Life and Operating Range Extension of the BPT-4000 Qualification Model Hall Thruster
NASA Technical Reports Server (NTRS)
Welander, Ben; Carpenter, Christian; deGrys, Kristi; Hofer, Richard R.; Randolph, Thomas M.; Manzella, David H.
2006-01-01
Following completion of the 5,600 hr qualification life test of the BPT-4000 4.5 kW Hall Thruster Propulsion System, NASA and Aerojet have undertaken efforts to extend the qualified operating range and lifetime of the thruster to support a wider range of NASA missions. The system was originally designed for orbit raising and stationkeeping applications on military and commercial geostationary satellites. As such, it was designed to operate over a range of power levels from 3 to 4.5 kW. Studies of robotic exploration applications have shown that the cost savings provided by utilizing commercial technology that can operate over a wider range of power levels provides significant mission benefits. The testing reported on here shows that the 4.5 kW thruster as designed has the capability to operate efficiently down to power levels as low as 1 kW. At the time of writing, the BPT-4000 qualification thruster and cathode have accumulated over 400 hr of operation between 1 to 2 kW with an additional 600 hr currently planned. The thruster has demonstrated no issues with longer duration operation at low power.
Solid oxide fuel cell operable over wide temperature range
Baozhen, Li; Ruka, Roswell J.; Singhal, Subhash C.
2001-01-01
Solid oxide fuel cells having improved low-temperature operation are disclosed. In one embodiment, an interfacial layer of terbia-stabilized zirconia is located between the air electrode and electrolyte of the solid oxide fuel cell. The interfacial layer provides a barrier which controls interaction between the air electrode and electrolyte. The interfacial layer also reduces polarization loss through the reduction of the air electrode/electrolyte interfacial electrical resistance. In another embodiment, the solid oxide fuel cell comprises a scandia-stabilized zirconia electrolyte having high electrical conductivity. The scandia-stabilized zirconia electrolyte may be provided as a very thin layer in order to reduce resistance. The scandia-stabilized electrolyte is preferably used in combination with the terbia-stabilized interfacial layer. The solid oxide fuel cells are operable over wider temperature ranges and wider temperature gradients in comparison with conventional fuel cells.
Forest operations for ecosystem management
Robert B. Rummer; John Baumgras; Joe McNeel
1997-01-01
The evolution of modern forest resource management is focusing on ecologically sensitive forest operations. This shift in management strategies is producing a new set of functional requirements for forest operations. Systems to implement ecosystem management prescriptions may need to be economically viable over a wider range of piece sizes, for example. Increasing...
Operations Management and Curriculum Design.
ERIC Educational Resources Information Center
Slack, Nigel
1983-01-01
The last few years have seen developments in the academic treatment of operations management which both broaden the subject to include a much wider range of industries in the nonmanufacturing sectors and place the operations function in a more strategic context. (MEAD Subscriptions, CSML, University of Lancaster, Lancaster LA1 4YX, England) (SSH)
Adjustable Tuning Spring for Bellows Pump
NASA Technical Reports Server (NTRS)
Green, G. L.; Tu Duc, D.; Hooper, S.
1985-01-01
Adjustable leaf spring increases maximum operating pressure of pump from 2 to over 60 psi (13 to over 400 kN/m2). Small commercial bellows pump using ac-powered electromagnet to vibrate bellows at mechanical resonance modified to operate over wider pressure range.
A Model for Evaluating Tactually Assistive Devices.
ERIC Educational Resources Information Center
Terrio, Lee; Haas, William
1986-01-01
Audiometric instruments and techniques adopted to measure tactual cueing characteristics of the Radioear B70A and the Siemens Fonator electromechanical vibrators were used by young adults. The Siemens Phonator demonstrated a wider suprathreshold operating range than did the Radioear B70A. (Author/CL)
Coupling of Transport and Chemical Processes in Catalytic Combustion
NASA Technical Reports Server (NTRS)
Bracco, F. V.; Bruno, C.; Royce, B. S. H.; Santavicca, D. A.; Sinha, N.; Stein, Y.
1983-01-01
Catalytic combustors have demonstrated the ability to operate efficiently over a much wider range of fuel air ratios than are imposed by the flammability limits of conventional combustors. Extensive commercial use however needs the following: (1) the design of a catalyst with low ignition temperature and high temperature stability, (2) reducing fatigue due to thermal stresses during transient operation, and (3) the development of mathematical models that can be used as design optimization tools to isolate promising operating ranges for the numerous operating parameters. The current program of research involves the development of a two dimensional transient catalytic combustion model and the development of a new catalyst with low temperature light-off and high temperature stablity characteristics.
Interfacial material for solid oxide fuel cell
Baozhen, Li; Ruka, Roswell J.; Singhal, Subhash C.
1999-01-01
Solid oxide fuel cells having improved low-temperature operation are disclosed. In one embodiment, an interfacial layer of terbia-stabilized zirconia is located between the air electrode and electrolyte of the solid oxide fuel cell. The interfacial layer provides a barrier which controls interaction between the air electrode and electrolyte. The interfacial layer also reduces polarization loss through the reduction of the air electrode/electrolyte interfacial electrical resistance. In another embodiment, the solid oxide fuel cell comprises a scandia-stabilized zirconia electrolyte having high electrical conductivity. The scandia-stabilized zirconia electrolyte may be provided as a very thin layer in order to reduce resistance. The scandia-stabilized electrolyte is preferably used in combination with the terbia-stabilized interfacial layer. The solid oxide fuel cells are operable over wider temperature ranges and wider temperature gradients in comparison with conventional fuel cells.
NASA Astrophysics Data System (ADS)
Li, Xin; Liang, Ji; Zhang, Hongxiang; Yang, Xing; Zhang, Hao; Pang, Wei; Zhang, Menglun
2017-06-01
This paper reports an uncooled infrared (IR) detector based on a micromachined piezoelectric resonator operating in resonant and resistive dual-modes. The two sensing modes achieved IR responsivities of 2.5 Hz/nW and 900 μdB/nW, respectively. Compared with the single mode operation, the dual-mode measurement improves the limit of detection by two orders of magnitude and meanwhile maintains high linearity and responsivity in a higher IR intensity range. A combination of the two sensing modes compensates for its own shortcomings and provides a much larger dynamic range, and thus, a wider application field of the proposed detector is realized.
NASA Astrophysics Data System (ADS)
Barazzetti, L.; Banfi, F.; Brumana, R.; Oreni, D.; Previtali, M.; Roncoroni, F.
2015-08-01
This paper describes a procedure for the generation of a detailed HBIM which is then turned into a model for mobile apps based on augmented and virtual reality. Starting from laser point clouds, photogrammetric data and additional information, a geometric reconstruction with a high level of detail can be carried out by considering the basic requirements of BIM projects (parametric modelling, object relations, attributes). The work aims at demonstrating that a complex HBIM can be managed in portable devices to extract useful information not only for expert operators, but also towards a wider user community interested in cultural tourism.
Combustion interaction with radiation-cooled chambers
NASA Technical Reports Server (NTRS)
Rosenberg, S. D.; Jassowski, D. M.; Barlow, R.; Lucht, R.; Mccarty, K.
1990-01-01
Over 15 hours of thruster operation at temperatures between 1916 and 2246 C without failure or erosion has been demonstrated using iridium-coated rhenium chamber materials with nitrogen tetroxide/monomethylhydrazine propellants operating over a mixture ratio range of 1.60-2.05. Research is now under way to provide a basic understanding of the mechanisms which make high-temperature operation possible and to extend the capability to a wider range of conditions, including other propellant combinations and chamber materials. Techniques have been demonstrated for studying surface fracture phenomena. These include surface Raman and Auger for study of oxide formation, surface Raman and X-ray diffraction to determine the oxide phase, Auger to study oxide stoichiometry, and sputter Auger to study interdiffusion of alloy species.
The Control Principles of the Wind Energy Based DC Microgrid
NASA Astrophysics Data System (ADS)
Zaleskis, G.; Rankis, I.
2018-04-01
According to the strategical objectives of the use of the renewable energy sources, it is important to minimise energy consumption of conventional power grid by effective use of the renewable energy sources and provi-ding stable operation of the consumers. The main aim of research is to develop technical solutions that can provide effective operation of the wind generators in the small power DC microgrids, which also means wind energy conversion at as wider generator speed range as possible.
Burners and combustion apparatus for carbon nanomaterial production
Alford, J. Michael; Diener, Michael D; Nabity, James; Karpuk, Michael
2013-02-05
The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.
Burners and combustion apparatus for carbon nanomaterial production
Alford, J. Michael; Diener, Michael D.; Nabity, James; Karpuk, Michael
2007-10-09
The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.
An Optimized Control for LLC Resonant Converter with Wide Load Range
NASA Astrophysics Data System (ADS)
Xi, Xia; Qian, Qinsong
2017-05-01
This paper presents an optimized control which makes LLC resonant converters operate with a wider load range and provides good closed-loop performance. The proposed control employs two paralleled digital compensations to guarantee the good closed-loop performance in a wide load range during the steady state, an optimized trajectory control will take over to change the gate-driving signals immediately at the load transients. Finally, the proposed control has been implemented and tested on a 150W 200kHz 400V/24V LLC resonant converter and the result validates the proposed method.
High temperature ion source for an on-line isotope separator
Mlekodaj, Ronald L.
1979-01-01
A reduced size ion source for on-line use with a cyclotron heavy-ion beam is provided. A sixfold reduction in source volume while operating with similar input power levels results in a 2000.degree. C. operating temperature. A combined target/window normally provides the reaction products for ionization while isolating the ion source plasma from the cyclotron beam line vacuum. A graphite felt catcher stops the recoiling reaction products and releases them into the plasma through diffusion and evaporation. Other target arrangements are also possible. A twenty-four hour lifetime of unattended operation is achieved, and a wider range of elements can be studied than was heretofore possible.
Development of a para-orthohydrogen catalytic converter for a solid hydrogen cooler
NASA Technical Reports Server (NTRS)
Nast, T. C.; Hsu, I. C.
1984-01-01
Design features of a tested catalytic converter for altering vented cryogenic parahydrogen used as a coolant on spacecraft into a para-ortho equilibrium for channeling to other cooling functions are described. The hydrogen is expected to be stored in either liquid or solid form. A high surface area Ni-on-Si catalyst was selected for tests at an operating pressure of 2 torr at a ratio of 1000 gr catalyst for a gr/sec hydrogen flow. Cylindrical and radial flow geometries were tried and measurements centered on the converter efficiencies at different operating temperatures when the converter was placed in the vent line of the H2 cooler. Efficiencies ranging from 10-100 percent were obtained for varying flow rates. Further testing is necessary to characterize the converter performance under a wider range of operating temperatures and environments.
Design and Implementation of a new Autonomous Sensor Fish to Support Advanced Hydropower Development
Deng, Zhiqun; Lu, Jun; Myjak, Mitchell J.; ...
2014-11-04
Acceleration in development of additional conventional hydropower requires tools and methods to perform laboratory and in-field validation of turbine performance and fish passage claims. The new-generation Sensor Fish has been developed with more capabilities to accommodate a wider range of users over a wider range of turbine designs and operating environments. It provides in situ measurements of three dimensional (3D) accelerations, 3D rotational velocities, 3D orientation, pressure, and temperature at a sampling frequency of 2048 Hz. It also has an automatic floatation system and built-in radio frequency transmitter for recovery. The relative errors of the pressure, acceleration and rotational velocitymore » were within ±2%, ±5%, and ±5%, respectively. The accuracy of orientation was within ±4° and accuracy of temperature was ±2°C. It is being deployed to evaluate the biological effects of turbines or other hydraulic structures in several countries.« less
Wavelength interrogation of fiber Bragg grating sensors based on crossed optical Gaussian filters.
Cheng, Rui; Xia, Li; Zhou, Jiaao; Liu, Deming
2015-04-15
Conventional intensity-modulated measurements require to be operated in linear range of filter or interferometric response to ensure a linear detection. Here, we present a wavelength interrogation system for fiber Bragg grating sensors where the linear transition is achieved with crossed Gaussian transmissions. This unique filtering characteristic makes the responses of the two branch detections follow Gaussian functions with the same parameters except for a delay. The substraction of these two delayed Gaussian responses (in dB) ultimately leads to a linear behavior, which is exploited for the sensor wavelength determination. Beside its flexibility and inherently power insensitivity, the proposal also shows a potential of a much wider operational range. Interrogation of a strain-tuned grating was accomplished, with a wide sensitivity tuning range from 2.56 to 8.7 dB/nm achieved.
ERIC Educational Resources Information Center
Brock, Jack L., Jr.
This testimony discusses ways in which some federal government agencies use technology to provide the public with cheaper, faster access to a wider range of information which can be searched and manipulated in ways never possible on the printed page. Technologies included in the discussion are compact disc-read only memory (CD-ROM), electronic…
ERIC Educational Resources Information Center
Bottani, Norberto; And Others
The educational indicators in this report show how education systems in the 24 member countries of the Organisation for Economic Co-Operation and Development (OECD) resemble each other and differ. This edition, the second, builds on the 1992 volume, with more up-to-date figures and coverage of a wider range of subjects and countries. The 38…
Operation and tests of a DDC101 A/D
NASA Astrophysics Data System (ADS)
Nguyen, H.
1994-11-01
For the KTeV PMT laser monitoring system, one needs a high resolution device with a large dynamic range to be used for digitizing PIN photodiodes. The dynamic range should be wider than or comparable to the KTeV digitizer (17-bits). The Burr-Brown DDC101 is a precision, wide dynamic range, charge digitizing A/D converter with 20-bit resolution, packaged in a 28-pin plastic, double-wide DP. Low level current output devices such as photosensors can be directly connected to its input. The digital output can be clocked-out serially from the pins. For typical operations, a relatively wide gate of 1 msec should be used. The full scale charge is 500 pC for unipolar mode. The bipolar mode scale is +/- 250 pC. The advertised integral nonlinearity is 0.003% of FSR. This document describes only the basic DDC101 operations since full detail can be found in the DDC101 manual. Tests results are given in section 3.
DOT National Transportation Integrated Search
2011-09-30
This study analyzes the influence of several site characteristics on the operational behavior of motorists when passing bicyclists on wider outside through lanes. More than 2000 videotaped passing events were analyzed. Several measures of effectivene...
All optical reconfiguration of optomechanical filters.
Deotare, Parag B; Bulu, Irfan; Frank, Ian W; Quan, Qimin; Zhang, Yinan; Ilic, Rob; Loncar, Marko
2012-05-22
Reconfigurable optical filters are of great importance for applications in optical communication and information processing. Of particular interest are tuning techniques that take advantage of mechanical deformation of the devices, as they offer wider tuning range. Here we demonstrate reconfiguration of coupled photonic crystal nanobeam cavities by using optical gradient force induced mechanical actuation. Propagating waveguide modes that exist over a wide wavelength range are used to actuate the structures and control the resonance of localized cavity modes. Using this all-optical approach, more than 18 linewidths of tuning range is demonstrated. Using an on-chip temperature self-referencing method, we determine that 20% of the total tuning was due to optomechanical reconfiguration and the rest due to thermo-optic effects. By operating the device at frequencies higher than the thermal cutoff, we show high-speed operation dominated by just optomechanical effects. Independent control of mechanical and optical resonances of our structures is also demonstrated.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kaminski, Adam
A method and apparatus to generate harmonically related laser wavelengths includes a pair of lenses at opposing faces of a non-linear optical material. The lenses are configured to promote incoming and outgoing beams to be normal to each outer lens surface over a range of acceptance angles of the incoming laser beam. This reduces reflection loss for higher efficiency operation. Additionally, the lenses allow a wider range of wavelengths for lasers for more universal application. Examples of the lenses include plano-cylindrical and plano-spherical form factors.
Spatiotemporal chaos of fractional order logistic equation in nonlinear coupled lattices
NASA Astrophysics Data System (ADS)
Zhang, Ying-Qian; Wang, Xing-Yuan; Liu, Li-Yan; He, Yi; Liu, Jia
2017-11-01
We investigate a new spatiotemporal dynamics with fractional order differential logistic map and spatial nonlinear coupling. The spatial nonlinear coupling features such as the higher percentage of lattices in chaotic behaviors for most of parameters and none periodic windows in bifurcation diagrams are held, which are more suitable for encryptions than the former adjacent coupled map lattices. Besides, the proposed model has new features such as the wider parameter range and wider range of state amplitude for ergodicity, which contributes a wider range of key space when applied in encryptions. The simulations and theoretical analyses are developed in this paper.
Spacelab energetic ion mass spectrometer
NASA Technical Reports Server (NTRS)
Whalen, B. A.; Mcdiarmid, I. B.; Burrows, J. R.; Sharp, R. D.; Johnson, R. G.; Shelley, E. G.
1980-01-01
Basic design criteria are given for an ion mass spectrometer for use in studying magnetospheric ion populations. The proposed instrument is composed of an electrostatic analyzer followed by a magnetic spectrometer and simultaneously measures the energy per unit and mass per unit charge of the ion species. An electromagnet is used for momentum analysis to extend the operational energy range over a much wider domain than is possible with the permanent magnets used in previous flights. The energetic ion source regions, ion energization mechanisms, field line tracing, coordinated investigations, and orbit considerations are discussed and operations of the momentum analyzer and of the electrostatic energy analyzer are examined.
Accelerated design of bioconversion processes using automated microscale processing techniques.
Lye, Gary J; Ayazi-Shamlou, Parviz; Baganz, Frank; Dalby, Paul A; Woodley, John M
2003-01-01
Microscale processing techniques are rapidly emerging as a means to increase the speed of bioprocess design and reduce material requirements. Automation of these techniques can reduce labour intensity and enable a wider range of process variables to be examined. This article examines recent research on various individual microscale unit operations including microbial fermentation, bioconversion and product recovery techniques. It also explores the potential of automated whole process sequences operated in microwell formats. The power of the whole process approach is illustrated by reference to a particular bioconversion, namely the Baeyer-Villiger oxidation of bicyclo[3.2.0]hept-2-en-6-one for the production of optically pure lactones.
Behaviour of fractional loop delay zero crossing digital phase locked loop (FR-ZCDPLL)
NASA Astrophysics Data System (ADS)
Nasir, Qassim
2018-01-01
This article analyses the performance of the first-order zero crossing digital phase locked loops (FR-ZCDPLL) when fractional loop delay is added to loop. The non-linear dynamics of the loop is presented, analysed and examined through bifurcation behaviour. Numerical simulation of the loop is conducted to proof the mathematical analysis of the loop operation. The results of the loop simulation show that the proposed FR-ZCDPLL has enhanced the performance compared to the conventional zero crossing DPLL in terms of wider lock range, captured range and stable operation region. In addition, extensive experimental simulation was conducted to find the optimum loop parameters for different loop environmental conditions. The addition of the fractional loop delay network in the conventional loop also reduces the phase jitter and its variance especially when the signal-to-noise ratio is low.
NASA Technical Reports Server (NTRS)
Gazzaniga, John A.; Rose, Gayle E.
1992-01-01
Tests of swirl recovery vanes designed for use in conjunction with advanced high speed propellers were carried out at the NASA Lewis Research Center. The eight bladed 62.23 cm vanes were tested with a 62.23 cm SR = 7A high speed propeller in the NASA Lewis 2.44 x 1.83 m Supersonic Wind Tunnel for a Mach number range of 0.60 to 0.80. At the design operating condition for cruise of Mach 0.80 at an advance ratio of 3.26, the vane contribution to the total efficiency approached 2 percent. At lower off-design Mach numbers, the vane efficiency is even higher, approaching 4.5 percent for the Mach 0.60 condition. Use of the swirl recovery vanes essentially shifts the peak of the high speed propeller efficiency to a higher operating speed. This allows a greater degree of freedom in the selection of rpm over a wider operating range. Another unique result of the swirl recovery vane configuration is their essentially constant torque split between the propeller and the swirl vanes over a wide range of operating conditions for the design vane angle.
FIR digital filter-based ZCDPLL for carrier recovery
NASA Astrophysics Data System (ADS)
Nasir, Qassim
2016-04-01
The objective of this work is to analyse the performance of the newly proposed two-tap FIR digital filter-based first-order zero-crossing digital phase-locked loop (ZCDPLL) in the absence or presence of additive white Gaussian noise (AWGN). The introduction of the two-tap FIR digital filter widens the lock range of a ZCDPLL and improves the loop's operation in the presence of AWGN. The FIR digital filter tap coefficients affect the loop convergence behaviour and appropriate selection of those gains should be taken into consideration. The new proposed loop has wider locking range and faster acquisition time and reduces the phase error variations in the presence of noise.
Vaughn, Mark R.; Robinett, III, Rush D.; Phelan, John R.; Van Zuiden, Don M.
1997-01-21
A new class of coplanar two-axis angular effectors. These effectors combine a two-axis rotational joint analogous to a Cardan joint with linear actuators in a manner to produce a wider range of rotational motion about both axes defined by the joint. This new class of effectors also allows design of robotic manipulators having very high strength and efficiency. These effectors are particularly suited for remote operation in unknown surroundings, because of their extraordinary versatility. An immediate application is to the problems which arise in nuclear waste remediation.
Diurnal evolution of wind structure and data availability measured by the DOE prototype radar system
NASA Astrophysics Data System (ADS)
Hirth, Brian D.; Schroeder, John L.; Guynes, Jerry G.
2017-11-01
A new Doppler radar prototype has been developed and deployed at Texas Tech University with a focus on enhancing the technologies’ capability to contribute to wind plant relevant complex flow measurements. In particular, improvements in data availability, total data coverage, and autonomous operation were targeted to enable contributions to a wider range of wind energy applications. Doppler radar offers rapid scan speeds, extended maximum range and excellent along-beam range resolution allowing for the simultaneous measurement of various wind phenomena ranging from regional and wind plant scales to inflow and wake flow assessment for an individual turbine. Data examples and performance improvements relative to a previous edition of the technology are presented, including insights into the influence of diurnal atmospheric stability evolution of wind structure and system performance.
Stabilizing detached Bridgman melt crystal growth: Model-based nonlinear feedback control
NASA Astrophysics Data System (ADS)
Yeckel, Andrew; Daoutidis, Prodromos; Derby, Jeffrey J.
2012-12-01
The dynamics and operability limits of a nonlinear-proportional-integral controller designed to stabilize detached vertical Bridgman crystal growth are studied. The manipulated variable is the pressure difference between upper and lower vapor spaces, and the controlled variable is the gap width at the triple-phase line. The controller consists of a model-based nonlinear component coupled with a standard proportional-integral controller. The nonlinear component is based on a capillary model of shape stability. Perturbations to gap width, pressure difference, wetting angle, and growth angle are studied under both shape stable and shape unstable conditions. The nonlinear-PI controller allows a wider operating range of gain than a standard PI controller used alone, is easier to tune, and eliminates solution multiplicity from closed-loop operation.
NASA Astrophysics Data System (ADS)
Tanoi, Satoru; Endoh, Tetsuo
2012-04-01
A wide-range tunable level-keeper using vertical metal-oxide-semiconductor field-effect transistors (MOSFETs) is proposed for current-reuse analog systems. The design keys for widening tunable range of the operation are a two-path feed-back and a vertical MOSFET with back-bias-effect free. The proposed circuit with the vertical MOSFETs shows the 1.23-V tunable-range of the input level with the 2.4-V internal-supply voltage (VDD) in the simulation. This tunable-range of the proposed circuit is 4.7 times wider than that of the conventional. The achieved current efficiency of the proposed level-keeper is 66% at the 1.2-V output with the 2.4-V VDD. This efficiency of the proposed circuit is twice higher than that of the traditional voltage down converter.
Code of Federal Regulations, 2010 CFR
2010-07-01
... operation of motorboats and yachts. (c) Foster a wider knowledge of, and better compliance with, the laws, rules, and regulations governing the operation of motorboats and yachts. (d) Facilitate other operations...
Code of Federal Regulations, 2011 CFR
2011-07-01
... operation of motorboats and yachts. (c) Foster a wider knowledge of, and better compliance with, the laws, rules, and regulations governing the operation of motorboats and yachts. (d) Facilitate other operations...
Interactive Classification Technology
NASA Technical Reports Server (NTRS)
deBessonet, Cary
2000-01-01
The investigators upgraded a knowledge representation language called SL (Symbolic Language) and an automated reasoning system called SMS (Symbolic Manipulation System) to enable the more effective use of the technologies in automated reasoning and interactive classification systems. The overall goals of the project were: 1) the enhancement of the representation language SL to accommodate a wider range of meaning; 2) the development of a default inference scheme to operate over SL notation as it is encoded; and 3) the development of an interpreter for SL that would handle representations of some basic cognitive acts and perspectives.
Flow Range of Centrifugal Compressor Being Extended
NASA Technical Reports Server (NTRS)
Skoch, Gary J.
2001-01-01
General Aviation will benefit from turbine engines that are both fuel-efficient and reliable. Current engines fall short of their potential to achieve these attributes. The reason is compressor surge, which is a flow stability problem that develops when the compressor is subjected to conditions that are outside of its operating range. Compressor surge can occur when fuel flow to the engine is increased, temporarily back pressuring the compressor and pushing it past its stability limit, or when the compressor is subjected to inlet flow-field distortions that may occur during takeoff and landing. Compressor surge can result in the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. Unfortunately, the most efficient operating line for the compressor is usually closer to its stability limit line than it is to the line that provides an adequate margin of safety. A wider stable flow range will permit operation along the most efficient operating line of the compressor, improving the specific fuel consumption of the engine and reducing emissions. The NASA Glenn Research Center is working to extend the stable flow range of the compressor. Significant extension has been achieved in axial compressors by injecting air upstream of the compressor blade rows. Recently, the technique was successfully applied to a 4:1 pressure ratio centrifugal compressor by injecting streams of air into the diffuser. Both steady and controlled unsteady injection were used to inject air through the diffuser shroud surface and extend the range. Future work will evaluate the effect of air injection through the diffuser hub surface and diffuser vanes with the goal of maximizing the range extension while minimizing the amount of injected air that is required.
Comparison of microtweezers based on three lateral thermal actuator configurations
NASA Astrophysics Data System (ADS)
Luo, J. K.; Flewitt, A. J.; Spearing, S. M.; Fleck, N. A.; Milne, W. I.
2005-06-01
Thermal actuator-based microtweezers with three different driving configurations have been designed, fabricated and characterized. Finite element analysis has been used to model the device performance. It was found that one configuration of microtweezer, based on two lateral bimorph thermal actuators, has a small displacement (tip opening of the tweezers) and a very limited operating power range. An alternative configuration consisting of two horizontal hot bars with separated beams as the arms can deliver a larger displacement with a much-extended operating power range. This structure can withstand a higher temperature due to the wider beams used, and has flexible arms for increased displacement. Microtweezers driven by a number of chevron structures in parallel have similar maximum displacements but at a cost of higher power consumption. The measured temperature of the devices confirms that the device with the chevron structure can deliver the largest displacement for a given working temperature, while the bimorph thermal actuator design has the highest operating temperature at the same power due to its thin hot arm, and is prone to structural failure.
NASA Technical Reports Server (NTRS)
Hunt, Mitchell; Sayyah, Rana; Mitchell, Cody; Laws, Crystal; MacLeod, Todd C.; Ho, Fat D.
2013-01-01
Collected data for both common-source and common-gate amplifiers is presented in this paper. Characterizations of the two amplifier circuits using metal-ferroelectric-semiconductor field effect transistors (MFSFETs) are developed with wider input frequency ranges and varying device sizes compared to earlier characterizations. The effects of the ferroelectric layer's capacitance and variation load, quiescent point, or input signal on each circuit are discussed. Comparisons between the MFSFET and MOSFET circuit operation and performance are discussed at length as well as applications and advantages for the MFSFETs.
Operation of a New COTS Crystal Oscillator - CXOMHT over a Wide Temperature Range
NASA Technical Reports Server (NTRS)
Patterson, Richard; Hammoud, Ahmad
2011-01-01
Crystal oscillators are extensively used in electronic circuits to provide timing or clocking signals in data acquisition, communications links, and control systems, to name a few. They are affordable, small in size, and reliable. Because of the inherent characteristics of the crystal, the oscillator usually exhibits extreme accuracy in its output frequency within the intrinsic crystal stability. Stability of the frequency could be affected under varying load levels or other operational conditions. Temperature is one of those important factors that influence the frequency stability of an oscillator; as it does to the functionality of other electronic components. Electronics designed for use in NASA deep space and planetary exploration missions are expected to be exposed to extreme temperatures and thermal cycling over a wide range. Thus, it is important to design and develop circuits that are able to operate efficiently and reliably under in these harsh temperature environments. Most of the commercial-off-the-shelf (COTS) devices are very limited in terms of their specified operational temperature while very few custom-made commercial and military-grade parts have the ability to operate in a slightly wider range of temperature than those of the COTS parts. These parts are usually designed for operation under one temperature extreme, i.e. hot or cold, and do not address the wide swing in the operational temperature, which is typical of the space environment. For safe and successful space missions, electronic systems must therefore be designed not only to withstand the extreme temperature exposure but also to operate efficiently and reliably. This report presents the results obtained on the evaluation of a new COTS crystal oscillator under extreme temperatures.
Reverse Engineering and 3d Modelling for Digital Documentation of Maritime Heritage
NASA Astrophysics Data System (ADS)
Menna, F.; Nocerino, E.; Scamardella, A.
2011-09-01
heritage in general. Despite this has been stressed with emphasis, three dimensional modelling of maritime cultural heritage is still not usual as for archaeology and architecture. Three-dimensional modelling in the maritime heritage needs particular requirements. Objects to be recorded range from small replicas in maritime museums up to full-scale vessels still in operation. High geometric accuracy, photorealism of final model and faithful rendering of salient details are usually needed, together with the classical requisites characterising the 3D modelling-from-reality process, i.e. automation, low cost, reliability and flexibility of the modelling technique. In this paper, a hybrid multi-technique approach is proposed for maritime heritage preservation and, as case study, the 3D modelling of a 3-meter-long scale model of a historic warship, the "Indomito", is presented. The survey is placed in a wider project aiming to realize the virtual maritime museum of Parthenope University of Naples, for making it available to a wider public and also preserving its cultural heritage. Preliminary results are presented and discussed, highlighting relevant aspects that emerged during the experiment.
Polylactides in additive biomanufacturing.
Poh, Patrina S P; Chhaya, Mohit P; Wunner, Felix M; De-Juan-Pardo, Elena M; Schilling, Arndt F; Schantz, Jan-Thorsten; van Griensven, Martijn; Hutmacher, Dietmar W
2016-12-15
New advanced manufacturing technologies under the alias of additive biomanufacturing allow the design and fabrication of a range of products from pre-operative models, cutting guides and medical devices to scaffolds. The process of printing in 3 dimensions of cells, extracellular matrix (ECM) and biomaterials (bioinks, powders, etc.) to generate in vitro and/or in vivo tissue analogue structures has been termed bioprinting. To further advance in additive biomanufacturing, there are many aspects that we can learn from the wider additive manufacturing (AM) industry, which have progressed tremendously since its introduction into the manufacturing sector. First, this review gives an overview of additive manufacturing and both industry and academia efforts in addressing specific challenges in the AM technologies to drive toward AM-enabled industrial revolution. After which, considerations of poly(lactides) as a biomaterial in additive biomanufacturing are discussed. Challenges in wider additive biomanufacturing field are discussed in terms of (a) biomaterials; (b) computer-aided design, engineering and manufacturing; (c) AM and additive biomanufacturing printers hardware; and (d) system integration. Finally, the outlook for additive biomanufacturing was discussed. Copyright © 2016 Elsevier B.V. All rights reserved.
'Systemic Failures' and 'Human Error' in Canadian TSB Aviation Reports Between 1996 and 2002
NASA Technical Reports Server (NTRS)
Holloway, C. M.; Johnson, C. W.
2004-01-01
This paper describes the results of an independent analysis of the primary and contributory causes of aviation accidents in Canada between 1996 and 2003. The purpose of the study was to assess the comparative frequency of a range of causal factors in the reporting of these adverse events. Our results suggest that the majority of these high consequence accidents were attributed to human error. A large number of reports also mentioned wider systemic issues, including the managerial and regulatory context of aviation operations. These issues are more likely to appear as contributory rather than primary causes in this set of accident reports.
ODES (Online Data Extraction Service) for hydrology
NASA Astrophysics Data System (ADS)
Rosmorduc, Vinca; Birol, Florence; Briol, Frederic; Bronner, Emilie; Dibarboure, Gerald; Guinle, Thierry; Nicolas, Clara; Nino, Fernando; Valladeau, Guillaume
2015-04-01
AVISO+ proposes a new dissemination service, the Online Data Extraction Service (ODES), in order to provide users and applications with a wider range of altimetry-derived data (including high-resolution and experimental data). The platform is designed to distribute both operational products from CNES and partner Agencies (Eumetsat, ESA, NOAA, NASA) but also research-grade data from LEGOS/CTOH and CLS and other contributions from the OSTST research community. An example of use of ODES to extract hydrology experimental expert product (from Pistach processor) for hydrology will be shown. ODES is available at http://odes.altimetry.cnes.fr, download with your Aviso FTP login / password.
ODES (Online Data Extraction Service) for cryosphere studies
NASA Astrophysics Data System (ADS)
Rosmorduc, Vinca; Birol, Florence; Briol, Frederic; Bronner, Emilie; Dibarboure, Gerald; Guinle, Thierry; Nicolas, Clara; Nino, Fernando; Valladeau, Guillaume
2015-04-01
AVISO+ proposes a new dissemination service, the Online Data Extraction Service (ODES), in order to provide users and applications with a wider range of altimetry-derived data (including high-resolution and experimental data). The platform is designed to distribute both operational products from CNES and partner Agencies (Eumetsat, ESA, NOAA, NASA) but also research-grade data from LEGOS/CTOH and CLS and other contributions from the OSTST research community. An example of the use of ODES to extract AltiKa experimental expert products (from PEACHI prototype) over iced areas will be shown. ODES is available at http://odes.altimetry.cnes.fr, download with your Aviso FTP login / password.
Hyperspectral imaging using the single-pixel Fourier transform technique
NASA Astrophysics Data System (ADS)
Jin, Senlin; Hui, Wangwei; Wang, Yunlong; Huang, Kaicheng; Shi, Qiushuai; Ying, Cuifeng; Liu, Dongqi; Ye, Qing; Zhou, Wenyuan; Tian, Jianguo
2017-03-01
Hyperspectral imaging technology is playing an increasingly important role in the fields of food analysis, medicine and biotechnology. To improve the speed of operation and increase the light throughput in a compact equipment structure, a Fourier transform hyperspectral imaging system based on a single-pixel technique is proposed in this study. Compared with current imaging spectrometry approaches, the proposed system has a wider spectral range (400-1100 nm), a better spectral resolution (1 nm) and requires fewer measurement data (a sample rate of 6.25%). The performance of this system was verified by its application to the non-destructive testing of potatoes.
Grassineau, N V; Nisbet, E G; Bickle, M J; Fowler, C M; Lowry, D; Mattey, D P; Abell, P; Martin, A
2001-01-01
Sulphur and carbon isotopic analyses on small samples of kerogens and sulphide minerals from biogenic and non-biogenic sediments of the 2.7 x 10(9) years(Ga)-old Belingwe Greenstone Belt (Zimbabwe) imply that a complex biological sulphur cycle was in operation. Sulphur isotopic compositions display a wider range of biological fractionation than hitherto reported from the Archaean. Carbon isotopic values in kerogen record fractionations characteristic of rubisco activity methanogenesis and methylotrophy and possibly anoxygenic photosynthesis. Carbon and sulphur isotopic fractionations have been interpreted in terms of metabolic processes in 2.7 Ga prokaryote mat communities, and indicate the operation of a diverse array of metabolic processes. The results are consistent with models of early molecular evolution derived from ribosomal RNA. PMID:11209879
Making Co-Operative Ideas Work
ERIC Educational Resources Information Center
Arnold, Phil
2013-01-01
Reddish Vale Technology College was the first co-operative trust in England. The democratic and co-operative nature of the experiment mean that students have gained a greater voice in the organisation of the school. As a result, new social enterprises, environmental interventions, connections with the community and with the wider co-operative…
The pasty propellant rocket engine development
NASA Astrophysics Data System (ADS)
Kukushkin, V. I.; Ivanchenko, A. N.
1993-06-01
The paper describes a newly developed pasty propellant rocket engine (PPRE) and the combustion process and presents results of performance tests. It is shown that, compared with liquid propellant rocket engines, the PPREs can regulate the thrust level within a wider range, are safer ecologically, and have better weight characteristics. Compared with solid propellant rocket engines, the PPREs may be produced with lower costs and more safely, are able to regulate thrust performance within a wider range, and are able to offer a greater scope for the variation of the formulation components and propellant characteristics. Diagrams of the PPRE are included.
Electronic brachytherapy—current status and future directions
2015-01-01
In the past decade, electronic brachytherapy (EB) has emerged as an attractive modality for the treatment of skin lesions and intraoperative partial breast irradiation, as well as finding wider applications in intracavitary and interstitial sites. These miniature X-ray sources, which operate at low kilovoltage energies (<100 kV), have reduced shielding requirements and inherent portability, therefore can be used outside the traditional realms of the radiotherapy department. However, steep dose gradients and increased sensitivity to inhomogeneities challenge accurate dosimetry. Secondly, ease of use does not mitigate the need for close involvement by medical physics experts and consultant oncologists. Finally, further studies are needed to relate the more heterogeneous dose distributions to clinical outcomes. With these provisos, the practical convenience of EB strongly suggests that it will become an established option for selected patients, not only in radiotherapy departments but also in a range of operating theatres and clinics around the world. PMID:25748070
Hypersonic Wind Tunnel Calibration Using the Modern Design of Experiments
NASA Technical Reports Server (NTRS)
Rhode, Matthew N.; DeLoach, Richard
2005-01-01
A calibration of a hypersonic wind tunnel has been conducted using formal experiment design techniques and response surface modeling. Data from a compact, highly efficient experiment was used to create a regression model of the pitot pressure as a function of the facility operating conditions as well as the longitudinal location within the test section. The new calibration utilized far fewer design points than prior experiments, but covered a wider range of the facility s operating envelope while revealing interactions between factors not captured in previous calibrations. A series of points chosen randomly within the design space was used to verify the accuracy of the response model. The development of the experiment design is discussed along with tactics used in the execution of the experiment to defend against systematic variation in the results. Trends in the data are illustrated, and comparisons are made to earlier findings.
MRI-guided robotics at the U of Houston: evolving methodologies for interventions and surgeries.
Tsekos, Nikolaos V
2009-01-01
Currently, we witness the rapid evolution of minimally invasive surgeries (MIS) and image guided interventions (IGI) for offering improved patient management and cost effectiveness. It is well recognized that sustaining and expand this paradigm shift would require new computational methodology that integrates sensing with multimodal imaging, actively controlled robotic manipulators, the patient and the operator. Such approach would include (1) assessing in real-time tissue deformation secondary to the procedure and physiologic motion, (2) monitoring the tool(s) in 3D, and (3) on-the-fly update information about the pathophysiology of the targeted tissue. With those capabilities, real time image guidance may facilitate a paradigm shift and methodological leap from "keyhole" visualization (i.e. endoscopy or laparoscopy) to one that uses a volumetric and informational rich perception of the Area of Operation (AoO). This capability may eventually enable a wider range and level of complexity IGI and MIS.
Cost (non)-recovery by platform technology facilities in the Bio21 Cluster.
Gibbs, Gerard; Clark, Stella; Quinn, Julieanne; Gleeson, Mary Joy
2010-04-01
Platform technologies (PT) are techniques or tools that enable a range of scientific investigations and are critical to today's advanced technology research environment. Once installed, they require specialized staff for their operations, who in turn, provide expertise to researchers in designing appropriate experiments. Through this pipeline, research outputs are raised to the benefit of the researcher and the host institution. Platform facilities provide access to instrumentation and expertise for a wide range of users beyond the host institution, including other academic and industry users. To maximize the return on these substantial public investments, this wider access needs to be supported. The question of support and the mechanisms through which this occurs need to be established based on a greater understanding of how PT facilities operate. This investigation was aimed at understanding if and how platform facilities across the Bio21 Cluster meet operating costs. Our investigation found: 74% of platforms surveyed do not recover 100% of direct operating costs and are heavily subsidized by their home institution, which has a vested interest in maintaining the technology platform; platform managers play a major role in establishing the costs and pricing of the facility, normally in a collaborative process with a management committee or institutional accountant; and most facilities have a three-tier pricing structure recognizing internal academic, external academic, and commercial clients.
Cost (Non)-Recovery by Platform Technology Facilities in the Bio21 Cluster
Gibbs, Gerard; Clark, Stella; Quinn, JulieAnne; Gleeson, Mary Joy
2010-01-01
Platform technologies (PT) are techniques or tools that enable a range of scientific investigations and are critical to today's advanced technology research environment. Once installed, they require specialized staff for their operations, who in turn, provide expertise to researchers in designing appropriate experiments. Through this pipeline, research outputs are raised to the benefit of the researcher and the host institution.1 Platform facilities provide access to instrumentation and expertise for a wide range of users beyond the host institution, including other academic and industry users. To maximize the return on these substantial public investments, this wider access needs to be supported. The question of support and the mechanisms through which this occurs need to be established based on a greater understanding of how PT facilities operate. This investigation was aimed at understanding if and how platform facilities across the Bio21 Cluster meet operating costs. Our investigation found: 74% of platforms surveyed do not recover 100% of direct operating costs and are heavily subsidized by their home institution, which has a vested interest in maintaining the technology platform; platform managers play a major role in establishing the costs and pricing of the facility, normally in a collaborative process with a management committee or institutional accountant; and most facilities have a three-tier pricing structure recognizing internal academic, external academic, and commercial clients. PMID:20357980
Winter Precipitation Efficiency of Mountain Ranges in the Colorado Rockies Under Climate Change
NASA Astrophysics Data System (ADS)
Eidhammer, Trude; Grubišić, Vanda; Rasmussen, Roy; Ikdea, Kyoko
2018-03-01
Orographic precipitation depends on the environmental conditions and the barrier shape. In this study we examine the sensitivity of the precipitation efficiency (i.e., drying ratio (DR)), defined as the ratio of precipitation to incoming water flux, to mountain shape, temperature, stability, and horizontal velocity of the incoming air mass. Furthermore, we explore how the DR of Colorado mountain ranges might change under warmer and moister conditions in the future. For given environmental conditions, we find the DR to be primarily dependent on the upwind slope for mountain ranges wider than about 70 km and on both the slope and width for narrower ranges. Temperature is found to exert an influence on the DR for all Colorado mountain ranges, with DR decreasing with increasing temperature, under both the current and future climate conditions. The decrease of DR with temperature under warmer climate was found to be stronger for wider mountains than the narrower ones. We attribute this asymmetry to the sensitivity of DR to reduced horizontal velocity under warmer conditions. Specifically, while DR for wider mountains shows no sensitivity to changes in horizontal velocity, the DR for narrow ranges increases as the horizontal velocity decreases and more time is provided for precipitation to form. Thus, for narrower ranges, the horizontal velocity appears to offset the temperature effect slightly. The percentagewise decrease of DR for all examined mountain ranges is about 4%K-1. In comparison, the increase in precipitation is about 6%K-1 while the vapor flux increase is about 9%K-1.
A dynamic method for magnetic torque measurement
NASA Technical Reports Server (NTRS)
Lin, C. E.; Jou, H. L.
1994-01-01
In a magnetic suspension system, accurate force measurement will result in better control performance in the test section, especially when a wider range of operation is required. Although many useful methods were developed to obtain the desired model, however, significant error is inevitable since the magnetic field distribution of the large-gap magnetic suspension system is extremely nonlinear. This paper proposed an easy approach to measure the magnetic torque of a magnetic suspension system using an angular photo encoder. Through the measurement of the velocity change data, the magnetic torque is converted. The proposed idea is described and implemented to obtain the desired data. It is useful to the calculation of a magnetic force in the magnetic suspension system.
Optical double-locked semiconductor lasers
NASA Astrophysics Data System (ADS)
AlMulla, Mohammad
2018-06-01
Self-sustained period-one (P1) nonlinear dynamics of a semiconductor laser are investigated when both optical injection and modulation are applied for stable microwave frequency generation. Locking the P1 oscillation through modulation on the bias current, injection strength, or detuning frequency stabilizes the P1 oscillation. Through the phase noise variance, the different modulation types are compared. It is demonstrated that locking the P1 oscillation through optical modulation on the output of the master laser outperforms bias-current modulation of the slave laser. Master laser modulation shows wider P1-oscillation locking range and lower phase noise variance. The locking characteristics of the P1 oscillation also depend on the operating conditions of the optical injection system
Cryogenic Behavior of the High Temperature Crystal Oscillator PX-570
NASA Technical Reports Server (NTRS)
Patterson, Richard; Hammoud, Ahmad; Scherer, Steven
2011-01-01
Microprocessors, data-acquisition systems, and electronic controllers usually require timing signals for proper and accurate operation. These signals are, in most cases, provided by circuits that utilize crystal oscillators due to availability, cost, ease of operation, and accuracy. Stability of these oscillators, i.e. crystal characteristics, is usually governed, amongst other things, by the ambient temperature. Operation of these devices under extreme temperatures requires, therefore, the implementation of some temperature-compensation mechanism either through the manufacturing process of the oscillator part or in the design of the circuit to maintain stability as well as accuracy. NASA future missions into deep space and planetary exploration necessitate operation of electronic instruments and systems in environments where extreme temperatures along with wide-range thermal swings are countered. Most of the commercial devices are very limited in terms of their specified operational temperature while very few custom-made and military-grade parts have the ability to operate in a slightly wider range of temperature. Thus, it is becomes mandatory to design and develop circuits that are capable of operation efficiently and reliably under the space harsh conditions. This report presents the results obtained on the evaluation of a new (COTS) commercial-off-the-shelf crystal oscillator under extreme temperatures. The device selected for evaluation comprised of a 10 MHz, PX-570-series crystal oscillator. This type of device was recently introduced by Vectron International and is designed as high temperature oscillator [1]. These parts are fabricated using proprietary manufacturing processes designed specifically for high temperature and harsh environment applications [1]. The oscillators have a wide continuous operating temperature range; making them ideal for use in military and aerospace industry, industrial process control, geophysical fields, avionics, and engine control. They exhibit low jitter and phase noise, consume little power, and are suited for high shock and vibration applications. The unique package design of these crystal oscillators offers a small ceramic package footprint, as well as providing both through-hole mounting and surface mount options.
A remote camera operation system using a marker attached cap
NASA Astrophysics Data System (ADS)
Kawai, Hironori; Hama, Hiromitsu
2005-12-01
In this paper, we propose a convenient system to control a remote camera according to the eye-gazing direction of the operator, which is approximately obtained through calculating the face direction by means of image processing. The operator put a marker attached cap on his head, and the system takes an image of the operator from above with only one video camera. Three markers are set up on the cap, and 'three' is the minimum number to calculate the tilt angle of the head. The more markers are used, the robuster system may be made to occlusion, and the wider moving range of the head is tolerated. It is supposed that the markers must not exist on any three dimensional straight line. To compensate the marker's color change due to illumination conditions, the threshold for the marker extraction is adaptively decided using a k-means clustering method. The system was implemented with MATLAB on a personal computer, and the real-time operation was realized. Through the experimental results, robustness of the system was confirmed and tilt and pan angles of the head could be calculated with enough accuracy to use.
Droplet combustion experiment drop tower tests using models of the space flight apparatus
NASA Technical Reports Server (NTRS)
Haggard, J. B.; Brace, M. H.; Kropp, J. L.; Dryer, F. L.
1989-01-01
The Droplet Combustion Experiment (DCE) is an experiment that is being developed to ultimately operate in the shuttle environment (middeck or Spacelab). The current experiment implementation is for use in the 2.2 or 5 sec drop towers at NASA Lewis Research Center. Initial results were reported in the 1986 symposium of this meeting. Since then significant progress was made in drop tower instrumentation. The 2.2 sec drop tower apparatus, a conceptual level model, was improved to give more reproducible performance as well as operate over a wider range of test conditions. Some very low velocity deployments of ignited droplets were observed. An engineering model was built at TRW. This model will be used in the 5 sec drop tower operation to obtain science data. In addition, it was built using the flight design except for changes to accommodate the drop tower requirements. The mechanical and electrical assemblies have the same level of complexity as they will have in flight. The model was tested for functional operation and then delivered to NASA Lewis. The model was then integrated into the 5 sec drop tower. The model is currently undergoing initial operational tests prior to starting the science tests.
Filevich, Jorge; Grava, Jonathan; Purvis, Mike; Marconi, Mario C; Rocca, Jorge J; Nilsen, Joseph; Dunn, James; Johnson, Walter R
2006-07-01
We present the calculated prediction and the experimental confirmation that doubly ionized Ag and Sn plasmas can have an index of refraction greater than one for soft x-ray wavelengths. Interferometry experiments conducted using a capillary discharge soft x-ray laser operating at a wavelength of confirm that in few times ionized laser-created plasmas of these elements the anomalous dispersion from bound electrons can dominate the free electron contribution, making the index of refraction greater than one. The results confirm that bound electrons can strongly influence the index of refraction of numerous plasmas over a broad range of soft x-ray wavelengths confirming recent observations. The understanding of index of refraction at short wavelengths will become even more essential during the next decade as x-ray free electron lasers will become available to probe a wider variety of plasmas at higher densities and shorter wavelengths.
Transient Phenomena: Opportunities for New Discoveries
NASA Technical Reports Server (NTRS)
Lazio, T. Joseph W.
2010-01-01
Known classes of radio wavelength transients range from the nearby (stellar flares and radio pulsars) to the distant Universe (gamma-ray burst afterglows). Hypothesized classes of radio transients include analogs of known objects, such as extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, such as prompt emission from gamma-ray bursts, evaporating black holes and transmitters from other civilizations. Time domain astronomy has been recognized internationally as a means of addressing key scientific questions in astronomy and physics, and pathfinders and Precursors to the Square Kilometre Array (SKA) are beginning to offer a combination of wider fields of view and more wavelength agility than has been possible in the past. These improvements will continue when the SKA itself becomes operational. I illustrate the range of transient phenomena and discuss how the detection and study of radio transients will improve immensely.
NASA Astrophysics Data System (ADS)
Wang, Hung-Ta; Kang, B. S.; Ren, F.; Fitch, R. C.; Gillespie, J. K.; Moser, N.; Jessen, G.; Jenkins, T.; Dettmer, R.; Via, D.; Crespo, A.; Gila, B. P.; Abernathy, C. R.; Pearton, S. J.
2005-10-01
Pt-gated AlGaN /GaN high electron mobility transistors can be used as room-temperature hydrogen gas sensors at hydrogen concentrations as low as 100ppm. A comparison of the changes in drain and gate current-voltage (I-V) characteristics with the introduction of 500ppm H2 into the measurement ambient shows that monitoring the change in drain-source current provides a wider gate voltage operation range for maximum detection sensitivity and higher total current change than measuring the change in gate current. However, over a narrow gate voltage range, the relative sensitivity of detection by monitoring the gate current changes is up to an order of magnitude larger than that of drain-source current changes. In both cases, the changes are fully reversible in <2-3min at 25°C upon removal of the hydrogen from the ambient.
Improved Performance of Ionic Liquid Supercapacitors by using Tetracyanoborate Anions.
Martins, Vitor L; Rennie, Anthony J R; Sanchez-Ramirez, Nedher; Torresi, Roberto M; Hall, Peter J
2018-02-01
Supercapacitors are energy storage devices designed to operate at higher power densities than conventional batteries, but their energy density is still too low for many applications. Efforts are made to design new electrolytes with wider electrochemical windows than aqueous or conventional organic electrolytes in order to increase energy density. Ionic liquids (ILs) with wide electrochemical stability windows are excellent candidates to be employed as supercapacitor electrolytes. ILs containing tetracyanoborate anions [B(CN) 4 ] offer wider electrochemical stability than conventional electrolytes and maintain a high ionic conductivity (6.9 mS cm -1 ). Herein, we report the use of ILs containing the [B(CN) 4 ] anion for such an application. They presented a high maximum operating voltage of 3.7 V, and two-electrode devices demonstrate high specific capacitances even when operating at relatively high rates (ca. 20 F g -1 @ 15 A g -1 ). This supercapacitor stored more energy and operated at a higher power at all rates studied when compared with cells using a commonly studied ILs.
Laterality and Left-sidedness in the Nose, Face, and Body: A New Finding.
Hafezi, Farhad; Javdani, Ali; Naghibzadeh, Bijan; Ashtiani, Abbas Kazemi
2017-12-01
Asymmetry is a common occurrence in bilaterian animals, particularly human beings. Through examination of patients and their photographs during rhinoplasty, we noted wider left-sided nasal and facial features in most patients. This observation led us to hypothesize that this might be consistent to the whole body. We conducted a study in 3 parts to test the question above. First, we analyzed operating notes of 50 rhinoplasty patients to determine the wider side of the upper, middle, and lower thirds of the nose. Second, we analyzed the width of the face and chest wall in 31 patients to discern any correlation between facial and bodily asymmetry. Third, computerized tomographic scans of the thorax and body of 48 patients were studied to measure the width of the hemithorax and hemipelvic bone. (1) Upper vault width was wider on left side (78%). Left middle vault width was wider (88%). The lower lateral cartilage, lateral crura convexity was more prominent on left side (48%), and a wider scroll area was found and trimmed in 21 (left) and 0 (right) cases. The alar base was wider on left side (56%). (2) In the body and face analysis, 64.5% had a wider left-sided face and body. (3) In the computed tomographic scan analysis, same-sided thorax and pelvis asymmetry was seen (85.35%), 33 and 7 of which were left- and right-sided, respectively. We observed generalized asymmetry of the face and body with left-sided predominance.
A Highly Linear and Wide Input Range Four-Quadrant CMOS Analog Multiplier Using Active Feedback
NASA Astrophysics Data System (ADS)
Huang, Zhangcai; Jiang, Minglu; Inoue, Yasuaki
Analog multipliers are one of the most important building blocks in analog signal processing circuits. The performance with high linearity and wide input range is usually required for analog four-quadrant multipliers in most applications. Therefore, a highly linear and wide input range four-quadrant CMOS analog multiplier using active feedback is proposed in this paper. Firstly, a novel configuration of four-quadrant multiplier cell is presented. Its input dynamic range and linearity are improved significantly by adding two resistors compared with the conventional structure. Then based on the proposed multiplier cell configuration, a four-quadrant CMOS analog multiplier with active feedback technique is implemented by two operational amplifiers. Because of both the proposed multiplier cell and active feedback technique, the proposed multiplier achieves a much wider input range with higher linearity than conventional structures. The proposed multiplier was fabricated by a 0.6µm CMOS process. Experimental results show that the input range of the proposed multiplier can be up to 5.6Vpp with 0.159% linearity error on VX and 4.8Vpp with 0.51% linearity error on VY for ±2.5V power supply voltages, respectively.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bunting, Bruce G; Farrell, John T
2006-01-01
The effects of fuel properties on gasoline HCCI operation have been investigated in a single cylinder, 500 cc, 11.3 CR port fuel injected research engine, operated at lambda=1 and equipped with hydraulic valve actuation. HCCI is promoted by early exhaust valve closing to retain hot exhaust in the cylinder, thereby increasing the cylinder gas temperature. Test fuels were formulated with pure components to have the same RON, MON, and octane sensitivity as an indolene reference fuel, but with a wide range of fuel composition differences. Experiments have been carried out to determine if fuel composition plays a role in HCCImore » combustion properties, independent of octane numbers. Fuel economy, emissions, and combustion parameters have been measured at several fixed speed/load conditions over a range of exhaust valve closing angles. When the data are compared at constant combustion phasing, fuel effects on emissions and other combustion properties are small. However, when compared at constant exhaust valve closing angle, fuel composition effects are more pronounced, specifically regarding ignition. Operability range differences are also related to fuel composition. An all-paraffinic (normal, iso, and cycloparaffins) fuel exhibited distinctly earlier combustion phasing, increased rate of cylinder pressure rise, and increased rate of maximum heat release compared to the indolene reference fuel. Conversely, olefin-containing fuels exhibited retarded combustion phasing. The fuels with the most advanced ignition showed a wider operating range in terms of engine speed and load, irrespective of exhaust closing angle. These ignition differences reflect contributions from both fuel and EGR kinetics, the effects of which are discussed. The fuel composition variables are somewhat inter-correlated, which makes the experimental separation their effects imprecise with this small set of fuels, though clear trends are evident. The overall effects of fuel composition on engine performance and emissions are small. However, the results suggest that the effects on combustion phasing and engine operability range may need to be considered in the practical implementation of HCCI for fuels with large compositional variations.« less
NASA Technical Reports Server (NTRS)
Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.
2008-01-01
Due to their attractive properties and proven success, Li-ion batteries have become identified as the battery chemistry of choice for a number of future NASA missions. A number of these applications would be greatly benefited by improved performance of Li-ion technology over a wider operating temperature range, especially at low temperatures, such as future ESMD missions. In many cases, these technology improvements may be mission enabling, and at the very least mission enhancing. In addition to aerospace applications, the DoE has interest in developing advanced Li-ion batteries that can operate over a wide temperature range to enable terrestrial HEV applications. Thus, our focus at JPL in recent years has been to extend the operating temperature range of Li-ion batteries, especially at low temperatures. To accomplish this, the main focus of the research has been devoted to developing improved lithium-ion conducting electrolytes. In the present paper, we would like to present some of the results we have obtained with six different ethylene carbonate-based electrolytes optimized for low temperature. In addition to investigating the behavior in experimental cells initially, the performance of these promising low temperature electrolytes was demonstrated in large capacity, aerospace quality Li-ion prototype cells, manufactured by Yardney Technical Products and Saft America, Inc. These cells were subjected to a number of performance tests, including discharge rate characterization, charge rate characterization, cycle life performance at various temperatures, and power characterization tests.
NASA Astrophysics Data System (ADS)
Wittek, Peter; Calderaro, Luca
2015-12-01
We extended a parallel and distributed implementation of the Trotter-Suzuki algorithm for simulating quantum systems to study a wider range of physical problems and to make the library easier to use. The new release allows periodic boundary conditions, many-body simulations of non-interacting particles, arbitrary stationary potential functions, and imaginary time evolution to approximate the ground state energy. The new release is more resilient to the computational environment: a wider range of compiler chains and more platforms are supported. To ease development, we provide a more extensive command-line interface, an application programming interface, and wrappers from high-level languages.
A Service Oriented Infrastructure for Earth Science exchange
NASA Astrophysics Data System (ADS)
Burnett, M.; Mitchell, A.
2008-12-01
NASA's Earth Science Distributed Information System (ESDIS) program has developed an infrastructure for the exchange of Earth Observation related resources. Fundamentally a platform for Service Oriented Architectures, ECHO provides standards-based interfaces based on the basic interactions for a SOA pattern: Publish, Find and Bind. This infrastructure enables the realization of the benefits of Service Oriented Architectures, namely the reduction of stove-piped systems, the opportunity for reuse and flexibility to meet dynamic business needs, on a global scale. ECHO is the result of the infusion of IT technologies, including those standards of Web Services and Service Oriented Architecture technologies. The infrastructure is based on standards and leverages registries for data, services, clients and applications. As an operational system, ECHO currently representing over 110 million Earth Observation resources from a wide number of provider organizations. These partner organizations each have a primary mission - serving a particular facet of the Earth Observation community. Through ECHO, those partners can serve the needs of not only their target portion of the community, but also enable a wider range of users to discover and leverage their data resources, thereby increasing the value of their offerings. The Earth Observation community benefits from this infrastructure because it provides a set of common mechanisms for the discovery and access to resources from a much wider range of data and service providers. ECHO enables innovative clients to be built for targeted user types and missions. There several examples of those clients already in process. Applications built on this infrastructure can include User-driven, GUI-clients (web-based or thick clients), analysis programs (as intermediate components of larger systems), models or decision support systems. This paper will provide insight into the development of ECHO, as technologies were evaluated for infusion, and a summary of how technologies where leveraged into a significant operational system for the Earth Observation community.
Univariate Analysis of Multivariate Outcomes in Educational Psychology.
ERIC Educational Resources Information Center
Hubble, L. M.
1984-01-01
The author examined the prevalence of multiple operational definitions of outcome constructs and an estimate of the incidence of Type I error rates when univariate procedures were applied to multiple variables in educational psychology. Multiple operational definitions of constructs were advocated and wider use of multivariate analysis was…
A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project.
Ewers, Robert M; Didham, Raphael K; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L; Turner, Edgar C
2011-11-27
Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project represents an advance on existing experiments in that it: (i) allows discrimination of the effects of landscape-level forest cover from patch-level processes; (ii) is designed to facilitate the unification of a wide range of data types on ecological patterns and processes that operate over a wide range of spatial scales; (iii) has greater replication than existing experiments; (iv) incorporates an experimental manipulation of riparian corridors; and (v) embeds the experimentally fragmented landscape within a wider gradient of land-use intensity than do existing projects. The SAFE Project represents an opportunity for ecologists across disciplines to participate in a large initiative designed to generate a broad understanding of the ecological impacts of tropical forest modification.
A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project
Ewers, Robert M.; Didham, Raphael K.; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D.; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L.; Turner, Edgar C.
2011-01-01
Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project represents an advance on existing experiments in that it: (i) allows discrimination of the effects of landscape-level forest cover from patch-level processes; (ii) is designed to facilitate the unification of a wide range of data types on ecological patterns and processes that operate over a wide range of spatial scales; (iii) has greater replication than existing experiments; (iv) incorporates an experimental manipulation of riparian corridors; and (v) embeds the experimentally fragmented landscape within a wider gradient of land-use intensity than do existing projects. The SAFE Project represents an opportunity for ecologists across disciplines to participate in a large initiative designed to generate a broad understanding of the ecological impacts of tropical forest modification. PMID:22006969
Thermo-Electron Ballistic Coolers or Heaters
NASA Technical Reports Server (NTRS)
Choi, Sang H.
2003-01-01
Electronic heat-transfer devices of a proposed type would exploit some of the quantum-wire-like, pseudo-superconducting properties of single-wall carbon nanotubes or, optionally, room-temperature-superconducting polymers (RTSPs). The devices are denoted thermo-electron ballistic (TEB) coolers or heaters because one of the properties that they exploit is the totally or nearly ballistic (dissipation or scattering free) transport of electrons. This property is observed in RTSPs and carbon nanotubes that are free of material and geometric defects, except under conditions in which oscillatory electron motions become coupled with vibrations of the nanotubes. Another relevant property is the high number density of electrons passing through carbon nanotubes -- sufficient to sustain electron current densities as large as 100 MA/square cm. The combination of ballistic motion and large current density should make it possible for TEB devices to operate at low applied potentials while pumping heat at rates several orders of magnitude greater than those of thermoelectric devices. It may also enable them to operate with efficiency close to the Carnot limit. In addition, the proposed TEB devices are expected to operate over a wider temperature range
Prefrontal cortex as a meta-reinforcement learning system.
Wang, Jane X; Kurth-Nelson, Zeb; Kumaran, Dharshan; Tirumala, Dhruva; Soyer, Hubert; Leibo, Joel Z; Hassabis, Demis; Botvinick, Matthew
2018-06-01
Over the past 20 years, neuroscience research on reward-based learning has converged on a canonical model, under which the neurotransmitter dopamine 'stamps in' associations between situations, actions and rewards by modulating the strength of synaptic connections between neurons. However, a growing number of recent findings have placed this standard model under strain. We now draw on recent advances in artificial intelligence to introduce a new theory of reward-based learning. Here, the dopamine system trains another part of the brain, the prefrontal cortex, to operate as its own free-standing learning system. This new perspective accommodates the findings that motivated the standard model, but also deals gracefully with a wider range of observations, providing a fresh foundation for future research.
Cundy, A B; Bardos, R P; Puschenreiter, M; Mench, M; Bert, V; Friesl-Hanl, W; Müller, I; Li, X N; Weyens, N; Witters, N; Vangronsveld, J
2016-12-15
Gentle remediation options (GROs) are risk management strategies or technologies involving plant (phyto-), fungi (myco-), and/or bacteria-based methods that result in a net gain (or at least no gross reduction) in soil function as well as effective risk management. GRO strategies can be customised along contaminant linkages, and can generate a range of wider economic, environmental and societal benefits in contaminated land management (and in brownfields management more widely). The application of GROs as practical on-site remedial solutions is still limited however, particularly in Europe and at trace element (typically metal and metalloid) contaminated sites. This paper discusses challenges to the practical adoption of GROs in contaminated land management, and outlines the decision support tools and best practice guidance developed in the European Commission FP7-funded GREENLAND project aimed at overcoming these challenges. The GREENLAND guidance promotes a refocus from phytoremediation to wider GROs- or phyto-management based approaches which place realisation of wider benefits at the core of site design, and where gentle remediation technologies can be applied as part of integrated, mixed, site risk management solutions or as part of "holding strategies" for vacant sites. The combination of GROs with renewables, both in terms of biomass generation but also with green technologies such as wind and solar power, can provide a range of economic and other benefits and can potentially support the return of low-level contaminated sites to productive usage, while combining GROs with urban design and landscape architecture, and integrating GRO strategies with sustainable urban drainage systems and community gardens/parkland (particularly for health and leisure benefits), has large potential for triggering GRO application and in realising wider benefits in urban and suburban systems. Quantifying these wider benefits and value (above standard economic returns) will be important in leveraging funding for GRO application and soft site end-use more widely at vacant or underutilized sites. Copyright © 2016 Elsevier Ltd. All rights reserved.
The PIT MkV pulsed inductive thruster
NASA Technical Reports Server (NTRS)
Dailey, C. Lee; Lovberg, Ralph H.
1993-01-01
The pulsed inductive thruster (PIT) is an electrodeless, magnetic rocket engine that can operate with any gaseous propellant. A puff of gas injected against the face of a flat (spiral) coil is ionized and ejected by the magnetic field of a fast-rising current pulse from a capacitor bank discharge. Single shot operation on an impulse balance has provided efficiency and I(sub sp) data that characterize operation at any power level (pulse rate). The 1-m diameter MkV thruster concept offers low estimated engine mass at low powers, together with power capability up to more than 1 MW for the 1-m diameter design. A 20 kW design estimate indicates specific mass comparable to Ion Engine specific mass for 10,000 hour operation, while a 100,000 hour design would have a specific mass 1/3 that of the Ion Engine. Performance data are reported for ammonia and hydrazine. With ammonia, at 32 KV coil voltage, efficiency is a little more than 50 percent from 4000 to more than 8000 seconds I(sub sp). Comparison with data at 24 and 28 kV indicates that a wider I(sub sp) range could be achieved at higher coil voltages, if required for deep space missions.
Geostationary satellite positioning by DLR/GSOC operations and management methods
NASA Technical Reports Server (NTRS)
Brittinger, Peter
1994-01-01
Starting with a short description of the GSOC (German Space Operations Center) and its role within the wider framework of the research institute DLR, this paper provides a review of the geostationary telecommunications satellites positioned by the GSOC. The paper then proceeds to describe the evolution of the operations and management structures and methods which have been effectively used to accomplish these missions.
78 FR 36749 - Determination Under the African Growth and Opportunity Act
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-19
... Benin. Articles must be ornamented in characteristic Benin or regional folk style. An article may not... synthetic fibers. Hand-woven on manually operated looms then hand or machine stitched. There [[Page 36750...-woven in manually operated looms then machine stitched together to form a wider substrate. This is a...
Improved Performance of Ionic Liquid Supercapacitors by using Tetracyanoborate Anions
Martins, Vitor L.; Rennie, Anthony J. R.; Sanchez‐Ramirez, Nedher; Torresi, Roberto M.; Hall, Peter J.
2018-01-01
Abstract Supercapacitors are energy storage devices designed to operate at higher power densities than conventional batteries, but their energy density is still too low for many applications. Efforts are made to design new electrolytes with wider electrochemical windows than aqueous or conventional organic electrolytes in order to increase energy density. Ionic liquids (ILs) with wide electrochemical stability windows are excellent candidates to be employed as supercapacitor electrolytes. ILs containing tetracyanoborate anions [B(CN)4] offer wider electrochemical stability than conventional electrolytes and maintain a high ionic conductivity (6.9 mS cm−1). Herein, we report the use of ILs containing the [B(CN)4] anion for such an application. They presented a high maximum operating voltage of 3.7 V, and two‐electrode devices demonstrate high specific capacitances even when operating at relatively high rates (ca. 20 F g−1 @ 15 A g−1). This supercapacitor stored more energy and operated at a higher power at all rates studied when compared with cells using a commonly studied ILs. PMID:29577008
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gao, Zhiming; Curran, Scott; Daw, C Stuart
2013-01-01
In-cylinder blending of gasoline and diesel fuels to achieve low-temperature reactivity controlled compression ignition (RCCI) can reduce NOx and PM emissions while maintaining or improving brake thermal efficiency compared to conventional diesel combustion (CDC). Moreover, the dual-fueling RCCI is able to achieve these benefits by tailoring combustion reactivity over a wider range of engine operation than is possible with a single fuel. However, the currently demonstrated range of stable RCCI combustion just covers a portion of the engine speed-load range required in several light-duty drive cycles. This means that engines must switch from RCCI to CDC when speed and loadmore » fall outside of the stable RCCI range. In this study we investigated the impact of RCCI as it has recently been demonstrated on practical engine-out exhaust temperature and emissions by simulating a multi-mode RCCI-enabled vehicle operating over two urban and two highway driving cycles. To implement our simulations, we employed experimental engine maps for a multi-mode RCCI/CDC engine combined with a standard mid-size, automatic transmission, passenger vehicle in the Autonomie vehicle simulation platform. Our results include both detailed transient and cycle-averaged engine exhaust temperature and emissions for each case, and we note the potential implications of the modified exhaust properties on catalytic emissions control and utilization of waste heat recovery on future RCCI-enabled vehicles.« less
Airport Traffic Conflict Detection and Resolution Algorithm Evaluation
NASA Technical Reports Server (NTRS)
Jones, Denise R.; Chartrand, Ryan C.; Wilson, Sara R.; Commo, Sean A.; Otero, Sharon D.; Barker, Glover D.
2012-01-01
A conflict detection and resolution (CD&R) concept for the terminal maneuvering area (TMA) was evaluated in a fast-time batch simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. The CD&R concept is being designed to enhance surface situation awareness and provide cockpit alerts of potential conflicts during runway, taxi, and low altitude air-to-air operations. The purpose of the study was to evaluate the performance of aircraft-based CD&R algorithms in the TMA, as a function of surveillance accuracy. This paper gives an overview of the CD&R concept, simulation study, and results. The Next Generation Air Transportation System (NextGen) concept for the year 2025 and beyond envisions the movement of large numbers of people and goods in a safe, efficient, and reliable manner [1]. NextGen will remove many of the constraints in the current air transportation system, support a wider range of operations, and provide an overall system capacity up to three times that of current operating levels. Emerging NextGen operational concepts [2], such as four-dimensional trajectory based airborne and surface operations, equivalent visual operations, and super density arrival and departure operations, require a different approach to air traffic management and as a result, a dramatic shift in the tasks, roles, and responsibilities for the flight deck and air traffic control (ATC) to ensure a safe, sustainable air transportation system.
A novel high temperature superconducting magnetic flux pump for MRI magnets
NASA Astrophysics Data System (ADS)
Bai, Zhiming; Yan, Guo; Wu, Chunli; Ding, Shufang; Chen, Chuan
2010-10-01
This paper presents a kind of minitype magnetic flux pump made of high temperature superconductor. This kind of novel high temperature superconducting (HTS) flux pump has not any mechanical revolving parts or thermal switches. The excitation current of copper coils in magnetic pole system is controlled by a singlechip. The structure design and operational principle have been described. The operating performance of the new model magnetic flux pump has been preliminarily tested. The experiments show that the maximum pumping current is approximately 200 A for Bi2223 flux pump and 80 A for MgB 2 flux pump operating at 20 K. By comparison, it is discovered that the operating temperature range is wider, the ripple is smaller and the pumping frequency is higher in Bi2223 flux pump than those in MgB 2 flux pump. These results indicate that the newly developed Bi2223 magnetic flux pump may efficiently compensate the magnetic field decay in HTS magnet and make the magnet operate in persistent current mode, this point is significant to the magnetic resonance imaging (MRI) magnets. This new flux pump is under construction presently. It is expected that the Bi2223 flux pump would be applied to the superconducting MRI magnets by further optimizing structure and improving working process.
"Interactive Classification Technology"
NASA Technical Reports Server (NTRS)
deBessonet, Cary
1999-01-01
The investigators are upgrading a knowledge representation language called SL (Symbolic Language) and an automated reasoning system called SMS (Symbolic Manipulation System) to enable the technologies to be used in automated reasoning and interactive classification systems. The overall goals of the project are: a) the enhancement of the representation language SL to accommodate multiple perspectives and a wider range of meaning; b) the development of a sufficient set of operators to enable the interpreter of SL to handle representations of basic cognitive acts; and c) the development of a default inference scheme to operate over SL notation as it is encoded. As to particular goals the first-year work plan focused on inferencing and.representation issues, including: 1) the development of higher level cognitive/ classification functions and conceptual models for use in inferencing and decision making; 2) the specification of a more detailed scheme of defaults and the enrichment of SL notation to accommodate the scheme; and 3) the adoption of additional perspectives for inferencing.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cerutti, L.; Rodriguez, J.-B.; Madiomanana, K.
We have investigated in detail the material, optical, and lasing properties of innovative GaInSb/AlInSb composite quantum wells (CQWs). The CQWs are confined by AlGaAsSb barrier layers, and a monolayer-thin AlInSb barrier layer has been inserted within the GaInSb QWs in order to achieve lasing emission within the telecom window. High-resolution X-ray diffraction, transmission electron microscopy, and photoluminescence spectroscopies reveal high structural quality of the samples. Inserting AlInSb layers allows wider QWs, and thus higher gain-material volume and CQW/optical mode overlap. This translates into better laser performances. Near room temperature, a threshold current of 85 mA and an output power of ∼30more » mW/uncoated-facet under continuous wave operation are demonstrated at 1.55 μm with 10 μm × 1 mm laser diodes.« less
NASA Astrophysics Data System (ADS)
Xie, Mengying; Zhang, Yan; Kraśny, Marcin J.; Rhead, Andrew; Bowen, Chris; Arafa, Mustafa
2018-07-01
The energy harvesting capability of resonant harvesting structures, such as piezoelectric cantilever beams, can be improved by utilizing coupled oscillations that generate favourable strain mode distributions. In this work, we present the first demonstration of the use of a laminated carbon fibre reinforced polymer to create cantilever beams that undergo coupled bending-twisting oscillations for energy harvesting applications. Piezoelectric layers that operate in bending and shear mode are attached to the bend-twist coupled beam surface at locations of maximum bending and torsional strains in the first mode of vibration to fully exploit the strain distribution along the beam. Modelling of this new bend-twist harvesting system is presented, which compares favourably with experimental results. It is demonstrated that the variety of bend and torsional modes of the harvesters can be utilized to create a harvester that operates over a wider range of frequencies and such multi-modal device architectures provides a unique approach to tune the frequency response of resonant harvesting systems.
Immobilization of pectinase on oxidized pulp fiber and its application in whitewater treatment.
Wu, Rina; He, Bei-Hai; Zhao, Guang-Lei; Qian, Li-Ying; Li, Xiao-Feng
2013-09-12
Modified pulp fiber was originally used as a new type of carrier for pectinase immobilization. Pulp fiber was oxidized by sodium periodate to produce aldehyde groups for covalently binding with amino groups of pectinase. Results showed that the enzymatic activity of immobilized pectinase on pulp fiber reached 65 μgg(-1)min(-1) when immobilization pH value, temperature and time were of 7.0, 20 °C and 15 min, respectively. The immobilized pectinase showed higher thermo stability in a wider temperature range of 40-70 °C than its free type and its optimal pH shifted from 8.0 to 8.8. Furthermore, the immobilized pectinase exhibited good operational stability. When employed in whitewater treatment of papermaking industry, it still efficiently decreased the cationic demand after operating repeatedly for six batches. The results obtained demonstrate a promising route to prepare available, cheap and biodegradable carrier for immobilizing enzymes with potential application in wastewater treatment in papermaking industry. Copyright © 2013 Elsevier Ltd. All rights reserved.
Liquid propellant gas generators
NASA Technical Reports Server (NTRS)
1972-01-01
The design of gas generators intended to provide hot gases for turbine drive is discussed. Emphasis is placed on the design and operation of bipropellant gas generators because of their wider use. Problems and limitations involved in turbine operation due to temperature effects are analyzed. Methods of temperature control of gas turbines and combustion products are examined. Drawings of critical sections of gas turbines to show their operation and areas of stress are included.
Sunlight readable avionics displays
NASA Astrophysics Data System (ADS)
Visinski, Joseph R.
1998-09-01
The theme of the Cockpit Displays V Conference of 'Custom versus Consumer -- Grade Displays in Defense Applications' reflects the Raytheon Systems Company field emission display (FED) development effort. Raytheon chose to license commercial FED technology and subsequently participate in a commercial industry 'FED Alliance' to insert this technology into commercial and avionics defense applications. The unaffordability of custom military displays makes them an unfeasible choice to build a business upon. The major differences between consumer FEDs and those adapted for military/avionics installations are: (1) high brightness for sunlight visibility; (2) extended environmental range; (3) high resolution; (4) wider dimming range for sunlight to NVIS operation; (5) extended gray scales; (6) lifetime product support well beyond two year consumer market life. The transition to defense applications is further being accomplished via industry/government partnerships as the DARPA Technology Reinvestment Project (TRP) and BAA 97-31. FEDs combine cathode ray tube (CRT) and matrix addressed flat panel display technology, parts, manufacturing, and test equipment, plus open systems interfaces into a new display.
Bentley , T A; Page, S J; Laird, I S
2000-01-01
Injuries and fatalities among participants of adventure tourism activities have the potential to seriously impact on New Zealand's tourism industry. However, the absence of statistics for tourist accidents in New Zealand, and the lack of detailed academic research into adventure tourism safety, means the extent of the problem is unknown. The aims of the present study were to determine the incidence of client injuries across a range of adventure tourism activity sectors, and to identify common accident events and contributory risk factors. A postal questionnaire survey of New Zealand adventure tourism operators was used. Operators were asked to provide information related to their business; the number of recorded client injuries during the preceding 12 month period, January to December 1998; common accident and injury events associated with their activity; and perceived risk factors for accidents in their sector of the adventure tourism industry. The survey was responded to by 142 New Zealand adventure tourism operators. The operators' reported client injury experience suggests the incidence of serious client injuries is very low. Highest client injury incidence rates were found for activities that involved the risk of falling from a moving vehicle or animal (e.g., cycle tours, quad biking, horse riding, and white-water rafting). Slips, trips, and falls on the level were common accident events across most sectors of the industry. Perceived accident/incident causes were most commonly related to the client, and in particular, failure to attend to and follow instructions. The prevalence of client injuries in activity sectors not presently covered by government regulation, suggests policy makers should look again at extending codes of practice to a wider range of adventure tourism activities. Further research considering adventure tourism involvement in overseas visitor hospitalized injuries in New Zealand, is currently in progress. This will provide supporting evidence for the risk associated with participation in a range of commercial and independently undertaken adventure activities.
NASA Astrophysics Data System (ADS)
Tatum, Jim
2007-02-01
Since the commercialization of Vertical Cavity Surface Emitting Lasers (VCSELs) in 1996, Finisar's Advanced Optical Components Division has shipped well over 50 Million VCSELs. The vast majority of these were shipped into the data communications industry, which was essentially the only volume application until 2005. The driver for VCSEL manufacturing might well shift to the increasingly popular laser based optical mouse. The advantages of the laser based mouse over traditional LED mice include operation on a wider range of surfaces, higher resolution, and increased battery lifetime. What is the next application that will drive growth in VCSELs? This paper will offer a historical perspective on the emergence of VCSELs from the laboratory to reality, and the companies that have played key roles in VCSEL commercialization. Furthermore, a perspective on the market needs of future VCSEL development and applications is described.
Redesigned Gas Mass Flow Sensors for Space Shuttle Pressure Control System and Fuel Cell System
NASA Technical Reports Server (NTRS)
1996-01-01
A program was conducted to determine if a state of the art micro-machined silicon solid state flow sensor could be used to replace the existing space shuttle orbiter flow sensors. The rather aggressive goal was to obtain a new sensor which would also be a multi-gas sensor and operate over a much wider flow range and with a higher degree of accuracy than the existing sensors. Two types of sensors were tested. The first type was a venturi throat design and the second was a bypass design. The accuracy of venturi design was found to be marginally acceptable. The bypass sensor was much better although it still did not fully reach the accuracy goal. Two main problems were identified which would require further work.
NASA Astrophysics Data System (ADS)
Morita, Kazuyo; Yamamoto, Kimiko
2017-03-01
Xylan, one of hemicellulose family, block copolymer was newly developed for wide-range directed self-assembly lithography (DSA). Xylan is higher hydrophilic material because of having many hydroxy groups in one molecule. It means that xylan block copolymer has a possibility of high-chi block copolymer. Generally, DSA is focused on microphase separation for smaller size with high-chi block copolymer and not well known for larger size. In this study, xylan block copolymer was confirmed enabling wider range of patterning size, from smaller size to larger size. The key of xylan block copolymer is a new molecular structure of block copolymer and sugar chain control technology. Sugar content is the important parameter for not only micro-phase separation property but also line edge roughness (LER) and defects. Based on the sugar control technology, wide-range (hp 8.3nm to 26nm L/S and CD 10nm to 51nm hole) DSA patterning was demonstrated. Additionally it was confirmed that xylan block copolymer is suitable for sequential infiltration synthesis (SIS) process.
Overseas Varietal Analysis 2009 Crop Soft Red Winter Wheat
USDA-ARS?s Scientific Manuscript database
Each customer in the survey has a preference for specific protein targets. Grain shipments within those protein ranges may perform better than individual varieties that often have a wider range in protein than normally observed in pooled cargos of commercial grain shipments. The feedback on protei...
Gehl, Julie; Sersa, Gregor; Matthiessen, Louise Wichmann; Muir, Tobian; Soden, Declan; Occhini, Antonio; Quaglino, Pietro; Curatolo, Pietro; Campana, Luca G; Kunte, Christian; Clover, A James P; Bertino, Giulia; Farricha, Victor; Odili, Joy; Dahlstrom, Karin; Benazzo, Marco; Mir, Lluis M
2018-03-25
Electrochemotherapy is now in routine clinical use to treat cutaneous metastases of any histology, and is listed in national and international guidelines for cutaneous metastases and primary skin cancer. Electrochemotherapy is used by dermatologists, surgeons, and oncologists, and for different degrees and manifestations of metastases to skin and primary skin tumours not amenable to surgery. This treatment utilises electric pulses to permeabilize cell membranes in tumours, thus allowing a dramatic increase of the cytotoxicity of anti-cancer agents. Response rates, often after only one treatment, are very high across all tumour types. The most frequent indications are cutaneous metastases from malignant melanoma and breast cancer. In 2006, standard operating procedures (SOPs) were written for this novel technology, greatly facilitating introduction and dissemination of the therapy. Since then considerable experience has been obtained treating a wider range of tumour histologies and increasing size of tumours which was not originally thought possible. A pan-European expert panel drawn from a range of disciplines from dermatology, general surgery, head and neck surgery, plastic surgery, and oncology met to form a consensus opinion to update the SOPs based on the experience obtained. This paper contains these updated recommendations for indications for electrochemotherapy, pre-treatment information and evaluation, treatment choices, as well as follow-up.
Nita, D; Mignot, J; Chuard, M; Sofa, M
1998-08-01
Measurement of cutaneous surface topography can be made by three-dimensional (3-D) profilometry. Different equipment is used for this measurement. The magnitude of the vertical scale required, which can vary from several tens of micrometers (microrelief) to several millimeters (skin pathologies), depends also on the precision required and the duration of acquisition time. Over the last few years, different apparatuses have been produced, with a vertical range that is most frequently used for classical industrial applications, i.e., 0-1000 μm. The system developed here has a wide range of about 7 mm and is accurate enough to analyse each of the different skin surfaces that fall in this range without changing magnification. An optical principle, operating without any contact with a skin replica, allows a precise measurement with a high scanning speed. The profilometer has a vertical sensitivity of 4 μm within a vertical range of 7 mm. This sensitivity is lower than that of a mechanical or focusing profilometer, but the vertical range is wider. The system has several advantages: because of its verticale range, it can measure large surfaces with great roughness variations; the initial position of the replica beneath the profilometer must be within the 7 mm vertical range; and skin topography can be quantified, without contact, in a short time.
... that they are embarrassed by in public. The parents' own temperament, usual mood, and daily pressures will also influence how they interpret the child's behavior. Easygoing parents may accept a wider range ...
Meyer, Raquel M; O'Brien-Pallas, Linda; Doran, Diane; Streiner, David; Ferguson-Paré, Mary; Duffield, Christine
2011-07-01
To examine the influence of nurse manager span (number of direct report staff), time in staff contact, transformational leadership practices and operational hours on nurse supervision satisfaction. Increasing role complexity has intensified the boundary spanning functions of managers. Because work demands and scope vary by management position, time in staff contact rather than span may better explain managers' capacity to support staff. A descriptive, correlational design was used to collect cross-sectional survey and prospective work log and administrative data from a convenience sample of 558 nurses in 51 clinical areas and 31 front-line nurse managers from four acute care hospitals in 2007-2008. Data were analysed using hierarchical linear modelling. Span, but not time in staff contact, interacted with leadership and operational hours to explain supervision satisfaction. With compressed operational hours, supervision satisfaction was lower with highly transformational leadership in combination with wider spans. With extended operational hours, supervision satisfaction was higher with highly transformational leadership, and this effect was more pronounced under wider spans. Operational hours, which influence the manager's daily span (average number of direct report staff working per weekday), should be factored into the design of front-line management positions. © 2011 The Authors. Journal compilation © 2011 Blackwell Publishing Ltd.
USDA-ARS?s Scientific Manuscript database
Multiple introductions of an exotic species can facilitate invasion success by allowing for a wider range of expressed trait values in the adventive range. Brazilian peppertree is an invasive shrub that was introduced into Florida multiple times and has subsequently hybridized, resulting in three di...
High-Quality Traineeships: Identifying What Works. Good Practice Guide
ERIC Educational Resources Information Center
National Centre for Vocational Education Research (NCVER), 2009
2009-01-01
Traineeships were introduced alongside apprenticeships to increase the reach of contracted training to a wider range of occupations and industries and to a broader range of learners (particularly women) and to improve the labour market prospects of young people. Traineeships have given hundreds of thousands of Australians access to nationally…
Computer Simulation Utilization in Graduate Behavior Therapy Training.
ERIC Educational Resources Information Center
Lambert, Matthew E.; And Others
Practicum experiences are thought to be a time for honing clinical skills and integrating content course material with clinical practice. Often, however, the range of clinical problems encountered during practica is restricted, limiting the variety of learning experiences available to practicum group members. To provide a wider range of…
NASA Technical Reports Server (NTRS)
Green, David F.; Otero, Sharon D.; Barker, Glover D.; Jones, Denise R.
2009-01-01
The Next Generation Air Transportation System (NextGen) concept for 2025 envisions the movement of large numbers of people and goods in a safe, efficient, and reliable manner. The NextGen will remove many of the constraints in the current air transportation system, support a wider range of operations, and deliver an overall system capacity up to 3 times that of current operating levels. In order to achieve the NextGen vision, research is necessary in the areas of surface traffic optimization, maximum runway capacity, reduced runway occupancy time, simultaneous single runway operations, and terminal area conflict prevention, among others. The National Aeronautics and Space Administration (NASA) is conducting Collision Avoidance for Airport Traffic (CAAT) research to develop technologies, data, and guidelines to enable Conflict Detection and Resolution (CD&R) in the Airport Terminal Maneuvering Area (ATMA) under current and emerging NextGen operating concepts. In this report, an initial concept for an aircraft-based method for CD&R in the ATMA is presented. This method is based upon previous NASA work in CD&R for runway incursion prevention, the Runway Incursion Prevention System (RIPS). CAAT research is conducted jointly under NASA's Airspace Systems Program, Airportal Project and the Aviation Safety Program, Integrated Intelligent Flight Deck Project.
Real-time classification of vehicles by type within infrared imagery
NASA Astrophysics Data System (ADS)
Kundegorski, Mikolaj E.; Akçay, Samet; Payen de La Garanderie, Grégoire; Breckon, Toby P.
2016-10-01
Real-time classification of vehicles into sub-category types poses a significant challenge within infra-red imagery due to the high levels of intra-class variation in thermal vehicle signatures caused by aspects of design, current operating duration and ambient thermal conditions. Despite these challenges, infra-red sensing offers significant generalized target object detection advantages in terms of all-weather operation and invariance to visual camouflage techniques. This work investigates the accuracy of a number of real-time object classification approaches for this task within the wider context of an existing initial object detection and tracking framework. Specifically we evaluate the use of traditional feature-driven bag of visual words and histogram of oriented gradient classification approaches against modern convolutional neural network architectures. Furthermore, we use classical photogrammetry, within the context of current target detection and classification techniques, as a means of approximating 3D target position within the scene based on this vehicle type classification. Based on photogrammetric estimation of target position, we then illustrate the use of regular Kalman filter based tracking operating on actual 3D vehicle trajectories. Results are presented using a conventional thermal-band infra-red (IR) sensor arrangement where targets are tracked over a range of evaluation scenarios.
Numerical preservation of symmetry properties of continuum problems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Caramana, E.J.; Whalen, P.
1997-12-31
The authors investigate the problem of perfectly preserving a symmetry associated naturally with one coordinate system when calculated in a different coordinate system. This allows a much wider range of problems that may be viewed as perturbations of the given symmetry to be investigated. They study the problem of preserving cylindrical symmetry in two-dimensional cartesian geometry and spherical symmetry in two-dimensional cylindrical geometry. They show that this can be achieved by a simple modification of the gradient operator used to compute the force in a staggered grid Lagrangian hydrodynamics algorithm. In the absence of the supposed symmetry they show thatmore » the new operator produces almost no change in the results because it is always close to the original gradient operator. Their technique this results in a subtle manipulation of the spatial truncation error in favor of the assumed symmetry but only to the extent that it is naturally present in the physical situation. This not only extends the range of previous algorithms and the use of new ones for these studies, but for spherical or cylindrical calculations reduces the sensitivity of the results to grid setup with equal angular zoning that has heretofore been necessary with these problems. Although this work is in two-dimensions, it does point the way to solving this problem in three-dimensions. This is particularly important for the ASCI initiative. The manner in which these results can be extended to three-dimensions will be discussed.« less
Performance of Low Temperature Electrolytes in Experimental and Prototype Li-Ion Cells
NASA Technical Reports Server (NTRS)
Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.
2007-01-01
Due to their attractive properties and proven success, Li-ion batteries have become identified as the battery chemistry of choice for a number of future NASA missions. A number of these applications would be greatly benefited by improved performance of Li-ion technology over a wider operating temperature range, especially at low temperatures, such as future ESMD missions. In many cases, these technology improvements may be mission enabling, and at the very least mission enhancing. In addition to aerospace applications, the DoE has interest in developing advanced Li-ion batteries that can operate over a wide temperature range to enable terrestrial HEV applications. Thus, our focus at JPL in recent years has been to extend the operating temperature range of Li-ion batteries, especially at low temperatures. To accomplish this, the main focus of the research has been devoted to developing improved lithium-ion conducting electrolytes. In the present paper, we would like to present some of the results we have obtained with ethylene carbonate-based electrolytes optimized for low temperature in experimental MCMB-LiNixCo1_x0 2 cells. In addition to obtaining discharge and charge rate performance data at various temperatures, electrochemical measurements were performed on individual electrodes (made possible by the incorporation of Li reference electrodes), including EIS, linear polarization and Tafel polarization measurements. The combination of techniques enables the elucidation of various trends associated with electrolyte composition. In addition to investigating the behavior in experimental cells, the performance of many promising low temperature electrolytes was demonstrated in large capacity, aerospace quality Li-ion prototype cells. These cells were subjected to a number of performance tests, including discharge rate characterization, charge rate characterization, cycle life performance at various temperatures, and power characterization tests.
Frequency pulling in a low-voltage medium-power gyrotron
NASA Astrophysics Data System (ADS)
Luo, Li; Du, Chao-Hai; Huang, Ming-Guang; Liu, Pu-Kun
2018-04-01
Many recent biomedical applications use medium-power frequency-tunable terahertz (THz) sources, such as sensitivity-enhanced nuclear magnetic resonance, THz imaging, and biomedical treatment. As a promising candidate, a low-voltage gyrotron can generate watt-level, continuous THz-wave radiation. In particular, the frequency-pulling effect in a gyrotron, namely, the effect of the electron beam parameters on the oscillation frequency, can be used to tune the operating frequency. Most previous investigations used complicated and time-consuming gyrotron nonlinear theory to study the influence of many beam parameters on the interaction performance. While gyrotron linear theory investigation demonstrates the advantages of rapidly and clearly revealing the physical influence of individual key beam parameters on the overall system performance, this paper demonstrates systematically the use of gyrotron linear theory to study the frequency-pulling effect in a low-voltage gyrotron with either a Gaussian or a sinusoidal axial-field profile. Furthermore, simulations of a gyrotron operating in the first axial mode are carried out in the framework of nonlinear theory as a contrast. Close agreement is achieved between the two theories. Besides, some interesting results are obtained. In a low-current sinusoidal-profile cavity, the ranges of frequency variation for different axial modes are isolated from each other, and the frequency tuning bandwidth for each axial mode increases by increasing either the beam voltage or pitch factor. Lowering the voltage, the total tuning ranges are squeezed and become concentrated. However, the isolated frequency regions of each axial mode cannot be linked up unless the beam current is increased, meaning that higher current operation is the key to achieving a wider and continuous tuning frequency range. The results presented in this paper can provide a reference for designing a broadband low-voltage gyrotron.
Travtek Evaluation Modeling Study
DOT National Transportation Integrated Search
1996-03-01
THE FOLLOWING REPORT DESCRIBES A MODELING STUDY THAT WAS PERFORMED TO EXTRAPOLATE, FROM THE TRAVTEK OPERATIONAL TEST DATA, A SET OF SYSTEM WIDE BENEFITS AND PERFORMANCE VALUES FOR A WIDER-SCALE DEPLOYMENT OF A TRAVTEK-LIKE SYSTEM. IN THE FIRST PART O...
Nonlinear dynamic range transformation in visual communication channels.
Alter-Gartenberg, R
1996-01-01
The article evaluates nonlinear dynamic range transformation in the context of the end-to-end continuous-input/discrete processing/continuous-display imaging process. Dynamic range transformation is required when we have the following: (i) the wide dynamic range encountered in nature is compressed into the relatively narrow dynamic range of the display, particularly for spatially varying irradiance (e.g., shadow); (ii) coarse quantization is expanded to the wider dynamic range of the display; and (iii) nonlinear tone scale transformation compensates for the correction in the camera amplifier.
Development of Portable Aerosol Mobility Spectrometer for Personal and Mobile Aerosol Measurement
Kulkarni, Pramod; Qi, Chaolong; Fukushima, Nobuhiko
2017-01-01
We describe development of a Portable Aerosol Mobility Spectrometer (PAMS) for size distribution measurement of submicrometer aerosol. The spectrometer is designed for use in personal or mobile aerosol characterization studies and measures approximately 22.5 × 22.5 × 15 cm and weighs about 4.5 kg including the battery. PAMS uses electrical mobility technique to measure number-weighted particle size distribution of aerosol in the 10–855 nm range. Aerosol particles are electrically charged using a dual-corona bipolar corona charger, followed by classification in a cylindrical miniature differential mobility analyzer. A condensation particle counter is used to detect and count particles. The mobility classifier was operated at an aerosol flow rate of 0.05 L/min, and at two different user-selectable sheath flows of 0.2 L/min (for wider size range 15–855 nm) and 0.4 L/min (for higher size resolution over the size range of 10.6–436 nm). The instrument was operated in voltage stepping mode to retrieve the size distribution, which took approximately 1–2 minutes, depending on the configuration. Sizing accuracy and resolution were probed and found to be within the 25% limit of NIOSH criterion for direct-reading instruments (NIOSH 2012). Comparison of size distribution measurements from PAMS and other commercial mobility spectrometers showed good agreement. The instrument offers unique measurement capability for on-person or mobile size distribution measurements of ultrafine and nanoparticle aerosol. PMID:28413241
NASA Technical Reports Server (NTRS)
Otero, Sharon D.; Barker, Glover D.; Jones, Denise R.
2013-01-01
The Next Generation Air Transportation System (NextGen) concept for 2025 envisions the movement of large numbers of people and goods in a safe, efficient, and reliable manner. The NextGen will remove many of the constraints in the current air transportation system, support a wider range of operations, and deliver an overall system capacity up to 3 times that of current operating levels. In order to achieve the NextGen vision, research is necessary in the areas of surface traffic optimization, maximum runway capacity, reduced runway occupancy time, simultaneous single runway operations, and terminal area conflict prevention, among others. The National Aeronautics and Space Administration (NASA) is conducting Collision Avoidance for Airport Traffic (CAAT) research to develop technologies, data, and guidelines to enable Conflict Detection and Resolution (CD&R) in the Airport Terminal Maneuvering Area (ATMA) under current and emerging NextGen operating concepts. The term ATMA was created to reflect the fact that the CD&R concept area of operation is focused near the airport within the terminal maneuvering area. In the following, an initial concept for an aircraft-based method for CD&R in the ATMA is presented. This method is based upon previous NASA work in CD&R for runway incursion prevention, the Runway Incursion Prevention System (RIPS).
Online Analysis of Wind and Solar Part I: Ramping Tool
DOE Office of Scientific and Technical Information (OSTI.GOV)
Etingov, Pavel V.; Ma, Jian; Makarov, Yuri V.
2012-01-31
To facilitate wider penetration of renewable resources without compromising system reliability concerns arising from the lack of predictability of intermittent renewable resources, a tool for use by California Independent System Operator (CAISO) power grid operators was developed by Pacific Northwest National Laboratory (PNNL) in conjunction with CAISO with funding from California Energy Commission. This tool predicts and displays additional capacity and ramping requirements caused by uncertainties in forecasts of loads and renewable generation. The tool is currently operational in the CAISO operations center. This is one of two final reports on the project.
NASA Astrophysics Data System (ADS)
Habtu, Solomon; Ludi, Eva; Jamin, Jean Yves; Oates, Naomi; Fissahaye Yohannes, Degol
2014-05-01
Practicing various innovations pertinent to irrigated farming at local field scale is instrumental to increase productivity and yield for small holder farmers in Africa. However the translation of innovations from local scale to the scale of a jointly operated irrigation scheme is far from trivial. It requires insight on the drivers for adoption of local innovations within the wider farmer communities. Participatory methods are expected to improve not only the acceptance of locally developed innovations within the wider farmer communities, but to allow also an estimation to which extend changes will occur within the entire irrigation scheme. On such a base, more realistic scenarios of future water productivity within an irrigation scheme, which is operated by small holder farmers, can be estimated. Initial participatory problem and innovation appraisal was conducted in Gumselassa small scale irrigation scheme, Ethiopia, from Feb 27 to March 3, 2012 as part of the EAU4FOOD project funded by EC. The objective was to identify and appraise problems which hinder sustainable water management to enhance production and productivity and to identify future research strategies. Workshops were conducted both at local (Community of Practices) and regional (Learning Practice Alliance) level. At local levels, intensive collaboration with farmers using participatory methods produced problem trees and a "Photo Safari" documented a range of problems that negatively impact on productive irrigated farming. A range of participatory methods were also used to identify local innovations. At regional level a Learning Platform was established that includes a wide range of stakeholders (technical experts from various government ministries, policy makers, farmers, extension agents, researchers). This stakeholder group did a range of exercise as well to identify major problems related to irrigated smallholder farming and already identified innovations. Both groups identified similar problems to productive smallholder irrigation: soil nutrient depletion, salinization, disease and pest resulting from inefficient irrigation practices, infrastructure problems leading to a reduction of the size of the command area and decrease in reservoir volume. The major causes have been poor irrigation infrastructure, poor on-farm soil and water management, prevalence of various crop pests and diseases, lack of inputs and reservoir siltation. On-farm participatory research focusing on soil, crop and water management issues, including technical, institutional and managerial aspects, to identify best performing innovations while taking care of the environment was recommended. Currently, a range of interlinked activities are implemented a multiple scales, combining participatory and scientific approaches towards innovation development and up-scaling of promising technologies and institutional and managerial approaches from local to regional scales. ____________________________ Key words: Irrigation scheme, productivity, innovation, participatory method, Gumselassa, Ethiopia
ICESAT GLAS Altimetry Measurements: Received Signal Dynamic Range and Saturation Correction
NASA Technical Reports Server (NTRS)
Sun, Xiaoli; Abshire, James B.; Borsa, Adrian A.; Fricker, Helen Amanda; Yi, Donghui; Dimarzio, John P.; Paolo, Fernando S.; Brunt, Kelly M.; Harding, David J.; Neumann, Gregory A.
2017-01-01
NASAs Ice, Cloud, and land Elevation Satellite (ICESat), which operated between 2003 and 2009, made the first satellite-based global lidar measurement of earths ice sheet elevations, sea-ice thickness, and vegetation canopy structure. The primary instrument on ICESat was the Geoscience Laser Altimeter System (GLAS), which measured the distance from the spacecraft to the earth's surface via the roundtrip travel time of individual laser pulses. GLAS utilized pulsed lasers and a direct detection receiver consisting of a silicon avalanche photodiode and a waveform digitizer. Early in the mission, the peak power of the received signal from snow and ice surfaces was found to span a wider dynamic range than anticipated, often exceeding the linear dynamic range of the GLAS 1064-nm detector assembly. The resulting saturation of the receiver distorted the recorded signal and resulted in range biases as large as approximately 50 cm for ice- and snow-covered surfaces. We developed a correction for this saturation range bias based on laboratory tests using a spare flight detector, and refined the correction by comparing GLAS elevation estimates with those derived from Global Positioning System surveys over the calibration site at the salar de Uyuni, Bolivia. Applying the saturation correction largely eliminated the range bias due to receiver saturation for affected ICESat measurements over Uyuni and significantly reduced the discrepancies at orbit crossovers located on flat regions of the Antarctic ice sheet.
ERIC Educational Resources Information Center
Sinkinson, Anne J.
2006-01-01
The research examines the range of effects of obtaining Specialist School status in two contrasting mathematics and computing colleges, concentrating on the mathematics department. The positive impact of a wider range of technology was evident in both schools although the inherent pedagogical perspectives within each mathematics department…
Sorokin, Victoria; Alkhoury, Razan; Al-Rawabdeh, Sura; Houston, Ronald H; Thornton, David; Kerlin, Bryce; O'Brien, Sarah; Baker, Peter; Boesel, Carl; Uddin, Minhaj; Yin, Han; Kahwash, Samir
This study sought to determine delta granule normal ranges for children and to validate methodology for the appropriate diagnosis of delta granule deficiency (storage pool disease) by using the whole-mount technique in electron microscopy. Specimens obtained from 40 healthy volunteers (2 months of age through 21 years old, 21 females and 19 males) were tested. Results showed dense granules/platelet (DG/Plt) ranged from 1.78 to 5.25. The 5th percentile was 1.96 DG/Plt with an overall mean ± SEM 3.07 ± 0.12 DG/Plt. In comparison, a previously published lower cutoff value, 3.68 DG/Plt, was significantly higher than the mean from our volunteers (P < 0.0001). We found no variability in dense granules/platelet based on race or sex and no significant variation by age subgroup. Pending wider studies, the value of 2 DG/Plt is a more appropriate lower limit of normal. In the absence of wider studies (in healthy volunteers and patients), laboratories should consider establishing their own reference ranges.
Extrapolation of operators acting into quasi-Banach spaces
NASA Astrophysics Data System (ADS)
Lykov, K. V.
2016-01-01
Linear and sublinear operators acting from the scale of L_p spaces to a certain fixed quasinormed space are considered. It is shown how the extrapolation construction proposed by Jawerth and Milman at the end of 1980s can be used to extend a bounded action of an operator from the L_p scale to wider spaces. Theorems are proved which generalize Yano's extrapolation theorem to the case of a quasinormed target space. More precise results are obtained under additional conditions on the quasinorm. Bibliography: 35 titles.
[Research progress of three-dimensional printing technique in joint surgery].
Wang, Fuyou; Ren, Xiang; Yang, Liu
2014-03-01
To summarize the application status of three-dimensional (3-D) printing technique in joint surgery and look forward to the future research directions. The recent original articles about the application and research of 3-D printing technique in joint surgery were extensively reviewed and analyzed. In clinical applications, 3-D printing technique can provide "tailored" treatment and custom implants for patients, which helps doctors to perform the complex operations easier and more safely; in fundamental research, tissue engineered scaffolds with desirable external shape and internal organization are easily fabricated with 3-D printing technique, which can meet the demand of cell adherence and proliferation. Even more, cells may be deposited with the biomaterials during the printing. With the development of medical imaging, digital medicine and new materials, 3-D printing technique will have a wider range of applications in joint surgery.
NASA Astrophysics Data System (ADS)
Rajchl, Martin; Abhari, Kamyar; Stirrat, John; Ukwatta, Eranga; Cantor, Diego; Li, Feng P.; Peters, Terry M.; White, James A.
2014-03-01
Multi-center trials provide the unique ability to investigate novel techniques across a range of geographical sites with sufficient statistical power, the inclusion of multiple operators determining feasibility under a wider array of clinical environments and work-flows. For this purpose, we introduce a new means of distributing pre-procedural cardiac models for image-guided interventions across a large scale multi-center trial. In this method, a single core facility is responsible for image processing, employing a novel web-based interface for model visualization and distribution. The requirements for such an interface, being WebGL-based, are minimal and well within the realms of accessibility for participating centers. We then demonstrate the accuracy of our approach using a single-center pacemaker lead implantation trial with generic planning models.
Applying fenton process in acrylic fiber wastewater treatment and practice teaching
NASA Astrophysics Data System (ADS)
Zhang, Chunhui; Jiang, Shan
2018-02-01
Acrylic fiber manufacturing wastewater, containing a wider range of pollutants, high concentration of refractory organics, poisonous and harmful matters, was significant to treat from the effluents of wastewater treatment plants (WWTPs). In this work, a Fenton reactor was employed for advanced treatment of the WWTP effluents. An orthogonal test and a parametric study were carried out to determine the effect of the main operating conditions and the Fenton process attain excellent performance on the degradation of pollutants under an optimal condition of ferrous dosage was 6.25 mM, hydrogen peroxide was 75 mM and initial pH value was 3.0 in 90 min reaction time. The removal efficiency of COD, TOC, NH4 +-N and TN reached from 45% to 69%. Lastly, as a teaching advice, the Fenton reactor was used in practicing teaching nicely.
NASA Technical Reports Server (NTRS)
Krainak, Michael A.
2015-01-01
Over the next two decades, the number of space based laser missions for mapping, spectroscopy, remote sensing and other scientific investigations will increase several fold. The demand for high wall-plug efficiency, low noise, narrow linewidth laser systems to meet different systems requirements that can reliably operate over the life of a mission will be high. The general trends will be for spatial quality very close to the diffraction limit, improved spectral performance, increased wall-plug efficiency and multi-beam processing. Improved spectral performance will include narrower spectral width (very near the transform limit), increased wavelength stability and or tuning (depending on application) and lasers reaching a wider range of wavelengths stretching into the mid-infrared and the near ultraviolet. We are actively developing high efficiency laser transmitter and high-sensitivity laser receiver systems that are suitable for spaceborne applications.
Dual-comb spectroscopy of water vapor with a free-running semiconductor disk laser.
Link, S M; Maas, D J H C; Waldburger, D; Keller, U
2017-06-16
Dual-comb spectroscopy offers the potential for high accuracy combined with fast data acquisition. Applications are often limited, however, by the complexity of optical comb systems. Here we present dual-comb spectroscopy of water vapor using a substantially simplified single-laser system. Very good spectroscopy measurements with fast sampling rates are achieved with a free-running dual-comb mode-locked semiconductor disk laser. The absolute stability of the optical comb modes is characterized both for free-running operation and with simple microwave stabilization. This approach drastically reduces the complexity for dual-comb spectroscopy. Band-gap engineering to tune the center wavelength from the ultraviolet to the mid-infrared could optimize frequency combs for specific gas targets, further enabling dual-comb spectroscopy for a wider range of industrial applications. Copyright © 2017, American Association for the Advancement of Science.
Custom Unit Pump Development for the EVA PLSS
NASA Technical Reports Server (NTRS)
Schuller, Michael; Kurwitz, Cable; Little, Frank; Oinuma, Ryoji; Larsen, Ben; Goldman, Jeff; Reinis, Filip; Trevino, Luis
2010-01-01
This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design and test a pre-flight prototype pump for use in the Extra-vehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump must accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting non-condensable gas without becoming air locked. The chosen pump design consists of a 28 V DC, brushless, seal-less, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES verified that the pump meets the design requirements for range of flow rates, pressure drop, power consumption, working fluid temperature, operating time, gas ingestion, and restart capability under both ambient and vacuum conditions. The pump operated at 40 to 240 lbm/hr flow rate, 35 to 100 oF pump temperature, and 5 to 10 psid pressure rise. Power consumption of the pump controller at the nominal operating point in both ambient and vacuum conditions was 9.5 W, which was less than the 12 W predicted. Gas ingestion capabilities were tested by injecting 100 cc of air into the fluid line; the pump operated normally throughout this test.
Andrew M. Minnis; Amy Y. Rossman; Nathan M. Kleczewski; S. Luke. Flory
2012-01-01
Many species of Bipolaris are important pathogens of grasses. This new species was isolated from Microstegium vimineum, an invasive plant in the USA. The fungus causes disease on Microstegium, but it also infects a wider range of hosts.
The Total-Pressure Recovery and Drag Characteristics of Several Auxiliary Inlets at Transonic Speeds
NASA Technical Reports Server (NTRS)
Dennard, John S.
1959-01-01
Several flush and scoop-type auxiliary inlets have been tested for a range of Mach numbers from 0.55 to 1.3 to determine their transonic total-pressure recovery and drag characteristics. The inlet dimensions were comparable with the thickness of the boundary layer in which they were tested. Results indicate that flush inlets should be inclined at very shallow angles with respect to the surface for optimum total-pressure recovery and drag characteristics. Deep, narrow inlets have lower drag than wide shallow ones at Mach numbers greater than 0.9 but at lower Mach numbers the wider inlets proved superior. Inlets with a shallow approach ramp, 7 deg, and diverging ramp walls which incorporated boundary-layer bypass had lower drag than any other inlet tested for Mach numbers up to 1.2 and had the highest pressure recovery of all of the flush inlets. The scoop inlets, which operated in a higher velocity flow than the flush inlets, had higher drag coefficients. Several of these auxiliary inlets projected multiple, periodic shock waves into the stream when they were operated at low mass-flow ratios.
Resonant Frequency Control For the PIP-II Injector Test RFQ: Control Framework and Initial Results
DOE Office of Scientific and Technical Information (OSTI.GOV)
Edelen, A. L.; Biedron, S. G.; Milton, S. V.
For the PIP-II Injector Test (PI-Test) at Fermilab, a four-vane radio frequency quadrupole (RFQ) is designed to accelerate a 30-keV, 1-mA to 10-mA, H- beam to 2.1 MeV under both pulsed and continuous wave (CW) RF operation. The available headroom of the RF amplifiers limits the maximum allowable detuning to 3 kHz, and the detuning is controlled entirely via thermal regulation. Fine control over the detuning, minimal manual intervention, and fast trip recovery is desired. In addition, having active control over both the walls and vanes provides a wider tuning range. For this, we intend to use model predictive controlmore » (MPC). To facilitate these objectives, we developed a dedicated control framework that handles higher-level system decisions as well as executes control calculations. It is written in Python in a modular fashion for easy adjustments, readability, and portability. Here we describe the framework and present the first control results for the PI-Test RFQ under pulsed and CW operation.« less
Single-crystalline aluminum film for ultraviolet plasmonic nanolasers
Chou, Bo-Tsun; Chou, Yu-Hsun; Wu, Yen-Mo; Chung, Yi-Cheng; Hsueh, Wei-Jen; Lin, Shih-Wei; Lu, Tien-Chang; Lin, Tzy-Rong; Lin, Sheng-Di
2016-01-01
Significant advances have been made in the development of plasmonic devices in the past decade. Plasmonic nanolasers, which display interesting properties, have come to play an important role in biomedicine, chemical sensors, information technology, and optical integrated circuits. However, nanoscale plasmonic devices, particularly those operating in the ultraviolet regime, are extremely sensitive to the metal and interface quality. Thus, these factors have a significant bearing on the development of ultraviolet plasmonic devices. Here, by addressing these material-related issues, we demonstrate a low-threshold, high-characteristic-temperature metal-oxide-semiconductor ZnO nanolaser that operates at room temperature. The template for the ZnO nanowires consists of a flat single-crystalline Al film grown by molecular beam epitaxy and an ultrasmooth Al2O3 spacer layer synthesized by atomic layer deposition. By effectively reducing the surface plasmon scattering and metal intrinsic absorption losses, the high-quality metal film and the sharp interfaces formed between the layers boost the device performance. This work should pave the way for the use of ultraviolet plasmonic nanolasers and related devices in a wider range of applications. PMID:26814581
NASA Astrophysics Data System (ADS)
Edera, Paolo; Bergamini, Davide; Trappe, Véronique; Giavazzi, Fabio; Cerbino, Roberto
2017-12-01
Particle-tracking microrheology (PT-μ r ) exploits the thermal motion of embedded particles to probe the local mechanical properties of soft materials. Despite its appealing conceptual simplicity, PT-μ r requires calibration procedures and operating assumptions that constitute a practical barrier to its wider application. Here we demonstrate differential dynamic microscopy microrheology (DDM-μ r ), a tracking-free approach based on the multiscale, temporal correlation study of the image intensity fluctuations that are observed in microscopy experiments as a consequence of the translational and rotational motion of the tracers. We show that the mechanical moduli of an arbitrary sample are determined correctly over a wide frequency range provided that the standard DDM analysis is reinforced with an iterative, self-consistent procedure that fully exploits the multiscale information made available by DDM. Our approach to DDM-μ r does not require any prior calibration, is in agreement with both traditional rheology and diffusing wave spectroscopy microrheology, and works in conditions where PT-μ r fails, providing thus an operationally simple, calibration-free probe of soft materials.
Sensor and tracking data integration into a common operating picture
NASA Astrophysics Data System (ADS)
Bailey, Mark E.
2003-09-01
With rapid technological developments, a new innovative range of possibilities can be actualized in mainstreaming a network with checks and balances to provide sensor and tracking data integration/information to a wider Department of Defense (DoD) audience or group of agencies. As technologies are developed, methods to display the data are required. Multiple diverse tracking devices and sensors need to be displayed on a common operating picture. Sensors and tracking devices are used to monitor an area or object for movement or boundary penetration. Tracking devices in turn determine transit patterns of humans, animals and/or vehicles. In consortium these devices can have dual applications for military requirements and for other general purposes. The DoD Counterdrug Technology Development Program Office (CDTDPO) has designed a system to distribute sensor and tracking data to multiple users in separate agencies. This information can be displayed in whole or in part as to the specific needs of the user. It is with this purpose that the Data Distribution Network (DDN) was created to disseminate information to a collective group or to a select audience.
Four Step Model for Experiential Counseling.
ERIC Educational Resources Information Center
Long, Vonda; Scherer, David
As experiential counseling gains wider acceptance, it becomes more important to operate from a structural framework promoting effective and ethical practices. This paper outlines a four-part model of experiential counseling: theoretical foundations, experiential activity and personnel, processing and communication skills, and prerequisites for…
Wide range stress intensity factor expressions for ASTM E 399 standard fracture toughness specimens
NASA Technical Reports Server (NTRS)
Srawley, J. E.
1976-01-01
For each of the two types of specimens, bend and compact, described previously for plane strain fracture toughness of materials, E 399, a polynominal expression is given for calculation of the stress intensity factor, K, from the applied force, P, and the specimen dimensions. It is explicitly stated, however, that these expressions should not be used outside the range of relative crack length, a/W, from 0.45 to 0.55. While this range is sufficient for the purpose of E 399, the same specimen types are often used for other purposes over a much wider range of a/W; for example, in the study of fatigue crack growth. Expressions are presented which are at least as accurate as those in E 399-74, and which cover much wider ranges of a/W: for the three-point bend specimen from 0 to 1; and for the compact specimen from 0.2 to 1. The range has to be restricted for the compact specimen because of the proximity of the loading pin holes to the crackline, which causes the stress intensity factor to be sensitive to small variations in dimensions when a/W is small. This is a penalty inherently associated with the compactness of the specimen.
Improved density discrimination using agfacontour film
NASA Technical Reports Server (NTRS)
Goodding, R. A.
1973-01-01
A technique was developed for obtaining tone separations from black and white photographic materials. Agfacontour film and photographic derivatives are utilized to improve the density discrimination and decrease the density range from 0.45 to 0.08 units. This increase in capability extends the usefulness of tone separations to a wider range of subject matter and problem areas.
Applications of subseasonal-to-seasonal (S2S) predictions
NASA Astrophysics Data System (ADS)
White, Christopher; Lamb, Rob; Carlsen, Henrik; Robertson, Andrew; Klein, Richard; Lazo, Jeffrey; Kumar, Arun; Vitart, Frederic; Coughlan de Perez, Erin; Ray, Andrea; Murray, Virginia; Graham, Richard; Buontempo, Carlo
2017-04-01
While long-range seasonal outlooks have been operational for many years, until recently the extended-range timescale - referred to as 'subseasonal-to-seasonal' (S2S) and which sits between the medium- to long-range forecasting timescales - has received relatively little attention. The S2S timescale has long been seen as a 'predictability desert', yet a new generation of S2S predictions are starting to bridge the gap between weather forecasts and longer-range prediction. Decisions in a range of sectors are made in this extended-range lead time, therefore there is a strong demand for this new generation of predictions. At least ten international weather centres now have some capability for issuing experimental or operational S2S predictions, including the European Centre for Medium-Range Weather Forecasting (ECMWF) and the National Oceanic and Atmospheric Administration (NOAA) that now have operational S2S outputs. International efforts are now underway to identify key sources of predictability, improve forecast skill and operationalise aspects of S2S forecasts, however challenges remain in advancing this new frontier. If S2S predictions are to be utilised effectively, it is important that along with science advances, we learn how to develop, communicate and apply these forecasts appropriately. In this study, we present the potential of the emerging operational S2S forecasts to the wider weather and climate applications community by undertaking the first comprehensive review of sectoral applications of S2S predictions, including public health, disaster preparedness, water management, energy and agriculture. We explore the value of applications-relevant S2S predictions, and highlight the opportunities and challenges facing their uptake. We show how social sciences can be integrated with S2S development - from communication to decision-making and valuation of forecasts - to enhance the benefits of 'climate services' approaches for extended-range forecasting. We highlight the availability of data repositories of near real-time S2S forecasts and hindcasts, including the WWRP-WCRP (http://apps.ecmwf.int/datasets/data/s2s) and North American Multimodel Ensemble (NMME; http://www.cpc.ncep.noaa.gov/products/NMME/data.html) repositories, and discuss how they are promoting the use (and aiding the development) of S2S predictions. While S2S forecasting is at a relatively early stage of development, we conclude that it presents a significant new window of opportunity that can be explored for application-ready capabilities that could allow many sectors the opportunity to systematically plan on a new time horizon.
NASA Astrophysics Data System (ADS)
Mishra, Arpit; Ghosh, Parthasarathi
2017-02-01
As a part of the developmental effort towards the realization of a staged combustion cycle based liquid rocket engine, a program on simulation of the LOX booster pump for performance characterization has been taken up. Earlier reported work shows that the pump inducer works satisfactorily under cavitating conditions for the throttling range varying from 90% to 113%. However stall occurs below 90% of the designed flow rate which is to be strongly associated with the inlet backflow vortices due to flow separation [1]. It is envisaged that leading edge sweep may help in to controls the incipience and growth of the backflow vortices at the inlet leading edge tip of axial flow inducer leading to a wider operating range. In this paper, steady state 3D CFD analysis of rotating inducer is performed to examine the effect of leading edge sweep on the performance of axial flow LOX pump inducer using ANSYS® CFX and has been compared with the performance of the inducer reported by Mishra and Ghosh [1].
Deng, Z D; Lu, J; Myjak, M J; Martinez, J J; Tian, C; Morris, S J; Carlson, T J; Zhou, D; Hou, H
2014-11-01
Acceleration in development of additional conventional hydropower requires tools and methods to perform laboratory and in-field validation of turbine performance and fish passage claims. The new-generation Sensor Fish has been developed with more capabilities to accommodate a wider range of users over a broader range of turbine designs and operating environments. It provides in situ measurements of three-dimensional (3D) linear accelerations, 3D rotational velocities, 3D orientation, pressure, and temperature at a sampling frequency of 2048 Hz. It also has an automatic floatation system and built-in radio-frequency transmitter for recovery. The relative errors of the pressure, acceleration, and rotational velocity were within ±2%, ±5%, and ±5%, respectively. The accuracy of orientation was within ±4° and accuracy of temperature was ±2 °C. The new-generation Sensor Fish is becoming a major technology and being deployed for evaluating the conditions for fish passage of turbines or other hydraulic structures in both the United States and several other countries.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dubberke, Frithjof H.; Baumhögger, Elmar; Vrabec, Jadran, E-mail: jadran.vrabec@upb.de
2015-05-15
The pulse-echo technique determines the propagation time of acoustic wave bursts in a fluid over a known propagation distance. It is limited by the signal quality of the received echoes of the acoustic wave bursts, which degrades with decreasing density of the fluid due to acoustic impedance and attenuation effects. Signal sampling is significantly improved in this work by burst design and signal processing such that a wider range of thermodynamic states can be investigated. Applying a Fourier transformation based digital filter on acoustic wave signals increases their signal-to-noise ratio and enhances their time and amplitude resolutions, improving the overallmore » measurement accuracy. In addition, burst design leads to technical advantages for determining the propagation time due to the associated conditioning of the echo. It is shown that the according operation procedure enlarges the measuring range of the pulse-echo technique for supercritical argon and nitrogen at 300 K down to 5 MPa, where it was limited to around 20 MPa before.« less
Silicon avalanche photodiodes developed at the Institute of Electron Technology
NASA Astrophysics Data System (ADS)
Wegrzecka, Iwona; Wegrzecki, Maciej; Bar, Jan; Grynglas, Maria; Uszynski, Andrzej; Grodecki, Remigiusz; Grabiec, Piotr B.; Krzeminski, Sylwester; Budzynski, Tadeusz
2004-07-01
Silicon avalanche photodiodes (APDs) -- due to the effect of avalanche multiplication of carriers in their structure -- are most sensitive and fastest detectors of visible and near infrared radiation. Also the value of noise equivalent power NEP of these detectors is the smallest. In the paper, the design, technology and properties of the silicon avalanche photodiodes with a n+ - p - π - p+ epiplanar structure developed at the Institute of Electron Technology (ITE) are presented. The diameters of photosensitive area range from 0.3 mm to 5 mm. The ITE photodiodes are optimized for the detection of the 800 nm - 850 nm radiation, but the detailed research on spectral dependencies of the gain and noise parameters has revealed that the spectral operating range of the ITE photodiodes is considerable wider and achieves 550 - 1000 nm. These photodiodes can be used in detection of very weak and very fast optical signals. Presently in the world, the studies are carried out on applying the avalanche photodiodes in detection of X radiation and in the scintillation detection of nuclear radiation.
Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector
NASA Technical Reports Server (NTRS)
Huntington, Andrew
2013-01-01
The purpose of this program was to develop single-photon-sensitive short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode photon-counting APDs are desired for lidar because they have a shorter pixel dead time than Geiger APDs, and can detect sequential pulse returns from multiple objects that are closely spaced in range. Linear-mode APDs can also measure photon number, which Geiger APDs cannot, adding an extra dimension to lidar scene data for multi-photon returns. High-gain APDs with low multiplication noise are required for efficient linear-mode detection of single photons because of APD gain statistics -- a low-excess-noise APD will generate detectible current pulses from single photon input at a much higher rate of occurrence than will a noisy APD operated at the same average gain. MWIR and LWIR electron-avalanche HgCdTe APDs have been shown to operate in linear mode at high average avalanche gain (M > 1000) without excess multiplication noise (F = 1), and are therefore very good candidates for linear-mode photon counting. However, detectors fashioned from these narrow-bandgap alloys require aggressive cooling to control thermal dark current. Wider-bandgap SWIR HgCdTe APDs were investigated in this program as a strategy to reduce detector cooling requirements.
Standoff concealed weapon detection using a 350-GHz radar imaging system
NASA Astrophysics Data System (ADS)
Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick L. J.
2010-04-01
The sub-millimeter (sub-mm) wave frequency band from 300 - 1000 GHz is currently being developed for standoff concealed weapon detection imaging applications. This frequency band is of interest due to the unique combination of high resolution and clothing penetration. The Pacific Northwest National Laboratory (PNNL) is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff detection. Standoff concealed weapon and explosive detection is a pressing national and international need for both civilian and military security, as it may allow screening at safer distances than portal screening techniques. PNNL has developed a prototype active wideband 350 GHz radar imaging system based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. This prototype system operates at ranges up to 10+ meters, and can acquire an image in 10 - 20 seconds, which is fast enough to scan cooperative personnel for concealed weapons. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. During the past year, several improvements to the system have been designed and implemented, including increased imaging speed using improved balancing techniques, wider bandwidth, and improved image processing techniques. In this paper, the imaging system is described in detail and numerous imaging results are presented.
NASA Astrophysics Data System (ADS)
Pandey, Gaind P.; Klankowski, Steven A.; Liu, Tao; Wu, Judy; Li, Jun
2017-02-01
A novel solid-state battery-supercapacitor hybrid device is fabricated for high-performance electrical energy storage using a Si anode and a TiO2 cathode in conjunction with a flexible, solid-like gel polymer electrolyte film as the electrolyte and separator. The electrodes were fabricated as three-dimensional nanostructured vertical arrays by sputtering active materials as conformal shells on vertically aligned carbon nanofibers (VACNFs) which serve as the current collector and structural template. Such nanostructured vertical core-shell array-electrodes enable short Li-ion diffusion path and large pseudocapacitive contribution by fast surface reactions, leading to the hybrid features of batteries and supercapacitors that can provide high specific energy over a wide range of power rates. Due to the improved mechanical stability of the infiltrated composite structure, the hybrid cell shows excellent cycling stability and is able to retain more than 95% of the original capacity after 3500 cycles. More importantly, this solid-state device can stably operate in a temperature range from -20 to 60 °C with a very low self-discharge rate and an excellent shelf life. This solid-state architecture is promising for the development of highly stable thin-film hybrid energy storage devices for unconventional applications requiring largely varied power, wider operation temperature, long shelf-life and higher safety standards.
75 FR 17410 - Agency Forms Undergoing Paperwork Reduction Act Review
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-06
... the practical barriers that may prevent wider adoption of NIOSH recommendations and practices designed to safeguard mine workers. In the Spring of 2007, NIOSH conducted a pretest of the survey questionnaire with nine underground coal mine operators. The pretest instrument contained 81 questions...
Distribution of Causes in Selected US Aviation Accident Reports Between 1996 and 2003
NASA Technical Reports Server (NTRS)
Holloway, C. M.; Johnson, C. W.
2004-01-01
This paper describes the results of an independent analysis of the probable and contributory causes of selected aviation accidents in the United States between 1996 and 2003. The purpose of the study was to assess the comparative frequency of a variety of causal factors in the reporting of these adverse events. Although our results show that more of these high consequence accidents were attributed to human error than to any other single factor, a large number of reports also mentioned wider systemic issues, including the managerial and regulatory context of aviation operations. These wider issues are more likely to appear as contributory rather than primary causes in this set of accident reports.
NASA Astrophysics Data System (ADS)
Knudson, Christa K.; Kemp, Michael C.; Lombardo, Nicholas J.
2009-05-01
The U.S. Department of Homeland Security's Standoff Technology Integration and Demonstration Program is designed to accelerate the development and integration of technologies, concepts of operations, and training to defeat explosives attacks at large public events and mass transit facilities. The program will address threats posed by suicide bombers, vehicle-borne improvised explosive devices, and leave-behind bombs. The program is focused on developing and testing explosives countermeasure architectures using commercial off-the-shelf and near-commercial standoff and remotely operated detection technologies in prototypic operational environments. An important part of the program is the integration of multiple technologies and systems to protect against a wider range of threats, improve countermeasure performance, increase the distance from the venue at which screening is conducted, and reduce staffing requirements. The program will routinely conduct tests in public venues involving successively more advanced technology, higher levels of system integration, and more complex scenarios. This paper describes the initial field test of an integrated countermeasure system that included infrared, millimeter-wave, and video analytics technologies for detecting person-borne improvised explosive devices at a public arena. The test results are being used to develop a concept for the next generation of integrated countermeasures, to refine technical and operational requirements for architectures and technologies, and engage industry and academia in solution development.
Asymmetry of projected increases in extreme temperature distributions
Kodra, Evan; Ganguly, Auroop R.
2014-01-01
A statistical analysis reveals projections of consistently larger increases in the highest percentiles of summer and winter temperature maxima and minima versus the respective lowest percentiles, resulting in a wider range of temperature extremes in the future. These asymmetric changes in tail distributions of temperature appear robust when explored through 14 CMIP5 climate models and three reanalysis datasets. Asymmetry of projected increases in temperature extremes generalizes widely. Magnitude of the projected asymmetry depends significantly on region, season, land-ocean contrast, and climate model variability as well as whether the extremes of consideration are seasonal minima or maxima events. An assessment of potential physical mechanisms provides support for asymmetric tail increases and hence wider temperature extremes ranges, especially for northern winter extremes. These results offer statistically grounded perspectives on projected changes in the IPCC-recommended extremes indices relevant for impacts and adaptation studies. PMID:25073751
A compact CCD-monitored atomic force microscope with optical vision and improved performances.
Mingyue, Liu; Haijun, Zhang; Dongxian, Zhang
2013-09-01
A novel CCD-monitored atomic force microscope (AFM) with optical vision and improved performances has been developed. Compact optical paths are specifically devised for both tip-sample microscopic monitoring and cantilever's deflection detecting with minimized volume and optimal light-amplifying ratio. The ingeniously designed AFM probe with such optical paths enables quick and safe tip-sample approaching, convenient and effective tip-sample positioning, and high quality image scanning. An image stitching method is also developed to build a wider-range AFM image under monitoring. Experiments show that this AFM system can offer real-time optical vision for tip-sample monitoring with wide visual field and/or high lateral optical resolution by simply switching the objective; meanwhile, it has the elegant performances of nanometer resolution, high stability, and high scan speed. Furthermore, it is capable of conducting wider-range image measurement while keeping nanometer resolution. Copyright © 2013 Wiley Periodicals, Inc.
Anna Schoettle; S. G. Rochelle
2000-01-01
Limber pine (Pinus flexilis James) grows across a wider range of elevations than any other tree species in the central Rockies, from ;1600 m at Pawnee Buttes to .3300 m at Rollins Pass. In this study we investigated two possible explanations for limber pineâs success across a broad range of elevations: (1) the sites on which it is found, although separated by...
Experimental and Computational Study of Trapped Vortex Combustor Sector Rig With Tri-Pass Diffuser
NASA Technical Reports Server (NTRS)
Hendricks, R. C.; Shouse, D. T.; Roquernore, W. M.; Burrus, D. L.; Duncan, B. S.; Ryder, R. C.; Brankovic, A.; Liu, N.-S.; Gallagher, J. R.; Hendricks, J. A.
2004-01-01
The Trapped Vortex Combustor (TVC) potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO) performance. Computational fluid dynamics (CFD) simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.
A long-wave infrared hyperspectral sensor for Shadow class UAVs
NASA Astrophysics Data System (ADS)
Lucey, P. G.; Akagi, Jason T.; Hinrichs, John L.; Crites, S. T.; Wright, R.
2013-05-01
The University of Hawaii has developed a concept to ruggedize an existing thermal infrared hyperspectral system for use in the NASA SIERRA UAV. The Hawaii Institute of Geophysics and Planetology has developed a suite of instruments that acquire high spectral resolution thermal infrared image data with low mass and power consumption by combining microbolometers with stationary interferometers, allowing us to achieve hyperspectral resolution (20 wavenumbers between 8 and 14 micrometers), with signal to noise ratios as high as 1500:1. Several similar instruments have been developed and flown by our research group. One recent iteration, developed under NASA EPSCoR funding and designed for inclusion on a microsatellite (Thermal Hyperspectral Imager; THI), has a mass of 11 kg. Making THI ready for deployment on the SIERRA will involve incorporating improvements made in building nine thermal interferometric hyperspectral systems for commercial and government sponsors as part of HIGP's wider program. This includes: a) hardening the system for operation in the SIERRA environment, b) compact design for the calibration system, c) reconfiguring software for autonomous operation, d) incorporating HIGP-developed detectors with increased responsiveness at the 8 micron end of the TIR range, and e) an improved interferometer to increase SNR for imaging at the SIERRA's air speed. UAVs provide a unique platform for science investigations that the proposed instrument, UAVTHI, will be well placed to facilitate (e.g. very high temporal resolution measurements of temporally dynamic phenomena, such as wildfires and volcanic ash clouds). Its spectral range is suited to measuring gas plumes, including sulfur dioxide and carbon dioxide, which exhibit absorption features in the 8 to 14 micron range.
Cope, Alexandra C; Mavroveli, Stella; Bezemer, Jeff; Hanna, George B; Kneebone, Roger
2015-08-01
The authors aimed to map and explicate what surgeons perceive they learn in the operating room. The researchers used a grounded theory method in which data were iteratively collected through semistructured one-to-one interviews in 2010 and 2011 at four participating hospital sites. A four-person data analysis team from differing academic backgrounds qualitatively analyzed the content of the transcripts employing an immersion/crystallization approach. Participants were 22 UK surgeons, some of whom were in training at the time of the study and some of whom were attending surgeons. Major themes of learning in the operating room were perceived to be factual knowledge, motor skills, sensory semiosis, adaptive strategies, team working and management, and attitudes and behaviors. The analysis team classified 277 data points (short paragraphs or groups of sentences conveying meaning) under these major themes and subthemes. A key component of learning in the operating room that emerged from these data was sensory semiosis, defined as learning to make sense of visual and haptic cues. Although the authors found that learning in the operating room occurred across a wide range of domains, sensory semiosis was found to be an important theme that has not previously been fully acknowledged or discussed in the surgical literature. The discussion draws on the wider literature from the social sciences and cognitive psychology literature to examine how professionals learn to make meaning from "signs" making parallels with other medical specialties.
Persistence and Cultural Maintenance Correlates of Change Obstruction.
ERIC Educational Resources Information Center
McGill, Jerrie L. B.
This dissertation suggests that persistence in concert with the force of resistance, exists within individual educators and the educational subsystem, and operates to maintain existing sociocultural structures. Anthropological explanations of the change process were examined with an indication that within the wider cultural milieu the educational…
The Effects of Working Memory on Brain-Computer Interface Performance
Sprague, Samantha A.; McBee, Matthew; Sellers, Eric W.
2015-01-01
Objective The purpose of the present study is to evaluate the relationship between working memory and BCI performance. Methods Participants took part in two separate sessions. The first session consisted of three computerized tasks. The LSWM was used to measure working memory, the TPVT was used to measure general intelligence, and the DCCS was used to measure executive function, specifically cognitive flexibility. The second session consisted of a P300-based BCI copy-spelling task. Results The results indicate that both working memory and general intelligence are significant predictors of BCI performance. Conclusions This suggests that working memory training could be used to improve performance on a BCI task. Significance Working memory training may help to reduce a portion of the individual differences that exist in BCI performance allowing for a wider range of users to successfully operate the BCI system as well as increase the BCI performance of current users. PMID:26620822
The LSST metrics analysis framework (MAF)
NASA Astrophysics Data System (ADS)
Jones, R. L.; Yoachim, Peter; Chandrasekharan, Srinivasan; Connolly, Andrew J.; Cook, Kem H.; Ivezic, Željko; Krughoff, K. S.; Petry, Catherine; Ridgway, Stephen T.
2014-07-01
We describe the Metrics Analysis Framework (MAF), an open-source python framework developed to provide a user-friendly, customizable, easily-extensible set of tools for analyzing data sets. MAF is part of the Large Synoptic Survey Telescope (LSST) Simulations effort. Its initial goal is to provide a tool to evaluate LSST Operations Simulation (OpSim) simulated surveys to help understand the effects of telescope scheduling on survey performance, however MAF can be applied to a much wider range of datasets. The building blocks of the framework are Metrics (algorithms to analyze a given quantity of data), Slicers (subdividing the overall data set into smaller data slices as relevant for each Metric), and Database classes (to access the dataset and read data into memory). We describe how these building blocks work together, and provide an example of using MAF to evaluate different dithering strategies. We also outline how users can write their own custom Metrics and use these within the framework.
NASA Astrophysics Data System (ADS)
Bieroza, Magdalena
2017-04-01
High-frequency nutrient (phosphorus and nitrogen) monitoring using wet-chemistry analysers and optical sensors has revolutionised the collection of biogeochemical data from streams, rivers and lakes. Matching the nutrient measurement time with timescales of hydrological responses has revealed biogeochemical patterns and nutrient hydrological responses not observed previously. Capturing a wider range of nutrient concentrations compared to traditional coarse resolution sampling enables more accurate estimation of mean concentrations and loads and thus improved water body classification. However, to date the scientific insights from the high-frequency nutrient monitoring studies have not been translated into policy and operational responses. The pertinent question is where and how often to measure nutrients to satisfy statutory monitoring requirements for the Water Framework Directive and the Nitrates Directive. Therefore this paper discusses how the reduced data uncertainty and improved process understanding obtained with the high-frequency measurements can improve statutory nutrient monitoring, using case studies from England and Sweden.
Knowledge-based load leveling and task allocation in human-machine systems
NASA Technical Reports Server (NTRS)
Chignell, M. H.; Hancock, P. A.
1986-01-01
Conventional human-machine systems use task allocation policies which are based on the premise of a flexible human operator. This individual is most often required to compensate for and augment the capabilities of the machine. The development of artificial intelligence and improved technologies have allowed for a wider range of task allocation strategies. In response to these issues a Knowledge Based Adaptive Mechanism (KBAM) is proposed for assigning tasks to human and machine in real time, using a load leveling policy. This mechanism employs an online workload assessment and compensation system which is responsive to variations in load through an intelligent interface. This interface consists of a loading strategy reasoner which has access to information about the current status of the human-machine system as well as a database of admissible human/machine loading strategies. Difficulties standing in the way of successful implementation of the load leveling strategy are examined.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Medros, F.G.; Eldridge, J.W.; Kittrell, J.R.
1989-08-01
The objective of the research discussed in this paper was to determine if a dual-catalyst system for NO reduction with NH/sub 3/ can achieve a given percent NO reduction over a wider range of temperatures and space velocities than either catalyst used alone in the same total reactor volume. Hydrogen mordenite (20/32 mesh) and copper-ion-exchanged hydrogen mordenite (2.2% Cu) were used in series at temperatures from 200 to 600 {sup 0}C and space velocities from 1000000 to 450000 h/sup -1/ (STP). The superiority of the dual-catalyst system was demonstrated experimentally, and a model was developed which predicted its performance verymore » well from data on the individual catalysts. A technique was then developed for predicting quantitatively the dual-catalyst enhancement of the space velocity versus temperature window for achieving a given percent NO conversion.« less
Is Self-organization a Rational Expectation?
NASA Astrophysics Data System (ADS)
Luediger, Heinz
Over decades and under varying names the study of biology-inspired algorithms applied to non-living systems has been the subject of a small and somewhat exotic research community. Only the recent coincidence of a growing inability to master the design, development and operation of increasingly intertwined systems and processes, and an accelerated trend towards a naïve if not romanticizing view of nature in the sciences, has led to the adoption of biology-inspired algorithmic research by a wider range of sciences. Adaptive systems, as we apparently observe in nature, are meanwhile viewed as a promising way out of the complexity trap and, propelled by a long list of ‘self’ catchwords, complexity research has become an influential stream in the science community. This paper presents four provocative theses that cast doubt on the strategic potential of complexity research and the viability of large scale deployment of biology-inspired algorithms in an expectation driven world.
Development of a combined feed forward-feedback system for an electron Linac
NASA Astrophysics Data System (ADS)
Meier, E.; Biedron, S. G.; LeBlanc, G.; Morgan, M. J.; Wu, J.
2009-10-01
This paper describes the results of an advanced control algorithm for the stabilization of electron beam energy in a Linac. The approach combines a conventional Proportional-Integral (PI) controller with a neural network (NNET) feed forward algorithm; it utilizes the robustness of PI control and the ability of a feed forward system in order to exert control over a wider range of frequencies. The NNET is trained to recognize jitter occurring in the phase and voltage of one of the klystrons, based on a record of these parameters, and predicts future energy deviations. A systematic approach is developed to determine the optimal NNET parameters that are then applied to the Australian Synchrotron Linac. The system's capability to fully cancel multi-frequency jitter is demonstrated. The NNET system is then augmented with the PI algorithm, and further jitter attenuation is achieved when the NNET is not operating optimally.
NASA Technical Reports Server (NTRS)
Venter, Gerhard; Sobieszczanski-Sobieski Jaroslaw
2002-01-01
The purpose of this paper is to show how the search algorithm known as particle swarm optimization performs. Here, particle swarm optimization is applied to structural design problems, but the method has a much wider range of possible applications. The paper's new contributions are improvements to the particle swarm optimization algorithm and conclusions and recommendations as to the utility of the algorithm, Results of numerical experiments for both continuous and discrete applications are presented in the paper. The results indicate that the particle swarm optimization algorithm does locate the constrained minimum design in continuous applications with very good precision, albeit at a much higher computational cost than that of a typical gradient based optimizer. However, the true potential of particle swarm optimization is primarily in applications with discrete and/or discontinuous functions and variables. Additionally, particle swarm optimization has the potential of efficient computation with very large numbers of concurrently operating processors.
Maximizing noise energy for noise-masking studies.
Jules Étienne, Cédric; Arleo, Angelo; Allard, Rémy
2017-08-01
Noise-masking experiments are widely used to investigate visual functions. To be useful, noise generally needs to be strong enough to noticeably impair performance, but under some conditions, noise does not impair performance even when its contrast approaches the maximal displayable limit of 100 %. To extend the usefulness of noise-masking paradigms over a wider range of conditions, the present study developed a noise with great masking strength. There are two typical ways of increasing masking strength without exceeding the limited contrast range: use binary noise instead of Gaussian noise or filter out frequencies that are not relevant to the task (i.e., which can be removed without affecting performance). The present study combined these two approaches to further increase masking strength. We show that binarizing the noise after the filtering process substantially increases the energy at frequencies within the pass-band of the filter given equated total contrast ranges. A validation experiment showed that similar performances were obtained using binarized-filtered noise and filtered noise (given equated noise energy at the frequencies within the pass-band) suggesting that the binarization operation, which substantially reduced the contrast range, had no significant impact on performance. We conclude that binarized-filtered noise (and more generally, truncated-filtered noise) can substantially increase the energy of the noise at frequencies within the pass-band. Thus, given a limited contrast range, binarized-filtered noise can display higher energy levels than Gaussian noise and thereby widen the range of conditions over which noise-masking paradigms can be useful.
Update on Emergency Department Visits Involving Energy Drinks: A Continuing Public Health Concern
... concentrated forms of energy drinks, known as energy shots, have become increasingly popular among a wider range ... 3 Marketing analysts reported increasing sales of energy shots in 2011 that were expected to continue through ...
Glavičić, Snježana; Anić, Ivica; Braut, Alen; Miletić, Ivana; Borčić, Josipa
2011-08-01
The purpose was to measure and analyse the vertical force and torque developed in the wider and narrower root canals during hand ProTaper instrumentation. Twenty human incisors were divided in two groups. Upper incisors were experimental model for the wide, while the lower incisors for the narrow root canals. Measurements of the force and torque were done by a device constructed for this purpose. Differences between the groups were statistically analysed by Mann-Whitney U-test with the significance level set to P<0.05. Vertical force in the upper incisors ranged 0.25-2.58 N, while in the lower incisors 0.38-6.94 N. Measured torque in the upper incisors ranged 0.53-12.03 Nmm, while in the lower incisor ranged 0.94-10.0 Nmm. Vertical force and torque were higher in the root canals of smaller diameter. The increase in the contact surface results in increase of the vertical force and torque as well in both narrower and wider root canals. © 2010 The Authors. Australian Endodontic Journal © 2010 Australian Society of Endodontology.
Vertical III-nitride thin-film power diode
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wierer, Jr., Jonathan; Fischer, Arthur J.; Allerman, Andrew A.
2017-03-14
A vertical III-nitride thin-film power diode can hold off high voltages (kV's) when operated under reverse bias. The III-nitride device layers can be grown on a wider bandgap template layer and growth substrate, which can be removed by laser lift-off of the epitaxial device layers grown thereon.
ERIC Educational Resources Information Center
Kuzyk, Raya
2007-01-01
Disaster planning focuses on future function and recovery, on helping libraries expeditiously return to their original states of operation. It all but ignores the concept of continuous function throughout a disaster. This is not true in the private and government sectors, however, which have managed to cover a wider load of disaster response…
Social Partnership: The Wider Context
ERIC Educational Resources Information Center
Bangs, John
2006-01-01
The Department for Education and Skills refers consistently to the Social Partnership Agreement (SPA) with unions representing teachers and support staff in education. Those inside the partnership will have their own perspectives on its operation. This article does not seek to describe, therefore, the day to day relationships of unions, Government…
Cooper, Virgil N; Oshiro, Thomas; Cagnon, Christopher H; Bassett, Lawrence W; McLeod-Stockmann, Tyler M; Bezrukiy, Nikita V
2003-10-01
Digital detectors in mammography have wide dynamic range in addition to the benefit of decoupled acquisition and display. How wide the dynamic range is and how it compares to film-screen systems in the clinical x-ray exposure domain are unclear. In this work, we compare the effective dynamic ranges of film-screen and flat panel mammography systems, along with the dynamic ranges of their component image receptors in the clinical x-ray exposure domain. An ACR mammography phantom was imaged using variable mAs (exposure) values for both systems. The dynamic range of the contrast-limited film-screen system was defined as that ratio of mAs (exposure) values for a 26 kVp Mo/Mo (HVL=0.34 mm Al) beam that yielded passing phantom scores. The same approach was done for the noise-limited digital system. Data from three independent observers delineated a useful phantom background optical density range of 1.27 to 2.63, which corresponded to a dynamic range of 2.3 +/- 0.53. The digital system had a dynamic range of 9.9 +/- 1.8, which was wider than the film-screen system (p<0.02). The dynamic range of the film-screen system was limited by the dynamic range of the film. The digital detector, on the other hand, had an estimated dynamic range of 42, which was wider than the dynamic range of the digital system in its entirety by a factor of 4. The generator/tube combination was the limiting factor in determining the digital system's dynamic range.
Using Drama to Support Literacy: Activities for Children Aged 7 to 14
ERIC Educational Resources Information Center
Goodwin, John
2006-01-01
The power of drama provides a real context for narrative writing, and in this book the tool kit of drama strategies has been laid out and used effectively by teachers across a wider range of imaginary contexts. Using drama makes possible a vast range of themes and story contexts which enthuse and hook children into the writing process. The real…
Active MRI tracking for robotic assisted FUS
NASA Astrophysics Data System (ADS)
Xiao, Xu; Huang, Zhihong; Melzer, Andreas
2017-03-01
MR guided FUS is a noninvasive method producing thermal necrosis at the position of tumors with high accuracy and temperature control. Because the typical size of the ultrasound focus is smaller than the area of interested treatment tissues, focus repositioning become necessary to achieve multiple sonications to cover the whole targeted area. Using MR compatible mechanical actuators could help the ultrasound beam to reach a wider treatment range than using electrical beam steering technique and more flexibility in position the transducer. An active MR tracking technique was combined into the MRgFUS system to help locating the position of the mechanical actuator and the FUS transducer. For this study, a precise agar reference model was designed and fabricated to test the performance of the active tracking technique when it was used on the MR-compatible robotics InnoMotion™ (IBSMM, Engineering spol. s r.o. / Ltd, Czech Republic). The precision, tracking range and positioning speed of the combined robotic FUS system were evaluated in this study. Compared to the existing MR guided HIFU systems, the combined robotic system with active tracking techniques provides a potential that allows the FUS treatment to operate in a larger spatial range and with a faster speed, which is one of the main challenges for organ motion tracking.
Sawalha, Ihab H; Meaton, Julia
2012-01-01
Culture is important to individuals and societies, as well as organisations. Failing to address cultural aspects will hinder the wider adoption and development of business continuity management (BCM) and will subsequently increase the vulnerabilities of organisations to crises, disasters and business interruptions. Three main issues are discussed in this paper. The first is the background to culture and the characteristics of the Jordanian culture. Secondly, the influence of the Arab culture on the wider adoption and development of BCM in Jordan is considered. Thirdly, the paper looks at potential factors that underpin the role of culture in the BCM process in Jordan. These issues are significant, as they represent the characteristics and influence of the Arab culture. This paper contributes to the understanding of the significance of culture in the adoption and development of BCM for organisations operating in Jordan and in the Arab world more generally. It also highlights current cultural changes and trends taking place in the Arab world in a time of huge political instability in the Middle East and Arab countries.
Soviet strategic air defense: The struggle for competence
DOE Office of Scientific and Technical Information (OSTI.GOV)
Quinlivan, J.T.
1989-10-01
All militaries face the problem of training in peace to prepare for war. Peacetime desires for safety, comfort and the accommodation of inertia frequently permit a certain formalism to creep into peacetime training. Formalism or pencil-whipping the training schedules comes to prominence when the shams of peacetime operations are stripped away by real wars or war-like incidents. The Soviet Air Defense Force, hereafter PVO, has been especially unlucky in the variety of incidents that have highlighted training deficiencies. In the Brezhnev period, incidents of incompetence could be resolved by simple punishment of the people involved and no wider implications weremore » drawn. In a period of glasnost and political debate, wider implications are always drawn. In a period of glasnost and political debate, wider implications are always drawn. PVO is working hard to overcome the widespread impression of PVO incompetence highlighted when Matthias Rust landed in Red Square. PVO must demonstrate its day-to-day competence and prudent expenditure of resources in order to assure its access to continued support for new systems and a good share of the best conscripts and officer cadets.« less
Jorge, Fátima; Perera, Ana; Poulin, Robert; Roca, Vicente; Carretero, Miguel A
2018-01-01
Episodes of expansion and isolation in geographic range over space and time, during which parasites have the opportunity to expand their host range, are linked to the development of host-parasite mosaic assemblages and parasite diversification. In this study, we investigated whether island colonization events lead to host range oscillations in a taxon of host-specific parasitic nematodes of the genus Spauligodon in the Canary Islands. We further investigated whether range oscillations also resulted in shifts in host breadth (i.e., specialization), as expected for parasites on islands. Parasite phylogeny and divergence time estimates were inferred from molecular data with Bayesian methods. Host divergence times were set as calibration priors after a priori evaluation with a global-fit method of which individual host-parasite associations likely represent cospeciation links. Parasite colonization history was reconstructed, followed by an estimation of oscillation events and specificity level. The results indicate the presence of four Spauligodon clades in the Canary Islands, which originated from at least three different colonization events. We found evidence of host range oscillations to truly novel hosts, which in one case led to higher diversification. Contemporary host-parasite associations show strong host specificity, suggesting that changes in host breadth were limited to the shift period. Lineages with more frequent and wider taxonomic host range oscillations prior to the initial colonization event showed wider range oscillations during colonization and diversification within the archipelago. Our results suggest that a lineage's evolutionary past may be the best indicator of a parasite's potential for future range expansions. © 2017 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Searle, Anthony; Petrachenko, Bill
2016-12-01
The VLBI Global Observing System (VGOS) has been designed to take advantage of advances in data recording speeds and storage capacity, allowing for smaller and faster antennas, wider bandwidths, and shorter observation durations. Here, schedules for a ``realistic" VGOS network, frequency sequences, and expanded source lists are presented using a new source-based scheduling algorithm. The VGOS aim for continuous observations presents new operational challenges. As the source-based strategy is independent of the observing network, there are operational advantages which allow for more flexible scheduling of continuous VLBI observations. Using VieVS, simulations of several schedules are presented and compared with previous VGOS studies.
Recent Advances in Modeling Hugoniots with Cheetah
DOE Office of Scientific and Technical Information (OSTI.GOV)
Glaesemann, K R; Fried, L E
2005-07-26
We describe improvements to the Cheetah thermochemical-kinetics code's equilibrium solver to enable it to find a wider range of thermodynamic states. Cheetah supports a wide range of elements, condensed detonation products, and gas phase reactions. Therefore, Cheetah can be applied to a wide range of shock problems involving both energetic and non-energetic materials. An improve equation of state is also introduced. New experimental validations of Cheetah's equation of state methodology have been performed, including both reacted and unreacted Hugoniots.
Scanning Shack-Hartmann wavefront sensor
NASA Astrophysics Data System (ADS)
Molebny, Vasyl V.
2004-09-01
Criss-crossing of focal images is the cause of a narrow dynamic range in Shack-Hartmann sensors. Practically, aberration range wider than +/-3 diopters can not be measured. A method has been proposed for ophthalmologic applications using a rarefied lenslet array through which a wave front is projected with the successive step-by-step changing of the global tilt. The data acquired in each step are accumulated and processed. In experimental setup, a doubled dynamic range was achieved with four steps of wave front tilting.
Recent Advances in Modeling Hugoniots with Cheetah
NASA Astrophysics Data System (ADS)
Glaesemann, K. R.; Fried, L. E.
2006-07-01
We describe improvements to the Cheetah thermochemical-kinetics code's equilibrium solver to enable it to find a wider range of thermodynamic states. Cheetah supports a wide range of elements, condensed detonation products, and gas phase reactions. Therefore, Cheetah can be applied to a wide range of shock problems involving both energetic and non-energetic materials. An improve equation of state is also introduced. New experimental validations of Cheetah's equation of state methodology have been performed, including both reacted and unreacted Hugoniots.
RANGE INCREASER FOR PNEUMATIC GAUGES
Fowler, A.H.; Seaborn, G.B. Jr.
1960-09-27
An improved pneumatic gage is offered in which the linear range has been increased without excessive air consumption. This has been accomplished by providing an expansible antechamber connected to the nozzle of the gage so that the position of the nozzle with respect to the workpiece is varied automatically by variation in pressure within the antechamber. This arrangement ensures that the nozzle-to-workpiece clearance is maintained within certain limits, thus obtaining a linear relation of air flow to nozzle-to-workpiece clearance over a wider range.
ERIC Educational Resources Information Center
Harris, Philip R.
1985-01-01
Looks at changes in the manager's role due to technological advancement in the workplace. Discusses wider range of uses for computers (analysis, decision making, communications, planning, tracking trends), importance of supervisor training, cyberphobia (fear of new technology), cyberphrenia (addiction to new technology), and the effect of a work…
Community College Faculty: Making the Paradigm Shift.
ERIC Educational Resources Information Center
Van Ast, John
1999-01-01
Discusses the need for paradigm shifts during the next decade that address the following challenges: (1) the wider range of student ability and mastery; (2) high attrition rates; and (3) differing and often contradicting perceptions of students, faculty, and administration. Contains 180 references. (TGO)
A ``Cyber Wind Facility'' for HPC Wind Turbine Field Experiments
NASA Astrophysics Data System (ADS)
Brasseur, James; Paterson, Eric; Schmitz, Sven; Campbell, Robert; Vijayakumar, Ganesh; Lavely, Adam; Jayaraman, Balaji; Nandi, Tarak; Jha, Pankaj; Dunbar, Alex; Motta-Mena, Javier; Craven, Brent; Haupt, Sue
2013-03-01
The Penn State ``Cyber Wind Facility'' (CWF) is a high-fidelity multi-scale high performance computing (HPC) environment in which ``cyber field experiments'' are designed and ``cyber data'' collected from wind turbines operating within the atmospheric boundary layer (ABL) environment. Conceptually the ``facility'' is akin to a high-tech wind tunnel with controlled physical environment, but unlike a wind tunnel it replicates commercial-scale wind turbines operating in the field and forced by true atmospheric turbulence with controlled stability state. The CWF is created from state-of-the-art high-accuracy technology geometry and grid design and numerical methods, and with high-resolution simulation strategies that blend unsteady RANS near the surface with high fidelity large-eddy simulation (LES) in separated boundary layer, blade and rotor wake regions, embedded within high-resolution LES of the ABL. CWF experiments complement physical field facility experiments that can capture wider ranges of meteorological events, but with minimal control over the environment and with very small numbers of sensors at low spatial resolution. I shall report on the first CWF experiments aimed at dynamical interactions between ABL turbulence and space-time wind turbine loadings. Supported by DOE and NSF.
Non-isothermal electrochemical model for lithium-ion cells with composite cathodes
NASA Astrophysics Data System (ADS)
Basu, Suman; Patil, Rajkumar S.; Ramachandran, Sanoop; Hariharan, Krishnan S.; Kolake, Subramanya Mayya; Song, Taewon; Oh, Dukjin; Yeo, Taejung; Doo, Seokgwang
2015-06-01
Transition metal oxide cathodes for Li-ion batteries offer high energy density and high voltage. Composites of these materials have shown excellent life expectancy and improved thermal performance. In the present work, a comprehensive non-isothermal electrochemical model for a Lithium ion cell with a composite cathode is developed. The present work builds on lithium concentration-dependent diffusivity and thermal gradient of cathode potential, obtained from experiments. The model validation is performed for a wide range of temperature and discharge rates. Excellent agreement is found for high and room temperature with moderate success at low temperatures, which can be attributed to the low fidelity of material properties at low temperature. Although the cell operation is limited by electronic conductivity of NCA at room temperature, at low temperatures a shift in controlling process is seen, and operation is limited by electrolyte transport. At room temperature, the lithium transport in Cathode appears to be the main source of heat generation with entropic heat as the primary contributor at low discharge rates and ohmic heat at high discharge rates respectively. Improvement in electronic conductivity of the cathode is expected to improve the performance of these composite cathodes and pave way for its wider commercialization.
Designing automation for complex work environments under different levels of stress.
Sauer, Juergen; Nickel, Peter; Wastell, David
2013-01-01
This article examines the effectiveness of different forms of static and adaptable automation under low- and high-stress conditions. Forty participants were randomly assigned to one of four experimental conditions, comparing three levels of static automation (low, medium and high) and one level of adaptable automation, with the environmental stressor (noise) being varied as a within-subjects variable. Participants were trained for 4 h on a simulation of a process control environment, called AutoCAMS, followed by a 2.5-h testing session. Measures of performance, psychophysiology and subjective reactions were taken. The results showed that operators preferred higher levels of automation under noise than under quiet conditions. A number of parameters indicated negative effects of noise exposure, such as performance impairments, physiological stress reactions and higher mental workload. It also emerged that adaptable automation provided advantages over low and intermediate static automation, with regard to mental workload, effort expenditure and diagnostic performance. The article concludes that for the design of automation a wider range of operational scenarios reflecting adverse as well as ideal working conditions needs to be considered. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.
Application of musical timbre discrimination features to active sonar classification
NASA Astrophysics Data System (ADS)
Young, Victor W.; Hines, Paul C.; Pecknold, Sean
2005-04-01
In musical acoustics significant effort has been devoted to uncovering the physical basis of timbre perception. Most investigations into timbre rely on multidimensional scaling (MDS), in which different musical sounds are arranged as points in multidimensional space. The Euclidean distance between points corresponds to the perceptual distance between sounds and the multidimensional axes are linked to measurable properties of the sounds. MDS has identified numerous temporal and spectral features believed to be important to timbre perception. There is reason to believe that some of these features may have wider application in the disparate field of underwater acoustics, since anecdotal evidence suggests active sonar returns from metallic objects sound different than natural clutter returns when auralized by human operators. This is particularly encouraging since attempts to develop robust automatic classifiers capable of target-clutter discrimination over a wide range of operational conditions have met with limited success. Spectral features relevant to target-clutter discrimination are believed to include click-pitch and envelope irregularity; relevant temporal features are believed to include duration, sub-band attack/decay time, and time separation pitch. Preliminary results from an investigation into the role of these timbre features in target-clutter discrimination will be presented. [Work supported by NSERC and GDC.
Waveguide Transition for Submillimeter-Wave MMICs
NASA Technical Reports Server (NTRS)
Leong, Kevin M.; Deal, William R.; Radisic, Vesna; Mei, Xiaobing; Uyeda, Jansen; Lai, Richard; Fung, King Man; Gaier, Todd C.
2009-01-01
An integrated waveguide-to-MMIC (monolithic microwave integrated circuit) chip operating in the 300-GHz range is designed to operate well on high-permittivity semiconductor substrates typical for an MMIC amplifier, and allows a wider MMIC substrate to be used, enabling integration with larger MMICs (power amplifiers). The waveguide-to- CBCPW (conductor-backed coplanar waveguide) transition topology is based on an integrated dipole placed in the E-plane of the waveguide module. It demonstrates low loss and good impedance matching. Measurement and simulation demonstrate that the loss of the transition and waveguide loss is less than 1-dB over a 340-to-380-GHz bandwidth. A transition is inserted along the propagation direction of the waveguide. This transition uses a planar dipole aligned with the maximum E-field of the TE10 waveguide mode as an inter face between the waveguide and the MMIC. Mode conversion between the coplanar striplines (CPS) that feed the dipole and the CBCPW transmission line is accomplished using a simple air-bridge structure. The bottom side ground plane is truncated at the same reference as the top-side ground plane, leaving the end of the MMIC suspended in air.
Environmental qualification testing of the prototype pool boiling experiment
NASA Technical Reports Server (NTRS)
Sexton, J. Andrew
1992-01-01
The prototype Pool Boiling Experiment (PBE) flew on the STS-47 mission in September 1992. This report describes the purpose of the experiment and the environmental qualification testing program that was used to prove the integrity of the prototype hardware. Component and box level vibration and thermal cycling tests were performed to give an early level of confidence in the hardware designs. At the system level, vibration, thermal extreme soaks, and thermal vacuum cycling tests were performed to qualify the complete design for the expected shuttle environment. The system level vibration testing included three axis sine sweeps and random inputs. The system level hot and cold soak tests demonstrated the hardware's capability to operate over a wide range of temperatures and gave the project team a wider latitude in determining which shuttle thermal altitudes were compatible with the experiment. The system level thermal vacuum cycling tests demonstrated the hardware's capability to operate in a convection free environment. A unique environmental chamber was designed and fabricated by the PBE team and allowed most of the environmental testing to be performed within the project's laboratory. The completion of the test program gave the project team high confidence in the hardware's ability to function as designed during flight.
Online Monitoring To Enable Improved Diagnostics, Prognostics and Maintenance
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bond, Leonard J.
2011-08-31
Only time will tell what the implications of the Fukushima incident will be. Discussions are on-going with regard to continued operation and life extension of the existing fleet, new build, and the wider policy issues including technologies needed to address spent fuel storage and ensure energy security, and the related desires to provide sustainable energy systems while at the same time limiting greenhouse gas emissions. The science base for advanced diagnostics and prognostics to support its use in nuclear power plants (NPPs) for active components (pumps, valves etc) has been demonstrated. A challenge is enabling adaption of these technologies formore » NPP deployment and the validation of the data from these technologies. Advanced diagnostics, monitoring and prognostics applied to passive structures, which in the USA context of longer term operation is up to 80 years, are being researched. Early laboratory work is demonstrating the potential for these methods, although technical challenges remain. It can be expected that there will be an increased need for and use of on-line monitoring for a wide range of both active and passive systems in all types of nuclear power plants.« less
More steps towards process automation for optical fabrication
NASA Astrophysics Data System (ADS)
Walker, David; Yu, Guoyu; Beaucamp, Anthony; Bibby, Matt; Li, Hongyu; McCluskey, Lee; Petrovic, Sanja; Reynolds, Christina
2017-06-01
In the context of Industrie 4.0, we have previously described the roles of robots in optical processing, and their complementarity with classical CNC machines, providing both processing and automation functions. After having demonstrated robotic moving of parts between a CNC polisher and metrology station, and auto-fringe-acquisition, we have moved on to automate the wash-down operation. This is part of a wider strategy we describe in this paper, leading towards automating the decision-making operations required before and throughout an optical manufacturing cycle.
Co-Operative Schools: A Democratic Alternative
ERIC Educational Resources Information Center
Audsley, Jamie; Cook, Philip
2012-01-01
Many fear that the pressures of running an Academy will be too great for individual schools, and that they will be forced to join chains run by private companies. These may offer hard-pressed school administrators valuable management expertise and back-office support, but seem to offer wider society little accountability and transparency. Are…
Using the Web to Bring Space Science and Technology Down To Earth
NASA Technical Reports Server (NTRS)
Miller, D. F.
1997-01-01
At JPL, the World-Wide Web has become an invaluable educational outreach mechanism. In the area of space flight mission operations, for example, we have been able to make publicly accessible two workbooks found to be of much wider interest than their original internal training purposes would have suggested.
Discourses on Employability: Constituting the Responsible Citizen
ERIC Educational Resources Information Center
Fejes, Andreas
2010-01-01
In the last couple of decades, there has been a shift from speaking about employment to speaking about employability. The interest in this article is directed at how discourses on employability are mobilised in the wider discursive terrain of governance. How does governance operate, what subject is produced and, more specifically, who is…
Academic Literacies: Providing a Space for the Socio-Political Dynamics of EAP
ERIC Educational Resources Information Center
Turner, Joan
2012-01-01
This article highlights the potential of academic literacies as a theoretical framework for EAP, encompassing not only work on texts, but the wider, socio-political, geopolitical, and institutional contexts and practices in and with which EAP operates. An academic literacies approach foregrounds social practices, and one particular practice, that…
GaN-based THz advanced quantum cascade lasers for manned and unmanned systems
NASA Astrophysics Data System (ADS)
Anwar, A. F. M.; Manzur, Tariq; Lefebvre, Kevin R.; Carapezza, Edward M.
2009-09-01
In recent years the use of Unmanned Autonomous Vehicles (UAV) has seen a wider range of applications. However, their applications are restricted due to (a) advanced integrated sensing and processing electronics and (b) limited energy storage or on-board energy generation to name a few. The availability of a wide variety of sensing elements, operating at room temperatures, provides a great degree of flexibility with an extended application domain. Though sensors responding to a variable spectrum of input excitations ranging from (a) chemical, (b) biological, (c) atmospheric, (d) magnetic and (e) visual/IR imaging have been implemented in UAVs, the use of THz as a technology has not been implemented due to the absence of systems operating at room temperature. The integration of multi-phenomenological onboard sensors on small and miniature unmanned air vehicles will dramatically impact the detection and processing of challenging targets, such as humans carrying weapons or wearing suicide bomb vests. Unmanned air vehicles have the potential of flying over crowds of people and quickly discriminating non-threat humans from treat humans. The state of the art in small and miniature UAV's has progressed to vehicles of less than 1 pound in weight but with payloads of only a fraction of a pound. Uncooled IR sensors, such as amorphous silicon and vanadium oxide microbolometers with MRT's of less than 70mK and requiring power of less than 250mW, are available for integration into small UAV's. These sensors are responsive only up to approximately 14 microns and do not favorably compare with THz imaging systems for remotely detecting and classifying concealed weapons and bombs. In the following we propose the use of THz GaN-based QCL operating at room temperature as a possible alternative.
Angle-domain inverse scattering migration/inversion in isotropic media
NASA Astrophysics Data System (ADS)
Li, Wuqun; Mao, Weijian; Li, Xuelei; Ouyang, Wei; Liang, Quan
2018-07-01
The classical seismic asymptotic inversion can be transformed into a problem of inversion of generalized Radon transform (GRT). In such methods, the combined parameters are linearly attached to the scattered wave-field by Born approximation and recovered by applying an inverse GRT operator to the scattered wave-field data. Typical GRT-style true-amplitude inversion procedure contains an amplitude compensation process after the weighted migration via dividing an illumination associated matrix whose elements are integrals of scattering angles. It is intuitional to some extent that performs the generalized linear inversion and the inversion of GRT together by this process for direct inversion. However, it is imprecise to carry out such operation when the illumination at the image point is limited, which easily leads to the inaccuracy and instability of the matrix. This paper formulates the GRT true-amplitude inversion framework in an angle-domain version, which naturally degrades the external integral term related to the illumination in the conventional case. We solve the linearized integral equation for combined parameters of different fixed scattering angle values. With this step, we obtain high-quality angle-domain common-image gathers (CIGs) in the migration loop which provide correct amplitude-versus-angle (AVA) behavior and reasonable illumination range for subsurface image points. Then we deal with the over-determined problem to solve each parameter in the combination by a standard optimization operation. The angle-domain GRT inversion method keeps away from calculating the inaccurate and unstable illumination matrix. Compared with the conventional method, the angle-domain method can obtain more accurate amplitude information and wider amplitude-preserved range. Several model tests demonstrate the effectiveness and practicability.
Promoting patient safety through prospective risk identification: example from peri-operative care.
Smith, A; Boult, M; Woods, I; Johnson, S
2010-02-01
Investigation of patient safety incidents has focused on retrospective analyses once incidents have occurred. Prospective risk analysis techniques complement this but have not been widely used in healthcare. Prospective risk identification of non-operative risks associated with adult elective surgery under general anaesthesia using a customised structured "what if" checklist and development of risk matrix. Prioritisation of recommendations arising by cost, ease and likely speed of implementation. Groups totalling 20 clinical and administrative healthcare staff involved in peri-operative care and risk experts convened by the UK National Patient Safety Agency. 102 risks were identified and 95 recommendations made. The top 20 recommendations together were judged to encompass about 75% of the total estimated risk attributable to the processes considered. Staffing and organisational issues (21% of total estimated risk) included recommendations for removing distractions from the operating theatre, ensuring the availability of senior anaesthetists and promoting standards and flexible working among theatre staff. Devices and equipment (19% of total estimated risk) could be improved by training and standardisation; airway control and temperature monitoring were identified as two specific areas. Pre-assessment of patients before admission to hospital (12% of estimated risk) could be improved by defining a data set for adequate pre-assessment and making this available throughout the NHS. This technique can be successfully applied by healthcare staff but expert facilitation of groups is advisable. Such wider-ranging processes can potentially lead to more comprehensive risk reduction than "single-issue" risk alerts.
A novel low-jitter plasma-jet triggered gas switch operated at a low working coefficient.
Tie, Weihao; Liu, Shanhong; Liu, Xuandong; Zhang, Qiaogen; Pang, Lei; Liu, Longchen
2014-02-01
In this paper, we described the fabrication and testing of a novel plasma-jet triggered gas switch (PJTGS) operated at extremely low working coefficients with excellent triggered jitters. While the structure of the PJTGS is similar to that of a traditional three-electrode field-distortion gas switch, to improve its triggered performance we used a conical micro-plasma-gun with a needle-to-plate spark gap embedded in the trigger electrode. Applying a nanosecond pulse to the trigger electrode caused a spark discharge in the micro-plasma-gun. The electric field drove the discharge plasma to spray into the spark gap of the gas switch, causing fast breakdown. We tested the PJTGS with charging voltages of ±25 kV and a trigger voltage of +80 kV (5 ns rise time and 80 ns full width at half maximum) in two working modes. The PJTGS operated in Mode II had a lower triggered jitter and could be operated over a wider range of working coefficients than in Mode I under the same conditions. At working coefficients higher than 70%, we obtained sub-ns triggered jitters (<0.89 ns) from the PJTGS, at working coefficients lower than 50%, we obtained triggered jitters of 1.6-3.5 ns without no-fires or pre-fires. Even at a working coefficient of 27.4%, the PJTGS could still be triggered reliably with a delay time of 96.1 ns and a triggered jitter of 3.5 ns, respectively.
Proteus mirabilis interkingdom swarming signals attract blow flies
USDA-ARS?s Scientific Manuscript database
Flies transport specific bacteria with their larvae which provides a wider range of nutrients for those bacteria. Our hypothesis was that this symbiotic interaction may depend on interkingdom signaling. We obtained Proteus mirabilis from the salivary glands of the blow fly Lucilia sericat. This s...
John R. Jones
1985-01-01
Quaking aspen is the most widely distributed native North American tree species (Little 1971, Sargent 1890). It grows in a great diversity of regions, environments, and communities (Harshberger 1911). Only one deciduous tree species in the world, the closely related Eurasian aspen (Populus tremula), has a wider range (Weigle and Frothingham 1911)....
A review of vagus nerve stimulation as a therapeutic intervention
Johnson, Rhaya L; Wilson, Christopher G
2018-01-01
In this review, we provide an overview of the US Food and Drug Administration (FDA)-approved clinical uses of vagus nerve stimulation (VNS) as well as information about the ongoing studies and preclinical research to expand the use of VNS to additional applications. VNS is currently FDA approved for therapeutic use in patients aged >12 years with drug-resistant epilepsy and depression. Recent studies of VNS in in vivo systems have shown that it has anti-inflammatory properties which has led to more preclinical research aimed at expanding VNS treatment across a wider range of inflammatory disorders. Although the signaling pathway and mechanism by which VNS affects inflammation remain unknown, VNS has shown promising results in treating chronic inflammatory disorders such as sepsis, lung injury, rheumatoid arthritis (RA), and diabetes. It is also being used to control pain in fibromyalgia and migraines. This new preclinical research shows that VNS bears the promise of being applied to a wider range of therapeutic applications. PMID:29844694
NASA Astrophysics Data System (ADS)
Qing, Jiasheng; Wang, Lei; Dou, Kun; Wang, Bao; Liu, Qing
2016-06-01
The influence of V-N microalloying on the high-temperature mechanical behavior of high strength weathering steel is discussed through thermomechanical simulation experiment. The difference of tensile strength caused by variation of [%V][%N] appears after proeutectoid phase change, and the higher level of [%V][%N] is, the stronger the tensile strength tends to be. The ductility trough apparently becomes deeper and wider with the increase of [%V][%N]. When the level of [%V][%N] reaches to 1.7 × 10-3, high strength weathering steel shows almost similar reduction of area to 0.03% Nb-containing steel in the temperature range of 800-900°, however, the ductility trough at the low-temperature stage is wider than that of Nb-containing steel. Moreover, the net crack defect of bloom is optimized through the stable control of N content in low range under the precondition of high strength weathering steel with sufficient strength.
Siblings of Children with Autism: the Siblings Embedded Systems Framework.
Kovshoff, Hanna; Cebula, Katie; Tsai, Hsiao-Wei Joy; Hastings, Richard P
2017-01-01
A range of interacting factors/mechanisms at the individual, family, and wider systems levels influences siblings living in families where one sibling has autism. We introduce the Sibling Embedded Systems Framework which aims to contextualise siblings' experience and characterise the multiple and interacting factors influencing family and, in particular, sibling outcomes. Findings from studies that have reported outcomes for siblings of children with autism are equivocal, ranging from negative impact, no difference, to positive experience. This is likely due to the complex nature of understanding the sibling experience. We focus on particular elements of the framework and review recent novel literature to help guide future directions for research and practice including the influence of culture, methodological considerations, and wider participatory methods. The Siblings Embedded System Framework can be used to understand interactive factors that affect sibling adjustment and to develop clinically, educationally and empirically based work that aims to enhance and support sibling adjustment, relationships, and well-being in families of children with autism.
Planned second-look laparoscopy in the management of acute mesenteric ischemia
Yanar, Hakan; Taviloglu, Korhan; Ertekin, Cemalettin; Ozcinar, Beyza; Yanar, Fatih; Guloglu, Recep; Kurtoglu, Mehmet
2007-01-01
AIM: To investigate the role of second-look laparoscopy in patients with acute mesenteric ischemia (AMI). METHODS: Between January 2000 and November 2005, 71 patients were operated for the treatment of AMI. The indications for a second-look were low flow state, bowel resection and anastomosis or mesenteric thromboembolectomy performed during the first operation. Regardless of the clinical course of patients, the second-look laparoscopic examination was performed 72 h post-operatively at the bed side in the ICU or operating room. RESULTS: The average time of admission to the hospital after the initiation of symptoms was 3 d (range, 5 h-9 d). In 14 patients, laparotomy was performed. In 11 patients, small and/or large bowel necrosis was detected and initial resection and anastomosis were conducted. A low flow state was observed in two patients and superior mesenteric artery thromboembolectomy with small bowel resection was performed in one patient. In 13 patients, a second-look laparoscopic examination revealed normal bowel viability, but in one patient, intestinal necrosis was detected. In two of the patients, a third operation was necessary to correct anastomotic leakage. The overall complication rate was 42.8%, and in-hospital mortality rate was 57.1% (n = 6). CONCLUSION: Second-look laparoscopy is a minimally invasive, technically simple procedure that is performed for diagnostic as well as therapeutic purposes. The simplicity and ease of this method may encourage wider application to benefit more patients. However, the timing of a second-look procedure is unclear particularly in a patient with anastomosis. PMID:17659674
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Xingyu, E-mail: xzhang@utexas.edu, E-mail: swapnajit.chakravarty@omegaoptics.com, E-mail: chenrt@austin.utexas.edu; Chung, Chi-Jui; Pan, Zeyu
2015-11-30
We design, fabricate, and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78 μm-long coupled L0-type photonic crystal microcavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystal microcavity. Coupling between identical microcavities gives rise to bonding and anti-bonding states of the coupled photonic molecules. The coupled photonic crystal microcavities are numerically simulated and experimentally verified with a 6 nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-opticmore » switch is measured with an optical extinction ratio of 20 dB, an on-off switching power of 18.2 mW, a thermo-optic tuning efficiency of 0.63 nm/mW, a rise time of 14.8 μs, and a fall time of 18.5 μs. The measured on-chip loss on the transmission band is as low as 1 dB.« less
Miklaszewski, Andrzej; Jurczyk, Mieczysława U; Kaczmarek, Mariusz; Paszel-Jaworska, Anna; Romaniuk, Aleksandra; Lipińska, Natalia; Żurawski, Jakub; Urbaniak, Paulina; Jurczyk, Mieczyslaw
2017-04-01
Novel in situ Metal Matrix Nanocomposite (MMNC) materials based on titanium and boron, revealed their new properties in the nanoscale range. In situ nanocomposites, obtained through mechanical alloying and traditional powder metallurgy compaction and sintering, show obvious differences to their microstructural analogue. A unique microstructure connected with good mechanical properties reliant on the processing conditions favour the nanoscale range of results of the Ti-TiB in situ MMNC example. The data summarised in this work, support and extend the knowledge boundaries of the nanoscale size effect that influence not only the mechanical properties but also the studies on the cell viability and cytocompatibility. Prepared in the same bulk, in situ MMNC, based on titanium and boron, could be considered as a possible candidate for dental implants and other medical applications. The observed relations and research conclusions are transferable to the in situ MMNC material group. Aside from all the discussed relations, the increasing share of these composites in the ever-growing material markets, heavily depends on the attractiveness and a possible wider application of these composites as well as their operational simplicity presented in this work. Copyright © 2016 Elsevier B.V. All rights reserved.
Qi, Fei; Ju, Feng; Bai, Dong Ming; Chen, Bai
2018-02-01
For the outstanding compliance and dexterity of continuum robot, it is increasingly used in minimally invasive surgery. The wide workspace, high dexterity and strong payload capacity are essential to the continuum robot. In this article, we investigate the workspace of a cable-driven continuum robot that we proposed. The influence of section number on the workspace is discussed when robot is operated in narrow environment. Meanwhile, the structural parameters of this continuum robot are optimized to achieve better kinematic performance. Moreover, an indicator based on the dexterous solid angle for evaluating the dexterity of robot is introduced and the distal end dexterity is compared for the three-section continuum robot with different range of variables. Results imply that the wider range of variables achieve the better dexterity. Finally, the static model of robot based on the principle of virtual work is derived to analyze the relationship between the bending shape deformation and the driven force. The simulations and experiments for plane and spatial motions are conducted to validate the feasibility of model, respectively. Results of this article can contribute to the real-time control and movement and can be a design reference for cable-driven continuum robot.
Robotic active positioning for magnetic resonance-guided high-intensity focused ultrasound
NASA Astrophysics Data System (ADS)
Xiao, Xu; Huang, Zhihong; Volovick, Alexander; Melzer, Andreas
2012-11-01
Magnetic resonance (MR) guided High-intensity focused ultrasound (HIFU) is a noninvasive method producing thermal necrosis and cavitation at the position of tumors with high accuracy. Because the typical size of the high-intensity focused ultrasound focus are much smaller than the targeted tumor or other tissues, multiple sonications and focus repositioning become necessary for HIFU treatment. In order to reach a much wider range, manual repositioning or using MR compatible mechanical actuators could be used. The repositioning technique is a time consuming procedure because it needs a series of MR imaging to detect the transducer and markers preplaced on the mechanical devices. We combined an active tracking technique into the MR guided HIFU system. In this work, the robotic system used is the MR-compatible robotics from InnoMotion{trade mark, serif} (IBSMM, Engineering spol. s r.o. / Ltd, Czech) which is originally designed for MR-guided needle biopsy. The precision and positioning speed of the combined robotic HIFU system are evaluated in this study. Compared to the existing MR guided HIFU systems, the combined robotic system with active tracking techniques provides a potential that allows the HIFU treatment to operate in a larger spatial range and with a faster speed.
Thermostatic Valves Containing Silicone-Oil Actuators
NASA Technical Reports Server (NTRS)
Bhandari, Pradeep; Birur, Gajanana C.; Bame, David P.; Karlmann, Paul B.; Prina, Mauro; Young, William; Fisher, Richard
2009-01-01
Flow-splitting and flow-mixing thermally actuated spool valves have been developed for controlling flows of a heat-transfer fluid in a temperature-regulation system aboard the Mars Science Laboratory (MSL) rover. Valves like these could also be useful in terrestrial temperature-regulation systems, including automobile air-conditioning systems and general refrigeration systems. These valves are required to provide smoother actuation over a wider temperature range than the flow-splitting, thermally actuated spool valves used in the Mars Explorer Rover (MER). Also, whereas the MER valves are unstable (tending to oscillate) in certain transition temperature ranges, these valves are required not to oscillate. The MER valves are actuated by thermal expansion of a wax against spring-loaded piston rods (as in common automotive thermostats). The MSL valves contain similar actuators that utilize thermal expansion of a silicone oil, because silicone-oil actuators were found to afford greater and more nearly linear displacements, needed for smoother actuation, over the required wider temperature range. The MSL valves also feature improved spool designs that reflect greater understanding of fluid dynamics, consideration of pressure drops in valves, and a requirement for balancing of pressures in different flow branches.
Experimental and Computational Study of Trapped Vortex Combustor Sector Rig with Tri-pass Diffuser
NASA Technical Reports Server (NTRS)
Hendricks, Robert C.; Shouse, D. T.; Roquemore, W. M.; Burrus, D. L.; Duncan, B. S.; Ryder, R. C.; Brankovic, A.; Liu, N.-S.; Gallagher, J. R.; Hendricks, J. A.
2001-01-01
The Trapped Vortex Combustor (TVC) potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL (Rich burn/Quick mix/Lean burn) modes of combustion. The present work describes the operational principles of the TVC, and provides detailed performance data on a configuration featuring a tri-pass diffusion system. Performance data include EINOx (NO(sub x) emission index) results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO) performance. Computational fluid dynamics (CFD) simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable in comparison to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.
Bis(Dioxolene)Bis(Pyridine)Ruthenium Redox Series.
1991-08-20
wurking and counter electrodes, and a AgCl/Ag quasi-reference electrode with ferrocene (Fc) as an internal standard. The Fc+/Fc couple was assumed to...assigning the electronic spectra of these species. Similar work has been completed on phosphine substituted species which offer a wider range of
DOT National Transportation Integrated Search
2016-05-01
Over the past 20 years, drilled shafts have demonstrated increasing popularity over driven : precast piles. Drilled shafts can accommodate a wider range of sizes, and noise and vibration : during construction are significantly reduced. On the other h...
Gale, C P; Manda, S O M; Weston, C F; Birkhead, J S; Batin, P D; Hall, A S
2009-03-01
To compare the discriminative performance of the PURSUIT, GUSTO-1, GRACE, SRI and EMMACE risk models, assess their performance among risk supergroups and evaluate the EMMACE risk model over the wider spectrum of acute coronary syndrome (ACS). Observational study of a national registry. All acute hospitals in England and Wales. 100 686 cases of ACS between 2003 and 2005. Model performance (C-index) in predicting the likelihood of death over the time period for which they were designed. The C-index, or area under the receiver-operating curve, range 0-1, is a measure of the discriminative performance of a model. The C-indexes were: PURSUIT C-index 0.79 (95% confidence interval 0.78 to 0.80); GUSTO-1 0.80 (0.79 to 0.81); GRACE in-hospital 0.80 (0.80 to 0.81); GRACE 6-month 0.80 (0.79 to 0.80); SRI 0.79 (0.78 to 0.80); and EMMACE 0.78 (0.77 to 0.78). EMMACE maintained its ability to discriminate 30-day mortality throughout different ACS diagnoses. Recalibration of the model offered no notable improvement in performance over the original risk equation. For all models the discriminative performance was reduced in patients with diabetes, chronic renal failure or angina. The five ACS risk models maintained their discriminative performance in a large unselected English and Welsh ACS population, but performed less well in higher-risk supergroups. Simpler risk models had comparable performance to more complex risk models. The EMMACE risk score performed well across the wider spectrum of ACS diagnoses.
The International AIDS Vaccine Initiative's Capacity Building Activities in East Africa
Cochrane, Gavin; Robin, Enora; Hanlin, Rebecca; Castle-Clarke, Sophie; MacLure, Calum; Parks, Sarah; Chataway, Joanna
2016-01-01
Abstract The International AIDS Vaccine Initiative (IAVI) is one of a number of Product Development Partnerships created to bridge the gap between scientific and technological potential and the needs of low income populations in low and middle income countries. Specifically IAVI is focused on creating a preventative vaccine for HIV/AIDS. Whilst the remit of IAVI is to create new science, technology and products, its work necessarily involves a wide range of stakeholders and different constituencies in industrially developing and developed countries. Its capacity building activities relate to strengthening the ability to conduct clinical trials and are broad based, spanning scientific and technological capacity through to organisational, advocacy and broader development capabilities. The aim of this study was to deepen IAVI's understanding of how it contributes to capacity building activities in East Africa (Uganda, Kenya and Rwanda), spanning scientific and technological capacity through to organisational, advocacy and broader development capabilities. IAVI's mission to develop an HIV vaccine has become increasingly connected to wider health systems strengthening, through its clinical research activities in East Africa. Since it began its operations in the region, IAVI has made a significant contribution to training interventions to support scientific excellence and good clinical practice and invested in infrastructure and laboratories at Clinical Research Centres in East Africa. Although clear challenges still exist with ensuring sustained investment, accessing marginalized populations and demonstrating progress in capacity building, the experiences of IAVI to date suggest that substantial progress is being made towards wider health systems strengthening in the region. PMID:28083400
Wedemeyer, Gary A.; Nelson, Nancy C.
1975-01-01
Gaussian and nonparametric (percentile estimate and tolerance interval) statistical methods were used to estimate normal ranges for blood chemistry (bicarbonate, bilirubin, calcium, hematocrit, hemoglobin, magnesium, mean cell hemoglobin concentration, osmolality, inorganic phosphorus, and pH for juvenile rainbow (Salmo gairdneri, Shasta strain) trout held under defined environmental conditions. The percentile estimate and Gaussian methods gave similar normal ranges, whereas the tolerance interval method gave consistently wider ranges for all blood variables except hemoglobin. If the underlying frequency distribution is unknown, the percentile estimate procedure would be the method of choice.
ERIC Educational Resources Information Center
Oldfield, Chrissie
2017-01-01
It is becoming apparent that the environment in which Executive Masters in Public Administration programmes operate has changed dramatically in the wake of economic crisis and subsequent cuts in public spending. Changes in the funding of public sector organisations has been compounded by a broader "crisis" in the wider public sector…
DOT National Transportation Integrated Search
2011-01-01
Bicycling is an integral part of a sustainable transportation system. It is energy efficient, cost : effective, and environmentally friendly. Dedi-cated bike lanes provide the ideal conditions for both motorists and bicyclists. However, it is not alw...
Yamada, Akira; Terakawa, Mitsuhiro
2015-04-10
We present a design method of a bull's eye structure with asymmetric grooves for focusing oblique incident light. The design method is capable of designing transmission peaks to a desired oblique angle with capability of collecting light from a wider range of angles. The bull's eye groove geometry for oblique incidence is designed based on the electric field intensity pattern around an isolated subwavelength aperture on a thin gold film at oblique incidence, calculated by the finite difference time domain method. Wide angular transmission efficiency is successfully achieved by overlapping two different bull's eye groove patterns designed with different peak angles. Our novel design method would overcome the angular limitations of the conventional methods.
Biographies of Exclusion: Poor Work and Poor Transitions
ERIC Educational Resources Information Center
Shildrick, Tracy; MacDonald, Robert
2007-01-01
The usefulness of the concept of transition has been hotly contested in Anglophone youth studies over the past decade. A variety of criticisms have been ranged against it, including that it: presumes the continuing predominance of linear, obvious, mainstream pathways to adulthood; excludes wider youth questions in focusing narrowly on educational…
Biphenyl-grown cells and cell extracts prepared from biphenyl-grown cells of Pseudomonas sp. strain LB400 oxidize a much wider range of chlorinated biphenyls than do analogous preparations from Pseudomonas pseudoalcaligenes KF707. These results are attributed to differences in th...
Parents Guide on Choice. The Right To Choose.
ERIC Educational Resources Information Center
Raywid, Mary Anne
Starting with the contention that we need to restore a wider range of choice to parents in their children's education, this paper lists and reviews the varieties of public education currently available throughout the country, and discusses their advantages and disadvantages. These varieties include magnet schools, alternative schools, independent…
Response Strength in Extreme Multiple Schedules
ERIC Educational Resources Information Center
McLean, Anthony P.; Grace, Randolph C.; Nevin, John A.
2012-01-01
Four pigeons were trained in a series of two-component multiple schedules. Reinforcers were scheduled with random-interval schedules. The ratio of arranged reinforcer rates in the two components was varied over 4 log units, a much wider range than previously studied. When performance appeared stable, prefeeding tests were conducted to assess…
Aging: Prospects and Issues. Revised. 1976.
ERIC Educational Resources Information Center
Davis, Richard H., Ed.
Completely revised and updated since its first edition in 1973, the book explores an even wider range of concerns regarding gerontology. Part 1 presents an overview of the multiple aspects of gerontology, and includes the following chapters: (1) Aging: Prospects and Issues, Richard H. Davis; (2) Aging: The Psychologist's Perspective, James E.…
Heavy Metal Music and Reckless Behavior among Adolescents.
ERIC Educational Resources Information Center
Arnett, Jeffrey
1991-01-01
Fifty-four male and 30 female adolescents who like heavy metal music were compared on various outcome variables to 56 male and 105 female peers who do not like it. Those who like heavy metal report a wider range of reckless behavior than those who do not like it. (SLD)
Alternative Instructional Strategies in an IS Curriculum
ERIC Educational Resources Information Center
Parker, Kevin R.; LeRouge, Cynthia; Trimmer, Ken
2005-01-01
Systems Analysis and Design is a core component of an education in information systems. To appeal to a wider range of constituents and facilitate the learning process, the content of a traditional Systems Analysis and Design course has been supplemented with an alternative modeling approach. This paper presents an instructional design that…
Culture vs. Technology: Mass Media Policy of the Netherlands Attempts a Balance.
ERIC Educational Resources Information Center
Heuterman, Thomas H.; Rennen, Toon
Telecommunications policy makers in Western Europe face the dilema of satisfying public demand for a wider range of television viewing alternatives without sacrificing national cultural integrity. The Dutch Parliament addressed this problem in 1984, 1985, and 1986 as it approved steps to implement the "Medianota," the comprehensive…
Arginase: A Novel Proliferative Determinant in Prostate Cancer
2005-04-01
neoplastic prostate samples. The purpose of the present research funded by USAMRMC is to examine the expression of All in a wider range of benign and - malignant prostate...of polyamine synthesis levels in these lines, and our measurement and localization of arginase expression in benign and malignant prostate tissue samples.
Understanding Online Knowledge Sharing: An Interpersonal Relationship Perspective
ERIC Educational Resources Information Center
Ma, Will W. K.; Yuen, Allan H. K.
2011-01-01
The unique features and capabilities of online learning are built on the ability to connect to a wider range of learning resources and peer learners that benefit individual learners, such as through discussion forums, collaborative learning, and community building. The success of online learning thus depends on the participation, engagement, and…
Documenting Variation in (Endangered) Heritage Languages: How and Why?
ERIC Educational Resources Information Center
Nagy, Naomi
2017-01-01
This paper contributes to recently expanded interest in documenting variable as well as categorical patterns of endangered languages. It describes approaches, tools and curricular developments that have benefitted from involving students who are heritage language community members, key to expanding variationist focus to a wider range of languages.…
Assessment Using Multi-Criteria Decision Approach for "Higher Order Skills" Learning Domains
ERIC Educational Resources Information Center
Ramakishnan, Sadhu Balasundaram; Ramadoss, Balakrishnan
2009-01-01
Over the past several decades, a wider range of assessment strategies has gained prominence in classrooms, including complex assessment items such as individual or group projects, student journals and other creative writing tasks, graphic/artistic representations of knowledge, clinical interviews, student presentations and performances, peer- and…
Levels of Student Responses in a Spreadsheet-Based Environment
ERIC Educational Resources Information Center
Tabach, Michal; Friedlander, Alex
2004-01-01
The purpose of this report is to investigate the range of student responses in three domains--hypothesizing, organizing data, and algebraic generalization of patterns during their work on a spreadsheet-based activity. In a wider context, we attempted to investigate students' utilization schemes of spreadsheets in their learning of introductory…
Promising Practices in Small High Schools. A Report of 15 Northwest Projects.
ERIC Educational Resources Information Center
Northwest Regional Educational Lab., Portland, OR.
Promising methods utilized in small rural high schools to provide a wider range of experiences for students are identified and described. Programs reported on include the Arctic Nursing Program, Career Research Program, Contractual Study Program, Eye-opening Experience, Field Experience Program, Guitar and Folk Music Program, Individualized…
A Wider Spectrum of Opportunities.
ERIC Educational Resources Information Center
Council for Industry and Higher Education (United Kingdom).
The United Kingdom must invest in a comprehensive system of post-18 education that is broadly inclusive and that offers a broad range of educational opportunities to meet the needs of both the increasing numbers of 16-year-olds choosing to pursue postsecondary education and the many older individuals needing additional education throughout their…
Persuading and Dissuading by Conditional Argument
ERIC Educational Resources Information Center
Thompson, V.A.; Evans, J.St.B.T.; Handley, S.J.
2005-01-01
Informal reasoning typically draws on a wider range of inferential behaviour than is measured by traditional inference tasks. In this paper, we developed several tasks to study informal reasoning with two novel types of conditional statements: Persuasions (e.g., if the Kyoto accord is ratified, greenhouse gas emissions will be reduced) and…
Bipolaris microstegii Minnis, Rossman, Kleczewki & S.L. Flory, sp. nov.
USDA-ARS?s Scientific Manuscript database
Many species of Bipolaris are significant pathogens of grasses. A new species of Bipolaris was isolated from Microstegium vimineum, an invasive plant in the USA. The fungus causes disease on Microstegium, but it also infects a wider range of hosts. Comparison of ITS and gpd sequence data to sequence...
Effect of salt and ethanol addition on zein-starch dough and bread quality
USDA-ARS?s Scientific Manuscript database
Development of viscoelastic doughs from non-wheat proteins allows for a wider range of gluten-free products. Littlework has been completed to describemechanisms of zein functionality in food systems. To identify factors responsible for dough development in zein–starchmixtures and their influence on ...
3D parallel-detection microwave tomography for clinical breast imaging
Meaney, P. M.; Paulsen, K. D.
2014-01-01
A biomedical microwave tomography system with 3D-imaging capabilities has been constructed and translated to the clinic. Updates to the hardware and reconfiguration of the electronic-network layouts in a more compartmentalized construct have streamlined system packaging. Upgrades to the data acquisition and microwave components have increased data-acquisition speeds and improved system performance. By incorporating analog-to-digital boards that accommodate the linear amplification and dynamic-range coverage our system requires, a complete set of data (for a fixed array position at a single frequency) is now acquired in 5.8 s. Replacement of key components (e.g., switches and power dividers) by devices with improved operational bandwidths has enhanced system response over a wider frequency range. High-integrity, low-power signals are routinely measured down to −130 dBm for frequencies ranging from 500 to 2300 MHz. Adequate inter-channel isolation has been maintained, and a dynamic range >110 dB has been achieved for the full operating frequency range (500–2900 MHz). For our primary band of interest, the associated measurement deviations are less than 0.33% and 0.5° for signal amplitude and phase values, respectively. A modified monopole antenna array (composed of two interwoven eight-element sub-arrays), in conjunction with an updated motion-control system capable of independently moving the sub-arrays to various in-plane and cross-plane positions within the illumination chamber, has been configured in the new design for full volumetric data acquisition. Signal-to-noise ratios (SNRs) are more than adequate for all transmit/receive antenna pairs over the full frequency range and for the variety of in-plane and cross-plane configurations. For proximal receivers, in-plane SNRs greater than 80 dB are observed up to 2900 MHz, while cross-plane SNRs greater than 80 dB are seen for 6 cm sub-array spacing (for frequencies up to 1500 MHz). We demonstrate accurate recovery of 3D dielectric property distributions for breast-like phantoms with tumor inclusions utilizing both the in-plane and new cross-plane data. PMID:25554311
Analysis of optical scheme for medium-range directed energy laser weapon system
NASA Astrophysics Data System (ADS)
Jabczyński, Jan K.; Kaśków, Mateusz; Gorajek, Łukasz; Kopczyński, Krzysztof
2017-10-01
The relations between range of operation and aperture of laser weapon system were investigated, taking into account diffraction and technical limitations as beam quality, accuracy of point tracking, technical quality of optical train, etc. As a result for the medium ranges of 1 - 2 km we restricted the analysis to apertures not wider than 150 mm and the optical system without adaptive optics. To choose the best laser beam shape, the minimization of aperture losses and thermooptical effects inside optics as well as the effective width of laser beam in far field should be taken into account. We have analyzed theoretically such a problem for the group of a few most interesting from that point of view profiles including for reference two limiting cases of Gaussian beam and `top hat' profile. We have found that the most promising is the SuperGaussian profile of index p = 2 for which the surfaces of beam shaper elements can be manufactured in the acceptable cost-effective way and beam quality does not decrease noticeably. Further, we have investigated the thermo-optic effects on the far field parameters of Gaussian and `top hat' beams to determine the influence of absorption in optical elements on beam quality degradation. The simplified formulae were derived for beam quality measures (parameter M2 and Strehl ratio) which enables to estimate the influence of absorption losses on degradation of beam quality.
Dynamic calibration of pan-tilt-zoom cameras for traffic monitoring.
Song, Kai-Tai; Tai, Jen-Chao
2006-10-01
Pan-tilt-zoom (PTZ) cameras have been widely used in recent years for monitoring and surveillance applications. These cameras provide flexible view selection as well as a wider observation range. This makes them suitable for vision-based traffic monitoring and enforcement systems. To employ PTZ cameras for image measurement applications, one first needs to calibrate the camera to obtain meaningful results. For instance, the accuracy of estimating vehicle speed depends on the accuracy of camera calibration and that of vehicle tracking results. This paper presents a novel calibration method for a PTZ camera overlooking a traffic scene. The proposed approach requires no manual operation to select the positions of special features. It automatically uses a set of parallel lane markings and the lane width to compute the camera parameters, namely, focal length, tilt angle, and pan angle. Image processing procedures have been developed for automatically finding parallel lane markings. Interesting experimental results are presented to validate the robustness and accuracy of the proposed method.
Various supercritical carbon dioxide cycle layouts study for molten carbonate fuel cell application
NASA Astrophysics Data System (ADS)
Bae, Seong Jun; Ahn, Yoonhan; Lee, Jekyoung; Lee, Jeong Ik
2014-12-01
Various supercritical carbon dioxide (S-CO2) cycles for a power conversion system of a Molten Carbonate Fuel Cell (MCFC) hybrid system are studied in this paper. Re-Compressing Brayton (RCB) cycle, Simple Recuperated Brayton (SRB) cycle and Simple Recuperated Transcritical (SRT) cycle layouts were selected as candidates for this study. In addition, a novel concept of S-CO2 cycle which combines Brayton cycle and Rankine cycle is proposed and intensively studied with other S-CO2 layouts. A parametric study is performed to optimize the total system to be compact and to achieve wider operating range. Performances of each S-CO2 cycle are compared in terms of the thermal efficiency, net electricity of the MCFC hybrid system and approximate total volumes of each S-CO2 cycle. As a result, performance and total physical size of S-CO2 cycle can be better understood for MCFC S-CO2 hybrid system and especially, newly suggested S-CO2 cycle shows some success.
Design issues for a reinforcement-based self-learning fuzzy controller
NASA Technical Reports Server (NTRS)
Yen, John; Wang, Haojin; Dauherity, Walter
1993-01-01
Fuzzy logic controllers have some often cited advantages over conventional techniques such as PID control: easy implementation, its accommodation to natural language, the ability to cover wider range of operating conditions and others. One major obstacle that hinders its broader application is the lack of a systematic way to develop and modify its rules and as result the creation and modification of fuzzy rules often depends on try-error or pure experimentation. One of the proposed approaches to address this issue is self-learning fuzzy logic controllers (SFLC) that use reinforcement learning techniques to learn the desirability of states and to adjust the consequent part of fuzzy control rules accordingly. Due to the different dynamics of the controlled processes, the performance of self-learning fuzzy controller is highly contingent on the design. The design issue has not received sufficient attention. The issues related to the design of a SFLC for the application to chemical process are discussed and its performance is compared with that of PID and self-tuning fuzzy logic controller.
NASA Astrophysics Data System (ADS)
Chen, Xiaolong; Honda, Hiroshi; Kuroda, Seiji; Araki, Hiroshi; Murakami, Hideyuki; Watanabe, Makoto; Sakka, Yoshio
2016-12-01
Effects of the ceramic powder size used for suspension as well as several processing parameters in suspension plasma spraying of YSZ were investigated experimentally, aiming to fabricate highly segmented microstructures for thermal barrier coating (TBC) applications. Particle image velocimetry (PIV) was used to observe the atomization process and the velocity distribution of atomized droplets and ceramic particles travelling toward the substrates. The tested parameters included the secondary plasma gas (He versus H2), suspension injection flow rate, and substrate surface roughness. Results indicated that a plasma jet with a relatively higher content of He or H2 as the secondary plasma gas was critical to produce highly segmented YSZ TBCs with a crack density up to 12 cracks/mm. The optimized suspension flow rate played an important role to realize coatings with a reduced porosity level and improved adhesion. An increased powder size and higher operation power level were beneficial for the formation of highly segmented coatings onto substrates with a wider range of surface roughness.
The effects of working memory on brain-computer interface performance.
Sprague, Samantha A; McBee, Matthew T; Sellers, Eric W
2016-02-01
The purpose of the present study is to evaluate the relationship between working memory and BCI performance. Participants took part in two separate sessions. The first session consisted of three computerized tasks. The List Sorting Working Memory Task was used to measure working memory, the Picture Vocabulary Test was used to measure general intelligence, and the Dimensional Change Card Sort Test was used to measure executive function, specifically cognitive flexibility. The second session consisted of a P300-based BCI copy-spelling task. The results indicate that both working memory and general intelligence are significant predictors of BCI performance. This suggests that working memory training could be used to improve performance on a BCI task. Working memory training may help to reduce a portion of the individual differences that exist in BCI performance allowing for a wider range of users to successfully operate the BCI system as well as increase the BCI performance of current users. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Morichetti, Francesco; Canciamilla, Antonio; Ferrari, Carlo; Samarelli, Antonio; Sorel, Marc; Melloni, Andrea
2011-01-01
Wave mixing inside optical resonators, while experiencing a large enhancement of the nonlinear interaction efficiency, suffers from strong bandwidth constraints, preventing its practical exploitation for processing broad-band signals. Here we show that such limits are overcome by the new concept of travelling-wave resonant four-wave mixing (FWM). This approach combines the efficiency enhancement provided by resonant propagation with a wide-band conversion process. Compared with conventional FWM in bare waveguides, it exhibits higher robustness against chromatic dispersion and propagation loss, while preserving transparency to modulation formats. Travelling-wave resonant FWM has been demonstrated in silicon-coupled ring resonators and was exploited to realize a 630-μm-long wavelength converter operating over a wavelength range wider than 60 nm and with 28-dB gain with respect to a bare waveguide of the same physical length. Full compatibility of the travelling-wave resonant FWM with optical signal processing applications has been demonstrated through signal retiming and reshaping at 10 Gb s(-1).
Morichetti, Francesco; Canciamilla, Antonio; Ferrari, Carlo; Samarelli, Antonio; Sorel, Marc; Melloni, Andrea
2011-01-01
Wave mixing inside optical resonators, while experiencing a large enhancement of the nonlinear interaction efficiency, suffers from strong bandwidth constraints, preventing its practical exploitation for processing broad-band signals. Here we show that such limits are overcome by the new concept of travelling-wave resonant four-wave mixing (FWM). This approach combines the efficiency enhancement provided by resonant propagation with a wide-band conversion process. Compared with conventional FWM in bare waveguides, it exhibits higher robustness against chromatic dispersion and propagation loss, while preserving transparency to modulation formats. Travelling-wave resonant FWM has been demonstrated in silicon-coupled ring resonators and was exploited to realize a 630-μm-long wavelength converter operating over a wavelength range wider than 60 nm and with 28-dB gain with respect to a bare waveguide of the same physical length. Full compatibility of the travelling-wave resonant FWM with optical signal processing applications has been demonstrated through signal retiming and reshaping at 10 Gb s−1 PMID:21540838
NASA Technical Reports Server (NTRS)
Johnson, C. W.; Holloway, C, M.
2007-01-01
Accident reports provide important insights into the causes and contributory factors leading to particular adverse events. In contrast, this paper provides an analysis that extends across the findings presented over ten years investigations into maritime accidents by both the US National Transportation Safety Board (NTSB) and Canadian Transportation Safety Board (TSB). The purpose of the study was to assess the comparative frequency of a range of causal factors in the reporting of adverse events. In order to communicate our findings, we introduce J-H graphs as a means of representing the proportion of causes and contributory factors associated with human error, equipment failure and other high level classifications in longitudinal studies of accident reports. Our results suggest the proportion of causal and contributory factors attributable to direct human error may be very much smaller than has been suggested elsewhere in the human factors literature. In contrast, more attention should be paid to wider systemic issues, including the managerial and regulatory context of maritime operations.
Notes on critical care-review of seminal management and leadership papers in the United Kingdom.
Coombs, Maureen
2009-06-01
Review of recent critical care provision reveals substantial changes in clinical unit operating, and policy drivers influencing international critical care delivery. Practitioners who have worked in healthcare environments over this time, will have witnessed substantial shifts in healthcare policy, changes in professional body guidance and greater service evaluation have impacted on critical care management and leadership. This paper offers a personal perspective on seminal management and leadership papers published in the critical care literature over the past decade. Presenting a range of national and international work that utilise diverse approaches, ten key papers are highlighted that have impacted in the United Kingdom setting. Through this, the influence of the modernisation agenda, the increasing significance of outcome studies, and the need for flexible, interdependent practice emerges. A key message to surface from this paper is the need for all in critical care to engage with, and understand the wider implications of management and leadership change for critical care delivery.
Adaptive variable-length coding for efficient compression of spacecraft television data.
NASA Technical Reports Server (NTRS)
Rice, R. F.; Plaunt, J. R.
1971-01-01
An adaptive variable length coding system is presented. Although developed primarily for the proposed Grand Tour missions, many features of this system clearly indicate a much wider applicability. Using sample to sample prediction, the coding system produces output rates within 0.25 bit/picture element (pixel) of the one-dimensional difference entropy for entropy values ranging from 0 to 8 bit/pixel. This is accomplished without the necessity of storing any code words. Performance improvements of 0.5 bit/pixel can be simply achieved by utilizing previous line correlation. A Basic Compressor, using concatenated codes, adapts to rapid changes in source statistics by automatically selecting one of three codes to use for each block of 21 pixels. The system adapts to less frequent, but more dramatic, changes in source statistics by adjusting the mode in which the Basic Compressor operates on a line-to-line basis. Furthermore, the compression system is independent of the quantization requirements of the pulse-code modulation system.
The Robonaut 2 Hand - Designed to do Work with Tools
NASA Technical Reports Server (NTRS)
Bridgwater, L. B.; Ihrke, C. A.; Diftler, M. A.; Abdallah, M. E.; Radford, N. A.; Rogers, J. M.; Yayathi, S.; Askew, R. S.; Linn, D. M.
2011-01-01
The second generation Robonaut hand has many advantages over its predecessor. This mechatronic device is more dexterous and has improved force control and sensing giving it the capability to grasp and actuate a wider range of tools. It can achieve higher peak forces at higher speeds than the original. Developed as part of a partnership between General Motors and NASA, the hand is designed to more closely approximate a human hand. Having a more anthropomorphic design allows the hand to attain a larger set of useful grasps for working with human interfaces. Key to the hand s improved performance is the use of lower friction drive elements and a redistribution of components from the hand to the forearm, permitting more sensing in the fingers and palm where it is most important. The following describes the design, mechanical/electrical integration, and control features of the hand. Lessons learned during the development and initial operations along with planned refinements to make it more effective are presented.
NASA Astrophysics Data System (ADS)
Meier, E.; Biedron, S. G.; LeBlanc, G.; Morgan, M. J.; Wu, J.
2009-11-01
This paper describes the results of an advanced control algorithm for the stabilization of electron beam energy in a Linac. The approach combines a conventional Proportional-Integral (PI) controller with a neural network (NNET) feed forward algorithm; it utilizes the robustness of PI control and the ability of a feed forward system in order to exert control over a wider range of frequencies. The NNET is trained to recognize jitter occurring in the phase and voltage of one of the klystrons, based on a record of these parameters, and predicts future energy deviations. A systematic approach is developed to determine the optimal NNET parameters that are then applied to the Australian Synchrotron Linac. The system's capability to fully cancel multi-frequency jitter is demonstrated. The NNET system is then augmented with the PI algorithm, and further jitter attenuation is achieved when the NNET is not operating optimally.
Hysteresis compensation for piezoelectric actuators in single-point diamond turning
NASA Astrophysics Data System (ADS)
Wang, Haifeng; Hu, Dejin; Wan, Daping; Liu, Hongbin
2006-02-01
In recent years, interests have been growing for fast tool servo (FTS) systems to increase the capability of existing single-point diamond turning machines. Although piezoelectric actuator is the most universal base of FTS system due to its high stiffness, accuracy and bandwidth, nonlinearity in piezoceramics limits both the static and dynamic performance of piezoelectric-actuated control systems evidently. To compensate the nonlinear hysteresis behavior of piezoelectric actuators, a hybrid model coupled with Preisach model and feedforward neural network (FNN) has been described. Since the training of FNN does not require a special calibration sequence, it is possible for on-line identification and real-time implementation with general operating data of a specific piezoelectric actuator. To describe the rate dependent behavior of piezoelectric actuators, a hybrid dynamic model was developed to predict the response of piezoelectric actuators in a wider range of input frequency. Experimental results show that a maximal error of less than 3% was accomplished by this dynamic model.
Interval Management: Development and Implementation of an Airborne Spacing Concept
NASA Technical Reports Server (NTRS)
Barmore, Bryan E.; Penhallegon, William J.; Weitz, Lesley A.; Bone, Randall S.; Levitt, Ian; Flores Kriegsfeld, Julia A.; Arbuckle, Doug; Johnson, William C.
2016-01-01
Interval Management is a suite of ADS-B-enabled applications that allows the air traffic controller to instruct a flight crew to achieve and maintain a desired spacing relative to another aircraft. The flight crew, assisted by automation, manages the speed of their aircraft to deliver more precise inter-aircraft spacing than is otherwise possible, which increases traffic throughput at the same or higher levels of safety. Interval Management has evolved from a long history of research and is now seen as a core NextGen capability. With avionics standards recently published, completion of an Investment Analysis Readiness Decision by the FAA, and multiple flight tests planned, Interval Management will soon be part of everyday use in the National Airspace System. Second generation, Advanced Interval Management capabilities are being planned to provide a wider range of operations and improved performance and benefits. This paper briefly reviews the evolution of Interval Management and describes current development and deployment plans. It also reviews concepts under development as the next generation of applications.
NASA Astrophysics Data System (ADS)
Hasegawa, Manabu; Hiramatsu, Kotaro
2013-10-01
The effectiveness of the Metropolis algorithm (MA) (constant-temperature simulated annealing) in optimization by the method of search-space smoothing (SSS) (potential smoothing) is studied on two types of random traveling salesman problems. The optimization mechanism of this hybrid approach (MASSS) is investigated by analyzing the exploration dynamics observed in the rugged landscape of the cost function (energy surface). The results show that the MA can be successfully utilized as a local search algorithm in the SSS approach. It is also clarified that the optimization characteristics of these two constituent methods are improved in a mutually beneficial manner in the MASSS run. Specifically, the relaxation dynamics generated by employing the MA work effectively even in a smoothed landscape and more advantage is taken of the guiding function proposed in the idea of SSS; this mechanism operates in an adaptive manner in the de-smoothing process and therefore the MASSS method maintains its optimization function over a wider temperature range than the MA.
Towards an Operations Strategy for the Infusion of Product-Centric Services into Manufacturing
NASA Astrophysics Data System (ADS)
Baines, Tim S.; Lightfoot, Howard W.
The work in this chapter is concerned with product-centric servitization. This is where a portfolio of services are formed and integrated to support product availability and use. Such servitization can be a valuable source of revenue for a manufacturer, yet little attention has been given to the configuration of the wider operations strategy that needs to be in place to deliver integrated products and services successfully. Therefore, the purpose of this chapter is to put forward a generic set of characteristics for such operations. Our intention is that these characteristics will be valuable to practitioners contemplating sophisticated forms of servitization, as they suggest the likely and significant changes that will be needed to the operations strategy of a conventional manufacturing organisation.
MMI-based MOEMS FT spectrometer for visible and IR spectral ranges
NASA Astrophysics Data System (ADS)
Al-Demerdash, Bassem M.; Medhat, Mostafa; Sabry, Yasser M.; Saadany, Bassam; Khalil, Diaa
2014-03-01
MEMS spectrometers have very strong potential in future healthcare and environmental monitoring applications, where Michelson interferometers are the core optical engine. Recently, MEMS Michelson interferometers based on using silicon interface as a beam splitter (BS) has been proposed [7, 8]. This allows having a monolithically-integrated on-chip FTIR spectrometer. However silicon BS exhibits high absorption loss in the visible range and high material dispersion in the near infrared (NIR) range. For this reason, we propose in this work a novel MOEMS interferometer allowing operation over wider spectral range covering both the infrared (IR) and the visible ranges. The proposed architecture is based on spatial splitting and combining of optical beams using the imaging properties of Multi-Mode Interference MMI waveguide. The proposed structure includes an optical splitter for spatial splitting an input beam into two beams and a combiner for spatial combining the two interferometer beams. A MEMS moveable mirror is provided to produce an optical path difference between the two beams. The new interferometer is fabricated using DRIE technology on an SOI wafer. The movable mirror is metalized and attached to a comb-drive actuator fabricated in the same lithography step in a self-aligned manner on chip. The novel interferometer is tested as a Fourier transform spectrometer. Red laser, IR laser and absorption spectra of different materials are measured with a resolution of 2.5 nm at 635-nm wavelength. The structure is a very compact one that allows its integration and fabrication on a large scale with very low cost.
Daly, Ryan; Froneman, Pierre W; Smale, Malcolm J
2013-01-01
As apex predators, sharks play an important role shaping their respective marine communities through predation and associated risk effects. Understanding the predatory dynamics of sharks within communities is, therefore, necessary to establish effective ecologically based conservation strategies. We employed non-lethal sampling methods to investigate the feeding ecology of bull sharks (Carcharhinus leucas) using stable isotope analysis within a subtropical marine community in the southwest Indian Ocean. The main objectives of this study were to investigate and compare the predatory role that sub-adult and adult bull sharks play within a top predatory teleost fish community. Bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and relatively enriched range of δ(13)C values relative to the local marine community. This suggests that bull sharks forage from a more diverse range of δ(13)C sources over a wider geographical range than the predatory teleost community. Adult bull sharks appeared to exhibit a shift towards consistently higher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Although predatory teleost fish are also capable of substantial migrations, bull sharks may have the ability to exploit a more diverse range of habitats and appeared to prey on a wider diversity of larger prey. This suggests that bull sharks play an important predatory role within their respective marine communities and adult sharks in particular may shape and link ecological processes of a variety of marine communities over a broad range.
Daly, Ryan; Froneman, Pierre W.; Smale, Malcolm J.
2013-01-01
As apex predators, sharks play an important role shaping their respective marine communities through predation and associated risk effects. Understanding the predatory dynamics of sharks within communities is, therefore, necessary to establish effective ecologically based conservation strategies. We employed non-lethal sampling methods to investigate the feeding ecology of bull sharks (Carcharhinus leucas) using stable isotope analysis within a subtropical marine community in the southwest Indian Ocean. The main objectives of this study were to investigate and compare the predatory role that sub-adult and adult bull sharks play within a top predatory teleost fish community. Bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and relatively enriched range of δ13C values relative to the local marine community. This suggests that bull sharks forage from a more diverse range of δ13C sources over a wider geographical range than the predatory teleost community. Adult bull sharks appeared to exhibit a shift towards consistently higher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Although predatory teleost fish are also capable of substantial migrations, bull sharks may have the ability to exploit a more diverse range of habitats and appeared to prey on a wider diversity of larger prey. This suggests that bull sharks play an important predatory role within their respective marine communities and adult sharks in particular may shape and link ecological processes of a variety of marine communities over a broad range. PMID:24205168
Optical devices integrated with semiconductor optical amplifier
NASA Astrophysics Data System (ADS)
Oh, Kwang R.; Park, Moon S.; Jeong, Jong S.; Baek, Yongsoon; Oh, Dae-Kon
2000-07-01
Semiconductor optical amplifiers (SOA's) have been used as a key optical component for the high capacity communication systems. The monolithic integration is necessary for the stable operation of these devices and the wider applications. In this paper, the coupling technique between different waveguides and the integration of SSC's are discussed and the research results of optical devices integrated with SOA's are presented.
HazMatID (trademark) Replacement Project
2013-05-09
replacement for the Smiths Detection HazMatIDTM on the 886H allowance standard, a search of Fourier transform infrared spectroscopy ( FTIR ) instruments was...uses FTIR spectroscopy. It has the capability to identify chemical warfare agents, explosives , toxic industrial chemicals, narcotics, and...uses FTIR technology , providing a wider spectral coverage and higher spectral resolution. Findings: As I operated the Mobile-IR, I found it to
John R. Britt; Jason P. Reynolds
2013-01-01
In plantation forestry, several silvicultural treatments can be row oriented. When rows are treated individually, planting trees in wider rows may result in lower silvicultural treatment cost, facilitate future operations, such as thinning and fire fighting, and provide a longer period with open canopy conditions. All these scenarios could provide benefit to landowners...
Integrated Vehicle Thermal Management for Advanced Vehicle Propulsion Technologies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bennion, K.; Thornton, M.
A critical element to the success of new propulsion technologies that enable reductions in fuel use is the integration of component thermal management technologies within a viable vehicle package. Vehicle operation requires vehicle thermal management systems capable of balancing the needs of multiple vehicle systems that may require heat for operation, require cooling to reject heat, or require operation within specified temperature ranges. As vehicle propulsion transitions away from a single form of vehicle propulsion based solely on conventional internal combustion engines (ICEs) toward a wider array of choices including more electrically dominant systems such as plug-in hybrid electric vehiclesmore » (PHEVs), new challenges arise associated with vehicle thermal management. As the number of components that require active thermal management increase, so do the costs in terms of dollars, weight, and size. Integrated vehicle thermal management is one pathway to address the cost, weight, and size challenges. The integration of the power electronics and electric machine (PEEM) thermal management with other existing vehicle systems is one path for reducing the cost of electric drive systems. This work demonstrates techniques for evaluating and quantifying the integrated transient and continuous heat loads of combined systems incorporating electric drive systems that operate primarily under transient duty cycles, but the approach can be extended to include additional steady-state duty cycles typical for designing vehicle thermal management systems of conventional vehicles. The work compares opportunities to create an integrated low temperature coolant loop combining the power electronics and electric machine with the air conditioning system in contrast to a high temperature system integrated with the ICE cooling system.« less
Locata Performance Evaluation in the Presence of Wide- and Narrow-Band Interference
NASA Astrophysics Data System (ADS)
Khan, Faisal A.; Rizos, Chris; Dempster, Andrew G.
Classically difficult positioning environments often call for augmentation technology to assist the GPS, or more generally the Global Navigation Satellite System (GNSS) technology. The ground-based ranging technology offers augmentation, and even replacement, to GPS in such environments. However, like any other system relying on wireless technology, a Locata positioning network also faces issues in the presence of RF interference (RFI). This problem is magnified due to the fact that Locata operates in the licence-free 2·4 GHz Industrial, Scientific and Medical (ISM) band. The licence-free nature of this band attracts a much larger number of devices using a wider range of signal types than for licensed bands, resulting in elevation of the noise floor. Also, harmonics from out-of-band signals can act as potential interferers. WiFi devices operating in this band have been identified as the most likely potential interferer, due partially to their use of the whole ISM band, but also because Locata applications often also may use a wireless network. This paper evaluates the performance of Locata in the presence of both narrow- and wide-band interfering signals. Effects of received interference on both raw measurements and final solutions are reported and analysed. Test results show that Locata performance degrades in the presence of received interference. It is also identified that high levels of received interference can affect Locata carriers even if the interference is not in co-frequency situation with the affected carrier. Finally, Locata characteristics have been identified which can be exploited to mitigate RFI issues.
Sharma, Umesh; Yadav, Sher Singh; Tomar, Vinay; Garg, Amit
2016-01-01
This is a prospective study of the use and efficacy of a novel technique of circumferential tubularised lingual mucosal graft (LMG) in obliterative and near obliterative bulbar urethral stricture of >2 cm where excisional and augmented anastomotic urethroplasty are not feasible. The stenotic urethral segment was opened dorsally in midline and fibrosed urethra was excised taking care to preserve the healthy spongiosum tissue. LMG (av. Length 3 cm) was placed from one end of corporal body towards spongy tissue in a circumferential manner. Another LMG was placed in similar manner to deal with longer stricture. The urethra was tubularised over 14 Fr silicone catheter. A total of 12 men, of mean age 47 years underwent this procedure. The mean follow up period was 11 months starting from July 2014 till manuscript submission. Follow up included voiding cystourethrogram at 3 weeks, cystoscopy at 3 months (one patient didn't turned up) and subsequent follow up. Mean stricture length was 4.66 cm (range, 3-8.5 cm) and mean operative time was 195 min. (range, 160 to 200 min.). The technique was successful (normal voiding with no need for any post-operative procedure) in 11(91.6%) patients. One patient developed early recurrence at 4 month of surgery and had anastomotic stricture which was successfully managed by direct visual internal urethrotomy. Single stage circumferential tubularised graft urethroplasty is an excellent technique for strictures that include segments of obliterative and near obliterative diseased urethra. It provide a wider neourethra than patch graft urethroplasty.
Lamers, Patrick; Tan, Eric C. D.; Searcy, Erin M.; ...
2015-08-20
Here, pioneer cellulosic biorefineries across the United States rely on a conventional feedstock supply system based on one-year contracts with local growers, who harvest, locally store, and deliver feed-stock in low-density format to the conversion facility. While the conventional system is designed for high biomass yield areas, pilot scale operations have experienced feedstock supply shortages and price volatilities due to reduced harvests and competition from other industries. Regional supply dependency and the inability to actively manage feedstock stability and quality, provide operational risks to the biorefinery, which translate into higher investment risk. The advanced feedstock supply system based on amore » network of depots can mitigate many of these risks and enable wider supply system benefits. This paper compares the two concepts from a system-level perspective beyond mere logistic costs. It shows that while processing operations at the depot increase feedstock supply costs initially, they enable wider system benefits including supply risk reduction (leading to lower interest rates on loans), industry scale-up, conversion yield improvements, and reduced handling equipment and storage costs at the biorefinery. When translating these benefits into cost reductions per liter of gasoline equivalent (LGE), we find that total cost reductions between -0.46 to -0.21 per LGE for biochemical and -0.32 to -0.12 per LGE for thermochemical conversion pathways are possible. Naturally, these system level benefits will differ between individual actors along the feedstock supply chain. Further research is required with respect to depot sizing, location, and ownership structures.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lamers, Patrick; Tan, Eric C. D.; Searcy, Erin M.
Here, pioneer cellulosic biorefineries across the United States rely on a conventional feedstock supply system based on one-year contracts with local growers, who harvest, locally store, and deliver feed-stock in low-density format to the conversion facility. While the conventional system is designed for high biomass yield areas, pilot scale operations have experienced feedstock supply shortages and price volatilities due to reduced harvests and competition from other industries. Regional supply dependency and the inability to actively manage feedstock stability and quality, provide operational risks to the biorefinery, which translate into higher investment risk. The advanced feedstock supply system based on amore » network of depots can mitigate many of these risks and enable wider supply system benefits. This paper compares the two concepts from a system-level perspective beyond mere logistic costs. It shows that while processing operations at the depot increase feedstock supply costs initially, they enable wider system benefits including supply risk reduction (leading to lower interest rates on loans), industry scale-up, conversion yield improvements, and reduced handling equipment and storage costs at the biorefinery. When translating these benefits into cost reductions per liter of gasoline equivalent (LGE), we find that total cost reductions between -0.46 to -0.21 per LGE for biochemical and -0.32 to -0.12 per LGE for thermochemical conversion pathways are possible. Naturally, these system level benefits will differ between individual actors along the feedstock supply chain. Further research is required with respect to depot sizing, location, and ownership structures.« less
Minderman, Jeroen; Pendlebury, Chris J.; Pearce-Higgins, James W.; Park, Kirsty J.
2012-01-01
The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating <50 kW) sector is growing rapidly. In spite of evidence of effects of large wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6–18 m hub height) and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0–5 m), bat activity (measured as the probability of a bat “pass” per hour) decreases from 84% (71–91%) to 28% (11–54%) as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20–25 m) from operating turbines (activity decreases from 80% (65–89%) to 59% (32–81%)), and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat. PMID:22859969
Kodavasal, Janardhan; Kolodziej, Christopher P.; Ciatti, Stephen A.; ...
2016-11-03
In this study, we study the effects of injector nozzle inclusion angle, injection pressure, boost, and swirl ratio on gasoline compression ignition combustion. Closed-cycle computational fluid dynamics simulations using a 1/7th sector mesh representing a single cylinder of a four-cylinder 1.9 L diesel engine, operated in gasoline compression ignition mode with 87 anti-knock index (AKI) gasoline, were performed. Two different operating conditions were studied—the first is representative of idle operation (4 mg fuel/cylinder/cycle, 850 r/min), and the second is representative of a low-load condition (10 mg fuel/cylinder/cycle, 1500 r/min). The mixture preparation and reaction space from the simulations were analyzedmore » to gain insights into the effects of injection pressure, nozzle inclusion angle, boost, and swirl ratio on achieving stable low-load to idle gasoline compression ignition operation. It was found that narrower nozzle inclusion angles allow for more reactivity or propensity to ignition (determined qualitatively by computing constant volume ignition delays) and are suitable over a wider range of injection timings. Under idle conditions, it was found that lower injection pressures helped to reduce overmixing of the fuel, resulting in greater reactivity and ignitability (ease with which ignition can be achieved) of the gasoline. However, under the low-load condition, lower injection pressures did not increase ignitability, and it is hypothesized that this is because of reduced chemical residence time resulting from longer injection durations. Reduced swirl was found to maintain higher in-cylinder temperatures through compression, resulting in better ignitability. It was found that boosting the charge also helped to increase reactivity and advanced ignition timing.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kodavasal, Janardhan; Kolodziej, Christopher P.; Ciatti, Stephen A.
In this study, we study the effects of injector nozzle inclusion angle, injection pressure, boost, and swirl ratio on gasoline compression ignition combustion. Closed-cycle computational fluid dynamics simulations using a 1/7th sector mesh representing a single cylinder of a four-cylinder 1.9 L diesel engine, operated in gasoline compression ignition mode with 87 anti-knock index (AKI) gasoline, were performed. Two different operating conditions were studied—the first is representative of idle operation (4 mg fuel/cylinder/cycle, 850 r/min), and the second is representative of a low-load condition (10 mg fuel/cylinder/cycle, 1500 r/min). The mixture preparation and reaction space from the simulations were analyzedmore » to gain insights into the effects of injection pressure, nozzle inclusion angle, boost, and swirl ratio on achieving stable low-load to idle gasoline compression ignition operation. It was found that narrower nozzle inclusion angles allow for more reactivity or propensity to ignition (determined qualitatively by computing constant volume ignition delays) and are suitable over a wider range of injection timings. Under idle conditions, it was found that lower injection pressures helped to reduce overmixing of the fuel, resulting in greater reactivity and ignitability (ease with which ignition can be achieved) of the gasoline. However, under the low-load condition, lower injection pressures did not increase ignitability, and it is hypothesized that this is because of reduced chemical residence time resulting from longer injection durations. Reduced swirl was found to maintain higher in-cylinder temperatures through compression, resulting in better ignitability. It was found that boosting the charge also helped to increase reactivity and advanced ignition timing.« less
Towards an autonomous sensor architecture for persistent area protection
NASA Astrophysics Data System (ADS)
Thomas, Paul A.; Marshall, Gillian F.; Stubbins, Daniel J.; Faulkner, David A.
2016-10-01
The majority of sensor installations for area protection (e.g. critical national infrastructure, military forward operating bases, etc.) make use of banks of screens each containing one or more sensor feeds, such that the burden of combining data from the various sources, understanding the situation, and controlling the sensors all lies with the human operator. Any automation in the system is generally heavily bespoke for the particular installation, leading to an inflexible system which is difficult to change or upgrade. We have developed a modular system architecture consisting of intelligent autonomous sensor modules, a high level decision making module, a middleware integration layer and an end-user GUI. The modules are all effectively "plug and play", and we have demonstrated that it is relatively simple to incorporate legacy sensors into the architecture. We have extended our previously-reported SAPIENT demonstration system to operate with a larger number and variety of sensor modules, over an extended area, detecting and classifying a wider variety of "threat activities", both vehicular and pedestrian. We report the results of a demonstration of the SAPIENT system containing multiple autonomous sensor modules with a range of modalities including laser scanners, radar, TI, EO, acoustic and seismic sensors. They operate from a combination of mains, generator and battery power, and communicate with the central "hub" over Ethernet, point-to-point wireless links and Wi-Fi. The system has been configured to protect an extended area in a complex semi-urban environment. We discuss the operation of the SAPIENT system in a realistic demonstration environment (which included significant activity not under trial control), showing sensor cueing, multi-modal sensor fusion, threat prioritisation and target hand-off.
Minderman, Jeroen; Pendlebury, Chris J; Pearce-Higgins, James W; Park, Kirsty J
2012-01-01
The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating <50 kW) sector is growing rapidly. In spite of evidence of effects of large wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6-18 m hub height) and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0-5 m), bat activity (measured as the probability of a bat "pass" per hour) decreases from 84% (71-91%) to 28% (11-54%) as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20-25 m) from operating turbines (activity decreases from 80% (65-89%) to 59% (32-81%)), and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat.
Re-Conceptualising Rural Resources as Countryside Capital: The Case of Rural Tourism
ERIC Educational Resources Information Center
Garrod, Brian; Wornell, Roz; Youell, Ray
2006-01-01
Commentators tend to agree that the rural resource is becoming increasingly subject to pressures arising from an ever wider range of economic, social, political and environmental influences. This paper focuses on the case of rural tourism in illustrating the advantages of adopting a sustainable development approach to identifying suitable policies…
New Perspectives on Human Problem Solving
ERIC Educational Resources Information Center
Goldstone, Robert L.; Pizlo, Zygmunt
2009-01-01
In November 2008 at Purdue University, the 2nd Workshop on Human Problem Solving was held. This workshop, which was a natural continuation of the first workshop devoted almost exclusively to optimization problems, addressed a wider range of topics that reflect the scope of the "Journal of Problem Solving." The workshop was attended by 35…
The Neoliberalization of Higher Education in England: An Alternative is Possible*
ERIC Educational Resources Information Center
Maisuria, Alpesh; Cole, Mike
2017-01-01
In this article, we provide a critical explanation and critique of neoliberalism. We attempt an innovative focus ranging from the wider contemporary political and ideological shifts, to the way in which neoliberal policy specifically influences higher education and the consequences thereof. We follow a narrative logic in three parts where we first…
Sequence Matters but How Exactly? A Method for Evaluating Activity Sequences from Data
ERIC Educational Resources Information Center
Doroudi, Shayan; Holstein, Kenneth; Aleven, Vincent; Brunskill, Emma
2016-01-01
How should a wide variety of educational activities be sequenced to maximize student learning? Although some experimental studies have addressed this question, educational data mining methods may be able to evaluate a wider range of possibilities and better handle many simultaneous sequencing constraints. We introduce Sequencing Constraint…
ERIC Educational Resources Information Center
Adler, Jonathan M.; Matthews, Elizabeth A.
2009-01-01
Students bring an intact, if unarticulated, epistemological perspective into the classroom that influences how they receive and process new information. In this study, students who explored a wider range of perspectives had significantly improved learning outcomes as measured in 3 domains: retention of specific content, retention of general…
Additional Support Needs Reforms and Social Justice in Scotland
ERIC Educational Resources Information Center
Riddell, Sheila; Stead, Joan; Weedon, Elisabet; Wright, Kevin
2010-01-01
New additional support-needs legislation in Scotland sought to recognise the way in which poverty, as well as individual impairment, contribute to the creation of children's difficulties in learning. As well as identifying a wider range of needs, the legislation sought to provide parents, irrespective of social background, with more powerful means…
Learning through a Foreign Language: Models, Methods and Outcomes.
ERIC Educational Resources Information Center
Masih, John, Ed.
This book presents European perspectives on the means of structuring curricula that integrate content and language teaching, drawing on the experience of practitioners at a range of levels. It also provides details of the outcomes of such programs and describes the current and future challenges for wider scale adoption of content and language…
Knowledge Infrastructures and the Inscrutability of Openness in Education
ERIC Educational Resources Information Center
Edwards, Richard
2015-01-01
Openness has a long genealogy in education. Whether through the use of post, radio, television and digital technologies, extending learning opportunities to more and a wider range of people has been a significant aspect of educational history. Transcending barriers to learning has been promoted as the means of opening educational opportunities in…
Activities in Science Related to Space.
ERIC Educational Resources Information Center
National Aeronautics and Space Administration, Washington, DC. Educational Programs Div.
Contained are a collection of science activities based upon forty-six scientific concepts related to space science. These activities are designed for junior high school science, but a much wider grade level range of use is possible. The booklet is primarily intended for teacher use. Each series of concept-oriented activities is independent of the…
Characterizing Twitter Communication--A Case Study of International Engineering Academic Units
ERIC Educational Resources Information Center
Palmer, Stuart
2014-01-01
Engineering academic units might engage with social media for a range of purposes including for general communication with students, staff, alumni, other important stakeholders and the wider community at large; for student recruitment and for marketing and promotion more generally. This paper presents an investigation into the use of Twitter by…
Liquid Spray Characterization in Flow Fields with Centripetal Acceleration
2014-03-27
25 2.4.1 Atomization of Liquid Jets ...volumetric heat release rates, easier light-up, wider burning range, and lower exhaust pollutant emissions [11]. 26 2.4.1 Atomization of Liquid Jets ...Atomization involves the interaction of consolidating and disruptive forces acting on a jet of liquid . The process of atomization can be further
The Politics of Testing When Measures "Go Public"
ERIC Educational Resources Information Center
Henig, Jeffrey R.
2013-01-01
Background/Context: Validity issues are often discussed in technical terms, but the context changes when measures enter broad public debate, and a wider range of interests come into play. Purpose: This article, part of a special section of TCR, considers the political dimensions of validity questions as raised by a keynote address and panel…
ERIC Educational Resources Information Center
Reeves, Matthew Jonathan; Bailey, Richard P.
2016-01-01
Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental psychiatric disorder among children. Despite the noted positive aspects of the disorder, it is often associated with a range of negative outcomes for that are detrimental to children's education and wider well-being. This comprehensive scoping review examined…
The Revised DCDQ: Is It a Suitable Screening Measure for Motor Difficulties in Adolescents?
ERIC Educational Resources Information Center
Pannekoek, Linda; Rigoli, Daniela; Piek, Jan P.; Barrett, Nicholas C.; Schoemaker, Marina
2012-01-01
The parent-rated Developmental Coordination Disorder Questionnaire (DCDQ) has been revised to incorporate a wider age range, including adolescence. In this exploratory study, internal consistency and validity of the DCDQ-2007 was assessed using a community-based sample of 87 adolescents. Psychometric properties of the DCDQ-2007 were investigated…
Interactional Competence in a Paired Speaking Test: Features Salient to Raters
ERIC Educational Resources Information Center
May, Lyn
2011-01-01
Paired speaking tests are now commonly used in both high-stakes testing and classroom assessment contexts. The co-construction of discourse by candidates is regarded as a strength of paired speaking tests, as candidates have the opportunity to display a wider range of interactional competencies, including turn taking, initiating topics, and…
Education Policy Studies in South Africa, 1995-2006
ERIC Educational Resources Information Center
Deacon, Roger; Osman, Ruksana; Buchler, Michelle
2010-01-01
This article reports on findings pertaining to scholarship in education policy drawn from a wider study on all education research in South Africa from 1995 to 2006. This study, which defined education research as broadly pertaining to teaching and/or learning, obtained extensive data from a wide range of sources, including universities, public…
A table for converting pH to hydrogen ion concentration [H+] over the range 5-9.
DOT National Transportation Integrated Search
1968-10-01
The wider use, in the future, of hydrogen ion concentration (H+) rather than pH to describe and evaluate acid-base status will require interconversion of the two notations until a final standard is adopted. The relationship between pH and (H+) is giv...
Burns, Jacky; Conway, David I; Gnich, Wendy; Macpherson, Lorna M D
2017-03-08
Poor health and health inequalities persist despite increasing investment in health improvement programmes across high-income countries. Evidence suggests that to reduce health inequalities, a range of activities targeted at different levels within society and throughout the life course should be employed. There is a particular focus on addressing inequalities in early years as this may influence the experience of health in adulthood. To address the wider determinants of health at a community level, a key intervention which can be considered is supporting patients to access wider community resources. This can include processes such as signposting, referral and facilitation. There is a lack of evidence synthesis in relation to the most effective methods for linking individuals from health services to other services within communities, especially when considering interventions aimed at families with young children. The aim of this study is to understand the way health services can best help parents, carers and families with pre-school children to engage with local services, groups and agencies to address their wider health and social needs. The review may inform future guidance to support families to address wider determinants of health. The study is a systematic review, and papers will be identified from the following electronic databases: Web of Science, Embase, MEDLINE and CINAHL. A grey literature search will be conducted using an internet search engine and specific grey literature databases (TRiP, EThOS and Open Grey). Reference lists/bibliographies of selected papers will be searched. Quality will be assessed using the Effective Public Health Practice Project Quality Assessment Tool for quantitative studies and the CASP tool for qualitative studies. Data will be synthesised in a narrative form and weighted by study quality. It is important to understand how health services can facilitate access to wider services for their patients to address the wider determinants of health. This may impact on the experience of health inequalities. This review focuses on how this can be achieved for families with pre-school children, and the evidence obtained will be useful for informing future guidance on this topic. PROSPERO CRD42016034066.
New families of carbon gels based on natural resources
NASA Astrophysics Data System (ADS)
Szczurek, Andrzej; Amaral-Labat, Gisele; Fierro, Vanessa; Pizzi, Antonio; Celzard, Alain
2013-03-01
Carbon gels are versatile materials which can be used for many applications. They are extremely expensive, because generally prepared from resorcinol - formaldehyde (RF) resins first gelled and next dried with supercritical carbon dioxide. In the present work, resorcinol has been substituted partly or completely by tannins, a family of molecules extracted from mimosa tree barks. Tannins are natural, non-toxic products, typically thirty times cheaper than resorcinol. Their chemical resemblance with the latter makes them be often called natural resorcinol. Using tannins not only substantially decreases the cost but also allows preparing materials in a much wider range of pHs than that usually employed for RF gels. Consequently the main pore size and the fraction of given families of pores, controlling the carbon gels' properties, are tuned in an easier way, and a much wider range of pore structures is obtained. Finally, two alternative ways of drying are suggested for further decreasing the cost: freeze-drying and supercritical drying in acetone. Both are shown to lead, in some conditions described below, to materials having similar characteristics to those of expensive RF carbon aerogels previously dried in supercritical CO2.
A new catalogue of ultraluminous X-ray sources (and more!)
NASA Astrophysics Data System (ADS)
Roberts, T.; Earnshaw, H.; Walton, D.; Middleton, M.; Mateos, S.
2017-10-01
Many of the critical issues of ultraluminous X-ray source (ULX) science - for example the prevalence of IMBH and/or ULX pulsar candidates within the wider ULX population - can only be addressed by studying statistical samples of ULXs. Similarly, characterising the range of properties displayed by ULXs, and so understanding their accretion physics, requires large samples of objects. To this end, we introduce a new catalogue of 376 ultraluminous X-ray sources and 1092 less luminous point X-ray sources associated with nearby galaxies, derived from the 3XMM-DR4 catalogue. We highlight applications of this catalogue, for example the identification of new IMBH candidates from the most luminous ULXs; and examining the physics of objects at the Eddington threshold, where their luminosities of ˜ 10^{39} erg s^{-1} indicate their accretion rates are ˜ Eddington. We also show how the catalogue can be used to start to examine a wider range of lower luminosity (sub-ULX) point sources in star forming galaxies than previously accessible through spectral stacking, and argue why this is important for galaxy formation in the high redshift Universe.
Precise and versatile formula for birefringent filters
NASA Astrophysics Data System (ADS)
Shao, Zhongxing
1996-07-01
In an investigation of extraordinary-(E-) ray behavior and the index of refraction for E waves in a uniaxial crystal, a precise and versatile formula for birefringent filters, based on the exact construction of the optical path difference, is set up with neither the approximation Delta n = no - ne less than or equals no (or n e), nor the ambiguity sin( theta )/sin(rw) = ne. The exact construction gives the correct variation of the position and the dimension in each path, yielding the path difference while the filter is tuning. The formula is applicable not only to a filter with its optical axis parallel to the entrance surface (FAPS) but also to a filter with its axis inclined to the surface (FAIS). Also, the formula indicates that a FAIS allows laser wavelengths to be tuned over a wider range than does a FAPS. The origin of the wider range is interpreted to be the greater variation in the index for the FAIS while the filter is tuning. With the help of the formula we design a FAIS for tuning a cw 42.25.Lc.
Kempthorne, Joshua T; Armour, Paul C; Rietveld, John A; Hooper, Gary J
2011-06-01
Surgical dislocation of the hip has been developed to deal with the problems causing femoroacetabular impingement (FAI). This is a relatively recent procedure that was historically reserved for larger areas specializing in hip surgery. We hypothesized that surgical dislocation can be used for symptomatic FAI in a typical Australasian tertiary orthopaedic centre with acceptable results. This prospective study reviews the results of 53 surgical dislocations in this setting, looking particularly at functional outcomes and early complications. There were significant improvements in the Western Ontario and McMaster University Osteoarthritis Index score at 1, 2, 3 and 4 years post-operatively. Western Ontario and McMaster University Osteoarthritis Index scores increased by 23, 28, 34 and 35 points, respectively (P 0.0039). There was no significant improvement in hip range of motion. There were two (4%) early failures with conversion to total hip arthroplasty, and no cases of post-operative avascular necrosis of the femoral head. We believe that as the diagnosis of FAI and conservative nonarthroplasty surgery of the hip gains wider acceptance, it will become a procedure that should be offered to all appropriate patients in an attempt to delay or limit total hip arthroplasty in this young age group.
Taylor, Martin J; Jiang, Li; Reichert, Joachim; Papageorgiou, Anthoula C; Beaumont, Simon K; Wilson, Karen; Lee, Adam F; Barth, Johannes V; Kyriakou, Georgios
2017-04-20
Furfural is a key bioderived platform chemical whose reactivity under hydrogen atmospheres affords diverse chemical intermediates. Here, temperature-programmed reaction spectrometry and complementary scanning tunneling microscopy (STM) are employed to investigate furfural adsorption and reactivity over a Pt(111) model catalyst. Furfural decarbonylation to furan is highly sensitive to reaction conditions, in particular, surface crowding and associated changes in the adsorption geometry: furfural adopts a planar geometry on clean Pt(111) at low coverage, tilting at higher coverage to form a densely packed furfural adlayer. This switch in adsorption geometry strongly influences product selectivity. STM reveals the formation of hydrogen-bonded networks for planar furfural, which favor decarbonylation on clean Pt(111) and hydrogenolysis in the presence of coadsorbed hydrogen. Preadsorbed hydrogen promotes furfural hydrogenation to furfuryl alcohol and its subsequent hydrogenolysis to methyl furan, while suppressing residual surface carbon. Furfural chemistry over Pt is markedly different from that over Pd, with weaker adsorption over the former affording a simpler product distribution than the latter; Pd catalyzes a wider range of chemistry, including ring-opening to form propene. Insight into the role of molecular orientation in controlling product selectivity will guide the design and operation of more selective and stable Pt catalysts for furfural hydrogenation.
Environmental qualification testing of payload G-534, the Pool Boiling Experiment
NASA Technical Reports Server (NTRS)
Sexton, J. Andrew
1992-01-01
Payload G-534, the prototype Pool Boiling Experiment (PBE), is scheduled to fly on the STS-47 mission in September 1992. This paper describes the purpose of the experiment and the environmental qualification testing program that was used to prove the integrity of the hardware. Component and box level vibration and thermal cycling tests were performed to give an early level of confidence in the hardware designs. At the system level, vibration, thermal extreme soaks, and thermal vacuum cycling tests were performed to qualify the complete design for the expected shuttle environment. The system level vibration testing included three axis sine sweeps and random inputs. The system level hot and cold soak tests demonstrated the hardware's capability to operate over a wide range of temperatures and gave wider latitude in determining which shuttle thermal attitudes were compatible with the experiment. The system level thermal vacuum cycling tests demonstrated the hardware's capability to operate in a convection free environment. A unique environmental chamber was designed and fabricated by the PBE team and allowed most of the environmental testing to be performed within the hardware build laboratory. The completion of the test program gave the project team high confidence in the hardware's ability to function as designed during flight.
2017-01-01
Furfural is a key bioderived platform chemical whose reactivity under hydrogen atmospheres affords diverse chemical intermediates. Here, temperature-programmed reaction spectrometry and complementary scanning tunneling microscopy (STM) are employed to investigate furfural adsorption and reactivity over a Pt(111) model catalyst. Furfural decarbonylation to furan is highly sensitive to reaction conditions, in particular, surface crowding and associated changes in the adsorption geometry: furfural adopts a planar geometry on clean Pt(111) at low coverage, tilting at higher coverage to form a densely packed furfural adlayer. This switch in adsorption geometry strongly influences product selectivity. STM reveals the formation of hydrogen-bonded networks for planar furfural, which favor decarbonylation on clean Pt(111) and hydrogenolysis in the presence of coadsorbed hydrogen. Preadsorbed hydrogen promotes furfural hydrogenation to furfuryl alcohol and its subsequent hydrogenolysis to methyl furan, while suppressing residual surface carbon. Furfural chemistry over Pt is markedly different from that over Pd, with weaker adsorption over the former affording a simpler product distribution than the latter; Pd catalyzes a wider range of chemistry, including ring-opening to form propene. Insight into the role of molecular orientation in controlling product selectivity will guide the design and operation of more selective and stable Pt catalysts for furfural hydrogenation. PMID:29225721
Li, Xingang; Gao, Yujie; Ding, Hui
2013-10-01
The lead removal from the metallic mixture of waste printed circuit boards by vacuum distillation was optimized using experimental design, and a mathematical model was established to elucidate the removal mechanism. The variables studied in lead evaporation consisted of the chamber pressure, heating temperature, heating time, particle size and initial mass. The low-level chamber pressure was fixed at 0.1 Pa as the operation pressure. The application of two-level factorial design generated a first-order polynomial that agreed well with the data for evaporation efficiency of lead. The heating temperature and heating time exhibited significant effects on the efficiency, which was validated by means of the copper-lead mixture experiments. The optimized operating conditions within the region studied were the chamber pressure of 0.1 Pa, heating temperature of 1023 K and heating time of 120 min. After the conditions were employed to remove lead from the metallic mixture of waste printed circuit boards, the efficiency was 99.97%. The mechanism of the effects was elucidated by mathematical modeling that deals with evaporation, mass transfer and condensation, and can be applied to a wider range of metal removal by vacuum distillation. Copyright © 2013 Elsevier Ltd. All rights reserved.
Fogel, Ronen; Limson, Janice; Seshia, Ashwin A
2016-06-30
Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.
NASA Technical Reports Server (NTRS)
Haynes, C. M.
1980-01-01
A 5 x 40 cm rectangular-beam ion source was designed and fabricated. A multipole field configuration was used to facilitate design of the modular rectangular chamber, while a three-grid ion optics system was used for increased ion current densities. For the multipole chamber, a magnetic integral of 0.000056 Tesla-m was used to contain the primary electrons. This integral value was reduced from the initial design value, with the reduction found necessary for discharge stability. The final value of magnetic integral resulted in discharge losses at typical operating conditions which ranged from 600 to 1000 eV/ion, in good agreement with the design value of 800 eV/ion. The beam current density at the ion optics was limited to about 3.2 mA/sq cm at 500 eV and to about 3.5 mA/sq cm at 1000 ev. The effects of nonuniform ion current, dimension tolerance, and grid thermal warping were considered. The use of multiple rectangular-beam ion sources to process wider areas than would be possible with a single source (approx. 40 cm) was also studied. Beam profiles were surveyed at a variety of operating conditions and the results of various amounts of beam overlap calculated.
Tunable and mode-locked laser action of Cr4+ in codoped forsterite Cr, Sc:Mg2SiO4
NASA Astrophysics Data System (ADS)
Sanina, V. V.; Mitrokhin, V. P.; Subbotin, K. A.; Lis, D. A.; Lis, O. N.; Ivanov, A. A.; Zharikov, E. V.
2018-01-01
The laser oscillation of tetravalent chromium and scandium codoped forsterite Cr4+,Sc:Mg2SiO4 single crystal has been demonstrated for the first time for continuous wave, tunable and mode-locked regimes. For comparison, the laser experiments have also been performed in the same configuration with the reference forsterite single crystal solely doped by chromium. The aim of scandium codoping is to inhibit the formation of parasitic trivalent chromium in the crystal. The crystal with scandium demonstrates a wider tuning range, lower lasing threshold and wider mode-locked lasing spectrum than those of the reference crystal, although the total lasing efficiency achieved by both crystals is nearly the same. The obtained results are discussed.
[A difficult stabilisation. Chlorpromazine in the fifties in Belgium].
Majerus, Benoît
2010-01-01
Through a Belgian case study the article tries to trace the gradual stabilisation of chlorpromazine as an antipsychotic in the 1950s. By varying ranges and angles of approach it shows the heterogeneity of actors involved and the semantic bricolage that accompany the marketing of the first antipsychotic. Far from being a revolution, the presence of Largactil in psychiatric practice is rather characterised by integration into a wider range of medicines and sinuous searching to give sense to this new drug.
C4 Photosynthesis in Tree Form Euphorbia Species from Hawaiian Rainforest Sites 1
Pearcy, Robert W.; Troughton, John
1975-01-01
The 13C 12C isotope ratios and the leaf anatomy of 18 species and varieties of Euphorbia native to the Hawaian Islands indicated that all possess C4 photosynthesis. These species range from small prostrate coastal strand shrubs to shrubs and trees in rainforest and bog habitats. The results show that C4 photosynthesis occurs in plants from a much wider range of habitats and life-forms than has been previously reported. PMID:16659208
NASA Astrophysics Data System (ADS)
Yang, Qingchun; Chetehouna, Khaled; Gascoin, Nicolas; Bao, Wen
2016-05-01
To enable the scramjet operate in a wider flight Mach number, a staged-combustor with dual-strut is introduced to hold more heat release at low flight Mach conditions. The behavior of mode transition was examined using a direct-connect model scramjet experiment along with pressure measurements. The typical operating modes of the staged-combustor are analyzed. Fuel injection scheme has a significant effect on the combustor operating modes, particularly for the supersonic combustion mode. Thrust performances of the combustor with different combustion modes and fuel distributions are reported in this paper. The first-staged strut injection has a better engine performance in the operation of subsonic combustion mode. On the contrast, the second-staged strut injection has a better engine performance in the operation of supersonic combustion mode.
The national free delivery policy in Nepal: early evidence of its effects on health facilities.
Witter, Sophie; Khadka, Sunil; Nath, Hom; Tiwari, Suresh
2011-11-01
Nepal faces the challenge of high levels of poverty, difficult access to health facilities and poor, though improving, health indicators. In response, in the past 5 years it has been experimenting with a range of approaches to removing user fees. Access to health care is now enshrined as a constitutional right for all. This article examines the latest policy, which was introduced in January 2009: free delivery care across the country. The study objective was to understand the effects of the policy on health facilities. Study methods included structured forms to retrieve financial and activity data from national, district and facility records (comparing 10 months before implementation with 10 months after). These were supplemented by semi-structured interviews with key informants at different levels of the health system. Findings include that utilization of services (at the facilities visited) continues to rise, with caesareans proportionate to the general growth in deliveries. Funds for the free delivery policy ('Aama') are found to be adequate to cover the main costs of services, with some surplus which can be invested in staff and in improving services. The system for reimbursing facilities is operating without undue delay and there is satisfaction with the flexibility of use of resources which it allows and the additional incentives for staff. The main concerns relate to wider systemic issues-in particular, understaffing in some key posts and areas, and dwindling general revenues for the facilities, especially through loss of wider user fee revenues. This may explain the ongoing charges for patients, which both facilities and patients report. It will be challenging to build on the gains of the past few years and sustain them, at the same time as merging the separate free care funding streams.
ERIC Educational Resources Information Center
Peerbhoy, D.; Majumdar, A. J.; Wightman, N. A.; Brand, V. L.
2008-01-01
Objective: To document the lifestyle health impacts (activity, diet and physiological), along with the operational success and challenges, of a programme for families presenting one or more coronary heart disease (CHD) risk factor. Design: Data are based on a wider evaluation of a government-funded community initiative conducted in a deprived area…
Overview of NASA's Supersonic Cruise Efficiency - Propulsion Research
NASA Technical Reports Server (NTRS)
DeBonis, James R.
2009-01-01
The research in Supersonic Cruise Efficiency Propulsion (SCE-P) Technical Challenge area of NASA's Supersonics project is discussed. The research in SCE-P is being performed to enable efficient supersonic flight over land. Research elements in this area include: Advance Inlet Concepts, High Performance/Wider Operability Fan and Compressor, Advanced Nozzle Concepts, and Intelligent Sensors/Actuators. The research under each of these elements is briefly discussed.
Jet Noise Modeling for Suppressed and Unsuppressed Aircraft in Simulated Flight
NASA Technical Reports Server (NTRS)
Stone, James R.; Krejsa, Eugene A.; Clark, Bruce J; Berton, Jeffrey J.
2009-01-01
This document describes the development of further extensions and improvements to the jet noise model developed by Modern Technologies Corporation (MTC) for the National Aeronautics and Space Administration (NASA). The noise component extraction and correlation approach, first used successfully by MTC in developing a noise prediction model for two-dimensional mixer ejector (2DME) nozzles under the High Speed Research (HSR) Program, has been applied to dual-stream nozzles, then extended and improved in earlier tasks under this contract. Under Task 6, the coannular jet noise model was formulated and calibrated with limited scale model data, mainly at high bypass ratio, including a limited-range prediction of the effects of mixing-enhancement nozzle-exit chevrons on jet noise. Under Task 9 this model was extended to a wider range of conditions, particularly those appropriate for a Supersonic Business Jet, with an improvement in simulated flight effects modeling and generalization of the suppressor model. In the present task further comparisons are made over a still wider range of conditions from more test facilities. The model is also further generalized to cover single-stream nozzles of otherwise similar configuration. So the evolution of this prediction/analysis/correlation approach has been in a sense backward, from the complex to the simple; but from this approach a very robust capability is emerging. Also from these studies, some observations emerge relative to theoretical considerations. The purpose of this task is to develop an analytical, semi-empirical jet noise prediction method applicable to takeoff, sideline and approach noise of subsonic and supersonic cruise aircraft over a wide size range. The product of this task is an even more consistent and robust model for the Footprint/Radius (FOOTPR) code than even the Task 9 model. The model is validated for a wider range of cases and statistically quantified for the various reference facilities. The possible role of facility effects will thus be documented. Although the comparisons that can be accomplished within the limited resources of this task are not comprehensive, they provide a broad enough sampling to enable NASA to make an informed decision on how much further effort should be expended on such comparisons. The improved finalized model is incorporated into the FOOTPR code. MTC has also supported the adaptation of this code for incorporation in NASA s Aircraft Noise Prediction Program (ANOPP).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vecchiola, Aymeric; Concept Scientific Instruments, ZA de Courtaboeuf, 2 rue de la Terre de Feu, 91940 Les Ulis; Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau
An imaging technique associating a slowly intermittent contact mode of atomic force microscopy (AFM) with a home-made multi-purpose resistance sensing device is presented. It aims at extending the widespread resistance measurements classically operated in contact mode AFM to broaden their application fields to soft materials (molecular electronics, biology) and fragile or weakly anchored nano-objects, for which nanoscale electrical characterization is highly demanded and often proves to be a challenging task in contact mode. Compared with the state of the art concerning less aggressive solutions for AFM electrical imaging, our technique brings a significantly wider range of resistance measurement (over 10more » decades) without any manual switching, which is a major advantage for the characterization of materials with large on-sample resistance variations. After describing the basics of the set-up, we report on preliminary investigations focused on academic samples of self-assembled monolayers with various thicknesses as a demonstrator of the imaging capabilities of our instrument, from qualitative and semi-quantitative viewpoints. Then two application examples are presented, regarding an organic photovoltaic thin film and an array of individual vertical carbon nanotubes. Both attest the relevance of the technique for the control and optimization of technological processes.« less
Kalingan, A E; Liao, Chung-Min; Chen, Jein-Wen; Chen, Szu-Chieh
2004-01-01
The purpose of this research was to neutralize livestock-generated ammonia by using biofilters packed with inexpensive inorganic and organic packing material combined with multicultural microbial load at typical ambient temperatures. Peat and inorganic supporting materials were used as biofiltration matrix packed in a perfusion column through which gas was transfused. Results show the ammonia removal significantly fell in between 99 and 100% when ammonia concentration of 200 ppmv was used at different gas flow rates ranged from 0.030 to 0.060 m3 h(-1) at a fluctuating room temperature of 27.5 +/- 4.5 C (Mean +/- SD). Under these conditions, the emission concentration of ammonia that is liberated after biofiltration is less than 1 ppmv (0.707 mg m(-3)) over the period of our study, suggesting the usage of low-cost biofiltration systems for long-term function is effective at wider ranges of temperature fluctuations. The maximum (100%) ammonia removal efficiency was obtained in this biofilter was having an elimination capacity of 2.217 g m(-3) h(-1). This biofilter had high nitrification efficiencies and hence controlled ammonia levels with the reduced backpressure. The response of this biofilter to shut down and start up operation showed that the biofilm has a superior stability.
Laser ignition of engines: a realistic option!
NASA Astrophysics Data System (ADS)
Weinrotter, M.; Srivastava, D. K.; Iskra, K.; Graf, J.; Kopecek, H.; Klausner, J.; Herdin, G.; Wintner, E.
2006-01-01
Due to the demands of the market to increase efficiencies and power densities of gas engines, existing ignition schemes are gradually reaching their limits. These limitations initially triggered the development of laser ignition as an effective alternative, first only for gas engines and now for a much wider range of internal combustion engines revealing a number of immediate advantages like no electrode erosion or flame kernel quenching. Furthermore and most noteworthy, already the very first engine tests about 5 years ago had resulted in a drastic reduction of NO x emissions. Within this broad range investigation, laser plasmas were generated by ns Nd-laser pulses and characterized by emission and Schlieren diagnostic methods. High-pressure chamber experiments with lean hydrogen-methane-air mixtures were successfully performed and allowed the determination of essential parameters like minimum pulse energies at different ignition pressures and temperatures as well as at variable fuel air compositions. Multipoint ignition was studied for different ignition point locations. In this way, relevant parameters were acquired allowing to estimate future laser ignition systems. Finally, a prototype diode-pumped passively Q-switched Nd:YAG laser was tested successfully at a gasoline engine allowing to monitor the essential operation characteristics. It is expected that laser ignition involving such novel solid-state lasers will allow much lower maintenance efforts.
Through-barrier detection of explosive components for security screening applications
NASA Astrophysics Data System (ADS)
Lee, Linda; Frisby, Alex; Mansson, Ralph; Hopkins, Rebecca J.
2011-11-01
The detection of materials through containers is a vital capability for security screening applications at high risk locations, such as airports and checkpoints. Current detection procedures require suspect containers to be opened and the contents sampled, which is laborious and potentially hazardous to the operator. The capability to detect through-barrier would overcome these issues. Spatially Offset Raman Spectroscopy (SORS) is an innovative spectroscopic technique that avoids fluorescence and Raman scatter from containers, which can mask the Raman signature from the sample. This novel approach enables noninvasive detection of hazardous and benign materials through a wider range of container materials than is possible using conventional Raman spectroscopy. SORS spectra were acquired from explosive compounds and benign materials within a range of coloured glass and plastic containers. The SORS spectra were compared to the reference Raman signatures of the materials studied. Two data analysis methods were then applied to the resultant data to investigate the ability of SORS to detect the target materials through the barriers tested. Furthermore, the potential for reduction of sample fluorescence was investigated by using longer excitation wavelength (1064 nm) than is typically used in commercially available Raman instruments that use silicon detector technology. For some fluorescent samples, Raman spectral features that were masked by fluorescence at 785 nm were revealed at 1064 nm.
Wideband electromagnetic energy harvesting from ambient vibrations
NASA Astrophysics Data System (ADS)
Mallick, Dhiman; Podder, Pranay; Roy, Saibal
2015-06-01
Different bandwidth widening schemes of electromagnetic energy harvesters have been reported in this work. The devices are fabricated on FR4 substrate using laser micromachining techniques. The linear device operate in a narrow band around the resonance; in order to tune resonant frequency of the device electrically, two different types of complex load topologies are adopted. Using capacitive load, the resonant frequency is tuned in the low frequency direction whereas using inductive load, the resonant frequency is tuned in the high frequency direction. An overall tuning range of ˜2.4 Hz is obtained at 0.3g though the output power dropped significantly over the tuning range. In order to improve the off-resonance performance, nonlinear oscillation based systems are adopted. A specially designed spring arm with fixed-guided configuration produced single well nonlinear monostable configuration. With increasing input acceleration, wider bandwidth is obtained with such a system as large displacement, stretching nonlinearity comes into play and 9.55 Hz bandwidth is obtained at 0.5g. The repulsive force between one static and one vibrating oppositely polarized magnets are used to generate bistable nonlinear potential system. The distance between the mentioned magnets is varied between 4 to 10 mm to produce tunable nonlinearity with a maximum half power bandwidth over 3 Hz at 0.5g.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Warren, Emily L.; Deceglie, Michael G.; Stradins, Paul
Three-terminal (3T) tandem cells fabricated by combining an interdigitated back contact (IBC) Si device with a wider bandgap top cell have the potential to provide a robust operating mechanism to efficiently capture the solar spectrum without the need to current match sub-cells or fabricate complicated metal interconnects between cells. Here we develop a two dimensional device physics model to study the behavior of IBC Si solar cells operated in a 3T configuration. We investigate how different cell designs impact device performance and discuss the analysis protocol used to understand and optimize power produced from a single junction, 3T device.
A systemic approach to understanding mental health and services.
Cohen, Mark
2017-10-01
In the UK mental health and associated NHS services face considerable challenges. This paper aims to form an understanding both of the complexity of context in which services operate and the means by which services have sought to meet these challenges. Systemic principles as have been applied to public service organisations with reference to interpersonal relations, the wider social culture and its manifestation in service provision. The analysis suggests that the wider culture has shaped service demand and the approaches adopted by services resulting in a number of unintended consequences, reinforcing loops, increased workload demands and the limited value of services. The systemic modelling of this situation provides a necessary overview prior to future policy development. The paper concludes that mental health and attendant services requires a systemic understanding and a whole system approach to reform. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.
What Can the Work of Habermas Offer Educational Researcher Development Programmes?
ERIC Educational Resources Information Center
Garland, Paul
2014-01-01
Although certain aspects of the work of Habermas have had much influence on emancipatory and action research, this article draws on a wider range of his thinking in order to explore how his ideas can inform the content and process of educational researcher development programmes. Habermas's theory of communicative action, his discourse ethics…
ERIC Educational Resources Information Center
Rudd, Tim
2017-01-01
This paper offers conceptual and theoretical insights relating to the Teaching Excellence Framework (TEF), highlighting a range of potential systemic and institutional outcomes and issues. The paper is organised around three key areas of discussion that are often under-explored in debates. Firstly, after considering the TEF in the wider context of…
ERIC Educational Resources Information Center
Welch, Karla Conn; Hieb, Jeffrey; Graham, James
2015-01-01
Coursework that instills patterns of rigorous logical thought has long been a hallmark of the engineering curriculum. However, today's engineering students are expected to exhibit a wider range of thinking capabilities both to satisfy ABET requirements and to prepare the students to become successful practitioners. This paper presents the initial…
A Review of Self-Report and Alternative Approaches in the Measurement of Student Motivation
ERIC Educational Resources Information Center
Fulmer, Sara M.; Frijters, Jan C.
2009-01-01
Within psychological and educational research, self-report methodology dominates the study of student motivation. The present review argues that the scope of motivation research can be expanded by incorporating a wider range of methodologies and measurement tools. Several authors have suggested that current study of motivation is overly reliant on…
ERIC Educational Resources Information Center
Ari, Omer
2009-01-01
Fluency instruction has had limited effects on reading comprehension relative to reading rate and prosodic reading (Dowhower, 1987; Herman, 1985; National Institute of Child Health and Human Development, 2000a). More specific components (i.e., error detection) of comprehension may yield larger effects through exposure to a wider range of materials…
ERIC Educational Resources Information Center
Loyalka, Prashant Kumar
2009-01-01
Since the late 1990s, China has dramatically increased its college enrollments, the number and diversity of its higher education institutions, university tuition fees, and financial aid. Now students from a wider range of backgrounds have significantly more opportunities to attend college and also compete for entry into more selective…
Transforming Science Education for the Anthropocene--Is It Possible?
ERIC Educational Resources Information Center
Gilbert, Jane
2016-01-01
Since its inception, science education has been the focus of a great many reform attempts. In general, the aim has been to improve science understanding and/or make science study more interesting and/or relevant to a wider range of students. However, these reform attempts have had limited success. This paper argues that this is in part because…
The Socio-Cultural and Learning Experiences of Music Students in a British University
ERIC Educational Resources Information Center
Dibben, Nicola
2006-01-01
Research into student experience in Higher Education has largely focused on students' role as learners. However, the student experience encompasses a much wider range of behaviours and beliefs than can be captured through a focus on teaching and learning alone. I report the findings of a research project which explored student experience in the…
Archaebacterial Involvement in Microbial Metal Corrosion
1990-03-19
viand /or + I A-o- - iP’ " ’ I m I I | | A more complete study using a wider range of sizes of organo groups is currently being completed to further...replaced with Dr. Boopathy, who comes from the University of Missouri. Through Dr. Rajogopal’s visit last year to work with the French-Georgia group ( Le
ERIC Educational Resources Information Center
Stansfield, Jayne
2008-01-01
To make the Mathematics Enhancement Course (MEC) students realize that mathematics exist in a wider range of forms and environments than most will have encountered before, they are sent out on several trips and visits during the six-month course. This year one of the trips was to spend a day at the ATM conference. Afterwards the students had to…
Galactic water vapor emission: further observations of variability.
Knowles, S H; Mayer, C H; Sullivan, W T; Cheung, A C
1969-10-10
Recent observations of the 1.35-centimeter line emission of water vapor from galactic sources show short-term variability in the spectra of several sources. Two additional sources, Cygnus 1 and NGC 6334N, have been observed, and the spectra of W49 and VY Canis Majoris were measured over a wider range of radial velocity.
Measures of Disadvantage: Is Car Ownership a Good Indicator?
ERIC Educational Resources Information Center
Johnson, Victoria; Currie, Graham; Stanley, Janet
2010-01-01
A need to better understand the multidimensional nature of disadvantage is leading to the adoption of a wider range of measurement variables. One variable now commonly adopted is zero car ownership. This paper challenges the logic of including "not having a car" as an indicator of disadvantage. It argues that this can distort the real picture of…
What We Learned from a Tomato: Partnering with a Content Expert Plants New Ideas for Instruction
ERIC Educational Resources Information Center
Ermeling, Bradley A.
2014-01-01
The interactions described in this article represent an example of teachers expanding horizons of instructional plans as a direct result of outside expert contributions. After alerting teachers to oversimplified claims about the benefits of lycopene, the research fellow presented the team with a wider range of instructional options to consider…
The Relations Between Student Organizations and the Wider University. Final Report.
ERIC Educational Resources Information Center
Gamson, Zelda F.
This report presents the findings from a study of student organizations at the University of Michigan. Four religious groups, 5 political groups, 10 sororities and 10 fraternities were chosen to represent a range of groups within each of the types. The study was undertaken to determine (1) the impact of formal student organizations on their…
Parent-Child Moments of Meeting in Art-Making with Collage, iPad, Tuxpaint and Crayons
ERIC Educational Resources Information Center
Sakr, Mona; Kucirkova, Natalia
2017-01-01
Previous research suggests that parent-child art making can foster opportunities for closeness between children and parents. Most studies however, have focused on art-making that involves paint and paper, or non-digital drawing technologies. There is a need for researchers to consider how a wider range of technologies, including digital…
Reflecting on the Challenges of Applied Theatre in Kenya
ERIC Educational Resources Information Center
Okuto, Maxwel; Smith, Bobby
2017-01-01
In this article the authors draw on their own experience and research in applied theatre in Kenya in order to reflect on challenges currently facing practitioners working in the country. In order to outline the range of challenges faced by practitioners, issues related to the wider landscapes of government and politics in Kenya are explored,…
The mouse lymphoma assay is widely used to identify chemicals that are capable of inducing mutational damages. The Tk+/- gene located on an autosome in mouse lymphoma cells may recover a wider range of mutational events than the X-linked Hprt locus. However, chemical-induced muta...
The College Ladder: Linking Secondary and Postsecondary Education for Success for All Students
ERIC Educational Resources Information Center
Lerner, Jennifer Brown; Brand, Betsy
2006-01-01
This compendium identifies and describes schools, programs, and policies that link secondary and postsecondary education to help students earn college credit or take college-level courses while in high school. It raises issues for practitioners and policymakers to consider as these program grow and target a wider range of students. This compendium…
Resource Delivery and Teaching in Live Chat Reference: Comparing Two Libraries
ERIC Educational Resources Information Center
Dempsey, Paula R.
2017-01-01
This study investigates how reference staff at two libraries balance teaching with resource delivery in live chat reference. Analysis of 410 transcripts from one week shows that one library tends to deliver more resources from a wider range of database suggestions, to take more time in chat interactions, and to incorporate more teaching behavior…
Reviews of National Policies for Education: Quality Assurance in Higher Education in Chile 2013
ERIC Educational Resources Information Center
OECD Publishing (NJ3), 2013
2013-01-01
Growth and diversity have characterised higher education in OECD countries for fifty years. Chile is no exception and has experienced dramatic increases in the number of students, the range of institutions and the programmes that they offer. But wider participation and diversification are only part of the story. Chilean society remains highly…
Three Million Apprenticeships: Building Ladders of Opportunity
ERIC Educational Resources Information Center
Learning and Work Institute, 2017
2017-01-01
Apprenticeships are a great way to combine learning and earning and meet employers' skills needs. That is why they have a long history dating back several centuries, though today's apprenticeships have a wider focus including on all ages, a range of levels, and existing as well as new employees. Changes in the economy, and the importance of skills…
Conceptual Design for the New RPI 2020 Linac
DOE Office of Scientific and Technical Information (OSTI.GOV)
Adolphsen, C.; Bane, K.; Dolgashev, V.
2014-10-29
The Rensselaer Polytechnic Institute (RPI) spectrometer is an installation based on an L-band linear accelerator designed and installed many decades ago. While this installation has served many important experiments over the decades, a new more powerful and more flexible linac to serve a wider range of experiments is envisioned as an upgrade to the existing installation by 2020.
Semantic Interaction in Early and Late Bilinguals: All Words Are Not Created Equally
ERIC Educational Resources Information Center
Gathercole, Virginia C. Mueller; Moawad, Ruba Abdelmatloub
2010-01-01
This study examines L1-L2 interaction in semantic categorization in early and late L2 learners. Word categories that overlapped but were not identical in Arabic and English were tested. Words always showed a "wider" range of application in one language, "narrower" in the other. Three types of categories--"classical", "radial", and…
Do Junior High School Students Perceive Their Learning Environment as Constructivist?
ERIC Educational Resources Information Center
Moustafa, Asely; Ben-Zvi-Assaraf, Orit; Eshach, Haim
2013-01-01
The purpose of this study is to examine the manner in which the features of a constructivist learning environment, and the mechanisms at its base, are expressed in junior high school students' conceptions. Our research is based on an integration of quantitative and qualitative approaches, deigned to provide a wider ranging and deeper…
Implications of non-covalent interactions in zein-starch dough and bread quality
USDA-ARS?s Scientific Manuscript database
Breads made from non-wheat flours are made from thick batters and are lower quality than wheat bread. The development of visco-elastic doughs from non-wheat proteins would allow a wider range of gluten-free products and would improve the quality of such foods. Only recently has the mechanism of zei...
Framing health for land-use planning legislation: A qualitative descriptive content analysis.
Harris, Patrick; Kent, Jennifer; Sainsbury, Peter; Thow, Anne Marie
2016-01-01
Framing health as a relevant policy issue for other sectors is not well understood. A recent review of the New South Wales (Australia) land-use planning system resulted in the drafting of legislation with an internationally unprecedented focus on human health. We apply a political science approach to investigate the question 'how and to what extent were health and wider issues framed in submissions to the review?' We investigated a range of stakeholder submissions including health focussed agencies (n = 31), purposively identified key stakeholders with influence on the review (n = 24), and a random sample of other agencies and individuals (n = 47). Using qualitative descriptive analysis we inductively coded for the term 'health' and sub-categories. We deductively coded for 'wider concerns' using a locally endorsed 'Healthy Urban Development Checklist'. Additional inductive analysis uncovered further 'wider concerns'. Health was explicitly identified as a relevant issue for planning policy only in submissions by health-focussed agencies. This framing concerned the new planning system promoting and protecting health as well as connecting health to wider planning concerns including economic issues, transport, public open space and, to a slightly lesser extent, environmental sustainability. Key stakeholder and other agency submissions focussed on these and other wider planning concerns but did not mention health in detail. Health agency submissions did not emphasise infrastructure, density or housing as explicitly as others. Framing health as a relevant policy issue has the potential to influence legislative change governing the business of other sectors. Without submissions from health agencies arguing the importance of having health as an objective in the proposed legislation it is unlikely health considerations would have gained prominence in the draft bill. The findings have implications for health agency engagement with legislative change processes and beyond in land use planning. Copyright © 2015 Elsevier Ltd. All rights reserved.
ADCS controllers comparison for small satellitess in Low Earth Orbit
NASA Astrophysics Data System (ADS)
Calvo, Daniel; Laverón-Simavilla, Ana; Lapuerta, Victoria
2016-07-01
Fuzzy logic controllers are flexible and simple, suitable for small satellites Attitude Determination and Control Subsystems (ADCS). In a previous work, a tailored Fuzzy controller was designed for a nanosatellite. Its performance and efficiency were compared with a traditional Proportional Integrative Derivative (PID) controller within the same specific mission. The orbit height varied along the mission from injection at around 380 km down to 200 km height, and the mission required pointing accuracy over the whole time. Due to both, the requirements imposed by such a low orbit, and the limitations in the power available for the attitude control, an efficient ADCS is required. Both methodologies, fuzzy and PID, were fine-tuned using an automated procedure to grant maximum efficiency with fixed performances. The simulations showed that the Fuzzy controller is much more efficient (up to 65% less power required) in single manoeuvres, achieving similar, or even better, precision than the PID. The accuracy and efficiency improvement of the Fuzzy controller increase with orbit height because the environmental disturbances decrease, approaching the ideal scenario. However, the controllers are meant to be used in a vast range of situations and configurations which exceed those used in the calibration process carried out in the previous work. To assess the suitability and performance of both controllers in a wider framework, parametric and statistical methods have been applied using the Monte Carlo technique. Several parameters have been modified randomly at the beginning of each simulation: the moments of inertia of the whole satellite and of the momentum wheel, the residual magnetic dipole and the initial conditions of the test. These parameters have been chosen because they are the main source of uncertainty during the design phase. The variables used for the analysis are the error (critical for science) and the operation cost (which impacts the mission lifetime and outcome). The analysis of the simulations has shown that, in overall, the PID error is over twice the Fuzzy error and the PID cost is over 40% bigger than the Fuzzy cost. This suggests that a Fuzzy controller may be a better solution in a wider range of configurations than other classical solutions like the PID.
Safeguarding the provision of ecosystem services in catchment systems.
Everard, Mark
2013-04-01
A narrow technocentric focus on a few favored ecosystem services (generally provisioning services) has led to ecosystem degradation globally, including catchment systems and their capacities to support human well-being. Increasing recognition of the multiple benefits provided by ecosystems is slowly being translated into policy and some areas of practice, although there remains a significant shortfall in the incorporation of a systemic perspective into operation management and decision-making tools. Nevertheless, a range of ecosystem-based solutions to issues as diverse as flooding and green space provision in the urban environment offers hope for improving habitat and optimization of beneficial services. The value of catchment ecosystem processes and their associated services is also being increasingly recognized and internalized by the water industry, improving water quality and quantity through catchment land management rather than at greater expense in the treatment costs of contaminated water abstracted lower in catchments. Parallel recognition of the value of working with natural processes, rather than "defending" built assets when catchment hydrology is adversely affected by unsympathetic upstream development, is being progressively incorporated into flood risk management policy. This focus on wider catchment processes also yields a range of cobenefits for fishery, wildlife, amenity, flood risk, and other interests, which may be optimized if multiple stakeholders and their diverse value systems are included in decision-making processes. Ecosystem services, particularly implemented as a central element of the ecosystem approach, provide an integrated framework for building in these different perspectives and values, many of them formerly excluded, into commercial and resource management decision-making processes, thereby making tractable the integrative aspirations of sustainable development. This can help redress deeply entrenched inherited assumptions, habits, and vested interests, replacing them in many management situations with wider recognition of the multiple values of ecosystems and their services. Global interest in taking an ecosystem approach is promoting novel scientific and policy thinking, yet there is a shortfall in its translation into practical management tools. Professional associations may have key roles to play in breaking down barriers to the "mainstreaming" of systemic perspectives into common practice, particularly through joining u different sectors of society essential to their implementation and ongoing adaptive management. Copyright © 2012 SETAC.
Dorchin, Netta; Astrin, Jonas J.; Bodner, Levona; Harris, Keith M.
2015-01-01
The Palaearctic gall-midge genus Ozirhincus is unique among the Cecidomyiidae for its morphology and biology. Unlike most other phytophagous gall midges, species in this genus do not induce galls but develop inside achenes of Asteraceae plants. The heads of adults are characterized by an unusually elongate proboscis, the function of which is unclear. Despite a lot of attention from taxonomists in the 19th and early 20th century, a proper revision of the genus has been hindered by complex host associations, the loss of most relevant type material, and the lack of a thorough comparative study of all life stages. The present revision integrated morphological, molecular, and life-history data to clearly define species boundaries within Ozirhincus, and delimit host-plant ranges for each of them. A phylogenetic analysis based on the mitochondrial COI and 16S genes confirmed the validity of four distinct species but did not resolve the relationships among them. All species are oligophages, and some may occur together on the same host plant. Species with wider host-plant ranges have wider European and circum-Mediterranean distribution ranges, whereas species with narrower host ranges are limited to Europe and the Russian Far East. As part of the present work, O. hungaricus is reinstated from synonymy, O. tanaceti is synonymized under O. longicollis, neotypes are designated for O. longicollis and O. millefolii, and a lectotype is designated for O. anthemidis. PMID:26134526
NASA Astrophysics Data System (ADS)
Gordon, John
2013-04-01
Geodiversity delivers or underpins many key ecosystem processes and services that deliver valuable benefits for society. With a growing recognition of the wider economic, social and environmental relevance of geodiversity, it is timely to consider the research requirements and priorities that are necessary to underpin a broader interdisciplinary approach to geodiversity that incorporates the links between natural and human systems in a changing world. A key challenge is to develop the scientific framework of geodiversity and at the same time to enhance the protection of geoheritage. Research that helps to support environmental policy and meet the wider needs of society for sustainable development and improved human wellbeing is fundamental both to improve the recognition of geodiversity and to demonstrate the wider relevance and value of geoheritage and geoconservation. Within this wider context, priorities for research include: 1) assessment of geoheritage and best-practice management of geosites for multiple uses including science, education and tourism; 2) evaluation of geodiversity and the ecosystem services it provides, both in economic and non-economic terms, to help build policy support and public awareness; 3) understanding the functional links between geodiversity and biodiversity across a range of spatial and temporal scales to help assess ecosystem sensitivity and inform management adaptations to climate change, particularly in dynamic environments such as the coast, river catchments and mountain areas; 4) providing a longer time perspective on ecosystem trends and services from palaeoenvironmental records; 5) applications of geodiversity in terrestrial and marine spatial planning.
ERIC Educational Resources Information Center
Walker, David; Tennant, Marc; Short, Stephanie D.
2011-01-01
Objective: This research was undertaken to explore factors operating at the level of the clinic and the community which influence the development of the oral health role of Indigenous Health Workers. The research is a significant aspect of a wider study of the disconnect between the strong national policy support for the development of the oral…
2011-04-25
must adapt its planning to vehicle size, shape, wheelbase, wheel and axle configuration, the specific obstacle-crossing capabilities of the vehicle...scalability of the ANS is a consequence of making each sensing modality capable of performing reasonable perception tasks while allowing a wider...autonomous system design achieves flexibility by exploiting redundant sensing modalities where possible, and by a decision-making process that
Entanglement and asymmetric steering over two octaves of frequency difference
NASA Astrophysics Data System (ADS)
Olsen, M. K.
2017-12-01
The development of quantum technologies which use quantum states of the light field interacting with other systems creates a demand for entangled states spanning wide frequency ranges. In this work we analyze a parametric scheme of cascaded harmonic generation which promises to deliver bipartite entangled states in which the two modes are separated by two octaves in frequency. This scheme is potentially very useful for applications in quantum communication and computation networks as well as providing for quantum interfaces between a wider range of light and atomic ensembles than is presently practicable. It doubles the frequency range over which entanglement is presently available.
Water Pump Development for the EVA PLSS
NASA Technical Reports Server (NTRS)
Schuller, Michael; Kurwitz, Cable; Goldman, Jeff; Morris, Kim; Trevino, Luis
2009-01-01
This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design, fabricate, and test a preflight prototype pump for use in the Extravehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump will accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting noncondensable gas without becoming "air locked." The chosen pump design consists of a 28 V DC, brushless, sealless, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. Although the planned flight unit will use a sensorless motor with custom designed controller, the preflight prototype to be provided for this project incorporates Hall effect sensors, allowing an interface with a readily available commercial motor controller. This design approach reduced the cost of this project and gives NASA more flexibility in future PLSS laboratory testing. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES will simulate the vacuum environment in which the flight pump will operate. Testing will verify that the pump meets design requirements for range of flow rates, pressure rise, power consumption, working fluid temperature, operating time, and restart capability. Pump testing is currently scheduled for March, 2009, after which the pump will be delivered to NASA for further testing.
NASA Astrophysics Data System (ADS)
Mignani, Anna G.; Ciaccheri, Leonardo; Cimato, Antonio; Sani, Graziano; Smith, Peter R.
2004-03-01
Absorption spectroscopy and multi-angle scattering measurements in the visible spectral range are innovately used to analyze samples of extra virgin olive oils coming from selected areas of Tuscany, a famous Italian region for the production of extra virgin olive oil. The measured spectra are processed by means of the Principal Component Analysis method, so as to create a 3D map capable of clustering the Tuscan oils within the wider area of Italian extra virgin olive oils.
Kito, Keiji; Okada, Mitsuhiro; Ishibashi, Yuko; Okada, Satoshi; Ito, Takashi
2016-05-01
The accurate and precise absolute abundance of proteins can be determined using mass spectrometry by spiking the sample with stable isotope-labeled standards. In this study, we developed a strategy of hierarchical use of peptide-concatenated standards (PCSs) to quantify more proteins over a wider dynamic range. Multiple primary PCSs were used for quantification of many target proteins. Unique "ID-tag peptides" were introduced into individual primary PCSs, allowing us to monitor the exact amounts of individual PCSs using a "secondary PCS" in which all "ID-tag peptides" were concatenated. Furthermore, we varied the copy number of the "ID-tag peptide" in each PCS according to a range of expression levels of target proteins. This strategy accomplished absolute quantification over a wider range than that of the measured ratios. The quantified abundance of budding yeast proteins showed a high reproducibility for replicate analyses and similar copy numbers per cell for ribosomal proteins, demonstrating the accuracy and precision of this strategy. A comparison with the absolute abundance of transcripts clearly indicated different post-transcriptional regulation of expression for specific functional groups. Thus, the approach presented here is a faithful method for the absolute quantification of proteomes and provides insights into biological mechanisms, including the regulation of expressed protein abundance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
ERIC Educational Resources Information Center
Rubino, Antonia; Cruickshank, Ken
2016-01-01
Australian research on immigrant languages has paid little attention to interactional approaches to language alternation as identity construction, and sites other than the family and the mainstream school. We argue for the need of studies that take into account a wider range of sites, in particular "community" sites, and adopt…
ERIC Educational Resources Information Center
Gillespie, Simon
2017-01-01
Educating a diverse student population is a core principle of international school education. Historically, many international schools have had admissions policies that excluded students with special learning needs. However, admission policies have changed to require more inclusiveness and school support for a wider range of students and for…
System for corrosion monitoring in pipeline applying fuzzy logic mathematics
NASA Astrophysics Data System (ADS)
Kuzyakov, O. N.; Kolosova, A. L.; Andreeva, M. A.
2018-05-01
A list of factors influencing corrosion rate on the external side of underground pipeline is determined. Principles of constructing a corrosion monitoring system are described; the system performance algorithm and program are elaborated. A comparative analysis of methods for calculating corrosion rate is undertaken. Fuzzy logic mathematics is applied to reduce calculations while considering a wider range of corrosion factors.
Darius M. Adams; Ralph J. Alig; J.M. Callaway; Bruce A. McCarl; Steven M. Winnett
1996-01-01
The Forest and Agricultural Sector Optimization Model (FASOM) is a dynamic, nonlinear programming model of the forest and agricultural sectors in the United States. The FASOM model initially was developed to evaluate welfare and market impacts of alternative policies for sequestering carbon in trees but also has been applied to a wider range of forest and agricultural...
How Organisations Are Using Blended E-Learning to Deliver More Flexible Approaches to Trade Training
ERIC Educational Resources Information Center
Callan, Victor James; Johnston, Margaret Alison; Poulsen, Alison Louise
2015-01-01
Training organisations are being asked to respond to the growing levels of diversity around the contexts for training and to examine a wider range of training solutions than in the past. This research investigates how training organisations in Australia are using blended forms of e-learning to provide more responsive, flexible and innovative…
Deeper Learning: Improving Student Outcomes for College, Career, and Civic Life. Policy Brief
ERIC Educational Resources Information Center
Bitter, Catherine; Loney, Emily
2015-01-01
The Issue: To prepare for the demands of postsecondary education and the workforce, students need to master content and build skills that allow them to collaborate with others, and then apply that knowledge to new situations. Students will be able to access a wider range of opportunities in college, career, and civic life if they possess the…
A Longitudinal Study of Post-School Provision for Irish School-Leavers with Intellectual Disability
ERIC Educational Resources Information Center
McConkey, Roy; Kelly, Fionnola; Craig, Sarah; Keogh, Fiona
2017-01-01
Background: In recent years, efforts have been made to improve the transition of pupils with intellectual disabilities to adult services and to offer a wider range of choices. However, there have been few longitudinal studies to monitor the services provided to young adults post-school. This case study in the Republic of Ireland identified the…
Assessing the Impact of Regeneration Spending: Lessons from the United Kingdom and the Wider World
ERIC Educational Resources Information Center
Potts, David
2008-01-01
The government increased the funding for regional development agencies to 2.3 billion British Pounds in 2007/8, yet hard evidence on the effectiveness of the spending is difficult to find. Techniques for valuing benefits in difficult areas have existed for many years. They range from the hedonic methods and contingent valuation studies of…
The Library of Birmingham Project: Lifelong Learning for the Digital Age
ERIC Educational Resources Information Center
Blewitt, John; Gambles, Brian
2010-01-01
The Library of Birmingham (LoB) is a 193 million British pounds project designed to provide a new space for lifelong learning and knowledge growth, a physical and virtual portal for Birmingham's citizens to the wider world. In cooperation with a range of private, public, and third-sector bodies, as well as individual citizens, the library, due to…
Responding to Self-Harm: A Documentary Analysis of Agency Policy and Procedure
ERIC Educational Resources Information Center
Paul, Sally; Hill, Malcolm
2013-01-01
This paper reports on the findings of a documentary analysis of policies and procedures relating to self-harm from a range of organisations working with young people in the UK. It identifies the extent to which policies and/or procedures relating to self-harm are available for service providers and offers a wider understanding of the concepts of…
ERIC Educational Resources Information Center
Soler, Josep; Björkman, Beyza; Kuteeva, Maria
2018-01-01
As universities seek to become more international, their need to engage with a wider range of languages, particularly English, seems more prominent. At the same time, universities are also regarded by many stakeholders as key institutions to preserve a given national language and culture. This apparent tension makes universities a fruitful ground…
ERIC Educational Resources Information Center
Cretchley, Patricia
2009-01-01
The Australian Federal Government and Australian universities have embarked on a bid to raise the profile of learning and teaching (L&T) in universities. Current strategies include increased funding of competitive grants for L&T projects, a wider range of teaching awards and fellowships and a controversial new national competitive Learning…
Dale G. Brockway; Kenneth W. Outcalt
2017-01-01
Though longleaf pine (Pinus palustris Mill.) forests have been primarily managed with even-aged methods, interest is increasing in uneven-aged systems, as a means of achieving a wider range of stewardship goals. Selection silviculture has been practiced on a limited scale in longleaf pine, but difficulty with using traditional approaches and...
ERIC Educational Resources Information Center
Plane, Karen
In a competitive market training economy, vocational education and training (VET) and small business in Australia face a number of challenges. They need to qualify the extent of lifelong learning skills being used in the small firm workplace, define the range of learning partnerships both within VET and the wider informal learning community in…
ERIC Educational Resources Information Center
Osborne, Lisa A.; Reed, Phil
2009-01-01
Two 9- to 10-month-Iong studies (N = 137) examined the interaction between parenting stress and behavior problems in children with autistic spectrum disorders (ASDs). Study 1 focused on very young children, and Study 2 employed a wider range of child ages; both studies assessed these factors at 2 points in time. The researchers noted a strong…
ERIC Educational Resources Information Center
Qingquan, Ni; Chatupote, Monta; Teo, Adisa
2008-01-01
This article focused on the investigation of the differences in the frequency of language learning strategy use by successful and unsuccessful first-year students of a Chinese university. The study found that successful students used a wider range of learning strategies for EFL learning significantly more frequently than unsuccessful students. It…
Defect-enhanced void filling and novel filled phases of open-structure skutterudites
Xi, Lili; Qiu, Yuting; Shi, Xun; ...
2015-05-14
Here, we report the design of novel filled CoSb 3 skutterudite phases based on a combination of filling and Sb-substituted Ga/In defects. Ga/In doped skutterudite phases with Li-, Nd-, and Sm-fillings can be formed via this strategy, which can have relatively wider ranges of carrier concentration than other conventional filled skutterudite phases.
ERIC Educational Resources Information Center
Goatman, Mike; Moody, Louise
2014-01-01
There are currently a wide range of Higher Education Industrial Design courses available in the UK. In the present era, a wider breadth of narrative has developed within the subject, and as a result the content of industrial design educational offerings varies considerably. The paper assesses the industry view of Industrial Design as a discipline…
Rodney J. Keenan; David Lamb; John Parrotta
1999-01-01
Management of tropical timber plantations is generally based on a single-product output, high-input model, often using an exotic species that has been successfully used for plantation timber production in many temperate regions. This intensive model may be appropriate in areas designated solely for wood production but where the aim is to produce a wider range...
ERIC Educational Resources Information Center
Lyon, Edward G.; Bunch, George C.; Shaw, Jerome M.
2012-01-01
Science performance assessments (SPAs) are designed to elicit a wider range of scientific knowledge and abilities than ordinarily measured by more traditional paper-and-pencil tests. To engage in SPAs and thus demonstrate abilities such as scientific inquiry, students must interact with various participants and communicate in a variety of ways.…
The Role of Silence in Teaching and Learning
ERIC Educational Resources Information Center
Schultz, Katherine
2013-01-01
The author's first teaching position was as a 4th and 5th grade teacher at a school in Philadelphia. There, she learned the Quaker value of adding silence and periods of reflection to her teaching to provide a wider range of students with the opportunity to participate in classroom discussions. Later, a focus on silence as a teaching strategy led…
ERIC Educational Resources Information Center
Nagtalon-Ramos, Jamille Kristine
2017-01-01
Although Filipino and Filipino American nurses represent an impressive share of the nursing workforce, they are not well represented in advanced practice, faculty, and executive leadership positions. Obtaining a graduate degree in nursing has the potential to open a wider range of opportunities to meet the healthcare demands of a population that…
Math Across the Community College Curriculum (MAC3): A Successful Path to Quantitative Literacy
ERIC Educational Resources Information Center
Hillyard, Cinnamon; Korey, Jane; Leoni, Deann; Hartzler, Rebecca
2010-01-01
In recent years, mathematical and quantitative arguments have become prominent in the media as well as in politics, business, and science conversations. This has led to multiple calls for mathematics to be more accessible and meaningful to a wider range of the population (AMATYC, 2006; Cerrito, 1996; Cheney, 1989; Cohen, 1982; College Board, 1983;…
ERIC Educational Resources Information Center
Yue, Siwei; Wang, Xuefei
2014-01-01
Based on a corpus of 296 authentic business emails produced in computer-mediated business communication from 7 Chinese international trade enterprises, this paper addresses the language strategy applied in CMC (Computer-mediated Communication) by examining the use of hedges. With the emergence of internet, a wider range of hedges are applied…
On temporal stochastic modeling of precipitation, nesting models across scales
NASA Astrophysics Data System (ADS)
Paschalis, Athanasios; Molnar, Peter; Fatichi, Simone; Burlando, Paolo
2014-01-01
We analyze the performance of composite stochastic models of temporal precipitation which can satisfactorily reproduce precipitation properties across a wide range of temporal scales. The rationale is that a combination of stochastic precipitation models which are most appropriate for specific limited temporal scales leads to better overall performance across a wider range of scales than single models alone. We investigate different model combinations. For the coarse (daily) scale these are models based on Alternating renewal processes, Markov chains, and Poisson cluster models, which are then combined with a microcanonical Multiplicative Random Cascade model to disaggregate precipitation to finer (minute) scales. The composite models were tested on data at four sites in different climates. The results show that model combinations improve the performance in key statistics such as probability distributions of precipitation depth, autocorrelation structure, intermittency, reproduction of extremes, compared to single models. At the same time they remain reasonably parsimonious. No model combination was found to outperform the others at all sites and for all statistics, however we provide insight on the capabilities of specific model combinations. The results for the four different climates are similar, which suggests a degree of generality and wider applicability of the approach.
SEAL Studies of Variant Blanket Concepts and Materials
NASA Astrophysics Data System (ADS)
Cook, I.; Taylor, N. P.; Forty, C. B. A.; Han, W. E.
1997-09-01
Within the European SEAL ( Safety and Environmental Assessment of fusion power, Long-term) program, safety and environmental assessments have been performed which extend the results of the earlier SEAFP (Safety and Environmental Assessment of Fusion Power) program to a wider range of blanket designs and material choices. The four blanket designs analysed were those which had been developed within the Blanket program of the European Fusion Programme. All four are based on martensitic steel as structural material, and otherwise may be summarized as: water-cooled lithium-lead; dual-cooled lithium-lead; helium-cooled lithium silicate (BOT geometry); helium-cooled lithium aluminate (or zirconate) (BIT geometry). The results reveal that all the blankets show the favorable S&E characteristics of fusion, though there are interesting and significant differences between them. The key results are described. Assessments have also been performed of a wider range of materials than was considered in SEAFP. These were: an alternative vanadium alloy, an alternative low-activation martensitic steel, titanium-aluminum intermetallic, and SiC composite. Assessed impurities were included in the compositions, and these had very important effects upon some of the results. Key results impacting upon accident characteristics, recycling, and waste management are described.
NASA Astrophysics Data System (ADS)
Venet, N.; Sotom, M.; Gachon, H.; Foucal, V.; Pez, M.; Heikkinen, V.; Tuominen, T.; Pantoja, S.
2017-11-01
The satellite telecommunication sector is continuously facing new challenges. Operators turn towards increasing capacity payloads with higher number of beams and broader bandwidth, in order to cope with exhausting orbital positions and to lower the cost of in-orbit delivery of bit. Only satellites able to provide high data rate connections to numerous users are expected to achieve affordable communication prices. On the other hand, as the telecom market grows and the range of offered services (HDTV, Video On Demand, Triple Play), operators call for more versatile solutions to quickly grasp new markets and to adapt to these evolutions over the average 15 years of a satellite lifetime. Flexible payloads have found an increasing interest for a number of years. Flexibility is considered as a means for a better commercial exploitation of a satellite fleet and a better allocation of resource in response to traffic evolution and/or changing business plans, with potential advantages such as a wider range of applications, less customization for specific missions, increased production runs of equipment, enhancement of reliability, reduction of equipment cost, reduction of program schedules [1]. Flexibility is expected to be offered in spectrum management and frequency plan, in coverage, or in the repeater power allocation. The industry is taking up the challenge both by improving current telecom satellites and offering new payload technology, more flexible and able to address the new markets. From a system integrator perspective, flexibility is as an opportunity to design more generic payloads, that can be customized during or after fabrication only, thus shortening the design-to-manufacturing cycle, and improving the industry competitiveness.
Sensor Fish: an autonomous sensor package for characterizing complex flow fields and fish passage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Deng, Zhiqun; Martinez, Jayson J.; Lu, Jun
Fish passing through dams or other hydraulic structures may be injured or killed despite advances in turbine design, project operations, and other fish bypass systems. The Sensor Fish (SF) device is an autonomous sensor package that characterizes the physical conditions and stressors to which fish are exposed during passage through hydro facilities. It was designed to move passively as a neutrally buoyant object through severe hydraulic environments, while collecting high-resolution sensor data. Since its first generation1, the SF device has been successfully deployed in many fish passage studies and has evolved to be a major tool for characterizing fish passagemore » conditions during fish passage in the Columbia River Basin. To better accelerate hydropower development, the U.S. Department of Energy Water Power Program provided funding to develop a new generation (Gen 2 SF) to incorporate more capabilities and accommodate a wider range of users over a broader range of turbine designs and operating environments. The Gen 2 SF (Figure 1) is approximately the size and density of a yearling salmon smolt and is nearly neutrally buoyant. It contains three-dimensional (3D) rotation sensors, 3D linear acceleration sensors, a pressure sensor, a temperature sensor, a 3D orientation sensor, a radiofrequency (RF) transmitter, and a recovery module2. A low-power microcontroller collects data from the sensors and stores up to 5 min of data on internal flash memory at a sampling frequency of 2048 Hz. The recovery module makes the SF positively buoyant after a pre-programmed period of time, causing it to float to the surface for recovery.« less
Snapshot hyperspectral fovea vision system (HyperVideo)
NASA Astrophysics Data System (ADS)
Kriesel, Jason; Scriven, Gordon; Gat, Nahum; Nagaraj, Sheela; Willson, Paul; Swaminathan, V.
2012-06-01
The development and demonstration of a new snapshot hyperspectral sensor is described. The system is a significant extension of the four dimensional imaging spectrometer (4DIS) concept, which resolves all four dimensions of hyperspectral imaging data (2D spatial, spectral, and temporal) in real-time. The new sensor, dubbed "4×4DIS" uses a single fiber optic reformatter that feeds into four separate, miniature visible to near-infrared (VNIR) imaging spectrometers, providing significantly better spatial resolution than previous systems. Full data cubes are captured in each frame period without scanning, i.e., "HyperVideo". The current system operates up to 30 Hz (i.e., 30 cubes/s), has 300 spectral bands from 400 to 1100 nm (~2.4 nm resolution), and a spatial resolution of 44×40 pixels. An additional 1.4 Megapixel video camera provides scene context and effectively sharpens the spatial resolution of the hyperspectral data. Essentially, the 4×4DIS provides a 2D spatially resolved grid of 44×40 = 1760 separate spectral measurements every 33 ms, which is overlaid on the detailed spatial information provided by the context camera. The system can use a wide range of off-the-shelf lenses and can either be operated so that the fields of view match, or in a "spectral fovea" mode, in which the 4×4DIS system uses narrow field of view optics, and is cued by a wider field of view context camera. Unlike other hyperspectral snapshot schemes, which require intensive computations to deconvolve the data (e.g., Computed Tomographic Imaging Spectrometer), the 4×4DIS requires only a linear remapping, enabling real-time display and analysis. The system concept has a range of applications including biomedical imaging, missile defense, infrared counter measure (IRCM) threat characterization, and ground based remote sensing.
NASA Astrophysics Data System (ADS)
Cantoni, Elena; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.
2011-03-01
The KASCADE-Grande experiment operates at Karlsruhe Institute of Technology (KIT) in Germany. It's aim is the study of the primary cosmic radiation, through Extensive Air Shower detection, in the range 1016-1018 eV. Here, measurements are of main interest to understand the high energy evolution of cosmic radiation: a change in the slope of the heavy primary spectrum is expected (as measured at lower energies for lighter primaries) as a possible confirmation of the predicted astrophysical mechanisms; moreover, in this range the transition from galactic to extragalactic radiation is supposed to take place and the observations could clarify the features of this transition, putting the basis for the interpretation of the data at the highest energies. For these tasks KASCADE-Grande fulfills very well the requirements, both concerning the acceptance and the experimental performances. The experiment is constituted by two co-operating arrays of detectors: the KASCADE array, with its 252 detectors in a dense grid of 200×200 m2 and the Grande array, made of 37 detectors arranged on a wider area of 700×700 m2. The Grande array samples the total charged particles size of the air shower, while the KASCADE array provides the muon size In this contribution, KASCADE-Grande measurement of the cosmic ray primary energy spectrum is presented. The exploited technique, calibrated with simulations, combines the charged particles component and muon component on a shower by shower basis, performing the energy estimation of each primary event. Other techniques are also performed, for a better evaluation of systematics and a check of consistency of the hadronic interaction model used in simulations.
Emanuelsson, P; Gunnarsson, U; Strigård, K; Stark, B
2014-08-01
The aim of this study was to evaluate early complications following retromuscular mesh repair with those after dual layer suture of the anterior rectus sheath in a randomised controlled clinical trial for abdominal rectus muscle diastasis (ARD). Patients with an ARD wider than 3 cm and clinical symptoms related to the ARD were included in a prospective randomised study. They were assigned to either retromuscular inset of a lightweight polypropylene mesh or to dual closure of the anterior rectus fascia using Quill self-locking technology. All patients completed a validated questionnaire for pain assessment (Ventral Hernia Pain Questionnaire, VHPQ) and for quality of life (SF36) prior to and 3 months after surgery. The most frequently seen adverse event was minor wound infection. Of the patients, 14/57 had a superficial wound infection; five related to Quill and nine to mesh repair. No deep wound infections were reported. Patient rating for subjective muscular improvement postoperatively was better in the mesh technique group with a mean of 6.9 (range 0-10) compared to a mean of 4.8 (range 0-10) in the Quill group (p=0.01). The pre- and post-operative SF36 scores improved in both groups. There was no significant difference between the two surgical techniques in terms of early complications and perceived pain at the 3-month follow-up. Both techniques may be considered equally reliable for ARD repair in terms of adverse outcomes during the early postoperative phase, even though patients operated with a mesh experienced better improvement in muscular strength. ClinicalTrial.gov: 2009/227-31/3/PE/96. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Microelectromechanical systems for experimental physics and optical telecommunications
NASA Astrophysics Data System (ADS)
Aksyuk, Vladimir Anatolyevich
1999-12-01
Micro-Electro-Mechanical Systems (MEMS) are an emerging technology, which, when applied to the field of physical sensors, offers not only an obvious advantage of being small and cheap, but more importantly, provides some unique experimental opportunities. These are based on the way physical properties scale with decreasing size. This thesis discusses these basic principles and corresponding advantages and limitations of MEMS technology and presents several experiments in which micromachines are used to do physical measurements that could not be done before. Three types of micromechanical magnetometers are demonstrated. When compared to the state of the art traditional techniques they show greater sensitivity, faster response and can be applied over a wider range of experimental conditions. The high-Q micromechanical torsional oscillator magnetometer is used to observe mesoscopic vortex physics, including single flux lines penetrating into a type-II superconductor just above the first critical field. The Faraday balance ``Trampoline'' magnetometer combines high sensitivity, high bandwidth and can be operated in a wide temperature range. It is used in both high pulsed magnetic fields to record deHaas-vanAlphen oscillations and in DC magnetic fields for magnetization measurements at temperatures down to 100mK. The high sensitivity DC torque magnetometer offers yet higher sensitivity and can be used for a variety of magnetization measurements. Several other MEMS devices for physics and telecommunications applications are presented, including a micromachined near field scanning optical microscope, MEMS fiberoptic switches and large-area large-angle scanners. They provide examples of complex functionality that can be achieved with micromechanics by combining sensors with inherently low-power electrostatic actuators. The optically powered optical power limiter demonstrates the possibility of operating MEMS with optical rather than electrical power.
Tunable-Bandwidth Filter System
NASA Technical Reports Server (NTRS)
Bailey, John W.
2004-01-01
A tunable-bandwidth filter system (TBFS), now undergoing development, is intended to be part of a remote sensing multispectral imaging system that will operate in the visible and near infrared spectral region (wavelengths from 400 to 900 nm). Attributes of the TBFS include rapid tunability of the pass band over a wide wavelength range and high transmission efficiency. The TBFS is based on a unique integration of two pairs of broadband Raman reflection holographic filters with two rotating spherical lenses. In experiments, a prototype of the TBFS, was shown to be capable of spectral sampling of images in the visible range over a 200 nm spectral range with a spectral resolution of 30 nm. The figure depicts the optical layout of a prototype of the TBFS as part of a laboratory multispectral imaging system for the spectral sampling of color test images in two orthogonal polarizations. Each pair of broadband Raman reflection holographic filters is mounted at an equatorial plane between two halves of a spherical lens. The two filters in each pair are characterized by steep spectral slopes (equivalently, narrow spectral edges), no ripple or side lobes in their pass bands, and a few nanometers of non-overlapping wavelength range between their pass bands. Each spherical lens and thus the filter pair within it is rotated in order to rapidly tune its pass band. The rotations of are effected by electronically controlled, programmable, high-precision rotation stages. The rotations are coordinated by electronic circuits operating under overall supervision of a personal computer in order to obtain the desired variation of the overall pass bands with time. Embedding the filters inside the spherical lenses increases the range of the hologram incidence angles, making it possible to continuously tune the pass and stop bands of the filters over a wider wavelength range. In addition, each spherical lens also serves as part of the imaging optics: The telephoto lens focuses incoming light to a field stop that is also a focal point of each spherical lens. A correcting lens in front of the field stop compensates for the spherical aberration of the spherical lenses. The front surface of each spherical lens collimates the light coming from the field stop. After the collimated light passes through the filter in the spherical lens, the rear surface of the lens focuses the light onto a charge-coupled-device image detector.
Tunable-Bandwidth Filter System
NASA Technical Reports Server (NTRS)
Aye, Tin; Yu, Kevin; Dimov, Fedor; Savant, Gajendra
2006-01-01
A tunable-bandwidth filter system (TBFS), now undergoing development, is intended to be part of a remote-sensing multispectral imaging system that will operate in the visible and near infrared spectral region (wavelengths from 400 to 900 nm). Attributes of the TBFS include rapid tunability of the pass band over a wide wavelength range and high transmission efficiency. The TBFS is based on a unique integration of two pairs of broadband Raman reflection holographic filters with two rotating spherical lenses. In experiments, a prototype of the TBFS was shown to be capable of spectral sampling of images in the visible range over a 200-nm spectral range with a spectral resolution of .30 nm. The figure depicts the optical layout of a prototype of the TBFS as part of a laboratory multispectral imaging system for the spectral sampling of color test images in two orthogonal polarizations. Each pair of broadband Raman reflection holographic filters is mounted at an equatorial plane between two halves of a spherical lens. The two filters in each pair are characterized by steep spectral slopes (equivalently, narrow spectral edges), no ripple or side lobes in their pass bands, and a few nanometers of non-overlapping wavelength range between their pass bands. Each spherical lens and thus the filter pair within it is rotated in order to rapidly tune its pass band. The rotations of the lenses are effected by electronically controlled, programmable, high-precision rotation stages. The rotations are coordinated by electronic circuits operating under overall supervision of a personal computer in order to obtain the desired variation of the overall pass bands with time. Embedding the filters inside the spherical lenses increases the range of the hologram incidence angles, making it possible to continuously tune the pass and stop bands of the filters over a wider wavelength range. In addition, each spherical lens also serves as part of the imaging optics: The telephoto lens focuses incoming light to a field stop that is also a focal point of each spherical lens. A correcting lens in front of the field stop compensates for the spherical aberration of the spherical lenses. The front surface of each spherical lens collimates the light coming from the field stop. After the collimated light passes through the filter in the spherical lens, the rear surface of the lens focuses the light onto a charge-coupled-device image detector.
Khandelia, Piyush; Yap, Karen; Makeyev, Eugene V
2011-08-02
Sequence-specific gene silencing by short hairpin (sh) RNAs has recently emerged as an indispensable tool for understanding gene function and a promising avenue for drug discovery. However, a wider biomedical use of this approach is hindered by the lack of straightforward methods for achieving uniform expression of shRNAs in mammalian cell cultures. Here we report a high-efficiency and low-background (HILO) recombination-mediated cassette exchange (RMCE) technology that yields virtually homogeneous cell pools containing doxycycline-inducible shRNA elements in a matter of days and with minimal efforts. To ensure immediate utility of this approach for a wider research community, we modified 11 commonly used human (A549, HT1080, HEK293T, HeLa, HeLa-S3, and U2OS) and mouse (CAD, L929, N2a, NIH 3T3, and P19) cell lines to be compatible with the HILO-RMCE process. Because of its technical simplicity and cost efficiency, the technology will be advantageous for both low- and high-throughput shRNA experiments. We also provide evidence that HILO-RMCE will facilitate a wider range of molecular and cell biology applications by allowing one to rapidly engineer cell populations expressing essentially any transgene of interest.
Streamlined platform for short hairpin RNA interference and transgenesis in cultured mammalian cells
Khandelia, Piyush; Yap, Karen; Makeyev, Eugene V.
2011-01-01
Sequence-specific gene silencing by short hairpin (sh) RNAs has recently emerged as an indispensable tool for understanding gene function and a promising avenue for drug discovery. However, a wider biomedical use of this approach is hindered by the lack of straightforward methods for achieving uniform expression of shRNAs in mammalian cell cultures. Here we report a high-efficiency and low-background (HILO) recombination-mediated cassette exchange (RMCE) technology that yields virtually homogeneous cell pools containing doxycycline-inducible shRNA elements in a matter of days and with minimal efforts. To ensure immediate utility of this approach for a wider research community, we modified 11 commonly used human (A549, HT1080, HEK293T, HeLa, HeLa-S3, and U2OS) and mouse (CAD, L929, N2a, NIH 3T3, and P19) cell lines to be compatible with the HILO-RMCE process. Because of its technical simplicity and cost efficiency, the technology will be advantageous for both low- and high-throughput shRNA experiments. We also provide evidence that HILO-RMCE will facilitate a wider range of molecular and cell biology applications by allowing one to rapidly engineer cell populations expressing essentially any transgene of interest. PMID:21768390
Synthetic microfluidic paper: high surface area and high porosity polymer micropillar arrays.
Hansson, Jonas; Yasuga, Hiroki; Haraldsson, Tommy; van der Wijngaart, Wouter
2016-01-21
We introduce Synthetic Microfluidic Paper, a novel porous material for microfluidic applications that consists of an OSTE polymer that is photostructured in a well-controlled geometry of slanted and interlocked micropillars. We demonstrate the distinct benefits of Synthetic Microfluidic Paper over other porous microfluidic materials, such as nitrocellulose, traditional paper and straight micropillar arrays: in contrast to straight micropillar arrays, the geometry of Synthetic Microfluidic Paper was miniaturized without suffering capillary collapse during manufacturing and fluidic operation, resulting in a six-fold increased internal surface area and a three-fold increased porous fraction. Compared to commercial nitrocellulose materials for capillary assays, Synthetic Microfluidic Paper shows a wider range of capillary pumping speed and four times lower device-to-device variation. Compared to the surfaces of the other porous microfluidic materials that are modified by adsorption, Synthetic Microfluidic Paper contains free thiol groups and has been shown to be suitable for covalent surface chemistry, demonstrated here for increasing the material hydrophilicity. These results illustrate the potential of Synthetic Microfluidic Paper as a porous microfluidic material with improved performance characteristics, especially for bioassay applications such as diagnostic tests.
Double closed-loop resonant micro optic gyro using hybrid digital phase modulation.
Ma, Huilian; Zhang, Jianjie; Wang, Linglan; Jin, Zhonghe
2015-06-15
It is well-known that the closed-loop operation in optical gyros offers wider dynamic range and better linearity. By adding a stair-like digital serrodyne wave to a phase modulator can be used as a frequency shifter. The width of one stair in this stair-like digital serrodyne wave should be set equal to the optical transmission time in the resonator, which is relaxed in the hybrid digital phase modulation (HDPM) scheme. The physical mechanism for this relaxation is firstly indicated in this paper. Detailed theoretical and experimental investigations are presented for the HDPM. Simulation and experimental results show that the width of one stair is not restricted by the optical transmission time, however, it should be optimized according to the rise time of the output of the digital-to-analogue converter. Based on the optimum parameters of the HDPM, a bias stability of 0.05°/s for the integration time of 400 seconds in 1 h has been carried out in an RMOG with a waveguide ring resonator with a length of 7.9 cm and a diameter of 2.5 cm.
Compton suppression gamma-counting: The effect of count rate
Millard, H.T.
1984-01-01
Past research has shown that anti-coincidence shielded Ge(Li) spectrometers enhanced the signal-to-background ratios for gamma-photopeaks, which are situated on high Compton backgrounds. Ordinarily, an anti- or non-coincidence spectrum (A) and a coincidence spectrum (C) are collected simultaneously with these systems. To be useful in neutron activation analysis (NAA), the fractions of the photopeak counts routed to the two spectra must be constant from sample to sample to variations must be corrected quantitatively. Most Compton suppression counting has been done at low count rate, but in NAA applications, count rates may be much higher. To operate over the wider dynamic range, the effect of count rate on the ratio of the photopeak counts in the two spectra (A/C) was studied. It was found that as the count rate increases, A/C decreases for gammas not coincident with other gammas from the same decay. For gammas coincident with other gammas, A/C increases to a maximum and then decreases. These results suggest that calibration curves are required to correct photopeak areas so quantitative data can be obtained at higher count rates. ?? 1984.
Status of NTD Ge bolometer material and devices
NASA Technical Reports Server (NTRS)
Haller, E. E.; Haegel, N. M.; Park, I. S.
1986-01-01
The first IR Detector Technology Workshop took place at NASA Ames Research Center on July 12 and 13, 1983. The conclusions presented at that meeting are still valid. More was learned about the physics of hopping conduction at very low temperatures which will be important for bolometer design and operation at ever decreasing temperatures. Resistivity measurements were extended down to 50 mK. At such low temperatures, precise knowledge of the neutron capture cross sections sigma (sub n) of the various Ge isotopes is critical if one is to make an accurate prediction of the dopant concentrations and compensation, and therefore resistivity, that will result from a given irradiation. An empirical approach for obtaining the desired resistivity material is described and the process of conducting a set of experiments which will improve the knowledge of the effective sigma (sub n) values for a given location in a particular reactor is discussed. A wider range of NTD Ge samples is now available. Noise measurements on bolometers with ion implanted contacts show the no 1/f noise component appears down to 1 Hz and probably lower.
Overload characteristics of paper-polypropylene-paper cable
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ernst, A.
1990-09-01
The short-time rating of PPP pipe-type cable may be lower than the equivalent paper cable sized to carry the same normal load. The ratings depend on the relative conductor sizes and the maximum allowable conductor temperatures of the insulation. The insulation thermal resistivity may be a significant parameter for overload times of approximately one hour and should be verified for PPP insulation. The thermal capacitance temperature characteristic of PPP insulation is not known. However, the overload ratings are not very sensitive to this parameter. Overload ratings are given for maximum conductor temperatures from 105 C to 130 C. Use ofmore » ratings based on temperatures greater than 105 C would require testing to determine the extent of degradation of the insulation at these higher temperatures. PPP-insulated cable will be thermally stable over a wider range of operating conditions (voltage and current) compared with paper-insulated cable. The short-circuit ratings of PPP- and paper-insulated cable systems and the positive/negative and zero sequence impedances are compared. 21 refs., 22 figs., 5 tabs.« less
Robotic Assisted Transanal Polypectomies: Is There Any Indication?
Gómez Ruiz, Marcos; Cagigas Fernández, Carmen; Alonso Martín, Joaquín; Cristobal Poch, Lidia; Manuel Palazuelos, Carlos; Barredo Cañibano, Francisco Javier; Gómez Fleitas, Manuel; Castillo Diego, Julio
2017-12-01
Robotic assisted transanal polipectomy may have advantages compared with the conventional transanal minimally invasive surgery technique. We evaluate the safety, feasibility and advantages of this technique. Between February 2014 and October 2015, 9patients underwent robotic transanal polypectomy. We performed a retrospective study in which we analyse prospectively collected data regarding patient and tumor characteristics, perioperative outcomes, pathological report, morbidity and mortality. A total of 5 male and 4 female patients underwent robotic TAMIS. Lesions were 6,22cm from the anal verge. Mean size was 15,8cm 2 . All procedures were performed in the lithotomy position. Closure of the defect was performed in all cases. Mean blood loss was 39,8ml. Mean operative time was 71,9min. No severe postoperative complications or readmissions occured. Median hospital stay was 2,5 days. Robotic TAMIS is useful to treat complex rectal lesions. Our transanal platform allowed a wider range of movements of the robotic arms and to perform all procedures in the lithotomy position. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.
NASA Technical Reports Server (NTRS)
Yen, John; Wang, Haojin; Daugherity, Walter C.
1992-01-01
Fuzzy logic controllers have some often-cited advantages over conventional techniques such as PID control, including easier implementation, accommodation to natural language, and the ability to cover a wider range of operating conditions. One major obstacle that hinders the broader application of fuzzy logic controllers is the lack of a systematic way to develop and modify their rules; as a result the creation and modification of fuzzy rules often depends on trial and error or pure experimentation. One of the proposed approaches to address this issue is a self-learning fuzzy logic controller (SFLC) that uses reinforcement learning techniques to learn the desirability of states and to adjust the consequent part of its fuzzy control rules accordingly. Due to the different dynamics of the controlled processes, the performance of a self-learning fuzzy controller is highly contingent on its design. The design issue has not received sufficient attention. The issues related to the design of a SFLC for application to a petrochemical process are discussed, and its performance is compared with that of a PID and a self-tuning fuzzy logic controller.
WFIRST: Astrometry with the Wide-Field Imager
NASA Astrophysics Data System (ADS)
Bellini, Andrea; WFIRST Astrometry Working Group
2018-01-01
The wide field of view and stable, sharp images delivered by WFIRST's Wide-Field Imager make it an excellent instrument for astrometry, one of five major discovery areas identified in the 2010 Decadal Survey. Compared to the Hubble Space Telescope, WFIRST's wider field of view with similar image quality will provide hundreds more astrometric targets per image as well as background galaxies and stars with precise positions in the Gaia catalog. In addition, WFIRST will operate in the infrared, a wavelength regime where the most precise astrometry has so far been achieved with adaptive optics images from large ground-based telescopes. WFIRST will provide at least a factor of three improvement in astrometry over the current state of the art in this wavelength range, while spanning a field of view thousands of times larger. WFIRST is thus poised to make major contributions to multiple science topics in which astrometry plays an important role, without major alterations to the planned mission or instrument. We summarize a few of the most compelling science cases where WFIRST astrometry could prove transformational.
Integrated computer-aided design using minicomputers
NASA Technical Reports Server (NTRS)
Storaasli, O. O.
1980-01-01
Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), a highly interactive software, has been implemented on minicomputers at the NASA Langley Research Center. CAD/CAM software integrates many formerly fragmented programs and procedures into one cohesive system; it also includes finite element modeling and analysis, and has been interfaced via a computer network to a relational data base management system and offline plotting devices on mainframe computers. The CAD/CAM software system requires interactive graphics terminals operating at a minimum of 4800 bits/sec transfer rate to a computer. The system is portable and introduces 'interactive graphics', which permits the creation and modification of models interactively. The CAD/CAM system has already produced designs for a large area space platform, a national transonic facility fan blade, and a laminar flow control wind tunnel model. Besides the design/drafting element analysis capability, CAD/CAM provides options to produce an automatic program tooling code to drive a numerically controlled (N/C) machine. Reductions in time for design, engineering, drawing, finite element modeling, and N/C machining will benefit productivity through reduced costs, fewer errors, and a wider range of configuration.
Martian Radiative Transfer Modeling Using the Optimal Spectral Sampling Method
NASA Technical Reports Server (NTRS)
Eluszkiewicz, J.; Cady-Pereira, K.; Uymin, G.; Moncet, J.-L.
2005-01-01
The large volume of existing and planned infrared observations of Mars have prompted the development of a new martian radiative transfer model that could be used in the retrievals of atmospheric and surface properties. The model is based on the Optimal Spectral Sampling (OSS) method [1]. The method is a fast and accurate monochromatic technique applicable to a wide range of remote sensing platforms (from microwave to UV) and was originally developed for the real-time processing of infrared and microwave data acquired by instruments aboard the satellites forming part of the next-generation global weather satellite system NPOESS (National Polarorbiting Operational Satellite System) [2]. As part of our on-going research related to the radiative properties of the martian polar caps, we have begun the development of a martian OSS model with the goal of using it to perform self-consistent atmospheric corrections necessary to retrieve caps emissivity from the Thermal Emission Spectrometer (TES) spectra. While the caps will provide the initial focus area for applying the new model, it is hoped that the model will be of interest to the wider Mars remote sensing community.
Developing a Graphical User Interface for the ALSS Crop Planning Tool
NASA Technical Reports Server (NTRS)
Koehlert, Erik
1997-01-01
The goal of my project was to create a graphical user interface for a prototype crop scheduler. The crop scheduler was developed by Dr. Jorge Leon and Laura Whitaker for the ALSS (Advanced Life Support System) program. The addition of a system-independent graphical user interface to the crop planning tool will make the application more accessible to a wider range of users and enhance its value as an analysis, design, and planning tool. My presentation will demonstrate the form and functionality of this interface. This graphical user interface allows users to edit system parameters stored in the file system. Data on the interaction of the crew, crops, and waste processing system with the available system resources is organized and labeled. Program output, which is stored in the file system, is also presented to the user in performance-time plots and organized charts. The menu system is designed to guide the user through analysis and decision making tasks, providing some help if necessary. The Java programming language was used to develop this interface in hopes of providing portability and remote operation.
A 5 x 40 cm rectangular-beam multipole ion source
NASA Technical Reports Server (NTRS)
Robinson, R. S.; Kaufman, H. R.; Haynes, C. M.
1981-01-01
A rectangular ion source particularly suited for the continuous sputter processing of materials over a wide area is discussed. A multipole magnetic field configuration was used to design an ion source with a 5 x 40 cm beam area, while a three-grid ion optics system was used to maximize ion current density at the design ion energy of 500 eV. An average extracted current density of about 4 mA/sq cm could be obtained from 500 eV Ar ions. The difference between the experimental performance and the design value of 6 mA/sq cm is attributed to grid misalignment due to thermal expansion. The discharge losses at typical operating conditions ranged from about 600 to 1000 eV/ion, in reasonable agreement with the design value of 800 eV/ion. The use of multiple rectangular-beam ion sources to process wider areas than would be possible with a single source was also studied, and the most uniform coverage was found to be obtainable with a 0 to 2 cm overlap.
Multiple-Zone Diffractive Optic Element for Laser Ranging Applications
NASA Technical Reports Server (NTRS)
Ramos-Izquierdo, Luis A.
2011-01-01
A diffractive optic element (DOE) can be used as a beam splitter to generate multiple laser beams from a single input laser beam. This technology has been recently used in LRO s Lunar Orbiter Laser Altimeter (LOLA) instrument to generate five laser beams that measure the lunar topography from a 50-km nominal mapping orbit (see figure). An extension of this approach is to use a multiple-zone DOE to allow a laser altimeter instrument to operate over a wider range of distances. In particular, a multiple-zone DOE could be used for applications that require both mapping and landing on a planetary body. In this case, the laser altimeter operating range would need to extend from several hundred kilometers down to a few meters. The innovator was recently involved in an investigation how to modify the LOLA instrument for the OSIRIS asteroid mapping and sample return mission. One approach is to replace the DOE in the LOLA laser beam expander assembly with a multiple-zone DOE that would allow for the simultaneous illumination of the asteroid with mapping and landing laser beams. The proposed OSIRIS multiple-zone DOE would generate the same LOLA five-beam output pattern for high-altitude topographic mapping, but would simultaneously generate a wide divergence angle beam using a small portion of the total laser energy for the approach and landing portion of the mission. Only a few percent of the total laser energy is required for approach and landing operations as the return signal increases as the inverse square of the ranging height. A wide divergence beam could be implemented by making the center of the DOE a diffractive or refractive negative lens. The beam energy and beam divergence characteristics of a multiple-zone DOE could be easily tailored to meet the requirements of other missions that require laser ranging data. Current single-zone DOE lithographic manufacturing techniques could also be used to fabricate a multiple-zone DOE by masking the different DOE zones during the manufacturing process, and the same space-compatible DOE substrates (fused silica, sapphire) that are used on standard DOE s could be used for multiple- zone DOE s. DOEs are an elegant and cost-effective optical design option for spacebased laser altimeters that require multiple output laser beams. The use of multiple-zone DOEs would allow for the design and optimization of a laser altimeter instrument required to operate over a large range of target distances, such as those designed to both map and land on a planetary body. In addition to space-based laser altimeters, this technology could find applications in military or commercial unmanned aerial vehicles (UAVs) that fly at an altitude of several kilometers and need to land. It is also conceivable that variations of this approach could be used in land-based applications such as collision avoidance and robotic control of cars, trains, and ships.
Visual Detection Under Uncertainty Operates Via an Early Static, Not Late Dynamic, Non-Linearity
Neri, Peter
2010-01-01
Signals in the environment are rarely specified exactly: our visual system may know what to look for (e.g., a specific face), but not its exact configuration (e.g., where in the room, or in what orientation). Uncertainty, and the ability to deal with it, is a fundamental aspect of visual processing. The MAX model is the current gold standard for describing how human vision handles uncertainty: of all possible configurations for the signal, the observer chooses the one corresponding to the template associated with the largest response. We propose an alternative model in which the MAX operation, which is a dynamic non-linearity (depends on multiple inputs from several stimulus locations) and happens after the input stimulus has been matched to the possible templates, is replaced by an early static non-linearity (depends only on one input corresponding to one stimulus location) which is applied before template matching. By exploiting an integrated set of analytical and experimental tools, we show that this model is able to account for a number of empirical observations otherwise unaccounted for by the MAX model, and is more robust with respect to the realistic limitations imposed by the available neural hardware. We then discuss how these results, currently restricted to a simple visual detection task, may extend to a wider range of problems in sensory processing. PMID:21212835
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cohen, Timothy; Dolan, Matthew J.; El Hedri, Sonia
Simplified Models are a useful way to characterize new physics scenarios for the LHC. Particle decays are often represented using non-renormalizable operators that involve the minimal number of fields required by symmetries. Generalizing to a wider class of decay operators allows one to model a variety of final states. This approach, which we dub the $n$-body extension of Simplified Models, provides a unifying treatment of the signal phase space resulting from a variety of signals. In this paper, we present the first application of this framework in the context of multijet plus missing energy searches. The main result of thismore » work is a global performance study with the goal of identifying which set of observables yields the best discriminating power against the largest Standard Model backgrounds for a wide range of signal jet multiplicities. Our analysis compares combinations of one, two and three variables, placing emphasis on the enhanced sensitivity gain resulting from non-trivial correlations. Utilizing boosted decision trees, we compare and classify the performance of missing energy, energy scale and energy structure observables. We demonstrate that including an observable from each of these three classes is required to achieve optimal performance. In conclusion, this work additionally serves to establish the utility of $n$-body extended Simplified Models as a diagnostic for unpacking the relative merits of different search strategies, thereby motivating their application to new physics signatures beyond jets and missing energy.« less
Huang, Jingfeng; Wei, Chen; Zhang, Yao; Blackburn, George Alan; Wang, Xiuzhen; Wei, Chuanwen; Wang, Jing
2015-01-01
Passive optical hyperspectral remote sensing of plant pigments offers potential for understanding plant ecophysiological processes across a range of spatial scales. Following a number of decades of research in this field, this paper undertakes a systematic meta-analysis of 85 articles to determine whether passive optical hyperspectral remote sensing techniques are sufficiently well developed to quantify individual plant pigments, which operational solutions are available for wider plant science and the areas which now require greater focus. The findings indicate that predictive relationships are strong for all pigments at the leaf scale but these decrease and become more variable across pigment types at the canopy and landscape scales. At leaf scale it is clear that specific sets of optimal wavelengths can be recommended for operational methodologies: total chlorophyll and chlorophyll a quantification is based on reflectance in the green (550–560nm) and red edge (680–750nm) regions; chlorophyll b on the red, (630–660nm), red edge (670–710nm) and the near-infrared (800–810nm); carotenoids on the 500–580nm region; and anthocyanins on the green (550–560nm), red edge (700–710nm) and near-infrared (780–790nm). For total chlorophyll the optimal wavelengths are valid across canopy and landscape scales and there is some evidence that the same applies for chlorophyll a. PMID:26356842
Hydrology of the Chicod Creek basin, North Carolina, prior to channel improvements
Simmons, Clyde E.; Aldridge, Mary C.
1980-01-01
Extensive modification and excavation of stream channels in the 6-square mile Chicod Creek basin began in mid-1979 to reduce flooding and improve stream runoff conditions. The effects of channel improvements on this Coastal Pain basin 's hydrology will be determined from data collected prior to, during, and for several years following channel alternations. This report summarizes the findings of data collected prior to these improvements. During the 3-year study period, flow data collected from four stream gaging stations in the basin show that streams are dry approximately 10 percent of the time. Chemical analyses of water samples from the streams and from eight shallow groundwater observation wells indicate that water discharge from the surficial aquifer is the primary source of streamflow during rainless periods. Concentrations of Kjeldahl nitrogen, total nitrogen, and total phosphorus were often 5 to 10 times greater at Chicod Creek sites than those at nearby baseline sites. It is probable that runoff from farming and livestock operations contributes significantly to these elevated concentrations in Chicod Creek. The only pesticides detected in stream water were low levels of DDT and dieldrin, which occurred during storm runoff. A much wider range of pesticides, however, are found associated with streambed materials. The ratio of fecal coliform counts to those of fecal streptococcus indicate that the streams receive fecal wastes from livestock and poultry operations.
Automated Planning and Scheduling for Space Mission Operations
NASA Technical Reports Server (NTRS)
Chien, Steve; Jonsson, Ari; Knight, Russell
2005-01-01
Research Trends: a) Finite-capacity scheduling under more complex constraints and increased problem dimensionality (subcontracting, overtime, lot splitting, inventory, etc.) b) Integrated planning and scheduling. c) Mixed-initiative frameworks. d) Management of uncertainty (proactive and reactive). e) Autonomous agent architectures and distributed production management. e) Integration of machine learning capabilities. f) Wider scope of applications: 1) analysis of supplier/buyer protocols & tradeoffs; 2) integration of strategic & tactical decision-making; and 3) enterprise integration.
Modernization of Deployable Airfield Debris Removal Equipment
2017-04-01
cleared the debris away from the crater by lowering the front bucket and setting the bottom blade at a 45-deg angle. The debris was pushed...the Komatsu WA 150 baseline loader. The crater clearing process involved the loader orienting the bucket blade at approximately 45 deg to the...wider than the track’s width (Figure 30). This caused debris to run under the track and lift the equipment, potentially throwing the operator. The final
2016-04-15
natural gas is commercially viable as an automobile fuel in Afghanistan and to promote its wider use in the country. According to TFBSO documents, the... commercial fashion industry, which is the primary end user for cashmere.98 When the project began, Afghanistan...from suppliers is far more expensive than sustainable grazing, and this additional expenditure directly affected the commercial viability of the farm
The changing brain: Neuroscience and the enduring import of everyday experience
Martin, Paul; Cunningham-Burley, Sarah
2015-01-01
Discourses of ‘neuroplasticity’ have become increasingly apparent in the neurosciences and wider society. These connect with broader narratives about the ‘changing brain’ throughout the life-course. Here, we explore their presence in the talk of a range of publics. Their presence is indicative of how novel neuroscience is accepted, or not, by our participants. In particular, we suggest that any acceptance of the science relates to their personal and/or professional experiences of change (to their own or others’ subjectivities) rather than to some intrinsic and widely-held significance of scientific concepts per se. Accordingly, we also submit that it is in part through the congruence of some neuroscientific claims to everyday experiences and perspectives that the former are rendered legible and salient. In this respect, ‘lay’ knowledge has considerable import for the wider cultural authorisation of that of ‘experts’. PMID:24598481
Use of Monte Carlo simulation for the interpretation and analysis of diffuse scattering
NASA Astrophysics Data System (ADS)
Welberry, T. R.; Chan, E. J.; Goossens, D. J.; Heerdegen, A. P.
2010-02-01
With the development of computer simulation methods there is, for the first time, the possibility of having a single general method that can be used for any diffuse scattering problem in any type of system. As computers get ever faster it is expected that current methods will become increasingly powerful and applicable to a wider and wider range of problems and materials and provide results in increasingly fine detail. In this article we discuss two contrasting recent examples. The first is concerned with the two polymorphic forms of the pharmaceutical compound benzocaine. The strong and highly structured diffuse scattering in these is shown to be symptomatic of the presence of highly correlated molecular motions. The second concerns Ag+ fast ion conduction in the pearceite/polybasite family of mineral solid electrolytes. Here Monte-Carlo simulation is used to model the diffuse scattering and gain insight into how the ionic conduction arises.
NASA Astrophysics Data System (ADS)
Soto-Crespo, J. M.; Akhmediev, Nail
2002-12-01
The complex quintic Swift-Hohenberg equation (CSHE) is a model for describing pulse generation in mode-locked lasers with fast saturable absorbers and a complicated spectral response. Using numerical simulations, we study the single- and two-soliton solutions of the (1+1)-dimensional complex quintic Swift-Hohenberg equations. We have found that several types of stationary and moving composite solitons of this equation are generally stable and have a wider range of existence than for those of the complex quintic Ginzburg-Landau equation. We have also found that the CSHE has a wider variety of localized solutions. In particular, there are three types of stable soliton pairs with π and π/2 phase difference and three different fixed separations between the pulses. Different types of soliton pairs can be generated by changing the parameter corresponding to the nonlinear gain (ɛ).
Andrews, Jonathan
2012-03-01
This article examines the management and meaning of post-mortem examinations, and the spatial ordering of patients' death, dissection and burial at the Victorian asylum, referencing a range of institutional contexts and exploiting a case study of the Royal Edinburgh Asylum. The routinizing of dissection and the development of the dead-house from a more marginal asylum sector to a lynchpin of laboratory medicine is stressed. External and internal pressure to modernize pathological research facilities is assessed alongside governmental, public and professional critiques of variable necroscopy practices. This is contextualized against wider issues and attitudes surrounding consent and funereal rituals. Onus is placed on tendencies in anatomizing insanity towards the conversion of deceased lunatics--pauper lunatics especially--into mere pathological specimens. On the other hand, significant but compromised resistance on the part of a minority of practitioners, relatives and the wider public is also identified.
Gibbs, Andrew; Dunkle, Kristin; Washington, Laura; Willan, Samantha; Shai, Nwabisa; Jewkes, Rachel
2018-01-01
Childhood traumas, in the form of physical, sexual, and emotional abuse and neglect, are globally widespread and highly prevalent, and associated with a range of subsequent poor health outcomes. This study sought to understand the relationship between physical, sexual and emotional childhood abuse and subsequent HIV-risk behaviours amongst young people (18-30) living in urban informal settlements in Durban, South Africa. Data came from self-completed questionnaires amongst 680 women and 677 men comprising the baseline of the Stepping Stones and Creating Futures intervention trial. Men and women were analysed separately. Logistic regression models assessed the relationship between six HIV-risk behaviours and four measures of trauma: the form of trauma, the severity of each trauma, the range of traumas, and overall severity of childhood trauma. Childhood traumas were incredibly prevalent in this population. All childhood traumas were associated with a range of HIV-risk behaviours. This was for the ever/never trauma, as well as the severity of each type of trauma, the range of trauma, and overall severity of childhood trauma. Despite the wider harsh contexts of urban informal settlements, childhood traumas still play a significant role in shaping subsequent HIV-risk behaviours amongst young people. Interventions to reduce childhood traumas for populations in informal settlements need to be developed. In addition, trauma focused therapies need to be considered as part of wider HIV-prevention interventions for young adults. ClinicalTrials.gov NCT03022370.
NASA Astrophysics Data System (ADS)
Chardin, Jonathan; Haehnelt, Martin G.; Bosman, Sarah E. I.; Puchwein, Ewald
2018-01-01
High signal-to-noise observations of the Ly α forest transmissivity in the z = 7.085 quasi-stellar object (QSO) ULAS J1120+0641 show seven narrow transmission spikes followed by a long 240 cMpc h-1 trough. Here, we use radiative transfer simulations of cosmic reionization previously calibrated to match a wider range of Ly α forest data to show that the occurrence of seven transmission spikes in the narrow redshift range z = 5.85-6.1 is very sensitive to the exact timing of reionization. Occurrence of the spikes requires the most underdense regions of the intergalactic medium to be already fully ionized. The rapid onset of a long trough at z = 6.12 requires a strong decrease of the photoionization rate Γ at z ≳ 6.1 in this line of sight, consistent with the end of percolation at this redshift. The narrow range of reionization histories that we previously found to be consistent with a wider range of Ly α forest data have a reasonable probability of showing seven spikes and the mock absorption spectra provide an excellent match to the spikes and the trough in the observed spectrum of ULAS J1120+0641. Larger samples of high signal-to-noise searches for rare Ly α transmission spikes at z > 5.8 should therefore provide important further insights into the exact timing of the percolation of H II bubbles at the tail end of reionization.
Dunkle, Kristin; Washington, Laura; Willan, Samantha; Shai, Nwabisa; Jewkes, Rachel
2018-01-01
Childhood traumas, in the form of physical, sexual, and emotional abuse and neglect, are globally widespread and highly prevalent, and associated with a range of subsequent poor health outcomes. This study sought to understand the relationship between physical, sexual and emotional childhood abuse and subsequent HIV-risk behaviours amongst young people (18–30) living in urban informal settlements in Durban, South Africa. Data came from self-completed questionnaires amongst 680 women and 677 men comprising the baseline of the Stepping Stones and Creating Futures intervention trial. Men and women were analysed separately. Logistic regression models assessed the relationship between six HIV-risk behaviours and four measures of trauma: the form of trauma, the severity of each trauma, the range of traumas, and overall severity of childhood trauma. Childhood traumas were incredibly prevalent in this population. All childhood traumas were associated with a range of HIV-risk behaviours. This was for the ever/never trauma, as well as the severity of each type of trauma, the range of trauma, and overall severity of childhood trauma. Despite the wider harsh contexts of urban informal settlements, childhood traumas still play a significant role in shaping subsequent HIV-risk behaviours amongst young people. Interventions to reduce childhood traumas for populations in informal settlements need to be developed. In addition, trauma focused therapies need to be considered as part of wider HIV-prevention interventions for young adults. Trial registration: ClinicalTrials.gov NCT03022370 PMID:29624612
Copper Filtration and kVp: Effect on Entrance Skin Exposure.
Barba, James; Culp, Melissa
2015-01-01
The selection of technical factors to produce an image is driven primarily by the patient, body part, and factors regarding the status of that patient or part. Analog receptor systems are restricted by the ranges of data they are able to record, as well as the quantity and quality of data required to record an image. Using digital receptors allows for a wider range of exposure factors because of the nature of the receptor systems and the data processing methods employed. Thus, factor selection can be more patient centered when using digital receptors to produce a radiograph. To explore the relationship between milliampere seconds (mAs), kilovoltage peak (kVp), and additional copper filtration with exposure indicators and entrance skin exposure (ESE) using both analog and digital receptors. Researchers conducted 2-tailed t-tests using Stata/IC version 11.2 software (StataCorp LP) to compare ESE from several trials using hip and knee phantoms. The analysis indicated that increasing kVp, adding 0.1 mm copper filtration, and correspondingly reducing mAs reduced ESE on a hip phantom by 64%, from 151 mR to 54.4 mR and reduced ESE on a knee phantom by 51%, from 27.2 mR to 13.4 mR. Radiology departments and radiologic technologists can consider these data when creating dose reduction protocols. The wider latitude range of digital radiography can be used to minimize patient exposure while still producing images of diagnostic quality within the acceptable exposure indicator range stated by the manufacturer.
ERIC Educational Resources Information Center
Hutchins, Tiffany L.; Howard, Malinda; Prelock, Patricia A.; Belin, Gayle
2010-01-01
Nationally, the shortage of speech-language pathologists (SLPs) in the schools is growing. As such, it is important to understand factors related to the retention of SLPs in this setting. This study expanded on previous research by examining a wider range of factors that may be related to the retention of SLPs including caseload size, workload…
Watson, Derrick G
2017-01-01
I propose that there remains a central role for the item (or its equivalent) in a wider range of search and search-related tasks/functions than might be conveyed by the article. I consider the functional relationship between the framework and some aspects of previous theories, and suggest some challenges that the new framework might encounter.
The Building 549 auditorium is often packed with high school interns eager to hear a scientific lecture. On April 22, however, the room swelled with interns spanning a wider age range. At the 25th Werner H. Kirsten Student Intern Program (WHK SIP) Anniversary Symposium, incoming, current, and former interns gathered to celebrate the program, which has provided biomedical
Weathering of iron sulfides under Mars surface ambient conditions
NASA Technical Reports Server (NTRS)
Blackburn, T. R.
1981-01-01
The study of iron sulfide surface alternation reactions under Mars' surface ambient conditions begun during 1980 was extended through improved irradiation design and experimental protocols. A wider range of humidities and more intense irradiation were incorporated in the study. X-ray photoelectron spectra of irradiated chips suggest formation of FeSO4, FeCO3, and an iron oxide on the iron sulfide substrates studied.
Flexistudy: A Development at Barnet College. Coombe Lodge Case Study. Information Bank Number 1351.
ERIC Educational Resources Information Center
Albrecht, A.; Spencer, D. C.
An outline is presented of Barnet College's flexistudy program, a system for providing a wider range of learning opportunities through a more flexible arrangement of course times and content to students who are unable to attend college regularly, who are too few in number to form a specialist class, or who wish to start school at some time other…
John Podgwaite; Viatcheslav Martemyanov; Stanislav Bakhvalov
2007-01-01
Periodic intrusions of Asian strains of gypsy moth, Lymantria dispar L., into North America have occurred over the past several years. Preventative measures in the countries of origin and around ports of entry in North America have lowered the risk of invasion and establishment but the threat remains current. Asian strains have a wider host range...
Medtech: Potential for innovation.
Bestetti, Gilberto
2009-10-17
Switzerland, with its ETHZ and EPFL, universities, advanced technical colleges, the CSEM, the Empa and the Paul Scherrer Institute, possesses a complete chain of knowledge and interdisciplinary competence which ranks it among the worldwide leaders in medical technology. To ensure that a wider range of excellent research results are translated into marketable products and methods, the CTI Agency for the Promotion of Innovation launched the Medtech initiative, a success story.
Multinational Experiment 7. Regional Analysis: Wider Mediterranean
2013-07-08
crossroads for the maritime trade and the global economic flows, the Mediterranean Sea is something like a lab where maritime security initiatives could...and their economic development. One of the most critical areas in the world partially faces the Mediterranean: the Middle East. As stated, 21...Nations have a coastline on the Mediterranean Sea, offering a wide range of economical , political, cultural and religious perspectives that hamper the
The 2015 National Security Strategy: Authorities, Changes, Issues for Congress
2016-02-26
climate change ; ensure access to shared spaces (expanding cyberspace and including outer space and air and maritime security); and increase global...hand, one could conclude that these, along with confronting climate change , convey both a wider range of national security challenges in terms of...The 2015 National Security Strategy: Authorities, Changes , Issues for Congress Nathan J. Lucas, Coordinator Section Research Manager Kathleen
Range Estimation Algorithm Comparison in 3-D Flash LADAR Data
2009-03-01
formed from LADAR intensity data viewed at sample 10. Target is about 70 meters from receiver and normal to line of sight. White square indicates region...that when averaged form a pulse that is slightly wider than the individual returns. . . . . . . . 35 4.1 Examples of simulated LADAR waveforms of...varying widths used for PWE tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.2 Simulated noiseless data buffered through LADAR sytem
Phosphorus translocation by red deer on a subalpine grassland in the central European Alps
Martin Schutz; Anita C. Risch; Gerald Achermann; Conny Thiel-Egenter; Deborah Page-Dumroese; Martin F. Jurgensen; Peter J. Edward
2006-01-01
We examined the role of red deer (Cervus elaphus L.) in translocating phosphorus (P) from their preferred grazing sites (short-grass vegetation on subalpine grasslands) to their wider home range in a subalpine grassland ecosystem in the Central European Alps. Phosphorus was used because it is the limiting nutrient in these grasslands. When we compared P removal of...
Universal Declaration of Human Rights, A Lay Version for the Common Man, Woman and Child.
ERIC Educational Resources Information Center
Tankard, Alice Doumanian
This lay version of the Universal Declaration of Human Rights (the original version was adopted by the General Assembly of the United Nations in 1948) has been written in simplified vocabulary to make it understandable to a wider range of ages and reading abilities. The declaration consists of a preamble followed by a listing of 30 goals common to…
Plantation Spacing Affects Early Growth of Planted Virginia Pine
T.E. Russell
1979-01-01
Spacings ranging from 4 x 4 to 8 x 8 ft did not affect 15 year height growth of Virginia pines planted on a cutover Cumberland Plateau site. Wider spacings produced trees of larger diameters than did closer spacings; closer spacings had more basal area and volume. Although height to the base of the live crown increased as spacing narrowed, self-pruning was poor at all...
ERIC Educational Resources Information Center
Boatman, Angela; Long, Bridget Terry
2018-01-01
We examine the impact of remedial and developmental courses on college students with varying levels of academic preparedness, thus focusing on a wider range of students than previous studies. Using a regression discontinuity design, we provide causal estimates of the effects of placement in different levels of remedial courses on short-,…
Adding the Human Element to Ship Manoeuvring Simulations
NASA Astrophysics Data System (ADS)
Aarsæther, Karl Gunnar; Moan, Torgeir
Time-domain simulation of ship manoeuvring has been utilized in risk analysis to assess the effect of changes to the ship-lane, development in traffic volume and the associated risk. The process of ship manoeuvring in a wider socio-technical context consists of the technical systems, operational procedures, the human operators and support functions. Automated manoeuvring simulations without human operators in the simulation loop have often been preferred in simulation studies due to the low time required for simulations. Automatic control has represented the human element with little effort devoted to explain the relationship between the guidance and control algorithms and the human operator which they replace. This paper describes the development and application of a model for the human element for autonomous time-domain manoeuvring simulations. The method is applicable in the time-domain, modular and found to be capable of reproducing observed manoeuvre patterns, but limited to represent the intended behaviour.
Kiyokawa, Masatoshi; Sakuma, Toshiro; Hatano, Noriko; Mizota, Atsushi; Tanaka, Minoru
2009-06-01
The purpose of this article is to report the characteristics and advantages of using a newly designed quartz contact lens with slit illumination from an operating microscope for intraocular surgery. The new contact lens is made of quartz. The lens is convex-concave and is used in combination with slit illumination from an operating microscope. The optical properties of quartz make this lens less reflective with greater transmittance. The combination of a quartz contact lens with slit illumination provided a brighter and wider field of view than conventional lenses. This system enabled us to perform bimanual vitrectomy and scleral buckling surgery without indirect ophthalmoscope. Small intraocular structures in the posterior pole or in the periphery were detected more easily. In conclusion, the newly designed quartz lens with slit beam illumination from an operating microscope provided a bright, clear and wide surgical field, and allowed intraocular surgery to be performed more easily.
Dynamic multicast routing scheme in WDM optical network
NASA Astrophysics Data System (ADS)
Zhu, Yonghua; Dong, Zhiling; Yao, Hong; Yang, Jianyong; Liu, Yibin
2007-11-01
During the information era, the Internet and the service of World Wide Web develop rapidly. Therefore, the wider and wider bandwidth is required with the lower and lower cost. The demand of operation turns out to be diversified. Data, images, videos and other special transmission demands share the challenge and opportunity with the service providers. Simultaneously, the electrical equipment has approached their limit. So the optical communication based on the wavelength division multiplexing (WDM) and the optical cross-connects (OXCs) shows great potentials and brilliant future to build an optical network based on the unique technical advantage and multi-wavelength characteristic. In this paper, we propose a multi-layered graph model with inter-path between layers to solve the problem of multicast routing wavelength assignment (RWA) contemporarily by employing an efficient graph theoretic formulation. And at the same time, an efficient dynamic multicast algorithm named Distributed Message Copying Multicast (DMCM) mechanism is also proposed. The multicast tree with minimum hops can be constructed dynamically according to this proposed scheme.
Computational and Mathematical Modeling of Coupled Superconducting Quantum Interference Devices
NASA Astrophysics Data System (ADS)
Berggren, Susan Anne Elizabeth
This research focuses on conducting an extensive computational investigation and mathematical analysis into the average voltage response of arrays of Superconducting Quantum Interference Devices (SQUIDs). These arrays will serve as the basis for the development of a sensitive, low noise, significantly lower Size, Weight and Power (SWaP) antenna integrated with Low-Noise Amplifier (LNA) using the SQUID technology. The goal for this antenna is to be capable of meeting all requirements for Guided Missile Destroyers (DDG) 1000 class ships for Information Operations/Signals Intelligence (IO/SIGINT) applications in Very High Frequency/Ultra High Frequency (V/UHF) bands. The device will increase the listening capability of receivers by moving technology into a new regime of energy detection allowing wider band, smaller size, more sensitive, stealthier systems. The smaller size and greater sensitivity will allow for ships to be “de-cluttered” of their current large dishes and devices, replacing everything with fewer and smaller SQUID antenna devices. The fewer devices present on the deck of a ship, the more invisible the ship will be to enemy forces. We invent new arrays of SQUIDs, optimized for signal detection with very high dynamic range and excellent spur-free dynamic range, while maintaining extreme small size (and low radar cross section), wide bandwidth, and environmentally noise limited sensitivity, effectively shifting the bottle neck of receiver systems forever away from the antenna itself deeper into the receiver chain. To accomplish these goals we develop and validate mathematical models for different designs of SQUID arrays and use them to invent a new device and systems design. This design is capable of significantly exceeding, per size weight and power, state-of-the-art receiver system measures of performance, such as bandwidth, sensitivity, dynamic range, and spurious-free dynamic range.
MODELING OF HUMAN EXPOSURE TO IN-VEHICLE PM2.5 FROM ENVIRONMENTAL TOBACCO SMOKE
Cao, Ye; Frey, H. Christopher
2012-01-01
Environmental tobacco smoke (ETS) is estimated to be a significant contributor to in-vehicle human exposure to fine particulate matter of 2.5 µm or smaller (PM2.5). A critical assessment was conducted of a mass balance model for estimating PM2.5 concentration with smoking in a motor vehicle. Recommendations for the range of inputs to the mass-balance model are given based on literature review. Sensitivity analysis was used to determine which inputs should be prioritized for data collection. Air exchange rate (ACH) and the deposition rate have wider relative ranges of variation than other inputs, representing inter-individual variability in operations, and inter-vehicle variability in performance, respectively. Cigarette smoking and emission rates, and vehicle interior volume, are also key inputs. The in-vehicle ETS mass balance model was incorporated into the Stochastic Human Exposure and Dose Simulation for Particulate Matter (SHEDS-PM) model to quantify the potential magnitude and variability of in-vehicle exposures to ETS. The in-vehicle exposure also takes into account near-road incremental PM2.5 concentration from on-road emissions. Results of probabilistic study indicate that ETS is a key contributor to the in-vehicle average and high-end exposure. Factors that mitigate in-vehicle ambient PM2.5 exposure lead to higher in-vehicle ETS exposure, and vice versa. PMID:23060732
Understanding the organization of public health delivery systems: an empirical typology.
Mays, Glen P; Scutchfield, F Douglas; Bhandari, Michelyn W; Smith, Sharla A
2010-03-01
Policy discussions about improving the U.S. health care system increasingly recognize the need to strengthen its capacities for delivering public health services. A better understanding of how public health delivery systems are organized across the United States is critical to improvement. To facilitate the development of such evidence, this article presents an empirical method of classifying and comparing public health delivery systems based on key elements of their organizational structure. This analysis uses data collected through a national longitudinal survey of local public health agencies serving communities with at least 100,000 residents. The survey measured the availability of twenty core public health activities in local communities and the types of organizations contributing to each activity. Cluster analysis differentiated local delivery systems based on the scope of activities delivered, the range of organizations contributing, and the distribution of effort within the system. Public health delivery systems varied widely in organizational structure, but the observed patterns of variation suggested that systems adhere to one of seven distinct configurations. Systems frequently migrated from one configuration to another over time, with an overall trend toward offering a broader scope of services and engaging a wider range of organizations. Public health delivery systems exhibit important structural differences that may influence their operations and outcomes. The typology developed through this analysis can facilitate comparative studies to identify which delivery system configurations perform best in which contexts.
NASA Astrophysics Data System (ADS)
Park, Sieun; Kang, Seok-Won; Kim, Ketack
2017-12-01
The operation of electrochemical double layer capacitors at high currents and viscosities and at low temperatures is difficult. Under these conditions, ion transport is limited, and some of the electrode area is unavailable for adsorption, which results in a low capacitance. Increasing the temperature helps to increase the ionic movement, leading to enhanced adsorption and increased capacitance. In contrast, ion desorption (self-discharge) surpasses the capacitance improvement when ions gain a high amount of energy with increasing temperature. For example, temperatures as high as 70 °C cause a very high rate of ionic desorption in acetonitrile solutions in which the individual properties of the two electrolytes-tetraethylammonium tetrafluoroborate (TEA BF4) and ethylmethylimidazolium tetrafluoroborate (EMI BF4)-are not distinguishable. The capacitance improvement and self-discharge are balanced, resulting in a capacitance peak at mid-range temperatures, i.e., 35-45 °C, in the more viscous electrolyte, i.e., TEA BF4. The less viscous electrolyte, i.e., EMI BF4 has a wider capacitance peak from 25 to 45 °C and higher capacitance than that of TEA BF4. Because the maximum power is obtained in the mid-temperature range (35-45 °C), it is necessary to control the viscosity and temperature to obtain the maximum power in a given device.
A New Finite Difference Q-compensated RTM Algorithm in Tilted Transverse Isotropic (TTI) Media
NASA Astrophysics Data System (ADS)
Zhou, T.; Hu, W.; Ning, J.
2017-12-01
Attenuating anisotropic geological body is difficult to image with conventional migration methods. In such kind of scenarios, recorded seismic data suffer greatly from both amplitude decay and phase distortion, resulting in degraded resolution, poor illumination and incorrect migration depth in imaging results. To efficiently obtain high quality images, we propose a novel TTI QRTM algorithm based on Generalized Standard Linear Solid model combined with a unique multi-stage optimization technique to simultaneously correct the decayed amplitude and the distorted phase velocity. Numerical tests (shown in the figure) demonstrate that our TTI QRTM algorithm effectively corrects migration depth, significantly improves illumination, and enhances resolution within and below the low Q regions. The result of our new method is very close to the reference RTM image, while QRTM without TTI cannot get a correct image. Compared to the conventional QRTM method based on a pseudo-spectral operator for fractional Laplacian evaluation, our method is more computationally efficient for large scale applications and more suitable for GPU acceleration. With the current multi-stage dispersion optimization scheme, this TTI QRTM method best performs in the frequency range 10-70 Hz, and could be used in a wider frequency range. Furthermore, as this method can also handle frequency dependent Q, it has potential to be applied in imaging deep structures where low Q exists, such as subduction zones, volcanic zones or fault zones with passive source observations.
Laser-induced changes in intraretinal oxygen distribution in pigmented rabbits.
Yu, Dao-Yi; Cringle, Stephen J; Su, Erning; Yu, Paula K; Humayun, Mark S; Dorin, Giorgio
2005-03-01
To make the first measurements of intraretinal oxygen distribution and consumption after laser photocoagulation of the retina and to compare the efficiency of micropulsed (MP) and continuous wave (CW) laser delivery in achieving an oxygen benefit in the treated area. Oxygen-sensitive microelectrodes were used to measure oxygen tension as a function of retinal depth before and after laser treatment in anesthetized, mechanically ventilated, Dutch Belted rabbits (n = 11). Laser lesions were created by using a range of power levels from an 810-nm diode laser coupled with an operating microscope delivery system. MP duty cycles of 5%, 10%, and 15% were compared with CW delivery in each eye. Sufficient power levels of both the CW and MP laser reduced outer retinal oxygen consumption and increased oxygen level within the retina. At these power levels, which correlated with funduscopically visible lesions, there was histologically visible damage to the RPE and photoreceptors. Retinal damage was energy dependent but short-duty-cycle MP delivery was more selective in terms of retinal cell damage, with a wider safety range in comparison with CW delivery. The relationship between laser power level and mode of delivery and the resultant changes in oxygen metabolism and oxygen level in the retina was determined. Only partial destruction of RPE and photoreceptors is necessary, to produce a measurable oxygen benefit in the treated area of retina.
A Step Towards the Characterization of SAR Mode Altimetry to Inform Hydrodynamic Models
NASA Astrophysics Data System (ADS)
Fabry, Pierre; Bercher, Nicolas; Ambrozio, Americo; Restano, Marco; Benveniste, Jerome
2016-08-01
Inland water scenes are highly variable, both in space and time, which leads to a much broader range of radar signatures than ocean surfaces. This applies to both LRM and "SAR" mode (SARM) altimetry. Nevertheless the enhanced along-track resolution of SARM altimeters should help improve the accuracy and precision of inland water height measurements from satellite. The SHAPE project - Sentinel-3 Hydrologic Altimetry Processor prototypE - which is funded by ESA through the Scientific Exploitation of Operational Missions Programme Element (contract number 4000115205/15/I-BG) aims at preparing for the exploitation of Sentinel-3 data over the inland water domain. In order to define refine the L1B processor and the retrackers for alti-hydrology applications, we need to characterise the SARM Individual Echoes, Multi- Look Stacks as well as 20Hz waveforms over the inland water domain.This paper deals with the continuation of works presented in 2015 [Fabry et Bercher, Venice 2015b] [Fabry et Bercher, Frascati 2015a/c] where we introduced an automated technique to assess the water fraction within the Beam-Doppler limited footprint through its intersection area with a water mask. We hereby refine the utilisation of these water classes and run the classification on a wider dataset so as to improve the readout of the Range Integrated Power1 (RIP) parameters and the waveforms versus the Water Fraction.
ERIC Educational Resources Information Center
Meyer, Mary C.
2006-01-01
From a very young age, shoes for boys tend to be wider than shoes for girls. Is this because boys have wider feet, or because it is assumed that girls are willing to sacrifice comfort for fashion, even in elementary school? To assess the former, a statistician measures kids' feet. (Contains 2 tables and 3 figures.)
Towards a Standardized Line List for G 191-B2B and other DA Type Objects
NASA Astrophysics Data System (ADS)
Preval, S. P.; Barstow, M. A.; Holberg, J. B.; Dickinson, N. J.
2013-01-01
We present a comprehensive analysis of the far UV spectrum of G 191-B2B over the range of 900-1700Å using co-added data from the FUSE and STIS archives. While previous identifications made by Holberg et al. (2003) are reaffirmed in this work, it is found that many previously unidentified lines can now be attributed to Fe, Ni, and a few lighter metals. Future work includes extending this detailed analysis to a wider range of DA objects, in the expectation that a more complete analysis of their atmospheres can be realised.
Practical problems which women encounter with available contraception in Australia.
Weisberg, E
1994-06-01
Australian women face major difficulties with contraception because of the limited range of choices, the need for meticulous attention to compliance with most available methods and because of cost limitations for a significant minority of the population. The most commonly used methods are oral contraceptive pills and barrier methods, and each has substantial compliance problems which can be minimized with care and counselling. There is an urgent need for a wider range of options in Australia and for good information and publicity about them. Present progress in this direction gives some hope for the near future.
NASA Astrophysics Data System (ADS)
Bodryakov, V. Yu.; Bykov, A. A.
2016-05-01
The correlation between the volumetric thermal expansion coefficient β( T) and the heat capacity C( T) of aluminum is considered in detail. It is shown that a clear correlation is observed in a significantly wider temperature range, up to the melting temperature of the metal, along with the low-temperature range where it is linear. The significant deviation of dependence β( C) from the low-temperature linear behavior is observed up to the point where the heat capacity achieves the classical Dulong-Petit limit of 3 R ( R is the universal gas constant).
Wealth generation through recycling of material for reuse
NASA Astrophysics Data System (ADS)
Chukwudum, Okechukw John; Patience I., E.
2018-06-01
Management of solid waste needs appropriate technology, which is economically affordable, socially accepted and environmentally friendly. The public needs to be sensitized on the potential wealth that their inorganic and organic wastes contain. The paper deals with the idea of recycling as a means of solid waste treatment and explores. In developing countries, where standards are often lower and raw materials very expensive, there is a wider scope for use of recycled material. The range of products varies from building materials to shoes, home to office equipment, sewage pipe to beauty aids. Recyclingand reuse issues overlap a range of disciplines.
Design and development of high frequency matrix phased-array ultrasonic probes
NASA Astrophysics Data System (ADS)
Na, Jeong K.; Spencer, Roger L.
2012-05-01
High frequency matrix phased-array (MPA) probes have been designed and developed for more accurate and repeatable assessment of weld conditions of thin sheet metals commonly used in the auto industry. Unlike the line focused ultrasonic beam generated by a linear phased-array (LPA) probe, a MPA probe can form a circular shaped focused beam in addition to the typical beam steering capabilities of phased-array probes. A CIVA based modeling and simulation method has been used to design the probes in terms of various probe parameters such as number of elements, element size, overall dimensions, frequency etc. Challenges associated with the thicknesses of thin sheet metals have been resolved by optimizing these probe design parameters. A further improvement made on the design of the MPA probe proved that a three-dimensionally shaped matrix element can provide a better performing probe at a much lower probe manufacturing cost by reducing the total number of elements and lowering the operational frequency. This three dimensional probe naturally matches to the indentation shape of the weld on the thin sheet metals and hence a wider inspection area with the same level of spatial resolution obtained by a twodimensional flat MPA probe operating at a higher frequency. The two aspects, a wider inspection area and a lower probe manufacturing cost, make this three-dimensional MPA sensor more attractive to auto manufacturers demanding a quantitative nondestructive inspection method.
Typlt, Marei; Englitz, Bernhard; Sonntag, Mandy; Dehmel, Susanne; Kopp-Scheinpflug, Cornelia; Ruebsamen, Rudolf
2012-01-01
Multiple parallel auditory pathways ascend from the cochlear nucleus. It is generally accepted that the origin of these pathways are distinct groups of neurons differing in their anatomical and physiological properties. In extracellular in vivo recordings these neurons are typically classified on the basis of their peri-stimulus time histogram. In the present study we reconsider the question of classification of neurons in the anteroventral cochlear nucleus (AVCN) by taking a wider range of response properties into account. The study aims at a better understanding of the AVCN's functional organization and its significance as the source of different ascending auditory pathways. The analyses were based on 223 neurons recorded in the AVCN of the Mongolian gerbil. The range of analysed parameters encompassed spontaneous activity, frequency coding, sound level coding, as well as temporal coding. In order to categorize the unit sample without any presumptions as to the relevance of certain response parameters, hierarchical cluster analysis and additional principal component analysis were employed which both allow a classification on the basis of a multitude of parameters simultaneously. Even with the presently considered wider range of parameters, high number of neurons and more advanced analytical methods, no clear boundaries emerged which would separate the neurons based on their physiology. At the current resolution of the analysis, we therefore conclude that the AVCN units more likely constitute a multi-dimensional continuum with different physiological characteristics manifested at different poles. However, more complex stimuli could be useful to uncover physiological differences in future studies. PMID:22253838
Gaidajis, George
2003-01-01
To assess ambient air quality at the wider area of TVX Hellas mining facilities, the Total Suspended Particulate matter (TSP) and its content in characteristic elements, i.e., As, Cd, Cu, Fe, Mn, Pb, Zn are being monitored for more than thirty months as part of the established Environmental Monitoring Program. High Volume air samplers equipped with Tissue Quartz filters were employed for the collection of TSP. Analyses were effected after digestion of the suspended particulate with an HNO3-HCl solution and determination of elemental concentrations with an Atomic Absorption Spectroscopy equipped with graphite furnace. The sampling stations were selected to record representatively the existing ambient air quality in the vicinity of the facilities and at remote sites not affected from industrial activities. Monitoring data indicated that the background TSP concentrations ranged from 5-60 microg/m3. Recorded TSP concentrations at the residential sites close to the facilities ranged between 20-100 microg/m3, indicating only a minimal influence from the mining and milling activities. Similar spatial variation was observed for the TSP constituents and specifically for Pb and Zn. To validate the monitoring procedures, a parallel sampling campaign took place with different High Volume samplers at days where low TSP concentrations were expected. The satisfactory agreement (+/- 11%) at low concentrations (50-100 microg/m3) clearly supported the reproducibility of the techniques employed specifically at the critical range of lower concentrations.
Meningitis in HIV-positive patients in sub-Saharan Africa: a review
Veltman, Jennifer A; Bristow, Claire C; Klausner, Jeffrey D
2014-01-01
Introduction Meningitis is one of the leading causes of death among patients living with HIV in sub-Saharan Africa. There is no widespread tracking of the incidence rates of causative agents among patients living with HIV, yet the aetiologies of meningitis are different than those of the general population. Methods We reviewed the scientific literature published in PubMed to determine the incidence rates of meningitis among hospitalized people living with HIV in sub-Saharan Africa and report our findings from seven studies across sub-Saharan Africa. Results We found high rates of cryptococcal meningitis (19–68%). Tuberculous meningitis was lower (1–36%), although some centres included possible cases as “other” meningitis; therefore, this may not be a true representation of the total cases. Pyogenic meningitis ranged from 6 to 30% and “other” meningitis ranged from 7 to 28% of all reported cases of meningitis. Mortality rates ranged from 25 to 68%. This review describes the most common aetiologies and provides practical diagnostic, treatment and prevention considerations as they apply to the individual living with HIV in sub-Saharan Africa. Conclusions Diagnosis is often limited, and wider availability of accurate and low-cost laboratory diagnostics is desperately needed for prompt diagnosis and initiation of appropriate treatment. Wider acceptance and adoption of available preventative modalities can decrease the incidence of potentially fatal central nervous system infections in African patients living with HIV. PMID:25308903
Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-22
... shape. Such fruit, if it is wider than it is tall, is considered to be badly misshapen. Identification... the current parameters for misshapen fruit; from ``fruit that is not wider than tall'' to fruit that is a certain percentage wider than it is tall. This alternative would allow for flatter/wider fruit...
Evaluating the Wider Outcomes of Schools: Complex Systems Modelling for Leadership Decisioning
ERIC Educational Resources Information Center
Crick, Ruth Deakin; Barr, Steven; Green, Howard; Pedder, David
2017-01-01
A continuing challenge for the education system is how to evaluate the wider outcomes of schools. Wider measures of success--such as citizenship or lifelong learning--influence each other and emerge over time from complex interactions between students, teachers and leaders, and the wider community. Unless methods are found to evaluate these…
Custom Unit Pump Design and Testing for the EVA PLSS
NASA Technical Reports Server (NTRS)
Schuller, Michael; Kurwitz, Cable; Goldman, Jeff; Morris, Kim; Trevino, Luis
2009-01-01
This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design and test a pre-flight prototype pump for use in the Extra-vehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump must accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting non-condensable gas without becoming air locked. The chosen pump design consists of a 28 V DC, brushless, sealless, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. Although the planned flight unit will use a sensorless motor with custom designed controller, the pre-flight prototype to be provided for this project incorporates Hall effect sensors, allowing an interface with a readily available commercial motor controller. This design approach reduced the cost of this project and gives NASA more flexibility in future PLSS laboratory testing. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES verified that the pump meets the design requirements for range of flow rates, pressure drop, power consumption, working fluid temperature, operating time, gas ingestion , and restart capability under both ambient and vacuum conditions. The pump operated between 40 and 240 lbm/hr flowrate, 35 to 100 F pump temperature range, and 5 to 10 psid pressure rise. Power consumption of the pump controller at the nominal operating point in both ambient and vacuum conditions was 9.5 W, which was less than the 12 W predicted. Gas ingestion capabilities were tested by injecting 100 cc of air into the fluid line; the pump operated normally throughout this test. The test results contained a number of anomalies, specifically power increases and a few flow stoppages, that prompted TEES and Honeywell to disassemble and inspect the pump. Inspection indicated contamination in the pump and fit issues may have played roles in the observed anomalies. Testing following reassembly indicated that the performance of the pump 1) matched both the predicted performance values, 2) the performance values measured prior to disassembly, and 3) was free of the anomalies noted in the pre-disassembly testing.
NASA Astrophysics Data System (ADS)
Klein, Laura M.; McNamara, Laura A.
2017-05-01
In this paper, we address the needed components to create usable engineering and operational user interfaces (UIs) for airborne Synthetic Aperture Radar (SAR) systems. As airborne SAR technology gains wider acceptance in the remote sensing and Intelligence, Surveillance, and Reconnaissance (ISR) communities, the need for effective and appropriate UIs to command and control these sensors has also increased. However, despite the growing demand for SAR in operational environments, the technology still faces an adoption roadblock, in large part due to the lack of effective UIs. It is common to find operational interfaces that have barely grown beyond the disparate tools engineers and technologists developed to demonstrate an initial concept or system. While sensor usability and utility are common requirements to engineers and operators, their objectives for interacting with the sensor are different. As such, the amount and type of information presented ought to be tailored to the specific application.
Brea-Rivero, Pilar; Herrera-Usagre, Manuel; Rojas-de-Mora-Figueroa, Ana; Esposito, Thomas
2016-01-01
. The accreditation of professional competence: the analysis of nursing interventions to control anxiety in surgical patients. The preoperative anxiety is a state of discomfort or unpleasant tension resulting from concerns about illness, hospitalization, anesthesia, surgery or the unknown. Nurses play a vital role reducing preoperative anxiety. An accreditation program was developed in Andalusia (Spain) to measure nurses' competences in this and others fields. To analyze the accredited nurses' interventions spectrum to reduce anxiety in surgical patients and to check if their range of interventions depends upon their professional skills accreditation level. Cross-sectional study. From 20016 to 2014, 1.282 interventions performed by 303 operating room nurses accredited through the Professional Skills Accreditation Program of the Andalusian Agency for Health Care Quality (ACSA) were analyzed with the latent class analysis (LCA) and multinomial logistic regression. Two-thirds of the sample was accredited in Advanced level, about 31% in Expert level and 2.6% in Excellent level. Mean age of patients was 58.5±19.8 years. Three professional profiles were obtained from the LCA. Those nurses classified in Class I (22.4% of the sample) were more likely to be women, to can for younger patients, and to be accredited in Expert or Excellent Level and to perform the larger range of interventions, becoming therefore the most complete professional profile. Those nurses who perform a wider range of interventions and specifically two evidence based interventions such Calming Technique and Coping Enhancement are those who have a higher level of accreditation level.
Online Analysis of Wind and Solar Part II: Transmission Tool
DOE Office of Scientific and Technical Information (OSTI.GOV)
Makarov, Yuri V.; Etingov, Pavel V.; Ma, Jian
2012-01-31
To facilitate wider penetration of renewable resources without compromising system reliability concerns arising from the lack of predictability of intermittent renewable resources, a tool for use by California Independent System Operator (CAISO) power grid operators was developed by Pacific Northwest National Laboratory (PNNL) in conjunction with CAISO with funding from California Energy Commission. The tool analyzes and displays the impacts of uncertainties in forecasts of loads and renewable generation on: (1) congestion, (2)voltage and transient stability margins, and (3)voltage reductions and reactive power margins. The impacts are analyzed in the base case and under user-specified contingencies.A prototype of the toolmore » has been developed and implemented in software.« less
[Standardization of operation monitoring and control of the clinical laboratory automation system].
Tao, R
2000-10-01
Laboratory automation systems showed up in the 1980s and have been introduced to many clinical laboratories since early 1990s. Meanwhile, it was found that the difference in the specimen tube dimensions, specimen identification formats, specimen carrier transportation equipment architecture, electromechanical interfaces between the analyzers and the automation systems was preventing the systems from being introduced to a wider extent. To standardize the different interfaces and reduce the cost of laboratory automation, NCCLS and JCCLS started establishing standards for laboratory automation in 1996 and 1997 respectively. Operation monitoring and control of the laboratory automation system have been included in their activities, resulting in the publication of an NCCLS proposed standard in 1999.
Zulu, Halalisani Goodman; Mewa Kinoo, Suman; Singh, Bhugwan
2016-07-01
Ours was a retrospective chart review of all elective open inguinal hernia repairs performed in a single unit at King Edward VIII Hospital, South Africa over an 18-month period. Comparison was made regarding duration of operation, length of hospital stay and complications such as pain, haematoma formation and recurrence between the Lichtenstein and Desarda techniques. The latter was noted to have a shorter operative time and avoided cost and possible complications of mesh usage, which are significant in resource-deprived settings. A larger comparative study with longer follow-up is needed to evaluate the wider suitability of the Desarda repair. © The Author(s) 2016.
Sim, Jae-Ang; Kim, Jong-Min; Lee, Sahnghoon; Bae, Ji-Yong; Seon, Jong-Keun
2017-04-01
Although trans-portal and outside-in techniques are commonly used for anatomical ACL reconstruction, there is very little information on variability in tunnel placement between two techniques. A total of 103 patients who received ACL reconstruction using trans-portal (50 patients) and outside-in techniques (53 patients) were included in the study. The ACL tunnel location, length and graft-femoral tunnel angle were analyzed using the 3D CT knee models, and we compared the location and length of the femoral and tibial tunnels, and graft bending angle between the two techniques. The variability in each technique regarding the tunnel location, length and graft tunnel angle using the range values was also compared. There were no differences in the average of femoral tunnel depth and height between the two groups. The ranges of femoral tunnel depth and height showed no difference between two groups (36 and 41 % in trans-portal technique vs. 32 and 41 % in outside-in technique). The average value and ranges of tibial tunnel location also showed similar results in two groups. The outside-in technique showed longer femoral tunnel than the trans-portal technique (34.0 vs. 36.8 mm, p = 0.001). The range of femoral tunnel was also wider in trans-portal technique than in outside-in technique. Although the outside-in technique showed significant acute graft bending angle than trans-portal technique in average values, the trans-portal technique showed wider ranges in graft bending angle than outside-in technique [ranges 73° (SD 13.6) vs. 53° (SD 10.7), respectively]. Although both trans-portal and outside-in techniques in ACL reconstruction can provide relatively consistent in femoral and tibial tunnel locations, trans-portal technique showed high variability in femoral tunnel length and graft bending angles than outside-in technique. Therefore, the outside-in technique in ACL reconstruction is considered as the effective method for surgeons to make more consistent femoral tunnel. III.
Application of TOPEX/Poseidon altimetry to ocean dynamics and geophysics
NASA Technical Reports Server (NTRS)
Douglas, Bruce; Cheney, R.; Miller, L.; Mcadoo, D.; Leetmaa, A.; Schopf, P.; Schwiderski, E. W.
1991-01-01
We will analyze the TOPEX/POSEIDON data using techniques developed for Geosat, although the more accurate TOPEX/POSEIDON data will enable a wider range of problems to be addressed. Our proposed investigations will have five distinct areas: (1) a description of global sea level variability; (2) tropical ocean dynamics; (3) coupled models for El Nino prediction; (4) structure of the lithosphere; and (5) global tide model improvement.
ERIC Educational Resources Information Center
Briggs, Lianne
2012-01-01
Despite retention being a significant focus of higher education research, graduation rates remain of concern. Increased numbers of students are advancing to college bringing with them a wider range of abilities, attributes, and characteristics. There is much we know about what predicts success for these students but our knowledge is far from…
The Case of Perrin and Thomson: An Example of the Use of a Mini-Corpus
ERIC Educational Resources Information Center
Banks, David
2005-01-01
Although recent trends have been towards large corpora, there is a valid place for the study of small corpora. This article is an example of one such study using a corpus of late 19th century texts, consisting of 1783 words in French by Perrin, and 2824 words in English by Thomson. Perrin uses more first person pronouns in a wider range of…
Children's Responses to Line Spacing in Early Reading Books or "Holes to Tell Which Line You're On"
ERIC Educational Resources Information Center
Reynolds, Linda; Walker, Sue; Duncan, Alison
2006-01-01
This paper describes a study designed to find out whether children's reading would be affected by line spacing that is wider or narrower than the commonly used default values. The realistic, high quality test material was set using a range of four different line spacing values, and twenty-four children in Years 1 and 2 (between five and seven…
ERIC Educational Resources Information Center
Angouri, Jo
2010-01-01
The current international nature of socio-economic activities is reshaping workplace settings and creating the need for large numbers of employees to perform successful communicative acts with a wider range of interactants than in the past, often using a language other than their mother tongue. Against this backdrop much emphasis has been placed…
ERIC Educational Resources Information Center
Kimitris, Petros N.
2017-01-01
The present study was designed to explore the role of history school books in evaluating the experience of a nation but also to examine the causes behind the reactions of political parties, historians and the wider public. Depending on the sociohistorical context, the aims of history education may range from the inculcation of national identity to…
ERIC Educational Resources Information Center
Feinstein, Leon; Hammond, Cathie; Woods, Laura; Preston, John; Bynner, John
Researchers investigated effects of adult learning (AL) on a range of measures of health and social capital and cohesion. Data from the National Child Development Study relating to almost 10,000 adults born in Britain in 1958 were used, with focus on changes in their lives between age 33 in 1991 and 42 in 2000. Findings indicated AL played an…
Nanocrystal thin film fabrication methods and apparatus
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kagan, Cherie R.; Kim, David K.; Choi, Ji-Hyuk
Nanocrystal thin film devices and methods for fabricating nanocrystal thin film devices are disclosed. The nanocrystal thin films are diffused with a dopant such as Indium, Potassium, Tin, etc. to reduce surface states. The thin film devices may be exposed to air during a portion of the fabrication. This enables fabrication of nanocrystal-based devices using a wider range of techniques such as photolithography and photolithographic patterning in an air environment.
Thermal dependence of cardiac function in arctic fish: implications of a warming world.
Franklin, Craig E; Farrell, Anthony P; Altimiras, Jordi; Axelsson, Michael
2013-11-15
With the Arctic experiencing one of the greatest and most rapid increases in sea temperatures in modern time, predicting how Arctic marine organisms will respond to elevated temperatures has become crucial for conservation biology. Here, we examined the thermal sensitivity of cardiorespiratory performance for three closely related species of sculpins that inhabit the Arctic waters, two of which, Gymnocanthus tricuspis and Myoxocephalus scorpioides, have adapted to a restricted range within the Arctic, whereas the third species, Myoxocephalus scorpius, has a wider distribution. We tested the hypothesis that the fish restricted to Arctic cold waters would show reduced cardiorespiratory scope in response to an increase in temperature, as compared with the more eurythermal M. scorpius. As expected from their biogeography, M. scorpioides and G. tricuspis maximised cardiorespiratory performance at temperatures between 1 and 4°C, whereas M. scorpius maximised performance over a wider range of temperatures (1-10°C). Furthermore, factorial scope for cardiac output collapsed at elevated temperature for the two high-latitude species, negatively impacting their ability to support aerobically driven metabolic processes. Consequently, these results concurred with our hypothesis, suggesting that the sculpin species restricted to the Arctic are likely to be negatively impacted by increases in ocean temperatures.
Growth-direction dependence of steady-state Saffman-Taylor flow in an anisotropic Hele-Shaw cell
DOE Office of Scientific and Technical Information (OSTI.GOV)
McCloud, K.V.; Maher, J.V.
1996-08-01
Selection of steady-state fingers has been measured in a Hele-Shaw cell perturbed by having a square lattice etched onto one of the plates. Flows at different orientations {theta} between the direction of flow and the lattice axes have been studied, in a wide range of observable tip velocities where the perturbation was made microscopic in the sense that the capillary length of the flow was much greater than the etched lattice cell size. The full range of dynamically interesting angles for the square lattice was examined, and above a threshold, the microscopic perturbation always results in wider fingers than aremore » selected in the unperturbed case. There is some dependence of the width of the fingers on the orientation of the flow, with fingers at {theta}=0{degree} being the widest with respect to the unperturbed fingers, and fingers at 45{degree} being the least wide, although still wider than the unperturbed fingers. All observed solutions are symmetric, centered in the channel, and have the relation between tip-curvature and finger width expected of members of the Saffman-Taylor family of solutions. Selected solutions narrow again at tip velocities where the perturbation can no longer be considered microscopic. {copyright} {ital 1996 The American Physical Society.}« less
Identifying future models for delivering genetic services: a nominal group study in primary care
Elwyn, Glyn; Edwards, Adrian; Iredale, Rachel; Davies, Peter; Gray, Jonathon
2005-01-01
Background To enable primary care medical practitioners to generate a range of possible service delivery models for genetic counselling services and critically assess their suitability. Methods Modified nominal group technique using in primary care professional development workshops. Results 37 general practitioners in Wales, United Kingdom too part in the nominal group process. The practitioners who attended did not believe current systems were sufficient to meet anticipated demand for genetic services. A wide range of different service models was proposed, although no single option emerged as a clear preference. No argument was put forward for genetic assessment and counselling being central to family practice, neither was there a voice for the view that the family doctor should become skilled at advising patients about predictive genetic testing and be able to counsel patients about the wider implications of genetic testing for patients and their family members, even for areas such as common cancers. Nevertheless, all the preferred models put a high priority on providing the service in the community, and often co-located in primary care, by clinicians who had developed expertise. Conclusion There is a need for a wider debate about how healthcare systems address individual concerns about genetic concerns and risk, especially given the increasing commercial marketing of genetic tests. PMID:15831099
Zarotti, Nicolò; Simpson, Jane; Fletcher, Ian
2017-01-01
Objectives This study explored the perspectives of people affected by Huntington's disease (HD) on their own communicative abilities. Methods Qualitative semi-structured interviews were carried out with eight people with early HD. The data were analysed through thematic analysis. Results Four themes were constructed from the data, characterised by the following core topics: How HD directs and mediates communication; Regaining control to improve communication; Emotional outflows into communication and the struggle for separation; Sheltering as a way to boost confidence in communication. Discussion Separating patients' identity as individuals from that of a person with a disease can help increase communicative control. Consistent with the general theory and model of self-regulation, patients should be allowed a wider range of choices to regain control over communication. Achieving better emotion regulation is of paramount importance for communication, and factors such as medication regimes, relationships and existing coping strategies should be strengthened. Consistent with previous research, feelings of safety and the idea of a safe place ('sheltering') represent an effective coping mechanism. Practical implications include the refinement of communication and relationships among clinicians, caregivers, and patients with HD by considering a wider range of medical, psychological and socio-environmental factors.
Blind Spectroscopic Galaxy Surveys Using an Ultra-Wide-Band Imaging Spectrograph on AtLAST and LST
NASA Astrophysics Data System (ADS)
Kohno, Kotaro
2018-01-01
A novel approach to elucidation of cosmic star formation history is a blind search for CO and [CII] emissions using a ultra-wide-band imaging spectrograph on the future large submm telescopes like AtLAST and LST. In particular, searching for [CII] emitters in the appropriate frequency range allows us to sample those sources very efficiently for a redshift range of 3.5 to 9 (190 to 420 GHz), reaching the star-formation in the EoR. Further, spectroscopic analysis of CO in the lower frequency bands will constrain the evolution of CO luminosity functions across cosmic time. We conducted a feasibility study of ``CO/[CII] tomography'' based on a mock galaxy catalog containing 1.4 million objects drawn from the S(3) -SAX (Obreschkow et al. 2009). We find that a blind spectroscopic survey using a 50-m telescope equipped with a 100-pixel imaging spectrograph, which covers 70-370 GHz simultaneously, will be promising indeed. A survey of 2 deg(2) in 1,000 hr (on-source) will uncover > 10^5 line-emitting galaxies in total, including 10^3 [CII] emitters in the EoR (Tamura et al., in prep.). Wider surveys (10 deg^2 or wider) will also be discussed for RSD science cases.
Kostrzewski, Tomasz; Sceats, Emma L
2017-01-01
Liver disease represents a growing global health burden. The development of in vitro liver models which allow the study of disease and the prediction of metabolism and drug-induced liver injury in humans remains a challenge. The maintenance of functional primary hepatocytes cultures, the parenchymal cell of the liver, has historically been difficult with dedifferentiation and the consequent loss of hepatic function limiting utility. The desire for longer term functional liver cultures sparked the development of numerous systems, including collagen sandwiches, spheroids, micropatterned co-cultures and liver microphysiological systems. This review will focus on liver microphysiological systems, often referred to as liver-on-a-chip, and broaden to include platforms with interconnected microphysiological systems or multi-organ-chips. The interconnection of microphysiological systems presents the opportunity to explore system level effects, investigate organ cross talk, and address questions which were previously the preserve of animal experimentation. As a field, microphysiological systems have reached a level of maturity suitable for commercialization and consequent evaluation by a wider community of users, in academia and the pharmaceutical industry. Here scientific, operational, and organizational considerations relevant to the wider adoption of microphysiological systems will be discussed. Applications in which microphysiological systems might offer unique scientific insights or enable studies currently feasible only with animal models are described, and challenges which might be addressed to enable wider adoption of the technologies are highlighted. A path forward which envisions the development of microphysiological systems in partnerships between academia, vendors and industry, is proposed. Impact statement Microphysiological systems are in vitro models of human tissues and organs. These systems have advanced rapidly in recent years and are now being commercialized. To achieve wide adoption in the biological and pharmaceutical research communities, microphysiological systems must provide unique insights which translate to humans. This will be achieved by identifying key applications and making microphysiological systems intuitive to use. PMID:28504617
Hughes, David J; Kostrzewski, Tomasz; Sceats, Emma L
2017-10-01
Liver disease represents a growing global health burden. The development of in vitro liver models which allow the study of disease and the prediction of metabolism and drug-induced liver injury in humans remains a challenge. The maintenance of functional primary hepatocytes cultures, the parenchymal cell of the liver, has historically been difficult with dedifferentiation and the consequent loss of hepatic function limiting utility. The desire for longer term functional liver cultures sparked the development of numerous systems, including collagen sandwiches, spheroids, micropatterned co-cultures and liver microphysiological systems. This review will focus on liver microphysiological systems, often referred to as liver-on-a-chip, and broaden to include platforms with interconnected microphysiological systems or multi-organ-chips. The interconnection of microphysiological systems presents the opportunity to explore system level effects, investigate organ cross talk, and address questions which were previously the preserve of animal experimentation. As a field, microphysiological systems have reached a level of maturity suitable for commercialization and consequent evaluation by a wider community of users, in academia and the pharmaceutical industry. Here scientific, operational, and organizational considerations relevant to the wider adoption of microphysiological systems will be discussed. Applications in which microphysiological systems might offer unique scientific insights or enable studies currently feasible only with animal models are described, and challenges which might be addressed to enable wider adoption of the technologies are highlighted. A path forward which envisions the development of microphysiological systems in partnerships between academia, vendors and industry, is proposed. Impact statement Microphysiological systems are in vitro models of human tissues and organs. These systems have advanced rapidly in recent years and are now being commercialized. To achieve wide adoption in the biological and pharmaceutical research communities, microphysiological systems must provide unique insights which translate to humans. This will be achieved by identifying key applications and making microphysiological systems intuitive to use.
A monostable piezoelectric energy harvester for broadband low-level excitations
NASA Astrophysics Data System (ADS)
Fan, Kangqi; Tan, Qinxue; Zhang, Yiwei; Liu, Shaohua; Cai, Meiling; Zhu, Yingmin
2018-03-01
This letter presents a monostable piezoelectric energy harvester (PEH) for achieving enhanced energy extraction from low-level excitations. The proposed PEH is realized by introducing symmetric magnetic attraction to a piezoelectric cantilever beam and a pair of stoppers to confine the maximum deflection of the beam. The lumped parameter model of such a system is presented and experimentally validated. Theoretical simulations and experimental measurements demonstrate that the proposed design can bring about a wider operating bandwidth and higher output voltage than the linear PEH. Under a sinusoidal vibration with an amplitude of 3 m/s2, a 54% increase in the operating bandwidth and a 253% increase in the magnitude of output power are achieved compared to its linear counterpart. Moreover, the proposed PEH exhibits rich dynamic features, including the tunable operating bandwidth, adjustable voltage and power levels, and softening hysteresis.
Stafrace, Simon; Lilly, Alan
2008-08-01
This case study demonstrates how leadership was harnessed to turn around a decline in the performance of an aged persons' mental health service - the Namarra Nursing Home at Caulfield General Medical Centre in Melbourne, Australia. In 2000 the nursing home faced a crisis of public confidence due to failings in the management of quality, clinical risk and human resources within the service. These problems reflected structural and operational shortcomings in the clinical directorate and wider organisation. In this article, we detail the process of turnaround from the perspective of senior executive managers with professional and operational responsibility for the service. This turnaround required attention to local clinical accountability and transformation of the mental health program from a collocated but operationally isolated service to one integrated within the governance structures of the auspicing organisation.
Is the NIHSS Certification Process Too Lenient?
Hills, Nancy K.; Josephson, S. Andrew; Lyden, Patrick D.; Johnston, S. Claiborne
2009-01-01
Background and Purpose The National Institutes of Health Stroke Scale (NIHSS) is a widely used measure of neurological function in clinical trials and patient assessment; inter-rater scoring variability could impact communications and trial power. The manner in which the rater certification test is scored yields multiple correct answers that have changed over time. We examined the range of possible total NIHSS scores from answers given in certification tests by over 7,000 individual raters who were certified. Methods We analyzed the results of all raters who completed one of two standard multiple-patient videotaped certification examinations between 1998 and 2004. The range for the correct score, calculated using NIHSS ‘correct answers’, was determined for each patient. The distribution of scores derived from those who passed the certification test then was examined. Results A total of 6,268 raters scored 5 patients on Test 1; 1,240 scored 6 patients on Test 2. Using a National Stroke Association (NSA) answer key, we found that correct total scores ranged from 2 correct scores to as many as 12 different correct total scores. Among raters who achieved a passing score and were therefore qualified to administer the NIHSS, score distributions were even wider, with 1 certification patient receiving 18 different correct total scores. Conclusions Allowing multiple acceptable answers for questions on the NIHSS certification test introduces scoring variability. It seems reasonable to assume that the wider the range of acceptable answers in the certification test, the greater the variability in the performance of the test in trials and clinical practice by certified examiners. Greater consistency may be achieved by deriving a set of ‘best’ answers through expert consensus on all questions where this is possible, then teaching raters how to derive these answers using a required interactive training module. PMID:19295205
Joukainen, Antti; Kröger, Heikki; Niemitukia, Lea; Mäkelä, E. Antero; Väätäinen, Urho
2014-01-01
Background: The optimal treatment of acute, complete dislocation of the acromioclavicular joint (ACJ) is still unresolved. Purpose: To determine the difference between operative and nonoperative treatment in acute Rockwood types III and V ACJ dislocation. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: In the operative treatment group, the ACJ was reduced and fixed with 2 transarticular Kirschner wires and ACJ ligament suturing. The Kirschner wires were extracted after 6 weeks. Nonoperatively treated patients received a reduction splint for 4 weeks. At the 18- to 20-year follow-up, the Constant, University of California at Los Angeles Shoulder Rating Scale (UCLA), Larsen, and Simple Shoulder Test (SST) scores were obtained, and clinical and radiographic examinations of both shoulders were performed. Results: Twenty-five of 35 potential patients were examined at the 18- to 20-year follow-up. There were 11 patients with Rockwood type III and 14 with type V dislocations. Delayed surgical treatment for ACJ was used in 2 patients during follow-up: 1 in the operatively treated group and 1 in the nonoperatively treated group. Clinically, ACJs were statistically significantly less prominent or unstable in the operative group than in the nonoperative group (normal/prominent/unstable: 9/4/3 and 0/6/3, respectively; P = .02) and in the operative type III (P = .03) but not type V dislocation groups. In operatively and nonoperatively treated patients, the mean Constant scores were 83 and 85, UCLA scores 25 and 27, Larsen scores 11 and 11, and SST scores 11 and 12 at follow-up, respectively. There were no statistically significant differences in type III and type V dislocations. In the radiographic analysis, the ACJ was wider in the nonoperative than the operative group (8.3 vs 3.4 mm; P = .004), and in the type V dislocations (nonoperative vs operative: 8.5 vs 2.4 mm; P = .007). There was no statistically significant difference between study groups in the elevation of the lateral end of the clavicle. Both groups showed equal levels of radiologic signs of ACJ osteoarthritis and calcification of the coracoclavicular ligaments. Conclusion: Nonoperative treatment was shown to produce more prominent or unstable and radiographically wider ACJs than was operative treatment, but clinical results were equally good in the study groups at 18- to 20-year follow-up. Both treatment methods showed statistically significant radiographic elevations of the lateral clavicle when compared with a noninjured ACJ. PMID:26535287
Endoscopy in neuro-otologic surgery.
Wackym, Phillip A; King, Wesley A; Meyer, Glenn A; Poe, Dennis S
2002-04-01
Endoscopy offers several distinct advantages over the operating microscope during neuro-otologic surgery that make it an excellent adjunctive tool to the microscope or independent modality during cranial base surgery. The high magnification gives excellent definition of perforating blood vessels, cranial nerves, and neural structures, which in many cases is superior to that achieved with the microscope. Furthermore, the use of angled or flexible endoscopes allows one to look around corners and behind anatomic structures blocking the view seen via a 0 degree microscope. Endoscopy also has the theoretical advantage that a less invasive operative procedure is required, which should reduce the operative morbidity. Several notable disadvantages of endoscopy include the problems associated with blood soiling the endoscope, making visualization difficult or impossible, the lack of readily available instrumentation designed specifically for endoscopic neuro-otology, and the poor overview of the operative field. This last point is an important one because the endoscope is placed adjacent to the lesion and does not allow one to look backward to prevent [figure: see text] injury to structures next to the shaft of the telescope. Furthermore, the surgeon must be cognizant of potential thermal injury to structures caused by the heat generated by the light source. The present endoscopic technology limits the image that the surgeon sees to two dimensions, which results in certain unique problems when operating in a three-dimensional milieu. Because of this, there is a steep learning curve to acquire endoscopic dexterity and three-dimensional orientation. Finally, bimanual operation requires the use of an articulated endoscope holder or the commitment of the co-surgeon to hold the endoscope. One of the limitations of the operative microscope is that the angle of view is determined by the distance of the lens to the skull, retractor, or obstructing tissue, which is a function of the lens focal length; the longer the focal length, the narrower the viewing angle. During most microsurgical procedures, the focal distance varies between 200 and 400 mm. Using a previous analogy, if one looks through a door's keyhole at close range, nearly the entire room on the opposite side of the door can be seen, although nothing can be seen when the hole is viewed from a long distance. This is similar to what happens when using the endoscope with focal lengths ranging from 5 to 20 mm: a wider angle of view can be achieved. Based on their, experience the authors believe that endoscopes can be used safely during neuro-otologic surgery. As an adjunct to or substitution for the operative microscope, this modality does improve visualization of bony, neural, and vascular structures while minimizing cerebellar retraction.
Abdelgaied, Abdellatif; Fisher, John; Jennings, Louise M
2017-07-01
More robust preclinical experimental wear simulation methods are required in order to simulate a wider range of activities, observed in different patient populations such as younger more active patients, as well as to fully meet and be capable of going well beyond the existing requirements of the relevant international standards. A new six-station electromechanically driven simulator (Simulation Solutions, UK) with five fully independently controlled axes of articulation for each station, capable of replicating deep knee bending as well as other adverse conditions, which can be operated in either force or displacement control with improved input kinematic following, has been developed to meet these requirements. This study investigated the wear of a fixed-bearing total knee replacement using this electromechanically driven fully independent knee simulator and compared it to previous data from a predominantly pneumatically controlled simulator in which each station was not fully independently controlled. In addition, the kinematic performance and the repeatability of the simulators have been investigated and compared to the international standard requirements. The wear rates from the electromechanical and pneumatic knee simulators were not significantly different, with wear rates of 2.6 ± 0.9 and 2.7 ± 0.9 mm 3 /million cycles (MC; mean ± 95% confidence interval, p = 0.99) and 5.4 ± 1.4 and 6.7 ± 1.5 mm 3 /MC (mean ± 95 confidence interval, p = 0.54) from the electromechanical and pneumatic simulators under intermediate levels (maximum 5 mm) and high levels (maximum 10 mm) of anterior-posterior displacements, respectively. However, the output kinematic profiles of the control system, which drive the motion of the simulator, followed the input kinematic profiles more closely on the electromechanical simulator than the pneumatic simulator. In addition, the electromechanical simulator was capable of following kinematic and loading input cycles within the tolerances of the international standard requirements (ISO 14243-3). The new-generation electromechanical knee simulator with fully independent control has the potential to be used for a much wider range of kinematic conditions, including high-flexion and other severe conditions, due to its improved capability and performance in comparison to the previously used pneumatic-controlled simulators.
Abdelgaied, Abdellatif; Fisher, John; Jennings, Louise M
2017-01-01
More robust preclinical experimental wear simulation methods are required in order to simulate a wider range of activities, observed in different patient populations such as younger more active patients, as well as to fully meet and be capable of going well beyond the existing requirements of the relevant international standards. A new six-station electromechanically driven simulator (Simulation Solutions, UK) with five fully independently controlled axes of articulation for each station, capable of replicating deep knee bending as well as other adverse conditions, which can be operated in either force or displacement control with improved input kinematic following, has been developed to meet these requirements. This study investigated the wear of a fixed-bearing total knee replacement using this electromechanically driven fully independent knee simulator and compared it to previous data from a predominantly pneumatically controlled simulator in which each station was not fully independently controlled. In addition, the kinematic performance and the repeatability of the simulators have been investigated and compared to the international standard requirements. The wear rates from the electromechanical and pneumatic knee simulators were not significantly different, with wear rates of 2.6 ± 0.9 and 2.7 ± 0.9 mm3/million cycles (MC; mean ± 95% confidence interval, p = 0.99) and 5.4 ± 1.4 and 6.7 ± 1.5 mm3/MC (mean ± 95 confidence interval, p = 0.54) from the electromechanical and pneumatic simulators under intermediate levels (maximum 5 mm) and high levels (maximum 10 mm) of anterior–posterior displacements, respectively. However, the output kinematic profiles of the control system, which drive the motion of the simulator, followed the input kinematic profiles more closely on the electromechanical simulator than the pneumatic simulator. In addition, the electromechanical simulator was capable of following kinematic and loading input cycles within the tolerances of the international standard requirements (ISO 14243-3). The new-generation electromechanical knee simulator with fully independent control has the potential to be used for a much wider range of kinematic conditions, including high-flexion and other severe conditions, due to its improved capability and performance in comparison to the previously used pneumatic-controlled simulators. PMID:28661228
Theory and Applications of Elliptically Contoured and Related Distributions
1990-09-01
is invariant under n x n orthogonal transfor- mations. When the parent distribution is more generally ECp(pA, X, 4), the c.f. of X is n E(eitrTIX...those properties to some wider class than that of SD? 18 A largest characterization of SD is a demonstration that there is no generating vector Y...Takemura’s Generalizations of Cochran’s Theorem," George P.H. Styan, September 1982. 3. " Some Further Applications of Finite Difference Operators," Kai
NASA Technical Reports Server (NTRS)
Dixon, G. V.; Barringer, S. R.; Gray, C. E.; Leatherman, A. D.
1975-01-01
Computer programs and resulting tabulations are presented of pipeline length-to-diameter ratios as a function of Mach number and pressure ratios for compressible flow. The tabulations are applicable to air, nitrogen, oxygen, and hydrogen for compressible isothermal flow with friction and compressible adiabatic flow with friction. Also included are equations for the determination of weight flow. The tabulations presented cover a wider range of Mach numbers for choked, adiabatic flow than available from commonly used engineering literature. Additional information presented, but which is not available from this literature, is unchoked, adiabatic flow over a wide range of Mach numbers, and choked and unchoked, isothermal flow for a wide range of Mach numbers.
Electron impact ionization from p-orbital targets
NASA Astrophysics Data System (ADS)
Saha, Bidhan; Basak, Arun K.; Alfaz Uddin, M.
2006-05-01
Electron impact ionization cross sections are evaluated using a modified version [1] of the BELL formula [2] for a wide range of isoelectronic targets, ranging from Li to Ne targets with both the open and closed shell configurations. In this report the MBELL parameters are generalized for treating the orbital quantum numbers nl dependency; its accuracy has been tested by evaluating cross sections for a wider range of species and energies. Details will be presented at the meeting. [1] A. K. F. Haque, M. A. Uddin, A. K. Basak, K. R. Karim and B. C. Saha, Phys. Rev. A73, 012708 (2005). [2] K. L. Bell, H. B. Gilbody, J. G. Hughes, A. E. Kingston, and F. J. Smith, J. Phys. Chem. Ref. Data 12, 891 (1983).
South Polar Cap Erosion and Aprons
NASA Technical Reports Server (NTRS)
2000-01-01
This scene is illuminated by sunlight from the upper left.
While Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images have shown that the north and south polar cap surfaces are very different from each other, one thing that the two have in common is that they both seem to have been eroded. Erosion in the north appears mostly to come in the form of pits from which ice probably sublimed to vapor and was transported away from the polar cap by wind. Erosion in the south takes on a wider range of possible processes that include collapse, slumping and mass-movement on slopes, and probably sublimation. Among the landforms created by these process on the south polar cap are the 'aprons' that surround mesas and buttes of remnant layers such as the two almost triangular features in the lower quarter of this image. The upper slopes of the two triangular features show a stair-stepped pattern that suggest these hills are layered.This image shows part of the south polar residual cap near 86.9oS, 78.5oW, and covers an area approximately 1.2 by 1.0 kilometers (0.7 x 0.6 miles) in size. The image has a resolution of 2.2 meters per pixel. The picture was taken on September 11, 1999.Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.NASA Astrophysics Data System (ADS)
Kondakov, D. Y.; Sandifer, J. R.; Tang, C. W.; Young, R. H.
2003-01-01
Organic light-emitting diodes (OLEDs) are attractive for display applications because of their high brightness, low driving voltage, and tunable color. Their operating lifetimes, hundreds or thousands of hours, are sufficient for only a limited range of applications. The luminance efficiency decreases gradually as the device is operated (electrically aged), for reasons that are poorly understood. A prototypical OLED has the structure anode|HTL|ETL|cathode, where the HTL and ETL are hole- and electron-transporting layers, and the recombination and emission occur at or near the HTL|ETL interface. We find that the decreasing luminance efficiency is linearly correlated with an accumulation of immobile positive charge at the HTL|ETL interface, and the magnitude of the charge is comparable to the total charge at that interface when an unaged device is operated. A natural explanation of the connection between the two phenomena is that electrical aging either generates hole traps (and trapped holes) or drives metal ions into the device, and that either species act as nonradiative recombination centers. To estimate the accumulating immobile charge and determine its location, we use a variant of a recently introduced capacitance versus voltage technique. In the prototypical OLEDs described here, the HTL is a ca. 1000 Å layer of NPB, and the ETL is a 300-1800 Å layer of Alq3. A device with an additional "emission layer" (EML) of an anthracene derivative between the HTL and ETL, in which the electroluminescence spectrum is characteristic of the EML, behaved similarly. We surmise that the phenomena reported here may be common to a wider variety of OLED structures and compositions.
Huang, Jinhai; Savini, Giacomo; Wu, Fan; Yu, Xinxin; Yang, Jing; Yu, Ayong; Yu, Ye; Wang, Qinmei
2015-10-01
To assess the precision of ocular biometry with a new noncontact optical low-coherence interferometer (Aladdin) in healthy subjects and patients with cataracts. Eye Hospital of Wenzhou Medical University, Wenzhou, China. Observational cross-sectional study. Eyes from healthy subjects and eyes from patients with cataracts were examined with the new interferometer. Axial length (AL), anterior chamber depth (ACD), keratometry (K), and white-to-white (WTW) values were measured by 2 operators. The test-retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability. Different-operator comparison was analyzed with paired t tests and Bland-Altman plots to assess interoperator reproducibility. Ninety-eight people were enrolled for this study, of which 52 eyes were from healthy subjects and 46 eyes were from patients with cataracts. The AL was the most repeatable and reproducible parameter. The ACD, K values, and WTW measurements were highly repeatable in healthy subjects with CoV less than 0.89% and ICC more than 0.94. However, in patients with cataracts, high repeatability could only be observed for AL, ACD, and K values, whereas WTW measurement had test-retest repeatability of 0.80 mm and an ICC of 0.795. Bland-Altman analysis also showed good agreement between the 2 operators for ocular component measurements, except that the WTW in patients with cataracts had wider 95% limits of agreement (range -0.88 to 0.95 mm). The new biometer showed excellent intraoperator repeatability and interoperator reproducibility for AL, ACD, and K values measurements in both groups. The precision of WTW measurements was lower in patients with cataracts. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Höhnle, H.; Stober, J.; Herrmann, A.; Kasparek, W.; Leuterer, F.; Monaco, F.; Neu, R.; Schmid-Lorch, D.; Schütz, H.; Schweinzer, J.; Stroth, U.; Wagner, D.; Vorbrugg, S.; Wolfrum, E.; ASDEX Upgrade Team
2011-08-01
ASDEX Upgrade has been operated with tungsten-coated plasma-facing components for several years. H-mode operation with good confinement has been demonstrated. Nevertheless, purely neutral beam injection-heated H-modes with reduced gas puff, moderate heating power or/and increased triangularity tend to accumulate tungsten, followed by a radiative collapse. Under these conditions, central electron heating with electron cyclotron resonance heating (ECRH), usually in X2 polarization, changes the impurity transport in the plasma centre, reducing the central tungsten concentration and, in many cases, stabilizing the plasma. In order to extend the applicability of central ECRH to a wider range of magnetic field and plasma current additional ECRH schemes with reduced single-pass absorption have been implemented: X3 heating allows us to reduce the magnetic field by 30%, such that the first H-modes with an ITER-like value of the safety factor of q95 = 3 could be run in the tungsten-coated device. O2 heating increases the cutoff density by a factor of 2 allowing higher currents and triangularities to be addressed. For both schemes, scenarios have been developed to cope with the associated reduced absorption. In the case of central X3 heating, the X2 resonance lies close to the pedestal top at the high-field side of the plasma, serving as a beam dump. For O2, holographic mirrors have been developed which guarantee a second pass through the plasma centre. The beam position on these reflectors is controlled by fast thermocouples. Stray-radiation protection has been implemented using sniffer probes.
NASA Astrophysics Data System (ADS)
Lyan, Oleg; Jankunas, Valdas; Guseinoviene, Eleonora; Pašilis, Aleksas; Senulis, Audrius; Knolis, Audrius; Kurt, Erol
2018-02-01
In this study, a permanent magnet synchronous generator (PMSG) topology with compensated reactance windings in parallel rod configuration is proposed to reduce the armature reactance X L and to achieve higher efficiency of PMSG. The PMSG was designed using iron-cored bifilar coil topology to overcome problems of market-dominant rotary type generators. Often the problem is a comparatively high armature reactance X L, which is usually bigger than armature resistance R a. Therefore, the topology is proposed to partially compensate or negligibly reduce the PMSG reactance. The study was performed by using finite element method (FEM) analysis and experimental investigation. FEM analysis was used to investigate magnetic field flux distribution and density in PMSG. The PMSG experimental analyses of no-load losses and electromotive force versus frequency (i.e., speed) was performed. Also terminal voltage, power output and efficiency relation with load current at different frequencies have been evaluated. The reactance of PMSG has low value and a linear relation with operating frequency. The low reactance gives a small variation of efficiency (from 90% to 95%) in a wide range of load (from 3 A to 10 A) and operation frequency (from 44 Hz to 114 Hz). The comparison of PMSG characteristics with parallel and series winding connection showed insignificant power variation. The research results showed that compensated reactance winding in parallel rod configuration in PMSG design provides lower reactance and therefore, higher efficiency under wider load and frequency variation.
Intermittent control: a computational theory of human control.
Gawthrop, Peter; Loram, Ian; Lakie, Martin; Gollee, Henrik
2011-02-01
The paradigm of continuous control using internal models has advanced understanding of human motor control. However, this paradigm ignores some aspects of human control, including intermittent feedback, serial ballistic control, triggered responses and refractory periods. It is shown that event-driven intermittent control provides a framework to explain the behaviour of the human operator under a wider range of conditions than continuous control. Continuous control is included as a special case, but sampling, system matched hold, an intermittent predictor and an event trigger allow serial open-loop trajectories using intermittent feedback. The implementation here may be described as "continuous observation, intermittent action". Beyond explaining unimodal regulation distributions in common with continuous control, these features naturally explain refractoriness and bimodal stabilisation distributions observed in double stimulus tracking experiments and quiet standing, respectively. Moreover, given that human control systems contain significant time delays, a biological-cybernetic rationale favours intermittent over continuous control: intermittent predictive control is computationally less demanding than continuous predictive control. A standard continuous-time predictive control model of the human operator is used as the underlying design method for an event-driven intermittent controller. It is shown that when event thresholds are small and sampling is regular, the intermittent controller can masquerade as the underlying continuous-time controller and thus, under these conditions, the continuous-time and intermittent controller cannot be distinguished. This explains why the intermittent control hypothesis is consistent with the continuous control hypothesis for certain experimental conditions.
NASA Astrophysics Data System (ADS)
Sheen, David M.; Fernandes, Justin L.; Tedeschi, Jonathan R.; McMakin, Douglas L.; Jones, A. Mark; Lechelt, Wayne M.; Severtsen, Ronald H.
2013-05-01
Active millimeter-wave imaging is currently being used for personnel screening at airports and other high-security facilities. The cylindrical imaging techniques used in the deployed systems are based on licensed technology developed at the Pacific Northwest National Laboratory. The cylindrical and a related planar imaging technique form three-dimensional images by scanning a diverging beam swept frequency transceiver over a two-dimensional aperture and mathematically focusing or reconstructing the data into three-dimensional images of the person being screened. The resolution, clothing penetration, and image illumination quality obtained with these techniques can be significantly enhanced through the selection of the aperture size, antenna beamwidth, center frequency, and bandwidth. The lateral resolution can be improved by increasing the center frequency, or it can be increased with a larger antenna beamwidth. The wide beamwidth approach can significantly improve illumination quality relative to a higher frequency system. Additionally, a wide antenna beamwidth allows for operation at a lower center frequency resulting in less scattering and attenuation from the clothing. The depth resolution of the system can be improved by increasing the bandwidth. Utilization of extremely wide bandwidths of up to 30 GHz can result in depth resolution as fine as 5 mm. This wider bandwidth operation may allow for improved detection techniques based on high range resolution. In this paper, the results of an extensive imaging study that explored the advantages of using extremely wide beamwidth and bandwidth are presented, primarily for 10-40 GHz frequency band.
Dissecting jets and missing energy searches using $n$-body extended simplified models
Cohen, Timothy; Dolan, Matthew J.; El Hedri, Sonia; ...
2016-08-04
Simplified Models are a useful way to characterize new physics scenarios for the LHC. Particle decays are often represented using non-renormalizable operators that involve the minimal number of fields required by symmetries. Generalizing to a wider class of decay operators allows one to model a variety of final states. This approach, which we dub the $n$-body extension of Simplified Models, provides a unifying treatment of the signal phase space resulting from a variety of signals. In this paper, we present the first application of this framework in the context of multijet plus missing energy searches. The main result of thismore » work is a global performance study with the goal of identifying which set of observables yields the best discriminating power against the largest Standard Model backgrounds for a wide range of signal jet multiplicities. Our analysis compares combinations of one, two and three variables, placing emphasis on the enhanced sensitivity gain resulting from non-trivial correlations. Utilizing boosted decision trees, we compare and classify the performance of missing energy, energy scale and energy structure observables. We demonstrate that including an observable from each of these three classes is required to achieve optimal performance. In conclusion, this work additionally serves to establish the utility of $n$-body extended Simplified Models as a diagnostic for unpacking the relative merits of different search strategies, thereby motivating their application to new physics signatures beyond jets and missing energy.« less
The application of CRM to military operations
NASA Technical Reports Server (NTRS)
Cavanagh, Dale E.; Williams, Kenneth R.
1987-01-01
The detailed content of the CRM training component of the C-5 Aircrew Training System (ATS) was left to the discretion of the contractor. As a part of determining what the content should be, United Airlines Services Corporation has made an effort to understand how the needs of MAC crews compare with those of civilian airline crews. There are distinct similarities between the crew roles in the cockpits of civilian airliners and military air transports. Many of the attitudes and behaviors exhibited by civil and military crew members are comparable, hence much of the training in the field referred to as Cockpit Resource Management (CRM) is equally appropriate to civil or military aircrews. At the same time, there are significant differences which require assessment to determine if modifications to what might be termed generic CRM are necessary. The investigation enabled the definition and specification of CRM training which is believed to address the needs of the C-5 operational community. The study has concentrated largely on military airlift, but the training objectives and course content of the CRM training are readily adaptable to a wider range of military cockpits than are found in strategic airlift. For instance, CRM training focusing on communication, leadership, situational awareness, and crew coordination is just as appropriate, with some modification, to the pilots manning a flight to Tactical Airlift Command A-7's as it is to the pilots, flight engineers, and loadmasters crewing a C-5.
1967-05-25
Artist’s concept of the Local Scientific Survey Module (LSSM), one of two designs for a Lunar Roving Vehicle (LRV), depicted on the lunar surface A Bendix Corporation concept, this configuration weighs more than 8,000 pounds, is 21-feet long, 15-feet wide and has 6 wheels with 5-foot diameters. The LRV was developed under the direction of the Marshall Space Flight Center (MSFC) to give Apollo astronauts a wider range of mobility on the lunar surface.
New name can sharpen a hospital's image--or diffuse checkered past.
Burns, J
1992-06-22
Hospitals change their names for a variety of reasons. Some seek a new identity that conveys a wider range of services; others need a new moniker as a result of a merger; still others hope a change can help the facility erase past problems. Whatever the case may be, a hospital's decision to change its name has evolved from a mere technical formality to a competitive, and often costly, marketing strategy.
Design of the TMT Mid-Infrared Echelle: Science Drivers and Design Overview
2006-01-01
plausibility of an extra-terrestrial origin for the prebiotic compounds that led to the emergence of life on Earth. MIRES imaging of debris disks will...explore mechanisms by which water and prebiotic organic compounds may have been delivered to planetary surfaces. These studies will be highly synergistic...that are precursors to complex prebiotic compounds. The high sensitivity also allows the exploration of a wider range of wavelengths, including those
The Building 549 auditorium is often packed with high school interns eager to hear a scientific lecture. On April 22, however, the room swelled with interns spanning a wider age range. At the 25th Werner H. Kirsten Student Intern Program (WHK SIP) Anniversary Symposium, incoming, current, and former interns gathered to celebrate the program, which has provided biomedical research experience for local high school seniors.
Measurements of the reflection factor of flat ground surfaces
NASA Technical Reports Server (NTRS)
Ventres, C. S.; Myles, M. M.; Ver, I. L.
1977-01-01
Measurements are made of the reflection factors of asphalt, concrete, and sod at oblique angles of incidence. Initial measurements were carried out in an anechoic chamber to eliminate the effects of wind and temperature gradients. These were followed by measurements made outdoors over a wider frequency range. Data are presented for the magnitudes of the reflection factors of asphalt, concrete, and sod at angles of incidence of 38 deg and 45 deg.
The thoracic paraspinal shadow: normal appearances.
Lien, H H; Kolbenstvedt, A
1982-01-01
The width of the right and left thoracic paraspinal shadows were measured at all levels in 200 presumably normal individuals. The paraspinal shadow could be identified in nearly all cases on the left side and in approximately one-third on the right. The range of variation was greater on the left side than one the right. The left paraspinal shadow was wider at the upper levels and in individuals above 40 years of age.
Numerical study of centrifugal compressor stage vaneless diffusers
NASA Astrophysics Data System (ADS)
Galerkin, Y.; Soldatova, K.; Solovieva, O.
2015-08-01
The authors analyzed CFD calculations of flow in vaneless diffusers with relative width in range from 0.014 to 0.100 at inlet flow angles in range from 100 to 450 with different inlet velocity coefficients, Reynolds numbers and surface roughness. The aim is to simulate calculated performances by simple algebraic equations. The friction coefficient that represents head losses as friction losses is proposed for simulation. The friction coefficient and loss coefficient are directly connected by simple equation. The advantage is that friction coefficient changes comparatively little in range of studied parameters. Simple equations for this coefficient are proposed by the authors. The simulation accuracy is sufficient for practical calculations. To create the complete algebraic model of the vaneless diffuser the authors plan to widen this method of modeling to diffusers with different relative length and for wider range of Reynolds numbers.
Domínguez-Peñafiel, G.; Giménez-Pardo, C.; Gegúndez, M.I.; Lledó, L.
2011-01-01
This paper reports the prevalence of ectoparasitic arthropods in sampled groups of wild (n = 128; 16 species) and domestic (n = 69; 3 species) animals in the Las Merindades area of the Province of Burgos, Spain. The study revealed that wild animals were more infested and with a wider variety of ectoparasites than domestic animals. The parasitic prevalence was 67% for wild animals and 48% for livestock. In this way, 39% of animals were infected by ticks. Ixodes ricinus and Ixodes hexagonus were the most prevalent species whereas Dermacentor reticulatus showed affinity for the fox and wolf. The overall prevalence of parasitisation by fleas was 27%. Ctenophthalmus spp. showed the wider range host in wild animals, while Pulex irritans was the most frequent specie found. The parasitic prevalences by lice (Trichodectes melis, Trichodectes canis and Trichodectes mustelae) and by mite (Neotrombicula spp., Laelaps agilis and Sarcoptes scabiei) were 4% and 12%, respectively. In both cases only wild animals were found parasited. PMID:21894267
Hunt, Geoffrey; Lynch, Iseult; Cassee, Flemming; Handy, Richard D.; Fernandes, Teresa F.; Berges, Markus; Kuhlbusch, Thomas A. J.; Dusinska, Maria; Riediker, Michael
2013-01-01
The aim of this article is to present an overview of salient issues of exposure, characterisation and hazard assessment of nanomaterials as they emerged from the consensus-building of experts undertaken within the four year European Commission coordination project NanoImpactNet. The approach adopted is to consolidate and condense the findings and problem-identification in such a way as to identify knowledge-gaps and generate a set of interim recommendations of use to industry, regulators, research bodies and funders. The categories of recommendation arising from the consensual view address: significant gaps in vital factual knowledge of exposure, characterisation and hazards; the development, dissemination and standardisation of appropriate laboratory protocols; address a wide range of technical issues in establishing an adequate risk assessment platform; the more efficient and coordinated gathering of basic data; greater inter-organisational cooperation; regulatory harmonization; the wider use of the life-cycle approaches; and the wider involvement of all stakeholders in the discussion and solution-finding efforts for nanosafety. PMID:28809359
Domínguez-Peñafiel, G; Giménez-Pardo, C; Gegúndez, Mi; Lledó, L
2011-08-01
This paper reports the prevalence of ectoparasitic arthropods in sampled groups of wild (n = 128; 16 species) and domestic (n = 69; 3 species) animals in the Las Merindades area of the Province of Burgos, Spain. The study revealed that wild animals were more infested and with a wider variety of ectoparasites than domestic animals. The parasitic prevalence was 67% for wild animals and 48% for livestock. In this way, 39% of animals were infected by ticks. Ixodes ricinus and Ixodes hexagonus were the most prevalent species whereas Dermacentor reticulatus showed affinity for the fox and wolf. The overall prevalence of parasitisation by fleas was 27%. Ctenophthalmus spp. showed the wider range host in wild animals, while Pulex irritans was the most frequent specie found. The parasitic prevalences by lice (Trichodectes melis, Trichodectes canis and Trichodectes mustelae) and by mite (Neotrombicula spp., Laelaps agilis and Sarcoptes scabiei) were 4% and 12%, respectively. In both cases only wild animals were found parasited.
Vestergård, Gunver Lystbæk; Nielsen, Kristian H
2017-02-01
In an attempt to qualify changes to science news reporting due to the impact of the Internet, we studied all science news articles published in Danish national newspapers in a November week in 1999 and 2012, respectively. We find the same amount of science coverage, about 4% of the total news production, in both years, although the tabloids produce more science news in 2012. Online science news also received high priority. Journalists in 2012 more often than in 1999 make reference to scientific journals and cite a wider range of journals. Science news in 2012 is more international and politically oriented than in 1999. Based on these findings, we suggest that science news, due partly to the emergence of online resources, is becoming more diverse and available to a wider audience. Science news is no longer for the elite but has spread to virtually everywhere in the national news system.
Ancient DNA evidence of Iberian lynx palaeoendemism
NASA Astrophysics Data System (ADS)
Rodríguez-Varela, Ricardo; Tagliacozzo, Antonio; Ureña, Irene; García, Nuria; Crégut-Bonnoure, Evelyne; Mannino, Marcello A.; Arsuaga, Juan Luis; Valdiosera, Cristina
2015-03-01
The Iberian lynx, endemic to the Iberian Peninsula, is the most threatened carnivore in Europe and the most endangered felid in the world. Widely distributed throughout Iberia during the Pleistocene and Holocene it is now confined to two small populations in southern Spain. Lynx species differentiation, based solely on morphological analysis from skeletal traits, is a difficult task and can potentially lead to misidentification. In order to verify whether Iberian lynx had a wider geographical distribution in the past, we successfully sequenced 152 base pairs (bp) of the cytochrome b gene and 183 bp of the mitochondrial control region in 20 Late Pleistocene and Holocene fossil remains of Lynx sp. from southern Europe. Our results confirm the presence of Iberian lynx outside the Iberian Peninsula demonstrating that this is a palaeoendemic species that had a wider distribution range in southern Europe during the Holocene and the Late Pleistocene. In addition, we documented the presence of both Palaearctic extant lynx species in the Arene Candide (north Italy) site during the Last Glacial Maximum.
Andrews, Jonathan
2014-01-01
This article examines the management and meaning of post-mortem examinations, and the spatial ordering of patients’ death, dissection and burial at the Victorian asylum, referencing a range of institutional contexts and exploiting a case study of the Royal Edinburgh Asylum. The routinizing of dissection and the development of the dead-house from a more marginal asylum sector to a lynchpin of laboratory medicine is stressed. External and internal pressure to modernize pathological research facilities is assessed alongside governmental, public and professional critiques of variable necroscopy practices. This is contextualized against wider issues and attitudes surrounding consent and funereal rituals. Onus is placed on tendencies in anatomizing insanity towards the conversion of deceased lunatics – pauper lunatics especially – into mere pathological specimens. On the other hand, significant but compromised resistance on the part of a minority of practitioners, relatives and the wider public is also identified. PMID:22701924
NASA Technical Reports Server (NTRS)
Gratz, Andrew J.; Bird, Peter
1993-01-01
The range of the measured quartz dissolution rates, as a function of temperature and pOH, extent of saturation, and ionic strength, is extended to cover a wider range of solution chemistries, using the negative crystal methodology of Gratz et al. (1990) to measure the dissolution rate. A simple rate law describing the quartz dissolution kinetics above the point of zero charge of quartz is derived for ionic strengths above 0.003 m. Measurements were performed on some defective crystals, and the mathematics of step motion was developed for quartz dissolution and was compared with rough-face behavior using two different models.
Spatial Stochastic Intracellular Kinetics: A Review of Modelling Approaches.
Smith, Stephen; Grima, Ramon
2018-05-21
Models of chemical kinetics that incorporate both stochasticity and diffusion are an increasingly common tool for studying biology. The variety of competing models is vast, but two stand out by virtue of their popularity: the reaction-diffusion master equation and Brownian dynamics. In this review, we critically address a number of open questions surrounding these models: How can they be justified physically? How do they relate to each other? How do they fit into the wider landscape of chemical models, ranging from the rate equations to molecular dynamics? This review assumes no prior knowledge of modelling chemical kinetics and should be accessible to a wide range of readers.