Examining Changes in Certification/Licensure Requirements and the International Medical Graduate Examinee Pool

ERIC Educational Resources Information Center

McKinley, Danette W.; Hess, Brian J.; Boulet, John R.; Lipner, Rebecca S.

2014-01-01

Changes in certification requirements and examinee characteristics are likely to influence the validity of the evidence associated with interpretations made based on test data. We examined whether changes in Educational Commission for Foreign Medical Graduates (ECFMG) certification requirements over time were associated with changes in internal…

Electrical probe characteristic recovery by measuring only one time-dependent parameter

NASA Astrophysics Data System (ADS)

Costin, C.; Popa, G.; Anita, V.

2016-03-01

Two straightforward methods for recovering the current-voltage characteristic of an electrical probe are proposed. Basically, they consist of replacing the usual power supply from the probe circuit with a capacitor which can be charged or discharged by the probe current drained from the plasma. The experiment requires the registration of only one time-dependent electrical parameter, either the probe current or the probe voltage. The corresponding time-dependence of the second parameter, the probe voltage, or the probe current, respectively, can be calculated using an integral or a differential relation and the current-voltage characteristic of the probe can be obtained.

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics I : effect of air bleed at compressor outlet

NASA Technical Reports Server (NTRS)

Rebeske, John J , Jr; Rohlik, Harold E

1953-01-01

An analytical investigation was made to determine from component performance characteristics the effect of air bleed at the compressor outlet on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Consideration of several operating lines on the compressor performance map with two turbine-inlet temperatures showed that for a minimum acceleration time the turbine-inlet temperature should be the maximum allowable, and the operating line on the compressor map should be as close to the surge region as possible throughout the speed range. Operation along such a line would require a continuously varying bleed area. A relatively simple two-step area bleed gives only a small increase in acceleration time over a corresponding variable-area bleed. For the modes of operation considered, over 84 percent of the total acceleration time was required to accelerate through the low-speed range ; therefore, better low-speed compressor performance (higher pressure ratios and efficiencies) would give a significant reduction in acceleration time.

How "the best" companies use MRP (materiel requirements planning) and just-in-time for successful manufacturing.

PubMed

Spencer, M S

1994-08-01

A study of production planning and control methods used in six leading companies found that a blending strategy is more effective than reliance on a single system. The blending of just-in-time and materiel requirements planning and other approaches allowed companies to select methods that best fit the unique characteristics of their production environments.

Tactical radar technology study. Volume 1: Executive summary

NASA Astrophysics Data System (ADS)

Rosien, R.; Cardone, L.; Hammers, D.; Klein, A.; Nozawa, E.

1980-03-01

This report presents results of a study to identify new technology required to provide advanced multi-threat performance capabilities in future tactical surveillance radar designs. A baseline design with optional subsystem characteristics has been synthesized to provide both functional and operational survivability in a dynamic and hostile situation postulated for the post 1985 time frame. Comparisons have been made of available technology with that required by the new baseline design to identify new technology requirements. Recommendations are presented for critical new technology programs including estimates of technical risks, costs and required development time.

The impact of integrated water management on the Space Station propulsion system

NASA Technical Reports Server (NTRS)

Schmidt, George R.

1987-01-01

The water usage of elements in the Space Station integrated water system (IWS) is discussed, and the parameters affecting the overall water balance and the water-electrolysis propulsion-system requirements are considered. With nominal IWS operating characteristics, extra logistic water resupply (LWR) is found to be unnecessary in the satisfaction of the nominal propulsion requirements. With the consideration of all possible operating characteristics, LWR will not be required in 65.5 percent of the cases, and for 17.9 percent of the cases LWR can be eliminated by controlling the stay time of theShuttle Orbiter orbiter.

Temperature transducer has high output, is time stable

NASA Technical Reports Server (NTRS)

Follett, W. H.

1965-01-01

Compact, lightweight temperature transducer requires no amplification of its output signal and is time stable. It uses the temperature-dependent characteristics of a silicon transistor to provide a zero-to-five-volt signal proportional to temperature.

Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

NASA Astrophysics Data System (ADS)

Duten, X.; Redolfi, M.; Aggadi, N.; Vega, A.; Hassouni, K.

2011-10-01

This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

Clinical Characteristics and Lesions Responsible for Swallowing Hesitation After Acute Cerebral Infarction.

PubMed

Saito, Tsukasa; Hayashi, Keisuke; Nakazawa, Hajime; Ota, Tetsuo

2016-08-01

Some stroke patients with a unilateral lesion demonstrate acute dysphagia characterized by a markedly prolonged swallowing time, making us think they are reluctant to swallow. In order to clarify the clinical characteristics and causative lesions of delayed swallowing, we conducted a retrospective analysis of 20 right-handed patients without a history of swallowing dysfunction who underwent videofluorography on suspicion of dysphagia after a first ischemic stroke. The oral processing time plus the postfaucial aggregation time required to swallow jelly for patients classified as having delayed swallowing was over 10 s. The time required for swallowing jelly was significantly longer than that without the hesitation (median value, 24.1 vs. 8.9 s, P < 0.001). The oral processing time plus the postfaucial aggregation time required for patients with delayed swallowing to swallow thickened water was largely over 5 s and significantly longer than that of patients without swallowing hesitation (median value, 10.2 vs. 3.3 s, P < 0.001). Swallowing hesitation caused by acute unilateral infarction could be separated into two different patterns. Because four of the five patients with a rippling tongue movement in the swallowing hesitation pattern had a lesion in the left primary motor cortex, which induces some kinds of apraxia, swallowing hesitation with a rippling tongue movement seems to be a representative characteristic of apraxia. The patients with swallowing hesitation with a temporary stasis of the tongue in this study tended to have broad lesions in the frontal lobe, especially in the middle frontal gyrus, which is thought to be involved in higher cognition.

Workflow and maintenance characteristics of five automated laboratory instruments for the diagnosis of sexually transmitted infections.

PubMed

Ratnam, Sam; Jang, Dan; Gilchrist, Jodi; Smieja, Marek; Poirier, Andre; Hatchette, Todd; Flandin, Jean-Frederic; Chernesky, Max

2014-07-01

The choice of a suitable automated system for a diagnostic laboratory depends on various factors. Comparative workflow studies provide quantifiable and objective metrics to determine hands-on time during specimen handling and processing, reagent preparation, return visits and maintenance, and test turnaround time and throughput. Using objective time study techniques, workflow characteristics for processing 96 and 192 tests were determined on m2000 RealTime (Abbott Molecular), Viper XTR (Becton Dickinson), cobas 4800 (Roche Molecular Diagnostics), Tigris (Hologic Gen-Probe), and Panther (Hologic Gen-Probe) platforms using second-generation assays for Chlamydia trachomatis and Neisseria gonorrhoeae. A combination of operational and maintenance steps requiring manual labor showed that Panther had the shortest overall hands-on times and Viper XTR the longest. Both Panther and Tigris showed greater efficiency whether 96 or 192 tests were processed. Viper XTR and Panther had the shortest times to results and m2000 RealTime the longest. Sample preparation and loading time was the shortest for Panther and longest for cobas 4800. Mandatory return visits were required only for m2000 RealTime and cobas 4800 when 96 tests were processed, and both required substantially more hands-on time than the other systems due to increased numbers of return visits when 192 tests were processed. These results show that there are substantial differences in the amount of labor required to operate each system. Assay performance, instrumentation, testing capacity, workflow, maintenance, and reagent costs should be considered in choosing a system. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

How to improve the promotion of Korean beef barbecue, bulgogi, for international customers. An application of quality function deployment.

PubMed

Park, So-Hyun; Ham, Sunny; Lee, Min-A

2012-10-01

Quality function deployment (QFD) is a product development technique that translates customer requirements into activities for the development of products and services. This study utilizes QFD to identify American customer's requirements for bulgogi, a popular Korean dish among international customers, and how to fulfill those requirements. A customer survey and an expert opinion survey were conducted for US customers. The top five customer requirements for bulgogi were identified as taste, freshness, flavor, tenderness, and juiciness; ease of purchase was included in the place of tenderness after calculating the weight requirements. Eighteen engineering characteristics were developed, and a 'localization of bulgogi menu' is strongly related to the other characteristics as well. The results from the calculation of relative importance of engineering characteristics identified that the 'control of marinating time', 'localization of bulgogi menu', 'improvement of cooking and serving process', 'development of recipe by parts of beef', and 'use of various seasonings' were the highest contributors to the overall improvement of bulgogi. The relative importance of engineering characteristics, correlation, and technical difficulties are ranked and integrated to develop the most effective strategy. The findings are discussed relative to industry implications. Copyright © 2012 Elsevier Ltd. All rights reserved.

Real-time Avatar Animation from a Single Image.

PubMed

Saragih, Jason M; Lucey, Simon; Cohn, Jeffrey F

2011-01-01

A real time facial puppetry system is presented. Compared with existing systems, the proposed method requires no special hardware, runs in real time (23 frames-per-second), and requires only a single image of the avatar and user. The user's facial expression is captured through a real-time 3D non-rigid tracking system. Expression transfer is achieved by combining a generic expression model with synthetically generated examples that better capture person specific characteristics. Performance of the system is evaluated on avatars of real people as well as masks and cartoon characters.

Real-time Avatar Animation from a Single Image

PubMed Central

Saragih, Jason M.; Lucey, Simon; Cohn, Jeffrey F.

2014-01-01

A real time facial puppetry system is presented. Compared with existing systems, the proposed method requires no special hardware, runs in real time (23 frames-per-second), and requires only a single image of the avatar and user. The user’s facial expression is captured through a real-time 3D non-rigid tracking system. Expression transfer is achieved by combining a generic expression model with synthetically generated examples that better capture person specific characteristics. Performance of the system is evaluated on avatars of real people as well as masks and cartoon characters. PMID:24598812

Transition times between the extremum points of the current–voltage characteristic of a resonant tunneling diode with hysteresis

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

Grishakov, K. S., E-mail: ksgrishakov@yahoo.com; Elesin, V. F.

A numerical solution to the problem of transient processes in a resonant tunneling diode featuring a current–voltage characteristic with hysteresis is found for the first time in the context of a coherent model (based on the coupled Schrödinger and Poisson equations) taking into account the Fermi distribution of electrons. The transitions from the high-current to the low-current state and vice versa, which result from the existence of hysteresis and are of great practical importance for ultrafast switches based on resonant tunneling diodes, are studied in detail. It is shown that the transition times for such processes initiated by the applicationmore » of a small voltage can significantly exceed the characteristic time ℏ/Γ (where G is the width of the resonance level). It is established for the first time that the transition time can be reduced and made as short as the characteristic time ℏ/Γ by applying a sufficiently high voltage. For the parameters of the resonant-tunnelingdiode structure considered in this study, the required voltage is about 0.01 V.« less

Semi-implicit time integration of atmospheric flows with characteristic-based flux partitioning

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

Ghosh, Debojyoti; Constantinescu, Emil M.

2016-06-23

Here, this paper presents a characteristic-based flux partitioning for the semi-implicit time integration of atmospheric flows. Nonhydrostatic models require the solution of the compressible Euler equations. The acoustic time scale is significantly faster than the advective scale, yet it is typically not relevant to atmospheric and weather phenomena. The acoustic and advective components of the hyperbolic flux are separated in the characteristic space. High-order, conservative additive Runge-Kutta methods are applied to the partitioned equations so that the acoustic component is integrated in time implicitly with an unconditionally stable method, while the advective component is integrated explicitly. The time step ofmore » the overall algorithm is thus determined by the advective scale. Benchmark flow problems are used to demonstrate the accuracy, stability, and convergence of the proposed algorithm. The computational cost of the partitioned semi-implicit approach is compared with that of explicit time integration.« less

Nondestructive test determines overload destruction characteristics of current limiter fuses

NASA Technical Reports Server (NTRS)

Swartz, G. A.

1968-01-01

Nondestructive test predicts the time required for current limiters to blow /open the circuit/ when subjected to a given overload. The test method is based on an empirical relationship between the voltage rise across a current limiter for a fixed time interval and the time to blow.

Pilot/vehicle model analysis of visual and motion cue requirements in flight simulation. [helicopter hovering

NASA Technical Reports Server (NTRS)

Baron, S.; Lancraft, R.; Zacharias, G.

1980-01-01

The optimal control model (OCM) of the human operator is used to predict the effect of simulator characteristics on pilot performance and workload. The piloting task studied is helicopter hover. Among the simulator characteristics considered were (computer generated) visual display resolution, field of view and time delay.

Experimental investigation of drying characteristics of cornelian cherry fruits ( Cornus mas L.)

NASA Astrophysics Data System (ADS)

Ozgen, Filiz

2015-03-01

Major target of present paper is to investigate the drying kinetics of cornelian cherry fruits ( Cornus mas L.) in a convective dryer, by varying the temperature and the velocity of drying air. Freshly harvested fruits are dried at drying air temperature of 35, 45 and 55 °C. The considered drying air velocities are V air = 1 and 1.5 m/s for each temperature. The required drying time is determined by taking into consideration the moisture ratio measurements. When the moisture ratio reaches up to 10 % at the selected drying air temperature, then the time is determined ( t = 40-67 h). The moisture ratio, fruit temperature and energy requirement are presented as the functions of drying time. The lowest drying time (40 h) is obtained when the air temperature is 55 °C and air velocity is 1.5 m/s. The highest drying time (67 h) is found under the conditions of 35 °C temperature and 1 m/s velocity. Both the drying air temperature and the air velocity significantly affect the required energy for drying system. The minimum amount of required energy is found as 51.12 kWh, at 55 °C and 1 m/s, whilst the maximum energy requirement is 106.7 kWh, at 35 °C and 1.5 m/s. It is also found that, air temperature significantly influences the total drying time. Moreover, the energy consumption is decreasing with increasing air temperature. The effects of three parameters (air temperature, air velocity and drying time) on drying characteristics have also been analysed by means of analysis of variance method to show the effecting levels. The experimental results have a good agreement with the predicted ones.

Reverse-time migration for subsurface imaging using single- and multi- frequency components

NASA Astrophysics Data System (ADS)

Ha, J.; Kim, Y.; Kim, S.; Chung, W.; Shin, S.; Lee, D.

2017-12-01

Reverse-time migration is a seismic data processing method for obtaining accurate subsurface structure images from seismic data. This method has been applied to obtain more precise complex geological structure information, including steep dips, by considering wave propagation characteristics based on two-way traveltime. Recently, various studies have reported the characteristics of acquired datasets from different types of media. In particular, because real subsurface media is comprised of various types of structures, seismic data represent various responses. Among them, frequency characteristics can be used as an important indicator for analyzing wave propagation in subsurface structures. All frequency components are utilized in conventional reverse-time migration, but analyzing each component is required because they contain inherent seismic response characteristics. In this study, we propose a reverse-time migration method that utilizes single- and multi- frequency components for analyzing subsurface imaging. We performed a spectral decomposition to utilize the characteristics of non-stationary seismic data. We propose two types of imaging conditions, in which decomposed signals are applied in complex and envelope traces. The SEG/EAGE Overthrust model was used to demonstrate the proposed method, and the 1st derivative Gaussian function with a 10 Hz cutoff was used as the source signature. The results were more accurate and stable when relatively lower frequency components in the effective frequency range were used. By combining the gradient obtained from various frequency components, we confirmed that the results are clearer than the conventional method using all frequency components. Also, further study is required to effectively combine the multi-frequency components.

Qualities Required from Engineers of the Global Times

NASA Astrophysics Data System (ADS)

Senuma, Takehide

In this paper, the qualities and characteristics required from an engineer who works globally are discussed based on my own experience of a joint research project with a European company. The most important qualities and characteristics are integrity, one‧s own initiative, basic and expert knowledge, creativity, communicative skills and broad world view. Having initiative seems to be especially significant but is a weak point of young engineers in Japan at present. Ways to develop students‧ initiative are discussed in detail from a view point of the engineering education.

Engineering design manual of parachute decelerator characteristics for space shuttle solid rocket booster recovery

NASA Technical Reports Server (NTRS)

Mansfield, D. L.

1973-01-01

The design criteria and characteristics of parachutes for recovery of the solid rocket boosters used with the space shuttle launch are presented. A computer program for analyzing the requirements of the parachute decelerators is described. The computer inputs for both the drogue and main parachute decelerators are; (1) parachute size, (2) deployment conditions, (3) inflation times, (4) reefing times, (5) mass properties, (6) spring properties, and (7) aerodynamic coefficients. Graphs of the parachute performance are included.

Identification of bearing faults using time domain zero-crossings

NASA Astrophysics Data System (ADS)

William, P. E.; Hoffman, M. W.

2011-11-01

In this paper, zero-crossing characteristic features are employed for early detection and identification of single point bearing defects in rotating machinery. As a result of bearing defects, characteristic defect frequencies appear in the machine vibration signal, normally requiring spectral analysis or envelope analysis to identify the defect type. Zero-crossing features are extracted directly from the time domain vibration signal using only the duration between successive zero-crossing intervals and do not require estimation of the rotational frequency. The features are a time domain representation of the composite vibration signature in the spectral domain. Features are normalized by the length of the observation window and classification is performed using a multilayer feedforward neural network. The model was evaluated on vibration data recorded using an accelerometer mounted on an induction motor housing subjected to a number of single point defects with different severity levels.

Physical characteristics cannot be used to predict cooling time using cold-water immersion as a treatment for exertional hyperthermia.

PubMed

Poirier, Martin P; Notley, Sean R; Flouris, Andreas D; Kenny, Glen P

2018-03-12

We examined if physical characteristics could be used to predict cooling time during cold water immersion (CWI, 2°C) following exertional hyperthermia (rectal temperature ≥39.5°C) in a physically heterogeneous group of men and women (n=62). Lean body mass was the only significant predictor of cooling time following CWI (R²=0.137; P<0.001); however that prediction did not provide the precision (mean residual square error: 3.18±2.28 min) required to act as a safe alternative to rectal temperature measurements.

Characteristics of clinical trials that require participants to be fluent in English

PubMed Central

Egleston, Brian L; Pedraza, Omar; Wong, Yu-Ning; Dunbrack, Roland L; Griffin, Candace L; Ross, Eric A; Beck, J Robert

2015-01-01

Background/Aims Diverse samples in clinical trials can make findings more generalizable. We sought to characterize the prevalence of clinical trials in the United States that required English fluency for participants to enroll in the trial. Methods We randomly chose over 10,000 clinical trial protocols registered with ClinicalTrials.gov and examined the inclusion and exclusion criteria of the trials. We compared the relationship of clinical trial characteristics with English fluency inclusion requirements. We merged the ClinicalTrials.gov data with U.S. Census and American Community Survey data to investigate the association of English language restrictions with ZIP-code level demographic characteristics of participating institutions. We used Chi-squared tests, t-tests, and logistic regression models for analyses. Results English fluency requirements have been increasing over time, from 1.7% of trials having such requirements before 2000 to 9.0% after 2010 (p<0.001 from Chi-squared test). Industry sponsored trials had low rates of English fluency requirements (1.8%) while behavioral trials had high rates (28.4%). Trials opening in the Northeast of the U.S. had the highest regional English requirement rates (10.7%) while trials opening in more than one region had the lowest (3.3%, p<0.001). Since 1995, trials opening in ZIP-codes with larger Hispanic populations were less likely to have English fluency requirements (OR=0.92 for each 10 percent increase in proportion of Hispanics, 95% CI 0.86–0.98, p=0.013). Trials opening in ZIP-codes with more residents self-identifying as Black/African American (OR=1.87, 95% CI 1.36–2.58, p<0.001 for restricted cubic spline term) or Asian (OR=1.16 for linear term, 95% CI 1.07–1.25, p<0.001) were more likely to have English fluency requirements. ZIP-codes with higher poverty rates had trials with more English language restrictions (OR=1.06 for a 10 percent poverty rate increase, 95% CI 1.001–1.11, p=0.045). There was a statistically significant interaction between year and intervention type, such that the increase in English fluency requirements was more common for some interventions than for others. Conclusions The proportion of clinical trials registered with ClinicalTrials.gov that have English fluency requirements for study inclusion has been increasing over time. English language restrictions are associated with a number of characteristics, including the demographic characteristics of communities in which the sponsoring institutions are located. PMID:26152834

Characteristics of clinical trials that require participants to be fluent in English.

PubMed

Egleston, Brian L; Pedraza, Omar; Wong, Yu-Ning; Dunbrack, Roland L; Griffin, Candace L; Ross, Eric A; Beck, J Robert

2015-12-01

Diverse samples in clinical trials can make findings more generalizable. We sought to characterize the prevalence of clinical trials in the United States that required English fluency for participants to enroll in the trial. We randomly chose over 10,000 clinical trial protocols registered with ClinicalTrials.gov and examined the inclusion and exclusion criteria of the trials. We compared the relationship of clinical trial characteristics with English fluency inclusion requirements. We merged the ClinicalTrials.gov data with US Census and American Community Survey data to investigate the association of English-language restrictions with ZIP-code-level demographic characteristics of participating institutions. We used Chi-squared tests, t-tests, and logistic regression models for analyses. English fluency requirements have been increasing over time, from 1.7% of trials having such requirements before 2000 to 9.0% after 2010 (p < 0.001 from Chi-squared test). Industry-sponsored trials had low rates of English fluency requirements (1.8%), while behavioral trials had high rates (28.4%). Trials opening in the Northeast of the United States had the highest regional English requirement rates (10.7%), while trials opening in more than one region had the lowest (3.3%, p<0.001). Since 1995, trials opening in ZIP codes with larger Hispanic populations were less likely to have English fluency requirements (odds ratio=0.92 for each 10% increase in proportion of Hispanics, 95% confidence interval=0.86-0.98, p=0.013). Trials opening in ZIP codes with more residents self-identifying as Black/African American (odds ratio=1.87, 95% confidence interval=1.36-2.58, p<0.001 for restricted cubic spline term) or Asian (odds ratio=1.16 for linear term, 95% confidence interval=1.07-1.25, p<0.001) were more likely to have English fluency requirements. ZIP codes with higher poverty rates had trials with more English-language restrictions (odds ratio=1.06 for a 10% poverty rate increase, 95% confidence interval=1.001-1.11, p=0.045). There was a statistically significant interaction between year and intervention type, such that the increase in English fluency requirements was more common for some interventions than for others. The proportion of clinical trials registered with ClinicalTrials.gov that have English fluency requirements for study inclusion has been increasing over time. English-language restrictions are associated with a number of characteristics, including the demographic characteristics of communities in which the sponsoring institutions are located. © The Author(s) 2015.

An approach to the design of wide-angle optical systems with special illumination and IFOV requirements

NASA Astrophysics Data System (ADS)

Pravdivtsev, Andrey V.

2012-06-01

The article presents the approach to the design wide-angle optical systems with special illumination and instantaneous field of view (IFOV) requirements. The unevenness of illumination reduces the dynamic range of the system, which negatively influence on the system ability to perform their task. The result illumination on the detector depends among other factors from the IFOV changes. It is also necessary to consider IFOV in the synthesis of data processing algorithms, as it directly affects to the potential "signal/background" ratio for the case of statistically homogeneous backgrounds. A numerical-analytical approach that simplifies the design of wideangle optical systems with special illumination and IFOV requirements is presented. The solution can be used for optical systems which field of view greater than 180 degrees. Illumination calculation in optical CAD is based on computationally expensive tracing of large number of rays. The author proposes to use analytical expression for some characteristics which illumination depends on. The rest characteristic are determined numerically in calculation with less computationally expensive operands, the calculation performs not every optimization step. The results of analytical calculation inserts in the merit function of optical CAD optimizer. As a result we reduce the optimizer load, since using less computationally expensive operands. It allows reducing time and resources required to develop a system with the desired characteristics. The proposed approach simplifies the creation and understanding of the requirements for the quality of the optical system, reduces the time and resources required to develop an optical system, and allows creating more efficient EOS.

Fibre Optic Sensors for Selected Wastewater Characteristics

PubMed Central

Chong, Su Sin; Abdul Aziz, A. R.; Harun, Sulaiman W.

2013-01-01

Demand for online and real-time measurements techniques to meet environmental regulation and treatment compliance are increasing. However the conventional techniques, which involve scheduled sampling and chemical analysis can be expensive and time consuming. Therefore cheaper and faster alternatives to monitor wastewater characteristics are required as alternatives to conventional methods. This paper reviews existing conventional techniques and optical and fibre optic sensors to determine selected wastewater characteristics which are colour, Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). The review confirms that with appropriate configuration, calibration and fibre features the parameters can be determined with accuracy comparable to conventional method. With more research in this area, the potential for using FOS for online and real-time measurement of more wastewater parameters for various types of industrial effluent are promising. PMID:23881131

Correlates of State Enactment of Elementary School Physical Education Laws

PubMed Central

Monnat, Shannon M.; Lounsbery, Monica A.F.; Smith, Nicole J.

2014-01-01

Objective To describe variation in U.S. state elementary school physical education (PE) policies and to assess associations between state PE policy enactment and education funding, academic achievement, sociodemographic disadvantage, and political characteristics. Methods U.S. state laws regarding school PE time, staffing, curriculum, fitness assessment, and moderate-to-vigorous physical activity (MVPA) in 2012 were classified as strong/specific, weak/nonspecific, or none based on codified law ratings within the Classification of Laws Associated with School Students (C.L.A.S.S.). Laws were merged with state-level data from multiple sources. Logistic regression was used to determine associations between state characteristics and PE laws (N=51). Results Laws with specific PE and MVPA time requirements and evidence-based curriculum standards were more likely in states with low academic performance and in states with sociodemographically disadvantaged populations. School day length was positively associated with enacting a PE curriculum that referenced evidence-based standards. School funding and political characteristics were not associated with PE laws. Conclusions Limited time and high-stakes testing requirements force schools to prioritize academic programs, posing barriers to state passage of specific PE laws. To facilitate PE policy enactment, it may be necessary to provide evidence of how PE policies can be implemented within existing time and staffing structures. PMID:25230368

Correlates of state enactment of elementary school physical education laws.

PubMed

Monnat, Shannon M; Lounsbery, Monica A F; Smith, Nicole J

2014-12-01

To describe variation in U.S. state elementary school physical education (PE) policies and to assess associations between state PE policy enactment and education funding, academic achievement, sociodemographic disadvantage, and political characteristics. U.S. state laws regarding school PE time, staffing, curriculum, fitness assessment, and moderate-to-vigorous physical activity (MVPA) in 2012 were classified as strong/specific, weak/nonspecific, or none based on codified law ratings within the Classification of Laws Associated with School Students (C.L.A.S.S.). Laws were merged with state-level data from multiple sources. Logistic regression was used to determine associations between state characteristics and PE laws (N=51). Laws with specific PE and MVPA time requirements and evidence-based curriculum standards were more likely in states with low academic performance and in states with sociodemographically disadvantaged populations. School day length was positively associated with enacting a PE curriculum that referenced evidence-based standards. School funding and political characteristics were not associated with PE laws. Limited time and high-stake testing requirements force schools to prioritize academic programs, posing barriers to state passage of specific PE laws. To facilitate PE policy enactment, it may be necessary to provide evidence on how PE policies can be implemented within existing time and staffing structures. Copyright © 2014 Elsevier Inc. All rights reserved.

Gone to the Beach — Using GIS to infer how people value ...

EPA Pesticide Factsheets

Estimating the non-market value of beaches for saltwater recreation is complex. An individual’s preference for a beach depends on their perception of beach characteristics. When choosing one beach over another, an individual balances these personal preferences with any additional costs including travel time and/or fees to access the beach. This trade-off can be used to infer how people value different beach characteristics; especially when beaches are free to the public, beach value estimates rely heavily on accurate travel times. A current case study focused on public access on Cape Cod, MA will be used to demonstrate how travel costs can be used to determine the service area of different beaches, and model expected use of those beaches based on demographics. We will describe several of the transportation networks and route services available and compare a few based on their ability to meet our specific requirements of scale and seasonal travel time accuracy. We are currently developing a recreational demand model, based on visitation data and beach characteristics, that will allow decision makers to predict the benefits of different levels of water quality improvement. An important part of that model is the time required for potential recreation participants to get to different beaches. This presentation will describe different ways to estimate travel times and the advantages/disadvantages for our particular application. It will go on to outline how freely a

MORPHOLOGICAL DIFFERENCES BETWEEN TWO WHITE-FOOTED MICE, PEROMYSCUS BOYU AND PEROMYSCUS CALIFORNICUS, IN OAK WOODLANDS OF FRESNO COUNTY, CALIFORNIA

Treesearch

ROBERTA J. FARGO; William F. Laudenslayer

1995-01-01

Identification ofPeromyscus species in the field can often be time consuming and inaccurate. Determination of several morphological characteristics is usually required for reliable identification. Characteristics may differ only slightly, can be highly variable, or can overlap among species. In oak woodlands of the southern Sierra Nevada in Fresno county, most...

The Costs of Today's Jobs: Job Characteristics and Organizational Supports as Antecedents of Negative Spillover

ERIC Educational Resources Information Center

Grotto, Angela R.; Lyness, Karen S.

2010-01-01

This study examined job characteristics and organizational supports as antecedents of negative work-to-nonwork spillover for 1178 U.S. employees. Based on hierarchical regression analyses of 2002 National Study of the Changing Workforce data and O*NET data, job demands (requirements to work at home beyond scheduled hours, job complexity, time and…

Upper stages utilizing electric propulsion

NASA Technical Reports Server (NTRS)

Byers, D. C.

1980-01-01

The payload characteristics of geocentric missions which utilize electron bombardment ion thruster systems are discussed. A baseline LEO to GEO orbit transfer mission was selected to describe the payload capabilities. The impacts on payloads of both mission parameters and electric propulsion technology options were evaluated. The characteristics of the electric propulsion thrust system and the power requirements were specified in order to predict payload mass. This was completed by utilizing a previously developed methodology which provides a detailed thrust system description after the final mass on orbit, the thrusting time, and the specific impulse are specified. The impact on payloads of total mass in LEO, thrusting time, propellant type, specific impulse, and power source characteristics was evaluated.

The relationship between worker, occupational and workplace characteristics and whether an injury requires time off work: a matched case-control analysis in Ontario, Canada.

PubMed

Smith, Peter; Chen, Cynthia; Mustard, Cameron; Hogg-Johnson, Sheilah; Tompa, Emile

2015-04-01

The objective of this study was to examine individual, occupational, and workplace level factors associated with time loss following a similar injury. Seven thousand three hundred and forty-eight workers' compensation claims that did not require time off work were matched with up to four claims that required time off work on the event, nature, and part of body injured as well as injury year. Conditional logistic regression models examined individual, occupational, and workplace level factors that were associated with the likelihood of not requiring time off work. Employees from firms with higher premium rates were more likely to report no time loss from work and workers in more physically demanding occupations were less likely to report no time loss from work. We observed no association between age or gender and the probability of a time loss claim submission. Our results suggest that insurance costs are an incentive for workplaces to adopt policies and practices that minimize time loss following a work injury. © 2015 Wiley Periodicals, Inc.

Associations of various family characteristics and time use with children's body mass index.

PubMed

Forshee, Richard A; Anderson, Patricia A; Storey, Maureen L

2009-04-01

This study used multiple regression models to estimate associations of various family characteristics and time use with the body mass index (BMI) z-scores of 734 boys and 725 girls aged 5-18y from the Panel Study of Income Dynamics Child Development Supplement 2003. The strongest relationship in the data was between the BMI of the head of household and a child's BMI z-score (p < 0.001). Time spent sleeping, performing sedentary behaviors, and participating in physical activities was not associated with a child's BMI z-score. This suggests that a family-oriented approach to prevent and treat childhood and adolescent overweight is required.

Sperm collection by transrectal ultrasound-guided massage of the accessory sex glands is less stressful than electroejaculation without altering sperm characteristics in conscious goat bucks.

PubMed

Abril-Sánchez, Silvia; Freitas-de-Melo, Aline; Beracochea, Florencia; Damián, Juan Pablo; Giriboni, Julia; Santiago-Moreno, Julián; Ungerfeld, Rodolfo

2017-08-01

In anesthetized non-domestic ruminants transrectal ultrasound-guided massage of the accessory sex glands (TUMASG) is an alternative method to collect semen slightly less stressful than electroejaculation (EE). However, some sperm characteristics are better when semen is collected with EE than with TUMASG. As anesthesia reduces the response to stressors, the advantages of TUMASG may be reduced in anesthetized animals, and thus, TUMASG may be even more advantageous in conscious animals. Therefore, the aim of the present study was to compare the stress response and the characteristics of the sperm collected with TUMASG and EE in conscious goat bucks. Semen was collected in 10 bucks with both procedures. During each procedure, the time required for ejaculation, the number of electric pulses applied and the number of vocalizations were recorded. Rectal temperature, heart rate, serum cortisol concentration, biochemical and hematological parameters were measured before and after each procedure. Sperm characteristics [ejaculated volume, sperm concentration, sperm mass motility (scale 0-5), sperm vigor (scale 0-5), the percentages of motile and progressive motile sperm, of sperm vitality, of sperm with plasma membrane integrity, and with acrosome damage and morphological abnormalities] were also determined. Electroejaculation required more electric pulses than TUMASG (P < 0.0001), but TUMASG took more time than EE (P < 0.0001). The EE provoked more vocalizations (P = 0.02) and a greater increase of cortisol concentrations than TUMASG (P = 0.04). Heart rate also tended to be greater with EE than with TUMASG (P = 0.07). The sperm characteristics did not differ between TUMASG and EE. In conclusion, TUMASG was less stressful and probably less painful than EE without affecting the semen quality. Thus, although it required more time, TUMASG is an alternative procedure to decrease the welfare concerns raised by EE in conscious goat bucks. Copyright © 2017 Elsevier Inc. All rights reserved.

Methods of determining complete sensor requirements for autonomous mobility

NASA Technical Reports Server (NTRS)

Curtis, Steven A. (Inventor)

2012-01-01

A method of determining complete sensor requirements for autonomous mobility of an autonomous system includes computing a time variation of each behavior of a set of behaviors of the autonomous system, determining mobility sensitivity to each behavior of the autonomous system, and computing a change in mobility based upon the mobility sensitivity to each behavior and the time variation of each behavior. The method further includes determining the complete sensor requirements of the autonomous system through analysis of the relative magnitude of the change in mobility, the mobility sensitivity to each behavior, and the time variation of each behavior, wherein the relative magnitude of the change in mobility, the mobility sensitivity to each behavior, and the time variation of each behavior are characteristic of the stability of the autonomous system.

[CMACPAR an modified parallel neuro-controller for control processes].

PubMed

Ramos, E; Surós, R

1999-01-01

CMACPAR is a Parallel Neurocontroller oriented to real time systems as for example Control Processes. Its characteristics are mainly a fast learning algorithm, a reduced number of calculations, great generalization capacity, local learning and intrinsic parallelism. This type of neurocontroller is used in real time applications required by refineries, hydroelectric centers, factories, etc. In this work we present the analysis and the parallel implementation of a modified scheme of the Cerebellar Model CMAC for the n-dimensional space projection using a mean granularity parallel neurocontroller. The proposed memory management allows for a significant memory reduction in training time and required memory size.

Air Force Training: Further Analysis and Planning Needed to Improve Effectiveness

DTIC Science & Technology

2016-09-01

training, and (3) established virtual training plans that include desirable characteristics of a comprehensive strategy. GAO reviewed Air Force training...requirements may not reflect current and emerging training needs, because the Air Force has not comprehensively reassessed the assumptions underlying them...include all desirable characteristics of a comprehensive strategy, such as a risk-based investment strategy or a time line for addressing training needs

Glycemic control and insulin requirements in type 1 diabetic patients depending on the clinical characteristics at diabetes onset.

PubMed

Beato-Víbora, Pilar Isabel; Tormo-García, M Ángeles

2014-01-01

The long-term prognosis of type 1 diabetes (T1DM) was evaluated in relation to the clinical characteristics at the time of diabetes onset. We examined retrospectively the clinical and laboratory characteristics present at the time of diagnosis in 301 adult patients (187 men) consecutively admitted to hospital with T1DM onset and evaluated the clinical outcome of T1DM during 6 ± 4.8 years following diagnosis. Women needed a greater insulin dose per kg of body weight over the first 2 years following diagnosis. Younger patients at diagnosis had greater insulin requirements during follow-up. Patients with at least one positive pancreatic antibody needed a greater insulin dose 2 years after diagnosis and developed poorer glycemic control during follow-up than patients with no detectable pancreatic antibodies at onset. Diabetic ketoacidosis at onset was associated with greater insulin requirements over the first 2 years of follow-up and with poorer glycemic control during the course of the illness. C-peptide levels at diagnosis correlated with insulin requirements during the first 2 years of follow-up. Patients with higher HbA1c levels at diagnosis had greater insulin requirements in the first year of follow-up. A correlation was found between the HbA1c levels at the consecutive years of follow-up. Female sex, younger age, humoral pancreatic autoimmunity, diabetic ketoacidosis, lower pancreatic reserve and higher HbA1c levels at onset could predict a poor long-term clinical outcome of T1DM in terms of insulin requirements and glycemic control.

Targeting Ovarian Cancer with Porphysome Nanotechnology

DTIC Science & Technology

2015-10-01

human administration; these specifications include requirements/restrictions on the volume, pH , appearance, sterility, bacterial endotoxins ...the translational success of nanomedicines is the ability to produce agents in accordance with quality control systems such as current Good...sufficiently robust and reliable for producing the same product time after time with the intended physicochemical characteristics, biological behaviors, and

Time Management and Professional Identity of Students of Pedagogical Universities

ERIC Educational Resources Information Center

Lebedeva, Ekaterina V.; Shchipanova, Dina Ye.; Konovalova, Maria E.; Kutyin, Anton O.

2016-01-01

Topicality of the problem under research is stipulated by the necessity of personal characteristics consideration in the process of organization of educational and vocational activities of the future teachers in the conditions of educational medium, which sets high requirements to the students' time competence. The aim of the article is to study…

Preliminary flight evaluation of F100 engine model derivative airstart capability in an F-15 airplane

NASA Technical Reports Server (NTRS)

Cho, T. K.; Burcham, F. W., Jr.

1984-01-01

A series of airstarts was conducted in an F-15 airplane with two prototype F100 engine model derivative (EMD) engines equipped with digital electronic engine control (DEEC) systems. The airstart envelope and time required for airstarts were defined. The success of an airstart is most heavily dependent on airspeed. Spooldown airstarts at 200 knots and higher were all successful. Spooldown airstart times ranged from 53 sec at 250 knots to 170 sec at 175 knots. Jet fuel starter (JFS) assisted airstarts were conducted at 175 knots at two altitudes, and airstart times were 50 and 60 sec, significantly faster than unassisted airstart. The effect of altitude on airstarts was small. In addition, the airstart characteristics of the two test engines were found to closely resemble each other. The F100 EMD airstart characteristics were very similar to the DEEC equipped F100 engine tested previously. Finally, the time required to spool down from intermediate power compressor rotor speed to a given compressor rotor speed was found to be a strong function of altitude and a weaker function of airspeed.

The four spot time-of-flight laser anemometer

NASA Technical Reports Server (NTRS)

Wernet, Mark P.

1985-01-01

The newly constructed, four-spot anemometer was shown to perform as predicted. The new anemometer's measurement region has the required characteristics: wide acceptance angle and high spatial selectivity to permit measurements in turbulent, hostile environments.

Characteristics of Paraspinal Muscle Spindle Response to Mechanically Assisted Spinal Manipulation: A Preliminary Report.

PubMed

Reed, William R; Pickar, Joel G; Sozio, Randall S; Liebschner, Michael A K; Little, Joshua W; Gudavalli, Maruti R

The purpose of this preliminary study is to determine muscle spindle response characteristics related to the use of 2 solenoid powered clinical mechanically assisted manipulation (MAM) devices. L6 muscle spindle afferents with receptive fields in paraspinal muscles were isolated in 6 cats. Neural recordings were made during L7 MAM thrusts using the Activator V (Activator Methods Int. Ltd., Phoenix, AZ) and/or Pulstar (Sense Technology Inc., Pittsburgh, PA) devices at their 3 lowest force settings. Mechanically assisted manipulation response measures included (a) the time required post-thrust until the first action potential, (b) differences in mean frequency (MF) and mean instantaneous frequency (MIF) 2 seconds before and after MAM, and (c) the time required for muscle spindle discharge (MF and MIF) to return to 95% of baseline after MAM. Depending on device setting, between 44% to 80% (Pulstar) and 11% to 63% (Activator V) of spindle afferents required >6 seconds to return to within 95% of baseline MF values; whereas 66% to 89% (Pulstar) and 75% to 100% (Activator V) of spindle responses returned to within 95% of baseline MIF in <6 seconds after MAM. Nonparametric comparisons between the 22 N and 44 N settings of the Pulstar yielded significant differences for the time required to return to baseline MF and MIF. Short duration (<10 ms) MAM thrusts decrease muscle spindle discharge with a majority of afferents requiring prolonged periods (>6 seconds) to return to baseline MF activity. Physiological consequences and clinical relevance of described MAM mechanoreceptor responses will require additional investigation. Copyright © 2017. Published by Elsevier Inc.

Study on time-frequency analysis method of very fast transient overvoltage

NASA Astrophysics Data System (ADS)

Li, Shuai; Liu, Shiming; Huang, Qiyan; Fu, Chuanshun

2018-04-01

The operation of the disconnector in the gas insulated substation (GIS) may produce very fast transient overvoltage (VFTO), which has the characteristics of short rise time, short duration, high amplitude and rich frequency components. VFTO can cause damage to GIS and secondary equipment, and the frequency components contained in the VFTO can cause resonance overvoltage inside the transformer, so it is necessary to study the spectral characteristics of the VFTO. From the perspective of signal processing, VFTO is a kind of non-stationary signal, the traditional Fourier transform is difficult to describe its frequency which changes with time, so it is necessary to use time-frequency analysis to analyze VFTO spectral characteristics. In this paper, we analyze the performance of short time Fourier transform (STFT), Wigner-Ville distribution (WVD), pseudo Wigner-Ville distribution (PWVD) and smooth pseudo Wigner-Ville distribution (SPWVD). The results show that SPWVD transform is the best. The time-frequency aggregation of SPWVD is higher than STFT, and it does not have cross-interference terms, which can meet the requirements of VFTO spectrum analysis.

Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing

PubMed Central

Sapir, Nir; Elimelech, Yossef

2017-01-01

The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle—especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna’s hummingbird (Calypte anna). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing’s leading-edge differs from the attached vorticity structure that was typically found over insects’ wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies. PMID:28878971

Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing.

PubMed

Achache, Yonathan; Sapir, Nir; Elimelech, Yossef

2017-08-01

The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle-especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna's hummingbird ( Calypte anna ). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing's leading-edge differs from the attached vorticity structure that was typically found over insects' wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies.

Round-trip mission requirements for Asteroids 1976 AA and 1973 EC

NASA Technical Reports Server (NTRS)

Niehoff, J. C.

1977-01-01

The feasibility of manned or unmanned missions to two recently discovered asteroids is assessed. Characteristics of a likely target for a round-trip exploratory excursion include: a period close to one year; and an orbit that is nearly circular and nearly coplanar with the ecliptic. Mass requirements and optimal times of launch are investigated for unmanned and manned missions to Asteroids 1976 AA and 1973 EC (recently numbered 1943); 365-day round-trip trajectories in the first half of the 1990s are proposed. However, since neither of the two targets considered entirely fulfills all the necessary orbital characteristics, neither can offer the opportunity for a fast low-energy round-trip mission; nevertheless, other minor planets crossing earth's orbit may be found to meet the requirements.

Ergonomics and patient handling.

PubMed

McCoskey, Kelsey L

2007-11-01

This study aimed to describe patient-handling demands in inpatient units during a 24-hour period at a military health care facility. A 1-day total population survey described the diverse nature and impact of patient-handling tasks relative to a variety of nursing care units, patient characteristics, and transfer equipment. Productivity baselines were established based on patient dependency, physical exertion, type of transfer, and time spent performing the transfer. Descriptions of the physiological effect of transfers on staff based on patient, transfer, and staff characteristics were developed. Nursing staff response to surveys demonstrated how patient-handling demands are impacted by the staff's physical exertion and level of patient dependency. The findings of this study describe the types of transfers occurring in these inpatient units and the physical exertion and time requirements for these transfers. This description may guide selection of the most appropriate and cost-effective patient-handling equipment required for specific units and patients.

Read margin analysis of crossbar arrays using the cell-variability-aware simulation method

NASA Astrophysics Data System (ADS)

Sun, Wookyung; Choi, Sujin; Shin, Hyungsoon

2018-02-01

This paper proposes a new concept of read margin analysis of crossbar arrays using cell-variability-aware simulation. The size of the crossbar array should be considered to predict the read margin characteristic of the crossbar array because the read margin depends on the number of word lines and bit lines. However, an excessively high-CPU time is required to simulate large arrays using a commercial circuit simulator. A variability-aware MATLAB simulator that considers independent variability sources is developed to analyze the characteristics of the read margin according to the array size. The developed MATLAB simulator provides an effective method for reducing the simulation time while maintaining the accuracy of the read margin estimation in the crossbar array. The simulation is also highly efficient in analyzing the characteristic of the crossbar memory array considering the statistical variations in the cell characteristics.

Higher-Order Hurst Signatures: Dynamical Information in Time Series

NASA Astrophysics Data System (ADS)

Ferenbaugh, Willis

2005-10-01

Understanding and comparing time series from different systems requires characteristic measures of the dynamics embedded in the series. The Hurst exponent is a second-order dynamical measure of a time series which grew up within the blossoming fractal world of Mandelbrot. This characteristic measure is directly related to the behavior of the autocorrelation, the power-spectrum, and other second-order things. And as with these other measures, the Hurst exponent captures and quantifies some but not all of the intrinsic nature of a series. The more elusive characteristics live in the phase spectrum and the higher-order spectra. This research is a continuing quest to (more) fully characterize the dynamical information in time series produced by plasma experiments or models. The goal is to supplement the series information which can be represented by a Hurst exponent, and we would like to develop supplemental techniques in analogy with Hurst's original R/S analysis. These techniques should be another way to plumb the higher-order dynamics.

V and V of ISHM Software for Space Exploration

NASA Technical Reports Server (NTRS)

Markosian, Lawrence; Feather, Martin, S.; Brinza, David; Figueroa, F.

2005-01-01

NASA has established a far-reaching and long-term program for robotic and manned exploration of the solar system, beginning with missions to the moon and Mars. The Crew Transportation System (CTS), a key system for space exploration, imposes four requirements' that ISHM addresses. These requirements have a wide range of implications for V&V and certification of ISHM. There is a range of time-criticality for ISHM actions, from prognostication, which is often (but not always) non-time-critical, to time-critical state estimation and system management under off-nominal emergency conditions. These are externally imposed requirements on ISHM that are subject to V&V. - In addition, a range of techniques are needed to implement an ISHM. The approaches to ISHM are described elsewhere. These approaches range from well-understood algorithms for low-level data analysis, validation and reporting, to AI techniques for state estimation and planning. The range of techniques, and specifically the use of AI techniques such as reasoning under uncertainty and mission planning (and re-planning), implies that several V&V approaches may be required. Depending on the ISHM architecture, traditional testing approaches may be adequate for some ISHM functionality. The AI-based approaches to reasoning under uncertainty, model-based reasoning, and planning share characteristics typical of other complex software systems, but they also have characteristics that set them apart and challenge standard V&V techniques. The range of possible solutions to the overall ISHM problem impose internal challenges to V&V. The V&V challenges increase when hard real-time constraints are imposed for time-critical functionality. For example, there is an external requirement that impending catastrophic failure of the Launch Vehicle (LV) at launch time be detected and life-saving action be taken within two seconds. In this paper we outline the challenges for ISHM V&V, existing approaches and analogs in other software application areas, and possible new approaches to the V&V challenges for space exploration ISHM.

Laser diode ignition characteristics of Zirconium Potassium Perchlorate (ZPP)

NASA Technical Reports Server (NTRS)

Callaghan, Jerry D.; Tindol, Scot

1993-01-01

Hi-Shear Technology, Corp., (HSTC) has designed and built a Laser equivalent NASA Standard Initiator (LNSI). Langlie tests with a laser diode output initiating ZPP were conducted as a part of this effort. The test parameters include time to first pressure, laser power density requirements, and ignition time. The data from these laser tests on ZPP are presented.

Techniques to improve maneuver stability characteristics of a nonlinear wide-body transport airplane in cruise flight

NASA Technical Reports Server (NTRS)

Grantham, William D.; Person, Lee H., Jr.; Bailey, Melvin L.; Tingas, Stephen A.

1994-01-01

The maneuver control stability characteristics of an aircraft are a flying qualities parameter of critical importance, to ensure structural protection as well as adequate predictability to the pilot. Currently, however, maneuver stability characteristics are not uniquely addressed in the Federal Aviation Regulations (FAR) Part 25, for transport aircraft. In past transport category certification programs, the Federal Aviation Administration (FAA) has used a combination of requirements (longitudinal control, vibration and buffeting, high-speed characteristics, and out-of-trim characteristics) to ensure safe and controllable maneuver stability characteristics over a range of flight conditions and airplane configurations. Controversies exist regarding each of these regulations, however, and considerable expenditures in terms of design studies and testing time have resulted from the requirements. It is also recognized that additional engineering guidance is needed for identifying acceptable nonlinear maneuver stability characteristics, particularly as they relate to relaxed stability, highly augmented transport configurations. The current trend in large aircraft design is toward relaxed, or even negative, static margins for improved fuel efficiency. The advanced flight control systems developed for these aircraft, in many instances, have rendered current aforementioned maneuver stability criteria either too stringent or of little practical use. Current design requirements do not account for these advanced designs. The objective was to evaluate a broad spectrum of linear and nonlinear longitudinal stability characteristics to generate data for defining satisfactory and unacceptable maneuver characteristics, as defined by pilot opinion. Primary emphasis was placed on two techniques of varying column force per normal acceleration. This study was a joint venture with four pilots participating; one from NASA, one from the FAA, and two from industry.

Mesoscale Models of Fluid Dynamics

NASA Astrophysics Data System (ADS)

Boghosian, Bruce M.; Hadjiconstantinou, Nicolas G.

During the last half century, enormous progress has been made in the field of computational materials modeling, to the extent that in many cases computational approaches are used in a predictive fashion. Despite this progress, modeling of general hydrodynamic behavior remains a challenging task. One of the main challenges stems from the fact that hydrodynamics manifests itself over a very wide range of length and time scales. On one end of the spectrum, one finds the fluid's "internal" scale characteristic of its molecular structure (in the absence of quantum effects, which we omit in this chapter). On the other end, the "outer" scale is set by the characteristic sizes of the problem's domain. The resulting scale separation or lack thereof as well as the existence of intermediate scales are key to determining the optimal approach. Successful treatments require a judicious choice of the level of description which is a delicate balancing act between the conflicting requirements of fidelity and manageable computational cost: a coarse description typically requires models for underlying processes occuring at smaller length and time scales; on the other hand, a fine-scale model will incur a significantly larger computational cost.

Updated Review of the Applied Physiology of American College Football: Physical Demands, Strength and Conditioning, Nutrition, and Injury Characteristics of America's Favorite Game.

PubMed

Fullagar, Hugh H K; McCunn, Robert; Murray, Andrew

2017-11-01

While there are various avenues for performance improvement in college American football (AF), there is no comprehensive evaluation of the collective array of resources around performance, physical conditioning, and injury and training/game characteristics to guide future research and inform practitioners. Accordingly, the aim of the present review was to provide a current examination of these areas in college AF. Recent studies show that there is a wide range of body compositions and strength characteristics between players, which appear to be influenced by playing position, level of play, training history/programming, and time of season. Collectively, game demands may require a combination of upper- and lower-body strength and power production, rapid acceleration (positive and negative), change of direction, high running speed, high-intensity and repetitive collisions, and muscle-strength endurance. These may be affected by the timing of and between-plays and/or coaching style. AF players appear to possess limited nutrition and hydration practices, which may be disadvantageous to performance. AF injuries appear due to a multitude of factors-strength, movement quality, and previous injury-while there is also potential for extrinsic factors such as playing surface type, travel, time of season, playing position, and training load. Future proof-of-concept studies are required to determine the quantification of game demands with regard to game style, type of opposition, and key performance indicators. Moreover, more research is required to understand the efficacy of recovery and nutrition interventions. Finally, the assessment of the relationship between external/internal-load constructs and injury risk is warranted.

Function Allocation in a Robust Distributed Real-Time Environment

DTIC Science & Technology

1991-12-01

fundamental characteristic of a distributed system is its ability to map individual logical functions of an application program onto many physical nodes... how much of a node’s processor time is scheduled for function processing. IMC is the function- to -function communication required to facilitate...indicator of how much excess processor time a node has. The reconfiguration algorithms use these variables to determine the most appropriate node(s) to

Library Consultant: Career or Dead-End Job?

ERIC Educational Resources Information Center

Holt, Raymond M.

1984-01-01

Enumerates characteristics required of the library consultant--motivation; character traits; education and experience; other qualifications (specialized knowledge, financial resources, adequate time, good health, communication skills, objectivity, perspective); special skills. The library-consultant marketplace (e.g., automation, public relations,…

Regression modeling and prediction of road sweeping brush load characteristics from finite element analysis and experimental results.

PubMed

Wang, Chong; Sun, Qun; Wahab, Magd Abdel; Zhang, Xingyu; Xu, Limin

2015-09-01

Rotary cup brushes mounted on each side of a road sweeper undertake heavy debris removal tasks but the characteristics have not been well known until recently. A Finite Element (FE) model that can analyze brush deformation and predict brush characteristics have been developed to investigate the sweeping efficiency and to assist the controller design. However, the FE model requires large amount of CPU time to simulate each brush design and operating scenario, which may affect its applications in a real-time system. This study develops a mathematical regression model to summarize the FE modeled results. The complex brush load characteristic curves were statistically analyzed to quantify the effects of cross-section, length, mounting angle, displacement and rotational speed etc. The data were then fitted by a multiple variable regression model using the maximum likelihood method. The fitted results showed good agreement with the FE analysis results and experimental results, suggesting that the mathematical regression model may be directly used in a real-time system to predict characteristics of different brushes under varying operating conditions. The methodology may also be used in the design and optimization of rotary brush tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cryogenic Test Technology 1984.

DTIC Science & Technology

1985-04-01

requirements. The material selection for the Pathfinder I was further restricted by long delivery times before Nitronic 40 was chosen. The alloys under...severe requirements of cryogenic model building. A detailed study of the characteristics of Nitronic 40 is reported in reference 36. This paper, and...remarks elsewhere about experience with Pathfinder I (made from Nitronic 40 ), suggest that quality control problems were encountered with at least one batch

An Implicit Characteristic Based Method for Electromagnetics

NASA Technical Reports Server (NTRS)

Beggs, John H.; Briley, W. Roger

2001-01-01

An implicit characteristic-based approach for numerical solution of Maxwell's time-dependent curl equations in flux conservative form is introduced. This method combines a characteristic based finite difference spatial approximation with an implicit lower-upper approximate factorization (LU/AF) time integration scheme. This approach is advantageous for three-dimensional applications because the characteristic differencing enables a two-factor approximate factorization that retains its unconditional stability in three space dimensions, and it does not require solution of tridiagonal systems. Results are given both for a Fourier analysis of stability, damping and dispersion properties, and for one-dimensional model problems involving propagation and scattering for free space and dielectric materials using both uniform and nonuniform grids. The explicit Finite Difference Time Domain Method (FDTD) algorithm is used as a convenient reference algorithm for comparison. The one-dimensional results indicate that for low frequency problems on a highly resolved uniform or nonuniform grid, this LU/AF algorithm can produce accurate solutions at Courant numbers significantly greater than one, with a corresponding improvement in efficiency for simulating a given period of time. This approach appears promising for development of dispersion optimized LU/AF schemes for three dimensional applications.

Neighbourhood inequalities in physical inactivity: the role of neighbourhood attractiveness, proximity to local facilities and safety in the Netherlands.

PubMed

van Lenthe, F J; Brug, J; Mackenbach, J P

2005-02-01

We investigated the association between the neighbourhood socioeconomic environment and physical inactivity, and explored the contribution of neighbourhood characteristics to this association. Data were analysed of 20-69 years old participants of the Dutch GLOBE study who lived in 78 neighbourhoods of Eindhoven (n = 8.767). The neighbourhood socioeconomic environment was assessed from aggregated self-reported information of participants' education and occupation level, and employment status. Aspects of physical inactivity investigated were based on the time spent on (a) walking and cycling to shops or work, (b) walking, cycling and gardening in leisure time, and (c) participation in sports activities. Characteristics of neighbourhoods included the proximity to food shops, general physical design of neighbourhoods, quality of green facilities, noise pollution from traffic and required police attention as evaluated by municipal services (professionals) responsible for these characteristics. Compared to those living in the most advantaged neighbourhoods, residents living in the quartile of socio-economically most disadvantaged neighbourhoods were more likely to walk or cycle to shops or work, but less likely to walk, cycle or garden in leisure time and less likely to participate in sports activities (adjusted for age, sex and individual educational level). Neighbourhood inequalities in walking or cycling to shops or work were not mediated by specific neighbourhood characteristics included in our analyses. The increased probability of almost never walking, cycling and gardening in leisure time in the most disadvantaged neighbourhoods was partly mediated by a poorer general physical design in these neighbourhoods. Similarly, the increased probability of almost never participating in sports activities in the most disadvantaged neighbourhoods was partly mediated by larger amounts of required police attention. The direction of neighbourhood inequalities differs for aspects of physical inactivity. Neighbourhood characteristics are related to physical inactivity and contribute to neighbourhood socioeconomic inequalities in physical inactivity.

Investigations of Novel Surface Modification Techniques for Wear Resistant Al and Mg Based Materials

DTIC Science & Technology

1994-01-01

microhardness to resist the abrasive wear. Moreover it is required to form dense or fine-porous uniform layers to provide the antifriction characteristics...technological regimes for production of OCC having maximum of thickness, microhardness and uniformity is expediently to carry on using the silicate-alkali...includes at the same time both the index of the process effectiveness and the strength and geometrical characteristics of the product . In connection

A high-fidelity weather time series generator using the Markov Chain process on a piecewise level

NASA Astrophysics Data System (ADS)

Hersvik, K.; Endrerud, O.-E. V.

2017-12-01

A method is developed for generating a set of unique weather time-series based on an existing weather series. The method allows statistically valid weather variations to take place within repeated simulations of offshore operations. The numerous generated time series need to share the same statistical qualities as the original time series. Statistical qualities here refer mainly to the distribution of weather windows available for work, including durations and frequencies of such weather windows, and seasonal characteristics. The method is based on the Markov chain process. The core new development lies in how the Markov Process is used, specifically by joining small pieces of random length time series together rather than joining individual weather states, each from a single time step, which is a common solution found in the literature. This new Markov model shows favorable characteristics with respect to the requirements set forth and all aspects of the validation performed.

Lunar Prospecting: Searching for Volatiles at the South Pole

NASA Technical Reports Server (NTRS)

Trimble, Jay; Carvalho, Robert

2016-01-01

The Resource Prospector is an in-situ resource utilization (ISRU) technology demonstration mission, planned for a 2021 launch to search for and analyze volatiles at the Lunar South Pole. The mission poses unique operational challenges. Operating at the Lunar South Pole requires navigating a surface with lighting, shadow and regolith characteristics unlike those of previous missions. The short round trip communications time enables reactive surface operations for science and engineering. Navigation of permanently shadowed regions with a solar powered rover creates risks, including power and thermal management, and requires constant real time decision making for safe entry, path selection and egress. The mission plan requires a faster rover egress from the lander than any previous NASA rover mission.

Financing the Air Transportation Industry

NASA Technical Reports Server (NTRS)

Lloyd-Jones, D. J.

1972-01-01

The basic characteristics of the air transportation industry are outlined and it is shown how they affect financing requirements and patterns of production. The choice of financial timing is imperative in order to get the best interest rates available and to insure a fair return to investors. The fact that the industry cannot store its products has a fairly major effect on the amount of equipment to purchase, the amount of capital investment required, and the amount of return required to offset industry depriciation.

Requirements Development Issues for Advanced Life Support Systems: Solid Waste Management

NASA Technical Reports Server (NTRS)

Levri, Julie A.; Fisher, John W.; Alazraki, Michael P.; Hogan, John A.

2002-01-01

Long duration missions pose substantial new challenges for solid waste management in Advanced Life Support (ALS) systems. These possibly include storing large volumes of waste material in a safe manner, rendering wastes stable or sterilized for extended periods of time, and/or processing wastes for recovery of vital resources. This is further complicated because future missions remain ill-defined with respect to waste stream quantity, composition and generation schedule. Without definitive knowledge of this information, development of requirements is hampered. Additionally, even if waste streams were well characterized, other operational and processing needs require clarification (e.g. resource recovery requirements, planetary protection constraints). Therefore, the development of solid waste management (SWM) subsystem requirements for long duration space missions is an inherently uncertain, complex and iterative process. The intent of this paper is to address some of the difficulties in writing requirements for missions that are not completely defined. This paper discusses an approach and motivation for ALS SWM requirements development, the characteristics of effective requirements, and the presence of those characteristics in requirements that are developed for uncertain missions. Associated drivers for life support system technological capability are also presented. A general means of requirements forecasting is discussed, including successive modification of requirements and the need to consider requirements integration among subsystems.

P-wave characteristics on routine preoperative electrocardiogram improve prediction of new-onset postoperative atrial fibrillation in cardiac surgery.

PubMed

Wong, Jim K; Lobato, Robert L; Pinesett, Andre; Maxwell, Bryan G; Mora-Mangano, Christina T; Perez, Marco V

2014-12-01

To test the hypothesis that including preoperative electrocardiogram (ECG) characteristics with clinical variables significantly improves the new-onset postoperative atrial fibrillation prediction model. Retrospective analysis. Single-center university hospital. Five hundred twenty-six patients, ≥ 18 years of age, who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement/repair, or a combination of valve surgery and coronary artery bypass grafting requiring cardiopulmonary bypass. Retrospective review of medical records. Baseline characteristics and cardiopulmonary bypass times were collected. Digitally-measured timing and voltages from preoperative electrocardiograms were extracted. Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Two hundred eight (39.5%) patients developed postoperative atrial fibrillation. Clinical predictors were age, ejection fraction<55%, history of atrial fibrillation, history of cerebral vascular event, and valvular surgery. Three ECG parameters associated with postoperative atrial fibrillation were observed: Premature atrial contraction, p-wave index, and p-frontal axis. Adding electrocardiogram variables to the prediction model with only clinical predictors significantly improved the area under the receiver operating characteristic curve, from 0.71 to 0.78 (p<0.01). Overall net reclassification improvement was 0.059 (p = 0.09). Among those who developed postoperative atrial fibrillation, the net reclassification improvement was 0.063 (p = 0.03). Several p-wave characteristics are independently associated with postoperative atrial fibrillation. Addition of these parameters improves the postoperative atrial fibrillation prediction model. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Deriving video content type from HEVC bitstream semantics

NASA Astrophysics Data System (ADS)

Nightingale, James; Wang, Qi; Grecos, Christos; Goma, Sergio R.

2014-05-01

As network service providers seek to improve customer satisfaction and retention levels, they are increasingly moving from traditional quality of service (QoS) driven delivery models to customer-centred quality of experience (QoE) delivery models. QoS models only consider metrics derived from the network however, QoE models also consider metrics derived from within the video sequence itself. Various spatial and temporal characteristics of a video sequence have been proposed, both individually and in combination, to derive methods of classifying video content either on a continuous scale or as a set of discrete classes. QoE models can be divided into three broad categories, full reference, reduced reference and no-reference models. Due to the need to have the original video available at the client for comparison, full reference metrics are of limited practical value in adaptive real-time video applications. Reduced reference metrics often require metadata to be transmitted with the bitstream, while no-reference metrics typically operate in the decompressed domain at the client side and require significant processing to extract spatial and temporal features. This paper proposes a heuristic, no-reference approach to video content classification which is specific to HEVC encoded bitstreams. The HEVC encoder already makes use of spatial characteristics to determine partitioning of coding units and temporal characteristics to determine the splitting of prediction units. We derive a function which approximates the spatio-temporal characteristics of the video sequence by using the weighted averages of the depth at which the coding unit quadtree is split and the prediction mode decision made by the encoder to estimate spatial and temporal characteristics respectively. Since the video content type of a sequence is determined by using high level information parsed from the video stream, spatio-temporal characteristics are identified without the need for full decoding and can be used in a timely manner to aid decision making in QoE oriented adaptive real time streaming.

Mountain pine beetle voltinism and life history characteristics across latitudinal and elevational gradients in the western United States

Treesearch

Barbara Bentz; James Vandygriff; Camille Jensen; Tom Coleman; Patricia Maloney; Sheri Smith; Amanda Grady; Greta Schen-Langenheim

2014-01-01

Substantial genetic variation in development time is known to exist among mountain pine beetle (Dendroctonus ponderosae Hopkins) populations across the western United States. The effect of this variation on geographic patterns in voltinism (generation time) and thermal requirements to produce specific voltinism pathways have not been investigated. The influence of...

Dimensionless figure of merit and its efficiency estimation for transient response of thermoelectric module based on impedance spectroscopy

NASA Astrophysics Data System (ADS)

Otsuka, Mioko; Hasegawa, Yasuhiro; Arisaka, Taichi; Shinozaki, Ryo; Morita, Hiroyuki

2017-11-01

The dimensionless figure of merit and its efficiency for the transient response of a Π-shaped thermoelectric module are estimated according to the theory of impedance spectroscopy. The effective dimensionless figure of merit is described as a function of the product of the characteristic time to reduce the temperature and the representative angular frequency of the module, which is expressed by the thermal diffusivity and the length of the elements used. The characteristic time required for achieving a higher dimensionless figure of merit and efficiency is derived quantitatively for the transient response using the properties of a commercial thermoelectric module.

Neutron and gamma irradiation effects on power semiconductor switches

NASA Technical Reports Server (NTRS)

Schwarze, G. E.; Frasca, A. J.

1990-01-01

The performance characteristics of high-power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

Neutron and gamma irradiation effects on power semiconductor switches

NASA Technical Reports Server (NTRS)

Schwarze, G. E.; Frasca, A. J.

1990-01-01

The performance characteristics of high power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

Human Mars Mission: Launch Window from Earth Orbit. Pt. 1

NASA Technical Reports Server (NTRS)

Young, Archie

1999-01-01

The determination of orbital window characteristics is of major importance in the analysis of human interplanetary missions and systems. The orbital launch window characteristics are directly involved in the selection of mission trajectories, the development of orbit operational concepts, and the design of orbital launch systems. The orbital launch window problem arises because of the dynamic nature of the relative geometry between outgoing (departure) asymptote of the hyperbolic escape trajectory and the earth parking orbit. The orientation of the escape hyperbola asymptotic relative to earth is a function of time. The required hyperbola energy level also varies with time. In addition, the inertial orientation of the parking orbit is a function of time because of the perturbations caused by the Earth's oblateness. Thus, a coplanar injection onto the escape hyperbola can be made only at a point in time when the outgoing escape asymptote is contained by the plane of parking orbit. Even though this condition may be planned as a nominal situation, it will not generally represent the more probable injection geometry. The general case of an escape injection maneuver performed at a time other than the coplanar time will involve both a path angle and plane change and, therefore, a DELTA V penalty. Usually, because of the DELTA V penalty the actual departure injection window is smaller in duration than that determined by energy requirement alone. This report contains the formulation, characteristics, and test cases for five different launch window modes for Earth orbit. These modes are: (1) One impulsive maneuver from a Highly Elliptical Orbit (HEO) (2) Two impulsive maneuvers from a Highly Elliptical Orbit (HEO) (3) One impulsive maneuver from a Low Earth Orbit (LEO) (4) Two impulsive maneuvers from LEO (5) Three impulsive maneuvers from LEO.

Atmospheric density models

NASA Technical Reports Server (NTRS)

Mueller, A. C.

1977-01-01

An atmospheric model developed by Jacchia, quite accurate but requiring a large amount of computer storage and execution time, was found to be ill-suited for the space shuttle onboard program. The development of a simple atmospheric density model to simulate the Jacchia model was studied. Required characteristics including variation with solar activity, diurnal variation, variation with geomagnetic activity, semiannual variation, and variation with height were met by the new atmospheric density model.

Flight dynamic investigations of flying wing with winglet configured unmanned aerial vehicle

NASA Astrophysics Data System (ADS)

Ro, Kapseong

2006-05-01

A swept wing tailless vehicle platform is well known in the radio control (RC) and sailing aircraft community for excellent spiral stability during soaring or thermaling, while exhibiting no Dutch roll behavior at high speed. When an unmanned aerial vehicle (UAV) is subjected to fly a mission in a rugged mountainous terrain where air current or thermal up-drift is frequently present, this is great aerodynamic benefit over the conventional cross-tailed aircraft which requires careful balance between lateral and directional stability. Such dynamic characteristics can be studied through vehicle dynamic modeling and simulation, but it requires configuration aerodynamic data through wind tunnel experiments. Obtaining such data is very costly and time consuming, and it is not feasible especially for low cost and dispensable UAVs. On the other hand, the vehicle autonomy is quite demanding which requires substantial understanding of aircraft dynamic characteristics. In this study, flight dynamics of an UAV platform based on flying wing with a large winglet was investigated through analytical modeling and numerical simulation. Flight dynamic modeling software and experimental formulae were used to obtain essential configuration aerodynamic characteristics, and linear flight dynamic analysis was carried out to understand the effect of wing sweep angle and winglet size on the vehicle dynamic characteristics.

Automated space processing payloads study. Volume 2, book 1: Technical report. [instrument packages and space shuttles

NASA Technical Reports Server (NTRS)

1975-01-01

The extent was investigated to which experiment hardware and operational requirements can be met by automatic control and material handling devices; payload and system concepts that make extensive use of automation technology are defined. Hardware requirements for each experiment were established and tabulated, and investigations of applicable existing hardware were documented. The capabilities and characteristics of industrial automation equipment, controls, and techniques are presented in the form of a summary of applicable equipment characteristics in three basic mutually-supporting formats. Facilities for performing groups of experiments are defined along with four levitation groups and three furnace groups; major hardware elements required to implement them were identified. A conceptual design definition of ten different automated processing facilities is presented along with the specific equipment to implement each facility and the design layouts of the different units. Constraints and packaging, weight, and power requirements for six payloads postulated for shuttle missions in the 1979 to 1982 time period were examined.

Recovery Characteristics of Anomalous Stress-Induced Leakage Current of 5.6 nm Oxide Films

NASA Astrophysics Data System (ADS)

Inatsuka, Takuya; Kumagai, Yuki; Kuroda, Rihito; Teramoto, Akinobu; Sugawa, Shigetoshi; Ohmi, Tadahiro

2012-04-01

Anomalous stress-induced leakage current (SILC), which has a much larger current density than average SILC, causes severe bit error in flash memories. To suppress anomalous SILC, detailed evaluations are strongly required. We evaluate the characteristics of anomalous SILC of 5.6 nm oxide films using a fabricated array test pattern, and recovery characteristics are observed. Some characteristics of typical anomalous cells in the time domain are measured, and the recovery characteristics of average and anomalous SILCs are examined. Some of the anomalous cells have random telegraph signals (RTSs) of gate leakage current, which are characterized as discrete and random switching phenomena. The dependence of RTSs on the applied electric field is investigated, and the recovery tendency of anomalous SILC with and without RTSs are also discussed.

Criteria for Handling Qualities of Military Aircraft.

DTIC Science & Technology

1982-06-01

loop precognitive manner. The pilot is able to apply discrete, step-like inputs which more or less exactly produce the desired aircraft response. Some...While closed loop operation depends upon the frequency domain response characteristics, successful precognitive control requires the time domain...represents the other extreme of the pilot task from the precognitive time response situation. Mich work was done in attempting to predict pilot opinion from

TIME-TAG mode of STIS observations using the MAMA detectors

NASA Astrophysics Data System (ADS)

Sahu, Kailash; Danks, Anthony; Baum, Stefi; Balzano, Vicki; Kraemer, Steve; Kutina, Ray; Sears, William

1995-04-01

We summarize the time-tag mode of STIS observations using the MAMA detectors, both in imaging and spectroscopic modes. After a brief outline on the MAMA detector characteristics and the astronomical applications of the time-tag mode, the general philosophy and the details of the data management strategy are described in detail. The GO specifications, and the consequent different modes of data transfer strategy are outlined. Restrictions on maximum data rates, integration times, and BUFFER-TIME requirements are explained. A few cases where the subarray option would be useful are outlined.

Speckle-field propagation in 'frozen' turbulence: brightness function approach

NASA Astrophysics Data System (ADS)

Dudorov, Vadim V.; Vorontsov, Mikhail A.; Kolosov, Valeriy V.

2006-08-01

Speckle-field long- and short-exposure spatial correlation characteristics for target-in-the-loop (TIL) laser beam propagation and scattering in atmospheric turbulence are analyzed through the use of two different approaches: the conventional Monte Carlo (MC) technique and the recently developed brightness function (BF) method. Both the MC and the BF methods are applied to analysis of speckle-field characteristics averaged over target surface roughness realizations under conditions of 'frozen' turbulence. This corresponds to TIL applications where speckle-field fluctuations associated with target surface roughness realization updates occur within a time scale that can be significantly shorter than the characteristic atmospheric turbulence time. Computational efficiency and accuracy of both methods are compared on the basis of a known analytical solution for the long-exposure mutual correlation function. It is shown that in the TIL propagation scenarios considered the BF method provides improved accuracy and requires significantly less computational time than the conventional MC technique. For TIL geometry with a Gaussian outgoing beam and Lambertian target surface, both analytical and numerical estimations for the speckle-field long-exposure correlation length are obtained. Short-exposure speckle-field correlation characteristics corresponding to propagation in 'frozen' turbulence are estimated using the BF method. It is shown that atmospheric turbulence-induced static refractive index inhomogeneities do not significantly affect the characteristic correlation length of the speckle field, whereas long-exposure spatial correlation characteristics are strongly dependent on turbulence strength.

Speckle-field propagation in 'frozen' turbulence: brightness function approach.

PubMed

Dudorov, Vadim V; Vorontsov, Mikhail A; Kolosov, Valeriy V

2006-08-01

Speckle-field long- and short-exposure spatial correlation characteristics for target-in-the-loop (TIL) laser beam propagation and scattering in atmospheric turbulence are analyzed through the use of two different approaches: the conventional Monte Carlo (MC) technique and the recently developed brightness function (BF) method. Both the MC and the BF methods are applied to analysis of speckle-field characteristics averaged over target surface roughness realizations under conditions of 'frozen' turbulence. This corresponds to TIL applications where speckle-field fluctuations associated with target surface roughness realization updates occur within a time scale that can be significantly shorter than the characteristic atmospheric turbulence time. Computational efficiency and accuracy of both methods are compared on the basis of a known analytical solution for the long-exposure mutual correlation function. It is shown that in the TIL propagation scenarios considered the BF method provides improved accuracy and requires significantly less computational time than the conventional MC technique. For TIL geometry with a Gaussian outgoing beam and Lambertian target surface, both analytical and numerical estimations for the speckle-field long-exposure correlation length are obtained. Short-exposure speckle-field correlation characteristics corresponding to propagation in 'frozen' turbulence are estimated using the BF method. It is shown that atmospheric turbulence-induced static refractive index inhomogeneities do not significantly affect the characteristic correlation length of the speckle field, whereas long-exposure spatial correlation characteristics are strongly dependent on turbulence strength.

Improved performance characteristics of a high temperature superconductor bolometer using photo-thermoelectrical feedback

NASA Astrophysics Data System (ADS)

Kaila, M. M.; Russell, G. J.

2000-12-01

We have designed a liquid nitrogen cooled detector where a thermoelectric feedback is combined with electrothermal feedback to produce an improvement of three orders of magnitude in the response time of the detector. We have achieved this by considering a parallel resistance combination of thermoelectric and High Temperature Superconductor (HTSC) material legs of an approximate geometry 1mm /spl times/ 2 mm /spl times/ 1micron operated at 80K. One end of this thermocouple acts as the sensitive area where the radiation is absorbed. The other end remains unexposed and stays basically at substrate temperature. It is found that micron thick films in our bolometer produce characteristics very close to those found for nanometer thick films required in semiconductor detectors and Low Temperature Superconductor (LTSC) bolometers.

Frontline Nurse Engagement and Empowerment: Characteristics and Processes for Building Leadership Capacity.

PubMed

Riley, Bettina H; Dearmon, Valorie; Mestas, Lisa; Buckner, Ellen B

2016-01-01

Improving health care quality is the responsibility of nurses at all levels of the organization. This article describes a study that examined frontline staff nurses' professional practice characteristics to advance leadership through the understanding of relationships among practice environment, quality improvement, and outcomes. The study design was a descriptive quantitative design at 2 time points. Findings support the use of research and quality processes to build leadership capacity required for positive resolution of interdisciplinary operational failures.

Speeding up image quality improvement in random phase-free holograms using ringing artifact characteristics.

PubMed

Nagahama, Yuki; Shimobaba, Tomoyoshi; Kakue, Takashi; Masuda, Nobuyuki; Ito, Tomoyoshi

2017-05-01

A holographic projector utilizes holography techniques. However, there are several barriers to realizing holographic projections. One is deterioration of hologram image quality caused by speckle noise and ringing artifacts. The combination of the random phase-free method and the Gerchberg-Saxton (GS) algorithm has improved the image quality of holograms. However, the GS algorithm requires significant computation time. We propose faster methods for image quality improvement of random phase-free holograms using the characteristics of ringing artifacts.

Simulator study of flight characteristics of a large twin-fuselage cargo transport airplane during approach and landing

NASA Technical Reports Server (NTRS)

Grantham, W. D.; Deal, P. L.; Keyser, G. L., Jr.; Smith, P. M.

1983-01-01

A six degree-of-freedom, ground-based simulator study was conducted to evaluate the low speed flight characteristics of a twin fuselage cargo transport airplane and to compare these characteristics with those of a large, single fuselage (reference) transport configuration which was similar to the Lockheed C-5C airplane. The primary piloting task was the approach and landing. The results indicated that in order to achieve "acceptable' low speed handling qualities on the twin fuselage concept, considerable stability and control augmentation was required, and although the augmented airplane could be landed safely under adverse conditions, the roll performance of the aircraft had to be improved appreciably before the handling qualities were rated as being "satisfactory.' These ground-based simulation results indicated that a value of t sub phi = 30 (time required to bank 30 deg) less than 6 sec should result in "acceptable' roll response characteristics, and when t sub phi = 30 is less than 3.8 sec, "satisfactory' roll response should be attainable on such large and unusually configured aircraft as the subject twin fuselage cargo transport concept.

Energy flux and characteristic energy of an elemental auroral structure

NASA Technical Reports Server (NTRS)

Lanchester, B. S.; Palmer, J. R.; Rees, M. H.; Lummerzheim, D.; Kaila, K.; Turunen, T.

1994-01-01

Electron density profiles acquired with the EISCAT radar at 0.2 s time resolution, together with TV images and photometric intensities, were used to study the characteristics of thin (less than 1 km) auroral arc structures that drifted through the field of view of the instruments. It is demonstrated that both high time and space resolution are essential for deriving the input parameters of the electron flux responsible for the elemental auroral structures. One such structure required a 400 mW/sq m (erg/sq cm s) downward energy flux carried by an 8 keV monochromatic electron flux equivalent to a current density of 50 micro Angstrom/sq m.

A multi-criteria decision aid methodology to design electric vehicles public charging networks

NASA Astrophysics Data System (ADS)

Raposo, João; Rodrigues, Ana; Silva, Carlos; Dentinho, Tomaz

2015-05-01

This article presents a new multi-criteria decision aid methodology, dynamic-PROMETHEE, here used to design electric vehicle charging networks. In applying this methodology to a Portuguese city, results suggest that it is effective in designing electric vehicle charging networks, generating time and policy based scenarios, considering offer and demand and the city's urban structure. Dynamic-PROMETHE adds to the already known PROMETHEE's characteristics other useful features, such as decision memory over time, versatility and adaptability. The case study, used here to present the dynamic-PROMETHEE, served as inspiration and base to create this new methodology. It can be used to model different problems and scenarios that may present similar requirement characteristics.

Distributed systems status and control

NASA Technical Reports Server (NTRS)

Kreidler, David; Vickers, David

1990-01-01

Concepts are investigated for an automated status and control system for a distributed processing environment. System characteristics, data requirements for health assessment, data acquisition methods, system diagnosis methods and control methods were investigated in an attempt to determine the high-level requirements for a system which can be used to assess the health of a distributed processing system and implement control procedures to maintain an accepted level of health for the system. A potential concept for automated status and control includes the use of expert system techniques to assess the health of the system, detect and diagnose faults, and initiate or recommend actions to correct the faults. Therefore, this research included the investigation of methods by which expert systems were developed for real-time environments and distributed systems. The focus is on the features required by real-time expert systems and the tools available to develop real-time expert systems.

Simulation Evaluation of Pilot Inputs for Real Time Modeling During Commercial Flight Operations

NASA Technical Reports Server (NTRS)

Martos, Borja; Ranaudo, Richard; Oltman, Ryan; Myhre, Nick

2017-01-01

Aircraft dynamics characteristics can only be identified from flight data when the aircraft dynamics are excited sufficiently. A preliminary study was conducted into what types and levels of manual piloted control excitation would be required for accurate Real-Time Parameter IDentification (RTPID) results by commercial airline pilots. This includes assessing the practicality for the pilot to provide this excitation when cued, and to further understand if pilot inputs during various phases of flight provide sufficient excitation naturally. An operationally representative task was evaluated by 5 commercial airline pilots using the NASA Ice Contamination Effects Flight Training Device (ICEFTD). Results showed that it is practical to use manual pilot inputs only as a means of achieving good RTPID in all phases of flight and in flight turbulence conditions. All pilots were effective in satisfying excitation requirements when cued. Much of the time, cueing was not even necessary, as just performing the required task provided enough excitation for accurate RTPID estimation. Pilot opinion surveys reported that the additional control inputs required when prompted by the excitation cueing were easy to make, quickly mastered, and required minimal training.

Chronic subdural haematoma evolving from traumatic subdural hydroma.

PubMed

Wang, Yaodong; Wang, Chuanwei; Liu, Yuguang

2015-01-01

This study aimed to investigate the incidence and clinical characteristics of chronic subdural haematoma (CSDH) evolving from traumatic subdual hydroma (TSH). The clinical characteristics of 44 patients with CSDH evolving from TSH were analysed retrospectively and the relevant literature was reviewed. In 22.6% of patients, TSH evolved into CSDH. The time required for this evolution was 14-100 days after injury. All patients were cured with haematoma drainage. TSH is one possible origin of CSDH. The clinical characteristics of TSH evolving into CSDH include polarization of patient age and chronic small effusion. The injuries usually occur during deceleration and are accompanied by mild cerebral damage.

Design features and operational characteristics of the Langley pilot transonic cryogenic tunnel

NASA Technical Reports Server (NTRS)

Kilgore, R. A.

1974-01-01

A fan-driven transonic cryogenic tunnel was designed, and its purging, cooldown, and warmup times were determined satisfactory. Cooling with liquid nitrogen is at the power levels required for transonic testing. Good temperature distributions are obtained by using a simple nitrogen injection system.

Speech Restoration: An Interactive Process

ERIC Educational Resources Information Center

Grataloup, Claire; Hoen, Michael; Veuillet, Evelyne; Collet, Lionel; Pellegrino, Francois; Meunier, Fanny

2009-01-01

Purpose: This study investigates the ability to understand degraded speech signals and explores the correlation between this capacity and the functional characteristics of the peripheral auditory system. Method: The authors evaluated the capability of 50 normal-hearing native French speakers to restore time-reversed speech. The task required them…

Numerical study on response time of a parallel plate capacitive polyimide humidity sensor based on microhole upper electrode

NASA Astrophysics Data System (ADS)

Zhou, Wenhe; He, Xuan; Wu, Jianyun; Wang, Liangbi; Wang, Liangcheng

2017-07-01

The parallel plate capacitive humidity sensor based on the grid upper electrode is considered to be a promising one in some fields which require a humidity sensor with better dynamic characteristics. To strengthen the structure and balance the electric charge of the grid upper electrode, a strip is needed. However, it is the strip that keeps the dynamic characteristics of the sensor from being further improved. The numerical method is time- and cost-saving, but the numerical study on the response time of the sensor is just of bits and pieces. The numerical models presented by these studies did not consider the porosity effect of the polymer film on the dynamic characteristics. To overcome the defect of the grid upper electrode, a new structure of the upper electrode is provided by this paper first, and then a model considering the porosity effects of the polymer film on the dynamic characteristics is presented and validated. Finally, with the help of software FLUENT, parameter effects on the response time of the humidity sensor based on the microhole upper electrode are studied by the numerical method. The numerical results show that the response time of the microhole upper electrode sensor is 86% better than that of the grid upper electrode sensor, the response time of humidity sensor can be improved by reducing the hole spacing, increasing the aperture, reducing film thickness, and reasonably enlarging the porosity of the film.

Measuring relative work values for home care nursing services in Japan.

PubMed

Ogata, Yasuko; Kobayashi, Yasuki; Fukuda, Takashi; Mori, Katsumi; Hashimoto, Michio; Otosaka, Kayo

2004-01-01

Japan's system of Home Visit Nursing Care Stations (Station) began in 1991. To maintain the quality of services in home health nursing provided by Stations, reimbursement needs to account not only for the number of home visits, but also for the time and intensity of nursing services. This study aimed primarily to investigate the total work value and the three dimensions (time, mental effort, and physical effort) of actual visiting nursing services for the aged, and to quantify the contribution made by the three dimensions of nursing services to total work. The secondary purpose was to determine whether patient characteristics, nurse characteristics, and types of nursing services contributed to the variance in total work. Total work is defined as comprehensive work input of nursing services, with careful consideration given to both the intensity and duration of work. Self-report questionnaires about actual visiting nursing services, based on the Resource-Based Relative Value Scale, were answered by 32 nurses from three Stations in urban Yokohama, Japan. Regression analysis showed that time and intensity (physical effort and mental effort) explained 96% the variance in total work. Time alone accounted for only 39% of the variance in total work. Patient characteristics, nurse characteristics, and service type accounted for less variance in total work than did time and intensity. The study findings indicate that reimbursement of nursing services should reflect not only the time required for each visit, but also the intensity of nursing services provided, including mental effort and physical effort.

A Comparison of Forecast Error Generators for Modeling Wind and Load Uncertainty

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

Lu, Ning; Diao, Ruisheng; Hafen, Ryan P.

2013-07-25

This paper presents four algorithms to generate random forecast error time series. The performance of four algorithms is compared. The error time series are used to create real-time (RT), hour-ahead (HA), and day-ahead (DA) wind and load forecast time series that statistically match historically observed forecasting data sets used in power grid operation to study the net load balancing need in variable generation integration studies. The four algorithms are truncated-normal distribution models, state-space based Markov models, seasonal autoregressive moving average (ARMA) models, and a stochastic-optimization based approach. The comparison is made using historical DA load forecast and actual load valuesmore » to generate new sets of DA forecasts with similar stoical forecast error characteristics (i.e., mean, standard deviation, autocorrelation, and cross-correlation). The results show that all methods generate satisfactory results. One method may preserve one or two required statistical characteristics better the other methods, but may not preserve other statistical characteristics as well compared with the other methods. Because the wind and load forecast error generators are used in wind integration studies to produce wind and load forecasts time series for stochastic planning processes, it is sometimes critical to use multiple methods to generate the error time series to obtain a statistically robust result. Therefore, this paper discusses and compares the capabilities of each algorithm to preserve the characteristics of the historical forecast data sets.« less

Quasi Real Time Data Analysis for Air Quality Monitoring with an Electronic Nose

NASA Technical Reports Server (NTRS)

Zhou, Hanying; Shevade, Abhijit V.; Pelletier, Christine C.; Homer, Margie L.; Ryan, M. Amy

2006-01-01

Cabin Air Quality Monitoring: A) Functions; 1) Incident monitor for targeted contaminants exceeding targeted concentrations. Identify and quantify. 2) Monitor for presence of compounds associated with fires or overheating electronics. 3) Monitor clean-up process. B) Characteristics; 1) Low mass, low power device. 2) Requires little crew time for maintenance and calibration. 3) Detects, identifies and quantifies selected chemical species at or below 24 hour SMAC.

Transfers between libration-point orbits in the elliptic restricted problem

NASA Astrophysics Data System (ADS)

Hiday, L. A.; Howell, K. C.

The present time-fixed impulsive transfers between 3D libration point orbits in the vicinity of the interior L(1) libration point of the sun-earth-moon barycenter system are 'optimal' in that the total characteristic velocity required for implementation of the transfer exhibits a local minimum. The conditions necessary for a time-fixed, two-impulse transfer trajectory to be optimal are stated in terms of the primer vector, and the conditions necessary for satisfying the local optimality of a transfer trajectory containing additional impulses are addressed by requiring continuity of the Hamiltonian and the derivative of the primer vector at all interior impulses.

Characteristic analysis and simulation for polysilicon comb micro-accelerometer

NASA Astrophysics Data System (ADS)

Liu, Fengli; Hao, Yongping

2008-10-01

High force update rate is a key factor for achieving high performance haptic rendering, which imposes a stringent real time requirement upon the execution environment of the haptic system. This requirement confines the haptic system to simplified environment for reducing the computation cost of haptic rendering algorithms. In this paper, we present a novel "hyper-threading" architecture consisting of several threads for haptic rendering. The high force update rate is achieved with relatively large computation time interval for each haptic loop. The proposed method was testified and proved to be effective with experiments on virtual wall prototype haptic system via Delta Haptic Device.

Pulsed x-ray sources for characterization of gated framing cameras

NASA Astrophysics Data System (ADS)

Filip, Catalin V.; Koch, Jeffrey A.; Freeman, Richard R.; King, James A.

2017-08-01

Gated X-ray framing cameras are used to measure important characteristics of inertial confinement fusion (ICF) implosions such as size and symmetry, with 50 ps time resolution in two dimensions. A pulsed source of hard (>8 keV) X-rays, would be a valuable calibration device, for example for gain-droop measurements of the variation in sensitivity of the gated strips. We have explored the requirements for such a source and a variety of options that could meet these requirements. We find that a small-size dense plasma focus machine could be a practical single-shot X-ray source for this application if timing uncertainties can be overcome.

On the Time Scale of Nocturnal Boundary Layer Cooling in Valleys and Basins and over Plains

NASA Astrophysics Data System (ADS)

de Wekker, Stephan F. J.; Whiteman, C. David

2006-06-01

Sequences of vertical temperature soundings over flat plains and in a variety of valleys and basins of different sizes and shapes were used to determine cooling-time-scale characteristics in the nocturnal stable boundary layer under clear, undisturbed weather conditions. An exponential function predicts the cumulative boundary layer cooling well. The fitting parameter or time constant in the exponential function characterizes the cooling of the valley atmosphere and is equal to the time required for the cumulative cooling to attain 63.2% of its total nighttime value. The exponential fit finds time constants varying between 3 and 8 h. Calculated time constants are smallest in basins, are largest over plains, and are intermediate in valleys. Time constants were also calculated from air temperature measurements made at various heights on the sidewalls of a small basin. The variation with height of the time constant exhibited a characteristic parabolic shape in which the smallest time constants occurred near the basin floor and on the upper sidewalls of the basin where cooling was governed by cold-air drainage and radiative heat loss, respectively.

Surgical problems and complex procedures: issues for operative time in robotic totally endoscopic coronary artery bypass grafting.

PubMed

Wiedemann, Dominik; Bonaros, Nikolaos; Schachner, Thomas; Weidinger, Felix; Lehr, Eric J; Vesely, Mark; Bonatti, Johannes

2012-03-01

Robotically assisted totally endoscopic coronary artery bypass grafting (TECAB) is a viable option for closed chest coronary surgery, but it requires learning curves and longer operative times. This study evaluated the effect of extended operation times on the outcome of patients undergoing TECAB. From 2001 to 2009, 325 patients underwent TECAB with the da Vinci telemanipulation system. Correlations between operative times and preoperative, intraoperative, and early postoperative parameters were investigated. Receiver operating characteristic analysis was used to define the threshold of the procedure duration above which intensive care unit stay and ventilation time were prolonged. Demographic data, intraoperative and postoperative parameters, and survival data were compared. Patients with prolonged operative times more often underwent multivessel revascularization (P < .001) and beating-heart TECAB (P =.023). Other preoperative parameters were not associated with longer operative times. Incidences of technical difficulties and conversions (P < .001) were higher among patients with longer operative times. Prolonged intensive care unit stay, mechanical ventilation, hospital stay, and with requirement of blood products were associated with longer operative times. Receiver operating characteristic analysis showed operative times >445 minutes and >478 minutes to predict prolonged (>48 hours) intensive care unit stay and mechanical ventilation, respectively. Patients with procedures >478 minutes had longer hospital stays and higher perioperative morbidity and mortality. Kaplan-Meier analysis revealed decreased survival among patients with operative times >478 minutes. Multivessel revascularization and conversions lead to prolonged operative times in totally endoscopic coronary artery bypass grafting. Longer operative times significantly influence early postoperative and midterm outcomes. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Complications and adequacy of transplant kidney biopsies: A comparison of techniques.

PubMed

Plattner, Brett W; Chen, Pauline; Cross, Richard; Leavitt, Matthew A; Killen, Paul D; Heung, Michael

2018-05-01

Kidney biopsies are an essential tool in the diagnosis and management of kidney diseases, particularly in kidney transplant recipients. Biopsies carry a risk for serious complications and not all biopsies achieve adequate tissue. We examined the impact of kidney biopsy technique on complications and biopsy adequacy. The cohort consisted of consecutive kidney transplant patients undergoing biopsy by one of three techniques: ultrasound localization, real-time ultrasound guidance, and ultrasound-guided trocar placement. Variables of interest included patient characteristics and procedural characteristics. The primary outcome was serious complication attributable to kidney biopsy, and the secondary outcome was biopsy adequacy as defined by Banff criteria. Among 263 patients undergoing biopsy, 27 (10.3%) had a complication (14 with gross hematuria, 10 requiring blood transfusion, 3 requiring an unplanned interventional radiology procedure, 1 kidney loss; no deaths). Complications were more common among patients biopsied using ultrasound-guided trocar compared to real-time ultrasound and ultrasound localization (21.4% vs 7.9% vs 7.1%, respectively, p = 0.008). After adjusting for patient and procedure characteristics, technique was no longer significantly associated with complication. Biopsy adequacy was significantly higher when using ultrasound localization and real-time ultrasound compared to ultrasound-guided trocar (84.6% vs 86.8% vs 69.6%, p = 0.029), and this finding persisted in adjusted analysis. Kidney biopsy complications appear to be similar when using any of the three techniques examined in our study. However, ultrasound-guided trocar technique may yield lower biopsy adequacy when compared to non-trocar techniques.

Vector Doppler: spatial sampling analysis and presentation techniques for real-time systems

NASA Astrophysics Data System (ADS)

Capineri, Lorenzo; Scabia, Marco; Masotti, Leonardo F.

2001-05-01

The aim of the vector Doppler (VD) technique is the quantitative reconstruction of a velocity field independently of the ultrasonic probe axis to flow angle. In particular vector Doppler is interesting for studying vascular pathologies related to complex blood flow conditions. Clinical applications require a real-time operating mode and the capability to perform Doppler measurements over a defined volume. The combination of these two characteristics produces a real-time vector velocity map. In previous works the authors investigated the theory of pulsed wave (PW) vector Doppler and developed an experimental system capable of producing off-line 3D vector velocity maps. Afterwards, for producing dynamic velocity vector maps, we realized a new 2D vector Doppler system based on a modified commercial echograph. The measurement and presentation of a vector velocity field requires a correct spatial sampling that must satisfy the Shannon criterion. In this work we tackled this problem, establishing a relationship between sampling steps and scanning system characteristics. Another problem posed by the vector Doppler technique is the data representation in real-time that should be easy to interpret for the physician. With this in mine we attempted a multimedia solution that uses both interpolated images and sound to represent the information of the measured vector velocity map. These presentation techniques were experimented for real-time scanning on flow phantoms and preliminary measurements in vivo on a human carotid artery.

10 CFR 63.305 - Required characteristics of the reference biosphere.

Code of Federal Regulations, 2011 CFR

2011-01-01

....305 Section 63.305 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE... biosphere (other than climate), human biology, or increases or decreases of human knowledge or technology... factors remain constant as they are at the time of submission of the license application. (c) DOE must...

Body Composition and Aerobic Requirements of Male and Female Marathon Runners.

ERIC Educational Resources Information Center

Wells, Christine L.; And Others

This study investigates the physical characteristics, body composition, cardiovascular and pulmonary functions, and aerobic capabilities of male and female long distance runners. Eleven runners volunteered to take tests to determine background information, body fat, oxygen uptake, and running time and pace. Conclusions made from this study…

Rhythms of Mental Performance

ERIC Educational Resources Information Center

Valdez, Pablo; Reilly, Thomas; Waterhouse, Jim

2008-01-01

Cognitive performance is affected by an individual's characteristics and the environment, as well as by the nature of the task and the amount of practice at it. Mental performance tests range in complexity and include subjective estimates of mood, simple objective tests (reaction time), and measures of complex performance that require decisions to…

Development of near-infrared spectroscopy calibrations to measure quality characteristics in intact Brassicaceae germplasm

USDA-ARS?s Scientific Manuscript database

Determining seed quality parameters is an integral part of cultivar improvement and germplasm screening. However, quality tests are often time cnsuming, seed destructive, and can require large seed samples. This study describes the development of near-infrared spectroscopy (NIRS) calibrations to mea...

Effect of sintering methods and temperatures on porosity of the ceramics from aluminum oxinitride

NASA Astrophysics Data System (ADS)

Prosvirnin, D. V.; Kolmakov, A. G.; Larionov, M. D.; Prutskov, M. E.; Alikhanyan, A. S.; Samokhin, A. V.; Lysenkov, A. S.; Titov, D. D.

2018-04-01

The paper presents the results of studies of the effect of temperature regimes and time on porosity in ceramic samples made of aluminum oxynitride. Getting rid of the porous structure allows reducing the scattering of rays and, as a result, achieving the required optical characteristics.

Correlation of fermentation characteristics with intake and digestibility of alfalfa silage in gestating ewes

USDA-ARS?s Scientific Manuscript database

Baled silage production provides benefits to farmers because it reduces leaf losses, and requires a shorter wilting time, thereby limiting risks of exposure to rain compared with making hay. Our objective was to investigate the correlation of alfalfa silage fermentation parameters with intake and di...

Self-Consciousness, Evaluation of Physical Characteristics, and Physical Attractiveness.

ERIC Educational Resources Information Center

Turner, Robert G.; Gilliland, LuNell

1981-01-01

Investigated the relationship between public self-consciousness and speed of processing information about self. Results indicated that high public self-conciousness subjects required less time to report evaluations of their physical features. In a second study high public self-conciousness was shown to be positively related to judged physical…

Implications of path tolerance and path characteristics on critical vehicle manoeuvres

NASA Astrophysics Data System (ADS)

Lundahl, K.; Frisk, E.; Nielsen, L.

2017-12-01

Path planning and path following are core components in safe autonomous driving. Typically, a path planner provides a path with some tolerance on how tightly the path should be followed. Based on that, and other path characteristics, for example, sharpness of curves, a speed profile needs to be assigned so that the vehicle can stay within the given tolerance without going unnecessarily slow. Here, such trajectory planning is based on optimal control formulations where critical cases arise as on-the-limit solutions. The study focuses on heavy commercial vehicles, causing rollover to be of a major concern, due to the relatively high centre of gravity. Several results are obtained on required model complexity depending on path characteristics, for example, quantification of required path tolerance for a simple model to be sufficient, quantification of when yaw inertia needs to be considered in more detail, and how the curvature rate of change interplays with available friction. Overall, in situations where the vehicle is subject to a wide range of driving conditions, from good transport roads to more tricky avoidance manoeuvres, the requirements on the path following will vary. For this, the provided results form a basis for real-time path following.

14 CFR 133.41 - Flight characteristics requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight characteristics requirements. 133.41... EXTERNAL-LOAD OPERATIONS Airworthiness Requirements § 133.41 Flight characteristics requirements. (a) The applicant must demonstrate to the Administrator, by performing the operational flight checks prescribed in...

14 CFR 133.41 - Flight characteristics requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight characteristics requirements. 133.41... EXTERNAL-LOAD OPERATIONS Airworthiness Requirements § 133.41 Flight characteristics requirements. (a) The applicant must demonstrate to the Administrator, by performing the operational flight checks prescribed in...

14 CFR 133.41 - Flight characteristics requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight characteristics requirements. 133.41... EXTERNAL-LOAD OPERATIONS Airworthiness Requirements § 133.41 Flight characteristics requirements. (a) The applicant must demonstrate to the Administrator, by performing the operational flight checks prescribed in...

The 1973 NASA payload model: Space opportunities 1973 - 1991. [characteristics of payloads and requirements of user community

NASA Technical Reports Server (NTRS)

1973-01-01

The tables of schedules and descriptions which portray the 1973 NASA Payload Model are presented. The schedules cover all NASA programs and the anticipated requirements of the user community, not including the Department of Defense, for the 1973 to 1991 period. The descriptions give an indication of what the payload is expected to accomplish, its characteristics, and where it is going. The payload flight schedules shown for each of the discipline areas indicate the time frame in which individual payloads will be launched, serviced, or retrieved. These do not necessarily constitute shuttle flights, however, since more than one payload can be flown on a single shuttle flight depending on size, weight, orbital destination, and the suitability of combining them. The weight, dimension, and destination data represent approximations of the payload characteristics as estimated by the Program Offices. Payload codes are provided for easy correlation between the schedules and descriptions of the Payload Model and subsequent documentation which may reference this model.

Impact of torrefaction on the grindability and fuel characteristics of forest biomass.

PubMed

Phanphanich, Manunya; Mani, Sudhagar

2011-01-01

Thermal pretreatment or torrefaction of biomass under anoxic condition can produce an energy dense and consistent quality solid biomass fuel for combustion and co-firing applications. This paper investigates the fuel characteristics and grindability of pine chips and logging residues torrefied at temperatures ranging from 225 °C to 300 °C and 30 min residence time. Grinding performance of torrefied biomass evaluated by determining energy required for grinding, particle size distribution and average particle size were compared with raw biomass and coal. Specific energy required for grinding of torrefied biomass decreased significantly with increase in torrefaction temperatures. The grinding energy of torrefied biomass was reduced to as low as 24 kW h/t at 300 °C torrefaction temperature. The gross calorific value of torrefied chips increased with increase in torrefaction temperature. Torrefaction of biomass clearly showed the improved fuel characteristics and grinding properties closer to coal. Copyright © 2010 Elsevier Ltd. All rights reserved.

Experiences that develop the ability to think strategically.

PubMed

Goldman, Ellen; Cahill, Terrence; Filho, Rubens Pessanha

2009-01-01

The ability to think strategically is an admired and a sought-after leadership requirement, yet we know little about how it develops. The purpose of this study is to identify specific experiences that contribute to the development of an individual's ability to think strategically. We identified eight work experiences, including different types of organizational projects, processes, and relationships, that contribute to an individual's strategic thinking ability. We also delineate specific characteristics material to each experience. These characteristics indicate that considerable time and focus are required to develop the ability to think strategically. In addition, the experiences are not all accessed equally: Women are less likely to have nonrelational experiences, while chief executive officers are more likely to have the most challenging ones. In addition, we found differences regarding work-related continuing education activities. Respondents rated nonhealthcare conferences and reading behind all other identified experiences that contribute to strategic thinking ability. Individuals can implement several strategies to improve their strategic thinking ability, including deliberately incorporating the requisite experiences into their development plans, ensuring that the experiences incorporate the required characteristics, and improving the benefit received from attending educational programs in nonhealthcare industries. Organizations can implement several strategies to ensure the experiences are as effective as possible, such as appraising gender differences across the experiences and reviewing the organization's strategic planning processes for the characteristics that best encourage strategic thinking.

Parametric studies of North East Corridor rail passenger service between New York City and Washington, D. C.. [propulsive efficiency studies

NASA Technical Reports Server (NTRS)

Stallkamp, J. A.

1977-01-01

Speed profiles of rail passenger service between New York City and Washington, D.C. were developed and showed progressively fewer speed restrictions and increasing maximum speeds. The significant equipment characteristics include the portion of the total weight on driven axles, i.e., multiple unit (MU) cars versus locomotive hauled trains, and the short term tractive effort rating of the motors. The ratio of acceleration plus braking time to total time is provided for validation of the use of the short term propulsion equipment ratings. Absolute trip times are shown to be determined primarily by the allowed speed profile. Locomotive hauled train weights and lengths and the locomotive capabilities and characteristics that are required to make the performance of this type of train comparable to that of MU trains are given.

Effect of perineural dexmedetomidine on the quality of supraclavicular brachial plexus block with 0.5% ropivacaine and its interaction with general anaesthesia.

PubMed

Gurajala, Indira; Thipparampall, Anil Kumar; Durga, Padmaja; Gopinath, R

2015-02-01

The effect of perineural dexmedetomidine on the time to onset, quality and duration of motor block with ropivacaine has been equivocal and its interaction with general anaesthesia (GA) has not been reported. We assessed the influence of dexmedetomidine added to 0.5% ropivacaine on the characteristics of supraclavicular brachial plexus block and its interaction with GA. In a randomised, double blind study, 36 patients scheduled for orthopaedic surgery on the upper limb under supraclavicular block and GA were divided into either R group (35 ml of 0.5% ropivacaine with 0.5 ml of normal saline [n - 18]) or RD group (35 mL of 0.5% ropivacaine with 50 μg dexmedetomidine [n - 18]). The onset time and duration of motor and sensory blockade were noted. The requirement of general anaesthetics was recorded. Both the groups were comparable in demographic characteristics. The time of onset of sensory block was not significantly different. The proportion of patients who achieved complete motor blockade was more in the RD group. The onset of motor block was earlier in group RD than group R (P < 0.05). The durations of analgesia, sensory and motor blockade were significantly prolonged in group RD (P < 0.00). The requirement of entropy guided anaesthetic agents was not different in both groups. The addition of dexmedetomidine to 0.5% ropivacaine improved the time of onset, quality and duration of supraclavicular brachial plexus block but did not decrease the requirement of anaesthetic agents during GA.

Rationale choosing interval of a piecewise-constant approximation of input rate of non-stationary queue system

NASA Astrophysics Data System (ADS)

Korelin, Ivan A.; Porshnev, Sergey V.

2018-01-01

The paper demonstrates the possibility of calculating the characteristics of the flow of visitors to objects carrying out mass events passing through checkpoints. The mathematical model is based on the non-stationary queuing system (NQS) where dependence of requests input rate from time is described by the function. This function was chosen in such way that its properties were similar to the real dependencies of speed of visitors arrival on football matches to the stadium. A piecewise-constant approximation of the function is used when statistical modeling of NQS performing. Authors calculated the dependencies of the queue length and waiting time for visitors to service (time in queue) on time for different laws. Time required to service the entire queue and the number of visitors entering the stadium at the beginning of the match were calculated too. We found the dependence for macroscopic quantitative characteristics of NQS from the number of averaging sections of the input rate.

Evaluation of transit-time and electromagnetic flow measurement in a chronically instrumented nonhuman primate model.

PubMed

Koenig, S C; Reister, C A; Schaub, J; Swope, R D; Ewert, D; Fanton, J W

1996-01-01

The Physiology Research Branch at Brooks AFB conducts both human and nonhuman primate experiments to determine the effects of microgravity and hypergravity on the cardiovascular system and to identify the particular mechanisms that invoke these responses. Primary investigative efforts in our nonhuman primate model require the determination of total peripheral resistance, systemic arterial compliance, and pressure-volume loop characteristics. These calculations require beat-to-beat measurement of aortic flow. This study evaluated accuracy, linearity, biocompatability, and anatomical features of commercially available electromagnetic (EMF) and transit-time flow measurement techniques. Five rhesus monkeys were instrumented with either EMF (3 subjects) or transit-time (2 subjects) flow sensors encircling the proximal ascending aorta. Cardiac outputs computed from these transducers taken over ranges of 0.5 to 2.0 L/min were compared to values obtained using thermodilution. In vivo experiments demonstrated that the EMF probe produced an average error of 15% (r = .896) and 8.6% average linearity per reading, and the transit-time flow probe produced an average error of 6% (r = .955) and 5.3% average linearity per reading. Postoperative performance and biocompatability of the probes were maintained throughout the study. The transit-time sensors provided the advantages of greater accuracy, smaller size, and lighter weight than the EMF probes. In conclusion, the characteristic features and performance of the transit-time sensors were superior to those of the EMF sensors in this study.

Evaluation of transit-time and electromagnetic flow measurement in a chronically instrumented nonhuman primate model

NASA Technical Reports Server (NTRS)

Koenig, S. C.; Reister, C. A.; Schaub, J.; Swope, R. D.; Ewert, D.; Fanton, J. W.; Convertino, V. A. (Principal Investigator)

1996-01-01

The Physiology Research Branch at Brooks AFB conducts both human and nonhuman primate experiments to determine the effects of microgravity and hypergravity on the cardiovascular system and to identify the particular mechanisms that invoke these responses. Primary investigative efforts in our nonhuman primate model require the determination of total peripheral resistance, systemic arterial compliance, and pressure-volume loop characteristics. These calculations require beat-to-beat measurement of aortic flow. This study evaluated accuracy, linearity, biocompatability, and anatomical features of commercially available electromagnetic (EMF) and transit-time flow measurement techniques. Five rhesus monkeys were instrumented with either EMF (3 subjects) or transit-time (2 subjects) flow sensors encircling the proximal ascending aorta. Cardiac outputs computed from these transducers taken over ranges of 0.5 to 2.0 L/min were compared to values obtained using thermodilution. In vivo experiments demonstrated that the EMF probe produced an average error of 15% (r = .896) and 8.6% average linearity per reading, and the transit-time flow probe produced an average error of 6% (r = .955) and 5.3% average linearity per reading. Postoperative performance and biocompatability of the probes were maintained throughout the study. The transit-time sensors provided the advantages of greater accuracy, smaller size, and lighter weight than the EMF probes. In conclusion, the characteristic features and performance of the transit-time sensors were superior to those of the EMF sensors in this study.

Rapid gait termination: effects of age, walking surfaces and footwear characteristics.

PubMed

Menant, Jasmine C; Steele, Julie R; Menz, Hylton B; Munro, Bridget J; Lord, Stephen R

2009-07-01

The aim of this study was to systematically investigate the influence of various walking surfaces and footwear characteristics on the ability to terminate gait rapidly in 10 young and 26 older people. Subjects walked at a self-selected speed in eight randomized shoe conditions (standard versus elevated heel, soft sole, hard sole, high-collar, flared sole, bevelled heel and tread sole) on three surfaces: control, irregular and wet. In response to an audible cue, subjects were required to stop as quickly as possible in three out of eight walking trials in each condition. Time to last foot contact, total stopping time, stopping distance, number of steps to stop, step length and step width post-cue and base of support length at total stop were calculated from kinematic data collected using two CODA scanner units. The older subjects took more time and a longer distance to last foot contact and were more frequently classified as using a three or more-steps stopping strategy compared to the young subjects. The wet surface impeded gait termination, as indicated by greater total stopping time and stopping distance. Subjects required more time to terminate gait in the soft sole shoes compared to the standard shoes. In contrast, the high-collar shoes reduced total stopping time on the wet surface. These findings suggest that older adults have more difficulty terminating gait rapidly than their younger counterparts and that footwear is likely to influence whole-body stability during challenging postural tasks on wet surfaces.

Anesthesiology residents' perspective about good teaching--a qualitative needs assessment.

PubMed

Ortwein, Heiderose; Blaum, Wolf E; Spies, Claudia D

2014-01-01

Germany, like many other countries, will soon have a shortage of qualified doctors. One reason for the dissatisfaction amongst medical residents are the relatively unstructured residency training programs despite increasing importance of outcome-based education. The aim of our study was to identify characteristics and requirements for good teaching during anesthesiology residency training from the resident's point of view. A consensus workshop with residents from all medical universities in Germany was held. Participants were allocated to one of the three topics, chosen based on a 2009 nationwide evaluation of residency. The three topics were (A) characteristics of helpful/good teachers, (B) characteristics of helpful/good conditions and (C) characteristics of helpful/good curricular structure. Each group followed a nominal group technique consensus process to define and rank characteristics for a good residency. 31 (79.5%) resident representatives were present. The consented results put emphasis on the importance of structured curricula including transparent goals and objectives, in training formative assessments and quality assurance measures for the program. Residents further long for trained trainers with formal teaching qualifications and protected teaching time. Good residency training requires careful consideration of all stakeholders' needs. Results reflect and extend previous findings and are at least to some degree easily implemented. These findings are an important step to establish a broader consensus within the discipline.

Evolving Requirements for Magnetic Tape Data Storage Systems

NASA Technical Reports Server (NTRS)

Gniewek, John J.

1996-01-01

Magnetic tape data storage systems have evolved in an environment where the major applications have been back-up/restore, disaster recovery, and long term archive. Coincident with the rapidly improving price-performance of disk storage systems, the prime requirements for tape storage systems have remained: (1) low cost per MB, (2) a data rate balanced to the remaining system components. Little emphasis was given to configuring the technology components to optimize retrieval of the stored data. Emerging new applications such as network attached high speed memory (HSM), and digital libraries, place additional emphasis and requirements on the retrieval of the stored data. It is therefore desirable to consider the system to be defined both by STorage And Retrieval System (STARS) requirements. It is possible to provide comparative performance analysis of different STARS by incorporating parameters related to (1) device characteristics, and (2) application characteristics in combination with queuing theory analysis. Results of these analyses are presented here in the form of response time as a function of system configuration for two different types of devices and for a variety of applications.

Evolution of magnetic field and atmospheric response. I - Three-dimensional formulation by the method of projected characteristics. II - Formulation of proper boundary equations. [stellar magnetohydrodynamics

NASA Technical Reports Server (NTRS)

Nakagawa, Y.

1981-01-01

The method described as the method of nearcharacteristics by Nakagawa (1980) is renamed the method of projected characteristics. Making full use of properties of the projected characteristics, a new and simpler formulation is developed. As a result, the formulation for the examination of the general three-dimensional problems is presented. It is noted that since in practice numerical solutions must be obtained, the final formulation is given in the form of difference equations. The possibility of including effects of viscous and ohmic dissipations in the formulation is considered, and the physical interpretation is discussed. A systematic manner is then presented for deriving physically self-consistent, time-dependent boundary equations for MHD initial boundary problems. It is demonstrated that the full use of the compatibility equations (differential equations relating variations at two spatial locations and times) is required in determining the time-dependent boundary conditions. In order to provide a clear physical picture as an example, the evolution of axisymmetric global magnetic field by photospheric differential rotation is considered.

Study of a tracking and data acquisition system for the 1990's. Volume 1: User community characteristics

NASA Technical Reports Server (NTRS)

Mccreary, T.

1981-01-01

Projected 1990's experiments; navigation requirements and potentials; communications requirements associated with space experiments; alternative forecast options; and operational impacts on experiments are covered. A baseline of plans for the TDAS User Community, including a set of generic experiments developed to supplement existing planning for the 1990's time frame is generated. It includes extensive summaries of collected data, and a bibliography. The data are representative of inputs obtained from NASA planning sources through September 1981.

Characteristics of low-speed vehicle run-over events in children: an 11-year review.

PubMed

Griffin, Bronwyn R; Watt, Kerrianne; Shields, Linda E; Kimble, Roy M

2014-10-01

The purpose of this study was to investigate the characteristics associated with fatal and non-fatal low-speed vehicle run-over (LSVRO) events in relation to person, incident and injury characteristics, in order to identify appropriate points for intervention and injury prevention. Data on all known LSVRO events in Queensland, Australia, over 11 calendar years (1999-2009) were extracted from five different databases representing the continuum of care (prehospital to fatality) and manually linked. Descriptive and multivariate analyses were used to analyse the sample characteristics in relation to demographics, health service usage, outcomes, incident characteristics, and injury characteristics. Of the 1641 LSVRO incidents, 98.4% (n=1615) were non-fatal, and 1.6% were fatal (n=26). Over half the children required admission to hospital (56%, n=921); mean length of stay was 3.4 days. Younger children aged 0-4 years were more frequently injured, and experienced more serious injuries with worse outcomes. Patterns of injury (injury type and severity), injury characteristics (eg, time of injury, vehicle type, driver of vehicle, incident location), and demographic characteristics (such as socioeconomic status, indigenous status, remoteness), varied according to age group. Almost half (45.6%; n=737) the events occurred outside major cities, and approximately 10% of events involved indigenous children. Parents were most commonly the vehicle drivers in fatal incidents. While larger vehicles such as four-wheel drives (4WD) were most frequently involved in LSVRO events resulting in fatalities, cars were most frequently involved in non-fatal events. This is the first study, to the authors' knowledge, to analyse the characteristics of fatal and non-fatal LSVRO events in children aged 0-15 years on a state-wide basis. Characteristics of LSVRO events varied with age, thus age-specific interventions are required. Children living outside major cities, and indigenous children, were over-represented in these data. Further research is required to identify the burden of injury in these groups. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Impact of minor actinide recycling on sustainable fuel cycle options

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

Heidet, F.; Kim, T. K.; Taiwo, T. A.

The recent Evaluation and Screening study chartered by the U.S. Department of Energy, Office of Nuclear Energy, has identified four fuel cycle options as being the most promising. Among these four options, the two single-stage fuel cycles rely on a fast reactor and are differing in the fact that in one case only uranium and plutonium are recycled while in the other case minor actinides are also recycled. The two other fuel cycles are two-stage and rely on both fast and thermal reactors. They also differ in the fact that in one case only uranium and plutonium are recycled whilemore » in the other case minor actinides are also recycled. The current study assesses the impact of recycling minor actinides on the reactor core design, its performance characteristics, and the characteristics of the recycled material and waste material. The recycling of minor actinides is found not to affect the reactor core performance, as long as the same cycle length, core layout and specific power are being used. One notable difference is that the required transuranics (TRU) content is slightly increased when minor actinides are recycled. The mass flows are mostly unchanged given a same specific power and cycle length. Although the material mass flows and reactor performance characteristics are hardly affected by recycling minor actinides, some differences are observed in the waste characteristics between the two fuel cycles considered. The absence of minor actinides in the waste results in a different buildup of decay products, and in somewhat different behaviors depending on the characteristic and time frame considered. Recycling of minor actinides is found to result in a reduction of the waste characteristics ranging from 10% to 90%. These results are consistent with previous studies in this domain and depending on the time frame considered, packaging conditions, repository site, repository strategy, the differences observed in the waste characteristics could be beneficial and help improve the repository performance. On the other hand, recycling minor actinides also results in an increase of the recycled fuel characteristics and therefore of the charged fuel. The radioactivity is slightly increased while the decay heat and radiotoxicities are very significantly increased. Despite these differences, the characteristics of the fuel at time of discharge remain similar whether minor actinides are recycled or not, with the exception of the inhalation radiotoxicity which is significantly larger with minor actinide recycling. After some cooling the characteristics of the discharged fuel become larger when minor actinides are recycled, potentially affecting the reprocessing plant requirements. Recycling minor actinides has a negative impact on the characteristics of the fresh fuel and will make it more challenging to fabricate fuel containing minor actinides.« less

Modeling of Millimeter-Wave Modulation Characteristics of Semiconductor Lasers under Strong Optical Feedback

PubMed Central

Bakry, Ahmed

2014-01-01

This paper presents modeling and simulation on the characteristics of semiconductor laser modulated within a strong optical feedback (OFB-)induced photon-photon resonance over a passband of millimeter (mm) frequencies. Continuous wave (CW) operation of the laser under strong OFB is required to achieve the photon-photon resonance in the mm-wave band. The simulated time-domain characteristics of modulation include the waveforms of the intensity and frequency chirp as well as the associated distortions of the modulated mm-wave signal. The frequency domain characteristics include the intensity modulation (IM) and frequency modulation (FM) responses in addition to the associated relative intensity noise (RIN). The signal characteristics under modulations with both single and two mm-frequencies are considered. The harmonic distortion and the third order intermodulation distortion (IMD3) are examined and the spurious free dynamic range (SFDR) is calculated. PMID:25383381

Determinants of holmium:yttrium-aluminum-garnet laser time and energy during ureteroscopic laser lithotripsy.

PubMed

Molina, Wilson R; Marchini, Giovanni S; Pompeo, Alexandre; Sehrt, David; Kim, Fernando J; Monga, Manoj

2014-04-01

To evaluate the association of preoperative noncontrast computed tomography stone characteristics, laser settings, and stone composition with cumulative holmium:yttrium-aluminum-garnet (Ho:YAG) laser time/energy. We retrospectively reviewed patients who underwent semirigid/flexible ureteroscopy and Ho:YAG laser lithotripsy (200 or 365 μm laser fiber; 0.8-1.0 J energy; and 8-10 Hz rate) at 2 tertiary care centers (April 2010-May 2012). Studied parameters were as follows: patient's characteristics; stone characteristics (location, burden, hardness, and composition); total laser time and energy; and surgical outcomes. One hundred patients met our inclusion criteria. Mean stone size was 1.01 ± 0.42 cm and volume 0.33 ± 0.04 cm(3). Mean stone radiodensity was 990 ± 296 HU, and Hounsfield units density 13.8 ± 6.0 HU/mm. All patients were considered stone free. Stone size and volume had a significant positive correlation with laser energy (R = 0.516, P <.001; R = 0.621, P <.001) and laser time (R = 0.477, P <.001; R = 0.567, P <.001). When controlling for stone size, only the correlation between HU and laser time was significant (R = 0.262, P = .011). In the multivariate analysis, with exception of stone composition (P = .103), all parameters significantly increased laser energy (R(2) = 0.524). Multivariate analysis revealed a positive significant association of laser time with stone volume (P <.001) and Hounsfield units density (P <.001; R(2) = 0.512). In multivariate analysis for laser energy, only calcium phosphate stones required less energy to fragment compared with uric acid stones. No significant differences were found in the multivariate laser time model. Ho:YAG laser cumulative energy and total time are significantly affected by stone dimensions, hardness location, fiber size, and power. Kidney location, laser fiber size, and laser power have more influence on the final laser energy than on the total laser time. Calcium phosphate stones require less laser energy to fragment. Copyright © 2014 Elsevier Inc. All rights reserved.

47 CFR 2.1047 - Measurements required: Modulation characteristics.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Measurements required: Modulation characteristics. 2.1047 Section 2.1047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY... Certification § 2.1047 Measurements required: Modulation characteristics. (a) Voice modulated communication...

47 CFR 2.1047 - Measurements required: Modulation characteristics.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Measurements required: Modulation characteristics. 2.1047 Section 2.1047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY... Certification § 2.1047 Measurements required: Modulation characteristics. (a) Voice modulated communication...

Commercial applications of satellite oceanography

NASA Technical Reports Server (NTRS)

Montgomery, D. R.

1981-01-01

It is shown that in the next decade the oceans' commercial users will require an operational oceanographic satellite system or systems capable of maximizing real-time coverage over all ocean areas. Seasat studies suggest that three spacecraft are required to achieve this. Here, the sensor suite would measure surface winds, wave heights (and spectral energy distribution), ice characteristics, sea-surface temperature, ocean colorimetry, height of the geoid, salinity, and subsurface thermal structure. The importance of oceanographic data being distributed to commercial users within two hours of observation time is stressed. Also emphasized is the importance of creating a responsive oceanographic satellite data archive. An estimate of the potential dollar benefits of such an operational oceanographic satellite system is given.

Out-of-Band 40 DB Bandwidth of EESS (Active) Spaceborne SARS

NASA Technical Reports Server (NTRS)

Huneycutt, Bryan L.

2005-01-01

This document presents a study of out of band (OOB) 40 dB bandwidth requirements of spaceborne SARs in the Earth Exploration-Satellite Service (active) and Space Research Service (active). The purpose of the document is to study the OOB 40 dB bandwidth requirements and compare the 40 dB bandwidth B-40 as measured in simulations with that calculated using the ITU-R Rec SM.1541 equations. The spectra roll-off and resulting OOB 40 dB bandwidth of the linear FM signal is affected by the time-bandwidth product and the rise/fall times. Typical values of these waveform characteristics are given for existing EESS (active) sensors.

Time Step Considerations when Simulating Dynamic Behavior of High Performance Homes

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

Tabares-Velasco, Paulo Cesar

2016-09-01

Building energy simulations, especially those concerning pre-cooling strategies and cooling/heating peak demand management, require careful analysis and detailed understanding of building characteristics. Accurate modeling of the building thermal response and material properties for thermally massive walls or advanced materials like phase change materials (PCMs) are critically important.

Further Development, Fabrication, and Testing of XM36E1 Fuze Setter

DTIC Science & Technology

1978-08-01

primary func- tion of this circuit, has the same timing characteristics as the original circuit: Half-period pulses are required to be greater than...temperature of -40 0 C. 9 The following corrective action was taken for this mal- fuction : (1) The batteries were replaced, and an investigation of battery

Reciprocity, Responsiveness, and Timing in Interactions between Mothers and Deaf and Hearing Children.

ERIC Educational Resources Information Center

Waxman, Robyn P.; Spencer, Patricia E.; Poisson, Susan S.

1996-01-01

The Greenspan-Lieberman Observational System Revised was used to evaluate characteristics of dyadic interactions between 10 hearing mothers and hearing toddlers (HH), 10 deaf mothers and deaf toddlers (DD), and 10 hearing mothers and deaf toddlers (HD). Findings suggest that assessment instruments require some modifications and results must be…

Stress and the Workplace: A Comparison of Occupational Fields.

ERIC Educational Resources Information Center

Matthews, Doris B.; Casteel, Jim Frank

Stress in various occupations is of interest to managers, counselors, and personnel workers. A study was undertaken to examine, through the use of self-report scales, stress-related characteristics of workers in occupations which require many and varied human interactions. Subjects were 244 full-time employees in six professions: health services,…

75 FR 64773 - Study Required by Section 989G(b) of the Dodd-Frank Act Regarding Compliance With Section 404(b...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

..., which addresses management's responsibility for reporting on the effectiveness of internal control over...) Quantitative and qualitative information about the trends of internal and external costs of having an external... over time; (3) Characteristics of internal controls, management's evaluation process and corporate...

75 FR 35813 - Notice of Public Information Collection(s) Being Submitted for Review and Approval to the Office...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-23

... requires station licensees to measure the carrier frequency, output power, and modulation of each..., 409,048 responses. Estimated Time per Response: .033 hours. Frequency of Response: Recordkeeping... installed and when any changes are made which would likely affect the modulation characteristics. Such...

Influence of Stimulus Symmetry and Complexity upon Haptic Scanning Strategies During Detection, Learning and Recognition Tasks.

ERIC Educational Resources Information Center

Locher, Paul J.; Simmons, Roger W.

Two experiments were conducted to investigate the perceptual processes involved in haptic exploration of randomly generated shapes. Experiment one required subjects to detect symmetrical or asymmetrical characteristics of individually presented plastic shapes, also varying in complexity. Scanning time for both symmetrical and asymmetrical shapes…

Uranus and Neptune orbiter missions via solar electric propulsion

NASA Technical Reports Server (NTRS)

Friedlander, A. L.; Brandenburg, R. K.

1971-01-01

The characteristics and capabilities of solar electric propulsion for performing orbiter missions at the planets Uranus and Neptune are described. An assessment of the scientific objectives and instrumentation requirements, their relation to orbit size selection, and parametric analysis of solar electric propulsion trajectory/payload performance are included. Utilizing the Titan 3D/Centaur launch vehicle, minimum flight times of about 3400 days to Uranus and 5300 days to Neptune are required to place the TOPS spacecraft into the nominal orbits. It has been shown that solar electric propulsion can be used effectively to accomplish elliptical orbiter missions at Uranus and Neptune. However, because of the very long flight time required, these mission profiles are not too attractive. Previous studies have shown that nuclear electric propulsion, if developed, would allow much faster trips; 5 years to Uranus and 8 years to Neptune.

Compensation for Blur Requires Increase in Field of View and Viewing Time

PubMed Central

Kwon, MiYoung; Liu, Rong; Chien, Lillian

2016-01-01

Spatial resolution is an important factor for human pattern recognition. In particular, low resolution (blur) is a defining characteristic of low vision. Here, we examined spatial (field of view) and temporal (stimulus duration) requirements for blurry object recognition. The spatial resolution of an image such as letter or face, was manipulated with a low-pass filter. In experiment 1, studying spatial requirement, observers viewed a fixed-size object through a window of varying sizes, which was repositioned until object identification (moving window paradigm). Field of view requirement, quantified as the number of “views” (window repositions) for correct recognition, was obtained for three blur levels, including no blur. In experiment 2, studying temporal requirement, we determined threshold viewing time, the stimulus duration yielding criterion recognition accuracy, at six blur levels, including no blur. For letter and face recognition, we found blur significantly increased the number of views, suggesting a larger field of view is required to recognize blurry objects. We also found blur significantly increased threshold viewing time, suggesting longer temporal integration is necessary to recognize blurry objects. The temporal integration reflects the tradeoff between stimulus intensity and time. While humans excel at recognizing blurry objects, our findings suggest compensating for blur requires increased field of view and viewing time. The need for larger spatial and longer temporal integration for recognizing blurry objects may further challenge object recognition in low vision. Thus, interactions between blur and field of view should be considered for developing low vision rehabilitation or assistive aids. PMID:27622710

[Development of wireless monitoring system based on Zigbee technology in blood and bacterin cold chain].

PubMed

Zhao, Peng; Sun, Jian-Jun; Wu, Tai-Hu

2008-11-01

Real-time monitoring for temperature is required in cold chain for the medical products that are sensible with temperature, such as blood and bacterin, to guarantee the quality and reduce their wastage. This wireless monitoring system in cold chain is developed with Zigbee technology. Functions such as real-time monitoring, analyzing, alarming are realized. The system boasts such characteristics as low power consumption, low cost, big capacity and high reliability, and could improve the capability of real-time monitoring and management in cold chain effectively.

A Metallurgical Investigation of Large Forged Discs of Low-carbon N-155 Alloy

NASA Technical Reports Server (NTRS)

Cross, Howard C; Freeman, J W

1947-01-01

Research was undertaken to ascertain the properties of better wrought heat resisting alloys in the form of large discs required for gas turbine rotors. The properties of large discs of low carbon N-155 alloy in both the as-forged and water-quenched and aged conditions were determined by means of stress-rupture and creep tests for time periods up to about 2000 hours at 1200, 1350, and 1500 F. Short-time tensile test, impact test, and time-total deformation characteristics are included. The principle results are given.

Genetic noise mechanism for power-law switching in bacterial flagellar motors

NASA Astrophysics Data System (ADS)

Krivonosov, M. I.; Zaburdaev, V.; Denisov, S. V.; Ivanchenko, M. V.

2018-06-01

Switching of the direction of flagella rotations is the key control mechanism governing the chemotactic activity of E. coli and many other bacteria. Power-law distributions of switching times are most peculiar because their emergence cannot be deduced from simple thermodynamic arguments. Recently, it was suggested that by adding finite-time correlations into Gaussian fluctuations regulating the energy height of the barrier between the two rotation states, it is possible to generate switching statistics with an intermediate power-law asymptotics. By using a simple model of a regulatory pathway, we demonstrate that the required amount of correlated ‘noise’ can be produced by finite number fluctuations of reacting protein molecules, a condition common to the intracellular chemistry. The corresponding power-law exponent appears as a tunable characteristic controlled by parameters of the regulatory pathway network such as the equilibrium number of molecules, sensitivities, and the characteristic relaxation time.

Simultaneous multi-beam planar array IR (pair) spectroscopy

DOEpatents

Elmore, Douglas L.; Rabolt, John F.; Tsao, Mei-Wei

2005-09-13

An apparatus and method capable of providing spatially multiplexed IR spectral information simultaneously in real-time for multiple samples or multiple spatial areas of one sample using IR absorption phenomena requires no moving parts or Fourier Transform during operation, and self-compensates for background spectra and degradation of component performance over time. IR spectral information and chemical analysis of the samples is determined by using one or more IR sources, sampling accessories for positioning the samples, optically dispersive elements, a focal plane array (FPA) arranged to detect the dispersed light beams, and a processor and display to control the FPA, and display an IR spectrograph. Fiber-optic coupling can be used to allow remote sensing. Portability, reliability, and ruggedness is enhanced due to the no-moving part construction. Applications include determining time-resolved orientation and characteristics of materials, including polymer monolayers. Orthogonal polarizers may be used to determine certain material characteristics.

Temporal characteristics of imagined and actual walking in frail older adults.

PubMed

Nakano, Hideki; Murata, Shin; Shiraiwa, Kayoko; Iwase, Hiroaki; Kodama, Takayuki

2018-05-09

Mental chronometry, commonly used to evaluate motor imagery ability, measures the imagined time required for movements. Previous studies investigating mental chronometry of walking have investigated healthy older adults. However, mental chronometry in frail older adults has not yet been clarified. To investigate temporal characteristics of imagined and actual walking in frail older adults. We investigated the time required for imagined and actual walking along three walkways of different widths [width(s): 50, 25, 15 cm × length: 5 m] in 29 frail older adults and 20 young adults. Imagined walking was measured with mental chronometry. We observed significantly longer imagined and actual walking times along walkways of 50, 25, and 15 cm width in frail older adults compared with young adults. Moreover, temporal differences (absolute error) between imagined and actual walking were significantly greater in frail older adults than in young adults along walkways with a width of 25 and 15 cm. Furthermore, we observed significant differences in temporal differences (constant error) between frail older adults and young adults for walkways with a width of 25 and 15 cm. Frail older adults tended to underestimate actual walking time in imagined walking trials. Our results suggest that walkways of different widths may be a useful tool to evaluate age-related changes in imagined and actual walking in frail older adults.

Are there good reasons for inequalities in access to renal transplantation in children?

PubMed

Hogan, Julien; Audry, Benoit; Harambat, Jérôme; Dunand, Olivier; Garnier, Arnaud; Salomon, Rémi; Ulinski, Tim; Macher, Marie-Alice; Couchoud, Cécile

2015-12-01

Studies in the USA and Europe have demonstrated inequalities in adult access to renal transplants. We previously demonstrate that the centre of treatment was impacting the time to be registered on the renal waiting list. In this study, we sought to ascertain the influence of patient and centre characteristics on the probability of transplantation within 1 year after registration on the waiting list for children. We included patients <18 years awaiting transplantation from the French ESRD National Registry. The effects of patient and centre characteristics were studied by hierarchical logistic regression. Centre effects were assessed by centre-level residual variance. A descriptive survey was performed to investigate differences in the centres' practices, and linear regression was used to confirm findings of different HLA compatibility requirements between centres. The study included 556 patients treated at 54 centres; 450 (80.9%) received transplants in the year after their listing. HLA group scarcity, time of inactive status during the year, pre-emptive listing and listing after age 18 were associated with lower probabilities of transplantation. Patient characteristics explained most of the variability among centres, but patients treated in paediatric centres had a lower probability of transplantation within 1 year because of higher HLA compatibility requirements for transplants. Although patient characteristics explained most of the inter-centre variability, harmonization of some practices might enable us to reduce some inequalities in access to renal transplantation while maintaining optimal transplant survival and chances to get a second transplant when needed. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

What powers the 3000-day light curve of SN 2006gy?

DOE PAGES

Fox, Ori D.; Smith, Nathan; Ammons, S. Mark; ...

2015-10-27

SN 2006gy was the most luminous supernova (SN) ever observed at the time of its discovery and the first of the newly defined class of superluminous supernovae (SLSNe). The extraordinary energetics of SN 2006gy and all SLSNe (>10 51 erg) require either atypically large explosion energies (e.g. pair-instability explosion) or the efficient conversion of kinetic into radiative energy (e.g. shock interaction). The mass-loss characteristics can therefore offer important clues regarding the progenitor system. For the case of SN 2006gy, both a scattered and thermal light echo from circumstellar material (CSM) have been reported at later epochs (day ~800), ruling outmore » the likelihood of a pair-instability event and leading to constraints on the characteristics of the CSM. Owing to the proximity of the SN to the bright host-galaxy nucleus, continued monitoring of the light echo has not been trivial, requiring the high resolution offered by the Hubble Space Telescope ( HST) or ground-based adaptive optics (AO). Furthermore, we report detections of SN 2006gy using HST and Keck AO at ~3000 d post-explosion and consider the emission mechanism for the very late-time light curve. While the optical light curve and optical spectral energy distribution are consistent with a continued scattered-light echo, a thermal echo is insufficient to power the K'-band emission by day 3000. Instead, we present evidence for late-time infrared emission from dust that is radiatively heated by CSM interaction within an extremely dense dust shell, and we consider the implications on the CSM characteristics and progenitor system.« less

What powers the 3000-day light curve of SN 2006gy?

NASA Astrophysics Data System (ADS)

Fox, Ori D.; Smith, Nathan; Ammons, S. Mark; Andrews, Jennifer; Bostroem, K. Azalee; Cenko, S. Bradley; Clayton, Geoffrey C.; Dwek, Eli; Filippenko, Alexei V.; Gallagher, Joseph S.; Kelly, Patrick L.; Mauerhan, Jon C.; Miller, Adam A.; Van Dyk, Schuyler D.

2015-12-01

SN 2006gy was the most luminous supernova (SN) ever observed at the time of its discovery and the first of the newly defined class of superluminous supernovae (SLSNe). The extraordinary energetics of SN 2006gy and all SLSNe (>1051 erg) require either atypically large explosion energies (e.g. pair-instability explosion) or the efficient conversion of kinetic into radiative energy (e.g. shock interaction). The mass-loss characteristics can therefore offer important clues regarding the progenitor system. For the case of SN 2006gy, both a scattered and thermal light echo from circumstellar material (CSM) have been reported at later epochs (day ˜800), ruling out the likelihood of a pair-instability event and leading to constraints on the characteristics of the CSM. Owing to the proximity of the SN to the bright host-galaxy nucleus, continued monitoring of the light echo has not been trivial, requiring the high resolution offered by the Hubble Space Telescope (HST) or ground-based adaptive optics (AO). Here, we report detections of SN 2006gy using HST and Keck AO at ˜3000 d post-explosion and consider the emission mechanism for the very late-time light curve. While the optical light curve and optical spectral energy distribution are consistent with a continued scattered-light echo, a thermal echo is insufficient to power the K'-band emission by day 3000. Instead, we present evidence for late-time infrared emission from dust that is radiatively heated by CSM interaction within an extremely dense dust shell, and we consider the implications on the CSM characteristics and progenitor system.

EMF Rapid Program Engineering Projects, Project 1, Development of Recommendations for Guidelines for Field Source Measurement

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

Electric Research and Management, Inc.

1997-03-11

The goal of this project is to develop a protocol for measuring the electric and magnetic fields around sources. Data from these measurements may help direct future biological effects research by better defining the complexity of magnetic and electric fields to which humanity is exposed, as well asprovide the basis for rigorous field exposure analysis and risk assessment once the relationship between field exposure and biological response. is better understood. The data base also should have sufficient spatial and temporal characteristics to guide electric and magnetic field management. The goal of Task A is to construct a set of characteristicsmore » that would be ideal to have for guiding and interpreting biological studies and for focusing any future effort at field management. This ideal set will then be quantified and reduced according to the availability (or possible development of) instrumentation to measure the desired characteristics. Factors that also will be used to define pragmatic data sets will be the cost of collecting the data, the cost of developing an adequate data base, and the needed precision in measuring specific characteristics. A field, electric or magnetic, will always be ,some function of time and space. The first step in this section of the protocol development will be to determine what span of time and what portion of space are required to quantify the electric and magnetic fields around sources such as appliances and electrical apparatus. Constraints on time will be set by examining measurement limitations and biological data requirements.« less

Exposure Time Distributions reveal Denitrification Rates along Groundwater Flow Path of an Agricultural Unconfined Aquifer

NASA Astrophysics Data System (ADS)

Kolbe, T.; Abbott, B. W.; Thomas, Z.; Labasque, T.; Aquilina, L.; Laverman, A.; Babey, T.; Marçais, J.; Fleckenstein, J. H.; Peiffer, S.; De Dreuzy, J. R.; Pinay, G.

2016-12-01

Groundwater contamination by nitrate is nearly ubiquitous in agricultural regions. Nitrate is highly mobile in groundwater and though it can be denitrified in the aquifer (reduced to inert N2 gas), this process requires the simultaneous occurrence of anoxia, an electron donor (e.g. organic carbon, pyrite), nitrate, and microorganisms capable of denitrification. In addition to this the ratio of the time groundwater spent in a denitrifying environment (exposure time) to the characteristic denitrification reaction time plays an important role, because denitrification can only occur if the exposure time is longer than the characteristic reaction time. Despite a long history of field studies and numerical models, it remains exceedingly difficult to measure or model exposure times in the subsurface at the catchment scale. To approach this problem, we developed a unified modelling approach combining measured environmental proxies with an exposure time based reactive transport model. We measured groundwater age, nitrogen and sulfur isotopes, and water chemistry from agricultural wells in an unconfined aquifer in Brittany, France, to quantify changes in nitrate concentration due to dilution and denitrification. Field data showed large differences in nitrate concentrations among wells, associated with differences in the exposure time distributions. By constraining a catchment-scale characteristic reaction time for denitrification with water chemistry proxies and exposure times, we were able to assess rates of denitrification along groundwater flow paths. This unified modeling approach is transferable to other catchments and could be further used to investigate how catchment structure and flow dynamics interact with biogeochemical processes such as denitrification.

Studies on spectral analysis of randomly sampled signals: Application to laser velocimetry data

NASA Technical Reports Server (NTRS)

Sree, David

1992-01-01

Spectral analysis is very useful in determining the frequency characteristics of many turbulent flows, for example, vortex flows, tail buffeting, and other pulsating flows. It is also used for obtaining turbulence spectra from which the time and length scales associated with the turbulence structure can be estimated. These estimates, in turn, can be helpful for validation of theoretical/numerical flow turbulence models. Laser velocimetry (LV) is being extensively used in the experimental investigation of different types of flows, because of its inherent advantages; nonintrusive probing, high frequency response, no calibration requirements, etc. Typically, the output of an individual realization laser velocimeter is a set of randomly sampled velocity data. Spectral analysis of such data requires special techniques to obtain reliable estimates of correlation and power spectral density functions that describe the flow characteristics. FORTRAN codes for obtaining the autocorrelation and power spectral density estimates using the correlation-based slotting technique were developed. Extensive studies have been conducted on simulated first-order spectrum and sine signals to improve the spectral estimates. A first-order spectrum was chosen because it represents the characteristics of a typical one-dimensional turbulence spectrum. Digital prefiltering techniques, to improve the spectral estimates from randomly sampled data were applied. Studies show that the spectral estimates can be increased up to about five times the mean sampling rate.

[Hygienic assessment of the characteristics of centralized hot water supply in case of Moscow].

PubMed

Bukshuk, A A; Egorova, N A

2011-01-01

The paper considers the characteristics of domestic hot water consumption by Moscow dwellers. It gives the results of questionnaire surveys in 100 respondents aged 20-80 years about the modes and intensity of hot water use, by indicating the time and frequency of contact with hot water complaints about hot water supply. According to the authors'studies, the daily consumption of hot water per capita was 1.1-2 times greater than that of cold water; at the same time the total water use remained to be 1.3-3 times less than the Moscow standard levels. Top stationary point measurements of water temperature showed the noncompliance with its hygienic requirements: 95 of 98 hot water samples had a temperature of 5-22 degrees C less than the standard temperature (60 degrees C). A decrease in hot water temperature in the centralized hot water supply systems creates conditions for Legionella pneumophila propagation and ensures no hot water safety with regards to the possible development of Legionella pneumonia.

Age, training, and previous experience predict race performance in long-distance inline skaters, not anthropometry.

PubMed

Knechtle, Beat; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

2012-02-01

The association of characteristics of anthropometry, training, and previous experience with race time in 84 recreational, long-distance, inline skaters at the longest inline marathon in Europe (111 km), the Inline One-eleven in Switzerland, was investigated to identify predictor variables for performance. Age, duration per training unit, and personal best time were the only three variables related to race time in a multiple regression, while none of the 16 anthropometric variables were related. Anthropometric characteristics seem to be of no importance for a fast race time in a long-distance inline skating race in contrast to training volume and previous experience, when controlled with covariates. Improving performance in a long-distance inline skating race might be related to a high training volume and previous race experience. Also, doing such a race requires a parallel psychological effort, mental stamina, focus, and persistence. This may be reflected in the preparation and training for the event. Future studies should investigate what motivates these athletes to train and compete.

Lightweight Adaptation of Classifiers to Users and Contexts: Trends of the Emerging Domain

PubMed Central

Vildjiounaite, Elena; Gimel'farb, Georgy; Kyllönen, Vesa; Peltola, Johannes

2015-01-01

Intelligent computer applications need to adapt their behaviour to contexts and users, but conventional classifier adaptation methods require long data collection and/or training times. Therefore classifier adaptation is often performed as follows: at design time application developers define typical usage contexts and provide reasoning models for each of these contexts, and then at runtime an appropriate model is selected from available ones. Typically, definition of usage contexts and reasoning models heavily relies on domain knowledge. However, in practice many applications are used in so diverse situations that no developer can predict them all and collect for each situation adequate training and test databases. Such applications have to adapt to a new user or unknown context at runtime just from interaction with the user, preferably in fairly lightweight ways, that is, requiring limited user effort to collect training data and limited time of performing the adaptation. This paper analyses adaptation trends in several emerging domains and outlines promising ideas, proposed for making multimodal classifiers user-specific and context-specific without significant user efforts, detailed domain knowledge, and/or complete retraining of the classifiers. Based on this analysis, this paper identifies important application characteristics and presents guidelines to consider these characteristics in adaptation design. PMID:26473165

Spatial and temporal variation in evacuee risk perception throughout the evacuation and return-entry process.

PubMed

Siebeneck, Laura K; Cova, Thomas J

2012-09-01

Developing effective evacuation and return-entry plans requires understanding the spatial and temporal dimensions of risk perception experienced by evacuees throughout a disaster event. Using data gathered from the 2008 Cedar Rapids, Iowa Flood, this article explores how risk perception and location influence evacuee behavior during the evacuation and return-entry process. Three themes are discussed: (1) the spatial and temporal characteristics of risk perception throughout the evacuation and return-entry process, (2) the relationship between risk perception and household compliance with return-entry orders, and (3) the role social influences have on the timing of the return by households. The results indicate that geographic location and spatial variation of risk influenced household risk perception and compliance with return-entry plans. In addition, sociodemographic characteristics influenced the timing and characteristics of the return groups. The findings of this study advance knowledge of evacuee behavior throughout a disaster and can inform strategies used by emergency managers throughout the evacuation and return-entry process. © 2012 Society for Risk Analysis.

Can generic paediatric mortality scores calculated 4 hours after admission be used as inclusion criteria for clinical trials?

PubMed Central

Leteurtre, Stéphane; Leclerc, Francis; Wirth, Jessica; Noizet, Odile; Magnenant, Eric; Sadik, Ahmed; Fourier, Catherine; Cremer, Robin

2004-01-01

Introduction Two generic paediatric mortality scoring systems have been validated in the paediatric intensive care unit (PICU). Paediatric RISk of Mortality (PRISM) requires an observation period of 24 hours, and PRISM III measures severity at two time points (at 12 hours and 24 hours) after admission, which represents a limitation for clinical trials that require earlier inclusion. The Paediatric Index of Mortality (PIM) is calculated 1 hour after admission but does not take into account the stabilization period following admission. To avoid these limitations, we chose to conduct assessments 4 hours after PICU admission. The aim of the present study was to validate PRISM, PRISM III and PIM at the time points for which they were developed, and to compare their accuracy in predicting mortality at those times with their accuracy at 4 hours. Methods All children admitted from June 1998 to May 2000 in one tertiary PICU were prospectively included. Data were collected to generate scores and predictions using PRISM, PRISM III and PIM. Results There were 802 consecutive admissions with 80 deaths. For the time points for which the scores were developed, observed and predicted mortality rates were significantly different for the three scores (P < 0.01) whereas all exhibited good discrimination (area under the receiver operating characteristic curve ≥0.83). At 4 hours after admission only the PIM had good calibration (P = 0.44), but all three scores exhibited good discrimination (area under the receiver operating characteristic curve ≥0.82). Conclusions Among the three scores calculated at 4 hours after admission, all had good discriminatory capacity but only the PIM score was well calibrated. Further studies are required before the PIM score at 4 hours can be used as an inclusion criterion in clinical trials. PMID:15312217

10 CFR 61.56 - Waste characteristics.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 2 2012-01-01 2012-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements are...

10 CFR 61.56 - Waste characteristics.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 2 2013-01-01 2013-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements are...

10 CFR 61.56 - Waste characteristics.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements are...

10 CFR 61.56 - Waste characteristics.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements are...

10 CFR 61.56 - Waste characteristics.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 2 2014-01-01 2014-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements are...

Development of an impulsive noise source to study the acoustic reflection characteristics of hard-walled wind tunnels

NASA Technical Reports Server (NTRS)

Salikuddin, M.; Burrin, R. H.; Ahuja, K. K.; Bartel, H. W.

1986-01-01

Two impulsive sound sources, one using multiple acoustic drivers and the other using a spark discharge were developed to study the acoustic reflection characteristics of hard-walled wind tunnels, and the results of laboratory tests are presented. The analysis indicates that though the intensity of the pulse generated by the spark source was higher than that obtained from the acoustic source, the number of averages needed for a particular test may require an unacceptibly long tunnel-run time due to the low spark generation repeat rate because of capacitor charging time. The additional hardware problems associated with the longevity of electrodes and electrode holders in sustaining the impact of repetitive spark discharges, show the multidriver acoustic source to be more suitable for this application.

Gender and pensions: an analysis of factors affecting women's private pension scheme membership in the United Kingdom.

PubMed

Foster, Liam; Smetherham, Jon

2013-01-01

There has been considerable debate about the future sustainability of pension provision and, in particular, the precarious position of many female pensioners. The reasons for women's lower participation rates in private pensions than men's require greater investigation. Using the General Lifestyle Survey (GLF) 2008, this article examines the impact of various characteristics on the likelihood of contributing to a private pension, such as educational attainments, income, occupational group, full-time/part-time status, and whether an individual has any dependent children. It shows that these characteristics play an important role in access to private pensions. Finally, it suggests that strategies to alleviate disadvantages must take into account the complex circumstances that individuals experience throughout the life course, which result in gendered pension provision.

Simbol-X Telescope Scientific Calibrations: Requirements and Plans

NASA Astrophysics Data System (ADS)

Malaguti, G.; Angelini, L.; Raimondi, L.; Moretti, A.; Trifoglio, M.

2009-05-01

The Simbol-X telescope characteristics and the mission scientific requirements impose a challenging calibration plan with a number of unprecedented issues. The 20 m focal length implies for the incoming X-ray beam a divergence comparable to the incidence angle of the mirror surface also for 100 m-long facilities. Moreover this is the first time that a direct focussing X-ray telescope will be calibrated on an energy band covering about three decades, and with a complex focal plane. These problems require a careful plan and organization of the measurements, together with an evaluation of the calibration needs in terms of both hardware and software.

The effectiveness of robotic training depends on motor task characteristics.

PubMed

Marchal-Crespo, Laura; Rappo, Nicole; Riener, Robert

2017-12-01

Previous research suggests that the effectiveness of robotic training depends on the motor task to be learned. However, it is still an open question which specific task's characteristics influence the efficacy of error-modulating training strategies. Motor tasks can be classified based on the time characteristics of the task, in particular the task's duration (discrete vs. continuous). Continuous tasks require movements without distinct beginning or end. Discrete tasks require fast movements that include well-defined postures at the beginning and the end. We developed two games, one that requires a continuous movement-a tracking task-and one that requires discrete movements-a fast reaching task. We conducted an experiment with thirty healthy subjects to evaluate the effectiveness of three error-modulating training strategies-no guidance, error amplification (i.e., repulsive forces proportional to errors) and haptic guidance-on self-reported motivation and learning of the continuous and discrete games. Training with error amplification resulted in better motor learning than haptic guidance, besides the fact that error amplification reduced subjects' interest/enjoyment and perceived competence during training. Only subjects trained with error amplification improved their performance after training the discrete game. In fact, subjects trained without guidance improved the performance in the continuous game significantly more than in the discrete game, probably because the continuous task required greater attentional levels. Error-amplifying training strategies have a great potential to provoke better motor learning in continuous and discrete tasks. However, their long-lasting negative effects on motivation might limit their applicability in intense neurorehabilitation programs.

[Chemical characteristics and uses of instant corn flour II].

PubMed

Martínez, F; el-Dahs, A A

1993-12-01

The hydrothermal process using corn grits soaked in water at room temperature (28-30 degrees C) for 5 hours and steaming for 1 minute at 118 degrees C did not affect the proximal composition of the corn flour. However, the amino acid content was reduced approximately 18% (specially lysine and tryptophan). Vitamin and pigment contents were few affected. The characteristics of color and shelf life of corn flour were improved with the hydrothermal process. Tortillas prepared with instant corn flour showed better color and texture in comparison to the tortillas prepared by the conventional process. Polentas prepared with instant corn flour with 30 seconds of mixing showed better characteristics of flavor, odor, texture and required less preparation time than commercial polentas.

ONEGUN: an interior ballistics code for closed breech guns

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

Reis, G.E.

1982-07-01

This program computes the gun and projectile motion and the gas thermodynamic properties (the internal ballistics) of a closed breech gun. Heat losses and friction losses are taken into account. A dual grain charge can be used. The inputs required are the usual propellant characteristics (density, impetus, gamma, burn rate coefficient and exponent, grain geometry, covolume and isochoric flame temperature). The gun characteristics (chamber volume and length, rifle twist rate, bore diameter, gun weight and start pressure) and the projectile characteristics (projectile weight, radius of gyration and start pressure). The output consists of the motion (displacement, velocity, and acceleration) ofmore » both the projectile and the recoiling gun and the gas pressures and temperature, all as a function of time.« less

Performance characteristics of a slagging gasifier for MHD combustor systems

NASA Technical Reports Server (NTRS)

Smith, K. O.

1979-01-01

The performance of a two stage, coal combustor concept for magnetohydrodynamic (MHD) systems was investigated analytically. The two stage MHD combustor is comprised of an entrained flow, slagging gasifier as the first stage, and a gas phase reactor as the second stage. The first stage was modeled by assuming instantaneous coal devolatilization, and volatiles combustion and char gasification by CO2 and H2O in plug flow. The second stage combustor was modeled assuming adiabatic instantaneous gas phase reactions. Of primary interest was the dependence of char gasification efficiency on first stage particle residence time. The influence of first stage stoichiometry, heat loss, coal moisture, coal size distribution, and degree of coal devolatilization on gasifier performance and second stage exhaust temperature was determined. Performance predictions indicate that particle residence times on the order of 500 msec would be required to achieve gasification efficiencies in the range of 90 to 95 percent. The use of a finer coal size distribution significantly reduces the required gasifier residence time for acceptable levels of fuel use efficiency. Residence time requirements are also decreased by increased levels of coal devolatilization. Combustor design efforts should maximize devolatilization by minimizing mixing times associated with coal injection.

A Preliminary Investigation of the Direct Standard Setting Method.

ERIC Educational Resources Information Center

Jones, J. Patrick; And Others

Three studies assessed the psychometric characteristics of the Direct Standard Setting Method (DSSM). The Angoff technique was also used in each study. The DSSM requires judges to consider an examination 10 items at a time and determine the minimum items in that set a candidate should answer correctly to receive the credential. Nine judges set a…

Notes on some rooting characteristics of antelope bitterbrush.

Treesearch

Burt R. McConnell

1961-01-01

Information on the root habits of native forage species is limited and the need for such data is keenly appreciated by most range managers. The lack of such information results mainly from the time and care required to obtain it. Consequently, when 24 antelope bitterbrush (Purshia tridentata) root systems were excavated during a study of seasonal...

Improved-Bandwidth Transimpedance Amplifier

NASA Technical Reports Server (NTRS)

Chapsky, Jacob

2009-01-01

The widest available operational amplifier, with the best voltage and current noise characteristics, is considered for transimpedance amplifier (TIA) applications where wide bandwidth is required to handle fast rising input signals (as for time-of-flight measurement cases). The added amplifier inside the TIA feedback loop can be configured to have slightly lower voltage gain than the bandwidth reduction factor.

Simulation of time-dispersion spectral device with sample spectra accumulation

NASA Astrophysics Data System (ADS)

Zhdanov, Arseny; Khansuvarov, Ruslan; Korol, Georgy

2014-09-01

This research is conducted in order to design a spectral device for light sources power spectrum analysis. The spectral device should process radiation from sources, direct contact with radiation of which is either impossible or undesirable. Such sources include jet blast of an aircraft, optical radiation in metallurgy and textile industry. In proposed spectral device optical radiation is guided out of unfavorable environment via a piece of optical fiber with high dispersion. It is necessary for analysis to make samples of analyzed radiation as short pulses. Dispersion properties of such optical fiber cause spectral decomposition of input optical pulses. The faster time of group delay vary the stronger the spectral decomposition effect. This effect allows using optical fiber with high dispersion as a major element of proposed spectral device. Duration of sample must be much shorter than group delay time difference of a dispersive system. In the given frequency range this characteristic has to be linear. The frequency range is 400 … 500 THz for typical optical fiber. Using photonic-crystal fiber (PCF) gives much wider spectral range for analysis. In this paper we propose simulation of single pulse transmission through dispersive system with linear dispersion characteristic and quadratic-detected output responses accumulation. During simulation we propose studying influence of optical fiber dispersion characteristic angle on spectral measurement results. We also consider pulse duration and group delay time difference impact on output pulse shape and duration. Results show the most suitable dispersion characteristic that allow choosing the structure of PCF - major element of time-dispersion spectral analysis method and required number of samples for reliable assessment of measured spectrum.

Physical characteristics and evolutionary trends of continental rifts

NASA Technical Reports Server (NTRS)

Ramberg, I. B.; Morgan, P.

1984-01-01

Rifts may be defined as zones beneath which the entire lithosphere has ruptured in extension. They are widespread and occur in a variety of tectonic settings, and range up to 2,600 m.y. in age. The object of this review is to highlight characteristic features of modern and ancient rifts, to emphasize differences and similarities in order to help characterize evolutionary trends, to identify physical conditions favorable for initiation as well as termination of rifting, and to provide constraints for future modeling studies of rifting. Rifts are characterized on the basis of their structural, geomorphic, magmatic and geophysical features and the diverse character of these features and their evolutionary trends through time are discussed. Mechanisms of rifting are critically examined in terms of the physical characteristics and evolutionary trends of rifts, and it is concluded that while simple models can give valuable insight into specific processes of rifting, individual rifts can rarely, if ever, be characterized by well defined trends predicted by these models. More data are required to clearly define evolutionary trends, and the models require development to incorporate the effects of lithospheric heterogeneities and complex geologic histories.

Family and infant characteristics associated with timing of core and non-core food introduction in early childhood.

PubMed

Schrempft, S; van Jaarsveld, C H M; Fisher, A; Wardle, J

2013-06-01

To identify family and infant characteristics associated with timing of introduction of two food types: core foods (nutrient-dense) and non-core foods (nutrient-poor) in a population-based sample of mothers and infants. Participants were 1861 mothers and infants from the Gemini twin birth cohort (one child per family). Family and infant characteristics were assessed when the infants were around 8 months old. Timing of introducing core and non-core foods was assessed at 8 and 15 months. As the distributions of timing were skewed, three similar-sized groups were created for each food type: earlier (core: 1-4 months; non-core: 3-8 months), average (core: 5 months; non-core: 9-10 months) and later introduction (core: 6-12 months; non-core: 11-18 months). Ordinal logistic regression was used to examine predictors of core and non-core food introduction, with bootstrapping to test for differences between the core and non-core models. Younger maternal age, lower education level and higher maternal body mass index were associated with earlier core and non-core food introduction. Not breastfeeding for at least 3 months and higher birth weight were specifically associated with earlier introduction of core foods. Having older children was specifically associated with earlier introduction of non-core foods. There are similarities and differences in the characteristics associated with earlier introduction of core and non-core foods. Successful interventions may require a combination of approaches to target both food types.

Operational procedure for computer program for design point characteristics of a gas generator or a turbojet lift engine for V/STOL applications

NASA Technical Reports Server (NTRS)

Krebs, R. P.

1972-01-01

The computer program described calculates the design-point characteristics of a gas generator or a turbojet lift engine for V/STOL applications. The program computes the dimensions and mass, as well as the thermodynamic performance of the model engine and its components. The program was written in FORTRAN 4 language. Provision has been made so that the program accepts input values in either SI Units or U.S. Customary Units. Each engine design-point calculation requires less than 0.5 second of 7094 computer time.

Can CH-53K 3D Technical Data Support the Provisioning Process

DTIC Science & Technology

2017-05-01

contain the minimum required data characteristics and elements (Appendix A) and (2) are fully anno - tated, they can be converted to 3D PDF files that...were anno - tated as part of the original model development/creation process, the time to perform an annotation would be about 50 percent (about 1.5...files, after the fact. If the models had been anno - tated at the time they were created, we estimate that the cost to implement a 3D PDF solution for

A Summary of the Space-Time Conservation Element and Solution Element (CESE) Method

NASA Technical Reports Server (NTRS)

Wang, Xiao-Yen J.

2015-01-01

The space-time Conservation Element and Solution Element (CESE) method for solving conservation laws is examined for its development motivation and design requirements. The characteristics of the resulting scheme are discussed. The discretization of the Euler equations is presented to show readers how to construct a scheme based on the CESE method. The differences and similarities between the CESE method and other traditional methods are discussed. The strengths and weaknesses of the method are also addressed.

Design of point-of-care (POC) microfluidic medical diagnostic devices

NASA Astrophysics Data System (ADS)

Leary, James F.

2018-02-01

Design of inexpensive and portable hand-held microfluidic flow/image cytometry devices for initial medical diagnostics at the point of initial patient contact by emergency medical personnel in the field requires careful design in terms of power/weight requirements to allow for realistic portability as a hand-held, point-of-care medical diagnostics device. True portability also requires small micro-pumps for high-throughput capability. Weight/power requirements dictate use of super-bright LEDs and very small silicon photodiodes or nanophotonic sensors that can be powered by batteries. Signal-to-noise characteristics can be greatly improved by appropriately pulsing the LED excitation sources and sampling and subtracting noise in between excitation pulses. The requirements for basic computing, imaging, GPS and basic telecommunications can be simultaneously met by use of smartphone technologies, which become part of the overall device. Software for a user-interface system, limited real-time computing, real-time imaging, and offline data analysis can be accomplished through multi-platform software development systems that are well-suited to a variety of currently available cellphone technologies which already contain all of these capabilities. Microfluidic cytometry requires judicious use of small sample volumes and appropriate statistical sampling by microfluidic cytometry or imaging for adequate statistical significance to permit real-time (typically < 15 minutes) medical decisions for patients at the physician's office or real-time decision making in the field. One or two drops of blood obtained by pin-prick should be able to provide statistically meaningful results for use in making real-time medical decisions without the need for blood fractionation, which is not realistic in the field.

Data inversion algorithm development for the hologen occultation experiment

NASA Technical Reports Server (NTRS)

Gordley, Larry L.; Mlynczak, Martin G.

1986-01-01

The successful retrieval of atmospheric parameters from radiometric measurement requires not only the ability to do ideal radiometric calculations, but also a detailed understanding of instrument characteristics. Therefore a considerable amount of time was spent in instrument characterization in the form of test data analysis and mathematical formulation. Analyses of solar-to-reference interference (electrical cross-talk), detector nonuniformity, instrument balance error, electronic filter time-constants and noise character were conducted. A second area of effort was the development of techniques for the ideal radiometric calculations required for the Halogen Occultation Experiment (HALOE) data reduction. The computer code for these calculations must be extremely complex and fast. A scheme for meeting these requirements was defined and the algorithms needed form implementation are currently under development. A third area of work included consulting on the implementation of the Emissivity Growth Approximation (EGA) method of absorption calculation into a HALOE broadband radiometer channel retrieval algorithm.

46 CFR 153.284 - Characteristics of required quick closing valves.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Characteristics of required quick closing valves. 153.284 Section 153.284 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK... and Equipment Piping Systems and Cargo Handling Equipment § 153.284 Characteristics of required quick...

46 CFR 153.284 - Characteristics of required quick closing valves.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Characteristics of required quick closing valves. 153.284 Section 153.284 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK... and Equipment Piping Systems and Cargo Handling Equipment § 153.284 Characteristics of required quick...

The Wind Integration National Dataset (WIND) toolkit (Presentation)

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

Caroline Draxl: NREL

2014-01-01

Regional wind integration studies require detailed wind power output data at many locations to perform simulations of how the power system will operate under high penetration scenarios. The wind datasets that serve as inputs into the study must realistically reflect the ramping characteristics, spatial and temporal correlations, and capacity factors of the simulated wind plants, as well as being time synchronized with available load profiles.As described in this presentation, the WIND Toolkit fulfills these requirements by providing a state-of-the-art national (US) wind resource, power production and forecast dataset.

Evaluation of actuator energy storage and power sources for spacecraft applications

NASA Technical Reports Server (NTRS)

Simon, William E.; Young, Fred M.

1993-01-01

The objective of this evaluation is to determine an optimum energy storage/power source combination for electrical actuation systems for existing (Solid Rocket Booster (SRB), Shuttle) and future (Advanced Launch System (ALS), Shuttle Derivative) vehicles. Characteristic of these applications is the requirement for high power pulses (50-200 kW) for short times (milliseconds to seconds), coupled with longer-term base or 'housekeeping' requirements (5-16 kW). Specific study parameters (e.g., weight, volume, etc.) as stated in the proposal and specified in the Statement of Work (SOW) are included.

Operations Assessment of Launch Vehicle Architectures using Activity Based Cost Models

NASA Technical Reports Server (NTRS)

Ruiz-Torres, Alex J.; McCleskey, Carey

2000-01-01

The growing emphasis on affordability for space transportation systems requires the assessment of new space vehicles for all life cycle activities, from design and development, through manufacturing and operations. This paper addresses the operational assessment of launch vehicles, focusing on modeling the ground support requirements of a vehicle architecture, and estimating the resulting costs and flight rate. This paper proposes the use of Activity Based Costing (ABC) modeling for this assessment. The model uses expert knowledge to determine the activities, the activity times and the activity costs based on vehicle design characteristics. The approach provides several advantages to current approaches to vehicle architecture assessment including easier validation and allowing vehicle designers to understand the cost and cycle time drivers.

Evaluation of Flow Biosensor Technology in a Chronically-Instrumented Non-Human Primate Model

NASA Technical Reports Server (NTRS)

Koenig, S. C.; Reister, C.; Schaub, J.; Muniz, G.; Ferguson, T.; Fanton, J. W.

1995-01-01

The Physiology Research Branch of Brooks AFB conducts both human and non-human primate experiments to determine the effects of microgravity and hypergravity on the cardiovascular system and to indentify the particular mechanisms that invoke these responses. Primary investigative research efforts in a non-human primate model require the calculation of total peripheral resistance (TPR), systemic arterial compliance (SAC), and pressure-volume loop characteristics. These calculations require beat-to-beat measurement of aortic flow. We have evaluated commercially available electromagnetic (EMF) and transit-time flow measurement techniques. In vivo and in vitro experiments demonstrated that the average error of these techniques is less than 25 percent for EMF and less than 10 percent for transit-time.

Sustainability: orthopaedic surgery wait time management strategies.

PubMed

Amar, Claudia; Pomey, Marie-Pascale; SanMartin, Claudia; De Coster, Carolyn; Noseworthy, Tom

2015-01-01

The purpose of this paper is to examine Canadian organizational and systemic factors that made it possible to keep wait times within federally established limits for at least 18 months. The research design is a multiple cases study. The paper selected three cases: Case 1 - staff were able to maintain compliance with requirements for more than 18 months; Case 2 - staff were able to meet requirements for 18 months, but unable to sustain this level; Case 3 - staff were never able to meet the requirements. For each case the authors interviewed persons involved in the strategies and collected documents. The paper analysed systemic and organizational-level factors; including governance and leadership, culture, resources, methods and tools. Findings indicate that the hospital that was able to maintain compliance with the wait time requirements had specific characteristics: an exclusive mandate to do only hip and knee replacement surgery; motivated staff who were not distracted by other concerns; and a strong team spirit. The authors' research highlights an important gradient between three cases regarding the factors that sustain waiting times. The paper show that the hospital factory model seems attractive in a super-specialized surgery context. However, patients are selected for simple surgeries, without complications, and so this cannot be considered a unique model.

Optimal nodal flyby with near-Earth asteroids using electric sail

NASA Astrophysics Data System (ADS)

Mengali, Giovanni; Quarta, Alessandro A.

2014-11-01

The aim of this paper is to quantify the performance of an Electric Solar Wind Sail for accomplishing flyby missions toward one of the two orbital nodes of a near-Earth asteroid. Assuming a simplified, two-dimensional mission scenario, a preliminary mission analysis has been conducted involving the whole known population of those asteroids at the beginning of the 2013 year. The analysis of each mission scenario has been performed within an optimal framework, by calculating the minimum-time trajectory required to reach each orbital node of the target asteroid. A considerable amount of simulation data have been collected, using the spacecraft characteristic acceleration as a parameter to quantify the Electric Solar Wind Sail propulsive performance. The minimum time trajectory exhibits a different structure, which may or may not include a solar wind assist maneuver, depending both on the Sun-node distance and the value of the spacecraft characteristic acceleration. Simulations show that over 60% of near-Earth asteroids can be reached with a total mission time less than 100 days, whereas the entire population can be reached in less than 10 months with a spacecraft characteristic acceleration of 1 mm/s2.

Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

NASA Technical Reports Server (NTRS)

Decker, A. J.

1984-01-01

The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed.

Modulation of isochronous movements in a flexible environment: links between motion and auditory experience.

PubMed

Bravi, Riccardo; Del Tongo, Claudia; Cohen, Erez James; Dalle Mura, Gabriele; Tognetti, Alessandro; Minciacchi, Diego

2014-06-01

The ability to perform isochronous movements while listening to a rhythmic auditory stimulus requires a flexible process that integrates timing information with movement. Here, we explored how non-temporal and temporal characteristics of an auditory stimulus (presence, interval occupancy, and tempo) affect motor performance. These characteristics were chosen on the basis of their ability to modulate the precision and accuracy of synchronized movements. Subjects have participated in sessions in which they performed sets of repeated isochronous wrist's flexion-extensions under various conditions. The conditions were chosen on the basis of the defined characteristics. Kinematic parameters were evaluated during each session, and temporal parameters were analyzed. In order to study the effects of the auditory stimulus, we have minimized all other sensory information that could interfere with its perception or affect the performance of repeated isochronous movements. The present study shows that the distinct characteristics of an auditory stimulus significantly influence isochronous movements by altering their duration. Results provide evidence for an adaptable control of timing in the audio-motor coupling for isochronous movements. This flexibility would make plausible the use of different encoding strategies to adapt audio-motor coupling for specific tasks.

46 CFR 15.405 - Familiarity with vessel characteristics.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Familiarity with vessel characteristics. 15.405 Section... MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.405 Familiarity with vessel characteristics. Each credentialed individual must become familiar with the relevant characteristics of the vessel on...

Expert system constant false alarm rate processor

NASA Astrophysics Data System (ADS)

Baldygo, William J., Jr.; Wicks, Michael C.

1993-10-01

The requirements for high detection probability and low false alarm probability in modern wide area surveillance radars are rarely met due to spatial variations in clutter characteristics. Many filtering and CFAR detection algorithms have been developed to effectively deal with these variations; however, any single algorithm is likely to exhibit excessive false alarms and intolerably low detection probabilities in a dynamically changing environment. A great deal of research has led to advances in the state of the art in Artificial Intelligence (AI) and numerous areas have been identified for application to radar signal processing. The approach suggested here, discussed in a patent application submitted by the authors, is to intelligently select the filtering and CFAR detection algorithms being executed at any given time, based upon the observed characteristics of the interference environment. This approach requires sensing the environment, employing the most suitable algorithms, and applying an appropriate multiple algorithm fusion scheme or consensus algorithm to produce a global detection decision.

The Challenging Pupil in the Classroom: Child Effects on Teachers

PubMed Central

Houts, Renate M.; Caspi, Avshalom; Pianta, Robert C.; Arseneault, Louise; Moffitt, Terrie E.

2012-01-01

Teaching children requires effort and some children naturally require more effort than others. This study tests whether teacher effort devoted to individual children varies as a function of children’s personal characteristics. Using a nation-wide longitudinal study of twins followed between ages 5-12 years, we asked teachers about the effort they invested in each child enrolled in our study. We found that teacher effort was a function of heritable child characteristics; that children’s challenging behavior assessed at age 5 predicted teacher effort at age 12; and that challenging child behavior and teacher effort share common etiology in children’s genes. While child effects accounted for a significant proportion of variance in teacher effort, we also found variation that could not be attributed to children’s behavior. Treating children with challenging behavior and enhancing teachers’ skills in behavior management could increase the time and energy teachers have to deliver curriculum in their classrooms. PMID:21078897

Performance, emissions, and physical characteristics of a rotating combustion aircraft engine

NASA Technical Reports Server (NTRS)

Berkowitz, M.; Hermes, W. L.; Mount, R. E.; Myers, D.

1976-01-01

The RC2-75, a liquid cooled two chamber rotary combustion engine (Wankel type), designed for aircraft use, was tested and representative baseline (212 KW, 285 BHP) performance and emissions characteristics established. The testing included running fuel/air mixture control curves and varied ignition timing to permit selection of desirable and practical settings for running wide open throttle curves, propeller load curves, variable manifold pressure curves covering cruise conditions, and EPA cycle operating points. Performance and emissions data were recorded for all of the points run. In addition to the test data, information required to characterize the engine and evaluate its performance in aircraft use is provided over a range from one half to twice its present power. The exhaust emissions results are compared to the 1980 EPA requirements. Standard day take-off brake specific fuel consumption is 356 g/KW-HR (.585 lb/BHP-HR) for the configuration tested.

Building a Relationship between Robot Characteristics and Teleoperation User Interfaces.

PubMed

Mortimer, Michael; Horan, Ben; Seyedmahmoudian, Mehdi

2017-03-14

The Robot Operating System (ROS) provides roboticists with a standardized and distributed framework for real-time communication between robotic systems using a microkernel environment. This paper looks at how ROS metadata, Unified Robot Description Format (URDF), Semantic Robot Description Format (SRDF), and its message description language, can be used to identify key robot characteristics to inform User Interface (UI) design for the teleoperation of heterogeneous robot teams. Logical relationships between UI components and robot characteristics are defined by a set of relationship rules created using relevant and available information including developer expertise and ROS metadata. This provides a significant opportunity to move towards a rule-driven approach for generating the designs of teleoperation UIs; in particular the reduction of the number of different UI configurations required to teleoperate each individual robot within a heterogeneous robot team. This approach is based on using an underlying rule set identifying robots that can be teleoperated using the same UI configuration due to having the same or similar robot characteristics. Aside from reducing the number of different UI configurations an operator needs to be familiar with, this approach also supports consistency in UI configurations when a teleoperator is periodically switching between different robots. To achieve this aim, a Matlab toolbox is developed providing users with the ability to define rules specifying the relationship between robot characteristics and UI components. Once rules are defined, selections that best describe the characteristics of the robot type within a particular heterogeneous robot team can be made. A main advantage of this approach is that rather than specifying discrete robots comprising the team, the user can specify characteristics of the team more generally allowing the system to deal with slight variations that may occur in the future. In fact, by using the defined relationship rules and characteristic selections, the toolbox can automatically identify a reduced set of UI configurations required to control possible robot team configurations, as opposed to the traditional ad-hoc approach to teleoperation UI design. In the results section, three test cases are presented to demonstrate how the selection of different robot characteristics builds a number of robot characteristic combinations, and how the relationship rules are used to determine a reduced set of required UI configurations needed to control each individual robot in the robot team.

Building a Relationship between Robot Characteristics and Teleoperation User Interfaces

PubMed Central

Mortimer, Michael; Horan, Ben; Seyedmahmoudian, Mehdi

2017-01-01

The Robot Operating System (ROS) provides roboticists with a standardized and distributed framework for real-time communication between robotic systems using a microkernel environment. This paper looks at how ROS metadata, Unified Robot Description Format (URDF), Semantic Robot Description Format (SRDF), and its message description language, can be used to identify key robot characteristics to inform User Interface (UI) design for the teleoperation of heterogeneous robot teams. Logical relationships between UI components and robot characteristics are defined by a set of relationship rules created using relevant and available information including developer expertise and ROS metadata. This provides a significant opportunity to move towards a rule-driven approach for generating the designs of teleoperation UIs; in particular the reduction of the number of different UI configurations required to teleoperate each individual robot within a heterogeneous robot team. This approach is based on using an underlying rule set identifying robots that can be teleoperated using the same UI configuration due to having the same or similar robot characteristics. Aside from reducing the number of different UI configurations an operator needs to be familiar with, this approach also supports consistency in UI configurations when a teleoperator is periodically switching between different robots. To achieve this aim, a Matlab toolbox is developed providing users with the ability to define rules specifying the relationship between robot characteristics and UI components. Once rules are defined, selections that best describe the characteristics of the robot type within a particular heterogeneous robot team can be made. A main advantage of this approach is that rather than specifying discrete robots comprising the team, the user can specify characteristics of the team more generally allowing the system to deal with slight variations that may occur in the future. In fact, by using the defined relationship rules and characteristic selections, the toolbox can automatically identify a reduced set of UI configurations required to control possible robot team configurations, as opposed to the traditional ad-hoc approach to teleoperation UI design. In the results section, three test cases are presented to demonstrate how the selection of different robot characteristics builds a number of robot characteristic combinations, and how the relationship rules are used to determine a reduced set of required UI configurations needed to control each individual robot in the robot team. PMID:28335431

Site characteristics and prey abundance at foraging sites used by Lesser Scaup (Aythya affinis) wintering in Florida

USGS Publications Warehouse

Herring, Garth; Collazo, Jaime

2009-01-01

We examined site characteristics and prey abundances where wintering Aythya affinis (Lesser Scaup; hereafter scaup) foraged within three regions of the Indian River Lagoon system in central Florida. We observed that scaup concentrated in the Indian and Banana rivers; however, density of prey items did not differ between foraging sites and random sites. We also found that site characteristics were similar between foraging and random sites. Differences in site characteristics between random points across all three regions did not explain the distribution of Foraging scaup (no scaup foraged in the Mosquito Lagoon); however, prey densities were approximately 3 times lower in the Mosquito Lagoon region. Our study suggests that current habitat conditions within the northern Indian River Lagoon system meet the overwintering requirements of scaup; however, prey densities in the Mosquito Lagoon may have been too low to be profitable for foraging scaup during the period of our study.

[Pharmaceutical logistic in turnover of pharmaceutical products of Azerbaijan].

PubMed

Dzhalilova, K I

2009-11-01

Development of pharmaceutical logistic system model promotes optimal strategy for pharmaceutical functioning. The goal of such systems is organization of pharmaceutical product's turnover in required quantity and assortment, at preset time and place, at a highest possible degree of consumption readiness with minimal expenses and qualitative service. Organization of the optimal turnover chain in the region is offered to start from approximate classification of medicaments by logistic characteristics. Supplier selection was performed by evaluation of timeliness of delivery, quality of delivered products (according to the minimum acceptable level of quality) and time-keeping of time spending for orders delivery.

Analysis of acoustic emission signals and monitoring of machining processes

PubMed

Govekar; Gradisek; Grabec

2000-03-01

Monitoring of a machining process on the basis of sensor signals requires a selection of informative inputs in order to reliably characterize and model the process. In this article, a system for selection of informative characteristics from signals of multiple sensors is presented. For signal analysis, methods of spectral analysis and methods of nonlinear time series analysis are used. With the aim of modeling relationships between signal characteristics and the corresponding process state, an adaptive empirical modeler is applied. The application of the system is demonstrated by characterization of different parameters defining the states of a turning machining process, such as: chip form, tool wear, and onset of chatter vibration. The results show that, in spite of the complexity of the turning process, the state of the process can be well characterized by just a few proper characteristics extracted from a representative sensor signal. The process characterization can be further improved by joining characteristics from multiple sensors and by application of chaotic characteristics.

Parametric fate and transport profiling for selective groundwater monitoring at closed landfills: a case study.

PubMed

Sizirici, Banu; Tansel, Berrin

2015-04-01

Monitoring contaminant concentrations in groundwater near closed municipal solid waste landfills requires long term monitoring program which can require significant investment for monitoring efforts. The groundwater monitoring data from a closed landfill in Florida was analyzed to reduce the monitoring efforts. The available groundwater monitoring data (collected over 20 years) were analyzed (i.e., type, concentration and detection level) to identify the trends in concentrations of contaminants and spatial mobility characteristics of groundwater (i.e., groundwater direction, retardation characteristics of contaminants, groundwater well depth, subsoil characteristics), to identify critical monitoring locations. Among the 7 groundwater monitoring well clusters (totaling 22 wells) in landfill, the data from two monitoring well clusters (totaling 7 wells) located along direction of groundwater flow showed similarities (the highest concentrations and same contaminants). These wells were used to assess the transport characteristics of the contaminants. Some parameters (e.g., iron, sodium, ammonia as N, chlorobenzene, 1,4-dichlorobenzene) showed decreasing trends in the groundwater due to soil absorption and retardation. Metals were retarded by ion exchange and their concentration increased by depth indicating soil reached breakthrough over time. Soil depth did not have a significant effect on the concentrations of volatile organic contaminants. Based on the analyses, selective groundwater monitoring modifications were developed for effective monitoring to acquire data from the most critical locations which may be impacted by leachate mobility. The adjustments in the sampling strategy reduced the amount of data collected by as much as 97.7% (i.e., total number of parameters monitored). Effective groundwater sampling strategies can save time, effort and monitoring costs while improving the quality of sample handling and data analyses for better utilization of post closure monitoring funds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structural characterization of product ions by electrospray ionization and quadrupole time-of-flight mass spectrometry to support regulatory analysis of veterinary drug residues in foods Part 2: Benzimidazoles nitromidaz.....

USDA-ARS?s Scientific Manuscript database

RATIONALE: Analysis for identification and quantification of regulated veterinary drug residues in foods are usually achieved by liquid chromatography coupled to tandem mass spectrometry. The instrument method requires the selection of characteristic ions, but structure elucidation is seldom perform...

Stationarity conditions for physicochemical processes in the interior ballistics of a gun

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

Lipanov, A.M.

1995-09-01

An original method is proposed for ensuring time-invariant (stationary) interior ballistic parameters in the postprojectile space of a gun barrel. Stationarity of the parameters is achieved by investing the solid-propellant charge with highly original structures that produce the required pressure condition and linear growth of the projectile velocity. Simple relations are obtained for calculating the principal characteristics.

Estimating FIA plot characteristics using NAIP imagery, function modeling, and the RMRS Raster Utility coding library

Treesearch

John S. Hogland; Nathaniel M. Anderson

2015-01-01

Raster modeling is an integral component of spatial analysis. However, conventional raster modeling techniques can require a substantial amount of processing time and storage space, often limiting the types of analyses that can be performed. To address this issue, we have developed Function Modeling. Function Modeling is a new modeling framework that...

Estimating FIA plot characteristics using NAIP imagery, function modeling, and the RMRS raster utility coding library

Treesearch

John S. Hogland; Nathaniel M. Anderson

2015-01-01

Raster modeling is an integral component of spatial analysis. However, conventional raster modeling techniques can require a substantial amount of processing time and storage space, often limiting the types of analyses that can be performed. To address this issue, we have developed Function Modeling. Function Modeling is a new modeling framework that streamlines the...

Non-contact fluid characterization in containers using ultrasonic waves

DOEpatents

Sinha, Dipen N [Los Alamos, NM

2012-05-15

Apparatus and method for non-contact (stand-off) ultrasonic determination of certain characteristics of fluids in containers or pipes are described. A combination of swept frequency acoustic interferometry (SFAI), wide-bandwidth, air-coupled acoustic transducers, narrowband frequency data acquisition, and data conversion from the frequency domain to the time domain, if required, permits meaningful information to be extracted from such fluids.

Rodent repellent studies. IV. Preparation and properties of trinitrobenzene-aryl amine complexes

USGS Publications Warehouse

DeWitt, J.B.; Bellack, E.; Welch, J.F.

1953-01-01

Data are presented on methods of preparation, chemical arid physical characteristics, toxicity, and repellency to rodents of complexes of symmetrical trinitrohenzene with various aromatic amines: When applied in suitable carriers or incorporated in plastic .films, members of this series ofmaterials were shown to offer significant increases in time required by wild rodents to damage common packaging materials.

The biometric recognition on contactless multi-spectrum finger images

NASA Astrophysics Data System (ADS)

Kang, Wenxiong; Chen, Xiaopeng; Wu, Qiuxia

2015-01-01

This paper presents a novel multimodal biometric system based on contactless multi-spectrum finger images, which aims to deal with the limitations of unimodal biometrics. The chief merits of the system are the richness of the permissible texture and the ease of data access. We constructed a multi-spectrum instrument to simultaneously acquire three different types of biometrics from a finger: contactless fingerprint, finger vein, and knuckleprint. On the basis of the samples with these characteristics, a moderate database was built for the evaluation of our system. Considering the real-time requirements and the respective characteristics of the three biometrics, the block local binary patterns algorithm was used to extract features and match for the fingerprints and finger veins, while the Oriented FAST and Rotated BRIEF algorithm was applied for knuckleprints. Finally, score-level fusion was performed on the matching results from the aforementioned three types of biometrics. The experiments showed that our proposed multimodal biometric recognition system achieves an equal error rate of 0.109%, which is 88.9%, 94.6%, and 89.7% lower than the individual fingerprint, knuckleprint, and finger vein recognitions, respectively. Nevertheless, our proposed system also satisfies the real-time requirements of the applications.

Robust modular product family design

NASA Astrophysics Data System (ADS)

Jiang, Lan; Allada, Venkat

2001-10-01

This paper presents a modified Taguchi methodology to improve the robustness of modular product families against changes in customer requirements. The general research questions posed in this paper are: (1) How to effectively design a product family (PF) that is robust enough to accommodate future customer requirements. (2) How far into the future should designers look to design a robust product family? An example of a simplified vacuum product family is used to illustrate our methodology. In the example, customer requirements are selected as signal factors; future changes of customer requirements are selected as noise factors; an index called quality characteristic (QC) is set to evaluate the product vacuum family; and the module instance matrix (M) is selected as control factor. Initially a relation between the objective function (QC) and the control factor (M) is established, and then the feasible M space is systemically explored using a simplex method to determine the optimum M and the corresponding QC values. Next, various noise levels at different time points are introduced into the system. For each noise level, the optimal values of M and QC are computed and plotted on a QC-chart. The tunable time period of the control factor (the module matrix, M) is computed using the QC-chart. The tunable time period represents the maximum time for which a given control factor can be used to satisfy current and future customer needs. Finally, a robustness index is used to break up the tunable time period into suitable time periods that designers should consider while designing product families.

Considerations in development of expert systems for real-time space applications

NASA Technical Reports Server (NTRS)

Murugesan, S.

1988-01-01

Over the years, demand on space systems has increased tremendously and this trend will continue for the near future. Enhanced capabilities of space systems, however, can only be met with increased complexity and sophistication of onboard and ground systems. Artificial Intelligence and expert system techniques have great potential in space applications. Expert systems could facilitate autonomous decision making, improve in-orbit fault diagnosis and repair, enhance performance and reduce reliance on ground support. However, real-time expert systems, unlike conventional off-line consultative systems, have to satisfy certain special stringent requirements before they could be used for onboard space applications. Challenging and interesting new environments are faced while developing expert system space applications. This paper discusses the special characteristics, requirements and typical life cycle issues for onboard expert systems. Further, it also describes considerations in design, development, and implementation which are particularly important to real-time expert systems for space applications.

Testing of Performance of a Scroll Pump in Support of Improved Vapor Phase Catalytic Ammonia Removal (VPCAR) Mass Reduction

NASA Technical Reports Server (NTRS)

Nahra, Henry K.; Kraft, Thomas G.; Yee, Glenda F.; Jankovsky, Amy L.; Flynn, Michael

2006-01-01

This paper describes the results of ground testing of a scroll pump with a potential of being a substitute for the current vacuum pump of the Vapor Phase Catalytic Ammonia Reduction (VPCAR). Assessments of the pressure-time, pump-down time, pump power and the pump noise were made for three configurations of the pump the first of which was without the gas ballast, the second with the gas ballast installed but not operating and the third with the gas ballast operating. The tested scroll pump exhibited optimum characteristics given its mass and power requirements. The pump down time required to reach a pressure of 50 Torr ranged from 60 minutes without the ballast to about 120 minutes with the gas ballast operational. The noise emission and the pump power were assessed in this paper as well.

Net present biodiversity value and the design of biodiversity offsets.

PubMed

Overton, Jacob McC; Stephens, R T Theo; Ferrier, Simon

2013-02-01

There is an urgent need to develop sound theory and practice for biodiversity offsets to provide a better basis for offset multipliers, to improve accounting for time delays in offset repayments, and to develop a common framework for evaluating in-kind and out-of-kind offsets. Here, we apply concepts and measures from systematic conservation planning and financial accounting to provide a basis for determining equity across type (of biodiversity), space, and time. We introduce net present biodiversity value (NPBV) as a theoretical and practical measure for defining the offset required to achieve no-net-loss. For evaluating equity in type and space we use measures of biodiversity value from systematic conservation planning. Time discount rates are used to address risk of non-repayment, and loss of utility. We illustrate these concepts and measures with two examples of biodiversity impact-offset transactions. Considerable further work is required to understand the characteristics of these approaches.

The Solid Phase Curing Time Effect of Asbuton with Texapon Emulsifier at the Optimum Bitumen Content

NASA Astrophysics Data System (ADS)

Sarwono, D.; Surya D, R.; Setyawan, A.; Djumari

2017-07-01

Buton asphalt (asbuton) could not be utilized optimally in Indonesia. Asbuton utilization rate was still low because the processed product of asbuton still have impracticable form in the term of use and also requiring high processing costs. This research aimed to obtain asphalt products from asbuton practical for be used through the extraction process and not requiring expensive processing cost. This research was done with experimental method in laboratory. The composition of emulsify asbuton were 5/20 grain, premium, texapon, HCl, and aquades. Solid phase was the mixture asbuton 5/20 grain and premium with 3 minutes mixing time. Liquid phase consisted texapon, HCl and aquades. The aging process was done after solid phase mixing process in order to reaction and tie of solid phase mixed become more optimal for high solubility level of asphalt production. Aging variable time were 30, 60, 90, 120, and 150 minutes. Solid and liquid phase was mixed for emulsify asbuton production, then extracted for 25 minutes. Solubility level of asphalt, water level, and asphalt characteristic was tested at extraction result of emulsify asbuton with most optimum ashphal level. The result of analysis tested data asphalt solubility level at extract asbuton resulted 94.77% on 120 minutes aging variable time. Water level test resulted water content reduction on emulsify asbuton more long time on occurring of aging solid phase. Examination of asphalt characteristic at extraction result of emulsify asbuton with optimum asphalt solubility level, obtain specimen that have rigid and strong texture in order that examination result have not sufficient ductility and penetration value.

49 CFR 240.231 - Requirements for locomotive engineers unfamiliar with physical characteristics in other than...

Code of Federal Regulations, 2011 CFR

2011-10-01

... with physical characteristics in other than joint operations. 240.231 Section 240.231 Transportation... Process § 240.231 Requirements for locomotive engineers unfamiliar with physical characteristics in other... characteristics of the territory pursuant to the railroad's certification program. (b) Except as provided in...

49 CFR 240.231 - Requirements for locomotive engineers unfamiliar with physical characteristics in other than...

Code of Federal Regulations, 2010 CFR

2010-10-01

... with physical characteristics in other than joint operations. 240.231 Section 240.231 Transportation... Process § 240.231 Requirements for locomotive engineers unfamiliar with physical characteristics in other... characteristics of the territory pursuant to the railroad's certification program. (b) Except as provided in...

40 CFR 161.190 - Physical and chemical characteristics.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Physical and chemical characteristics... Requirements § 161.190 Physical and chemical characteristics. (a) Table. Sections 161.100 through 161.102 describe how to use this table to determine the physical and chemical characteristics data requirements and...

Study on photoelectric parameter measurement method of high capacitance solar cell

NASA Astrophysics Data System (ADS)

Zhang, Junchao; Xiong, Limin; Meng, Haifeng; He, Yingwei; Cai, Chuan; Zhang, Bifeng; Li, Xiaohui; Wang, Changshi

2018-01-01

The high efficiency solar cells usually have high capacitance characteristic, so the measurement of their photoelectric performance usually requires long pulse width and long sweep time. The effects of irradiance non-uniformity, probe shielding and spectral mismatch on the IV curve measurement are analyzed experimentally. A compensation method for irradiance loss caused by probe shielding is proposed, and the accurate measurement of the irradiance intensity in the IV curve measurement process of solar cell is realized. Based on the characteristics that the open circuit voltage of solar cell is sensitive to the junction temperature, an accurate measurement method of the temperature of solar cell under continuous irradiation condition is proposed. Finally, a measurement method with the characteristic of high accuracy and wide application range for high capacitance solar cell is presented.

Operational procedure for computer program for design point characteristics of a compressed-air generator with through-flow combustor for V/STOL applications

NASA Technical Reports Server (NTRS)

Krebs, R. P.

1971-01-01

The computer program described in this report calculates the design-point characteristics of a compressed-air generator for use in V/STOL applications such as systems with a tip-turbine-driven lift fan. The program computes the dimensions and mass, as well as the thermodynamic performance of a model air generator configuration which involves a straight through-flow combustor. Physical and thermodynamic characteristics of the air generator components are also given. The program was written in FORTRAN IV language. Provision has been made so that the program will accept input values in either SI units or U.S. customary units. Each air generator design-point calculation requires about 1.5 seconds of 7094 computer time for execution.

Inlet-engine matching for SCAR including application of a bicone variable geometry inlet

NASA Technical Reports Server (NTRS)

Wasserbauer, J. F.; Gerstenmaier, W. H.

1978-01-01

Airflow characteristics of variable cycle engines (VCE) designed for Mach 2.32 can have transonic airflow requirements as high as 1.6 times the cruise airflow. This is a formidable requirement for conventional, high performance, axisymmetric, translating centerbody mixed compression inlets. An alternate inlet is defined, where the second cone of a two cone center body collapses to the initial cone angle to provide a large off-design airflow capability, and incorporates modest centerbody translation to minimize spillage drag. Estimates of transonic spillage drag are competitive with those of conventional translating centerbody inlets. The inlet's cruise performance exhibits very low bleed requirements with good recovery and high angle of attack capability.

CONSUMER PREFERENCES FOR SCANNING MODALITY TO DIAGNOSE FOCAL LIVER LESIONS.

PubMed

Whitty, Jennifer; Filby, Alexandra; Smith, Adam B; Carr, Louise M

2015-01-01

Differences in the process of using liver imaging technologies might be important to patients. This study aimed to investigate preferences for scanning modalities used in diagnosing focal liver lesions. A discrete choice experiment was administered to 504 adults aged 25 ≥years. Respondents made repeated choices between two hypothetical scans, described according to waiting time for scan and results, procedure type, the chance of minor side-effects, and whether further scanning procedures were likely to be required. Choice data were analyzed using mixed-logit models with respondent characteristics used to explain preference heterogeneity. Respondents preferred shorter waiting times, the procedure to be undertaken with a handheld scanner on a couch instead of within a body scanner, no side-effects, and no follow–up scans (p≤.01). The average respondent was willing to wait an additional 2 weeks for the scan if it resulted in avoiding side-effects, 1.5 weeks to avoid further procedures or to be told the results immediately, and 1 week to have the scan performed on a couch with a handheld scanner. However, substantial heterogeneity was observed in the strength of preference for desirable imaging characteristics. An average individual belonging to a general population sub–group most likely to require imaging to characterize focal liver lesions in the United Kingdom would prefer contrast–enhanced ultrasound over magnetic resonance imaging or computed tomography. Insights into the patient perspective around differential characteristics of imaging modalities have the potential to be used to guide recommendations around the use of these technologie

Human Mars Mission: Launch Window from Earth Orbit. Pt. 1

NASA Technical Reports Server (NTRS)

Young, Archie

1999-01-01

The determination of orbital window characteristics is of major importance in the analysis of human interplanetary missions and systems. The orbital launch window characteristics are directly involved in the selection of mission trajectories, the development of orbit operational concepts, and the design of orbital launch systems. The orbital launch window problem arises because of the dynamic nature of the relative geometry between outgoing (departure) asymptote of the hyperbolic escape trajectory and the earth parking orbit. The orientation of the escape hyperbola asymptotic relative to the earth is a function of time. The required hyperbola energy level also varies with time. In addition, the inertial orientation of the parking orbit is a function of time because of the perturbations caused by the Earth's oblateness. Thus, a coplanar injection onto the escape hyperbola can be made only at a point in time when the outgoing escape asymptote is contained by the plane of parking orbit. Even though this condition may be planned as a nominal situation, it will not generally represent the more probable injection geometry. The general case of an escape injection maneuver performed at a time other than the coplanar time will involve both a path angle and plane change and, therefore, a delta V penalty. Usually, because of the delta V penalty the actual departure injection window is smaller in duration than that determined by energy requirement alone. This report contains the formulation, characteristics, and test cases for five different launch window modes for Earth orbit. These modes are: 1) One impulsive maneuver from a Highly Elliptical Orbit (HEO); 2) Two impulsive maneuvers from a Highly Elliptical Orbit (HEO); 3) One impulsive maneuver from a Low Earth Orbit (LEO); 4) Two impulsive maneuvers form LEO; and 5) Three impulsive maneuvers form LEO. The formulation of these five different launch window modes provides a rapid means of generating realistic parametric data for space exploration studies. Also the formulation provides vector and geometrical data sufficient for use as a good starting point in detail trajectory analysis based on calculus of variations, steepest descent, or parameter optimization program techniques.

Human Exploration Missions Study Launch Window from Earth Orbit

NASA Technical Reports Server (NTRS)

Young, Archie

2001-01-01

The determination of orbital launch window characteristics is of major importance in the analysis of human interplanetary missions and systems. The orbital launch window characteristics are directly involved in the selection of mission trajectories, the development of orbit operational concepts, and the design of orbital launch systems. The orbital launch window problem arises because of the dynamic nature of the relative geometry between outgoing (departure) asymptote of the hyperbolic escape trajectory and the earth parking orbit. The orientation of the escape hyperbola asymptotic relative to earth is a function of time. The required hyperbola energy level also varies with time. In addition, the inertial orientation of the parking orbit is a function of time because of the perturbations caused by the Earth's oblateness. Thus, a coplanar injection onto the escape hyperbola can be made only at a point in time when the outgoing escape asymptote is contained by the plane of parking orbit. Even though this condition may be planned as a nominal situation, it will not generally represent the more probable injection geometry. The general case of an escape injection maneuver performed at a time other than the coplanar time will involve both a path angle and plane change and, therefore, a Delta(V) penalty. Usually, because of the Delta(V) penalty the actual departure injection window is smaller in duration than that determined by energy requirement alone. This report contains the formulation, characteristics, and test cases for five different launch window modes for Earth orbit. These modes are: (1) One impulsive maneuver from a Low Earth Orbit (LEO), (2) Two impulsive maneuvers from LEO, (3) Three impulsive maneuvers from LEO, (4) One impulsive maneuvers from a Highly Elliptical Orbit (HEO), (5) Two impulsive maneuvers from a Highly Elliptical Orbit (HEO) The formulation of these five different launch window modes provides a rapid means of generating realistic parametric data for space exploration studies. Also the formulation provides vector and geometrical data sufficient for use as a good starting point in detail trajectory analysis based on calculus of variations, steepest descent, or parameter optimization program techniques.

High frequency dynamic engine simulation. [TF-30 engine

NASA Technical Reports Server (NTRS)

Schuerman, J. A.; Fischer, K. E.; Mclaughlin, P. W.

1977-01-01

A digital computer simulation of a mixed flow, twin spool turbofan engine was assembled to evaluate and improve the dynamic characteristics of the engine simulation to disturbance frequencies of at least 100 Hz. One dimensional forms of the dynamic mass, momentum and energy equations were used to model the engine. A TF30 engine was simulated so that dynamic characteristics could be evaluated against results obtained from testing of the TF30 engine at the NASA Lewis Research Center. Dynamic characteristics of the engine simulation were improved by modifying the compression system model. Modifications to the compression system model were established by investigating the influence of size and number of finite dynamic elements. Based on the results of this program, high frequency engine simulations using finite dynamic elements can be assembled so that the engine dynamic configuration is optimum with respect to dynamic characteristics and computer execution time. Resizing of the compression systems finite elements improved the dynamic characteristics of the engine simulation but showed that additional refinements are required to obtain close agreement simulation and actual engine dynamic characteristics.

Associations between statewide prescription drug monitoring program (PDMP) requirement and physician patterns of prescribing opioid analgesics for patients with non-cancer chronic pain.

PubMed

Lin, Hsien-Chang; Wang, Zhi; Boyd, Carol; Simoni-Wastila, Linda; Buu, Anne

2018-01-01

State-level prescription drug monitoring programs (PDMPs) have been implemented in most states. PDMPs enable registered prescribers to obtain real-time information on patients' prescription history to reduce non-medical use of controlled drugs. This study examined whether PDMP implementation and different levels of PDMP requirements were associated with physicians' patterns of prescribing opioid analgesics for patients with non-cancer chronic pain. This is a secondary analysis study using cross-sectional national data. Patients with non-cancer chronic pain from the 2012 National Ambulatory Medical Care Survey were included (weighted N=81,018,131; unweighted N=3295). Heckman two-step selection procedure employing two logistic regressions was used to explore the associations between PDMP requirements and physicians' prescribing behaviors, controlling for physician characteristics, patient characteristics, physician-healthcare system interaction, and physician-patient relationship, guided by the Eisenberg's model of physician decision making. State PDMP implementation status and requirement levels were not associated with physician opioid prescribing for non-cancer chronic pain treatment (p's ranged 0.30-0.32). Patients with Medicare coverage were more likely to be prescribed opioid analgesics than those with private health insurance (OR=1.55, p<0.01). Hispanic patients were less likely to be prescribed opioid analgesics than non-Hispanic white patients (OR=0.61, p<0.05). Findings indicated that the effectiveness of PDMPs on physicians' opioid prescribing tendency for non-cancer chronic pain treatment could not be supported. Policy makers should be aware of the need for redesigning PDMPs regarding requirements and enforcement for prescribers and related stakeholders. Future studies also are needed to identify characteristics contributing to PDMP effectiveness in reducing non-medical use of prescription opioids. Copyright © 2017 Elsevier Ltd. All rights reserved.

System verification and validation: a fundamental systems engineering task

NASA Astrophysics Data System (ADS)

Ansorge, Wolfgang R.

2004-09-01

Systems Engineering (SE) is the discipline in a project management team, which transfers the user's operational needs and justifications for an Extremely Large Telescope (ELT) -or any other telescope-- into a set of validated required system performance characteristics. Subsequently transferring these validated required system performance characteris-tics into a validated system configuration, and eventually into the assembled, integrated telescope system with verified performance characteristics and provided it with "objective evidence that the particular requirements for the specified intended use are fulfilled". The latter is the ISO Standard 8402 definition for "Validation". This presentation describes the verification and validation processes of an ELT Project and outlines the key role System Engineering plays in these processes throughout all project phases. If these processes are implemented correctly into the project execution and are started at the proper time, namely at the very beginning of the project, and if all capabilities of experienced system engineers are used, the project costs and the life-cycle costs of the telescope system can be reduced between 25 and 50 %. The intention of this article is, to motivate and encourage project managers of astronomical telescopes and scientific instruments to involve the entire spectrum of Systems Engineering capabilities performed by trained and experienced SYSTEM engineers for the benefit of the project by explaining them the importance of Systems Engineering in the AIV and validation processes.

A real time Pegasus propulsion system model for VSTOL piloted simulation evaluation

NASA Technical Reports Server (NTRS)

Mihaloew, J. R.; Roth, S. P.; Creekmore, R.

1981-01-01

A real time propulsion system modeling technique suitable for use in man-in-the-loop simulator studies was developd. This technique provides the system accuracy, stability, and transient response required for integrated aircraft and propulsion control system studies. A Pegasus-Harrier propulsion system was selected as a baseline for developing mathematical modeling and simulation techniques for VSTOL. Initially, static and dynamic propulsion system characteristics were modeled in detail to form a nonlinear aerothermodynamic digital computer simulation of a Pegasus engine. From this high fidelity simulation, a real time propulsion model was formulated by applying a piece-wise linear state variable methodology. A hydromechanical and water injection control system was also simulated. The real time dynamic model includes the detail and flexibility required for the evaluation of critical control parameters and propulsion component limits over a limited flight envelope. The model was programmed for interfacing with a Harrier aircraft simulation. Typical propulsion system simulation results are presented.

Initial Study of an Effective Fast-Time Simulation Platform for Unmanned Aircraft System Traffic Management

NASA Technical Reports Server (NTRS)

Xue, Min; Rios, Joseph

2017-01-01

Small Unmanned Aerial Vehicles (sUAVs), typically 55 lbs and below, are envisioned to play a major role in surveilling critical assets, collecting important information, and delivering goods. Large scale small UAV operations are expected to happen in low altitude airspace in the near future. Many static and dynamic constraints exist in low altitude airspace because of manned aircraft or helicopter activities, various wind conditions, restricted airspace, terrain and man-made buildings, and conflict-avoidance among sUAVs. High sensitivity and high maneuverability are unique characteristics of sUAVs that bring challenges to effective system evaluations and mandate such a simulation platform different from existing simulations that were built for manned air traffic system and large unmanned fixed aircraft. NASA's Unmanned aircraft system Traffic Management (UTM) research initiative focuses on enabling safe and efficient sUAV operations in the future. In order to help define requirements and policies for a safe and efficient UTM system to accommodate a large amount of sUAV operations, it is necessary to develop a fast-time simulation platform that can effectively evaluate requirements, policies, and concepts in a close-to-reality environment. This work analyzed the impacts of some key factors including aforementioned sUAV's characteristics and demonstrated the importance of these factors in a successful UTM fast-time simulation platform.

Initial Study of An Effective Fast-Time Simulation Platform for Unmanned Aircraft System Traffic Management

NASA Technical Reports Server (NTRS)

Xue, Min; Rios, Joseph

2017-01-01

Small Unmanned Aerial Vehicles (sUAVs), typically 55 lbs and below, are envisioned to play a major role in surveilling critical assets, collecting important information, and delivering goods. Large scale small UAV operations are expected to happen in low altitude airspace in the near future. Many static and dynamic constraints exist in low altitude airspace because of manned aircraft or helicopter activities, various wind conditions, restricted airspace, terrain and man-made buildings, and conflict-avoidance among sUAVs. High sensitivity and high maneuverability are unique characteristics of sUAVs that bring challenges to effective system evaluations and mandate such a simulation platform different from existing simulations that were built for manned air traffic system and large unmanned fixed aircraft. NASA's Unmanned aircraft system Traffic Management (UTM) research initiative focuses on enabling safe and efficient sUAV operations in the future. In order to help define requirements and policies for a safe and efficient UTM system to accommodate a large amount of sUAV operations, it is necessary to develop a fast-time simulation platform that can effectively evaluate requirements, policies, and concepts in a close-to-reality environment. This work analyzed the impacts of some key factors including aforementioned sUAV's characteristics and demonstrated the importance of these factors in a successful UTM fast-time simulation platform.

An investigation of self-subtraction holography in LiNbO3

NASA Technical Reports Server (NTRS)

Vahey, D. W.; Kenan, R. P.; Hartman, N. F.; Sherman, R. C.

1981-01-01

A sample having self subtraction characteristics that were very promising was tested in depth: hologram formation times were on the order of 150 sec, the null signal was less than 2.5% of the peak signal, and no fatigue nor instability was detected over the span of the experiments. Another sample, fabricated with, at most, slight modifications did not perform nearly as well. In all samples, attempts to improve self subtraction characteristics by various thermal treatments had no effects or adverse effects, with one exception in which improvement was noted after a time delay of several days. A theory developed to describe self subtraction showed the observed decrease in beam intensity with time, but the shape of the predicted decay curve was oscillatory in contrast to the exponential like decay observed. The theory was also inadequate to account for the experimental sensitivity of self subtraction to the Bragg angle of the hologram. It is concluded that self subtraction is a viable method for optical processing systems requiring background discrimination.

Family and infant characteristics associated with timing of core and non-core food introduction in early childhood

PubMed Central

Schrempft, Stephanie; van Jaarsveld, Cornelia H.M.; Fisher, Abigail; Wardle, Jane

2013-01-01

Objective To identify family and infant characteristics associated with timing of introduction of two food types: core foods (nutrient-dense) and non-core foods (nutrient-poor) in a population-based sample of mothers and infants. Method Participants were 1861 mothers and infants from the Gemini twin birth cohort (one child per family). Family and infant characteristics were assessed when the infants were around 8 months old. Timing of introducing core and non-core foods was assessed at 8 and 15 months. As the distributions of timing were skewed, three similar-sized groups were created for each food type: earlier (core: 1–4 months; non-core: 3–8 months), average (core: 5 months; non-core: 9–10 months), and later introduction (core: 6–12 months; non-core: 11–18 months). Ordinal logistic regression was used to examine predictors of core and non-core food introduction, with bootstrapping to test for differences between the core and non-core models. Results Younger maternal age, lower education level, and higher maternal BMI were associated with earlier core and non-core food introduction. Not breastfeeding for at least 3 months and higher birth weight were specifically associated with earlier introduction of core foods. Having older children was specifically associated with earlier introduction of non-core foods. Conclusion There are similarities and differences in the characteristics associated with earlier introduction of core and non-core foods. Successful interventions may require a combination of approaches to target both food types. PMID:23486509

A study of selected environmental quality remote sensors for free flyer missions launched from the space shuttle

NASA Technical Reports Server (NTRS)

Goldstein, H. W.; Grenda, R. N.

1977-01-01

The sensors were examined for adaptability to shuttle by reviewing pertinent information regarding sensor characteristics as they related to the shuttle and Multimission Modular Spacecraft environments. This included physical and electrical characteristics, data output and command requirements, attitude and orientation requirements, thermal and safety requirements, and adaptability and modification for space. The sensor requirements and characteristics were compared with the corresponding shuttle and Multimission Modular Spacecraft characteristics and capabilities. On this basis the adaptability and necessary modifications for each sensor were determined. A number of the sensors were examined in more detail and estimated cost for the modifications was provided.

Advanced supersonic technology concept study: Hydrogen fueled configuration

NASA Technical Reports Server (NTRS)

Brewer, G. D.

1974-01-01

Conceptual designs of hydrogen fueled supersonic transport configurations for the 1990 time period were developed and compared with equivalent technology Jet A-1 fueled vehicles to determine the economic and performance potential of liquid hydrogen as an alternate fuel. Parametric evaluations of supersonic cruise vehicles with varying design and transport mission characteristics established the basis for selecting a preferred configuration which was then studied in greater detail. An assessment was made of the general viability of the selected concept including an evaluation of costs and environmental considerations, i.e., exhaust emissions and sonic boom characteristics. Technology development requirements and suggested implementation schedules are presented.

Sludge stabilization through aerobic digestion

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

Hartman, R.B.; Smith, D.G.; Bennett, E.R.

1979-10-01

The aerobic digestion process with certain modifications is evaluated as an alternative for sludge processing capable of developing a product with characteristics required for land application. Environmental conditions, including temperature, solids concentration, and digestion time, that affect the aerobic digestion of a mixed primary sludge-trickling filter humus are investigated. Variations in these parameters that influence the characteristics of digested sludge are determined, and the parameters are optimized to: provide the maximum rate of volatile solids reduction; develop a stable, nonodorous product sludge; and provide the maximum rate of oxidation of the nitrogenous material present in the feed sludge. (3 diagrams,more » 9 graphs, 15 references, 3 tables)« less

Lame problem for a multilayer viscoelastic hollow ball with regard to inhomogeneous aging

NASA Astrophysics Data System (ADS)

Davtyan, Z. A.; Mirzoyan, S. Y.; Gasparyan, A. V.

2018-04-01

Determination of characteristics of the stress strain state of compound viscoelastic bodies is of both theoretical and practical interest. In the present paper, the Lamé problem is investigated for an uneven-aged multilayer viscoelastic hollow ball in the framework of N. Kh. Arutyunyan’s theory of creep of nonhomogeneously aging bodies [1, 2]. Solving this problem reduces to solving an inhomogeneous finite-difference equation of second order that contains operators with coordinates of time and space. The obtained formulas allow one to determine the required contact stresses and other mechanical characteristics of the problem related to uneven age of contacting balls.

The use of the principle of superposition in measuring and predicting the thermal characteristics of an electronic equipment operated in a space environment

NASA Technical Reports Server (NTRS)

Gale, E. H.

1980-01-01

The advantages and possible pitfalls of using a generalized method of measuring and, based on these measurements, predicting the transient or steady-state thermal response characteristics of an electronic equipment designed to operate in a space environment are reviewed. The method requires generation of a set of thermal influence coefficients by test measurement in vacuo. A implified thermal mockup isused in this test. Once this data set is measured, temperatures resulting from arbitrary steady-state or time varying power profiles can be economically calculated with the aid of a digital computer.

Postmarket studies required by the US Food and Drug Administration for new drugs and biologics approved between 2009 and 2012: cross sectional analysis.

PubMed

Wallach, Joshua D; Egilman, Alexander C; Dhruva, Sanket S; McCarthy, Margaret E; Miller, Jennifer E; Woloshin, Steven; Schwartz, Lisa M; Ross, Joseph S

2018-05-24

To characterize postmarketing requirements for new drugs and biologics approved by the US Food and Drug Administration (FDA), and to examine rates and timeliness of registration, results reporting, and publication of required prospective cohort studies, registries, and clinical trials. Cross sectional analysis. Postmarketing requirements for all new drugs and biologics approved by the FDA between 1 January 2009 and 31 December 2012, with follow-up up to 15 November 2017. Postmarketing requirements and their characteristics known at the time of FDA approval, including FDA authority, study design, and study characteristics. Rates and timeliness of registration and results reporting on ClinicalTrials.gov and publication in peer reviewed journals of required prospective cohort studies, registries, and clinical trials. Between 2009 and 12, the FDA approved 97 new drugs and biologics for 106 indications with at least one postmarketing requirement at the time of first approval, for a total of 437 postmarketing requirements. Postmarket study descriptions were short (median word count 44 (interquartile range 29-71)) and often lacked information to determine an up to date progress (131 (30%)). 220 (50.3%) postmarketing requirements were for new animal or other studies (including pharmacokinetic studies); 134 (30.7%) were for prospective cohort studies, registries, and clinical trials; and 83 (19.0%) were for secondary analyses or follow-up studies. Of 110 clinical trials, 38 (34.5%), 44 (40.0%), 62 (56.4%), 66 (60.0%), and 98 (89.1%) did not report enough information to establish use of randomization, comparator type, allocation, outcome, and number of patients to be enrolled, respectively. Of 134 required prospective cohort studies, registries, and clinical trials, 102 (76.1%) were registered on ClinicalTrials.gov; of 50 registered and completed studies, 36 (72.0%) had reported results on ClinicalTrials.gov. Among 65 completed studies, 47 (72.3%) had either reported results or were published a median of 47 months (interquartile range 32-67) after FDA approval. 32 (68.1%) of these 47 studies did not report results publicly by the time of their original FDA report submission deadline. Postmarketing requirements for new drugs and biologics were often briefly described and did not contain enough information to characterize study designs. Approximately three quarters of postmarketing requirements for prospective cohort studies, registries, and clinical trials were registered on ClinicalTrials.gov, and nearly three quarters of completed studies reported results or were published, suggesting that at least a quarter of these required studies are not being publicly disseminated. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Development potential of Intermittent Combustion (I.C.) aircraft engines for commuter transport applications

NASA Technical Reports Server (NTRS)

Willis, E. A.

1982-01-01

An update on general aviation (g/a) and commuter aircraft propulsion research effort is reviewed. The following topics are discussed: on several advanced intermittent combustion engines emphasizing lightweight diesels and rotary stratified charge engines. The current state-of-the-art is evaluated for lightweight, aircraft suitable versions of each engine. This information is used to project the engine characteristics that can be expected on near-term and long-term time horizons. The key enabling technology requirements are identified for each engine on the long-term time horizon.

Field resonance propulsion concept

NASA Technical Reports Server (NTRS)

Holt, A. C.

1979-01-01

A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.

An assessment of the real-time application capabilities of the SIFT computer system

NASA Technical Reports Server (NTRS)

Butler, R. W.

1982-01-01

The real-time capabilities of the SIFT computer system, a highly reliable multicomputer architecture developed to support the flight controls of a relaxed static stability aircraft, are discussed. The SIFT computer system was designed to meet extremely high reliability requirements and to facilitate a formal proof of its correctness. Although SIFT represents a significant achievement in fault-tolerant system research it presents an unusual and restrictive interface to its users. The characteristics of the user interface and its impact on application system design are assessed.

Airloads on Bluff Bodies, with Application to the Rotor-Induced Downloads on Tilt-Rotor Aircraft.

DTIC Science & Technology

1983-09-01

interference aerodynamics would be tion on hover performance (Ref. (11). to study the two-dimensional sec- tion characteristics of a wing in the wake of a...resources for large numbers of vortices; a typical case requires 10-15 min CPU time on the Ames Cray IS computer. Figure 6 shows a typical result. Here...CPU time per case on a Prime 550UPPER SURFACE (WINDWARD) computer to converge to a steady solution; this would be equivalent to one or two seconds on

Miniature Rocket Motor for Aircraft Stall/Spin Recovery

NASA Technical Reports Server (NTRS)

Lucy, M. H.

1985-01-01

Design accommodates different thrust levels and burn times with minimum weight. Different thrust levels achieved by substituting other propellants of different diameter and burn-rate characteristics. Different burn times achieved by simply changing length of grain/tube assembly. Grain bond material also acts as insulator for fiberglass tube. Rocket motor attached to aircraft model and ignited from radio-controlled 4.8-volt power source. Device provides more than twice energy available in previous designs at only 60 percent of weight. Rocket motor used to identify energy requirements for aircraft stall/spin recovery positive propulsion system.

Biophoton distress flares signal the onset of the hypersensitive reaction.

PubMed

Mansfield, John W

2005-07-01

Detection of biophoton emission, a natural bioluminescence, has emerged as a non-destructive method to mark the onset of the hypersensitive resistance reaction in Arabidopsis, bean and tomato. Rapid biophoton emission in Arabidopsis requires an intact R-gene signalling network and increased levels of cytosolic calcium and nitric oxide. The burst of biophotons precedes macroscopic symptoms by several hours and its timing is characteristic for specific gene-for-gene interactions. The ability to monitor biophoton emission from whole plants in real time should allow detailed dissection of plant defence responses.

Proportion of infants meeting the Australian 24-hour Movement Guidelines for the Early Years: data from the Melbourne InFANT Program.

PubMed

Hesketh, Kylie D; Downing, Katherine L; Campbell, Karen; Crawford, David; Salmon, Jo; Hnatiuk, Jill A

2017-11-20

Little information is available on the movement behaviours of infants, despite evidence that these are important for development. The release of new Australian 24-hour Movement Guidelines provides an opportunity to document the current state of movement behaviours in infants relative to these guidelines. The aim of this study was to report the prevalence of 4 month old Australian infants meeting the 24-hour Movement Guidelines, individually, and in combination, and to describe associations with individual characteristics. Maternal report baseline data from the Melbourne Infant Feeding, Activity and Nutrition Trial Program were used to determine prevalence of infants meeting physical activity (30 min of tummy time per day), sedentary behaviour (no more than 1 h at a time kept restrained; zero screen time), and sleep guidelines (14-17 h for 0-3 month olds or 12-16 h for 4-11 month olds). Prevalence of infants meeting combined guidelines was also described. The odds of meeting guidelines based on infant and family characteristics was determined. Data are reported for 455 infants with a mean age of 3.6 months (SD = 1.0). The proportion of infants meeting each of the guidelines was 29.7% for tummy time, 56.9% for kept restrained, 27.9% for screen time, 58.7% for sleep and 3.5% for the combined guidelines (i.e. meeting all four guidelines). A significantly higher proportion of girls than boys met the screen time guideline (32.5% versus 24.0%, p = 0.04) and the combined guidelines (5.7% versus 1.6%, p = 0.01). Few associations were observed between infant and family characteristics and proportion of infants meeting individual guidelines. Very few infants met all of the guidelines contained in the new Australian 24-hour Movement Guidelines suggesting there is much room for improvement in movement behaviours from early life. Fewer infants met the tummy time and screen time guidelines hence these appear to be the behaviours requiring most attention. Parents and others providing care to infants require support and strategies to assist them in adhering to the guidelines to ensure optimal health and development for the youngest in our population.

[Preparation and evaluation of press-coated aminophylline tablet using crystalline cellulose and polyethylene glycol in the outer shell for timed-release dosage forms].

PubMed

Watanabe, Yoshiteru; Mukai, Baku; Kawamura, Ken-ichi; Ishikawa, Tatsuya; Namiki, Michihiro; Utoguchi, Naoki; Fujii, Makiko

2002-02-01

In an attempt to achieve chronopharmacotherapy for asthma, press-coated tablets (250 mg), which contained aminophylline in the core tablet in the form of low-substituted hydroxypropylcellulose (L-HPC) and coated with crystalline cellulose (PH-102) and polyethylene glycol (PEG) at various molecular weights and mixing ratios in the amounts of PH-102 and PEG as the outer shell (press-coating material), were prepared (chronopharmaceutics). Their applicability as timed-release (delayed-release) tablets with a lag time of disintegration and a subsequent rapid drug release phase was investigated. Various types of press-coated tablets were prepared using a tableting machine, and their aminophylline dissolution profiles were evaluated by the JP paddle method. Tablets with the timed-release characteristics could be prepared, and the lag time of disintegration was prolonged as the molecular weight and the amount of PEG, for example PEG 500,000, in the outer shell were increased. The lag time of disintegration could be controlled by the above-mentioned method, however, the pH of the medium had no effect on disintegration of the tablet and dissolution behavior of theophylline. The press-coated tablet (core tablet:aminophylline 50 mg, L-HPC and PEG 6000; outer shell:PH-102:PEG = 8:2 200 mg) with the timed-release characteristics was administered orally to rabbits for an in vivo test. Theophylline was first detected in plasma more than 2 h after administration; thus, this tablet showed a timed-release characteristics in the gastrointestinal tract. The time (tmax) required to reach the maximum plasma theophylline concentration (Cmax) observed after administration of the press-coated tablet was significantly (p < 0.05) delayed compared with that observed after administration of aminophylline solution in the control experiment. However, there was no difference in Cmax and area under the plasma theophylline concentration-time curve (AUC0-->24) between the press-coated tablet and aminophylline solution. These results suggest that the press-coated aminophylline tablet (with the timed-release characteristic) offers a promising forms of theophylline chronotherapy for asthma.

10 CFR 61.58 - Alternative requirements for waste classification and characteristics.

Code of Federal Regulations, 2014 CFR

2014-01-01

... LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.58 Alternative requirements for waste classification and characteristics. The Commission may, upon request or on... 10 Energy 2 2014-01-01 2014-01-01 false Alternative requirements for waste classification and...

10 CFR 61.58 - Alternative requirements for waste classification and characteristics.

Code of Federal Regulations, 2012 CFR

2012-01-01

... LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.58 Alternative requirements for waste classification and characteristics. The Commission may, upon request or on... 10 Energy 2 2012-01-01 2012-01-01 false Alternative requirements for waste classification and...

10 CFR 61.58 - Alternative requirements for waste classification and characteristics.

Code of Federal Regulations, 2010 CFR

2010-01-01

... LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.58 Alternative requirements for waste classification and characteristics. The Commission may, upon request or on... 10 Energy 2 2010-01-01 2010-01-01 false Alternative requirements for waste classification and...

10 CFR 61.58 - Alternative requirements for waste classification and characteristics.

Code of Federal Regulations, 2013 CFR

2013-01-01

... LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.58 Alternative requirements for waste classification and characteristics. The Commission may, upon request or on... 10 Energy 2 2013-01-01 2013-01-01 false Alternative requirements for waste classification and...

10 CFR 61.58 - Alternative requirements for waste classification and characteristics.

Code of Federal Regulations, 2011 CFR

2011-01-01

... LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.58 Alternative requirements for waste classification and characteristics. The Commission may, upon request or on... 10 Energy 2 2011-01-01 2011-01-01 false Alternative requirements for waste classification and...

Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

NASA Technical Reports Server (NTRS)

Decker, A. J.

1984-01-01

The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three-dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed. Previously announced in STAR as N84-21849

Signal and background considerations for the MRSt on the National Ignition Facility (NIF).

PubMed

Wink, C W; Frenje, J A; Hilsabeck, T J; Bionta, R; Khater, H Y; Gatu Johnson, M; Kilkenny, J D; Li, C K; Séguin, F H; Petrasso, R D

2016-11-01

A Magnetic Recoil Spectrometer (MRSt) has been conceptually designed for time-resolved measurements of the neutron spectrum at the National Ignition Facility. Using the MRSt, the goals are to measure the time-evolution of the spectrum with a time resolution of ∼20-ps and absolute accuracy better than 5%. To meet these goals, a detailed understanding and optimization of the signal and background characteristics are required. Through ion-optics, MCNP simulations, and detector-response calculations, it is demonstrated that the goals and a signal-to background >5-10 for the down-scattered neutron measurement are met if the background, consisting of ambient neutrons and gammas, at the MRSt is reduced 50-100 times.

Continuous-time quantum random walks require discrete space

NASA Astrophysics Data System (ADS)

Manouchehri, K.; Wang, J. B.

2007-11-01

Quantum random walks are shown to have non-intuitive dynamics which makes them an attractive area of study for devising quantum algorithms for long-standing open problems as well as those arising in the field of quantum computing. In the case of continuous-time quantum random walks, such peculiar dynamics can arise from simple evolution operators closely resembling the quantum free-wave propagator. We investigate the divergence of quantum walk dynamics from the free-wave evolution and show that, in order for continuous-time quantum walks to display their characteristic propagation, the state space must be discrete. This behavior rules out many continuous quantum systems as possible candidates for implementing continuous-time quantum random walks.

Reciprocity testing of Kodak film type SO-289 multispectral infrared aerial film

NASA Technical Reports Server (NTRS)

Lockwood, H. E.

1975-01-01

Kodak multispectral infrared aerial film type SO-289 was tested for reciprocity characteristics because of the variance between the I-B sensitometer exposure times (8 seconds and 4 seconds) and the camera exposure time (1/500 second) used on the ASTP stratospheric aerosol measurement project. Test exposures were made on the flight emulsion using a Mead star system sensitometer, the films were processed to ASTP control standards, and the resulting densities read and reciprocity data calculated. It was found that less exposure was required to produce a typical density (1.3) at 1/500 second exposure time than at an 8 second exposure time. This exposure factor was 2.8.

Sterile insect technique as a tool for increasing the efficacy of gypsy moth biocontrol

Treesearch

Julius Novotny; Milan Zubrik

2003-01-01

Characteristics such as the duration of the larval stage and attraction of larvae to oviposition by an endoparasitic wasp were evaluated between groups of irradiated and non irradiated gypsy moth larvae. Untreated larvae required a shorter time to reach the adult stage (both male and female). The mortality of larvae was highest at the highest irradiation dose. Pupae...

What Progress Has Been Made in Meeting the Needs of Seriously Maltreated Children? The Course of 200 Cases through the Boston Juvenile Court.

ERIC Educational Resources Information Center

Bishop, Sandra J.; Murphy, J. Michael; Hicks, Roger; Quinn, Dorothy; Lewis, Paul J.; Grace, Martha; Jellinek, Michael S.

2000-01-01

This study examined child, parent, and case characteristics over 4 years in 200 cases of serious child maltreatment in Boston, Massachusetts. Comparison with 1985-1986 cases (before relevant state legislative changes) found children permanently removed from parental custody in the 1994 sample required only slightly less time to achieve permanent…

Retrieval characteristics of the Bard Denali and Argon Option inferior vena cava filters.

PubMed

Dowell, Joshua D; Semaan, Dominic; Makary, Mina S; Ryu, John; Khayat, Mamdouh; Pan, Xueliang

2017-11-01

The purpose of this study was to compare the retrieval characteristics of the Option Elite (Argon Medical, Plano, Tex) and Denali (Bard, Tempe, Ariz) retrievable inferior vena cava filters (IVCFs), two filters that share a similar conical design. A single-center, retrospective study reviewed all Option and Denali IVCF removals during a 36-month period. Attempted retrievals were classified as advanced if the routine "snare and sheath" technique was initially unsuccessful despite multiple attempts or an alternative endovascular maneuver or access site was used. Patient and filter characteristics were documented. In our study, 63 Option and 45 Denali IVCFs were retrieved, with an average dwell time of 128.73 and 99.3 days, respectively. Significantly higher median fluoroscopy times were experienced in retrieving the Option filter compared with the Denali filter (12.18 vs 6.85 minutes; P = .046). Use of adjunctive techniques was also higher in comparing the Option filter with the Denali filter (19.0% vs 8.7%; P = .079). No significant difference was noted between these groups in regard to gender, age, or history of malignant disease. Option IVCF retrieval procedures required significantly longer retrieval fluoroscopy time compared with Denali IVCFs. Although procedure time was not analyzed in this study, as a surrogate, the increased fluoroscopy time may also have an impact on procedural direct costs and throughput. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

An assessment of the efficacy and peak catch rates of emergence tents for measuring bee nesting.

PubMed

Pane, Alexander M; Harmon-Threatt, Alexandra N

2017-06-01

Emergence tents are a new tool used to understand nesting ecology of ground nesting bee species. However, many questions remain about how to use tents effectively. We assessed (a) variance in tent capture rates over time, (b) the effects of site characteristics on proportion of tents capturing bees, and (c) the effect of soil characteristics on nest site choice. Emergence tents were placed out for one week in May, June, and August and checked daily. Soil, bee, and floral characteristics were recorded. Across all sites and months the average number of tents capturing bees was less than 20% during one week of sampling, but this varied between sites. Tent captures decreased after 48 h deployment, but accumulation differed seasonally, with slower accumulation of total bees caught in May than in June or August. Although capture rates were not affected by bee or floral abundance, soil moisture beneath a tent influenced where bees were captured. Effective use of emergence tents may require adjusting the length of deployment depending on season and will require a minimum of 48 h installation to help maximize efficacy. The overall low capture rates demonstrate the need to optimize emergence tent use.

LCDs are better: psychophysical and photometric estimates of the temporal characteristics of CRT and LCD monitors.

PubMed

Lagroix, Hayley E P; Yanko, Matthew R; Spalek, Thomas M

2012-07-01

Many cognitive and perceptual phenomena, such as iconic memory and temporal integration, require brief displays. A critical requirement is that the image not remain visible after its offset. It is commonly believed that liquid crystal displays (LCD) are unsuitable because of their poor temporal response characteristics relative to cathode-ray-tube (CRT) screens. Remarkably, no psychophysical estimates of visible persistence are available to verify this belief. A series of experiments in which white stimuli on a black background produced discernible persistence on CRT but not on LCD screens, during both dark- and light-adapted viewing, falsified this belief. Similar estimates using black stimuli on a white background produced no visible persistence on either screen. That said, photometric measurements are available that seem to confirm the poor temporal characteristics of LCD screens, but they were obtained before recent advances in LCD technology. Using current LCD screens, we obtained photometric estimates of rise time far shorter (1-6 ms) than earlier estimates (20-150 ms), and approaching those of CRTs (<1 ms). We conclude that LCDs are preferable to CRTs when visible persistence is a concern, except when black-on-white displays are used.

Study of space shuttle EVA/IVA support requirements. Volume 1: Technical summary report

NASA Technical Reports Server (NTRS)

Copeland, R. J.; Wood, P. W., Jr.; Cox, R. L.

1973-01-01

Results are summarized which were obtained for equipment requirements for the space shuttle EVA/IVA pressure suit, life support system, mobility aids, vehicle support provisions, and energy 4 support. An initial study of tasks, guidelines, and constraints and a special task on the impact of a 10 psia orbiter cabin atmosphere are included. Supporting studies not related exclusively to any one group of equipment requirements are also summarized. Representative EVA/IVA task scenarios were defined based on an evaluation of missions and payloads. Analysis of the scenarios resulted in a total of 788 EVA/IVA's in the 1979-1990 time frame, for an average of 1.3 per shuttle flight. Duration was estimated to be under 4 hours on 98% of the EVA/IVA's, and distance from the airlock was determined to be 70 feet or less 96% of the time. Payload water vapor sensitivity was estimated to be significant on 9%-17% of the flights. Further analysis of the scenarios was carried out to determine specific equipment characteristics, such as suit cycle and mobility requirements.

Development and application of a local linearization algorithm for the integration of quaternion rate equations in real-time flight simulation problems

NASA Technical Reports Server (NTRS)

Barker, L. E., Jr.; Bowles, R. L.; Williams, L. H.

1973-01-01

High angular rates encountered in real-time flight simulation problems may require a more stable and accurate integration method than the classical methods normally used. A study was made to develop a general local linearization procedure of integrating dynamic system equations when using a digital computer in real-time. The procedure is specifically applied to the integration of the quaternion rate equations. For this application, results are compared to a classical second-order method. The local linearization approach is shown to have desirable stability characteristics and gives significant improvement in accuracy over the classical second-order integration methods.

Mirror Langmuir probe: a technique for real-time measurement of magnetized plasma conditions using a single Langmuir electrode.

PubMed

LaBombard, B; Lyons, L

2007-07-01

A new method for the real-time evaluation of the conditions in a magnetized plasma is described. The technique employs an electronic "mirror Langmuir probe" (MLP), constructed from bipolar rf transistors and associated high-bandwidth electronics. Utilizing a three-state bias wave form and active feedback control, the mirror probe's I-V characteristic is continuously adjusted to be a scaled replica of the "actual" Langmuir electrode immersed in a plasma. Real-time high-bandwidth measurements of the plasma's electron temperature, ion saturation current, and floating potential can thereby be obtained using only a single electrode. Initial tests of a prototype MLP system are reported, proving the concept. Fast-switching metal-oxide-semiconductor field-effect transistors produce the required three-state voltage bias wave form, completing a full cycle in under 1 mus. Real-time outputs of electron temperature, ion saturation current, and floating potential are demonstrated, which accurately track an independent computation of these values from digitally stored I-V characteristics. The MLP technique represents a significant improvement over existing real-time methods, eliminating the need for multiple electrodes and sampling all three plasma parameters at a single spatial location.

Ruthenium Oxide Electrochemical Super Capacitor Optimization for Pulse Power Applications

NASA Technical Reports Server (NTRS)

Merryman, Stephen A.; Chen, Zheng

2000-01-01

Electrical actuator systems are being pursued as alternatives to hydraulic systems to reduce maintenance time, weight and costs while increasing reliability. Additionally, safety and environmental hazards associated with the hydraulic fluids can be eliminated. For most actuation systems, the actuation process is typically pulsed with high peak power requirements but with relatively modest average power levels. The power-time requirements for electrical actuators are characteristic of pulsed power technologies where the source can be sized for the average power levels while providing the capability to achieve the peak requirements. Among the options for the power source are battery systems, capacitor systems or battery-capacitor hybrid systems. Battery technologies are energy dense but deficient in power density; capacitor technologies are power dense but limited by energy density. The battery-capacitor hybrid system uses the battery to supply the average power and the capacitor to meet the peak demands. It has been demonstrated in previous work that the hybrid electrical power source can potentially provide a weight savings of approximately 59% over a battery-only source. Electrochemical capacitors have many properties that make them well-suited for electrical actuator applications. They have the highest demonstrated energy density for capacitive storage (up to 100 J/g), have power densities much greater than most battery technologies (greater than 30kW/kg), are capable of greater than one million charge-discharge cycles, can be charged at extremely high rates, and have non-explosive failure modes. Thus, electrochemical capacitors exhibit a combination of desirable battery and capacitor characteristics.

Effect of power system technology and mission requirements on high altitude long endurance aircraft

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

1994-01-01

An analysis was performed to determine how various power system components and mission requirements affect the sizing of a solar powered long endurance aircraft. The aircraft power system consists of photovoltaic cells and a regenerative fuel cell. Various characteristics of these components, such as PV cell type, PV cell mass, PV cell efficiency, fuel cell efficiency, and fuel cell specific mass, were varied to determine what effect they had on the aircraft sizing for a given mission. Mission parameters, such as time of year, flight altitude, flight latitude, and payload mass and power, were also altered to determine how mission constraints affect the aircraft sizing. An aircraft analysis method which determines the aircraft configuration, aspect ratio, wing area, and total mass, for maximum endurance or minimum required power based on the stated power system and mission parameters is presented. The results indicate that, for the power system, the greatest benefit can be gained by increasing the fuel cell specific energy. Mission requirements also substantially affect the aircraft size. By limiting the time of year the aircraft is required to fly at high northern or southern latitudes, a significant reduction in aircraft size or increase in payload capacity can be achieved.

Study of aircraft in intraurban transportation systems, San Francisco Bay area

NASA Technical Reports Server (NTRS)

1972-01-01

The nine-county San Francisco Bay area is examined in two time periods (1975-1980 and 1985-1990) as a scenario for analyzing the characteristics of an intraurban, commuter-oriented aircraft transportation system. Aircraft have dominated the long-haul passenger market for some time, but efforts to penetrate the very-short-haul intraurban market have met with only token success. Yet, the characteristics of an aircraft transportation system, speed and flexibility, are very much needed to solve the transportation ills of our major urban areas. The aircraft intraurban system is a technically feasible alternative to ground transportation systems. Although requiring some subsidy, it becomes socially viable where substantial commuter traffic exists at ranges of 10 to 15 mi or more and where topographic features constrain ground travel. The general problem areas of community noise, air traffic congestion, ground transportation interface, pollution, and safety appear to have workable solutions.

The Time Intensity of Childcare Provided by Older Immigrant Women in the United States.

PubMed

Vega, Alma

2017-08-01

Older adults comprise an increasing share of new legal admits to the United States. While many are financially dependent on their families, a more complete picture requires taking into account the nonmonetary contributions of this population. Using the American Time Use Survey, this study examines whether older recent immigrant women provide more unpaid childcare than their native-born and more established immigrant counterparts. Results suggest that while older recent immigrant women are more likely to provide unpaid childcare, this effect is eliminated upon controlling for demographic characteristics. However, among those who do provide childcare, older recent immigrant women provide more hours of care even after controlling for demographic and household characteristics. This pattern holds up even after restricting the analysis to women living with young children. These results may signal reciprocal supportive networks. Working-age adults may financially support older recent immigrants, while older recent immigrants provide unremunerated childcare for working-age adults.

Space-Time Data fusion for Remote Sensing Applications

NASA Technical Reports Server (NTRS)

Braverman, Amy; Nguyen, H.; Cressie, N.

2011-01-01

NASA has been collecting massive amounts of remote sensing data about Earth's systems for more than a decade. Missions are selected to be complementary in quantities measured, retrieval techniques, and sampling characteristics, so these datasets are highly synergistic. To fully exploit this, a rigorous methodology for combining data with heterogeneous sampling characteristics is required. For scientific purposes, the methodology must also provide quantitative measures of uncertainty that propagate input-data uncertainty appropriately. We view this as a statistical inference problem. The true but notdirectly- observed quantities form a vector-valued field continuous in space and time. Our goal is to infer those true values or some function of them, and provide to uncertainty quantification for those inferences. We use a spatiotemporal statistical model that relates the unobserved quantities of interest at point-level to the spatially aggregated, observed data. We describe and illustrate our method using CO2 data from two NASA data sets.

The data collection/data distribution center: building a sustainable African-American church-based research network.

PubMed

Goldmon, Moses; Roberson, James T; Carey, Tim; Godley, Paul; Howard, Daniel L; Boyd, Carlton; Ammerman, Alice

2008-01-01

This article describes the Carolina-Shaw Partnership for the Elimination of Health Disparities efforts to engage a diverse group of Black churches in a sustainable network. We sought to develop a diverse network of 25 churches to work with the Carolina-Shaw Partnership to develop sustainable health disparities research, education, and intervention initiatives. Churches were selected based on location, pastoral buy-in, and capacity to engage. A purposive sampling technique was applied. (1) Collecting information on the location and characteristics of churches helps to identify and recruit churches that possess the desired qualities and characteristics. (2) The process used to identify, recruit, and select churches is time intensive. (3) The time, energy, and effort required managing an inter-institutional partnership and engage churches in health disparities research and interventions lends itself to sustainability. The development of a sustainable network of churches could lead to successful health disparities initiatives.

Congruency effects in dot comparison tasks: convex hull is more important than dot area.

PubMed

Gilmore, Camilla; Cragg, Lucy; Hogan, Grace; Inglis, Matthew

2016-11-16

The dot comparison task, in which participants select the more numerous of two dot arrays, has become the predominant method of assessing Approximate Number System (ANS) acuity. Creation of the dot arrays requires the manipulation of visual characteristics, such as dot size and convex hull. For the task to provide a valid measure of ANS acuity, participants must ignore these characteristics and respond on the basis of number. Here, we report two experiments that explore the influence of dot area and convex hull on participants' accuracy on dot comparison tasks. We found that individuals' ability to ignore dot area information increases with age and display time. However, the influence of convex hull information remains stable across development and with additional time. This suggests that convex hull information is more difficult to inhibit when making judgements about numerosity and therefore it is crucial to control this when creating dot comparison tasks.

Design criteria for flightpath and airspeed control for the approach and landing of STOL aircraft

NASA Technical Reports Server (NTRS)

Franklin, J. A.; Innis, R. C.; Hardy, G. H.; Stephenson, J. D.

1982-01-01

A flight research program was conducted to assess requirements for flightpath and airspeed control for glide-slope tracking during a precision approach and for flare control, particularly as applied to powered-lift, short takeoff and landing (STOL) aircraft. Ames Research Center's Augmentor Wing Research Aircraft was used to fly approaches on a 7.5 deg glide slope to landings on a 30 X 518 m (100 X 1700 ft) STOL runway. The dominant aircraft response characteristics determined were flightpath overshoot, flightpath-airspeed coupling, and initial flightpath response time. The significant contribution to control of the landing flare using pitch attitude was the short-term flightpath response. The limiting condition for initial flightpath response time for flare control with thrust was also identified. It is possible to define flying-qualities design criteria for glide-slope and flare control based on the aforementioned response characteristics.

Soft wheat quality characteristics required for making baking powder biscuits

USDA-ARS?s Scientific Manuscript database

Fifteen soft wheat varieties were evaluated for their grain, milling, flour and dough mixing characteristics, as well as their solvent retention capacities (SRCs), pasting properties and suitability for making baking powder biscuits, to identify wheat quality characteristics required for making bisc...

Structural, thermal, and morphological characteristics of cassava amylodextrins.

PubMed

Costa, Mariana Souza; Volanti, Diogo Paschoalini; Grossmann, Maria Victória Eiras; Franco, Célia Maria Landi

2018-05-01

Amylodextrins from cassava starch were obtained by acid hydrolysis, and their structural, thermal and morphological characteristics were evaluated and compared to those from potato and corn amylodextrins. Cassava starch was the most susceptible to hydrolysis due to imperfections in its crystalline structure. The crystalline patterns of amylodextrins remained unchanged, and crystallinity and peak temperature increased with hydrolysis time, whereas thermal degradation temperature decreased, independent of treatment time and starch source. Cassava amylodextrins had similar structural and morphological characteristics to those from corn amylodextrins due to their A-type crystalline arrangements. A-amylodextrins were structurally and thermally more stable than potato amylodextrins (B-type). Starch nanocrystals (SNC) were observed by transmission electron microscopy from the third day of hydrolysis in cassava amylodextrins, whereas potato and corn amylodextrins displayed SNC only on the fifth day. A-SNC displayed platelet shapes, whereas B-SNC were rounded. The SNC shape was related to the packing form and geometry of unit cells of allomorphs A and B. Microstructures (agglomerated crystalline particles) and nanostructures (double helix organization) were observed for amylodextrins. Cassava starch was shown to be a promising material for SNC production, since it requires less hydrolysis time to obtaining more stable crystals. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Effects of trawl selectivity and genetic parameters on fish body length under long-term trawling

NASA Astrophysics Data System (ADS)

Yu, Yang; Sun, Peng; Cui, He; Sheng, Huaxiang; Zhao, Fenfang; Tang, Yanli; Chen, Zelin

2015-10-01

Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail ( Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish's biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish's life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China.

Effects of state-level medicaid policies and patient characteristics on time to breast cancer surgery among medicaid beneficiaries.

PubMed

Halpern, Michael T; Schrag, Deborah

2016-08-01

Medicaid beneficiaries with cancer are less likely to receive timely and high-quality care. This study examined whether differences in state-level Medicaid policies affect delays in time to surgery (TTS) among women diagnosed with breast cancer. Using 2006-2008 Medicaid data, we identified women aged 18-64 enrolled in Medicaid diagnosed with breast cancer. Analyses examined associations of state-specific Medicaid surgery reimbursements, Medicaid eligibility recertification period (annually vs. shorter) and required patient copayment on time from breast cancer diagnosis to receipt of breast surgery. Patients receiving neoadjuvant therapy were excluded. Separate multivariable regression analyses controlling for patient demographic characteristics and clustering by state were performed for breast conserving surgery (BCS), inpatient mastectomy, and outpatient mastectomy. The study included 7542 Medicaid beneficiaries with breast cancer: 3272 received BCS, 2156 outpatient mastectomy, and 2115 inpatient mastectomy. Higher Medicaid reimbursements for BCS were associated with decreased time from diagnosis to surgery. A 12-month (vs. <12 month) Medicaid eligibility recertification period was associated with decreased TTS for BCS and outpatient mastectomy. Black Medicaid beneficiaries (compared with non-Hispanic White beneficiaries) were more likely to experience delays for all three types of surgery, while Hispanic beneficiaries were more likely to experience delays only for outpatient mastectomy. State-level Medicaid policies and patient characteristics can affect receipt of timely surgery among Medicaid beneficiaries with breast cancer. As delays in surgery can increase morbidity and mortality, changes to state Medicaid policies and health system programs are needed to improve access to care for this vulnerable population.

Genetic transformation of tobacco NT1 cells with Agrobacterium tumefaciens.

PubMed

Mayo, Kristin J; Gonzales, Barbara J; Mason, Hugh S

2006-01-01

This protocol is used to produce stably transformed tobacco (Nicotiana tabacum) NT1 cell lines, using Agrobacterium tumefaciens-mediated DNA delivery of a binary vector containing a gene encoding hepatitis B surface antigen and a gene encoding the kanamycin selection marker. The NT1 cultures, at the appropriate stage of growth, are inoculated with A. tumefaciens containing the binary vector. A 3-day cocultivation period follows, after which the cultures are rinsed and placed on solid selective medium. Transformed colonies ('calli') appear in approximately 4 weeks; they are subcultured until adequate material is obtained for analysis of antigen production. 'Elite' lines are selected based on antigen expression and growth characteristics. The time required for the procedure from preparation of the plant cell materials to callus development is approximately 5 weeks. Growth of selected calli to sufficient quantities for antigen screening may require 4-6 weeks beyond the initial selection. Creation of the plasmid constructs, transformation of the A. tumefaciens line, and ELISA and Bradford assays to assess protein production require additional time.

Characteristics of Emergency Medicine Residency Programs in Colombia

PubMed Central

Patiño, Andrés; Alcalde, Victor; Gutierrez, Camilo; Romero, Mauricio Garcia; Carrillo, Atilio Moreno; Vargas, Luis E.; Vallejo, Carlos E.; Zarama, Virginia; Mora Rodriguez, José L.; Bustos, Yury; Granada, Juliana; Aguiar, Leonar G.; Menéndez, Salvador; Cohen, Jorge I.; Saavedra, Miguel A.; Rodriguez, Juan M.; Roldan, Tatiana; Arbelaez, Christian

2017-01-01

Introduction Emergency medicine (EM) is in different stages of development around the world. Colombia has made significant strides in EM development in the last two decades and recognized it as a medical specialty in 2005. The country now has seven EM residency programs: three in the capital city of Bogotá, two in Medellin, one in Manizales, and one in Cali. The seven residency programs are in different stages of maturity, with the oldest founded 20 years ago and two founded in the last two years. The objective of this study was to characterize these seven residency programs. Methods We conducted semi-structured interviews with faculty and residents from all the existing programs in 2013–2016. Topics included program characteristics and curricula. Results Colombian EM residencies are three-year programs, with the exception of one four-year program. Programs accept 3–10 applicants yearly. Only one program has free tuition and the rest charge tuition. The number of EM faculty ranges from 2–15. EM rotation requirements range from 11–33% of total clinical time. One program does not have a pediatric rotation. The other programs require 1–2 months of pediatrics or pediatric EM. Critical care requirements range from 4–7 months. Other common rotations include anesthesia, general surgery, internal medicine, obstetrics, gynecology, orthopedics, ophthalmology, radiology, toxicology, psychiatry, neurology, cardiology, pulmonology, and trauma. All programs offer 4–6 hours of protected didactic time each week. Some programs require Advanced Cardiac Life Support, Pediatric Advanced Life Support and Advanced Trauma Life Support, with some programs providing these trainings in-house or subsidizing the cost. Most programs require one research project for graduation. Resident evaluations consist of written tests and oral exams several times per year. Point-of-care ultrasound training is provided in four of the seven programs. Conclusion As emergency medicine continues to develop in Colombia, more residency programs are expected to emerge. Faculty development and sustainability of academic pursuits will be critically important. In the long term, the specialty will need to move toward certifying board exams and professional development through a national EM organization to promote standardization across programs. PMID:29085546

Characteristics of Emergency Medicine Residency Programs in Colombia.

PubMed

Patiño, Andrés; Alcalde, Victor; Gutierrez, Camilo; Romero, Mauricio Garcia; Carrillo, Atilio Moreno; Vargas, Luis E; Vallejo, Carlos E; Zarama, Virginia; Mora Rodriguez, José L; Bustos, Yury; Granada, Juliana; Aguiar, Leonar G; Menéndez, Salvador; Cohen, Jorge I; Saavedra, Miguel A; Rodriguez, Juan M; Roldan, Tatiana; Arbelaez, Christian

2017-10-01

Emergency medicine (EM) is in different stages of development around the world. Colombia has made significant strides in EM development in the last two decades and recognized it as a medical specialty in 2005. The country now has seven EM residency programs: three in the capital city of Bogotá, two in Medellin, one in Manizales, and one in Cali. The seven residency programs are in different stages of maturity, with the oldest founded 20 years ago and two founded in the last two years. The objective of this study was to characterize these seven residency programs. We conducted semi-structured interviews with faculty and residents from all the existing programs in 2013-2016. Topics included program characteristics and curricula. Colombian EM residencies are three-year programs, with the exception of one four-year program. Programs accept 3-10 applicants yearly. Only one program has free tuition and the rest charge tuition. The number of EM faculty ranges from 2-15. EM rotation requirements range from 11-33% of total clinical time. One program does not have a pediatric rotation. The other programs require 1-2 months of pediatrics or pediatric EM. Critical care requirements range from 4-7 months. Other common rotations include anesthesia, general surgery, internal medicine, obstetrics, gynecology, orthopedics, ophthalmology, radiology, toxicology, psychiatry, neurology, cardiology, pulmonology, and trauma. All programs offer 4-6 hours of protected didactic time each week. Some programs require Advanced Cardiac Life Support, Pediatric Advanced Life Support and Advanced Trauma Life Support, with some programs providing these trainings in-house or subsidizing the cost. Most programs require one research project for graduation. Resident evaluations consist of written tests and oral exams several times per year. Point-of-care ultrasound training is provided in four of the seven programs. As emergency medicine continues to develop in Colombia, more residency programs are expected to emerge. Faculty development and sustainability of academic pursuits will be critically important. In the long term, the specialty will need to move toward certifying board exams and professional development through a national EM organization to promote standardization across programs.

A Framework for Evaluating the Software Product Quality of Pregnancy Monitoring Mobile Personal Health Records.

PubMed

Idri, Ali; Bachiri, Mariam; Fernández-Alemán, José Luis

2016-03-01

Stakeholders' needs and expectations are identified by means of software quality requirements, which have an impact on software product quality. In this paper, we present a set of requirements for mobile personal health records (mPHRs) for pregnancy monitoring, which have been extracted from literature and existing mobile apps on the market. We also use the ISO/IEC 25030 standard to suggest the requirements that should be considered during the quality evaluation of these mPHRs. We then go on to design a checklist in which we contrast the mPHRs for pregnancy monitoring requirements with software product quality characteristics and sub-characteristics in order to calculate the impact of these requirements on software product quality, using the ISO/IEC 25010 software product quality standard. The results obtained show that the requirements related to the user's actions and the app's features have the most impact on the external sub-characteristics of the software product quality model. The only sub-characteristic affected by all the requirements is Appropriateness of Functional suitability. The characteristic Operability is affected by 95% of the requirements while the lowest degrees of impact were identified for Compatibility (15%) and Transferability (6%). Lastly, the degrees of the impact of the mPHRs for pregnancy monitoring requirements are discussed in order to provide appropriate recommendations for the developers and stakeholders of mPHRs for pregnancy monitoring.

Characteristics and requirements of robotic manipulators for space operations

NASA Technical Reports Server (NTRS)

Andary, James F.; Hewitt, Dennis R.; Spidaliere, Peter D.; Lambeck, Robert W.

1992-01-01

A robotic manipulator, DTF-1, developed as part of the Flight Telerobotic Servicer (FTS) project at Goddard Space Flight Center is discussed focusing on the technical, operational, and safety requirements. The DTF-1 system design, which is based on the manipulator, gripper, cameras, computer, and an operator control station incorporates the fundamental building blocks of the original FTS, the end product of which was to have been a light-weight, dexterous telerobotic device. For the first time in the history of NASA, space technology and robotics were combined to find new and unique solutions to the demanding requirements of flying a sophisticated robotic manipulator in space. DTF-1 is considered to be the prototype for all future development in space robotics.

46 CFR 15.405 - Familiarity with vessel characteristics.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Familiarity with vessel characteristics. 15.405 Section 15.405 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.405 Familiarity with vessel characteristics...

46 CFR 15.405 - Familiarity with vessel characteristics.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Familiarity with vessel characteristics. 15.405 Section 15.405 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.405 Familiarity with vessel characteristics...

46 CFR 15.405 - Familiarity with vessel characteristics.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Familiarity with vessel characteristics. 15.405 Section 15.405 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.405 Familiarity with vessel characteristics...

46 CFR 15.405 - Familiarity with vessel characteristics.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Familiarity with vessel characteristics. 15.405 Section 15.405 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; All Vessels § 15.405 Familiarity with vessel characteristics...

Simulating Non-Fickian Transport across Péclet Regimes by doing Lévy Flights in the Rank Space of Velocity

NASA Astrophysics Data System (ADS)

Most, S.; Dentz, M.; Bolster, D.; Bijeljic, B.; Nowak, W.

2017-12-01

Transport in real porous media shows non-Fickian characteristics. In the Lagrangian perspective this leads to skewed distributions of particle arrival times. The skewness is triggered by particles' memory of velocity that persists over a characteristic length. Capturing process memory is essential to represent non-Fickianity thoroughly. Classical non-Fickian models (e.g., CTRW models) simulate the effects of memory but not the mechanisms leading to process memory. CTRWs have been applied successfully in many studies but nonetheless they have drawbacks. In classical CTRWs each particle makes a spatial transition for which each particle adapts a random transit time. Consecutive transit times are drawn independently from each other, and this is only valid for sufficiently large spatial transitions. If we want to apply a finer numerical resolution than that, we have to implement memory into the simulation. Recent CTRW methods use transitions matrices to simulate correlated transit times. However, deriving such transition matrices require transport data of a fine-scale transport simulation, and the obtained transition matrix is solely valid for this single Péclet regime. The CTRW method we propose overcomes all three drawbacks: 1) We simulate transport without restrictions in transition length. 2) We parameterize our CTRW without requiring a transport simulation. 3) Our parameterization scales across Péclet regimes. We do so by sampling the pore-scale velocity distribution to generate correlated transit times as a Lévy flight on the CDF-axis of velocities with reflection at 0 and 1. The Lévy flight is parametrized only by the correlation length. We explicitly model memory including the evolution and decay of non-Fickianity, so it extends from local via pre-asymptotic to asymptotic scales.

Rehabilitation time before disability pension.

PubMed

Støver, Morten; Pape, Kristine; Johnsen, Roar; Fleten, Nils; Sund, Erik R; Claussen, Bjørgulf; Ose, Solveig Osborg; Bjørngaard, Johan Håkon

2012-10-30

The decision to grant a disability pension is usually the end of a long process of medical examinations, treatment and rehabilitation attempts. This study investigates to what extent the time spent on rehabilitation time prior to disability pension is associated with characteristics of the individual or the local employment and welfare office, measured as municipality variance. A study of 2,533 40 to 42 year olds who received disability pension over a period of 18 years. The logarithm of the rehabilitation time before granting a disability pension was analysed with multilevel regression. The rehabilitation time before a disability pension was granted ranged from 30 to 5,508 days. Baseline health characteristics were only moderately associated with rehabilitation time. Younger people and people with unemployment periods had longer rehabilitation time before a disability pension was granted. There were only minor differences in rehabilitation time between men and women and between different levels of education. Approximately 2% of the total variance in rehabilitation time could be attributed to the municipality of residence. There is a higher threshold for granting a disability pension to younger persons and those who are expecting periods of unemployment, which is reflected in the extended rehabilitation requirements for these groups. The longer rehabilitation period for persons with psychiatric disorders might reflect a lack of common knowledge on the working capacity of and the fitted rehabilitation programs for people with psychiatric disorders.

Rehabilitation time before disability pension

PubMed Central

2012-01-01

Background The decision to grant a disability pension is usually the end of a long process of medical examinations, treatment and rehabilitation attempts. This study investigates to what extent the time spent on rehabilitation time prior to disability pension is associated with characteristics of the individual or the local employment and welfare office, measured as municipality variance. Methods A study of 2,533 40 to 42 year olds who received disability pension over a period of 18 years. The logarithm of the rehabilitation time before granting a disability pension was analysed with multilevel regression. Results The rehabilitation time before a disability pension was granted ranged from 30 to 5,508 days. Baseline health characteristics were only moderately associated with rehabilitation time. Younger people and people with unemployment periods had longer rehabilitation time before a disability pension was granted. There were only minor differences in rehabilitation time between men and women and between different levels of education. Approximately 2% of the total variance in rehabilitation time could be attributed to the municipality of residence. Conclusions There is a higher threshold for granting a disability pension to younger persons and those who are expecting periods of unemployment, which is reflected in the extended rehabilitation requirements for these groups. The longer rehabilitation period for persons with psychiatric disorders might reflect a lack of common knowledge on the working capacity of and the fitted rehabilitation programs for people with psychiatric disorders. PMID:23110397

Designed microstructure based on color filter and metallic nanoslit for multiband spectral compatible control

NASA Astrophysics Data System (ADS)

Zhan, Zhigang; Han, Yuge

2018-01-01

Controlling the spectral characteristics by regulating the geometry of microstructure has become an effective method to meet the requirements of various applications. To mediate the spectral characteristics, metallic subwavelength slits with different structures and color filters consisting of diverse materials were discussed, and then a designed microstructure composed of color filter and metallic slits, which were surrounded by grooves, was put forward for a compatible effect of controlling the spectral characteristics. Afterward, the spectral characteristics of the proposed structure were simulated by finite-difference time-domain method in the wavelength range of 300 to 10,000 nm. Additionally, the effects of geometric parameters on the spectral characteristics were studied. The results show that the presented microstructure can reflect a monochromatic color at the wavelength of 600 nm and its reflectance is ˜40%. The average absorptance near the wavelength of 1060 nm is more than 95%, and the average reflectance in the infrared band exceeds 80%. In conclusion, the compatible spectrum control in three bands (i.e., visible, near-infrared, and mid-infrared) was realized.

Understanding the health care utilization of children who require medical technology: A descriptive study of children who require tracheostomies.

PubMed

Spratling, Regena

2017-04-01

Children who require medical technology have complex chronic illnesses. This medical technology, including ventilators, oximeters, tracheostomy tubes, and feeding tubes, allows children and their families to live at home; however, the management of the children's care by informal caregivers is complex with the need for intensive, specialized care. The purpose of this study was to examine the sociodemographic and clinical characteristics that affect health care utilization in a population of children who require medical technology. A retrospective electronic health record (EHR) review was completed on the EHR records on 171 children who require medical technology, specifically tracheostomies, at an outpatient technology dependent pulmonary clinic over a three year period (January 2010-December 2012). Descriptive statistics were used to analyze sociodemographic and clinical characteristics, including medical diagnoses, and emergency department (ED) visits and hospitalizations. Of the 171 children requiring medical technology studied, there were numerous medical diagnoses (n=791), 99% had chronic illnesses affecting two or more body systems, and 88% required two or more technologies, including a tracheostomy and a feeding tube. In addition, 91% of the children had at least one ED visit or hospitalization and were treated in the ED approximately three times over the three year period. The findings from this study noted an increased utilization of health care by these children, and identified common symptoms and medical technologies for which caregivers may need interventions, focusing on education in managing symptoms and medical technology prior to presentation to the ED or hospital. Copyright © 2017 Elsevier Inc. All rights reserved.

Maintainability Program Requirements for Space Systems

NASA Technical Reports Server (NTRS)

1987-01-01

This document is established to provide common general requirements for all NASA programs to: design maintainability into all systems where maintenance is a factor in system operation and mission success; and ensure that maintainability characteristics are developed through the systems engineering process. These requirements are not new. Design for ease of maintenance and minimization of repair time have always been fundamental requirements of the systems engineering process. However, new or reusable orbital manned and in-flight maintainable unmanned space systems demand special emphasis on maintainability, and this document has been prepared to meet that need. Maintainability requirements on many NASA programs differ in phasing and task emphasis from requirements promulgated by other Government agencies. This difference is due to the research and development nature of NASA programs where quantities produced are generally small; therefore, the depth of logistics support typical of many programs is generally not warranted. The cost of excessive maintenance is very high due to the logistics problems associated with the space environment. The ability to provide timely maintenance often involves safety considerations for manned space flight applications. This document represents a basic set of requirements that will achieve a design for maintenance. These requirements are directed primarily at manned and unmanned orbital space systems. To be effective, maintainability requirements should be tailored to meet specific NASA program and project needs and constraints. NASA activities shall invoke the requirements of this document consistent with program planning in procurements or on inhouse development efforts.

Effects of geared motor characteristics on tactile perception of tissue stiffness.

PubMed

Longnion, J; Rosen, J; Sinanan, M; Hannaford, B

2001-01-01

Endoscopic haptic surgical devices have shown promise in addressing the loss of tactile sensation associated with minimally invasive surgery. However, these devices must be capable of generating forces and torques similar to those applied on the tissue with a standard endoscopic tool. Geared motors are a possible solution for actuation; however, they possess mechanical characteristics that could potentially interfere with tactile perception of tissue qualities. The aim of the current research was to determine how the characteristics of a geared motor suitable for a haptic surgical device affect a user's perception of stiffness. The experiment involved six blindfolded subjects who were asked to discriminate the stiffness of six distinct silicone rubber samples whose mechanical properties are similar to those of soft tissue. Using a novel testing device whose dimensions approximated those of an endoscopic grasper, each subject palpated 30 permutations of sample pairs for each of three types of mechanical loads; the motor (friction and inertia), a flywheel (with the same inertia as motor), and a control (no significant mechanical interference). One factor ANOVA of the error scores and palpation time showed that no significant difference existed among error scores, but mean palpation time for the control was significantly less than for the other two methods. These results indicated that the mechanical characteristics of a geared motor chosen for application in a haptic surgical device did not interfere with the subjects' perception of the silicone samples' stiffness, but these characteristics may significantly affect the energy expenditure and time required for tissue palpation. Therefore, before geared motors can be considered for use in haptic surgical devices, consideration should be given to factors such as palpation speed and fatigue.

Development and evaluation of a new alcohol-based surgical hand scrub formulation with persistent antimicrobial characteristics and brushless application.

PubMed

Hobson, D W; Woller, W; Anderson, L; Guthery, E

1998-10-01

Since the introduction in the 1970s of surgical hand scrub formulations that contain 4% chlorhexidine gluconate (CHG), new surgical scrub formulations that have improved efficacy, persistence, or significantly improved use characteristics have not been forthcoming. In addition, the manufacturer's labeling for popular hand scrub products generally requires scrub times in excess of 6 minutes, whereas current practical needs call for products with substantially shorter scrub times. A new alcohol-based surgical scrub formulation, which has ingredients that provide emollient, surfactant, and antimicrobial persistence characteristics to complement the rapid and broad-spectrum antiseptic qualities of alcohol, has been developed in an effort to address these current practical needs. The relative efficacy of a new alcohol-based surgical scrub formulation that contains ingredients that provide surfactant and antimicrobial persistence characteristics was compared with that of commercial 4% CHG and 7.5% povidone iodine (PVPI) formulations with use of human subjects. Hand antimicrobial count sampling was performed by using standardized "glove juice" methodology. The efficacy and persistence results of the new formulation showed statistically significant improvement over both CHG and PVPI at a substantially lessened scrub time (3 minutes). In addition, use of the new formulation without a scrub brush produced results statistically similar to 3-minute applications with either a brush or a sponge. The new alcohol-based formulation demonstrates promise as a new surgical hand scrub formulation with antimicrobial and use characteristics that are significantly improved over current CHG and PVPI formulations. These studies demonstrate the suitability of this formulation for use as a surgical hand scrub and for brushless application.

Hovering and Low-Speed Performance and Control Characteristics of the Kaman Helicopter Rotor System as Determined on the Langley Helicopter Tower. TED No. NACA DE 205

NASA Technical Reports Server (NTRS)

Carpenter, Paul J.; Paulnock, Russell S.

1949-01-01

An investigation has been conducted with the Langley helicopter tower to obtain basic performance and control characteristics of the Raman rotor system. Blade-pitch control is obtained in this configuration by utilizing an auxiliary flap to twist the blades. Rotor thrust and power required were measured for the hovering condition and over a range of wind velocities from 0 to 30 miles per hour. The control characteristics and the transient response of the rotor to various control movements were also measured. The hovering-performance data are presented as a survey of the wake velocities and the variation of torque coefficient with thrust coefficient. The power required for the test rotor to hover at a thrust of 1350 pounds and a rotor speed of 240 rpm is approximately 6.5 percent greater than that estimated for a conventional rotor of the same diameter and solidity. It is believed that most of this difference is caused by th e flap servomechanism. The reduction in total power required for sustentation of the single-rotor configuration tested at various wind velocities and at the normal operating rotor thrust was found to be similar to the theoretical and experimental results for ro tors with conventionally actuated pitch. The control effectiveness was determined as a function of rotor speed. Sufficient control was available to give a thrust range of 0 to 1500 pounds and a rotor tilt of plus or minus 7 degrees. The time lag between flap motion and blade-pitch response is approximately 0.02 to 0.03 second. The response of the rotor following the blade-pitch response is similar to that of a rotor with conventionally actuated pitch changes. The over-all characteristics of the rotor investigated indicate that satisfactory performance and control characteristics were obtained.

Use of ultrasounds in the food industry-Methods and effects on quality, safety, and organoleptic characteristics of foods: A review.

PubMed

Arvanitoyannis, Ioannis S; Kotsanopoulos, Konstantinos V; Savva, Amalia G

2017-01-02

The use of ultrasounds has recently gained significant interest in the food industry mainly due to the new trends of consumers toward functional foods. Offering several advantages, this form of energy can be applied for the improvement of qualitative characteristics of high-quality foods as well as for assuring safety of a vast variety of foodstuffs, and at the same time minimizing any negative effects of the sensory characteristics of foods. Furthermore, the non-destructive nature of this technology offers several opportunities for the compositional analysis of foods. However, further research is required for the improvement of related techniques and the reduction of application costs in order to render this technology efficient for industrial use. This review paper covers the main applications of ultrasounds as well as several advantages of the use of the technology in combination with conventional techniques. The effects of ultrasounds on the characteristics, microbial safety, and quality of several foods are also detailed.

Integrating a Linear Signal Model with Groundwater and Rainfall time-series on the Characteristic Identification of Groundwater Systems

NASA Astrophysics Data System (ADS)

Chen, Yu-Wen; Wang, Yetmen; Chang, Liang-Cheng

2017-04-01

Groundwater resources play a vital role on regional supply. To avoid irreversible environmental impact such as land subsidence, the characteristic identification of groundwater system is crucial before sustainable management of groundwater resource. This study proposes a signal process approach to identify the character of groundwater systems based on long-time hydrologic observations include groundwater level and rainfall. The study process contains two steps. First, a linear signal model (LSM) is constructed and calibrated to simulate the variation of underground hydrology based on the time series of groundwater levels and rainfall. The mass balance equation of the proposed LSM contains three major terms contain net rate of horizontal exchange, rate of rainfall recharge and rate of pumpage and four parameters are required to calibrate. Because reliable records of pumpage is rare, the time-variant groundwater amplitudes of daily frequency (P ) calculated by STFT are assumed as linear indicators of puamage instead of pumpage records. Time series obtained from 39 observation wells and 50 rainfall stations in and around the study area, Pintung Plain, are paired for model construction. Second, the well-calibrated parameters of the linear signal model can be used to interpret the characteristic of groundwater system. For example, the rainfall recharge coefficient (γ) means the transform ratio between rainfall intention and groundwater level raise. The area around the observation well with higher γ means that the saturated zone here is easily affected by rainfall events and the material of unsaturated zone might be gravel or coarse sand with high infiltration ratio. Considering the spatial distribution of γ, the values of γ decrease from the upstream to the downstream of major rivers and also are correlated to the spatial distribution of grain size of surface soil. Via the time-series of groundwater levels and rainfall, the well-calibrated parameters of LSM have ability to identify the characteristic of aquifer.

Advancements in Wind Integration Study Data Modeling: The Wind Integration National Dataset (WIND) Toolkit; Preprint

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

Draxl, C.; Hodge, B. M.; Orwig, K.

2013-10-01

Regional wind integration studies in the United States require detailed wind power output data at many locations to perform simulations of how the power system will operate under high-penetration scenarios. The wind data sets that serve as inputs into the study must realistically reflect the ramping characteristics, spatial and temporal correlations, and capacity factors of the simulated wind plants, as well as be time synchronized with available load profiles. The Wind Integration National Dataset (WIND) Toolkit described in this paper fulfills these requirements. A wind resource dataset, wind power production time series, and simulated forecasts from a numerical weather predictionmore » model run on a nationwide 2-km grid at 5-min resolution will be made publicly available for more than 110,000 onshore and offshore wind power production sites.« less

Smart Sampling and HPC-based Probabilistic Look-ahead Contingency Analysis Implementation and its Evaluation with Real-world Data

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

Chen, Yousu; Etingov, Pavel V.; Ren, Huiying

This paper describes a probabilistic look-ahead contingency analysis application that incorporates smart sampling and high-performance computing (HPC) techniques. Smart sampling techniques are implemented to effectively represent the structure and statistical characteristics of uncertainty introduced by different sources in the power system. They can significantly reduce the data set size required for multiple look-ahead contingency analyses, and therefore reduce the time required to compute them. High-performance-computing (HPC) techniques are used to further reduce computational time. These two techniques enable a predictive capability that forecasts the impact of various uncertainties on potential transmission limit violations. The developed package has been tested withmore » real world data from the Bonneville Power Administration. Case study results are presented to demonstrate the performance of the applications developed.« less

Design and application of a new control system for tokamak ECRH power supply

NASA Astrophysics Data System (ADS)

Hao, Xu; Zhang, Jian; Huang, Yiyun

2016-03-01

The biggest challenge of designing and building tokamak electron cyclotron resonance heating (ECRH) pulse step modulation (PSM) power supply is satisfying its required output voltage rising time to be less than 100 µs while suppressing the voltage overshoot to be no more than 1%. To fulfill the two requirements, a new control strategy with startup time in microsecond range is proposed in this paper, and a new control system to realize the control strategy is introduced. The control system was built and tested on 60 kV/50 A ECRH power supply. The experimental results indicate that the control system can restrain the overshoot effectively, increase response speed, and obviously improve the dynamic characteristics of the PSM power supply system. Thus, the proposed control system helps the PSM power supply to meet the design specifications.

Traffic shaping and scheduling for OBS-based IP/WDM backbones

NASA Astrophysics Data System (ADS)

Elhaddad, Mahmoud S.; Melhem, Rami G.; Znati, Taieb; Basak, Debashis

2003-10-01

We introduce Proactive Reservation-based Switching (PRS) -- a switching architecture for IP/WDM networks based on Labeled Optical Burst Switching. PRS achieves packet delay and loss performance comparable to that of packet-switched networks, without requiring large buffering capacity, or burst scheduling across a large number of wavelengths at the core routers. PRS combines proactive channel reservation with periodic shaping of ingress-egress traffic aggregates to hide the offset latency and approximate the utilization/buffering characteristics of discrete-time queues with periodic arrival streams. A channel scheduling algorithm imposes constraints on burst departure times to ensure efficient utilization of wavelength channels and to maintain the distance between consecutive bursts through the network. Results obtained from simulation using TCP traffic over carefully designed topologies indicate that PRS consistently achieves channel utilization above 90% with modest buffering requirements.

Enhanced use of phylogenetic data to inform public health approaches to HIV among MSM

PubMed Central

German, Danielle; Grabowski, Mary Kate; Beyrer, Chris

2017-01-01

The multi-dimensional nature and continued evolution of HIV epidemics among men who have sex with men (MSM) requires innovative intervention approaches. Strategies are needed that recognize the individual, social, and structural factors driving HIV transmission; that can pinpoint networks with heightened transmission risk; and that can help target intervention in real-time. HIV phylogenetics is a rapidly evolving field with strong promise for informing innovative responses to the HIV epidemic among MSM. Currently, HIV phylogenetic insights are providing new understandings of characteristics of HIV epidemics involving MSM, social networks influencing transmission, characteristics of HIV transmission clusters involving MSM, targets for antiretroviral and other prevention strategies, and dynamics of emergent epidemics. Maximizing the potential of HIV phylogenetics for HIV responses among MSM will require attention to key methodological challenges and ethical considerations, as well as resolving key implementation and scientific questions. Enhanced and integrated use of HIV surveillance, socio-behavioral, and phylogenetic data resources are becoming increasingly critical for informing public health approaches to HIV among MSM. PMID:27584826

A Mathematical Model of Marine Diesel Engine Speed Control System

NASA Astrophysics Data System (ADS)

Sinha, Rajendra Prasad; Balaji, Rajoo

2018-02-01

Diesel engine is inherently an unstable machine and requires a reliable control system to regulate its speed for safe and efficient operation. Also, the diesel engine may operate at fixed or variable speeds depending upon user's needs and accordingly the speed control system should have essential features to fulfil these requirements. This paper proposes a mathematical model of a marine diesel engine speed control system with droop governing function. The mathematical model includes static and dynamic characteristics of the control loop components. Model of static characteristic of the rotating fly weights speed sensing element provides an insight into the speed droop features of the speed controller. Because of big size and large time delay, the turbo charged diesel engine is represented as a first order system or sometimes even simplified to a pure integrator with constant gain which is considered acceptable in control literature. The proposed model is mathematically less complex and quick to use for preliminary analysis of the diesel engine speed controller performance.

AFGL Fiscal Year 1984 Air Force Technical Objectives Document.

DTIC Science & Technology

1982-11-01

the near term, to design the performance characteristics of sensors operating from the Shuttle. In the long term, these sensors will provide the...atmosphere are determined from sensors on rockets and satellites. These data, which are used to develop tailored analytic and predictive models for...toward increasing the flight time of the various vehicles. Future research and test- ing of advanced sensors will require rockets with increased

Acid precipitation effects on soil pH and base saturation of exchange sites

Treesearch

W. W. McFee; J. M. Kelly; R. H. Beck

1976-01-01

The typical values and probable ranges of acid-precipitation are evaluated in terms of their theoretical effects on pH and cation exchange equilibrium of soils characteristic of the humid temperature region. The extent of probable change in soil pH and the time required to cause such a change are calculated for a range of common soils. Hydrogen ion input by acid...

A Possible Link between Supra-Second Open-Ended Timing Sensitivity and Obsessive-Compulsive Tendencies

PubMed Central

Gilaie-Dotan, Sharon; Ashkenazi, Hamutal; Dar, Reuven

2016-01-01

One of the main characteristics of obsessive-compulsive disorder (OCD) is the persistent feeling of uncertainty, affecting many domains of actions and feelings. It was recently hypothesized that OCD uncertainty is related to attenuated access to internal states. As supra-second timing is associated with bodily and interoceptive awareness, we examined whether supra-second timing would be associated with OC tendencies. We measured supra-second (~9 s) and sub-second (~450 ms) timing along with control non-temporal perceptual tasks in a group of 60 university students. Supra-second timing was measured either with fixed criterion tasks requiring to temporally discriminate between two predefined fixed interval durations (9 vs. 9.9 s), or with an open-ended task requiring to discriminate between 9 s and longer intervals which were of varying durations that were not a priori known to the participants. The open-ended task employed an adaptive Bayesian procedure that efficiently estimated the duration difference required to discriminate 9 s from longer intervals. We also assessed symptoms of OCD, depression, and anxiety. Open-ended supra-second temporal sensitivity was correlated with OC tendencies, as predicted (even after controlling for depression and anxiety), whereas the other tasks were not. Higher OC tendencies were associated with lower timing sensitivity to 9 s intervals such that participants with higher OC tendency scores required longer interval differences to discriminate 9 s from longer intervals. While these results need to be substantiated in future research, they suggest that open-ended timing tasks, as those encountered in real-life (e.g., estimating how long it would take to complete a task), might be adversely affected in OCD. PMID:27445725

A national survey of medical education fellowships.

PubMed

Thompson, Britta M; Searle, Nancy S; Gruppen, Larry D; Hatem, Charles J; Nelson, Elizabeth A

2011-04-04

The purpose of our study was to determine the prevalence, focus, time commitment, graduation requirements and programme evaluation methods of medical education fellowships throughout the United States. Medical education fellowships are defined as a single cohort of medical teaching faculty who participate in an extended faculty development programme. A 26-item online questionnaire was distributed to all US medical schools (n=127) in 2005 and 2006. The questionnaire asked each school if it had a medical education fellowship and the characteristics of the fellowship programme. Almost half (n=55) of the participating schools (n=120, response rate 94.5 %) reported having fellowships. Duration (10-584 hours) and length (<1 month-48 months) varied; most focused on teaching skills, scholarly dissemination and curriculum design, and required the completion of a scholarly project. A majority collected participant satisfaction; few used other programme evaluation strategies. The number of medical education fellowships increased rapidly during the 1990s and 2000s. Across the US, programmes are similar in participant characteristics and curricular focus but unique in completion requirements. Fellowships collect limited programme evaluation data, indicating a need for better outcome data. These results provide benchmark data for those implementing or revising existing medical education fellowships.

A national survey of medical education fellowships

PubMed Central

Thompson, Britta M.; Searle, Nancy S.; Gruppen, Larry D.; Hatem, Charles J.; Nelson, Elizabeth A.

2011-01-01

Purpose The purpose of our study was to determine the prevalence, focus, time commitment, graduation requirements and programme evaluation methods of medical education fellowships throughout the United States. Medical education fellowships are defined as a single cohort of medical teaching faculty who participate in an extended faculty development programme. Methods A 26-item online questionnaire was distributed to all US medical schools (n=127) in 2005 and 2006. The questionnaire asked each school if it had a medical education fellowship and the characteristics of the fellowship programme. Results Almost half (n=55) of the participating schools (n=120, response rate 94.5 %) reported having fellowships. Duration (10–584 hours) and length (<1 month–48 months) varied; most focused on teaching skills, scholarly dissemination and curriculum design, and required the completion of a scholarly project. A majority collected participant satisfaction; few used other programme evaluation strategies. Conclusions The number of medical education fellowships increased rapidly during the 1990s and 2000s. Across the US, programmes are similar in participant characteristics and curricular focus but unique in completion requirements. Fellowships collect limited programme evaluation data, indicating a need for better outcome data. These results provide benchmark data for those implementing or revising existing medical education fellowships. PMID:21475643

Design of partially supervised classifiers for multispectral image data

NASA Technical Reports Server (NTRS)

Jeon, Byeungwoo; Landgrebe, David

1993-01-01

A partially supervised classification problem is addressed, especially when the class definition and corresponding training samples are provided a priori only for just one particular class. In practical applications of pattern classification techniques, a frequently observed characteristic is the heavy, often nearly impossible requirements on representative prior statistical class characteristics of all classes in a given data set. Considering the effort in both time and man-power required to have a well-defined, exhaustive list of classes with a corresponding representative set of training samples, this 'partially' supervised capability would be very desirable, assuming adequate classifier performance can be obtained. Two different classification algorithms are developed to achieve simplicity in classifier design by reducing the requirement of prior statistical information without sacrificing significant classifying capability. The first one is based on optimal significance testing, where the optimal acceptance probability is estimated directly from the data set. In the second approach, the partially supervised classification is considered as a problem of unsupervised clustering with initially one known cluster or class. A weighted unsupervised clustering procedure is developed to automatically define other classes and estimate their class statistics. The operational simplicity thus realized should make these partially supervised classification schemes very viable tools in pattern classification.

The use of ionisation chambers for dose rate measurements at industrial irradiation plants

NASA Astrophysics Data System (ADS)

Sephton, J. P.; Sharpe, P. H. G.; Chu, R. D. H.

2002-03-01

The use of ionisation chambers to measure dose rate at industrial irradiation plants has been studied as part of a wider project on real time dosimetry. The characteristics required of such a chamber are discussed. These include the ability to withstand operation at high cumulative doses (up to 5 MGy) and dose rates of up to about 150 kGy h -1. Other desirable features are water equivalence and immunity to environmental conditions such as temperature, pressure and humidity. A number of chambers have been assessed experimentally and a suitable chamber selected. The dosimetric characteristics of the chosen chamber have been assessed by comparison with absorbed dose measurements made using chemical dosimeters.

Time Counts! Some Comments on System Latency in Head-Referenced Displays

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Adelstein, Bernard D.

2013-01-01

System response latency is a prominent characteristic of human-computer interaction. Laggy systems are; however, not simply annoying but substantially reduce user productivity. The impact of latency on head referenced display systems, particularly head-mounted systems, is especially disturbing since not only can it interfere with dynamic registration in augmented reality displays but it also can in some cases indirectly contribute to motion sickness. We will summarize several experiments using standard psychophysical discrimination techniques that suggest what system latencies will be required to achieve perceptual stability for spatially referenced computer-generated imagery. In conclusion I will speculate about other system performance characteristics that I would hope to have for a dream augmented reality system.

Explicit evaluation of discontinuities in 2-D unsteady flows solved by the method of characteristics

NASA Astrophysics Data System (ADS)

Osnaghi, C.

When shock waves appear in the numerical solution of flows, a choice is necessary between shock capturing techniques, possible when equations are written in conservative form, and shock fitting techniques. If the second one is preferred, e.g. in order to obtain better definition and more physical description of the shock evolution in time, the method of characteristics is advantageous in the vicinity of the shock and it seems natural to use this method everywhere. This choice requires to improve the efficiency of the numerical scheme in order to produce competitive codes, preserving accuracy and flexibility, which are intrinsic features of the method: this is the goal of the present work.

An analytical procedure for evaluating shuttle abort staging aerodynamic characteristics

NASA Technical Reports Server (NTRS)

Meyer, R.

1973-01-01

An engineering analysis and computer code (AERSEP) for predicting Space Shuttle Orbiter - HO Tank longitudinal aerodynamic characteristics during abort separation has been developed. Computed results are applicable at Mach numbers above 2 for angle-of-attack between plus or minus 10 degrees. No practical restrictions on orbiter-tank relative positioning are indicated for tank-under-orbiter configurations. Input data requirements and computer running times are minimal facilitating program use for parametric studies, test planning, and trajectory analysis. In a majority of cases AERSEP Orbiter-Tank interference predictions are as accurate as state-of-the-art estimates for interference-free or isolated-vehicle configurations. AERSEP isolated-orbiter predictions also show excellent correlation with data.

JT8D and JT9D jet engine performance improvement program. Task 1: Feasibility analysis

NASA Technical Reports Server (NTRS)

Gaffin, W. O.; Webb, D. E.

1979-01-01

JT8D and JT9D component performance improvement concepts which have a high probability of incorporation into production engines were identified and ranked. An evaluation method based on airline payback period was developed for the purpose of identifying the most promising concepts. The method used available test data and analytical models along with conceptual/preliminary designs to predict the performance improvements, weight, installation characteristics, cost for new production and retrofit, maintenance cost, and qualitative characteristics of candidate concepts. These results were used to arrive at the concept payback period, which is the time required for an airline to recover the investment cost of concept implementation.

Assessing therapeutic relevance of biologically interesting, ampholytic substances based on their physicochemical and spectral characteristics with chemometric tools

NASA Astrophysics Data System (ADS)

Judycka, U.; Jagiello, K.; Bober, L.; Błażejowski, J.; Puzyn, T.

2018-06-01

Chemometric tools were applied to investigate the biological behaviour of ampholytic substances in relation to their physicochemical and spectral properties. Results of the Principal Component Analysis suggest that size of molecules and their electronic and spectral characteristics are the key properties required to predict therapeutic relevance of the compounds examined. These properties were used for developing the structure-activity classification model. The classification model allows assessing the therapeutic behaviour of ampholytic substances on the basis of solely values of descriptors that can be obtained computationally. Thus, the prediction is possible without necessity of carrying out time-consuming and expensive laboratory tests, which is its main advantage.

Selection of the battery pack parameters for an electric vehicle based on performance requirements

NASA Astrophysics Data System (ADS)

Koniak, M.; Czerepicki, A.

2017-06-01

Each type of vehicle has specific power requirements. Some require a rapid charging, other make long distances between charges, but a common feature is the longest battery life time. Additionally, the battery is influenced by factors such as temperature, depth of discharge and the operation current. The article contain the parameters of chemical cells that should be taken into account during the design of the battery for a specific application. This is particularly important because the batteries are not properly matched and can wear prematurely and cause an additional costs. The method of selecting the correct cell type should take previously discussed features and operating characteristics of the vehicle into account. The authors present methods of obtaining such characteristics along with their assessment and examples. Also there has been described an example of the battery parameters selection based on design assumptions of the vehicle and the expected performance characteristics. Selecting proper battery operating parameters is important due to its impact on the economic result of investments in electric vehicles. For example, for some Li-Ion technologies, the earlier worn out of batteries in a fleet of cruise boats or buses having estimated lifetime of 10 years is not acceptable, because this will cause substantial financial losses for the owner of the rolling stock. The presented method of choosing the right cell technology in the selected application, can be the basis for making the decision on future battery technical parameters.

Experimental investigation on the development characteristics of initial electrons in a gas pressurized closing switch under DC voltage

NASA Astrophysics Data System (ADS)

Rongxiao, ZHAI; Mengtong, QIU; Weixi, LUO; Peitian, CONG; Tao, HUANG; Jiahui, YIN; Tianyang, ZHANG

2018-04-01

As one of the most important elements in linear transformer driver (LTD) based systems, the gas pressurized closing switches are required to operate with a very low prefire probability during the DC-charging process to ensure reliable operation and stable output of the whole pulsed power system. The most direct and effective way to control the prefire probability is to select a suitable working coefficient. The study of the development characteristics of the initially generated electrons is useful for optimizing the working coefficient and improving the prefire characteristic of the switches. In this paper an ultraviolet pulsed laser is used to generate initial electrons inside the gap volume. A current measuring system is used to measure the time-dependent current generated by the growth of the initial electrons so as to study the development characteristics of the electrons under different working coefficients. Experimental results show that the development characteristics of the initial electrons are influenced obviously by the working coefficient. With the increase of the working coefficient, the development degree of the electrons increases consequently. At the same times, there is a threshold of working coefficient which produces the effect of ionization on electrons. The range of the threshold has a slow growth but remains close to 65% with the gas pressure increase. When the working coefficient increases further, γ processes are starting to be generated inside the gap volume. In addition, an optimal working coefficient beneficial for improving the prefire characteristic is indicated and further tested.

33 CFR 118.60 - Characteristics of lights.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Characteristics of lights. 118.60... LIGHTING AND OTHER SIGNALS § 118.60 Characteristics of lights. All lights required or authorized under this.... Lights must meet the requirements of this part. Lights shall be fixed lights excepting as provided in...

33 CFR 118.60 - Characteristics of lights.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Characteristics of lights. 118.60... LIGHTING AND OTHER SIGNALS § 118.60 Characteristics of lights. All lights required or authorized under this.... Lights must meet the requirements of this part. Lights shall be fixed lights excepting as provided in...

33 CFR 118.60 - Characteristics of lights.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Characteristics of lights. 118.60... LIGHTING AND OTHER SIGNALS § 118.60 Characteristics of lights. All lights required or authorized under this.... Lights must meet the requirements of this part. Lights shall be fixed lights excepting as provided in...

33 CFR 118.60 - Characteristics of lights.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Characteristics of lights. 118.60... LIGHTING AND OTHER SIGNALS § 118.60 Characteristics of lights. All lights required or authorized under this.... Lights must meet the requirements of this part. Lights shall be fixed lights excepting as provided in...

33 CFR 118.60 - Characteristics of lights.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Characteristics of lights. 118.60... LIGHTING AND OTHER SIGNALS § 118.60 Characteristics of lights. All lights required or authorized under this.... Lights must meet the requirements of this part. Lights shall be fixed lights excepting as provided in...

A Phase Correction Technique Based on Spatial Movements of Antennas in Real-Time (S.M.A.R.T.) for Designing Self-Adapting Conformal Array Antennas

NASA Astrophysics Data System (ADS)

Roy, Sayan

This research presents a real-time adaptive phase correction technique for flexible phased array antennas on conformal surfaces of variable shapes. Previously reported pattern correctional methods for flexible phased array antennas require prior knowledge on the possible non-planar shapes in which the array may adapt for conformal applications. For the first time, this initial requirement of shape curvature knowledge is no longer needed and the instantaneous information on the relative location of array elements is used here for developing a geometrical model based on a set of Bezier curves. Specifically, by using an array of inclinometer sensors and an adaptive phase-correctional algorithm, it has been shown that the proposed geometrical model can successfully predict different conformal orientations of a 1-by-4 antenna array in real-time without the requirement of knowing the shape-changing characteristics of the surface the array is attached upon. Moreover, the phase correction technique is validated by determining the field patterns and broadside gain of the 1-by-4 antenna array on four different conformal surfaces with multiple points of curvatures. Throughout this work, measurements are shown to agree with the analytical solutions and full-wave simulations.

Obligatory consultation of an independent physician on euthanasia requests in the Netherlands: what influences the SCEN physicians judgment of the legal requirements of due care?

PubMed

Brinkman-Stoppelenburg, Arianne; Vergouwe, Yvonne; van der Heide, Agnes; Onwuteaka-Philipsen, Bregje D

2014-03-01

In the Netherlands, euthanasia is allowed if physicians adhere to legal requirements. Consultation of an independent physician is one of the requirements. SCEN (Support and Consultation on Euthanasia in the Netherlands) physicians have been trained to provide such consultations. To study why euthanasia requests are sometimes judged not to meet requirements of due care and to find out which characteristics are associated with the SCEN physicians' judgments. During 5 years (2006, 2008-2011) standardized registration forms were used for data-collection. We used multilevel logistic regression analysis to assess the associations of characteristics and SCEN physicians' judgments. We analyzed 1631 euthanasia requests, involving 415 SCEN physicians. Patient characteristics that were associated with a lower likelihood to meet due care requirements were: being tired with life, depression and not wanting to be a burden. Physical suffering and higher patient age were related to greater chances of meeting the requirements. There was no clear association between SCEN physicians' characteristics and their judgment. Psychological suffering involves a greater chance that SCEN physicians judge that requirements of due care are not met. The association between SCEN physician characteristics and the judgment of euthanasia requests is limited, suggesting uniformity in their judgment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Engineering Design of ITER Prototype Fast Plant System Controller

NASA Astrophysics Data System (ADS)

Goncalves, B.; Sousa, J.; Carvalho, B.; Rodrigues, A. P.; Correia, M.; Batista, A.; Vega, J.; Ruiz, M.; Lopez, J. M.; Rojo, R. Castro; Wallander, A.; Utzel, N.; Neto, A.; Alves, D.; Valcarcel, D.

2011-08-01

The ITER control, data access and communication (CODAC) design team identified the need for two types of plant systems. A slow control plant system is based on industrial automation technology with maximum sampling rates below 100 Hz, and a fast control plant system is based on embedded technology with higher sampling rates and more stringent real-time requirements than that required for slow controllers. The latter is applicable to diagnostics and plant systems in closed-control loops whose cycle times are below 1 ms. Fast controllers will be dedicated industrial controllers with the ability to supervise other fast and/or slow controllers, interface to actuators and sensors and, if necessary, high performance networks. Two prototypes of a fast plant system controller specialized for data acquisition and constrained by ITER technological choices are being built using two different form factors. This prototyping activity contributes to the Plant Control Design Handbook effort of standardization, specifically regarding fast controller characteristics. Envisaging a general purpose fast controller design, diagnostic use cases with specific requirements were analyzed and will be presented along with the interface with CODAC and sensors. The requirements and constraints that real-time plasma control imposes on the design were also taken into consideration. Functional specifications and technology neutral architecture, together with its implications on the engineering design, were considered. The detailed engineering design compliant with ITER standards was performed and will be discussed in detail. Emphasis will be given to the integration of the controller in the standard CODAC environment. Requirements for the EPICS IOC providing the interface to the outside world, the prototype decisions on form factor, real-time operating system, and high-performance networks will also be discussed, as well as the requirements for data streaming to CODAC for visualization and archiving.

Identification of periods of clear sky irradiance in time series of GHI measurements

DOE PAGES

Reno, Matthew J.; Hansen, Clifford W.

2016-01-18

In this study, we present a simple algorithm for identifying periods of time with broadband global horizontal irradiance (GHI) similar to that occurring during clear sky conditions from a time series of GHI measurements. Other available methods to identify these periods do so by identifying periods with clear sky conditions using additional measurements, such as direct or diffuse irradiance. Our algorithm compares characteristics of the time series of measured GHI with the output of a clear sky model without requiring additional measurements. We validate our algorithm using data from several locations by comparing our results with those obtained from amore » clear sky detection algorithm, and with satellite and ground-based sky imagery.« less

Identification of periods of clear sky irradiance in time series of GHI measurements

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

Reno, Matthew J.; Hansen, Clifford W.

In this study, we present a simple algorithm for identifying periods of time with broadband global horizontal irradiance (GHI) similar to that occurring during clear sky conditions from a time series of GHI measurements. Other available methods to identify these periods do so by identifying periods with clear sky conditions using additional measurements, such as direct or diffuse irradiance. Our algorithm compares characteristics of the time series of measured GHI with the output of a clear sky model without requiring additional measurements. We validate our algorithm using data from several locations by comparing our results with those obtained from amore » clear sky detection algorithm, and with satellite and ground-based sky imagery.« less

Signal and background considerations for the MRSt on the National Ignition Facility (NIF)

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

Wink, C. W., E-mail: cwink@mit.edu; Frenje, J. A.; Gatu Johnson, M.

2016-11-15

A Magnetic Recoil Spectrometer (MRSt) has been conceptually designed for time-resolved measurements of the neutron spectrum at the National Ignition Facility. Using the MRSt, the goals are to measure the time-evolution of the spectrum with a time resolution of ∼20-ps and absolute accuracy better than 5%. To meet these goals, a detailed understanding and optimization of the signal and background characteristics are required. Through ion-optics, MCNP simulations, and detector-response calculations, it is demonstrated that the goals and a signal-to background >5–10 for the down-scattered neutron measurement are met if the background, consisting of ambient neutrons and gammas, at the MRStmore » is reduced 50–100 times.« less

Signal and background considerations for the MRSt on the National Ignition Facility (NIF)

DOE PAGES

Wink, C. W.; Frenje, J. A.; Hilsabeck, T. J.; ...

2016-08-03

A Magnetic Recoil Spectrometer (MRSt) has been conceptually designed for time-resolved measurements of the neutron spectrum at the National Ignition Facility. Using the MRSt, the goals are to measure the time-evolution of the spectrum with a time resolution of ~20-ps and absolute accuracy better than 5%. To meet these goals, a detailed understanding and optimization of the signal and background characteristics are required. Through ion-optics, MCNP simulations, and detector-response calculations, we demonstrate that the goals and a signal-to background >5-10 for the down-scattered neutron measurement are met if the background, consisting of ambient neutrons and gammas, at the MRSt ismore » reduced 50-100 times.« less

Elbow Injuries in Professional Baseball: Epidemiological Findings From the Major League Baseball Injury Surveillance System.

PubMed

Ciccotti, Michael G; Pollack, Keisha M; Ciccotti, Michael C; D'Angelo, John; Ahmad, Christopher S; Altchek, David; Andrews, James; Curriero, Frank C

2017-08-01

Elbow injuries cause significant disability for the throwing athlete. Scant data are available on the distribution and characteristics of these injuries in elite baseball players. No study exists that focuses solely on the epidemiological characteristics of elbow injuries in professional baseball players using a comprehensive injury surveillance system. Professional baseball players have a high occurrence of elbow injuries influenced by factors including length of time playing, time period within the annual baseball season, and specific position played. Descriptive epidemiological study. Data on elbow injuries occurring during the 2011-2014 seasons were collected from Major League Baseball's Health Injury and Tracking System, a comprehensive injury surveillance system. Each specific type of elbow injury was evaluated with respect to overall injury rate, years as a professional player, mechanism of injury, treatment, average time lost, and return to play. During the study period, 3185 elbow injuries (n = 430 Major League; n = 2755 Minor League) occurred. The mean number of days missed and percentage requiring surgery were similar between Major and Minor League players. Overall, 20.0% (650/3185) of the injuries required surgical treatment. Pitchers were the most likely to incur an elbow injury (40.0% of injured athletes were pitchers), were the most likely to require surgery (34.2% of injured pitchers required surgery), and had the greatest mean number of days missed when treated nonsurgically (33.2 days). Medial injuries composed 42.1% (1342/3185) of all elbow injuries. Of all elbow surgeries performed during the study period, the highest percentage involved ligaments (372/650; 57.2%). Elbow injuries are a considerable source of disability in professional baseball players. Pitchers are most likely to incur these injuries, are most likely to require surgery, and have the highest mean number of days missed when treated nonsurgically. The most common injuries involve the medial elbow, with ligament injuries most often requiring surgery. This study represents the only investigation to date using a comprehensive injury surveillance system to examine elbow injuries in professional baseball players. It provides a basis for injury prevention and treatment recommendations, establishes the most thorough framework for determining elbow injury risk, and focuses continued research on elbow injury prevention in the elite baseball player.

SU-E-T-755: Timing Characteristics of Proton and Carbon Ion Treatments Using a Synchrotron and Modulated Scanning

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

Zhao, J; Li, Y; Huang, Z

2015-06-15

Purpose: The time required to deliver a treatment impacts not only the number of patients that can be treated each day but also the accuracy of delivery due to potential movements of patient tissues. Both macroscopic and microscopic timing characteristics of a beam delivery system were studied to examine their impacts on patient treatments. Methods: 35 patients were treated during a clinical trial to demonstrate safety and efficacy of a Siemens Iontris system prior to receiving approval from the Chinese Food and Drug Administration. The system has a variable cycle time and can provide proton beams from 48 to 221more » MeV/n and carbon ions from 86 to 430 MeV/n. A modulated scanning beam delivery technique is used where the beam remains stationary at each spot aiming location and is not turned off while the spot quickly moves from one aiming location to the next. The treatment log files for 28 of the trial patients were analyzed to determine several timing characteristics. Results: The average portal time per target dose was 172.5 s/Gy for protons and 150.7 s/Gy for carbon ions. The maximum delivery time for any portal was less than 300 s. The average dwell time per spot was 12 ms for protons and 3.0 ms for carbon ions. The number of aiming positions per energy layer varied from 1 to 258 for protons and 1 to 621 for carbon ions. The average spill time and cycle time per energy layer were 1.20 and 2.68 s for protons and 0.95 and 4.73 s for carbon ions respectively. For 3 of the patients, the beam was gated on and off to reduce the effects of respiration. Conclusion: For a typical target volume of 153 cc as used in this clinical trial, the portal delivery times were acceptable.« less

Time of travel of solutes in selected reaches of the Sandusky River Basin, Ohio, 1972 and 1973

USGS Publications Warehouse

Westfall, Arthur O.

1976-01-01

A time of travel study of a 106-mile (171-kilometer) reach of the Sandusky River and a 39-mile (63-kilometer) reach of Tymochtee Creek was made to determine the time required for water released from Killdeer Reservoir on Tymochtee Creek to reach selected downstream points. In general, two dye sample runs were made through each subreach to define the time-discharge relation for approximating travel times at selected discharges within the measured range, and time-discharge graphs are presented for 38 subreaches. Graphs of dye dispersion and variation in relation to time are given for three selected sampling sites. For estimating travel time and velocities between points in the study reach, tables for selected flow durations are given. Duration curves of daily discharge for four index stations are presented to indicate the lo-flow characteristics and for use in shaping downward extensions of the time-discharge curves.

Patient preferences and willingness to pay for different options of anticoagulant therapy.

PubMed

Moia, Marco; Mantovani, Lorenzo Giovanni; Carpenedo, Monica; Scalone, Luciana; Monzini, Mara Silvia; Cesana, Giancarlo; Mannucci, Pier Mannuccio

2013-04-01

New anticoagulant drugs alternative to vitamin K antagonists are currently under clinical evaluation. Patient's preferences should be considered in the development of new therapeutic strategies. Our study aim was to elicit patient preferences, and estimate their willingness to pay for the different treatment options. A Discrete Choice Experiment was administered to patients consecutively attending an anticoagulation clinic, either on stable oral anticoagulant therapy, or during their first visit at the time of starting therapy. Six treatment characteristics were analysed: route and number of medication administrations, frequency of monitoring, risk of some minor bleeding, the amount of attention required for drug/food interactions, requirement for dose adjustment, and out-of-pocket treatment cost. Relationships between patient's preferences and their characteristics were analysed. 255 patients participated (55 % men, with a mean age 64 years; 35.7 % on stable therapy). A statistically significant importance was attributed to all but two characteristics (the amount of attention required for interaction with other drugs/food and for dose adjustment.) Monthly patient willingness to pay was 79 for tablets versus injections; 41 for once-daily versus twice-daily tablets, 25 for drugs without risk of minor bleeding events and 20 for once-monthly versus twice-monthly monitoring. Patients on stable therapy considered more important the amount of attention required for drug/food interactions than did the starters. Younger or working patients considered the reduction of monitoring frequency more important than did the older or not working patients (retired, housewives). This study elicited preferences from patients on oral anticoagulant therapy with a simple and well established method, which allows to obtain information warranted for planning optimal healthcare.

Aeroelastic Uncertainty Quantification Studies Using the S4T Wind Tunnel Model

NASA Technical Reports Server (NTRS)

Nikbay, Melike; Heeg, Jennifer

2017-01-01

This paper originates from the joint efforts of an aeroelastic study team in the Applied Vehicle Technology Panel from NATO Science and Technology Organization, with the Task Group number AVT-191, titled "Application of Sensitivity Analysis and Uncertainty Quantification to Military Vehicle Design." We present aeroelastic uncertainty quantification studies using the SemiSpan Supersonic Transport wind tunnel model at the NASA Langley Research Center. The aeroelastic study team decided treat both structural and aerodynamic input parameters as uncertain and represent them as samples drawn from statistical distributions, propagating them through aeroelastic analysis frameworks. Uncertainty quantification processes require many function evaluations to asses the impact of variations in numerous parameters on the vehicle characteristics, rapidly increasing the computational time requirement relative to that required to assess a system deterministically. The increased computational time is particularly prohibitive if high-fidelity analyses are employed. As a remedy, the Istanbul Technical University team employed an Euler solver in an aeroelastic analysis framework, and implemented reduced order modeling with Polynomial Chaos Expansion and Proper Orthogonal Decomposition to perform the uncertainty propagation. The NASA team chose to reduce the prohibitive computational time by employing linear solution processes. The NASA team also focused on determining input sample distributions.

Service offerings and interfaces for the ACTS network of Earth stations

NASA Technical Reports Server (NTRS)

Coney, Thom A.

1988-01-01

The Advanced Communications Satellite (ACTS) is capable of two modes of communication. Mode 1 is a mesh network of Earth stations using baseband-switched, time-division multiple-access (BBS-TDMA) and hopping beams. Mode 2 is a mesh network using satellite-switched, time-division multiple-access (SS-TDMA) and fixed (or hopping) beams. The purpose of this paper is to present the functional requirements and the design of the ACTS Mode 1 Earth station terrestrial interface. Included among the requirements are that: (1) the interface support standard telecommunications service offerings (i.e., voice, video and data at rates ranging from 9.6 kbps to 44 Mbps); (2) the interface support the unique design characteristics of the ACTS communications systems (e.g., the real time demand assignment of satellite capacity); and (3) the interface support test hardware capable of validating ACTS communications processes. The resulting interface design makes use of an appropriate combination of T1 or T3 multiplexers and a small central office (maximum capacity 56 subscriber lines per unit).

The temporal variability of a rainfall synthetic hyetograph for the dimensioning of stormwater retention tanks in small urban catchments

NASA Astrophysics Data System (ADS)

Pochwat, Kamil; Słyś, Daniel; Kordana, Sabina

2017-06-01

The paper presents issues relating to the influence of time distribution of rainfall on the required storage capacity of stormwater reservoirs. The research was based on data derived from simulations of existing drainage systems. The necessary models of catchments and the drainage system were prepared using the hydrodynamic modelling software SWMM 5.0 (Storm Water Management Model). The research results obtained were used to determine the critical rainfall distribution in time which required reserving the highest capacity of stormwater reservoir. In addition, it can be confirmed based on the research that dimensioning of enclosed structures should rely on using the critical precipitation generated as the characteristics of a synthetically developed rainfall vary dynamically in time. In the final part of the paper, the results of the analyses are compared and followed with the ensuing conclusions. The results of the research will have impact on the development of methodologies for dimensioning retention facilities in drainage systems.

Characteristics of a dynamic holographic sensor for shape control of a large reflector

NASA Technical Reports Server (NTRS)

Welch, Sharon S.; Cox, David E.

1991-01-01

Design of a distributed holographic interferometric sensor for measuring the surface displacement of a large segmented reflector is proposed. The reflector's surface is illuminated by laser light of two wavelengths and volume holographic gratings are formed in photorefractive crystals of the wavefront returned from the surface. The sensor is based on holographic contouring with a multiple frequency source. It is shown that the most stringent requirement of temporal stability affects both the temporal resolution and the dynamic range. Principal factor which limit the sensor performance include the response time of photorefractive crystal, laser power required to write a hologram, and the size of photorefractive crystal.

Operation and performance of the Ciba-Corning 512 coagulation monitor during parabolic flight

NASA Technical Reports Server (NTRS)

Gocke, Robyn; Lloyd, Charles W.; Greenthaner, Nancy K.

1991-01-01

The goal was to assess the functionality and evaluate the procedures and operations required to operate the Ciba-Corning 512 Coagulation Monitor during parabolic flight. This monitor determines the clotting characteristics of blood. The analyzer operates by laser detection of the cessation of blood flow in a capillary channel within a test cartridge. Test simulator results were excellent for both pre-and post-flight. In-flight results were not obtained due to the warm-up time required for the simulator. Since this is an electronic function only, the expected results on the simulator would be the same in zero-g.

Automatic vehicle monitoring systems study. Report of phase O. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1977-01-01

A set of planning guidelines is presented to help law enforcement agencies and vehicle fleet operators decide which automatic vehicle monitoring (AVM) system could best meet their performance requirements. Improvements in emergency response times and resultant cost benefits obtainable with various operational and planned AVM systems may be synthesized and simulated by means of special computer programs for model city parameters applicable to small, medium, and large urban areas. Design characteristics of various AVM systems and the implementation requirements are illustrated and cost estimated for the vehicles, the fixed sites, and the base equipments. Vehicle location accuracies for different RF links and polling intervals are analyzed.

Storage peak gas-turbine power unit

NASA Technical Reports Server (NTRS)

Tsinkotski, B.

1980-01-01

A storage gas-turbine power plant using a two-cylinder compressor with intermediate cooling is studied. On the basis of measured characteristics of a .25 Mw compressor computer calculations of the parameters of the loading process of a constant capacity storage unit (05.3 million cu m) were carried out. The required compressor power as a function of time with and without final cooling was computed. Parameters of maximum loading and discharging of the storage unit were calculated, and it was found that for the complete loading of a fully unloaded storage unit, a capacity of 1 to 1.5 million cubic meters is required, depending on the final cooling.

A comparison of multiprocessor scheduling methods for iterative data flow architectures

NASA Technical Reports Server (NTRS)

Storch, Matthew

1993-01-01

A comparative study is made between the Algorithm to Architecture Mapping Model (ATAMM) and three other related multiprocessing models from the published literature. The primary focus of all four models is the non-preemptive scheduling of large-grain iterative data flow graphs as required in real-time systems, control applications, signal processing, and pipelined computations. Important characteristics of the models such as injection control, dynamic assignment, multiple node instantiations, static optimum unfolding, range-chart guided scheduling, and mathematical optimization are identified. The models from the literature are compared with the ATAMM for performance, scheduling methods, memory requirements, and complexity of scheduling and design procedures.

Effect of the conditions of sintering of sodium-reduced tantalum powders on their characteristics

NASA Astrophysics Data System (ADS)

Prokhorova, T. Yu.; Orlov, V. M.; Miroshnichenko, M. N.; Kolosov, V. N.

2014-07-01

The effect of the granulation and heat treatment of sodium-reduced tantalum powders with a specific surface area of 2.5-3.6 m2/g on the bulk density, the powder flow time, and the specific surface area of the powders and the specific capacitance of the anodes made of them is studied. It is shown that heat treatment of a granulated powder in vacuum at 1100°C or in a mixture with magnesium at 800°C makes it possible to achieve the required powder flow time.

Real-time simulation of an F110/STOVL turbofan engine

NASA Technical Reports Server (NTRS)

Drummond, Colin K.; Ouzts, Peter J.

1989-01-01

A traditional F110-type turbofan engine model was extended to include a ventral nozzle and two thrust-augmenting ejectors for Short Take-Off Vertical Landing (STOVL) aircraft applications. Development of the real-time F110/STOVL simulation required special attention to the modeling approach to component performance maps, the low pressure turbine exit mixing region, and the tailpipe dynamic approximation. Simulation validation derives by comparing output from the ADSIM simulation with the output for a validated F110/STOVL General Electric Aircraft Engines FORTRAN deck. General Electric substantiated basic engine component characteristics through factory testing and full scale ejector data.

The Structure Lacuna

PubMed Central

Boeyens, Jan C.A.; Levendis, Demetrius C.

2012-01-01

Molecular symmetry is intimately connected with the classical concept of three-dimensional molecular structure. In a non-classical theory of wave-like interaction in four-dimensional space-time, both of these concepts and traditional quantum mechanics lose their operational meaning, unless suitably modified. A required reformulation should emphasize the importance of four-dimensional effects like spin and the symmetry effects of space-time curvature that could lead to a fundamentally different understanding of molecular symmetry and structure in terms of elementary number theory. Isolated single molecules have no characteristic shape and macro-biomolecules only develop robust three-dimensional structure in hydrophobic response to aqueous cellular media. PMID:22942753

GrammarViz 3.0: Interactive Discovery of Variable-Length Time Series Patterns

DOE PAGES

Senin, Pavel; Lin, Jessica; Wang, Xing; ...

2018-02-23

The problems of recurrent and anomalous pattern discovery in time series, e.g., motifs and discords, respectively, have received a lot of attention from researchers in the past decade. However, since the pattern search space is usually intractable, most existing detection algorithms require that the patterns have discriminative characteristics and have its length known in advance and provided as input, which is an unreasonable requirement for many real-world problems. In addition, patterns of similar structure, but of different lengths may co-exist in a time series. In order to address these issues, we have developed algorithms for variable-length time series pattern discoverymore » that are based on symbolic discretization and grammar inference—two techniques whose combination enables the structured reduction of the search space and discovery of the candidate patterns in linear time. In this work, we present GrammarViz 3.0—a software package that provides implementations of proposed algorithms and graphical user interface for interactive variable-length time series pattern discovery. The current version of the software provides an alternative grammar inference algorithm that improves the time series motif discovery workflow, and introduces an experimental procedure for automated discretization parameter selection that builds upon the minimum cardinality maximum cover principle and aids the time series recurrent and anomalous pattern discovery.« less

GrammarViz 3.0: Interactive Discovery of Variable-Length Time Series Patterns

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

Senin, Pavel; Lin, Jessica; Wang, Xing

The problems of recurrent and anomalous pattern discovery in time series, e.g., motifs and discords, respectively, have received a lot of attention from researchers in the past decade. However, since the pattern search space is usually intractable, most existing detection algorithms require that the patterns have discriminative characteristics and have its length known in advance and provided as input, which is an unreasonable requirement for many real-world problems. In addition, patterns of similar structure, but of different lengths may co-exist in a time series. In order to address these issues, we have developed algorithms for variable-length time series pattern discoverymore » that are based on symbolic discretization and grammar inference—two techniques whose combination enables the structured reduction of the search space and discovery of the candidate patterns in linear time. In this work, we present GrammarViz 3.0—a software package that provides implementations of proposed algorithms and graphical user interface for interactive variable-length time series pattern discovery. The current version of the software provides an alternative grammar inference algorithm that improves the time series motif discovery workflow, and introduces an experimental procedure for automated discretization parameter selection that builds upon the minimum cardinality maximum cover principle and aids the time series recurrent and anomalous pattern discovery.« less

Repeated Habitat Disturbances by Fire Decrease Local Effective Population Size

PubMed Central

Ragsdale, Alexandria K.; McCoy, Earl D.; Mushinsky, Henry R.

2016-01-01

Effective population size is a fundamental parameter in population genetics, and factors that alter effective population size will shape the genetic characteristics of populations. Habitat disturbance may have a large effect on genetic characteristics of populations by influencing immigration and gene flow, particularly in fragmented habitats. We used the Florida Sand Skink (Plestiodon reynoldsi) to investigate the effect of fire-based habitat disturbances on the effective population size in the highly threatened, severely fragmented, and fire dependent Florida scrub habitat. We screened 7 microsatellite loci in 604 individuals collected from 12 locations at Archbold Biological Station. Archbold Biological Station has an active fire management plan and detailed records of fires dating to 1967. Our objective was to determine how the timing, number, and intervals between fires affect effective population size, focusing on multiple fires in the same location. Effective population size was higher in areas that had not been burned for more than 10 years and decreased with number of fires and shorter time between fires. A similar pattern was observed in abundance: increasing abundance with time-since-fire and decreasing abundance with number of fires. The ratio of effective population size to census size was higher at sites with more recent fires and tended to decrease with time-since-last-fire. These results suggest that habitat disturbances, such as fire, may have a large effect in the genetic characteristics of local populations and that Florida Sand Skinks are well adapted to the natural fire dynamics required to maintain Florida scrub. PMID:26976940

Impact of timing of cranioplasty on hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction.

PubMed

Finger, Tobias; Prinz, Vincent; Schreck, Evelyn; Pinczolits, Alexandra; Bayerl, Simon; Liman, Thomas; Woitzik, Johannes; Vajkoczy, Peter

2017-02-01

Patients with malignant middle cerebral artery infarction frequently develop hydrocephalus after decompressive hemicraniectomy. Hydrocephalus itself and known shunt related complications after ventriculo-peritoneal shunt implantation may negatively impact patientś outcome. Here, we aimed to identify factors associated with the development of hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction. A total of 99 consecutive patients with the diagnosis of large hemispheric infarctions and the indication for decompressive hemicraniectomy were included. We retrospectively evaluated patient characteristics (gender, age and selected preoperative risk factors), stroke characteristics (side, stroke volume and existing mass effect) and surgical characteristics (size of the bone flap, initial complication rate, time to cranioplasty, complication rate following cranioplasty, type of implant, number of revision surgeries and mortality). Frequency of hydrocephalus development was 10% in our cohort. Patients who developed a hydrocephalus had an earlier time point of bone flap reimplantation compared to the control group (no hydrocephalus=164±104days, hydrocephalus=108±52days, p<0.05). Additionally, numbers of revision surgeries after cranioplasty was associated with hydrocephalus with a trend towards significance (p=0.08). Communicating hydrocephalus is frequent in patients with malignant middle cerebral artery infarction after decompressive hemicraniectomy. A later time point of cranioplasty might lead to a lower incidence of required shunting procedures in general as we could show in our patient cohort. Copyright © 2016 Elsevier B.V. All rights reserved.

Practical design and evaluation methods of omnidirectional vision sensors

NASA Astrophysics Data System (ADS)

Ohte, Akira; Tsuzuki, Osamu

2012-01-01

A practical omnidirectional vision sensor, consisting of a curved mirror, a mirror-supporting structure, and a megapixel digital imaging system, can view a field of 360 deg horizontally and 135 deg vertically. The authors theoretically analyzed and evaluated several curved mirrors, namely, a spherical mirror, an equidistant mirror, and a single viewpoint mirror (hyperboloidal mirror). The focus of their study was mainly on the image-forming characteristics, position of the virtual images, and size of blur spot images. The authors propose here a practical design method that satisfies the required characteristics. They developed image-processing software for converting circular images to images of the desired characteristics in real time. They also developed several prototype vision sensors using spherical mirrors. Reports dealing with virtual images and blur-spot size of curved mirrors are few; therefore, this paper will be very useful for the development of omnidirectional vision sensors.

Processing Conversational Implicatures: Alternatives and Counterfactual Reasoning.

PubMed

van Tiel, Bob; Schaeken, Walter

2017-05-01

In a series of experiments, Bott and Noveck (2004) found that the computation of scalar inferences, a variety of conversational implicature, caused a delay in response times. In order to determine what aspect of the inferential process that underlies scalar inferences caused this delay, we extended their paradigm to three other kinds of inferences: free choice inferences, conditional perfection, and exhaustivity in "it"-clefts. In contrast to scalar inferences, the computation of these three kinds of inferences facilitated response times. Following a suggestion made by Chemla and Bott (2014), we propose that the time it takes to compute a conversational implicature depends on the structural characteristics of the required alternatives. Copyright © 2016 Cognitive Science Society, Inc.

Liquid Rocket Booster (LRB) for the Space Transportation System (STS) systems study. Appendix G: LRB for the STS system study level 2 requirements, revision 1

NASA Technical Reports Server (NTRS)

1989-01-01

Requirements are presented for shuttle system definition; performance and design characteristics; shuttle vehicle end item performance and design characteristics; ground operations complex performance and design characteristics; operability and system design and construction standards; and quality control.

Optimization of stent implantation using a high pressure inflation protocol.

PubMed

Vallurupalli, Srikanth; Bahia, Amit; Ruiz-Rodriguez, Ernesto; Ahmed, Zubair; Hakeem, Abdul; Uretsky, Barry F

2016-01-01

High-pressure inflation is the universal standard for stent deployment but a specific protocol for its use is lacking. We developed a standardized "pressure optimization protocol" (POP) using time to inflation pressure stability as an endpoint for determining the required duration of stent inflation. The primary study purpose was to determine the stent inflation time (IT) in a large patient cohort using the standardized inflation protocol, to correlate various patient and lesion characteristics with IT, and ascertain in an in vitro study the time for pressure accommodation within an inflation system. Six hundred fifteen stent implants in 435 patients were studied. Multivariate analysis was performed to determine predictors of longer ITs. In an in vitro study, various stents and balloons were inflated in air to determine the pressure accommodation time of the inflation system. The mean stent IT was 104 ± 41 sec (range 30-380 sec). Stent length was the only predictor of prolonged stent inflation. The "accommodation time" in vitro of the stent inflation system itself was 33 ± 24 sec. The protocol was safe requiring premature inflation termination in <3% of stent implants. No serious adverse events occurred. Achieving stable inflation pressure requires on average over 100 sec and may require several minutes in individual cases. Stent length increases IT. These results suggest that the widespread practice of rapid inflation/deflation may not be sufficient to fully expand the stent and that the use of a pressure stability protocol will allow for safe, predictable, and more complete stent deployment. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Photoacoustic study of the penetration kinetics of nimesulid into human skin

NASA Astrophysics Data System (ADS)

Barja, P. R.; Veloso, D. J. D. V.

2010-03-01

The photoacoustic (PA) effect is observed when modulated (or pulsed) light is absorbed by a sample inside a closed chamber and converted in heat, generating acoustic waves; PA measurements have been employed to evaluate transdermal penetration of topically applied drugs. Phonophoresis is the utilization of ultrasonic (US) energy to enhance absorption of drugs across the epidermal barrier, and its usefulness has been shown by PA measurements. The aim of the present work was to determine the characteristic absorption times of the anti-inflammatory Nimesulid (gel) in human skin, with and without help of therapeutic phonophoresis. After local cleaning, measurements were performed in the forearm of each volunteer before Nimesulid application and for different times after application through massage with the US equipment head; the protocol was repeated for the opposite forearm, but without US emission. Curves of the PA signal level as a function of time were adjusted by a Boltzmann equation, leading to the determination of the characteristic absorption time (about 12 minutes). No significant gain was observed in Nimesulid absorption with the utilization of US radiation, indicating that topic application of Nimesulid does not require the use of phonophoresis, due to the natural fast penetration of the Nimesulid gel.

The Investigation of Laparoscopic Instrument Movement Control and Learning Effect

PubMed Central

Lin, Chiuhsiang Joe

2013-01-01

Laparoscopic surgery avoids large incisions for intra-abdominal operations as required in conventional open surgery. Whereas the patient benefits from laparoscopic techniques, the surgeon encounters new difficulties that were not present during open surgery procedures. However, limited literature has been published in the essential movement characteristics such as magnification, amplitude, and angle. For this reason, the present study aims to investigate the essential movement characteristics of instrument manipulation via Fitts' task and to develop an instrument movement time predicting model. Ten right-handed subjects made discrete Fitts' pointing tasks using a laparoscopic trainer. The experimental results showed that there were significant differences between the three factors in movement time and in throughput. However, no significant differences were observed in the improvement rate for movement time and throughput between these three factors. As expected, the movement time was rather variable and affected markedly by direction to target. The conventional Fitts' law model was extended by incorporating a directional parameter into the model. The extended model was shown to better fit the data than the conventional model. These findings pointed to a design direction for the laparoscopic surgery training program, and the predictive model can be used to establish standards in the training procedure. PMID:23984348

Modern representation of databases on the example of the Catalog of Solar Proton Events in the 23rd Cycle of Solar Activity

NASA Astrophysics Data System (ADS)

Ishkov, V. N.; Zabarinskaya, L. P.; Sergeeva, N. A.

2017-11-01

The development of studies of solar sources and their effects on the state of the near-Earth space required systematization of the corresponding information in the form of databases and catalogs for the entire time of observation of any geoeffective phenomenon that includes, if possible at the time of creation, all of the characteristics of the phenomena themselves and the sources of these phenomena on the Sun. A uniform presentation of information in the form of a series of similar catalogs that cover long time intervals is of particular importance. The large amount of information collected in such catalogs makes it necessary to use modern methods of its organization and presentation that allow a transition between individual parts of the catalog and a quick search for necessary events and their characteristics, which is implemented in the presented Catalog of Solar Proton Events in the 23rd Cycle of Solar Activity of the sequence of catalogs (six separate issues) that cover the period from 1970 to 2009 (20th-23rd solar cycles).

The practice and earnings of preventive medicine physicians.

PubMed

Salive, M E

1992-01-01

A shortage of preventive medicine (PM) physicians exists in the United States. Researchers know little about these physicians' earnings and practice characteristics. The American College of Preventive Medicine (ACPM) mailed a survey to all self-identified PM physicians on the American Medical Association (AMA) Physician Masterfile. A total of 3,771 (54%) responded; respondents' sex and region of residence were typical for PM physicians in general, with a slight excess of older physicians and those reporting board certification. A total of 2,664 (71%) were working full time, with median earnings of $85,000 (mean $90,000). Among full-time physicians, relatively higher earnings were associated with the following characteristics: male sex; age 45 to 64 years; major source of income from clinical, business, or industrial sources, rather than governmental or academic; and PM board certification. Full-time PM physicians earned much less than office-based private practitioners in several primary care specialties in 1989. The gap in earnings between PM specialists in government positions and those in the private sector is also substantial. Both disparities may require creative solutions.

Body mass index affects time to definitive closure after damage control surgery.

PubMed

Haricharan, Ramanath N; Dooley, Adam C; Weinberg, Jordan A; McGwin, Gerald; MacLennan, Paul A; Griffin, Russell L; Rue, Loring W; Reiff, Donald A

2009-06-01

A growing body of literature demonstrates that irrespective of the mechanism of injury, obesity is associated with significantly worse morbidity and mortality after trauma. Among patients requiring damage control laparotomy (DCL), clinical experience suggests that obesity affects time to definitive closure though this association has never been demonstrated quantitatively. All patients at an academic Level I trauma center requiring a DCL between January 2002 and December 2006 (N = 148) were included. Information pertaining to demographic, injury, and clinical characteristics was abstracted from patient medical records. The risk of specific complications including pneumonia, renal failure, and sepsis was compared between normal and overweight/obese patients, as measured by body mass index (BMI). The lengths of intensive care unit (ICU) stay and mechanical ventilation as well as time to abdominal closure were also compared. The risk of pneumonia, sepsis, and renal failure was 2.05-times, 1.77-times, and 2.84-times higher among overweight patients compared with patients with a normal BMI. The risk of pneumonia, sepsis, and renal failure was 2.01-times, 4.24-times, and 1.85-times higher among obese patients compared with those with a normal BMI. Obese patients also had a significantly longer ICU length of stay (28.7 days vs. 15.1 days; p < 0.0001), longer hospitalization (39.3 days vs. 27.0 days; p = 0.008), and time to definitive closure (8.4 days vs. 3.9 days; p = 0.03) compared with patients with a normal BMI. Among patients requiring DCL, those who are overweight or obese have a prolonged time to definitive closure. These patients also experience a significantly longer ICU course and a higher risk of pneumonia.

Loran-C time management

NASA Technical Reports Server (NTRS)

Justice, Charles; Mason, Norm; Taggart, Doug

1994-01-01

As of 1 Oct. 1993, the US Coast Guard (USCG) supports and operates fifteen Loran-C chains. With the introduction of the Global Positioning Systems (GPS) and the termination of the Department of Defense (DOD) overseas need for Loran-C, the USCG will cease operating the three remaining overseas chains by 31 Dec. 1994. Following this date, the USCG Loran-C system will consist of twelve chains. Since 1971, management of time synchronization of the Loran-C system has been conducted under a Memorandum of Agreement between the US Naval Observatory (USNO) and the USCG. The requirement to maintain synchronization with Coordinated Universal Time (UTC) was initially specified as +/- 25 microseconds. This tolerance was rapidly lowered to +/- 2.5 microseconds in 1974. To manage this synchronization requirement, the USCG incorporated administrative practices which kept the USNO appraised of all aspects of the master timing path. This included procedures for responding to timing path failures, timing adjustments, and time steps. Conducting these aspects of time synchronization depended on message traffic between the various master stations and the USNO. To determine clock adjustment the USCG relied upon the USNO's Series 4 and 100 updates so that the characteristics of the master clock could be plotted and controls appropriately applied. In 1987, Public Law 100-223, under the Airport and Airway Improvement Act Amendment, reduced the synchronization tolerance to approximately 100 nanoseconds for chains serving the National Airspace System (NAS). This action caused changes in the previous administrative procedures and techniques. The actions taken by the USCG to meet the requirements of this law are presented.

Compact Si-based asymmetric MZI waveguide on SOI as a thermo-optical switch

NASA Astrophysics Data System (ADS)

Rizal, C. S.; Niraula, B.

2018-03-01

A compact low power consuming asymmetric MZI based optical modulator with fast response time has been proposed on SOI platform. The geometrical and performance characteristics were analyzed in depth and optimized using coupled mode analysis and FDTD simulation tools, respectively. It was tested with and without implementation of thermo-optic (TO) effect. The device showed good frequency modulating characteristics when tested without the implementation of the TO effect. The fabricated device showed quality factor, Q ≈ 10,000, and this value is comparable to the Q of the device simulated with 25% transmission loss, showing FSR of 0.195 nm, FWHM ≈ 0.16 nm, and ER of 13 dB. With TO effect, it showed temperature sensitivity of 0.01 nm/°C and FSR of 0.19 nm. With the heater length of 4.18 mm, the device required 0.26 mW per π shift power with a switching voltage of 0.309 V, response time of 10 μ, and figure-of-merit of 2.6 mW μs. All of these characteristics make this device highly attractive for use in integrated Si photonics network as optical switch and wavelength modulator.

Dosimetry characteristics of HDPE-SWCNT nanocomposite for real time application

NASA Astrophysics Data System (ADS)

Malekie, Shahryar; Ziaie, Farhood; Feizi, Shahzad; Esmaeli, Abdolreza

2016-10-01

In this experimental work, different dosimetric characteristics of high density polyethylene-single wall carbon nanotube nanocomposite were investigated. The nanocomposite samples were prepared with different nanotube contents of 0.22, 0.25, and 0.39 weight percentages which were before, exactly in, and after percolation region of the nanocomposite, respectively. The samples were exposed to 60Co gamma radiation source over the dose rate of 65-214 mGy/min, while the applied bias was 100 V. A linear response achieved for the sample contained 0.25 nanotube wt% verified that the percolation threshold is the optimum point for dosimetric purposes. The current-voltage characteristics curve measured for 0.25 CNT wt% nanocomposite showed that the behavior of this sample was bias polarity independent. Also, the results showed that the response of this nanocomposite was energy-independent. The maximum discrepancy of photocurrent due to angular variation within 0-90° with respect to beam incidence and the reproducibility of the response were measured as 5.4% and 0.8%, respectively. The stability study showed that this material may be suitable for protection dose level control. Therefore, this kind of nanocomposite requiring calibration can be used as a real-time dosimeter.

Applying CBR to machine tool product configuration design oriented to customer requirements

NASA Astrophysics Data System (ADS)

Wang, Pengjia; Gong, Yadong; Xie, Hualong; Liu, Yongxian; Nee, Andrew Yehching

2017-01-01

Product customization is a trend in the current market-oriented manufacturing environment. However, deduction from customer requirements to design results and evaluation of design alternatives are still heavily reliant on the designer's experience and knowledge. To solve the problem of fuzziness and uncertainty of customer requirements in product configuration, an analysis method based on the grey rough model is presented. The customer requirements can be converted into technical characteristics effectively. In addition, an optimization decision model for product planning is established to help the enterprises select the key technical characteristics under the constraints of cost and time to serve the customer to maximal satisfaction. A new case retrieval approach that combines the self-organizing map and fuzzy similarity priority ratio method is proposed in case-based design. The self-organizing map can reduce the retrieval range and increase the retrieval efficiency, and the fuzzy similarity priority ratio method can evaluate the similarity of cases comprehensively. To ensure that the final case has the best overall performance, an evaluation method of similar cases based on grey correlation analysis is proposed to evaluate similar cases to select the most suitable case. Furthermore, a computer-aided system is developed using MATLAB GUI to assist the product configuration design. The actual example and result on an ETC series machine tool product show that the proposed method is effective, rapid and accurate in the process of product configuration. The proposed methodology provides a detailed instruction for the product configuration design oriented to customer requirements.

Study of high-speed civil transports

NASA Technical Reports Server (NTRS)

1989-01-01

A systems study to identify the economic potential for a high-speed commercial transport (HSCT) has considered technology, market characteristics, airport infrastructure, and environmental issues. Market forecasts indicate a need for HSCT service in the 2000/2010 time frame conditioned on economic viability and environmental acceptability. Design requirements focused on a 300 passenger, 3 class service, and 6500 nautical mile range based on the accelerated growth of the Pacific region. Compatibility with existing airports was an assumed requirement. Mach numbers between 2 and 25 were examined in conjunction with the appropriate propulsion systems, fuels, structural materials, and thermal management systems. Aircraft productivity was a key parameter with aircraft worth, in comparison to aircraft price, being the airline-oriented figure of merit. Aircraft screening led to determination that Mach 3.2 (TSJF) would have superior characteristics to Mach 5.0 (LNG) and the recommendation that the next generation high-speed commercial transport aircraft use a kerosene fuel. The sensitivity of aircraft performance and economics to environmental constraints (e.g., sonic boom, engine emissions, and airport/community noise) was identified together with key technologies. In all, current technology is not adequate to produce viable HSCTs for the world marketplace. Technology advancements must be accomplished to meet environmental requirements (these requirements are as yet undetermined for sonic boom and engine emissions). High priority is assigned to aircraft gross weight reduction which benefits both economics and environmental aspects. Specific technology requirements are identified and national economic benefits are projected.

Panel of polymorphic heterologous microsatellite loci to genotype critically endangered Bengal tiger: a pilot study.

PubMed

Mishra, Sudhanshu; Singh, Sujeet Kumar; Munjal, Ashok Kumar; Aspi, Jouni; Goyal, Surendra Prakash

2014-01-03

In India, six landscapes and source populations that are important for long-term conservation of Bengal tigers (Panthera tigris tigris) have been identified. Except for a few studies, nothing is known regarding the genetic structure and extent of gene flow among most of the tiger populations across India as the majority of them are small, fragmented and isolated. Thus, individual-based relationships are required to understand the species ecology and biology for planning effective conservation and genetics-based individual identification has been widely used. But this needs screening and describing characteristics of microsatellite loci from DNA from good-quality sources so that the required number of loci can be selected and the genotyping error rate minimized. In the studies so far conducted on the Bengal tiger, a very small number of loci (n = 35) have been tested with high-quality source of DNA, and information on locus-specific characteristics is lacking. The use of such characteristics has been strongly recommended in the literature to minimize the error rate and by the International Society for Forensic Genetics (ISFG) for forensic purposes. Therefore, we describe for the first time locus-specific genetic and genotyping profile characteristics, crucial for population genetic studies, using high-quality source of DNA of the Bengal tiger. We screened 39 heterologous microsatellite loci (Sumatran tiger, domestic cat, Asiatic lion and snow leopard) in captive individuals (n = 8), of which 21 loci are being reported for the first time in the Bengal tiger, providing an additional choice for selection. The mean relatedness coefficient (R = -0.143) indicates that the selected tigers were unrelated. Thirty-four loci were polymorphic, with the number of alleles ranging from 2 to 7 per locus, and the remaining five loci were monomorphic. Based on the PIC values (> 0.500), and other characteristics, we suggest that 16 loci (3 to 7 alleles) be used for genetic and forensic study purposes. The probabilities of matching genotypes of unrelated individuals (3.692 × 10(-19)) and siblings (4.003 × 10(-6)) are within the values needed for undertaking studies in population genetics, relatedness, sociobiology and forensics.

A Comprehensive Analysis of Multiscale Field-Aligned Currents: Characteristics, Controlling Parameters, and Relationships

NASA Astrophysics Data System (ADS)

McGranaghan, Ryan M.; Mannucci, Anthony J.; Forsyth, Colin

2017-12-01

We explore the characteristics, controlling parameters, and relationships of multiscale field-aligned currents (FACs) using a rigorous, comprehensive, and cross-platform analysis. Our unique approach combines FAC data from the Swarm satellites and the Advanced Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) to create a database of small-scale (˜10-150 km, <1° latitudinal width), mesoscale (˜150-250 km, 1-2° latitudinal width), and large-scale (>250 km) FACs. We examine these data for the repeatable behavior of FACs across scales (i.e., the characteristics), the dependence on the interplanetary magnetic field orientation, and the degree to which each scale "departs" from nominal large-scale specification. We retrieve new information by utilizing magnetic latitude and local time dependence, correlation analyses, and quantification of the departure of smaller from larger scales. We find that (1) FACs characteristics and dependence on controlling parameters do not map between scales in a straight forward manner, (2) relationships between FAC scales exhibit local time dependence, and (3) the dayside high-latitude region is characterized by remarkably distinct FAC behavior when analyzed at different scales, and the locations of distinction correspond to "anomalous" ionosphere-thermosphere behavior. Comparing with nominal large-scale FACs, we find that differences are characterized by a horseshoe shape, maximizing across dayside local times, and that difference magnitudes increase when smaller-scale observed FACs are considered. We suggest that both new physics and increased resolution of models are required to address the multiscale complexities. We include a summary table of our findings to provide a quick reference for differences between multiscale FACs.

VIIRS S-NPP Nighttime DNB Spectral Response Function (SRF): The At-launch Characteristics and How the SRF Changes with Time Due to Tungsten Oxides Chromaticity

NASA Astrophysics Data System (ADS)

Guenther, B.; Lei, N.; Moeller, C.

2015-12-01

The VIIRS Day-Night Band (DNB) is designed with 3 gain stages: Low (LGS), Mid (MGS) and High (HGS) to span bright daytime to moonlit night earth scene signal levels. The published at-launch DNB relative spectral response (RSR) is based upon the LGS spectral measurements, since it was well measured in the pre-launch test program and the LGS can be calibrated by the on-board solar diffuser (MGS and HGS saturate on the SD). The LGS RSR however does not fully represent the spectral characteristics of nighttime DNB data from the MGS and HGS. Nighttime data users who apply the detailed DNB spectral characteristics in their analyses should use modulated RSR appropriate to the MGS and HGS observations. The RSR modulation is due to spectral darkening of the 4 mirrors of the S-NPP VIIRS telescope, which were contaminated with tungsten oxides in fabrication. These tungsten oxides are 'in family' with transition lenses on eyeglasses that darken when exposed to sunlight but do not recover when VIIRS goes into darkness because VIIRS in space is in a vacuum (transition lenses require atmospheric oxygen to recover). The on-going mirror darkening has caused a time-dependent shift in DNB RSR towards blue wavelengths. This presentation will provide access to the correct RSR to use for S-NPP DNB nighttime data over the mission time on-orbit. The changes in characteristics will be described in engineering terms to facilitate clear user understanding of how to handle RSR for nighttime observations over the mission lifetime.

Temporal Characterization of Aircraft Noise Sources

NASA Technical Reports Server (NTRS)

Grosveld, Ferdinand W.; Sullivan, Brenda M.; Rizzi, Stephen A.

2004-01-01

Current aircraft source noise prediction tools yield time-independent frequency spectra as functions of directivity angle. Realistic evaluation and human assessment of aircraft fly-over noise require the temporal characteristics of the noise signature. The purpose of the current study is to analyze empirical data from broadband jet and tonal fan noise sources and to provide the temporal information required for prediction-based synthesis. Noise sources included a one-tenth-scale engine exhaust nozzle and a one-fifth scale scale turbofan engine. A methodology was developed to characterize the low frequency fluctuations employing the Short Time Fourier Transform in a MATLAB computing environment. It was shown that a trade-off is necessary between frequency and time resolution in the acoustic spectrogram. The procedure requires careful evaluation and selection of the data analysis parameters, including the data sampling frequency, Fourier Transform window size, associated time period and frequency resolution, and time period window overlap. Low frequency fluctuations were applied to the synthesis of broadband noise with the resulting records sounding virtually indistinguishable from the measured data in initial subjective evaluations. Amplitude fluctuations of blade passage frequency (BPF) harmonics were successfully characterized for conditions equivalent to take-off and approach. Data demonstrated that the fifth harmonic of the BPF varied more in frequency than the BPF itself and exhibited larger amplitude fluctuations over the duration of the time record. Frequency fluctuations were found to be not perceptible in the current characterization of tonal components.

Application of wavelet multi-resolution analysis for correction of seismic acceleration records

NASA Astrophysics Data System (ADS)

Ansari, Anooshiravan; Noorzad, Assadollah; Zare, Mehdi

2007-12-01

During an earthquake, many stations record the ground motion, but only a few of them could be corrected using conventional high-pass and low-pass filtering methods and the others were identified as highly contaminated by noise and as a result useless. There are two major problems associated with these noisy records. First, since the signal to noise ratio (S/N) is low, it is not possible to discriminate between the original signal and noise either in the frequency domain or in the time domain. Consequently, it is not possible to cancel out noise using conventional filtering methods. The second problem is the non-stationary characteristics of the noise. In other words, in many cases the characteristics of the noise are varied over time and in these situations, it is not possible to apply frequency domain correction schemes. When correcting acceleration signals contaminated with high-level non-stationary noise, there is an important question whether it is possible to estimate the state of the noise in different bands of time and frequency. Wavelet multi-resolution analysis decomposes a signal into different time-frequency components, and besides introducing a suitable criterion for identification of the noise among each component, also provides the required mathematical tool for correction of highly noisy acceleration records. In this paper, the characteristics of the wavelet de-noising procedures are examined through the correction of selected real and synthetic acceleration time histories. It is concluded that this method provides a very flexible and efficient tool for the correction of very noisy and non-stationary records of ground acceleration. In addition, a two-step correction scheme is proposed for long period correction of the acceleration records. This method has the advantage of stable results in displacement time history and response spectrum.

The use of AntiMisting Kerosene (AMK) in turbojet engines

NASA Technical Reports Server (NTRS)

Schmidt, H. W.

1981-01-01

The effect of antimisting kerosene (AMK) flow characteristics on fan jet engines and the impact of degradation requirements on the fuel system was evaluated. It was determined from the present program that AMK fuel cannot be used without predegradation, although some degradation occurs throughout the fuel feed system, expecially in the fuel pumps. There is a tendency toward FM-9 AMK additive agglomeration and gel formation when the liquid flows at a critical velocity through very small passages. The data indicate this phenomenon to be a function of the degree of degradation, the passage size, the differential pressure, the fluid temperature, and the accumulated flow time. Additionally, test results indicate that the long term cumulative effects of this phenomenon may require more degradation than the theoretical requirement determined from short term tests.

Transition paths in single-molecule force spectroscopy

NASA Astrophysics Data System (ADS)

Cossio, Pilar; Hummer, Gerhard; Szabo, Attila

2018-03-01

In a typical single-molecule force spectroscopy experiment, the ends of the molecule of interest are connected by long polymer linkers to a pair of mesoscopic beads trapped in the focus of two laser beams. At constant force load, the total extension, i.e., the end-to-end distance of the molecule plus linkers, is measured as a function of time. In the simplest systems, the measured extension fluctuates about two values characteristic of folded and unfolded states, with occasional transitions between them. We have recently shown that molecular (un)folding rates can be recovered from such trajectories, with a small linker correction, as long as the characteristic time of the bead fluctuations is shorter than the residence time in the unfolded (folded) state. Here, we show that accurate measurements of the molecular transition path times require an even faster apparatus response. Transition paths, the trajectory segments in which the molecule (un)folds, are properly resolved only if the beads fluctuate more rapidly than the end-to-end distance of the molecule. Therefore, over a wide regime, the measured rates may be meaningful but not the transition path times. Analytic expressions for the measured mean transition path times are obtained for systems diffusing anisotropically on a two-dimensional free energy surface. The transition path times depend on the properties both of the molecule and of the pulling device.

Describing Directional Cell Migration with a Characteristic Directionality Time

PubMed Central

Loosley, Alex J.; O’Brien, Xian M.; Reichner, Jonathan S.; Tang, Jay X.

2015-01-01

Many cell types can bias their direction of locomotion by coupling to external cues. Characteristics such as how fast a cell migrates and the directedness of its migration path can be quantified to provide metrics that determine which biochemical and biomechanical factors affect directional cell migration, and by how much. To be useful, these metrics must be reproducible from one experimental setting to another. However, most are not reproducible because their numerical values depend on technical parameters like sampling interval and measurement error. To address the need for a reproducible metric, we analytically derive a metric called directionality time, the minimum observation time required to identify motion as directionally biased. We show that the corresponding fit function is applicable to a variety of ergodic, directionally biased motions. A motion is ergodic when the underlying dynamical properties such as speed or directional bias do not change over time. Measuring the directionality of nonergodic motion is less straightforward but we also show how this class of motion can be analyzed. Simulations are used to show the robustness of directionality time measurements and its decoupling from measurement errors. As a practical example, we demonstrate the measurement of directionality time, step-by-step, on noisy, nonergodic trajectories of chemotactic neutrophils. Because of its inherent generality, directionality time ought to be useful for characterizing a broad range of motions including intracellular transport, cell motility, and animal migration. PMID:25992908

Characterising an aluminium oxide dosimetry system.

PubMed

Conheady, Clement F; Gagliardi, Frank M; Ackerly, Trevor

2015-09-01

In vivo dosimetry is recommended as a defence-in-depth strategy in radiotherapy treatments and is currently employed by clinics around the world. The characteristics of a new optically stimulated luminescence dosimetry system were investigated for the purpose of replacing an aging thermoluminescence dosimetry system for in vivo dosimetry. The stability of the system was not sufficient to satisfy commissioning requirements and therefore it has not been released into clinical service at this time.

Creep and Fracture Characteristics of Materials and Structures at Elevated Temperatures

DTIC Science & Technology

1988-05-01

evident until the crack velocity and length have grown appreciably. At the larger da/dt values, many of the assumptions required for the application of the...to difficulties in the practical application of the energy balance concept, new approaches had to be found to characterize the material behavior...fracture mechanics (LEFM). Irwin [8] broadened the applicability of LEFM by introducing a modified stress intensity factor KI. At the same time Wells [9

Improving the Selection, Classification, and Utilization of Army Enlisted Personnel: Final Report on Project A

DTIC Science & Technology

1991-08-01

being used in both current and long-range research programs that are expected to make the Army more effective in matching the requirements for first- and... make substantial improvements to the existing selection and classifi- cation system. xi IMPROVING THE SELECTION, CLASSIFICATION, AND UTILIZATION OF...basis for new methods of allocating personnel, and making near-real-time decisions on the best match between characteristics of an individual enlistee

Music Tune Restoration Based on a Mother Wavelet Construction

NASA Astrophysics Data System (ADS)

Fadeev, A. S.; Konovalov, V. I.; Butakova, T. I.; Sobetsky, A. V.

2017-01-01

It is offered to use the mother wavelet function obtained from the local part of an analyzed music signal. Requirements for the constructed function are proposed and the implementation technique and its properties are described. The suggested approach allows construction of mother wavelet families with specified identifying properties. Consequently, this makes possible to identify the basic signal variations of complex music signals including local time-frequency characteristics of the basic one.

Evaluation of Cement, Lime, and Asphalt Amended Municipal Solid Waste Incinerator Residues

DTIC Science & Technology

1989-09-01

the lime column over time ( Atlas & Bartha , 1987). Certainly, a more extensive evaluation of the lime amended residue’s microbial activity is required...4.02 ASTM D 1559 (1988) Annual Book of ASTM Standards: Road & Paving Materials; Traveled Surface Characteristics, Sec 4, Vol 4.03 Atlas , R. & R. Bartha ...1987) Microbial Ecology : Fundamentals & Applications, Benjamin-Cummings, Menlo, CA Barrow N., J. Bowden, A. Posner, & J. Quirk (1981) Describing the

Nano-fabricated size exclusion chromatograph

NASA Technical Reports Server (NTRS)

Svehla, D.; Feldman, S.; Feldman, J.; Grunthaner, F.; Shakkottai, P.; Castillo, L. del; White, V.

2002-01-01

This paper describes the development of a nano-fabricated size exclusion chromatograph (nSEC) based on the principle that molecules traveling through amicrocolumn containing nano-fabricated features will have characteristic elution times that directly correlate to molecular weight. Compared to conventional size exclusion chromatography, the nSEC offers greater control over the size exclusion process; mass fabrication; integration of the separation column with associated valves, pumps, and detectors; and dramatic reductions in instrument mass and power requirements.

Specialized data analysis for the Space Shuttle Main Engine and diagnostic evaluation of advanced propulsion system components

NASA Technical Reports Server (NTRS)

1993-01-01

The Marshall Space Flight Center is responsible for the development and management of advanced launch vehicle propulsion systems, including the Space Shuttle Main Engine (SSME), which is presently operational, and the Space Transportation Main Engine (STME) under development. The SSME's provide high performance within stringent constraints on size, weight, and reliability. Based on operational experience, continuous design improvement is in progress to enhance system durability and reliability. Specialized data analysis and interpretation is required in support of SSME and advanced propulsion system diagnostic evaluations. Comprehensive evaluation of the dynamic measurements obtained from test and flight operations is necessary to provide timely assessment of the vibrational characteristics indicating the operational status of turbomachinery and other critical engine components. Efficient performance of this effort is critical due to the significant impact of dynamic evaluation results on ground test and launch schedules, and requires direct familiarity with SSME and derivative systems, test data acquisition, and diagnostic software. Detailed analysis and evaluation of dynamic measurements obtained during SSME and advanced system ground test and flight operations was performed including analytical/statistical assessment of component dynamic behavior, and the development and implementation of analytical/statistical models to efficiently define nominal component dynamic characteristics, detect anomalous behavior, and assess machinery operational condition. In addition, the SSME and J-2 data will be applied to develop vibroacoustic environments for advanced propulsion system components, as required. This study will provide timely assessment of engine component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. This contract will be performed through accomplishment of negotiated task orders.

Assessing students' readiness towards e-learning

NASA Astrophysics Data System (ADS)

Rahim, Nasrudin Md; Yusoff, Siti Hawa Mohd; Latif, Shahida Abd

2014-07-01

The usage of e-Learning methodology has become a new attraction for potential students as shown by some higher learning institutions in Malaysia. As such, Universiti Selangor (Unisel) should be ready to embark on e-Learning teaching and learning in the near future. The purpose of the study is to gauge the readiness of Unisel's students in e-Learning environment. A sample of 110 students was chosen to participate in this study which was conducted in January 2013. This sample consisted of students from various levels of study that are foundation, diploma and degree program. Using a structured questionnaire, respondents were assessed on their basic Internet skills, access to technology required for e-Learning and their attitude towards characteristics of successful e-Learning student based on study habits, abilities, motivation and time management behaviour. The result showed that respondents did have access to technology that are required for e-Learning environment, and respondents were knowledgeable regarding the basic Internet skills. The finding also showed that respondents' attitude did meet all characteristics of successful e-Learning student. Further analysis showed that there is no significant relationshipeither among gender, level of study or faculty with those characteristics. As a conclusion, the study shows that current Unisel's students are ready to participate in e-Learning environment if the institution decided to embark on e-Learning methodology.

Attitudes towards requiring ignition interlocks for all driving while intoxicated offenders: findings from the 2010 HealthStyles Survey

PubMed Central

Shults, Ruth A; Bergen, Gwen

2017-01-01

Ignition interlocks are effective in reducing recidivism among driving while intoxicated (DWI) offenders while installed on their vehicles. However, the devices are not widely used in the USA. This survey gauged public support for requiring ignition interlocks for all convicted DWI offenders including first-time offenders. 69% of respondents supported such a policy. Support was lowest (38%) among persons who reported drinking and driving in the past 30 days. Multivariate regression analysis indicated that support varied little by region, community size or most measured individual characteristics. Persons who did not drink and drive were 80% more likely to support the requirement than those who drink and drive. These findings suggest that laws requiring ignition interlocks for all convicted DWI offenders may face the most opposition in communities with high levels of drinking and driving. PMID:22773020

Low thermal budget annealing technique for high performance amorphous In-Ga-ZnO thin film transistors

NASA Astrophysics Data System (ADS)

Shin, Joong-Won; Cho, Won-Ju

2017-07-01

In this paper, we investigate a low thermal budget post-deposition-annealing (PDA) process for amorphous In-Ga-ZnO (a-IGZO) oxide semiconductor thin-film-transistors (TFTs). To evaluate the electrical characteristics and reliability of the TFTs after the PDA process, microwave annealing (MWA) and rapid thermal annealing (RTA) methods were applied, and the results were compared with those of the conventional annealing (CTA) method. The a-IGZO TFTs fabricated with as-deposited films exhibited poor electrical characteristics; however, their characteristics were improved by the proposed PDA process. The CTA-treated TFTs had excellent electrical properties and stability, but the CTA method required high temperatures and long processing times. In contrast, the fabricated RTA-treated TFTs benefited from the lower thermal budget due to the short process time; however, they exhibited poor stability. The MWA method uses a low temperature (100 °C) and short annealing time (2 min) because microwaves transfer energy directly to the substrate, and this method effectively removed the defects in the a-IGZO TFTs. Consequently, they had a higher mobility, higher on-off current ratio, lower hysteresis voltage, lower subthreshold swing, and higher interface trap density than TFTs treated with CTA or RTA, and exhibited excellent stability. Based on these results, low thermal budget MWA is a promising technology for use on various substrates in next generation displays.

Chemical Characteristics of Particulate Matter from Vehicle emission using High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS)

NASA Astrophysics Data System (ADS)

Park, T.; Lee, T.; Kang, S.; Lee, J.; Kim, J.; Son, J.; Yoo, H. M.; Kim, K.; Park, G.

2015-12-01

Car emissions are major contributors of particulate matter (PM) in the urban environment and effects of air pollution, climate change, and human activities. By increasing of interest in research of car emission for assessment of the PM control, it became require to understand the chemical composition and characteristics of the car exhaust gases and particulate matter. To understand car emission characteristics of PM, we will study PM of car emissions for five driving modes (National Institute Environmental Research (NIER)-5, NIER-9, NIER-12, NIER-14) and three fixed speed driving modes (30km/h, 70km/h, 110km/h) using different fuel types (gasoline, diesel, and LPG) at Transportation Pollution Research Center (TPRC) of NIER in Incheon, South Korea. PM chemical composition of car emission was measured for concentrations of organics, sulfate, nitrate, ammonium, PAHs, oxidation states and size distribution using an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and engine exhaust particle sizer (EEPS) on real-time. In the study, organics concentration was dominated for all cases of driving modes and the concentration of organics was increased in 110km/h fixed speed mode for gasoline and diesel. The presentation will provide an overview of the chemical composition of PM in the car emissions.

Selected plantar pressure characteristics associated with the skating performance of national in-line speed skaters.

PubMed

Wu, Wen-Lan; Hsu, Hsiu-Tao; Chu, I-Hua; Tsai, Feng-Hua; Liang, Jing-Min

2017-06-01

In order to help coaches analyse the techniques of professional in-line speed skaters for making the required fine adjustments and corrections in their push-off work, this study analysed the specific plantar pressure characteristics during a 300-m time-trial test. Fourteen elite in-line speed skaters from the national team were recruited in this study. The total completion time of the 300-m time-trial test, duration of each skating phase, and plantar pressure distribution were measured. The correlation between plantar pressure distribution and skating performance was assessed using Pearson correlation analyses. The results showed that the contact time of the total foot and force-time integral (FTI) in the medial forefoot were significantly correlated with the duration of the start phase, and the FTIs in the medial forefoot of the gliding (left) leg and lateral forefoot of the pushing (right) leg were significantly correlated with the duration of the turning phase. The maximum force in the medial heel, medial forefoot, and median forefoot and the FTI in the medial heel and medial forefoot were significantly correlated with the duration of the linear acceleration phase. The results suggest that a correct plantar loading area and push-off strategy can enhance the skating performance.

Energetic particle penetrations into the inner magnetosphere

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

Ejiri, M.; Hoffman, R.A.; Smith, P.H.

Data from Explorer 45 (S/sup 3/- A) instruments have revealed characteristics of magnetospheric storm or substorm time energetic particle enhancements in the inner magnetosphere (L< or approx. =5). The properties of the ion 'nose' structure in the dusk hemisphere are examined in detail. A statistical study of the local time dependence of noses places the highest probability of occurrence around 2000 MLT, but hey can be observed even near the noon meridian. It also appears that most noses are not isolated events but will appear on successive passes. A geoelectric field enhancement corresponding to a minimum value of AE ofmore » about 205 ..gamma.. seems to be required to convect the particles within the apogee of Explorer 45. The dynamical behavior of the nose characteristics observed along successive orbits is then explained quantitatively by the time-dependent convection theory in a Volland-Stern type geoelectric field (..gamma..=2). These calculations of adiabatic charged particle motions are also applied to expalin the energy spectra and dispersion in penetration distances for both electrons and ions observed in the postmidnight to morning hours. Finally, useful descriptions are given of the dispersion properties of particles penetrating the inter magnetosphere at all local times as a function of time after a sudden enhancement of the geoelectric field.« less

Effect of spinal needle characteristics on measurement of spinal canal opening pressure.

PubMed

Bellamkonda, Venkatesh R; Wright, Thomas C; Lohse, Christine M; Keaveny, Virginia R; Funk, Eric C; Olson, Michael D; Laack, Torrey A

2017-05-01

A wide variety of spinal needles are used in clinical practice. Little is currently known regarding the impact of needle length, gauge, and tip type on the needle's ability to measure spinal canal opening pressure. This study aimed to investigate the relationship between these factors and the opening-pressure measurement or time to obtain an opening pressure. Thirteen distinct spinal needles, chosen to isolate the effects of length, gauge, and needle-point type, were prospectively tested on a lumbar puncture simulator. The key outcomes were the opening-pressure measurement and the time required to obtain that measure. Pressures were recorded at 10-s intervals until 3 consecutive, identical readings were observed. Time to measure opening pressure increased with increasing spinal needle length, increasing gauge, and the Quincke-type (cutting) point (P<0.001 for all). The time to measurement ranged from 30s to 530s, yet all needle types were able to obtain a consistent opening pressure measure. Although opening pressure estimates are unlikely to vary markedly by needle type, the time required to obtain the measurement increased with increasing needle length and gauge and with Quincke-type needles. Copyright © 2017 Elsevier Inc. All rights reserved.

Giving cosmic redshift drift a whirl

NASA Astrophysics Data System (ADS)

Kim, Alex G.; Linder, Eric V.; Edelstein, Jerry; Erskine, David

2015-03-01

Redshift drift provides a direct kinematic measurement of cosmic acceleration but it occurs with a characteristic time scale of a Hubble time. Thus redshift observations with a challenging precision of 10-9 require a 10 year time span to obtain a signal-to-noise of 1. We discuss theoretical and experimental approaches to address this challenge, potentially requiring less observer time and having greater immunity to common systematics. On the theoretical side we explore allowing the universe, rather than the observer, to provide long time spans; speculative methods include radial baryon acoustic oscillations, cosmic pulsars, and strongly lensed quasars. On the experimental side, we explore beating down the redshift precision using differential interferometric techniques, including externally dispersed interferometers and spatial heterodyne spectroscopy. Low-redshift emission line galaxies are identified as having high cosmology leverage and systematics control, with an 8 h exposure on a 10-m telescope (1000 h of exposure on a 40-m telescope) potentially capable of measuring the redshift of a galaxy to a precision of 10-8 (few ×10-10). Low-redshift redshift drift also has very strong complementarity with cosmic microwave background measurements, with the combination achieving a dark energy figure of merit of nearly 300 (1400) for 5% (1%) precision on drift.

Within-field variability of plant and soil parameters

NASA Technical Reports Server (NTRS)

Ulaby, F. T. (Principal Investigator); Brisco, B.; Dobson, C.

1981-01-01

The variability of ground truth data collected for vegetation experiments was investigated. Two fields of wheat and one field of corn were sampled on two different dates. The variability of crop and soil parameters within a field, between two fields of the same type, and within a field over time were compared statistically. The number of samples from each test site required in order to be able to determine with confidence the mean and standard deviations for a given variable was determined. Eight samples were found to be adequate for plant height determinations, while twenty samples were required for plant moisture and soil moisture characterization. Eighteen samples were necessary for detecting within field variability over time and for between field variability for the same crop. The necessary sample sites vary according to the physiological growth stage of the crop and recent weather events that affect the moisture and/or height characteristics of the field in question.

Operating characteristics of a hydrogen-argon plasma torch for supersonic combustion applications

NASA Technical Reports Server (NTRS)

Barbi, E.; Mahan, J. R.; O'Brien, W. F.; Wagner, T. C.

1989-01-01

The residence time of the combustible mixture in the combustion chamber of a scramjet engine is much less than the time normally required for complete combustion. Hydrogen and hydrocarbon fuels require an ignition source under conditions typically found in a scramjet combustor. Analytical studies indicate that the presence of hydrogen atoms should greatly reduce the ignition delay in this environment. Because hydrogen plasmas are prolific sources of hydrogen atoms, a low-power, uncooled hydrogen plasma torch has been built and tested to evaluate its potential as a possible flame holder for supersonic combustion. The torch was found to be unstable when operated on pure hydrogen; however, stable operation could be obtained by using argon as a body gas and mixing in the desired amount of hydrogen. The stability limits of the torch are delineated and its electrical and thermal behavior documented. An average torch thermal efficiency of around 88 percent is demonstrated.

Automatic measurements and computations for radiochemical analyses

USGS Publications Warehouse

Rosholt, J.N.; Dooley, J.R.

1960-01-01

In natural radioactive sources the most important radioactive daughter products useful for geochemical studies are protactinium-231, the alpha-emitting thorium isotopes, and the radium isotopes. To resolve the abundances of these thorium and radium isotopes by their characteristic decay and growth patterns, a large number of repeated alpha activity measurements on the two chemically separated elements were made over extended periods of time. Alpha scintillation counting with automatic measurements and sample changing is used to obtain the basic count data. Generation of the required theoretical decay and growth functions, varying with time, and the least squares solution of the overdetermined simultaneous count rate equations are done with a digital computer. Examples of the complex count rate equations which may be solved and results of a natural sample containing four ??-emitting isotopes of thorium are illustrated. These methods facilitate the determination of the radioactive sources on the large scale required for many geochemical investigations.

Research on Matching Method of Power Supply Parameters for Dual Energy Source Electric Vehicles

NASA Astrophysics Data System (ADS)

Jiang, Q.; Luo, M. J.; Zhang, S. K.; Liao, M. W.

2018-03-01

A new type of power source is proposed, which is based on the traffic signal matching method of the dual energy source power supply composed of the batteries and the supercapacitors. First, analyzing the power characteristics is required to meet the excellent dynamic characteristics of EV, studying the energy characteristics is required to meet the mileage requirements and researching the physical boundary characteristics is required to meet the physical conditions of the power supply. Secondly, the parameter matching design with the highest energy efficiency is adopted to select the optimal parameter group with the method of matching deviation. Finally, the simulation analysis of the vehicle is carried out in MATLABSimulink, The mileage and energy efficiency of dual energy sources are analyzed in different parameter models, and the rationality of the matching method is verified.

Effect of gas release in hot molding on flexural strength of composite friction brake

NASA Astrophysics Data System (ADS)

Rusdja, Andy Permana; Surojo, Eko; Muhayat, Nurul; Raharjo, Wijang Wisnu

2018-02-01

Composite friction brake is a vital part of braking system which serves to reduce the speed of vehicle. To fulfill the requirement of brake performance, composite friction brake must have friction and mechanical characteristic as required. The characteristics of composite friction brake are affected by brake material formulation and manufacturing parameter. In the beginning of hot molding, intermittent hot pressing was carried out to release the gases that consist of ammonia gas and water vapor. In composite friction brake, phenolic resin containing hexamethylenetetramine (HMTA) is often used as a binder. During hot molding, the reaction of phenolic resin and HMTA forms ammonia gas. Hot molding also generates water vapor because raw materials absorb moisture from environment when they are placed in storage. The gas release in hot molding is supposed affecting mechanical properties because it avoid entrapped gas in composite, so that this research investigated effect of gas release on flexural strength. Manufacturing of composite specimen was carried out as follow: mixing of raw materials, cold molding, and hot molding. In this research, duration of intermittent hot pressing and number of gas release were varied. The flexural strength of specimen was measured using three point bending test. The results showed that flexural strength specimens that were manufactured without gas release, using 4 times gas release with intermittent hot pressing for 5 and 10 seconds were not remarkably different. Conversely, hot molding using 4 times gas release with intermittent hot pressing for 15 seconds decreased flexural strength of composite. Hot molding using 2, 4, and 8 times gas release with intermittent hot pressing for 10 seconds also had no effect on increasing flexural strength. Increasing of flexural strength of composite was obtained only by using 6 times gas release with intermittent hot pressing for 10 seconds.

The Characteristics and Limits of Rapid Visual Categorization

PubMed Central

Fabre-Thorpe, Michèle

2011-01-01

Visual categorization appears both effortless and virtually instantaneous. The study by Thorpe et al. (1996) was the first to estimate the processing time necessary to perform fast visual categorization of animals in briefly flashed (20 ms) natural photographs. They observed a large differential EEG activity between target and distracter correct trials that developed from 150 ms after stimulus onset, a value that was later shown to be even shorter in monkeys! With such strong processing time constraints, it was difficult to escape the conclusion that rapid visual categorization was relying on massively parallel, essentially feed-forward processing of visual information. Since 1996, we have conducted a large number of studies to determine the characteristics and limits of fast visual categorization. The present chapter will review some of the main results obtained. I will argue that rapid object categorizations in natural scenes can be done without focused attention and are most likely based on coarse and unconscious visual representations activated with the first available (magnocellular) visual information. Fast visual processing proved efficient for the categorization of large superordinate object or scene categories, but shows its limits when more detailed basic representations are required. The representations for basic objects (dogs, cars) or scenes (mountain or sea landscapes) need additional processing time to be activated. This finding is at odds with the widely accepted idea that such basic representations are at the entry level of the system. Interestingly, focused attention is still not required to perform these time consuming basic categorizations. Finally we will show that object and context processing can interact very early in an ascending wave of visual information processing. We will discuss how such data could result from our experience with a highly structured and predictable surrounding world that shaped neuronal visual selectivity. PMID:22007180

Time-dependent friction and the mechanics of stick-slip

USGS Publications Warehouse

Dieterich, J.H.

1978-01-01

Time-dependent increase of static friction is characteristic of rock friction undera variety of experimental circumstances. Data presented here show an analogous velocity-dependent effect. A theor of friction is proposed that establishes a common basis for static and sliding friction. Creep at points of contact causes increases in friction that are proportional to the logarithm of the time that the population of points of contact exist. For static friction that time is the time of stationary contact. For sliding friction the time of contact is determined by the critical displacement required to change the population of contacts and the slip velocity. An analysis of a one-dimensional spring and slider system shows that experimental observations establishing the transition from stable sliding to stick-slip to be a function of normal stress, stiffness and surface finish are a consequence of time-dependent friction. ?? 1978 Birkha??user Verlag.

Medial-Vowel Writing Difficulty in Korean Syllabic Writing: A Characteristic Sign of Alzheimer's Disease

PubMed Central

Yoon, Ji Hye; Jeong, Yong

2018-01-01

Background and Purpose Korean-speaking patients with a brain injury may show agraphia that differs from that of English-speaking patients due to the unique features of Hangul syllabic writing. Each grapheme in Hangul must be arranged from left to right and/or top to bottom within a square space to form a syllable, which requires greater visuospatial abilities than when writing the letters constituting an alphabetic writing system. Among the Hangul grapheme positions within a syllable, the position of a vowel is important because it determines the writing direction and the whole configuration in Korean syllabic writing. Due to the visuospatial characteristics of the Hangul vowel, individuals with early-onset Alzheimer's disease (EOAD) may experiences differences between the difficulties of writing Hangul vowels and consonants due to prominent visuospatial dysfunctions caused by parietal lesions. Methods Eighteen patients with EOAD and 18 age-and-education-matched healthy adults participated in this study. The participants were requested to listen to and write 30 monosyllabic characters that consisted of an initial consonant, medial vowel, and final consonant with a one-to-one phoneme-to-grapheme correspondence. We measured the writing time for each grapheme, the pause time between writing the initial consonant and the medial vowel (P1), and the pause time between writing the medial vowel and the final consonant (P2). Results All grapheme writing and pause times were significantly longer in the EOAD group than in the controls. P1 was also significantly longer than P2 in the EOAD group. Conclusions Patients with EOAD might require a higher judgment ability and longer processing time for determining the visuospatial grapheme position before writing medial vowels. This finding suggests that a longer pause time before writing medial vowels is an early marker of visuospatial dysfunction in patients with EOAD. PMID:29504296

Medial-Vowel Writing Difficulty in Korean Syllabic Writing: A Characteristic Sign of Alzheimer's Disease.

PubMed

Yoon, Ji Hye; Jeong, Yong; Na, Duk L

2018-04-01

Korean-speaking patients with a brain injury may show agraphia that differs from that of English-speaking patients due to the unique features of Hangul syllabic writing. Each grapheme in Hangul must be arranged from left to right and/or top to bottom within a square space to form a syllable, which requires greater visuospatial abilities than when writing the letters constituting an alphabetic writing system. Among the Hangul grapheme positions within a syllable, the position of a vowel is important because it determines the writing direction and the whole configuration in Korean syllabic writing. Due to the visuospatial characteristics of the Hangul vowel, individuals with early-onset Alzheimer's disease (EOAD) may experiences differences between the difficulties of writing Hangul vowels and consonants due to prominent visuospatial dysfunctions caused by parietal lesions. Eighteen patients with EOAD and 18 age-and-education-matched healthy adults participated in this study. The participants were requested to listen to and write 30 monosyllabic characters that consisted of an initial consonant, medial vowel, and final consonant with a one-to-one phoneme-to-grapheme correspondence. We measured the writing time for each grapheme, the pause time between writing the initial consonant and the medial vowel (P1), and the pause time between writing the medial vowel and the final consonant (P2). All grapheme writing and pause times were significantly longer in the EOAD group than in the controls. P1 was also significantly longer than P2 in the EOAD group. Patients with EOAD might require a higher judgment ability and longer processing time for determining the visuospatial grapheme position before writing medial vowels. This finding suggests that a longer pause time before writing medial vowels is an early marker of visuospatial dysfunction in patients with EOAD. Copyright © 2018 Korean Neurological Association.

Operating characteristics of HTS power supply for and improving temporal stability of coated conductor magnet in liquid helium

NASA Astrophysics Data System (ADS)

Park, D. K.; Kim, Y. J.; Yang, S. E.; Kwon, N. Y.; Lee, H. G.; Ko, T. K.

2009-10-01

High temperature superconducting (HTS) magnets have been studied for insert coils of high field nuclear magnetic resonance (NMR) magnets but the temporal stability required for NMR is hard to achieve due to low index value and high joint resistance. In this research, the HTS power supply with magnets using coated conductor (CC) was investigated and tested in helium cryogenic system. All joints were conducted by soldering after etching stabilizer of the CC to minimize joint resistance. The pumping rate was determined by current amplitude and timing sequential control of heaters and the electromagnet. Operating characteristics were analyzed to enhance charging efficiency and the feasibility of temporally stable CC magnet during persistent mode was studied.

On the choice of orbits for an altimetric satellite to study ocean circulation and tides

NASA Technical Reports Server (NTRS)

Parke, Michael E.; Stewart, Robert H.; Farless, David L.; Cartwright, David E.

1987-01-01

The choice of an orbit for satellite altimetric studies of the ocean's circulation and tides requires an understanding of the orbital characteristics that influence the accuracy of the satellite's measurements of sea level and the temporal and spatial distribution of the measurements. The orbital characteristics that influence accurate calculations of the satellite's position as a function of time are examined, and the pattern of ground tracks laid down on the ocean's surface as a function of the satellite's altitude and inclination is studied. The results are used to examine the aliases in the measurements of surface geostrophic currents and tides. Finally, these considerations are used to specify possible orbits that may be useful for the upcoming Topex/Poseidon mission.

Characteristics of General Education Reading Interventions Implemented in Elementary Schools for Students with Reading Difficulties.

PubMed

Wanzek, Jeanne; Cavanaugh, Christie

2012-05-01

The implementation of response to intervention requires interventions for struggling students be provided through general education prior to referral for special education. We surveyed elementary teachers (K-3) in one state to examine the characteristics of the supplemental reading interventions that their students receive through general education. Findings reveal differences between grade levels in the amount of time interventions are provided to students, the providers of the intervention, and the material selection for the interventions. No differences between grade levels were noted in the frequency of intervention or instructional group sizes. Three-quarters of the teachers reported providing the supplemental interventions to students in their class. The findings provide insight into the resources utilized by schools to implement supplemental interventions.

Design of laser diode driver with constant current and temperature control system

NASA Astrophysics Data System (ADS)

Wang, Ming-cai; Yang, Kai-yong; Wang, Zhi-guo; Fan, Zhen-fang

2017-10-01

A laser Diode (LD) driver with constant current and temperature control system is designed according to the LD working characteristics. We deeply researched the protection circuit and temperature control circuit based on thermos-electric cooler(TEC) cooling circuit and PID algorithm. The driver could realize constant current output and achieve stable temperature control of LD. Real-time feedback control method was adopted in the temperature control system to make LD work on its best temperature point. The output power variety and output wavelength shift of LD caused by current and temperature instability were decreased. Furthermore, the driving current and working temperature is adjustable according to specific requirements. The experiment result showed that the developed LD driver meets the characteristics of LD.

International ultraviolet explorer solar array power degradation

NASA Technical Reports Server (NTRS)

Day, J. H., Jr.

1983-01-01

The characteristic electrical performance of each International Ultraviolet Explorer (IUE) solar array panel is evaluated as a function of several prevailing variables (namely, solar illumination, array temperature and solar cell radiation damage). Based on degradation in the current-voltage characteristics of the array due to solar cell damage accumulated over time by space charged particle radiations, the available IUE solar array power is determined for life goals up to 10 years. Best and worst case calculations are normalized to actual IUE flight data (available solar array power versus observatory position) to accurately predict the future IUE solar array output. It is shown that the IUE solar array can continue to produce more power than is required at most observatory positions for at least 5 more years.

Data processing requirements for the Earth Resources Technology Satellite (ERTS)

NASA Technical Reports Server (NTRS)

Sos, J. Y.

1972-01-01

Some of the data handling considerations that led to the formulation of the data processing requirements for the ERTS system are discussed. The significant parameters that influence these requirements are: (1) payload characteristics, (2) spacecraft characteristics such as orbit, attitude and attitude rates, (3) payload coverage, and (4) product types and quantities. Items 3 and 4 have had the most significant influence on the generation of the requirements.

Formulation of detailed consumables management models for the development (preoperational) period of advanced space transportation system. Volume 2: Consumables data base workbook

NASA Technical Reports Server (NTRS)

Zamora, M. A.

1976-01-01

The consumables characteristic data associated with the performance of the mission activities required by the mission planning processor are defined to calculate the consumables requirements. The activity data is defined in terms of discrete time periods having a distinct rate for each consumable required to support the performance of a given operation. The data is structured in a series of consumable data worksheets for each activity that includes a profile of its operations and the rate of each consumable required to support the given activity. The data worksheets provide for the uniform specification of consumables data, allows for the ready identification of the consumables affected by a given activity, and facilitates the updating process. An activity and the data that must be included in the data worksheets are defined and an example of its use and application the consumables data requirements for the performance of the EVA are presented.

Spectral analysis for GNSS coordinate time series using chirp Fourier transform

NASA Astrophysics Data System (ADS)

Feng, Shengtao; Bo, Wanju; Ma, Qingzun; Wang, Zifan

2017-12-01

Spectral analysis for global navigation satellite system (GNSS) coordinate time series provides a principal tool to understand the intrinsic mechanism that affects tectonic movements. Spectral analysis methods such as the fast Fourier transform, Lomb-Scargle spectrum, evolutionary power spectrum, wavelet power spectrum, etc. are used to find periodic characteristics in time series. Among spectral analysis methods, the chirp Fourier transform (CFT) with less stringent requirements is tested with synthetic and actual GNSS coordinate time series, which proves the accuracy and efficiency of the method. With the length of series only limited to even numbers, CFT provides a convenient tool for windowed spectral analysis. The results of ideal synthetic data prove CFT accurate and efficient, while the results of actual data show that CFT is usable to derive periodic information from GNSS coordinate time series.

A Distributed Synchronization and Timing System on the EAST Tokamak

NASA Astrophysics Data System (ADS)

Luo, Jiarong; Wu, Yichun; Shu, Yantai

2008-08-01

A key requirement for the EAST distributed control system (EASTDCS) is time synchronization to an accuracy of <1 mus. In 2006 a Distributed Synchronization and Timing System (DSTS) was set up, which is based on the ATmega128 AVR microcontroller and the Nut/OS embedded Real Time Operating System (RTOS). The DSTS provides the control and the data acquisition systems with reference clocks (0.01 Hz 10 MHz) and delayed trigger times ( 1 mus 4294 s). These are produced by a Core Module Unit (CMU) connected by optical fibres to many Local Synchronized Node Units (LSNU). The fibres provide immunity from electrical noise and are of equal length to match clock and trigger delays between systems. This paper describes the architecture of the DSTS on the EAST tokamak and provides an overview of the characteristics of the main and local units.

Design of single-winding energy-storage reactors for dc-to-dc converters using air-gapped magnetic-core structures

NASA Technical Reports Server (NTRS)

Ohri, A. K.; Wilson, T. G.; Owen, H. A., Jr.

1977-01-01

A procedure is presented for designing air-gapped energy-storage reactors for nine different dc-to-dc converters resulting from combinations of three single-winding power stages for voltage stepup, current stepup and voltage stepup/current stepup and three controllers with control laws that impose constant-frequency, constant transistor on-time and constant transistor off-time operation. The analysis, based on the energy-transfer requirement of the reactor, leads to a simple relationship for the required minimum volume of the air gap. Determination of this minimum air gap volume then permits the selection of either an air gap or a cross-sectional core area. Having picked one parameter, the minimum value of the other immediately leads to selection of the physical magnetic structure. Other analytically derived equations are used to obtain values for the required turns, the inductance, and the maximum rms winding current. The design procedure is applicable to a wide range of magnetic material characteristics and physical configurations for the air-gapped magnetic structure.

Effects of stimulus characteristics and task demands on pilots' perception of dichotic messages

NASA Technical Reports Server (NTRS)

Wenzel, Elizabeth M.

1986-01-01

The experiment is an initial investigation of pilot performance when auditory advisory messages are presented dichotically, either with or without a concurrent pursuit task requiring visual/motor dexterity. The dependent measures were percent correct and correct reaction times for manual responses to the auditory messages. Two stimulus variables which show facilitory effects in traditional dichotic-listening paradigms, differences in pitch and semantic content of the messages, were examined to determine their effectiveness during the functional simulation of helicopter pursuit. In an effort to accumulate points for the advisory messages for accuracy alone or for both accuracy and reaction times which were faster than their opponent's. In general, the combined effects of the stimulus and task variables are additive. When interactions do occur they suggest that an increase in task demands can sometimes mitigate, but usually does not remove, any processing advantages accrued from stimulus characteristics. The implications of these results for cockpit displays are discussed.

Experimental research on time-resolved evolution of cathode plasma expansion velocity in a long pulsed magnetically insulated coaxial diode

NASA Astrophysics Data System (ADS)

Zhu, Danni; Zhang, Jun; Zhong, Huihuang; Ge, Xingjun; Gao, Jingming

2018-02-01

Unlike planar diodes, separate research of the axial and radial plasma expansion velocities is difficult for magnetically insulated coaxial diodes. Time-resolved electrical diagnostic which is based on the voltage-ampere characteristics has been employed to study the temporal evolution of the axial and radial cathode plasma expansion velocities in a long pulsed magnetically insulated coaxial diode. Different from a planar diode with a "U" shaped profile of temporal velocity evolution, the temporal evolution trend of the axial expansion velocity is proved to be a "V" shaped profile. Apart from the suppression on the radial expansion velocity, the strong magnetic field is also conducive to slowing down the axial expansion velocity. Compared with the ordinary graphite cathode, the carbon velvet and graphite composite cathode showed superior characteristics as judged by the low plasma expansion velocity and long-term electrical stability as a promising result for applications where long-pulsed and reliable operation at high power is required.

Laser-plasma interaction experiments and diagnostics at NRL (Naval Research Laboratory). Memorandum report

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

Ripin, B.H.; Grun, J.; Herbst, M.J.

Laser plasma interaction experiments have now advanced to the point where very quantitative measurements are required to elucidate the physic issues important for laser fusion and other applications. Detailed time-resolved knowledge of the plasma density, temperature, velocity gradients, spatial structure, heat flow characteristics, radiation emission, etc, are needed over tremendou ranges of plasma density and temperature. Moreover, the time scales are very short, aggrevating the difficulty of the measurements further. Nonetheless, such substantial progress has been made in diagnostic development during the past few years that we are now able to do well diagnosed experiments. In this paper the authorsmore » review recent diagnostic developments for laser-plasma interactions, outline their regimes of applicability, and show examples of their utility. In addition to diagnostics for the high densities and temperature characteristic of laser fusion physics studies, diagnostics designed to study the two-stream interactions of laser created plasma flowing through an ambient low density plasma will be described.« less

Non-Gated Laser Induced Breakdown Spectroscopy Provides a Powerful Segmentation Tool on Concomitant Treatment of Characteristic and Continuum Emission

PubMed Central

Dasari, Ramachandra Rao; Barman, Ishan; Gundawar, Manoj Kumar

2014-01-01

We demonstrate the application of non-gated laser induced breakdown spectroscopy (LIBS) for characterization and classification of organic materials with similar chemical composition. While use of such a system introduces substantive continuum background in the spectral dataset, we show that appropriate treatment of the continuum and characteristic emission results in accurate discrimination of pharmaceutical formulations of similar stoichiometry. Specifically, our results suggest that near-perfect classification can be obtained by employing suitable multivariate analysis on the acquired spectra, without prior removal of the continuum background. Indeed, we conjecture that pre-processing in the form of background removal may introduce spurious features in the signal. Our findings in this report significantly advance the prior results in time-integrated LIBS application and suggest the possibility of a portable, non-gated LIBS system as a process analytical tool, given its simple instrumentation needs, real-time capability and lack of sample preparation requirements. PMID:25084522

Discrete Mathematical Approaches to Graph-Based Traffic Analysis

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

Joslyn, Cliff A.; Cowley, Wendy E.; Hogan, Emilie A.

2014-04-01

Modern cyber defense and anlaytics requires general, formal models of cyber systems. Multi-scale network models are prime candidates for such formalisms, using discrete mathematical methods based in hierarchically-structured directed multigraphs which also include rich sets of labels. An exemplar of an application of such an approach is traffic analysis, that is, observing and analyzing connections between clients, servers, hosts, and actors within IP networks, over time, to identify characteristic or suspicious patterns. Towards that end, NetFlow (or more generically, IPFLOW) data are available from routers and servers which summarize coherent groups of IP packets flowing through the network. In thismore » paper, we consider traffic analysis of Netflow using both basic graph statistics and two new mathematical measures involving labeled degree distributions and time interval overlap measures. We do all of this over the VAST test data set of 96M synthetic Netflow graph edges, against which we can identify characteristic patterns of simulated ground-truth network attacks.« less

In situ passivation of GaAsP nanowires.

PubMed

Himwas, C; Collin, S; Rale, P; Chauvin, N; Patriarche, G; Oehler, F; Julien, F H; Travers, L; Harmand, J-C; Tchernycheva, M

2017-12-08

We report on the structural and optical properties of GaAsP nanowires (NWs) grown by molecular-beam epitaxy. By adjusting the alloy composition in the NWs, the transition energy was tuned to the optimal value required for tandem III-V/silicon solar cells. We discovered that an unintentional shell was also formed during the GaAsP NW growth. The NW surface was passivated by an in situ deposition of a radial Ga(As)P shell. Different shell compositions and thicknesses were investigated. We demonstrate that the optimal passivation conditions for GaAsP NWs (with a gap of 1.78 eV) are obtained with a 5 nm thick GaP shell. This passivation enhances the luminescence intensity of the NWs by 2 orders of magnitude and yields a longer luminescence decay. The luminescence dynamics changes from single exponential decay with a 4 ps characteristic time in non-passivated NWs to a bi-exponential decay with characteristic times of 85 and 540 ps in NWs with GaP shell passivation.

Comparison of Plastic Surgery Residency Training in United States and China.

PubMed

Zheng, Jianmin; Zhang, Boheng; Yin, Yiqing; Fang, Taolin; Wei, Ning; Lineaweaver, William C; Zhang, Feng

2015-12-01

Residency training is internationally recognized as the only way for the physicians to be qualified to practice independently. China has instituted a new residency training program for the specialty of plastic surgery. Meanwhile, plastic surgery residency training programs in the United States are presently in a transition because of restricted work hours. The purpose of this study is to compare the current characteristics of plastic surgery residency training in 2 countries. Flow path, structure, curriculum, operative experience, research, and evaluation of training in 2 countries were measured. The number of required cases was compared quantitatively whereas other aspects were compared qualitatively. Plastic surgery residency training programs in 2 countries differ regarding specific characteristics. Requirements to become a plastic surgery resident in the United States are more rigorous. Ownership structure of the regulatory agency for residency training in 2 countries is diverse. Training duration in the United States is more flexible. Clinical and research training is more practical and the method of evaluation of residency training is more reasonable in the United States. The job opportunities after residency differ substantially between 2 countries. Not every resident has a chance to be an independent surgeon and would require much more training time in China than it does in the United States. Plastic surgery residency training programs in the United States and China have their unique characteristics. The training programs in the United States are more standardized. Both the United States and China may complement each other to create training programs that will ultimately provide high-quality care for all people.

Sprouting characteristics and associated changes in nutritional composition of cowpea (Vigna unguiculata).

PubMed

Devi, Chingakham Basanti; Kushwaha, Archana; Kumar, Anil

2015-10-01

Cowpea (Vigna unguiculata), is an important arid legume with a good source of energy, protein, vitamins, minerals and dietary fibre. Sprouting of legumes enhances the bioavailability and digestibility of nutrients and therefore plays an important role in human nutrition. Improved varieties of grain cowpea viz. Pant Lobia-1 (PL-1) and Pant Lobia-2 (PL-2) and Pant Lobia-3 (PL-3) were examined for sprouting characteristics and associated changes in nutritional quality. Soaking time, sprouting time and sprouting temperature combinations for desirable sprout length of ¼ to ½ inch for cowpea seed samples were standardized. All the observations were taken in triplicate except soaking time, where six observations were taken in a completely randomized design of three treatments. Results revealed that optimum soaking time of PL-1 and PL-2 seed was 3 h whereas PL-3 required 9 h. Sprouting period of 24 h at 25 °C was found to be desirable for obtaining good sprouts. Significant improvement in nutritional quality was observed after sprouting at 25 °C for 24 h; protein increased by 9-12 %, vitamin C increased by 4-38 times, phytic acid decreased by 4-16 times, trypsin inhibitor activity decreased by 28-55 % along with an increase of 8-20 % in in-vitro protein digestibility.

Temporal and spatial binning of TCSPC data to improve signal-to-noise ratio and imaging speed

NASA Astrophysics Data System (ADS)

Walsh, Alex J.; Beier, Hope T.

2016-03-01

Time-correlated single photon counting (TCSPC) is the most robust method for fluorescence lifetime imaging using laser scanning microscopes. However, TCSPC is inherently slow making it ineffective to capture rapid events due to the single photon product per laser pulse causing extensive acquisition time limitations and the requirement of low fluorescence emission efficiency to avoid bias of measurement towards short lifetimes. Furthermore, thousands of photons per pixel are required for traditional instrument response deconvolution and fluorescence lifetime exponential decay estimation. Instrument response deconvolution and fluorescence exponential decay estimation can be performed in several ways including iterative least squares minimization and Laguerre deconvolution. This paper compares the limitations and accuracy of these fluorescence decay analysis techniques to accurately estimate double exponential decays across many data characteristics including various lifetime values, lifetime component weights, signal-to-noise ratios, and number of photons detected. Furthermore, techniques to improve data fitting, including binning data temporally and spatially, are evaluated as methods to improve decay fits and reduce image acquisition time. Simulation results demonstrate that binning temporally to 36 or 42 time bins, improves accuracy of fits for low photon count data. Such a technique reduces the required number of photons for accurate component estimation if lifetime values are known, such as for commercial fluorescent dyes and FRET experiments, and improve imaging speed 10-fold.

Effect of meal size and body size on specific dynamic action and gastric processing in decapod crustaceans.

PubMed

McGaw, Iain J; Curtis, Daniel L

2013-11-01

Meal size and animal size are important factors affecting the characteristics of the specific dynamic action (SDA) response across a variety of taxa. The effects of these two variables on the SDA of decapod crustaceans are based on just a couple of articles, and are not wholly consistent with the responses reported for other aquatic ectotherms. Therefore, the effects of meal size and animal size on the characteristics of SDA response were investigated in a variety of decapod crustaceans from different families. A 6 fold increase in meal size (0.5%-3% body mass) resulted a pronounced increase in the duration of increased oxygen consumption, resulting in an increase in the SDA of Callinectes sapidus, Cancer gracilis, Hemigrapsus nudus, Homarus americanus, Pugettia producta and Procambarus clarkii. Unlike many other aquatic ectotherms a substantial increase between meal sizes was required, with meal size close to their upper feeding limit (3% body mass), before changes were evident. In many organisms increases in both duration and scope contribute to the overall SDA, here changes in scope as a function of meal size were weak, suggesting that a similar amount of energy is required to upregulate gastric processes, regardless of meal size. The SDA characteristics were less likely to be influenced by the size of the animal, and there was no difference in the SDA (kJ) as a function of size in H. americanus or Cancer irroratus when analysed as mass specific values. In several fish species characteristics of the SDA response are more closely related to the transit times of food, rather than the size of a meal. To determine if a similar trend occurred in crustaceans, the transit rates of different sized meals were followed through the digestive system using a fluoroscope. Although there was a trend towards larger meals taking longer to pass through the gut, this was only statistically significant for P. clarkii. There were some changes in transit times as a function of animal size. The foregut clearance times for Cancer magister increased with increasing body size, while smaller Carcinus maenas cleared the hindgut region at a faster rate than larger individuals. Unlike fish there was no clear relationship between transit rates and any of the SDA characteristics. While the fluoroscopy method is useful for assessing foregut activity and food passage, it is limited when inferring connections between nutrient assimilation and post-absorptive processes in crustaceans. Therefore, at least with respect to meal size, transit rates do not make a good proxy for determining the SDA characteristics in crustaceans. © 2013.

Platform options for the Space Station program

NASA Technical Reports Server (NTRS)

Mangano, M. J.; Rowley, R. W.

1986-01-01

Platforms for polar and 28.5 deg orbits were studied to determine the platform requirements and characteristics necessary to support the science objectives. Large platforms supporting the Earth-Observing System (EOS) were initially studied. Co-orbiting platforms were derived from these designs. Because cost estimates indicated that the large platform approach was likely to be too expensive, require several launches, and generally be excessively complex, studies of small platforms were undertaken. Results of these studies show the small platform approach to be technically feasible at lower overall cost. All designs maximized hardware inheritance from the Space Station program to reduce costs. Science objectives as defined at the time of these studies are largely achievable.

Data management system advanced development

NASA Technical Reports Server (NTRS)

Douglas, Katherine; Humphries, Terry

1990-01-01

The Data Management System (DMS) Advanced Development task provides for the development of concepts, new tools, DMS services, and for the testing of the Space Station DMS hardware and software. It also provides for the development of techniques capable of determining the effects of system changes/enhancements, additions of new technology, and/or hardware and software growth on system performance. This paper will address the built-in characteristics which will support network monitoring requirements in the design of the evolving DMS network implementation, functional and performance requirements for a real-time, multiprogramming, multiprocessor operating system, and the possible use of advanced development techniques such as expert systems and artificial intelligence tools in the DMS design.

AAFE man-made noise experiment project. Volume 1: Introduction experiment definition and requirements

NASA Technical Reports Server (NTRS)

1974-01-01

An experiment was conducted to measure and map the man-made radio frequency emanations which exist at earth orbital altitudes. The major objectives of the program are to develop a complete conceptual experiment and developmental hardware for the collection and processing of data required to produce meaningful statistics on man-made noise level variations as functions of time, frequency, and geographic location. A wide dispersion measurement receiver mounted in a spacecraft operating in a specialized orbit is used to obtain the data. A summary of the experiment designs goals and constraints is provided. The recommended orbit for the spacecraft is defined. The characteristics of the receiver and the antennas are analyzed.

An Internet Resource for Self-Assessment of Mental Health and Health Behavior: Development and Implementation of the Self-Assessment Kiosk.

PubMed

Maunder, Robert G; Hunter, Jonathan J

2018-05-16

Standardized measurement of physical and mental health is useful for identification of health problems. Personalized feedback of the results can influence health behavior, and treatment outcomes can be improved by monitoring feedback over time. However, few resources are available that are free for users, provide feedback from validated measurement instruments, and measure a wide range of health domains. This study aimed to develop an internet self-assessment resource that fills the identified gap and collects data to generate and test hypotheses about health, to test its feasibility, and to describe the characteristics of its users. The Self-Assessment Kiosk was built using validated health measurement instruments and implemented on a commercial internet survey platform. Data regarding usage and the characteristics of users were collected over 54 weeks. The rate of accrual of new users, popularity of measurement domains, frequency with which multiple domains were selected for measurement, and characteristics of users who chose particular questionnaires were assessed. Of the 1435 visits, 441 (30.73%) were visiting for the first time, completed at least 1 measure, indicated that their responses were truthful, and consented to research. Growth in the number of users over time was approximately linear. Users were skewed toward old age and higher income and education. Most (53.9%, 234/434) reported at least 1 medical condition. The median number of questionnaires completed was 5. Internal reliability of most measures was good (Cronbach alpha>.70), with lower reliability for some subscales of coping (self-distraction alpha=.35, venting alpha=.50, acceptance alpha=.51) and personality (agreeableness alpha=.46, openness alpha=.45). The popular questionnaires measured depression (61.0%, 269/441), anxiety (60.5%, 267/441), attachment insecurity (54.2%, 239/441), and coping (46.0%, 203/441). Demographic characteristics somewhat influenced choice of instruments, accounting for <9% of the variance in this choice. Mean depression and anxiety scores were intermediate between previously studied populations with and without mental illness. Modeling to estimate the sample size required to study relationships between variables suggested that the accrual of users required to study the relationship between 3 variables was 2 to 3 times greater than that required to study a single variable. The value of the Self-Assessment Kiosk to users and the feasibility of providing this resource are supported by the steady accumulation of new users over time. The Self-Assessment Kiosk database can be interrogated to understand the relationships between health variables. Users who select particular instruments tend to have scores that are higher than those found in the general population, indicating that instruments are more likely to be selected when they are salient. Self-selection bias limits generalizability and needs to be taken into account when using the Self-Assessment Kiosk database for research. Ethical issues that were considered in developing and implementing the Self-Assessment Kiosk are discussed. ©Robert G Maunder, Jonathan J Hunter. Originally published in JMIR Mental Health (http://mental.jmir.org), 16.05.2018.

FLIS Procedures Manual. Document Identifier Code Input/Output Formats (Fixed Length). Volume 8.

DTIC Science & Technology

1997-04-01

DATA ELE- MENTS. SEGMENT R MAY BE REPEATED A MAXIMUM OF THREE (3) TIMES IN ORDER TO ACQUIRE THE REQUIRED MIX OF SEGMENTS OR INDIVIDUAL DATA ELEMENTS TO...preceding record. Marketing input DICs. QI Next DRN of appropriate segment will be QF The assigned NSN or PSCN being can- reflected in accordance with Table...Classified KFC Notification of Possible Duplicate (Sub- KRP Characteristics Data mitter) Follow-Up Interrogation LFU Notification of Return, SSR Transaction

Computer-Assisted Instruction and Its Application to Air Force Civil Engineering.

DTIC Science & Technology

1987-09-01

train the student. The student’s respesees my cause the ceeputot to preseet the previous material In a different =mus if these resposes indicaed that the...presented by Schlechter. He reports study results that indicate that CAI time savings may be due to self - pacing, a characteristic of other less-expenLve...lesson developer must ask: Is this instruc- tional requirement suited for Individual self -paced inter- active instruction? If the answer is no, then

Survey of Methods and Algorithms of Robot Swarm Aggregation

NASA Astrophysics Data System (ADS)

E Shlyakhov, N.; Vatamaniuk, I. V.; Ronzhin, A. L.

2017-01-01

The paper considers the problem of swarm aggregation of autonomous robots with the use of three methods based on the analogy of the behavior of biological objects. The algorithms substantiating the requirements for hardware realization of sensor, computer and network resources and propulsion devices are presented. Techniques for efficiency estimation of swarm aggregation via space-time characteristics are described. The developed model of the robot swarm reconfiguration into a predetermined three-dimensional shape is presented.

The Georgia Information Sharing and Analysis Center: A Model for State And Local Governments Role in the Intelligence Community

DTIC Science & Technology

2004-06-01

my thesis advisor, which in my case, required the characteristics of being a nanny , coach, psychiatrist, and English teacher. Without your...information relating to Georgia. GISAC was not intended to replace or duplicate the counter-terrorism duties of the Federal Bureau of Investigation, but...time employees of GISAC, their respective assignments and parent agencies are listed below: Georgia Bureau of Investigation Inspectors – 1 Special

Simplified dichromated gelatin hologram recording process

NASA Technical Reports Server (NTRS)

Georgekutty, Tharayil G.; Liu, Hua-Kuang

1987-01-01

A simplified method for making dichromated gelatin (DCG) holographic optical elements (HOE) has been discovered. The method is much less tedious and it requires a period of processing time comparable with that for processing a silver halide hologram. HOE characteristics including diffraction efficiency (DE), linearity, and spectral sensitivity have been quantitatively investigated. The quality of the holographic grating is very high. Ninety percent or higher diffraction efficiency has been achieved in simple plane gratings made by this process.

Data Obtained in the Flight Measurements to Determine the Stability and Control Characteristics of a C-54D Airplane (AAF No. 42-72713) and a Summary of the Test Program

NASA Technical Reports Server (NTRS)

Talmage, Donald B.; Reeder, John P.

1947-01-01

The flight investigation of the C-54D airplane was initiated to determine the necessity of changes or additions to existing handling-qualities requirements to cove the case of instrument approaches with large airplanes. This paper gives a brief synopsis of the results and presents the measured data of tests to determine the stability and control characteristics. It was found that no new requirements were necessary to cover the problems of instrument approaches. The C-54D airplane tested met the Amy and Navy stability and control requirements except for the following items. The control-system friction with autopilot installed vas double that allowed by the requirements. The amount of friction was found to impair the controllability of the airplane in precision flying. The lateral and directional characteristics were good except that the maximum pb/2V was slightly below the minimum required, and the elevator-control forces to obtain the maximum pb/2V at low speeds were above the Army and Navy requirements. The longitudinal stability and control characteristics were good except that the elevator-control forces exceeded the limits of the Army and Navy requirements in turns and in landings. The stalling characteristics were considered good in all conditions with the stall warning in the form of tail buffeting occurring at speeds approximately 5 miles per hour above the stall.

Vertical radar profiles for the calibration of unsaturated flow models under dynamic water table conditions

NASA Astrophysics Data System (ADS)

Cassiani, G.; Gallotti, L.; Ventura, V.; Andreotti, G.

2003-04-01

The identification of flow and transport characteristics in the vadose zone is a fundamental step towards understanding the dynamics of contaminated sites and the resulting risk of groundwater pollution. Borehole radar has gained popularity for the monitoring of moisture content changes, thanks to its apparent simplicity and its high resolution characteristics. However, cross-hole radar requires closely spaced (a few meters), plastic-cased boreholes, that are rarely available as a standard feature in sites of practical interest. Unlike cross-hole applications, Vertical Radar Profiles (VRP) require only one borehole, with practical and financial benefits. High-resolution, time-lapse VRPs have been acquired at a crude oil contaminated site in Trecate, Northern Italy, on a few existing boreholes originally developed for remediation via bioventing. The dynamic water table conditions, with yearly oscillations of roughly 5 m from 6 to 11 m bgl, offers a good opportunity to observe via VRP a field scale drainage-imbibition process. Arrival time inversion has been carried out using a regularized tomographic algorithm, in order to overcome the noise introduced by first arrival picking. Interpretation of the vertical profiles in terms of moisture content has been based on standard models (Topp et al., 1980; Roth et al., 1990). The sedimentary sequence manifests itself as a cyclic pattern in moisture content over most of the profiles. We performed preliminary Richards' equation simulations with time varying later table boundary conditions, in order to estimate the unsaturated flow parameters, and the results have been compared with laboratory evidence from cores.

The physiology of mountain biking.

PubMed

Impellizzeri, Franco M; Marcora, Samuele M

2007-01-01

Mountain biking is a popular outdoor recreational activity and an Olympic sport. Cross-country circuit races have a winning time of approximately equal 120 minutes and are performed at an average heart rate close to 90% of the maximum, corresponding to 84% of maximum oxygen uptake (VO2max). More than 80% of race time is spent above the lactate threshold. This very high exercise intensity is related to the fast starting phase of the race; the several climbs, forcing off-road cyclists to expend most of their effort going against gravity; greater rolling resistance; and the isometric contractions of arm and leg muscles necessary for bike handling and stabilisation. Because of the high power output (up to 500W) required during steep climbing and at the start of the race, anaerobic energy metabolism is also likely to be a factor of off-road cycling and deserves further investigation. Mountain bikers' physiological characteristics indicate that aerobic power (VO2max >70 mL/kg/min) and the ability to sustain high work rates for prolonged periods of time are prerequisites for competing at a high level in off-road cycling events. The anthropometric characteristics of mountain bikers are similar to climbers and all-terrain road cyclists. Various parameters of aerobic fitness are correlated to cross-country performance, suggesting that these tests are valid for the physiological assessment of competitive mountain bikers, especially when normalised to body mass. Factors other than aerobic power and capacity might influence off-road cycling performance and require further investigation. These include off-road cycling economy, anaerobic power and capacity, technical ability and pre-exercise nutritional strategies.

Fractual interrelationships in field and seismic data. Final report

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

NONE

1997-01-07

Fractals provide a description of physical patterns over a range of scales in both time and space. Studies presented herein examine the fractal characteristics of various geological variables such as deformed bed-lengths, fold relief, seismic reflection arrival time variations, drainage and topographic patterns, and fracture systems. The studies are also extended to consider the possibility that the fractal characteristics of these variables are interrelated. Fractal interrelationships observed in these studies provide a method for relating variations in the fractal characteristics of seismic reflection events from reservoir intervals to the fractal characteristics of reservoir fracture systems, faults, and fold distributions. Themore » work is motivated by current exploration and development interests to detect fractured reservoirs and to accurately predict flow rates and flow patterns within the fractured reservoir. Accurate prediction requires an understanding of several reservoir properties including the fractal geometry of the reservoir fracture network. Results of these studies provide a method to remotely assess the fractal characteristics of a fractured reservoir, and help guide field development activities. The most significant outgrowth of this research is that the fractal properties of structural relief inferred from seismic data and structural cross sections provide a quantitative means to characterize and compare complex structural patterns. Production from fractured reservoirs is the result of complex structural and stratigraphic controls; hence, the import of fractal characterization to the assessment of fractured reservoirs lies in its potential to quantitatively define interrelationships between subtle structural variation and production. The potential uses are illustrated using seismic data from the Granny Creek oil field in the Appalachian Plateau.« less

A Time Tree Medium Access Control for Energy Efficiency and Collision Avoidance in Wireless Sensor Networks

PubMed Central

Lee, Kilhung

2010-01-01

This paper presents a medium access control and scheduling scheme for wireless sensor networks. It uses time trees for sending data from the sensor node to the base station. For an energy efficient operation of the sensor networks in a distributed manner, time trees are built in order to reduce the collision probability and to minimize the total energy required to send data to the base station. A time tree is a data gathering tree where the base station is the root and each sensor node is either a relaying or a leaf node of the tree. Each tree operates in a different time schedule with possibly different activation rates. Through the simulation, the proposed scheme that uses time trees shows better characteristics toward burst traffic than the previous energy and data arrival rate scheme. PMID:22319270

Crohn's disease patients carrying Nod2/CARD15 gene variants have an increased and early need for first surgery due to stricturing disease and higher rate of surgical recurrence.

PubMed

Alvarez-Lobos, Manuel; Arostegui, Juan I; Sans, Miquel; Tassies, Dolors; Plaza, Susana; Delgado, Salvadora; Lacy, Antonio M; Pique, Josep M; Yagüe, Jordi; Panés, Julián

2005-11-01

To study the predictive value of Nod2/CARD15 gene variants along with disease phenotypic characteristics for requirement of initial surgery and for surgical recurrence in Crohn's disease (CD). Nod2/CARD15 gene variants play an important role in the susceptibility to CD. Studies of genotype-phenotype relationship suggest that these variants are associated with development of intestinal strictures. Preliminary reports analyzing the association between these variants and need for surgery have produced inconsistent results. A total of 170 CD patients were included prospectively in the study and followed up regularly for a mean of 7.4 +/- 6.1 years. Clinical characteristics of CD, time and indication for surgery, and recurrence were registered. Nod2/CARD15 gene variants were determined by DNA sequencing analysis. Surgery for stricturing disease was significantly more frequent in patients with Nod2/CARD15 variants in the univariate analysis (odds ratio [OR], 3.63; 95% confidence interval [CI], 1.42-9.27), and it was required at an earlier time (P = 0.004). Only Nod2/CARD15 variants (OR, 3.58; 95% CI, 1.21-10.5) and stricturing phenotype at diagnosis of CD (OR, 9.34; 95% CI, 2.56-33.3) were independent predictive factors of initial surgery for stricturing lesions in the multivariate analysis. Among 70 patients that required surgery, postoperative recurrence was also more frequent in patients with Nod2/CARD15 variants in the univariate and multivariate analysis (OR, 3.29; 95% CI, 1.13-9.56), and reoperation was needed at an earlier time (P = 0.03). Nod2/CARD15 variants are associated with early initial surgery due to stenosis and with surgical recurrence in Crohn's disease. Patients with these variants could benefit from preventive and/or early therapeutic strategies.

Development of Automatic Controller of Brain Temperature Based on the Conditions of Clinical Use

NASA Astrophysics Data System (ADS)

Utsuki, Tomohiko; Wakamatsu, Hidetoshi

A new automatic controller of brain temperature was developed based on the inevitable conditions of its clinical use from the viewpoint of various kinds of feasibility, in particular, electric power consumption of less than 1,500W in ICU. The adaptive algorithm was employed to cope with individual time-varying characteristic change of patients. The controller under water-surface cooling hypothermia requires much power for the frequent regulation of the water temperature of cooling blankets. Thus, in this study, the power consumption of the controller was checked by several kinds of examinations involving the control simulation of brain temperature using a mannequin with thermal characteristics similar to that of adult patients. The required accuracy of therapeutic brain hypothermia, i.e. control deviation within ±0.1C was experimentally confirmed using “root mean square of the control error”, despite the present controller consumes less energy comparing with the one in the case of our conventional controller, where it can still keeps remaining power margin more than 300W even in the full operation. Thereby, the clinically required water temperature was also confirmed within the limit of power supply, thus its practical application is highly expected with less physical burden of medical staff inclusive of more usability and more medical cost performance.

Bioavailability and dissolution of different formulations of oxytetracycline preparations.

PubMed Central

Hart, A; Barber, H E; Calvey, T N

1975-01-01

1 The concentration of oxytetracycline in plasma was studied by microbiological assay after oral administration of five different preparations of the antibiotic. None of these preparations had been studied previously. 2 There was a statistically significant correlation between the time required for 50% dissolution at pH 2 and biological availability, as assessed by the peak plasma level or the area under the plasma concentration-time curve. 3 The mean bioavailability of oxytetracycline was greatest with preparations of the hydrochloride, and with film-coated tablets of the dihydrate. In contrast, sugar-coated tablets of oxytetracycline dihydrate were associated with poorer dissolution characteristics and reduced biological availability. PMID:10944

Recording 2-D Nutation NQR Spectra by Random Sampling Method

PubMed Central

Sinyavsky, Nikolaj; Jadzyn, Maciej; Ostafin, Michal; Nogaj, Boleslaw

2010-01-01

The method of random sampling was introduced for the first time in the nutation nuclear quadrupole resonance (NQR) spectroscopy where the nutation spectra show characteristic singularities in the form of shoulders. The analytic formulae for complex two-dimensional (2-D) nutation NQR spectra (I = 3/2) were obtained and the condition for resolving the spectral singularities for small values of an asymmetry parameter η was determined. Our results show that the method of random sampling of a nutation interferogram allows significant reduction of time required to perform a 2-D nutation experiment and does not worsen the spectral resolution. PMID:20949121

Measuring discharge with ADCPs: Inferences from synthetic velocity profiles

USGS Publications Warehouse

Rehmann, C.R.; Mueller, D.S.; Oberg, K.A.

2009-01-01

Synthetic velocity profiles are used to determine guidelines for sampling discharge with acoustic Doppler current profilers (ADCPs). The analysis allows the effects of instrument characteristics, sampling parameters, and properties of the flow to be studied systematically. For mid-section measurements, the averaging time required for a single profile measurement always exceeded the 40 s usually recommended for velocity measurements, and it increased with increasing sample interval and increasing time scale of the large eddies. Similarly, simulations of transect measurements show that discharge error decreases as the number of large eddies sampled increases. The simulations allow sampling criteria that account for the physics of the flow to be developed. ?? 2009 ASCE.

Mission Design Considerations for Mars Cargo of the Human Spaceflight Architecture Team's Evolvable Mars Campaign

NASA Technical Reports Server (NTRS)

Sjauw, Waldy K.; McGuire, Melissa L.; Freeh, Joshua E.

2016-01-01

Recent NASA interest in human missions to Mars has led to an Evolvable Mars Campaign by the agency's Human Architecture Team. Delivering the crew return propulsion stages and Mars surface landers, SEP based systems are employed because of their high specific impulse characteristics enabling missions requiring less propellant although with longer transfer times. The Earth departure trajectories start from an SLS launch vehicle delivery orbit and are spiral shaped because of the low SEP thrust. Previous studies have led to interest in assessing the divide in trip time between the Earth departure and interplanetary legs of the mission for a representative SEP cargo vehicle.

Experiences on p-Version Time-Discontinuous Galerkin's Method for Nonlinear Heat Transfer Analysis and Sensitivity Analysis

NASA Technical Reports Server (NTRS)

Hou, Gene

2004-01-01

The focus of this research is on the development of analysis and sensitivity analysis equations for nonlinear, transient heat transfer problems modeled by p-version, time discontinuous finite element approximation. The resulting matrix equation of the state equation is simply in the form ofA(x)x = c, representing a single step, time marching scheme. The Newton-Raphson's method is used to solve the nonlinear equation. Examples are first provided to demonstrate the accuracy characteristics of the resultant finite element approximation. A direct differentiation approach is then used to compute the thermal sensitivities of a nonlinear heat transfer problem. The report shows that only minimal coding effort is required to enhance the analysis code with the sensitivity analysis capability.

The temporal spectrum of adult mosquito population fluctuations: conceptual and modeling implications.

PubMed

Jian, Yun; Silvestri, Sonia; Brown, Jeff; Hickman, Rick; Marani, Marco

2014-01-01

An improved understanding of mosquito population dynamics under natural environmental forcing requires adequate field observations spanning the full range of temporal scales over which mosquito abundance fluctuates in natural conditions. Here we analyze a 9-year daily time series of uninterrupted observations of adult mosquito abundance for multiple mosquito species in North Carolina to identify characteristic scales of temporal variability, the processes generating them, and the representativeness of observations at different sampling resolutions. We focus in particular on Aedes vexans and Culiseta melanura and, using a combination of spectral analysis and modeling, we find significant population fluctuations with characteristic periodicity between 2 days and several years. Population dynamical modelling suggests that the observed fast fluctuations scales (2 days-weeks) are importantly affected by a varying mosquito activity in response to rapid changes in meteorological conditions, a process neglected in most representations of mosquito population dynamics. We further suggest that the range of time scales over which adult mosquito population variability takes place can be divided into three main parts. At small time scales (indicatively 2 days-1 month) observed population fluctuations are mainly driven by behavioral responses to rapid changes in weather conditions. At intermediate scales (1 to several month) environmentally-forced fluctuations in generation times, mortality rates, and density dependence determine the population characteristic response times. At longer scales (annual to multi-annual) mosquito populations follow seasonal and inter-annual environmental changes. We conclude that observations of adult mosquito populations should be based on a sub-weekly sampling frequency and that predictive models of mosquito abundance must include behavioral dynamics to separate the effects of a varying mosquito activity from actual changes in the abundance of the underlying population.

Influence of median surgeon operative duration on adverse outcomes in bariatric surgery.

PubMed

Reames, Bradley N; Bacal, Daniel; Krell, Robert W; Birkmeyer, John D; Birkmeyer, Nancy J O; Finks, Jonathan F

2015-01-01

Evidence suggests that prolonged operative time adversely affects surgical outcomes. However, whether faster surgeons have better outcomes is unclear, as a surgeon׳s speed could reflect skill and efficiency, but may alternatively reflect haste. This study evaluates whether median surgeon operative time is associated with adverse surgical outcomes after laparoscopic Roux-en-Y gastric bypass. We performed a retrospective cohort study using statewide clinical registry data from the years 2006 to 2012. Surgeons were ranked by their median operative time and grouped into terciles. Multivariable logistic regression with robust standard errors was used to evaluate the influence of median surgeon operative time on 30-day surgical outcomes, adjusting for patient and surgeon characteristics, trainee involvement, concurrent procedures, and the complex interaction between these variables. A total of 16,344 patients underwent surgery during the study period. Compared to surgeons in the fastest tercile, slow surgeons required 53 additional minutes to complete a gastric bypass procedure (median [interquartile range] 139 [133-150] versus 86 [69-91], P<.001). After adjustment for patient characteristic only, slow surgeons had significantly higher adjusted rates of any complication, prolonged length of stay, emergency department visits or readmissions, and venous thromboembolism (VTE). After further adjustment for surgeon characteristics, resident involvement, and the interaction between these variables, slow surgeons had higher rates of any complication (10.5% versus 7.1%, P=.039), prolonged length of stay (14.0% versus 4.4%, P=.002), and VTE (0.39% versus .22%, P<.001). Median surgeon operative duration is independently associated with adjusted rates of certain adverse outcomes after laparoscopic Roux-en-Y gastric bypass. Improving surgeon efficiency while operating may reduce operative time and improve the safety of bariatric surgery. Copyright © 2015 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

The science of badminton: game characteristics, anthropometry, physiology, visual fitness and biomechanics.

PubMed

Phomsoupha, Michael; Laffaye, Guillaume

2015-04-01

Badminton is a racket sport for two or four people, with a temporal structure characterized by actions of short duration and high intensity. This sport has five events: men's and women's singles, men's and women's doubles, and mixed doubles, each requiring specific preparation in terms of technique, control and physical fitness. Badminton is one of the most popular sports in the world, with 200 million adherents. The decision to include badminton in the 1992 Olympics Game increased participation in the game. This review focuses on the game characteristics, anthropometry, physiology, visual attributes and biomechanics of badminton. Players are generally tall and lean, with an ectomesomorphic body type suited to the high physiological demands of a match. Indeed, a typical match characteristic is a rally time of 7 s and a resting time of 15 s, with an effective playing time of 31%. This sport is highly demanding, with an average heart rate (HR) of over 90% of the player's maximal HR. The intermittent actions during a game are demanding on both the aerobic and anaerobic systems: 60-70% on the aerobic system and approximately 30% on the anaerobic system, with greater demand on the alactic metabolism with respect to the lactic anaerobic metabolism. The shuttlecock has an atypical trajectory, and the players perform specific movements such as lunging and jumping, and powerful strokes using a specific pattern of movement. Lastly, badminton players are visually fit, picking up accurate visual information in a short time. Knowledge of badminton can help to improve coaching and badminton skills.

Repeated Habitat Disturbances by Fire Decrease Local Effective Population Size.

PubMed

Schrey, Aaron W; Ragsdale, Alexandria K; McCoy, Earl D; Mushinsky, Henry R

2016-07-01

Effective population size is a fundamental parameter in population genetics, and factors that alter effective population size will shape the genetic characteristics of populations. Habitat disturbance may have a large effect on genetic characteristics of populations by influencing immigration and gene flow, particularly in fragmented habitats. We used the Florida Sand Skink (Plestiodon reynoldsi) to investigate the effect of fire-based habitat disturbances on the effective population size in the highly threatened, severely fragmented, and fire dependent Florida scrub habitat. We screened 7 microsatellite loci in 604 individuals collected from 12 locations at Archbold Biological Station. Archbold Biological Station has an active fire management plan and detailed records of fires dating to 1967. Our objective was to determine how the timing, number, and intervals between fires affect effective population size, focusing on multiple fires in the same location. Effective population size was higher in areas that had not been burned for more than 10 years and decreased with number of fires and shorter time between fires. A similar pattern was observed in abundance: increasing abundance with time-since-fire and decreasing abundance with number of fires. The ratio of effective population size to census size was higher at sites with more recent fires and tended to decrease with time-since-last-fire. These results suggest that habitat disturbances, such as fire, may have a large effect in the genetic characteristics of local populations and that Florida Sand Skinks are well adapted to the natural fire dynamics required to maintain Florida scrub. © The American Genetic Association. 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Soft Material-Enabled, Flexible Hybrid Electronics for Medicine, Healthcare, and Human-Machine Interfaces

PubMed Central

Herbert, Robert; Kim, Jong-Hoon; Kim, Yun Soung; Lee, Hye Moon

2018-01-01

Flexible hybrid electronics (FHE), designed in wearable and implantable configurations, have enormous applications in advanced healthcare, rapid disease diagnostics, and persistent human-machine interfaces. Soft, contoured geometries and time-dynamic deformation of the targeted tissues require high flexibility and stretchability of the integrated bioelectronics. Recent progress in developing and engineering soft materials has provided a unique opportunity to design various types of mechanically compliant and deformable systems. Here, we summarize the required properties of soft materials and their characteristics for configuring sensing and substrate components in wearable and implantable devices and systems. Details of functionality and sensitivity of the recently developed FHE are discussed with the application areas in medicine, healthcare, and machine interactions. This review concludes with a discussion on limitations of current materials, key requirements for next generation materials, and new application areas. PMID:29364861

Soft Material-Enabled, Flexible Hybrid Electronics for Medicine, Healthcare, and Human-Machine Interfaces.

PubMed

Herbert, Robert; Kim, Jong-Hoon; Kim, Yun Soung; Lee, Hye Moon; Yeo, Woon-Hong

2018-01-24

Flexible hybrid electronics (FHE), designed in wearable and implantable configurations, have enormous applications in advanced healthcare, rapid disease diagnostics, and persistent human-machine interfaces. Soft, contoured geometries and time-dynamic deformation of the targeted tissues require high flexibility and stretchability of the integrated bioelectronics. Recent progress in developing and engineering soft materials has provided a unique opportunity to design various types of mechanically compliant and deformable systems. Here, we summarize the required properties of soft materials and their characteristics for configuring sensing and substrate components in wearable and implantable devices and systems. Details of functionality and sensitivity of the recently developed FHE are discussed with the application areas in medicine, healthcare, and machine interactions. This review concludes with a discussion on limitations of current materials, key requirements for next generation materials, and new application areas.

48 CFR 6.502 - Duties and responsibilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of functions to be performed, performance required or essential physical characteristics, and... burdensome contract clauses. (b) Agency competition advocates shall— (1) Review the contracting operations of... functions to be performed, performance required or essential physical characteristics; (iv) Any condition or...

Centaur engine gimbal friction characteristics under simulated thrust load

NASA Technical Reports Server (NTRS)

Askew, J. W.

1986-01-01

An investigation was performed to determine the friction characteristics of the engine gimbal system of the Centaur upper stage rocket. Because the Centaur requires low-gain autopilots in order to meet all stability requirements for some configurations, control performance (response to transients and limit-cycle amplitudes) depends highly on these friction characteristics. Forces required to rotate the Centaur engine gimbal system were measured under a simulated thrust load of 66,723 N (15,000 lb) and in an altitude/thermal environment. A series of tests was performed at three test conditions; ambient temperature and pressure, ambient temperature and vacuum, and cryogenic temperature and vacuum. Gimbal rotation was controlled, and tests were performed in which rotation amplitude and frequency were varied by using triangular and sinusoidal waveforms. Test data revealed an elastic characteristic of the gimbal, independent of the input signal, which was evident prior to true gimbal sliding. The torque required to initiate gimbal sliding was found to decrease when both pressure and temperature decreased. Results from the low amplitude and low frequency data are currently being used in mathematically modeling the gimbal friction characteristics for Centaur autopilot performance studies.

Centaur engine gimbal friction characteristics under simulated thrust load

NASA Astrophysics Data System (ADS)

Askew, J. W.

1986-09-01

An investigation was performed to determine the friction characteristics of the engine gimbal system of the Centaur upper stage rocket. Because the Centaur requires low-gain autopilots in order to meet all stability requirements for some configurations, control performance (response to transients and limit-cycle amplitudes) depends highly on these friction characteristics. Forces required to rotate the Centaur engine gimbal system were measured under a simulated thrust load of 66,723 N (15,000 lb) and in an altitude/thermal environment. A series of tests was performed at three test conditions; ambient temperature and pressure, ambient temperature and vacuum, and cryogenic temperature and vacuum. Gimbal rotation was controlled, and tests were performed in which rotation amplitude and frequency were varied by using triangular and sinusoidal waveforms. Test data revealed an elastic characteristic of the gimbal, independent of the input signal, which was evident prior to true gimbal sliding. The torque required to initiate gimbal sliding was found to decrease when both pressure and temperature decreased. Results from the low amplitude and low frequency data are currently being used in mathematically modeling the gimbal friction characteristics for Centaur autopilot performance studies.

Developing preventive mental health interventions for refugee families in resettlement.

PubMed

Weine, Stevan Merrill

2011-09-01

In refugee resettlement, positive psychosocial outcomes for youth and adults depend to a great extent on their families. Yet refugee families find few empirically based services geared toward them. Preventive mental health interventions that aim to stop, lessen, or delay possible negative individual mental health and behavioral sequelae through improving family and community protective resources in resettled refugee families are needed. This paper describes 8 characteristics that preventive mental health interventions should address to meet the needs of refugee families, including: Feasibility, Acceptability, Culturally Tailored, Multilevel, Time Focused, Prosaicness, Effectiveness, and Adaptability. To address these 8 characteristics in the complex environment of refugee resettlement requires modifying the process of developmental research through incorporating innovative mental health services research strategies, including: resilience framework, community collaboration, mixed methods with focused ethnography, and the comprehensive dynamic trial. A preventive intervention development cycle for refugee families is proposed based on a program of research on refugees and migrants using these services research strategies. Furthering preventive mental health for refugee families also requires new policy directives, multisystemic partnerships, and research training. 2011 © FPI, Inc.

Developing Preventive Mental Health Interventions for Refugee Families in Resettlement

PubMed Central

WEINE, STEVAN MERRILL

2014-01-01

In refugee resettlement, positive psychosocial outcomes for youth and adults depend to a great extent on their families. Yet refugee families find few empirically based services geared toward them. Preventive mental health interventions that aim to stop, lessen, or delay possible negative individual mental health and behavioral sequelae through improving family and community protective resources in resettled refugee families are needed. This paper describes 8 characteristics that preventive mental health interventions should address to meet the needs of refugee families, including: Feasibility, Acceptability, Culturally Tailored, Multilevel, Time Focused, Prosaicness, Effectiveness, and Adaptability. To address these 8 characteristics in the complex environment of refugee resettlement requires modifying the process of developmental research through incorporating innovative mental health services research strategies, including: resilience framework, community collaboration, mixed methods with focused ethnography, and the comprehensive dynamic trial. A preventive intervention development cycle for refugee families is proposed based on a program of research on refugees and migrants using these services research strategies. Furthering preventive mental health for refugee families also requires new policy directives, multisystemic partnerships, and research training. PMID:21884078

Techniques for the Installation of Internal Fiber Optic Instrumentation on an 11-Inch Hybrid Motor Test Bed

NASA Technical Reports Server (NTRS)

Cornelius, Michael; Smartt, Ziba; Henrie, Vaughn; Johnson, Mont

2003-01-01

The recent developments in Fabry-Perot fiber optic instruments have resulted in accurate transducers with some of the physical characteristics required for use in obtaining internal data from solid rocket motors. These characteristics include small size, non-electrical excitation, and immunity to electro-magnetic interference. These transducers have not been previously utilized in this environment due to the high temperatures typically encountered. A series of tests were conducted using a 1 1-Inch Hybrid test bed to develop installation techniques that will allow the fiber optic instruments to survive and obtain data for a short period of time following the motor ignition. The installation methods developed during this test series have the potential to allow data to be acquired in the motor chamber, propellant bore, and nozzle during the ignition transient. These measurements would prove to be very useful in the characterization of current motor designs and provide insight into the requirements for further refinements. The process of developing these protective methods and the installation techniques used to apply them is summarized.

Enhanced use of phylogenetic data to inform public health approaches to HIV among men who have sex with men.

PubMed

German, Danielle; Grabowski, Mary Kate; Beyrer, Chris

2017-02-01

The multidimensional nature and continued evolution of HIV epidemics among men who have sex with men (MSM) requires innovative intervention approaches. Strategies are needed that recognise the individual, social and structural factors driving HIV transmission; that can pinpoint networks with heightened transmission risk; and that can help target intervention in real time. HIV phylogenetics is a rapidly evolving field with strong promise for informing innovative responses to the HIV epidemic among MSM. Currently, HIV phylogenetic insights are providing new understandings of characteristics of HIV epidemics involving MSM, social networks influencing transmission, characteristics of HIV transmission clusters involving MSM, targets for antiretroviral and other prevention strategies and dynamics of emergent epidemics. Maximising the potential of HIV phylogenetics for HIV responses among MSM will require attention to key methodological challenges and ethical considerations, as well as resolving key implementation and scientific questions. Enhanced and integrated use of HIV surveillance, sociobehavioural and phylogenetic data resources are becoming increasingly critical for informing public health approaches to HIV among MSM.

Imaging and Quantifying Solute Transport Across Periosteum: Implications for Muscle-Bone Crosstalk

PubMed Central

Lai, Xiaohan; Price, Christopher; Lu, Xin (Lucas); Wang, Liyun

2014-01-01

Muscle and bone are known to act as a functional unit and communicate biochemically during tissue development and maintenance. Muscle-derived factors (myokines) have been found to affect bone functions in vitro. However, the transport times of myokines to penetrate into bone, a critical step required for local muscle-bone crosstalk, have not been quantified in situ or in vivo. In this study, we investigated the permeability of the periosteum, a major barrier to muscle-bone crosstalk by tracking and modeling fluorescent tracers that mimic myokines under confocal microscopy. Periosteal surface boundaries and tracer penetration within the boundaries were imaged in intact murine tibiae using reflected light and time-series xz confocal imaging, respectively. Four fluorescent tracers including sodium fluorescein (376Da) and dextrans (3kDa, 10kDa and 40kDa) were chosen because they represented a wide range of molecular weights (MW) of myokines. We found that i) murine periosteum was permeable to the three smaller tracers while the 40kDa could not penetrate beyond 40% of the outer periosteum within 8 hours, suggesting that periosteum is semi-permeable with a cut-off MW of approximately 40kDa, and ii) the characteristic penetration time through the periosteum (~60μm thick) increased with tracer MW and fit well with a relationship (((tc[sec]=−(4.43×104)−0.57×(MW[Da]−4×104)−8.65×108MW[Da]−4×104)), from which, the characteristic penetration times of various myokines were extrapolated. To achieve effective muscle-bone crosstalk, likely signaling candidates should have shorter penetration time than their bioactive time, which we assumed to be 5 times of the molecule’s half-life time in the body. Myokines such as PGE2, IGF-1, IL-15 and FGF-2 were predicted to satisfy this requirement. In summary, a novel imaging approach was developed and used to investigate the transport of myokine mimicking-tracers through the periosteum, enabling further quantitative studies of muscle-bone communication in physiologically normal and pathological conditions. PMID:24928492

Soil moisture mapping using Sentinel 1 images: the proposed approach and its preliminary validation carried out in view of an operational product

NASA Astrophysics Data System (ADS)

Paloscia, S.; Pettinato, S.; Santi, E.; Pierdicca, N.; Pulvirenti, L.; Notarnicola, C.; Pace, G.; Reppucci, A.

2011-11-01

The main objective of this research is to develop, test and validate a soil moisture (SMC)) algorithm for the GMES Sentinel-1 characteristics, within the framework of an ESA project. The SMC product, to be generated from Sentinel-1 data, requires an algorithm able to process operationally in near-real-time and deliver the product to the GMES services within 3 hours from observations. Two different complementary approaches have been proposed: an Artificial Neural Network (ANN), which represented the best compromise between retrieval accuracy and processing time, thus allowing compliance with the timeliness requirements and a Bayesian Multi-temporal approach, allowing an increase of the retrieval accuracy, especially in case where little ancillary data are available, at the cost of computational efficiency, taking advantage of the frequent revisit time achieved by Sentinel-1. The algorithm was validated in several test areas in Italy, US and Australia, and finally in Spain with a 'blind' validation. The Multi-temporal Bayesian algorithm was validated in Central Italy. The validation results are in all cases very much in line with the requirements. However, the blind validation results were penalized by the availability of only VV polarization SAR images and MODIS lowresolution NDVI, although the RMS is slightly > 4%.

Current interruption in inductive storage systems with inertial current source

NASA Astrophysics Data System (ADS)

Vitkovitsky, I. M.; Conte, D.; Ford, R. D.; Lupton, W. H.

1980-03-01

Utilization of inertial current source inductive storage with high power output requires a switch with short opening time. This switch must operate as a circuit breaker, i.e., be capable to carry the current for a time period characteristic of inertial systems, such as homopolar generators. For reasonable efficiency, its opening time must be fast to minimize the energy dissipated in downstream fuse stages required for any additional pulse compression. A switch that satisfies these criteria, as well as other requirements such as that for high voltage operation associated with high power output, is an explosively driven switch consisting of large number of gaps arranged in series. The performance of this switch in limiting and/or interrupting currents produced by large generators has been studied. Single switch modules were designed and tested for limiting the commutating current output of 1 MW, 60 Hz, generator and 500 KJ capacitor banks. Current limiting and commutation were evaluated, using these sources, for currents ranging up to 0.4 MA. The explosive opening of the switch was found to provide an effective first stage for further pulse compression. It opens in tens of microseconds, commutates current at high efficiency ( = 905) recovers very rapidly over a wide range of operating conditions.

Modeling hard clinical end-point data in economic analyses.

PubMed

Kansal, Anuraag R; Zheng, Ying; Palencia, Roberto; Ruffolo, Antonio; Hass, Bastian; Sorensen, Sonja V

2013-11-01

The availability of hard clinical end-point data, such as that on cardiovascular (CV) events among patients with type 2 diabetes mellitus, is increasing, and as a result there is growing interest in using hard end-point data of this type in economic analyses. This study investigated published approaches for modeling hard end-points from clinical trials and evaluated their applicability in health economic models with different disease features. A review of cost-effectiveness models of interventions in clinically significant therapeutic areas (CV diseases, cancer, and chronic lower respiratory diseases) was conducted in PubMed and Embase using a defined search strategy. Only studies integrating hard end-point data from randomized clinical trials were considered. For each study included, clinical input characteristics and modeling approach were summarized and evaluated. A total of 33 articles (23 CV, eight cancer, two respiratory) were accepted for detailed analysis. Decision trees, Markov models, discrete event simulations, and hybrids were used. Event rates were incorporated either as constant rates, time-dependent risks, or risk equations based on patient characteristics. Risks dependent on time and/or patient characteristics were used where major event rates were >1%/year in models with fewer health states (<7). Models of infrequent events or with numerous health states generally preferred constant event rates. The detailed modeling information and terminology varied, sometimes requiring interpretation. Key considerations for cost-effectiveness models incorporating hard end-point data include the frequency and characteristics of the relevant clinical events and how the trial data is reported. When event risk is low, simplification of both the model structure and event rate modeling is recommended. When event risk is common, such as in high risk populations, more detailed modeling approaches, including individual simulations or explicitly time-dependent event rates, are more appropriate to accurately reflect the trial data.

Calculating the number of shock waves, expulsion time, and optimum stone parameters based on noncontrast computerized tomography characteristics.

PubMed

Foda, Khaled; Abdeldaeim, Hussein; Youssif, Mohamed; Assem, Akram

2013-11-01

To define the parameters that accompanied a successful extracorporeal shock wave lithotripsy (ESWL), namely the number of shock waves (SWs), expulsion time (ET), mean stone density (MSD), and the skin-to-stone distance (SSD). A total of 368 patients diagnosed with renal calculi using noncontrast computerized tomography had their MSD, diameter, and SSD recorded. All patients were treated using a Siemens lithotripter. ESWL success meant a stone-free status or presence of residual fragments <3 mm, ET was the time in days for the successful clearance of stone fragments. Correlation was performed between the stone characteristics, number of SWs, and ET. Two multiple regression analysis models defined the number of SWs and ET. Two receiver operating characteristic curves plotted the best MSD cutoff value and optimum SSD for a successful ESWL. Three hundred one patients were ESWL successes. A significant positive correlation was elicited between number of SWs and stone diameter, density and SSD; between ET and stone diameter and density. Multiple regressions concluded 2 equations: Number of SWs = 265.108 + 5.103 x1 + 22.39 x2 + 10.931 x3 ET (days) = -10.85 + 0.031 x1 + 2.11 x2 x1 = stone density (Hounsfield unit [HUs]), x2 = stone diameter (mm), and x3 = SSD (mm). Receiver operating characteristic curves demonstrated a cutoff value of ≤ 934 HUs with 94.4% sensitivity and 66.7% specificity and P = .0211. The SSD curve showed that a distance ≤ 99 mm was 85.7% sensitive, 87.5% specific, P <.0001. Stone disintegration is not recommended if MSD is >934 HUs and SSD >99 mm. The required number of SWs and the expected ET can be anticipated. Copyright © 2013 Elsevier Inc. All rights reserved.

Exploring the time course of face matching: temporal constraints impair unfamiliar face identification under temporally unconstrained viewing.

PubMed

Ozbek, Müge; Bindemann, Markus

2011-10-01

The identification of unfamiliar faces has been studied extensively with matching tasks, in which observers decide if pairs of photographs depict the same person (identity matches) or different people (mismatches). In experimental studies in this field, performance is usually self-paced under the assumption that this will encourage best-possible accuracy. Here, we examined the temporal characteristics of this task by limiting display times and tracking observers' eye movements. Observers were required to make match/mismatch decisions to pairs of faces shown for 200, 500, 1000, or 2000ms, or for an unlimited duration. Peak accuracy was reached within 2000ms and two fixations to each face. However, intermixing exposure conditions produced a context effect that generally reduced accuracy on identity mismatch trials, even when unlimited viewing of faces was possible. These findings indicate that less than 2s are required for face matching when exposure times are variable, but temporal constraints should be avoided altogether if accuracy is truly paramount. The implications of these findings are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Numerical Analysis of Heat Transfer During Quenching Process

NASA Astrophysics Data System (ADS)

Madireddi, Sowjanya; Krishnan, Krishnan Nambudiripad; Reddy, Ammana Satyanarayana

2018-04-01

A numerical model is developed to simulate the immersion quenching process of metals. The time of quench plays an important role if the process involves a defined step quenching schedule to obtain the desired characteristics. Lumped heat capacity analysis used for this purpose requires the value of heat transfer coefficient, whose evaluation requires large experimental data. Experimentation on a sample work piece may not represent the actual component which may vary in dimension. A Fluid-Structure interaction technique with a coupled interface between the solid (metal) and liquid (quenchant) is used for the simulations. Initial times of quenching shows boiling heat transfer phenomenon with high values of heat transfer coefficients (5000-2.5 × 105 W/m2K). Shape of the work piece with equal dimension shows less influence on the cooling rate Non-uniformity in hardness at the sharp corners can be reduced by rounding off the edges. For a square piece of 20 mm thickness, with 3 mm fillet radius, this difference is reduced by 73 %. The model can be used for any metal-quenchant combination to obtain time-temperature data without the necessity of experimentation.

Rapid Identification of Mycobacterial Whole Cells in Solid and Liquid Culture Media by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry ▿

PubMed Central

Lotz, Aurélie; Ferroni, Agnès; Beretti, Jean-Luc; Dauphin, Brunhilde; Carbonnelle, Etienne; Guet-Revillet, Hélène; Veziris, Nicolas; Heym, Béate; Jarlier, Vincent; Gaillard, Jean-Louis; Pierre-Audigier, Catherine; Frapy, Eric; Berche, Patrick; Nassif, Xavier; Bille, Emmanuelle

2010-01-01

Mycobacterial identification is based on several methods: conventional biochemical tests that require several weeks for accurate identification, and molecular tools that are now routinely used. However, these techniques are expensive and time-consuming. In this study, an alternative method was developed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). This approach allows a characteristic mass spectral fingerprint to be obtained from whole inactivated mycobacterial cells. We engineered a strategy based on specific profiles in order to identify the most clinically relevant species of mycobacteria. To validate the mycobacterial database, a total of 311 strains belonging to 31 distinct species and 4 species complexes grown in Löwenstein-Jensen (LJ) and liquid (mycobacterium growth indicator tube [MGIT]) media were analyzed. No extraction step was required. Correct identifications were obtained for 97% of strains from LJ and 77% from MGIT media. No misidentification was noted. Our results, based on a very simple protocol, suggest that this system may represent a serious alternative for clinical laboratories to identify mycobacterial species. PMID:20943874

A look at motion in the frequency domain

NASA Technical Reports Server (NTRS)

Watson, A. B.; Ahumada, A. J., Jr.

1983-01-01

A moving image can be specified by a contrast distribution, c(x,y,t), over the dimensions of space x,y, and time t. Alternatively, it can be specified by the distribution C(u,v,w) over spatial frequency u,v and temporal frequency w. The frequency representation of a moving image is shown to have a characteristic form. This permits two useful observations. The first is that the apparent smoothness of time-sampled moving images (apparent motion) can be explained by the filtering action of the human visual system. This leads to the following formula for the required update rate for time-sampled displays. W(c)=W(l)+ru(l) where w(c) is the required update rate in Hz, W(l) is the limit of human temporal resolution in Hz, r is the velocity of the moving image in degrees/sec, and u(l) is the limit of human spatial resolution in cycles/deg. The second observation is that it is possible to construct a linear sensor that responds to images moving in a particular direction. The sensor is derived and its properties are discussed.

The adaption and use of research codes for performance assessment

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

Liebetrau, A.M.

1987-05-01

Models of real-world phenomena are developed for many reasons. The models are usually, if not always, implemented in the form of a computer code. The characteristics of a code are determined largely by its intended use. Realizations or implementations of detailed mathematical models of complex physical and/or chemical processes are often referred to as research or scientific (RS) codes. Research codes typically require large amounts of computing time. One example of an RS code is a finite-element code for solving complex systems of differential equations that describe mass transfer through some geologic medium. Considerable computing time is required because computationsmore » are done at many points in time and/or space. Codes used to evaluate the overall performance of real-world physical systems are called performance assessment (PA) codes. Performance assessment codes are used to conduct simulated experiments involving systems that cannot be directly observed. Thus, PA codes usually involve repeated simulations of system performance in situations that preclude the use of conventional experimental and statistical methods. 3 figs.« less

Improving Gastric Cancer Outcome Prediction Using Single Time-Point Artificial Neural Network Models

PubMed Central

Nilsaz-Dezfouli, Hamid; Abu-Bakar, Mohd Rizam; Arasan, Jayanthi; Adam, Mohd Bakri; Pourhoseingholi, Mohamad Amin

2017-01-01

In cancer studies, the prediction of cancer outcome based on a set of prognostic variables has been a long-standing topic of interest. Current statistical methods for survival analysis offer the possibility of modelling cancer survivability but require unrealistic assumptions about the survival time distribution or proportionality of hazard. Therefore, attention must be paid in developing nonlinear models with less restrictive assumptions. Artificial neural network (ANN) models are primarily useful in prediction when nonlinear approaches are required to sift through the plethora of available information. The applications of ANN models for prognostic and diagnostic classification in medicine have attracted a lot of interest. The applications of ANN models in modelling the survival of patients with gastric cancer have been discussed in some studies without completely considering the censored data. This study proposes an ANN model for predicting gastric cancer survivability, considering the censored data. Five separate single time-point ANN models were developed to predict the outcome of patients after 1, 2, 3, 4, and 5 years. The performance of ANN model in predicting the probabilities of death is consistently high for all time points according to the accuracy and the area under the receiver operating characteristic curve. PMID:28469384

VALDRIFT 1.0: A valley atmospheric dispersion model with deposition

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

Allwine, K.J.; Bian, X.; Whiteman, C.D.

1995-05-01

VALDRIFT version 1.0 is an atmospheric transport and diffusion model for use in well-defined mountain valleys. It is designed to determine the extent of ddft from aedal pesticide spraying activities, but can also be applied to estimate the transport and diffusion of various air pollutants in valleys. The model is phenomenological -- that is, the dominant meteorological processes goveming the behavior of the valley atmosphere are formulated explicitly in the model, albeit in a highly parameterized fashion. The key meteorological processes treated are: (1) nonsteady and nonhomogeneous along-valley winds and turbulent diffusivities, (2) convective boundary layer growth, (3) inversion descent,more » (4) noctumal temperature inversion breakup, and (5) subsidence. The model is applicable under relatively cloud-free, undisturbed synoptic conditions and is configured to operate through one diumal cycle for a single valley. The inputs required are the valley topographical characteristics, pesticide release rate as a function of time and space, along-valley wind speed as a function of time and space, temperature inversion characteristics at sunrise, and sensible heat flux as a function of time following sunrise. Default values are provided for certain inputs in the absence of detailed observations. The outputs are three-dimensional air concentration and ground-level deposition fields as a function of time.« less

Psychoacoustic Analysis of Synthesized Jet Noise

NASA Technical Reports Server (NTRS)

Okcu, Selen; Rathsam, Jonathan; Rizzi, Stephen A.

2013-01-01

An aircraft noise synthesis capability is being developed so the annoyance caused by proposed aircraft can be assessed during the design stage. To make synthesized signals as realistic as possible, high fidelity simulation is required for source (e.g., engine noise, airframe noise), propagation and receiver effects. This psychoacoustic study tests whether the jet noise component of synthesized aircraft engine noise can be made more realistic using a low frequency oscillator (LFO) technique to simulate fluctuations in level observed in recordings. Jet noise predictions are commonly made in the frequency domain based on models of time-averaged empirical data. The synthesis process involves conversion of the frequency domain prediction into an audible pressure time history. However, because the predictions are time-invariant, the synthesized sound lacks fluctuations observed in recordings. Such fluctuations are hypothesized to be perceptually important. To introduce time-varying characteristics into jet noise synthesis, a method has been developed that modulates measured or predicted 1/3-octave band levels with a (<20Hz) LFO. The LFO characteristics are determined through analysis of laboratory jet noise recordings. For the aft emission angle, results indicate that signals synthesized using a generic LFO are perceived as more similar to recordings than those using no LFO, and signals synthesized with an angle-specific LFO are more similar to recordings than those synthesized with a generic LFO.

Not all trust is created equal: dispositional and history-based trust in human-automation interactions.

PubMed

Merritt, Stephanie M; Ilgen, Daniel R

2008-04-01

We provide an empirical demonstration of the importance of attending to human user individual differences in examinations of trust and automation use. Past research has generally supported the notions that machine reliability predicts trust in automation, and trust in turn predicts automation use. However, links between user personality and perceptions of the machine with trust in automation have not been empirically established. On our X-ray screening task, 255 students rated trust and made automation use decisions while visually searching for weapons in X-ray images of luggage. We demonstrate that individual differences affect perceptions of machine characteristics when actual machine characteristics are constant, that perceptions account for 52% of trust variance above the effects of actual characteristics, and that perceptions mediate the effects of actual characteristics on trust. Importantly, we also demonstrate that when administered at different times, the same six trust items reflect two types of trust (dispositional trust and history-based trust) and that these two trust constructs are differentially related to other variables. Interactions were found among user characteristics, machine characteristics, and automation use. Our results suggest that increased specificity in the conceptualization and measurement of trust is required, future researchers should assess user perceptions of machine characteristics in addition to actual machine characteristics, and incorporation of user extraversion and propensity to trust machines can increase prediction of automation use decisions. Potential applications include the design of flexible automation training programs tailored to individuals who differ in systematic ways.

Development and application of a model for the analysis of trades between space launch system operations and acquisition costs

NASA Astrophysics Data System (ADS)

Nix, Michael B.

2005-12-01

Early design decisions in the development of space launch systems determine the costs to acquire and operate launch systems. Some sources indicate that as much as 90% of life cycle costs are fixed by the end of the critical design review phase. System characteristics determined by these early decisions are major factors in the acquisition cost of flight hardware elements and facilities and influence operations costs through the amount of maintenance and support labor required to sustain system function. Operations costs are also dependent on post-development management decisions regarding how much labor will be deployed to meet requirements of market demand and ownership profit. The ability to perform early trade-offs between these costs is vital to the development of systems that have the necessary capacity to provide service and are profitable to operate. An Excel-based prototype model was developed for making early analyses of trade-offs between the costs to operate a space launch system and to acquire the necessary assets to meet a given set of operational requirements. The model, integrating input from existing models and adding missing capability, allows the user to make such trade-offs across a range of operations concepts (required flight rates, staffing levels, shifts per workday, workdays per week and per year, unreliability, wearout and depot maintenance) and the number, type and capability of assets (flight hardware elements, processing and supporting facilities and infrastructure). The costs and capabilities of hypothetical launch systems can be modeled as a function of interrelated turnaround times and labor resource levels, and asset loss and retirement. The number of flight components and facilities required can be calculated and the operations and acquisition costs compared for a specified scenario. Findings, based on the analysis of a hypothetical two stage to orbit, reusable, unmanned launch system, indicate that the model is suitable for the trade-off analyses desired. The minimum turnaround time/maximum labor allocation for specific hardware configurations and characteristics and corresponding asset requirements can be estimated. Either turnaround time or resources can be varied and the resulting operations and acquisition costs can be compared. Asset reliability, wearout and depot maintenance intervals and durations can be varied as well to analyze the effects on costs. Likewise, the effects on operations and acquisitions costs of the introduction of alternative technologies that affect reliability, maintainability and supportability in various hardware configurations can be evaluated.

Automatic detection and analysis of cell motility in phase-contrast time-lapse images using a combination of maximally stable extremal regions and Kalman filter approaches.

PubMed

Kaakinen, M; Huttunen, S; Paavolainen, L; Marjomäki, V; Heikkilä, J; Eklund, L

2014-01-01

Phase-contrast illumination is simple and most commonly used microscopic method to observe nonstained living cells. Automatic cell segmentation and motion analysis provide tools to analyze single cell motility in large cell populations. However, the challenge is to find a sophisticated method that is sufficiently accurate to generate reliable results, robust to function under the wide range of illumination conditions encountered in phase-contrast microscopy, and also computationally light for efficient analysis of large number of cells and image frames. To develop better automatic tools for analysis of low magnification phase-contrast images in time-lapse cell migration movies, we investigated the performance of cell segmentation method that is based on the intrinsic properties of maximally stable extremal regions (MSER). MSER was found to be reliable and effective in a wide range of experimental conditions. When compared to the commonly used segmentation approaches, MSER required negligible preoptimization steps thus dramatically reducing the computation time. To analyze cell migration characteristics in time-lapse movies, the MSER-based automatic cell detection was accompanied by a Kalman filter multiobject tracker that efficiently tracked individual cells even in confluent cell populations. This allowed quantitative cell motion analysis resulting in accurate measurements of the migration magnitude and direction of individual cells, as well as characteristics of collective migration of cell groups. Our results demonstrate that MSER accompanied by temporal data association is a powerful tool for accurate and reliable analysis of the dynamic behaviour of cells in phase-contrast image sequences. These techniques tolerate varying and nonoptimal imaging conditions and due to their relatively light computational requirements they should help to resolve problems in computationally demanding and often time-consuming large-scale dynamical analysis of cultured cells. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

A study of low-cost reliable actuators for light aircraft. Part A: Chapters 1-8

NASA Technical Reports Server (NTRS)

Eijsink, H.; Rice, M.

1978-01-01

An analysis involving electro-mechanical, electro-pneumatic, and electro-hydraulic actuators was performed to study which are compatible for use in the primary and secondary flight controls of a single engine light aircraft. Actuator characteristics under investigation include cost, reliability, weight, force, volumetric requirements, power requirements, response characteristics and heat accumulation characteristics. The basic types of actuators were compared for performance characteristics in positioning a control surface model and then were mathematically evaluated in an aircraft to get the closed loop dynamic response characteristics. Conclusions were made as to the suitability of each actuator type for use in an aircraft.

Decomposition-Based Decision Making for Aerospace Vehicle Design

NASA Technical Reports Server (NTRS)

Borer, Nicholas K.; Mavris, DImitri N.

2005-01-01

Most practical engineering systems design problems have multiple and conflicting objectives. Furthermore, the satisfactory attainment level for each objective ( requirement ) is likely uncertain early in the design process. Systems with long design cycle times will exhibit more of this uncertainty throughout the design process. This is further complicated if the system is expected to perform for a relatively long period of time, as now it will need to grow as new requirements are identified and new technologies are introduced. These points identify a need for a systems design technique that enables decision making amongst multiple objectives in the presence of uncertainty. Traditional design techniques deal with a single objective or a small number of objectives that are often aggregates of the overarching goals sought through the generation of a new system. Other requirements, although uncertain, are viewed as static constraints to this single or multiple objective optimization problem. With either of these formulations, enabling tradeoffs between the requirements, objectives, or combinations thereof is a slow, serial process that becomes increasingly complex as more criteria are added. This research proposal outlines a technique that attempts to address these and other idiosyncrasies associated with modern aerospace systems design. The proposed formulation first recasts systems design into a multiple criteria decision making problem. The now multiple objectives are decomposed to discover the critical characteristics of the objective space. Tradeoffs between the objectives are considered amongst these critical characteristics by comparison to a probabilistic ideal tradeoff solution. The proposed formulation represents a radical departure from traditional methods. A pitfall of this technique is in the validation of the solution: in a multi-objective sense, how can a decision maker justify a choice between non-dominated alternatives? A series of examples help the reader to observe how this technique can be applied to aerospace systems design and compare the results of this so-called Decomposition-Based Decision Making to more traditional design approaches.

Recovering the time-variable gravitational field using satellite gradiometry: requirements and gradiometer concept

NASA Astrophysics Data System (ADS)

Douch, Karim; Müller, Jürgen; Heinzel, Gerhard; Wu, Hu

2017-04-01

The successful GRACE mission and its far-reaching benefits have highlighted the interest to continue and extend the mapping of the Earth's time-variable gravitational field with follow-on missions and ideally a higher spatiotemporal resolution. Here, we would like to put forward satellite gravitational gradiometry as an alternative solution to satellite-to-satellite tracking for future missions. Besides the higher sensitivity to smaller scales compared to GRACE-like missions, a gradiometry mission would only require one satellite and would provide a direct estimation of a functional of the gravitational field. GOCE, the only gradiometry mission launched so far, was not sensitive enough to map the time-variable part of the gravity field. However, the unprecedented precision of the state-of-the-art optical metrology system on-board the LISA PATHFINDER satellite has opened the way to more performant space inertial sensors. We will therefore examine whether it is technically possible to go beyond GOCE performances and to quantify to what extent the time-variable gravitational field could be determined. First, we derive the requirements on the knowledge of the attitude and the position of the satellite and on the measured gradients in terms of sensitivity and calibration accuracy for a typical repeat low-orbit. We conclude in particular that a noise level smaller than 0.1 mE/√Hz- is required in the measurement bandwidth [5x10-4 ; 10-2]Hz so as to be sensitive to the time-variable gravity signal. We introduce then the design and characteristics of the new gradiometer concept and give an assessment of its noise budget. Contrary to the GOCE electrostatic gradiometer, the position of the test-mass in the accelerometer is measured here by laser interferometry rather than by a capacitive readout system, which improves the overall measurement chain. Finally, the first results of a performance analysis carried out thanks to an end-to-end simulator are discussed and compared to the previously defined requirements.

The development of a peak-time criterion for designing controlled-release devices.

PubMed

Simon, Laurent; Ospina, Juan

2016-08-25

This work consists of estimating dynamic characteristics for topically-applied drugs when the magnitude of the flux increases to a maximum value, called peak flux, before declining to zero. This situation is typical of controlled-released systems with a finite donor or vehicle volume. Laplace transforms were applied to the governing equations and resulted in an expression for the flux in terms of the physical characteristics of the system. After approximating this function by a second-order model, three parameters of this reduced structure captured the essential features of the original process. Closed-form relationships were then developed for the peak flux and time-to-peak based on the empirical representation. Three case studies that involve mechanisms, such as diffusion, partitioning, dissolution and elimination, were selected to illustrate the procedure. The technique performed successfully as shown by the ability of the second-order flux to match the prediction of the original transport equations. A main advantage of the proposed method is that it does not require a solution of the original partial differential equations. Less accurate results were noted for longer lag times. Copyright © 2016 Elsevier B.V. All rights reserved.

The COMPASS study: a longitudinal hierarchical research platform for evaluating natural experiments related to changes in school-level programs, policies and built environment resources.

PubMed

Leatherdale, Scott T; Brown, K Stephen; Carson, Valerie; Childs, Ruth A; Dubin, Joel A; Elliott, Susan J; Faulkner, Guy; Hammond, David; Manske, Steve; Sabiston, Catherine M; Laxer, Rachel E; Bredin, Chad; Thompson-Haile, Audra

2014-04-08

Few researchers have the data required to adequately understand how the school environment impacts youth health behaviour development over time. COMPASS is a prospective cohort study designed to annually collect hierarchical longitudinal data from a sample of 90 secondary schools and the 50,000+ grade 9 to 12 students attending those schools. COMPASS uses a rigorous quasi-experimental design to evaluate how changes in school programs, policies, and/or built environment (BE) characteristics are related to changes in multiple youth health behaviours and outcomes over time. These data will allow for the quasi-experimental evaluation of natural experiments that will occur within schools over the course of COMPASS, providing a means for generating "practice based evidence" in school-based prevention programming. COMPASS is the first study with the infrastructure to robustly evaluate the impact that changes in multiple school-level programs, policies, and BE characteristics within or surrounding a school might have on multiple youth health behaviours or outcomes over time. COMPASS will provide valuable new insight for planning, tailoring and targeting of school-based prevention initiatives where they are most likely to have impact.

Comparison between Field Effect Transistors and Bipolar Junction Transistors as Transducers in Electrochemical Sensors

NASA Astrophysics Data System (ADS)

Zafar, Sufi; Lu, Minhua; Jagtiani, Ashish

2017-01-01

Field effect transistors (FET) have been widely used as transducers in electrochemical sensors for over 40 years. In this report, a FET transducer is compared with the recently proposed bipolar junction transistor (BJT) transducer. Measurements are performed on two chloride electrochemical sensors that are identical in all details except for the transducer device type. Comparative measurements show that the transducer choice significantly impacts the electrochemical sensor characteristics. Signal to noise ratio is 20 to 2 times greater for the BJT sensor. Sensitivity is also enhanced: BJT sensing signal changes by 10 times per pCl, whereas the FET signal changes by 8 or less times. Also, sensor calibration curves are impacted by the transducer choice. Unlike a FET sensor, the calibration curve of the BJT sensor is independent of applied voltages. Hence, a BJT sensor can make quantitative sensing measurements with minimal calibration requirements, an important characteristic for mobile sensing applications. As a demonstration for mobile applications, these BJT sensors are further investigated by measuring chloride levels in artificial human sweat for potential cystic fibrosis diagnostic use. In summary, the BJT device is demonstrated to be a superior transducer in comparison to a FET in an electrochemical sensor.

Comparison between Field Effect Transistors and Bipolar Junction Transistors as Transducers in Electrochemical Sensors

PubMed Central

Zafar, Sufi; Lu, Minhua; Jagtiani, Ashish

2017-01-01

Field effect transistors (FET) have been widely used as transducers in electrochemical sensors for over 40 years. In this report, a FET transducer is compared with the recently proposed bipolar junction transistor (BJT) transducer. Measurements are performed on two chloride electrochemical sensors that are identical in all details except for the transducer device type. Comparative measurements show that the transducer choice significantly impacts the electrochemical sensor characteristics. Signal to noise ratio is 20 to 2 times greater for the BJT sensor. Sensitivity is also enhanced: BJT sensing signal changes by 10 times per pCl, whereas the FET signal changes by 8 or less times. Also, sensor calibration curves are impacted by the transducer choice. Unlike a FET sensor, the calibration curve of the BJT sensor is independent of applied voltages. Hence, a BJT sensor can make quantitative sensing measurements with minimal calibration requirements, an important characteristic for mobile sensing applications. As a demonstration for mobile applications, these BJT sensors are further investigated by measuring chloride levels in artificial human sweat for potential cystic fibrosis diagnostic use. In summary, the BJT device is demonstrated to be a superior transducer in comparison to a FET in an electrochemical sensor. PMID:28134275

Photoelectric professional students in common universities cultivate way to explore under the background of professional certification

NASA Astrophysics Data System (ADS)

Sun, Yan-jun; Wang, Li; Leng, Yan-bing

2017-08-01

In view of the engineering education professional certification of specialty construction and the specific requirements of the training system, combining with our school optoelectronic information science and engineering characteristics, analysis of the optoelectronic information science and engineering in our school problems and challenges, to locate the specific professional training objectives. From the service oriented industry demand for talent ability, at the same time, according to the ministry of education professional norms of the development of the photoelectric teaching steering committee, and the professional development and the characteristics of target, to build a set to conform to the goal of cultivating the professional curriculum system. At the same time set up a from fundamental to professional practice teaching system, covers the course experiment, course design, case teaching, comprehensive training, such as graduation design practice. Which implements a whole ability training from the practice of foundation to high-end chain, embodies the training goal emphasize "outstanding practical skills, quality education is distinct culture characteristic. By further speed up the professional construction, professional certification standards to standardize our training process, improved the level of professional training, and improve the comprehensive quality of the graduates and talent of social competitiveness, fostered more professional talents for the country.

Remote Sensing and Geochemistry of Planetary Surfaces

NASA Technical Reports Server (NTRS)

Jakosky, Bruce M.

2002-01-01

We have been examining the resources required to support potential life on Mars, as a way of understanding the possible abundance and distribution of life. Based on our understanding of the Earth, the necessary requirements for the environment to allow it to support life are (i) presence of liquid water, (ii) access to the biogenic elements (C, H, O, N, S, P, Ca, Fe, etc.), and (iii) a source of energy to drive chemical disequilibrium, such that the reactions back toward equilibrium can release energy to support metabolism. While even demonstrating that all of these requirements have been met would not mean that life would necessarily exist on Mars, they provide the context in which a search for life or analysis of geochemical characteristics that might be indicative of life might be carried out. Our previous work has focused on the first and third of these characteristics determine where and when liquid water might have been present, and understanding the availability of chemical energy from weathering reactions that might ID support life. In the analysis supported by this grant (covering the time period 2/15/01-2/14/02), we have been examining the second requirement--the abundance of the necessary biogenic elements, their geographical distribution on Mars and the information on the possible vertical distribution within the crust, and their geochemical accessibility and mobility within the crust and at the surface. In particular, our work during the performance period has emphasized phosphorous.

78 FR 15112 - Rulemaking Advisory Committee; Transport Airplane Performance and Handling Characteristics-New Task

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-08

... coordination with other working groups. 2. Takeoff and Landing Performance. Regulatory requirements and... Committee; Transport Airplane Performance and Handling Characteristics--New Task AGENCY: Federal Aviation... new or revised requirements and guidance material for airplane performance and handling...

Requirements for satisfactory flying qualities of airplanes

NASA Technical Reports Server (NTRS)

Gilruth, R R

1943-01-01

Report discusses the results of an analysis of available data to determine what measured characteristics are significant in defining satisfactory flying qualities, what characteristics are reasonable to require of an airplane, and what influence the various design features have on the observed flying qualities.

Electric charge requirements of pediatric cochlear implant recipients enrolled in the Childhood Development After Cochlear Implantation study.

PubMed

Zwolan, Teresa A; O'Sullivan, Mary Beth; Fink, Nancy E; Niparko, John K

2008-02-01

To evaluate mapping characteristics of children with cochlear implants who are enrolled in the Childhood Development After Cochlear Implantation (CDACI) multicenter study. Longitudinal evaluation during 24 months of speech processor maps of children with cochlear implants prospectively enrolled in the study. Six tertiary referral centers. One hundred eighty-eight children enrolled in the CDACI study who were 5 years old or younger at the time of enrollment. Of these children, 184 received unilateral implants, and 4 received simultaneous bilateral implants. Children attended regular mapping sessions at their implant clinic as part of the study protocol. Maps were examined for each subject at 4 different time intervals: at device activation and 6, 12, and 24 months postactivation. Mean C/M levels (in charge per phase) were compared for 4 different time intervals, for 3 different devices, for 6 different implant centers, and for children with normal and abnormal cochleae. All 3 types of implant devices demonstrate significant increases in C/M levels between device activation and the 24-month appointment. Significant differences in mean C/M levels were noted between devices. Children with cochlear anomalies demonstrate significantly greater C/M levels than children with normal cochleae. The CDACI study has enabled us to evaluate the mapping characteristics of pediatric patients who use 3 different devices and were implanted at a variety of implant centers. Analysis of such data enables us to better understand the mapping characteristics of children with cochlear implants.

Prediction of Aerodynamic Characteristics of Fighter Wings at High Angles of Attack.

DTIC Science & Technology

1984-03-01

potential distribution throughout the network of four points on a body surface great- ly facilitates the flow analysis procedure. Tangential velocity...expensive of computer time. For example, as quoted by McLean, using this coarsest grid network , each 0 surface of the 727-200 wing required 10 minutes of...1980. 19. Le Balleur, J.C. and Neron , M., "Calcul D’Ecoulements3 Visqueux Decolles sur Profils D’Ailes par une Approche de Couplage", AGARn CP-291

Design criteria for a self-actuated shutdown system to ensure limitation of core damage. [LMFBR

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

Deane, N.A.; Atcheson, D.B.

1981-09-01

Safety-based functional requirements and design criteria for a self-actuated shutdown system (SASS) are derived in accordance with LOA-2 success criteria and reliability goals. The design basis transients have been defined and evaluated for the CDS Phase II design, which is a 2550 MWt mixed oxide heterogeneous core reactor. A partial set of reactor responses for selected transients is provided as a function of SASS characteristics such as reactivity worth, trip points, and insertion times.

Design manual: Oxygen Thermal Test Article (OTTA)

NASA Technical Reports Server (NTRS)

Chronic, W. L.; Baese, C. L.; Conder, R. L.

1974-01-01

The characteristics of a cryogenic tank for storing liquid hydrogen, nitrogen, oxygen, methane, or helium for an extended period of time with minimum losses are discussed. A description of the tank and control module, assembly drawings and details of major subassemblies, specific requirements controlling development of the system, thermal concept considerations, thermal analysis methods, and a record of test results are provided. The oxygen thermal test article thermal protection system has proven that the insulation system for cryogenic vessels is effective.

Proceedings of the Conference on the Design of Experiments in Army Research Development and Testing (21st)

DTIC Science & Technology

1976-05-01

treatment groups are in the ctual treatment received. This requires comparability of patients as they are intered into study , managed when on study , and...at time of entry into study is to select patients for a control group according to certain characteristics, namely those which are known to influence...control group of B patients could be selected from the literature, chosen on a matched basis from previously or concurrently conducted clinical studies