A YOUNG SCIENTIST'S GUIDE TO GAINFUL EMPLOYMENT: RECENT GRADUATES' EXPERIENCES AND SUCCESSFUL STRATEGIES

EPA Science Inventory

Securing a job after completing a graduate degree is among a graduate student's most rewarding (and most stressful) experiences. The job hunting process, from submitting an application to signing a contract, varies greatly among individuals. It is difficult for any applicant to a...

Intelligent Processing Equipment Projects at DLA

NASA Technical Reports Server (NTRS)

Obrien, Donald F.

1992-01-01

The Defense Logistics Agency is successfully incorporating Intelligent Processing Equipment (IPE) into each of its Manufacturing Technology thrust areas. Several IPE applications are addressed in the manufacturing of two 'soldier support' items: combat rations and military apparel. In combat rations, in-line sensors for food processing are being developed or modified from other industries. In addition, many process controls are being automated to achieve better quality and to gain higher use (soldier) acceptance. IPE applications in military apparel include: in-process quality controls for identification of sewing defects, use of robots in the manufacture of shirt collars, and automated handling of garments for pressing.

Intelligent processing equipment projects at DLA

NASA Astrophysics Data System (ADS)

Obrien, Donald F.

1992-04-01

The Defense Logistics Agency is successfully incorporating Intelligent Processing Equipment (IPE) into each of its Manufacturing Technology thrust areas. Several IPE applications are addressed in the manufacturing of two 'soldier support' items: combat rations and military apparel. In combat rations, in-line sensors for food processing are being developed or modified from other industries. In addition, many process controls are being automated to achieve better quality and to gain higher use (soldier) acceptance. IPE applications in military apparel include: in-process quality controls for identification of sewing defects, use of robots in the manufacture of shirt collars, and automated handling of garments for pressing.

High-Temperature Oxidation Behavior of Two Nickel-Based Superalloys Produced by Metal Injection Molding for Aero Engine Applications

NASA Astrophysics Data System (ADS)

Albert, Benedikt; Völkl, Rainer; Glatzel, Uwe

2014-09-01

For different high-temperature applications like aero engines or turbochargers, metal injection molding (MIM) of superalloys is an interesting processing alternative. For operation at high temperatures, oxidation behavior of superalloys produced by MIM needs to match the standard of cast or forged material. The oxidation behavior of nickel-based superalloys Inconel 713 and MAR-M247 in the temperature interval from 1073 K to 1373 K (800 °C to 1100 °C) is investigated and compared to cast material. Weight gain is measured discontinuously at different oxidation temperatures and times. Analysis of oxidized samples is done via SEM and EDX-measurements. MIM samples exhibit homogeneous oxide layers with a thickness up to 4 µm. After processing by MIM, Inconel 713 exhibits lower weight gain and thinner oxide layers than MAR-M247.

Wave-mixing-induced transparency with zero phase shift in atomic vapors

NASA Astrophysics Data System (ADS)

Zhou, F.; Zhu, C. J.; Li, Y.

2017-12-01

We present a wave-mixing induced transparency that can lead to a hyper-Raman gain-clamping effect. This new type of transparency is originated from a dynamic gain cancellation effect in a multiphoton process where a highly efficient light field of new frequency is generated and amplified. We further show that this novel dynamic gain cancellation effect not only makes the medium transparent to a probe light field at appropriate frequency but also eliminates the probe field propagation phase shift. This gain-cancellation-based induced transparency holds for many potential applications on optical communication and may lead to effective suppression of parasitic Raman/hyper-Raman noise field generated in high intensity optical fiber transmissions.

Frequency non-degenerate phase-sensitive optical parametric amplification based on four-wave-mixing in width-modulated silicon waveguides.

PubMed

Wang, Zhaolu; Liu, Hongjun; Sun, Qibing; Huang, Nan; Li, Xuefeng

2014-12-15

A width-modulated silicon waveguide is proposed to realize non-degenerate phase sensitive optical parametric amplification. It is found that the relative phase at the input of the phase sensitive amplifier (PSA) θIn-PSA can be tuned by tailoring the width and length of the second segment of the width-modulated silicon waveguide, which will influence the gain in the parametric amplification process. The maximum gain of PSA is larger by 9 dB compared with the phase insensitive amplifier (PIA) gain, and the gain bandwidth of PSA is larger by 35 nm compared with the gain bandwidth of PIA. Our on-chip PSA can find important potential applications in highly integrated optical circuits for optical chip-to-chip communication and computers.

High average power scaleable thin-disk laser

DOEpatents

Beach, Raymond J.; Honea, Eric C.; Bibeau, Camille; Payne, Stephen A.; Powell, Howard; Krupke, William F.; Sutton, Steven B.

2002-01-01

Using a thin disk laser gain element with an undoped cap layer enables the scaling of lasers to extremely high average output power values. Ordinarily, the power scaling of such thin disk lasers is limited by the deleterious effects of amplified spontaneous emission. By using an undoped cap layer diffusion bonded to the thin disk, the onset of amplified spontaneous emission does not occur as readily as if no cap layer is used, and much larger transverse thin disks can be effectively used as laser gain elements. This invention can be used as a high average power laser for material processing applications as well as for weapon and air defense applications.

Proceedings of the ASPE/MSFC Symposium on Engineering and Productivity Gains from Space Technology

NASA Technical Reports Server (NTRS)

1977-01-01

Aerospace technology findings were examined in regard to nonaerospace applications. Studies of energy generation, materials and processes, earth observation as well as advances and benefits of electronics are included.

On Performance of Linear Multiuser Detectors for Wireless Multimedia Applications

NASA Astrophysics Data System (ADS)

Agarwal, Rekha; Reddy, B. V. R.; Bindu, E.; Nayak, Pinki

In this paper, performance of different multi-rate schemes in DS-CDMA system is evaluated. The analysis of multirate linear multiuser detectors with multiprocessing gain is analyzed for synchronous Code Division Multiple Access (CDMA) systems. Variable data rate is achieved by varying the processing gain. Our conclusion is that bit error rate for multirate and single rate systems can be made same with a tradeoff with number of users in linear multiuser detectors.

Application of ICME Methods for the Development of Rapid Manufacturing Technologies

NASA Astrophysics Data System (ADS)

Maiwald-Immer, T.; Göhler, T.; Fischersworring-Bunk, A.; Körner, C.; Osmanlic, F.; Bauereiß, A.

Rapid manufacturing technologies are lately gaining interest as alternative manufacturing method. Due to the large parameter sets applicable in these manufacturing methods and their impact on achievable material properties and quality, support of the manufacturing process development by the use of simulation is highly attractive. This is especially true for aerospace applications with their high quality demands and controlled scatter in the resulting material properties. The applicable simulation techniques to these manufacturing methods are manifold. The paper will focus on the melt pool simulation for a SLM (selective laser melting) process which was originally developed for EBM (electron beam melting). It will be discussed in the overall context of a multi-scale simulation within a virtual process chain.

An amorphous silicon photodiode with 2 THz gain-bandwidth product based on cycling excitation process

NASA Astrophysics Data System (ADS)

Yan, Lujiang; Yu, Yugang; Zhang, Alex Ce; Hall, David; Niaz, Iftikhar Ahmad; Raihan Miah, Mohammad Abu; Liu, Yu-Hsin; Lo, Yu-Hwa

2017-09-01

Since impact ionization was observed in semiconductors over half a century ago, avalanche photodiodes (APDs) using impact ionization in a fashion of chain reaction have been the most sensitive semiconductor photodetectors. However, APDs have relatively high excess noise, a limited gain-bandwidth product, and high operation voltage, presenting a need for alternative signal amplification mechanisms of superior properties. As an amplification mechanism, the cycling excitation process (CEP) was recently reported in a silicon p-n junction with subtle control and balance of the impurity levels and profiles. Realizing that CEP effect depends on Auger excitation involving localized states, we made the counter intuitive hypothesis that disordered materials, such as amorphous silicon, with their abundant localized states, can produce strong CEP effects with high gain and speed at low noise, despite their extremely low mobility and large number of defects. Here, we demonstrate an amorphous silicon low noise photodiode with gain-bandwidth product of over 2 THz, based on a very simple structure. This work will impact a wide range of applications involving optical detection because amorphous silicon, as the primary gain medium, is a low-cost, easy-to-process material that can be formed on many kinds of rigid or flexible substrates.

On the application of hybrid meshes in hydraulic machinery CFD simulations

NASA Astrophysics Data System (ADS)

Schlipf, M.; Tismer, A.; Riedelbauch, S.

2016-11-01

The application of two different hybrid mesh types for the simulation of a Francis runner for automated optimization processes without user input is investigated. Those mesh types are applied to simplified test cases such as flow around NACA airfoils to identify the special mesh resolution effects with reduced complexity, like rotating cascade flows, as they occur in a turbomachine runner channel. The analysis includes the application of those different meshes on the geometries by keeping defined quality criteria and exploring the influences on the simulation results. All results are compared with reference values gained by simulations with blockstructured hexahedron meshes and the same numerical scheme. This avoids additional inaccuracies caused by further numerical and experimental measurement methods. The results show that a simulation with hybrid meshes built up by a blockstructured domain with hexahedrons around the blade in combination with a tetrahedral far field in the channel is sufficient to get results which are almost as accurate as the results gained by the reference simulation. Furthermore this method is robust enough for automated processes without user input and enables comparable meshes in size, distribution and quality for different similar geometries as occurring in optimization processes.

Coherent Pump-Probe Interactions and Terahertz Intersubband Gain in Semiconductor Quantum Wells

NASA Technical Reports Server (NTRS)

Liu, Ansheng; Ning, Cun-Zheng

1999-01-01

In recent years there has been considerable interest in intersubband-transition-based infrared semiconductor quantum well (QW) lasers because of their potential applications. In the mid-infrared range, both electrically-injected quantum cascade lasers [1] and optically-pumped multiple QW lasers [2] have been experimentally realized. In these studies, optical gain is due to population inversion between the lasing subbands. It was also proposed that stimulated Raman scattering in QW systems can produce net infrared optical gain [3j. In such a nonlinear optical scheme, the appearance of optical gain that may lead to intersubband Raman lasers does not rely on the population inversion. Since, in tile resonant Raman process (Raman gain is the largest in this case), the pump field induces population redistribution among subbands in the QW s ystem, it seems that a realistic estimate of the optical gain has to include this effect. Perturbative calculations used in the previous work [3] may overestimate the Raman gain. In this paper we present a nonperturbative calculation of terahertz gain of optically-pumped semiconductor step quantum wells. Limiting optical transitions within the conduction band of QW, we solve the pump-field-induced nonequilibrium distribution function for each subband of the QW system from a set of coupled rate equations. Both intrasubband and intersubband relaxation processes in the quantum well system are included. Taking into account the coherent interactions between pump and THz (signal) waves, we we derive the susceptibility of the QW system for the THz field. For a GaAs/AlGaAs step QW, we calculate the Thz gain spectrum for different pump frequencies and intensities. Under moderately strong pumping (approximately 0.3 MW/sq cm), a significant THz gain (approximately 300/m) is predicted. It is also shown that the coherent wave interactions (resonant stimulated Raman processes) contribute significantly to the THz gain.

Tuning maps for setpoint changes and load disturbance upsets in a three capacity process under multivariable control

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Smith, Ira C.

1991-01-01

Tuning maps are an aid in the controller tuning process because they provide a convenient way for the plant operator to determine the consequences of adjusting different controller parameters. In this application the maps provide a graphical representation of the effect of varying the gains in the state feedback matrix on startup and load disturbance transients for a three capacity process. Nominally, the three tank system, represented in diagonal form, has a Proportional-Integral control on each loop. Cross coupling is then introduced between the loops by using non-zero off-diagonal proportional parameters. Changes in transient behavior due to setpoint and load changes are examined by varying the gains of the cross coupling terms.

Application of Yb:YAG short pulse laser system

DOEpatents

Erbert, Gaylen V.; Biswal, Subrat; Bartolick, Joseph M.; Stuart, Brent C.; Crane, John K.; Telford, Steve; Perry, Michael D.

2004-07-06

A diode pumped, high power (at least 20W), short pulse (up to 2 ps), chirped pulse amplified laser using Yb:YAG as the gain material is employed for material processing. Yb:YAG is used as the gain medium for both a regenerative amplifier and a high power 4-pass amplifier. A single common reflective grating optical device is used to both stretch pulses for amplification purposes and to recompress amplified pulses before being directed to a workpiece.

Hot-melt extrusion--basic principles and pharmaceutical applications.

PubMed

Lang, Bo; McGinity, James W; Williams, Robert O

2014-09-01

Originally adapted from the plastics industry, the use of hot-melt extrusion has gained favor in drug delivery applications both in academia and the pharmaceutical industry. Several commercial products made by hot-melt extrusion have been approved by the FDA, demonstrating its commercial feasibility for pharmaceutical processing. A significant number of research articles have reported on advances made regarding the pharmaceutical applications of the hot-melt extrusion processing; however, only limited articles have been focused on general principles regarding formulation and process development. This review provides an in-depth analysis and discussion of the formulation and processing aspects of hot-melt extrusion. The impact of physicochemical properties of drug substances and excipients on formulation development using a hot-melt extrusion process is discussed from a material science point of view. Hot-melt extrusion process development, scale-up, and the interplay of formulation and process attributes are also discussed. Finally, recent applications of hot-melt extrusion to a variety of dosage forms and drug substances have also been addressed.

Higher Education Institution Branding as a Component of Country Branding in Ghana: Renaming Kwame Nkrumah University of Science and Technology

ERIC Educational Resources Information Center

Williams, Robert, Jr.; Osei, Collins; Omar, Maktoba

2012-01-01

As Higher Education Institutions (HEI) become more marketised and increasingly promotionalised, brand building gains in intensity and names become increasingly important. This conceptual paper plans to explore the application of the Renaming Process Model which depicts the key components that impact the organization brand renaming process,…

Considerations for the Systematic Analysis and Use of Single-Case Research

ERIC Educational Resources Information Center

Horner, Robert H.; Swaminathan, Hariharan; Sugai, George; Smolkowski, Keith

2012-01-01

Single-case research designs provide a rigorous research methodology for documenting experimental control. If single-case methods are to gain wider application, however, a need exists to define more clearly (a) the logic of single-case designs, (b) the process and decision rules for visual analysis, and (c) an accepted process for integrating…

Simulation based analysis of laser beam brazing

NASA Astrophysics Data System (ADS)

Dobler, Michael; Wiethop, Philipp; Schmid, Daniel; Schmidt, Michael

2016-03-01

Laser beam brazing is a well-established joining technology in car body manufacturing with main applications in the joining of divided tailgates and the joining of roof and side panels. A key advantage of laser brazed joints is the seam's visual quality which satisfies highest requirements. However, the laser beam brazing process is very complex and process dynamics are only partially understood. In order to gain deeper knowledge of the laser beam brazing process, to determine optimal process parameters and to test process variants, a transient three-dimensional simulation model of laser beam brazing is developed. This model takes into account energy input, heat transfer as well as fluid and wetting dynamics that lead to the formation of the brazing seam. A validation of the simulation model is performed by metallographic analysis and thermocouple measurements for different parameter sets of the brazing process. These results show that the multi-physical simulation model not only can be used to gain insight into the laser brazing process but also offers the possibility of process optimization in industrial applications. The model's capabilities in determining optimal process parameters are exemplarily shown for the laser power. Small deviations in the energy input can affect the brazing results significantly. Therefore, the simulation model is used to analyze the effect of the lateral laser beam position on the energy input and the resulting brazing seam.

Annual Report on Electronics Research at the University of Texas at Austin. Appendix-JSEP Sponsored Publications

DTIC Science & Technology

1993-02-14

screening and significantly larger than that of majority electrons. plasmon-phonon coupling in the two-band hole sys - C! Later, Monte-Carlo simulations of...potential application to other laser sys - versus drive current for three cases; a nonlasing device tems as well. with no gain saturation, gain saturation...SAKU1, K,, HASEGAWA, T., FUSE, T., SMITA. T., ARITOME, S., WATA- were identically processed as the type A devices except for a NABE , $., 0HUCHI. K

LNA with wide range of gain control and wideband interference rejection

NASA Astrophysics Data System (ADS)

Wang, Jhen-Ji; Chen, Duan-Yu

2016-10-01

This work presents a low-noise amplifier (LNA) design with a wide-range gain control characteristic that integrates adjustable current distribution and output impedance techniques. For a given gain characteristic, the proposed LNA provides better wideband interference rejection performance than conventional LNA. Moreover, the proposed LNA also has a wider gain control range than conventional LNA. Therefore, it is suitable for satellite communications systems. The simulation results demonstrate that the voltage gain control range is between 14.5 and 34.2 dB for such applications (2600 MHz); the input reflection coefficient is less than -18.9 dB; the noise figure (NF) is 1.25 dB; and the third-order intercept point (IIP3) is 4.52 dBm. The proposed LNA consumes 23.85-28.17 mW at a supply voltage of 1.8 V. It is implemented by using TSMC 0.18-um RF CMOS process technology.

Advances in microscale separations towards nanoproteomics applications

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

Yi, Lian; Piehowski, Paul D.; Shi, Tujin

Microscale separations (e.g., liquid chromatography or capillary electrophoresis) coupled with mass spectrometry (MS) has become the primary tool for advanced proteomics, an indispensable technology for gaining understanding of complex biological processes. While significant advances have been achieved in MS-based proteomics, the current platforms still face a significant challenge in overall sensitivity towards nanoproteomics (i.e., with less than 1 g total amount of proteins available) applications such as cellular heterogeneity in tissue pathologies. Herein, we review recent advances in microscale separation techniques and integrated sample processing systems that improve the overall sensitivity and coverage of the proteomics workflow, and their contributionsmore » towards nanoproteomics applications.« less

Biopharmaceutical production: Applications of surface plasmon resonance biosensors.

PubMed

Thillaivinayagalingam, Pranavan; Gommeaux, Julien; McLoughlin, Michael; Collins, David; Newcombe, Anthony R

2010-01-15

Surface plasmon resonance (SPR) permits the quantitative analysis of therapeutic antibody concentrations and impurities including bacteria, Protein A, Protein G and small molecule ligands leached from chromatography media. The use of surface plasmon resonance has gained popularity within the biopharmaceutical industry due to the automated, label free, real time interaction that may be exploited when using this method. The application areas to assess protein interactions and develop analytical methods for biopharmaceutical downstream process development, quality control, and in-process monitoring are reviewed. 2009 Elsevier B.V. All rights reserved.

Ionic Liquids and Relative Process Design

NASA Astrophysics Data System (ADS)

Zhang, S.; Lu, X.; Zhang, Y.; Zhou, Q.; Sun, J.; Han, L.; Yue, G.; Liu, X.; Cheng, W.; Li, S.

Ionic liquids have gained increasing attention in recent years due to their significant advantages, not only as alternative solvents but also as new materials and catalysts. Until now, most research work on ionic liquids has been at the laboratory or pilot scale. In view of the multifarious applications of ionic liquids, more new knowledge is needed and more systematic work on ionic liquids should be carried out deeply and broadly in order to meet the future needs of process design. For example, knowledge of the physicochemical properties is indispensable for the design of new ionic liquids and for the development of novel processes. The synthesis and application of ionic liquids are fundamental parts of engineering science, and the toxicity and environmental assessment of ionic liquids is critical importance for their large scale applications, especially for process design. These research aspects are closely correlated to the industrial applications of ionic liquids and to sustainable processes. However, material process design in the industrial applications of ionic liquids has hardly been implemented. Therefore, this chapter reviews several essential issues that are closely related to process design, such as the synthesis, structure-property relationships, important applications, and toxicity of ionic liquids.

Gain determination of optical active doped planar waveguides

NASA Astrophysics Data System (ADS)

Šmejcký, J.; Jeřábek, V.; Nekvindová, P.

2017-12-01

This paper summarizes the results of the gain transmission characteristics measurement carried out on the new ion exchange Ag+ - Na+ optical Er3+ and Yb3+ doped active planar waveguides realized on a silica based glass substrates. The results were used for optimization of the precursor concentration in the glass substrates. The gain measurements were performed by the time domain method using a pulse generator, as well as broadband measurement method using supercontinuum optical source in the wavelength domain. Both methods were compared and the results were graphically processed. It has been confirmed that pulse method is useful as it provides a very accurate measurement of the gain - pumping power characteristics for one wavelength. In the case of radiation spectral characteristics, our measurement exactly determined the maximum gain wavelength bandwidth of the active waveguide. The spectral characteristics of the pumped and unpumped waveguides were compared. The gain parameters of the reported silica-based glasses can be compared with the phosphate-based parameters, typically used for optical active devices application.

Neural Net Gains Estimation Based on an Equivalent Model

PubMed Central

Aguilar Cruz, Karen Alicia; Medel Juárez, José de Jesús; Fernández Muñoz, José Luis; Esmeralda Vigueras Velázquez, Midory

2016-01-01

A model of an Equivalent Artificial Neural Net (EANN) describes the gains set, viewed as parameters in a layer, and this consideration is a reproducible process, applicable to a neuron in a neural net (NN). The EANN helps to estimate the NN gains or parameters, so we propose two methods to determine them. The first considers a fuzzy inference combined with the traditional Kalman filter, obtaining the equivalent model and estimating in a fuzzy sense the gains matrix A and the proper gain K into the traditional filter identification. The second develops a direct estimation in state space, describing an EANN using the expected value and the recursive description of the gains estimation. Finally, a comparison of both descriptions is performed; highlighting the analytical method describes the neural net coefficients in a direct form, whereas the other technique requires selecting into the Knowledge Base (KB) the factors based on the functional error and the reference signal built with the past information of the system. PMID:27366146

Neural Net Gains Estimation Based on an Equivalent Model.

PubMed

Aguilar Cruz, Karen Alicia; Medel Juárez, José de Jesús; Fernández Muñoz, José Luis; Esmeralda Vigueras Velázquez, Midory

2016-01-01

A model of an Equivalent Artificial Neural Net (EANN) describes the gains set, viewed as parameters in a layer, and this consideration is a reproducible process, applicable to a neuron in a neural net (NN). The EANN helps to estimate the NN gains or parameters, so we propose two methods to determine them. The first considers a fuzzy inference combined with the traditional Kalman filter, obtaining the equivalent model and estimating in a fuzzy sense the gains matrix A and the proper gain K into the traditional filter identification. The second develops a direct estimation in state space, describing an EANN using the expected value and the recursive description of the gains estimation. Finally, a comparison of both descriptions is performed; highlighting the analytical method describes the neural net coefficients in a direct form, whereas the other technique requires selecting into the Knowledge Base (KB) the factors based on the functional error and the reference signal built with the past information of the system.

Electroactive polymers for gaining sea power

NASA Astrophysics Data System (ADS)

Scherber, Benedikt; Grauer, Matthias; Köllnberger, Andreas

2013-04-01

Target of this article will be the energy harvesting with dielectric elastomers for wave energy conversion. The main goal of this article is to introduce a new developed material profile enabling a specific amount of energy, making the harvesting process competitive against other existing offshore generation technologies. Electroactive polymers offer the chance to start with small wave energy converters to gain experiences and carry out a similar development as wind energy. Meanwhile there is a consortium being formed in Germany to develop such materials and processes for future products in this new business area. In order to demonstrate the applicability of the technological advancements, a scale demonstrator of a wave energy generator will be developed as well.

Developing and Optimizing Applications in Hadoop

NASA Astrophysics Data System (ADS)

Kothuri, P.; Garcia, D.; Hermans, J.

2017-10-01

This contribution is about sharing our recent experiences of building Hadoop based application. Hadoop ecosystem now offers myriad of tools which can overwhelm new users, yet there are successful ways these tools can be leveraged to solve problems. We look at factors to consider when using Hadoop to model and store data, best practices for moving data in and out of the system and common processing patterns, at each stage relating with the real world experience gained while developing such application. We share many of the design choices, tools developed and how to profile a distributed application which can be applied for other scenarios as well. In conclusion, the goal of the presentation is to provide guidance to architect Hadoop based application and share some of the reusable components developed in this process.

Clinical operations management in radiology.

PubMed

Ondategui-Parra, Silvia; Gill, Ileana E; Bhagwat, Jui G; Intrieri, Lisa A; Gogate, Adheet; Zou, Kelly H; Nathanson, Eric; Seltzer, Steven E; Ros, Pablo R

2004-09-01

Providing radiology services is a complex and technically demanding enterprise in which the application of operations management (OM) tools can play a substantial role in process management and improvement. This paper considers the benefits of an OM process in a radiology setting. Available techniques and concepts of OM are addressed, along with gains and benefits that can be derived from these processes. A reference framework for the radiology processes is described, distinguishing two phases in the initial assessment of a unit: the diagnostic phase and the redesign phase.

Numerical simulation of controlled directional solidification under microgravity conditions

NASA Astrophysics Data System (ADS)

Holl, S.; Roos, D.; Wein, J.

The computer-assisted simulation of solidification processes influenced by gravity has gained increased importance during the previous years regarding ground-based as well as microgravity research. Depending on the specific needs of the investigator, the simulation model ideally covers a broad spectrum of applications. These primarily include the optimization of furnace design in interaction with selected process parameters to meet the desired crystallization conditions. Different approaches concerning the complexity of the simulation models as well as their dedicated applications will be discussed in this paper. Special emphasis will be put on the potential of software tools to increase the scientific quality and cost-efficiency of microgravity experimentation. The results gained so far in the context of TEXUS, FSLP, D-1 and D-2 (preparatory program) experiments, highlighting their simulation-supported preparation and evaluation will be discussed. An outlook will then be given on the possibilities to enhance the efficiency of pre-industrial research in the Columbus era through the incorporation of suitable simulation methods and tools.

Broadly tunable thin-film intereference coatings: active thin films for telecom applications

NASA Astrophysics Data System (ADS)

Domash, Lawrence H.; Ma, Eugene Y.; Lourie, Mark T.; Sharfin, Wayne F.; Wagner, Matthias

2003-06-01

Thin film interference coatings (TFIC) are the most widely used optical technology for telecom filtering, but until recently no tunable versions have been known except for mechanically rotated filters. We describe a new approach to broadly tunable TFIC components based on the thermo-optic properties of semiconductor thin films with large thermo-optic coefficients 3.6X10[-4]/K. The technology is based on amorphous silicon thin films deposited by plasma-enhanced chemical vapor deposition (PECVD), a process adapted for telecom applications from its origins in the flat-panel display and solar cell industries. Unlike MEMS devices, tunable TFIC can be designed as sophisticated multi-cavity, multi-layer optical designs. Applications include flat-top passband filters for add-drop multiplexing, tunable dispersion compensators, tunable gain equalizers and variable optical attenuators. Extremely compact tunable devices may be integrated into modules such as optical channel monitors, tunable lasers, gain-equalized amplifiers, and tunable detectors.

Accounting For Gains And Orientations In Polarimetric SAR

NASA Technical Reports Server (NTRS)

Freeman, Anthony

1992-01-01

Calibration method accounts for characteristics of real radar equipment invalidating standard 2 X 2 complex-amplitude R (receiving) and T (transmitting) matrices. Overall gain in each combination of transmitting and receiving channels assumed different even when only one transmitter and one receiver used. One characterizes departure of polarimetric Synthetic Aperture Radar (SAR) system from simple 2 X 2 model in terms of single parameter used to transform measurements into format compatible with simple 2 X 2 model. Data processed by applicable one of several prior methods based on simple model.

Advances in microscale separations towards nanoproteomics applications

DOE PAGES

Yi, Lian; Piehowski, Paul D.; Shi, Tujin; ...

2017-07-21

Microscale separation (e.g., liquid chromatography or capillary electrophoresis) coupled with mass spectrometry (MS) has become the primary tool for advanced proteomics, an indispensable technology for gaining understanding of complex biological processes. In recent decades significant advances have been achieved in MS-based proteomics. But, the current proteomics platforms still face an analytical challenge in overall sensitivity towards nanoproteomics applications for starting materials of less than 1 μg total proteins (e.g., cellular heterogeneity in tissue pathologies). We review recent advances in microscale separation techniques and integrated sample processing strategies that improve the overall sensitivity and proteome coverage of the proteomics workflow, andmore » their contributions towards nanoproteomics applications.« less

Advances in microscale separations towards nanoproteomics applications

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

Yi, Lian; Piehowski, Paul D.; Shi, Tujin

Microscale separation (e.g., liquid chromatography or capillary electrophoresis) coupled with mass spectrometry (MS) has become the primary tool for advanced proteomics, an indispensable technology for gaining understanding of complex biological processes. In recent decades significant advances have been achieved in MS-based proteomics. But, the current proteomics platforms still face an analytical challenge in overall sensitivity towards nanoproteomics applications for starting materials of less than 1 μg total proteins (e.g., cellular heterogeneity in tissue pathologies). We review recent advances in microscale separation techniques and integrated sample processing strategies that improve the overall sensitivity and proteome coverage of the proteomics workflow, andmore » their contributions towards nanoproteomics applications.« less

Application of Hands-On Simulation Games to Improve Classroom Experience

ERIC Educational Resources Information Center

Hamzeh, Farook; Theokaris, Christina; Rouhana, Carel; Abbas, Yara

2017-01-01

While many construction companies claim substantial productivity and profit gains when applying lean construction principles, it remains a challenge to teach these principles in a classroom. Lean construction emphasises collaborative processes and integrated delivery practices. Consequently, new teaching methods that nurture such values should…

Exploring the Role of Usability in the Software Process: A Study of Irish Software SMEs

NASA Astrophysics Data System (ADS)

O'Connor, Rory V.

This paper explores the software processes and usability techniques used by Small and Medium Enterprises (SMEs) that develop web applications. The significance of this research is that it looks at development processes used by SMEs in order to assess to what degree usability is integrated into the process. This study seeks to gain an understanding into the level of awareness of usability within SMEs today and their commitment to usability in practice. The motivation for this research is to explore the current development processes used by SMEs in developing web applications and to understand how usability is represented in those processes. The background for this research is provided by the growth of the web application industry beyond informational web sites to more sophisticated applications delivering a broad range of functionality. This paper presents an analysis of the practices of several Irish SMEs that develop web applications through a series of case studies. With the focus on SMEs that develop web applications as Management Information Systems and not E-Commerce sites, informational sites, online communities or web portals. This study gathered data about the usability techniques practiced by these companies and their awareness of usability in the context of the software process in those SMEs. The contribution of this study is to further the understanding of the current role of usability within the software development processes of SMEs that develop web applications.

Application of a Model for Simulating the Vacuum Arc Remelting Process in Titanium Alloys

NASA Astrophysics Data System (ADS)

Patel, Ashish; Tripp, David W.; Fiore, Daniel

Mathematical modeling is routinely used in the process development and production of advanced aerospace alloys to gain greater insight into system dynamics and to predict the effect of process modifications or upsets on final properties. This article describes the application of a 2-D mathematical VAR model presented in previous LMPC meetings. The impact of process parameters on melt pool geometry, solidification behavior, fluid-flow and chemistry in Ti-6Al-4V ingots will be discussed. Model predictions were first validated against the measured characteristics of industrially produced ingots, and process inputs and model formulation were adjusted to match macro-etched pool shapes. The results are compared to published data in the literature. Finally, the model is used to examine ingot chemistry during successive VAR melts.

Application of gain scheduling to the control of batch bioreactors

NASA Technical Reports Server (NTRS)

Cardello, Ralph; San, Ka-Yiu

1987-01-01

The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

Digital multi-channel high resolution phase locked loop for surveillance radar systems

NASA Astrophysics Data System (ADS)

Rizk, Mohamed; Shaaban, Shawky; Abou-El-Nadar, Usama M.; Hafez, Alaa El-Din Sayed

This paper present a multi-channel, high resolution, fast lock phase locked loop (PLL) for surveillance radar applications. Phase detector based PLLs are simple to design, suffer no systematic phase error, and can run at the highest speed. Reducing loop gain can proportionally improve jitter performance, but also reduces locking time and pull-in range. The proposed system is based on digital process and control the error signal to the voltage controlled oscillator (VCO) adaptively to control its gain in order to achieve fast lock times while improving in lock jitter performance. Under certain circumstances the design also improves the frequency agility capability of the radar system. The results show a fast lock, high resolution PLL with transient time less than 10 µ sec which is suitable to radar applications.

Widely wavelength tunable gain-switched Er³⁺-doped ZBLAN fiber laser around 2.8 μm.

PubMed

Wei, Chen; Luo, Hongyu; Shi, Hongxia; Lyu, YanJia; Zhang, Han; Liu, Yong

2017-04-17

In this paper, we demonstrate a wavelength widely tunable gain-switched Er³⁺-doped ZBLAN fiber laser around 2.8 μm. The laser can be tuned over 170 nm (2699 nm~2869.9 nm) for various pump power levels, while maintaining stable μs-level single-pulse gain-switched operation with controllable output pulse duration at a selectable repetition rate. To the best of our knowledge, this is the first wavelength tunable gain-switched fiber laser in the 3 μm spectral region with the broadest tuning range (doubling the record tuning range) of the pulsed fiber lasers around 3 μm. Influences of pump energy and power on the output gain-switched laser performances are investigated in detail. This robust, simple, and versatile mid-infrared pulsed fiber laser source is highly suitable for many applications including laser surgery, material processing, sensing, spectroscopy, as well as serving as a practical seed source in master oscillator power amplifiers.

Towards zero-threshold optical gain using charged semiconductor quantum dots

DOE PAGES

Wu, Kaifeng; Park, Young -Shin; Lim, Jaehoon; ...

2017-10-16

Colloidal semiconductor quantum dots are attractive materials for the realization of solution-processable lasers. However, their applications as optical-gain media are complicated by a non-unity degeneracy of band-edge states, because of which multiexcitons are required to achieve the lasing regime. This increases the lasing thresholds and leads to very short optical gain lifetimes limited by nonradiative Auger recombination. Here, we show that these problems can be at least partially resolved by employing not neutral but negatively charged quantum dots. By applying photodoping to specially engineered quantum dots with impeded Auger decay, we demonstrate a considerable reduction of the optical gain thresholdmore » due to suppression of ground-state absorption by pre-existing carriers. Moreover, by injecting approximately one electron per dot on average, we achieve a more than twofold reduction in the amplified spontaneous emission threshold, bringing it to the sub-single-exciton level. Furthermore, these measurements indicate the feasibility of ‘zero-threshold’ gain achievable by completely blocking the band-edge state with two electrons.« less

Design of an Auto-zeroed, Differential, Organic Thin-film Field-effect Transistor Amplifier for Sensor Applications

NASA Technical Reports Server (NTRS)

Binkley, David M.; Verma, Nikhil; Crawford, Robert L.; Brandon, Erik; Jackson, Thomas N.

2004-01-01

Organic strain gauge and other sensors require high-gain, precision dc amplification to process their low-level output signals. Ideally, amplifiers would be fabricated using organic thin-film field-effect transistors (OTFT's) adjacent to the sensors. However, OTFT amplifiers exhibit low gain and high input-referred dc offsets that must be effectively managed. This paper presents a four-stage, cascaded differential OTFT amplifier utilizing switched capacitor auto-zeroing. Each stage provides a nominal voltage gain of four through a differential pair driving low-impedance active loads, which provide common-mode output voltage control. p-type pentacence OTFT's are used for the amplifier devices and auto-zero switches. Simulations indicate the amplifier provides a nominal voltage gain of 280 V/V and effectively amplifies a 1-mV dc signal in the presence of 500-mV amplifier input-referred dc offset voltages. Future work could include the addition of digital gain calibration and offset correction of residual offsets associated with charge injection imbalance in the differential circuits.

Towards zero-threshold optical gain using charged semiconductor quantum dots

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

Wu, Kaifeng; Park, Young -Shin; Lim, Jaehoon

Colloidal semiconductor quantum dots are attractive materials for the realization of solution-processable lasers. However, their applications as optical-gain media are complicated by a non-unity degeneracy of band-edge states, because of which multiexcitons are required to achieve the lasing regime. This increases the lasing thresholds and leads to very short optical gain lifetimes limited by nonradiative Auger recombination. Here, we show that these problems can be at least partially resolved by employing not neutral but negatively charged quantum dots. By applying photodoping to specially engineered quantum dots with impeded Auger decay, we demonstrate a considerable reduction of the optical gain thresholdmore » due to suppression of ground-state absorption by pre-existing carriers. Moreover, by injecting approximately one electron per dot on average, we achieve a more than twofold reduction in the amplified spontaneous emission threshold, bringing it to the sub-single-exciton level. Furthermore, these measurements indicate the feasibility of ‘zero-threshold’ gain achievable by completely blocking the band-edge state with two electrons.« less

FPGA applications for single dish activity at Medicina radio telescopes

NASA Astrophysics Data System (ADS)

Bartolini, M.; Naldi, G.; Mattana, A.; Maccaferri, A.; De Biaggi, M.

FPGA technologies are gaining major attention in the recent years in the field of radio astronomy. At Medicina radio telescopes, FPGAs have been used in the last ten years for a number of purposes and in this article we will take into exam the applications developed and installed for the Medicina Single Dish 32m Antenna: these range from high performance digital signal processing to instrument control developed on top of smaller FPGAs.

Biofiltration holds VOCs, odors at bay

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

Vembu, K.; Walker, C.S

1995-02-01

Biofiltration has been applied to air pollution control in other countries for over 30 years. In North America, a few dozen systems have been installed. Biofiltration is gaining recognition because of it`s low cost and it is a clean air pollution control technology. This paper describes the process of biofiltration and applications.

Polyimide Prepregs With Improved Tack

NASA Technical Reports Server (NTRS)

Vanucci, R.

1987-01-01

Drape and tack improved without loss of strength. Composites made with PMR-15 (or equivalent) polyimides have gained acceptance as viable engineering materials for high-use-temperature applications. Acceptance due to both thermo-oxidative stability of PMR-15 (or equivalent) and ease which PMR-15 (or equivalent) prepreg materials processed into composite structures.

Some Properties of Poly(Methyl Methacrylate) Studied by Radiation Degradation: An Interdisciplinary Student Experiment.

ERIC Educational Resources Information Center

Hill, D. J. T.; O'Donnell, J. H.

1981-01-01

Describes an interdisciplinary student experiment based upon the radiation effects on polymers, integrating some of the fundamentals of radiation chemistry, polymer chemistry, and material science. Also demonstrates how the information gained in the experiment has direct commercial application in product manufacture or processing. (CS)

Eportfolios in Business Communication Courses as Tools for Employment

ERIC Educational Resources Information Center

Okoro, Ephraim A.; Washington, Melvin C.; Cardon, Peter W.

2011-01-01

Eportfolios are a powerful tool for business students to gain self-awareness and take control of their learning experiences. Ideally, they can be used as online profiles in the job application process, allowing more authenticity, personalization, and completeness than traditional resumes. In our colleges, eportfolios help students reflect on their…

An Automated DAKOTA and VULCAN-CFD Framework with Application to Supersonic Facility Nozzle Flowpath Optimization

NASA Technical Reports Server (NTRS)

Axdahl, Erik L.

2015-01-01

Removing human interaction from design processes by using automation may lead to gains in both productivity and design precision. This memorandum describes efforts to incorporate high fidelity numerical analysis tools into an automated framework and applying that framework to applications of practical interest. The purpose of this effort was to integrate VULCAN-CFD into an automated, DAKOTA-enabled framework with a proof-of-concept application being the optimization of supersonic test facility nozzles. It was shown that the optimization framework could be deployed on a high performance computing cluster with the flow of information handled effectively to guide the optimization process. Furthermore, the application of the framework to supersonic test facility nozzle flowpath design and optimization was demonstrated using multiple optimization algorithms.

The LITERACY-Portal as the Subject of a Case Study on a Human-Centered Design Solution Supporting Users with Special Needs

ERIC Educational Resources Information Center

Hagelkruys, Dominik; Motschnig, Renate

2017-01-01

Case studies help to reflect and to capture information about complex processes and domains and to make it reusable for future application in related contexts. In the case study reported in this article, we aim to capture and share processes and experience that we gained while designing a web-portal for supporting the specific user group of…

Simulating the Composite Propellant Manufacturing Process

NASA Technical Reports Server (NTRS)

Williamson, Suzanne; Love, Gregory

2000-01-01

There is a strategic interest in understanding how the propellant manufacturing process contributes to military capabilities outside the United States. The paper will discuss how system dynamics (SD) has been applied to rapidly assess the capabilities and vulnerabilities of a specific composite propellant production complex. These facilities produce a commonly used solid propellant with military applications. The authors will explain how an SD model can be configured to match a specific production facility followed by a series of scenarios designed to analyze operational vulnerabilities. By using the simulation model to rapidly analyze operational risks, the analyst gains a better understanding of production complexities. There are several benefits of developing SD models to simulate chemical production. SD is an effective tool for characterizing complex problems, especially the production process where the cascading effect of outages quickly taxes common understanding. By programming expert knowledge into an SD application, these tools are transformed into a knowledge management resource that facilitates rapid learning without requiring years of experience in production operations. It also permits the analyst to rapidly respond to crisis situations and other time-sensitive missions. Most importantly, the quantitative understanding gained from applying the SD model lends itself to strategic analysis and planning.

On-road anomaly detection by multimodal sensor analysis and multimedia processing

NASA Astrophysics Data System (ADS)

Orhan, Fatih; Eren, P. E.

2014-03-01

The use of smartphones in Intelligent Transportation Systems is gaining popularity, yet many challenges exist in developing functional applications. Due to the dynamic nature of transportation, vehicular social applications face complexities such as developing robust sensor management, performing signal and image processing tasks, and sharing information among users. This study utilizes a multimodal sensor analysis framework which enables the analysis of sensors in multimodal aspect. It also provides plugin-based analyzing interfaces to develop sensor and image processing based applications, and connects its users via a centralized application as well as to social networks to facilitate communication and socialization. With the usage of this framework, an on-road anomaly detector is being developed and tested. The detector utilizes the sensors of a mobile device and is able to identify anomalies such as hard brake, pothole crossing, and speed bump crossing. Upon such detection, the video portion containing the anomaly is automatically extracted in order to enable further image processing analysis. The detection results are shared on a central portal application for online traffic condition monitoring.

High-gain 1.3  μm GaInNAs semiconductor optical amplifier with enhanced temperature stability for all-optical signal processing at 10  Gb/s.

PubMed

Fitsios, D; Giannoulis, G; Korpijärvi, V-M; Viheriälä, J; Laakso, A; Iliadis, N; Dris, S; Spyropoulou, M; Avramopoulos, H; Kanellos, G T; Pleros, N; Guina, M

2015-01-01

We report on the complete experimental evaluation of a GaInNAs/GaAs (dilute nitride) semiconductor optical amplifier that operates at 1.3 μm and exhibits 28 dB gain and a gain recovery time of 100 ps. Successful wavelength conversion operation is demonstrated using pseudorandom bit sequence 2⁷-1 non-return-to-zero bit streams at 5 and 10  Gb/s, yielding error-free performance and showing feasibility for implementation in various signal processing functionalities. The operational credentials of the device are analyzed in various operational regimes, while its nonlinear performance is examined in terms of four-wave mixing. Moreover, characterization results reveal enhanced temperature stability with almost no gain variation around the 1320 nm region for a temperature range from 20°C to 50°C. The operational characteristics of the device, along with the cost and energy benefits of dilute nitride technology, make it very attractive for application in optical access networks and dense photonic integrated circuits.

Nanostructured raspberry-like gelatin microspheres for local delivery of multiple biomolecules.

PubMed

Diba, Mani; Pape, Bram; Klymov, Alexey; Zhang, Yang; Song, Jiankang; Löwik, Dennis W P M; Seyednejad, Hajar; Leeuwenburgh, Sander C G

2017-08-01

Multicompartment particles, which are particles composed of smaller building units, have gained considerable interest during the past decade to facilitate simultaneous and differential delivery of several biomolecules in various applications. Supercritical carbon dioxide (CO 2 ) processing is an industrial technology widely used for large-scale synthesis and processing of materials. However, the application of this technology for production of multicompartment particles from colloidal particles has not yet been explored. Here, we report the formation of raspberry-like gelatin (RLG) microparticles composed of gelatin nanoparticles as colloidal building blocks through supercritical CO 2 processing. We show that these RLG microparticles exhibit a high stability upon dispersion in aqueous media without requiring chemical cross-linking. We further demonstrate that these microparticles are cytocompatible and facilitate differential release of two different model compounds. The strategy presented here can be utilized as a cost-effective route for production of various types of multicompartment particles using colloidal particles with suitable interparticle interactions. Multicompartment particles have gained considerable interest during the past decade to facilitate simultaneous and differential delivery of multiple biomolecules in various biomedical applications. Nevertheless, common methods employed for the production of such particles are often complex and only offer small-scale production. Here, we report the formation of raspberry-like gelatin (RLG) microparticles composed of gelatin nanoparticles as colloidal building blocks through supercritical CO 2 processing. We show that these microparticles are cytocompatible and facilitate differential release of two model compounds with different molecular sizes, promising successful applications in various biomedical areas. Summarizing, this paper presents a novel strategy that can be utilized as a cost-effective route for production of various types of multicompartment particles using a wide range of colloidal building blocks. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Healthcare4VideoStorm: Making Smart Decisions Based on Storm Metrics.

PubMed

Zhang, Weishan; Duan, Pengcheng; Chen, Xiufeng; Lu, Qinghua

2016-04-23

Storm-based stream processing is widely used for real-time large-scale distributed processing. Knowing the run-time status and ensuring performance is critical to providing expected dependability for some applications, e.g., continuous video processing for security surveillance. The existing scheduling strategies' granularity is too coarse to have good performance, and mainly considers network resources without computing resources while scheduling. In this paper, we propose Healthcare4Storm, a framework that finds Storm insights based on Storm metrics to gain knowledge from the health status of an application, finally ending up with smart scheduling decisions. It takes into account both network and computing resources and conducts scheduling at a fine-grained level using tuples instead of topologies. The comprehensive evaluation shows that the proposed framework has good performance and can improve the dependability of the Storm-based applications.

Development of Si/SiGe heterostructures

NASA Astrophysics Data System (ADS)

Hauenstein, R. J.; Veteran, J. L.; Young, M. H.

1991-01-01

New molecular beam epitaxy (MBE) materials growth and doping processes were developed for the fabrication of Si/SiGe heterostructure devices. These new materials processes are applied to the demonstration of cryogenic n-p-n Si/Si 1-x Gex/Si heterojunction bipolar transistors (HBT). This application has special significance as an enabling DoD technology for fast low noise, high performance readout and signal processing circuits for IR focal systems. Reliable, versatile methods were developed to grow very high quality Si/SiGe strained layer heterostructures and multilayers. In connection with this program methods were developed to dope the Si and SiGe with B, Sb and Ga. B and Sb were found to be the preferred dopants for p and n regions respectively, of the HBT devices. The test devices clearly displayed gain enhancement due to the heterojunction and provided useful gains from room temperature down to 10 K.

Studying Radiation Damage in Structural Materials by Using Ion Accelerators

NASA Astrophysics Data System (ADS)

Hosemann, Peter

2011-02-01

Radiation damage in structural materials is of major concern and a limiting factor for a wide range of engineering and scientific applications, including nuclear power production, medical applications, or components for scientific radiation sources. The usefulness of these applications is largely limited by the damage a material can sustain in the extreme environments of radiation, temperature, stress, and fatigue, over long periods of time. Although a wide range of materials has been extensively studied in nuclear reactors and neutron spallation sources since the beginning of the nuclear age, ion beam irradiations using particle accelerators are a more cost-effective alternative to study radiation damage in materials in a rather short period of time, allowing researchers to gain fundamental insights into the damage processes and to estimate the property changes due to irradiation. However, the comparison of results gained from ion beam irradiation, large-scale neutron irradiation, and a variety of experimental setups is not straightforward, and several effects have to be taken into account. It is the intention of this article to introduce the reader to the basic phenomena taking place and to point out the differences between classic reactor irradiations and ion irradiations. It will also provide an assessment of how accelerator-based ion beam irradiation is used today to gain insight into the damage in structural materials for large-scale engineering applications.

Calibrated Noise Measurements with Induced Receiver Gain Fluctuations

NASA Technical Reports Server (NTRS)

Racette, Paul; Walker, David; Gu, Dazhen; Rajola, Marco; Spevacek, Ashly

2011-01-01

The lack of well-developed techniques for modeling changing statistical moments in our observations has stymied the application of stochastic process theory in science and engineering. These limitations were encountered when modeling the performance of radiometer calibration architectures and algorithms in the presence of non stationary receiver fluctuations. Analyses of measured signals have traditionally been limited to a single measurement series. Whereas in a radiometer that samples a set of noise references, the data collection can be treated as an ensemble set of measurements of the receiver state. Noise Assisted Data Analysis is a growing field of study with significant potential for aiding the understanding and modeling of non stationary processes. Typically, NADA entails adding noise to a signal to produce an ensemble set on which statistical analysis is performed. Alternatively as in radiometric measurements, mixing a signal with calibrated noise provides, through the calibration process, the means to detect deviations from the stationary assumption and thereby a measurement tool to characterize the signal's non stationary properties. Data sets comprised of calibrated noise measurements have been limited to those collected with naturally occurring fluctuations in the radiometer receiver. To examine the application of NADA using calibrated noise, a Receiver Gain Modulation Circuit (RGMC) was designed and built to modulate the gain of a radiometer receiver using an external signal. In 2010, an RGMC was installed and operated at the National Institute of Standards and Techniques (NIST) using their Noise Figure Radiometer (NFRad) and national standard noise references. The data collected is the first known set of calibrated noise measurements from a receiver with an externally modulated gain. As an initial step, sinusoidal and step-function signals were used to modulate the receiver gain, to evaluate the circuit characteristics and to study the performance of a variety of calibration algorithms. The receiver noise temperature and time-bandwidth product of the NFRad are calculated from the data. Statistical analysis using temporal-dependent calibration algorithms reveals that the natural occurring fluctuations in the receiver are stationary over long intervals (100s of seconds); however the receiver exhibits local non stationarity over the interval over which one set of reference measurements are collected. A variety of calibration algorithms have been applied to the data to assess algorithms' performance with the gain fluctuation signals. This presentation will describe the RGMC, experiment design and a comparative analysis of calibration algorithms.

High quality image-pair-based deblurring method using edge mask and improved residual deconvolution

NASA Astrophysics Data System (ADS)

Cui, Guangmang; Zhao, Jufeng; Gao, Xiumin; Feng, Huajun; Chen, Yueting

2017-04-01

Image deconvolution problem is a challenging task in the field of image process. Using image pairs could be helpful to provide a better restored image compared with the deblurring method from a single blurred image. In this paper, a high quality image-pair-based deblurring method is presented using the improved RL algorithm and the gain-controlled residual deconvolution technique. The input image pair includes a non-blurred noisy image and a blurred image captured for the same scene. With the estimated blur kernel, an improved RL deblurring method based on edge mask is introduced to obtain the preliminary deblurring result with effective ringing suppression and detail preservation. Then the preliminary deblurring result is served as the basic latent image and the gain-controlled residual deconvolution is utilized to recover the residual image. A saliency weight map is computed as the gain map to further control the ringing effects around the edge areas in the residual deconvolution process. The final deblurring result is obtained by adding the preliminary deblurring result with the recovered residual image. An optical experimental vibration platform is set up to verify the applicability and performance of the proposed algorithm. Experimental results demonstrate that the proposed deblurring framework obtains a superior performance in both subjective and objective assessments and has a wide application in many image deblurring fields.

26 CFR 1.643(a)-3 - Capital gains and losses.

Code of Federal Regulations, 2010 CFR

2010-04-01

... applicable local law), capital gains realized by Trust are allocated to income. Because the capital gains are... (CONTINUED) INCOME TAXES Estates, Trusts, and Beneficiaries § 1.643(a)-3 Capital gains and losses. (a) In... income to the extent they are, pursuant to the terms of the governing instrument and applicable local law...

Apply or Die: On the Role and Assessment of Application Papers in Visualization

DOE PAGES

Weber, Gunther H.; Carpendale, Sheelagh; Ebert, David; ...

2017-04-26

Application-oriented papers provide an important way to invigorate and cross-pollinate the visualization field, but the exact criteria for judging an application paper's merit remain an open question. This article builds on a panel at the 2016 IEEE Visualization Conference entitled "Application Papers: What Are They, and How Should They Be Evaluated?" that sought to gain a better understanding of prevalent views in the visualization community. This article surveys current trends that favor application papers, reviews the benefits and contributions of this paper type, and discusses their assessment in the review process. It concludes with recommendations to ensure that the visualizationmore » community is more inclusive to application papers.« less

Apply or Die: On the Role and Assessment of Application Papers in Visualization

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

Weber, Gunther H.; Carpendale, Sheelagh; Ebert, David

Application-oriented papers provide an important way to invigorate and cross-pollinate the visualization field, but the exact criteria for judging an application paper's merit remain an open question. This article builds on a panel at the 2016 IEEE Visualization Conference entitled "Application Papers: What Are They, and How Should They Be Evaluated?" that sought to gain a better understanding of prevalent views in the visualization community. This article surveys current trends that favor application papers, reviews the benefits and contributions of this paper type, and discusses their assessment in the review process. It concludes with recommendations to ensure that the visualizationmore » community is more inclusive to application papers.« less

Holistic, model-based optimization of edge leveling as an enabler for lithographic focus control: application to a memory use case

NASA Astrophysics Data System (ADS)

Hasan, T.; Kang, Y.-S.; Kim, Y.-J.; Park, S.-J.; Jang, S.-Y.; Hu, K.-Y.; Koop, E. J.; Hinnen, P. C.; Voncken, M. M. A. J.

2016-03-01

Advancement of the next generation technology nodes and emerging memory devices demand tighter lithographic focus control. Although the leveling performance of the latest-generation scanners is state of the art, challenges remain at the wafer edge due to large process variations. There are several customer configurable leveling control options available in ASML scanners, some of which are application specific in their scope of leveling improvement. In this paper, we assess the usability of leveling non-correctable error models to identify yield limiting edge dies. We introduce a novel dies-inspec based holistic methodology for leveling optimization to guide tool users in selecting an optimal configuration of leveling options. Significant focus gain, and consequently yield gain, can be achieved with this integrated approach. The Samsung site in Hwaseong observed an improved edge focus performance in a production of a mid-end memory product layer running on an ASML NXT 1960 system. 50% improvement in focus and a 1.5%p gain in edge yield were measured with the optimized configurations.

Organic Lasers: Recent Developments on Materials, Device Geometries, and Fabrication Techniques.

PubMed

Kuehne, Alexander J C; Gather, Malte C

2016-11-09

Organic dyes have been used as gain medium for lasers since the 1960s, long before the advent of today's organic electronic devices. Organic gain materials are highly attractive for lasing due to their chemical tunability and large stimulated emission cross section. While the traditional dye laser has been largely replaced by solid-state lasers, a number of new and miniaturized organic lasers have emerged that hold great potential for lab-on-chip applications, biointegration, low-cost sensing and related areas, which benefit from the unique properties of organic gain materials. On the fundamental level, these include high exciton binding energy, low refractive index (compared to inorganic semiconductors), and ease of spectral and chemical tuning. On a technological level, mechanical flexibility and compatibility with simple processing techniques such as printing, roll-to-roll, self-assembly, and soft-lithography are most relevant. Here, the authors provide a comprehensive review of the developments in the field over the past decade, discussing recent advances in organic gain materials, which are today often based on solid-state organic semiconductors, as well as optical feedback structures, and device fabrication. Recent efforts toward continuous wave operation and electrical pumping of solid-state organic lasers are reviewed, and new device concepts and emerging applications are summarized.

Application of Online Discussion and Cooperative Learning Strategies to Online and Blended College Courses

ERIC Educational Resources Information Center

Lynch, Douglas J.

2010-01-01

Effective online instructional practices may be applied to online and blended college courses. Carefully orchestrated online discussions support learning well beyond the limited face-to-face course time. Students gain greater depth of academic understanding and leadership skills if cooperative learning groups use research-based process and…

Evolving Better Cars: Teaching Evolution by Natural Selection with a Digital Inquiry Activity

ERIC Educational Resources Information Center

Royer, Anne M.; Schultheis, Elizabeth H.

2014-01-01

Evolutionary experiments are usually difficult to perform in the classroom because of the large sizes and long timescales of experiments testing evolutionary hypotheses. Computer applications give students a window to observe evolution in action, allowing them to gain comfort with the process of natural selection and facilitating inquiry…

Clinical Cognition and Diagnostic Error: Applications of a Dual Process Model of Reasoning

ERIC Educational Resources Information Center

Croskerry, Pat

2009-01-01

Both systemic and individual factors contribute to missed or delayed diagnoses. Among the multiple factors that impact clinical performance of the individual, the caliber of cognition is perhaps the most relevant and deserves our attention and understanding. In the last few decades, cognitive psychologists have gained substantial insights into the…

Losses, gain, and lasing in organic and perovskite active materials (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pourdavoud, Neda; Riedl, Thomas J.

2016-09-01

Organic solid state lasers (OSLs) based on semiconducting polymers or small molecules have seen some significant progress over the past decade. Highly efficient organic gain materials combined with high-Q resonator geometries (distributed feedback (DFB), VCSEL, etc.) have enabled OSLs, optically pumped by simple inorganic laser diodes or even LEDs. However, some fundamental goals remain to be reached, like continuous wave (cw) operation and injection lasing. I will address various loss mechanisms related to accumulated triplet excitons or long-lived polarons that in combination with the particular photo-physics of organic gain media state the dominant road-blocks on the way to reach these goals. I will discuss the recent progress in fundamental understanding of these loss processes, which now provides a solid basis for modelling, e.g. of laser dynamics. Avenues to mitigate these fundamental loss mechanisms, e.g. by alternative materials will be presented. In this regard, a class of gain materials based on organo-lead halide perovskites re-entered the scene as light emitters, recently. Enjoying a tremendous lot of attention as active material for solution processed solar cells with a 20+% efficiency, they have recently unveiled their exciting photo-physics for lasing applications. Optically pumped lasing in these materials has been achieved. I will discuss some of the unique properties that render this class of materials a promising candidate to overcome some of the limitations of "classical" organic gain media.

Positive and negative gain exceeding unity magnitude in silicon quantum well metal-oxide-semiconductor transistors

NASA Astrophysics Data System (ADS)

Hu, Gangyi; Wijesinghe, Udumbara; Naquin, Clint; Maggio, Ken; Edwards, H. L.; Lee, Mark

2017-10-01

Intrinsic gain (AV) measurements on Si quantum well (QW) n-channel metal-oxide-semiconductor (NMOS) transistors show that these devices can have |AV| > 1 in quantum transport negative transconductance (NTC) operation at room temperature. QW NMOS devices were fabricated using an industrial 45 nm technology node process incorporating ion implanted potential barriers to define a lateral QW in the conduction channel under the gate. While NTC at room temperature arising from transport through gate-controlled QW bound states has been previously established, it was unknown whether the quantum NTC mechanism could support gain magnitude exceeding unity. Bias conditions were found giving both positive and negative AV with |AV| > 1 at room temperature. This result means that QW NMOS devices could be useful in amplifier and oscillator applications.

Optofluidic lasers and their applications in bioanalysis (Conference Presentation)

NASA Astrophysics Data System (ADS)

Fan, Xudong

2016-03-01

The optofluidic laser is an emerging technology that integrates microfluidics, miniaturized laser cavity, and laser gain medium in liquid. It is unique due to its biocompatibility, thus can be used for unconventional bioanalysis, in which biointeraction or process takes place within the optical cavity mode volume. Rather than using fluorescence, the optofluidic laser based detection employs laser emission, i.e., stimulated emission, as the sensing signal, which takes advantage of optical amplification provided by the laser cavity to achieve much higher sensitivity. In this presentation, I will first introduce the concept of optofluidic laser based bioanalysis. Then I will discuss each of the three components (cavity, gain medium, and fluidics) of the optofluidic laser and describe how to use the optofluidic laser in bioanalysis at the molecular, cellular, and tissue level. Finally, I will discuss future research and application directions.

Clinical cognition and diagnostic error: applications of a dual process model of reasoning.

PubMed

Croskerry, Pat

2009-09-01

Both systemic and individual factors contribute to missed or delayed diagnoses. Among the multiple factors that impact clinical performance of the individual, the caliber of cognition is perhaps the most relevant and deserves our attention and understanding. In the last few decades, cognitive psychologists have gained substantial insights into the processes that underlie cognition, and a new, universal model of reasoning and decision making has emerged, Dual Process Theory. The theory has immediate application to medical decision making and provides an overall schema for understanding the variety of theoretical approaches that have been taken in the past. The model has important practical applications for decision making across the multiple domains of healthcare, and may be used as a template for teaching decision theory, as well as a platform for future research. Importantly, specific operating characteristics of the model explain how diagnostic failure occurs.

NASA Applications of Molecular Nanotechnology

NASA Technical Reports Server (NTRS)

Globus, Al; Bailey, David; Han, Jie; Jaffe, Richard; Levit, Creon; Merkle, Ralph; Srivastava, Deepak

1998-01-01

Laboratories throughout the world are rapidly gaining atomically precise control over matter. As this control extends to an ever wider variety of materials, processes and devices, opportunities for applications relevant to NASA's missions will be created. This document surveys a number of future molecular nanotechnology capabilities of aerospace interest. Computer applications, launch vehicle improvements, and active materials appear to be of particular interest. We also list a number of applications for each of NASA's enterprises. If advanced molecular nanotechnology can be developed, almost all of NASA's endeavors will be radically improved. In particular, a sufficiently advanced molecular nanotechnology can arguably bring large scale space colonization within our grasp.

Catalytic Properties of Surfaces Sites on Metal Oxides and Their Characterization by X-Ray Photoelectron Spectroscopy

DTIC Science & Technology

1974-01-01

gas now supplies one third of our 9 national energy needs and its use is the fastest growing of all fossil fuels , conversion of coal to...the possibilities of profiling oxidation states and to gain further insight into the mechanism of the bombarding process . (2) Application of ESCA to...the surface sites—which will be measured using x-ray photoelectron spectroscopy. This technique has general applicability to a large atttibM of

Framework Requirements for MDO Application Development

NASA Technical Reports Server (NTRS)

Salas, A. O.; Townsend, J. C.

1999-01-01

Frameworks or problem solving environments that support application development form an active area of research. The Multidisciplinary Optimization Branch at NASA Langley Research Center is investigating frameworks for supporting multidisciplinary analysis and optimization research. The Branch has generated a list of framework requirements, based on the experience gained from the Framework for Interdisciplinary Design Optimization project and the information acquired during a framework evaluation process. In this study, four existing frameworks are examined against these requirements. The results of this examination suggest several topics for further framework research.

Innovative Treatment Technologies for Natural Waters and Wastewaters

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

Childress, Amy E.

2011-07-01

The research described in this report focused on the development of novel membrane contactor processes (in particular, forward osmosis (FO), pressure retarded osmosis (PRO), and membrane distillation (MD)) in low energy desalination and wastewater treatment applications and in renewable energy generation. FO and MD are recently gaining national and international attention as viable, economic alternatives for removal of both established and emerging contaminants from natural and process waters; PRO is gaining worldwide attention as a viable source of renewable energy. The interrelationship of energy and water are at the core of this study. Energy and water are inextricably bound; energymore » usage and production must be considered when evaluating any water treatment process for practical application. Both FO and MD offer the potential for substantial energy and resource savings over conventional treatment processes and PRO offers the potential for renewable energy or energy offsets in desalination. Combination of these novel technologies with each other, with existing technologies (e.g., reverse osmosis (RO)), and with existing renewable energy sources (e.g., salinity gradient solar ponds) may enable much less expensive water production and also potable water production in remote or distributed locations. Two inter-related projects were carried out in this investigation. One focused on membrane bioreactors for wastewater treatment and PRO for renewable energy generation; the other focused on MD driven by a salinity gradient solar pond.« less

Summary of Pressure Gain Combustion Research at NASA

NASA Technical Reports Server (NTRS)

Perkins, H. Douglas; Paxson, Daniel E.

2018-01-01

NASA has undertaken a systematic exploration of many different facets of pressure gain combustion over the last 25 years in an effort to exploit the inherent thermodynamic advantage of pressure gain combustion over the constant pressure combustion process used in most aerospace propulsion systems. Applications as varied as small-scale UAV's, rotorcraft, subsonic transports, hypersonics and launch vehicles have been considered. In addition to studying pressure gain combustor concepts such as wave rotors, pulse detonation engines, pulsejets, and rotating detonation engines, NASA has studied inlets, nozzles, ejectors and turbines which must also process unsteady flow in an integrated propulsion system. Other design considerations such as acoustic signature, combustor material life and heat transfer that are unique to pressure gain combustors have also been addressed in NASA research projects. In addition to a wide range of experimental studies, a number of computer codes, from 0-D up through 3-D, have been developed or modified to specifically address the analysis of unsteady flow fields. Loss models have also been developed and incorporated into these codes that improve the accuracy of performance predictions and decrease computational time. These codes have been validated numerous times across a broad range of operating conditions, and it has been found that once validated for one particular pressure gain combustion configuration, these codes are readily adaptable to the others. All in all, the documentation of this work has encompassed approximately 170 NASA technical reports, conference papers and journal articles to date. These publications are very briefly summarized herein, providing a single point of reference for all of NASA's pressure gain combustion research efforts. This documentation does not include the significant contributions made by NASA research staff to the programs of other agencies, universities, industrial partners and professional society committees through serving as technical advisors, technical reviewers and research consultants.

Methods for destriping Landsat Thematic Mapper images - A feasibility study for an online destriping process in the Thematic Mapper Image Processing System (TIPS)

NASA Technical Reports Server (NTRS)

Poros, D. J.; Peterson, C. J.

1985-01-01

Methods for destriping TM images and results of the application of these methods to selected TM scenes with sensor and scan striping, which was not removed by the radiometric correction during the TM Archive Generation Phase in TIPS, are presented. These methods correct only for gain and offset differences between detectors over many image lines and do not consider within-line effects. The feasibility of implementing a destriping process online in TIPS is also described.

Image processing for optical mapping.

PubMed

Ravindran, Prabu; Gupta, Aditya

2015-01-01

Optical Mapping is an established single-molecule, whole-genome analysis system, which has been used to gain a comprehensive understanding of genomic structure and to study structural variation of complex genomes. A critical component of Optical Mapping system is the image processing module, which extracts single molecule restriction maps from image datasets of immobilized, restriction digested and fluorescently stained large DNA molecules. In this review, we describe robust and efficient image processing techniques to process these massive datasets and extract accurate restriction maps in the presence of noise, ambiguity and confounding artifacts. We also highlight a few applications of the Optical Mapping system.

Extrusion Process by Finite Volume Method Using OpenFoam Software

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

Matos Martins, Marcelo; Tonini Button, Sergio; Divo Bressan, Jose

The computational codes are very important tools to solve engineering problems. In the analysis of metal forming process, such as extrusion, this is not different because the computational codes allow analyzing the process with reduced cost. Traditionally, the Finite Element Method is used to solve solid mechanic problems, however, the Finite Volume Method (FVM) have been gaining force in this field of applications. This paper presents the velocity field and friction coefficient variation results, obtained by numerical simulation using the OpenFoam Software and the FVM to solve an aluminum direct cold extrusion process.

On the Modeling of Vacuum Arc Remelting Process in Titanium Alloys

NASA Astrophysics Data System (ADS)

Patel, Ashish; Fiore, Daniel

2016-07-01

Mathematical modeling is routinely used in the process development and production of advanced aerospace alloys to gain greater insight into the effect of process parameters on final properties. This article describes the application of a 2-D mathematical VAR model presented at previous LMPC meetings. The impact of process parameters on melt pool geometry, solidification behavior, fluid-flow and chemistry in a Ti-6Al-4V ingot is discussed. Model predictions are validated against published data from a industrial size ingot, and results of a parametric study on particle dissolution are also discussed.

THz spectroscopy: An emerging technology for pharmaceutical development and pharmaceutical Process Analytical Technology (PAT) applications

NASA Astrophysics Data System (ADS)

Wu, Huiquan; Khan, Mansoor

2012-08-01

As an emerging technology, THz spectroscopy has gained increasing attention in the pharmaceutical area during the last decade. This attention is due to the fact that (1) it provides a promising alternative approach for in-depth understanding of both intermolecular interaction among pharmaceutical molecules and pharmaceutical product quality attributes; (2) it provides a promising alternative approach for enhanced process understanding of certain pharmaceutical manufacturing processes; and (3) the FDA pharmaceutical quality initiatives, most noticeably, the Process Analytical Technology (PAT) initiative. In this work, the current status and progress made so far on using THz spectroscopy for pharmaceutical development and pharmaceutical PAT applications are reviewed. In the spirit of demonstrating the utility of first principles modeling approach for addressing model validation challenge and reducing unnecessary model validation "burden" for facilitating THz pharmaceutical PAT applications, two scientific case studies based on published THz spectroscopy measurement results are created and discussed. Furthermore, other technical challenges and opportunities associated with adapting THz spectroscopy as a pharmaceutical PAT tool are highlighted.

Development and Application of Eddy Current Sensor Arrays for Process Integrated Inspection of Carbon Fibre Preforms.

PubMed

Berger, Dietrich; Lanza, Gisela

2017-12-21

This publication presents the realisation of a sensor concept, which is based on eddy current testing, to detect textile defects during preforming of semi-finished carbon fibre parts. The presented system has the potential for 100% control of manufactured carbon fibre based components, allowing the immediate exclusion of defective parts from further process steps. The core innovation of this system is given by the high degree of process integration, which has not been implemented in the state of the art. The publication presents the functional principle of the sensor that is based on half-transmission probes as well as the signals that can be gained by its application. Furthermore, a method to determine the optimum sensor resolution is presented as well as the sensor housing and its integration in the preforming process.

How to Apply for an IDA Grant

ERIC Educational Resources Information Center

Kezar, Adrianna; Frank, Vikki; Lester, Jaime; Yang, Hannah

2009-01-01

This document provides resources to both begin and carry out the application process for an IDA grant. The authors offer some key advice to consider when applying for an IDA when in the education sector. They close with some challenges and ways to overcome them. The authors gained much of this information from an education organization's…

Reduced state feedback gain computation. [optimization and control theory for aircraft control

NASA Technical Reports Server (NTRS)

Kaufman, H.

1976-01-01

Because application of conventional optimal linear regulator theory to flight controller design requires the capability of measuring and/or estimating the entire state vector, it is of interest to consider procedures for computing controls which are restricted to be linear feedback functions of a lower dimensional output vector and which take into account the presence of measurement noise and process uncertainty. Therefore, a stochastic linear model that was developed is presented which accounts for aircraft parameter and initial uncertainty, measurement noise, turbulence, pilot command and a restricted number of measurable outputs. Optimization with respect to the corresponding output feedback gains was performed for both finite and infinite time performance indices without gradient computation by using Zangwill's modification of a procedure originally proposed by Powell. Results using a seventh order process show the proposed procedures to be very effective.

Parity-time-symmetry enhanced optomechanically-induced-transparency

PubMed Central

Li, Wenlin; Jiang, Yunfeng; Li, Chong; Song, Heshan

2016-01-01

We propose and analyze a scheme to enhance optomechanically-induced-transparency (OMIT) based on parity-time-symmetric optomechanical system. Our results predict that an OMIT window which does not exist originally can appear in weak optomechanical coupling and driving system via coupling an auxiliary active cavity with optical gain. This phenomenon is quite different from these reported in previous works in which the gain is considered just to damage OMIT phenomenon even leads to electromagnetically induced absorption or inverted-OMIT. Such enhanced OMIT effects are ascribed to the additional gain which can increase photon number in cavity without reducing effective decay. We also discuss the scheme feasibility by analyzing recent experiment parameters. Our work provide a promising platform for the coherent manipulation and slow light operation, which has potential applications for quantum information processing and quantum optical device. PMID:27489193

Quantum-Limited Directional Amplifiers with Optomechanics

NASA Astrophysics Data System (ADS)

Malz, Daniel; Tóth, László D.; Bernier, Nathan R.; Feofanov, Alexey K.; Kippenberg, Tobias J.; Nunnenkamp, Andreas

2018-01-01

Directional amplifiers are an important resource in quantum-information processing, as they protect sensitive quantum systems from excess noise. Here, we propose an implementation of phase-preserving and phase-sensitive directional amplifiers for microwave signals in an electromechanical setup comprising two microwave cavities and two mechanical resonators. We show that both can reach their respective quantum limits on added noise. In the reverse direction, they emit thermal noise stemming from the mechanical resonators; we discuss how this noise can be suppressed, a crucial aspect for technological applications. The isolation bandwidth in both is of the order of the mechanical linewidth divided by the amplitude gain. We derive the bandwidth and gain-bandwidth product for both and find that the phase-sensitive amplifier has an unlimited gain-bandwidth product. Our study represents an important step toward flexible, on-chip integrated nonreciprocal amplifiers of microwave signals.

HARM processing techniques for MEMS and MOEMS devices using bonded SOI substrates and DRIE

NASA Astrophysics Data System (ADS)

Gormley, Colin; Boyle, Anne; Srigengan, Viji; Blackstone, Scott C.

2000-08-01

Silicon-on-Insulator (SOI) MEMS devices (1) are rapidly gaining popularity in realizing numerous solutions for MEMS, especially in the optical and inertia application fields. BCO recently developed a DRIE trench etch, utilizing the Bosch process, and refill process for high voltage dielectric isolation integrated circuits on thick SOI substrates. In this paper we present our most recently developed DRIE processes for MEMS and MOEMS devices. These advanced etch techniques are initially described and their integration with silicon bonding demonstrated. This has enabled process flows that are currently being utilized to develop optical router and filter products for fiber optics telecommunications and high precision accelerometers.

Extremozymes from metagenome: Potential applications in food processing.

PubMed

Khan, Mahejibin; Sathya, T A

2017-06-12

The long-established use of enzymes for food processing and product formulation has resulted in an increased enzyme market compounding to 7.0% annual growth rate. Advancements in molecular biology and recognition that enzymes with specific properties have application for industrial production of infant, baby and functional foods boosted research toward sourcing the genes of microorganisms for enzymes with distinctive properties. In this regard, functional metagenomics for extremozymes has gained attention on the premise that such enzymes can catalyze specific reactions. Hence, metagenomics that can isolate functional genes of unculturable extremophilic microorganisms has expanded attention as a promising tool. Developments in this field of research in relation to food sector are reviewed.

Discrete Film Cooling in a Rocket with Curved Walls

DTIC Science & Technology

2009-12-01

insight to be gained by observing the process of effusion cooling in its most basic elements. In rocket applications, the first desired condition is...ηspan. Convergence was determined by doubling the number of cells, mostly in the region near the hole, until less than a 1 % change was observed in the...method was required to determine the absolute start time for the transient process . To find the time error, start again with TS − Ti Taw − Ti = 1 − exp

Using process monitor wafers to understand directed self-assembly defects

NASA Astrophysics Data System (ADS)

Cao, Yi; Her, YoungJun; Delgadillo, Paulina R.; Vandenbroeck, Nadia; Gronheid, Roel; Chan, Boon Teik; Hashimoto, Yukio; Romo, Ainhoa; Somervell, Mark; Nafus, Kathleen; Nealey, Paul F.

2013-03-01

As directed self-assembly (DSA) has gained momentum over the past few years, questions about its application to high volume manufacturing have arisen. One of the major concerns is about the fundamental limits of defectivity that can be attained with the technology. If DSA applications demonstrate defectivity that rivals of traditional lithographic technologies, the pathway to the cost benefits of the technology creates a very compelling case for its large scale implementation. To address this critical question, our team at IMEC has established a process monitor flow to track the defectivity behaviors of an exemplary chemo-epitaxy application for printing line/space patterns. Through establishing this baseline, we have been able to understand both traditional lithographic defect sources in new materials as well as new classes of assembly defects associated with DSA technology. Moreover, we have explored new materials and processing to lower the level of the defectivity baseline. The robustness of the material sets and process is investigated as well. In this paper, we will report the understandings learned from the IMEC DSA process monitor flow.

Direct X-ray photoconversion in flexible organic thin film devices operated below 1 V

PubMed Central

Basiricò, Laura; Ciavatti, Andrea; Cramer, Tobias; Cosseddu, Piero; Bonfiglio, Annalisa; Fraboni, Beatrice

2016-01-01

The application of organic electronic materials for the detection of ionizing radiations is very appealing thanks to their mechanical flexibility, low-cost and simple processing in comparison to their inorganic counterpart. In this work we investigate the direct X-ray photoconversion process in organic thin film photoconductors. The devices are realized by drop casting solution-processed bis-(triisopropylsilylethynyl)pentacene (TIPS-pentacene) onto flexible plastic substrates patterned with metal electrodes; they exhibit a strong sensitivity to X-rays despite the low X-ray photon absorption typical of low-Z organic materials. We propose a model, based on the accumulation of photogenerated charges and photoconductive gain, able to describe the magnitude as well as the dynamics of the X-ray-induced photocurrent. This finding allows us to fabricate and test a flexible 2 × 2 pixelated X-ray detector operating at 0.2 V, with gain and sensitivity up to 4.7 × 104 and 77,000 nC mGy−1 cm−3, respectively. PMID:27708274

Two-zone SiGe base heterojunction bipolar charge plasma transistor for next generation analog and RF applications

NASA Astrophysics Data System (ADS)

Bramhane, Lokesh Kumar; Singh, Jawar

2017-01-01

For next generation terahertz applications, heterojunction bipolar transistor (HBT) with reduced dimensions and charge plasma (CP) can be a potential candidate due to simplified and inexpensive process. In this paper, a symmetric lateral two-zone SiGe base heterojunction bipolar charge plasma transistor (HBCPT) with an extruded (extended) base is proposed and its performance at circuit level is studied. The linearly graded electric field in the proposed HBCPT provides improved self gain (β) and cut-off frequency (fT). Two-dimensional (2-D) TCAD and small-signal model based simulations of the proposed HBCPT demonstrates high self gain β 35-172.93 and fT of 1-4 THz for different device parameters. Moreover, fT of 1104.9 GHz and β of 35 can be achieved by decreasing Nb up to 8.2 ×1017cm-3 . Although, fT of 2 THz and 4 THz can also be achieved by reducing the base resistance up to 10 Ω and increasing the emitter/collector length up to 63 nm, respectively. The small-signal analysis of common-emitter amplifier based on the proposed HBCPT demonstrate high voltage gain of 50.11 as compared to conventional HBT (18.1).

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

Holmlid, Leif, E-mail: holmlid@chem.gu.se

Previous results from laser-induced processes in ultra-dense deuterium D(0) give conclusive evidence for ejection of neutral massive particles with energy >10 MeV u{sup −1}. Such particles can only be formed from nuclear processes like nuclear fusion at the low laser intensity used. Heat generation is of interest for future fusion energy applications and has now been measured by a small copper (Cu) cylinder surrounding the laser target. The temperature rise of the Cu cylinder is measured with an NTC resistor during around 5000 laser shots per measured point. No heating in the apparatus or the gas feed is normally used.more » The fusion process is suboptimal relative to previously published studies by a factor of around 10. The small neutral particles H{sub N}(0) of ultra-dense hydrogen (size of a few pm) escape with a substantial fraction of the energy. Heat loss to the D{sub 2} gas (at <1 mbar pressure) is measured and compensated for under various conditions. Heat release of a few W is observed, at up to 50% higher energy than the total laser input thus a gain of 1.5. This is uniquely high for the use of deuterium as fusion fuel. With a slightly different setup, a thermal gain of 2 is reached, thus clearly above break-even for all neutronicity values possible. Also including the large kinetic energy which is directly measured for MeV particles leaving through a small opening gives a gain of 2.3. Taking into account the lower efficiency now due to the suboptimal fusion process, previous studies indicate a gain of at least 20 during long periods.« less

Modern educational information technologies in formation of communicative competency in a foreign language in the process of training postgraduates at the aerospace university

NASA Astrophysics Data System (ADS)

Savelyeva, M. V.; Shumakova, N. A.

2016-04-01

The research analyses the issues of competency-based approach implementation in connection with practical experience gained in SibSAU in teaching English for scientific purposes to postgraduate students. The article focuses on IT application for the objectives of both class room and independent work of post graduates organization.

New Technologies for Smart Grid Operation

NASA Astrophysics Data System (ADS)

Mak, Sioe T.

2015-02-01

This book is a handbook for advanced applications design and integration of new and future technologies into Smart Grids for researchers and engineers in academia and industry, looking to pull together disparate technologies and apply them for greater gains. The book covers Smart Grids as the midpoint in the generation, storage, transmission and distribution process through to database management, communication technologies, intelligent devices and synchronisation.

General Electric composite ring-disk flywheel: Recent and potential developments

NASA Technical Reports Server (NTRS)

Coppa, A. P.

1984-01-01

Recent developments of the General Electric hybrid rotor design are described. The relation of the hybrid rotor design to flywheel designs that are especially suitable for spacecraft applications is discussed. Potential performance gains that can be achieved in such rotor designs by applying latest developments in materials, processing, and design methodology are projected. Indications are that substantial improvements can be obtained.

Curbing variations in packaging process through Six Sigma way in a large-scale food-processing industry

NASA Astrophysics Data System (ADS)

Desai, Darshak A.; Kotadiya, Parth; Makwana, Nikheel; Patel, Sonalinkumar

2015-03-01

Indian industries need overall operational excellence for sustainable profitability and growth in the present age of global competitiveness. Among different quality and productivity improvement techniques, Six Sigma has emerged as one of the most effective breakthrough improvement strategies. Though Indian industries are exploring this improvement methodology to their advantage and reaping the benefits, not much has been presented and published regarding experience of Six Sigma in the food-processing industries. This paper is an effort to exemplify the application of Six Sigma quality improvement drive to one of the large-scale food-processing sectors in India. The paper discusses the phase wiz implementation of define, measure, analyze, improve, and control (DMAIC) on one of the chronic problems, variations in the weight of milk powder pouch. The paper wraps up with the improvements achieved and projected bottom-line gain to the unit by application of Six Sigma methodology.

Usability Evaluation of an Unstructured Clinical Document Query Tool for Researchers.

PubMed

Hultman, Gretchen; McEwan, Reed; Pakhomov, Serguei; Lindemann, Elizabeth; Skube, Steven; Melton, Genevieve B

2018-01-01

Natural Language Processing - Patient Information Extraction for Researchers (NLP-PIER) was developed for clinical researchers for self-service Natural Language Processing (NLP) queries with clinical notes. This study was to conduct a user-centered analysis with clinical researchers to gain insight into NLP-PIER's usability and to gain an understanding of the needs of clinical researchers when using an application for searching clinical notes. Clinical researcher participants (n=11) completed tasks using the system's two existing search interfaces and completed a set of surveys and an exit interview. Quantitative data including time on task, task completion rate, and survey responses were collected. Interviews were analyzed qualitatively. Survey scores, time on task and task completion proportions varied widely. Qualitative analysis indicated that participants found the system to be useful and usable in specific projects. This study identified several usability challenges and our findings will guide the improvement of NLP-PIER 's interfaces.

Needleless Electrospinning of Pure and Blended Chitosan

NASA Astrophysics Data System (ADS)

Grimmelsmann, Nils; Homburg, Sarah Vanessa; Ehrmann, Andrea

2017-08-01

Chitosan is a biopolymer with bactericidal, fungicidal, hemostatic and other interesting properties. It can be used, e.g., in medical products, as a filter medium, in biotechnological purposes etc. For these possible applications, nanofiber mats with a large inner surface will be most efficient. This is why in a recent project, the electrospinning properties of pure chitosan as well as chitosan blended with poly(ethylene oxide) were investigated. Using a needleless nanospinning process, the technology under examination can be upscaled from lab to industrial scale, enabling direct transfer of the gained experiences to the intended application.

VisAdapt: A Visualization Tool to Support Climate Change Adaptation.

PubMed

Johansson, Jimmy; Opach, Tomasz; Glaas, Erik; Neset, Tina-Simone; Navarra, Carlo; Linner, Bjorn-Ola; Rod, Jan Ketil

2017-01-01

The web-based visualization VisAdapt tool was developed to help laypeople in the Nordic countries assess how anticipated climate change will impact their homes. The tool guides users through a three-step visual process that helps them explore risks and identify adaptive actions specifically modified to their location and house type. This article walks through the tool's multistep, user-centered design process. Although VisAdapt's target end users are Nordic homeowners, the insights gained from the development process and the lessons learned from the project are applicable to a wide range of domains.

Controlled decomposition and oxidation: A treatment method for gaseous process effluents

NASA Technical Reports Server (NTRS)

Mckinley, Roger J. B., Sr.

1990-01-01

The safe disposal of effluent gases produced by the electronics industry deserves special attention. Due to the hazardous nature of many of the materials used, it is essential to control and treat the reactants and reactant by-products as they are exhausted from the process tool and prior to their release into the manufacturing facility's exhaust system and the atmosphere. Controlled decomposition and oxidation (CDO) is one method of treating effluent gases from thin film deposition processes. CDO equipment applications, field experience, and results of the use of CDO equipment and technological advances gained from the field experiences are discussed.

Engineering the temporal response of photoconductive photodetectors via selective introduction of surface trap states.

PubMed

Konstantatos, Gerasimos; Levina, Larissa; Fischer, Armin; Sargent, Edward H

2008-05-01

Photoconductive photodetectors fabricated using simple solution-processing have recently been shown to exhibit high gains (>1000) and outstanding sensitivities ( D* > 10(13) Jones). One ostensible disadvantage of exploiting photoconductive gain is that the temporal response is limited by the release of carriers from trap states. Here we show that it is possible to introduce specific chemical species onto the surfaces of colloidal quantum dots to produce only a single, desired trap state having a carefully selected lifetime. In this way we demonstrate a device that exhibits an attractive photoconductive gain (>10) combined with a response time ( approximately 25 ms) useful in imaging. We achieve this by preserving a single surface species, lead sulfite, while eliminating lead sulfate and lead carboxylate. In doing so we preserve the outstanding sensitivity of these devices, achieving a specific detectivity of 10(12) Jones in the visible, while generating a temporal response suited to imaging applications.

From data to information and knowledge for geospatial applications

NASA Astrophysics Data System (ADS)

Schenk, T.; Csatho, B.; Yoon, T.

2006-12-01

An ever-increasing number of airborne and spaceborne data-acquisition missions with various sensors produce a glut of data. Sensory data rarely contains information in a explicit form such that an application can directly use it. The processing and analyzing of data constitutes a real bottleneck; therefore, automating the processes of gaining useful information and knowledge from the raw data is of paramount interest. This presentation is concerned with the transition from data to information and knowledge. With data we refer to the sensor output and we notice that data provide very rarely direct answers for applications. For example, a pixel in a digital image or a laser point from a LIDAR system (data) have no direct relationship with elevation changes of topographic surfaces or the velocity of a glacier (information, knowledge). We propose to employ the computer vision paradigm to extract information and knowledge as it pertains to a wide range of geoscience applications. After introducing the paradigm we describe the major steps to be undertaken for extracting information and knowledge from sensory input data. Features play an important role in this process. Thus we focus on extracting features and their perceptual organization to higher order constructs. We demonstrate these concepts with imaging data and laser point clouds. The second part of the presentation addresses the problem of combining data obtained by different sensors. An absolute prerequisite for successful fusion is to establish a common reference frame. We elaborate on the concept of sensor invariant features that allow the registration of such disparate data sets as aerial/satellite imagery, 3D laser point clouds, and multi/hyperspectral imagery. Fusion takes place on the data level (sensor registration) and on the information level. We show how fusion increases the degree of automation for reconstructing topographic surfaces. Moreover, fused information gained from the three sensors results in a more abstract surface representation with a rich set of explicit surface information that can be readily used by an analyst for applications such as change detection.

Crowded Cluster Cores. Algorithms for Deblending in Dark Energy Survey Images

DOE PAGES

Zhang, Yuanyuan; McKay, Timothy A.; Bertin, Emmanuel; ...

2015-10-26

Deep optical images are often crowded with overlapping objects. We found that this is especially true in the cores of galaxy clusters, where images of dozens of galaxies may lie atop one another. Accurate measurements of cluster properties require deblending algorithms designed to automatically extract a list of individual objects and decide what fraction of the light in each pixel comes from each object. In this article, we introduce a new software tool called the Gradient And Interpolation based (GAIN) deblender. GAIN is used as a secondary deblender to improve the separation of overlapping objects in galaxy cluster cores inmore » Dark Energy Survey images. It uses image intensity gradients and an interpolation technique originally developed to correct flawed digital images. Our paper is dedicated to describing the algorithm of the GAIN deblender and its applications, but we additionally include modest tests of the software based on real Dark Energy Survey co-add images. GAIN helps to extract an unbiased photometry measurement for blended sources and improve detection completeness, while introducing few spurious detections. When applied to processed Dark Energy Survey data, GAIN serves as a useful quick fix when a high level of deblending is desired.« less

Control systems engineering for optimizing a prenatal weight gain intervention to regulate infant birth weight.

PubMed

Savage, Jennifer S; Downs, Danielle Symons; Dong, Yuwen; Rivera, Daniel E

2014-07-01

We used dynamical systems modeling to describe how a prenatal behavioral intervention that adapts to the needs of each pregnant woman may help manage gestational weight gain and alter the obesogenic intrauterine environment to regulate infant birth weight. This approach relies on integrating mechanistic energy balance, theory of planned behavior, and self-regulation models to describe how internal processes can be impacted by intervention dosages, and reinforce positive outcomes (e.g., healthy eating and physical activity) to moderate gestational weight gain and affect birth weight. A simulated hypothetical case study from MATLAB with Simulink showed how, in response to our adaptive intervention, self-regulation helps adjust perceived behavioral control. This, in turn, changes the woman's intention and behavior with respect to healthy eating and physical activity during pregnancy, affecting gestational weight gain and infant birth weight. This article demonstrates the potential for real-world applications of an adaptive intervention to manage gestational weight gain and moderate infant birth weight. This model could be expanded to examine the long-term sustainable impacts of an intervention that varies according to the participant's needs on maternal postpartum weight retention and child postnatal eating behavior.

Improvement of radiology services based on the process management approach.

PubMed

Amaral, Creusa Sayuri Tahara; Rozenfeld, Henrique; Costa, Janaina Mascarenhas Hornos; Magon, Maria de Fátima de Andrade; Mascarenhas, Yvone Maria

2011-06-01

The health sector requires continuous investments to ensure the improvement of products and services from a technological standpoint, the use of new materials, equipment and tools, and the application of process management methods. Methods associated with the process management approach, such as the development of reference models of business processes, can provide significant innovations in the health sector and respond to the current market trend for modern management in this sector (Gunderman et al. (2008) [4]). This article proposes a process model for diagnostic medical X-ray imaging, from which it derives a primary reference model and describes how this information leads to gains in quality and improvements. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

An open-closed-loop iterative learning control approach for nonlinear switched systems with application to freeway traffic control

NASA Astrophysics Data System (ADS)

Sun, Shu-Ting; Li, Xiao-Dong; Zhong, Ren-Xin

2017-10-01

For nonlinear switched discrete-time systems with input constraints, this paper presents an open-closed-loop iterative learning control (ILC) approach, which includes a feedforward ILC part and a feedback control part. Under a given switching rule, the mathematical induction is used to prove the convergence of ILC tracking error in each subsystem. It is demonstrated that the convergence of ILC tracking error is dependent on the feedforward control gain, but the feedback control can speed up the convergence process of ILC by a suitable selection of feedback control gain. A switched freeway traffic system is used to illustrate the effectiveness of the proposed ILC law.

Using a mass balance to determine the potency loss during the production of a pharmaceutical blend.

PubMed

Mackaplow, Michael B

2010-09-01

The manufacture of a blend containing the active pharmaceutical ingredient (API) and inert excipients is a precursor for the production of most pharmaceutical capsules and tablets. However, if there is a net water gain or preferential loss of API during production, the potency of the final drug product may be less than the target value. We use a mass balance to predict the mean potency loss during the production of a blend via wet granulation and fluidized bed drying. The result is an explicit analytical equation for the change in blend potency a function of net water gain, solids losses (both regular and high-potency), and the fraction of excipients added extragranularly. This model predicts that each 1% gain in moisture content (as determined by a loss on drying test) will decrease the API concentration of the final blend at least 1% LC. The effect of pre-blend solid losses increases with their degree of superpotency. This work supports Quality by Design by providing a rational method to set the process design space to minimize blend potency losses. When an overage is necessary, the model can help justify it by providing a quantitative, first-principles understanding of the sources of potency loss. The analysis is applicable to other manufacturing processes where the primary sources of potency loss are net water gain and/or mass losses.

Experiences Using Formal Methods for Requirements Modeling

NASA Technical Reports Server (NTRS)

Easterbrook, Steve; Lutz, Robyn; Covington, Rick; Kelly, John; Ampo, Yoko; Hamilton, David

1996-01-01

This paper describes three cases studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, the formal modeling provided a cost effective enhancement of the existing verification and validation processes. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations.

Knowledge Creation in Nursing Education

PubMed Central

Hassanian, Zahra Marzieh; Ahanchian, Mohammad Reza; Ahmadi, Suleiman; Gholizadeh, Rezvan Hossein; Karimi-Moonaghi, Hossein

2015-01-01

In today’s society, knowledge is recognized as a valuable social asset and the educational system is in search of a new strategy that allows them to construct their knowledge and experience. The purpose of this study was to explore the process of knowledge creation in nursing education. In the present study, the grounded theory approach was used. This method provides a comprehensive approach to collecting, organizing, and analyzing data. Data were obtained through 17 semi-structured interviews with nursing faculties and nursing students. Purposeful and theoretical sampling was conducted. Based on the method of Strauss and Corbin, the data were analyzed using fragmented, deep, and constant-comparative methods. The main categories included striving for growth and reduction of ambiguity, use of knowledge resources, dynamism of mind and social factors, converting knowledge, and creating knowledge. Knowledge was converted through mind processes, individual and group reflection, praxis and research, and resulted in the creation of nursing knowledge. Discrete nursing knowledge is gained through disconformity research in order to gain more individual advantages. The consequence of this analysis was gaining new knowledge. Knowledge management must be included in the mission and strategic planning of nursing education, and it should be planned through operational planning in order to create applicable knowledge. PMID:25716383

Capturing, Sharing, and Discovering Product Data at a Semantic Level--Moving Forward to the Semantic Web for Advancing the Engineering Product Design Process

ERIC Educational Resources Information Center

Zhu, Lijuan

2011-01-01

Along with the greater productivity that CAD automation provides nowadays, the product data of engineering applications needs to be shared and managed efficiently to gain a competitive edge for the engineering product design. However, exchanging and sharing the heterogeneous product data is still challenging. This dissertation first presents a…

Applications of multiple-constraint matrix updates to the optimal control of large structures

NASA Technical Reports Server (NTRS)

Smith, S. W.; Walcott, B. L.

1992-01-01

Low-authority control or vibration suppression in large, flexible space structures can be formulated as a linear feedback control problem requiring computation of displacement and velocity feedback gain matrices. To ensure stability in the uncontrolled modes, these gain matrices must be symmetric and positive definite. In this paper, efficient computation of symmetric, positive-definite feedback gain matrices is accomplished through the use of multiple-constraint matrix update techniques originally developed for structural identification applications. Two systems were used to illustrate the application: a simple spring-mass system and a planar truss. From these demonstrations, use of this multiple-constraint technique is seen to provide a straightforward approach for computing the low-authority gains.

Sol-gel processing of bioactive glass nanoparticles: A review.

PubMed

Zheng, Kai; Boccaccini, Aldo R

2017-11-01

Silicate-based bioactive glass nanoparticles (BGN) are gaining increasing attention in various biomedical applications due to their unique properties. Controlled synthesis of BGN is critical to their effective use in biomedical applications since BGN characteristics, such as morphology and composition, determining the properties of BGN, are highly related to the synthesis process. In the last decade, numerous investigations focusing on BGN synthesis have been reported. BGN can mainly be produced through the conventional melt-quench approach or by sol-gel methods. The latter approaches are drawing widespread attention, considering the convenience and versatility they offer to tune the properties of BGN. In this paper, we review the strategies of sol-gel processing of BGN, including those adopting different catalysts for initiating the hydrolysis and condensation of silicate precursors as well as those combining sol-gel chemistry with other techniques. The processes and mechanism of different synthesis approaches are introduced and discussed in detail. Considering the importance of the BGN morphology and composition to their biomedical applications, strategies put forward to control the size, shape, pore structure and composition of BGN are discussed. BGN are particularly interesting biomaterials for bone-related applications, however, they also have potential for other biomedical applications, e.g. in soft tissue regeneration/repair. Therefore, in the last part of this review, recently reported applications of BGN in soft tissue repair and wound healing are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

Accelerated Application Development: The ORNL Titan Experience

DOE PAGES

Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; ...

2015-05-09

The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

Accelerated application development: The ORNL Titan experience

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

Joubert, Wayne; Archibald, Rick; Berrill, Mark

2015-08-01

The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

QATT: a Natural Language Interface for QPE. M.S. Thesis

NASA Technical Reports Server (NTRS)

White, Douglas Robert-Graham

1989-01-01

QATT, a natural language interface developed for the Qualitative Process Engine (QPE) system is presented. The major goal was to evaluate the use of a preexisting natural language understanding system designed to be tailored for query processing in multiple domains of application. The other goal of QATT is to provide a comfortable environment in which to query envisionments in order to gain insight into the qualitative behavior of physical systems. It is shown that the use of the preexisting system made possible the development of a reasonably useful interface in a few months.

Induced Pluripotency and Epigenetic Reprogramming

PubMed Central

Hochedlinger, Konrad; Jaenisch, Rudolf

2015-01-01

SUMMARY Induced pluripotency defines the process by which somatic cells are converted into induced pluripotent stem cells (iPSCs) upon overexpression of a small set of transcription factors. In this article, we put transcription factor–induced pluripotency into a historical context, review current methods to generate iPSCs, and discuss mechanistic insights that have been gained into the process of reprogramming. In addition, we focus on potential therapeutic applications of induced pluripotency and emerging technologies to efficiently engineer the genomes of human pluripotent cells for scientific and therapeutic purposes. PMID:26626939

CAD/CAM guided surgery in implant dentistry. A review of software packages and step-by-step protocols for planning surgical guides.

PubMed

Scherer, Michael D; Kattadiyil, Mathew T; Parciak, Ewa; Puri, Shweta

2014-01-01

Three-dimensional radiographic imaging for dental implant treatment planning is gaining widespread interest and popularity. However, application of the data from 30 imaging can be a complex and daunting process initially. The purpose of this article is to describe features of three software packages and the respective computerized guided surgical templates (GST) fabricated from them. A step-by-step method of interpreting and ordering a GST to simplify the process of the surgical planning and implant placement is discussed.

Long-pulse-width narrow-bandwidth solid state laser

DOEpatents

Dane, C. Brent; Hackel, Lloyd A.

1997-01-01

A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications.

Long-pulse-width narrow-bandwidth solid state laser

DOEpatents

Dane, C.B.; Hackel, L.A.

1997-11-18

A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications. 5 figs.

Optical amplifiers for coherent lidar

NASA Technical Reports Server (NTRS)

Fork, Richard

1996-01-01

We examine application of optical amplification to coherent lidar for the case of a weak return signal (a number of quanta of the return optical field close to unity). We consider the option that has been explored to date, namely, incorporation of an optical amplifier operated in a linear manner located after reception of the signal and immediately prior to heterodyning and photodetection. We also consider alternative strategies where the coherent interaction, the nonlinear processes, and the amplification are not necessarily constrained to occur in the manner investigated to date. We include the complications that occur because of mechanisms that occur at the level of a few, or one, quantum excitation. Two factors combine in the work to date that limit the value of the approach. These are: (1) the weak signal tends to require operation of the amplifier in the linear regime where the important advantages of nonlinear optical processing are not accessed, (2) the linear optical amplifier has a -3dB noise figure (SN(out)/SN(in)) that necessarily degrades the signal. Some improvement is gained because the gain provided by the optical amplifier can be used to overcome losses in the heterodyned process and photodetection. The result, however, is that introduction of an optical amplifier in a well optimized coherent lidar system results in, at best, a modest improvement in signal to noise. Some improvement may also be realized on incorporating more optical components in a coherent lidar system for purely practical reasons. For example, more compact, lighter weight, components, more robust alignment, or more rapid processing may be gained. We further find that there remain a number of potentially valuable, but unexplored options offered both by the rapidly expanding base of optical technology and the recent investigation of novel nonlinear coherent interference phenomena occurring at the single quantum excitation level. Key findings are: (1) insertion of linear optical amplifiers in well optimized conventional lidar systems offers modest improvements, at best, (2) the practical advantages of optical amplifiers, especially fiber amplifiers, such as ease of alignment, compactness, efficiency, lightweight, etc., warrant further investigation for coherent lidar, (3) the possibility of more fully optical lidar systems should be explored, (4) advantages gained by use of coherent interference of optical fields at the level of one, or a few, signal quanta should be explored, (5) amplification without inversion, population trapping, and use of electromagnetic induced transparency warrant investigation in connection with coherent lidar, (6) these new findings are probably more applicable to earth related NASA work, although applications to deep space should not be excluded, and (7) our own work in the Ultrafast Laboratory at UAH along some of the above lines of investigation, may be useful.

Stress effects on framed decisions: there are differences for gains and losses.

PubMed

Pabst, Stephan; Brand, Matthias; Wolf, Oliver T

2013-01-01

Recent studies have shown that acute stress can lead to riskier decision making. Yet, the underlying mechanisms of the stress effects on decisions under risk remain poorly understood. To gain a better understanding of decision-making processes and potential strategy application under stress, we investigated decision making in pure gain and loss domains with unequal expected values (EVs) across alternatives. We conducted an experimental study with a 2 × 2 design (stress vs. no stress and gain domain vs. loss domain). The Trier Social Stress Test (TSST) was utilized to induce acute stress. Controls performed the placebo-TSST (p-TSST). To validate the stress response we measured salivary cortisol and alpha-amylase concentrations. We used a modified version of the Game of Dice Task (GDT) to assess decision-making performance in a gain and a loss domain. Results showed that non-stressed participants made less risky decisions in the gain domain compared to those of the loss domain. This behavior is in accordance with previous studies and indicates the stability of the framing effect in even more complex tasks with changing EVs across alternatives. Stress did not alter risk taking behavior in the gain domain. Yet, in the loss domain stressed participants made less risky decisions compared to controls. Additionally, the data support earlier findings of longer reaction times in loss compared to gain domains due to higher cognitive effort for loss-framed decisions. It is discussed that stress may lead to reduced amygdala activation, which has been found to reduce riskier decisions in a loss domain. With respect to earlier results of riskier decisions in tasks that unite both gain and loss domains, it is discussed whether stress leads to a stronger evaluation of high gains and a neglect of losses.

A 14-bit 40-MHz analog front end for CCD application

NASA Astrophysics Data System (ADS)

Jingyu, Wang; Zhangming, Zhu; Shubin, Liu

2016-06-01

A 14-bit, 40-MHz analog front end (AFE) for CCD scanners is analyzed and designed. The proposed system incorporates a digitally controlled wideband variable gain amplifier (VGA) with nearly 42 dB gain range, a correlated double sampler (CDS) with programmable gain functionality, a 14-bit analog-to-digital converter and a programmable timing core. To achieve the maximum dynamic range, the VGA proposed here can linearly amplify the input signal in a gain range from -1.08 to 41.06 dB in 6.02 dB step with a constant bandwidth. A novel CDS takes image information out of noise, and further amplifies the signal accurately in a gain range from 0 to 18 dB in 0.035 dB step. A 14-bit ADC is adopted to quantify the analog signal with optimization in power and linearity. An internal timing core can provide flexible timing for CCD arrays, CDS and ADC. The proposed AFE was fabricated in SMIC 0.18 μm CMOS process. The whole circuit occupied an active area of 2.8 × 4.8 mm2 and consumed 360 mW. When the frequency of input signal is 6.069 MHz, and the sampling frequency is 40 MHz, the signal to noise and distortion (SNDR) is 70.3 dB, the effective number of bits is 11.39 bit. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033), the National High-Tech Program of China (No. 2013AA014103), and the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory (No. ZHD201302).

Warehouses information system design and development

NASA Astrophysics Data System (ADS)

Darajatun, R. A.; Sukanta

2017-12-01

Materials/goods handling industry is fundamental for companies to ensure the smooth running of their warehouses. Efficiency and organization within every aspect of the business is essential in order to gain a competitive advantage. The purpose of this research is design and development of Kanban of inventory storage and delivery system. Application aims to facilitate inventory stock checks to be more efficient and effective. Users easily input finished goods from production department, warehouse, customer, and also suppliers. Master data designed as complete as possible to be prepared applications used in a variety of process logistic warehouse variations. The author uses Java programming language to develop the application, which is used for building Java Web applications, while the database used is MySQL. System development methodology that I use is the Waterfall methodology. Waterfall methodology has several stages of the Analysis, System Design, Implementation, Integration, Operation and Maintenance. In the process of collecting data the author uses the method of observation, interviews, and literature.

A study of internal structure in components made by additive manufacturing process using 3 D X-ray tomography

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

Raguvarun, K., E-mail: prajagopal@iitm.ac.in; Balasubramaniam, Krishnan, E-mail: prajagopal@iitm.ac.in; Rajagopal, Prabhu, E-mail: prajagopal@iitm.ac.in

Additive manufacturing methods are gaining increasing popularity for rapidly and efficiently manufacturing parts and components in the industrial context, as well as for domestic applications. However, except when used for prototyping or rapid visualization of components, industries are concerned with the load carrying capacity and strength achievable by additive manufactured parts. In this paper, the wire-arc additive manufacturing (AM) process based on gas tungsten arc welding (GTAW) has been examined for the internal structure and constitution of components generated by the process. High-resolution 3D X-ray tomography is used to gain cut-views through wedge-shaped parts created using this GTAW additive manufacturingmore » process with titanium alloy materials. In this work, two different control conditions for the GTAW process are considered. The studies reveal clusters of porosities, located in periodic spatial intervals along the sample cross-section. Such internal defects can have a detrimental effect on the strength of the resulting AM components, as shown in destructive testing studies. Closer examination of this phenomenon shows that defect clusters are preferentially located at GTAW traversal path intervals. These results highlight the strong need for enhanced control of process parameters in ensuring components with minimal defects and higher strength.« less

A study of internal structure in components made by additive manufacturing process using 3 D X-ray tomography

NASA Astrophysics Data System (ADS)

Raguvarun, K.; Balasubramaniam, Krishnan; Rajagopal, Prabhu; Palanisamy, Suresh; Nagarajah, Romesh; Hoye, Nicholas; Curiri, Dominic; Kapoor, Ajay

2015-03-01

Additive manufacturing methods are gaining increasing popularity for rapidly and efficiently manufacturing parts and components in the industrial context, as well as for domestic applications. However, except when used for prototyping or rapid visualization of components, industries are concerned with the load carrying capacity and strength achievable by additive manufactured parts. In this paper, the wire-arc additive manufacturing (AM) process based on gas tungsten arc welding (GTAW) has been examined for the internal structure and constitution of components generated by the process. High-resolution 3D X-ray tomography is used to gain cut-views through wedge-shaped parts created using this GTAW additive manufacturing process with titanium alloy materials. In this work, two different control conditions for the GTAW process are considered. The studies reveal clusters of porosities, located in periodic spatial intervals along the sample cross-section. Such internal defects can have a detrimental effect on the strength of the resulting AM components, as shown in destructive testing studies. Closer examination of this phenomenon shows that defect clusters are preferentially located at GTAW traversal path intervals. These results highlight the strong need for enhanced control of process parameters in ensuring components with minimal defects and higher strength.

Laser 3D micro-manufacturing

NASA Astrophysics Data System (ADS)

Piqué, Alberto; Auyeung, Raymond C. Y.; Kim, Heungsoo; Charipar, Nicholas A.; Mathews, Scott A.

2016-06-01

Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications.

A DERATING METHOD FOR THERAPEUTIC APPLICATIONS OF HIGH INTENSITY FOCUSED ULTRASOUND

PubMed Central

Bessonova, O.V.; Khokhlova, V.A.; Canney, M.S.; Bailey, M.R.; Crum, L.A.

2010-01-01

Current methods of determining high intensity focused ultrasound (HIFU) fields in tissue rely on extrapolation of measurements in water assuming linear wave propagation both in water and in tissue. Neglecting nonlinear propagation effects in the derating process can result in significant errors. In this work, a new method based on scaling the source amplitude is introduced to estimate focal parameters of nonlinear HIFU fields in tissue. Focal values of acoustic field parameters in absorptive tissue are obtained from a numerical solution to a KZK-type equation and are compared to those simulated for propagation in water. Focal waveforms, peak pressures, and intensities are calculated over a wide range of source outputs and linear focusing gains. Our modeling indicates, that for the high gain sources which are typically used in therapeutic medical applications, the focal field parameters derated with our method agree well with numerical simulation in tissue. The feasibility of the derating method is demonstrated experimentally in excised bovine liver tissue. PMID:20582159

A derating method for therapeutic applications of high intensity focused ultrasound

NASA Astrophysics Data System (ADS)

Bessonova, O. V.; Khokhlova, V. A.; Canney, M. S.; Bailey, M. R.; Crum, L. A.

2010-05-01

Current methods of determining high intensity focused ultrasound (HIFU) fields in tissue rely on extrapolation of measurements in water assuming linear wave propagation both in water and in tissue. Neglecting nonlinear propagation effects in the derating process can result in significant errors. A new method based on scaling the source amplitude is introduced to estimate focal parameters of nonlinear HIFU fields in tissue. Focal values of acoustic field parameters in absorptive tissue are obtained from a numerical solution to a KZK-type equation and are compared to those simulated for propagation in water. Focal wave-forms, peak pressures, and intensities are calculated over a wide range of source outputs and linear focusing gains. Our modeling indicates, that for the high gain sources which are typically used in therapeutic medical applications, the focal field parameters derated with our method agree well with numerical simulation in tissue. The feasibility of the derating method is demonstrated experimentally in excised bovine liver tissue.

A DERATING METHOD FOR THERAPEUTIC APPLICATIONS OF HIGH INTENSITY FOCUSED ULTRASOUND.

PubMed

Bessonova, O V; Khokhlova, V A; Canney, M S; Bailey, M R; Crum, L A

2010-01-01

Current methods of determining high intensity focused ultrasound (HIFU) fields in tissue rely on extrapolation of measurements in water assuming linear wave propagation both in water and in tissue. Neglecting nonlinear propagation effects in the derating process can result in significant errors. In this work, a new method based on scaling the source amplitude is introduced to estimate focal parameters of nonlinear HIFU fields in tissue. Focal values of acoustic field parameters in absorptive tissue are obtained from a numerical solution to a KZK-type equation and are compared to those simulated for propagation in water. Focal waveforms, peak pressures, and intensities are calculated over a wide range of source outputs and linear focusing gains. Our modeling indicates, that for the high gain sources which are typically used in therapeutic medical applications, the focal field parameters derated with our method agree well with numerical simulation in tissue. The feasibility of the derating method is demonstrated experimentally in excised bovine liver tissue.

A novel "gain chip" concept for high-power lasers (Conference Presentation)

NASA Astrophysics Data System (ADS)

Li, Min; Li, Mingzhong; Wang, Zhenguo; Yan, Xiongwei; Jiang, Xinying; Zheng, Jiangang; Cui, Xudong; Zhang, Xiaomin

2017-05-01

High-power lasers, including high-peak power lasers (HPPL) and high-average power lasers (HAPL), attract much interest for enormous variety of applications in inertial fusion energy (IFE), materials processing, defense, spectroscopy, and high-field physics research. To meet the requirements of high efficiency and quality, a "gain chip" concept is proposed to properly design the pumping, cooling and lasing fields. The gain chip mainly consists of the laser diode arrays, lens duct, rectangle wave guide and slab-shaped gain media. For the pumping field, the pump light will be compressed and homogenized by the lens duct to high irradiance with total internal reflection, and further coupled into the gain media through its two edge faces. For the cooling field, the coolant travels along the flow channel created by the adjacent slabs in the other two edge-face direction, and cool the lateral faces of the gain media. For the lasing field, the laser beam travels through the lateral faces and experiences minimum thermal wavefront distortions. Thereby, these three fields are in orthogonality offering more spatial freedom to handle them during the construction of the lasers. Transverse gradient doping profiles for HPPL and HAPL have been employed to achieve uniform gain distributions (UGD) within the gain media, respectively. This UGD will improve the management for both amplified spontaneous emission (ASE) and thermal behavior. Since each "gain chip" has its own pump source, power scaling can be easily achieved by placing identical "gain chips" along the laser beam axis without disturbing the gain and thermal distributions. To detail our concept, a 1-kJ pulsed amplifier is designed and optical-to-optical efficiency up to 40% has been obtained. We believe that with proper coolant (gas or liquid) and gain media (Yb:YAG, Nd:glass or Nd:YAG) our "gain chip" concept might provide a general configuration for high-power lasers with high efficiency and quality.

Microwave gain medium with negative refractive index.

PubMed

Ye, Dexin; Chang, Kihun; Ran, Lixin; Xin, Hao

2014-12-19

Artificial effective media are attractive because of the fantastic applications they may enable, such as super lensing and electromagnetic invisibility. However, the inevitable loss due to their strongly dispersive nature is one of the fundamental challenges preventing such applications from becoming a reality. In this study, we demonstrate an effective gain medium based on negative resistance, to overcompensate the loss of a conventional passive metamaterial, meanwhile keeping its original negative-index property. Energy conservation-based theory, full-wave simulation and experimental measurement show that a fabricated sample consisting of conventional sub-wavelength building blocks with embedded microwave tunnel diodes exhibits a band-limited Lorentzian dispersion simultaneously with a negative refractive index and a net gain. Our work provides experimental evidence to the assertion that a stable net gain in negative-index gain medium is achievable, proposing a potential solution for the critical challenge current metamateiral technology faces in practical applications.

Information Assurance: Detection & Response to Web Spam Attacks

DTIC Science & Technology

2010-08-28

such as blogs, social bookmarking ( folksonomies ), and wikis continue to gain its popularity, concerns about the rapid proliferation of Web spam has...Attacks Report Title ABSTRACT As online social media applications such as blogs, social bookmarking ( folksonomies ), and wikis continue to gain its... folksonomies ), and wikis continue to gain its popularity, concerns about the rapid proliferation of Web spam has grown in recent years. These applications

Evaluation of a quarterwave stub antenna for TIROS satellite application

NASA Astrophysics Data System (ADS)

Stogner, L. B.

1980-06-01

The TIROS-N quarterwave stub antenna communicated accurate position locations during low power level operations based on data processed by the Local User's Terminal (LUT) and Service ARGOS. This style of antenna is the marine mammal transmitter package. The antenna gain and radiation pattern and vertical polarization enhance the applicability. However, for marine mammal transmitter applications, a spring at the base of the antenna is required to provide flexibility and protection to the animal and the antenna must serve as a seawater sensor requiring it to be insulated from the seawater environment except at the sensory location. These problems appear solved for the NIMBUS system, and the TIROS system will be designed accordingly.

Bioprospecting thermophiles for cellulase production: a review

PubMed Central

Acharya, Somen; Chaudhary, Anita

2012-01-01

Most of the potential bioprospecting is currently related to the study of the extremophiles and their potential use in industrial processes. Recently microbial cellulases find applications in various industries and constitute a major group of industrial enzymes. Considerable amount of work has been done on microbial cellulases, especially with resurgence of interest in biomass ethanol production employing cellulases and use of cellulases in textile and paper industry. Most efficient method of lignocellulosic biomass hydrolysis is through enzymatic saccharification using cellulases. Significant information has also been gained about the physiology of thermophilic cellulases producers and process development for enzyme production and biomass saccharification. The review discusses the current knowledge on cellulase producing thermophilic microorganisms, their physiological adaptations and control of cellulase gene expression. It discusses the industrial applications of thermophilic cellulases, their cost of production and challenges in cellulase research especially in the area of improving process economics of enzyme production. PMID:24031898

Bioprospecting thermophiles for cellulase production: a review.

PubMed

Acharya, Somen; Chaudhary, Anita

2012-07-01

Most of the potential bioprospecting is currently related to the study of the extremophiles and their potential use in industrial processes. Recently microbial cellulases find applications in various industries and constitute a major group of industrial enzymes. Considerable amount of work has been done on microbial cellulases, especially with resurgence of interest in biomass ethanol production employing cellulases and use of cellulases in textile and paper industry. Most efficient method of lignocellulosic biomass hydrolysis is through enzymatic saccharification using cellulases. Significant information has also been gained about the physiology of thermophilic cellulases producers and process development for enzyme production and biomass saccharification. The review discusses the current knowledge on cellulase producing thermophilic microorganisms, their physiological adaptations and control of cellulase gene expression. It discusses the industrial applications of thermophilic cellulases, their cost of production and challenges in cellulase research especially in the area of improving process economics of enzyme production.

Modelling of plasma processes in cometary and planetary atmospheres

NASA Astrophysics Data System (ADS)

Campbell, L.; Brunger, M. J.

2013-02-01

Electrons from the Sun, often accelerated by magnetospheric processes, produce low-density plasmas in the upper atmospheres of planets and their satellites. The secondary electrons can produce further ionization, dissociation and excitation, leading to enhancement of chemical reactions and light emission. Similar processes are driven by photoelectrons produced by sunlight in upper atmospheres during daytime. Sunlight and solar electrons drive the same processes in the atmospheres of comets. Thus for both understanding of planetary atmospheres and in predicting emissions for comparison with remote observations it is necessary to simulate the processes that produce upper atmosphere plasmas. In this review, we describe relevant models and their applications and address the importance of electron-impact excitation cross sections, towards gaining a quantitative understanding of the phenomena in question.

A Comparative Study : Microprogrammed Vs Risc Architectures For Symbolic Processing

NASA Astrophysics Data System (ADS)

Heudin, J. C.; Metivier, C.; Demigny, D.; Maurin, T.; Zavidovique, B.; Devos, F.

1987-05-01

It is oftenclaimed that conventional computers are not well suited for human-like tasks : Vision (Image Processing), Intelligence (Symbolic Processing) ... In the particular case of Artificial Intelligence, dynamic type-checking is one example of basic task that must be improved. The solution implemented in most Lisp work-stations consists in a microprogrammed architecture with a tagged memory. Another way to gain efficiency is to design a well suited instruction set for symbolic processing, which reduces the semantic gap between the high level language and the machine code. In this framework, the RISC concept provides a convenient approach to study new architectures for symbolic processing. This paper compares both approaches and describes our projectof designing a compact symbolic processor for Artificial Intelligence applications.

Electromagnetic Counter-Counter Measure (ECCM) Techniques of the Digital Microwave Radio.

DTIC Science & Technology

1982-05-01

Frequency hopping requires special synthesizers and filter banks. Large bandwidth expansion in a microwave radio relay application can best be achieved with...34 processing gain " performance as a function of jammer modulation type " pulse jammer performance • emission bandwidth and spectral shaping 0... spectral efficiency, implementation complexity, and suitability for ECCK techniques will be considered. A sumary of the requirements and characteristics of

A Review of the Use of Script-Based Tracking in CALL Research for Data Sharing: Applications Providing Meaning Aids

ERIC Educational Resources Information Center

Hwu, Fenfang

2013-01-01

Using script-based tracking to gain insights into the way students learn or process language information can be traced as far back as to the 1980s. Nevertheless, researchers continue to face challenges in collecting and studying this type of data. The objective of this study is to propose data sharing through data repositories as a way to (a) ease…

Expanding the Cognitive Behavioural Therapy Traditions: An Application of Functional Analytic Psychotherapy Treatment in a Case Study of Depression

ERIC Educational Resources Information Center

McClafferty, Catherine

2012-01-01

What can CBT therapists do when interpersonal issues are pertinent to therapeutic change and there is a deficit of CBT literature offering clinicians' guidance on how to address this as part of the therapy process? Do we say "clients are resistant?", "Not ready for change?", or "there is too much secondary gain?" As therapists we may not be…

Performance of the THS4302 and the Class V Radiation-Tolerant THS4304-SP Silicon Germanium Wideband Amplifiers at Extreme Temperatures

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Elbuluk, Malik; Hammoud, Ahmad; VanKeuls, Frederick W.

2009-01-01

This report discusses the performance of silicon germanium, wideband gain amplifiers under extreme temperatures. The investigated devices include Texas Instruments THS4304-SP and THS4302 amplifiers. Both chips are manufactured using the BiCom3 process based on silicon germanium technology along with silicon-on-insulator (SOI) buried oxide layers. The THS4304-SP device was chosen because it is a Class V radiation-tolerant (150 kRad, TID silicon), voltage-feedback operational amplifier designed for use in high-speed analog signal applications and is very desirable for NASA missions. It operates with a single 5 V power supply [1]. It comes in a 10-pin ceramic flatpack package, and it provides balanced inputs, low offset voltage and offset current, and high common mode rejection ratio. The fixed-gain THS4302 chip, which comes in a 16-pin leadless package, offers high bandwidth, high slew rate, low noise, and low distortion [2]. Such features have made the amplifier useful in a number of applications such as wideband signal processing, wireless transceivers, intermediate frequency (IF) amplifier, analog-to-digital converter (ADC) preamplifier, digital-to-analog converter (DAC) output buffer, measurement instrumentation, and medical and industrial imaging.

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

Mitchell, Dean J.; Harding, Lee T.

Isotope identification algorithms that are contained in the Gamma Detector Response and Analysis Software (GADRAS) can be used for real-time stationary measurement and search applications on platforms operating under Linux or Android operating sys-tems. Since the background radiation can vary considerably due to variations in natu-rally-occurring radioactive materials (NORM), spectral algorithms can be substantial-ly more sensitive to threat materials than search algorithms based strictly on count rate. Specific isotopes or interest can be designated for the search algorithm, which permits suppression of alarms for non-threatening sources, such as such as medical radionuclides. The same isotope identification algorithms that are usedmore » for search ap-plications can also be used to process static measurements. The isotope identification algorithms follow the same protocols as those used by the Windows version of GADRAS, so files that are created under the Windows interface can be copied direct-ly to processors on fielded sensors. The analysis algorithms contain provisions for gain adjustment and energy lineariza-tion, which enables direct processing of spectra as they are recorded by multichannel analyzers. Gain compensation is performed by utilizing photopeaks in background spectra. Incorporation of this energy calibration tasks into the analysis algorithm also eliminates one of the more difficult challenges associated with development of radia-tion detection equipment.« less

Trends in laser micromachining

NASA Astrophysics Data System (ADS)

Gaebler, Frank; van Nunen, Joris; Held, Andrew

2016-03-01

Laser Micromachining is well established in industry. Depending on the application lasers with pulse length from μseconds to femtoseconds and wavelengths from 1064nm and its harmonics up to 5μm or 10.6μm are used. Ultrafast laser machining using pulses with pico or femtosecond duration pulses is gaining traction, as it offers very precise processing of materials with low thermal impact. Large-scale industrial ultrafast laser applications show that the market can be divided into various sub segments. One set of applications demand low power around 10W, compact footprint and are extremely sensitive to the laser price whilst still demanding 10ps or shorter laser pulses. A second set of applications are very power hungry and only become economically feasible for large scale deployments at power levels in the 100+W class. There is also a growing demand for applications requiring fs-laser pulses. In our presentation we would like to describe these sub segments by using selected applications from the automotive and electronics industry e.g. drilling of gas/diesel injection nozzles, dicing of LED substrates. We close the presentation with an outlook to micromachining applications e.g. glass cutting and foil processing with unique new CO lasers emitting 5μm laser wavelength.

Operational uses of ACTS technology

NASA Astrophysics Data System (ADS)

Gedney, Richard T.; Wright, David L.; Balombin, Joseph L.; Sohn, Philip Y.; Cashman, William F.; Stern, Alan L.; Golding, Len; Palmer, Larry

1992-03-01

The NASA Advanced Communications Technology Satellite (ACTS) provides the technologies for very high gain hopping spot beam antennas, on-board baseband routing and processing, and wideband (1 GHz) Ka-band transponders. A number of studies have recently been completed using the experience gained in developing the actual ACTS system hardware to quantify how well the ACTS technology can be used in future operational systems. This paper provides a summary of these study results including the spacecraft (S/C) weight per unit circuit for providing services by ACTS technologies as compared to present-day satellites. The uses of the ACTS technology discussed are for providing T1 VSAT mesh networks, aeronautical mobile communications, supervisory control and data acquisition (SCADA) services, and high data rate networks for supercomputer and other applications.

Optofluidic Bio-Lasers: Concept and Applications

PubMed Central

Fan, Xudong; Yun, Seok-Hyun

2014-01-01

An optofluidic bio-laser integrates biological materials into the gain medium while forming an optical cavity in the fluidic environment, either on a microfluidic chip or within a biological system. The laser emission has characteristics fundamentally different from conventional fluorescence emission. It can be highly sensitive to a specific molecular change in the gain medium as the light-matter interaction is amplified by the resonance in the cavity. The enhanced sensitivity can be used to probe and quantify the underlying biochemical and biological processes in vitro in a microfluidic device, in situ in a cell (cytosol), or in vivo in a live organism. Here we describe the principle of the optofluidic bio-laser, review its recent progress and provide an outlook of this emerging technology. PMID:24481219

Experiences Using Lightweight Formal Methods for Requirements Modeling

NASA Technical Reports Server (NTRS)

Easterbrook, Steve; Lutz, Robyn; Covington, Rick; Kelly, John; Ampo, Yoko; Hamilton, David

1997-01-01

This paper describes three case studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, formal methods enhanced the existing verification and validation processes, by testing key properties of the evolving requirements, and helping to identify weaknesses. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations.

siGnum: graphical user interface for EMG signal analysis.

PubMed

Kaur, Manvinder; Mathur, Shilpi; Bhatia, Dinesh; Verma, Suresh

2015-01-01

Electromyography (EMG) signals that represent the electrical activity of muscles can be used for various clinical and biomedical applications. These are complicated and highly varying signals that are dependent on anatomical location and physiological properties of the muscles. EMG signals acquired from the muscles require advanced methods for detection, decomposition and processing. This paper proposes a novel Graphical User Interface (GUI) siGnum developed in MATLAB that will apply efficient and effective techniques on processing of the raw EMG signals and decompose it in a simpler manner. It could be used independent of MATLAB software by employing a deploy tool. This would enable researcher's to gain good understanding of EMG signal and its analysis procedures that can be utilized for more powerful, flexible and efficient applications in near future.

Adaptive Sensing of Time Series with Application to Remote Exploration

NASA Technical Reports Server (NTRS)

Thompson, David R.; Cabrol, Nathalie A.; Furlong, Michael; Hardgrove, Craig; Low, Bryan K. H.; Moersch, Jeffrey; Wettergreen, David

2013-01-01

We address the problem of adaptive informationoptimal data collection in time series. Here a remote sensor or explorer agent throttles its sampling rate in order to track anomalous events while obeying constraints on time and power. This problem is challenging because the agent has limited visibility -- all collected datapoints lie in the past, but its resource allocation decisions require predicting far into the future. Our solution is to continually fit a Gaussian process model to the latest data and optimize the sampling plan on line to maximize information gain. We compare the performance characteristics of stationary and nonstationary Gaussian process models. We also describe an application based on geologic analysis during planetary rover exploration. Here adaptive sampling can improve coverage of localized anomalies and potentially benefit mission science yield of long autonomous traverses.

Performance bounds for nonlinear systems with a nonlinear ℒ2-gain property

NASA Astrophysics Data System (ADS)

Zhang, Huan; Dower, Peter M.

2012-09-01

Nonlinear ℒ2-gain is a finite gain concept that generalises the notion of conventional (linear) finite ℒ2-gain to admit the application of ℒ2-gain analysis tools of a broader class of nonlinear systems. The computation of tight comparison function bounds for this nonlinear ℒ2-gain property is important in applications such as small gain design. This article presents an approximation framework for these comparison function bounds through the formulation and solution of an optimal control problem. Key to the solution of this problem is the lifting of an ℒ2-norm input constraint, which is facilitated via the introduction of an energy saturation operator. This admits the solution of the optimal control problem of interest via dynamic programming and associated numerical methods, leading to the computation of the proposed bounds. Two examples are presented to demonstrate this approach.

Embedded neural recording with TinyOS-based wireless-enabled processor modules.

PubMed

Farshchi, Shahin; Pesterev, Aleksey; Nuyujukian, Paul; Guenterberg, Eric; Mody, Istvan; Judy, Jack W

2010-04-01

To create a wireless neural recording system that can benefit from the continuous advancements being made in embedded microcontroller and communications technologies, an embedded-system-based architecture for wireless neural recording has been designed, fabricated, and tested. The system consists of commercial-off-the-shelf wireless-enabled processor modules (motes) for communicating the neural signals, and a back-end database server and client application for archiving and browsing the neural signals. A neural-signal-acquisition application has been developed to enable the mote to either acquire neural signals at a rate of 4000 12-bit samples per second, or detect and transmit spike heights and widths sampled at a rate of 16670 12-bit samples per second on a single channel. The motes acquire neural signals via a custom low-noise neural-signal amplifier with adjustable gain and high-pass corner frequency that has been designed, and fabricated in a 1.5-microm CMOS process. In addition to browsing acquired neural data, the client application enables the user to remotely toggle modes of operation (real-time or spike-only), as well as amplifier gain and high-pass corner frequency.

High Throughput Multispectral Image Processing with Applications in Food Science.

PubMed

Tsakanikas, Panagiotis; Pavlidis, Dimitris; Nychas, George-John

2015-01-01

Recently, machine vision is gaining attention in food science as well as in food industry concerning food quality assessment and monitoring. Into the framework of implementation of Process Analytical Technology (PAT) in the food industry, image processing can be used not only in estimation and even prediction of food quality but also in detection of adulteration. Towards these applications on food science, we present here a novel methodology for automated image analysis of several kinds of food products e.g. meat, vanilla crème and table olives, so as to increase objectivity, data reproducibility, low cost information extraction and faster quality assessment, without human intervention. Image processing's outcome will be propagated to the downstream analysis. The developed multispectral image processing method is based on unsupervised machine learning approach (Gaussian Mixture Models) and a novel unsupervised scheme of spectral band selection for segmentation process optimization. Through the evaluation we prove its efficiency and robustness against the currently available semi-manual software, showing that the developed method is a high throughput approach appropriate for massive data extraction from food samples.

A code inspection process for security reviews

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

Garzoglio, Gabriele; /Fermilab

2009-05-01

In recent years, it has become more and more evident that software threat communities are taking an increasing interest in Grid infrastructures. To mitigate the security risk associated with the increased numbers of attacks, the Grid software development community needs to scale up effort to reduce software vulnerabilities. This can be achieved by introducing security review processes as a standard project management practice. The Grid Facilities Department of the Fermilab Computing Division has developed a code inspection process, tailored to reviewing security properties of software. The goal of the process is to identify technical risks associated with an application andmore » their impact. This is achieved by focusing on the business needs of the application (what it does and protects), on understanding threats and exploit communities (what an exploiter gains), and on uncovering potential vulnerabilities (what defects can be exploited). The desired outcome of the process is an improvement of the quality of the software artifact and an enhanced understanding of possible mitigation strategies for residual risks. This paper describes the inspection process and lessons learned on applying it to Grid middleware.« less

A code inspection process for security reviews

NASA Astrophysics Data System (ADS)

Garzoglio, Gabriele

2010-04-01

In recent years, it has become more and more evident that software threat communities are taking an increasing interest in Grid infrastructures. To mitigate the security risk associated with the increased numbers of attacks, the Grid software development community needs to scale up effort to reduce software vulnerabilities. This can be achieved by introducing security review processes as a standard project management practice. The Grid Facilities Department of the Fermilab Computing Division has developed a code inspection process, tailored to reviewing security properties of software. The goal of the process is to identify technical risks associated with an application and their impact. This is achieved by focusing on the business needs of the application (what it does and protects), on understanding threats and exploit communities (what an exploiter gains), and on uncovering potential vulnerabilities (what defects can be exploited). The desired outcome of the process is an improvement of the quality of the software artifact and an enhanced understanding of possible mitigation strategies for residual risks. This paper describes the inspection process and lessons learned on applying it to Grid middleware.

Fuel processing for PEM fuel cells: transport and kinetic issues of system design

NASA Astrophysics Data System (ADS)

Zalc, J. M.; Löffler, D. G.

In light of the distribution and storage issues associated with hydrogen, efficient on-board fuel processing will be a significant factor in the implementation of PEM fuel cells for automotive applications. Here, we apply basic chemical engineering principles to gain insight into the factors that limit performance in each component of a fuel processor. A system consisting of a plate reactor steam reformer, water-gas shift unit, and preferential oxidation reactor is used as a case study. It is found that for a steam reformer based on catalyst-coated foils, mass transfer from the bulk gas to the catalyst surface is the limiting process. The water-gas shift reactor is expected to be the largest component of the fuel processor and is limited by intrinsic catalyst activity, while a successful preferential oxidation unit depends on strict temperature control in order to minimize parasitic hydrogen oxidation. This stepwise approach of sequentially eliminating rate-limiting processes can be used to identify possible means of performance enhancement in a broad range of applications.

Contact and non-contact ultrasonic measurement in the food industry: a review

NASA Astrophysics Data System (ADS)

Taufiq Mohd Khairi, Mohd; Ibrahim, Sallehuddin; Yunus, Mohd Amri Md; Faramarzi, Mahdi

2016-01-01

The monitoring of the food manufacturing process is vital since it determines the safety and quality level of foods which directly affect the consumers’ health. Companies which produce high quality products will gain trust from consumers. This factor helps the companies to make profits. The use of efficient and appropriate sensors for the monitoring process can also reduce cost. The food assessing process based on an ultrasonic sensor has attracted the attention of the food industry due to its excellent capabilities in several applications. The utilization of low or high frequencies for the ultrasonic transducer has provided an enormous benefit for analysing, modifying and guaranteeing the quality of food. The contact and non-contact ultrasonic modes for measurement also contributed significantly to the food processing. This paper presents a review of the application of the contact and non-contact mode of ultrasonic measurement focusing on safety and quality control areas. The results from previous researches are shown and elaborated.

Improving NASA's technology transfer process through increased screening and evaluation in the information dissemination program

NASA Technical Reports Server (NTRS)

Laepple, H.

1979-01-01

The current status of NASA's technology transfer system can be improved if the technology transfer process is better understood. This understanding will only be gained if a detailed knowledge about factors generally influencing technology transfer is developed, and particularly those factors affecting technology transfer from government R and D agencies to industry. Secondary utilization of aerospace technology is made more difficult because it depends on a transfer process which crosses established organizational lines of authority and which is outside well understood patterns of technical applications. In the absence of a sound theory about technology transfer and because of the limited capability of government agencies to explore industry's needs, a team approach to screening and evaluation of NASA generated technologies is proposed which calls for NASA, and other organizations of the private and public sectors which influence the transfer of NASA generated technology, to participate in a screening and evaluation process to determine the commercial feasibility of a wide range of technical applications.

A solid-state amorphous selenium avalanche technology for low photon flux imaging applications

PubMed Central

Wronski, M. M.; Zhao, W.; Reznik, A.; Tanioka, K.; DeCrescenzo, G.; Rowlands, J. A.

2010-01-01

Purpose: The feasibility of a practical solid-state technology for low photon flux imaging applications was investigated. The technology is based on an amorphous selenium photoreceptor with a voltage-controlled avalanche multiplication gain. If this photoreceptor can provide sufficient internal gain, it will be useful for an extensive range of diagnostic imaging systems. Methods: The avalanche photoreceptor under investigation is referred to as HARP-DRL. This is a novel concept in which a high-gain avalanche rushing photoconductor (HARP) is integrated with a distributed resistance layer (DRL) and sandwiched between two electrodes. The avalanche gain and leakage current characteristics of this photoreceptor were measured. Results: HARP-DRL has been found to sustain very high electric field strengths without electrical breakdown. It has shown avalanche multiplication gains as high as 104 and a very low leakage current (≤20 pA∕mm2). Conclusions: This is the first experimental demonstration of a solid-state amorphous photoreceptor which provides sufficient internal avalanche gain for photon counting and photon starved imaging applications. PMID:20964217

Application variables and their influence on forest herbicide efficacy and selectivity: gaining understanding and control

Treesearch

James H. Miller

1998-01-01

Available research is reviewed on the interactions of application variables, herbicides, and species. Objectives of this review are to gain insights into why variation occurs with herbicide performance, how current knowledge might be applied to enhance efficacy and consistency, and research pathways that should foster integration of application-efficacy models. A...

A Different Approach to Have Science and Technology Student-Teachers Gain Varied Methods in Laboratory Applications: A Sample of Computer Assisted POE Application

ERIC Educational Resources Information Center

Saka, Arzu

2012-01-01

The purpose of this study is to develop a new approach and assess the application for the science and technology student-teachers to gain varied laboratory methods in science and technology teaching. It is also aimed to describe the computer-assisted POE application in the subject of "Photosynthesis-Light" developed in the context of…

"I want a normal life like everyone else": Daily life of asylum seekers in Iceland.

PubMed

Ingvarsson, Lilja; Egilson, Snæfrídur Thóra; Skaptadottir, Unnur Dís

2016-11-01

An ever-increasing number of people seek asylum in Iceland. The wait for resolution on application for asylum can take up to three years. During this time participation in daily occupations is disrupted. This study was carried out to gain an understanding of the experience of living as an asylum seeker in Iceland. It explored asylum seekers' opportunities for participation in occupations as well as their overall experiences while waiting for the processing of their application. Eleven semi-structured interviews were conducted with nine participants, of whom six were asylum seekers. A constructivist grounded theory approach was applied to categorize and synthesize data. Four major categories emerged that reflected the participants' difficult living conditions, lack of opportunities for participation, lack of belonging, and feelings of powerlessness. The long processing time of their applications was enormously stressful as well as not being in charge of one's life, living conditions, or income. The results indicate that the long processing time of application for asylum has deteriorating effects on health. In order to promote asylum seekers' well-being and occupational rights attention needs to be focused on their living conditions and opportunities for participation in meaningful occupations, including work.

Ethics review as a component of institutional approval for a multicentre continuous quality improvement project: the investigator's perspective.

PubMed

Ezzat, Hanna; Ross, Sue; von Dadelszen, Peter; Morris, Tara; Liston, Robert; Magee, Laura A

2010-07-30

For ethical approval of a multicentre study in Canada, investigators must apply separately to individual Research Ethics Boards (REBs). In principle, the protection of human research subjects is of utmost importance. However, in practice, the process of multicentre ethics review can be time consuming and costly, requiring duplication of effort for researchers and REBs. We used our experience with ethical review of The Canadian Perinatal Network (CPN), to gain insight into the Canadian system. The applications forms of 16 different REBs were abstracted for a list of standardized items. The application process across sites was compared. Correspondence between the REB and the investigators was documented in order to construct a timeline to approval, identify the specific issues raised by each board, and describe how they were resolved. Each REB had a different application form. Most (n = 9) had a two or three step application process. Overall, it took a median of 31 days (range 2-174 days) to receive an initial response from the REB. Approval took a median of 42 days (range 4-443 days). Privacy and consent were the two major issues raised. Several additional minor or administrative issues were raised which delayed approval. For CPN, the Canadian REB process of ethical review proved challenging. REBs acted independently and without unified application forms or submission procedures. We call for a critical examination of the ethical, privacy and institutional review processes in Canada, to determine the best way to undertake multicentre review.

Ergonomics productivity enhancement at government-owned sugar cane factories in east Java, Indonesia.

PubMed

Manuaba, A

1995-06-01

To cope, both with the increasing demand for sugar and to win the global competition as well, government-owned sugar cane limited number xxi-xxii, has decided to enhance its productivity, among other things, by implementing ergonomics principles within their factories. In the execution, ergonomics application have been carried out since 1992, which resulted in safer, healthier, and more efficient working conditions and environment. Some of the improvements yielded economic gains through higher productivity via increased output, lower cost, faster processing, etc. Improvements related to cane transloading and unloading processes resulted in a higher amount of cane being transferred from the trucks to the lorries as well as from the lorries to the cane table. Fewer clinical visits, lower health care costs, more efficient inspection, and fewer fatigue complaints are also achieved by improvement steps, which increase the productivity as end results. With all those economic gains, full and long lasting management's concern and commitment could be created without a doubt.

Implicit emotion regulation affects outcome evaluation

PubMed Central

Yang, Qiwei; Tang, Ping; Luo, Wenbo; Luo, Yue-jia

2015-01-01

Efficient implicit emotion regulation processes, which run without awareness, are important for human well-being. In this study, to investigate the influence of implicit emotion regulation on psychological and electrophysiological responses to gains and losses, participants were required to select between two Chinese four-character idioms to match the meaning of the third one before they performed a monetary gambling task. According to whether their meanings were related to emotion regulation, the idioms fell into two categories. Event-related potentials and self-rating emotional experiences to outcome feedback were recorded during the task. Priming emotion regulation reduced subjective emotional experience to both gains and losses and the amplitudes of the feedback-related negativity, while the P3 component was not influenced. According to these results, we suggest that the application of implicit emotion regulation effectively modulated the subjective emotional experience and the motivational salience of current outcomes without the cost of cognitive resources. This study implicates the potential significance of implicit emotion regulation in decision-making processes. PMID:25332404

Estimating the delay-Doppler of target echo in a high clutter underwater environment using wideband linear chirp signals: Evaluation of performance with experimental data.

PubMed

Yu, Ge; Yang, T C; Piao, Shengchun

2017-10-01

A chirp signal is a signal with linearly varying instantaneous frequency over the signal bandwidth, also known as a linear frequency modulated (LFM) signal. It is widely used in communication, radar, active sonar, and other applications due to its Doppler tolerance property in signal detection using the matched filter (MF) processing. Modern sonar uses high-gain, wideband signals to improve the signal to reverberation ratio. High gain implies a high product of the signal bandwidth and duration. However, wideband and/or long duration LFM signals are no longer Doppler tolerant. The shortcoming of the standard MF processing is loss of performance, and bias in range estimation. This paper uses the wideband ambiguity function and the fractional Fourier transform method to estimate the target velocity and restore the performance. Target velocity or Doppler provides a clue for differentiating the target from the background reverberation and clutter. The methods are applied to simulated and experimental data.

A 1.2-V CMOS front-end for LTE direct conversion SAW-less receiver

NASA Astrophysics Data System (ADS)

Riyan, Wang; Jiwei, Huang; Zhengping, Li; Weifeng, Zhang; Longyue, Zeng

2012-03-01

A CMOS RF front-end for the long-term evolution (LTE) direct conversion receiver is presented. With a low noise transconductance amplifier (LNA), current commutating passive mixer and transimpedance operational amplifier (TIA), the RF front-end structure enables high-integration, high linearity and simple frequency planning for LTE multi-band applications. Large variable gain is achieved using current-steering transconductance stages. A current commutating passive mixer with 25% duty-cycle LO improves gain, noise and linearity. A direct coupled current-input filter (DCF) is employed to suppress the out-of-band interferer. Fabricated in a 0.13-μm CMOS process, the RF front-end achieves a 45 dB conversion voltage gain, 2.7 dB NF, -7 dBm IIP3, and +60 dBm IIP2 with calibration from 2.3 to 2.7 GHz. The total RF front end with divider draws 40 mA from a single 1.2-V supply.

Suppression of shot noise and spontaneous radiation in electron beams

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

Litvinenko,V.

2009-08-23

Shot noise in the electron beam distribution is the main source of noise in high-gain FEL amplifiers, which may affect applications ranging from single- and multi-stage HGHG FELs to an FEL amplifier for coherent electron cooling. This noise also imposes a fundamental limit of about 10{sup 6} on FEL gain, after which SASE FELs saturate. There are several advantages in strongly suppressing this shot noise in the electron beam, and the corresponding spontaneous radiation. For more than a half-century, a traditional passive method has been used successfully in practical low-energy microwave electronic devices to suppress shot noise. Recently, it wasmore » proposed for this purpose in FELs. However, being passive, the method has some significant limitations and is hardly suitable for the highly inhomogeneous beams of modern high-gain FELs. I present a novel active method of suppressing, by many orders-of-magnitude, the shot noise in relativistic electron beams. I give a theoretical description of the process, and detail its fundamental limitation.« less

Using lytic bacteriophages to eliminate or significantly reduce contamination of food by foodborne bacterial pathogens.

PubMed

Sulakvelidze, Alexander

2013-10-01

Bacteriophages (also called 'phages') are viruses that kill bacteria. They are arguably the oldest (3 billion years old, by some estimates) and most ubiquitous (total number estimated to be 10(30) -10(32) ) known organisms on Earth. Phages play a key role in maintaining microbial balance in every ecosystem where bacteria exist, and they are part of the normal microflora of all fresh, unprocessed foods. Interest in various practical applications of bacteriophages has been gaining momentum recently, with perhaps the most attention focused on using them to improve food safety. That approach, called 'phage biocontrol', typically includes three main types of applications: (i) using phages to treat domesticated livestock in order to reduce their intestinal colonization with, and shedding of, specific bacterial pathogens; (ii) treatments for decontaminating inanimate surfaces in food-processing facilities and other food establishments, so that foods processed on those surfaces are not cross-contaminated with the targeted pathogens; and (iii) post-harvest treatments involving direct applications of phages onto the harvested foods. This mini-review primarily focuses on the last type of intervention, which has been gaining the most momentum recently. Indeed, the results of recent studies dealing with improving food safety, and several recent regulatory approvals of various commercial phage preparations developed for post-harvest food safety applications, strongly support the idea that lytic phages may provide a safe, environmentally-friendly, and effective approach for significantly reducing contamination of various foods with foodborne bacterial pathogens. However, some important technical and nontechnical problems may need to be addressed before phage biocontrol protocols can become an integral part of routine food safety intervention strategies implemented by food industries in the USA. © 2013 Society of Chemical Industry.

Senior medical student opinions regarding the ideal urology interview day.

PubMed

Jacobs, Jesse C; Guralnick, Michael L; Sandlow, Jay I; Langenstroer, Peter; Begun, Frank P; See, William A; O'Connor, Robert Corey

2014-01-01

Applicant interviews for urology residency positions are a stressful and costly process for students, faculty, and staff. We conducted a prospective survey to better determine what urology applicants perceive as an ideal interview process to gain sufficient knowledge about a training program. A questionnaire was anonymously completed by all urology residency applicants interviewing at the Medical College of Wisconsin from 2007 to 2013. Questionnaire subject headings included "ideal interview format," "factors contributing to understanding the residency program," and "factors contributing to final rank list order." Questionnaires were distributed to and completed by 221 senior medical students applying for a urology residency position. Most respondents (>80%) reported they would prefer to partake in 5 to 7 faculty interviews in an office setting with the total interview process spanning half to three-fourths of the workday. Spending time with current residents was considered the most valuable tool to acquire knowledge about a residency program. The most important criteria when ranking a program were resident satisfaction, resident operative experience, and perceived strength of faculty. Academic urology programs may wish to consider applicant ideals when organizing residency interviews. Interaction with current residents appears to be the most valuable resource allowing applicants to garner knowledge about a urology training program. Copyright © 2014 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Computer Forensics Education - the Open Source Approach

NASA Astrophysics Data System (ADS)

Huebner, Ewa; Bem, Derek; Cheung, Hon

In this chapter we discuss the application of the open source software tools in computer forensics education at tertiary level. We argue that open source tools are more suitable than commercial tools, as they provide the opportunity for students to gain in-depth understanding and appreciation of the computer forensic process as opposed to familiarity with one software product, however complex and multi-functional. With the access to all source programs the students become more than just the consumers of the tools as future forensic investigators. They can also examine the code, understand the relationship between the binary images and relevant data structures, and in the process gain necessary background to become the future creators of new and improved forensic software tools. As a case study we present an advanced subject, Computer Forensics Workshop, which we designed for the Bachelor's degree in computer science at the University of Western Sydney. We based all laboratory work and the main take-home project in this subject on open source software tools. We found that without exception more than one suitable tool can be found to cover each topic in the curriculum adequately. We argue that this approach prepares students better for forensic field work, as they gain confidence to use a variety of tools, not just a single product they are familiar with.

Ergonomics action research I: shifting from hypothesis testing to experiential learning.

PubMed

Neumann, W P; Dixon, S M; Ekman, M

2012-01-01

This paper presents the case for the need for 'Action Research' (AR) approaches to gain understanding of how ergonomics considerations can best be integrated into the design of new work systems. The AR researchers work collaboratively with other stakeholders to solve a real-world problem: gaining insight into the problem and factors influencing solution building from an embedded position in the development process. This experience is interpreted in terms of available theory and can support further theory development. This non-experimental approach can help provide practical new approaches for integrating ergonomics considerations into real work system design processes. The AR approach suffers from a lack of acceptance by conventionally trained scientists. This paper aims to help overcome this weakness by developing the underlying theory and rationale for using AR approaches in ergonomics research. We propose further development of hybrid approaches which incorporate other evaluation techniques to extend the knowledge gains from AR projects. Researchers should engage directly with organisations in ergonomics projects so that they can better understand the challenges and needs of practitioners who are trying to apply available scientific knowledge in their own unique context. Such 'Action Research' could help develop theory and approaches useful to improve mobilisation and application of ergonomics knowledge in organisations.

A comparison between destructive and non-destructive techniques in determining coating thickness

NASA Astrophysics Data System (ADS)

Haider, F. I.; Suryanto; Ani, M. H.; Mahmood, M. H.

2018-01-01

Measuring coating thickness is an important part in research works related to coating applications. In general, techniques for measuring coating thickness may be divided into destructive and non-destructive methods which are commonly used depending on the applications. The objective of this study is to compare two methods measuring the coating thickness of electroplating copper coating on the austenitic stainless-steel substrate. The electroplating was carried out in a solution containing 200 g/L CuSO4, 100 g/L H2SO4 at room temperature and current of 40mA/cm2 during 20, 40, 60, 80 and 100 mins as coating periods. And the coating thickness was measured by two methods, cross sectional analysis as a destructive technique and weight gain as a non-destructive technique. The results show that at 20 mins coating time interval, the thickness measured by cross sectional method was 16.67 μm and by weight gain method was 17.37 μm, with difference of 0.7 μm and percentage error of 4.11%. This error increased to 5.27% at 100mins time interval, where the values of the thickness measured by cross sectional and weight gain were 86.33 μm and 81.9 μm respectively, and the difference was 4.43 μm. Moreover, though the weight gain method is fast and gives the indication for the termination of a coating process, information regarding the uniformity, porosity and the presence of cracks cannot be obtained. On the other hand, determining the coating thickness using destructive method will damage the sample.

Ion-implanted WN 0.25{mu}m gate MESFET fabricated using I-line photolithography for application to MMIC and digital IC

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

Oh, E.O.; Yang, J.W.; Park, C.S.

1995-12-31

Straightforward WN 0.25{mu}m gate MESFET process based on direct ion-implantation and i-line photolithography with double exposure process has produced high performance MESFETs. The maximum transconductance of 600mS/mm and the k-factor of 450ms/Vmm were obtained. As high as 65GHz of cut-off frequency has been realized without any deembedding of parasitic effects. The MESFET shows the minimum noise figure of 0.87 dB and the associated gain of 9.97dB at 12GHz.

Guidance Protocol: Application of Nucleic Acid-Based Tools for Monitoring Monitored Natural Attenuation (MNA), Biostimulation, and Bioaugmentation at Chlorinated Solvent Sites

DTIC Science & Technology

2011-02-01

Reductive dechlorination is a promising process for biodegradation of chlorinated solvents. The successful field evaluation and implementation of the...population. These specialized bacteria use the chlorinated ethenes as electron acceptors and gain energy for growth from the reductive...This guidance protocol addresses the use of MBTs to quantitatively assess the Dhc population at chlorinated ethene sites and aims at providing

Engineered Approaches to In Situ Bioremediation of Chlorinated Solvents: Fundamentals and Field Applications

DTIC Science & Technology

2000-07-01

scale system that consists of three injection wells currently is being installed at the site. The wells will deliver fructose corn syrup to the...aerobic reaction). The energy gained is stored as high energy compounds, such as ATP and low- energy compounds, such as nicotinamide adenine...processes at high redox potential values is limited; efficiency improves as the redox potential decreases. Pilot studies have been conducted at a variety of

Personal Portable Devices in the Light of the Internet of Things.

PubMed

Lhotska, Lenka; Stechova, Katerina; Pharow, Peter

2017-01-01

Personal portable devices have already gained their position in health services. However, mobile technologies and Internet of Things open new areas of applications. The possibility to collect many data types continuously over long time intervals brings various questions that must be answered in the design process. We also discuss briefly the role of the user. We illustrate the complexity of the field by a case study of diabetes management.

Domestication and Breeding of Tomatoes: What have We Gained and What Can We Gain in the Future?

PubMed Central

Bai, Yuling; Lindhout, Pim

2007-01-01

Background It has been shown that a large variation is present and exploitable from wild Solanum species but most of it is still untapped. Considering the thousands of Solanum accessions in different gene banks and probably even more that are still untouched in the Andes, it is a challenge to exploit the diversity of tomato. What have we gained from tomato domestication and breeding and what can we gain in the future? Scope This review summarizes progress on tomato domestication and breeding and current efforts in tomato genome research. Also, it points out potential challenges in exploiting tomato biodiversity and depicts future perspectives in tomato breeding with the emerging knowledge from tomato-omics. Conclusions From first domestication to modern breeding, the tomato has been continually subjected to human selection for a wide array of applications in both science and commerce. Current efforts in tomato breeding are focused on discovering and exploiting genes for the most important traits in tomato germplasm. In the future, breeders will design cultivars by a process named ‘breeding by design’ based on the combination of science and technologies from the genomic era as well as their practical skills. PMID:17717024

Numerical simulations of the optical gain of crystalline fiber doped by rare earth and transition ion

NASA Astrophysics Data System (ADS)

Daoui, A. K.; Boubir, B.; Adouane, A.; Demagh, N.; Ghoumazi, M.

2015-02-01

A fiber laser is a laser whose gain medium is a doped fiber, although lasers whose cavity is made wholly of fibers have also been called fiber lasers. The gain media in a fiber laser is usually fiber doped with rare-earth ions, such as erbium (Er), neodymium (Nd), ytterbium (Yb), thulium (Tm), or praseodymium (Pr), which is doped into the core of the optical fiber, similar to those used to transmit telecommunications signals. Fiber lasers find many applications in materials processing, including cutting, welding, drilling, and marking metal. To maximize their market penetration, it is necessary to increase their output power. In this work, we present a detailed study based on the numerical simulation using MATLAB, of one of the principal characteristics of a fiber laser doped with rare earth ions and transition ion. The gain depends on several parameters such as the length of the doped fiber, the density, the pump power, noise, etc.). The used program resolves the state equations in this context together with those governing the light propagation phenomena. The developed code can also be used to study the dynamic operating modes of a doped fiber laser.

Modelling surface water-groundwater interaction with a conceptual approach: model development and application in New Zealand

NASA Astrophysics Data System (ADS)

Yang, J.; Zammit, C.; McMillan, H. K.

2016-12-01

As in most countries worldwide, water management in lowland areas is a big concern for New Zealand due to its economic importance for water related human activities. As a result, the estimation of available water resources in these areas (e.g., for irrigation and water supply purpose) is crucial and often requires an understanding of complex hydrological processes, which are often characterized by strong interactions between surface water and groundwater (usually expressed as losing and gaining rivers). These processes are often represented and simulated using integrated physically based hydrological models. However models with physically based groundwater modules typically require large amount of non-readily available geologic and aquifer information and are computationally intensive. Instead, this paper presents a conceptual groundwater model that is fully integrated into New Zealand's national hydrological model TopNet based on TopModel concepts (Beven, 1992). Within this conceptual framework, the integrated model can simulate not only surface processes, but also groundwater processes and surface water-groundwater interaction processes (including groundwater flow, river-groundwater interaction, and groundwater interaction with external watersheds). The developed model was applied to two New Zealand catchments with different hydro-geological and climate characteristics (Pareora catchment in the Canterbury Plains and Grey catchment on the West Coast). Previous studies have documented strong interactions between the river and groundwater, based on the analysis of a large number of concurrent flow measurements and associated information along the river main stem. Application of the integrated hydrological model indicates flow simulation (compared to the original hydrological model conceptualisation) during low flow conditions are significantly improved and further insights on local river dynamics are gained. Due to its conceptual characteristics and low level of data requirement, the integrated model could be used at local and national scales to improve the simulation of hydrological processes in non-topographically driven areas (where groundwater processes are important), and to assess impact of climate change on the integrated hydrological cycle in these areas.

Data Provenance Hybridization Supporting Extreme-Scale Scientific WorkflowApplications

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

Elsethagen, Todd O.; Stephan, Eric G.; Raju, Bibi

As high performance computing (HPC) infrastructures continue to grow in capability and complexity, so do the applications that they serve. HPC and distributed-area computing (DAC) (e.g. grid and cloud) users are looking increasingly toward workflow solutions to orchestrate their complex application coupling, pre- and post-processing needs To gain insight and a more quantitative understanding of a workflow’s performance our method includes not only the capture of traditional provenance information, but also the capture and integration of system environment metrics helping to give context and explanation for a workflow’s execution. In this paper, we describe IPPD’s provenance management solution (ProvEn) andmore » its hybrid data store combining both of these data provenance perspectives.« less

Image processing and pattern recognition with CVIPtools MATLAB toolbox: automatic creation of masks for veterinary thermographic images

NASA Astrophysics Data System (ADS)

Mishra, Deependra K.; Umbaugh, Scott E.; Lama, Norsang; Dahal, Rohini; Marino, Dominic J.; Sackman, Joseph

2016-09-01

CVIPtools is a software package for the exploration of computer vision and image processing developed in the Computer Vision and Image Processing Laboratory at Southern Illinois University Edwardsville. CVIPtools is available in three variants - a) CVIPtools Graphical User Interface, b) CVIPtools C library and c) CVIPtools MATLAB toolbox, which makes it accessible to a variety of different users. It offers students, faculty, researchers and any user a free and easy way to explore computer vision and image processing techniques. Many functions have been implemented and are updated on a regular basis, the library has reached a level of sophistication that makes it suitable for both educational and research purposes. In this paper, the detail list of the functions available in the CVIPtools MATLAB toolbox are presented and how these functions can be used in image analysis and computer vision applications. The CVIPtools MATLAB toolbox allows the user to gain practical experience to better understand underlying theoretical problems in image processing and pattern recognition. As an example application, the algorithm for the automatic creation of masks for veterinary thermographic images is presented.

Ceramic processing: Experimental design and optimization

NASA Technical Reports Server (NTRS)

Weiser, Martin W.; Lauben, David N.; Madrid, Philip

1992-01-01

The objectives of this paper are to: (1) gain insight into the processing of ceramics and how green processing can affect the properties of ceramics; (2) investigate the technique of slip casting; (3) learn how heat treatment and temperature contribute to density, strength, and effects of under and over firing to ceramic properties; (4) experience some of the problems inherent in testing brittle materials and learn about the statistical nature of the strength of ceramics; (5) investigate orthogonal arrays as tools to examine the effect of many experimental parameters using a minimum number of experiments; (6) recognize appropriate uses for clay based ceramics; and (7) measure several different properties important to ceramic use and optimize them for a given application.

Loop gain stabilizing with an all-digital automatic-gain-control method for high-precision fiber-optic gyroscope.

PubMed

Zheng, Yue; Zhang, Chunxi; Li, Lijing; Song, Lailiang; Chen, Wen

2016-06-10

For a fiber-optic gyroscope (FOG) using electronic dithers to suppress the dead zone, without a fixed loop gain, the deterministic compensation for the dither signals in the control loop of the FOG cannot remain accurate, resulting in the dither residuals in the FOG rotation rate output and the navigation errors in the inertial navigation system. An all-digital automatic-gain-control method for stabilizing the loop gain of the FOG is proposed. By using a perturbation square wave to measure the loop gain of the FOG and adding an automatic gain control loop in the conventional control loop of the FOG, we successfully obtain the actual loop gain and make the loop gain converge to the reference value. The experimental results show that in the case of 20% variation in the loop gain, the dither residuals are successfully eliminated and the standard deviation of the FOG sampling outputs is decreased from 2.00  deg/h to 0.62  deg/h (sampling period 2.5 ms, 10 points smoothing). With this method, the loop gain of the FOG can be stabilized over the operation temperature range and in the long-time application, which provides a solid foundation for the engineering applications of the high-precision FOG.

Application of improved technology to a preprototype vapor compression distillation /VCD/ water recovery subsystem

NASA Technical Reports Server (NTRS)

Johnson, K. L.; Reysa, R. P.; Fricks, D. H.

1981-01-01

Vapor compression distillation (VCD) is considered the most efficient water recovery process for spacecraft application. This paper reports on a preprototype VCD which has undergone the most extensive operational and component development testing of any VCD subsystem to date. The component development effort was primarily aimed at eliminating corrosion and the need for lubrication, upgrading electronics, and substituting nonmetallics in key rotating components. The VCD evolution is documented by test results on specific design and/or materials changes. Innovations worthy of further investigation and additional testing are summarized for future VCD subsystem development reference. Conclusions on experience gained are presented.

Structural Optimisation Of Payload Fairings

NASA Astrophysics Data System (ADS)

Santschi, Y.; Eaton, N.; Verheyden, S.; Michaud, V.

2012-07-01

RUAG Space are developing materials and processing technologies for manufacture of the Next Generation Launcher (NGL) payload fairing, together with the Laboratory of Polymer and Composite Technology at the EPFL, in a project running under the ESA Future Launchers Preparatory Program (FLPP). In this paper the general aims and scope of the project are described, details of the results obtained shall be presented at a later stage. RUAG Space design, develop and manufacture fairings for the European launch vehicles Ariane 5 and VEGA using well proven composite materials and production methods which provide adequate cost/performance ratio for these applications. However, the NGL shall make full use of innovations in materials and process technologies to achieve a gain in performance at a much reduced overall manufacturing cost. NGL is scheduled to become operational in 2025, with actual development beginning in 2014. In this current project the basic technology is being developed and validated, in readiness for application in the NGL. For this new application, an entirely new approach to the fairing manufacture is evaluated.

Software for Remote Monitoring of Space-Station Payloads

NASA Technical Reports Server (NTRS)

Schneider, Michelle; Lippincott, Jeff; Chubb, Steve; Whitaker, Jimmy; Gillis, Robert; Sellers, Donna; Sims, Chris; Rice, James

2003-01-01

Telescience Resource Kit (TReK) is a suite of application programs that enable geographically dispersed users to monitor scientific payloads aboard the International Space Station (ISS). TReK provides local ground support services that can simultaneously receive, process, record, playback, and display data from multiple sources. TReK also provides interfaces to use the remote services provided by the Payload Operations Integration Center which manages all ISS payloads. An application programming interface (API) allows for payload users to gain access to all data processed by TReK and allows payload-specific tools and programs to be built or integrated with TReK. Used in conjunction with other ISS-provided tools, TReK provides the ability to integrate payloads with the operational ground system early in the lifecycle. This reduces the potential for operational problems and provides "cradle-to-grave" end-to-end operations. TReK contains user guides and self-paced tutorials along with training applications to allow the user to become familiar with the system.

Short-Range Noncontact Sensors for Healthcare and Other Emerging Applications: A Review

PubMed Central

Gu, Changzhan

2016-01-01

Short-range noncontact sensors are capable of remotely detecting the precise movements of the subjects or wirelessly estimating the distance from the sensor to the subject. They find wide applications in our day lives such as noncontact vital sign detection of heart beat and respiration, sleep monitoring, occupancy sensing, and gesture sensing. In recent years, short-range noncontact sensors are attracting more and more efforts from both academia and industry due to their vast applications. Compared to other radar architectures such as pulse radar and frequency-modulated continuous-wave (FMCW) radar, Doppler radar is gaining more popularity in terms of system integration and low-power operation. This paper reviews the recent technical advances in Doppler radars for healthcare applications, including system hardware improvement, digital signal processing, and chip integration. This paper also discusses the hybrid FMCW-interferometry radars and the emerging applications and the future trends. PMID:27472330

Lignin from Micro- to Nanosize: Applications

PubMed Central

Friedl, Anton

2017-01-01

Micro- and nanosize lignin has recently gained interest due to improved properties compared to standard lignin available today. As the second most abundant biopolymer after cellulose, lignin is readily available but used for rather low-value applications. This review focuses on the application of micro- and nanostructured lignin in final products or processes that all show potential for high added value. The fields of application are ranging from improvement of mechanical properties of polymer nanocomposites, bactericidal and antioxidant properties and impregnations to hollow lignin drug carriers for hydrophobic and hydrophilic substances. Also, a carbonization of lignin nanostructures can lead to high-value applications such as use in supercapacitors for energy storage. The properties of the final product depend on the surface properties of the nanomaterial and, therefore, on factors like the lignin source, extraction method, and production/precipitation methods, as discussed in this review. PMID:29117142

Micro Electromechanical Systems (MEMS) Based Microfluidic Devices for Biomedical Applications

PubMed Central

Ashraf, Muhammad Waseem; Tayyaba, Shahzadi; Afzulpurkar, Nitin

2011-01-01

Micro Electromechanical Systems (MEMS) based microfluidic devices have gained popularity in biomedicine field over the last few years. In this paper, a comprehensive overview of microfluidic devices such as micropumps and microneedles has been presented for biomedical applications. The aim of this paper is to present the major features and issues related to micropumps and microneedles, e.g., working principles, actuation methods, fabrication techniques, construction, performance parameters, failure analysis, testing, safety issues, applications, commercialization issues and future prospects. Based on the actuation mechanisms, the micropumps are classified into two main types, i.e., mechanical and non-mechanical micropumps. Microneedles can be categorized according to their structure, fabrication process, material, overall shape, tip shape, size, array density and application. The presented literature review on micropumps and microneedles will provide comprehensive information for researchers working on design and development of microfluidic devices for biomedical applications. PMID:21747700

Possibilities of Laser Processing of Paper Materials

NASA Astrophysics Data System (ADS)

Stepanov, Alexander; Saukkonen, Esa; Piili, Heidi

Nowadays, lasers are applied in many industrial processes: the most developed technologies include such processes as laser welding, hybrid welding, laser cutting of steel, etc. In addition to laser processing of metallic materials, there are also many industrial applications of laser processing of non-metallic materials, like laser welding of polymers, laser marking of glass and laser cutting of wood-based materials. It is commonly known that laser beam is suitable for cutting of paper materials as well as all natural wood-fiber based materials. This study reveals the potential and gives overview of laser application in processing of paper materials. In 1990's laser technology increased its volume in papermaking industry; lasers at paper industry gained acceptance for different perforating and scoring applications. Nowadays, with reduction in the cost of equipment and development of laser technology (especially development of CO2 technology), laser processing of paper material has started to become more widely used and more efficient. However, there exists quite little published research results and reviews about laser processing of paper materials. In addition, forest industry products with pulp and paper products in particular are among major contributors for the Finnish economy with 20% share of total exports in the year 2013. This has been the standpoint of view and motivation for writing this literature review article: when there exists more published research work, knowledge of laser technology can be increased to apply it for processing of paper materials.

"Structure and dynamics in complex chemical systems: Gaining new insights through recent advances in time-resolved spectroscopies.” ACS Division of Physical Chemistry Symposium presented at the Fall National ACS Meeting in Boston, MA, August 2015

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

Crawford, Daniel

8-Session Symposium on STRUCTURE AND DYNAMICS IN COMPLEX CHEMICAL SYSTEMS: GAINING NEW INSIGHTS THROUGH RECENT ADVANCES IN TIME-RESOLVED SPECTROSCOPIES. The intricacy of most chemical, biochemical, and material processes and their applications are underscored by the complex nature of the environments in which they occur. Substantial challenges for building a global understanding of a heterogeneous system include (1) identifying unique signatures associated with specific structural motifs within the heterogeneous distribution, and (2) resolving the significance of each of multiple time scales involved in both small- and large-scale nuclear reorganization. This symposium focuses on the progress in our understanding of dynamics inmore » complex systems driven by recent innovations in time-resolved spectroscopies and theoretical developments. Such advancement is critical for driving discovery at the molecular level facilitating new applications. Broad areas of interest include: Structural relaxation and the impact of structure on dynamics in liquids, interfaces, biochemical systems, materials, and other heterogeneous environments.« less

Gaining Regulator Acceptance of Natural Attenuation as a Remediation Tool

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

Hughes, M.B.

Monitored natural attenuation (MNA) makes use of biological degradation, chemical reactions with natural materials, and other processes to clean up contaminated soils and groundwater. In the past, the regulatory community has been slow to accept natural attenuation due to a misperception that natural attenuation is a ''do nothing'' approach. Recently however, regulators have been more open to considering MNA as part of an overall clean-up plan that includes active treatment technologies to remove or contain the source of contamination at a site. MNA is currently being implemented at the Savannah River Site for remediation of selected contaminants. The South Carolinamore » Department of Health and Environmental Control, who has regulatory authority over these actions, has accepted this process. Significant overall cost savings are forecast. Additionally, there will be less disruption to the ecosystem, compared with engineered technologies. This paper describes the monitored natural attenuation concept as well as the process of constructive engagement with the regulators to achieve acceptance. Application to DOE, DOD, and commercial sites, as well as acceptability to other regulatory bodies, will be discussed with an emphasis on strategies to prevent false starts in the negotiation process and inventing options that result in mutual gains for all parties.« less

Chiral Polychlorinated Biphenyl Transport, Metabolism and Distribution - A Review

PubMed Central

Lehmler, Hans-Joachim; Harrad, Stuart J.; Hühnerfuss, Heinrich; Kania-Korwel, Izabela; Lee, Cindy M.; Lu, Zhe; Wong, Charles S.

2009-01-01

Chirality can be exploited to gain insight into enantioselective fate processes that may otherwise remain undetected because only biological, but not physical and chemical transport and transformation processes in an achiral environment will change enantiomer compositions. This review provides an in-depth overview of the application of chirality to the study of chiral polychlorinated biphenyls (PCBs), an important group of legacy pollutants. Like other chiral compounds, individual PCB enantiomers may interact enantioselectively (or enantiospecifically) with chiral macromolecules, such as cytochrome P-450 enzymes or ryanodine receptors, leading to differences in their toxicological effects and the enantioselective formation of chiral biotransformation products. Species and congener-specific enantiomer enrichment has been demonstrated in environmental compartments, wildlife and mammals, including humans, typically due to a complex combination of biotransformation processes and uptake via the diet by passive diffusion. Changes in the enantiomer composition of chiral PCBs in the environment have been used to understand complex aerobic and anaerobic microbial transformation pathways, to delineate and quantify PCB sources and transport in the environment, to gain insight into the biotransformation of PCBs in aquatic food webs, and to investigate the enantioselective disposition of PCBs and their methylsulfonyl PCBs metabolites in rodents. Overall, changes in chiral signatures are powerful, but currently underutilized tools for studies of environmental and biological processes of PCBs. PMID:20384371

Qualitative and quantitative processing of side-scan sonar data

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

Dwan, F.S.; Anderson, A.L.; Hilde, T.W.C.

1990-06-01

Modern side-scan sonar systems allow vast areas of seafloor to be rapidly imaged and quantitatively mapped in detail. The application of remote sensing image processing techniques can be used to correct for various distortions inherent in raw sonography. Corrections are possible for water column, slant-range, aspect ratio, speckle and striping noise, multiple returns, power drop-off, and for georeferencing. The final products reveal seafloor features and patterns that are geometrically correct, georeferenced, and have improved signal/noise ratio. These products can be merged with other georeferenced data bases for further database management and information extraction. In order to compare data collected bymore » different systems from a common area and to ground truth measurements and geoacoustic models, quantitative correction must be made for calibrated sonar system and bathymetry effects. Such data inversion must account for system source level, beam pattern, time-varying gain, processing gain, transmission loss, absorption, insonified area, and grazing angle effects. Seafloor classification can then be performed on the calculated back-scattering strength using Lambert's Law and regression analysis. Examples are given using both approaches: image analysis and inversion of data based on the sonar equation.« less

Self-assembled nanotubes from single fluorescent amino acid

NASA Astrophysics Data System (ADS)

Babar, Dipak Gorakh; Sarkar, Sabyasachi

2017-04-01

Self-assembly of biomolecules has gained increasing attention as it generates various supramolecular structural assemblies having potential applications principally in biomedical sciences. Here, we show that amino acid like tryptophan or tyrosine readily aggregates as nanotubes via a simple self-assembly process. These were characterized by FTIR, scanning electron microscopy, and by fluorescence microscopy. Nanotubes prepared from tryptophan are having 200 nm inner diameter and those from tyrosine are having the same around 50 nm diameter.

Systems cell biology

PubMed Central

Mast, Fred D.; Ratushny, Alexander V.

2014-01-01

Systems cell biology melds high-throughput experimentation with quantitative analysis and modeling to understand many critical processes that contribute to cellular organization and dynamics. Recently, there have been several advances in technology and in the application of modeling approaches that enable the exploration of the dynamic properties of cells. Merging technology and computation offers an opportunity to objectively address unsolved cellular mechanisms, and has revealed emergent properties and helped to gain a more comprehensive and fundamental understanding of cell biology. PMID:25225336

[The design and applications of a non-invasive intelligent detector for cardiovascular functions].

PubMed

Li, Feng; Xing, Wu; Chen, Ming-zhi; Shang, Huai

2006-05-01

An apparatus based on a high sensitive sensor which detects cardiovascular functions is introduced in this paper. Some intelligent detecting technologies, such as syntactic pattern recognition and a medical expert system are used in this detector. Its embedded single-chip microcomputer processes and analyzes pulse signals for gaining automatically the parameters about heart, blood vessel and blood etc., so as to get the health evaluation, correct medical diagnosis and prediction of cardiovascular diseases.

Definition Of Touch-Sensitive Zones For Graphical Displays

NASA Technical Reports Server (NTRS)

Monroe, Burt L., III; Jones, Denise R.

1988-01-01

Touch zones defined simply by touching, while editing done automatically. Development of touch-screen interactive computing system, tedious task. Interactive Editor for Definition of Touch-Sensitive Zones computer program increases efficiency of human/machine communications by enabling user to define each zone interactively, minimizing redundancy in programming and eliminating need for manual computation of boundaries of touch areas. Information produced during editing process written to data file, to which access gained when needed by application program.

OPTICAL FIBRES AND FIBREOPTIC SENSORS: Bismuth-ring-doped fibres

NASA Astrophysics Data System (ADS)

Zlenko, Aleksandr S.; Akhmetshin, Ural G.; Dvoirin, Vladislav V.; Bogatyrev, Vladimir A.; Firstov, Sergei V.

2009-11-01

A new process for bismuth doping of optical fibres is proposed in which the dopant is introduced into a thin layer surrounding the fibre core. This enables bismuth stabilisation in the silica glass, with no limitations on the core composition. In particular, the GeO2 content of the fibre core in this study is 16 mol %. Spectroscopic characterisation of such fibres and optical gain measurements suggest that the proposed approach has considerable potential for laser applications.

Radiation Damage Workshop report. [solar cells

NASA Technical Reports Server (NTRS)

Rahilly, W. P.

1980-01-01

The starting material, cell design/geometry, and cell processing/fabrication for silicon and gallium arsenide solar cells are addressed with reference to radiation damage. In general, it is concluded that diagnostic sensitivities and material purities are basic to making significant gains in end-of-life performance and thermal annealability. Further, GaAs material characterization is so sketchy that a well defined program to evaluate such material for solar cell application is needed to maximize GaAs cell technology benefits.

Information Gain Based Dimensionality Selection for Classifying Text Documents

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

Dumidu Wijayasekara; Milos Manic; Miles McQueen

2013-06-01

Selecting the optimal dimensions for various knowledge extraction applications is an essential component of data mining. Dimensionality selection techniques are utilized in classification applications to increase the classification accuracy and reduce the computational complexity. In text classification, where the dimensionality of the dataset is extremely high, dimensionality selection is even more important. This paper presents a novel, genetic algorithm based methodology, for dimensionality selection in text mining applications that utilizes information gain. The presented methodology uses information gain of each dimension to change the mutation probability of chromosomes dynamically. Since the information gain is calculated a priori, the computational complexitymore » is not affected. The presented method was tested on a specific text classification problem and compared with conventional genetic algorithm based dimensionality selection. The results show an improvement of 3% in the true positives and 1.6% in the true negatives over conventional dimensionality selection methods.« less

Improved process robustness by using closed loop control in deep drawing applications

NASA Astrophysics Data System (ADS)

Barthau, M.; Liewald, M.; Christian, Held

2017-09-01

The production of irregular shaped deep-drawing parts with high quality requirements, which are common in today’s automotive production, permanently challenges production processes. High requirements on lightweight construction of passenger car bodies following European regulations until 2020 have been massively increasing the use of high strength steels substantially for years and are also leading to bigger challenges in sheet metal part production. Of course, the more and more complex shapes of today’s car body shells also intensify the issue due to modern and future design criteria. The metal forming technology tries to meet these challenges by developing a highly sophisticated layout of deep drawing dies that consider part quality requirements, process robustness and controlled material flow during the deep or stretch drawing process phase. A new method for controlling material flow using a closed loop system was developed at the IFU Stuttgart. In contrast to previous approaches, this new method allows a control intervention during the deep-drawing stroke. The blank holder force around the outline of the drawn part is used as control variable. The closed loop is designed as trajectory follow up with feed forward control. The used command variable is the part-wall stress that is measured with a piezo-electric measuring pin. In this paper the used control loop will be described in detail. The experimental tool that was built for testing the new control approach is explained here with its features. A method for gaining the follow up trajectories from simulation will also be presented. Furthermore, experimental results considering the robustness of the deep drawing process and the gain in process performance with developed control loop will be shown. Finally, a new procedure for the industrial application of the new control method of deep drawing will be presented by using a new kind of active element to influence the local blank holder pressure onto part flange.

Ethics review as a component of institutional approval for a multicentre continuous quality improvement project: the investigator's perspective

PubMed Central

2010-01-01

Background For ethical approval of a multicentre study in Canada, investigators must apply separately to individual Research Ethics Boards (REBs). In principle, the protection of human research subjects is of utmost importance. However, in practice, the process of multicentre ethics review can be time consuming and costly, requiring duplication of effort for researchers and REBs. We used our experience with ethical review of The Canadian Perinatal Network (CPN), to gain insight into the Canadian system. Methods The applications forms of 16 different REBs were abstracted for a list of standardized items. The application process across sites was compared. Correspondence between the REB and the investigators was documented in order to construct a timeline to approval, identify the specific issues raised by each board, and describe how they were resolved. Results Each REB had a different application form. Most (n = 9) had a two or three step application process. Overall, it took a median of 31 days (range 2-174 days) to receive an initial response from the REB. Approval took a median of 42 days (range 4-443 days). Privacy and consent were the two major issues raised. Several additional minor or administrative issues were raised which delayed approval. Conclusions For CPN, the Canadian REB process of ethical review proved challenging. REBs acted independently and without unified application forms or submission procedures. We call for a critical examination of the ethical, privacy and institutional review processes in Canada, to determine the best way to undertake multicentre review. PMID:20673343

A Web simulation of medical image reconstruction and processing as an educational tool.

PubMed

Papamichail, Dimitrios; Pantelis, Evaggelos; Papagiannis, Panagiotis; Karaiskos, Pantelis; Georgiou, Evangelos

2015-02-01

Web educational resources integrating interactive simulation tools provide students with an in-depth understanding of the medical imaging process. The aim of this work was the development of a purely Web-based, open access, interactive application, as an ancillary learning tool in graduate and postgraduate medical imaging education, including a systematic evaluation of learning effectiveness. The pedagogic content of the educational Web portal was designed to cover the basic concepts of medical imaging reconstruction and processing, through the use of active learning and motivation, including learning simulations that closely resemble actual tomographic imaging systems. The user can implement image reconstruction and processing algorithms under a single user interface and manipulate various factors to understand the impact on image appearance. A questionnaire for pre- and post-training self-assessment was developed and integrated in the online application. The developed Web-based educational application introduces the trainee in the basic concepts of imaging through textual and graphical information and proceeds with a learning-by-doing approach. Trainees are encouraged to participate in a pre- and post-training questionnaire to assess their knowledge gain. An initial feedback from a group of graduate medical students showed that the developed course was considered as effective and well structured. An e-learning application on medical imaging integrating interactive simulation tools was developed and assessed in our institution.

Integration Methodology For Oil-Free Shaft Support Systems: Four Steps to Success

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; DellaCorte, Christopher; Bruckner, Robert J.

2010-01-01

Commercial applications for Oil-Free turbomachinery are slowly becoming a reality. Micro-turbine generators, highspeed electric motors, and electrically driven centrifugal blowers are a few examples of products available in today's commercial marketplace. Gas foil bearing technology makes most of these applications possible. A significant volume of component level research has led to recent acceptance of gas foil bearings in several specialized applications, including those mentioned above. Component tests identifying such characteristics as load carrying capacity, power loss, thermal behavior, rotordynamic coefficients, etc. all help the engineer design foil bearing machines, but the development process can be just as important. As the technology gains momentum and acceptance in a wider array of machinery, the complexity and variety of applications will grow beyond the current class of machines. Following a robust integration methodology will help improve the probability of successful development of future Oil-Free turbomachinery. This paper describes a previously successful four-step integration methodology used in the development of several Oil-Free turbomachines. Proper application of the methods put forward here enable successful design of Oil-Free turbomachinery. In addition when significant design changes or unique machinery are developed, this four-step process must be considered.

Speeding Up Geophysical Research Using Docker Containers Within Multi-Cloud Environment.

NASA Astrophysics Data System (ADS)

Synytsky, R.; Henadiy, S.; Lobzakov, V.; Kolesnikov, L.; Starovoit, Y. O.

2016-12-01

How useful are the geophysical observations in a scope of minimizing losses from natural disasters today? Does it help to decrease number of human victims during tsunami and earthquake? Unfortunately it's still at early stage these days. It's a big goal and achievement to make such observations more useful by improving early warning and prediction systems with the help of cloud computing. Cloud computing technologies have proved the ability to speed up application development in many areas for 10 years already. Cloud unlocks new opportunities for geoscientists by providing access to modern data processing tools and algorithms including real-time high-performance computing, big data processing, artificial intelligence and others. Emerging lightweight cloud technologies, such as Docker containers, are gaining wide traction in IT due to the fact of faster and more efficient deployment of different applications in a cloud environment. It allows to deploy and manage geophysical applications and systems in minutes across multiple clouds and data centers that becomes of utmost importance for the next generation applications. In this session we'll demonstrate how Docker containers technology within multi-cloud can accelerate the development of applications specifically designed for geophysical researches.

Integrating manufacturing softwares for intelligent planning execution: a CIIMPLEX perspective

NASA Astrophysics Data System (ADS)

Chu, Bei Tseng B.; Tolone, William J.; Wilhelm, Robert G.; Hegedus, M.; Fesko, J.; Finin, T.; Peng, Yun; Jones, Chris H.; Long, Junshen; Matthews, Mike; Mayfield, J.; Shimp, J.; Su, S.

1997-01-01

Recent developments have made it possible to interoperate complex business applications at much lower costs. Application interoperation, along with business process re- engineering can result in significant savings by eliminating work created by disconnected business processes due to isolated business applications. However, we believe much greater productivity benefits can be achieved by facilitating timely decision-making, utilizing information from multiple enterprise perspectives. The CIIMPLEX enterprise integration architecture is designed to enable such productivity gains by helping people to carry out integrated enterprise scenarios. An enterprise scenario is triggered typically by some external event. The goal of an enterprise scenario is to make the right decisions considering the full context of the problem. Enterprise scenarios are difficult for people to carry out because of the interdependencies among various actions. One can easily be overwhelmed by the large amount of information. We propose the use of software agents to help gathering relevant information and present them in the appropriate context of an enterprise scenario. The CIIMPLEX enterprise integration architecture is based on the FAIME methodology for application interoperation and plug-and-play. It also explores the use of software agents in application plug-and- play.

Performance Analysis, Design Considerations, and Applications of Extreme-Scale In Situ Infrastructures

DOE PAGES

Ayachit, Utkarsh; Bauer, Andrew; Duque, Earl P. N.; ...

2016-11-01

A key trend facing extreme-scale computational science is the widening gap between computational and I/O rates, and the challenge that follows is how to best gain insight from simulation data when it is increasingly impractical to save it to persistent storage for subsequent visual exploration and analysis. One approach to this challenge is centered around the idea of in situ processing, where visualization and analysis processing is performed while data is still resident in memory. Our paper examines several key design and performance issues related to the idea of in situ processing at extreme scale on modern platforms: Scalability, overhead,more » performance measurement and analysis, comparison and contrast with a traditional post hoc approach, and interfacing with simulation codes. We illustrate these principles in practice with studies, conducted on large-scale HPC platforms, that include a miniapplication and multiple science application codes, one of which demonstrates in situ methods in use at greater than 1M-way concurrency.« less

Adaptive Signal Processing Testbed: VME-based DSP board market survey

NASA Astrophysics Data System (ADS)

Ingram, Rick E.

1992-04-01

The Adaptive Signal Processing Testbed (ASPT) is a real-time multiprocessor system utilizing digital signal processor technology on VMEbus based printed circuit boards installed on a Sun workstation. The ASPT has specific requirements, particularly as regards to the signal excision application, with respect to interfacing with current and planned data generation equipment, processing of the data, storage to disk of final and intermediate results, and the development tools for applications development and integration into the overall EW/COM computing environment. A prototype ASPT was implemented using three VME-C-30 boards from Applied Silicon. Experience gained during the prototype development led to the conclusions that interprocessor communications capability is the most significant contributor to overall ASPT performance. In addition, the host involvement should be minimized. Boards using different processors were evaluated with respect to the ASPT system requirements, pricing, and availability. Specific recommendations based on various priorities are made as well as recommendations concerning the integration and interaction of various tools developed during the prototype implementation.

Modulating Human Auditory Processing by Transcranial Electrical Stimulation

PubMed Central

Heimrath, Kai; Fiene, Marina; Rufener, Katharina S.; Zaehle, Tino

2016-01-01

Transcranial electrical stimulation (tES) has become a valuable research tool for the investigation of neurophysiological processes underlying human action and cognition. In recent years, striking evidence for the neuromodulatory effects of transcranial direct current stimulation, transcranial alternating current stimulation, and transcranial random noise stimulation has emerged. While the wealth of knowledge has been gained about tES in the motor domain and, to a lesser extent, about its ability to modulate human cognition, surprisingly little is known about its impact on perceptual processing, particularly in the auditory domain. Moreover, while only a few studies systematically investigated the impact of auditory tES, it has already been applied in a large number of clinical trials, leading to a remarkable imbalance between basic and clinical research on auditory tES. Here, we review the state of the art of tES application in the auditory domain focussing on the impact of neuromodulation on acoustic perception and its potential for clinical application in the treatment of auditory related disorders. PMID:27013969

High-precision laser microcutting and laser microdrilling using diffractive beam-splitting and high-precision flexible beam alignment

NASA Astrophysics Data System (ADS)

Zibner, F.; Fornaroli, C.; Holtkamp, J.; Shachaf, Lior; Kaplan, Natan; Gillner, A.

2017-08-01

High-precision laser micro machining gains more importance in industrial applications every month. Optical systems like the helical optics offer highest quality together with controllable and adjustable drilling geometry, thus as taper angle, aspect ratio and heat effected zone. The helical optics is based on a rotating Dove-prism which is mounted in a hollow shaft engine together with other optical elements like wedge prisms and plane plates. Although the achieved quality can be interpreted as extremely high the low process efficiency is a main reason that this manufacturing technology has only limited demand within the industrial market. The objective of the research studies presented in this paper is to dramatically increase process efficiency as well as process flexibility. During the last years, the average power of commercial ultra-short pulsed laser sources has increased significantly. The efficient utilization of the high average laser power in the field of material processing requires an effective distribution of the laser power onto the work piece. One approach to increase the efficiency is the application of beam splitting devices to enable parallel processing. Multi beam processing is used to parallelize the fabrication of periodic structures as most application only require a partial amount of the emitted ultra-short pulsed laser power. In order to achieve highest flexibility while using multi beam processing the single beams are diverted and re-guided in a way that enables the opportunity to process with each partial beam on locally apart probes or semimanufactures.

System-Level Integrated Circuit (SLIC) Technology Development for Phased Array Antenna Applications

NASA Technical Reports Server (NTRS)

Windyka, John A.; Zablocki, Ed G.

1997-01-01

This report documents the efforts and progress in developing a 'system-level' integrated circuit, or SLIC, for application in advanced phased array antenna systems. The SLIC combines radio-frequency (RF) microelectronics, digital and analog support circuitry, and photonic interfaces into a single micro-hybrid assembly. Together, these technologies provide not only the amplitude and phase control necessary for electronic beam steering in the phased array, but also add thermally-compensated automatic gain control, health and status feedback, bias regulation, and reduced interconnect complexity. All circuitry is integrated into a compact, multilayer structure configured for use as a two-by-four element phased array module, operating at 20 Gigahertz, using a Microwave High-Density Interconnect (MHDI) process. The resultant hardware is constructed without conventional wirebonds, maintains tight inter-element spacing, and leads toward low-cost mass production. The measured performances and development issues associated with both the two-by-four element module and the constituent elements are presented. Additionally, a section of the report describes alternative architectures and applications supported by the SLIC electronics. Test results show excellent yield and performance of RF circuitry and full automatic gain control for multiple, independent channels. Digital control function, while suffering from lower manufacturing yield, also proved successful.

270GHz SiGe BiCMOS manufacturing process platform for mmWave applications

NASA Astrophysics Data System (ADS)

Kar-Roy, Arjun; Preisler, Edward J.; Talor, George; Yan, Zhixin; Booth, Roger; Zheng, Jie; Chaudhry, Samir; Howard, David; Racanelli, Marco

2011-11-01

TowerJazz has been offering the high volume commercial SiGe BiCMOS process technology platform, SBC18, for more than a decade. In this paper, we describe the TowerJazz SBC18H3 SiGe BiCMOS process which integrates a production ready 240GHz FT / 270 GHz FMAX SiGe HBT on a 1.8V/3.3V dual gate oxide CMOS process in the SBC18 technology platform. The high-speed NPNs in SBC18H3 process have demonstrated NFMIN of ~2dB at 40GHz, a BVceo of 1.6V and a dc current gain of 1200. This state-of-the-art process also comes with P-I-N diodes with high isolation and low insertion losses, Schottky diodes capable of exceeding cut-off frequencies of 1THz, high density stacked MIM capacitors, MOS and high performance junction varactors characterized up to 50GHz, thick upper metal layers for inductors, and various resistors such as low value and high value unsilicided poly resistors, metal and nwell resistors. Applications of the SBC18H3 platform for millimeter-wave products for automotive radars, phased array radars and Wband imaging are presented.

Study of soft magnetic iron cobalt based alloys processed by powder injection molding

NASA Astrophysics Data System (ADS)

Silva, Aline; Lozano, Jaime A.; Machado, Ricardo; Escobar, Jairo A.; Wendhausen, Paulo A. P.

As a near net shape process, powder injection molding (PIM) opens new possibilities to process Fe-Co alloys for magnetic applications. Due to the fact that PIM does not involve plastic deformation of the material during processing, we envisioned the possibility of eliminating vanadium (V), which is generally added to Fe-Co alloys to improve the ductility in order to enable its further shaping by conventional processes such as forging and cold rolling. In our investigation we have found out two main futures related to the elimination of V, which lead to a cost-benefit gain in manufacturing small magnetic components where high-saturation induction is needed at low frequencies. Firstly, the elimination of V enables the achievement of much better magnetic properties when alloys are processed by PIM. Secondly, a lower sintering temperature can be used when the alloy is processed starting with elemental Fe and Co powders without the addition of V.

A CMMI-based approach for medical software project life cycle study.

PubMed

Chen, Jui-Jen; Su, Wu-Chen; Wang, Pei-Wen; Yen, Hung-Chi

2013-01-01

In terms of medical techniques, Taiwan has gained international recognition in recent years. However, the medical information system industry in Taiwan is still at a developing stage compared with the software industries in other nations. In addition, systematic development processes are indispensable elements of software development. They can help developers increase their productivity and efficiency and also avoid unnecessary risks arising during the development process. Thus, this paper presents an application of Light-Weight Capability Maturity Model Integration (LW-CMMI) to Chang Gung Medical Research Project (CMRP) in the Nuclear medicine field. This application was intended to integrate user requirements, system design and testing of software development processes into three layers (Domain, Concept and Instance) model. Then, expressing in structural System Modeling Language (SysML) diagrams and converts part of the manual effort necessary for project management maintenance into computational effort, for example: (semi-) automatic delivery of traceability management. In this application, it supports establishing artifacts of "requirement specification document", "project execution plan document", "system design document" and "system test document", and can deliver a prototype of lightweight project management tool on the Nuclear Medicine software project. The results of this application can be a reference for other medical institutions in developing medical information systems and support of project management to achieve the aim of patient safety.

Ethical issues: the multi-centre low-risk ethics/governance review process and AMOSS.

PubMed

Vaughan, Geraldine; Pollock, Wendy; Peek, Michael J; Knight, Marian; Ellwood, David; Homer, Caroline S; Pulver, Lisa Jackson; McLintock, Claire; Ho, Maria T; Sullivan, Elizabeth A

2012-04-01

The Australasian Maternity Outcomes Surveillance System (AMOSS) conducts surveillance and research of rare and serious conditions in pregnancy. This multi-centre population health study is considered low risk with minimal ethical impact. To describe the ethics/governance review pathway undertaken by AMOSS. Prospective, descriptive study during 2009-2011 of the governance/ethical review processes required to gain approval for Australian and New Zealand (ANZ) maternity units with more than 50 births per year (n = 303) to participate in AMOSS. Review processes ranged from a single application for 24 NZ sites, a single application for eligible hospitals in two Australian states, full Health Research Ethics Committee (HREC) applications for individual hospitals, through simple letters of support. As of September 2011, 46 full/expedited ethics applications, 131 site governance applications and 136 letters of support requests were made over 33 months, involving an estimated 3261 hours by AMOSS staff/investigators, and an associated resource burden by participating sites, to obtain approval to receive nonidentifiable data from 291 hospitals. The AMOSS research system provides an important resource to enhance knowledge of conditions that cause rare and serious maternal morbidity. Yet the highly variable ethical approval processes required to implement this study have been excessively repetitive and burdensome. This process jeopardises timely, efficient research project implementation, without corresponding benefits to research participants. The resource burden to establish research governance for AMOSS confirms the urgent need for the Harmonisation of Multi-centre Ethical Review (HoMER) to further streamline ethics/governance review processes for multi-centre research. © 2011 The Authors. Australian and New Zealand Journal of Obstetrics and Gynaecology © 2011 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Learning Experiences and Gains from Continuing Professional Education and Their Applicability to Work for Japanese Government Officials

ERIC Educational Resources Information Center

Noda, Ayaka; Kim, Mikyong Minsun

2014-01-01

This study aims to understand the perceived learning experiences and gains for Japanese government officials from US and Japanese graduate and professional schools, and how applicable their continuing professional education (CPE) is to professional performance. Interview participants were drawn from long-term overseas and domestic fellowship…

77 FR 42489 - Notice of Submission for OMB Review; Office of Postsecondary Education; Application for Gaining...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-19

... with the collection results from a program change to run this one-time college savings account...; Application for Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) College Savings... pairing federally supported college savings accounts with GEAR UP activities as part of an overall college...

Understanding the Role of Numeracy in Health: Proposed Theoretical Framework and Practical Insights

PubMed Central

Lipkus, Isaac M.; Peters, Ellen

2009-01-01

Numeracy, that is how facile people are with mathematical concepts and their applications, is gaining importance in medical decision making and risk communication. This paper proposes six critical functions of health numeracy. These functions are integrated into a theoretical framework on health numeracy that has implications for risk-communication and medical-decision-making processes. We examine practical underpinnings for targeted interventions aimed at improving such processes as a function of health numeracy. It is hoped that the proposed functions and theoretical framework will spur more research to determine how an understanding of health numeracy can lead to more effective communication and decision outcomes. PMID:19834054

Perspective for special Gurdon issue for differentiation: can cell fusion inform nuclear reprogramming?

PubMed

Burns, David; Blau, Helen M

2014-07-01

Nuclear reprogramming was first shown to be possible by Sir John Gurdon over a half century ago. The process has been revolutionized by the production of induced pluripotent cells by overexpression of the four transcription factors discovered by Shinya Yamanaka, which now enables mammalian applications. Yet, reprogramming by a few transcription factors remains incomplete and inefficient, whether to pluripotent or differentiated cells. We propose that a better understanding of mechanistic insights based on developmental principles gained from heterokaryon studies may inform the process of directing cell fate, fundamentally and clinically. Copyright © 2014 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

The ups and downs of peer review.

PubMed

Benos, Dale J; Bashari, Edlira; Chaves, Jose M; Gaggar, Amit; Kapoor, Niren; LaFrance, Martin; Mans, Robert; Mayhew, David; McGowan, Sara; Polter, Abigail; Qadri, Yawar; Sarfare, Shanta; Schultz, Kevin; Splittgerber, Ryan; Stephenson, Jason; Tower, Cristy; Walton, R Grace; Zotov, Alexander

2007-06-01

This article traces the history of peer review of scientific publications, plotting the development of the process from its inception to its present-day application. We discuss the merits of peer review and its weaknesses, both perceived and real, as well as the practicalities of several major proposed changes to the system. It is our hope that readers will gain a better appreciation of the complexities of the process and, when serving as reviewers themselves, will do so in a manner that will enhance the utility of the exercise. We also propose the development of an international on-line training program for accreditation of potential referees.

Summary of Skylab S-193 altimeter altitude results. [orbit calculation and studies of the ocean bottom

NASA Technical Reports Server (NTRS)

Mcgoogan, J. T.; Leitao, C. D.; Wells, W. T.

1975-01-01

The SKYLAB S-193 altimeter altitude results are presented in a concise format for further use and analysis by the scientific community. The altimeter mission and instrumentation is described along with the altimeter processing techniques and values of parameters used for processing. The determination of reference orbits is discussed, and the tracking systems utilized are tabulated. Techniques for determining satellite pointing are presented and a tabulation of pointing for each data mission included. The geographical location, the ocean bottom topography, the altimeter-determined ocean surface topography, and the altimeter automatic gain control history is presented. Some typical applications of this data are suggested.

Carpal tunnel syndrome: just a peripheral neuropathy?

PubMed

Fernández-de-Las-Peñas, César; Plaza-Manzano, Gustavo

2018-06-05

Carpal tunnel syndrome (CTS) is considered just a peripheral neuropathy of the upper extremity associated to the compression of the median nerve. There is evidence suggesting the presence of complex sensitization mechanisms in CTS. These processes are manifested by symptoms in extra-median regions and the presence of bilateral sensory and motor impairments. These sensory and motor changes are not associated to electrodiagnostic findings. The presence of sensitization mechanisms suggests that CTS should not be considered just as a peripheral neuropathy. The presence of altered nociceptive gain processing should be considered for therapeutic management of CTS by considering the application of therapeutic interventions that modulate nociceptive barrage into the CNS.

Cloning Should Be Simple: Escherichia coli DH5α-Mediated Assembly of Multiple DNA Fragments with Short End Homologies

PubMed Central

Richardson, Ruth E.; Suzuki, Yo

2015-01-01

Numerous DNA assembly technologies exist for generating plasmids for biological studies. Many procedures require complex in vitro or in vivo assembly reactions followed by plasmid propagation in recombination-impaired Escherichia coli strains such as DH5α, which are optimal for stable amplification of the DNA materials. Here we show that despite its utility as a cloning strain, DH5α retains sufficient recombinase activity to assemble up to six double-stranded DNA fragments ranging in size from 150 bp to at least 7 kb into plasmids in vivo. This process also requires surprisingly small amounts of DNA, potentially obviating the need for upstream assembly processes associated with most common applications of DNA assembly. We demonstrate the application of this process in cloning of various DNA fragments including synthetic genes, preparation of knockout constructs, and incorporation of guide RNA sequences in constructs for clustered regularly interspaced short palindromic repeats (CRISPR) genome editing. This consolidated process for assembly and amplification in a widely available strain of E. coli may enable productivity gain across disciplines involving recombinant DNA work. PMID:26348330

A Q-Ising model application for linear-time image segmentation

NASA Astrophysics Data System (ADS)

Bentrem, Frank W.

2010-10-01

A computational method is presented which efficiently segments digital grayscale images by directly applying the Q-state Ising (or Potts) model. Since the Potts model was first proposed in 1952, physicists have studied lattice models to gain deep insights into magnetism and other disordered systems. For some time, researchers have realized that digital images may be modeled in much the same way as these physical systems ( i.e., as a square lattice of numerical values). A major drawback in using Potts model methods for image segmentation is that, with conventional methods, it processes in exponential time. Advances have been made via certain approximations to reduce the segmentation process to power-law time. However, in many applications (such as for sonar imagery), real-time processing requires much greater efficiency. This article contains a description of an energy minimization technique that applies four Potts (Q-Ising) models directly to the image and processes in linear time. The result is analogous to partitioning the system into regions of four classes of magnetism. This direct Potts segmentation technique is demonstrated on photographic, medical, and acoustic images.

Subwavelength atom localization via coherent manipulation of the Raman gain process

NASA Astrophysics Data System (ADS)

Qamar, Sajid; Mehmood, Asad; Qamar, Shahid

2009-03-01

We present a simple scheme of atom localization in a subwavelength domain via manipulation of Raman gain process. We consider a four-level system with a pump and a weak probe field. In addition, we apply a coherent field to control the gain process. The system is similar to the one used by Agarwal and Dasgupta [Phys. Rev. A 70, 023802 (2004)] for the superluminal pulse propagation through Raman gain medium. For atom localization, we consider both pump and control fields to be the standing-wave fields of the cavity. We show that a much precise position of an atom passing through the standing-wave fields can be determined by measuring the gain spectrum of the probe field.

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

Wiebenga, J. H.; Atzema, E. H.; Boogaard, A. H. van den

Robust design of forming processes using numerical simulations is gaining attention throughout the industry. In this work, it is demonstrated how robust optimization can assist in further stretching the limits of metal forming processes. A deterministic and a robust optimization study are performed, considering a stretch-drawing process of a hemispherical cup product. For the robust optimization study, both the effect of material and process scatter are taken into account. For quantifying the material scatter, samples of 41 coils of a drawing quality forming steel have been collected. The stochastic material behavior is obtained by a hybrid approach, combining mechanical testingmore » and texture analysis, and efficiently implemented in a metamodel based optimization strategy. The deterministic and robust optimization results are subsequently presented and compared, demonstrating an increased process robustness and decreased number of product rejects by application of the robust optimization approach.« less

Infrared-thermography imaging system multiapplications for manufacturing

NASA Astrophysics Data System (ADS)

Stern, Sharon A.

1990-03-01

Imaging systems technology has been utilized traditionally for diagnosing structural envelope or insulation problems in the general thermographic comunity. Industrially, new applications for utilizing thermal imaging technology have been developed i n pred i cti ve/preventi ye mai ntenance and prod uct moni tori ng prociures at Eastman Kodak Company, the largest photographic manufacturering producer in the world. In the manufacturing processes used at Eastman Kodak Company, new applications for thermal imaging include: (1) Fluid transfer line insulation (2) Web coating drying uniformity (3) Web slitter knives (4) Heating/cooling coils (5) Overheated tail bearings, and (6) Electrical phase imbalance. The substantial cost benefits gained from these applications of infrared thermography substantiate the practicality of this approach and indicate the desirability of researching further appl i cati ons.

Smartphone Applications in Palliative Homecare

PubMed Central

Dhiliwal, Sunil R; Salins, Naveen

2015-01-01

Smartphone applications in healthcare delivery are a novel concept and is rapidly gaining ground in all fields of medicine. The modes of e-communications such as e-mail, short message service (SMS), multimedia messaging service (MMS) and WhatsApp in palliative care provides a means for quick tele-consultation, information sharing, cuts the waiting time and facilitates initiation of the treatment at the earliest. It also forms a means of communication with local general practitioner and local health care provider such that continuity of the care is maintained. It also minimizes needless transport of the patient to hospital, prevents needless hospitalization and investigations and minimizes cost and logistics involved in the care process. The two case studies provided highlights the use of smartphone application like WhatsApp in palliative care practice and demonstrates its utility. PMID:25709195

Recent Applications of Neutron Imaging Methods

NASA Astrophysics Data System (ADS)

Lehmann, E.; Mannes, D.; Kaestner, A.; Grünzweig, C.

The methodical progress in the field of neutron imaging is visible in general but on different levels in the particular labs. Consequently, the access to most suitable beam ports, the usage of advanced imaging detector systems and the professional image processing made the technique competitive to other non-destructive tools like X-ray imaging. Based on this performance gain and by new methodical approaches several new application fields came up - in addition to the already established ones. Accordingly, new image data are now mostly in the third dimension available in the format of tomography volumes. The radiography mode is still the basis of neutron imaging, but the extracted information from superimposed image data (like for a grating interferometer) enables completely new insights. In the consequence, many new applications were created.

Characterization study of an intensified complementary metal-oxide-semiconductor active pixel sensor.

PubMed

Griffiths, J A; Chen, D; Turchetta, R; Royle, G J

2011-03-01

An intensified CMOS active pixel sensor (APS) has been constructed for operation in low-light-level applications: a high-gain, fast-light decay image intensifier has been coupled via a fiber optic stud to a prototype "VANILLA" APS, developed by the UK based MI3 consortium. The sensor is capable of high frame rates and sparse readout. This paper presents a study of the performance parameters of the intensified VANILLA APS system over a range of image intensifier gain levels when uniformly illuminated with 520 nm green light. Mean-variance analysis shows the APS saturating around 3050 Digital Units (DU), with the maximum variance increasing with increasing image intensifier gain. The system's quantum efficiency varies in an exponential manner from 260 at an intensifier gain of 7.45 × 10(3) to 1.6 at a gain of 3.93 × 10(1). The usable dynamic range of the system is 60 dB for intensifier gains below 1.8 × 10(3), dropping to around 40 dB at high gains. The conclusion is that the system shows suitability for the desired application.

Characterization study of an intensified complementary metal-oxide-semiconductor active pixel sensor

NASA Astrophysics Data System (ADS)

Griffiths, J. A.; Chen, D.; Turchetta, R.; Royle, G. J.

2011-03-01

An intensified CMOS active pixel sensor (APS) has been constructed for operation in low-light-level applications: a high-gain, fast-light decay image intensifier has been coupled via a fiber optic stud to a prototype "VANILLA" APS, developed by the UK based MI3 consortium. The sensor is capable of high frame rates and sparse readout. This paper presents a study of the performance parameters of the intensified VANILLA APS system over a range of image intensifier gain levels when uniformly illuminated with 520 nm green light. Mean-variance analysis shows the APS saturating around 3050 Digital Units (DU), with the maximum variance increasing with increasing image intensifier gain. The system's quantum efficiency varies in an exponential manner from 260 at an intensifier gain of 7.45 × 103 to 1.6 at a gain of 3.93 × 101. The usable dynamic range of the system is 60 dB for intensifier gains below 1.8 × 103, dropping to around 40 dB at high gains. The conclusion is that the system shows suitability for the desired application.

Improving Thermal Performance of a Residential Building, Related to Its Orientations - A Case Study

NASA Astrophysics Data System (ADS)

Akshaya, S.; Harish, S.; Arthy, R.; Muthu, D.; Venkatasubramanian, C.

2017-07-01

Urban planners and stakeholders require knowledge about the effectiveness of city-scale climate adaptation measures in order to develop climate resilient cities and to push forward the political process for the implementation of climate adaptation strategies. This study examines the impact of modifications in orientation of buildings with respect to heat load. Heat load calculation is a mathematical process to determine the best capacity, application and style of HVAC system. The purpose is to ensure energy efficiency while also maximizing comfort inside the building. This study of load calculation is essential for a building because it helps to pick the best orientation and focuses to find an orientation that will reduce energy due to direct solar radiation. One of the factors affecting this assessment is the latitude of the location. The heat gain is effective through walls and fenestration. Improper management through ineffective orientation of the building’s natural heat gain leads to excessive consumption of energy in the form of CL. The total heat gain for the above factors is calculated with the equations and assumptions as per ASHRAE code. After the calculation of heat load for different orientations, the best suited orientation of the building is found. By altering the building to suitable orientation, the dependence on electrical equipment can be minimized and thereby helps in energy conservation.

A review of combined experimental and computational procedures for assessing biopolymer structure-process-property relationships.

PubMed

Gronau, Greta; Krishnaji, Sreevidhya T; Kinahan, Michelle E; Giesa, Tristan; Wong, Joyce Y; Kaplan, David L; Buehler, Markus J

2012-11-01

Tailored biomaterials with tunable functional properties are desirable for many applications ranging from drug delivery to regenerative medicine. To improve the predictability of biopolymer materials functionality, multiple design parameters need to be considered, along with appropriate models. In this article we review the state of the art of synthesis and processing related to the design of biopolymers, with an emphasis on the integration of bottom-up computational modeling in the design process. We consider three prominent examples of well-studied biopolymer materials - elastin, silk, and collagen - and assess their hierarchical structure, intriguing functional properties and categorize existing approaches to study these materials. We find that an integrated design approach in which both experiments and computational modeling are used has rarely been applied for these materials due to difficulties in relating insights gained on different length- and time-scales. In this context, multiscale engineering offers a powerful means to accelerate the biomaterials design process for the development of tailored materials that suit the needs posed by the various applications. The combined use of experimental and computational tools has a very broad applicability not only in the field of biopolymers, but can be exploited to tailor the properties of other polymers and composite materials in general. Copyright © 2012 Elsevier Ltd. All rights reserved.

Deep learning with convolutional neural network in radiology.

PubMed

Yasaka, Koichiro; Akai, Hiroyuki; Kunimatsu, Akira; Kiryu, Shigeru; Abe, Osamu

2018-04-01

Deep learning with a convolutional neural network (CNN) is gaining attention recently for its high performance in image recognition. Images themselves can be utilized in a learning process with this technique, and feature extraction in advance of the learning process is not required. Important features can be automatically learned. Thanks to the development of hardware and software in addition to techniques regarding deep learning, application of this technique to radiological images for predicting clinically useful information, such as the detection and the evaluation of lesions, etc., are beginning to be investigated. This article illustrates basic technical knowledge regarding deep learning with CNNs along the actual course (collecting data, implementing CNNs, and training and testing phases). Pitfalls regarding this technique and how to manage them are also illustrated. We also described some advanced topics of deep learning, results of recent clinical studies, and the future directions of clinical application of deep learning techniques.

Describing the clinical reasoning process: application of a model of enablement to a pediatric case.

PubMed

Furze, Jennifer; Nelson, Kelly; O'Hare, Megan; Ortner, Amanda; Threlkeld, A Joseph; Jensen, Gail M

2013-04-01

Clinical reasoning is a core tenet of physical therapy practice leading to optimal patient care. The purpose of this case was to describe the outcomes, subjective experience, and reflective clinical reasoning process for a child with cerebral palsy using the International Classification of Functioning, Disability, and Health (ICF) model. Application of the ICF framework to a 9-year-old boy with spastic triplegic cerebral palsy was utilized to capture the interwoven factors present in this case. Interventions in the pool occurred twice weekly for 1 h over a 10-week period. Immediately post and 4 months post-intervention, the child made functional and meaningful gains. The family unit also developed an enjoyment of exercising together. Each individual family member described psychological, emotional, or physical health improvements. Reflection using the ICF model as a framework to discuss clinical reasoning can highlight important factors contributing to effective patient management.

Information Architecture for Quality Management Support in Hospitals.

PubMed

Rocha, Álvaro; Freixo, Jorge

2015-10-01

Quality Management occupies a strategic role in organizations, and the adoption of computer tools within an aligned information architecture facilitates the challenge of making more with less, promoting the development of a competitive edge and sustainability. A formal Information Architecture (IA) lends organizations an enhanced knowledge but, above all, favours management. This simplifies the reinvention of processes, the reformulation of procedures, bridging and the cooperation amongst the multiple actors of an organization. In the present investigation work we planned the IA for the Quality Management System (QMS) of a Hospital, which allowed us to develop and implement the QUALITUS (QUALITUS, name of the computer application developed to support Quality Management in a Hospital Unit) computer application. This solution translated itself in significant gains for the Hospital Unit under study, accelerating the quality management process and reducing the tasks, the number of documents, the information to be filled in and information errors, amongst others.

Analytic methods for design of wave cycles for wave rotor core engines

NASA Technical Reports Server (NTRS)

Resler, Edwin L., Jr.; Mocsari, Jeffrey C.; Nalim, M. R.

1993-01-01

A procedure to design a preliminary wave rotor cycle for any application is presented. To complete a cycle with heat addition there are two separate but related design steps that must be followed. The 'wave' boundary conditions determine the allowable amount of heat added in any case and the ensuing wave pattern requires certain pressure discharge conditions to allow the process to be made cyclic. This procedure, when applied, gives a first estimate of the cycle performance and the necessary information for the next step in the design process, namely the application of a characteristic based or other appropriate detailed one dimensional wave calculation that locates the proper porting around the periphery of the wave rotor. Four examples of the design procedure are given to demonstrate its utility and generality. These examples also illustrate the large gains in performance that could be realized with the use of wave rotor enhanced propulsion cycles.

Alumina-zirconia machinable abutments for implant-supported single-tooth anterior crowns.

PubMed

Sadoun, M; Perelmuter, S

1997-01-01

Innovative materials and application techniques are constantly being developed in the ongoing search for improved restorations. This article describes a new material and the fabrication process of aesthetic machinable ceramic anterior implant abutments. The ceramic material utilized is a mixture of alumina (aluminum oxide) and ceria (cerium oxide) with partially stabilized zirconia (zirconium oxide). The initial core material is a cylinder with a 9-mm diameter and a 15-mm height, obtained by ceramic injection and presintering processes. The resultant alumina-zirconia core is porous and readily machinable. It is secured to the analog, and its design is customized by machining the abutment to suit the particular clinical circumstances. The machining is followed by glass infiltration, and the crown is finalized. The learning objective of this article is to gain a basic knowledge of the fabrication and clinical application of the custom machinable abutments.

Perovskite- and Heusler based materials for thermoelectric converters

NASA Astrophysics Data System (ADS)

Weidenkaff, Anke

2015-03-01

The broad application of thermoelectric converters in future energy technologies requires the development of active, stable, low cost and sustainable materials. Semiconductors based on perovskite and heusler structures show substantial potential for thermoelectric energy conversion processes. Their good performance can be explained based on their suitable band structure, adjusted charge carrier density, mass and mobility, limited phonon transport, electron filtering possibilities, strongly correlated electronic systems, etc. These properties are widely tuneable by following theoretical concepts and a deep composition-structure-property understanding to change the composition, structure and size of the crystallites in innovative scalable synthesis procedures. Improved thermoelectric materials are developed, synthesised and tested in diverse high temperature applications to improve the efficiency and energy density of the thermoelectric conversion process. The lecture will provide a summary on the field of advanced perovskite-type ceramics and Heusler compounds gaining importance for a large number of future energy technologies.

Plasmonic beaming and active control over fluorescent emission.

PubMed

Jun, Young Chul; Huang, Kevin C Y; Brongersma, Mark L

2011-01-01

Nanometallic optical antennas are rapidly gaining popularity in applications that require exquisite control over light concentration and emission processes. The search is on for high-performance antennas that offer facile integration on chips. Here we demonstrate a new, easily fabricated optical antenna design that achieves an unprecedented level of control over fluorescent emission by combining concepts from plasmonics, radiative decay engineering and optical beaming. The antenna consists of a nanoscale plasmonic cavity filled with quantum dots coupled to a miniature grating structure that can be engineered to produce one or more highly collimated beams. Electromagnetic simulations and confocal microscopy were used to visualize the beaming process. The metals defining the plasmonic cavity can be utilized to electrically control the emission intensity and wavelength. These findings facilitate the realization of a new class of active optical antennas for use in new optical sources and a wide range of nanoscale optical spectroscopy applications.

High pressure effect on optical gain in type-II InGaAs/GaAsSb nano-heterostructure

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

Yadav, Nisha; Nirmal, H. K.; Yadav, Rashmi

This paper reports the simulation of optical gain in type-II InGaAs/GaAsSb quantum well based nano-scale heterostructure. In order to simulate the optical gain, the heterostructure has been modeled with the help of six band k.p method. The 6 × 6 diagonalized k.p Hamiltonian has been solved to evaluate the valence sub-bands (i.e. light and heavy hole energies); and then optical matrix elements and optical gain within TE (Transverse Electric) mode has been calculated. The results obtained suggest that peak optical gain of the order of ∼ 9000 /cm in the heterostructure can be achieved at the lasing wavelength ∼ 1.95 µmmore » (SWIR region). The application of high pressure (2 and 5 GPa) on the structure shows that the gain as well as lasing wavelength both approach to higher values. Thus, the structure can be tuned externally by the application of high pressure.« less

National Research Program of the Water Resources Division, U.S. Geological Survey, fiscal year 1987

USGS Publications Warehouse

Friedman, Linda C.; Donato, Christine N.

1988-01-01

The National Research Program (NRP) of the U.S. Geological Survey's Water Resources Division (WRD) had its beginnings in the late 1950's when "core research" was added as a line item to the Congressional budget. Since that time, the NRP has grown to encompass a broad spectrum of scientific investigations. The sciences of hydrology, mathematics, chemistry, physics, biology, geology, and engineering are used to gain a fundamental understanding of the processes that affect the availability, movement, and quality of the Nation's water resources. The knowledge gained and methods developed have great value to WRD's operational program. Results of the investigations conducted by the NRP are applicable not only to the solution of current water problems, but also to future issues, anticipated or unanticipated, that may affect the Nation's water resources.

National Research Program of the Water Resources Division, U. S. Geological Survey, Fiscal Year 1989

USGS Publications Warehouse

Eggers, JoAnn; Friedman, Linda C.

1989-01-01

The National Research Program (NRP) of the U.S. Geological Survey's Water Resources Division (WRD) had its beginnings in the late 1950's when "core research" was added as a line item to the Congressional budget. Since that time, the NRP has grown to encompass a broad spectrum of scientific investigations. The sciences of hydrology, mathematics, chemistry, physics, ecology, biology, geology, and engineering are used to gain a fundamental understanding of the processes that affect the availability, movement, and quality of the Nation's water resources. The knowledge gained and methods developed have great value to WRD's operational program. Results of the investigations conducted by the NRP are applicable not only to the solution of current water problems but also to future issues, anticipated or unanticipated, that may affect the Nation's water resources.

Recent advances in very large area avalanche photodiodes

NASA Astrophysics Data System (ADS)

Squillante, Michael R.; Christian, James; Entine, Gerald; Farrell, Richard; Karger, Arieh M.; McClish, Mickel; Myers, Richard; Shah, Kanai S.; Taylor, David; Vanderpuye, Kofi; Waer, Peter; Woodring, Mitchell

2003-09-01

The Avalanche Photodiode (APD) is a unique device that combines the advantages of solid state photodetectors with those of high gain devices such as photomultiplier tubes (PMTs). APDs have internal gain that provides a high signal-to-noise ratio. APDs have high quantum efficiency, are fast, compact, and rugged. These properties make them suitable detectors for important applications such as LADAR, detection and identification toxic chemicals and bio-warfare agents, LIDAR fluorescence detection, stand-off laser induced breakdown spectroscopy (LIBS), and nuclear detectors and imagers. Recently there have been significant technical breakthroughs in fabricating very large APDs, APD arrays, and position sensitive APD arrays (PSAPD). Signal gain of over 10,000 has been achieved, single element APDs have been fabricated with active area greater than 40 cm2, monolithic pixelated arrays with up to 28 x 28 elements have been fabricated, and position sensitive APDs have been developed and tested. Additionally, significant progress has been made in improving the fabrication process to provide better uniformity and high yield, permitting cost effective manufacturing of APDs for reduced cost.

Small Business Innovation Research (SBIR) Program, FY 1993. Program Solicitation 93.1, Closing Date: 15 January 1993

DTIC Science & Technology

1992-01-01

tactical computers. The module must correct for optical irregularities in illumination, pixel gain, offset nonuniformities due to dark currents and...large search FOR, for IR FPA. DESCRIPTION: Large area staring IR lPAs in both Medium Wavelength Infrared (MWIR) and Long Wavelength Infrared ( LWIR ) are a...of HTS materials to BLIP limited detection of radiation in the optical, IR, MWIR, and LWIR bands as well as for signal processing applications is also

Systems cell biology.

PubMed

Mast, Fred D; Ratushny, Alexander V; Aitchison, John D

2014-09-15

Systems cell biology melds high-throughput experimentation with quantitative analysis and modeling to understand many critical processes that contribute to cellular organization and dynamics. Recently, there have been several advances in technology and in the application of modeling approaches that enable the exploration of the dynamic properties of cells. Merging technology and computation offers an opportunity to objectively address unsolved cellular mechanisms, and has revealed emergent properties and helped to gain a more comprehensive and fundamental understanding of cell biology. © 2014 Mast et al.

Quantum Image Processing and Storage with Four Wave Mixing

DTIC Science & Technology

2016-08-10

have studied squeezed light in interferometric applications. During the grant period one graduate student, Jeremy Clark, finished with a PhD [1] in...just one phase-quadrature of the signal, it would seem disturbing if we had the same dispersion as in the PIA case , but no noise, and if we were thus...to achieve the maximum gain condition. Thus, with the same geometry as the twin-beam, phase-insensitive case , if one pumps on what would have been

Information Environments

NASA Technical Reports Server (NTRS)

Follen, Gregory J.; Naiman, Cynthia

2003-01-01

The objective of GRC CNIS/IE work is to build a plug-n-play infrastructure that provides the Grand Challenge Applications with a suite of tools for coupling codes together, numerical zooming between fidelity of codes and gaining deployment of these simulations onto the Information Power Grid. The GRC CNIS/IE work will streamline and improve this process by providing tighter integration of various tools through the use of object oriented design of component models and data objects and through the use of CORBA (Common Object Request Broker Architecture).

Parts, materials, and processes experience summary, volume 2. [design, engineering, and quality control

NASA Technical Reports Server (NTRS)

1973-01-01

This summary provides the general engineering community with the accumulated experience from ALERT reports issued by NASA and the Government-Industry. Data Exchange Program, and related experience gained by Government and industry. It provides expanded information on selected topics by relating the problem area (failure) to the cause, the investigation and findings, the suggestions for avoidance (inspections, screening tests, proper part applications, requirements for manufacturer's plant facilities, etc.), and failure analysis procedures. Diodes, integrated circuits, and transistors are covered in this volume.

Engineered Structured Sorbents for the Adsorption of Carbon Dioxide and Water Vapor from Manned Spacecraft Atmospheres: Applications and Testing 2008/2009

NASA Technical Reports Server (NTRS)

Howard, David F.; Perry, Jay L.; Knox, James C.; Junaedi, Christian

2009-01-01

This paper describes efforts to improve on typical packed beds of sorbent pellets by making use of structured sorbents and alternate bed configurations to improve system efficiency and reliability. The benefits of the alternate configurations include increased structural stability gained by eliminating clay bound zeolite pellets that tend to fluidize and erode, and better thermal control during sorption to increase process efficiency. Test results that demonstrate such improvements are described and presented.

Optimal estimates of free energies from multistate nonequilibrium work data.

PubMed

Maragakis, Paul; Spichty, Martin; Karplus, Martin

2006-03-17

We derive the optimal estimates of the free energies of an arbitrary number of thermodynamic states from nonequilibrium work measurements; the work data are collected from forward and reverse switching processes and obey a fluctuation theorem. The maximum likelihood formulation properly reweights all pathways contributing to a free energy difference and is directly applicable to simulations and experiments. We demonstrate dramatic gains in efficiency by combining the analysis with parallel tempering simulations for alchemical mutations of model amino acids.

Off-design analysis of a gas turbine powerplant augmented by steam injection using various fuels

NASA Technical Reports Server (NTRS)

Stochl, R. J.

1980-01-01

Results are compared using coal derived low and intermediate heating valve fuel gases and a conventional distillate. The results indicate that steam injection provides substantial increases in both power and efficiency within the available compressor surge margin. The results also indicate that these performance gains are relatively insensitive as to the type of fuel. Also, in a cogeneration application, steam injection could provide some degree of flexibility by varying the split between power and process steam.

An Evaluation of Grazing-Incidence Optics for Neutron Imaging

NASA Technical Reports Server (NTRS)

Gubarev, M. V.; Ramsey, B. D.; Engelhaupt, D. E.; Burgess, J.; Mildner, D. F. R.

2007-01-01

The focusing capabilities of neutron imaging optic based on the Wolter-1 geometry have been successfully demonstrated with a beam of long wavelength neutrons with low angular divergence.. A test mirror was fabricated using an electroformed nickel replication process at Marshall Space Flight Center. The neutron current density gain at the focal spot of the mirror is found to be at least 8 for neutron wavelengths in the range from 6 to 20 A. Possible applications of the optics are briefly discussed.

Experience in highly parallel processing using DAP

NASA Technical Reports Server (NTRS)

Parkinson, D.

1987-01-01

Distributed Array Processors (DAP) have been in day to day use for ten years and a large amount of user experience has been gained. The profile of user applications is similar to that of the Massively Parallel Processor (MPP) working group. Experience has shown that contrary to expectations, highly parallel systems provide excellent performance on so-called dirty problems such as the physics part of meteorological codes. The reasons for this observation are discussed. The arguments against replacing bit processors with floating point processors are also discussed.

Absorptivity Measurements and Heat Source Modeling to Simulate Laser Cladding

NASA Astrophysics Data System (ADS)

Wirth, Florian; Eisenbarth, Daniel; Wegener, Konrad

The laser cladding process gains importance, as it does not only allow the application of surface coatings, but also additive manufacturing of three-dimensional parts. In both cases, process simulation can contribute to process optimization. Heat source modeling is one of the main issues for an accurate model and simulation of the laser cladding process. While the laser beam intensity distribution is readily known, the other two main effects on the process' heat input are non-trivial. Namely the measurement of the absorptivity of the applied materials as well as the powder attenuation. Therefore, calorimetry measurements were carried out. The measurement method and the measurement results for laser cladding of Stellite 6 on structural steel S 235 and for the processing of Inconel 625 are presented both using a CO2 laser as well as a high power diode laser (HPDL). Additionally, a heat source model is deduced.

Investigation about the Chrome Steel Wire Arc Spray Process and the Resulting Coating Properties

NASA Astrophysics Data System (ADS)

Wilden, J.; Bergmann, J. P.; Jahn, S.; Knapp, S.; van Rodijnen, F.; Fischer, G.

2007-12-01

Nowadays, wire-arc spraying of chromium steel has gained an important market share for corrosion and wear protection applications. However, detailed studies are the basis for further process optimization. In order to optimize the process parameters and to evaluate the effects of the spray parameters DoE-based experiments had been carried out with high-speed camera shoots. In this article, the effects of spray current, voltage, and atomizing gas pressure on the particle jet properties, mean particle velocity and mean particle temperature and plume width on X46Cr13 wire are presented using an online process monitoring device. Moreover, the properties of the coatings concerning the morphology, composition and phase formation were subject of the investigations using SEM, EDX, and XRD-analysis. These deep investigations allow a defined verification of the influence of process parameters on spray plume and coating properties and are the basis for further process optimization.

Application of the Toyota Production System improves core laboratory operations.

PubMed

Rutledge, Joe; Xu, Min; Simpson, Joanne

2010-01-01

To meet the increased clinical demands of our hospital expansion, improve quality, and reduce costs, our tertiary care, pediatric core laboratory used the Toyota Production System lean processing to reorganize our 24-hour, 7 d/wk core laboratory. A 4-month, consultant-driven process removed waste, led to a physical reset of the space to match the work flow, and developed a work cell for our random access analyzers. In addition, visual controls, single piece flow, standard work, and "5S" were instituted. The new design met our goals as reflected by achieving and maintaining improved turnaround time (TAT; mean for creatinine reduced from 54 to 23 minutes) with increased testing volume (20%), monetary savings (4 full-time equivalents), decreased variability in TAT, and better space utilization (25% gain). The project had the unanticipated consequence of eliminating STAT testing because our in-laboratory TAT for routine testing was less than our prior STAT turnaround goal. The viability of this approach is demonstrated by sustained gains and further PDCA (Plan, Do, Check, Act) improvements during the 4 years after completion of the project.

Implicit emotion regulation affects outcome evaluation.

PubMed

Yang, Qiwei; Tang, Ping; Gu, Ruolei; Luo, Wenbo; Luo, Yue-jia

2015-06-01

Efficient implicit emotion regulation processes, which run without awareness, are important for human well-being. In this study, to investigate the influence of implicit emotion regulation on psychological and electrophysiological responses to gains and losses, participants were required to select between two Chinese four-character idioms to match the meaning of the third one before they performed a monetary gambling task. According to whether their meanings were related to emotion regulation, the idioms fell into two categories. Event-related potentials and self-rating emotional experiences to outcome feedback were recorded during the task. Priming emotion regulation reduced subjective emotional experience to both gains and losses and the amplitudes of the feedback-related negativity, while the P3 component was not influenced. According to these results, we suggest that the application of implicit emotion regulation effectively modulated the subjective emotional experience and the motivational salience of current outcomes without the cost of cognitive resources. This study implicates the potential significance of implicit emotion regulation in decision-making processes. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Injection-salting of pre rigor fillets of Atlantic salmon (Salmo salar).

PubMed

Birkeland, Sveinung; Akse, Leif; Joensen, Sjurdur; Tobiassen, Torbjørn; Skåra, Torstein

2007-01-01

The effects of temperature (-1, 4, and 10 degrees C), brine concentration (12% and 25% NaCl), injection volumes, and needle densities were investigated on fillet weight gain (%), salt content (%), fillet contraction (%), and muscle gaping in pre rigor brine-injected fillets of Atlantic salmon (Salmo salar). Increased brine concentration (12% to 25%) significantly increased the initial (< 5 min after injection) and final contraction (24 h after injection) of pre rigor fillets. Increased brine concentration significantly reduced weight gain and increased salt content but had no significant effect on muscle gaping. The temperatures tested did not significantly affect weight gain, fillet contraction, or gaping score. Significant regressions (P < 0.01) between the injection volume and weight gain (range: 2.5% to 15.5%) and salt content (range: 1.7% to 6.5%) were observed for injections of pre rigor fillets. Double injections significantly increased the weight gain and salt content compared to single injections. Initial fillet contraction measured 30 min after brine injection increased significantly (P < 0.01) with increasing brine injection volume but no significant difference in the fillet contraction was observed 12 h after brine injection (range: 7.9% to 8.9%). Brine-injected post rigor control fillets obtained higher weight gain, higher salt content, more muscle gaping, and significantly lower fillet contraction compared to the pre rigor injected fillets. Injection-salting is an applicable technology as a means to obtain satisfactory salt contents and homogenously distribute the salt into the muscle of pre rigor fillets of Atlantic salmon before further processing steps such as drying and smoking.

Demonstration of a fully differential VGA chip with small THD for ECG acquisition system

NASA Astrophysics Data System (ADS)

Gongli, Xiao; Yuliang, Qin; Weilin, Xu; Baolin, Wei; Jihai, Duan; Xueming, Wei

2015-10-01

We present both a theoretical and experimental demonstration of a fully differential variable gain amplifier (VGA) with small total harmonic distortion (THD) for an electrocardiogram (ECG) acquisition system. Capacitive feedback technology is adopted to reduce the nonlinearity of VGA. The fully differential VGA has been fabricated in SMIC 0.18-μm CMOS process, and it only occupies 0.11 mm2. The measurements are in good agreement with simulation results. Experimental results show that the gain of VGA changes from 6.17 to 43.75 dB with a gain step of 3 dB. The high-pass corner frequency and low-pass corner frequency are around 0.22 Hz and 7.9 kHz, respectively. For each gain configuration, a maximal THD of 0.13% is obtained. The fully differential VGA has a low THD and its key performance parameters are well satisfied with the demands of ECG acquisition system application in the UWB wireless body area network. Project supported by the National Natural Science Foundation of China (Nos. 61264001, 61465004, 61161003, 61166004), the Guangxi Natural Science Foundation (Nos. 2013GXNSFAA019333, 2013GXNSFAA019338), the Science and Technology Research Key Project of Guangxi Department of Education (No. 2013ZD026), and the Innovation Project of GUET Graduate Education (No. GDYCSZ201457).

A high-gain, low ion-backflow double micro-mesh gaseous structure for single electron detection

NASA Astrophysics Data System (ADS)

Zhang, Zhiyong; Qi, Binbin; Liu, Chengming; Feng, Jianxin; Liu, Jianbei; Shao, Ming; Zhou, Yi; Hong, Daojin; Lv, You; Song, Guofeng; Wang, Xu; You, Wenhao

2018-05-01

Application of micro-pattern gaseous detectors to gaseous photomultiplier tubes has been widely investigated over the past two decades. In this paper, we present a double micro-mesh gaseous structure that has been designed and fabricated for this application. Tests with X-rays and UV laser light indicate that this structure exhibits an excellent gas gain of > 7 × 104 and good energy resolution of 19% (full width at half maximum) for 5.9 keV X-rays. The gas gain can reach up to 106 for single electrons while maintaining a very low ion-backflow ratio down to 0.0005. This structure has good potential for other applications requiring a very low level of ion backflow.

Bacteriocins: Recent Trends and Potential Applications.

PubMed

Bali, Vandana; Panesar, Parmjit S; Bera, Manab B; Kennedy, John F

2016-01-01

In the modern era, there is great need for food preservation in both developing and developed countries due to increasing demand for extending shelf life and prevention of spoilage of food material. With the emergence of new pathogens and ability of micro-organisms to undergo changes, exploration of new avenues for the food preservation has gained importance. Moreover, awareness among consumers regarding harmful effects of chemical preservatives has been increased. Globally, altogether there is increasing demand by consumers for chemical-free and minimal processed food products. Potential of bacteriocin and its application in reducing the microbiological spoilages and in the preservation of food is long been recognized. Bacteriocins are normally specific to closely related species without disrupting the growth of other microbial populations. A number of applications of bacteriocin have been reported for humans, live stock, aquaculture etc. This review is focused on recent trends and applications of bacteriocins in different areas in addition to their biopreservative potential.

A novel digital image sensor with row wise gain compensation for Hyper Spectral Imager (HySI) application

NASA Astrophysics Data System (ADS)

Lin, Shengmin; Lin, Chi-Pin; Wang, Weng-Lyang; Hsiao, Feng-Ke; Sikora, Robert

2009-08-01

A 256x512 element digital image sensor has been developed which has a large pixel size, slow scan and low power consumption for Hyper Spectral Imager (HySI) applications. The device is a mixed mode, silicon on chip (SOC) IC. It combines analog circuitry, digital circuitry and optical sensor circuitry into a single chip. This chip integrates a 256x512 active pixel sensor array, a programming gain amplifier (PGA) for row wise gain setting, I2C interface, SRAM, 12 bit analog to digital convertor (ADC), voltage regulator, low voltage differential signal (LVDS) and timing generator. The device can be used for 256 pixels of spatial resolution and 512 bands of spectral resolution ranged from 400 nm to 950 nm in wavelength. In row wise gain readout mode, one can set a different gain on each row of the photo detector by storing the gain setting data on the SRAM thru the I2C interface. This unique row wise gain setting can be used to compensate the silicon spectral response non-uniformity problem. Due to this unique function, the device is suitable for hyper-spectral imager applications. The HySI camera located on-board the Chandrayaan-1 satellite, was successfully launched to the moon on Oct. 22, 2008. The device is currently mapping the moon and sending back excellent images of the moon surface. The device design and the moon image data will be presented in the paper.

A generalized predictive model for direct gain

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

Givoni, B.

In the correlational model for direct gain developed by the Los Alamos National Laboratory, a list of constants applicable to different types of buildings or passive solar systems was specified separately for each type. In its original form, the model was applicable only to buildings similar in their heat capacity, type of glazing, or night insulation to the types specified by the model. While maintaining the general form of the predictive equations, the new model, the predictive model for direct gain (PMDG), replaces the constants with functions dependent upon the thermal properties of the building, or the components of themore » solar system, or both. By this transformation, the LANL model for direct gain becomes a generalized one. The new model predicts the performance of buildings heated by direct gain with any heat capacity, glazing, and night insulation as functions of their thermophysical properties and climatic conditions.« less

Measurement and analysis of the conversion gain degradation of the CIS detectors in harsh radiation environments

NASA Astrophysics Data System (ADS)

Wang, Zujun; Xue, Yuanyuan; Guo, Xiaoqiang; Bian, Jingying; Yao, Zhibin; He, Baoping; Ma, Wuying; Sheng, Jiangkun; Dong, Guantao; Liu, Yan

2018-07-01

The conversion gain of the CMOS image sensor (CIS) is one of the most important key parameters to the CIS detector. The conversion gain degradation induced by radiation damage will seriously affect the performances of the CIS detector. The experiments of the CISs irradiated by protons, neutrons, and gamma rays are presented. The CISs have 4 Megapixels and pinned photodiode (PPD) pixel architecture with a standard 0.18 μm CMOS technology. The conversion gains versus the proton fluence (including the proton ionizing dose), neutron fluence and gamma total ionizing dose are presented, respectively. The mechanisms of the conversion gain degradation induced by radiation damage are analyzed in details. The investigations will help to improve the PPD CIS detector design, reliability and applicability for applications in the harsh radiation environments such as space and nuclear environments.

Octopaminergic Modulation of Temporal Frequency Coding in an Identified Optic Flow-Processing Interneuron

PubMed Central

Longden, Kit D.; Krapp, Holger G.

2010-01-01

Flying generates predictably different patterns of optic flow compared with other locomotor states. A sensorimotor system tuned to rapid responses and a high bandwidth of optic flow would help the animal to avoid wasting energy through imprecise motor action. However, neural processing that covers a higher input bandwidth itself comes at higher energetic costs which would be a poor investment when the animal was not flying. How does the blowfly adjust the dynamic range of its optic flow-processing neurons to the locomotor state? Octopamine (OA) is a biogenic amine central to the initiation and maintenance of flight in insects. We used an OA agonist chlordimeform (CDM) to simulate the widespread OA release during flight and recorded the effects on the temporal frequency coding of the H2 cell. This cell is a visual interneuron known to be involved in flight stabilization reflexes. The application of CDM resulted in (i) an increase in the cell's spontaneous activity, expanding the inhibitory signaling range (ii) an initial response gain to moving gratings (20–60 ms post-stimulus) that depended on the temporal frequency of the grating and (iii) a reduction in the rate and magnitude of motion adaptation that was also temporal frequency-dependent. To our knowledge, this is the first demonstration that the application of a neuromodulator can induce velocity-dependent alterations in the gain of a wide-field optic flow-processing neuron. The observed changes in the cell's response properties resulted in a 33% increase of the cell's information rate when encoding random changes in temporal frequency of the stimulus. The increased signaling range and more rapid, longer lasting responses employed more spikes to encode each bit, and so consumed a greater amount of energy. It appears that for the fly investing more energy in sensory processing during flight is more efficient than wasting energy on under-performing motor control. PMID:21152339

26 CFR 1.58-2 - General rules for conduit entities; partnerships and partners.

Code of Federal Regulations, 2012 CFR

2012-04-01

... example, if a trust has $100,000 of capital gains for the taxable year, all of which are distributed to A... reflect the net section 1201 gain to A of $40,000. Thus, A's capital gains items of tax preference would be $20,000. By application of this rule, A, in effect, treats capital gains distributed to him from...

26 CFR 1.58-2 - General rules for conduit entities; partnerships and partners.

Code of Federal Regulations, 2011 CFR

2011-04-01

... example, if a trust has $100,000 of capital gains for the taxable year, all of which are distributed to A... reflect the net section 1201 gain to A of $40,000. Thus, A's capital gains items of tax preference would be $20,000. By application of this rule, A, in effect, treats capital gains distributed to him from...

26 CFR 1.58-2 - General rules for conduit entities; partnerships and partners.

Code of Federal Regulations, 2010 CFR

2010-04-01

... example, if a trust has $100,000 of capital gains for the taxable year, all of which are distributed to A... reflect the net section 1201 gain to A of $40,000. Thus, A's capital gains items of tax preference would be $20,000. By application of this rule, A, in effect, treats capital gains distributed to him from...

26 CFR 1.58-2 - General rules for conduit entities; partnerships and partners.

Code of Federal Regulations, 2014 CFR

2014-04-01

... example, if a trust has $100,000 of capital gains for the taxable year, all of which are distributed to A... reflect the net section 1201 gain to A of $40,000. Thus, A's capital gains items of tax preference would be $20,000. By application of this rule, A, in effect, treats capital gains distributed to him from...

26 CFR 1.58-2 - General rules for conduit entities; partnerships and partners.

Code of Federal Regulations, 2013 CFR

2013-04-01

... example, if a trust has $100,000 of capital gains for the taxable year, all of which are distributed to A... reflect the net section 1201 gain to A of $40,000. Thus, A's capital gains items of tax preference would be $20,000. By application of this rule, A, in effect, treats capital gains distributed to him from...

Application of the microbiological method DEFT/APC to detect minimally processed vegetables treated with gamma radiation

NASA Astrophysics Data System (ADS)

Araújo, M. M.; Duarte, R. C.; Silva, P. V.; Marchioni, E.; Villavicencio, A. L. C. H.

2009-07-01

Marketing of minimally processed vegetables (MPV) are gaining impetus due to its convenience, freshness and apparent health effect. However, minimal processing does not reduce pathogenic microorganisms to safe levels. Food irradiation is used to extend the shelf life and to inactivate food-borne pathogens. In combination with minimal processing it could improve safety and quality of MPV. A microbiological screening method based on the use of direct epifluorescent filter technique (DEFT) and aerobic plate count (APC) has been established for the detection of irradiated foodstuffs. The aim of this study was to evaluate the applicability of this technique in detecting MPV irradiation. Samples from retail markets were irradiated with 0.5 and 1.0 kGy using a 60Co facility. In general, with a dose increment, DEFT counts remained similar independent of the irradiation while APC counts decreased gradually. The difference of the two counts gradually increased with dose increment in all samples. It could be suggested that a DEFT/APC difference over 2.0 log would be a criteria to judge if a MPV was treated by irradiation. The DEFT/APC method could be used satisfactorily as a screening method for indicating irradiation processing.

75 FR 33990 - Built-in Gains and Losses Under Section 382(h)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

... Gains and Losses Under Section 382(h) AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Final... section 382(h). DATES: Effective Date: These regulations are effective on June 11, 2010. Applicability...) regarding the treatment of prepaid income under the built-in gain provisions of section 382(h) were...

47 CFR 20.21 - Signal boosters.

Code of Federal Regulations, 2014 CFR

2014-10-01

... operation to ensure compliance with applicable noise and gain limits and either self-correct or shut down... provide equivalent uplink and downlink gain and conducted uplink power output that is at least 0.05 watts... referenced to the booster's input port for each band of operation. (C) Booster Gain Limits. (1) The uplink...

47 CFR 20.21 - Signal boosters.

Code of Federal Regulations, 2013 CFR

2013-10-01

... operation to ensure compliance with applicable noise and gain limits and either self-correct or shut down... provide equivalent uplink and downlink gain and conducted uplink power output that is at least 0.05 watts... referenced to the booster's input port for each band of operation. (C) Booster Gain Limits. (1) The uplink...

A Neuropsychological Approach to Understanding Risk-Taking for Potential Gains and Losses

PubMed Central

Levin, Irwin P.; Xue, Gui; Weller, Joshua A.; Reimann, Martin; Lauriola, Marco; Bechara, Antoine

2012-01-01

Affective neuroscience has helped guide research and theory development in judgment and decision-making by revealing the role of emotional processes in choice behavior, especially when risk is involved. Evidence is emerging that qualitatively and quantitatively different processes may be involved in risky decision-making for gains and losses. We start by reviewing behavioral work by Kahneman and Tversky (1979) and others, which shows that risk-taking differs for potential gains and potential losses. We then turn to the literature in decision neuroscience to support the gain versus loss distinction. Relying in part on data from a new task that separates risky decision-making for gains and losses, we test a neural model that assigns unique mechanisms for risky decision-making involving potential losses. Included are studies using patients with lesions to brain areas specified as important in the model and studies with healthy individuals whose brains are scanned to reveal activation in these and other areas during risky decision-making. In some cases, there is evidence that gains and losses are processed in different regions of the brain, while in other cases the same region appears to process risk in a different manner for gains and losses. At a more general level, we provide strong support for the notion that decisions involving risk-taking for gains and decisions involving risk-taking for losses represent different psychological processes. At a deeper level, we present mounting evidence that different neural structures play different roles in guiding risky choices in these different domains. Some structures are differentially activated by risky gains and risky losses while others respond uniquely in one domain or the other. Taken together, these studies support a clear functional dissociation between risk-taking for gains and risk-taking for losses, and further dissociation at the neural level. PMID:22347161

Gaining Research Access into the Lives of Muslim Girls: Researchers Negotiating "Muslimness", Modesty, "Inshallah", and "Haram"

ERIC Educational Resources Information Center

Hamzeh, Manal Z.; Oliver, Kimberly

2010-01-01

This paper explores the process of gaining research access into the lives of Muslim girls in the southwest USA. We discuss four emerging "entry markers" that challenged the process of gaining and sustaining access over a period of 14 months. These included being Muslim enough, being modest enough, "inshallah" ("Allah"…

Dressed Gain from the Parametrically Amplified Four-Wave Mixing Process in an Atomic Vapor.

PubMed

Zhang, Zhaoyang; Wen, Feng; Che, Junling; Zhang, Dan; Li, Changbiao; Zhang, Yanpeng; Xiao, Min

2015-10-14

With a forward cone emitting from the strong pump laser in a thermal rubidium atomic vapor, we investigate the non-degenerate parametrically amplified four-wave mixing (PA-FWM) process with dressing effects in a three-level "double-Λ" configuration both theoretically and experimentally. By seeding a weak probe field into the Stokes or anti-Stokes channel of the FWM, the gain processes are generated in the bright twin beams which are called conjugate and probe beams, respectively. However, the strong dressing effect of the pump beam will dramatically affect the gain factors both in the probe and conjugate channels, and can inevitably impose an influence on the quantum effects such as entangled degree and the quantum noise reduction between the two channels. We systematically investigate the intensity evolution of the dressed gain processes by manipulating the atomic density, the Rabi frequency and the frequency detuning. Such dressing effects are also visually evidenced by the observation of Autler-Townes splitting of the gain peaks. The investigation can contribute to the development of quantum information processing and quantum communications.

Dressed Gain from the Parametrically Amplified Four-Wave Mixing Process in an Atomic Vapor

NASA Astrophysics Data System (ADS)

Zhang, Zhaoyang; Wen, Feng; Che, Junling; Zhang, Dan; Li, Changbiao; Zhang, Yanpeng; Xiao, Min

2015-10-01

With a forward cone emitting from the strong pump laser in a thermal rubidium atomic vapor, we investigate the non-degenerate parametrically amplified four-wave mixing (PA-FWM) process with dressing effects in a three-level “double-Λ” configuration both theoretically and experimentally. By seeding a weak probe field into the Stokes or anti-Stokes channel of the FWM, the gain processes are generated in the bright twin beams which are called conjugate and probe beams, respectively. However, the strong dressing effect of the pump beam will dramatically affect the gain factors both in the probe and conjugate channels, and can inevitably impose an influence on the quantum effects such as entangled degree and the quantum noise reduction between the two channels. We systematically investigate the intensity evolution of the dressed gain processes by manipulating the atomic density, the Rabi frequency and the frequency detuning. Such dressing effects are also visually evidenced by the observation of Autler-Townes splitting of the gain peaks. The investigation can contribute to the development of quantum information processing and quantum communications.

Floating Solar Photovoltaics Gaining Ground | State, Local, and Tribal

Science.gov Websites

Gaining Ground January 24, 2017 by Alison Holm Floating solar photovoltaic (PV) systems, so-called flotovoltaics (a trademarked term) or floating solar, represent an emerging application in which PV panels are sited on bodies of water. The PV panel technology used for floating solar applications is very similar

14 CFR 1230.120 - Evaluation and disposition of applications and proposals for research to be conducted or...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Evaluation and disposition of applications... Section 1230.120 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PROTECTION OF HUMAN... subjects and others, and the importance of the knowledge gained or to be gained. (b) On the basis of this...

14 CFR 1230.120 - Evaluation and disposition of applications and proposals for research to be conducted or...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Evaluation and disposition of applications... Section 1230.120 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PROTECTION OF HUMAN... subjects and others, and the importance of the knowledge gained or to be gained. (b) On the basis of this...

Examining Information Problem-Solving, Knowledge, and Application Gains within Two Instructional Methods: Problem-Based and Computer-Mediated Participatory Simulation

ERIC Educational Resources Information Center

Newell, Terrance S.

2008-01-01

This study compared the effectiveness of two instructional methods--problem-based instruction within a face-to-face context and computer-mediated participatory simulation--in increasing students' content knowledge and application gains in the area of information problem-solving. The instructional methods were implemented over a four-week period. A…

45 CFR 690.120 - Evaluation and disposition of applications and proposals for research to be conducted or...

Code of Federal Regulations, 2010 CFR

2010-10-01

... PROTECTION OF HUMAN SUBJECTS § 690.120 Evaluation and disposition of applications and proposals for research... risks to the subjects, the adequacy of protection against these risks, the potential benefits of the research to the subjects and others, and the importance of the knowledge gained or to be gained. (b) On the...

A modular, programmable measurement system for physiological and spaceflight applications

NASA Technical Reports Server (NTRS)

Hines, John W.; Ricks, Robert D.; Miles, Christopher J.

1993-01-01

The NASA-Ames Sensors 2000! Program has developed a small, compact, modular, programmable, sensor signal conditioning and measurement system, initially targeted for Life Sciences Spaceflight Programs. The system consists of a twelve-slot, multi-layer, distributed function backplane, a digital microcontroller/memory subsystem, conditioned and isolated power supplies, and six application-specific, physiological signal conditioners. Each signal condition is capable of being programmed for gains, offsets, calibration and operate modes, and, in some cases, selectable outputs and functional modes. Presently, the system has the capability for measuring ECG, EMG, EEG, Temperature, Respiration, Pressure, Force, and Acceleration parameters, in physiological ranges. The measurement system makes heavy use of surface-mount packaging technology, resulting in plug in modules sized 125x55 mm. The complete 12-slot system is contained within a volume of 220x150x70mm. The system's capabilities extend well beyond the specific objectives of NASA programs. Indeed, the potential commercial uses of the technology are virtually limitless. In addition to applications in medical and biomedical sensing, the system might also be used in process control situations, in clinical or research environments, in general instrumentation systems, factory processing, or any other applications where high quality measurements are required.

A modular, programmable measurement system for physiological and spaceflight applications

NASA Astrophysics Data System (ADS)

Hines, John W.; Ricks, Robert D.; Miles, Christopher J.

1993-02-01

The NASA-Ames Sensors 2000] Program has developed a small, compact, modular, programmable, sensor signal conditioning and measurement system, initially targeted for Life Sciences Spaceflight Programs. The system consists of a twelve-slot, multi-layer, distributed function backplane, a digital microcontroller/memory subsystem, conditioned and isolated power supplies, and six application-specific, physiological signal conditioners. Each signal condition is capable of being programmed for gains, offsets, calibration and operate modes, and, in some cases, selectable outputs and functional modes. Presently, the system has the capability for measuring ECG, EMG, EEG, Temperature, Respiration, Pressure, Force, and Acceleration parameters, in physiological ranges. The measurement system makes heavy use of surface-mount packaging technology, resulting in plug in modules sized 125x55 mm. The complete 12-slot system is contained within a volume of 220x150x70mm. The system's capabilities extend well beyond the specific objectives of NASA programs. Indeed, the potential commercial uses of the technology are virtually limitless. In addition to applications in medical and biomedical sensing, the system might also be used in process control situations, in clinical or research environments, in general instrumentation systems, factory processing, or any other applications where high quality measurements are required.

Carbon Nanotubes for Human Space Flight

NASA Technical Reports Server (NTRS)

Scott, Carl D.; Files, Brad; Yowell, Leonard

2003-01-01

Single-wall carbon nanotubes offer the promise of a new class of revolutionary materials for space applications. The Carbon Nanotube Project at NASA Johnson Space Center has been actively researching this new technology by investigating nanotube production methods (arc, laser, and HiPCO) and gaining a comprehensive understanding of raw and purified material using a wide range of characterization techniques. After production and purification, single wall carbon nanotubes are processed into composites for the enhancement of mechanical, electrical, and thermal properties. This "cradle-to-grave" approach to nanotube composites has given our team unique insights into the impact of post-production processing and dispersion on the resulting material properties. We are applying our experience and lessons-learned to developing new approaches toward nanotube material characterization, structural composite fabrication, and are also making advances in developing thermal management materials and electrically conductive materials in various polymer-nanotube systems. Some initial work has also been conducted with the goal of using carbon nanotubes in the creation of new ceramic materials for high temperature applications in thermal protection systems. Human space flight applications such as advanced life support and fuel cell technologies are also being investigated. This discussion will focus on the variety of applications under investigation.

Design and Experiment of Electrooculogram (EOG) System and Its Application to Control Mobile Robot

NASA Astrophysics Data System (ADS)

Sanjaya, W. S. M.; Anggraeni, D.; Multajam, R.; Subkhi, M. N.; Muttaqien, I.

2017-03-01

In this paper, we design and investigate a biological signal detection of eye movements (Electrooculogram). To detect a signal of Electrooculogram (EOG) used 4 instrument amplifier process; differential instrumentation amplifier, High Pass Filter (HPF) with 3 stage filters, Low Pass Filter (LPF) with 3 stage filters and Level Shifter circuit. The total of amplifying is 1000 times of gain, with frequency range 0.5-30 Hz. IC OP-Amp OP07 was used for all amplifying process. EOG signal will be read as analog input for Arduino microprocessor, and will interfaced with serial communication to PC Monitor using Processing® software. The result of this research show a differences value of eye movements. Differences signal of EOG have been applied to navigation control of the mobile robot. In this research, all communication process using Bluetooth HC-05.

Effect of ZrB2 addition on the oxidation behavior of Si-SiC-ZrB2 composites exposed at 1500°C in air.

PubMed

D'Amico, Claudio; Bianchi, Giovanni; Padovano, Elisa; Biamino, Sara; Aversa, Alberta; Badini, Claudio; Ortona, Alberto

2018-01-01

Silicon carbide ceramics obtained by reactive infiltration of silicon (SRI) have many industrial applications especially involving severe and high temperature conditions. In this study, the oxidation behavior in air of Si-SiC-ZrB 2 systems at a high temperature (1500°C) for dwelling times of up to 48 hours was examined. The oxidation process was analyzed on the basis of elemental maps and X-ray diffraction patterns taken, respectively, on the core and on the surface of the specimens, together with weight gains and the average thicknesses of the resulting scale. Further, flexural strength at room temperature was examined as a function of different oxidation times. The main chemical reactions and phase transformations involved in the oxidation process are reported. Several oxides were detected on the surface: zirconia, silica, zircon and 3-zirconium monoxide. All of the samples showed a parabolic oxidation kinetics, suggesting that the controlling mechanism was the diffusion; however, even after 48 hours, the oxidation process was not finished - indeed, all of the samples continued to gain weight. The oxidation of Si-SiC-ZrB 2 material produced via SRI was slower compared with previously investigated ZrB 2 -SiC composites processed with a different techniques and tested in similar conditions. The oxidation mechanism was found to be consistent with the convection cells model.

Factors Affecting Bacterial Inactivation during High Hydrostatic Pressure Processing of Foods: A Review.

PubMed

Syed, Qamar-Abbas; Buffa, Martin; Guamis, Buenaventura; Saldo, Jordi

2016-01-01

Although, the High Hydrostatic Pressure (HHP) technology has been gaining gradual popularity in food industry since last two decades, intensive research is needed to explore the missing information. Bacterial inactivation in food by using HHP applications can be enhanced by getting deeper insights of the process. Some of these aspects have been already studied in detail (like pressure, time, and temperature, etc.), while some others still need to be investigated in more details (like pH, rates of compression, and decompression, etc.). Selection of process parameters is mainly dependent on type of matrix and target bacteria. This intensive review provides comprehensive information about the variety of aspects that can determine the bacterial inactivation potential of HHP process indicating the fields of future research on this subject including pH shifts of the pressure treated samples and critical limits of compression and decompression rates to accelerate the process efficacy.

Application of process mining to assess the data quality of routinely collected time-based performance data sourced from electronic health records by validating process conformance.

PubMed

Perimal-Lewis, Lua; Teubner, David; Hakendorf, Paul; Horwood, Chris

2016-12-01

Effective and accurate use of routinely collected health data to produce Key Performance Indicator reporting is dependent on the underlying data quality. In this research, Process Mining methodology and tools were leveraged to assess the data quality of time-based Emergency Department data sourced from electronic health records. This research was done working closely with the domain experts to validate the process models. The hospital patient journey model was used to assess flow abnormalities which resulted from incorrect timestamp data used in time-based performance metrics. The research demonstrated process mining as a feasible methodology to assess data quality of time-based hospital performance metrics. The insight gained from this research enabled appropriate corrective actions to be put in place to address the data quality issues. © The Author(s) 2015.

Development of smartphone applications for nutrition and physical activity behavior change.

PubMed

Hebden, Lana; Cook, Amelia; van der Ploeg, Hidde P; Allman-Farinelli, Margaret

2012-08-22

Young adults (aged 18 to 35) are a population group at high risk for weight gain, yet we know little about how to intervene in this group. Easy access to treatment and support with self-monitoring of their behaviors may be important. Smartphones are gaining in popularity with this population group and software applications ("apps") used on these mobile devices are a novel technology that can be used to deliver brief health behavior change interventions directly to individuals en masse, with potentially favorable cost-utility. However, existing apps for modifying nutrition or physical activity behaviors may not always reflect best practice guidelines for weight management. This paper describes the process of developing four apps aimed at modifying key lifestyle behaviors associated with weight gain during young adulthood, including physical activity, and consumption of take-out foods (fast food), fruit and vegetables, and sugar-sweetened drinks. The development process involved: (1) deciding on the behavior change strategies, relevant guidelines, graphic design, and potential data collection; (2) selecting the platform (Web-based versus native); (3) creating the design, which required decisions about the user interface, architecture of the relational database, and programming code; and (4) testing the prototype versions with the target audience (young adults aged 18 to 35). The four apps took 18 months to develop, involving the fields of marketing, nutrition and dietetics, physical activity, and information technology. Ten subjects provided qualitative feedback about using the apps. The slow running speed of the apps (due to a reliance on an active Internet connection) was the primary issue identified by this group, as well as the requirement to log in to the apps. Smartphone apps may be an innovative medium for delivering individual health behavior change intervention en masse, but researchers must give consideration to the target population, available technologies, existing commercial apps, and the possibility that their use will be irregular and short-lived.

Development of Smartphone Applications for Nutrition and Physical Activity Behavior Change

PubMed Central

Cook, Amelia; van der Ploeg, Hidde P; Allman-Farinelli, Margaret

2012-01-01

Background Young adults (aged 18 to 35) are a population group at high risk for weight gain, yet we know little about how to intervene in this group. Easy access to treatment and support with self-monitoring of their behaviors may be important. Smartphones are gaining in popularity with this population group and software applications (“apps”) used on these mobile devices are a novel technology that can be used to deliver brief health behavior change interventions directly to individuals en masse, with potentially favorable cost-utility. However, existing apps for modifying nutrition or physical activity behaviors may not always reflect best practice guidelines for weight management. Objective This paper describes the process of developing four apps aimed at modifying key lifestyle behaviors associated with weight gain during young adulthood, including physical activity, and consumption of take-out foods (fast food), fruit and vegetables, and sugar-sweetened drinks. Methods The development process involved: (1) deciding on the behavior change strategies, relevant guidelines, graphic design, and potential data collection; (2) selecting the platform (Web-based versus native); (3) creating the design, which required decisions about the user interface, architecture of the relational database, and programming code; and (4) testing the prototype versions with the target audience (young adults aged 18 to 35). Results The four apps took 18 months to develop, involving the fields of marketing, nutrition and dietetics, physical activity, and information technology. Ten subjects provided qualitative feedback about using the apps. The slow running speed of the apps (due to a reliance on an active Internet connection) was the primary issue identified by this group, as well as the requirement to log in to the apps. Conclusions Smartphone apps may be an innovative medium for delivering individual health behavior change intervention en masse, but researchers must give consideration to the target population, available technologies, existing commercial apps, and the possibility that their use will be irregular and short-lived. PMID:23611892

Characterization of vector stimulated Brillouin scattering gain over wide power range

NASA Astrophysics Data System (ADS)

Li, Yongqian; An, Qi; Li, Xiaojuan; Zhang, Lixin

2017-07-01

The wide range power dependence of vector stimulated Brillouin scattering (SBS) gain is theoretically and experimentally characterized by a mathematical model and measurement system based on the heterodyne pump-Stokes technique. The results show that SBS phase shift is much more tolerant of pump depletion than SBS amplitude gain, hence the performance improvement of the SBS-based distributed sensing system can be achieved by measuring the SBS phase shift spectrum. The discussion about the measured Brillouin spectrum width versus pump power at different Stokes powers reveals that the occurrence of nonnegligible pump depletion imposes a restriction on the determination of pump and Stokes powers in an SBS amplitude gain-based application system. The amplitude gain and phase shift of vector SBS gain increase with the increase of pump power and decrease with the increase of Stokes power, which indicates that the design strategy with smaller Stokes power and higher pump power is reasonable. And the measured center-asymmetry of the SBS phase shift spectrum is mainly caused by the nonlinear refractive index, which puts a limitation on the maximum pump power. The obtained results can provide a useful basis for the optimal design of practical vector SBS gain-based application systems.

Simple video format for mobile applications

NASA Astrophysics Data System (ADS)

Smith, John R.; Miao, Zhourong; Li, Chung-Sheng

2000-04-01

With the advent of pervasive computing, there is a growing demand for enabling multimedia applications on mobile devices. Large numbers of pervasive computing devices, such as personal digital assistants (PDAs), hand-held computer (HHC), smart phones, portable audio players, automotive computing devices, and wearable computers are gaining access to online information sources. However, the pervasive computing devices are often constrained along a number of dimensions, such as processing power, local storage, display size and depth, connectivity, and communication bandwidth, which makes it difficult to access rich image and video content. In this paper, we report on our initial efforts in designing a simple scalable video format with low-decoding and transcoding complexity for pervasive computing. The goal is to enable image and video access for mobile applications such as electronic catalog shopping, video conferencing, remote surveillance and video mail using pervasive computing devices.

Time Difference Amplifier with Robust Gain Using Closed-Loop Control

NASA Astrophysics Data System (ADS)

Nakura, Toru; Mandai, Shingo; Ikeda, Makoto; Asada, Kunihiro

This paper presents a Time Difference Amplifier (TDA) that amplifies the input time difference into the output time difference. Cross coupled chains of variable delay cells with the same number of stages are applicable for TDA, and the gain is adjusted via the closed-loop control. The TDA was fabricated using 65nm CMOS and the measurement results show that the time difference gain is 4.78 at a nominal power supply while the designed gain is 4.0. The gain is stable enough to be less than 1.4% gain shift under ±10% power supply voltage fluctuation.

Application Of Moldex3D For Thin-wall Injection Moulding Simulation

NASA Astrophysics Data System (ADS)

Šercer, Mladen; Godec, Damir; Bujanić, Božo

2007-05-01

The benefits associated with decreasing wall thicknesses below their current values are still measurable and desired even if the final wall thickness is nowhere near those of the aggressive portable electronics industry. It is important to note that gains in wall section reduction do not always occur without investment, in this case, in tooling and machinery upgrades. Equally important is the fact that productivity and performance benefits of reduced material usage, fast cycle times, and lighter weight can often outweigh most of the added costs. In order to eliminate unnecessary mould trials, minimize product development cycle, reduce overall costs and improve product quality, polymeric engineers use new CAE technology (Computer Aided Engineering). This technology is a simulation tool, which combines proven theories, material properties and process conditions to generate realistic simulations and produce valuable recommendations. Based on these recommendations, an optional combination of product design, material and process conditions can be identified. In this work, Moldex3D software was used for simulation of injection moulding in order to avoid potential moulding problems. The results gained from the simulation were used for the optimization of an existing product design, for mould development and for optimization of processing parameters, e.g. injection pressure, mould cavity temperature, etc.

Low power generation of equalized broadband CW supercontinua using a novel technique incorporating modulation instability of line broadened pump

NASA Astrophysics Data System (ADS)

Prakash, Roopa; Choudhury, Vishal; Arun, S.; Supradeepa, V. R.

2018-02-01

Continuous-wave(CW) supercontinuum sources find applications in various domains such as imaging, spectroscopy, test and measurement. They are generated by pumping an optical fiber with a CW laser in the anomalous-dispersion region close to its zero-dispersion wavelength. Modulation instability(MI) sidebands are created, and further broadened and equalized by additional nonlinear processes generating the supercontinuum. This necessitates high optical powers and at lower powers, only MI sidebands can be seen without the formation of the supercontinuum. Obtaining a supercontinuum at low, easily manageable optical powers is attractive for many applications, but current techniques cannot achieve this. In this work, we propose a new mechanism for low power supercontinuum generation utilizing the modified MI gain spectrum for a line-broadened, decorrelated pump. A novel two-stage generation mechanism is demonstrated, where the first stage constituting standard telecom fiber slightly broadens the input pump linewidth. However, this process in the presence of dispersion, acts to de-correlate the different spectral components of the pump signal. When this is sent through highly nonlinear fiber near its zero-dispersion wavelength, the shape of the MI gain spectrum is modified, and this process naturally results in the generation of a broadband, equalized supercontinuum source at much lower powers than possible using conventional single stage spectral broadening. Here, we demonstrate a 0.5W supercontinuum source pumped using a 4W Erbium-Ytterbium co-doped fiber laser with a bandwidth spanning from 1300nm to 2000nm. We also demonstrate an interesting behaviour of this technique of relative insensitivity to the pump wavelength vis-a-vis zero-dispersion wavelength of the fiber.

Combined Th/U, Pa/U and Ra/Th dating of fossil reef corals

NASA Astrophysics Data System (ADS)

Obert, J. C.; Scholz, D.; Lippold, J.; Felis, T.; Jochum, K. P.; Andreae, M. O.

2016-12-01

Fossil reef corals are often subject to post-depositional open-system behaviour, which is a major problem for accurate absolute dating. The commonly used 230Th/U-system can be disturbed by diagenetic alteration resulting in wrong apparent 230Th/U-ages. Since fossil reef corals are important palaeoenvironmental archives, precise absolute dating is essential for sea-level reconstruction and high-resolution climate reconstruction. We have developed a method for combined preparation and analysis of fossil reef corals by the 230Th/U-, 231Pa/U- and 226Ra/230Th-methods. Inconsistencies between ages determined by the different methods provide a means to identify diagenetically altered corals. In addition, the comparison of the 230Th/U and 231Pa/U data on concordia diagrams reveals further information about the alteration processes. (226Ra/230Th) and (226Ra/U) ratios in particular provide information about the more recent past (last 10 to approx. 50 ka) of the coral's diagenetic history. We compare these data with quantitative modelling of various diagenetic scenarios in order to identify the potential open-system processes. Here we present new data on the combined application of the three isotope systems to fossil Last Interglacial corals from the Gulf of Aqaba, northern Red Sea. Previous studies have shown that these corals were subject to substantial open-system behaviour, documented by very high initial (234U/238U) activity ratios. The process that was proposed to explain the activity ratios of these corals is U gain with subsequent U loss after a specific amount of time. The amount of U loss is assumed to be proportional to the amount of U previously gained. The application of our new method aims to test whether this diagenetic scenario can be verified.

Terahertz Optical Gain Based on Intersubband Transitions in Optically-Pumped Semiconductor Quantum Wells: Coherent Pumped-Probe Interactions

NASA Technical Reports Server (NTRS)

Liu, Ansheng; Ning, Cun-Zheng

1999-01-01

Terahertz optical gain due to intersubband transitions in optically-pumped semiconductor quantum wells (QW's) is calculated nonperturbatively. We solve the pump- field-induced nonequilibrium distribution function for each subband of the QW system from a set of rate equations that include both intrasubband and intersubband relaxation processes. The gain arising from population inversion and stimulated Raman processes is calculated in a unified manner. We show that the coherent pump and signal wave interactions contribute significantly to the THz gain. Because of the optical Stark effect and pump-induced population redistribution, optical gain saturation at larger pump intensities is predicted.

Air-stable, solution-processed oxide p-n heterojunction ultraviolet photodetector.

PubMed

Kim, Do Young; Ryu, Jiho; Manders, Jesse; Lee, Jaewoong; So, Franky

2014-02-12

Air-stable solution processed all-inorganic p-n heterojunction ultraviolet photodetector is fabricated with a high gain (EQE, 25 300%). Solution-processed NiO and ZnO films are used as p-type and n-type ultraviolet sensitizing materials, respectively. The high gain in the detector is due to the interfacial trap-induced charge injection that occurs at the ITO/NiO interface by photogenerated holes trapped in the NiO film. The gain of the detector is controlled by the post-annealing temperature of the solution-processed NiO films, which are studied by X-ray photoelectron spectroscopy (XPS).

Design of an iterative auto-tuning algorithm for a fuzzy PID controller

NASA Astrophysics Data System (ADS)

Saeed, Bakhtiar I.; Mehrdadi, B.

2012-05-01

Since the first application of fuzzy logic in the field of control engineering, it has been extensively employed in controlling a wide range of applications. The human knowledge on controlling complex and non-linear processes can be incorporated into a controller in the form of linguistic terms. However, with the lack of analytical design study it is becoming more difficult to auto-tune controller parameters. Fuzzy logic controller has several parameters that can be adjusted, such as: membership functions, rule-base and scaling gains. Furthermore, it is not always easy to find the relation between the type of membership functions or rule-base and the controller performance. This study proposes a new systematic auto-tuning algorithm to fine tune fuzzy logic controller gains. A fuzzy PID controller is proposed and applied to several second order systems. The relationship between the closed-loop response and the controller parameters is analysed to devise an auto-tuning method. The results show that the proposed method is highly effective and produces zero overshoot with enhanced transient response. In addition, the robustness of the controller is investigated in the case of parameter changes and the results show a satisfactory performance.

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

PubMed Central

Todescato, Francesco; Fortunati, Ilaria; Minotto, Alessandro; Signorini, Raffaella; Jasieniak, Jacek J.; Bozio, Renato

2016-01-01

Semiconductor nanocrystals are rapidly spreading into the display and lighting markets. Compared with liquid crystal and organic LED displays, nanocrystalline quantum dots (QDs) provide highly saturated colors, wide color gamut, resolution, rapid response time, optical efficiency, durability and low cost. This remarkable progress has been made possible by the rapid advances in the synthesis of colloidal QDs and by the progress in understanding the intriguing new physics exhibited by these nanoparticles. In this review, we provide support to the idea that suitably engineered core/graded-shell QDs exhibit exceptionally favorable optical properties, photoluminescence and optical gain, while keeping the synthesis facile and producing QDs well suited for light emitting applications. Solid-state laser emitters can greatly profit from QDs as efficient gain materials. Progress towards fabricating low threshold, solution processed DFB lasers that are optically pumped using one- and two-photon absorption is reviewed. In the field of display technologies, the exploitation of the exceptional photoluminescence properties of QDs for LCD backlighting has already advanced to commercial levels. The next big challenge is to develop the electroluminescence properties of QD to a similar state. We present an overview of QLED devices and of the great perspectives for next generation display and lighting technologies. PMID:28773794

[Clinical decision making and critical thinking in the nursing diagnostic process].

PubMed

Müller-Staub, Maria

2006-10-01

The daily routine requires complex thinking processes of nurses, but clinical decision making and critical thinking are underestimated in nursing. A great demand for educational measures in clinical judgement related with the diagnostic process was found in nurses. The German literature hardly describes nursing diagnoses as clinical judgements about human reactions on health problems / life processes. Critical thinking is described as an intellectual, disciplined process of active conceptualisation, application and synthesis of information. It is gained through observation, experience, reflection and communication and leads thinking and action. Critical thinking influences the aspects of clinical decision making a) diagnostic judgement, b) therapeutic reasoning and c) ethical decision making. Human reactions are complex processes and in their course, human behavior is interpreted in the focus of health. Therefore, more attention should be given to the nursing diagnostic process. This article presents the theoretical framework of the paper "Clinical decision making: Fostering critical thinking in the nursing diagnostic process through case studies".

48 CFR 9904.412-50 - Techniques for application.

Code of Federal Regulations, 2012 CFR

2012-10-01

... shall be separately amortized over no more than 30 years nor less than 10 years. (v) Actuarial gains and... pursuant to the provisions of this Standard. The accounting treatment to be afforded to such gains and... cost accounting periods shall be measured by an immediate-gain actuarial cost method. (2) Where the...

26 CFR 1.341-6 - Exceptions to application of section.

Code of Federal Regulations, 2012 CFR

2012-04-01

... distributions in certain complete liquidations without having any gain considered under section 341(a)(1) or (2) as gain from the sale or exchange of property which is not a capital asset. Under section 341(e)(3..., relating to elections as to recognition of gain in certain complete liquidations occurring within one...

26 CFR 1.341-6 - Exceptions to application of section.

Code of Federal Regulations, 2013 CFR

2013-04-01

... distributions in certain complete liquidations without having any gain considered under section 341(a)(1) or (2) as gain from the sale or exchange of property which is not a capital asset. Under section 341(e)(3..., relating to elections as to recognition of gain in certain complete liquidations occurring within one...

26 CFR 1.341-6 - Exceptions to application of section.

Code of Federal Regulations, 2014 CFR

2014-04-01

... distributions in certain complete liquidations without having any gain considered under section 341(a)(1) or (2) as gain from the sale or exchange of property which is not a capital asset. Under section 341(e)(3..., relating to elections as to recognition of gain in certain complete liquidations occurring within one...

48 CFR 9904.409-50 - Techniques for application.

Code of Federal Regulations, 2012 CFR

2012-10-01

... accounting period in which the change is made and to subsequent periods. (j)(1) Gains and losses on... in subparagraphs (j) (2) and (3) of this subsection. The gain or loss for each asset disposed of is... involuntary conversion, and its undepreciated balance. However, the gain to be recognized for contract costing...

GPU-accelerated computation of electron transfer.

PubMed

Höfinger, Siegfried; Acocella, Angela; Pop, Sergiu C; Narumi, Tetsu; Yasuoka, Kenji; Beu, Titus; Zerbetto, Francesco

2012-11-05

Electron transfer is a fundamental process that can be studied with the help of computer simulation. The underlying quantum mechanical description renders the problem a computationally intensive application. In this study, we probe the graphics processing unit (GPU) for suitability to this type of problem. Time-critical components are identified via profiling of an existing implementation and several different variants are tested involving the GPU at increasing levels of abstraction. A publicly available library supporting basic linear algebra operations on the GPU turns out to accelerate the computation approximately 50-fold with minor dependence on actual problem size. The performance gain does not compromise numerical accuracy and is of significant value for practical purposes. Copyright © 2012 Wiley Periodicals, Inc.

Membrane oxidation in cell delivery and cell killing applications

PubMed Central

Wang, Ting-Yi; Libardo, M. Daben J.; Angeles-Boza, Alfredo M.; Pellois, Jean-Philippe

2018-01-01

Cell delivery or cell killing processes often involve the crossing or disruption of cellular membranes. We review how, by modifying the composition and properties of membranes, membrane oxidation can be exploited to enhance the delivery of macromolecular cargos into live human cells. We also describe how membrane oxidation can be utilized to achieve efficient killing of bacteria by antimicrobial peptides. Finally, we present recent evidence highlighting how membrane oxidation is intimately engaged in natural biological processes such as antigen delivery in dendritic cells and in the killing of bacteria by human macrophages. Overall, the insights that have been recently gained in this area should facilitate the development of more effective delivery technologies and antimicrobial therapeutic approaches. PMID:28355059

Impact of Energy Gain and Subsystem Characteristics on Fusion Propulsion Performance

NASA Technical Reports Server (NTRS)

Chakrabarti, S.; Schmidt, G. R.

2001-01-01

Rapid transport of large payloads and human crews throughout the solar system requires propulsion systems having very high specific impulse (I(sub sp) > 10(exp 4) to 10(exp 5) s). It also calls for systems with extremely low mass-power ratios (alpha < 10(exp -1) kg/kW). Such low alpha are beyond the reach of conventional power-limited propulsion, but may be attainable with fusion and other nuclear concepts that produce energy within the propellant. The magnitude of energy gain must be large enough to sustain the nuclear process while still providing a high jet power relative to the massive energy-intensive subsystems associated with these concepts. This paper evaluates the impact of energy gain and subsystem characteristics on alpha. Central to the analysis are general parameters that embody the essential features of any 'gain-limited' propulsion power balance. Results show that the gains required to achieve alpha = 10(exp -1) kg/kW with foreseeable technology range from approximately 100 to over 2000, which is three to five orders of magnitude greater than current fusion state of the arL Sensitivity analyses point to the parameters exerting the most influence for either: (1) lowering a and improving mission performance or (2) relaxing gain requirements and reducing demands on the fusion process. The greatest impact comes from reducing mass and increasing efficiency of the thruster and subsystems downstream of the fusion process. High relative gain, through enhanced fusion processes or more efficient drivers and processors, is also desirable. There is a benefit in improving driver and subsystem characteristics upstream of the fusion process, but it diminishes at relative gains > 100.

Nested effects models for learning signaling networks from perturbation data.

PubMed

Fröhlich, Holger; Tresch, Achim; Beissbarth, Tim

2009-04-01

Targeted gene perturbations have become a major tool to gain insight into complex cellular processes. In combination with the measurement of downstream effects via DNA microarrays, this approach can be used to gain insight into signaling pathways. Nested Effects Models were first introduced by Markowetz et al. as a probabilistic method to reverse engineer signaling cascades based on the nested structure of downstream perturbation effects. The basic framework was substantially extended later on by Fröhlich et al., Markowetz et al., and Tresch and Markowetz. In this paper, we present a review of the complete methodology with a detailed comparison of so far proposed algorithms on a qualitative and quantitative level. As an application, we present results on estimating the signaling network between 13 genes in the ER-alpha pathway of human MCF-7 breast cancer cells. Comparison with the literature shows a substantial overlap.

Development efforts to improve curved-channel microchannel plates

NASA Technical Reports Server (NTRS)

Corbett, M. B.; Feller, W. B.; Laprade, B. N.; Cochran, R.; Bybee, R.; Danks, A.; Joseph, C.

1993-01-01

Curved-channel microchannel plate (C-plate) improvements resulting from an ongoing NASA STIS microchannel plate (MCP) development program are described. Performance limitations of previous C-plates led to a development program in support of the STIS MAMA UV photon counter, a second generation instrument on the Hubble Space Telescope. C-plate gain, quantum detection efficiency, dark noise, and imaging distortion, which are influenced by channel curvature non-uniformities, have all been improved through use of a new centrifuge fabrication technique. This technique will be described, along with efforts to improve older, more conventional shearing methods. Process optimization methods used to attain targeted C-plate performance goals will be briefly characterized. Newly developed diagnostic measurement techniques to study image distortion, gain uniformity, input bias angle, channel curvature, and ion feedback, will be described. Performance characteristics and initial test results of the improved C-plates will be reported. Future work and applications will also be discussed.

The Influence of Unsteadiness on the Analysis of Pressure Gain Combustion Devices

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Kaemming, Tom

2013-01-01

Pressure gain combustion (PGC) has been the object of scientific study for over a century due to its promise of improved thermodynamic efficiency. In many recent application concepts PGC is utilized as a component in an otherwise continuous, normally steady flow system, such as a gas turbine or ram jet engine. However, PGC is inherently unsteady. Failure to account for the effects of this periodic unsteadiness can lead to misunderstanding and errors in performance calculations. This paper seeks to provide some clarity by presenting a consistent method of thermodynamic cycle analysis for a device utilizing PGC technology. The incorporation of the unsteady PGC process into the conservation equations for a continuous flow device is presented. Most importantly, the appropriate method for computing the conservation of momentum is presented. It will be shown that proper, consistent analysis of cyclic conservation principles produces representative performance predictions.

Experimental evidence of exciton-plasmon coupling in densely packed dye doped core-shell nanoparticles obtained via microfluidic technique

NASA Astrophysics Data System (ADS)

De Luca, A.; Iazzolino, A.; Salmon, J.-B.; Leng, J.; Ravaine, S.; Grigorenko, A. N.; Strangi, G.

2014-09-01

The interplay between plasmons and excitons in bulk metamaterials are investigated by performing spectroscopic studies, including variable angle pump-probe ellipsometry. Gain functionalized gold nanoparticles have been densely packed through a microfluidic chip, representing a scalable process towards bulk metamaterials based on self-assembly approach. Chromophores placed at the hearth of plasmonic subunits ensure exciton-plasmon coupling to convey excitation energy to the quasi-static electric field of the plasmon states. The overall complex polarizability of the system, probed by variable angle spectroscopic ellipsometry, shows a significant modification under optical excitation, as demonstrated by the behavior of the ellipsometric angles Ψ and Δ as a function of suitable excitation fields. The plasmon resonances observed in densely packed gain functionalized core-shell gold nanoparticles represent a promising step to enable a wide range of electromagnetic properties and fascinating applications of plasmonic bulk systems for advanced optical materials.

Design, production, and testing of field effect transistors. [cryogenic MOSFETS

NASA Technical Reports Server (NTRS)

Sclar, N.

1982-01-01

Cryogenic MOSFETS (CRYOFETS), specifically designed for low temperature preamplifier application with infrared extrinsic detectors were produced and comparatively tested with p-channel MOSFETs under matched conditions. The CRYOFETs exhibit lower voltage thresholds, high source-follower gains at lower bias voltage, and lower dc offset source voltage. The noise of the CRYOFET is found to be 2 to 4 times greater than the MOSFET with a correspondingly lower figure of merit (which is established for source-follower amplifiers). The device power dissipation at a gain of 0.98 is some two orders of magnitude lower than for the MOSFET. Further, CRYOFETs are free of low temperature I vs V character hysteresis and balky conduction turn-on effects and operate effectively in the 2.4 to 20 K range. These devices have promise for use on long term duration sensor missions and for on-focal-plane signal processing at low temperatures.

An optimal open/closed-loop control method with application to a pre-stressed thin duralumin plate

NASA Astrophysics Data System (ADS)

Nadimpalli, Sruthi Raju

The excessive vibrations of a pre-stressed duralumin plate, suppressed by a combination of open-loop and closed-loop controls, also known as open/closed-loop control, is studied in this thesis. The two primary steps involved in this process are: Step (I) with an assumption that the closed-loop control law is proportional, obtain the optimal open-loop control by direct minimization of the performance measure consisting of energy at terminal time and a penalty on open-loop control force via calculus of variations. If the performance measure also involves a penalty on closed-loop control effort then a Fourier based method is utilized. Step (II) the energy at terminal time is minimized numerically to obtain optimal values of feedback gains. The optimal closed-loop control gains obtained are used to describe the displacement and the velocity of open-loop, closed-loop and open/closed-loop controlled duralumin plate.

Development of a low-noise, 4th-order readout ASIC for CdZnTe detectors in gamma spectrometer applications

NASA Astrophysics Data System (ADS)

Wang, Jia; Su, Lin; Wei, Xiaomin; Zheng, Ran; Hu, Yann

2016-09-01

This paper presents an ASIC readout circuit development, which aims to achieve low noise. In order to compensate the leakage current and improve gain, a dual-stage CSA has been utilized. A 4th-order high-linearity shaper is proposed to obtain a Semi-Gaussian wave and further decrease the noise induced by the leakage current. The ASIC has been designed and fabricated in a standard commercial 2P4M 0.35 μm CMOS process. Die area of one channel is about 1190 μm×147 μm. The input charge range is 1.8 fC. The peaking time can be adjusted from 1 μs to 3 μs. Measured ENC is about 55e- (rms) at input capacitor of 0 F. The gain is 271 mV/fC at the peaking time of 1 μs.

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

NASA Astrophysics Data System (ADS)

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

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

Time and space integrating acousto-optic folded spectrum processing for SETI

NASA Technical Reports Server (NTRS)

Wagner, K.; Psaltis, D.

1986-01-01

Time and space integrating folded spectrum techniques utilizing acousto-optic devices (AOD) as 1-D input transducers are investigated for a potential application as wideband, high resolution, large processing gain spectrum analyzers in the search for extra-terrestrial intelligence (SETI) program. The space integrating Fourier transform performed by a lens channels the coarse spectral components diffracted from an AOD onto an array of time integrating narrowband fine resolution spectrum analyzers. The pulsing action of a laser diode samples the interferometrically detected output, aliasing the fine resolution components to baseband, as required for the subsequent charge coupled devices (CCD) processing. The raster scan mechanism incorporated into the readout of the CCD detector array is used to unfold the 2-D transform, reproducing the desired high resolution Fourier transform of the input signal.

Concise Review: Process Development Considerations for Cell Therapy

PubMed Central

Brieva, Thomas; Raviv, Lior; Rowley, Jon; Niss, Knut; Brandwein, Harvey; Oh, Steve; Karnieli, Ohad

2015-01-01

The development of robust and well-characterized methods of production of cell therapies has become increasingly important as therapies advance through clinical trials toward approval. A successful cell therapy will be a consistent, safe, and effective cell product, regardless of the cell type or application. Process development strategies can be developed to gain efficiency while maintaining or improving safety and quality profiles. This review presents an introduction to the process development challenges of cell therapies and describes some of the tools available to address production issues. This article will provide a summary of what should be considered to efficiently advance a cellular therapy from the research stage through clinical trials and finally toward commercialization. The identification of the basic questions that affect process development is summarized in the target product profile, and considerations for process optimization are discussed. The goal is to identify potential manufacturing concerns early in the process so they may be addressed effectively and thus increase the probability that a therapy will be successful. Significance The present study contributes to the field of cell therapy by providing a resource for those transitioning a potential therapy from the research stage to clinical and commercial applications. It provides the necessary steps that, when followed, can result in successful therapies from both a clinical and commercial perspective. PMID:26315572

Practical Aspects of Suspension Plasma Spray for Thermal Barrier Coatings on Potential Gas Turbine Components

NASA Astrophysics Data System (ADS)

Ma, X.; Ruggiero, P.

2018-04-01

Suspension plasma spray (SPS) process has attracted extensive efforts and interests to produce fine-structured and functional coatings. In particular, thermal barrier coatings (TBCs) applied by SPS process gain increasing interest due to its potential for superior thermal protection of gas turbine hot sections as compared to conventional TBCs. Unique columnar architectures and nano- and submicrometric grains in the SPS-TBC demonstrated some advantages of thermal shock durability, low thermal conductivity, erosion resistance and strain-tolerant microstructure. This work aimed to look into some practical aspects of SPS processing for TBC applications before it becomes a reliable industry method. The spray capability and applicability of SPS process to achieve uniformity thickness and microstructure on curved substrates were emphasized in designed spray trials to simulate the coating fabrication onto industrial turbine parts with complex configurations. The performances of the SPS-TBCs were tested in erosion, falling ballistic impact and indentational loading tests as to evaluate SPS-TBC performances in simulated turbine service conditions. Finally, a turbine blade was coated and sectioned to verify SPS sprayability in multiple critical sections. The SPS trials and test results demonstrated that SPS process is promising for innovative TBCs, but some challenges need to be addressed and resolved before it becomes an economic and capable industrial process, especially for complex turbine components.

Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure

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

Wronski, M.; Zhao, W.; Tanioka, K.

Purpose: The authors are investigating the feasibility of a new type of solid-state x-ray imaging sensor with programmable avalanche gain: scintillator high-gain avalanche rushing photoconductor active matrix flat panel imager (SHARP-AMFPI). The purpose of the present work is to investigate the inherent x-ray detection properties of SHARP and demonstrate its wide dynamic range through programmable gain. Methods: A distributed resistive layer (DRL) was developed to maintain stable avalanche gain operation in a solid-state HARP. The signal and noise properties of the HARP-DRL for optical photon detection were investigated as a function of avalanche gain both theoretically and experimentally, and themore » results were compared with HARP tube (with electron beam readout) used in previous investigations of zero spatial frequency performance of SHARP. For this new investigation, a solid-state SHARP x-ray image sensor was formed by direct optical coupling of the HARP-DRL with a structured cesium iodide (CsI) scintillator. The x-ray sensitivity of this sensor was measured as a function of avalanche gain and the results were compared with the sensitivity of HARP-DRL measured optically. The dynamic range of HARP-DRL with variable avalanche gain was investigated for the entire exposure range encountered in radiography/fluoroscopy (R/F) applications. Results: The signal from HARP-DRL as a function of electric field showed stable avalanche gain, and the noise associated with the avalanche process agrees well with theory and previous measurements from a HARP tube. This result indicates that when coupled with CsI for x-ray detection, the additional noise associated with avalanche gain in HARP-DRL is negligible. The x-ray sensitivity measurements using the SHARP sensor produced identical avalanche gain dependence on electric field as the optical measurements with HARP-DRL. Adjusting the avalanche multiplication gain in HARP-DRL enabled a very wide dynamic range which encompassed all clinically relevant medical x-ray exposures. Conclusions: This work demonstrates that the HARP-DRL sensor enables the practical implementation of a SHARP solid-state x-ray sensor capable of quantum noise limited operation throughout the entire range of clinically relevant x-ray exposures. This is an important step toward the realization of a SHARP-AMFPI x-ray flat-panel imager.« less

Interviewing in Virtual Worlds: A Phenomenological Study Exploring the Success Factors of Job Applicants Utilizing Second Life to Gain Employment

ERIC Educational Resources Information Center

Koufoudakis-Whittington, Stefania

2014-01-01

This study explored the phenomenon of success factors of job applicants utilizing Second Life to gain employment. The study focused on identifying the perception of what qualified as a successful interview through the lived common experiences of 16 employment recruiters. The research problem was that a gap existed in scholarly research on…

78 FR 79602 - Definitions and Reporting Requirements for Shareholders of Passive Foreign Investment Companies...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-31

.... Applicability Date: For dates of applicability, see Sec. Sec. 1.1291-1T(k), 1.1291-9T(k)(3), 1.1298-1T(h), 1... distribution (within the meaning of section 1291(b)) from a PFIC or recognizes gain derived from a disposition... meaning of section 1291(b)) or as recognizing gain that is treated as an excess distribution (under...

Brain signatures of monetary loss and gain: outcome-related potentials in a single outcome gambling task

PubMed Central

Kamarajan, Chella; Porjesz, Bernice; Rangaswamy, Madhavi; Tang, Yongqiang; Chorlian, David B.; Padmanabhapillai, Ajayan; Saunders, Ramotse; Pandey, Ashwini K.; Roopesh, Bangalore N.; Manz, Niklas; Stimus, Arthur T.; Begleiter, Henri

2009-01-01

This study evaluates the event-related potential (ERP) components in a single outcome gambling task that involved monetary losses and gains. The participants were 50 healthy young volunteers (25 males and 25 females). The gambling task involved valence (loss and gain) and amount (50¢ and 10¢) as outcomes. The outcome-related negativity (ORN/N2) and outcome-related positivity (ORP/P3) were analyzed and compared across conditions and gender. Monetary gain (compared to loss) and higher amount (50¢ compared to 10¢) produced higher amplitudes and shorter latencies in both ORN and ORP components. Difference wave plots showed that earlier processing (200-400 ms) is dominated by the valence (loss/gain) while later processing (after 400 ms) is marked by the amount (50¢/10¢). Functional mapping using Low Resolution Electromagnetic Tomography (LORETA) indicated that the ORN separated the loss against gain in both genders, while the ORP activity distinguished the 50¢ against 10¢ in males. This study further strengthens the view that separate brain processes/circuitry may mediate loss and gain. Although there were no gender differences in behavioral and impulsivity scores, ORN and ORP measures for different task conditions had significant correlations with behavioral scores. This gambling paradigm may potentially offer valuable indicators to study outcome processing and impulsivity in normals as well as in clinical populations. PMID:18775749

Design and Analysis of a Neuromemristive Reservoir Computing Architecture for Biosignal Processing

PubMed Central

Kudithipudi, Dhireesha; Saleh, Qutaiba; Merkel, Cory; Thesing, James; Wysocki, Bryant

2016-01-01

Reservoir computing (RC) is gaining traction in several signal processing domains, owing to its non-linear stateful computation, spatiotemporal encoding, and reduced training complexity over recurrent neural networks (RNNs). Previous studies have shown the effectiveness of software-based RCs for a wide spectrum of applications. A parallel body of work indicates that realizing RNN architectures using custom integrated circuits and reconfigurable hardware platforms yields significant improvements in power and latency. In this research, we propose a neuromemristive RC architecture, with doubly twisted toroidal structure, that is validated for biosignal processing applications. We exploit the device mismatch to implement the random weight distributions within the reservoir and propose mixed-signal subthreshold circuits for energy efficiency. A comprehensive analysis is performed to compare the efficiency of the neuromemristive RC architecture in both digital(reconfigurable) and subthreshold mixed-signal realizations. Both Electroencephalogram (EEG) and Electromyogram (EMG) biosignal benchmarks are used for validating the RC designs. The proposed RC architecture demonstrated an accuracy of 90 and 84% for epileptic seizure detection and EMG prosthetic finger control, respectively. PMID:26869876

Electron beams in research and technology

NASA Astrophysics Data System (ADS)

Mehnert, R.

1995-11-01

Fast electrons lose their energy by inelastic collisions with electrons of target molecules forming secondary electrons and excited molecules. Coulomb interaction of secondary electrons with valence electrons of neighboring molecules leads to the formation of radical cations, thermalized electrons, excited molecular states and radicals. The primary reactive species initiate chemical reactions in the materials irradiated. Polymer modifications using accelerated electrons such as cross-linking of cable insulation, tubes, pipes and moldings, vulcanization of elastomers, grafting of polymer surfaces, processing of foamed plastics and heat shrinkable materials have gained wide industrial acceptance. A steadily growing electron beam technology is curing of paints, lacquers, printing inks and functional coatings. Electron beam processing offers high productivity, the possibility to treat the materials at normal temperature and pressure, excellent process control and clean production conditions. On an industrial scale the most important application of fast electrons is curing of 100% reactive monomer/prepolymer systems. Mainly acrylates and epoxides are used to formulate functional coatings on substrates such as paper, foil, wood, fibre board and high pressure laminates. A survey is given about the reaction mechanism of curing, the characterization of cured coatings, and of some industrial application.

Near Real-Time Image Reconstruction

NASA Astrophysics Data System (ADS)

Denker, C.; Yang, G.; Wang, H.

2001-08-01

In recent years, post-facto image-processing algorithms have been developed to achieve diffraction-limited observations of the solar surface. We present a combination of frame selection, speckle-masking imaging, and parallel computing which provides real-time, diffraction-limited, 256×256 pixel images at a 1-minute cadence. Our approach to achieve diffraction limited observations is complementary to adaptive optics (AO). At the moment, AO is limited by the fact that it corrects wavefront abberations only for a field of view comparable to the isoplanatic patch. This limitation does not apply to speckle-masking imaging. However, speckle-masking imaging relies on short-exposure images which limits its spectroscopic applications. The parallel processing of the data is performed on a Beowulf-class computer which utilizes off-the-shelf, mass-market technologies to provide high computational performance for scientific calculations and applications at low cost. Beowulf computers have a great potential, not only for image reconstruction, but for any kind of complex data reduction. Immediate access to high-level data products and direct visualization of dynamic processes on the Sun are two of the advantages to be gained.

Embedded processor extensions for image processing

NASA Astrophysics Data System (ADS)

Thevenin, Mathieu; Paindavoine, Michel; Letellier, Laurent; Heyrman, Barthélémy

2008-04-01

The advent of camera phones marks a new phase in embedded camera sales. By late 2009, the total number of camera phones will exceed that of both conventional and digital cameras shipped since the invention of photography. Use in mobile phones of applications like visiophony, matrix code readers and biometrics requires a high degree of component flexibility that image processors (IPs) have not, to date, been able to provide. For all these reasons, programmable processor solutions have become essential. This paper presents several techniques geared to speeding up image processors. It demonstrates that a gain of twice is possible for the complete image acquisition chain and the enhancement pipeline downstream of the video sensor. Such results confirm the potential of these computing systems for supporting future applications.

Development of expert system for biobased polymer material selection: food packaging application.

PubMed

Sanyang, M L; Sapuan, S M

2015-10-01

Biobased food packaging materials are gaining more attention owing to their intrinsic biodegradable nature and renewability. Selection of suitable biobased polymers for food packaging applications could be a tedious task with potential mistakes in choosing the best materials. In this paper, an expert system was developed using Exsys Corvid software to select suitable biobased polymer materials for packaging fruits, dry food and dairy products. If - Then rule based system was utilized to accomplish the material selection process whereas a score system was formulated to facilitate the ranking of selected materials. The expert system selected materials that satisfied all constraints and selection results were presented in suitability sequence depending on their scores. The expert system selected polylactic acid (PLA) as the most suitable material.

Mushroom immunomodulators: unique molecules with unlimited applications.

PubMed

El Enshasy, Hesham A; Hatti-Kaul, Rajni

2013-12-01

For centuries, mushrooms have been used as food and medicine in different cultures. More recently, many bioactive compounds have been isolated from different types of mushrooms. Among these, immunomodulators have gained much interest based on the increasing growth of the immunotherapy sector. Mushroom immunomodulators are classified under four categories based on their chemical nature as: lectins, terpenoids, proteins, and polysaccharides. These compounds are produced naturally in mushrooms cultivated in greenhouses. For effective industrial production, cultivation is carried out in submerged culture to increase the bioactive compound yield, decrease the production time, and reduce the cost of downstream processing. This review provides a comprehensive overview on mushroom immunomodulators in terms of chemistry, industrial production, and applications in medical and nonmedical sectors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Driving with Bioptic Telescopes: Organizing a Research Agenda

PubMed Central

Owsley, Cynthia

2012-01-01

Being a licensed driver in the U. S. and many other countries facilitates health and well-being. Based on the vision standards in most states, individuals with worse than 20/40 visual acuity who desire licensure are denied through the usual licensure application process. However, over 40 states have bioptic telescope licensing programs where applicants can gain licensure contingent on meeting specific requirements. In spite of the existence of the bioptic telescope and these licensing programs since the 1970s, there has been little rigorous scientific study of this topic. Here I offer an organizing perspective for a research agenda on driving with bioptic telescopes, with the long term practical goal being to provide an evidence basis for licensure policies and training programs. PMID:22863791

Improved Drain Current Saturation and Voltage Gain in Graphene-on-Silicon Field Effect Transistors.

PubMed

Song, Seung Min; Bong, Jae Hoon; Hwang, Wan Sik; Cho, Byung Jin

2016-05-04

Graphene devices for radio frequency (RF) applications are of great interest due to their excellent carrier mobility and saturation velocity. However, the insufficient current saturation in graphene field effect transistors (FETs) is a barrier preventing enhancements of the maximum oscillation frequency and voltage gain, both of which should be improved for RF transistors. Achieving a high output resistance is therefore a crucial step for graphene to be utilized in RF applications. In the present study, we report high output resistances and voltage gains in graphene-on-silicon (GoS) FETs. This is achieved by utilizing bare silicon as a supporting substrate without an insulating layer under the graphene. The GoSFETs exhibit a maximum output resistance of 2.5 MΩ∙μm, maximum intrinsic voltage gain of 28 dB, and maximum voltage gain of 9 dB. This method opens a new route to overcome the limitations of conventional graphene-on-insulator (GoI) FETs and subsequently brings graphene electronics closer to practical usage.

Colossal photo-conductive gain in low temperature processed TiO2 films and their application in quantum dot solar cells

NASA Astrophysics Data System (ADS)

Mandal, Debranjan; Goswami, Prasenjit N.; Rath, Arup K.

2017-03-01

Colloidal quantum dot (QD) solar cells have seen remarkable progress in recent past to reach the certified efficiency of 10.6%. Anatase titanium oxide (TiO2) is a widely studied n-type widow layer for the collection of photogenerated electrons in QD solar cells. Requirement of high temperature (˜500 °C) processing steps proved to be disadvantageous for its applications in flexible solar cells and roll to roll processing, and it also has adverse commercial implications. Here, we report that solar light exposure to low temperature processed (80 °C-150 °C) TiO2 and niobium doped TiO2 films leads to unprecedented enhancement in their electron densities and electron mobilities, which enables them to be used as efficient n-type layers in quantum dot solar cells. Such photoinduced high conducting states in these films show gradual decay over hours after the light bias is taken off and can be retrieved under solar illumination. On the contrary, TiO2 films processed at 500 °C show marginal photo induced enhancements in their characteristics. In bilayer configuration with PbS QDs, photovoltaic devices based on low temperature processed TiO2 films show improved performance over high temperature processed TiO2 films. The stability of photovoltaic devices also improved in low temperature processed TiO2 films under ambient working conditions.

Manufacturing of tailored tubes with a process integrated heat treatment

NASA Astrophysics Data System (ADS)

Hordych, Illia; Boiarkin, Viacheslav; Rodman, Dmytro; Nürnberger, Florian

2017-10-01

The usage of work-pieces with tailored properties allows for reducing costs and materials. One example are tailored tubes that can be used as end parts e.g. in the automotive industry or in domestic applications as well as semi-finished products for subsequent controlled deformation processes. An innovative technology to manufacture tubes is roll forming with a subsequent inductive heating and adapted quenching to obtain tailored properties in the longitudinal direction. This processing offers a great potential for the production of tubes with a wide range of properties, although this novel approach still requires a suited process design. Based on experimental data, a process simulation is being developed. The simulation shall be suitable for a virtual design of the tubes and allows for gaining a deeper understanding of the required processing. The model proposed shall predict microstructural and mechanical tube properties by considering process parameters, different geometries, batch-related influences etc. A validation is carried out using experimental data of tubes manufactured from various steel grades.

Bayesian Treed Multivariate Gaussian Process with Adaptive Design: Application to a Carbon Capture Unit

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

Konomi, Bledar A.; Karagiannis, Georgios; Sarkar, Avik

2014-05-16

Computer experiments (numerical simulations) are widely used in scientific research to study and predict the behavior of complex systems, which usually have responses consisting of a set of distinct outputs. The computational cost of the simulations at high resolution are often expensive and become impractical for parametric studies at different input values. To overcome these difficulties we develop a Bayesian treed multivariate Gaussian process (BTMGP) as an extension of the Bayesian treed Gaussian process (BTGP) in order to model and evaluate a multivariate process. A suitable choice of covariance function and the prior distributions facilitates the different Markov chain Montemore » Carlo (MCMC) movements. We utilize this model to sequentially sample the input space for the most informative values, taking into account model uncertainty and expertise gained. A simulation study demonstrates the use of the proposed method and compares it with alternative approaches. We apply the sequential sampling technique and BTMGP to model the multiphase flow in a full scale regenerator of a carbon capture unit. The application presented in this paper is an important tool for research into carbon dioxide emissions from thermal power plants.« less

EMG amplifier with wireless data transmission

NASA Astrophysics Data System (ADS)

Kowalski, Grzegorz; Wildner, Krzysztof

2017-08-01

Wireless medical diagnostics is a trend in modern technology used in medicine. This paper presents a concept of realization, architecture of hardware and software implementation of an elecromyography signal (EMG) amplifier with wireless data transmission. This amplifier consists of three components: analogue processing of bioelectric signal module, micro-controller circuit and an application enabling data acquisition via a personal computer. The analogue bioelectric signal processing circuit receives electromyography signals from the skin surface, followed by initial analogue processing and preparation of the signals for further digital processing. The second module is a micro-controller circuit designed to wirelessly transmit the electromyography signals from the analogue signal converter to a personal computer. Its purpose is to eliminate the need for wired connections between the patient and the data logging device. The third block is a computer application designed to display the transmitted electromyography signals, as well as data capture and analysis. Its purpose is to provide a graphical representation of the collected data. The entire device has been thoroughly tested to ensure proper functioning. In use, the device displayed the captured electromyography signal from the arm of the patient. Amplitude- frequency characteristics were set in order to investigate the bandwidth and the overall gain of the device.

26 CFR 1.1014-5 - Gain or loss.

Code of Federal Regulations, 2010 CFR

2010-04-01

... TAXES Basis Rules of General Application § 1.1014-5 Gain or loss. (a) Sale or other disposition of a life interest, remainder interest, or other interest in property acquired from a decedent. (1) Except... October 9, 1969, of a term interest in property, gain or loss from a sale or other disposition of a life...

26 CFR 1.301-1 - Rules applicable with respect to distributions of money and other property.

Code of Federal Regulations, 2010 CFR

2010-04-01

... adjusted basis of the stock, treated as gain from the sale or exchange of property, or (in the case of... immediately before the distribution and increased for any gain recognized to the distributing corporation... amount of any gain resulting from such distribution, are to be determined by reference to such adjusted...

26 CFR 1.301-1 - Rules applicable with respect to distributions of money and other property.

Code of Federal Regulations, 2014 CFR

2014-04-01

... against and reduce the adjusted basis of the stock, treated as gain from the sale or exchange of property... corporation (determined immediately before the distribution and increased for any gain recognized to the... amount of any gain resulting from such distribution, are to be determined by reference to such adjusted...

26 CFR 1.301-1 - Rules applicable with respect to distributions of money and other property.

Code of Federal Regulations, 2013 CFR

2013-04-01

... against and reduce the adjusted basis of the stock, treated as gain from the sale or exchange of property... corporation (determined immediately before the distribution and increased for any gain recognized to the... amount of any gain resulting from such distribution, are to be determined by reference to such adjusted...

26 CFR 1.301-1 - Rules applicable with respect to distributions of money and other property.

Code of Federal Regulations, 2012 CFR

2012-04-01

... against and reduce the adjusted basis of the stock, treated as gain from the sale or exchange of property... corporation (determined immediately before the distribution and increased for any gain recognized to the... amount of any gain resulting from such distribution, are to be determined by reference to such adjusted...

26 CFR 1.301-1 - Rules applicable with respect to distributions of money and other property.

Code of Federal Regulations, 2011 CFR

2011-04-01

... adjusted basis of the stock, treated as gain from the sale or exchange of property, or (in the case of... immediately before the distribution and increased for any gain recognized to the distributing corporation... amount of any gain resulting from such distribution, are to be determined by reference to such adjusted...

The Nova Upgrade Facility for ICF ignition and gain

NASA Astrophysics Data System (ADS)

Lowdermilk, W. H.; Campbell, E. M.; Hunt, J. T.; Murray, J. R.; Storm, E.; Tobin, M. T.; Trenholme, J. B.

1992-01-01

Research on Inertial Confinement Fusion (ICF) is motivated by its potential defense and civilian applications, including ultimately the generation of electric power. The U.S. ICF Program was reviewed recently by the National Academy of Science (NAS) and the Fusion Policy Advisory Committee (FPAC). Both committees issued final reports in 1991 which recommended that first priority in the ICF program be placed on demonstrating fusion ignition and modest gain (G less than 10). The U.S. Department of Energy and Lawrence Livermore National Laboratory (LLNL) have proposed an upgrade of the existing Nova Laser Facility at LLNL to accomplish these goals. Both the NAS and FPAC have endorsed the upgrade of Nova as the optimal path to achieving ignition and gain. Results from Nova Upgrade Experiments will be used to define requirements for driver and target technology both for future high-yield military applications, such as the Laboratory Microfusion Facility (LMF) proposed by the Department of Energy, and for high-gain energy applications leading to an ICF engineering test facility. The central role and modifications which Nova Upgrade would play in the national ICF strategy are described.

Reliable gain-scheduled control of discrete-time systems and its application to CSTR model

NASA Astrophysics Data System (ADS)

Sakthivel, R.; Selvi, S.; Mathiyalagan, K.; Shi, Y.

2016-10-01

This paper is focused on reliable gain-scheduled controller design for a class of discrete-time systems with randomly occurring nonlinearities and actuator fault. Further, the nonlinearity in the system model is assumed to occur randomly according to a Bernoulli distribution with measurable time-varying probability in real time. The main purpose of this paper is to design a gain-scheduled controller by implementing a probability-dependent Lyapunov function and linear matrix inequality (LMI) approach such that the closed-loop discrete-time system is stochastically stable for all admissible randomly occurring nonlinearities. The existence conditions for the reliable controller is formulated in terms of LMI constraints. Finally, the proposed reliable gain-scheduled control scheme is applied on continuously stirred tank reactor model to demonstrate the effectiveness and applicability of the proposed design technique.

Application of variable-gain output feedback for high-alpha control

NASA Technical Reports Server (NTRS)

Ostroff, Aaron J.

1990-01-01

A variable-gain, optimal, discrete, output feedback design approach that is applied to a nonlinear flight regime is described. The flight regime covers a wide angle-of-attack range that includes stall and post stall. The paper includes brief descriptions of the variable-gain formulation, the discrete-control structure and flight equations used to apply the design approach, and the high performance airplane model used in the application. Both linear and nonlinear analysis are shown for a longitudinal four-model design case with angles of attack of 5, 15, 35, and 60 deg. Linear and nonlinear simulations are compared for a single-point longitudinal design at 60 deg angle of attack. Nonlinear simulations for the four-model, multi-mode, variable-gain design include a longitudinal pitch-up and pitch-down maneuver and high angle-of-attack regulation during a lateral maneuver.

Prediction of the mass gain during high temperature oxidation of aluminized nanostructured nickel using adaptive neuro-fuzzy inference system

NASA Astrophysics Data System (ADS)

Hayati, M.; Rashidi, A. M.; Rezaei, A.

2012-10-01

In this paper, the applicability of ANFIS as an accurate model for the prediction of the mass gain during high temperature oxidation using experimental data obtained for aluminized nanostructured (NS) nickel is presented. For developing the model, exposure time and temperature are taken as input and the mass gain as output. A hybrid learning algorithm consists of back-propagation and least-squares estimation is used for training the network. We have compared the proposed ANFIS model with experimental data. The predicted data are found to be in good agreement with the experimental data with mean relative error less than 1.1%. Therefore, we can use ANFIS model to predict the performances of thermal systems in engineering applications, such as modeling the mass gain for NS materials.

Using parahydrogen to hyperpolarize amines, amides, carboxylic acids, alcohols, phosphates, and carbonates

PubMed Central

Iali, Wissam; Rayner, Peter J.; Duckett, Simon B.

2018-01-01

Hyperpolarization turns weak nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) responses into strong signals, so normally impractical measurements are possible. We use parahydrogen to rapidly hyperpolarize appropriate 1H, 13C, 15N, and 31P responses of analytes (such as NH3) and important amines (such as phenylethylamine), amides (such as acetamide, urea, and methacrylamide), alcohols spanning methanol through octanol and glucose, the sodium salts of carboxylic acids (such as acetic acid and pyruvic acid), sodium phosphate, disodium adenosine 5′-triphosphate, and sodium hydrogen carbonate. The associated signal gains are used to demonstrate that it is possible to collect informative single-shot NMR spectra of these analytes in seconds at the micromole level in a 9.4-T observation field. To achieve these wide-ranging signal gains, we first use the signal amplification by reversible exchange (SABRE) process to hyperpolarize an amine or ammonia and then use their exchangeable NH protons to relay polarization into the analyte without changing its identity. We found that the 1H signal gains reach as high as 650-fold per proton, whereas for 13C, the corresponding signal gains achieved in a 1H-13C refocused insensitive nuclei enhanced by polarization transfer (INEPT) experiment exceed 570-fold and those in a direct-detected 13C measurement exceed 400-fold. Thirty-one examples are described to demonstrate the applicability of this technique. PMID:29326984

Active integrated filters for RF-photonic channelizers.

PubMed

El Nagdi, Amr; Liu, Ke; LaFave, Tim P; Hunt, Louis R; Ramakrishna, Viswanath; Dabkowski, Mieczyslaw; MacFarlane, Duncan L; Christensen, Marc P

2011-01-01

A theoretical study of RF-photonic channelizers using four architectures formed by active integrated filters with tunable gains is presented. The integrated filters are enabled by two- and four-port nano-photonic couplers (NPCs). Lossless and three individual manufacturing cases with high transmission, high reflection, and symmetric couplers are assumed in the work. NPCs behavior is dependent upon the phenomenon of frustrated total internal reflection. Experimentally, photonic channelizers are fabricated in one single semiconductor chip on multi-quantum well epitaxial InP wafers using conventional microelectronics processing techniques. A state space modeling approach is used to derive the transfer functions and analyze the stability of these filters. The ability of adapting using the gains is demonstrated. Our simulation results indicate that the characteristic bandpass and notch filter responses of each structure are the basis of channelizer architectures, and optical gain may be used to adjust filter parameters to obtain a desired frequency magnitude response, especially in the range of 1-5 GHz for the chip with a coupler separation of ∼9 mm. Preliminarily, the measurement of spectral response shows enhancement of quality factor by using higher optical gains. The present compact active filters on an InP-based integrated photonic circuit hold the potential for a variety of channelizer applications. Compared to a pure RF channelizer, photonic channelizers may perform both channelization and down-conversion in an optical domain.

Environmental and biomedical applications of natural metal stable isotope variations

USGS Publications Warehouse

Bullen, T.D.; Walczyk, T.

2009-01-01

etal stable isotopes are now being used to trace metal contaminants in the environment and as indicators of human systemic function where metals play a role. Stable isotope abundance variations provide information about metal sources and the processes affecting metals in complex natural systems, complementing information gained from surrogate tracers, such as metal abundance ratios or biochemical markers of metal metabolism. The science is still in its infancy, but the results of initial studies confirm that metal stable isotopes can provide a powerful tool for forensic and biomedical investigations.

Eugene P. Wigner's Visionary Contributions to Generations-I through IV Fission Reactors

NASA Astrophysics Data System (ADS)

Carré, Frank

2014-09-01

Among Europe's greatest scientists who fled to Britain and America in the 1930s, Eugene P. Wigner made instrumental advances in reactor physics, reactor design and technology, and spent nuclear fuel processing for both purposes of developing atomic weapons during world-war II and nuclear power afterwards. Wigner who had training in chemical engineering and self-education in physics first gained recognition for his remarkable articles and books on applications of Group theory to Quantum mechanics, Solid state physics and other topics that opened new branches of Physics.

The evolution of Orbiter depot support, with applications to future space vehicles

NASA Technical Reports Server (NTRS)

Mcclain, Michael L.

1990-01-01

The reasons for depot consolidation and the processes established to implement the Orbiter depot are presented. The Space Shuttle Orbiter depot support is presently being consolidated due to equipment suppliers leaving the program, escalating depot support costs, and increasing repair turnaround times. Details of the depot support program for orbiter hardware and selected pieces of support equipment are discussed. The benefits gained from this consolidation and the lessons learned are then applied to future reuseable space vehicles to provide program managers a forward look at the need for efficient depot support.

Fast, optically controlled Kerr phase shifter for digital signal processing.

PubMed

Li, R B; Deng, L; Hagley, E W; Payne, M G; Bienfang, J C; Levine, Z H

2013-05-01

We demonstrate an optically controlled Kerr phase shifter using a room-temperature 85Rb vapor operating in a Raman gain scheme. Phase shifts from zero to π relative to an unshifted reference wave are observed, and gated operations are demonstrated. We further demonstrate the versatile digital manipulation of encoded signal light with an encoded phase-control light field using an unbalanced Mach-Zehnder interferometer. Generalizations of this scheme should be capable of full manipulation of a digitized signal field at high speed, opening the door to future applications.

Local governments LANDSAT applications program

NASA Technical Reports Server (NTRS)

1983-01-01

The approach used to develop the internal capabilities of local governments to handle and evaluate LANDSAT data included remote sensing training, development of a low-cost digital image processing system, and technical assistance. Cost sharing, program management and coordination, and networking were also employed to address problems related to land use, water resources, environmental assessment, and air quality as experienced by urban planners. Local experiences gained in Atlanta, Georgia; Henrico County, Virginia; Oklahoma City; Oklahoma; and San Jose, California are described. Policy recommendations formulated for transferring remote sensing technologies to local governments are included.

Large-scale visualization projects for teaching software engineering.

PubMed

Müller, Christoph; Reina, Guido; Burch, Michael; Weiskopf, Daniel

2012-01-01

The University of Stuttgart's software engineering major complements the traditional computer science major with more practice-oriented education. Two-semester software projects in various application areas offered by the university's different computer science institutes are a successful building block in the curriculum. With this realistic, complex project setting, students experience the practice of software engineering, including software development processes, technologies, and soft skills. In particular, visualization-based projects are popular with students. Such projects offer them the opportunity to gain profound knowledge that would hardly be possible with only regular lectures and homework assignments.

Optical coatings on polymers

NASA Astrophysics Data System (ADS)

Bauer, Thomas

2005-09-01

Optical transparent polymers are used for technical optics for more than 50 years and currently replace glass as optical material in several application fields. Optical functional coatings like mirrors, filters, beam splitters and anti-reflection coatings gain increasingly in importance. New light sources and head mounted systems need light and effective reflector designs. The paper gives an overview about vacuum coating technologies for metal and dielectric layers on polymers for technical optics. Especially for polymers controlling the complete process chain from injection moulding to storing, coating and shipping decides on the technological and commercial success.

A review of combined experimental and computational procedures for assessing biopolymer structure–process–property relationships

PubMed Central

Gronau, Greta; Krishnaji, Sreevidhya T.; Kinahan, Michelle E.; Giesa, Tristan; Wong, Joyce Y.; Kaplan, David L.; Buehler, Markus J.

2013-01-01

Tailored biomaterials with tunable functional properties are desirable for many applications ranging from drug delivery to regenerative medicine. To improve the predictability of biopolymer materials functionality, multiple design parameters need to be considered, along with appropriate models. In this article we review the state of the art of synthesis and processing related to the design of biopolymers, with an emphasis on the integration of bottom-up computational modeling in the design process. We consider three prominent examples of well-studied biopolymer materials – elastin, silk, and collagen – and assess their hierarchical structure, intriguing functional properties and categorize existing approaches to study these materials. We find that an integrated design approach in which both experiments and computational modeling are used has rarely been applied for these materials due to difficulties in relating insights gained on different length- and time-scales. In this context, multiscale engineering offers a powerful means to accelerate the biomaterials design process for the development of tailored materials that suit the needs posed by the various applications. The combined use of experimental and computational tools has a very broad applicability not only in the field of biopolymers, but can be exploited to tailor the properties of other polymers and composite materials in general. PMID:22938765

On the Use of PLA-PHB Blends for Sustainable Food Packaging Applications.

PubMed

Arrieta, Marina Patricia; Samper, María Dolores; Aldas, Miguel; López, Juan

2017-08-29

Poly(lactic acid) (PLA) is the most used biopolymer for food packaging applications. Several strategies have been made to improve PLA properties for extending its applications in the packaging field. Melt blending approaches are gaining considerable interest since they are easy, cost-effective and readily available processing technologies at the industrial level. With a similar melting temperature and high crystallinity, poly(hydroxybutyrate) (PHB) represents a good candidate to blend with PLA. The ability of PHB to act as a nucleating agent for PLA improves its mechanical resistance and barrier performance. With the dual objective to improve PLAPHB processing performance and to obtain stretchable materials, plasticizers are frequently added. Current trends to enhance PLA-PHB miscibility are focused on the development of composite and nanocomposites. PLA-PHB blends are also interesting for the controlled release of active compounds in the development of active packaging systems. This review explains the most relevant processing aspects of PLA-PHB based blends such as the influence of polymers molecular weight, the PLA-PHB composition as well as the thermal stability. It also summarizes the recent developments in PLA-PHB formulations with an emphasis on their performance with interest in the sustainable food packaging field. PLA-PHB blends shows highly promising perspectives for the replacement of traditional petrochemical based polymers currently used for food packaging.

Hot-melt co-extrusion: requirements, challenges and opportunities for pharmaceutical applications.

PubMed

Vynckier, An-Katrien; Dierickx, Lien; Voorspoels, Jody; Gonnissen, Yves; Remon, Jean Paul; Vervaet, Chris

2014-02-01

Co-extrusion implies the simultaneous hot-melt extrusion of two or more materials through the same die, creating a multi-layered extrudate. It is an innovative continuous production technology that offers numerous advantages over traditional pharmaceutical processing techniques. This review provides an overview of the co-extrusion equipment, material requirements and medical and pharmaceutical applications. The co-extrusion equipment needed for pharmaceutical production has been summarized. Because the geometrical design of the die dictates the shape of the final product, different die types have been discussed. As one of the major challenges at the moment is shaping the final product in a continuous way, an overview of downstream solutions for processing co-extrudates into drug products is provided. Layer adhesion, extrusion temperature and viscosity matching are pointed out as most important requirements for material selection. Examples of medical and pharmaceutical applications are presented and some recent findings considering the production of oral drug delivery systems have been summarized. Co-extrusion provides great potential for the continuous production of fixed-dose combination products which are gaining importance in pharmaceutical industry. There are still some barriers to the implementation of co-extrusion in the pharmaceutical industry. The optimization of downstream processing remains a point of attention. © 2013 Royal Pharmaceutical Society.

Inverter Circuits Using ZnO Nanoparticle Based Thin-Film Transistors for Flexible Electronic Applications

PubMed Central

Vidor, Fábio F.; Meyers, Thorsten; Hilleringmann, Ulrich

2016-01-01

Innovative systems exploring the flexibility and the transparency of modern semiconducting materials are being widely researched by the scientific community and by several companies. For a low-cost production and large surface area applications, thin-film transistors (TFTs) are the key elements driving the system currents. In order to maintain a cost efficient integration process, solution based materials are used as they show an outstanding tradeoff between cost and system complexity. In this paper, we discuss the integration process of ZnO nanoparticle TFTs using a high-k resin as gate dielectric. The performance in dependence on the transistor structure has been investigated, and inverted staggered setups depict an improved performance over the coplanar device increasing both the field-effect mobility and the ION/IOFF ratio. Aiming at the evaluation of the TFT characteristics for digital circuit applications, inverter circuits using a load TFT in the pull-up network and an active TFT in the pull-down network were integrated. The inverters show reasonable switching characteristics and V/V gains. Conjointly, the influence of the geometry ratio and the supply voltage on the devices have been analyzed. Moreover, as all integration steps are suitable to polymeric templates, the fabrication process is fully compatible to flexible substrates. PMID:28335282

Application of Magnetized Target Fusion to High-Energy Space Propulsion

NASA Technical Reports Server (NTRS)

Thio, Y. C. F.; Schmidt, G. R.; Kirkpatrick, R. C.; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

Most fusion propulsion concepts that have been investigated in the past employ some form of inertial or magnetic confinement. Although the prospective performance of these concepts is excellent, the fusion processes on which these concepts are based still require considerable development before they can be seriously considered for actual applications. Furthermore, these processes are encumbered by the need for sophisticated plasma and power handling systems that are generally quite inefficient and have historically resulted in large, massive spacecraft designs. Here we present a comparatively new approach, Magnetized Target Fusion (MTF), which offers a nearer-term avenue for realizing the tremendous performance benefits of fusion propulsion'. The key advantage of MTF is its less demanding requirements for driver energy and power processing. Additional features include: 1) very low system masses and volumes, 2) high gain and relatively low waste heat, 3) substantial utilization of energy from product neutrons, 4) efficient, low peak-power drivers based on existing pulsed power technology, and 5) very high Isp, specific power and thrust. MTF overcomes many of the problems associated with traditional fusion techniques, thus making it particularly attractive for space applications. Isp greater than 50,000 seconds and specific powers greater than 50 kilowatts/kilogram appear feasible using relatively near-term pulse power and plasma gun technology.

Inverter Circuits Using ZnO Nanoparticle Based Thin-Film Transistors for Flexible Electronic Applications.

PubMed

Vidor, Fábio F; Meyers, Thorsten; Hilleringmann, Ulrich

2016-08-23

Innovative systems exploring the flexibility and the transparency of modern semiconducting materials are being widely researched by the scientific community and by several companies. For a low-cost production and large surface area applications, thin-film transistors (TFTs) are the key elements driving the system currents. In order to maintain a cost efficient integration process, solution based materials are used as they show an outstanding tradeoff between cost and system complexity. In this paper, we discuss the integration process of ZnO nanoparticle TFTs using a high- k resin as gate dielectric. The performance in dependence on the transistor structure has been investigated, and inverted staggered setups depict an improved performance over the coplanar device increasing both the field-effect mobility and the I ON / I OFF ratio. Aiming at the evaluation of the TFT characteristics for digital circuit applications, inverter circuits using a load TFT in the pull-up network and an active TFT in the pull-down network were integrated. The inverters show reasonable switching characteristics and V / V gains. Conjointly, the influence of the geometry ratio and the supply voltage on the devices have been analyzed. Moreover, as all integration steps are suitable to polymeric templates, the fabrication process is fully compatible to flexible substrates.

Automatic Parallelization of Numerical Python Applications using the Global Arrays Toolkit

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

Daily, Jeffrey A.; Lewis, Robert R.

2011-11-30

Global Arrays is a software system from Pacific Northwest National Laboratory that enables an efficient, portable, and parallel shared-memory programming interface to manipulate distributed dense arrays. The NumPy module is the de facto standard for numerical calculation in the Python programming language, a language whose use is growing rapidly in the scientific and engineering communities. NumPy provides a powerful N-dimensional array class as well as other scientific computing capabilities. However, like the majority of the core Python modules, NumPy is inherently serial. Using a combination of Global Arrays and NumPy, we have reimplemented NumPy as a distributed drop-in replacement calledmore » Global Arrays in NumPy (GAiN). Serial NumPy applications can become parallel, scalable GAiN applications with only minor source code changes. Scalability studies of several different GAiN applications will be presented showing the utility of developing serial NumPy codes which can later run on more capable clusters or supercomputers.« less

Application of optimal control theory to the design of the NASA/JPL 70-meter antenna servos

NASA Technical Reports Server (NTRS)

Alvarez, L. S.; Nickerson, J.

1989-01-01

The application of Linear Quadratic Gaussian (LQG) techniques to the design of the 70-m axis servos is described. Linear quadratic optimal control and Kalman filter theory are reviewed, and model development and verification are discussed. Families of optimal controller and Kalman filter gain vectors were generated by varying weight parameters. Performance specifications were used to select final gain vectors.

Electron Acceleration by Beating of Two Intense Cross-Focused Hollow Gaussian Laser Beams in Plasma

NASA Astrophysics Data System (ADS)

Mahmoud, Saleh T.; Gauniyal, Rakhi; Ahmad, Nafis; Rawat, Priyanka; Purohit, Gunjan

2018-01-01

This paper presents propagation of two cross-focused intense hollow Gaussian laser beams (HGBs) in collisionless plasma and its effect on the generation of electron plasma wave (EPW) and electron acceleration process, when relativistic and ponderomotive nonlinearities are simultaneously operative. Nonlinear differential equations have been set up for beamwidth of laser beams, power of generated EPW, and energy gain by electrons using WKB and paraxial approximations. Numerical simulations have been carried out to investigate the effect of typical laser-plasma parameters on the focusing of laser beams in plasmas and further its effect on power of excited EPW and acceleration of electrons. It is observed that focusing of two laser beams in plasma increases for higher order of hollow Gaussian beams, which significantly enhanced the power of generated EPW and energy gain. The amplitude of EPW and energy gain by electrons is found to enhance with an increase in the intensity of laser beams and plasma density. This study will be useful to plasma beat wave accelerator and in other applications requiring multiple laser beams. Supported by United Arab Emirates University for Financial under Grant No. UPAR (2014)-31S164

Synthesis of graphene nanomaterials and their application in electrochemical energy storage

NASA Astrophysics Data System (ADS)

Xiong, Guoping

The need to store and use energy on diverse scales in a modern technological society necessitates the design of large and small energy systems, among which electrical energy storage systems such as batteries and capacitors have attracted much interest in the past several decades. Supercapacitors, also known as ultracapacitors, or electrochemical capacitors, with fast power delivery and long cycle life are complementing or even replacing batteries in many applications. The rapid development of miniaturized electronic devices has led to a growing need for rechargeable micro-power sources with high performance. Among different sources, electrochemical micro-capacitors or micro-supercapacitors provide higher power density than their counterparts and are gaining increased interest from the research and engineering communities. Rechargeable Li ion batteries with high energy and power density, long cycling life, high charge-discharge rate (1C - 3C) and safe operation are in high demand as power sources and power backup for hybrid electric vehicles and other applications. In the present work, graphene-based graphene materials have been designed and synthesized for electrochemical energy storage applications, e.g., conventional supercapacitors (macro-supercapacitors), microsupercapacitors and lithium ion batteries. Factors influencing the formation and structure of graphitic petals grown by microwave plasma-enhanced chemical vapor deposition on oxidized silicon substrates were investigated through process variation and materials analysis. Insights gained into the growth mechanism of these graphitic petals suggest a simple scribing method can be used to control both the location and formation of petals on flat Si substrates. Transitional metal oxides and conducting polymers have been coated on the graphitic petal-based electrodes by facile chemical methods for multifunctional energy storage applications. Detailed electrochemical characterization (e.g., cyclic voltammetry and constant galvanostatic charge/discharge) has been carried out to evaluate the performance of electrodes.

Quantitative methods for compensation of matrix effects and self-absorption in Laser Induced Breakdown Spectroscopy signals of solids

NASA Astrophysics Data System (ADS)

Takahashi, Tomoko; Thornton, Blair

2017-12-01

This paper reviews methods to compensate for matrix effects and self-absorption during quantitative analysis of compositions of solids measured using Laser Induced Breakdown Spectroscopy (LIBS) and their applications to in-situ analysis. Methods to reduce matrix and self-absorption effects on calibration curves are first introduced. The conditions where calibration curves are applicable to quantification of compositions of solid samples and their limitations are discussed. While calibration-free LIBS (CF-LIBS), which corrects matrix effects theoretically based on the Boltzmann distribution law and Saha equation, has been applied in a number of studies, requirements need to be satisfied for the calculation of chemical compositions to be valid. Also, peaks of all elements contained in the target need to be detected, which is a bottleneck for in-situ analysis of unknown materials. Multivariate analysis techniques are gaining momentum in LIBS analysis. Among the available techniques, principal component regression (PCR) analysis and partial least squares (PLS) regression analysis, which can extract related information to compositions from all spectral data, are widely established methods and have been applied to various fields including in-situ applications in air and for planetary explorations. Artificial neural networks (ANNs), where non-linear effects can be modelled, have also been investigated as a quantitative method and their applications are introduced. The ability to make quantitative estimates based on LIBS signals is seen as a key element for the technique to gain wider acceptance as an analytical method, especially in in-situ applications. In order to accelerate this process, it is recommended that the accuracy should be described using common figures of merit which express the overall normalised accuracy, such as the normalised root mean square errors (NRMSEs), when comparing the accuracy obtained from different setups and analytical methods.

A novel in-line NIR spectroscopy application for the monitoring of tablet film coating in an industrial scale process.

PubMed

Möltgen, C-V; Puchert, T; Menezes, J C; Lochmann, D; Reich, G

2012-04-15

Film coating of tablets is a multivariate pharmaceutical unit operation. In this study an innovative in-line Fourier-Transform Near-Infrared Spectroscopy (FT-NIRS) application is described which enables real-time monitoring of a full industrial scale pan coating process of heart-shaped tablets. The tablets were coated with a thin hydroxypropyl methylcellulose (HPMC) film of up to approx. 28 μm on the tablet face as determined by SEM, corresponding to a weight gain of 2.26%. For a better understanding of the aqueous coating process the NIR probe was positioned inside the rotating tablet bed. Five full scale experimental runs have been performed to evaluate the impact of process variables such as pan rotation, exhaust air temperature, spray rate and pan load and elaborate robust and selective quantitative calibration models for the real-time determination of both coating growth and tablet moisture content. Principal Component (PC) score plots allowed each coating step, namely preheating, spraying and drying to be distinguished and the dominating factors and their spectral effects to be identified (e.g. temperature, moisture, coating growth, change of tablet bed density, and core/coat interactions). The distinct separation of HPMC coating growth and tablet moisture in different PCs enabled a real-time in-line monitoring of both attributes. A PLS calibration model based on Karl Fischer reference values allowed the tablet moisture trajectory to be determined throughout the entire coating process. A 1-latent variable iPLS weight gain calibration model with calibration samples from process stages dominated by the coating growth (i.e. ≥ 30% of the theoretically applied amount of coating) was sufficiently selective and accurate to predict the progress of the thin HPMC coating layer. At-line NIR Chemical Imaging (NIR-CI) in combination with PLS Discriminant Analysis (PLSDA) verified the HPMC coating growth and physical changes at the core/coat interface during the initial stages of the coating process. In addition, inter- and intra-tablet coating variability throughout the process could be assessed. These results clearly demonstrate that in-line NIRS and at-line NIR-CI can be applied as complimentary PAT tools to monitor a challenging pan coating process. Copyright © 2012 Elsevier B.V. All rights reserved.

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

PubMed Central

2015-01-01

Summary The implementation of continuous flow processing as a key enabling technology has transformed the way we conduct chemistry and has expanded our synthetic capabilities. As a result many new preparative routes have been designed towards commercially relevant drug compounds achieving more efficient and reproducible manufacture. This review article aims to illustrate the holistic systems approach and diverse applications of flow chemistry to the preparation of pharmaceutically active molecules, demonstrating the value of this strategy towards every aspect ranging from synthesis, in-line analysis and purification to final formulation and tableting. Although this review will primarily concentrate on large scale continuous processing, additional selected syntheses using micro or meso-scaled flow reactors will be exemplified for key transformations and process control. It is hoped that the reader will gain an appreciation of the innovative technology and transformational nature that flow chemistry can leverage to an overall process. PMID:26425178

System decontamination as a tool to control radiation fields

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

Riess, R.; Bertholdt, H.O.

1995-03-01

Since chemical decontamination of the Reactor Coolant Systems (RCS) and subsystems has the highest potential to reduce radiation fields in a short term this technology has gained an increasing importance. The available decontamination process at Siemens, i.e., the CORD processes, will be described. It is characterized by using permanganic acid for preoxidation and diluted organic acid for the decontamination step. It is a regenerative process resulting in very low waste volumes. This technology has been used frequently in Europe and Japan in both RCS and subsystems. An overview will be given i.e. on the 1993 applications. This overview will includemore » plant, scope, date of performance, system volume specal features of the process removed activities, decon factor time, waste volumes, and personnel dose during decontamination. This overview will be followed by an outlook on future developments in this area.« less

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry.

PubMed

Baumann, Marcus; Baxendale, Ian R

2015-01-01

The implementation of continuous flow processing as a key enabling technology has transformed the way we conduct chemistry and has expanded our synthetic capabilities. As a result many new preparative routes have been designed towards commercially relevant drug compounds achieving more efficient and reproducible manufacture. This review article aims to illustrate the holistic systems approach and diverse applications of flow chemistry to the preparation of pharmaceutically active molecules, demonstrating the value of this strategy towards every aspect ranging from synthesis, in-line analysis and purification to final formulation and tableting. Although this review will primarily concentrate on large scale continuous processing, additional selected syntheses using micro or meso-scaled flow reactors will be exemplified for key transformations and process control. It is hoped that the reader will gain an appreciation of the innovative technology and transformational nature that flow chemistry can leverage to an overall process.

Σ-Δ modulator for a programmable gain, low-power, high-linearity automotive sensor interface

NASA Astrophysics Data System (ADS)

de la Rosa, Jose M.; Medeiro, Fernando; Perez-Verdu, Belen; del Rio, Rocio; Rodriguez-Vazquez, Angel

2003-04-01

Smart sensors play a critical role in modern automotive electronic systems, covering a wide range of data capturing functions and operating under adverse environmental conditions - temperature range of [-40¦C,175¦C]. In such sensors, the signal provided by transducers is composed of an offset voltage, which depends on the manufacturing process, and a low-frequency signal carrying the information. In practice, the offset voltage is subject to temperature variations, thus causing a shifting of the signal range to be measured. Therefore, the measuring circuit driving the sensor, normally formed by a low-noise preamplifier and an Analog-to-Digital Converter (ADC), must accommodate the complete range of possible offsets and real signals. In this scenario, the use of ADCs based on Sigma-Delta Modulators (SDMs) is convenient for several reasons. On the one hand, the noise-shaping performed by SDMs allows to achieve high resolution (16-17bits), in the band of interest (10-20kHz), with less power consumption than full Nyquist ADCs. On the other hand, the action of feedback renders SDMs very linear, and high-linearity is a must for automotive applications. Last but not least, the robustness of SDMs with respect to circuit imperfections make them suitable to include programmable gain without significant performance degradation. This feature allows to accommodate the complete range of possible offsets and information signals in a sensor interface with relaxed specifications for the preamplifier circuitry. This paper describes the design and implementation of a third-order cascade (2-1) SDM with programmable gain in a 0.35mm CMOS technology - the type of technology commonly employed for automotive applications (deep submicron is mostly employed for telecom). It is capable of handling signals up to 20-kHz bandwidth with 17-bit resolution. The programmable gain is implemented by a capacitor array whose unitary capacitors are connected or disconnected depending on the value of the selected gain. In order to relax the amplifier dynamics requirements as the modulator gain varies, switchable capacitor arrays have been used for all the capacitors in the first integrator. The design of the modulator building blocks is based upon a top-down CAD methodology which combines simulation and statistical optimization at different levels of the modulator hierarchy. As a result, a dynamic range equal to 105 dB is obtained for all cases of the modulator gain, which corresponds to 17 bit resolution.

Quantifying effectiveness of failure prediction and response in HPC systems : methodology and example.

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

Mayo, Jackson R.; Chen, Frank Xiaoxiao; Pebay, Philippe Pierre

2010-06-01

Effective failure prediction and mitigation strategies in high-performance computing systems could provide huge gains in resilience of tightly coupled large-scale scientific codes. These gains would come from prediction-directed process migration and resource servicing, intelligent resource allocation, and checkpointing driven by failure predictors rather than at regular intervals based on nominal mean time to failure. Given probabilistic associations of outlier behavior in hardware-related metrics with eventual failure in hardware, system software, and/or applications, this paper explores approaches for quantifying the effects of prediction and mitigation strategies and demonstrates these using actual production system data. We describe context-relevant methodologies for determining themore » accuracy and cost-benefit of predictors. While many research studies have quantified the expected impact of growing system size, and the associated shortened mean time to failure (MTTF), on application performance in large-scale high-performance computing (HPC) platforms, there has been little if any work to quantify the possible gains from predicting system resource failures with significant but imperfect accuracy. This possibly stems from HPC system complexity and the fact that, to date, no one has established any good predictors of failure in these systems. Our work in the OVIS project aims to discover these predictors via a variety of data collection techniques and statistical analysis methods that yield probabilistic predictions. The question then is, 'How good or useful are these predictions?' We investigate methods for answering this question in a general setting, and illustrate them using a specific failure predictor discovered on a production system at Sandia.« less

Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use.

PubMed

Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R

2013-01-01

Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior.

Multidisciplinary Optimization Branch Experience Using iSIGHT Software

NASA Technical Reports Server (NTRS)

Padula, S. L.; Korte, J. J.; Dunn, H. J.; Salas, A. O.

1999-01-01

The Multidisciplinary Optimization (MDO) Branch at NASA Langley Research Center is investigating frameworks for supporting multidisciplinary analysis and optimization research. An optimization framework call improve the design process while reducing time and costs. A framework provides software and system services to integrate computational tasks and allows the researcher to concentrate more on the application and less on the programming details. A framework also provides a common working environment and a full range of optimization tools, and so increases the productivity of multidisciplinary research teams. Finally, a framework enables staff members to develop applications for use by disciplinary experts in other organizations. Since the release of version 4.0, the MDO Branch has gained experience with the iSIGHT framework developed by Engineous Software, Inc. This paper describes experiences with four aerospace applications: (1) reusable launch vehicle sizing, (2) aerospike nozzle design, (3) low-noise rotorcraft trajectories, and (4) acoustic liner design. All applications have been successfully tested using the iSIGHT framework, except for the aerospike nozzle problem, which is in progress. Brief overviews of each problem are provided. The problem descriptions include the number and type of disciplinary codes, as well as all estimate of the multidisciplinary analysis execution time. In addition, the optimization methods, objective functions, design variables, and design constraints are described for each problem. Discussions on the experience gained and lessons learned are provided for each problem. These discussions include the advantages and disadvantages of using the iSIGHT framework for each case as well as the ease of use of various advanced features. Potential areas of improvement are identified.

Enzyme-MOF (metal-organic framework) composites.

PubMed

Lian, Xizhen; Fang, Yu; Joseph, Elizabeth; Wang, Qi; Li, Jialuo; Banerjee, Sayan; Lollar, Christina; Wang, Xuan; Zhou, Hong-Cai

2017-06-06

The ex vivo application of enzymes in various processes, especially via enzyme immobilization techniques, has been extensively studied in recent years in order to enhance the recyclability of enzymes, to minimize enzyme contamination in the product, and to explore novel horizons for enzymes in biomedical applications. Possessing remarkable amenability in structural design of the frameworks as well as almost unparalelled surface tunability, Metal-Organic Frameworks (MOFs) have been gaining popularity as candidates for enzyme immobilization platforms. Many MOF-enzyme composites have achieved unprecedented results, far outperforming free enzymes in many aspects. This review summarizes recent developments of MOF-enzyme composites with special emphasis on preparative techniques and the synergistic effects of enzymes and MOFs. The applications of MOF-enzyme composites, primarily in transferation, catalysis and sensing, are presented as well. The enhancement of enzymatic activity of the composites over free enzymes in biologically incompatible conditions is emphasized in many cases.

Fast Inference with Min-Sum Matrix Product.

PubMed

Felzenszwalb, Pedro F; McAuley, Julian J

2011-12-01

The MAP inference problem in many graphical models can be solved efficiently using a fast algorithm for computing min-sum products of n × n matrices. The class of models in question includes cyclic and skip-chain models that arise in many applications. Although the worst-case complexity of the min-sum product operation is not known to be much better than O(n(3)), an O(n(2.5)) expected time algorithm was recently given, subject to some constraints on the input matrices. In this paper, we give an algorithm that runs in O(n(2) log n) expected time, assuming that the entries in the input matrices are independent samples from a uniform distribution. We also show that two variants of our algorithm are quite fast for inputs that arise in several applications. This leads to significant performance gains over previous methods in applications within computer vision and natural language processing.

Prospects for the application of GaN power devices in hybrid electric vehicle drive systems

NASA Astrophysics Data System (ADS)

Su, Ming; Chen, Chingchi; Rajan, Siddharth

2013-07-01

GaN, a wide bandgap semiconductor successfully implemented in optical and high-speed electronic devices, has gained momentum in recent years for power electronics applications. Along with rapid progress in material and device processing technologies, high-voltage transistors over 600 V have been reported by a number of teams worldwide. These advances make GaN highly attractive for the growing market of electrified vehicles, which currently employ bipolar silicon devices in the 600-1200 V class for the traction inverter. However, to capture this billion-dollar power market, GaN has to compete with existing IGBT products and deliver higher performance at comparable or lower cost. This paper reviews key achievements made by the GaN semiconductor industry, requirements of the automotive electric drive system and remaining challenges for GaN power devices to fit in the inverter application of hybrid vehicles.

Clinical applications of decellularized extracellular matrices for tissue engineering and regenerative medicine.

PubMed

Parmaksiz, Mahmut; Dogan, Arin; Odabas, Sedat; Elçin, A Eser; Elçin, Y Murat

2016-03-17

Decellularization is the process of removing the cellular components from tissues or organs. It is a promising technology for obtaining a biomaterial with a highly preserved extracellular matrix (ECM), which may also act as a biological scaffold for tissue engineering and regenerative therapies. Decellularized products are gaining clinical importance and market space due to their ease of standardized production, constant availability for grafting and mechanical or biochemical superiority against competing clinical options, yielding clinical results ahead of the ones with autografts in some applications. Current drawbacks and limitations of traditional treatments and clinical applications can be overcome by using decellularized or acellular matrices. Several companies are leading the market with versatile acellular products designed for diverse use in the reconstruction of tissues and organs. This review describes ECM-based decellularized and acellular products that are currently in use for different branches of clinic.

Systems modeling and simulation applications for critical care medicine

PubMed Central

2012-01-01

Critical care delivery is a complex, expensive, error prone, medical specialty and remains the focal point of major improvement efforts in healthcare delivery. Various modeling and simulation techniques offer unique opportunities to better understand the interactions between clinical physiology and care delivery. The novel insights gained from the systems perspective can then be used to develop and test new treatment strategies and make critical care delivery more efficient and effective. However, modeling and simulation applications in critical care remain underutilized. This article provides an overview of major computer-based simulation techniques as applied to critical care medicine. We provide three application examples of different simulation techniques, including a) pathophysiological model of acute lung injury, b) process modeling of critical care delivery, and c) an agent-based model to study interaction between pathophysiology and healthcare delivery. Finally, we identify certain challenges to, and opportunities for, future research in the area. PMID:22703718

Modelling transport phenomena in a multi-physics context

NASA Astrophysics Data System (ADS)

Marra, Francesco

2015-01-01

Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

Modelling transport phenomena in a multi-physics context

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

Marra, Francesco

2015-01-22

Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. Inmore » the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.« less

Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

PubMed Central

Poojary, Mahesha M.; Barba, Francisco J.; Aliakbarian, Bahar; Donsì, Francesco; Pataro, Gianpiero; Dias, Daniel A.; Juliano, Pablo

2016-01-01

Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability. PMID:27879659

Super-Resolution Microscopy: Shedding Light on the Cellular Plasma Membrane.

PubMed

Stone, Matthew B; Shelby, Sarah A; Veatch, Sarah L

2017-06-14

Lipids and the membranes they form are fundamental building blocks of cellular life, and their geometry and chemical properties distinguish membranes from other cellular environments. Collective processes occurring within membranes strongly impact cellular behavior and biochemistry, and understanding these processes presents unique challenges due to the often complex and myriad interactions between membrane components. Super-resolution microscopy offers a significant gain in resolution over traditional optical microscopy, enabling the localization of individual molecules even in densely labeled samples and in cellular and tissue environments. These microscopy techniques have been used to examine the organization and dynamics of plasma membrane components, providing insight into the fundamental interactions that determine membrane functions. Here, we broadly introduce the structure and organization of the mammalian plasma membrane and review recent applications of super-resolution microscopy to the study of membranes. We then highlight some inherent challenges faced when using super-resolution microscopy to study membranes, and we discuss recent technical advancements that promise further improvements to super-resolution microscopy and its application to the plasma membrane.

Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds.

PubMed

Poojary, Mahesha M; Barba, Francisco J; Aliakbarian, Bahar; Donsì, Francesco; Pataro, Gianpiero; Dias, Daniel A; Juliano, Pablo

2016-11-22

Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.

Functionalization of polymer powders for SLS-processes using an atmospheric plasma jet in a fluidized bed reactor

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

Sachs, Marius; Schmitt, Adeliene; Schmidt, Jochen

2015-05-22

Recently additive manufacturing processes such as selective laser sintering (SLS) of polymers have gained more importance for industrial applications [1]. Tailor-made modification of polymers is essential in order to make these processes more efficient and to cover the industrial demands. The so far used polymer materials show weak performance regarding the mechanical stability of processed parts. To overcome this limitation, a new route to functionalize the surface of commercially available polymer particles (PA12; PE-HD; PP) using an atmospheric plasma jet in combination with a fluidized bed reactor has been investigated. Consequently, an improvement of adhesion and wettability [2] of themore » polymer surface without restraining the bulk properties of the powder is achieved. The atmospheric plasma jet process can provide reactive species at moderate temperatures which are suitable for polymer material. The functionalization of the polymer powders improves the quality of the devices build in a SLS-process.« less

Optical gain in an optically driven three-level ? system in atomic Rb vapor

NASA Astrophysics Data System (ADS)

Ballmann, C. W.; Yakovlev, V. V.

2018-06-01

In this work, we report experimentally achieved optical gain of a weak probe beam in a three-level ? system in a low density Rubidium vapor cell driven by a single pump beam. The maximum measured gain of the probe beam was about 0.12%. This work could lead to new approaches for enhancing molecular spectroscopy applications.

Signal processing for distributed sensor concept: DISCO

NASA Astrophysics Data System (ADS)

Rafailov, Michael K.

2007-04-01

Distributed Sensor concept - DISCO proposed for multiplication of individual sensor capabilities through cooperative target engagement. DISCO relies on ability of signal processing software to format, to process and to transmit and receive sensor data and to exploit those data in signal synthesis process. Each sensor data is synchronized formatted, Signal-to-Noise Ration (SNR) enhanced and distributed inside of the sensor network. Signal processing technique for DISCO is Recursive Adaptive Frame Integration of Limited data - RAFIL technique that was initially proposed [1] as a way to improve the SNR, reduce data rate and mitigate FPA correlated noise of an individual sensor digital video-signal processing. In Distributed Sensor Concept RAFIL technique is used in segmented way, when constituencies of the technique are spatially and/or temporally separated between transmitters and receivers. Those constituencies include though not limited to two thresholds - one is tuned for optimum probability of detection, the other - to manage required false alarm rate, and limited frame integration placed somewhere between the thresholds as well as formatters, conventional integrators and more. RAFIL allows a non-linear integration that, along with SNR gain, provides system designers more capability where cost, weight, or power considerations limit system data rate, processing, or memory capability [2]. DISCO architecture allows flexible optimization of SNR gain, data rates and noise suppression on sensor's side and limited integration, re-formatting and final threshold on node's side. DISCO with Recursive Adaptive Frame Integration of Limited data may have flexible architecture that allows segmenting the hardware and software to be best suitable for specific DISCO applications and sensing needs - whatever it is air-or-space platforms, ground terminals or integration of sensors network.

Chemistry in microstructured reactors.

PubMed

Jähnisch, Klaus; Hessel, Volker; Löwe, Holger; Baerns, Manfred

2004-01-16

The application of microstructured reactors in the chemical process industry has gained significant importance in recent years. Companies that offer not only microstructured reactors, but also entire chemical process plants and services relating to them, are already in existence. In addition, many institutes and universities are active within this field, and process-engineering-oriented reviews and a specialized book are available. Microstructured systems can be applied with particular success in the investigation of highly exothermic and fast reactions. Often the presence of temperature-induced side reactions can be significantly reduced through isothermal operations. Although microstructured reaction techniques have been shown to optimize many synthetic procedures, they have not yet received the attention they deserve in organic chemistry. For this reason, this Review aims to address this by providing an overview of the chemistry in microstructured reactors, grouped into liquid-phase, gas-phase, and gas-liquid reactions.

The use of writing assignments to help students synthesize content in upper-level undergraduate biology courses.

PubMed

Sparks-Thissen, Rebecca L

2017-02-01

Biology education is undergoing a transformation toward a more student-centered, inquiry-driven classroom. Many educators have designed engaging assignments that are designed to help undergraduate students gain exposure to the scientific process and data analysis. One of these types of assignments is use of a grant proposal assignment. Many instructors have used these assignments in lecture-based courses to help students process information in the literature and apply that information to a novel problem such as design of an antiviral drug or a vaccine. These assignments have been helpful in engaging students in the scientific process in the absence of an inquiry-driven laboratory. This commentary discusses the application of these grant proposal writing assignments to undergraduate biology courses. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

sUAS and their application in observing geomorphological processes

NASA Astrophysics Data System (ADS)

Gallik, Jozef; Bolešová, Lenka

2016-07-01

Methodologies and procedures in processing gained data vary based on possibilities and needs of scientific projects. This paper should help to get a general overview in the choice of small unmanned aircraft systems (sUAS - commonly known as drones) for scientific purposes, namely remote sensing of geomorphologic processes such as soil degradation in high mountainous areas that are hard to access and have unfavourable weather conditions. All high mountain areas in European countries are legislatively protected, and so various permissions and observation of strict procedures are needed in order to not have a negative influence on the environment. Nowadays, several types of UAS exist that could effectively help us in such protection, as well as in full-fledged utilization when answering scientific questions about the alpine lake genesis. We demonstrate it here with selected examples of our photo documentation.

Environmental Adaptations, Ecological Filtering, and Dispersal Central to Insect Invasions.

PubMed

Renault, David; Laparie, Mathieu; McCauley, Shannon J; Bonte, Dries

2018-01-07

Insect invasions, the establishment and spread of nonnative insects in new regions, can have extensive economic and environmental consequences. Increased global connectivity accelerates rates of introductions, while climate change may decrease the barriers to invader species' spread. We follow an individual-level insect- and arachnid-centered perspective to assess how the process of invasion is influenced by phenotypic heterogeneity associated with dispersal and stress resistance, and their coupling, across the multiple steps of the invasion process. We also provide an overview and synthesis on the importance of environmental filters during the entire invasion process for the facilitation or inhibition of invasive insect population spread. Finally, we highlight important research gaps and the relevance and applicability of ongoing natural range expansions in the context of climate change to gain essential mechanistic insights into insect invasions.

Application of automatic gain control for radiometer diagnostic in SST-1 tokamak.

PubMed

Makwana, Foram R; Siju, Varsha; Edappala, Praveenlal; Pathak, S K

2017-12-01

This paper describes the characterisation of a negative feedback type of automatic gain control (AGC) circuit that will be an integral part of the heterodyne radiometer system operating at a frequency range of 75-86 GHz at SST-1 tokamak. The developed AGC circuit is a combination of variable gain amplifier and log amplifier which provides both gain and attenuation typically up to 15 dB and 45 dB, respectively, at a fixed set point voltage and it has been explored for the first time in tokamak radiometry application. The other important characteristics are that it exhibits a very fast response time of 390 ns to understand the fast dynamics of electron cyclotron emission and can operate at very wide input RF power dynamic range of around 60 dB that ensures signal level within the dynamic range of the detection system.

Finding a roadmap to achieve large neuromorphic hardware systems

PubMed Central

Hasler, Jennifer; Marr, Bo

2013-01-01

Neuromorphic systems are gaining increasing importance in an era where CMOS digital computing techniques are reaching physical limits. These silicon systems mimic extremely energy efficient neural computing structures, potentially both for solving engineering applications as well as understanding neural computation. Toward this end, the authors provide a glimpse at what the technology evolution roadmap looks like for these systems so that Neuromorphic engineers may gain the same benefit of anticipation and foresight that IC designers gained from Moore's law many years ago. Scaling of energy efficiency, performance, and size will be discussed as well as how the implementation and application space of Neuromorphic systems are expected to evolve over time. PMID:24058330

Intraband Raman laser gain in a boron nitride coupled quantum well

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

Moorthy, N. Narayana; Peter, A. John, E-mail: a.john.peter@gmail.com

2016-05-23

On-centre impurity related electronic and optical properties are studied in a Boron nitride coupled quantum well. Confined energies for the intraband transition are investigated by studying differential cross section of electron Raman scattering taking into consideration of spatial confinement in a B{sub 0.3}Ga{sub 0.7}N/BN coupled quantum well. Raman gain as a function of incident optical pump intensity is computed for constant well width. The enhancement of Raman gain is observed with the application of pump power. The results can be applied for the potential applications for fabricating some optical devices such as optical switches, infrared photo-detectors and electro-optical modulator.

Testing spatial heterogeneity with stock assessment models

PubMed Central

Eero, Margit; Silva, Alexandra; Ulrich, Clara; Pawlowski, Lionel; Holmes, Steven J.; Ibaibarriaga, Leire; De Oliveira, José A. A.; Riveiro, Isabel; Alzorriz, Nekane; Citores, Leire; Scott, Finlay; Uriarte, Andres; Carrera, Pablo; Duhamel, Erwan; Mosqueira, Iago

2018-01-01

This paper describes a methodology that combines meta-population theory and stock assessment models to gain insights about spatial heterogeneity of the meta-population in an operational time frame. The methodology was tested with stochastic simulations for different degrees of connectivity between sub-populations and applied to two case studies, North Sea cod (Gadus morua) and Northeast Atlantic sardine (Sardina pilchardus). Considering that the biological components of a population can be partitioned into discrete spatial units, we extended this idea into a property of additivity of sub-population abundances. If the additivity results hold true for putative sub-populations, then assessment results based on sub-populations will provide information to develop and monitor the implementation of finer scale/local management. The simulation study confirmed that when sub-populations are independent and not too heterogeneous with regards to productivity, the sum of stock assessment model estimates of sub-populations’ SSB is similar to the SSB estimates of the meta-population. It also showed that a strong diffusion process can be detected and that the stronger the connection between SSB and recruitment, the better the diffusion process will be detected. On the other hand it showed that weak to moderate diffusion processes are not easy to identify and large differences between sub-populations productivities may be confounded with weak diffusion processes. The application to North Sea cod and Atlantic sardine exemplified how much insight can be gained. In both cases the results obtained were sufficiently robust to support the regional analysis. PMID:29364901

Comparison of three different collectors for process heat applications

NASA Astrophysics Data System (ADS)

Brunold, Stefan; Frey, R.; Frei, Ulrich

1994-09-01

In general vacuum tube collectors are used in solar process heat systems. Another possibility is to use transparent insulated flat plate collectors. A critical point however, is that most of the common transparent insulating materials can not withstand high temperatures because they consist of plastics. Thus, temperature resistive collector covers combining a high tranmisivity with a low U-value are required. One possibility is to use capillaries made of glass instead of plastics. Measurement results of collector efficiency and incident angle modifier will be presented as well as calculated energy gains for three different collectors: a vacuum tube collector (Giordano Ind., France), a CPC vacuum tube collector (microtherm Energietechnik Germany; a new flat plate collector using glass capillary as transparent insulation (SET, Germany).

Low-complexity camera digital signal imaging for video document projection system

NASA Astrophysics Data System (ADS)

Hsia, Shih-Chang; Tsai, Po-Shien

2011-04-01

We present high-performance and low-complexity algorithms for real-time camera imaging applications. The main functions of the proposed camera digital signal processing (DSP) involve color interpolation, white balance, adaptive binary processing, auto gain control, and edge and color enhancement for video projection systems. A series of simulations demonstrate that the proposed method can achieve good image quality while keeping computation cost and memory requirements low. On the basis of the proposed algorithms, the cost-effective hardware core is developed using Verilog HDL. The prototype chip has been verified with one low-cost programmable device. The real-time camera system can achieve 1270 × 792 resolution with the combination of extra components and can demonstrate each DSP function.

P300 amplitude variation is related to ventral striatum BOLD response during gain and loss anticipation: an EEG and fMRI experiment.

PubMed

Pfabigan, Daniela M; Seidel, Eva-Maria; Sladky, Ronald; Hahn, Andreas; Paul, Katharina; Grahl, Arvina; Küblböck, Martin; Kraus, Christoph; Hummer, Allan; Kranz, Georg S; Windischberger, Christian; Lanzenberger, Rupert; Lamm, Claus

2014-08-01

The anticipation of favourable or unfavourable events is a key component in our daily life. However, the temporal dynamics of anticipation processes in relation to brain activation are still not fully understood. A modified version of the monetary incentive delay task was administered during separate functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG) sessions in the same 25 participants to assess anticipatory processes with a multi-modal neuroimaging set-up. During fMRI, gain and loss anticipation were both associated with heightened activation in ventral striatum and reward-related areas. EEG revealed most pronounced P300 amplitudes for gain anticipation, whereas CNV amplitudes distinguished neutral from gain and loss anticipation. Importantly, P300, but not CNV amplitudes, were correlated to neural activation in the ventral striatum for both gain and loss anticipation. Larger P300 amplitudes indicated higher ventral striatum blood oxygen level dependent (BOLD) response. Early stimulus evaluation processes indexed by EEG seem to be positively related to higher activation levels in the ventral striatum, indexed by fMRI, which are usually associated with reward processing. The current results, however, point towards a more general motivational mechanism processing salient stimuli during anticipation. Copyright © 2014. Published by Elsevier Inc.

Application of carbon nanotubes in perovskite solar cells: A review

NASA Astrophysics Data System (ADS)

Oo, Thet Tin; Debnath, Sujan

2017-11-01

Solar power, as alternative renewable energy source, has gained momentum in global energy generation in recent time. Solar photovoltaics (PV) systems now fulfill a significant portion of electricity demand and the capacity of solar PV capacity is growing every year. PV cells efficiency has improved significantly following decades of research, evolving into third generations of PV cells. These third generation PV cells are set out to provide low-cost and efficient PV systems, further improving the commercial competitiveness of solar energy generation. Among these latest generations of PV cells, perovskite solar cells have gained attraction due to the simple manufacturing process and the immense growth in PV efficiency in a short period of research and development. Despite these advantages, perovskite solar cells are known for the weak stability and decomposition in exposure to humidity and high temperature, hindering the possibility of commercialization. This paper will discuss the role of carbon nanotubes (CNTs) in improving the efficiency and stability of perovskite solar cells, in various components such as perovskite layer and hole transport layer, as well as the application of CNTs in unique aspects. These includes the use of CNTs fiber in making the perovskite solar cells flexible, as well as simplification of perovskite PV production by using CNT flash evaporation printing process. Despite these advances, challenges remain in incorporation CNTs into perovskite such as lower conversion efficiency compared to rare earth metals and improvements need to be made. Thus, the paper will be also highlighting the CNTs materials suggested for further research and improvement of perovskite solar cells.

Quantum Image Processing and Its Application to Edge Detection: Theory and Experiment

NASA Astrophysics Data System (ADS)

Yao, Xi-Wei; Wang, Hengyan; Liao, Zeyang; Chen, Ming-Cheng; Pan, Jian; Li, Jun; Zhang, Kechao; Lin, Xingcheng; Wang, Zhehui; Luo, Zhihuang; Zheng, Wenqiang; Li, Jianzhong; Zhao, Meisheng; Peng, Xinhua; Suter, Dieter

2017-07-01

Processing of digital images is continuously gaining in volume and relevance, with concomitant demands on data storage, transmission, and processing power. Encoding the image information in quantum-mechanical systems instead of classical ones and replacing classical with quantum information processing may alleviate some of these challenges. By encoding and processing the image information in quantum-mechanical systems, we here demonstrate the framework of quantum image processing, where a pure quantum state encodes the image information: we encode the pixel values in the probability amplitudes and the pixel positions in the computational basis states. Our quantum image representation reduces the required number of qubits compared to existing implementations, and we present image processing algorithms that provide exponential speed-up over their classical counterparts. For the commonly used task of detecting the edge of an image, we propose and implement a quantum algorithm that completes the task with only one single-qubit operation, independent of the size of the image. This demonstrates the potential of quantum image processing for highly efficient image and video processing in the big data era.

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

Dritz, K.W.; Boyle, J.M.

This paper addresses the problem of measuring and analyzing the performance of fine-grained parallel programs running on shared-memory multiprocessors. Such processors use locking (either directly in the application program, or indirectly in a subroutine library or the operating system) to serialize accesses to global variables. Given sufficiently high rates of locking, the chief factor preventing linear speedup (besides lack of adequate inherent parallelism in the application) is lock contention - the blocking of processes that are trying to acquire a lock currently held by another process. We show how a high-resolution, low-overhead clock may be used to measure both lockmore » contention and lack of parallel work. Several ways of presenting the results are covered, culminating in a method for calculating, in a single multiprocessing run, both the speedup actually achieved and the speedup lost to contention for each lock and to lack of parallel work. The speedup losses are reported in the same units, ''processor-equivalents,'' as the speedup achieved. Both are obtained without having to perform the usual one-process comparison run. We chronicle also a variety of experiments motivated by actual results obtained with our measurement method. The insights into program performance that we gained from these experiments helped us to refine the parts of our programs concerned with communication and synchronization. Ultimately these improvements reduced lock contention to a negligible amount and yielded nearly linear speedup in applications not limited by lack of parallel work. We describe two generally applicable strategies (''code motion out of critical regions'' and ''critical-region fissioning'') for reducing lock contention and one (''lock/variable fusion'') applicable only on certain architectures.« less

Numerical analysis on thermal energy storage device to improve the drying time of indirect type solar dryer

NASA Astrophysics Data System (ADS)

Yadav, Satyapal; Lingayat, Abhay Bhanudas; Chandramohan, V. P.; Raju, V. R. K.

2018-05-01

Thermal energy storage (TES) device that uses phase change material (PCM) in the field of indirect solar drying is economical due to its energy storage characteristics. In this work, a low-temperature latent heat TES device has been numerically analyzed for the application of solar drying of agricultural products in an indirect type solar dryer. Paraffin wax is used as a PCM material. The study has been performed on a single set of concentric tubes which consist of an inner copper tube and an outer plastic tube. A 2D geometry is created and computational fluid dynamics (CFD) simulations are performed using ANSYS Fluent 2015. The hot air coming from solar collector enters the copper tube and then the drying chamber to dry the sample. PCM material is placed in the outer plastic tube. It was found that the drying process can be continued up to 10.00 pm without further source of heating. At a given time, the melting fraction is increased during the heating process and solidification factor is increased during the cooling process while increasing the air flow velocities from 1 to 4 m/s, but 1 m/s is good for maintaining outlet temperature of air (T oa ) for a long time. Heat lost and gained by air was estimated. It was found that air flow velocity influenced the heat lost and gain by air.

26 CFR 1.402(a)-1 - Taxability of beneficiary under a trust which meets the requirements of section 401(a).

Code of Federal Regulations, 2013 CFR

2013-04-01

... taxable as long-term capital gains. For the treatment of such total distributions, see subparagraph (6) of... be considered a gain from the sale or exchange of a capital asset held for more than six months. The... payments received by the employee after retirement), will not defeat application of the capital gains...

26 CFR 1.402(a)-1 - Taxability of beneficiary under a trust which meets the requirements of section 401(a).

Code of Federal Regulations, 2011 CFR

2011-04-01

... taxable as long-term capital gains. For the treatment of such total distributions, see subparagraph (6) of... be considered a gain from the sale or exchange of a capital asset held for more than six months. The... payments received by the employee after retirement), will not defeat application of the capital gains...

26 CFR 1.402(a)-1 - Taxability of beneficiary under a trust which meets the requirements of section 401(a).

Code of Federal Regulations, 2012 CFR

2012-04-01

... taxable as long-term capital gains. For the treatment of such total distributions, see subparagraph (6) of... be considered a gain from the sale or exchange of a capital asset held for more than six months. The... payments received by the employee after retirement), will not defeat application of the capital gains...

26 CFR 1.402(a)-1 - Taxability of beneficiary under a trust which meets the requirements of section 401(a).

Code of Federal Regulations, 2014 CFR

2014-04-01

... taxable as long-term capital gains. For the treatment of such total distributions, see subparagraph (6) of... be considered a gain from the sale or exchange of a capital asset held for more than six months. The... payments received by the employee after retirement), will not defeat application of the capital gains...

Improved Drain Current Saturation and Voltage Gain in Graphene–on–Silicon Field Effect Transistors

PubMed Central

Song, Seung Min; Bong, Jae Hoon; Hwang, Wan Sik; Cho, Byung Jin

2016-01-01

Graphene devices for radio frequency (RF) applications are of great interest due to their excellent carrier mobility and saturation velocity. However, the insufficient current saturation in graphene field effect transistors (FETs) is a barrier preventing enhancements of the maximum oscillation frequency and voltage gain, both of which should be improved for RF transistors. Achieving a high output resistance is therefore a crucial step for graphene to be utilized in RF applications. In the present study, we report high output resistances and voltage gains in graphene-on-silicon (GoS) FETs. This is achieved by utilizing bare silicon as a supporting substrate without an insulating layer under the graphene. The GoSFETs exhibit a maximum output resistance of 2.5 MΩ∙μm, maximum intrinsic voltage gain of 28 dB, and maximum voltage gain of 9 dB. This method opens a new route to overcome the limitations of conventional graphene-on-insulator (GoI) FETs and subsequently brings graphene electronics closer to practical usage. PMID:27142861

Enhnacing the science of the WFIRST coronagraph instrument with post-processing.

NASA Astrophysics Data System (ADS)

Pueyo, Laurent; WFIRST CGI data analysis and post-processing WG

2018-01-01

We summarize the results of a three years effort investigating how to apply to the WFIRST coronagraph instrument (CGI) modern image analysis methods, now routinely used with ground-based coronagraphs. In this post we quantify the gain associated post-processing for WFIRST-CGI observing scenarios simulated between 2013 and 2017. We also show based one simulations that spectrum of planet can be confidently retrieved using these processing tools with and Integral Field Spectrograph. We then discuss our work using CGI experimental data and quantify coronagraph post-processing testbed gains. We finally introduce stability metrics that are simple to define and measure, and place useful lower bound and upper bounds on the achievable RDI post-processing contrast gain. We show that our bounds hold in the case of the testbed data.

Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use

PubMed Central

Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R.

2013-01-01

Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior. PMID:24009567

Directed evolution of bacteriorhodopsin for applications in bioelectronics

PubMed Central

Wagner, Nicole L.; Greco, Jordan A.; Ranaghan, Matthew J.; Birge, Robert R.

2013-01-01

In nature, biological systems gradually evolve through complex, algorithmic processes involving mutation and differential selection. Evolution has optimized biological macromolecules for a variety of functions to provide a comparative advantage. However, nature does not optimize molecules for use in human-made devices, as it would gain no survival advantage in such cooperation. Recent advancements in genetic engineering, most notably directed evolution, have allowed for the stepwise manipulation of the properties of living organisms, promoting the expansion of protein-based devices in nanotechnology. In this review, we highlight the use of directed evolution to optimize photoactive proteins, with an emphasis on bacteriorhodopsin (BR), for device applications. BR, a highly stable light-activated proton pump, has shown great promise in three-dimensional optical memories, real-time holographic processors and artificial retinas. PMID:23676894

Nanocrystals: The preparation, precise control, and application toward the pharmaceutics and foods industry.

PubMed

Wu, Cao; Chen, Zhou; Hu, Ya; Rao, Zhiyuan; Wu, Wangping; Yang, Zhaogang

2018-05-15

Crystallization is a significant process employed to produce a wide variety of materials in pharmaceutical and food area. The control of crystal dimension, crystallinity, and shape is very important because they will affect the subsequent filtration, drying and grinding performance as well as the physical and chemical properties of the material. This review summarizes the special features of crystallization technology and the preparation methods of nanocrystals, and discusses analytical technology which is used to control crystal quality and performance. The crystallization technology applications in pharmaceutics and foods are also outlined. These illustrated examples further help us to gain a better understanding of the crystallization technology for pharmaceutics and foods. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Laminates

NASA Astrophysics Data System (ADS)

Lepedat, Karin; Wagner, Robert; Lang, Jürgen

The use of phenolic resin for the impregnation of a carrier material such as paper or fabric based on either organic or inorganic fibers was and still is one of the most important application areas for liquid phenolic resins. Substrates like paper, cotton, or glass fabric impregnated with phenolic resins are used as core layers for decorative and technical laminates and for many other different industrial applications. Nowadays, phenolic resins for decorative laminates used for furniture, flooring, or in the construction and transportation industry have gained significant market share. The Laminates chapter mainly describes the manufacture of decorative laminates especially the impregnation and pressing process with special emphasis to new technological developments and recent trends. Moreover, the different types of laminates are introduced, combined with some brief comments as they relate to the market for decorative surfaces.

Recent advancements in electrospinning design for tissue engineering applications: A review.

PubMed

Kishan, Alysha P; Cosgriff-Hernandez, Elizabeth M

2017-10-01

Electrospinning, a technique used to fabricate fibrous scaffolds, has gained popularity in recent years as a method to produce tissue engineered grafts with architectural similarities to the extracellular matrix. Beyond its versatility in material selection, electrospinning also provides many tools to tune the fiber morphology and scaffold geometry. Recent efforts have focused on extending the capabilities of electrospinning to produce scaffolds that better recapitulate tissue properties and enhance regeneration. This review highlights these advancements by providing an overview of the processing variables and setups used to modulate scaffold architecture, discussing strategies to improve cellular infiltration and guide cell behavior, and providing a summary of electrospinning applications in tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2892-2905, 2017. © 2017 Wiley Periodicals, Inc.

Advanced Chemical Propulsion Study

NASA Technical Reports Server (NTRS)

Woodcock, Gordon; Byers, Dave; Alexander, Leslie A.; Krebsbach, Al

2004-01-01

A study was performed of advanced chemical propulsion technology application to space science (Code S) missions. The purpose was to begin the process of selecting chemical propulsion technology advancement activities that would provide greatest benefits to Code S missions. Several missions were selected from Code S planning data, and a range of advanced chemical propulsion options was analyzed to assess capabilities and benefits re these missions. Selected beneficial applications were found for higher-performing bipropellants, gelled propellants, and cryogenic propellants. Technology advancement recommendations included cryocoolers and small turbopump engines for cryogenic propellants; space storable propellants such as LOX-hydrazine; and advanced monopropellants. It was noted that fluorine-bearing oxidizers offer performance gains over more benign oxidizers. Potential benefits were observed for gelled propellants that could be allowed to freeze, then thawed for use.

An experimental investigation of fault tolerant software structures in an avionics application

NASA Technical Reports Server (NTRS)

Caglayan, Alper K.; Eckhardt, Dave E., Jr.

1989-01-01

The objective of this experimental investigation is to compare the functional performance and software reliability of competing fault tolerant software structures utilizing software diversity. In this experiment, three versions of the redundancy management software for a skewed sensor array have been developed using three diverse failure detection and isolation algorithms and incorporated into various N-version, recovery block and hybrid software structures. The empirical results show that, for maximum functional performance improvement in the selected application domain, the results of diverse algorithms should be voted before being processed by multiple versions without enforced diversity. Results also suggest that when the reliability gain with an N-version structure is modest, recovery block structures are more feasible since higher reliability can be obtained using an acceptance check with a modest reliability.

An Integrated Low-Power Lock-In Amplifier and Its Application to Gas Detection

PubMed Central

Maya-Hernández, Paulina M.; Álvarez-Simón, Luis C.; Sanz-Pascual, María Teresa; Calvo-López, Belén

2014-01-01

This paper presents a new micropower analog lock-in amplifier (LIA) suitable for battery-operated applications thanks to its reduced size and power consumption as well as its operation with single-supply voltage. The proposed LIA was designed in a 0.18 μm CMOS process with a single supply voltage of 1.8 V. Experimental results show a variable DC gain ranging from 24.7 to 42 dB, power consumption of 417 μW and integration area of 0.013 mm2. The LIA performance was demonstrated by measuring carbon monoxide concentrations as low as 1 ppm in dry N2. The experimental results show that the response to CO of the sensing system can be considerably improved by means of the proposed LIA. PMID:25166501

Arab Perspective About the Application of Information Technology in Science Education

NASA Astrophysics Data System (ADS)

Haidar, Abdullateef H.

1998-12-01

This paper discusses influences and concerns of the application of information technology (IT) in the Arab World. The paper argues that IT can influence the four elements of curriculum. Goals that are related to higher order thinking and problem solving abilities will gain much significance, while goals that are related to lower order thinking will gain much less significance. Science education goals will have to contain a goal that indicates the importance of preparing scientifically and technologically literate citizens. Content will have to match changes in goals. Rather than enforcing heavy content, more emphasis will be given to IT skills as well as to integrating technology in the science laboratory. Pedagogy will be more student-centered. Students will be held responsible for their own learning. Assessment will be facilitated by technology, where both process and content will be equally important. This paper discusses several concerns that are related to the application of IT in science education in the Arab World. Some of these concerns are: ignorance of incorporating the positive aspects of the Arab culture; Arab World view; language difficulties; high cost of IT hardware and software; and the use of IT to find information rather than make meaning (education). This paper recommends that successful implementation of IT in science education is a major professional challenge to Arab science educators. To meet this challenge effectively in science education, both of its promises and our concerns should be taken into consideration.

Transparent Large-Area MoS2 Phototransistors with Inkjet-Printed Components on Flexible Platforms.

PubMed

Kim, Tae-Young; Ha, Jewook; Cho, Kyungjune; Pak, Jinsu; Seo, Jiseok; Park, Jongjang; Kim, Jae-Keun; Chung, Seungjun; Hong, Yongtaek; Lee, Takhee

2017-10-24

Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have gained considerable attention as an emerging semiconductor due to their promising atomically thin film characteristics with good field-effect mobility and a tunable band gap energy. However, their electronic applications have been generally realized with conventional inorganic electrodes and dielectrics implemented using conventional photolithography or transferring processes that are not compatible with large-area and flexible device applications. To facilitate the advantages of 2D TMDCs in practical applications, strategies for realizing flexible and transparent 2D electronics using low-temperature, large-area, and low-cost processes should be developed. Motivated by this challenge, we report fully printed transparent chemical vapor deposition (CVD)-synthesized monolayer molybdenum disulfide (MoS 2 ) phototransistor arrays on flexible polymer substrates. All the electronic components, including dielectric and electrodes, were directly deposited with mechanically tolerable organic materials by inkjet-printing technology onto transferred monolayer MoS 2 , and their annealing temperature of <180 °C allows the direct fabrication on commercial flexible substrates without additional assisted-structures. By integrating the soft organic components with ultrathin MoS 2 , the fully printed MoS 2 phototransistors exhibit excellent transparency and mechanically stable operation.

The emergence of Clostridium thermocellum as a high utility candidate for consolidated bioprocessing applications

PubMed Central

Akinosho, Hannah; Yee, Kelsey; Close, Dan; Ragauskas, Arthur

2014-01-01

First isolated in 1926, Clostridium thermocellum has recently received increased attention as a high utility candidate for use in consolidated bioprocessing (CBP) applications. These applications, which seek to process lignocellulosic biomass directly into useful products such as ethanol, are gaining traction as economically feasible routes toward the production of fuel and other high value chemical compounds as the shortcomings of fossil fuels become evident. This review evaluates C. thermocellum's role in this transitory process by highlighting recent discoveries relating to its genomic, transcriptomic, proteomic, and metabolomic responses to varying biomass sources, with a special emphasis placed on providing an overview of its unique, multivariate enzyme cellulosome complex and the role that this structure performs during biomass degradation. Both naturally evolved and genetically engineered strains are examined in light of their unique attributes and responses to various biomass treatment conditions, and the genetic tools that have been employed for their creation are presented. Several future routes for potential industrial usage are presented, and it is concluded that, although there have been many advances to significantly improve C. thermocellum's amenability to industrial use, several hurdles still remain to be overcome as this unique organism enjoys increased attention within the scientific community. PMID:25207268

The emergence of Clostridium thermocellum as a high utility candidate for consolidated bioprocessing applications

NASA Astrophysics Data System (ADS)

Ragauskas, Arthur; Akinosho, Hannah; Yee, Kelsey; Close, Dan

2014-08-01

First isolated in 1926, Clostridium thermocellum has recently received increased attention as a high utility candidate for use in consolidated bioprocessing applications. These applications, which seek to process lignocellulosic biomass directly into useful products such as ethanol, are gaining traction as economically feasible routes towards the production of fuel and other high value chemical compounds as the shortcomings of fossil fuels become evident. This review evaluates C. thermocellum’s role in this transitory process by highlighting recent discoveries relating to its genomic, transcriptomic, proteomic, and metabolomic responses to varying biomass sources, with a special emphasis placed on providing an overview of its unique, multivariate enzyme cellulosome complex and the role that this structure performs during biomass degradation. Both naturally evolved and genetically engineered strains are examined in light of their unique attributes and responses to various biomass treatment conditions, and the genetic tools that have been employed for their creation are presented. Several future routes for potential industrial usage are presented, and it is concluded that, although there have been many advances to significantly improve C. thermocellum’s amenability to industrial use, several hurdles still remain to be overcome as this unique organism enjoys increased attention within the scientific community.

Excitonic Gain and Laser Action in Zinc Selenide Based Quantum Confined Structures

NASA Astrophysics Data System (ADS)

Ding, Jian

1992-01-01

Successful doping (both n and p type) and the knowledge obtained through optical pumping studies of ZnSe/ZnCdSe quantum well laser structures have led to the successful realization of ZnCdSe/ZnSe/ZnCdSSe and ZnCdSe/ZnSe injection diode lasers at temperatures above 200K, so far under pulsed excitation, where ZnSe/ZnCdSe quantum wells (single or multiple) are used as the gain media. One of the key design issues in optimizing such diode lasers for eventual room temperature, continuous-wave (cw) operation in technological applications (such as high density optical memories) is the question about the microscopic mechanism responsible for gain and stimulated emission. In other words, are there departures from the standard degenerate electron -hole pair picture which is rooted in population inversion models e.g. for the III-V semiconductor lasers, including quantum wells (QW). That some closer consideration may indeed be appropriate is suggested by the strong excitonic effects which have been recently observed in the optical properties of ZnSe based QW's. In particular, it has been demonstrated that for the type I (Zn,Cd)Se/ZnSe QW system, the quasi-2 dimensional (2D) confinement of electron-hole pairs leads to enhancement of the exciton binding energy E_{rm x}, such that it exceeds the longitudinal optical (LO) phonon energy hbaromega_{sc LO }. In striking contrast to bulk ZnSe, strong, distinct exciton absorption features can be seen well above room temperature. The question hence arises whether exciton effects might also be of fundamental and practical consequence in laser structures. In this thesis, we present experimental evidence to argue that excitons indeed do play a central role in the formation of gain in the (Zn,Cd)Se/ZnSe QW's which have emerged as the prime candidates for diode lasers in the blue-green portion of the spectrum. By employing both steady state and picosecond spectroscopy, we show that the origin of gain and laser action in (Zn,Cd)Se/ZnSe quantum wells in the blue-green is of excitonic nature. Among other observations we find that stimulated emission occurs when excitation takes place resonantly into the n = 1 HH exciton absorption line. Picosecond excite-probe measurements demonstrate directly the existence of gain as well as dynamical process of exciton relaxation. A simple excitonic gain model is also given to explain the phenomena observed in the stimulated emission process in ZnCdSe/ZnSe quantum well structures.

The parameterization of microchannel-plate-based detection systems

NASA Astrophysics Data System (ADS)

Gershman, Daniel J.; Gliese, Ulrik; Dorelli, John C.; Avanov, Levon A.; Barrie, Alexander C.; Chornay, Dennis J.; MacDonald, Elizabeth A.; Holland, Matthew P.; Giles, Barbara L.; Pollock, Craig J.

2016-10-01

The most common instrument for low-energy plasmas consists of a top-hat electrostatic analyzer (ESA) geometry coupled with a microchannel-plate-based (MCP-based) detection system. While the electrostatic optics for such sensors are readily simulated and parameterized during the laboratory calibration process, the detection system is often less well characterized. Here we develop a comprehensive mathematical description of particle detection systems. As a function of instrument azimuthal angle, we parameterize (1) particle scattering within the ESA and at the surface of the MCP, (2) the probability distribution of MCP gain for an incident particle, (3) electron charge cloud spreading between the MCP and anode board, and (4) capacitive coupling between adjacent discrete anodes. Using the Dual Electron Spectrometers on the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission as an example, we demonstrate a method for extracting these fundamental detection system parameters from laboratory calibration. We further show that parameters that will evolve in flight, namely, MCP gain, can be determined through application of this model to specifically tailored in-flight calibration activities. This methodology provides a robust characterization of sensor suite performance throughout mission lifetime. The model developed in this work is not only applicable to existing sensors but also can be used as an analytical design tool for future particle instrumentation.

MisTec - A software application for supporting space exploration scenario options and technology development analysis and planning

NASA Technical Reports Server (NTRS)

Horsham, Gary A. P.

1992-01-01

This structure and composition of a new, emerging software application, which models and analyzes space exploration scenario options for feasibility based on technology development projections is presented. The software application consists of four main components: a scenario generator for designing and inputting scenario options and constraints; a processor which performs algorithmic coupling and options analyses of mission activity requirements and technology capabilities; a results display which graphically and textually shows coupling and options analysis results; and a data/knowledge base which contains information on a variety of mission activities and (power and propulsion) technology system capabilities. The general long-range study process used by NASA to support recent studies is briefly introduced to provide the primary basis for comparison for discussing the potential advantages to be gained from developing and applying this kind of application. A hypothetical example of a scenario option to facilitate the best conceptual understanding of what the application is, how it works, or the operating methodology, and when it might be applied is presented.

MisTec: A software application for supporting space exploration scenario options and technology development analysis and planning

NASA Technical Reports Server (NTRS)

Horsham, Gary A. P.

1991-01-01

The structure and composition of a new, emerging software application, which models and analyzes space exploration scenario options for feasibility based on technology development projections is presented. The software application consists of four main components: a scenario generator for designing and inputting scenario options and constraints; a processor which performs algorithmic coupling and options analyses of mission activity requirements and technology capabilities; a results display which graphically and textually shows coupling and options analysis results; and a data/knowledge base which contains information on a variety of mission activities and (power and propulsion) technology system capabilities. The general long-range study process used by NASA to support recent studies is briefly introduced to provide the primary basis for comparison for discussing the potential advantages to be gained from developing and applying this king of application. A hypothetical example of a scenario option to facilitate the best conceptual understanding of what the application is, how it works, or the operating methodology, and when it might be applied is presented.

Segregated and integrated coding of reward and punishment in the cingulate cortex.

PubMed

Fujiwara, Juri; Tobler, Philippe N; Taira, Masato; Iijima, Toshio; Tsutsui, Ken-Ichiro

2009-06-01

Reward and punishment have opposite affective value but are both processed by the cingulate cortex. However, it is unclear whether the positive and negative affective values of monetary reward and punishment are processed by separate or common subregions of the cingulate cortex. We performed a functional magnetic resonance imaging study using a free-choice task and compared cingulate activations for different levels of monetary gain and loss. Gain-specific activation (increasing activation for increasing gain, but no activation change in relation to loss) occurred mainly in the anterior part of the anterior cingulate and in the posterior cingulate cortex. Conversely, loss-specific activation (increasing activation for increasing loss, but no activation change in relation to gain) occurred between these areas, in the middle and posterior part of the anterior cingulate. Integrated coding of gain and loss (increasing activation throughout the full range, from biggest loss to biggest gain) occurred in the dorsal part of the anterior cingulate, at the border with the medial prefrontal cortex. Finally, unspecific activation increases to both gains and losses (increasing activation to increasing gains and increasing losses, possibly reflecting attention) occurred in dorsal and middle regions of the cingulate cortex. Together, these results suggest separate and common coding of monetary reward and punishment in distinct subregions of the cingulate cortex. Further meta-analysis suggested that the presently found reward- and punishment-specific areas overlapped with those processing positive and negative emotions, respectively.

3D Printing Optical Engine for Controlling Material Microstructure

NASA Astrophysics Data System (ADS)

Huang, Wei-Chin; Chang, Kuang-Po; Wu, Ping-Han; Wu, Chih-Hsien; Lin, Ching-Chih; Chuang, Chuan-Sheng; Lin, De-Yau; Liu, Sung-Ho; Horng, Ji-Bin; Tsau, Fang-Hei

Controlling the cooling rate of alloy during melting and resolidification is the most commonly used method for varying the material microstructure and consequently the resuling property. However, the cooling rate of a selective laser melting (SLM) production is restricted by a preset optimal parameter of a good dense product. The head room for locally manipulating material property in a process is marginal. In this study, we invent an Optical Engine for locally controlling material microstructure in a SLM process. It develops an invovative method to control and adjust thermal history of the solidification process to gain desired material microstucture and consequently drastically improving the quality. Process parameters selected locally for specific materials requirement according to designed characteristics by using thermal dynamic principles of solidification process. It utilize a technique of complex laser beam shape of adaptive irradiation profile to permit local control of material characteristics as desired. This technology could be useful for industrial application of medical implant, aerospace and automobile industries.

Visualization of DNA in highly processed botanical materials.

PubMed

Lu, Zhengfei; Rubinsky, Maria; Babajanian, Silva; Zhang, Yanjun; Chang, Peter; Swanson, Gary

2018-04-15

DNA-based methods have been gaining recognition as a tool for botanical authentication in herbal medicine; however, their application in processed botanical materials is challenging due to the low quality and quantity of DNA left after extensive manufacturing processes. The low amount of DNA recovered from processed materials, especially extracts, is "invisible" by current technology, which has casted doubt on the presence of amplifiable botanical DNA. A method using adapter-ligation and PCR amplification was successfully applied to visualize the "invisible" DNA in botanical extracts. The size of the "invisible" DNA fragments in botanical extracts was around 20-220 bp compared to fragments of around 600 bp for the more easily visualized DNA in botanical powders. This technique is the first to allow characterization and visualization of small fragments of DNA in processed botanical materials and will provide key information to guide the development of appropriate DNA-based botanical authentication methods in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

A stable solution-processed polymer semiconductor with record high-mobility for printed transistors

PubMed Central

Li, Jun; Zhao, Yan; Tan, Huei Shuan; Guo, Yunlong; Di, Chong-An; Yu, Gui; Liu, Yunqi; Lin, Ming; Lim, Suo Hon; Zhou, Yuhua; Su, Haibin; Ong, Beng S.

2012-01-01

Microelectronic circuits/arrays produced via high-speed printing instead of traditional photolithographic processes offer an appealing approach to creating the long-sought after, low-cost, large-area flexible electronics. Foremost among critical enablers to propel this paradigm shift in manufacturing is a stable, solution-processable, high-performance semiconductor for printing functionally capable thin-film transistors — fundamental building blocks of microelectronics. We report herein the processing and optimisation of solution-processable polymer semiconductors for thin-film transistors, demonstrating very high field-effect mobility, high on/off ratio, and excellent shelf-life and operating stabilities under ambient conditions. Exceptionally high-gain inverters and functional ring oscillator devices on flexible substrates have been demonstrated. This optimised polymer semiconductor represents a significant progress in semiconductor development, dispelling prevalent skepticism surrounding practical usability of organic semiconductors for high-performance microelectronic devices, opening up application opportunities hitherto functionally or economically inaccessible with silicon technologies, and providing an excellent structural framework for fundamental studies of charge transport in organic systems. PMID:23082244

Linearity enhancement design of a 16-channel low-noise front-end readout ASIC for CdZnTe detectors

NASA Astrophysics Data System (ADS)

Zeng, Huiming; Wei, Tingcun; Wang, Jia

2017-03-01

A 16-channel front-end readout application-specific integrated circuit (ASIC) with linearity enhancement design for cadmium zinc telluride (CdZnTe) detectors is presented in this paper. The resistors in the slow shaper are realized using a high-Z circuit to obtain constant resistance value instead of using only a metal-oxide-semiconductor (MOS) transistor, thus the shaping time of the slow shaper can be kept constant for different amounts of input energies. As a result, the linearity of conversion gain is improved significantly. The ASIC was designed and fabricated in a 0.35 μm CMOS process with a die size of 2.60 mm×3.53 mm. The tested results show that a typical channel provides an equivalent noise charge (ENC) of 109.7e-+16.3e-/pF with a power consumption of 4 mW and achieves a conversion gain of 87 mV/fC with a nonlinearity of <0.4%. The linearity of conversion gain is improved by at least 86.6% as compared with the traditional approaches using the same front-end readout architecture and manufacture process. Moreover, the inconsistency among channels is <0.3%. An energy resolution of 2.975 keV (FWHM) for gamma rays of 59.5 keV was measured by connecting the ASIC to a 5 mm×5 mm ×2 mm CdZnTe detector at room temperature. The front-end readout ASIC presented in this paper achieves an outstanding linearity performance without compromising the noise, power consumption, and chip size performances.

Noise analysis for near-field 3D FM-CW radar imaging systems

NASA Astrophysics Data System (ADS)

Sheen, David M.

2015-05-01

Near field radar imaging systems are used for demanding security applications including concealed weapon detection in airports and other high-security venues. Despite the near-field operation, phase noise and thermal noise can limit performance in several ways. Practical imaging systems can employ arrays with low gain antennas and relatively large signal distribution networks that have substantial losses which limit transmit power and increase the effective noise figure of the receiver chain, resulting in substantial thermal noise. Phase noise can also limit system performance. The signal coupled from transmitter to receiver is much larger than expected target signals. Phase noise from this coupled signal can set the system noise floor if the oscillator is too noisy. Frequency modulated continuous wave (FM-CW) radar transceivers used in short range systems are relatively immune to the effects of the coupled phase noise due to range correlation effects. This effect can reduce the phase-noise floor such that it is below the thermal noise floor for moderate performance oscillators. Phase noise is also manifested in the range response around bright targets, and can cause smaller targets to be obscured. Noise in synthetic aperture imaging systems is mitigated by the processing gain of the system. In this paper, the effects of thermal noise, phase noise, and processing gain are analyzed in the context of a near field 3-D FM-CW imaging radar as might be used for concealed weapon detection. In addition to traditional frequency domain analysis, a time-domain simulation is employed to graphically demonstrate the effect of these noise sources on a fast-chirping FM-CW system.

Performance of a novel wafer scale CMOS active pixel sensor for bio-medical imaging.

PubMed

Esposito, M; Anaxagoras, T; Konstantinidis, A C; Zheng, Y; Speller, R D; Evans, P M; Allinson, N M; Wells, K

2014-07-07

Recently CMOS active pixels sensors (APSs) have become a valuable alternative to amorphous silicon and selenium flat panel imagers (FPIs) in bio-medical imaging applications. CMOS APSs can now be scaled up to the standard 20 cm diameter wafer size by means of a reticle stitching block process. However, despite wafer scale CMOS APS being monolithic, sources of non-uniformity of response and regional variations can persist representing a significant challenge for wafer scale sensor response. Non-uniformity of stitched sensors can arise from a number of factors related to the manufacturing process, including variation of amplification, variation between readout components, wafer defects and process variations across the wafer due to manufacturing processes. This paper reports on an investigation into the spatial non-uniformity and regional variations of a wafer scale stitched CMOS APS. For the first time a per-pixel analysis of the electro-optical performance of a wafer CMOS APS is presented, to address inhomogeneity issues arising from the stitching techniques used to manufacture wafer scale sensors. A complete model of the signal generation in the pixel array has been provided and proved capable of accounting for noise and gain variations across the pixel array. This novel analysis leads to readout noise and conversion gain being evaluated at pixel level, stitching block level and in regions of interest, resulting in a coefficient of variation ⩽1.9%. The uniformity of the image quality performance has been further investigated in a typical x-ray application, i.e. mammography, showing a uniformity in terms of CNR among the highest when compared with mammography detectors commonly used in clinical practice. Finally, in order to compare the detection capability of this novel APS with the technology currently used (i.e. FPIs), theoretical evaluation of the detection quantum efficiency (DQE) at zero-frequency has been performed, resulting in a higher DQE for this detector compared to FPIs. Optical characterization, x-ray contrast measurements and theoretical DQE evaluation suggest that a trade off can be found between the need of a large imaging area and the requirement of a uniform imaging performance, making the DynAMITe large area CMOS APS suitable for a range of bio-medical applications.

An Item Gains and Losses Analysis of False Memories Suggests Critical Items Receive More Item-Specific Processing than List Items

ERIC Educational Resources Information Center

Burns, Daniel J.; Martens, Nicholas J.; Bertoni, Alicia A.; Sweeney, Emily J.; Lividini, Michelle D.

2006-01-01

In a repeated testing paradigm, list items receiving item-specific processing are more likely to be recovered across successive tests (item gains), whereas items receiving relational processing are likely to be forgotten progressively less on successive tests. Moreover, analysis of cumulative-recall curves has shown that item-specific processing…

Process Evaluation of a School-Based Weight Gain Prevention Program: The Dutch Obesity Intervention in Teenagers (DOiT)

ERIC Educational Resources Information Center

Singh, A. S.; Chinapaw, M. J. M.; Brug, J.; van Mechelen, W.

2009-01-01

Health promotion programs benefit from an accompanying process evaluation since it can provide more insight in the strengths and weaknesses of a program. A process evaluation was conducted to assess the reach, implementation, satisfaction and maintenance of a school-based program aimed at the prevention of excessive weight gain among Dutch…

Energetic consequences of thermal and nonthermal food processing

PubMed Central

Carmody, Rachel N.; Weintraub, Gil S.; Wrangham, Richard W.

2011-01-01

Processing food extensively by thermal and nonthermal techniques is a unique and universal human practice. Food processing increases palatability and edibility and has been argued to increase energy gain. Although energy gain is a well-known effect from cooking starch-rich foods, the idea that cooking meat increases energy gain has never been tested. Moreover, the relative energetic advantages of cooking and nonthermal processing have not been assessed, whether for meat or starch-rich foods. Here, we describe a system for characterizing the energetic effects of cooking and nonthermal food processing. Using mice as a model, we show that cooking substantially increases the energy gained from meat, leading to elevations in body mass that are not attributable to differences in food intake or activity levels. The positive energetic effects of cooking were found to be superior to the effects of pounding in both meat and starch-rich tubers, a conclusion further supported by food preferences in fasted animals. Our results indicate significant contributions from cooking to both modern and ancestral human energy budgets. They also illuminate a weakness in current food labeling practices, which systematically overestimate the caloric potential of poorly processed foods. PMID:22065771

Energetic consequences of thermal and nonthermal food processing.

PubMed

Carmody, Rachel N; Weintraub, Gil S; Wrangham, Richard W

2011-11-29

Processing food extensively by thermal and nonthermal techniques is a unique and universal human practice. Food processing increases palatability and edibility and has been argued to increase energy gain. Although energy gain is a well-known effect from cooking starch-rich foods, the idea that cooking meat increases energy gain has never been tested. Moreover, the relative energetic advantages of cooking and nonthermal processing have not been assessed, whether for meat or starch-rich foods. Here, we describe a system for characterizing the energetic effects of cooking and nonthermal food processing. Using mice as a model, we show that cooking substantially increases the energy gained from meat, leading to elevations in body mass that are not attributable to differences in food intake or activity levels. The positive energetic effects of cooking were found to be superior to the effects of pounding in both meat and starch-rich tubers, a conclusion further supported by food preferences in fasted animals. Our results indicate significant contributions from cooking to both modern and ancestral human energy budgets. They also illuminate a weakness in current food labeling practices, which systematically overestimate the caloric potential of poorly processed foods.

FPGA implementation of sparse matrix algorithm for information retrieval

NASA Astrophysics Data System (ADS)

Bojanic, Slobodan; Jevtic, Ruzica; Nieto-Taladriz, Octavio

2005-06-01

Information text data retrieval requires a tremendous amount of processing time because of the size of the data and the complexity of information retrieval algorithms. In this paper the solution to this problem is proposed via hardware supported information retrieval algorithms. Reconfigurable computing may adopt frequent hardware modifications through its tailorable hardware and exploits parallelism for a given application through reconfigurable and flexible hardware units. The degree of the parallelism can be tuned for data. In this work we implemented standard BLAS (basic linear algebra subprogram) sparse matrix algorithm named Compressed Sparse Row (CSR) that is showed to be more efficient in terms of storage space requirement and query-processing timing over the other sparse matrix algorithms for information retrieval application. Although inverted index algorithm is treated as the de facto standard for information retrieval for years, an alternative approach to store the index of text collection in a sparse matrix structure gains more attention. This approach performs query processing using sparse matrix-vector multiplication and due to parallelization achieves a substantial efficiency over the sequential inverted index. The parallel implementations of information retrieval kernel are presented in this work targeting the Virtex II Field Programmable Gate Arrays (FPGAs) board from Xilinx. A recent development in scientific applications is the use of FPGA to achieve high performance results. Computational results are compared to implementations on other platforms. The design achieves a high level of parallelism for the overall function while retaining highly optimised hardware within processing unit.

Vehicle antenna development for mobile satellite applications

NASA Technical Reports Server (NTRS)

Woo, K.

1988-01-01

The paper summarizes results of a vehicle antenna program at JPL in support of a developing U.S. mobile satellite services (MSS) designed to provide telephone and data services for the continental United States. Two classes of circularly polarized vehicle antennas have been considered for the MSS: medium-gain, satellite-tracking antennas with 10-12-dBic gain; and low-gain, azimuthally omnidirectional antennas with 3-5-dBic gain. The design and performance of these antennas are described, and the two antennas are shown to have peculiar advantages and disadvantages.

Possibility of Recombination Gain Increase in CV Ions at 4.0 nm Via Coherence

NASA Astrophysics Data System (ADS)

Luo, Y.; Morozov, A.; Gordon, D.; Sprangle, P.; Svidzinsky, A.; Xia, H.; Scully, M.; Suckewer, S.

This paper is about the recent experimental results on amplification of the CV line in the "water window" at 4.03 nm from resonance transition to the ground level of He-like ions in recombination scheme. The indication of the amplification of the CV line has been observed when an elongated narrow plasma channel was created, where high intensity 100 fs beams, optimal for creating CV ions in high density plasma, was propagated up to 0.5-0.6 mm. Without channeling the effective plasma length was much shorter and there was no indication of amplification.The large interest in gain generation in He-like ions in the transition to ground state is due to the possibility of applying a recently developed theory of Lasing Without Inversion (LWI) in XUV and X-ray regions to largely increase the gain for such transitions. The presented results of the indication of CV line amplifications are being discussed from the point of view of using LWI as a superradiance gain increase, hence to construct a very compact soft X-ray laser in the "water window".The last part of the paper is related to the application of the ultra-intensive fs plasma laser, which is currently in the process of development by using stimulated Raman backscattering (SRBS) to create a plasma amplifier and compressor, as the pump for compact laser operating in the "water window" and also at shorter wavelengths.

Nova Upgrade: A proposed ICF facility to demonstrate ignition and gain, revision 1

NASA Astrophysics Data System (ADS)

1992-07-01

The present objective of the national Inertial Confinement Fusion (ICF) Program is to determine the scientific feasibility of compressing and heating a small mass of mixed deuterium and tritium (DT) to conditions at which fusion occurs and significant energy is released. The potential applications of ICF will be determined by the resulting fusion energy yield (amount of energy produced) and gain (ratio of energy released to energy required to heat and compress the DT fuel). Important defense and civilian applications, including weapons physics, weapons effects simulation, and ultimately the generation of electric power will become possible if yields of 100 to 1,000 MJ and gains exceeding approximately 50 can be achieved. Once ignition and propagating bum producing modest gain (2 to 10) at moderate drive energy (1 to 2 MJ) has been achieved, the extension to high gain (greater than 50) is straightforward. Therefore, the demonstration of ignition and modest gain is the final step in establishing the scientific feasibility of ICF. Lawrence Livermore National Laboratory (LLNL) proposes the Nova Upgrade Facility to achieve this demonstration by the end of the decade. This facility would be constructed within the existing Nova building at LLNL for a total cost of approximately $400 M over the proposed FY 1995-1999 construction period. This report discusses this facility.

Activating Developmental Reserve Capacity Via Cognitive Training or Non-invasive Brain Stimulation: Potentials for Promoting Fronto-Parietal and Hippocampal-Striatal Network Functions in Old Age

PubMed Central

Passow, Susanne; Thurm, Franka; Li, Shu-Chen

2017-01-01

Existing neurocomputational and empirical data link deficient neuromodulation of the fronto-parietal and hippocampal-striatal circuitries with aging-related increase in processing noise and declines in various cognitive functions. Specifically, the theory of aging neuronal gain control postulates that aging-related suboptimal neuromodulation may attenuate neuronal gain control, which yields computational consequences on reducing the signal-to-noise-ratio of synaptic signal transmission and hampering information processing within and between cortical networks. Intervention methods such as cognitive training and non-invasive brain stimulation, e.g., transcranial direct current stimulation (tDCS), have been considered as means to buffer cognitive functions or delay cognitive decline in old age. However, to date the reported effect sizes of immediate training gains and maintenance effects of a variety of cognitive trainings are small to moderate at best; moreover, training-related transfer effects to non-trained but closely related (i.e., near-transfer) or other (i.e., far-transfer) cognitive functions are inconsistent or lacking. Similarly, although applying different tDCS protocols to reduce aging-related cognitive impairments by inducing temporary changes in cortical excitability seem somewhat promising, evidence of effects on short- and long-term plasticity is still equivocal. In this article, we will review and critically discuss existing findings of cognitive training- and stimulation-related behavioral and neural plasticity effects in the context of cognitive aging, focusing specifically on working memory and episodic memory functions, which are subserved by the fronto-parietal and hippocampal-striatal networks, respectively. Furthermore, in line with the theory of aging neuronal gain control we will highlight that developing age-specific brain stimulation protocols and the concurrent applications of tDCS during cognitive training may potentially facilitate short- and long-term cognitive and brain plasticity in old age. PMID:28280465

Heterobimetallic Complexes for Theranostic Applications.

PubMed

Fernández-Moreira, Vanesa; Gimeno, M Concepción

2018-03-07

The design of more efficient anticancer drugs requires a deeper understanding of their biodistribution and mechanism of action. Cell imaging agents could help to gain insight into biological processes and, consequently, the best strategy for attaining suitable scaffolds in which both biological and imaging properties are maximized. A new concept arises in this field that is the combination of two metal fragments as collaborative partners to provide the precise emissive properties to visualize the cell as well as the optimum cytotoxic activity to build more potent and selective chemotherapeutic agents. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Frequency-degenerate phase-sensitive optical parametric amplification based on four-wave mixing in graphene–silicon slot waveguide

NASA Astrophysics Data System (ADS)

Li, Zhen; Liu, Hongjun; Huang, Nan; Wang, Zhaolu; Han, Jing

2018-06-01

The phase-sensitive amplification process of a hybrid graphene–silicon (HyGS) slot waveguide with trilayers of graphene is investigated in this paper. Numerical simulation shows that a relatively high extinction ratio (42 dB) is achieved, because of the ultrahigh nonlinear coefficients, with a waveguide length of only 680 µm. In addition, the graphene layer provides the possibility of modulating the phase status and gain of the output signal. This study is expected to be highly beneficial to applications such as integrated optics and graphene-related active optical devices.

Femtosecond Fiber Lasers Based on Dissipative Processes for Nonlinear Microscopy.

PubMed

Wise, Frank W

2012-01-01

Recent progress in the development of femtosecond-pulse fiber lasers with parameters appropriate for nonlinear microscopy is reviewed. Pulse-shaping in lasers with only normal-dispersion components is briefly described, and the performance of the resulting lasers is summarized. Fiber lasers based on the formation of dissipative solitons now offer performance competitive with that of solid-state lasers, but with the benefits of the fiber medium. Lasers based on self-similar pulse evolution in the gain section of a laser also offer a combination of short pulse duration and high pulse energy that will be attractive for applications in nonlinear bioimaging.

Historical review of missile aerodynamic developments

NASA Technical Reports Server (NTRS)

Spearman, M. Leroy

1989-01-01

A comprehensive development history to about 1970 is presented for missile technologies and their associated capabilities and difficulties. Attention is given to the growth of an experimental data base for missile design, as well as to the critical early efforts to develop analytical methods applicable to missiles. Most of the important missile development efforts made during the period from the end of the Second World War to the early 1960s were based primarily on experiences gained through wind tunnel and flight testing; analytical techniques began to demonstrate their usefulness in the design process only in the late 1960s.

Development of Matrix Microstructures in UHTC Composites

NASA Technical Reports Server (NTRS)

Johnson, Sylvia; Stackpoole, Margaret; Gusman, Michael

2012-01-01

One of the major issues hindering the use of ultra high temperature ceramics for aerospace applications is low fracture toughness. There is considerable interest in developing fiber-reinforced composites to improve fracture toughness. Considerable knowledge has been gained in controlling and improving the microstructure of monolithic UHTCs, and this paper addresses the question of transferring that knowledge to composites. Some model composites have been made and the microstructures of the matrix developed has been explored and compared to the microstructure of monolithic materials in the hafnium diboride/silicon carbide family. Both 2D and 3D weaves have been impregnated and processed.

Remote sensing of vegetation pattern and condition to monitor changes in Everglades biogeochemistry

USGS Publications Warehouse

Jones, John W.

2011-01-01

Ground-based studies of biogeochemistry and vegetation patterning yield process understanding, but the amount of information gained by ground-based studies can be greatly enhanced by efficient, synoptic, and temporally resolute monitoring afforded by remote sensing. The variety of presently available Everglades vegetation maps reflects both the wide range of application requirements and the need to balance cost and capability. More effort needs to be applied to documenting and understanding vegetation distribution and condition as indicators of biogeochemistry and contamination. Ground-based and remote sensing studies should be modified to maximize their synergy and utility for adaptive management.

The test of VLSI circuits

NASA Astrophysics Data System (ADS)

Baviere, Ph.

Tests which have proven effective for evaluating VLSI circuits for space applications are described. It is recommended that circuits be examined after each manfacturing step to gain fast feedback on inadequacies in the production system. Data from failure modes which occur during operational lifetimes of circuits also permit redefinition of the manufacturing and quality control process to eliminate the defects identified. Other tests include determination of the operational envelope of the circuits, examination of the circuit response to controlled inputs, and the performance and functional speeds of ROM and RAM memories. Finally, it is desirable that all new circuits be designed with testing in mind.

Developing effective child psychiatry collaboration with primary care: leadership and management strategies.

PubMed

Sarvet, Barry D; Wegner, Lynn

2010-01-01

By working in collaboration with pediatric primary care providers, child and adolescent psychiatrists have the opportunity to address significant levels of unmet need for the majority of children and teenagers with serious mental health problems who have been unable to gain access to care. Effective collaboration with primary care represents a significant change from practice-as-usual for many child and adolescent psychiatrists. Implementation of progressive levels of collaborative practice, from the improvement of provider communication through the development of comprehensive collaborative systems, may be possible with sustained management efforts and application of process improvement methodology.

[Application of computed tomography (CT) examination for forensic medicine].

PubMed

Urbanik, Andrzej; Chrzan, Robert

2013-01-01

The aim of the study is to present a own experiences in usage of post mortem CT examination for forensic medicine. With the help of 16-slice CT scanner 181 corpses were examined. Obtained during acquisition imaging data are later developed with dedicated programmes. Analyzed images were extracted from axial sections, multiplanar reconstructions as well as 3D reconstructions. Gained information helped greatly when classical autopsy was performed by making it more accurate. A CT scan images recorded digitally enable to evaluate corpses at any time, despite processes of putrefaction or cremation. If possible CT examination should precede classical autopsy.

What Do Smokers Want in A Smartphone-Based Cessation Application?

PubMed

Oliver, Jason A; Hallyburton, Matthew B; Pacek, Lauren R; Mitchell, John T; Vilardaga, Roger; Fuemmeler, Bernard F; Joseph McClernon, F

2017-08-03

Fueled by rapid technological advances over the past decade, there is growing interest in the use of smartphones to aid in smoking cessation. Hundreds of applications have been developed for this purpose, but little is known about how these applications are accessed and used by smokers or what features smokers believe would be most useful. The present study sought to understand the prevalence of smartphone ownership and patterns of use among smokers as well as the perceived utility of various smartphone application features for smoking cessation that are currently in development or already available. Daily cigarette smokers (n = 224) reported on smartphone ownership, their patterns of smartphone usage, and perceived utility of features. Features were ranked according to perceived utility and differences in both perceived utility and general smartphone use patterns were examined as a function of demographic and smoking-related variables. Most smokers (80.4%) own a smartphone, but experience with smoking cessation applications is extremely rare (6.1%). Ownership and patterns of usage differed as a function of demographic and smoking-related variables. Overall, gain-framed features were rated as most useful, while loss-framed and interpersonal features were rated as least useful. Mobile health interventions have the potential to reach a large number of smokers but are currently underutilized. Additional effort is needed to ensure parity in treatment access. Gain-framed messages may be especially useful for engaging smokers, even if other features ultimately drive treatment effects. This study describes patterns of smartphone usage among smokers and identifies the smartphone application features smokers believe would be most useful during a quit attempt. Findings indicate which subgroups of smokers are most likely to be reached with mobile health interventions and suggests that inclusion of specific features may be helpful for engaging smokers in the smoking cessation process. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Clinical Natural Language Processing in languages other than English: opportunities and challenges.

PubMed

Névéol, Aurélie; Dalianis, Hercules; Velupillai, Sumithra; Savova, Guergana; Zweigenbaum, Pierre

2018-03-30

Natural language processing applied to clinical text or aimed at a clinical outcome has been thriving in recent years. This paper offers the first broad overview of clinical Natural Language Processing (NLP) for languages other than English. Recent studies are summarized to offer insights and outline opportunities in this area. We envision three groups of intended readers: (1) NLP researchers leveraging experience gained in other languages, (2) NLP researchers faced with establishing clinical text processing in a language other than English, and (3) clinical informatics researchers and practitioners looking for resources in their languages in order to apply NLP techniques and tools to clinical practice and/or investigation. We review work in clinical NLP in languages other than English. We classify these studies into three groups: (i) studies describing the development of new NLP systems or components de novo, (ii) studies describing the adaptation of NLP architectures developed for English to another language, and (iii) studies focusing on a particular clinical application. We show the advantages and drawbacks of each method, and highlight the appropriate application context. Finally, we identify major challenges and opportunities that will affect the impact of NLP on clinical practice and public health studies in a context that encompasses English as well as other languages.

Integration agent-based models and GIS as a virtual urban dynamic laboratory

NASA Astrophysics Data System (ADS)

Chen, Peng; Liu, Miaolong

2007-06-01

Based on the Agent-based Model and spatial data model, a tight-coupling integrating method of GIS and Agent-based Model (ABM) is to be discussed in this paper. The use of object-orientation for both spatial data and spatial process models facilitates their integration, which can allow exploration and explanation of spatial-temporal phenomena such as urban dynamic. In order to better understand how tight coupling might proceed and to evaluate the possible functional and efficiency gains from such a tight coupling, the agent-based model and spatial data model are discussed, and then the relationships affecting spatial data model and agent-based process models interaction. After that, a realistic crowd flow simulation experiment is presented. Using some tools provided by general GIS systems and a few specific programming languages, a new software system integrating GIS and MAS as a virtual laboratory applicable for simulating pedestrian flows in a crowd activity centre has been developed successfully. Under the environment supported by the software system, as an applicable case, a dynamic evolution process of the pedestrian's flows (dispersed process for the spectators) in a crowds' activity center - The Shanghai Stadium has been simulated successfully. At the end of the paper, some new research problems have been pointed out for the future.

Secure Display of Space-Exploration Images

NASA Technical Reports Server (NTRS)

Cheng, Cecilia; Thornhill, Gillian; McAuley, Michael

2006-01-01

Java EDR Display Interface (JEDI) is software for either local display or secure Internet distribution, to authorized clients, of image data acquired from cameras aboard spacecraft engaged in exploration of remote planets. ( EDR signifies experimental data record, which, in effect, signifies image data.) Processed at NASA s Multimission Image Processing Laboratory (MIPL), the data can be from either near-realtime processing streams or stored files. JEDI uses the Java Advanced Imaging application program interface, plus input/output packages that are parts of the Video Image Communication and Retrieval software of the MIPL, to display images. JEDI can be run as either a standalone application program or within a Web browser as a servlet with an applet front end. In either operating mode, JEDI communicates using the HTTP(s) protocol(s). In the Web-browser case, the user must provide a password to gain access. For each user and/or image data type, there is a configuration file, called a "personality file," containing parameters that control the layout of the displays and the information to be included in them. Once JEDI has accepted the user s password, it processes the requested EDR (provided that user is authorized to receive the specific EDR) to create a display according to the user s personality file.

Porous coordination polymers as novel sorption materials for heat transformation processes.

PubMed

Janiak, Christoph; Henninger, Stefan K

2013-01-01

Porous coordination polymers (PCPs)/metal-organic frameworks (MOFs) are inorganic-organic hybrid materials with a permanent three-dimensional porous metal-ligand network. PCPs or MOFs are inorganic-organic analogs of zeolites in terms of porosity and reversible guest exchange properties. Microporous water-stable PCPs with high water uptake capacity are gaining attention for low temperature heat transformation applications in thermally driven adsorption chillers (TDCs) or adsorption heat pumps (AHPs). TDCs or AHPs are an alternative to traditional air conditioners or heat pumps operating on electricity or fossil fuels. By using solar or waste heat as the operating energy TDCs or AHPs can significantly help to minimize primary energy consumption and greenhouse gas emissions generated by industrial or domestic heating and cooling processes. TDCs and AHPs are based on the evaporation and consecutive adsorption of coolant liquids, preferably water, under specific conditions. The process is driven and controlled by the microporosity and hydrophilicity of the employed sorption material. Here we summarize the current investigations, developments and possibilities of PCPs/MOFs for use in low-temperature heat transformation applications as alternative materials for the traditional inorganic porous substances like silica gel, aluminophosphates or zeolites.

Cloning should be simple: Escherichia coli DH5α-mediated assembly of multiple DNA fragments with short end homologies

DOE PAGES

Kostylev, Maxim; Otwell, Anne E.; Richardson, Ruth E.; ...

2015-09-08

Numerous DNA assembly technologies exist for generating plasmids for biological studies. Many procedures require complex in vitro or in vivo assembly reactions followed by plasmid propagation in recombination-impaired Escherichia coli strains such as DH5α, which are optimal for stable amplification of the DNA materials. Here we show that despite its utility as a cloning strain, DH5α retains sufficient recombinase activity to assemble up to six doublestranded DNA fragments ranging in size from 150 bp to at least 7 kb into plasmids in vivo. This process also requires surprisingly small amounts of DNA, potentially obviating the need for upstream assembly processesmore » associated with most common applications of DNA assembly. In addition, we demonstrate the application of this process in cloning of various DNA fragments including synthetic genes, preparation of knockout constructs, and incorporation of guide RNA sequences in constructs for clustered regularly interspaced short palindromic repeats (CRISPR) genome editing. This consolidated process for assembly and amplification in a widely available strain of E. coli may enable productivity gain across disciplines involving recombinant DNA work.« less

Cloning should be simple: Escherichia coli DH5α-mediated assembly of multiple DNA fragments with short end homologies

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

Kostylev, Maxim; Otwell, Anne E.; Richardson, Ruth E.

Numerous DNA assembly technologies exist for generating plasmids for biological studies. Many procedures require complex in vitro or in vivo assembly reactions followed by plasmid propagation in recombination-impaired Escherichia coli strains such as DH5α, which are optimal for stable amplification of the DNA materials. Here we show that despite its utility as a cloning strain, DH5α retains sufficient recombinase activity to assemble up to six doublestranded DNA fragments ranging in size from 150 bp to at least 7 kb into plasmids in vivo. This process also requires surprisingly small amounts of DNA, potentially obviating the need for upstream assembly processesmore » associated with most common applications of DNA assembly. In addition, we demonstrate the application of this process in cloning of various DNA fragments including synthetic genes, preparation of knockout constructs, and incorporation of guide RNA sequences in constructs for clustered regularly interspaced short palindromic repeats (CRISPR) genome editing. This consolidated process for assembly and amplification in a widely available strain of E. coli may enable productivity gain across disciplines involving recombinant DNA work.« less

Industrial applications of new sulphur biotechnology.

PubMed

Janssen, A J; Ruitenberg, R; Buisman, C J

2001-01-01

The emission of sulphur compounds into the environment is undesirable because of their acidifying characteristics. The processing of sulphidic ores, oil refining and sulphuric acid production are major sources of SO2 emissions. Hydrogen sulphide is emitted into the environment as dissolved sulphide in wastewater or as H2S in natural gas, biogas, syngas or refinery gases. Waste streams containing sulphate are generated by many industries, including mining, metallurgical, pulp and paper and petrochemical industries. Applying process technologies that rely on the biological sulphur cycle can prevent environmental pollution. In nature sulphur compounds may cycle through a series of oxidation states (-2, 0, +2, +4, +6). Bacteria of a wide range of genera gain metabolic energy from either oxidising or reducing sulphur compounds. Paques B.V. develops and constructs reactor systems to remove sulphur compounds from aqueous and gaseous streams by utilising naturally occurring bacteria from the sulphur cycle. Due to the presence of sulphide, heavy metal removal is also achieved with very high removal efficiencies. Ten years of extensive laboratory and pilot plant research has, to date, resulted in the construction of over 30 full-scale installations. This paper presents key processes from the sulphur cycle and discusses recent developments about their application in industry.

Increasing the hydrophobicity degree of stonework by means of laser surface texturing: An application on Zimbabwe black granites

NASA Astrophysics Data System (ADS)

Chantada, A.; Penide, J.; Riveiro, A.; del Val, J.; Quintero, F.; Meixus, M.; Soto, R.; Lusquiños, F.; Pou, J.

2017-10-01

Tailoring the wetting characteristics of materials has gained much interest in applications related to surface cleaning in both industry and home. Zimbabwe black granite is a middle-to-fine-grained natural stone commonly used as countertops in kitchens and bathrooms. In this study, the laser texturing of Zimbabwe black granite surfaces is investigated with the aim to enhance its hydrophobic character, thus reducing the attachment of contaminants on the surface. Two laser sources (λ = 1064 and 532 nm) were used for this purpose. The treatment is based on the irradiation of the stone by a laser focused on the surface of the targeting sample. The influence of different laser processing parameters on the surface characteristics of granite (wettability, roughness, and chemistry) was statistically assessed. Most suitable laser processing parameters required to obtain the highest hydrophobicity degree were identified. It has been possible to identify the 532 nm laser wavelength as the most effective one to increase the hydrophobic degree of Zimbabwe black granite surface. The phenomenon governing wettability changes was found to be the surface roughness patterns, given the unaltered chemical surface composition after laser processing.

Seal Technology Development for Advanced Component for Airbreathing Engines

NASA Technical Reports Server (NTRS)

Snyder, Philip H.

2008-01-01

Key aspects of the design of sealing systems for On Rotor Combustion/Wave Rotor (ORC/WR) systems were addressed. ORC/WR systems generally fit within a broad class of pressure gain Constant Volume Combustors (CVCs) or Pulse Detonation Combustors (PDCs) which are currently being considered for use in many classes of turbine engines for dramatic efficiency improvement. Technology readiness level of this ORC/WR approaches are presently at 2.0. The results of detailed modeling of an ORC/WR system as applied to a regional jet engine application were shown to capture a high degree of pressure gain capabilities. The results of engine cycle analysis indicated the level of specific fuel consumption (SFC) benefits to be 17 percent. The potential losses in pressure gain due to leakage were found to be closely coupled to the wave processes at the rotor endpoints of the ORC/WR system. Extensive investigation into the sealing approaches is reported. Sensitivity studies show that SFC gains of 10 percent remain available even when pressure gain levels are highly penalized. This indicates ORC/WR systems to have a high degree of tolerance to rotor leakage effects but also emphasizes their importance. An engine demonstration of an ORC/WR system is seen as key to progressing the TRL of this technology. An industrial engine was judged to be a highly advantageous platform for demonstration of a first generation ORC/WR system. Prior to such a demonstration, the existing NASA pressure exchanger wave rotor rig was identified as an opportunity to apply both expanded analytical modeling capabilities developed within this program and to identify and fix identified leakage issues existing within this rig. Extensive leakage analysis of the rig was performed and a detailed design of additional sealing strategies for this rig was generated.

Design and Development of 256x256 Linear Mode Low-Noise Avalanche Photodiode Arrays

NASA Technical Reports Server (NTRS)

Yuan, Ping; Sudharsanan, Rengarajan; Bai, Xiaogang; Boisvert, Joseph; McDonald, Paul; Chang, James

2011-01-01

A larger format photodiode array is always desirable for many LADAR imaging applications. However, as the array format increases, the laser power or the lens aperture has to increase to maintain the same flux per pixel thus increasing the size, weight and power of the imaging system. In order to avoid this negative impact, it is essential to improve the pixel sensitivity. The sensitivity of a short wavelength infrared linear-mode avalanche photodiode (APD) is a delicate balance of quantum efficiency, usable gain, excess noise factor, capacitance, and dark current of APD as well as the input equivalent noise of the amplifier. By using InA1As as a multiplication layer in an InP-based APD, the ionization coefficient ratio, k, is reduced from 0.40 (lnP) to 0.22, and the excess noise is reduced by about 50%. An additional improvement in excess noise of 25% was achieved by employing an impact-ionization-engineering structure with a k value of 0.15. Compared with the traditional InP structure, about 30% reduction in the noise-equivalent power with the following amplifier can be achieved. Spectrolab demonstrated 30-um mesa APD pixels with a dark current less than 10 nA and a capacitance of 60 fF at gain of 10. APD gain uninformity determines the usable gain of most pixels in an array, which is critical to focal plane array sensitivity. By fine tuning the material growth and device process, a break-down-voltage standard deviation of 0.1 V and gain of 30 on individual pixels were demonstrated in our 256x256 linear-mode APD arrays.

Solar-Blind Photodetector with High Avalanche Gains and Bias-Tunable Detecting Functionality Based on Metastable Phase α-Ga2O3/ZnO Isotype Heterostructures.

PubMed

Chen, Xuanhu; Xu, Yang; Zhou, Dong; Yang, Sen; Ren, Fang-Fang; Lu, Hai; Tang, Kun; Gu, Shulin; Zhang, Rong; Zheng, Youdou; Ye, Jiandong

2017-10-25

The metastable α-phase Ga 2 O 3 is an emerging material for developing solar-blind photodetectors and power electronic devices toward civil and military applications. Despite its superior physical properties, the high quality epitaxy of metastable phase α-Ga 2 O 3 remains challenging. To this end, single crystalline α-Ga 2 O 3 epilayers are achieved on nonpolar ZnO (112̅0) substrates for the first time and a high performance Au/α-Ga 2 O 3 /ZnO isotype heterostructure-based Schottky barrier avalanche diode is demonstrated. The device exhibits self-powered functions with a dark current lower than 1 pA, a UV/visible rejection ratio of 10 3 and a detectivity of 9.66 × 10 12 cm Hz 1/2 W -1 . Dual responsivity bands with cutoff wavelengths at 255 and 375 nm are observed with their peak responsivities of 0.50 and 0.071 A W -1 at -5 V, respectively. High photoconductive gain at low bias is governed by a barrier lowing effect at the Au/Ga 2 O 3 and Ga 2 O 3 /ZnO heterointerfaces. The device also allows avalanche multiplication processes initiated by pure electron and hole injections under different illumination conditions. High avalanche gains over 10 3 and a low ionization coefficient ratio of electrons and holes are yielded, leading to a total gain over 10 5 and a high responsivity of 1.10 × 10 4 A W -1 . Such avalanche heterostructures with ultrahigh gains and bias-tunable UV detecting functionality hold promise for developing high performance solar-blind photodetectors.

Achieving high strength and high ductility in magnesium alloy using hard-plate rolling (HPR) process

NASA Astrophysics Data System (ADS)

Wang, Hui–Yuan; Yu, Zhao–Peng; Zhang, Lei; Liu, Chun–Guo; Zha, Min; Wang, Cheng; Jiang, Qi–Chuan

2015-11-01

Magnesium alloys are highly desirable for a wide range of lightweight structural components. However, rolling Mg alloys can be difficult due to their poor plasticity, and the strong texture yielded from rolling often results in poor plate forming ability, which limits their further engineering applications. Here we report a new hard-plate rolling (HPR) route which achieves a large reduction during a single rolling pass. The Mg-9Al-1Zn (AZ91) plates processed by HPR consist of coarse grains of 30-60 μm, exhibiting a typical basal texture, fine grains of 1-5 μm and ultrafine (sub) grains of 200-500 nm, both of the latter two having a weakened texture. More importantly, the HPR was efficient in gaining a simultaneous high strength and uniform ductility, i.e., ~371 MPa and ~23%, respectively. The superior properties should be mainly attributed to the cooperation effect of the multimodal grain structure and weakened texture, where the former facilitates a strong work hardening while the latter promotes the basal slip. The HPR methodology is facile and effective, and can avoid plate cracking that is prone to occur during conventional rolling processes. This strategy is applicable to hard-to-deform materials like Mg alloys, and thus has a promising prospect for industrial application.

On the Use of PLA-PHB Blends for Sustainable Food Packaging Applications

PubMed Central

Arrieta, Marina Patricia; Samper, María Dolores; Aldas, Miguel; López, Juan

2017-01-01

Poly(lactic acid) (PLA) is the most used biopolymer for food packaging applications. Several strategies have been made to improve PLA properties for extending its applications in the packaging field. Melt blending approaches are gaining considerable interest since they are easy, cost-effective and readily available processing technologies at the industrial level. With a similar melting temperature and high crystallinity, poly(hydroxybutyrate) (PHB) represents a good candidate to blend with PLA. The ability of PHB to act as a nucleating agent for PLA improves its mechanical resistance and barrier performance. With the dual objective to improve PLAPHB processing performance and to obtain stretchable materials, plasticizers are frequently added. Current trends to enhance PLA-PHB miscibility are focused on the development of composite and nanocomposites. PLA-PHB blends are also interesting for the controlled release of active compounds in the development of active packaging systems. This review explains the most relevant processing aspects of PLA-PHB based blends such as the influence of polymers molecular weight, the PLA-PHB composition as well as the thermal stability. It also summarizes the recent developments in PLA-PHB formulations with an emphasis on their performance with interest in the sustainable food packaging field. PLA-PHB blends shows highly promising perspectives for the replacement of traditional petrochemical based polymers currently used for food packaging. PMID:28850102

An integrated multichannel neural recording analog front-end ASIC with area-efficient driven right leg circuit.

PubMed

Tao Tang; Wang Ling Goh; Lei Yao; Jia Hao Cheong; Yuan Gao

2017-07-01

This paper describes an integrated multichannel neural recording analog front end (AFE) with a novel area-efficient driven right leg (DRL) circuit to improve the system common mode rejection ratio (CMRR). The proposed AFE consists of an AC-coupled low-noise programmable-gain amplifier, an area-efficient DRL block and a 10-bit SAR ADC. Compared to conventional DRL circuit, the proposed capacitor-less DRL design achieves 90% chip area reduction with enhanced CMRR performance, making it ideal for multichannel biomedical recording applications. The AFE circuit has been designed in a standard 0.18-μm CMOS process. Post-layout simulation results show that the AFE provides two gain settings of 54dB/60dB while consuming 1 μA per channel under a supply voltage of 1 V. The input-referred noise of the AFE integrated from 1 Hz to 10k Hz is only 4 μVrms and the CMRR is 110 dB.

An Analysis of Offset, Gain, and Phase Corrections in Analog to Digital Converters

NASA Astrophysics Data System (ADS)

Cody, Devin; Ford, John

2015-01-01

Many high-speed analog to digital converters (ADCs) use interwoven ADCs to greatly boost their sample rate. This interwoven architecture can introduce problems if the low speed ADCs do not have identical outputs. These errors are manifested as phantom frequencies that appear in the digitized signal although they never existed in the analog domain. Through the application of offset, gain, and phase (OGP) corrections to the ADC, this problem can be reduced. Here we report on an implementation of such a correction in a high speed ADC chip used for radio astronomy. While the corrections could not be implemented in the ADCs themselves, a partial solution was devised and implemented digitally inside of a signal processing field programmable gate array (FPGA). Positive results to contrived situations are shown, and null results are presented for implementation in an ADC083000 card with minimal error. Lastly, we discuss the implications of this method as well as its mathematical basis.

Nanoparticle-assisted high photoconductive gain in polymer/fullerene matrix

PubMed Central

Chen, Hsiang-Yu; Lo, Michael K. F.; Yang, Guanwen; Monbouquette, Harold G.; Yang, Yang

2014-01-01

Polymer/inorganic nanocrystal composites1–10 offer an attractive means to combine the merits of organic and inorganic materials into novel electronic and photonic systems. However, many applications of these composites are limited by the solubility11 and distribution of nanocrystals (NCs) in polymer matrices. Here, a high photoconductive gain has been achieved by blending cadmium telluride (CdTe) nanoparticles (NPs) into a polymer/fullerene matrix followed by a solvent annealing12 process. The NP surface capping ligand, N-phenyl-N’-methyldithiocarbamate, renders the NPs highly soluble in the polymer blend thereby enabling high nanocrystal loadings. An external quantum efficiency (EQE) as high as ~8000% (at 350nm) is reached at −4.5V. Hole-dominant devices coupled with AFM images are studied to uncover the probable mechanism. We observe a higher concentration of CdTe NPs is located near the cathode/polymer interface. These NPs with trapped electrons assist hole injection into the polymer under reverse bias, which contributes to greater than 100% EQE. PMID:18772915

A highly linear power amplifier for WLAN

NASA Astrophysics Data System (ADS)

Jie, Jin; Jia, Shi; Baoli, Ai; Xuguang, Zhang

2016-02-01

A three-stage power amplifier (PA) for WLAN application in 2.4-2.5 GHz is presented. The proposed PA employs an adaptive bias circuit to adjust the operating point of the PA to improve the linearity of the PA. Two methods to short the 2nd harmonic circuit are compared in the area of efficiency and gain of the PA. The PA is taped out in the process of 2 μm InGaP/GaAs HBT and is tested by the evaluation board. The measured results show that 31.5 dB power gain and 29.3 dBm P1dB with an associated 40.4% power added efficiency (PAE) under the single tone stimulus. Up to 26.5 dBm output power can be achieved with an error vector magnitude (EVM) of lower than 3% under the 64QAM/OFDM WLAN stimulus. Project supported by the National Natural Science Foundation of China (No. 61201244) and the Natural Science Fund of SUES (No. E1-0501-14-0168).

Positive Gain Spirals at Work: From Job Resources to Work Engagement, Personal Initiative and Work-Unit Innovativeness

ERIC Educational Resources Information Center

Hakanen, Jari J.; Perhoniemi, Riku; Toppinen-Tanner, Salla

2008-01-01

The present cross-lagged panel study aimed to investigate the energizing power of job resources and related gain spirals. Drawing on Hobfoll's Conservation of Resources (COR) theory's rarely tested assumptions of cumulative resource gains and gain spirals a reciprocal process was expected: (1) job resources lead to work engagement and work…

Controle d'attitude d'un lanceur en phase atmospherique approche par applications gardiennes

NASA Astrophysics Data System (ADS)

Dubanchet, Vincent

In a first phase, the modelling process underlines the presence of highly time varying parameters during the ascent, due to a fast mass variation along with propellant consumption. Linearizing the dynamical equations at six main flight instants yields linear time invariant models to be considered during control design. Each of them is to be stabilized by one control law, while respecting given specifications. The synthesis becomes even more complex when the bending modes are taken into account. Moreover, scheduling appears necessary to deal with the time variations. Indeed it is shown that no single gain setting is able to respect all the specifications along the trajectory. Furthermore, increasing complexity when modelling a whole launch vehicle pushes one to consider the model's errors and uncertainties. They represent a major issue in this study since it is asked to ensure the nominal performances in a robust fashion. Owing to their properties, guardian maps appear to be the most suitable tool to deal with such a problem of scheduling with robust performances. In light of this, the development of synthesis methods based on guardian maps is the main contribution of the project. It appears that actual state of the art in this field is focused on theoretical issues, whereas practical ones could be improved. Two approches are presented in the memoire. The first one is based on a graphical approach consisting in drawing the vanishing locus of guardian maps. A program using image analysis techniques is devised to check automatically which gain settings satisfy the constraints. The second one is based on an optimisation procedure involving guardian maps. Starting with the open loop system, the iterative process proposed ends up with a satisfactory gain setting for the closed-loop. These methods are tried and tested for the launch vehicle, with specifications from ASTRIUM-ST. Their practical application is motivated by the system complexity, the different kinds of constraints and the essential need for robustness. Many restrictions that finally bring about the interest and the efficiency of guardian maps for such a problem.

Pre-Hardware Optimization of Spacecraft Image Processing Software Algorithms and Hardware Implementation

NASA Technical Reports Server (NTRS)

Kizhner, Semion; Flatley, Thomas P.; Hestnes, Phyllis; Jentoft-Nilsen, Marit; Petrick, David J.; Day, John H. (Technical Monitor)

2001-01-01

Spacecraft telemetry rates have steadily increased over the last decade presenting a problem for real-time processing by ground facilities. This paper proposes a solution to a related problem for the Geostationary Operational Environmental Spacecraft (GOES-8) image processing application. Although large super-computer facilities are the obvious heritage solution, they are very costly, making it imperative to seek a feasible alternative engineering solution at a fraction of the cost. The solution is based on a Personal Computer (PC) platform and synergy of optimized software algorithms and re-configurable computing hardware technologies, such as Field Programmable Gate Arrays (FPGA) and Digital Signal Processing (DSP). It has been shown in [1] and [2] that this configuration can provide superior inexpensive performance for a chosen application on the ground station or on-board a spacecraft. However, since this technology is still maturing, intensive pre-hardware steps are necessary to achieve the benefits of hardware implementation. This paper describes these steps for the GOES-8 application, a software project developed using Interactive Data Language (IDL) (Trademark of Research Systems, Inc.) on a Workstation/UNIX platform. The solution involves converting the application to a PC/Windows/RC platform, selected mainly by the availability of low cost, adaptable high-speed RC hardware. In order for the hybrid system to run, the IDL software was modified to account for platform differences. It was interesting to examine the gains and losses in performance on the new platform, as well as unexpected observations before implementing hardware. After substantial pre-hardware optimization steps, the necessity of hardware implementation for bottleneck code in the PC environment became evident and solvable beginning with the methodology described in [1], [2], and implementing a novel methodology for this specific application [6]. The PC-RC interface bandwidth problem for the class of applications with moderate input-output data rates but large intermediate multi-thread data streams has been addressed and mitigated. This opens a new class of satellite image processing applications for bottleneck problems solution using RC technologies. The issue of a science algorithm level of abstraction necessary for RC hardware implementation is also described. Selected Matlab functions already implemented in hardware were investigated for their direct applicability to the GOES-8 application with the intent to create a library of Matlab and IDL RC functions for ongoing work. A complete class of spacecraft image processing applications using embedded re-configurable computing technology to meet real-time requirements, including performance results and comparison with the existing system, is described in this paper.

Advances in adaptive control theory: Gradient- and derivative-free approaches

NASA Astrophysics Data System (ADS)

Yucelen, Tansel

In this dissertation, we present new approaches to improve standard designs in adaptive control theory, and novel adaptive control architectures. We first present a novel Kalman filter based approach for approximately enforcing a linear constraint in standard adaptive control design. One application is that this leads to alternative forms for well known modification terms such as e-modification. In addition, it leads to smaller tracking errors without incurring significant oscillations in the system response and without requiring high modification gain. We derive alternative forms of e- and adaptive loop recovery (ALR-) modifications. Next, we show how to use Kalman filter optimization to derive a novel adaptation law. This results in an optimization-based time-varying adaptation gain that reduces the need for adaptation gain tuning. A second major contribution of this dissertation is the development of a novel derivative-free, delayed weight update law for adaptive control. The assumption of constant unknown ideal weights is relaxed to the existence of time-varying weights, such that fast and possibly discontinuous variation in weights are allowed. This approach is particulary advantageous for applications to systems that can undergo a sudden change in dynamics, such as might be due to reconfiguration, deployment of a payload, docking, or structural damage, and for rejection of external disturbance processes. As a third and final contribution, we develop a novel approach for extending all the methods developed in this dissertation to the case of output feedback. The approach is developed only for the case of derivative-free adaptive control, and the extension of the other approaches developed previously for the state feedback case to output feedback is left as a future research topic. The proposed approaches of this dissertation are illustrated in both simulation and flight test.

Gain- and Loss-Related Brain Activation Are Associated with Information Search Differences in Risky Gambles: An fMRI and Eye-Tracking Study.

PubMed

Häusler, Alexander Niklas; Oroz Artigas, Sergio; Trautner, Peter; Weber, Bernd

2016-01-01

People differ in the way they approach and handle choices with unsure outcomes. In this study, we demonstrate that individual differences in the neural processing of gains and losses relates to attentional differences in the way individuals search for information in gambles. Fifty subjects participated in two independent experiments. Participants first completed an fMRI experiment involving financial gains and losses. Subsequently, they performed an eye-tracking experiment on binary choices between risky gambles, each displaying monetary outcomes and their respective probabilities. We find that individual differences in gain and loss processing relate to attention distribution. Individuals with a stronger reaction to gains in the ventromedial prefrontal cortex paid more attention to monetary amounts, while a stronger reaction in the ventral striatum to losses was correlated with an increased attention to probabilities. Reaction in the posterior cingulate cortex to losses was also found to correlate with an increased attention to probabilities. Our data show that individual differences in brain activity and differences in information search processes are closely linked.

Influence of porewidening duration on the template assisted growth of graphitic carbon nitride nanostructures

NASA Astrophysics Data System (ADS)

Suchitra, S. M.; Udayashankar, N. K.

2018-01-01

Porous anodic aluminium oxide (AAO) membranes with a highly ordered pore arrangement are typically used as ideal templates for the synthesis of numerous nanostructured materials. Highly ordered templates gained significant attraction due to the fact that they are readily fabricated through self-organised simple anodization process. In this paper, the effect of different pore-widening treatments on the quality of the pores of the AAO templates prepared with different electrolytes were inspected. Results confirmed that, without altering the interpore distance different pore dimensions and diameters of the AAO templates can be easily achieved by chemical pore widening process at room temperature. Also, graphitic carbon nitride nanorods of different dimension have been fabricated from AAO template after porewidening process. These nanostructures are widely used in case of metal free visible light driven photo catalysis, photo degradation of organic pollutants, photo electric conversion and water splitting applications.

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.

Mathematical Modeling of Decarburization in Levitated Fe-Cr-C Droplets

NASA Astrophysics Data System (ADS)

Gao, Lei; Shi, Zhe; Yang, Yindong; Li, Donghui; Zhang, Guifang; McLean, Alexander; Chattopadhyay, Kinnor

2018-04-01

Using carbon dioxide to replace oxygen as an alternative oxidant gas has proven to be a viable solution in the decarburization process, with potential for industrial applications. In a recent study, the transport phenomena governing the carbon dioxide decarburization process through the use of electromagnetic levitation (EML) was examined. CO2/CO mass transfer was found to be the principal reaction rate control step, as a result gas diffusion has gained significant attention. In the present study, gas diffusion during decarburization process was investigated using computational fluid dynamics (CFD) modeling coupled with chemical reactions. The resulting model was verified through experimental data in a published paper, and employed to provide insights on phenomena typically unobservable through experiments. Based on the results, a new correction of the Frössling equation was presented which better represents the mass transfer phenomena at the metal-gas interface within the range of this research.