolution of sub-50 nm. A multilayer ellipsoidal condenser is used to focus and spectrally narrow the radiation from the plasma, producing a quasi-monochromatic EUV radiation (λ = 13.8 nm) illuminating the object, whereas a Fresnel zone plate objective forms the image. Design details, development, characterization and optimization of the EUV source and the microscope are described and discussed. Test object and other samples were imaged to demonstrate superior resolution compared to visible light microscopy. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Comparative Variable Temperature Studies of Polyamide II with a Benchtop Fourier Transform and a Miniature Handheld Near-Infrared Spectrometer Using 2D-COS and PCMW-2D Analysis.

PubMed

Unger, Miriam; Pfeifer, Frank; Siesler, Heinz W

2016-07-01

The main objective of this communication is to compare the performance of a miniaturized handheld near-infrared (NIR) spectrometer with a benchtop Fourier transform near-infrared (FT-NIR) spectrometer. Generally, NIR spectroscopy is an extremely powerful analytical tool to study hydrogen-bonding changes of amide functionalities in solid and liquid materials and therefore variable temperature NIR measurements of polyamide II (PAII) have been selected as a case study. The information content of the measurement data has been further enhanced by exploiting the potential of two-dimensional correlation spectroscopy (2D-COS) and the perturbation correlation moving window two-dimensional (PCMW2D) evaluation technique. The data provide valuable insights not only into the changes of the hydrogen-bonding structure and the recrystallization of the hydrocarbon segments of the investigated PAII but also in their sequential order. Furthermore, it has been demonstrated that the 2D-COS and PCMW2D results derived from the spectra measured with the miniaturized NIR instrument are equivalent to the information extracted from the data obtained with the high-performance FT-NIR instrument. © The Author(s) 2016.

Planck 2015 results. XXVI. The Second Planck Catalogue of Compact Sources

NASA Astrophysics Data System (ADS)

Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Argüeso, F.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Beichman, C.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Böhringer, H.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Carvalho, P.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Clemens, M.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leahy, J. P.; Leonardi, R.; León-Tavares, J.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Negrello, M.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Sanghera, H. S.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tornikoski, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Walter, B.; Wandelt, B. D.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zonca, A.

2016-09-01

The Second Planck Catalogue of Compact Sources is a list of discrete objects detected in single-frequency maps from the full duration of the Planck mission and supersedes previous versions. It consists of compact sources, both Galactic and extragalactic, detected over the entire sky. Compact sources detected in the lower frequency channels are assigned to the PCCS2, while at higher frequencies they are assigned to one of two subcatalogues, the PCCS2 or PCCS2E, depending on their location on the sky. The first of these (PCCS2) covers most of the sky and allows the user to produce subsamples at higher reliabilities than the target 80% integral reliability of the catalogue. The second (PCCS2E) contains sources detected in sky regions where the diffuse emission makes it difficult to quantify the reliability of the detections. Both the PCCS2 and PCCS2E include polarization measurements, in the form of polarized flux densities, or upper limits, and orientation angles for all seven polarization-sensitive Planck channels. The improved data-processing of the full-mission maps and their reduced noise levels allow us to increase the number of objects in the catalogue, improving its completeness for the target 80% reliability as compared with the previous versions, the PCCS and the Early Release Compact Source Catalogue (ERCSC).

Hydrodynamic simulations of stellar wind disruption by a compact X-ray source

NASA Technical Reports Server (NTRS)

Blondin, John M.; Kallman, Timothy R.; Fryxell, Bruce A.; Taam, Ronald E.

1990-01-01

This paper presents two-dimensional numerical simulations of the gas flow in the orbital plane of a massive X-ray binary system, in which the mass accretion is fueled by a radiation-driven wind from an early-type companion star. These simulations are used to examine the role of the compact object (either a neutron star or a black hole) in disturbing the radiatively accelerating wind of the OB companion, with an emphasis on understanding the origin of the observed soft X-ray photoelectric absorption seen at late orbital phases in these systems. On the basis of these simulations, it is suggested that the phase-dependent photoelectric absorption seen in several of these systems can be explained by dense filaments of compressend gas formed in the nonsteady accreation bow shock and wake of the compact object.

The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery

PubMed Central

Yuruk, Koray; Bezemer, Rick; Euser, Mariska; Milstein, Dan M.J.; de Geus, Hilde H.R.; Scholten, Evert W.; de Mol, Bas A.J.M.; Ince, Can

2012-01-01

OBJECTIVES To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery using conventional extracorporeal circulation systems has been associated with significantly reduced microcirculatory perfusion, but it remains unknown whether this could be prevented by an mECC system. Here, we aimed to test the hypothesis that microcirculatory perfusion decreases with the use of a conventional extracorporeal circulation system and would be preserved with the use of an miniaturized extracorporeal circulation system. METHODS Microcirculatory density and perfusion were assessed using sublingual side stream dark-field imaging in patients undergoing on-pump coronary artery bypass graft (CABG) surgery before, during and after the use of either a conventional extracorporeal circulation system (n = 10) or a miniaturized extracorporeal circulation system (n = 10). In addition, plasma neutrophil gelatinase-associated lipocalin and creatinine levels and creatinine clearance were assessed up to 5 days post-surgery to monitor renal function. RESULTS At the end of the CPB, one patient in the miniaturized extracorporeal circulation-treated group and five patients in the conventional extracorporeal circulation-treated group received one bag of packed red blood cells (300 ml). During the CPB, the haematocrit and haemoglobin levels were slightly higher in the miniaturized extracorporeal circulation-treated patients compared with the conventional extracorporeal circulation-treated patients (27.7 ± 3.3 vs 24.7 ± 2.0%; P = 0.03; and 6.42 ± 0.75 vs 5.41 ± 0.64 mmol/l; P < 0.01). The density of perfused vessels with a diameter <25 µm (i.e. perfused vessel density) decreased slightly in the conventional extracorporeal circulation-treated group from 16.4 ± 3.8 to 12.8 ± 3.3 mm/mm2 (P < 0.01) and remained stable in the miniaturized extracorporeal circulation-treated group (16.3 ± 2.7 and 15.2 ± 2.9 mm/mm2 before and during the pump, respectively). Plasma neutrophil gelatinase-associated lipocalin levels were increased following the use of extracorporeal circulation in both groups, and no differences were observed between the groups. Plasma creatinine levels and creatinine clearance were not affected by CABG surgery or CPB. CONCLUSIONS The results from this relatively small study suggest that the use of the miniaturized extracorporeal circulation system is associated with a statistically significant (but clinically insignificant) reduction in haemodilution and microcirculatory hypoperfusion compared with the use of the conventional extracorporeal circulation system. PMID:22700685

Point and Compact Hα Sources in the Interior of M33

NASA Astrophysics Data System (ADS)

Moody, J. Ward; Hintz, Eric G.; Joner, Michael D.; Roming, Peter W. A.; Hintz, Maureen L.

2017-12-01

A variety of interesting objects such as Wolf-Rayet stars, tight OB associations, planetary nebulae, X-ray binaries, etc., can be discovered as point or compact sources in Hα surveys. How these objects distribute through a galaxy sheds light on the galaxy star formation rate and history, mass distribution, and dynamics. The nearby galaxy M33 is an excellent place to study the distribution of Hα-bright point sources in a flocculant spiral galaxy. We have reprocessed an archived WIYN continuum-subtracted Hα image of the inner 6.‧5 × 6.‧5 of M33 and, employing both eye and machine searches, have tabulated sources with a flux greater than approximately 10-15 erg cm-2s-1. We have effectively recovered previously mapped H II regions and have identified 152 unresolved point sources and 122 marginally resolved compact sources, of which 39 have not been previously identified in any archive. An additional 99 Hα sources were found to have sufficient archival flux values to generate a Spectral Energy Distribution. Using the SED, flux values, Hα flux value, and compactness, we classified 67 of these sources.

I-Love-Q relations for gravastars and the approach to the black-hole limit

NASA Astrophysics Data System (ADS)

Pani, Paolo

2015-12-01

The multipole moments and the tidal Love numbers of neutron stars and quark stars satisfy certain relations which are almost insensitive to the star's internal structure. A natural question is whether the same relations hold for different compact objects and how they possibly approach the black-hole limit. Here we consider "gravastars," which are hypothetical compact objects sustained by their internal vacuum energy. Such solutions have been proposed as exotic alternatives to the black-hole paradigm because they can be as compact as black holes and exist in any mass range. By constructing slowly rotating, thin-shell gravastars to quadratic order in the spin, we compute the moment of inertia I , the mass quadrupole moment Q , and the tidal Love number λ in exact form. The I -λ -Q relations of a gravastar are dramatically different from those of an ordinary compact star, but the black-hole limit is continuous; i.e., these quantities approach their Kerr counterparts when the compactness is maximum. Therefore, such relations can be used to discern a gravastar from an ordinary compact star but not to break the degeneracy with the black-hole case. Based on these results, we conjecture that the full multipolar structure and the tidal deformability of a spinning, ultracompact gravastar are identical to those of a Kerr black hole. The approach to the black-hole limit is nonpolynomial, thus differing from the critical behavior recently found for strongly anisotropic neutron stars.

Origin of 10{sup 15}–10{sup 16} G magnetic fields in the central engine of gamma ray bursts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Souza, Rafael S. de; Opher, Reuven, E-mail: rafael@astro.iag.usp.br, E-mail: opher@astro.iag.usp.br

2010-02-01

Various authors have suggested that the gamma-ray burst (GRB) central engine is a rapidly rotating, strongly magnetized, ( ∼ 10{sup 15}–10{sup 16} G) compact object. The strong magnetic field can accelerate and collimate the relativistic flow and the rotation of the compact object can be the energy source of the GRB. The major problem in this scenario is the difficulty of finding an astrophysical mechanism for obtaining such intense fields. Whereas, in principle, a neutron star could maintain such strong fields, it is difficult to justify a scenario for their creation. If the compact object is a black hole, themore » problem is more difficult since, according to general relativity it has ''no hair'' (i.e., no magnetic field). Schuster, Blackett, Pauli, and others have suggested that a rotating neutral body can create a magnetic field by non-minimal gravitational-electromagnetic coupling (NMGEC). The Schuster-Blackett form of NMGEC was obtained from the Mikhail and Wanas's tetrad theory of gravitation (MW). We call the general theory NMGEC-MW. We investigate here the possible origin of the intense magnetic fields ∼ 10{sup 15}–10{sup 16} G in GRBs by NMGEC-MW. Whereas these fields are difficult to explain astrophysically, we find that they are easily explained by NMGEC-MW. It not only explains the origin of the ∼ 10{sup 15}–10{sup 16} G fields when the compact object is a neutron star, but also when it is a black hole.« less

Perspectives on Simulation and Miniaturization. Professional Paper No. 1472.

ERIC Educational Resources Information Center

McCluskey, Michael R.

Simulation--here defined as a physical, procedural, or symbolic representation of certain aspects of a functioning system, or as a working model or representation of a real world system--has at least four areas of application: (1) training where the objective of simulation is to provide the trainee with a learning environment that will facilitate…

The Melting Point of Palladium Using Miniature Fixed Points of Different Ceramic Materials: Part II—Analysis of Melting Curves and Long-Term Investigation

NASA Astrophysics Data System (ADS)

Edler, F.; Huang, K.

2016-12-01

Fifteen miniature fixed-point cells made of three different ceramic crucible materials (Al2O3, ZrO2, and Al2O3(86 %)+ZrO2(14 %)) were filled with pure palladium and used to calibrate type B thermocouples (Pt30 %Rh/Pt6 %Rh). A critical point by using miniature fixed points with small amounts of fixed-point material is the analysis of the melting curves, which are characterized by significant slopes during the melting process compared to flat melting plateaus obtainable using conventional fixed-point cells. The method of the extrapolated starting point temperature using straight line approximation of the melting plateau was applied to analyze the melting curves. This method allowed an unambiguous determination of an electromotive force (emf) assignable as melting temperature. The strict consideration of two constraints resulted in a unique, repeatable and objective method to determine the emf at the melting temperature within an uncertainty of about 0.1 μ V. The lifetime and long-term stability of the miniature fixed points was investigated by performing more than 100 melt/freeze cycles for each crucible of the different ceramic materials. No failure of the crucibles occurred indicating an excellent mechanical stability of the investigated miniature cells. The consequent limitation of heating rates to values below {± }3.5 K min^{-1} above 1100° C and the carefully and completely filled crucibles (the liquid palladium occupies the whole volume of the crucible) are the reasons for successfully preventing the crucibles from breaking. The thermal stability of the melting temperature of palladium was excellent when using the crucibles made of Al2O3(86 %)+ZrO2(14 %) and ZrO2. Emf drifts over the total duration of the long-term investigation were below a temperature equivalent of about 0.1 K-0.2 K.

Detection of orbital angular momentum using a photonic integrated circuit.

PubMed

Rui, Guanghao; Gu, Bing; Cui, Yiping; Zhan, Qiwen

2016-06-20

Orbital angular momentum (OAM) state of photons offer an attractive additional degree of freedom that has found a variety of applications. Measurement of OAM state, which is a critical task of these applications, demands photonic integrated devices for improved fidelity, miniaturization, and reconfiguration. Here we report the design of a silicon-integrated OAM receiver that is capable of detecting distinct and variable OAM states. Furthermore, the reconfiguration capability of the detector is achieved by applying voltage to the GeSe film to form gratings with alternate states. The resonant wavelength for arbitrary OAM state is demonstrated to be tunable in a quasi-linear manner through adjusting the duty cycle of the gratings. This work provides a viable approach for the realization of a compact integrated OAM detection device with enhanced functionality that may find important applications in optical communications and information processing with OAM states.

Full 3D modelling of pulse propagation enables efficient nonlinear frequency conversion with low energy laser pulses in a single-element tripler.

PubMed

Kardaś, Tomasz M; Nejbauer, Michał; Wnuk, Paweł; Resan, Bojan; Radzewicz, Czesław; Wasylczyk, Piotr

2017-02-22

Although new optical materials continue to open up access to more and more wavelength bands where femtosecond laser pulses can be generated, light frequency conversion techniques are still indispensable in filling the gaps on the ultrafast spectral scale. With high repetition rate, low pulse energy laser sources (oscillators) tight focusing is necessary for a robust wave mixing and the efficiency of broadband nonlinear conversion is limited by diffraction as well as spatial and temporal walk-off. Here we demonstrate a miniature third harmonic generator (tripler) with conversion efficiency exceeding 30%, producing 246 fs UV pulses via cascaded second order processes within a single laser beam focus. Designing this highly efficient and ultra compact frequency converter was made possible by full 3-dimentional modelling of propagation of tightly focused, broadband light fields in nonlinear and birefringent media.

A novel piezo vibration platform for probe dynamic performance calibration

NASA Astrophysics Data System (ADS)

Liang, Rong; Jusko, Otto; Lüdicke, Frank; Neugebauer, Michael

2001-09-01

A novel piezo vibration platform of compact size (120×120×120 mm3) for probe dynamic performance calibration has been developed. A piezo tube is employed to generate movement which is measured in real time by a miniature fibre interferometer and close-loop controlled by a fast digital signal processor, thus the calibration can be made traceable to the national length standard. 20 kHz control-loop frequency with 1.71 nm uncertainty has been achieved. The maximum calibration range is 20 µm with 0.3 nm resolution. The piezo vibration platform can generate up to 300 Hz sinusoidal signal and various other waveforms, such as square, triangle and saw tooth. It can also work in sweep mode to shift the frequency up to 100 Hz continuously, which is a very useful function when the amplitude-frequency response of the probe is to be investigated.

Solution-Grown ZnO Films toward Transparent and Smart Dual-Color Light-Emitting Diode.

PubMed

Huang, Xiaohu; Zhang, Li; Wang, Shijie; Chi, Dongzhi; Chua, Soo Jin

2016-06-22

An individual light-emitting diode (LED) capable of emitting different colors of light under different bias conditions not only allows for compact device integration but also extends the functionality of the LED beyond traditional illumination and display. Herein, we report a color-switchable LED based on solution-grown n-type ZnO on p-GaN/n-GaN heterojunction. The LED emits red light with a peak centered at ∼692 nm and a full width at half-maximum of ∼90 nm under forward bias, while it emits green light under reverse bias. These two lighting colors can be switched repeatedly by reversing the bias polarity. The bias-polarity-switched dual-color LED enables independent control over the lighting color and brightness of each emission with two-terminal operation. The results offer a promising strategy toward transparent, miniaturized, and smart LEDs, which hold great potential in optoelectronics and optical communication.

Full 3D modelling of pulse propagation enables efficient nonlinear frequency conversion with low energy laser pulses in a single-element tripler

NASA Astrophysics Data System (ADS)

Kardaś, Tomasz M.; Nejbauer, Michał; Wnuk, Paweł; Resan, Bojan; Radzewicz, Czesław; Wasylczyk, Piotr

2017-02-01

Although new optical materials continue to open up access to more and more wavelength bands where femtosecond laser pulses can be generated, light frequency conversion techniques are still indispensable in filling the gaps on the ultrafast spectral scale. With high repetition rate, low pulse energy laser sources (oscillators) tight focusing is necessary for a robust wave mixing and the efficiency of broadband nonlinear conversion is limited by diffraction as well as spatial and temporal walk-off. Here we demonstrate a miniature third harmonic generator (tripler) with conversion efficiency exceeding 30%, producing 246 fs UV pulses via cascaded second order processes within a single laser beam focus. Designing this highly efficient and ultra compact frequency converter was made possible by full 3-dimentional modelling of propagation of tightly focused, broadband light fields in nonlinear and birefringent media.

Sub-micrometer epsilon-near-zero electroabsorption modulators enabled by high-mobility cadmium oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campione, Salvatore; Wood, Michael; Serkland, Darwin K.

Here, epsilon-near-zero materials provide a new path for tailoring light-matter interactions at the nanoscale. In this paper, we analyze a compact electroabsorption modulator based on epsilon-near-zero confinement in transparent conducting oxide films. The non-resonant modulator operates through field-effect carrier density tuning. We compare the performance of modulators composed of two different conducting oxides, namely indium oxide (In2O3) and cadmium oxide (CdO), and show that better modulation performance is achieved when using high-mobility (i.e. low-loss) epsilon-near-zero materials such as CdO. In particular, we show that non-resonant electroabsorption modulators with sub-micron lengths and greater than 5 dB extinction ratios may be achievedmore » through the proper selection of high-mobility transparent conducting oxides, opening a path for device miniaturization and increased modulation depth.« less

Nanophotonic Image Sensors

PubMed Central

Hu, Xin; Wen, Long; Yu, Yan; Cumming, David R. S.

2016-01-01

The increasing miniaturization and resolution of image sensors bring challenges to conventional optical elements such as spectral filters and polarizers, the properties of which are determined mainly by the materials used, including dye polymers. Recent developments in spectral filtering and optical manipulating techniques based on nanophotonics have opened up the possibility of an alternative method to control light spectrally and spatially. By integrating these technologies into image sensors, it will become possible to achieve high compactness, improved process compatibility, robust stability and tunable functionality. In this Review, recent representative achievements on nanophotonic image sensors are presented and analyzed including image sensors with nanophotonic color filters and polarizers, metamaterial‐based THz image sensors, filter‐free nanowire image sensors and nanostructured‐based multispectral image sensors. This novel combination of cutting edge photonics research and well‐developed commercial products may not only lead to an important application of nanophotonics but also offer great potential for next generation image sensors beyond Moore's Law expectations. PMID:27239941

Design of miniaturized illumination for transvaginal co-registered photoacoustic and ultrasound imaging.

PubMed

Salehi, Hassan S; Wang, Tianheng; Kumavor, Patrick D; Li, Hai; Zhu, Quing

2014-09-01

A novel lens-array based illumination design for a compact co-registered photoacoustic/ultrasound transvaginal probe has been demonstrated. The lens array consists of four cylindrical lenses that couple the laser beams into four 1-mm-core multi-mode optical fibers with optical coupling efficiency of ~87%. The feasibility of our lens array was investigated by simulating the lenses and laser beam profiles using Zemax. The laser fluence on the tissue surface was experimentally measured and was below the American National Standards Institute (ANSI) safety limit. Spatial distribution of hemoglobin oxygen saturation (sO2) of a mouse tumor was obtained in vivo using photoacoustic measurements at multiple wavelengths. Furthermore, benign and malignant ovaries were imaged ex vivo and evaluated histologically. The co-registered images clearly showed different patterns of blood vasculature. These results highlight the clinical potential of our system for noninvasive photoacoustic and ultrasound imaging of ovarian tissue and cancer detection and diagnosis.

Design and Demonstration of a Miniature Lidar System for Rover Applications

NASA Technical Reports Server (NTRS)

Robinson, Benjamin

2011-01-01

Public awareness of harmful human environmental effects such as global warming has increased greatly in recent years and researchers have increased their efforts in gaining more knowledge about the Earth's atmosphere. Natural and man-made processes pose threats to the environment and human life, so knowledge of all atmospheric processes is necessary. Ozone and aerosols are important factors in many atmospheric processes and active remote sensing techniques provide a way to analyze their quantity and distribution. A compact ground-based lidar system for a robotic platform meant for atmospheric aerosol measurements was designed, tested, and evaluated. The system will eventually be deployed for ozone and aerosol measurements in Mars and lunar missions to improve our knowledge and understanding of atmospheres on Mars and the Moon. Atmospheric testing was performed to test the operability of the receiver system to acquire the lidar return signal from clouds and aerosols.

An Embedded Reconfigurable Logic Module

NASA Technical Reports Server (NTRS)

Tucker, Jerry H.; Klenke, Robert H.; Shams, Qamar A. (Technical Monitor)

2002-01-01

A Miniature Embedded Reconfigurable Computer and Logic (MERCAL) module has been developed and verified. MERCAL was designed to be a general-purpose, universal module that that can provide significant hardware and software resources to meet the requirements of many of today's complex embedded applications. This is accomplished in the MERCAL module by combining a sub credit card size PC in a DIMM form factor with a XILINX Spartan I1 FPGA. The PC has the ability to download program files to the FPGA to configure it for different hardware functions and to transfer data to and from the FPGA via the PC's ISA bus during run time. The MERCAL module combines, in a compact package, the computational power of a 133 MHz PC with up to 150,000 gate equivalents of digital logic that can be reconfigured by software. The general architecture and functionality of the MERCAL hardware and system software are described.

Low-cost rapid miniature optical pressure sensors for blast wave measurements.

PubMed

Wu, Nan; Wang, Wenhui; Tian, Ye; Zou, Xiaotian; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

2011-05-23

This paper presents an optical pressure sensor based on a Fabry-Perot (FP) interferometer formed by a 45° angle polished single mode fiber and an external silicon nitride diaphragm. The sensor is comprised of two V-shape grooves with different widths on a silicon chip, a silicon nitride diaphragm released on the surface of the wider V-groove, and a 45° angle polished single mode fiber. The sensor is especially suitable for blast wave measurements: its compact structure ensures a high spatial resolution; its thin diaphragm based design and the optical demodulation scheme allow a fast response to the rapid changing signals experienced during blast events. The sensor shows linearity with the correlation coefficient of 0.9999 as well as a hysteresis of less than 0.3%. The shock tube test demonstrated that the sensor has a rise time of less than 2 µs from 0 kPa to 140 kPa.

Optical and Electronic NO(x) Sensors for Applications in Mechatronics.

PubMed

Di Franco, Cinzia; Elia, Angela; Spagnolo, Vincenzo; Scamarcio, Gaetano; Lugarà, Pietro Mario; Ieva, Eliana; Cioffi, Nicola; Torsi, Luisa; Bruno, Giovanni; Losurdo, Maria; Garcia, Michael A; Wolter, Scott D; Brown, April; Ricco, Mario

2009-01-01

Current production and emerging NO(x) sensors based on optical and nanomaterials technologies are reviewed. In view of their potential applications in mechatronics, we compared the performance of: i) Quantum cascade lasers (QCL) based photoacoustic (PA) systems; ii) gold nanoparticles as catalytically active materials in field-effect transistor (FET) sensors, and iii) functionalized III-V semiconductor based devices. QCL-based PA sensors for NO(x) show a detection limit in the sub part-per-million range and are characterized by high selectivity and compact set-up. Electrochemically synthesized gold-nanoparticle FET sensors are able to monitor NO(x) in a concentration range from 50 to 200 parts per million and are suitable for miniaturization. Porphyrin-functionalized III-V semiconductor materials can be used for the fabrication of a reliable NO(x) sensor platform characterized by high conductivity, corrosion resistance, and strong surface state coupling.

III-V-on-Silicon Photonic Integrated Circuits for Spectroscopic Sensing in the 2-4 μm Wavelength Range.

PubMed

Wang, Ruijun; Vasiliev, Anton; Muneeb, Muhammad; Malik, Aditya; Sprengel, Stephan; Boehm, Gerhard; Amann, Markus-Christian; Šimonytė, Ieva; Vizbaras, Augustinas; Vizbaras, Kristijonas; Baets, Roel; Roelkens, Gunther

2017-08-04

The availability of silicon photonic integrated circuits (ICs) in the 2-4 μm wavelength range enables miniature optical sensors for trace gas and bio-molecule detection. In this paper, we review our recent work on III-V-on-silicon waveguide circuits for spectroscopic sensing in this wavelength range. We first present results on the heterogeneous integration of 2.3 μm wavelength III-V laser sources and photodetectors on silicon photonic ICs for fully integrated optical sensors. Then a compact 2 μm wavelength widely tunable external cavity laser using a silicon photonic IC for the wavelength selective feedback is shown. High-performance silicon arrayed waveguide grating spectrometers are also presented. Further we show an on-chip photothermal transducer using a suspended silicon-on-insulator microring resonator used for mid-infrared photothermal spectroscopy.

Optical cascaded Fabry-Perot interferometer hydrogen sensor based on vernier effect

NASA Astrophysics Data System (ADS)

Li, Yina; Zhao, Chunliu; Xu, Ben; Wang, Dongning; Yang, Minghong

2018-05-01

An optical cascaded Fabry-Perot interferometer hydrogen sensor based on vernier effect has been proposed and achieved. The proposed sensor, which total length is ∼594 μm, is composed of a segment of large mode area fiber (LMAF) and a segment of hollow-core fiber (HCF). The proposed sensor is coated with the Pt-loaded WO3/SiO2 powder which will result in the increase of local temperature of the sensor head when exposed to hydrogen atmosphere. Thus the hydrogen sensor can be achieved by monitoring the change of resonant envelope wavelength. The hydrogen sensitivity is -1.04 nm/% within the range of 0 % -2.4 % which is greatly improved because of the vernier effect. The response time is ∼80 s. Due to its compact configuration, the proposed sensor provides a feasible and miniature structure to achieve detection of hydrogen.

See-through ophthalmoscope for retinal imaging

NASA Astrophysics Data System (ADS)

Carpentras, Dino; Moser, Christophe

2017-05-01

With the miniaturization of scanning mirrors and the emergence of wearable health monitoring, an intriguing step is to investigate the potential of a laser scanning ophthalmoscope (LSO) for retinal imaging with wearable glasses. In addition to providing morphological information of the retina, such as vasculature, LSO images could also be used to provide information on general health conditions. A compact eyeglass with LSO capability would give access, on demand, to retinal parameters without disturbing the subject's activity. One of the main challenges in this field is the creation of a device that does not interrupt the user's field of view. We report, to our knowledge, the first see-through ophthalmoscope. The system is analyzed with three-dimensional simulations and tested in a proof-of-concept setup with the same key parameters of a wearable device. Finally, image quality is analyzed by acquiring images of an ex-vivo human eye sample.

Highly sensitive in-line microfluidic sensor based on microfiber-assisted Mach-Zehnder interferometer for glucose sensing

NASA Astrophysics Data System (ADS)

Xie, Nanjie; Zhang, Hao; Liu, Bo; Wu, Jixuan; Song, Binbin; Han, Tingting

2017-11-01

A highly sensitive microfluidic sensor based on a microfiber-assisted Mach-Zehnder interferometer (MAMZI) is proposed and experimentally demonstrated for the detection of low-concentration glucose solution. A segment of microfiber tapered from standard single-mode fiber (SMF) is spliced between two SMFs with pre-designed lateral offset to constitute the miniaturized MAMZI probe. The transmission spectral response to environmental refractive index variation has been experimentally investigated for glucose concentration ranges of 300 mg dL-1 to 3000 mg dL-1 and 0 to 270 mg dL-1 and the glucose concentration detection limit is 3 mg dL-1, and the experimentally observed transmission spectral responses are in accordance with our theoretical simulation results. Owing to its high sensitivity, non-enzymatic operation method, ease of fabrication and compact size, our proposed MAMZI for glucose sensing is anticipated to be employed in biomedical applications.

Sub-micrometer epsilon-near-zero electroabsorption modulators enabled by high-mobility cadmium oxide

DOE PAGES

Campione, Salvatore; Wood, Michael; Serkland, Darwin K.; ...

2017-07-06

Here, epsilon-near-zero materials provide a new path for tailoring light-matter interactions at the nanoscale. In this paper, we analyze a compact electroabsorption modulator based on epsilon-near-zero confinement in transparent conducting oxide films. The non-resonant modulator operates through field-effect carrier density tuning. We compare the performance of modulators composed of two different conducting oxides, namely indium oxide (In2O3) and cadmium oxide (CdO), and show that better modulation performance is achieved when using high-mobility (i.e. low-loss) epsilon-near-zero materials such as CdO. In particular, we show that non-resonant electroabsorption modulators with sub-micron lengths and greater than 5 dB extinction ratios may be achievedmore » through the proper selection of high-mobility transparent conducting oxides, opening a path for device miniaturization and increased modulation depth.« less

Hydrogen generation from biogenic and fossil fuels by autothermal reforming

NASA Astrophysics Data System (ADS)

Rampe, Thomas; Heinzel, Angelika; Vogel, Bernhard

Hydrogen generation for fuel cell systems by reforming technologies from various fuels is one of the main fields of investigation of the Fraunhofer ISE. Suitable fuels are, on the one hand, gaseous hydrocarbons like methane, propane but also, on the other hand, liquid hydrocarbons like gasoline and alcohols, e.g., ethanol as biogenic fuel. The goal is to develop compact systems for generation of hydrogen from fuel being suitable for small-scale membrane fuel cells. The most recent work is related to reforming according to the autothermal principle — fuel, air and steam is supplied to the reactor. Possible applications of such small-scale autothermal reformers are mobile systems and also miniature fuel cell as co-generation plant for decentralised electricity and heat generation. For small stand-alone systems without a connection to the natural gas grid liquid gas, a mixture of propane and butane is an appropriate fuel.

III–V-on-Silicon Photonic Integrated Circuits for Spectroscopic Sensing in the 2–4 μm Wavelength Range

PubMed Central

Wang, Ruijun; Vasiliev, Anton; Muneeb, Muhammad; Malik, Aditya; Sprengel, Stephan; Boehm, Gerhard; Amann, Markus-Christian; Šimonytė, Ieva; Vizbaras, Augustinas; Vizbaras, Kristijonas; Baets, Roel; Roelkens, Gunther

2017-01-01

The availability of silicon photonic integrated circuits (ICs) in the 2–4 μm wavelength range enables miniature optical sensors for trace gas and bio-molecule detection. In this paper, we review our recent work on III–V-on-silicon waveguide circuits for spectroscopic sensing in this wavelength range. We first present results on the heterogeneous integration of 2.3 μm wavelength III–V laser sources and photodetectors on silicon photonic ICs for fully integrated optical sensors. Then a compact 2 μm wavelength widely tunable external cavity laser using a silicon photonic IC for the wavelength selective feedback is shown. High-performance silicon arrayed waveguide grating spectrometers are also presented. Further we show an on-chip photothermal transducer using a suspended silicon-on-insulator microring resonator used for mid-infrared photothermal spectroscopy. PMID:28777291

Non-contact local temperature measurement inside an object using an infrared point detector

NASA Astrophysics Data System (ADS)

Hisaka, Masaki

2017-04-01

Local temperature measurement in deep areas of objects is an important technique in biomedical measurement. We have investigated a non-contact method for measuring temperature inside an object using a point detector for infrared (IR) light. An IR point detector with a pinhole was constructed and the radiant IR light emitted from the local interior of the object is photodetected only at the position of pinhole located in imaging relation. We measured the thermal structure of the filament inside the miniature bulb using the IR point detector, and investigated the temperature dependence at approximately human body temperature using a glass plate positioned in front of the heat source.

Accreting Compact Object at the Center of the Supernova Remnant RCW 103.

NASA Astrophysics Data System (ADS)

Sanwal, D.; Garmire, G. P.; Garmire, A.; Pavlov, G. G.; Mignani, R.

2002-05-01

We observed the radio-quiet central compact object of the supernova remnant RCW 103 with the Chandra ACIS during 13.8 hours on 2002 March 3, when the source was in high state, with a time-averaged flux of 8*E-12 erg cm-2 s-1 in the 0.5--8.0 keV band. The complex light curve of the source shows a period of about 6.4 hours and two partial eclipses or dips per period, separated by 180o in phase. The variability of the source proves that it is powered by accretion, likely from a low-mass companion in a binary system. Deep near-IR observations of the source with VLT suggest a potential counterpart of the compact object about 2'' from the nominal Chandra position. The magnitudes of the potential counterpart are J ≈ 22.3, H ≈ 19.6, and Ks ≈ 18.5, with an uncertainty of about 0.5 mag. We will discuss possible interpretations of the observational results. This work was partially supported by NASA grants NAS8-01128 and NAG5-10865.

A POSSIBLE SIGNATURE OF LENSE-THIRRING PRECESSION IN DIPPING AND ECLIPSING NEUTRON-STAR LOW-MASS X-RAY BINARIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Homan, Jeroen, E-mail: jeroen@space.mit.edu

2012-12-01

Relativistic Lense-Thirring precession of a tilted inner accretion disk around a compact object has been proposed as a mechanism for low-frequency ({approx}0.01-70 Hz) quasi-periodic oscillations (QPOs) in the light curves of X-ray binaries. A substantial misalignment angle ({approx}15 Degree-Sign -20 Degree-Sign ) between the inner-disk rotation axis and the compact-object spin axis is required for the effects of this precession to produce observable modulations in the X-ray light curve. A consequence of this misalignment is that in high-inclination X-ray binaries the precessing inner disk will quasi-periodically intercept our line of sight to the compact object. In the case of neutron-starmore » systems, this should have a significant observational effect, since a large fraction of the accretion energy is released on or near the neutron-star surface. In this Letter, I suggest that this specific effect of Lense-Thirring precession may already have been observed as {approx}1 Hz QPOs in several dipping/eclipsing neutron-star X-ray binaries.« less

Base compaction specification feasibility analysis.

DOT National Transportation Integrated Search

2012-12-01

The objective of this research is to establish the technical engineering and cost : analysis concepts that will enable WisDOT management to objectively evaluate the : feasibility of switching construction specification philosophies for aggregate base...

Compaction of quasi-one-dimensional elastoplastic materials.

PubMed

Shaebani, M Reza; Najafi, Javad; Farnudi, Ali; Bonn, Daniel; Habibi, Mehdi

2017-06-06

Insight into crumpling or compaction of one-dimensional objects is important for understanding biopolymer packaging and designing innovative technological devices. By compacting various types of wires in rigid confinements and characterizing the morphology of the resulting crumpled structures, here, we report how friction, plasticity and torsion enhance disorder, leading to a transition from coiled to folded morphologies. In the latter case, where folding dominates the crumpling process, we find that reducing the relative wire thickness counter-intuitively causes the maximum packing density to decrease. The segment size distribution gradually becomes more asymmetric during compaction, reflecting an increase of spatial correlations. We introduce a self-avoiding random walk model and verify that the cumulative injected wire length follows a universal dependence on segment size, allowing for the prediction of the efficiency of compaction as a function of material properties, container size and injection force.

Miniature photometric stereo system for textile surface structure reconstruction

NASA Astrophysics Data System (ADS)

Gorpas, Dimitris; Kampouris, Christos; Malassiotis, Sotiris

2013-04-01

In this work a miniature photometric stereo system is presented, targeting the three-dimensional structural reconstruction of various fabric types. This is a supportive module to a robot system, attempting to solve the well known "laundry problem". The miniature device has been designed for mounting onto the robot gripper. It is composed of a low-cost off-the-shelf camera, operating in macro mode, and eight light emitting diodes. The synchronization between image acquisition and lighting direction is controlled by an Arduino Nano board and software triggering. The ambient light has been addressed by a cylindrical enclosure. The direction of illumination is recovered by locating the reflection or the brightest point on a mirror sphere, while a flatfielding process compensates for the non-uniform illumination. For the evaluation of this prototype, the classical photometric stereo methodology has been used. The preliminary results on a large number of textiles are very promising for the successful integration of the miniature module to the robot system. The required interaction with the robot is implemented through the estimation of the Brenner's focus measure. This metric successfully assesses the focus quality with reduced time requirements in comparison to other well accepted focus metrics. Besides the targeting application, the small size of the developed system makes it a very promising candidate for applications with space restrictions, like the quality control in industrial production lines or object recognition based on structural information and in applications where easiness in operation and light-weight are required, like those in the Biomedical field, and especially in dermatology.

Towards next generation time-domain diffuse optics devices

NASA Astrophysics Data System (ADS)

Dalla Mora, Alberto; Contini, Davide; Arridge, Simon R.; Martelli, Fabrizio; Tosi, Alberto; Boso, Gianluca; Farina, Andrea; Durduran, Turgut; Martinenghi, Edoardo; Torricelli, Alessandro; Pifferi, Antonio

2015-03-01

Diffuse Optics is growing in terms of applications ranging from e.g. oximetry, to mammography, molecular imaging, quality assessment of food and pharmaceuticals, wood optics, physics of random media. Time-domain (TD) approaches, although appealing in terms of quantitation and depth sensibility, are presently limited to large fiber-based systems, with limited number of source-detector pairs. We present a miniaturized TD source-detector probe embedding integrated laser sources and single-photon detectors. Some electronics are still external (e.g. power supply, pulse generators, timing electronics), yet full integration on-board using already proven technologies is feasible. The novel devices were successfully validated on heterogeneous phantoms showing performances comparable to large state-of-the-art TD rack-based systems. With an investigation based on simulations we provide numerical evidence that the possibility to stack many TD compact source-detector pairs in a dense, null source-detector distance arrangement could yield on the brain cortex about 1 decade higher contrast as compared to a continuous wave (CW) approach. Further, a 3-fold increase in the maximum depth (down to 6 cm) is estimated, opening accessibility to new organs such as the lung or the heart. Finally, these new technologies show the way towards compact and wearable TD probes with orders of magnitude reduction in size and cost, for a widespread use of TD devices in real life.

A Compact and Low-Cost MEMS Loudspeaker for Digital Hearing Aids.

PubMed

Sang-Soo Je; Rivas, F; Diaz, R E; Jiuk Kwon; Jeonghwan Kim; Bakkaloglu, B; Kiaei, S; Junseok Chae

2009-10-01

A microelectromechanical-systems (MEMS)-based electromagnetically actuated loudspeaker to reduce form factor, cost, and power consumption, and increase energy efficiency in hearing-aid applications is presented. The MEMS loudspeaker has multilayer copper coils, an NiFe soft magnet on a thin polyimide diaphragm, and an NdFeB permanent magnet on the perimeter. The coil impedance is measured at 1.5 Omega, and the resonant frequency of the diaphragm is located far from the audio frequency range. The device is driven by a power-scalable, 0.25-mum complementary metal-oxide semiconductor class-D SigmaDelta amplifier stage. The class-D amplifier is formed by a differential H-bridge driven by a single bit, pulse-density-modulated SigmaDelta bitstream at a 1.2-MHz clock rate. The fabricated MEMS loudspeaker generates more than 0.8-mum displacement, equivalent to 106-dB sound pressure level (SPL), with 0.13-mW power consumption. Driven by the SigmaDelta class-D amplifier, the MEMS loudspeaker achieves measured 65-dB total harmonic distortion (THD) with a measurement uncertainty of less than 10%. Energy-efficient and cost-effective advanced hearing aids would benefit from further miniaturization via MEMS technology. The results from this study appear very promising for developing a compact, mass-producible, low-power loudspeaker with sufficient sound generation for hearing-aid applications.

A Colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) Detection Platform for a Point-of-Care Dengue Detection System on a Lab-on-Compact-Disc.

PubMed

Thiha, Aung; Ibrahim, Fatimah

2015-05-18

The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings.

Tidal deformability and I-Love-Q relations for gravastars with polytropic thin shells

NASA Astrophysics Data System (ADS)

Uchikata, Nami; Yoshida, Shijun; Pani, Paolo

2016-09-01

The moment of inertia, the spin-induced quadrupole moment, and the tidal Love number of neutron-star and quark-star models are related through some relations which depend only mildly on the stellar equation of state. These "I-Love-Q" relations have important implications for astrophysics and gravitational-wave astronomy. An interesting problem is whether similar relations hold for other compact objects and how they approach the black hole limit. To answer these questions, here we investigate the deformation properties of a large class of thin-shell gravastars, which are exotic compact objects that do not possess an event horizon nor a spacetime singularity. Working in a small-spin and small-tidal field expansion, we calculate the moment of inertia, the quadrupole moment, and the (quadrupolar electric) tidal Love number of gravastars with a polytropic thin shell. The I-Love-Q relations of a thin-shell gravastar are drastically different from those of an ordinary neutron star. The Love number and quadrupole moment for less compact models have the opposite sign relative to those of ordinary neutron stars, and the I-Love-Q relations continuously approach the black hole limit. We consider a variety of polytropic equations of state for the matter shell and find no universality in the I-Love-Q relations. However, we cannot deny the possibility that, similarly to the neutron-star case, an approximate universality might emerge for a limited class of equations of state. Finally, we discuss how a measurement of the tidal deformability from the gravitational-wave detection of a compact-binary inspiral can be used to constrain exotic compact objects like gravastars.

Circular common-path point diffraction interferometer.

PubMed

Du, Yongzhao; Feng, Guoying; Li, Hongru; Vargas, J; Zhou, Shouhuan

2012-10-01

A simple and compact point-diffraction interferometer with circular common-path geometry configuration is developed. The interferometer is constructed by a beam-splitter, two reflection mirrors, and a telescope system composed by two lenses. The signal and reference waves travel along the same path. Furthermore, an opaque mask containing a reference pinhole and a test object holder or test window is positioned in the common focal plane of the telescope system. The object wave is divided into two beams that take opposite paths along the interferometer. The reference wave is filtered by the reference pinhole, while the signal wave is transmitted through the object holder. The reference and signal waves are combined again in the beam-splitter and their interference is imaged in the CCD. The new design is compact, vibration insensitive, and suitable for the measurement of moving objects or dynamic processes.

Identification of the central compact object in the young supernova remnant 1E 0102.2-7219

NASA Astrophysics Data System (ADS)

Vogt, Frédéric P. A.; Bartlett, Elizabeth S.; Seitenzahl, Ivo R.; Dopita, Michael A.; Ghavamian, Parviz; Ruiter, Ashley J.; Terry, Jason P.

2018-04-01

Oxygen-rich young supernova remnants1 are valuable objects for probing the outcome of nucleosynthetic processes in massive stars, as well as the physics of supernova explosions. Observed within a few thousand years after the supernova explosion2, these systems contain fast-moving oxygen-rich and hydrogen-poor filaments visible at optical wavelengths: fragments of the progenitor's interior expelled at a few thousand kilometres per second during the supernova explosion. Here we report the identification of the compact object in the supernova remnant 1E 0102.2-7219 in reprocessed Chandra X-ray Observatory data, enabled by the discovery of a ring-shaped structure visible primarily in optical recombination lines of Ne i and O i. The optical ring has a radius of (2.10 ± 0.35)″ ≡ (0.63 ± 0.11) pc, and is expanding at a velocity of 90 .5-30+40 km s-1. It surrounds an X-ray point source with an intrinsic X-ray luminosity Li (1.2-2.0 keV) = (1.4 ± 0.2) × 1033 erg s-1. The energy distribution of the source indicates that this object is an isolated neutron star: a central compact object akin to those present in the Cas A3-5 and Pup A6 supernova remnants, and the first of its kind to be identified outside of our Galaxy.

Identification of the central compact object in the young supernova remnant 1E 0102.2-7219

NASA Astrophysics Data System (ADS)

Vogt, Frédéric P. A.; Bartlett, Elizabeth S.; Seitenzahl, Ivo R.; Dopita, Michael A.; Ghavamian, Parviz; Ruiter, Ashley J.; Terry, Jason P.

2018-06-01

Oxygen-rich young supernova remnants1 are valuable objects for probing the outcome of nucleosynthetic processes in massive stars, as well as the physics of supernova explosions. Observed within a few thousand years after the supernova explosion2, these systems contain fast-moving oxygen-rich and hydrogen-poor filaments visible at optical wavelengths: fragments of the progenitor's interior expelled at a few thousand kilometres per second during the supernova explosion. Here we report the identification of the compact object in the supernova remnant 1E 0102.2-7219 in reprocessed Chandra X-ray Observatory data, enabled by the discovery of a ring-shaped structure visible primarily in optical recombination lines of Ne i and O i. The optical ring has a radius of (2.10 ± 0.35)″ ≡ (0.63 ± 0.11) pc, and is expanding at a velocity of 90 .5-30+40 km s-1. It surrounds an X-ray point source with an intrinsic X-ray luminosity Li (1.2-2.0 keV) = (1.4 ± 0.2) × 1033 erg s-1. The energy distribution of the source indicates that this object is an isolated neutron star: a central compact object akin to those present in the Cas A3-5 and Pup A6 supernova remnants, and the first of its kind to be identified outside of our Galaxy.

Results from a multi aperture Fizeau interferometer ground testbed: demonstrator for a future space-based interferometer

NASA Astrophysics Data System (ADS)

Baccichet, Nicola; Caillat, Amandine; Rakotonimbahy, Eddy; Dohlen, Kjetil; Savini, Giorgio; Marcos, Michel

2016-08-01

In the framework of the European FP7-FISICA (Far Infrared Space Interferometer Critical Assessment) program, we developed a miniaturized version of the hyper-telescope to demonstrate multi-aperture interferometry on ground. This setup would be ultimately integrated into a CubeSat platform, therefore providing the first real demonstrator of a multi aperture Fizeau interferometer in space. In this paper, we describe the optical design of the ground testbed and the data processing pipeline implemented to reconstruct the object image from interferometric data. As a scientific application, we measured the Sun diameter by fitting a limb-darkening model to our data. Finally, we present the design of a CubeSat platform carrying this miniature Fizeau interferometer, which could be used to monitor the Sun diameter over a long in-orbit period.