Space station needs, attributes and architectural options study commercialization working group briefing

NASA Technical Reports Server (NTRS)

1983-01-01

The benefits for each of the following commercial areas was investigated: communications, remote sensing, materials processing in space, low Earth orbit (LEO) satellite assembly, testing, and servicing, and space tourism. In each case, where economic benefits are derived, the costs for accomplishing tasks with the Space Station are compared with the cost with the Space Transportation System only.

Study of low-cost fabrication of ablative heat shields

NASA Technical Reports Server (NTRS)

Norwood, L. B.

1972-01-01

The major objectives were accomplished in three tasks: (1) modification of the ablative material composition for ease of fabrication as well as thermal and mechanical performance; (2) scaled-up, simplified, manufacturing techniques which resulted in cost reductions; and (3) the identification of a significant design problem caused by the differential pressure buildup imposed on mechanically attached ablative heat shield panels during launch.

Age-Related Differences in Transfer Costs: Evidence From Go/Nogo Tasks

PubMed Central

Vallesi, Antonino; Hasher, Lynn; Stuss, Donald T.

2012-01-01

To assess whether age-related differences in suppressing nontarget material impact subsequent performance, the authors initially asked younger and older adults to perform a go/nogo task with colored letters used as conflicting go/nogo stimuli and 2 colored numbers as low-conflict nogo stimuli. Next, participants performed another go/nogo task. A previous number was reused as a nogo stimulus and the other as a go stimulus, with new numbers serving as a baseline. In a 1st block of trials, younger adults showed slower responses to previous nogo/now-go numbers than to new go numbers, an effect not shown by older adults. Alternative accounts of these differential transfer costs are discussed. PMID:20718536

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystem Concepts. Volume 1; Executive Summary

NASA Technical Reports Server (NTRS)

Levack, Daniel J. H.

2000-01-01

The Alternate Propulsion Subsystem Concepts contract had seven tasks defined that are reported under this contract deliverable. The tasks were: FAA Restart Study, J-2S Restart Study, Propulsion Database Development. SSME Upper Stage Use. CERs for Liquid Propellant Rocket Engines. Advanced Low Cost Engines, and Tripropellant Comparison Study. The two restart studies, F-1A and J-2S, generated program plans for restarting production of each engine. Special emphasis was placed on determining changes to individual parts due to obsolete materials, changes in OSHA and environmental concerns, new processes available, and any configuration changes to the engines. The Propulsion Database Development task developed a database structure and format which is easy to use and modify while also being comprehensive in the level of detail available. The database structure included extensive engine information and allows for parametric data generation for conceptual engine concepts. The SSME Upper Stage Use task examined the changes needed or desirable to use the SSME as an upper stage engine both in a second stage and in a translunar injection stage. The CERs for Liquid Engines task developed qualitative parametric cost estimating relationships at the engine and major subassembly level for estimating development and production costs of chemical propulsion liquid rocket engines. The Advanced Low Cost Engines task examined propulsion systems for SSTO applications including engine concept definition, mission analysis. trade studies. operating point selection, turbomachinery alternatives, life cycle cost, weight definition. and point design conceptual drawings and component design. The task concentrated on bipropellant engines, but also examined tripropellant engines. The Tripropellant Comparison Study task provided an unambiguous comparison among various tripropellant implementation approaches and cycle choices, and then compared them to similarly designed bipropellant engines in the SSTO mission This volume overviews each of the tasks giving its objectives, main results. and conclusions. More detailed Final Task Reports are available on each individual task.

Low cost solar array project. Task 1: Silicon material, gaseous melt replenishment system

NASA Technical Reports Server (NTRS)

Jewett, D. N.; Bates, H. E.; Hill, D. M.

1979-01-01

A system to combine silicon formation, by hydrogen reduction of trichlorosilane, with the capability to replenish a crystal growth system is described. A variety of process parameters to allow sizing and specification of gas handling system components was estimated.

Adapting to the 30-degree visual perspective by emulating the angled laparoscope: a simple and low-cost solution for basic surgical training.

PubMed

Daniel, Lorias Espinoza; Tapia, Fernando Montes; Arturo, Minor Martínez; Ricardo, Ordorica Flores

2014-12-01

The ability to handle and adapt to the visual perspectives generated by angled laparoscopes is crucial for skilled laparoscopic surgery. However, the control of the visual work space depends on the ability of the operator of the camera, who is often not the most experienced member of the surgical team. Here, we present a simple, low-cost option for surgical training that challenges the learner with static and dynamic visual perspectives at 30 degrees using a system that emulates the angled laparoscope. A system was developed using a low-cost camera and readily available materials to emulate the angled laparoscope. Nine participants undertook 3 tasks to test spatial adaptation to the static and dynamic visual perspectives at 30 degrees. Completing each task to a predefined satisfactory level ensured precision of execution of the tasks. Associated metrics (time and error rate) were recorded, and the performance of participants were determined. A total of 450 repetitions were performed by 9 residents at various stages of training. All the tasks were performed with a visual perspective of 30 degrees using the system. Junior residents were more proficient than senior residents. This system is a viable and low-cost alternative for developing the basic psychomotor skills necessary for the handling and adaptation to visual perspectives of 30 degrees, without depending on a laparoscopic tower, in junior residents. More advanced skills may then be acquired by other means, such as in the operating theater or through clinical experience.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, materials costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structure. Key technologies, such as large crown panel fabrication, were pursued for low cost. An intricate bond panel design and manufacturing concept were selected based on the efforts of the Design Build Team. The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and use of low cost materials forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing costs by 18 pct. and weight by 45 pct. relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, material costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structures. Boeing's efforts under the NASA ACT program have pursued key technologies for low-cost, large crown panel fabrication. An intricate bond panel design and manufacturing concepts were selected based on the efforts of the Design Build Team (DBT). The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with the Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and utilization of low-cost material forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing cost by 18 percent and weight by 45 percent relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Investigation of test methods, material properties and processes for solar cell encapsulants

NASA Technical Reports Server (NTRS)

Willis, P. B.; Baum, B.

1977-01-01

The potentially useful encapsulating materials for Task 3 of the Low-Cost Silicon Solar Array project were studied to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. Materials for study were chosen on the basis of existing knowledge of generic chemical types having high resistance to environmental weathering. The materials varied from rubbers to thermoplastics and presented a broad range of mechanical properties and processing requirements. Basic physical and optical properties were measured on the polymers and were redetermined after exposure to indoor artificial accelerated aging conditions covering four time periods. Strengths and weaknesses of the various materials were revealed and data was accumulated for the development of predictive methodologies. To date, silicone rubbers, fluorocarbons, and acrylic polymers appear to have the most promising combination of characteristics. The fluorocarbons may be used only as films, however, because of their high cost.

Low cost solar array project production process and equipment task. A Module Experimental Process System Development Unit (MEPSDU)

NASA Technical Reports Server (NTRS)

1981-01-01

Technical readiness for the production of photovoltaic modules using single crystal silicon dendritic web sheet material is demonstrated by: (1) selection, design and implementation of solar cell and photovoltaic module process sequence in a Module Experimental Process System Development Unit; (2) demonstration runs; (3) passing of acceptance and qualification tests; and (4) achievement of a cost effective module.

Georgetown University Integrated Community Energy System (GU-ICES). Phase III, Stage I. Feasibility analysis. Final report. Volume 1

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

None

This Feasibility Analysis covers a wide range of studies and evaluations. The Report is divided into five parts. Section 1 contains all material relating to the Institutional Assessment including consideration of the requirements and position of the Potomac Electric Co. as they relate to cogeneration at Georgetown in parallel with the utility (Task 1). Sections 2 through 7 contain all technical information relating to the Alternative Subsystems Analysis (Task 4). This includes the energy demand profiles upon which the evaluations were based (Task 3). It further includes the results of the Life-Cycle-Cost Analyses (Task 5) which are developed in detailmore » in the Appendix for evaluation in the Technical Report. Also included is the material relating to Incremental Savings and Optimization (Task 6) and the Conceptual Design for candidate alternate subsystems (Task 7). Section 8 contains all material relating to the Environmental Impact Assessment (Task 2). The Appendix contains supplementary material including the budget cost estimates used in the life-cycle-cost analyses, the basic assumptions upon which the life-cycle analyses were developed, and the detailed life-cycle-cost anlysis for each subsystem considered in detail.« less

JPL encapsulation task

NASA Technical Reports Server (NTRS)

Willis, P.

1986-01-01

A detailed summary of the diverse encapsulation materials and techniques that evolved to meet the cost goals of the Flat-plate Solar Array (FSA) Project is presented. A typical solar cell now consists of low iron glass, two layers of ethylene vinyl acetate (EVA) polymers, a porous space, primers/adhesives, a back cover of Tedlar, and a gasket/seal for a volume cost of $1.30/sq ft. This compares well with the project goal of $1.40/sq ft.

Investigation of test methods, material properties, and processes for solar cell encapsulants. Fourteenth quarterly progress report, August 12, 1978-November 12, 1979. [EVA, EPDM, aliphatic urethane, PVC plastisol, and butyl acrylate

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

Willis, P. B.; Baum, B.; Schnitzer, H. S.

1979-12-01

Springborn Laboratories is engaged in a study of evaluating potentially useful encapsulating materials for Task 3 of the Low-Cost Silicon Solar Array project (LSA) funded by DOE. The goal of this program is to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. This report presents the results of a cost analysis of candidate potting compounds for long life solar module encapsulation. Additionally, the two major encapsulation processes, sheet lamination and liquid casting, are costed on the basis of a large scale production facility. Potting compounds studied include EVA, sheet, clear; EVA,more » sheet, pigmented; EPDM, sheet, clear; Aliphatic urethane, syrup; PVC Plastisol; Butyl acrylate, syrup; and Butyl acrylate, sheet.« less

Evaluation of the ion implantation process for production of solar cells from silicon sheet materials

NASA Technical Reports Server (NTRS)

Spitzer, M. B.

1983-01-01

The objective of this program is the investigation and evaluation of the capabilities of the ion implantation process for the production of photovoltaic cells from a variety of present-day, state-of-the-art, low-cost silicon sheet materials. Task 1 of the program concerns application of ion implantation and furnace annealing to fabrication of cells made from dendritic web silicon. Task 2 comprises the application of ion implantation and pulsed electron beam annealing (PEBA) to cells made from SEMIX, SILSO, heat-exchanger-method (HEM), edge-defined film-fed growth (EFG) and Czochralski (CZ) silicon. The goals of Task 1 comprise an investigation of implantation and anneal processes applied to dendritic web. A further goal is the evaluation of surface passivation and back surface reflector formation. In this way, processes yielding the very highest efficiency can be evaluated. Task 2 seeks to evaluate the use of PEBA for various sheet materials. A comparison of PEBA to thermal annealing will be made for a variety of ion implantation processes.

Slicing of Silicon into Sheet Material. Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low Cost Solar Array Project

NASA Technical Reports Server (NTRS)

Fleming, J. R.; Holden, S. C.; Wolfson, R. G.

1979-01-01

The use of multiblade slurry sawing to produce silicon wafers from ingots was investigated. The commercially available state of the art process was improved by 20% in terms of area of silicon wafers produced from an ingot. The process was improved 34% on an experimental basis. Economic analyses presented show that further improvements are necessary to approach the desired wafer costs, mostly reduction in expendable materials costs. Tests which indicate that such reduction is possible are included, although demonstration of such reduction was not completed. A new, large capacity saw was designed and tested. Performance comparable with current equipment (in terms of number of wafers/cm) was demonstrated.

Toroid Joining Gun. [thermoplastic welding system using induction heating

NASA Technical Reports Server (NTRS)

Buckley, J. D.; Fox, R. L.; Swaim, R J.

1985-01-01

The Toroid Joining Gun is a low cost, self-contained, portable low powered (100-400 watts) thermoplastic welding system developed at Langley Research Center for joining plastic and composite parts using an induction heating technique. The device developed for use in the fabrication of large space sructures (LSST Program) can be used in any atmosphere or in a vacuum. Components can be joined in situ, whether on earth or on a space platform. The expanded application of this welding gun is in the joining of thermoplastic composites, thermosetting composites, metals, and combinations of these materials. Its low-power requirements, light weight, rapid response, low cost, portability, and effective joining make it a candidate for solving many varied and unique bonding tasks.

Development of a Novel Ultrasound-guided Peritonsillar Abscess Model for Simulation Training.

PubMed

Ng, Vivienne; Plitt, Jennifer; Biffar, David

2018-01-01

Peritonsillar abscess (PTA) is the most common deep space infection of the head and neck presenting to emergency departments.1 No commercial PTA task trainer exists for simulation training. Thus, resident physicians often perform their first PTA needle aspiration in the clinical setting, knowing that carotid artery puncture and hemorrhage are serious and devastating complications. While several low-fidelity PTA task trainers have been previously described, none allow for ultrasound image acquisition.6-9 We sought to create a cost-effective and realistic task trainer that allows trainees to acquire both diagnostic ultrasound and needle aspiration skills while draining a peritonsillar abscess. We built the task trainer with low-cost, replaceable, and easily cleanable materials. A damaged airway headskin was repurposed to build the model. A mesh wire cylinder attached to a wooden base was fashioned to provide infrastructure. PTAs were simulated with a water and lotion solution inside a water balloon that was glued to the bottom of a paper cup. The balloon was fully submerged with ordnance gelatin to facilitate ultrasound image acquisition, and an asymmetric soft palate and deviated uvula were painted on top after setting. PTA cups were replaced after use. We spent eight hours constructing three task trainers and used 50 PTA cups for a total cost <$110. Forty-six emergency medicine (EM) residents performed PTA needle aspirations using the task trainers and were asked to rate ultrasound image realism, task trainer realism, and trainer ease of use on a five-point visual analog scale, with five being very realistic and easy. Sixteen of 46 (35%) residents completed the survey and reported that ultrasound images were representative of real PTAs (mean 3.41). They found the model realistic (mean 3.73) and easy to use (mean 4.08). Residents rated their comfort with the drainage procedure as 2.07 before and 3.64 after practicing on the trainer. This low-cost, easy-to-construct simulator allows for ultrasound image acquisition while performing PTA needle aspirations and is the first reported of its kind. Educators from EM and otolaryngology can use this model to educate inexperienced trainees, thus ultimately improving patient safety in the clinical setting.

Age and Stress Prediction

NASA Technical Reports Server (NTRS)

2000-01-01

Genoa is a software product that predicts progressive aging and failure in a variety of materials. It is the result of a SBIR contract between the Glenn Research Center and Alpha Star Corporation. Genoa allows designers to determine if the materials they plan on applying to a structure are up to the task or if alternate materials should be considered. Genoa's two feature applications are its progressive failure simulations and its test verification. It allows for a reduction in inspection frequency, rapid design solutions, and manufacturing with low cost materials. It will benefit the aerospace, airline, and automotive industries, with future applications for other uses.

Unique Systems Analysis Task 7, Advanced Subsonic Technologies Evaluation Analysis

NASA Technical Reports Server (NTRS)

Eisenberg, Joseph D. (Technical Monitor); Bettner, J. L.; Stratton, S.

2004-01-01

To retain a preeminent U.S. position in the aircraft industry, aircraft passenger mile costs must be reduced while at the same time, meeting anticipated more stringent environmental regulations. A significant portion of these improvements will come from the propulsion system. A technology evaluation and system analysis was accomplished under this task, including areas such as aerodynamics and materials and improved methods for obtaining low noise and emissions. Previous subsonic evaluation analyses have identified key technologies in selected components for propulsion systems for year 2015 and beyond. Based on the current economic and competitive environment, it is clear that studies with nearer turn focus that have a direct impact on the propulsion industry s next generation product are required. This study will emphasize the year 2005 entry into service time period. The objective of this study was to determine which technologies and materials offer the greatest opportunities for improving propulsion systems. The goals are twofold. The first goal is to determine an acceptable compromise between the thermodynamic operating conditions for A) best performance, and B) acceptable noise and chemical emissions. The second goal is the evaluation of performance, weight and cost of advanced materials and concepts on the direct operating cost of an advanced regional transport of comparable technology level.

Does task shifting yield cost savings and improve efficiency for health systems? A systematic review of evidence from low-income and middle-income countries.

PubMed

Seidman, Gabriel; Atun, Rifat

2017-04-13

Task shifting has become an increasingly popular way to increase access to health services, especially in low-resource settings. Research has demonstrated that task shifting, including the use of community health workers (CHWs) to deliver care, can improve population health. This systematic review investigates whether task shifting in low-income and middle-income countries (LMICs) results in efficiency improvements by achieving cost savings. Using the PRISMA guidelines for systematic reviews, we searched PubMed, Embase, CINAHL, and the Health Economic Evaluation Database on March 22, 2016. We included any original peer-review articles that demonstrated cost impact of a task shifting program in an LMIC. We identified 794 articles, of which 34 were included in our study. We found that substantial evidence exists for achieving cost savings and efficiency improvements from task shifting activities related to tuberculosis and HIV/AIDS, and additional evidence exists for the potential to achieve cost savings from activities related to malaria, NCDs, NTDs, childhood illness, and other disease areas, especially at the primary health care and community levels. Task shifting presents a viable option for health system cost savings in LMICs. Going forward, program planners should carefully consider whether task shifting can improve population health and health systems efficiency in their countries, and researchers should investigate whether task shifting can also achieve cost savings for activities related to emerging global health priorities and health systems strengthening activities such as supply chain management or monitoring and evaluation.

Multi-layer imager design for mega-voltage spectral imaging

NASA Astrophysics Data System (ADS)

Myronakis, Marios; Hu, Yue-Houng; Fueglistaller, Rony; Wang, Adam; Baturin, Paul; Huber, Pascal; Morf, Daniel; Star-Lack, Josh; Berbeco, Ross

2018-05-01

The architecture of multi-layer imagers (MLIs) can be exploited to provide megavoltage spectral imaging (MVSPI) for specific imaging tasks. In the current work, we investigated bone suppression and gold fiducial contrast enhancement as two clinical tasks which could be improved with spectral imaging. A method based on analytical calculations that enables rapid investigation of MLI component materials and thicknesses was developed and validated against Monte Carlo computations. The figure of merit for task-specific imaging performance was the contrast-to-noise ratio (CNR) of the gold fiducial when the CNR of bone was equal to zero after a weighted subtraction of the signals obtained from each MLI layer. Results demonstrated a sharp increase in the CNR of gold when the build-up component or scintillation materials and thicknesses were modified. The potential for low-cost, prompt implementation of specific modifications (e.g. composition of the build-up component) could accelerate clinical translation of MVSPI.

The Array Automated Assembly Task for the Low Cost Solar Array Project, Phase 2

NASA Technical Reports Server (NTRS)

Campbell, R. B. (Editor); Farukhi, S. (Editor)

1978-01-01

During the program a process sequence was proposed and tested for the fabrication of dendritic welb silicon into solar modules. This sequence was analyzed as to yield and cost and these data suggest that the price goals of 1986 are attainable. Specifically, it was shown that a low cost POCL3 is a suitable replacement for the semiconductor grade, and that a suitable CVD oxide can be deposited from a silane/air mixture using a Silox reactor. A dip coating method was developed for depositing an antireflection coating from a metalorganic precursor. Application of photoresist to define contact grids was made cost effective through use of a dip coating technique. Electroplating of both Ag and Cu was shown feasible and cost effective for producing the conductive metal grids on the solar cells. Laser scribing was used to separate the cells from the dendrites without degradation. Ultrasonic welding methods were shown to be feasible for interconnecting the cells. A study of suitable low cost materials for encapsulation suggest that soda lime glass and phenolic filled board are preferred.

On the costs of parallel processing in dual-task performance: The case of lexical processing in word production.

PubMed

Paucke, Madlen; Oppermann, Frank; Koch, Iring; Jescheniak, Jörg D

2015-12-01

Previous dual-task picture-naming studies suggest that lexical processes require capacity-limited processes and prevent other tasks to be carried out in parallel. However, studies involving the processing of multiple pictures suggest that parallel lexical processing is possible. The present study investigated the specific costs that may arise when such parallel processing occurs. We used a novel dual-task paradigm by presenting 2 visual objects associated with different tasks and manipulating between-task similarity. With high similarity, a picture-naming task (T1) was combined with a phoneme-decision task (T2), so that lexical processes were shared across tasks. With low similarity, picture-naming was combined with a size-decision T2 (nonshared lexical processes). In Experiment 1, we found that a manipulation of lexical processes (lexical frequency of T1 object name) showed an additive propagation with low between-task similarity and an overadditive propagation with high between-task similarity. Experiment 2 replicated this differential forward propagation of the lexical effect and showed that it disappeared with longer stimulus onset asynchronies. Moreover, both experiments showed backward crosstalk, indexed as worse T1 performance with high between-task similarity compared with low similarity. Together, these findings suggest that conditions of high between-task similarity can lead to parallel lexical processing in both tasks, which, however, does not result in benefits but rather in extra performance costs. These costs can be attributed to crosstalk based on the dual-task binding problem arising from parallel processing. Hence, the present study reveals that capacity-limited lexical processing can run in parallel across dual tasks but only at the expense of extraordinary high costs. (c) 2015 APA, all rights reserved).

Low cost silicon solar array project silicon materials task: Establishment of the feasibility of a process capable of low-cost, high volume production of silane (step 1) and the pyrolysis of silane to semiconductor-grade silicon (step 2)

NASA Technical Reports Server (NTRS)

Breneman, W. C.; Cheung, H.; Farrier, E. G.; Morihara, H.

1977-01-01

A quartz fluid bed reactor capable of operating at temperatures of up to 1000 C was designed, constructed, and successfully operated. During a 30 minute experiment, silane was decomposed within the reactor with no pyrolysis occurring on the reactor wall or on the gas injection system. A hammer mill/roller-crusher system appeared to be the most practical method for producing seed material from bulk silicon. No measurable impurities were detected in the silicon powder produced by the free space reactor, using the cathode layer emission spectroscopic technique. Impurity concentration followed by emission spectroscopic examination of the residue indicated a total impurity level of 2 micrograms/gram. A pellet cast from this powder had an electrical resistivity of 35 to 45 ohm-cm and P-type conductivity.

Task report #2.2, developing very thin overlays with locally available aggregates for each district : TxDOT project 9-1529, low cost safety solutions, pavement preservation and maintenance practices for rural highways.

DOT National Transportation Integrated Search

2013-04-01

The objective of this subtask was to generate crack resistant hot mix designs which could be placed very thin using locally available materials for each of the West Texas Districts wanting to participate in this study. Crack Attenuating Mixes (CAMs) ...

Low spatial frequency characterization of holographic recording materials applied to correlation

NASA Astrophysics Data System (ADS)

Márquez, A.; Neipp, C.; Beléndez, A.; Campos, J.; Pascual, I.; Yzuel, M. J.; Fimia, A.

2003-09-01

Accurate recording of computer-generated holograms (CGH) on a phase material is not a trivial task. The range of available phase materials is large, and their suitability depends on the fabrication technique chosen to produce the hologram. We are particularly interested in low-cost fabrication techniques, easily available for any lab. In this work we present the results obtained with a wide variety of phase holographic recording materials, characterized at low spatial frequencies (leq32 lp mm-1) which is the range associated with the technique we use to produce the CGHs. We have considered bleached emulsion, silver halide sensitized gelatin (SHSG) and dichromated gelatin. Some interesting differences arise between the behaviour of these materials in the usual holographic range (>1000 lp mm-1), and the low-frequency range intended for digital holography. The ultimate goal of this paper is to establish the suitability of different phase materials as the media to generate correlation filters for optical pattern recognition. In all the materials considered, the phase filters generated ensure the discrimination of the target in the recognition process. Taking into account all the experimental results, we can say that SHSG is the best material to generate phase CGHs with low spatial frequencies.

Cubesat in-situ degradation detector (CIDD)

NASA Astrophysics Data System (ADS)

Rievers, Benny; Milke, Alexander; Salden, Daniel

2015-07-01

The design of the thermal control and management system (TCS) is a central task in satellite design. In order to evaluate and dimensionize the properties of the TCS, material parameters specifying the conductive and radiative properties of the different TCS components have to be known including their respective variations within the mission lifetime. In particular the thermo-optical properties of the outer surfaces including critical TCS components such as radiators and thermal insulation are subject to degradation caused by interaction with the space environment. The evaluation of these material parameters by means of ground testing is a time-consuming and expensive endeavor. Long-term in-situ measurements on board the ISS or large satellites not only realize a better implementation of the influence of the space environment but also imply high costs. Motivated by this we propose the utilization of low-cost nano-satellite systems to realize material tests within space at a considerably reduced cost. We present a nanosat-scale degradation sensor concept which realizes low power consumption and data rates compatible with nanosat boundaries at UHF radio. By means of a predefined measurement and messaging cycle temperature curves are measured and evaluated on ground to extract the change of absorptivity and emissivity over mission lifetime.

Proceedings of the International Congress (12th), Corrosion Control for Low-Cost Reliability, Held in Houston, Texas on September 19 -24, 1993. Volume 1. Coatings

DTIC Science & Technology

1993-09-24

3]) Gas-cooled reactors were first developed in Europe and have been built since 1956. HTGR , equipped with the core of ceramic coated particle fuels ...demands must also be covered by nuclear energy in not so long future. Programs on developing the process heating HTGR have been promoted mainly in Germany...Material programs for HTGR have been promoted in several countries since late 1960’s which include the tasks of developing and qualifying materials, eg

Adult age differences in task switching.

PubMed

Kray, J; Lindenberger, U

2000-03-01

Age differences in 2 components of task-set switching speed were investigated in 118 adults aged 20 to 80 years using task-set homogeneous (e.g., AAAA ...) and task-set heterogeneous (e.g., AABBAABB ... ) blocks. General switch costs were defined as latency differences between heterogeneous and homogeneous blocks. whereas specific switch costs were defined as differences between switch and nonswitch trials within heterogeneous blocks. Both types of costs generalized over verbal, figural, and numeric stimulus materials; were more highly correlated to fluid than to crystallized abilities; and were not eliminated after 6 sessions of practice, indicating that they reflect basic and domain-general aspects of cognitive control. Most important, age-associated increments in costs were significantly greater for general than for specific switch costs, suggesting that the ability to efficiently maintain and coordinate 2 alternating task sets in working memory instead of 1 is more negatively affected by advancing age than the ability to execute the task switch itself.

Automated array assembly task development of low-cost polysilicon solar cells

NASA Technical Reports Server (NTRS)

Jones, G. T.

1980-01-01

Development of low cost, large area polysilicon solar cells was conducted in this program. Three types of polysilicon materialk were investigated. A theoretical and experimenal comparison between single crystal silicon and polysilicon solar cell efficiency was performed. Significant electrical performance differences were observed between types of wafer material, i.e. fine grain and coarse grain polysilicon and single crystal silicon. Efficiency degradation due to grain boundaries in fin grain and coarse grain polysilicon was shown to be small. It was demonstrated that 10 percent efficient polysilicon solar cells can be produced with spray on n+ dopants. This result fulfills an important goal of this project, which is the production of batch quantity of 10 percent efficient polysilicon solar cells.

Integration mockup and process material management system

NASA Technical Reports Server (NTRS)

Verble, Adas James, Jr.

1992-01-01

Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were designed and built for each module to sufficiently move and rotate each module. Secondary structures such as floors, ceilings, bulkheads, standoffs, racks, etc. were developed and built.

Effect of type of cognitive task and walking speed on cognitive-motor interference during dual-task walking.

PubMed

Patel, P; Lamar, M; Bhatt, T

2014-02-28

We aimed to determine the effect of distinctly different cognitive tasks and walking speed on cognitive-motor interference of dual-task walking. Fifteen healthy adults performed four cognitive tasks: visuomotor reaction time (VMRT) task, word list generation (WLG) task, serial subtraction (SS) task, and the Stroop (STR) task while sitting and during walking at preferred-speed (dual-task normal walking) and slow-speed (dual-task slow-speed walking). Gait speed was recorded to determine effect on walking. Motor and cognitive costs were measured. Dual-task walking had a significant effect on motor and cognitive parameters. At preferred-speed, the motor cost was lowest for the VMRT task and highest for the STR task. In contrast, the cognitive cost was highest for the VMRT task and lowest for the STR task. Dual-task slow walking resulted in increased motor cost and decreased cognitive cost only for the STR task. Results show that the motor and cognitive cost of dual-task walking depends heavily on the type and perceived complexity of the cognitive task being performed. Cognitive cost for the STR task was low irrespective of walking speed, suggesting that at preferred-speed individuals prioritize complex cognitive tasks requiring higher attentional and processing resources over walking. While performing VMRT task, individuals preferred to prioritize more complex walking task over VMRT task resulting in lesser motor cost and increased cognitive cost for VMRT task. Furthermore, slow walking can assist in diverting greater attention towards complex cognitive tasks, improving its performance while walking. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Silicon materials task of the Low Cost Solar Array Project: Effect of impurities and processing on silicon solar cells

NASA Technical Reports Server (NTRS)

Hopkins, R. H.; Davis, J. R.; Rohatgi, A.; Hanes, M. H.; Rai-Choudhury, P.; Mollenkopf, H. C.

1982-01-01

The effects of impurities and processing on the characteristics of silicon and terrestrial silicon solar cells were defined in order to develop cost benefit relationships for the use of cheaper, less pure solar grades of silicon. The amount of concentrations of commonly encountered impurities that can be tolerated in typical p or n base solar cells was established, then a preliminary analytical model from which the cell performance could be projected depending on the kinds and amounts of contaminants in the silicon base material was developed. The impurity data base was expanded to include construction materials, and the impurity performace model was refined to account for additional effects such as base resistivity, grain boundary interactions, thermal processing, synergic behavior, and nonuniform impurity distributions. A preliminary assessment of long term (aging) behavior of impurities was also undertaken.

Silicon materials task of the low-cost solar array project. Phase 4: Effects of impurities and processing on silicon solar cells

NASA Technical Reports Server (NTRS)

Hopkins, R. H.; Hanes, M. H.; Davis, J. R.; Rohatgi, A.; Raichoudhury, P.; Mollenkopf, H. C.

1981-01-01

The results of the study form a basis for silicon producers, wafer manufacturers, and cell fabricators to develop appropriate cost-benefit relationships for the use of less pure, less costly solar grade silicon. Cr is highly mobile in silicon even at temperatures as low as 600 C. Contrasting with earlier data for Mo, Ti, and V, Cr concentrations vary from place to place in polycrystalline silicon wafers and the electrically-active Cr concentration in the polysilicon is more than an order of magnitude smaller than would be projected from single crystal impurity data. We hypothesize that Cr diffuses during ingot cooldown after growth, preferentially segregates to grain and becomes electrically deactivated. Accelerated aging data from Ni-contaminated silicon imply that no significant impurity-induced cell performance reduction should be expected over a twenty year device lifetime.

Advanced Launch System propulsion focused technology liquid methane turbopump technical implementation plan

NASA Technical Reports Server (NTRS)

Csomor, A.; Nielson, C. E.

1989-01-01

This program will focus on the integration of all functional disciplines of the design, manufacturing, materials, fabrication and producibility to define and demonstrate a highly reliable, easily maintained, low cost liquid methane turbopump as a component for the STBE (Space Transportation Booster Engine) using the STME (main engine) oxygen turbopump. A cost model is to be developed to predict the recurring cost of production hardware and operations. A prime objective of the program is to design the liquid methane turbopump to be used in common with a LH2 turbopump optimized for the STME. Time phasing of the effort is presented and interrelationship of the tasks is defined. Major subcontractors are identified and their roles in the program are described.

Neuroticism related differences in the functional neuroanatomical correlates of multitasking. An fMRI study.

PubMed

Szameitat, Andre J; Saylik, Rahmi; Parton, Andrew

2016-12-02

It is known that neuroticism impairs cognitive performance mostly in difficult tasks, but not so much in easier tasks. One pervasive situation of this type is multitasking, in which the combination of two simple tasks creates a highly demanding dual-task, and consequently high neurotics show higher dual-task costs than low neurotics. However, the functional neuroanatomical correlates of these additional performance impairments in high neurotics are unknown. To test for this, we assessed brain activity by means of functional magnetic resonance imaging (fMRI) in 17 low and 15 high neurotics while they were performing a demanding dual-task and the less demanding component tasks as single-tasks. Behavioural results showed that performance (response times and error rates) was lower in the dual-task than in the single-tasks (dual-task costs), and that these dual-task costs were significantly higher in high neurotics. Imaging data showed that high neurotics showed less dual-task specific activation in lateral (mainly middle frontal gyrus) and medial prefrontal cortices. We conclude that high levels of neuroticism impair behavioural performance in demanding tasks, and that this impairment is accompanied by reduced activation of the task-associated brain areas. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Space transfer vehicle concepts and requirements study. Volume 3, book 1: Program cost estimates

NASA Technical Reports Server (NTRS)

Peffley, Al F.

1991-01-01

The Space Transfer Vehicle (STV) Concepts and Requirements Study cost estimate and program planning analysis is presented. The cost estimating technique used to support STV system, subsystem, and component cost analysis is a mixture of parametric cost estimating and selective cost analogy approaches. The parametric cost analysis is aimed at developing cost-effective aerobrake, crew module, tank module, and lander designs with the parametric cost estimates data. This is accomplished using cost as a design parameter in an iterative process with conceptual design input information. The parametric estimating approach segregates costs by major program life cycle phase (development, production, integration, and launch support). These phases are further broken out into major hardware subsystems, software functions, and tasks according to the STV preliminary program work breakdown structure (WBS). The WBS is defined to a low enough level of detail by the study team to highlight STV system cost drivers. This level of cost visibility provided the basis for cost sensitivity analysis against various design approaches aimed at achieving a cost-effective design. The cost approach, methodology, and rationale are described. A chronological record of the interim review material relating to cost analysis is included along with a brief summary of the study contract tasks accomplished during that period of review and the key conclusions or observations identified that relate to STV program cost estimates. The STV life cycle costs are estimated on the proprietary parametric cost model (PCM) with inputs organized by a project WBS. Preliminary life cycle schedules are also included.

Low-cost solar array progress and plans

NASA Astrophysics Data System (ADS)

Callaghan, W. T.

It is pointed out that significant redirection has occurred in the U.S. Department of Energy (DOE) Photovoltaics Program, and thus in the Flat-Plate Solar Array Project (FSA), since the 3rd European Communities Conference. The Silicon Materials Task has now the objective to sponsor theoretical and experimental research on silicon material refinement technology suitable for photovoltaic flat-plate solar arrays. With respect to the hydrochlorination reaction, a process proof of concept was completed through definition of reaction kinetics, catalyst, and reaction characteristics. In connection with the dichlorosilane chemical vapor desposition process, a preliminary design was completed of an experimental process system development unit with a capacity of 100 to 200 MT/yr of Si.Attention is also given to the silicon-sheet formation research area, environmental isolation research, the cell and module formation task, the engineering sciences area, and the module performance and failure analysis area.

Cuing consumerism: situational materialism undermines personal and social well-being.

PubMed

Bauer, Monika A; Wilkie, James E B; Kim, Jung K; Bodenhausen, Galen V

2012-05-01

Correlational evidence indicates that materialistic individuals experience relatively low levels of well-being. Across four experiments, we found that situational cuing can also trigger materialistic mind-sets, with similarly negative personal and social consequences. Merely viewing desirable consumer goods resulted in increases in materialistic concerns and led to heightened negative affect and reduced social involvement (Experiment 1). Framing a computer task as a "Consumer Reaction Study" led to a stronger automatic bias toward values reflecting self-enhancement, compared with framing the same task as a "Citizen Reaction Study" (Experiment 2). Consumer cues also increased competitiveness (Experiment 3) and selfishness in a water-conservation dilemma (Experiment 4). Thus, the costs of materialism are not localized only in particularly materialistic people, but can also be found in individuals who happen to be exposed to environmental cues that activate consumerism-cues that are commonplace in contemporary society.

Slicing of silicon into sheet material: Silicon sheet growth development for the large area silicon sheet task of the Low Cost Silicon Solar Array project

NASA Technical Reports Server (NTRS)

Fleming, J. R.

1978-01-01

The limits of blade tolerance were defined. The standard blades are T-2 thickness tolerance. Good results were obtained by using a slurry fluid consisting of mineral oil and a lubricity additive. Adjustments of the formulation and fine tuning of the cutting process with the new fluid are necessary. Test results and consultation indicate that the blade breakage encountered with water based slurries is unavoidable. Two full capacity (974 wafer) runs were made on the large prototype saw. Both runs resulted in extremely low yield. However, the reasons for the low yield were lack of proper technique rather than problems with machine function. The test on the effect of amount of material etched off of an as-sawn wafer on solar cell efficiency were completed. The results agree with previous work at JPL in that the minimum material removed per side that gives maximum efficiency is on the order of 10 microns.

Bioinspired Wood Nanotechnology for Functional Materials.

PubMed

Berglund, Lars A; Burgert, Ingo

2018-05-01

It is a challenging task to realize the vision of hierarchically structured nanomaterials for large-scale applications. Herein, the biomaterial wood as a large-scale biotemplate for functionalization at multiple scales is discussed, to provide an increased property range to this renewable and CO 2 -storing bioresource, which is available at low cost and in large quantities. The Progress Report reviews the emerging field of functional wood materials in view of the specific features of the structural template and novel nanotechnological approaches for the development of wood-polymer composites and wood-mineral hybrids for advanced property profiles and new functions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cognitive caching promotes flexibility in task switching: evidence from event-related potentials.

PubMed

Lange, Florian; Seer, Caroline; Müller, Dorothea; Kopp, Bruno

2015-12-08

Time-consuming processes of task-set reconfiguration have been shown to contribute to the costs of switching between cognitive tasks. We describe and probe a novel mechanism serving to reduce the costs of task-set reconfiguration. We propose that when individuals are uncertain about the currently valid task, one task set is activated for execution while other task sets are maintained at a pre-active state in cognitive cache. We tested this idea by assessing an event-related potential (ERP) index of task-set reconfiguration in a three-rule task-switching paradigm involving varying degrees of task uncertainty. In high-uncertainty conditions, two viable tasks were equally likely to be correct whereas in low-uncertainty conditions, one task was more likely than the other. ERP and performance measures indicated substantial costs of task-set reconfiguration when participants were required to switch away from a task that had been likely to be correct. In contrast, task-set-reconfiguration costs were markedly reduced when the previous task set was chosen under high task uncertainty. These results suggest that cognitive caching of alternative task sets adds to human cognitive flexibility under high task uncertainty.

Cognitive caching promotes flexibility in task switching: evidence from event-related potentials

PubMed Central

Lange, Florian; Seer, Caroline; Müller, Dorothea; Kopp, Bruno

2015-01-01

Time-consuming processes of task-set reconfiguration have been shown to contribute to the costs of switching between cognitive tasks. We describe and probe a novel mechanism serving to reduce the costs of task-set reconfiguration. We propose that when individuals are uncertain about the currently valid task, one task set is activated for execution while other task sets are maintained at a pre-active state in cognitive cache. We tested this idea by assessing an event-related potential (ERP) index of task-set reconfiguration in a three-rule task-switching paradigm involving varying degrees of task uncertainty. In high-uncertainty conditions, two viable tasks were equally likely to be correct whereas in low-uncertainty conditions, one task was more likely than the other. ERP and performance measures indicated substantial costs of task-set reconfiguration when participants were required to switch away from a task that had been likely to be correct. In contrast, task-set-reconfiguration costs were markedly reduced when the previous task set was chosen under high task uncertainty. These results suggest that cognitive caching of alternative task sets adds to human cognitive flexibility under high task uncertainty. PMID:26643146

Impact damage in filament wound composite bottles

NASA Technical Reports Server (NTRS)

Highsmith, Alton L.

1993-01-01

Increasingly, composite materials are being used in advanced structural applications because of the significant weight savings they offer when compared to more traditional engineering materials. The higher cost of composites must be offset by the increased performance that results from reduced structural weight if these new materials are to be used effectively. At present, there is considerable interest in fabricating solid rocket motor cases out of composite materials, and capitalizing on the reduced structural weight to increase rocket performance. However, one of the difficulties that arises when composite materials are used is that composites can develop significant amounts of internal damage during low velocity impacts. Such low velocity impacts may be encountered in routine handling of a structural component like a rocket motor case. The ability to assess the reduction in structural integrity of composite motor cases that experience accidental impacts is essential if composite rocket motor cases are to be certified for manned flight. While experimental studies of the post-impact performance of filament wound composite motor cases haven been proven performed (2,3), scaling impact data from small specimens to full scale structures has proven difficult. If such a scaling methodology is to be achieved, an increased understanding of the damage processes which influence residual strength is required. The study described herein was part of an ongoing investigation of damage development and reduction of tensile strength in filament wound composites subjected to low velocity impacts. The present study, which focused on documenting the damage that develops in filament wound composites as a result of such impacts, included two distinct tasks. The first task was to experimentally assess impact damage in small, filament wound pressure bottles using x-ray radiography. The second task was to study the feasibility of using digital image processing techniques to assist in determining the 3-D distribution of damage from stereo x-ray pairs.

Low cost airborne microwave landing system receiver, task 3

NASA Technical Reports Server (NTRS)

Hager, J. B.; Vancleave, J. R.

1979-01-01

Work performed on the low cost airborne Microwave Landing System (MLS) receiver is summarized. A detailed description of the prototype low cost MLS receiver is presented. This detail includes block diagrams, schematics, board assembly drawings, photographs of subassemblies, mechanical construction, parts lists, and microprocessor software. Test procedures are described and results are presented.

Emerging low-cost LED thermal management materials

NASA Astrophysics Data System (ADS)

Zweben, Carl H.

2004-10-01

As chip size and power levels continue to increase, thermal management, thermal stresses and cost have become key LED packaging issues. Until recently, low-coefficient-of-thermal-expansion (CTE) materials, which are needed to minimize thermal stresses, had thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. Copper, which has a higher thermal conductivity (400 W/m-K), also has a high CTE, which can cause severe thermal stresses. We now have over a dozen low-CTE materials with thermal conductivities ranging between 400 and 1700 W/m-K, and almost a score with thermal conductivities at least 50% greater than that of aluminum. Some of these materials are low cost. Others have the potential to be low cost in high volume production. Emphasizing low cost, this paper reviews traditional packaging materials and the six categories of advanced materials: polymer matrix-, metal matrix-, ceramic matrix-, and carbon matrix composites; monolithic carbonaceous materials; and metal-metal composites/alloys. Topics include properties, status, applications, cost and likely future directions of new advanced materials, including carbon nanotubes and inexpensive graphite nanoplatelets.

The Association between High Neuroticism-Low Extraversion and Dual-Task Performance during Walking While Talking in Non-demented Older Adults

PubMed Central

LeMonda, Brittany C.; Mahoney, Jeannette R.; Verghese, Joe; Holtzer, Roee

2016-01-01

The Walking While Talking (WWT) dual-task paradigm is a mobility stress test that predicts major outcomes, including falls, frailty, disability, and mortality in aging. Certain personality traits, such as neuroticism, extraversion, and their combination, have been linked to both cognitive and motor outcomes. We examined whether individual differences in personality dimensions of neuroticism and extraversion predicted dual-task performance decrements (both motor and cognitive) on a WWT task in non-demented older adults. We hypothesized that the combined effect of high neuroticism-low extraversion would be related to greater dual-task costs in gait velocity and cognitive performance in non-demented older adults. Participants (N = 295; age range, = 65–95 years; female = 164) completed the Big Five Inventory and WWT task involving concurrent gait and a serial 7's subtraction task. Gait velocity was obtained using an instrumented walkway. The high neuroticism-low extraversion group incurred greater dual-task costs (i.e., worse performance) in both gait velocity {95% confidence interval (CI) [−17.68 to −3.07]} and cognitive performance (95% CI [−19.34 to −2.44]) compared to the low neuroticism-high extraversion group, suggesting that high neuroticism-low extraversion interferes with the allocation of attentional resources to competing task demands during the WWT task. Older individuals with high neuroticism-low extraversion may be at higher risk for falls, mobility decline and other adverse outcomes in aging. PMID:26527241

Comparison of low-cost and engineered materials for phosphorus removal from organic-rich surface water.

PubMed

Boyer, Treavor H; Persaud, Amar; Banerjee, Poulomi; Palomino, Pedro

2011-10-15

Excess phosphorus (P) in lakes and rivers remains a major water quality problem on a global scale. As a result, new materials and innovative approaches to P remediation are required. Natural materials and waste byproduct materials from industrial processes have the potential to be effective materials for P removal from surface water. Advantages of natural and waste byproduct materials include their low-cost, abundant supply, and minimal preparation, especially compared with engineered materials, such as ion exchange resins and polymeric adsorbents. As a result, natural and waste byproduct materials are commonly referred to as low-cost materials. Despite the potential advantages of low-cost materials, there are critical gaps in knowledge that are preventing their effective use. In particular, there are limited data on the performance of low-cost materials in surface waters that have high concentrations of natural organic matter (NOM), and there are no systematic studies that track the changes in water chemistry following treatment with low-cost materials or compare their performance with engineered materials. Accordingly, the goal of this work was to evaluate and compare the effectiveness of low-cost and engineered materials for P removal from NOM-rich surface water. Seven low-cost materials and three engineered materials were evaluated using jar tests and mini-column experiments. The test water was a surface water that had a total P concentration of 132-250 μg P/L and a total organic carbon concentration of 15-32 mg C/L. Alum sludge, a byproduct of drinking water treatment, and a hybrid anion exchange resin loaded with nanosize iron oxide were the best performing materials in terms of selective P removal in the presence of NOM and minimum undesirable secondary changes to the water chemistry. Copyright © 2011 Elsevier Ltd. All rights reserved.

Factors influencing analysis of complex cognitive tasks: a framework and example from industrial process control.

PubMed

Prietula, M J; Feltovich, P J; Marchak, F

2000-01-01

We propose that considering four categories of task factors can facilitate knowledge elicitation efforts in the analysis of complex cognitive tasks: materials, strategies, knowledge characteristics, and goals. A study was conducted to examine the effects of altering aspects of two of these task categories on problem-solving behavior across skill levels: materials and goals. Two versions of an applied engineering problem were presented to expert, intermediate, and novice participants. Participants were to minimize the cost of running a steam generation facility by adjusting steam generation levels and flows. One version was cast in the form of a dynamic, computer-based simulation that provided immediate feedback on flows, costs, and constraint violations, thus incorporating key variable dynamics of the problem context. The other version was cast as a static computer-based model, with no dynamic components, cost feedback, or constraint checking. Experts performed better than the other groups across material conditions, and, when required, the presentation of the goal assisted the experts more than the other groups. The static group generated richer protocols than the dynamic group, but the dynamic group solved the problem in significantly less time. Little effect of feedback was found for intermediates, and none for novices. We conclude that demonstrating differences in performance in this task requires different materials than explicating underlying knowledge that leads to performance. We also conclude that substantial knowledge is required to exploit the information yielded by the dynamic form of the task or the explicit solution goal. This simple model can help to identify the contextual factors that influence elicitation and specification of knowledge, which is essential in the engineering of joint cognitive systems.

LL13-MatModelRadDetect-PD2Jf Final Report: Materials Modeling for High-Performance Radiation Detectors

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

Lordi, Vincenzo

The aims of this project are to enable rational materials design for select high-payoff challenges in radiation detection materials by using state-of-the-art predictive atomistic modeling techniques. Three specific high-impact challenges are addressed: (i) design and optimization of electrical contact stacks for TlBr detectors to stabilize temporal response at room-temperature; (ii) identification of chemical design principles of host glass materials for large-volume, low-cost, highperformance glass scintillators; and (iii) determination of the electrical impacts of dislocation networks in Cd 1-xZn xTe (CZT) that limit its performance and usable single-crystal volume. The specific goals are to establish design and process strategies to achievemore » improved materials for high performance detectors. Each of the major tasks is discussed below in three sections, which include the goals for the task and a summary of the major results, followed by a listing of publications that contain the full details, including details of the methodologies used. The appendix lists 12 conference presentations given for this project, including 1 invited talk and 1 invited poster.« less

Efforts of the occupant to change physical quality of residential unit through the change of building material at low cost flats in Jakarta

NASA Astrophysics Data System (ADS)

Nurdiani, N.

2018-03-01

Low cost flats in Jakarta – Indonesia is provided by the government for low-income people in urban areas, in line with the program to redevelop or renew slum areas. Low cost flat is built with the minimum standard of building materials. The purpose of this study is to know efforts of the occupants to change of building materials at residential unit of low cost flats. The research was conducted by descriptive method at four of low cost housing in Jakarta: Rusuna Bendungan Hilir 1, Rusuna Tambora IIIA, Rusuna Bidara Cina, and Rusuna Sukapura. The results showed that physical changes which happened in low cost flats are aesthetic (residence paint color change), or improvement of physical quality of residential unit (change of building material), become dominant aspects done by residents in four rusuna.

Revolutionary opportunities for materials and structures study, addendum

NASA Technical Reports Server (NTRS)

Feig, P. D.

1987-01-01

This report is an addendum to the Revolutionary Opportunities for Materials and Structures Study (ROMS), modifying the original by the addition of two tasks. The primary purpose of these tasks was to conduct additional aircraft/engine sizing and mission analysis to obtain contributory aircraft performance data such as fuel burns and direct operating costs for both the subsonic and supersonic engines.

State-of-the-art low-cost solar reflector materials

NASA Astrophysics Data System (ADS)

Kennedy, C.; Jorgensen, G.

1994-11-01

Solar thermal technologies generate power by concentrating sunlight with large mirrors. The National Renewable Energy Laboratory (NREL) is working with industrial partners to develop the optical reflector materials needed for the successful deployment of this technology. The reflector materials must be low in cost and maintain high specular reflectance for extended lifetimes in severe outdoor environments. Currently, the best candidate materials for solar mirrors are silver-coated low-iron glass and silvered polymer films. Polymer reflectors are lighter in weight, offer greater flexibility in system design, and have the potential for lower cost than glass mirrors. In parallel with collaborative activities, several innovative candidate reflector-material constructions were investigated at NREL. The low-cost material requirement necessitates manufacturing compatible with mass-production techniques. Future cooperative efforts with the web-coating industry offers the promise of exciting new alternative materials and the potential for dramatic cost savings in developing advanced solar reflector materials.

Low cost silicon solar array project silicon materials task: Establishment of the feasibility of a process capable of low-cost, high volume production of silane (step 1) and the pyrolysis of silane to semiconductor-grade silicon (step 2)

NASA Technical Reports Server (NTRS)

Breneman, W. C.; Farrier, E. G.; Rexer, J.

1977-01-01

Extended operation of a small process-development unit routinely produced high quality silane in 97+% yield from dichlorosilane. The production rate was consistent with design loadings for the fractionating column and for the redistribution reactor. A glass fluid-bed reactor was constructed for room temperature operation. The behavior of a bed of silcon particles was observed as a function of various feedstocks, component configurations, and operating conditions. For operating modes other than spouting, the bed behaved in an erratic and unstable manner. A method was developed for casting molten silicon powder into crack-free solid pellets for process evaluation. The silicon powder was melted and cast into thin walled quartz tubes that sacrificially broke on cooling.

Slicing of Silicon into Sheet Material: Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low Cost Silicon Solar Array Project

NASA Technical Reports Server (NTRS)

Fleming, J. R.

1979-01-01

Testing of low cost low suspension power slurry vehicles is presented. Cutting oils are unlikely to work, but a mineral oil with additives should be workable. Two different abrasives were tested. A cheaper silicon carbide from Norton gave excellent results except for excessive kerf loss: the particles were too big. An abrasive treated for lubricity showed no lubricity improvement in mineral oil vehicle. The bounce fixture was tested for the first time under constant cut rate conditions (rather than constant force). Although the cut was not completed before the blades broke, the blade lifetime of thin (100 micrometer) blades was 120 times the lifetime without the fixture. The large prototype saw completed a successful run, producing 90% cutting yield (849 wafers) at 20 wafers/cm. Although inexperience with large numbers of wafers caused cleaning breakage to reduce this yield to 74%, the yield was high enough that the concept of the large saw is proven workable.

Low-cost encapsulation materials for terrestrial solar cell modules

NASA Technical Reports Server (NTRS)

Cuddihy, E. F.; Baum, B.; Willis, P.

1979-01-01

The paper presents the findings of material surveys intended to identify low cost materials which could be functional as encapsulants (by 1986) for terrestrial solar cell modules. Economic analyses have indicated that in order to meet the low cost goal of $2.70 per sq m, some or all of the following material technologies must be developed or advanced: (1) UV screening outer covers; (2) elastomeric acrylics; (3) weatherproofing and waterproofing of structural wood and paper products; (4) transparent UV stabilizers for the UV-sensitive transparent pottants; and (5) cost-effective utilization of silicone and fluorocarbon materials.

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

Johnson, Francis

A team led by GE Global Research developed new magnetic refrigerant materials needed to enhance the commercialization potential of residential appliances such as refrigerators and air conditioners based on the magnetocaloric effect (a nonvapor compression cooling cycle). The new magnetic refrigerant materials have potentially better performance at lower cost than existing materials, increasing technology readiness level. The performance target of the new magnetocaloric material was to reduce the magnetic field needed to achieve 4 °C adiabatic temperature change from 1.5 Tesla to 0.75 Tesla. Such a reduction in field minimizes the cost of the magnet assembly needed for a magneticmore » refrigerator. Such a reduction in magnet assembly cost is crucial to achieving commercialization of magnetic refrigerator technology. This project was organized as an iterative alloy development effort with a parallel material modeling task being performed at George Washington University. Four families of novel magnetocaloric alloys were identified, screened, and assessed for their performance potential in a magnetic refrigeration cycle. Compositions from three of the alloy families were manufactured into regenerator components. At the beginning of the project a previously studied magnetocaloric alloy was selected for manufacturing into the first regenerator component. Each of the regenerators was tested in magnetic refrigerator prototypes at a subcontractor at at GE Appliances. The property targets for operating temperature range, operating temperature control, magnetic field sensitivity, and corrosion resistance were met. The targets for adiabatic temperature change and thermal hysteresis were not met. The high thermal hysteresis also prevented the regenerator components from displaying measurable cooling power when tested in prototype magnetic refrigerators. Magnetic refrigerant alloy compositions that were predicted to have low hysteresis were not attainable with conventional alloy processing methods. Preliminary experiments with rapid solidification methods showed a path towards attaining low hysteresis compositions should this alloy development effort be continued.« less

Graphic support resources for workers with intellectual disability engaged in office tasks: a comparison with verbal instructions from a work mate.

PubMed

Becerra, María-Teresa; Montanero, Manuel; Lucero, Manuel

2018-02-01

Research into workplace adjustments for people with disabilities is a fundamental challenge of supported employment. The aim of the present work is to investigate the effect of several graphic resources as natural support for workers with intellectual disability. Two case studies were conducted to assess the performance of five workers engaged in office tasks, with three different support conditions. Results reveal a 20% increase in quality of performance of the tasks undertaken with graphic support as compared to support in which the participants received verbal instructions (VIs) from a work mate; and between 25 and 30% as compared to a control condition which included no help of any kind. These findings are consistent with previous studies which support the possibility of generating, at low cost, iconic materials (with maps or simple graphics), which progressively facilitate workers' autonomy, without dependence or help from the job trainer. We observed that the worst performance is in the support condition with VIs, this shows the limitations of this type of natural support, which is provided on demand by work mates without specialist knowledge of work support. Implications for Rehabilitation We studied the use of various types of natural support for people with intellectual disability in their workplace. The findings suggest that, with some brief training, the simple use in the workplace of graphic help on a card can increase between 20 and 30% the quality of performance of certain work tasks carried out by workers with intellectual disability. This advantage contrasts with the high cost or lower "manageability" of other material resources of natural support based on the use of technology.

Entorhinal Cortex Volume Is Associated With Dual-Task Gait Cost Among Older Adults With MCI: Results From the Gait and Brain Study.

PubMed

Sakurai, Ryota; Bartha, Robert; Montero-Odasso, Manuel

2018-05-15

Low dual-task gait performance (the slowing of gait speed while performing a demanding cognitive task) is associated with low cognitive performance and an increased risk of progression to dementia in older adults with mild cognitive impairment. However, the reason for this remains unclear. This study aimed to examine the relationship between dual-task cost and regional brain volume, focusing on the hippocampus, parahippocampal gyrus, entorhinal cortex, and motor and lateral frontal cortices in older adults with mild cognitive impairment. Forty older adults with mild cognitive impairment from the "Gait and Brain Study" were included in this study. Gait velocity was measured during single-task (ie, walking alone) and dual-task (ie, counting backwards, subtracting serial sevens, and naming animals, in addition to walking) conditions, using an electronic walkway. Regional brain volumes were derived by automated segmentation, using 3T magnetic resonance imaging. Partial rank correlation analyses demonstrated that a smaller volume of the left entorhinal cortex was associated with higher dual-task costs in counting backwards and subtracting serial sevens conditions. Subsequent logistic regression analyses demonstrated that a smaller volume of the left entorhinal cortex was independently associated with higher dual-task cost (slowing down >20% when performing cognitive task) in these two conditions. There were no other significant associations. Our results show that lower dual-task gait performance is associated with volume reduction in the entorhinal cortex. Cognitive and motor dysfunction in older adults with mild cognitive impairment may reflect a shared pathogenic mechanism, and dual-task-related gait changes might be a surrogate motor marker for Alzheimer's disease pathology.

Laser-zone growth in a Ribbon-To-Ribbon, RTR, process silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Gurtler, R. W.; Baghdadi, A.

1977-01-01

A ribbon-to-ribbon process was used for routine growth of samples for analysis and fabrication into solar cells. One lot of solar cells was completely evaluated: ribbon solar cell efficiencies averaged 9.23% with a highest efficiency of 11.7%. Spherical reflectors have demonstrated significant improvements in laser silicon coupling efficiencies. Material analyses were performed including silicon photovoltage and open circuit photovoltage diffusion length measurements, crystal morphology studies, modulus of rupture measurements, and annealing/gettering studies. An initial economic analysis was performed indicating that ribbon-to-ribbon add-on costs of $.10/watt might be expected in the early 1980's.

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

Ren, Hongbo; Qiao, Zemin; Liu, Xiao

Highlights: • Sol–gel route is combined with polymerization without using modifier. • Supercritical drying control is the key to obtain super-hydrophobic surfaces. • The whole fabrication is technologically controllable and with low costs. • The production rate is higher than 90%. • The method provides a cost-effective way for industry applications. - Abstract: We successfully synthesized one type of cheap super-hydrophobic hybrid porous materials in a sol–gel process. In this route, hydrophilic polymers and TEOS-base sol are used as precursors, the ultraviolet ray-initiated polymerization and supercritical fluid drying techniques are combined together to fulfill this task. All fabricated samples exhibitmore » lotus-leaf-like surface structures with super-hydrophobicity. The underlying mechanisms are carefully investigated using a field-emission scanning electron microscopy (FESEM) and an X-ray photoelectron spectroscopy (XPS). We found that a well-controlled drying process is crucial to the formation of such super-hydrophobic surfaces. As high as 90% production rate is obtained in our route and thus, it might provide a cost-effective way to produce super-hydrophobic hybrid materials for industry applications.« less

The effect of episodic retrieval on inhibition in task switching.

PubMed

Grange, James A; Kowalczyk, Agnieszka W; O'Loughlin, Rory

2017-08-01

Inhibition in task switching is inferred from n-2 repetition costs: the observation that ABA task switching sequences are responded to slower than CBA sequences. This is thought to reflect the persisting inhibition of Task A, which slows reactivation attempts. Mayr (2002) reported an experiment testing a critical noninhibitory account of this effect, namely episodic retrieval: If the trial parameters for Task A match across an ABA sequence, responses should be facilitated because of priming from episodic retrieval; a cost would occur if trial parameters mismatch. In a rule-switching paradigm, Mayr reported no significant difference in n-2 repetition cost when the trial parameters repeated or switched across an ABA sequence, in clear contrast to the episodic retrieval account. What remains unclear is whether successful episodic retrieval modulates the n-2 repetition cost. Across 3 experiments-including a close replication of Mayr-we find clear evidence of reduced n-2 task repetition costs when episodic retrieval is controlled. We find that the effect of episodic retrieval on the n-2 task repetition cost is increased when the cue-task relationship is made more abstract, suggesting the effect is because of interference in establishing the relevant attentional set. We also demonstrate that the episodic retrieval effect is not influenced by retrieval of low-level, perceptual, elements. Together, the data suggest the n-2 task repetition cost-typically attributable to an inhibitory mechanism-also reflects episodic retrieval effects. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Low cost, small form factor, and integration as the key features for the optical component industry takeoff

NASA Astrophysics Data System (ADS)

Schiattone, Francesco; Bonino, Stefano; Gobbi, Luigi; Groppi, Angelamaria; Marazzi, Marco; Musio, Maurizio

2003-04-01

In the past the optical component market has been mainly driven by performances. Today, as the number of competitors has drastically increased, the system integrators have a wide range of possible suppliers and solutions giving them the possibility to be more focused on cost and also on footprint reduction. So, if performances are still essential, low cost and Small Form Factor issues are becoming more and more crucial in selecting components. Another evolution in the market is the current request of the optical system companies to simplify the supply chain in order to reduce the assembling and testing steps at system level. This corresponds to a growing demand in providing subassemblies, modules or hybrid integrated components: that means also Integration will be an issue in which all the optical component companies will compete to gain market shares. As we can see looking several examples offered by electronic market, to combine low cost and SFF is a very challenging task but Integration can help in achieving both features. In this work we present how these issues could be approached giving examples of some advanced solutions applied to LiNbO3 modulators. In particular we describe the progress made on automation, new materials and low cost fabrication methods for the parts. We also introduce an approach in integrating optical and electrical functionality on LiNbO3 modulators including RF driver, bias control loop, attenuator and photodiode integrated in a single device.

Chemical vapor deposition growth

NASA Technical Reports Server (NTRS)

Ruth, R. P.; Manasevit, H. M.; Campbell, A. G.; Johnson, R. E.; Kenty, J. L.; Moudy, L. A.; Shaw, G. L.; Simpson, W. I.; Yang, J. J.

1978-01-01

The objective was to investigate and develop chemical vapor deposition (CVD) techniques for the growth of large areas of Si sheet on inexpensive substrate materials, with resulting sheet properties suitable for fabricating solar cells that would meet the technical goals of the Low Cost Silicon Solar Array Project. The program involved six main technical tasks: (1) modification and test of an existing vertical-chamber CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using impurity diffusion and other standard and near-standard processing techniques supplemented late in the program by the in situ CVD growth of n(+)/p/p(+) sheet structures subsequently processed into experimental cells.

9-1529 : low-cost safety solutions, pavement preservation, and maintenance practices for rural highways.

DOT National Transportation Integrated Search

2014-08-01

Task 1 : The objective of this project was to develop and : demonstrate innovative low-cost solutions to : improve safety at stop-controlled intersections. : Preliminary directives from the project panel : were to focus on treatments on the minor str...

A Review of Models of Cost and Training Effectiveness Analysis (CTEA). Volume 1. Training Effectiveness Analysis

DTIC Science & Technology

1987-10-01

19 treated in interaction with each other and the hardware and software design. The authors point out some of the inadequacies in HP technologies and...life cycle costs recognition performance on secondary tasks effort/efficiency number of wins ( gaming tasks) number of instructors needed amount of...student interacts with this material in real time via a terminal and display system. The computer performs many functions, such as diagnose student

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

Lutwack, R.

The goal of the Silicon Material Task, a part of the FSA Project, was to develop and demonstrate the technology for the low-cost production of silicon of suitable purity to be used as the basic material for the manufacture of terrestrial photovoltaic solar cells. To be compatible with the price goals of the FSA Project, the price of the produced silicon was to be less than $10/kg (in 1975 dollars). Summarized in this document are 11 different processes for the production of silicon that were investigated and developed to varying extent by industrial, university, and government researchers. The silane-production sectionmore » of the Union Carbide Corp. (UCC) silane process was developed completely in this program. Coupled with Siemens-type chemical vapor deposition reactors, the process was carried through the pilot plant stage. The overall UCC process involves the conversion of metallurgical-grade silicon to silane followed by decomposition of the silane to purified silicon. Production of very high-purity silane and silicon was demonstrated. Although it has as yet not achieved commercial application, the development of fluidized-bed technology for the low-cost, high-throughput conversion of silane-to-silicon has been demonstrated in the research laboratory and now is in engineering development.« less

Dip coating process: Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

NASA Technical Reports Server (NTRS)

Heaps, J. D.; Maciolek, R. B.; Zook, J. D.; Harrison, W. B.; Scott, M. W.; Hendrickson, G.; Wolner, H. A.; Nelson, L. D.; Schuller, T. L.; Peterson, A. A.

1976-01-01

The technical and economic feasibility of producing solar cell quality sheet silicon by dip-coating one surface of carbonized ceramic substrates with a thin layer of large grain polycrystalline silicon was investigated. The dip-coating methods studied were directed toward a minimum cost process with the ultimate objective of producing solar cells with a conversion efficiency of 10% or greater. The technique shows excellent promise for low cost, labor-saving, scale-up potentialities and would provide an end product of sheet silicon with a rigid and strong supportive backing. An experimental dip-coating facility was designed and constructed, several substrates were successfully dip-coated with areas as large as 25 sq cm and thicknesses of 12 micron to 250 micron. There appears to be no serious limitation on the area of a substrate that could be coated. Of the various substrate materials dip-coated, mullite appears to best satisfy the requirement of the program. An inexpensive process was developed for producing mullite in the desired geometry.

A study of methods for lowering aerial environmental survey cost

NASA Technical Reports Server (NTRS)

Stansberry, J. R.

1973-01-01

The results are presented of a study of methods for lowering the cost of environmental aerial surveys. A wide range of low cost techniques were investigated for possible application to current pressing urban and rural problems. The objective of the study is to establish a definition of the technical problems associated with conducting aerial surveys using various low cost techniques, to conduct a survey of equipment which may be used in low cost systems, and to establish preliminary estimates of cost. A set of candidate systems were selected and described for the environmental survey tasks.

The 40 KW of Solar Cell Modules for the Large Scale Production Task a Low Cost Silicon Solar Array Project

NASA Technical Reports Server (NTRS)

Jones, G. T.

1977-01-01

Forty kilowatts of solar cell modules was produced in this program. This is equivalent to 4123 modules. The average power output per module was 9.7 watts at 16.5 volts, 60 C and 100 mW/sq cm. The peak production rate was 200 modules per week which is equal to 1.9 kW per week. This rate was sustained for over four and one-half months and is equivalent to 100 kW per year. This final report covers the solar cell module design, electrical and power performance, module preproduction environmental test results, production and shipping schedule, program summary, and delivery. A cost analysis section is written. Particular emphasis on the percentage of labor and material utilized in constructing a solar cell module is presented. Also included are cost reduction recommendations.

Engineering design aspects of the heat-pipe power system

NASA Technical Reports Server (NTRS)

Capell, B. M.; Houts, M. G.; Poston, D. I.; Berte, M.

1997-01-01

The Heat-pipe Power System (HPS) is a near-term, low-cost space power system designed at Los Alamos that can provide up to 1,000 kWt for many space nuclear applications. The design of the reactor is simple, modular, and adaptable. The basic design allows for the use of a variety of power conversion systems and reactor materials (including the fuel, clad, and heat pipes). This paper describes a project that was undertaken to develop a database supporting many engineering aspects of the HPS design. The specific tasks discussed in this paper are: the development of an HPS materials database, the creation of finite element models that will allow a wide variety of investigations, and the verification of past calculations.

Recent progress in terrestrial photovoltaic collector technology

NASA Technical Reports Server (NTRS)

Ferber, R. R.

1982-01-01

The U.S. Photovoltaic Research and Development Program has the objective to develop the technology necessary to foster widespread grid-competitive electric power generation by the late 1980s. The flat-plate and the concentrator collector activities form the nucleus of the program. The project is concerned with the refining of silicon, silicon sheet production, solar cell processing and fabrication, encapsulation materials development, and collector design and production. The Large-Area Silicon Sheet Task has the objective to develop and demonstrate the feasibility of several methods for producing large area silicon sheet material suitable for fabricating low-cost, high-efficiency solar cells. It is expected that a variety of economic flat-plate and concentrator collectors will become commercially available for grid-connected applications.

Face-gender discrimination is possible in the near-absence of attention.

PubMed

Reddy, Leila; Wilken, Patrick; Koch, Christof

2004-03-02

The attentional cost associated with the visual discrimination of the gender of a face was investigated. Participants performed a face-gender discrimination task either alone (single-task) or concurrently (dual-task) with a known attentional demanding task (5-letter T/L discrimination). Overall performance on face-gender discrimination suffered remarkably little under the dual-task condition compared to the single-task condition. Similar results were obtained in experiments that controlled for potential training effects or the use of low-level cues in this discrimination task. Our results provide further evidence against the notion that only low-level representations can be accessed outside the focus of attention.

Modern laser technologies used for cutting textile materials

NASA Astrophysics Data System (ADS)

Isarie, Claudiu; Dragan, Anca; Isarie, Laura; Nastase, Dan

2006-02-01

With modern laser technologies we can cut multiple layers at once, yielding high production levels and short setup times between cutting runs. One example could be the operation of cutting the material named Nylon 66, used to manufacture automobile airbags. With laser, up to seven layers of Nylon 66 can be cut in one pass, that means high production rates on a single machine. Airbags must be precisely crafted piece of critical safety equipment that is built to very high levels of precision in a mass production environment. Of course, synthetic material, used for airbags, can be cut also by a conventional fixed blade system, but for a high production rates and a long term low-maintenance, laser cutting is most suitable. Most systems, are equipped with two material handling systems, which can cut on one half of he table while the finished product is being removed from the other half and the new stock material laid out. The laser system is reliable and adaptable to any flatbed-cutting task. Computer controlled industrial cutting and plotting machines are the latest offerings from a well established and experienced industrial engineering company that is dedicated to reduce cutting costs and boosting productivity in today's competitive industrial machine tool market. In this way, just one machine can carry out a multitude of production tasks. Authors have studied the cutting parameters for different textile materials, to reach the maximum output of the process.

A self-instructional manual for installing low-cost/no-cost weatherization materials: Experimental validation with scouts

PubMed Central

Pavlovich, Mark; Greene, Brandon F.

1984-01-01

In this study, we describe the development and evaluation of a self-instructional program for installing 10 low-cost/no-cost weatherization materials (e.g., weatherstripping, caulking). This program was a weatherization and retrofit manual (WARM) providing step-by-step instructions and illustrations. Boy and Girl Scouts participated and used either the WARM or existing product instructions (EPI) to apply the materials. Scouts installed the materials properly only when they used the WARM. PMID:16795671

Thermoplastic rubberlike material produced at low cost

NASA Technical Reports Server (NTRS)

Hendel, F. J.

1966-01-01

Thermoplastic rubberlike material is prepared by blending a copolymer of ethylene and vinyl acetate with asphalt and a petroleum distillate. This low cost material is easily molded or extruded and is compatible with a variety of fillers.

Low cost silicon solar array project silicon materials task

NASA Technical Reports Server (NTRS)

1977-01-01

A program was established to develop a high temperature silicon production process using existing electric arc heater technology. Silicon tetrachloride and a reductant will be injected into an arc heated mixture of hydrogen and argon. Under these high temperature conditions, a very rapid reaction is expected to occur and proceed essentially to completion, yielding silicon and gaseous sodium chloride. Techniques for high temperature separation and collection of the molten silicon will be developed using standard engineering approaches, and the salt vapor will later be electrolytically separated into its elemental constituents for recycle. Preliminary technical evaluations and economic projections indicate not only that this process appears to be feasible, but that it also has the advantages of rapid, high capacity production of good quality molten silicon at a nominal cost.

Evaluation of a low-cost, 3D-printed model for bronchoscopy training.

PubMed

Parotto, Matteo; Jiansen, Joshua Qua; AboTaiban, Ahmed; Ioukhova, Svetlana; Agzamov, Alisher; Cooper, Richard; O'Leary, Gerald; Meineri, Massimiliano

2017-01-01

Flexible bronchoscopy is a fundamental procedure in anaesthesia and critical care medicine. Although learning this procedure is a complex task, the use of simulation-based training provides significant advantages, such as enhanced patient safety. Access to bronchoscopy simulators may be limited in low-resource settings. We have developed a low-cost 3D-printed bronchoscopy training model. A parametric airway model was obtained from an online medical model repository and fabricated using a low-cost 3D printer. The participating physicians had no prior bronchoscopy experience. Participants received a 30-minute lecture on flexible bronchoscopy and were administered a 15-item pre-test questionnaire on bronchoscopy. Afterwards, participants were instructed to perform a series of predetermined bronchoscopy tasks on the 3D printed simulator on 4 consecutive occasions. The time needed to perform the tasks and the quality of task performance (identification of bronchial anatomy, technique, dexterity, lack of trauma) were recorded. Upon completion of the simulator tests, participants were administered the 15-item questionnaire (post-test) once again. Participant satisfaction data on the perceived usefulness and accuracy of the 3D model were collected. A statistical analysis was performed using the t-test. Data are reported as mean values (± standard deviation). The time needed to complete all tasks was 152.9 ± 71.5 sec on the 1st attempt vs. 98.7 ± 40.3 sec on the 4th attempt (P = 0.03). Likewise, the quality of performance score improved from 8.3 ± 6.7 to 18.2 ± 2.5 (P < 0.0001). The average number of correct answers in the questionnaire was 6.8 ± 1.9 pre-test and 13.3 ± 3.1 post-test (P < 0.0001). Participants reported a high level of satisfaction with the perceived usefulness and accuracy of the model. We developed a 3D-printed model for bronchoscopy training. This model improved trainee performance and may represent a valid, low-cost bronchoscopy training tool.

Bridge-in-a-Backpack(TM). Task 2 : reduction of costs through design modifications and optimization.

DOT National Transportation Integrated Search

2011-09-01

The cost effective use of FRP composites in infrastructure requires the efficient use of the : composite materials in the design. Previous work during the development phase and : demonstration phase illustrated the need to refine the design methods f...

Extraterrestrial applications of solar optics for interior illumination

NASA Technical Reports Server (NTRS)

Eijadi, David A.; Williams, Kyle D.

1992-01-01

Solar optics is a terrestrial technology that has potential extraterrestrial applications. Active solar optics (ASO) and passive solar optics (PSO) are two approaches to the transmission of sunlight to remote interior spaces. Active solar optics is most appropriate for task illumination, while PSO is most appropriate for general illumination. Research into solar optics, motivated by energy conservation, has produced lightweight and low-cost materials, products that have applications to NASA's Controlled Ecological Life Support System (CELSS) program and its lunar base studies. Specifically, prism light guides have great potential in these contexts. Several applications of solar optics to lunar base concepts are illustrated.

Low cost solar array project silicon materials task. Development of a process for high capacity arc heater production of silicon for solar arrays

NASA Technical Reports Server (NTRS)

Reed, W. H.

1978-01-01

Silicon tetrachloride and a reductant (sodium) will be injected into an arc heated mixture of hydrogen and argon, yielding silicon and gaseous sodium chloride. Detailed characterization of the Sonicore sodium injection nozzle, using water as the test fluid was completed. Results indicated that flow rates of 45 gph sodium and 50 scfm argon should produce sufficiently small droplet sizes. The design effort was also completed for the test system preparation which was divided into two categories: (1) system components and (2) test system-laboratory integration.

TSX-PLUS MULTI-TASKING UPGRADE FOR THE NICOLET L-11 POWDER DIFFRACTION SYSTEM.

USGS Publications Warehouse

Fitzpatrick, J.; Queen, David L.

1985-01-01

In August of 1982, a single-user, dual-translator, automated powder diffraction system was purchased by the Denver Research Institute for use on project work in the Chemical and Materials Sciences Division. Within a short period of time, the system had already become saturated with users. Scheduling conflicts arose. In view of these problems, an answer was sought in the form of hardware and software changes which would allow many users access to the system simultaneously. A low-cost, minimum impact solution was eventually found. The elements of the solution are reported.

Can low-cost motion-tracking systems substitute a Polhemus system when researching social motor coordination in children?

PubMed

Romero, Veronica; Amaral, Joseph; Fitzpatrick, Paula; Schmidt, R C; Duncan, Amie W; Richardson, Michael J

2017-04-01

Functionally stable and robust interpersonal motor coordination has been found to play an integral role in the effectiveness of social interactions. However, the motion-tracking equipment required to record and objectively measure the dynamic limb and body movements during social interaction has been very costly, cumbersome, and impractical within a non-clinical or non-laboratory setting. Here we examined whether three low-cost motion-tracking options (Microsoft Kinect skeletal tracking of either one limb or whole body and a video-based pixel change method) can be employed to investigate social motor coordination. Of particular interest was the degree to which these low-cost methods of motion tracking could be used to capture and index the coordination dynamics that occurred between a child and an experimenter for three simple social motor coordination tasks in comparison to a more expensive, laboratory-grade motion-tracking system (i.e., a Polhemus Latus system). Overall, the results demonstrated that these low-cost systems cannot substitute the Polhemus system in some tasks. However, the lower-cost Microsoft Kinect skeletal tracking and video pixel change methods were successfully able to index differences in social motor coordination in tasks that involved larger-scale, naturalistic whole body movements, which can be cumbersome and expensive to record with a Polhemus. However, we found the Kinect to be particularly vulnerable to occlusion and the pixel change method to movements that cross the video frame midline. Therefore, particular care needs to be taken in choosing the motion-tracking system that is best suited for the particular research.

Failure of structural elements made of polymer supported composite materials during the multiyear natural aging

NASA Astrophysics Data System (ADS)

Blinkov, Pavel; Ogorodov, Leonid; Grabovyy, Peter

2018-03-01

Modern high-rise construction introduces a number of limitations and tasks. In addition to durability, comfort and profitability, projects should take into account energy efficiency and environmental problems. Polymer building materials are used as substitutes for materials such as brick, concrete, metal, wood and glass, and in addition to traditional materials. Plastic materials are light, can be formed into complex shapes, durable and low, and also possess a wide range of properties. Plastic materials are available in various forms, colors and textures and require minimal or no color. They are resistant to heat transfer and diffusion of moisture and do not suffer from metal corrosion or microbial attack. Polymeric materials, including thermoplastics, thermoset materials and wood-polymer composites, have many structural and non-structural applications in the construction industry. They provide unique and innovative solutions at a low cost, and their use is likely to grow in the future. A number of polymer composite materials form complex material compositions, which are applied in the construction in order to analyze the processes of damage accumulation under the conditions of complex nonstationary loading modes, and to determine the life of structural elements considering the material aging. This paper present the results of tests on short-term compression loading with a deformation rate of v = 2 mm/min using composite samples of various shapes and sizes.

Applications of ethylene vinyl acetate as an encapsulation material for terrestrial photovoltaic modules

NASA Technical Reports Server (NTRS)

Cuddihy, E. F.; Coulbert, C. D.; Liang, R. H.; Gupta, A.; Willis, P.; Baum, B.

1983-01-01

Terrestrial photovoltaic modules must undergo substantial reductions in cost in order to become economically attractive as practical devices for large scale production of electricity. Part of the cost reductions must be realized by the encapsulation materials that are used to package, protect, and support the solar cells, electrical interconnects, and other ancillary components. As many of the encapsulation materials are polymeric, cost reductions necessitate the use of low cost polymers. The performance and status of ethylene vinyl acetate, a low cost polymer that is being investigated as an encapsulation material for terrestrial photovoltaic modules, are described.

Silicon materials task of the low cost solar array project. Phase 3: Effect of impurities and processing on silicon solar cells

NASA Technical Reports Server (NTRS)

Hopkins, R. H.; Davis, J. R.; Blais, P. D.; Rohatgi, A.; Campbell, R. B.; Rai-Choudhury, P.; Mollenkopf, H. C.; Mccormick, J. R.

1979-01-01

The 13th quarterly report of a study entitled an Investigation of the Effects of Impurities and Processing on Silicon Solar Cells is given. The objective of the program is to define the effects of impurities, various thermochemical processes and any impurity-process interactions on the performance of terrestrial silicon solar cells. The Phase 3 program effort falls in five areas: (1) cell processing studies; (2) completion of the data base and impurity-performance modeling for n-base cells; (3) extension of p-base studies to include contaminants likely to be introduced during silicon production, refining or crystal growth; (4) anisotropy effects; and (5) a preliminary study of the permanence of impurity effects in silicon solar cells. The quarterly activities for this report focus on tasks (1), (3) and (4).

Development of a low-cost double rotor axial flux motor with soft magnetic composite and ferrite permanent magnet materials

NASA Astrophysics Data System (ADS)

Liu, Chengcheng; Zhu, Jianguo; Wang, Youhua; Guo, Youguang; Lei, Gang; Liu, Xiaojing

2015-05-01

This paper proposes a low-cost double rotor axial flux motor (DRAFM) with low cost soft magnetic composite (SMC) core and ferrite permanent magnets (PMs). The topology and operating principle of DRAFM and design considerations for best use of magnetic materials are presented. A 905 W 4800 rpm DRAFM is designed for replacing the high cost NdFeB permanent magnet synchronous motor (PMSM) in a refrigerator compressor. By using the finite element method, the electromagnetic parameters and performance of the DRAFM operated under the field oriented control scheme are calculated. Through the analysis, it is shown that that the SMC and ferrite PM materials can be good candidates for low-cost electric motor applications.

Feasibility study of modern airships, phase 1. Volume 2: Parametric analysis (task 3). [lift, weight (mass)

NASA Technical Reports Server (NTRS)

Lancaster, J. W.

1975-01-01

Various types of lighter-than-air vehicles from fully buoyant to semibuoyant hybrids were examined. Geometries were optimized for gross lifting capabilities for ellipsoidal airships, modified delta planform lifting bodies, and a short-haul, heavy-lift vehicle concept. It is indicated that: (1) neutrally buoyant airships employing a conservative update of materials and propulsion technology provide significant improvements in productivity; (2) propulsive lift for VTOL and aerodynamic lift for cruise significantly improve the productivity of low to medium gross weight ellipsoidal airships; and (3) the short-haul, heavy-lift vehicle, consisting of a simple combination of an ellipsoidal airship hull and existing helicopter componentry, provides significant potential for low-cost, near-term applications for ultra-heavy lift missions.

The effects of response cost and species-typical behaviors on a daily time-place learning task.

PubMed

Deibel, Scott H; Thorpe, Christina M

2013-03-01

Two theories that have been hypothesized to mediate acquisition in daily time-place learning (TPL) tasks were investigated in a free operant daily TPL task: the response cost hypothesis and the species-typical behavior hypothesis. One lever at the end of one of the choice arms of a T-maze provided food in the morning, and 6 h later, a lever in the other choice arm provided food. Four groups were used to assess the effect of two possible sources of response cost: physical effort of the task and costs associated with foraging ecology. One group was used to assess the effect of explicitly allowing for species-typical behaviors. If only first arm choice data were considered, there was little evidence of learning. However, both first press and percentage of presses on the correct lever prior to the first reinforcement revealed evidence of TPL in most rats tested. Unexpectedly, the high response cost groups for both of the proposed sources did not perform better than the low response cost groups. The groups that allowed animals to display species-typical behaviors performed the worst. Skip session probe trials confirmed that the majority of the rats that acquired the task were using a circadian timing strategy. The results from the present study suggest that learning in free operant daily TPL tasks might not be dependent on response cost.

URINE SOURCE SEPARATION AND TREATMENT: NUTRIENT RECOVERY USING LOW-COST MATERIALS

EPA Science Inventory

Successful completion of this P3 Project will achieve the following expected outputs: identification of low-cost materials that can effectively recover ammonium, phosphate, and potassium from urine; material balance calculations for different urine separation and treatment scheme...

Developments in abatement technology for MOCVD processing

NASA Astrophysics Data System (ADS)

Sweeney, Joseph; Marganski, Paul; Olander, Karl; Watanabe, Tadaharu; Tomita, Nobuyasu; Orlando, Gary; Torres, Robert

2004-12-01

A newly developed technical solution has been developed for hydride gas abatement that utilizes a new material. The ULTIMA-Sorb™ material provides high capacity but low heat of reaction with the hydride gases. The new technology results in a low cost of ownership (COO) with stable operation and also reduces the cost and quantity of waste disposal. This can be significant benefit for device manufacturers since it provides a viable and cost effective solution without any risk of arsenic leakage that is a primary concern with wet chemical scrubber systems. The contents of this paper will discuss the technical and economic benefits of the newly developed material in comparison to conventional abatement materials and systems. The capacity of the dry abatement materials significantly influences both COO relating to cash outflow and the cost of lost production. High capacity materials enable significant savings in cost of lost production in cases of low and high factory utilization conditions. Capacity of the abatement material appears to be the largest single factor to reduce COO of dry abatement systems.

Continuous Czochralski growth: Silicon sheet growth development of the large area sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Johnson, C. M.

1980-01-01

The growth of 100 kg of silicon single crystal material, ten cm in diameter or greater, and 150 kg of silicon single crystal material 15 cm or greater utilizing one common silicon container material (one crucible) is investigated. A crystal grower that is recharged with a new supply of polysilicon material while still under vacuum and at temperatures above the melting point of silicon is developed. It accepts large polysilicon charges up to 30 kg, grows large crystal ingots (to 15 cm diameter and 25 kg in weight), and holds polysilicon material for recharging (rod or lump) while, at the same time, growing crystal ingots. Special equipment is designed to recharge polysilicon rods, recharge polysilicon lumps, and handle and store large, hot silicon crystal ingots. Many continuous crystal growth runs were performed lasting as long as 109 hours and producing as many as ten crystal ingots, 15 cm with weights progressing to 27 kg.

Silicon-on ceramic process: Silicon sheet growth and device development for the large-area silicon sheet task of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Grung, B. L.; Heaps, J. D.; Schmit, F. M.; Schuldt, S. B.; Zook, J. D.

1981-01-01

The technical feasibility of producing solar-cell-quality sheet silicon to meet the Department of Energy (DOE) 1986 overall price goal of $0.70/watt was investigated. With the silicon-on-ceramic (SOC) approach, a low-cost ceramic substrate is coated with large-grain polycrystalline silicon by unidirectional solidification of molten silicon. This effort was divided into several areas of investigation in order to most efficiently meet the goals of the program. These areas include: (1) dip-coating; (2) continuous coating designated SCIM-coating, and acronym for Silicon Coating by an Inverted Meniscus (SCIM); (3) material characterization; (4) cell fabrication and evaluation; and (5) theoretical analysis. Both coating approaches were successful in producing thin layers of large grain, solar-cell-quality silicon. The dip-coating approach was initially investigated and considerable effort was given to this technique. The SCIM technique was adopted because of its scale-up potential and its capability to produce more conventiently large areas of SOC.

Integration of Kinect and Low-Cost Gnss for Outdoor Navigation

NASA Astrophysics Data System (ADS)

Pagliaria, D.; Pinto, L.; Reguzzoni, M.; Rossi, L.

2016-06-01

Since its launch on the market, Microsoft Kinect sensor has represented a great revolution in the field of low cost navigation, especially for indoor robotic applications. In fact, this system is endowed with a depth camera, as well as a visual RGB camera, at a cost of about 200. The characteristics and the potentiality of the Kinect sensor have been widely studied for indoor applications. The second generation of this sensor has been announced to be capable of acquiring data even outdoors, under direct sunlight. The task of navigating passing from an indoor to an outdoor environment (and vice versa) is very demanding because the sensors that work properly in one environment are typically unsuitable in the other one. In this sense the Kinect could represent an interesting device allowing bridging the navigation solution between outdoor and indoor. In this work the accuracy and the field of application of the new generation of Kinect sensor have been tested outdoor, considering different lighting conditions and the reflective properties of the emitted ray on different materials. Moreover, an integrated system with a low cost GNSS receiver has been studied, with the aim of taking advantage of the GNSS positioning when the satellite visibility conditions are good enough. A kinematic test has been performed outdoor by using a Kinect sensor and a GNSS receiver and it is here presented.

A simple cost-effective design for construction of a laparoscopic trainer.

PubMed

Ricchiuti, Daniel; Ralat, Dane Arends; Evancho-Chapman, Michelle; Wyneski, Holly; Cerone, Jeffrey; Wegryn, John D

2005-10-01

Laparoscopic trainers have been shown to be effective tools for transitioning residents in surgical fields into live laparoscopic techniques. There have been few reports of homemade trainers, but each of these reports provides only scant detail about their construction, making production a novel task to those interested in employing this equipment. Virtual-reality trainers are gaining popularity and are exceptional modalities in the re-creation of laparoscopic surgery. In their present state, however, such trainers are very costly, making them unattainable by most urology residency programs. Numerous commercial non-virtual trainers are also available; however, these trainers are often cost-prohibitive or overly simplistic. We describe a detailed design template for creation of a laparoscopic trainer based on modifications of previous designs. This trainer can be made easily at a cost of approximately US$275.00 and may be used in conjunction with existing laparoscopic equipment. The methods described herein can be followed by any local machinist to create this trainer. The relatively low total cost, ready material availability, and ease of construction make this trainer an appropriate option for the training of residents in laparoscopic procedures.

Encapsulant selection and durability testing experience

NASA Technical Reports Server (NTRS)

Cuddihy, E. F.

1985-01-01

The Flat Plate Solar Array Project (FSA) has established technically challenging cost and service life goals for photovoltaic modules. These goals are a cost of $70 sq m and an expected 30 years of service life in an outdoor weathering environment. out of the cost goal, $14 sq m is allocated for encapsulation materials, which includes the cost of a structural panel. At FSA's inception in 1975, the cumulative cost of encapsulation materials in popular use, such as room temperature vulcanized (RTV) silicones, aluminum panels, etc., greatly exceeded $14/sq m. Accordingly, it became necessary to identify and/or develop new materials and new material technologies to achieve the goals. Many of these new materials are low cost polymers that satisfy module engineering and encapsulation processing requirements but unfortunately are not intrinsically weather stable. This necessitates identifying lifetime and/or weathering deficiencies inherent in these low cost materials and developing specific approaches to enhancing weather stability.

Multi Objective Optimization of Yarn Quality and Fibre Quality Using Evolutionary Algorithm

NASA Astrophysics Data System (ADS)

Ghosh, Anindya; Das, Subhasis; Banerjee, Debamalya

2013-03-01

The quality and cost of resulting yarn play a significant role to determine its end application. The challenging task of any spinner lies in producing a good quality yarn with added cost benefit. The present work does a multi-objective optimization on two objectives, viz. maximization of cotton yarn strength and minimization of raw material quality. The first objective function has been formulated based on the artificial neural network input-output relation between cotton fibre properties and yarn strength. The second objective function is formulated with the well known regression equation of spinning consistency index. It is obvious that these two objectives are conflicting in nature i.e. not a single combination of cotton fibre parameters does exist which produce maximum yarn strength and minimum cotton fibre quality simultaneously. Therefore, it has several optimal solutions from which a trade-off is needed depending upon the requirement of user. In this work, the optimal solutions are obtained with an elitist multi-objective evolutionary algorithm based on Non-dominated Sorting Genetic Algorithm II (NSGA-II). These optimum solutions may lead to the efficient exploitation of raw materials to produce better quality yarns at low costs.

The Role of Self-Esteem and Self-Efficacy in Detecting Responses to Feedback

DTIC Science & Technology

1998-07-01

self -efficacy on a novel task may be a function of self - esteem and initial instruction on the task. It may be that low SEs initial self ...than will persons low in self -efficacy. This may also have implications for the interaction between self -efficacy and self - esteem . In situations...feedback than persons with low SE. Persons with low self - esteem are likely to perceive 32 greater feedback seeking costs (as noted earlier).

Performance benefits and costs in forced choice perceptual identification in amnesia: Effects of prior exposure and word frequency.

PubMed

Keane, Margaret M; Martin, Elizabeth; Verfaellie, Mieke

2009-07-01

Accuracy in identifying a perceptually degraded word (e.g., stake) can be either enhanced by recent exposure to the same stimulus or reduced by recent exposure to a similar stimulus (e.g., stare). In the present study, we explored the mechanisms underlying these benefits and costs by examining the performance of amnesic and control groups in a forced choice perceptual identification (FCPI) task in which briefly flashed words (that were identical to studied words, similar to studied words, or new) had to be identified, and two response choices were provided that differed from each other by one letter. Control participants showed a performance benefit and cost in FCPI with both high- and low-frequency words. Amnesic participants showed a benefit (but no cost) with high-frequency words and a benefit and a cost with low-frequency words. The benefit/cost pattern with low-frequency words in amnesia was obtained even when the to-be-identified stimulus in the FCPI task was eliminated (Experiment 2), suggesting that this effect was driven by processes operating at the level of the response choices. Our findings suggest that implicit memory effects in FCPI reflect the operation of multiple mechanisms, the relative contributions of which may vary with the frequency of the test stimuli. The results also highlight the need for caution in interpreting results from normal participants in the FCPI task, since those findings may reflect a contribution of explicit memory processes.

Evaluation available encapsulation materials for low-cost long-life silicon photovoltaic arrays

NASA Technical Reports Server (NTRS)

Carmichael, D. C.; Gaines, G. B.; Noel, G. T.; Sliemers, F. A.; Nance, G. P.; Bunk, A. R.; Brockway, M. C.

1978-01-01

Experimental evaluation of selected encapsulation designs and materials based on an earlier study which have potential for use in low cost, long-life photovoltaic arrays are reported. The performance of candidate materials and encapsulated cells were evaluated principally for three types of encapsulation designs based on their potentially low materials and processing costs: (1) polymeric coatings, transparent conformal coatings over the cell with a structural-support substrate; (2) polymeric film lamination, cells laminated between two films or sheets of polymeric materials; and (3) glass-covered systems, cells adhesively bonded to a glass cover (superstrate) with a polymeric pottant and a glass or other substrate material. Several other design types, including those utilizing polymer sheet and pottant materials, were also included in the investigation.

Power Electronics Packaging Reliability | Transportation Research | NREL

Science.gov Websites

interface materials, are a key enabling technology for compact, lightweight, low-cost, and reliable power , reliability, and cost. High-temperature bonded interface materials are an important facilitating technology for compact, lightweight, low-cost, reliable power electronics packaging that fully utilizes the

Development of OTM Syngas Process and Testing of Syngas Derived Ultra-clean Fuels in Diesel Engines and Fuel Cells

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

E.T.; James P. Meagher; Prasad Apte

2002-12-31

This topical report summarizes work accomplished for the Program from November 1, 2001 to December 31, 2002 in the following task areas: Task 1: Materials Development; Task 2: Composite Development; Task 4: Reactor Design and Process Optimization; Task 8: Fuels and Engine Testing; 8.1 International Diesel Engine Program; 8.2 Nuvera Fuel Cell Program; and Task 10: Program Management. Major progress has been made towards developing high temperature, high performance, robust, oxygen transport elements. In addition, a novel reactor design has been proposed that co-produces hydrogen, lowers cost and improves system operability. Fuel and engine testing is progressing well, but wasmore » delayed somewhat due to the hiatus in program funding in 2002. The Nuvera fuel cell portion of the program was completed on schedule and delivered promising results regarding low emission fuels for transportation fuel cells. The evaluation of ultra-clean diesel fuels continues in single cylinder (SCTE) and multiple cylinder (MCTE) test rigs at International Truck and Engine. FT diesel and a BP oxygenate showed significant emissions reductions in comparison to baseline petroleum diesel fuels. Overall through the end of 2002 the program remains under budget, but behind schedule in some areas.« less

Heat storage capability of a rolling cylinder using Glauber's salt

NASA Technical Reports Server (NTRS)

Herrick, C. S.; Zarnoch, K. P.

1980-01-01

The rolling cylinder phase change heat storage concept was developed to the point where a prototype design is completed and a cost analysis is prepared. A series of experimental and analytical tasks are defined to establish the thermal, mechanical, and materials behavior of rolling cylinder devices. These tasks include: analyses of internal and external heat transfer; performance and lifetime testing of the phase change materials; corrosion evaluation; development of a mathematical model; and design of a prototype and associated test equipment.

Silicon-on-ceramic process: Silicon sheet growth and device development for the large-area silicon sheet task of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Whitehead, A. B.; Zook, J. D.; Grung, B. L.; Heaps, J. D.; Schmit, F.; Schuldt, S. B.; Chapman, P. W.

1981-01-01

The technical feasibility of producing solar cell quality sheet silicon to meet the DOE 1986 cost goal of 70 cents/watt was investigated. The silicon on ceramic approach is to coat a low cost ceramic substrate with large grain polycrystalline silicon by unidirectional solidification of molten silicon. Results and accomplishments are summarized.

Safety training priorities

NASA Astrophysics Data System (ADS)

Thompson, N. A.; Ruck, H. W.

1984-04-01

The Air Force is interested in identifying potentially hazardous tasks and prevention of accidents. This effort proposes four methods for determining safety training priorities for job tasks in three enlisted specialties. These methods can be used to design training aimed at avoiding loss of people, time, materials, and money associated with on-the-job accidents. Job tasks performed by airmen were measured using task and job factor ratings. Combining accident reports and job inventories, subject-matter experts identified tasks associated with accidents over a 3-year period. Applying correlational, multiple regression, and cost-benefit analysis, four methods were developed for ordering hazardous tasks to determine safety training priorities.

Advances in photonics thermal management and packaging materials

NASA Astrophysics Data System (ADS)

Zweben, Carl

2008-02-01

Heat dissipation, thermal stresses, and cost are key packaging design issues for virtually all semiconductors, including photonic applications such as diode lasers, light-emitting diodes (LEDs), solid state lighting, photovoltaics, displays, projectors, detectors, sensors and laser weapons. Heat dissipation and thermal stresses affect performance and reliability. Copper, aluminum and conventional polymeric printed circuit boards (PCBs) have high coefficients of thermal expansion, which can cause high thermal stresses. Most traditional low-coefficient-of-thermal-expansion (CTE) materials like tungsten/copper, which date from the mid 20 th century, have thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. There are an increasing number of low-CTE materials with thermal conductivities ranging between that of copper (400 W/m-K) and 1700 W/m-K, and many other new low-CTE materials with lower thermal conductivities. An important benefit of low-CTE materials is that they allow use of hard solders. Some advanced materials are low cost. Others have the potential to be low cost in high-volume production. High-thermal-conductivity materials enable higher power levels, potentially reducing the number of required devices. Advanced thermal materials can constrain PCB CTE and greatly increase thermal conductivity. This paper reviews traditional packaging materials and advanced thermal management materials. The latter provide the packaging engineer with a greater range of options than in the past. Topics include properties, status, applications, cost, using advanced materials to fix manufacturing problems, and future directions, including composites reinforced with carbon nanotubes and other thermally conductive materials.

OPTIMIZING EXPOSURE MEASUREMENT TECHNIQUES

EPA Science Inventory

The research reported in this task description addresses one of a series of interrelated NERL tasks with the common goal of optimizing the predictive power of low cost, reliable exposure measurements for the planned Interagency National Children's Study (NCS). Specifically, we w...

[Minimally invasive surgery and the economics of it. Can minimally invasive surgery be cost efficient from a business point of view?].

PubMed

Ritz, J P; Stufler, M; Buhr, H J

2007-06-01

Minimally invasive surgery (MIS) is now accepted as equally valid as the use of a standard access in some areas of surgery. It is not possible to decide whether this access is economically worthwhile and if so for whom without a full economic cost-benefit analysis, which must take account of the hospital's own characteristics in addition to the cost involved for surgery, staff, infrastructure and administration. In summary, the main economic advantage of MIS lies in the patient-related early postoperative results, while the main disadvantage is that the operative material costs are higher. At present, the payment made for each procedure performed under the DRG system includes 14-17% of the total cost for materials, regardless of the access route and of the technical sophistication of the operation. The actual material costs are greater by a factor of 2-50 for MIS than for a conventional procedure. The task of the hospital is thus to lower the costs for material and infrastructure; that of industry is to offer less expensive alternatives; and that of our politicians, to implement better remuneration of the material costs.

Current Status and Tasks in Development of Cable Recycling Technology

NASA Astrophysics Data System (ADS)

Ezure, Takashi; Goto, Kazuhiko

This paper shows current status and tasks in development of cable recycling technology and it’s items to be solved. Electric cable recycle system has been activated especially for copper conductor recycle in Japan. Previously removed cable coverings materials were mainly land filled. But landfill capacity is decreased and limited in recent years, at the same time, recycle technology was highly developed. A cable recycle technology has 4 tasks. (1) Applying new high efficiency separation system instead of electrostatic and gravity methods to classify mixed various kind of plastics materials including recently developed ecological material (ex PE, PVC, Rubber), (2) Removing heavy metal, especially lead from PVC material, (3) Treatment of optical glass fiber core, which has possibility going to be harmful micro particles, and (4) Establishment of social recycle system for electric wire and cable. Taking action for these tasks shall be proceeded under environmentally sensitive technology together with local government, user, manufacturer, and waste-disposal company on cost performance basis.

Advances in LED packaging and thermal management materials

NASA Astrophysics Data System (ADS)

Zweben, Carl

2008-02-01

Heat dissipation, thermal stresses and cost are key light-emitting diode (LED) packaging issues. Heat dissipation limits power levels. Thermal stresses affect performance and reliability. Copper, aluminum and conventional polymeric printed circuit boards (PCBs) have high coefficients of thermal expansion, which can cause high thermal stresses. Most traditional low-coefficient-of-thermal-expansion (CTE) materials like tungsten/copper, which date from the mid 20th century, have thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. An OIDA LED workshop cited a need for better thermal materials. There are an increasing number of low-CTE materials with thermal conductivities ranging between that of copper (400 W/m-K) and 1700 W/m-K, and many other low-CTE materials with lower thermal conductivities. Some of these materials are low cost. Others have the potential to be low cost in high-volume production. High-thermal-conductivity materials enable higher power levels, potentially reducing the number of required LEDs. Advanced thermal materials can constrain PCB CTE and greatly increase thermal conductivity. This paper reviews traditional packaging materials and advanced thermal management materials. The latter provide the packaging engineer with a greater range of options than in the past. Topics include properties, status, applications, cost, using advanced materials to fix manufacturing problems, and future directions, including composites reinforced with carbon nanotubes and other thermally conductive materials.

Total systems design analysis of high performance structures

NASA Technical Reports Server (NTRS)

Verderaime, V.

1993-01-01

Designer-control parameters were identified at interdiscipline interfaces to optimize structural systems performance and downstream development and operations with reliability and least life-cycle cost. Interface tasks and iterations are tracked through a matrix of performance disciplines integration versus manufacturing, verification, and operations interactions for a total system design analysis. Performance integration tasks include shapes, sizes, environments, and materials. Integrity integrating tasks are reliability and recurring structural costs. Significant interface designer control parameters were noted as shapes, dimensions, probability range factors, and cost. Structural failure concept is presented, and first-order reliability and deterministic methods, benefits, and limitations are discussed. A deterministic reliability technique combining benefits of both is proposed for static structures which is also timely and economically verifiable. Though launch vehicle environments were primarily considered, the system design process is applicable to any surface system using its own unique filed environments.

Experimental study of low-cost fiber optic distributed temperature sensor system performance

NASA Astrophysics Data System (ADS)

Dashkov, Michael V.; Zharkov, Alexander D.

2016-03-01

The distributed control of temperature is an actual task for various application such as oil & gas fields, high-voltage power lines, fire alarm systems etc. The most perspective are optical fiber distributed temperature sensors (DTS). They have advantages on accuracy, resolution and range, but have a high cost. Nevertheless, for some application the accuracy of measurement and localization aren't so important as cost. The results of an experimental study of low-cost Raman based DTS based on standard OTDR are represented.

Composite Structures and Materials Research at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Dexter, H. Benson; Johnston, Norman J.; Ambur, Damodar R.; Cano, roberto J.

2003-01-01

A summary of recent composite structures and materials research at NASA Langley Research Center is presented. Fabrication research to develop low-cost automated robotic fabrication procedures for thermosetting and thermoplastic composite materials, and low-cost liquid molding processes for preformed textile materials is described. Robotic fabrication procedures discussed include ply-by-ply, cure-on-the-fly heated placement head and out-of-autoclave electron-beam cure methods for tow and tape thermosetting and thermoplastic materials. Liquid molding fabrication processes described include Resin Film Infusion (RFI), Resin Transfer Molding (RTM) and Vacuum-Assisted Resin Transfer Molding (VARTM). Results for a full-scale composite wing box are summarized to identify the performance of materials and structures fabricated with these low-cost fabrication methods.

Composite Structures and Materials Research at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Dexter, H. Benson; Johnston, Norman J.; Ambur, Damodar R.; Cano, Roberto J.

2001-01-01

A summary of recent composite structures and materials research at NASA Langley Research Center is presented. Fabrication research to develop low-cost automated robotic fabrication procedures for thermosetting and thermoplastic composite materials, and low-cost liquid molding processes for preformed textile materials is described. Robotic fabrication procedures discussed include ply-by-ply, cure-on-the-fly heated placement head and out-of-autoclave electron-beam cure methods for tow and tape thermosetting and thermoplastic materials. Liquid molding fabrication processes described include Resin Film Infusion (RFI) Resin Transfer Molding (RTM) and Vacuum-Assisted Resin Transfer Molding (VARTM). Results for a full-scale composite wing box are summarized to identify the performance of materials and structures fabricated with these low-cost fabrication methods.

A Low-Cost EEG System-Based Hybrid Brain-Computer Interface for Humanoid Robot Navigation and Recognition

PubMed Central

Choi, Bongjae; Jo, Sungho

2013-01-01

This paper describes a hybrid brain-computer interface (BCI) technique that combines the P300 potential, the steady state visually evoked potential (SSVEP), and event related de-synchronization (ERD) to solve a complicated multi-task problem consisting of humanoid robot navigation and control along with object recognition using a low-cost BCI system. Our approach enables subjects to control the navigation and exploration of a humanoid robot and recognize a desired object among candidates. This study aims to demonstrate the possibility of a hybrid BCI based on a low-cost system for a realistic and complex task. It also shows that the use of a simple image processing technique, combined with BCI, can further aid in making these complex tasks simpler. An experimental scenario is proposed in which a subject remotely controls a humanoid robot in a properly sized maze. The subject sees what the surrogate robot sees through visual feedback and can navigate the surrogate robot. While navigating, the robot encounters objects located in the maze. It then recognizes if the encountered object is of interest to the subject. The subject communicates with the robot through SSVEP and ERD-based BCIs to navigate and explore with the robot, and P300-based BCI to allow the surrogate robot recognize their favorites. Using several evaluation metrics, the performances of five subjects navigating the robot were quite comparable to manual keyboard control. During object recognition mode, favorite objects were successfully selected from two to four choices. Subjects conducted humanoid navigation and recognition tasks as if they embodied the robot. Analysis of the data supports the potential usefulness of the proposed hybrid BCI system for extended applications. This work presents an important implication for the future work that a hybridization of simple BCI protocols provide extended controllability to carry out complicated tasks even with a low-cost system. PMID:24023953

A low-cost EEG system-based hybrid brain-computer interface for humanoid robot navigation and recognition.

PubMed

Choi, Bongjae; Jo, Sungho

2013-01-01

This paper describes a hybrid brain-computer interface (BCI) technique that combines the P300 potential, the steady state visually evoked potential (SSVEP), and event related de-synchronization (ERD) to solve a complicated multi-task problem consisting of humanoid robot navigation and control along with object recognition using a low-cost BCI system. Our approach enables subjects to control the navigation and exploration of a humanoid robot and recognize a desired object among candidates. This study aims to demonstrate the possibility of a hybrid BCI based on a low-cost system for a realistic and complex task. It also shows that the use of a simple image processing technique, combined with BCI, can further aid in making these complex tasks simpler. An experimental scenario is proposed in which a subject remotely controls a humanoid robot in a properly sized maze. The subject sees what the surrogate robot sees through visual feedback and can navigate the surrogate robot. While navigating, the robot encounters objects located in the maze. It then recognizes if the encountered object is of interest to the subject. The subject communicates with the robot through SSVEP and ERD-based BCIs to navigate and explore with the robot, and P300-based BCI to allow the surrogate robot recognize their favorites. Using several evaluation metrics, the performances of five subjects navigating the robot were quite comparable to manual keyboard control. During object recognition mode, favorite objects were successfully selected from two to four choices. Subjects conducted humanoid navigation and recognition tasks as if they embodied the robot. Analysis of the data supports the potential usefulness of the proposed hybrid BCI system for extended applications. This work presents an important implication for the future work that a hybridization of simple BCI protocols provide extended controllability to carry out complicated tasks even with a low-cost system.

Exploring the influence of constitutive models and associated parameters for the orthogonal machining of Ti6Al4V

NASA Astrophysics Data System (ADS)

Pervaiz, S.; Anwar, S.; Kannan, S.; Almarfadi, A.

2018-04-01

Ti6Al4V is known as difficult-to-cut material due to its inherent properties such as high hot hardness, low thermal conductivity and high chemical reactivity. Though, Ti6Al4V is utilized by industrial sectors such as aeronautics, energy generation, petrochemical and bio-medical etc. For the metal cutting community, competent and cost-effective machining of Ti6Al4V is a challenging task. To optimize cost and machining performance for the machining of Ti6Al4V, finite element based cutting simulation can be a very useful tool. The aim of this paper is to develop a finite element machining model for the simulation of Ti6Al4V machining process. The study incorporates material constitutive models namely Power Law (PL) and Johnson – Cook (JC) material models to mimic the mechanical behaviour of Ti6Al4V. The study investigates cutting temperatures, cutting forces, stresses, and plastic strains with respect to different PL and JC material models with associated parameters. In addition, the numerical study also integrates different cutting tool rake angles in the machining simulations. The simulated results will be beneficial to draw conclusions for improving the overall machining performance of Ti6Al4V.

Hierarchical Control Using Networks Trained with Higher-Level Forward Models

PubMed Central

Wayne, Greg; Abbott, L.F.

2015-01-01

We propose and develop a hierarchical approach to network control of complex tasks. In this approach, a low-level controller directs the activity of a “plant,” the system that performs the task. However, the low-level controller may only be able to solve fairly simple problems involving the plant. To accomplish more complex tasks, we introduce a higher-level controller that controls the lower-level controller. We use this system to direct an articulated truck to a specified location through an environment filled with static or moving obstacles. The final system consists of networks that have memorized associations between the sensory data they receive and the commands they issue. These networks are trained on a set of optimal associations that are generated by minimizing cost functions. Cost function minimization requires predicting the consequences of sequences of commands, which is achieved by constructing forward models, including a model of the lower-level controller. The forward models and cost minimization are only used during training, allowing the trained networks to respond rapidly. In general, the hierarchical approach can be extended to larger numbers of levels, dividing complex tasks into more manageable sub-tasks. The optimization procedure and the construction of the forward models and controllers can be performed in similar ways at each level of the hierarchy, which allows the system to be modified to perform other tasks, or to be extended for more complex tasks without retraining lower-levels. PMID:25058706

Can spectro-temporal complexity explain the autistic pattern of performance on auditory tasks?

PubMed

Samson, Fabienne; Mottron, Laurent; Jemel, Boutheina; Belin, Pascal; Ciocca, Valter

2006-01-01

To test the hypothesis that level of neural complexity explain the relative level of performance and brain activity in autistic individuals, available behavioural, ERP and imaging findings related to the perception of increasingly complex auditory material under various processing tasks in autism were reviewed. Tasks involving simple material (pure tones) and/or low-level operations (detection, labelling, chord disembedding, detection of pitch changes) show a superior level of performance and shorter ERP latencies. In contrast, tasks involving spectrally- and temporally-dynamic material and/or complex operations (evaluation, attention) are poorly performed by autistics, or generate inferior ERP activity or brain activation. Neural complexity required to perform auditory tasks may therefore explain pattern of performance and activation of autistic individuals during auditory tasks.

Design, processing and testing of LSI arrays hybrid microelectronics task

NASA Technical Reports Server (NTRS)

Himmel, R. P.; Stuhlbarg, S. M.; Salmassy, S.

1978-01-01

Those factors affecting the cost of electronic subsystems utilizing LSI microcircuits were determined and the most efficient methods for low cost packaging of LSI devices as a function of density and reliability were developed.

Performance Analysis of Abrasive Waterjet Machining Process at Low Pressure

NASA Astrophysics Data System (ADS)

Murugan, M.; Gebremariam, MA; Hamedon, Z.; Azhari, A.

2018-03-01

Normally, a commercial waterjet cutting machine can generate water pressure up to 600 MPa. This range of pressure is used to machine a wide variety of materials. Hence, the price of waterjet cutting machine is expensive. Therefore, there is a need to develop a low cost waterjet machine in order to make the technology more accessible for the masses. Due to its low cost, such machines may only be able to generate water pressure at a much reduced rate. The present study attempts to investigate the performance of abrasive water jet machining process at low cutting pressure using self-developed low cost waterjet machine. It aims to study the feasibility of machining various materials at low pressure which later can aid in further development of an effective low cost water jet machine. A total of three different materials were machined at a low pressure of 34 MPa. The materials are mild steel, aluminium alloy 6061 and plastics Delrin®. Furthermore, a traverse rate was varied between 1 to 3 mm/min. The study on cutting performance at low pressure for different materials was conducted in terms of depth penetration, kerf taper ratio and surface roughness. It was found that all samples were able to be machined at low cutting pressure with varied qualities. Also, the depth of penetration decreases with an increase in the traverse rate. Meanwhile, the surface roughness and kerf taper ratio increase with an increase in the traverse rate. It can be concluded that a low cost waterjet machine with a much reduced rate of water pressure can be successfully used for machining certain materials with acceptable qualities.

Design and development of a bio-inspired, under-actuated soft gripper.

PubMed

Hassan, Taimoor; Manti, Mariangela; Passetti, Giovanni; d'Elia, Nicolò; Cianchetti, Matteo; Laschi, Cecilia

2015-08-01

The development of robotic devices able to perform manipulation tasks mimicking the human hand has been assessed on large scale. This work stands in the challenging scenario where soft materials are combined with bio-inspired design in order to develop soft grippers with improved grasping and holding capabilities. We are going to show a low-cost, under-actuated and adaptable soft gripper, highlighting the design and the manufacturing process. In particular, a critical analysis is made among three versions of the gripper with same design and actuation mechanism, but based on different materials. A novel actuation principle has been implemented in both cases, in order to reduce the encumbrance of the entire system and improve its aesthetics. Grasping and holding capabilities have been tested for each device, with target objects varying in shape, size and material. Results highlight synergy between the geometry and the intrinsic properties of the soft material, showing the way to novel design principles for soft grippers.

Phase 2 of the Array Automated Assembly Task for the Low Cost Silicon Solar Array Project

NASA Technical Reports Server (NTRS)

Wihl, M.; Torro, J.; Scheinine, A.; Anderson, J.

1978-01-01

An automated process sequence, to manufacture photovoltaic modules at a capacity of approximately 500 MW per year at a cost of approximately $0.50 per peak watt is described. Verification tests were performed and are reported along with cost predictions.

Flipping the Calculus Classroom: A Cost-Effective Approach

ERIC Educational Resources Information Center

Young, Andrea

2015-01-01

This article discusses a cost-effective approach to flipping the calculus classroom. In particular, the emphasis is on low-cost choices, both monetarily and with regards to faculty time, that make the daunting task of flipping a course manageable for a single instructor. Student feedback and overall impressions are also presented.

Flat-plate solar array project. Volume 3: Silicon sheet: Wafers and ribbons

NASA Technical Reports Server (NTRS)

Briglio, A.; Dumas, K.; Leipold, M.; Morrison, A.

1986-01-01

The primary objective of the Silicon Sheet Task of the Flat-Plate Solar Array (FSA) Project was the development of one or more low cost technologies for producing silicon sheet suitable for processing into cost-competitive solar cells. Silicon sheet refers to high purity crystalline silicon of size and thickness for fabrication into solar cells. Areas covered in the project were ingot growth and casting, wafering, ribbon growth, and other sheet technologies. The task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the task cost goals were not achieved.

A Practical Solution Using A New Approach To Robot Vision

NASA Astrophysics Data System (ADS)

Hudson, David L.

1984-01-01

Up to now, robot vision systems have been designed to serve both application development and operational needs in inspection, assembly and material handling. This universal approach to robot vision is too costly for many practical applications. A new industrial vision system separates the function of application program development from on-line operation. A Vision Development System (VDS) is equipped with facilities designed to simplify and accelerate the application program development process. A complimentary but lower cost Target Application System (TASK) runs the application program developed with the VDS. This concept is presented in the context of an actual robot vision application that improves inspection and assembly for a manufacturer of electronic terminal keyboards. Applications developed with a VDS experience lower development cost when compared with conventional vision systems. Since the TASK processor is not burdened with development tools, it can be installed at a lower cost than comparable "universal" vision systems that are intended to be used for both development and on-line operation. The VDS/TASK approach opens more industrial applications to robot vision that previously were not practical because of the high cost of vision systems. Although robot vision is a new technology, it has been applied successfully to a variety of industrial needs in inspection, manufacturing, and material handling. New developments in robot vision technology are creating practical, cost effective solutions for a variety of industrial needs. A year or two ago, researchers and robot manufacturers interested in implementing a robot vision application could take one of two approaches. The first approach was to purchase all the necessary vision components from various sources. That meant buying an image processor from one company, a camera from another and lens and light sources from yet others. The user then had to assemble the pieces, and in most instances he had to write all of his own software to test, analyze and process the vision application. The second and most common approach was to contract with the vision equipment vendor for the development and installation of a turnkey inspection or manufacturing system. The robot user and his company paid a premium for their vision system in an effort to assure the success of the system. Since 1981, emphasis on robotics has skyrocketed. New groups have been formed in many manufacturing companies with the charter to learn about, test and initially apply new robot and automation technologies. Machine vision is one of new technologies being tested and applied. This focused interest has created a need for a robot vision system that makes it easy for manufacturing engineers to learn about, test, and implement a robot vision application. A newly developed vision system addresses those needs. Vision Development System (VDS) is a complete hardware and software product for the development and testing of robot vision applications. A complimentary, low cost Target Application System (TASK) runs the application program developed with the VDS. An actual robot vision application that demonstrates inspection and pre-assembly for keyboard manufacturing is used to illustrate the VDS/TASK approach.

Design and validation of low-cost assistive glove for hand assessment and therapy during activity of daily living-focused robotic stroke therapy.

PubMed

Nathan, Dominic E; Johnson, Michelle J; McGuire, John R

2009-01-01

Hand and arm impairment is common after stroke. Robotic stroke therapy will be more effective if hand and upper-arm training is integrated to help users practice reaching and grasping tasks. This article presents the design, development, and validation of a low-cost, functional electrical stimulation grasp-assistive glove for use with task-oriented robotic stroke therapy. Our glove measures grasp aperture while a user completes simple-to-complex real-life activities, and when combined with an integrated functional electrical stimulator, it assists in hand opening and closing. A key function is a new grasp-aperture prediction model, which uses the position of the end-effectors of two planar robots to define the distance between the thumb and index finger. We validated the accuracy and repeatability of the glove and its capability to assist in grasping. Results from five nondisabled subjects indicated that the glove is accurate and repeatable for both static hand-open and -closed tasks when compared with goniometric measures and for dynamic reach-to-grasp tasks when compared with motion analysis measures. Results from five subjects with stroke showed that with the glove, they could open their hands but without it could not. We present a glove that is a low-cost solution for in vivo grasp measurement and assistance.

Cost Modeling for low-cost planetary missions

NASA Technical Reports Server (NTRS)

Kwan, Eric; Habib-Agahi, Hamid; Rosenberg, Leigh

2005-01-01

This presentation will provide an overview of the JPL parametric cost models used to estimate flight science spacecrafts and instruments. This material will emphasize the cost model approaches to estimate low-cost flight hardware, sensors, and instrumentation, and to perform cost-risk assessments. This presentation will also discuss JPL approaches to perform cost modeling and the methodologies and analyses used to capture low-cost vs. key cost drivers.

In search of a representative sample of residential building work.

PubMed

Lobb, Brenda; Woods, Gregory R

2012-09-01

Most research investigating injuries in construction work is limited by reliance on work samples unrepresentative of the multiple, variable-cycle tasks involved, resulting in incomplete characterisation of ergonomic exposures. In this case study, a participatory approach was used including hierarchical task analysis and site observations of a typical team of house builders in New Zealand, over several working days, to obtain a representative work sample. The builders' work consisted of 14 goal-defined jobs using varying subsets of 15 task types, each taking from less than 1 s to more than 1 h and performed in a variety of postures. Task type and duration varied within and between participants and days, although all participants spent at least 25% of the time moving from place to place, mostly carrying materials, and more than half the time either reaching up or bending down to work. This research has provided a description of residential building work based on a work sample more nearly representative than those previously published and has demonstrated a simple, low-cost but robust field observation method that can provide a valid basis for further study of hazard exposures. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Continuous Czochralski growth: Silicon sheet growth development of the large area silicon sheet task of the Low Cost Silicon Solar Array project

NASA Technical Reports Server (NTRS)

1978-01-01

The primary objective of this contract is to develop equipment and methods for the economic production of single crystal ingot material by the continuous Czochralski (CZ) process. Continuous CZ is defined for the purpose of this work as the growth of at least 100 kilograms of ingot from only one melt container. During the reporting period (October, 1977 - September, 1978), a modified grower was made fully functional and several recharge runs were performed. The largest run lasted 44 hours and over 42 kg of ingot was produced. Little, if any, degradation in efficiency was observed as a result of pulling multiple crystals from one crucible. Solar efficiencies observed were between 9.3 and 10.4% AMO (13.0 and 14.6% AMI) compared to 10.5% (14.7% AMI) for optimum CZ material control samples. Using the SAMICS/IPEG format, economic analysis of continuous CZ suggests that 1986 DoE cost goals can only be met by the growth of large diameter, large mass crystals.

Ablative material testing for low-pressure, low-cost rocket engines

NASA Technical Reports Server (NTRS)

Richter, G. Paul; Smith, Timothy D.

1995-01-01

The results of an experimental evaluation of ablative materials suitable for the production of light weight, low cost rocket engine combustion chambers and nozzles are presented. Ten individual specimens of four different compositions of silica cloth-reinforced phenolic resin materials were evaluated for comparative erosion in a subscale rocket engine combustion chamber. Gaseous hydrogen and gaseous oxygen were used as propellants, operating at a nominal chamber pressure of 1138 kPa (165 psi) and a nominal mixture ratio (O/F) of 3.3. These conditions were used to thermally simulate operation with RP-1 and liquid oxygen, and achieved a specimen throat gas temperature of approximately 2456 K (4420 R). Two high-density composition materials exhibited high erosion resistance, while two low-density compositions exhibited approximately 6-75 times lower average erosion resistance. The results compare favorably with previous testing by NASA and provide adequate data for selection of ablatives for low pressure, low cost rocket engines.

Low-Cost Magnetic Stirrer from Recycled Computer Parts with Optional Hot Plate

ERIC Educational Resources Information Center

Guidote, Armando M., Jr.; Pacot, Giselle Mae M.; Cabacungan, Paul M.

2015-01-01

Magnetic stirrers and hot plates are key components of science laboratories. However, these are not readily available in many developing countries due to their high cost. This article describes the design of a low-cost magnetic stirrer with hot plate from recycled materials. Some of the materials used are neodymium magnets and CPU fans from…

Development of a Low cost Ultra tiny Line Laser Range Sensor

DTIC Science & Technology

2016-12-01

Development of a Low-cost Ultra-tiny Line Laser Range Sensor Xiangyu Chen∗, Moju Zhao∗, Lingzhu Xiang†, Fumihito Sugai∗, Hiroaki Yaguchi∗, Kei Okada...and Masayuki Inaba∗ Abstract— To enable robotic sensing for tasks with require- ments on weight, size, and cost, we develop an ultra-tiny line laser ...view customizable using different laser lenses. The optimal measurement range of the sensor is 0.05[m] ∼ 2[m]. Higher sampling rates can be achieved

Investigation of test methods, material properties, and processes for solar cell encapsulants

NASA Technical Reports Server (NTRS)

Willis, P. B.

1983-01-01

A study of potentially useful low cost encapsulation materials for the Flat-Plate Solar Array project is discussed. The goal is to identify, evaluate, test and recommend encapsulant materials and processes for the production of cost-effective, long life solar cell modules. Technical investigations included studies of aging and degradation of candidate encapsulation materials, continued identification of primers for durable bonding of module interfaces, continued evaluation of soil resistant treatments for the sunlit surface of the module and testing of corrosion protective coatings for use low cost mild steel substrates.

Phase 1 of the automated array assembly task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Pryor, R. A.; Grenon, L. A.; Coleman, M. G.

1978-01-01

The results of a study of process variables and solar cell variables are presented. Interactions between variables and their effects upon control ranges of the variables are identified. The results of a cost analysis for manufacturing solar cells are discussed. The cost analysis includes a sensitivity analysis of a number of cost factors.

Subscale solid motor nozzle tests, phase 4 and nozzle materials screening and thermal characterization, phase 5

NASA Technical Reports Server (NTRS)

Arnold, J.; Dodson, J.; Laub, B.

1979-01-01

Subscale solid motor nozzles containing a baseline material or low cost materials to be considered as potential replacements for the baseline material are designed and tested. Data are presented from tests of four identically designed 2.5 inch throat diameter nozzles and one 7 inch throat diameter nozzle. The screening of new candidate low cost materials, as well as their thermophysical and thermochemical characterization is also discussed.

Analysis and Evaluation of Processes and Equipment in Tasks 2 and 4 of the Low-cost Solar Array Project

NASA Technical Reports Server (NTRS)

Wolf, M.

1979-01-01

To facilitate the task of objectively comparing competing process options, a methodology was needed for the quantitative evaluation of their relative cost effectiveness. Such a methodology was developed and is described, together with three examples for its application. The criterion for the evaluation is the cost of the energy produced by the system. The method permits the evaluation of competing design options for subsystems, based on the differences in cost and efficiency of the subsystems, assuming comparable reliability and service life, or of competing manufacturing process options for such subsystems, which include solar cells or modules. This process option analysis is based on differences in cost, yield, and conversion efficiency contribution of the process steps considered.

Backwards Fading to Speed Task Learning

DTIC Science & Technology

2013-09-01

estimates.) Table 1 Finalized Task List Task Domain Task Name Knot Tying Hand Cuff Rappel First Aid Fracture Bleed Map Reading* Resection...materials used. Hand Cuff . There are 10 steps in this task. To complete this task, the learner must manipulate a short length of rope (e.g...Design for Experiment 1 – Step Fade Experiment 1 (Step Fade) Task Type: Knot Tying Task Type: First Aid Task Complexity: Low (1) Hand Cuff (10

Low-Cost Educational Materials. How to Make, How to Use, How to Adapt. Inventory. Volume III.

ERIC Educational Resources Information Center

United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and the Pacific.

This volume presents instructions for 61 low-cost and indigenous teaching materials that were developed from recommendations of the Fifth Regional Consultation Meeting on APEID (Asia and the Pacific Programme of Educational Innovation for Development) held in March 1978. Third in a series, this document describes materials that not only contribute…

Low-Cost Educational Materials: How To Make, How To Use, How To Adapt. Inventory, Volume I.

ERIC Educational Resources Information Center

United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and Oceania.

Instructions with line drawings and/or patterns are provided for making 85 of the exemplar products perpared in APEID-sponsored workshops, which reviewed current efforts and materials, and explored new strategies and directions in the utilization of low cost, simple, indigenous materials to fill the regional need for audiovisual resources. The…

Fault-tolerant dynamic task graph scheduling

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

Kurt, Mehmet C.; Krishnamoorthy, Sriram; Agrawal, Kunal

2014-11-16

In this paper, we present an approach to fault tolerant execution of dynamic task graphs scheduled using work stealing. In particular, we focus on selective and localized recovery of tasks in the presence of soft faults. We elicit from the user the basic task graph structure in terms of successor and predecessor relationships. The work stealing-based algorithm to schedule such a task graph is augmented to enable recovery when the data and meta-data associated with a task get corrupted. We use this redundancy, and the knowledge of the task graph structure, to selectively recover from faults with low space andmore » time overheads. We show that the fault tolerant design retains the essential properties of the underlying work stealing-based task scheduling algorithm, and that the fault tolerant execution is asymptotically optimal when task re-execution is taken into account. Experimental evaluation demonstrates the low cost of recovery under various fault scenarios.« less

Laparoscopic Common Bile Duct Exploration Four-Task Training Model: Construct Validity

PubMed Central

Otaño, Natalia; Rodríguez, Omaira; Sánchez, Renata; Benítez, Gustavo; Schweitzer, Michael

2012-01-01

Background: Training models in laparoscopic surgery allow the surgical team to practice procedures in a safe environment. We have proposed the use of a 4-task, low-cost inert model to practice critical steps of laparoscopic common bile duct exploration. Methods: The performance of 3 groups with different levels of expertise in laparoscopic surgery, novices (A), intermediates (B), and experts (C), was evaluated using a low-cost inert model in the following tasks: (1) intraoperative cholangiography catheter insertion, (2) transcystic exploration, (3) T-tube placement, and (4) choledochoscope management. Kruskal-Wallis and Mann-Whitney tests were used to identify differences among the groups. Results: A total of 14 individuals were evaluated: 5 novices (A), 5 intermediates (B), and 4 experts (C). The results involving intraoperative cholangiography catheter insertion were similar among the 3 groups. As for the other tasks, the expert had better results than the other 2, in which no significant differences occurred. The proposed model is able to discriminate among individuals with different levels of expertise, indicating that the abilities that the model evaluates are relevant in the surgeon's performance in CBD exploration. Conclusions: Construct validity for tasks 2 and 3 was demonstrated. However, task 1 was no capable of distinguishing between groups, and task 4 was not statistically validated. PMID:22906323

Xylo-Oligosaccharide Process Development, Composition, and Techno-Economic Analysis. Cooperative Research and Development Final Report, CRADA Number CRD-12-483

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

Shekiro, Joe; Elander, Richard

2015-12-01

The purpose of this cooperative work agreement between General Mills Inc. (GMI) and NREL is to determine the feasibility of producing a valuable food ingredient (xylo-oligosaccharides or XOS), a highly soluble fiber material, from agricultural waste streams, at an advantaged cost level relative to similar existing ingredients. The scope of the project includes pilot-scale process development (Task 1), compositional analysis (Task 2), and techno-economic analysis (Task 3).

Phase Two of the Array Automated Assembly Task for the Low Cost Solar Array Project

NASA Technical Reports Server (NTRS)

Campbell, R. B.; Page, D. J.; Rai-Choudhury, P.; Seman, E. J.; Hanes, M. H.; Rohatgi, A.; Davis, J. R.

1979-01-01

Various top contact metal systems were studied. Only Ti Pd Cu approaches baseline (Ti Pd Ag) quality, but this system shows a lack of long term stability. Aluminum back surface field structures were fabricated and thicknesses of p superscript + material of up to 7.0 microns were achieved with open circuit voltages of 0.59V. A general purpose ultrasonic welder was purchased and tests using various metal foils are under way. During fabrication of the demonstration module, several cells became cracked. Due to redundancy of interconnections, the module was not open circuited but the efficiency was reduced to 8.8%. The broken cell was interconnected with a strap across the back and the efficiency was increased to 11.5%. A cost analysis was made and the results indicate a selling price of $0.56/watt peak (in 1986 with 1975 dollars).

Discovery of high-performance low-cost n-type Mg3Sb2-based thermoelectric materials with multi-valley conduction bands

PubMed Central

Zhang, Jiawei; Song, Lirong; Pedersen, Steffen Hindborg; Yin, Hao; Hung, Le Thanh; Iversen, Bo Brummerstedt

2017-01-01

Widespread application of thermoelectric devices for waste heat recovery requires low-cost high-performance materials. The currently available n-type thermoelectric materials are limited either by their low efficiencies or by being based on expensive, scarce or toxic elements. Here we report a low-cost n-type material, Te-doped Mg3Sb1.5Bi0.5, that exhibits a very high figure of merit zT ranging from 0.56 to 1.65 at 300−725 K. Using combined theoretical prediction and experimental validation, we show that the high thermoelectric performance originates from the significantly enhanced power factor because of the multi-valley band behaviour dominated by a unique near-edge conduction band with a sixfold valley degeneracy. This makes Te-doped Mg3Sb1.5Bi0.5 a promising candidate for the low- and intermediate-temperature thermoelectric applications. PMID:28059069

Removal of heavy metals from emerging cellulosic low-cost adsorbents: a review

NASA Astrophysics Data System (ADS)

Malik, D. S.; Jain, C. K.; Yadav, Anuj K.

2017-09-01

Heavy metal pollution is a major problems in the environment. The impact of toxic metal ions can be minimized by different technologies, viz., chemical precipitation, membrane filtration, oxidation, reverse osmosis, flotation and adsorption. But among them, adsorption was found to be very efficient and common due to the low concentration of metal uptake and economically feasible properties. Cellulosic materials are of low cost and widely used, and very promising for the future. These are available in abundant quantity, are cheap and have low or little economic value. Different forms of cellulosic materials are used as adsorbents such as fibers, leaves, roots, shells, barks, husks, stems and seed as well as other parts also. Natural and modified types of cellulosic materials are used in different metal detoxifications in water and wastewater. In this review paper, the most common and recent materials are reviewed as cellulosic low-cost adsorbents. The elemental properties of cellulosic materials are also discussed along with their cellulose, hemicelluloses and lignin contents.

Ecological Relevance Determines Task Priority in Older Adults' Multitasking.

PubMed

Doumas, Michail; Krampe, Ralf Th

2015-05-01

Multitasking is a challenging aspect of human behavior, especially if the concurrently performed tasks are different in nature. Several studies demonstrated pronounced performance decrements (dual-task costs) in older adults for combinations of cognitive and motor tasks. However, patterns of costs among component tasks differed across studies and reasons for participants' resource allocation strategies remained elusive. We investigated young and older adults' multitasking of a working memory task and two sensorimotor tasks, one with low (finger force control) and one with high ecological relevance (postural control). The tasks were performed in single-, dual-, and triple-task contexts. Working memory accuracy was reduced in dual-task contexts with either sensorimotor task and deteriorated further under triple-task conditions. Postural and force performance deteriorated with age and task difficulty in dual-task contexts. However, in the triple-task context with its maximum resource demands, older adults prioritized postural control over both force control and memory. Our results identify ecological relevance as the key factor in older adults' multitasking. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Assessment of design parameters and construction requirements for full depth reclamation projects with cement.

DOT National Transportation Integrated Search

2015-02-01

The ability to efficiently rehabilitate and maintain the State of Vermonts Highway infrastructure in a : cost-effective manner is a daunting task. Historically, pavement overlay treatments were specified : because it was a rapid low cost solution ...

The role of metacognition in prospective memory: anticipated task demands influence attention allocation strategies.

PubMed

Rummel, Jan; Meiser, Thorsten

2013-09-01

The present study investigates how individuals distribute their attentional resources between a prospective memory task and an ongoing task. Therefore, metacognitive expectations about the attentional demands of the prospective-memory task were manipulated while the factual demands were held constant. In Experiments 1a and 1b, we found attentional costs from a prospective-memory task with low factual demands to be significantly reduced when information about the low to-be-expected demands were provided, while prospective-memory performance remained largely unaffected. In Experiment 2, attentional monitoring in a more demanding prospective-memory task also varied with information about the to-be-expected demands (high vs. low) and again there were no equivalent changes in prospective-memory performance. These findings suggest that attention-allocation strategies of prospective memory rely on metacognitive expectations about prospective-memory task demands. Furthermore, the results suggest that attentional monitoring is only functional for prospective memory to the extent to which anticipated task demands reflect objective task demands. Copyright © 2013 Elsevier Inc. All rights reserved.

Demonstration of the Low-Cost Virtual Collaborative Environment (VCE)

NASA Technical Reports Server (NTRS)

Bowers, David; Montes, Leticia; Ramos, Angel; Joyce, Brendan; Lumia, Ron

1997-01-01

This paper demonstrates the feasibility of a low-cost approach of remotely controlling equipment. Our demonstration system consists of a PC, the PUMA 560 robot with Barrett hand, and commercially available controller and teleconferencing software. The system provides a graphical user interface which allows a user to program equipment tasks and preview motions i.e., simulate the results. Once satisfied that the actions are both safe and accomplish the task, the remote user sends the data over the Internet to the local site for execution on the real equipment. A video link provides visual feedback to the remote sight. This technology lends itself readily to NASA's upcoming Mars expeditions by providing remote simulation and control of equipment.

Low Cost Electroencephalographic Acquisition Amplifier to serve as Teaching and Research Tool

PubMed Central

Jain, Ankit; Kim, Insoo; Gluckman, Bruce J.

2012-01-01

We describe the development and testing of a low cost, easily constructed electroencephalographic acquisition amplifier for noninvasive Brain Computer Interface (BCI) education and research. The acquisition amplifier is constructed from newly available off-the-shelf integrated circuit components, and readily sends a 24-bit data stream via USB bus to a computer platform. We demonstrate here the hardware’s use in the analysis of a visually evoked P300 paradigm for a choose one-of-eight task. This clearly shows the applicability of this system as a low cost teaching and research tool. PMID:22254699

Training Aids for Basic Combat Skills: A Procedure for Training-Aid Development

DTIC Science & Technology

2011-02-01

aids is a constant in training and education. Researchers in fields as varied as disability education, business, firefighting, vocal performance...the aids should (a) address tasks with which many Soldiers have difficulty mastering, (b) address tasks that are critical to basic combat training...candidates because of other practical considerations such as low cost, potential impact to critical IET tasks, etc

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

Liu, Jia

Biorefineries convert biomass into many useful intermediates. For bio-based products to be used for fuel, energy, chemical, and many other applications, water needs to be removed from these aqueous products. Membrane separation technologies can significantly reduce separation energy consumption compared with conventional separation processes such as distillation. Nanoporous inorganic membranes have superior pervaporation performance with excellent organic fouling resistance. However, their commercial applications are limited due to high membrane costs and poor production reproducibility. A novel cost-effective inorganic membrane fabrication technology has been developed with low cost materials and using an advanced membrane fabrication technology. Low cost precursor material formulationmore » was successfully developed with desired material properties for membrane fabrication. An advanced membrane fabrication process was developed using the novel membrane materials to enable the fabrication of separation membranes of various geometries. The structural robustness and separation performance of the low cost inorganic membranes were evaluated. The novel inorganic membranes demonstrated high structural integrity and were effective in pervaporation removal of water.« less

Pathways Intern Report

NASA Technical Reports Server (NTRS)

Bell, Evan A.

2015-01-01

During my time at NASA, I worked with the Granular Mechanics and Regolith Organization (GMRO), better known as Swamp Works. The goal of the lab is to find ways to utilize resources found after the astronaut or robot has landed on another planet or asteroid. This concept is known as in-situ resource utilization and it is critical to long term missions such as those to Mars. During my time here I worked on the Asteroid and Lava Tube Free Flyer project (ALTFF). A lava tube, such as the one shown in figure 1, is a long tear drop shaped cavern that is produced when molten lava tunnels through the surrounding rock creating large unground pathways. Before mining for resources on Mars or on asteroids, a sampling mission must be done to scout out useful resource deposits. ALTFF's goal is to provide a low cost, autonomous scout robot that can sample the surface and return to the mother ship or lander for further processing of the samples. The vehicle will be looking for water ice in the regolith that can be processed into either potable water, hydrogen and oxygen fuel, or a binder material for 3D printing. By using a low cost craft to sample, there is much less risk to the more expensive mother ship or lander. While my main task was the construction of a simulation environment to test control code in and the construction of the asteroid free flyer prototype, there were other tasks that I performed relating to the ALTFF project.

Low-cost infrared glass for IR imaging applications

NASA Astrophysics Data System (ADS)

Graham, Amy G.; LeBlanc, Richard A.; Hilton, Ray A., Sr.

2003-09-01

With the advent of the uncooled detectors, the fraction of infrared (IR) imaging system cost due to lens elements has risen to the point where work was needed in the area of cost. Since these IR imaging systems often have tight packaging requirements which drive the optical elements to have complex surfaces, typical IR optical elements are costly to manufacture. The drive of our current optical material research is to lower the cost of the materials as well as the element fabrication for IR imaging systems. A low cost, moldable amorphous material, Amtir-4, has been developed and characterized. Ray Hilton Sr., Amorphous Materials Inc., Richard A. LeBlanc, Amy Graham and Others at Lockheed Martin Missiles and Fire Control Orlando (LMMFC-O) and James Johnson, General Electric Global Research Center (GE-GRC), along with others have been doing research for the past three years characterizing and designing IR imaging systems with this material. These IR imaging systems have been conventionally fabricated via diamond turning and techniques required to mold infrared optical elements have been developed with this new material, greatly reducing manufacturing costs. This paper will outline efforts thus far in incorporating this new material into prototype IR imaging systems.

Silicon materials task of the low cost solar array project, phase 2

NASA Technical Reports Server (NTRS)

Hopkins, R. H.; Davis, J. R., Jr.; Blais, P. D.; Rohatgi, A.; Rai-Choudhury, P.; Hanes, M. H.; Mccormick, J. R.

1977-01-01

The object of phase 2 of this program is to investigate and define the effects of various processes, contaminants and process-contaminant interactions in the performance of terrestrial solar cells. The major effort this quarter was in the areas of crystal growth and thermal processing, comparison of impurity effects in low and high resistivity silicon, modeling the behavior of p-type ingots containing Mo, and C and, quantitative analysis of bulk lifetime and junction degradation effects in contaminated solar cells. The performance of solar cells fabricated on silicon web crystals grown from melts containing about 10 to the 18th power/cu cm of Cr, Mn, Fe, Ni, Ti, and V, respectively were measured. Deep level spectroscopy of metal-contaminated ingots was employed to determine the level and density of recombination centers due to Ti, V, Ni, and Cr.

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

Savic, Vesna; Hector, Louis G.; Ezzat, Hesham

This paper presents an overview of a four-year project focused on development of an integrated computational materials engineering (ICME) toolset for third generation advanced high-strength steels (3GAHSS). Following a brief look at ICME as an emerging discipline within the Materials Genome Initiative, technical tasks in the ICME project will be discussed. Specific aims of the individual tasks are multi-scale, microstructure-based material model development using state-of-the-art computational and experimental techniques, forming, toolset assembly, design optimization, integration and technical cost modeling. The integrated approach is initially illustrated using a 980 grade transformation induced plasticity (TRIP) steel, subject to a two-step quenching andmore » partitioning (Q&P) heat treatment, as an example.« less

Cost-driven materials selection criteria for redox flow battery electrolytes

NASA Astrophysics Data System (ADS)

Dmello, Rylan; Milshtein, Jarrod D.; Brushett, Fikile R.; Smith, Kyle C.

2016-10-01

Redox flow batteries show promise for grid-scale energy storage applications but are presently too expensive for widespread adoption. Electrolyte material costs constitute a sizeable fraction of the redox flow battery price. As such, this work develops a techno-economic model for redox flow batteries that accounts for redox-active material, salt, and solvent contributions to the electrolyte cost. Benchmark values for electrolyte constituent costs guide identification of design constraints. Nonaqueous battery design is sensitive to all electrolyte component costs, cell voltage, and area-specific resistance. Design challenges for nonaqueous batteries include minimizing salt content and dropping redox-active species concentration requirements. Aqueous battery design is sensitive to only redox-active material cost and cell voltage, due to low area-specific resistance and supporting electrolyte costs. Increasing cell voltage and decreasing redox-active material cost present major materials selection challenges for aqueous batteries. This work minimizes cost-constraining variables by mapping the battery design space with the techno-economic model, through which we highlight pathways towards low price and moderate concentration. Furthermore, the techno-economic model calculates quantitative iterations of battery designs to achieve the Department of Energy battery price target of 100 per kWh and highlights cost cutting strategies to drive battery prices down further.

Automatically producing tailored web materials for public administration

NASA Astrophysics Data System (ADS)

Colineau, Nathalie; Paris, Cécile; Vander Linden, Keith

2013-06-01

Public administration organizations commonly produce citizen-focused, informational materials describing public programs and the conditions under which citizens or citizen groups are eligible for these programs. The organizations write these materials for generic audiences because of the excessive human resource costs that would be required to produce personalized materials for everyone. Unfortunately, generic materials tend to be longer and harder to understand than materials tailored for particular citizens. Our work explores the feasibility and effectiveness of automatically producing tailored materials. We have developed an adaptive hypermedia application system that automatically produces tailored informational materials and have evaluated it in a series of studies. The studies demonstrate that: (1) subjects prefer tailored materials over generic materials, even if the tailoring requires answering a set of demographic questions first; (2) tailored materials are more effective at supporting subjects in their task of learning about public programs; and (3) the time required to specify the demographic information on which the tailoring is based does not significantly slow down the subjects in their information seeking task.

Comparison between low-cost marker-less and high-end marker-based motion capture systems for the computer-aided assessment of working ergonomics.

PubMed

Patrizi, Alfredo; Pennestrì, Ettore; Valentini, Pier Paolo

2016-01-01

The paper deals with the comparison between a high-end marker-based acquisition system and a low-cost marker-less methodology for the assessment of the human posture during working tasks. The low-cost methodology is based on the use of a single Microsoft Kinect V1 device. The high-end acquisition system is the BTS SMART that requires the use of reflective markers to be placed on the subject's body. Three practical working activities involving object lifting and displacement have been investigated. The operational risk has been evaluated according to the lifting equation proposed by the American National Institute for Occupational Safety and Health. The results of the study show that the risk multipliers computed from the two acquisition methodologies are very close for all the analysed activities. In agreement to this outcome, the marker-less methodology based on the Microsoft Kinect V1 device seems very promising to promote the dissemination of computer-aided assessment of ergonomics while maintaining good accuracy and affordable costs. PRACTITIONER’S SUMMARY: The study is motivated by the increasing interest for on-site working ergonomics assessment. We compared a low-cost marker-less methodology with a high-end marker-based system. We tested them on three different working tasks, assessing the working risk of lifting loads. The two methodologies showed comparable precision in all the investigations.

Slicing of silicon into sheet material: Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Holden, S. C.

1976-01-01

Multiblade slurry sawing is used to slice 10 cm diameter silicon ingots into wafers 0.024 cm thick using 0.050 cm of silicon per slice (0.026 cm kerf loss). Total slicing time is less than twenty hours, and 143 slices are produced simultaneously. Productivity (slice area per hour per blade) is shown as a function or blade load and thickness, and abrasive size. Finer abrasive slurries cause a reduction in slice productivity, and thin blades cause a reduction of wafer accuracy. Sawing induced surface damage is found to extend 18 microns into the wafer.

Technical considerations for designing low-cost, long-wave infrared objectives

NASA Astrophysics Data System (ADS)

Desroches, Gerard; Dalzell, Kristy; Robitaille, Blaise

2014-06-01

With the growth of uncooled infrared imaging in the consumer market, the balance between cost implications and performance criteria in the objective lens must be examined carefully. The increased availability of consumer-grade, long-wave infrared cameras is related to a decrease in military usage but it is also due to the decreasing costs of the cameras themselves. This has also driven up demand for low-cost, long-wave objectives that can resolve smaller pixels while maintaining high performance. Smaller pixels are traditionally associated with high cost objectives because of higher resolution requirements but, with careful consideration of all the requirements and proper selection of materials, costs can be moderated. This paper examines the cost/performance trade-off implications associated with optical and mechanical requirements of long-wave infrared objectives. Optical performance, f-number, field of view, distortion, focus range and thermal range all affect the cost of the objective. Because raw lens material cost is often the most expensive item in the construction, selection of the material as well as the shape of the lens while maintaining acceptable performance and cost targets were explored. As a result of these considerations, a low-cost, lightweight, well-performing objective was successfully designed, manufactured and tested.

Evaluation of Promotional Materials To Promote Low-Dose Computed Tomography (LDCT) Screening to High-Risk Consumers and Health Care Providers.

PubMed

Hudson, Janella N; Quinn, Gwendolyn P; Wilson, Lauren E; Simmons, Vani N

2017-03-11

Low-dose computed tomography (LDCT) screening is a promising screening modality for increasing the detection rate of early stage lung cancers among high-risk individuals. Despite being recommended by the US Preventative Services Task Force, uptake of LDCT remains low. The objective of the current study was to gather feedback from high-risk consumers and health care providers on LDCT promotional materials. Focus group discussions were conducted with high-risk individuals (8 focus groups; N = 38) and primary care providers (9 focus groups; N = 23). Participants reviewed existing LDCT promotional materials to assess their perceptions of media materials created to publicize LDCT. Data were analyzed using the constant comparative method. Several key themes emerged from focus groups that can be used to inform development of future LDCT promotional materials. High-risk (HR) participants expressed greater receptivity for promotional materials that did not further stigmatize lung cancer and/or smoking and expressed preferences for materials that clearly outlined the risks/benefits of screening. Primary care providers (PCPs) offered suggestions to facilitate the referral process such as diagnostic codes and requested a design that clearly outlined eligibility criteria. A clear and thorough explanation of LDCT eligibility, cost, harms, and benefits was of chief importance for both PCP and HR audiences. Given that PCPs and HR audiences are not well informed on the specifics of LDCT screening eligibility and insurance coverage, creating provider and patient education opportunities will aid in shared decision-making opportunities. Promotional materials that meet the needs of the target audience are needed to facilitate discussions of risks/benefits of screening with HR individuals.

Reversible inactivation of the lateral hypothalamus reversed high reward choices in cost-benefit decision-making in rats.

PubMed

Karimi, Sara; Mesdaghinia, Azam; Farzinpour, Zahra; Hamidi, Gholamali; Haghparast, Abbas

2017-11-01

The Lateral hypothalamus (LH) is an important component of the networks underlying the control of feeding and other motivated behaviors. Cost-benefit decision-making is mediated largely by the prefrontal cortex (PFC) which strongly innervates the LH. Therefore, in the current study, we conducted a series of experiments to elucidate the role of the perifornical area of the lateral hypothalamus (PeF-LH) in effort and/or delay-based decision-making. We trained different groups of rats in a delay-based and/or an effort-based form of cost-benefit T-maze decision- making task in which they could either choose to pay the cost to obtain a high reward in one arm or could obtain a low reward in the other arm with no cost. During test days, the rats received local injections of either vehicle or lidocaine4% (0.5 μl/side), in the PeF-LH. In an effort-based decision task, PeF-LH inactivation led to decrease in high reward choice. Similarly, in a delay-based decision task animals' preference changed to a low but immediately available reward. This was not caused by a spatial memory or motor deficit. PeF-LH inactivation modified decision behavior. The results imply that PeF-LH is important for allowing the animal to pay a cost to acquire greater rewards. Copyright © 2017 Elsevier Inc. All rights reserved.

Vaccum Gas Tungsten Arc Welding, phase 1

NASA Astrophysics Data System (ADS)

Weeks, J. L.; Krotz, P. D.; Todd, D. T.; Liaw, Y. K.

1995-03-01

This two year program will investigate Vacuum Gas Tungsten Arc Welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. VGTAW appears to offer a significant improvement in weldability because of the clean environment and lower heat input needed. The overall objective of the program is to develop the VGTAW technology and implement it into a manufacturing environment that will result in lower cost, better quality and higher reliability aerospace components for the space shuttle and other NASA space systems. Phase 1 of this program was aimed at demonstrating the process's ability to weld normally difficult-to-weld materials. Phase 2 will focus on further evaluation, a hardware demonstration and a plan to implement VGTAW technology into a manufacturing environment. During Phase 1, the following tasks were performed: (1) Task 11000 Facility Modification - an existing vacuum chamber was modified and adapted to a GTAW power supply; (2) Task 12000 Materials Selection - four difficult-to-weld materials typically used in the construction of aerospace hardware were chosen for study; (3) Task 13000 VGTAW Experiments - welding experiments were conducted under vacuum using the hollow tungsten electrode and evaluation. As a result of this effort, two materials, NARloy Z and Incoloy 903, were downselected for further characterization in Phase 2; and (4) Task 13100 Aluminum-Lithium Weld Studies - this task was added to the original work statement to investigate the effects of vacuum welding and weld pool vibration on aluminum-lithium alloys.

Vaccum Gas Tungsten Arc Welding, phase 1

NASA Technical Reports Server (NTRS)

Weeks, J. L.; Krotz, P. D.; Todd, D. T.; Liaw, Y. K.

1995-01-01

This two year program will investigate Vacuum Gas Tungsten Arc Welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. VGTAW appears to offer a significant improvement in weldability because of the clean environment and lower heat input needed. The overall objective of the program is to develop the VGTAW technology and implement it into a manufacturing environment that will result in lower cost, better quality and higher reliability aerospace components for the space shuttle and other NASA space systems. Phase 1 of this program was aimed at demonstrating the process's ability to weld normally difficult-to-weld materials. Phase 2 will focus on further evaluation, a hardware demonstration and a plan to implement VGTAW technology into a manufacturing environment. During Phase 1, the following tasks were performed: (1) Task 11000 Facility Modification - an existing vacuum chamber was modified and adapted to a GTAW power supply; (2) Task 12000 Materials Selection - four difficult-to-weld materials typically used in the construction of aerospace hardware were chosen for study; (3) Task 13000 VGTAW Experiments - welding experiments were conducted under vacuum using the hollow tungsten electrode and evaluation. As a result of this effort, two materials, NARloy Z and Incoloy 903, were downselected for further characterization in Phase 2; and (4) Task 13100 Aluminum-Lithium Weld Studies - this task was added to the original work statement to investigate the effects of vacuum welding and weld pool vibration on aluminum-lithium alloys.

Development of Low-Cost Method for Fabrication of Metal Neutron Guides

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

Engelhaupt, Darell; Khaykovich, Boris; Romaine, Suzanne

Neutron scattering is one of the most useful methods of studying the structure and dynamics of matter. US DOE neutron scattering research facilities at Oak Ridge National Laboratory are among the World’s most advanced, providing researchers with unmatched capabilities for probing the structure and properties of materials, including engineering and biological systems. This task is to develop a lower cost process to optimize and produce the required neutron guides capable of efficiently delivering neutron beams for tens of meters between neutron moderators and instruments. Therefore, our effort is to improve the performance and lower the production cost of neutron guides.more » Our approach aims at improving guide quality while controlling their rising costs by adopting a novel electroforming replication approach to their fabrication. These guides will be especially advantageous when used near the neutron source since the radiation resistance of nickel is superior to glass. Additionally, we are depositing low-stress nickel from an extremely low impurity solution completely free of stress-reducing agents, which nominally contain and impart sulfur, carbon and other elements that potentially activate in the neutron environment. This is achieved by using a pulsed periodically reversed current methodology. The best guides quote waviness of 0.1 mrad. It is reasonable to prepare just one mandrel of about 0.5 m long, for production of tens of guide segments, saving both the cost and supply time of guides to neutron facilities. We estimate that we can fabricate a single mandrel for the current cost of an individual one-meter guide, but from this, we can produce tens of meters of guide very inexpensively without mandrel refurbishment. While a multilayer coating will add to the overall cost, we expect this will be less than that of commercially available guides today. Therefore, we will produce higher quality guides, which are less susceptible to radiation damage, at the lower cost than those available today.« less

Development of Low-Cost Method for Fabrication of Metal Neutron Guides

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

Engelhaupt, Darell; Khaykovich, Boris; Romaine, Suzanne

2017-12-19

Neutron scattering is one of the most useful methods of studying the structure and dynamics of matter. US DOE neutron scattering research facilities at Oak Ridge National Laboratory are among the World’s most advanced, providing researchers with unmatched capabilities for probing the structure and properties of materials, including engineering and biological systems. This task is to develop a lower cost process to optimize and produce the required neutron guides capable of efficiently delivering neutron beams for tens of meters between neutron moderators and instruments. Therefore, our effort is to improve the performance and lower the production cost of neutron guides.more » Our approach aims at improving guide quality while controlling their rising costs by adopting a novel electroforming replication approach to their fabrication. These guides will be especially advantageous when used near the neutron source since the radiation resistance of nickel is superior to glass. Additionally, we are depositing low-stress nickel from an extremely low impurity solution completely free of stress-reducing agents, which nominally contain and impart sulfur, carbon and other elements that potentially activate in the neutron environment. This is achieved by using a pulsed periodically reversed current methodology. The best guides quote waviness of 0.1 mrad. It is reasonable to prepare just one mandrel of about 0.5 m long, for production of tens of guide segments, saving both the cost and supply time of guides to neutron facilities. We estimate that we can fabricate a single mandrel for the current cost of an individual one-meter guide, but from this, we can produce tens of meters of guide very inexpensively without mandrel refurbishment. While a multilayer coating will add to the overall cost, we expect this will be less than that of commercially available guides today. Therefore, we will produce higher quality guides, which are less susceptible to radiation damage, at the lower cost than those available today.« less

Fatigue modulates dopamine availability and promotes flexible choice reversals during decision making.

PubMed

Iodice, Pierpaolo; Ferrante, Claudio; Brunetti, Luigi; Cabib, Simona; Protasi, Feliciano; Walton, Mark E; Pezzulo, Giovanni

2017-04-03

During decisions, animals balance goal achievement and effort management. Despite physical exercise and fatigue significantly affecting the levels of effort that an animal exerts to obtain a reward, their role in effort-based choice and the underlying neurochemistry are incompletely known. In particular, it is unclear whether fatigue influences decision (cost-benefit) strategies flexibly or only post-decision action execution and learning. To answer this question, we trained mice on a T-maze task in which they chose between a high-cost, high-reward arm (HR), which included a barrier, and a low-cost, low-reward arm (LR), with no barrier. The animals were parametrically fatigued immediately before the behavioural tasks by running on a treadmill. We report a sharp choice reversal, from the HR to LR arm, at 80% of their peak workload (PW), which was temporary and specific, as the mice returned to choose the HC when the animals were successively tested at 60% PW or in a two-barrier task. These rapid reversals are signatures of flexible choice. We also observed increased subcortical dopamine levels in fatigued mice: a marker of individual bias to use model-based control in humans. Our results indicate that fatigue levels can be incorporated in flexible cost-benefits computations that improve foraging efficiency.

Analysis of defect structure in silicon. Characterization of SEMIX material. Silicon sheet growth development for the large area silicon sheet task of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Natesh, R.; Stringfellow, G. B.; Virkar, A. V.; Dunn, J.; Guyer, T.

1983-01-01

Statistically significant quantitative structural imperfection measurements were made on samples from ubiquitous crystalline process (UCP) Ingot 5848 - 13C. Important correlation was obtained between defect densities, cell efficiency, and diffusion length. Grain boundary substructure displayed a strong influence on the conversion efficiency of solar cells from Semix material. Quantitative microscopy measurements gave statistically significant information compared to other microanalytical techniques. A surface preparation technique to obtain proper contrast of structural defects suitable for quantimet quantitative image analyzer (QTM) analysis was perfected and is used routinely. The relationships between hole mobility and grain boundary density was determined. Mobility was measured using the van der Pauw technique, and grain boundary density was measured using quantitative microscopy technique. Mobility was found to decrease with increasing grain boundary density.

Recoding low-level simulator data into a record of meaningful task performance: the integrated task modeling environment (ITME).

PubMed

King, Robert; Parker, Simon; Mouzakis, Kon; Fletcher, Winston; Fitzgerald, Patrick

2007-11-01

The Integrated Task Modeling Environment (ITME) is a user-friendly software tool that has been developed to automatically recode low-level data into an empirical record of meaningful task performance. The present research investigated and validated the performance of the ITME software package by conducting complex simulation missions and comparing the task analyses produced by ITME with taskanalyses produced by experienced video analysts. A very high interrater reliability (> or = .94) existed between experienced video analysts and the ITME for the task analyses produced for each mission. The mean session time:analysis time ratio was 1:24 using video analysis techniques and 1:5 using the ITME. It was concluded that the ITME produced task analyses that were as reliable as those produced by experienced video analysts, and significantly reduced the time cost associated with these analyses.

Cognitive costs of encoding novel natural activities: Can "learning by doing" be distracting and deceptive?

PubMed

von Stülpnagel, Rul; Schult, Janette C; Richter, Claudia; Steffens, Melanie C

2016-01-01

Findings from action memory research suggest that the enactment of simple actions and naturalistic activities results in similar memory performance to that from their observation. However, little is known about potential differences between the conditions during the encoding of the to-be-studied actions and activities. We analysed the cognitive costs of encoding two novel naturalistic activities studied via enactment or via observation in four experiments. In addition to memory performance, we measured objective cognitive costs with a secondary task and subjective cognitive costs with repeated ratings of mental effort and estimates of general activity difficulty. Memory performance was comparable across study conditions throughout all experiments. The enactment of activities repeatedly resulted in slower reaction times in the secondary task than did observation, suggesting higher objective costs. In contrast, subjective costs were rated lower after enactment than after observation. Findings from a pantomimic enactment condition suggested that the low ratings of subjective costs after enactment represent a misinterpretation of task demands. Our findings imply that the widespread belief about "learning by doing" as an easy way of learning does not stem from an actual advantage in memory performance, but rather from continuous feedback about one's performance resulting from enactment.

Falls Risk and Simulated Driving Performance in Older Adults

PubMed Central

Gaspar, John G.; Neider, Mark B.; Kramer, Arthur F.

2013-01-01

Declines in executive function and dual-task performance have been related to falls in older adults, and recent research suggests that older adults at risk for falls also show impairments on real-world tasks, such as crossing a street. The present study examined whether falls risk was associated with driving performance in a high-fidelity simulator. Participants were classified as high or low falls risk using the Physiological Profile Assessment and completed a number of challenging simulated driving assessments in which they responded quickly to unexpected events. High falls risk drivers had slower response times (~2.1 seconds) to unexpected events compared to low falls risk drivers (~1.7 seconds). Furthermore, when asked to perform a concurrent cognitive task while driving, high falls risk drivers showed greater costs to secondary task performance than did low falls risk drivers, and low falls risk older adults also outperformed high falls risk older adults on a computer-based measure of dual-task performance. Our results suggest that attentional differences between high and low falls risk older adults extend to simulated driving performance. PMID:23509627

Recent advances in photonics packaging materials

NASA Astrophysics Data System (ADS)

Zweben, Carl

2006-02-01

There are now over a dozen low-CTE materials with thermal conductivities between that of copper (400 w/m-K) and over 4X copper (1700 W/m-K). Most have low densities. For comparison, traditional low-CTE packaging materials like copper/tungsten have thermal conductivities that are little or no better than that of aluminum (200 W/m-K) and high densities. There are also low-density thermal insulators with low CTEs. Some advanced materials are low cost. Most do not outgas. They have a wide range of electrical properties that can be used to minimize electromagnetic emissions or provide EMI shielding. Several are now in commercial and aerospace applications, including laser diode packages; light-emitting diode (LED) packages; thermoelectric cooler bases, plasma displays; power modules; servers; laptops; heat sinks; thermally conductive, low-CTE printed circuit boards; and printed circuit board cold plates. Advanced material payoffs include: improved thermal performance, reliability, alignment and manufacturing yield; reduced thermal stresses and heating power requirements; simplified thermal design; enablement of hard solder direct attach; weight savings up to 85%; size reductions up to 65%; and lower cost. This paper discusses the large and increasing number of advanced packaging materials, including properties, development status, applications, increasing manufacturing yield, cost, lessons learned and future directions, including nanocomposites.

Alternating between pro- and antisaccades: switch-costs manifest via decoupling the spatial relations between stimulus and response.

PubMed

Heath, Matthew; Gillen, Caitlin; Samani, Ashna

2016-03-01

Antisaccades are a nonstandard task requiring a response mirror-symmetrical to the location of a target. The completion of an antisaccade has been shown to delay the reaction time (RT) of a subsequent prosaccade, whereas the converse switch elicits a null RT cost (i.e., the unidirectional prosaccade switch-cost). The present study sought to determine whether the prosaccade switch-cost arises from low-level interference specific to the sensory features of a target (i.e., modality-dependent) or manifests via the high-level demands of dissociating the spatial relations between stimulus and response (i.e., modality-independent). Participants alternated between pro- and antisaccades wherein the target associated with the response alternated between visual and auditory modalities. Thus, the present design involved task-switch (i.e., switching from a pro- to antisaccade and vice versa) and modality-switch (i.e., switching from a visual to auditory target and vice versa) trials as well as their task- and modality-repetition counterparts. RTs were longer for modality-switch than modality-repetition trials. Notably, however, modality-switch trials did not nullify or lessen the unidirectional prosaccade switch-cost; that is, the magnitude of the RT cost for task-switch prosaccades was equivalent across modality-switch and modality-repetition trials. Thus, competitive interference within a sensory modality does not contribute to the unidirectional prosaccade switch-cost. Instead, the modality-independent findings evince that dissociating the spatial relations between stimulus and response instantiates a high-level and inertially persistent nonstandard task-set that impedes the planning of a subsequent prosaccade.

A noble metal-free proton-exchange membrane fuel cell based on bio-inspired molecular catalysts.

PubMed

Tran, P D; Morozan, A; Archambault, S; Heidkamp, J; Chenevier, P; Dau, H; Fontecave, M; Martinent, A; Jousselme, B; Artero, V

2015-03-01

Hydrogen is a promising energy vector for storing renewable energies: obtained from water-splitting, in electrolysers or photoelectrochemical cells, it can be turned back to electricity on demand in fuel cells (FCs). Proton exchange membrane (PEM) devices with low internal resistance, high compactness and stability are an attractive technology optimized over decades, affording fast start-up times and low operating temperatures. However, they rely on the powerful catalytic properties of noble metals such as platinum, while lower cost, more abundant materials would be needed for economic viability. Replacing these noble metals at both electrodes has long proven to be a difficult task, so far incompatible with PEM technologies. Here we take advantage of newly developed bio-inspired molecular H 2 oxidation catalysts and noble metal-free O 2 -reducing materials, to fabricate a noble metal-free PEMFC, with an 0.74 V open circuit voltage and a 23 μW cm -2 output power under technologically relevant conditions. X-ray absorption spectroscopy measurements confirm that the catalysts are stable and retain their structure during turnover.

The United States Special Operations Command Civil Military Engagement Program - A Model for Military-Interagency Low Cost / Small Footprint Activities

DTIC Science & Technology

2014-05-02

Interagency Coordination Centers (JIACs), Interagency Task Forces ( IATFs ) are found within GCCs and subordinate military units in an attempt to bridge...Interagency Tasks Forces ( IATFs ) that exist at each Geographic Combatant Command (GCC). Rather, this chapter serves to highlight the Civil Military

Optimizing sterilization logistics in hospitals.

PubMed

van de Klundert, Joris; Muls, Philippe; Schadd, Maarten

2008-03-01

This paper deals with the optimization of the flow of sterile instruments in hospitals which takes place between the sterilization department and the operating theatre. This topic is especially of interest in view of the current attempts of hospitals to cut cost by outsourcing sterilization tasks. Oftentimes, outsourcing implies placing the sterilization unit at a larger distance, hence introducing a longer logistic loop, which may result in lower instrument availability, and higher cost. This paper discusses the optimization problems that have to be solved when redesigning processes so as to improve material availability and reduce cost. We consider changing the logistic management principles, use of visibility information, and optimizing the composition of the nets of sterile materials.

Perceptual processing deficits underlying reduced FFOV efficiency in older adults.

PubMed

Power, Garry F; Conlon, Elizabeth G

2017-01-01

Older adults are known to perform more poorly on measures of the functional field of view (FFOV) than younger adults. Specific contributions by poor bottom-up and or top-down control of visual attention to the reduced FFOV of older adults were investigated. Error rates of older and younger adults were compared on a FFOV task in which a central identification task, peripheral localization task, and peripheral distractors were presented in high and low contrast. Older adults made more errors in all conditions. The effect of age was independent of the contrast of the peripheral target or distractors. The performance cost of including the central task was measured and found to be negligible for younger adults. For older adults performance costs were present in all conditions, greater with distractors than without, and greater for a low rather than high contrast central stimulus when the peripheral target was high contrast. These results are consistent with older adults compensating for reduced sensory input or bottom-up capture of attention by relying more heavily on top-down control for which they are resource limited.

Self mobile space manipulator project

NASA Technical Reports Server (NTRS)

Brown, H. Ben; Friedman, Mark; Xu, Yangsheng; Kanade, Takeo

1992-01-01

A relatively simple, modular, low mass, low cost robot is being developed for space EVA that is large enough to be independently mobile on a space station or platform exterior, yet versatile enough to accomplish many vital tasks. The robot comprises two long flexible links connected by a rotary joint, with 2-DOF 'wrist' joints and grippers at each end. It walks by gripping pre-positioned attachment points, such as trusswork nodes, and alternately shifting its base of support from one foot (gripper) to the other. The robot can perform useful tasks such as visual inspection, material transport, and light assembly by manipulating objects with one gripper, while stabilizing itself with the other. At SOAR '90, we reported development of 1/3 scale robot hardware, modular trusswork to serve as a locomotion substrate, and a gravity compensation system to allow laboratory tests of locomotion strategies on the horizontal face of the trusswork. In this paper, we report on project progress including the development of: (1) adaptive control for automatic adjustment to loads; (2) enhanced manipulation capabilities; (3) machine vision, including the use of neural nets, to guide autonomous locomotion; (4) locomotion between orthogonal trusswork faces; and (5) improved facilities for gravity compensation and telerobotic control.

Flat-plate solar array project. Volume 2: Silicon material

NASA Technical Reports Server (NTRS)

Lutwack, R.

1986-01-01

The goal of the Silicon Material Task, a part of the Flat Plate Solar Array (FSA) Project, was to develop and demonstate the technology for the low cost production of silicon of suitable purity to be used as the basic material for the manufacture of terrestrial photovoltaic solar cells. Summarized are 11 different processes for the production of silicon that were investigated and developed to varying extent by industrial, university, and Government researchers. The silane production section of the Union Carbide Corp. (UCC) silane process was developed completely in this program. Coupled with Siemens-type chemical vapor deposition reactors, the process was carried through the pilot stage. The overall UCC process involves the conversion of metallurgical-grade silicon to silane followed by decomposition of the silane to purified silicon. The other process developments are described to varying extents. Studies are reported on the effects of impurities in silicon on both silicon-material properties and on solar cell performance. These studies on the effects of impurities yielded extensive information and models for relating specific elemental concentrations to levels of deleterious effects.

Flat-plate solar array project. Volume 2: Silicon material

NASA Astrophysics Data System (ADS)

Lutwack, R.

1986-10-01

The goal of the Silicon Material Task, a part of the Flat Plate Solar Array (FSA) Project, was to develop and demonstate the technology for the low cost production of silicon of suitable purity to be used as the basic material for the manufacture of terrestrial photovoltaic solar cells. Summarized are 11 different processes for the production of silicon that were investigated and developed to varying extent by industrial, university, and Government researchers. The silane production section of the Union Carbide Corp. (UCC) silane process was developed completely in this program. Coupled with Siemens-type chemical vapor deposition reactors, the process was carried through the pilot stage. The overall UCC process involves the conversion of metallurgical-grade silicon to silane followed by decomposition of the silane to purified silicon. The other process developments are described to varying extents. Studies are reported on the effects of impurities in silicon on both silicon-material properties and on solar cell performance. These studies on the effects of impurities yielded extensive information and models for relating specific elemental concentrations to levels of deleterious effects.

Design, processing and testing of LSI arrays: Hybrid microelectronics task

NASA Technical Reports Server (NTRS)

Himmel, R. P.; Stuhlbarg, S. M.; Ravetti, R. G.; Zulueta, P. J.

1979-01-01

Mathematical cost factors were generated for both hybrid microcircuit and printed wiring board packaging methods. A mathematical cost model was created for analysis of microcircuit fabrication costs. The costing factors were refined and reduced to formulae for computerization. Efficient methods were investigated for low cost packaging of LSI devices as a function of density and reliability. Technical problem areas such as wafer bumping, inner/outer leading bonding, testing on tape, and tape processing, were investigated.

Fabrication of In(0.75)Zn(1.5)Sn(1.0) (IZTO) Thin-Film Transistors Using Solution-Processable Materials and PZT Inkjet-Printing.

PubMed

Lee, Tai-Kuang; Liuand, Chao-Te; Lee, Wen-Hsi

2017-01-01

Recently, Thin Film Transistors (TFTs) have been studied widely because of potential applications in low cost, low-temperature process and flexible displays. They can be fabricated by easy processes based on solution methods. But the mobility of organic TFTs is lower and the threshold voltage is higher than amorphous Si TFTs. In order to enhance the channel mobility and satisfy with the requirement of low-cost fabrication, we prepare a low-cost, mask-free, reduced material wastage, deposited technology using transparent, directly printable, air-stable semiconductor slurries and dielectric solutions. In our investigations, we attempt to obtain a high performance and low-cost TFT via preparing materials, designing device structure, and using PZT inkjet-printing technology. A stable and non-precipitated metal oxide ink with appropriate doping was prepared for the fabrication of an InxZn1.5Sn1.0 (IZTO) by PZT inkjet-printing. The soluble direct-printing process is a powerful tool for material research and implies that the printable materials and the printing technology enable the use of all-printed low-cost flexible displays and other transparent electronic applications. Transparent materials including dielectric PVP, conductive carbon nanotube (CNT) and active IZTO were employed into the fabrication of our PZT inkjet-printing process. After annealed at 180 °C, The experimental all-printed TFT exhibit the carrier mobility of 0.194 cm2/Vs, sub-threshold slope of 20 V/decade, and the threshold voltage of 5 V, initially. All-inkjet-printed films have great transparency, potentially in transparent electronics and the transmittance pattern in visible part of the spectrum (400–700 nm) is over 80%.

Unit Costs of Interlibrary Loans and Photocopies at a Regional Medical Library: Preliminary Report *

PubMed Central

Spencer, Carol C.

1970-01-01

Unit costs of providing interlibrary loans and photocopies were determined by a method not previously used for library cost studies: random time sampling with self-observation. The working time of all appropriate personnel was sampled using Random Alarm Mechanisms and a structured checklist of tasks. The total lender's unit cost per request received, including direct labor, materials, fringe benefits, and overhead, was $1.526 for originals mailed postpaid by lender, and $1.534 for photocopies mailed. Corresponding unit costs per request filled were: originals, $1.932, and photocopies, $1.763. PMID:5439910

A low-cost vector processor boosting compute-intensive image processing operations

NASA Technical Reports Server (NTRS)

Adorf, Hans-Martin

1992-01-01

Low-cost vector processing (VP) is within reach of everyone seriously engaged in scientific computing. The advent of affordable add-on VP-boards for standard workstations complemented by mathematical/statistical libraries is beginning to impact compute-intensive tasks such as image processing. A case in point in the restoration of distorted images from the Hubble Space Telescope. A low-cost implementation is presented of the standard Tarasko-Richardson-Lucy restoration algorithm on an Intel i860-based VP-board which is seamlessly interfaced to a commercial, interactive image processing system. First experience is reported (including some benchmarks for standalone FFT's) and some conclusions are drawn.

Development of flight experiment work performance and workstation interface requirements, part 1. Technical report and appendices A through G

NASA Technical Reports Server (NTRS)

Hatterick, R. G.

1973-01-01

A skill requirement definition method was applied to the problem of determining, at an early stage in system/mission definition, the skills required of on-orbit crew personnel whose activities will be related to the conduct or support of earth-orbital research. The experiment data base was selected from proposed experiments in NASA's earth orbital research and application investigation program as related to space shuttle missions, specifically those being considered for Sortie Lab. Concepts for two integrated workstation consoles for Sortie Lab experiment operations were developed, one each for earth observations and materials sciences payloads, utilizing a common supporting subsystems core console. A comprehensive data base of crew functions, operating environments, task dependencies, task-skills and occupational skills applicable to a representative cross section of earth orbital research experiments is presented. All data has been coded alphanumerically to permit efficient, low cost exercise and application of the data through automatic data processing in the future.

Process feasibility study in support of silicon material task 1

NASA Technical Reports Server (NTRS)

Yaws, C. L.; Li, K. Y.; Hopper, J. R.; Fang, C. S.; Hansen, K. C.

1981-01-01

Results for process system properties, chemical engineering and economic analyses of the new technologies and processes being developed for the production of lower cost silicon for solar cells are presented. Analyses of process system properties are important for chemical materials involved in the several processes under consideration for semiconductor and solar cell grade silicon production. Major physical, thermodynamic and transport property data are reported for silicon source and processing chemical materials.

Accelerating root system phenotyping of seedlings through a computer-assisted processing pipeline.

PubMed

Dupuy, Lionel X; Wright, Gladys; Thompson, Jacqueline A; Taylor, Anna; Dekeyser, Sebastien; White, Christopher P; Thomas, William T B; Nightingale, Mark; Hammond, John P; Graham, Neil S; Thomas, Catherine L; Broadley, Martin R; White, Philip J

2017-01-01

There are numerous systems and techniques to measure the growth of plant roots. However, phenotyping large numbers of plant roots for breeding and genetic analyses remains challenging. One major difficulty is to achieve high throughput and resolution at a reasonable cost per plant sample. Here we describe a cost-effective root phenotyping pipeline, on which we perform time and accuracy benchmarking to identify bottlenecks in such pipelines and strategies for their acceleration. Our root phenotyping pipeline was assembled with custom software and low cost material and equipment. Results show that sample preparation and handling of samples during screening are the most time consuming task in root phenotyping. Algorithms can be used to speed up the extraction of root traits from image data, but when applied to large numbers of images, there is a trade-off between time of processing the data and errors contained in the database. Scaling-up root phenotyping to large numbers of genotypes will require not only automation of sample preparation and sample handling, but also efficient algorithms for error detection for more reliable replacement of manual interventions.

Novel Composites for Wing and Fuselage Applications. Task 1; Novel Wing Design Concepts

NASA Technical Reports Server (NTRS)

Suarez, J. A.; Buttitta, C.; Flanagan, G.; DeSilva, T.; Egensteiner, W.; Bruno, J.; Mahon, J.; Rutkowski, C.; Collins, R.; Fidnarick, R.;

Student Task Analysis for the Development of E-Learning Lectural System in Basic Chemistry Courses in FKIP UMMY Solok

NASA Astrophysics Data System (ADS)

Afrahamiryano, A.; Ariani, D.

2018-04-01

The student task analysis is one part of the define stage in development research using the 4-D development model. Analysis of this task is useful to determine the level of understanding of students on lecture materials that have been given. The results of this task analysis serve as a measuring tool to determine the level of success of learning and as a basis in the development of lecture system. Analysis of this task is done by the method of observation and documentation study of the tasks undertaken by students. The results of this analysis are then described and after that triangulation are done to draw conclusions. The results of the analysis indicate that the students' level of understanding is high for theoretical and low material for counting material. Based on the results of this task analysis, it can be concluded that e-learning lecture system developed should be able to increase students' understanding on basic chemicals that are calculated.

A Low-Cost, Precision Hydrometer for Classroom Use.

ERIC Educational Resources Information Center

Murphy, Michael D.

1983-01-01

Describes a low cost hydrometer which can be assembled by students using stock laboratory items with a total retail cost of 17 cents. Includes list of required materials (with supplies) and experimental results on the instrument's accuracy. (JM)

Design study of wind turbines 50 kW to 3000 kW for electric utility applications: Analysis and design

NASA Technical Reports Server (NTRS)

1976-01-01

In the conceptual design task, several feasible wind generator systems (WGS) configurations were evaluated, and the concept offering the lowest energy cost potential and minimum technical risk for utility applications was selected. In the optimization task, the selected concept was optimized utilizing a parametric computer program prepared for this purpose. In the preliminary design task, the optimized selected concept was designed and analyzed in detail. The utility requirements evaluation task examined the economic, operational, and institutional factors affecting the WGS in a utility environment, and provided additional guidance for the preliminary design effort. Results of the conceptual design task indicated that a rotor operating at constant speed, driving an AC generator through a gear transmission is the most cost effective WGS configuration. The optimization task results led to the selection of a 500 kW rating for the low power WGS and a 1500 kW rating for the high power WGS.

Designing informed game-based rehabilitation tasks leveraging advances in virtual reality.

PubMed

Lange, Belinda; Koenig, Sebastian; Chang, Chien-Yen; McConnell, Eric; Suma, Evan; Bolas, Mark; Rizzo, Albert

2012-01-01

This paper details a brief history and rationale for the use of virtual reality (VR) technology for clinical research and intervention, and then focuses on game-based VR applications in the area of rehabilitation. An analysis of the match between rehabilitation task requirements and the assets available with VR technology is presented. Low-cost camera-based systems capable of tracking user behavior at sufficient levels for game-based virtual rehabilitation activities are currently available for in-home use. Authoring software is now being developed that aims to provide clinicians with a usable toolkit for leveraging this technology. This will facilitate informed professional input on software design, development and application to ensure safe and effective use in the rehabilitation context. The field of rehabilitation generally stands to benefit from the continual advances in VR technology, concomitant system cost reductions and an expanding clinical research literature and knowledge base. Home-based activity within VR systems that are low-cost, easy to deploy and maintain, and meet the requirements for "good" interactive rehabilitation tasks could radically improve users' access to care, adherence to prescribed training and subsequently enhance functional activity in everyday life in clinical populations.

Attention in a multi-task environment

NASA Technical Reports Server (NTRS)

Andre, Anthony D.; Heers, Susan T.

1993-01-01

Two experiments used a low fidelity multi-task simulation to investigate the effects of cue specificity on task preparation and performance. Subjects performed a continuous compensatory tracking task and were periodically prompted to perform one of several concurrent secondary tasks. The results provide strong evidence that subjects enacted a strategy to actively divert resources towards secondary task preparation only when they had specific information about an upcoming task to be performed. However, this strategy was not as much affected by the type of task cued (Experiment 1) or its difficulty level (Experiment 2). Overall, subjects seemed aware of both the costs (degraded primary task tracking) and benefits (improved secondary task performance) of cue information. Implications of the present results for computational human performance/workload models are discussed.

The Role of Task-Related Learned Representations in Explaining Asymmetries in Task Switching

PubMed Central

Barutchu, Ayla; Becker, Stefanie I.; Carter, Olivia; Hester, Robert; Levy, Neil L.

2013-01-01

Task switch costs often show an asymmetry, with switch costs being larger when switching from a difficult task to an easier task. This asymmetry has been explained by difficult tasks being represented more strongly and consequently requiring more inhibition prior to switching to the easier task. The present study shows that switch cost asymmetries observed in arithmetic tasks (addition vs. subtraction) do not depend on task difficulty: Switch costs of similar magnitudes were obtained when participants were presented with unsolvable pseudo-equations that did not differ in task difficulty. Further experiments showed that neither task switch costs nor switch cost asymmetries were due to perceptual factors (e.g., perceptual priming effects). These findings suggest that asymmetrical switch costs can be brought about by the association of some tasks with greater difficulty than others. Moreover, the finding that asymmetrical switch costs were observed (1) in the absence of a task switch proper and (2) without differences in task difficulty, suggests that present theories of task switch costs and switch cost asymmetries are in important ways incomplete and need to be modified. PMID:23613919

Micro-opto-mechanical devices and systems using epitaxial lift off

NASA Technical Reports Server (NTRS)

Camperi-Ginestet, C.; Kim, Young W.; Wilkinson, S.; Allen, M.; Jokerst, N. M.

1993-01-01

The integration of high quality, single crystal thin film gallium arsenide (GaAs) and indium phosphide (InP) based photonic and electronic materials and devices with host microstructures fabricated from materials such as silicon (Si), glass, and polymers will enable the fabrication of the next generation of micro-opto-mechanical systems (MOMS) and optoelectronic integrated circuits. Thin film semiconductor devices deposited onto arbitrary host substrates and structures create hybrid (more than one material) near-monolithic integrated systems which can be interconnected electrically using standard inexpensive microfabrication techniques such as vacuum metallization and photolithography. These integrated systems take advantage of the optical and electronic properties of compound semiconductor devices while still using host substrate materials such as silicon, polysilicon, glass and polymers in the microstructures. This type of materials optimization for specific tasks creates higher performance systems than those systems which must use trade-offs in device performance to integrate all of the function in a single material system. The low weight of these thin film devices also makes them attractive for integration with micromechanical devices which may have difficulty supporting and translating the full weight of a standard device. These thin film devices and integrated systems will be attractive for applications, however, only when the development of low cost, high yield fabrication and integration techniques makes their use economically feasible. In this paper, we discuss methods for alignment, selective deposition, and interconnection of thin film epitaxial GaAs and InP based devices onto host substrates and host microstructures.

A low cost, adaptive mixed reality system for home-based stroke rehabilitation.

PubMed

Chen, Yinpeng; Baran, Michael; Sundaram, Hari; Rikakis, Thanassis

2011-01-01

This paper presents a novel, low-cost, real-time adaptive multimedia environment for home-based upper extremity rehabilitation of stroke survivors. The primary goal of this system is to provide an interactive tool with which the stroke survivor can sustain gains achieved within the clinical phase of therapy and increase the opportunity for functional recovery. This home-based mediated system has low cost sensing, off the shelf components for the auditory and visual feedback, and remote monitoring capability. The system is designed to continue active learning by reducing dependency on real-time feedback and focusing on summary feedback after a single task and sequences of tasks. To increase system effectiveness through customization, we use data from the training strategy developed by the therapist at the clinic for each stroke survivor to drive automated system adaptation at the home. The adaptation includes changing training focus, selecting proper feedback coupling both in real-time and in summary, and constructing appropriate dialogues with the stroke survivor to promote more efficient use of the system. This system also allows the therapist to review participant's progress and adjust the training strategy weekly.

Individual differences in working memory capacity predict visual attention allocation.

PubMed

Bleckley, M Kathryn; Durso, Francis T; Crutchfield, Jerry M; Engle, Randall W; Khanna, Maya M

2003-12-01

To the extent that individual differences in working memory capacity (WMC) reflect differences in attention (Baddeley, 1993; Engle, Kane, & Tuholski, 1999), differences in WMC should predict performance on visual attention tasks. Individuals who scored in the upper and lower quartiles on the OSPAN working memory test performed a modification of Egly and Homa's (1984) selective attention task. In this task, the participants identified a central letter and localized a displaced letter flashed somewhere on one of three concentric rings. When the displaced letter occurred closer to fixation than the cue implied, high-WMC, but not low-WMC, individuals showed a cost in the letter localization task. This suggests that low-WMC participants allocated attention as a spotlight, whereas those with high WMC showed flexible allocation.

The acquisition of simple associations as observed in color-word contingency learning.

PubMed

Lin, Olivia Y-H; MacLeod, Colin M

2018-01-01

Three experiments investigated the learning of simple associations in a color-word contingency task. Participants responded manually to the print colors of 3 words, with each word associated strongly to 1 of the 3 colors and weakly to the other 2 colors. Despite the words being irrelevant, response times to high-contingency stimuli and to low-contingency stimuli quickly diverged. This high-low difference remained quite constant over successive blocks of trials, evidence of stable contingency learning. Inclusion of a baseline condition-an item having no color-word contingency-permitted separation of the contingency learning effect into 2 components: a cost due to low contingency and a benefit due to high contingency. Both cost and benefit were quick to acquire, quick to extinguish, and quick to reacquire. The color-word contingency task provides a simple way to directly study the learning of associations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Using 3D Printing (Additive Manufacturing) to Produce Low-Cost Simulation Models for Medical Training.

PubMed

Lichtenberger, John P; Tatum, Peter S; Gada, Satyen; Wyn, Mark; Ho, Vincent B; Liacouras, Peter

2018-03-01

This work describes customized, task-specific simulation models derived from 3D printing in clinical settings and medical professional training programs. Simulation models/task trainers have an array of purposes and desired achievements for the trainee, defining that these are the first step in the production process. After this purpose is defined, computer-aided design and 3D printing (additive manufacturing) are used to create a customized anatomical model. Simulation models then undergo initial in-house testing by medical specialists followed by a larger scale beta testing. Feedback is acquired, via surveys, to validate effectiveness and to guide or determine if any future modifications and/or improvements are necessary. Numerous custom simulation models have been successfully completed with resulting task trainers designed for procedures, including removal of ocular foreign bodies, ultrasound-guided joint injections, nerve block injections, and various suturing and reconstruction procedures. These task trainers have been frequently utilized in the delivery of simulation-based training with increasing demand. 3D printing has been integral to the production of limited-quantity, low-cost simulation models across a variety of medical specialties. In general, production cost is a small fraction of a commercial, generic simulation model, if available. These simulation and training models are customized to the educational need and serve an integral role in the education of our military health professionals.

Investigation of low cost material processes for liquid rocket engines

NASA Technical Reports Server (NTRS)

Nguyentat, Thinh; Kawashige, Chester M.; Scala, James G.; Horn, Ronald M.

1993-01-01

The development of low cost material processes is essential to the achievement of economical liquid rocket propulsion systems in the next century. This paper will present the results of the evaluation of some promising material processes including powder metallurgy, vacuum plasma spray, metal spray forming, and bulge forming. The physical and mechanical test results from the samples and subscale hardware fabricated from high strength copper alloys and superalloys will be discussed.

Task-Based Language Teaching with Smartphones: A Case Study in Pakistan

ERIC Educational Resources Information Center

Rashid, Shaista; Cunningham, Una; Watson, Kevin

2017-01-01

Integration of technology in task-based language teaching (TBLT) has long been a source of attraction for language teachers (Pierson, 2015). In the case of developing countries, such as Pakistan, mobile phones are the modern form of technology commonly available at low cost to individuals as well as institutions. The present descriptive case study…

Cost of best-practice primary care management of chronic disease in a remote Aboriginal community.

PubMed

Gador-Whyte, Andrew P; Wakerman, John; Campbell, David; Lenthall, Sue; Struber, Janet; Hope, Alex; Watson, Colin

2014-06-16

To estimate the cost of completing all chronic care tasks recommended by the Central Australian Rural Practitioners Association Standard Treatment Manual (CARPA STM) for patients with type 2 diabetes and chronic kidney disease (CKD). The study was conducted at a health service in a remote Central Australian Aboriginal community between July 2010 and May 2011. The chronic care tasks required were ascertained from the CARPA STM. The clinic database was reviewed for data on disease prevalence and adherence to CARPA STM guidelines. Recommended tasks were observed in a time-and-motion study of clinicians' work. Clinicians were interviewed about systematic management and its barriers. Expenditure records were analysed for salary and administrative costs. Diabetes and CKD prevalence; time spent on chronic disease care tasks; completion of tasks recommended by the CARPA STM; barriers to systematic care identified by clinicians; and estimated costs of optimal primary care management of all residents with diabetes or CKD. Projected annual costs of best-practice care for diabetes and CKD for this community of 542 people were $900 792, of which $645 313 would be met directly by the local primary care service. Estimated actual expenditure for these conditions in 2009-10 was $446 585, giving a projected funding gap of $198 728 per annum, or $1733 per patient. High staff turnover, acute care workload and low health literacy also hindered optimal chronic disease care. Barriers to optimal care included inadequate funding and workforce issues. Reduction of avoidable hospital admissions and overall costs necessitates adequate funding of primary care of chronic disease in remote communities.

A Cost-Benefit Analysis of Low-Dose Aspirin Prophylaxis for the Prevention of Preeclampsia in the United States.

PubMed

Werner, Erika F; Hauspurg, Alisse K; Rouse, Dwight J

2015-12-01

To develop a decision model to evaluate the risks, benefits, and costs of different approaches to aspirin prophylaxis for the approximately 4 million pregnant women in the United States annually. We created a decision model to evaluate four approaches to aspirin prophylaxis in the United States: no prophylaxis, prophylaxis per American College of Obstetricians and Gynecologists (the College) recommendations, prophylaxis per U.S. Preventive Services Task Force recommendations, and universal prophylaxis. We included the costs associated with aspirin, preeclampsia, preterm birth, and potential aspirin-associated adverse effects. TreeAge Pro 2011 was used to perform the analysis. The estimated rate of preeclampsia would be 4.18% without prophylaxis compared with 4.17% with the College approach in which 0.35% (n=14,000) of women receive aspirin, 3.83% with the U.S. Preventive Services Task Force approach in which 23.5% (n=940,800) receive aspirin, and 3.81% with universal prophylaxis. Compared with no prophylaxis, the U.S. Preventive Services Task Force approach would save $377.4 million in direct medical care costs annually, and universal prophylaxis would save $365 million assuming 4 million births each year. The U.S. Preventive Services Task Force approach is the most cost-beneficial in 79% of probabilistic simulations. Assuming a willingness to pay of $100,000 per neonatal quality-adjusted life-year gained, the universal approach is the most cost-effective in more than 99% of simulations. Both the U.S. Preventive Services Task Force approach and universal prophylaxis would reduce morbidity, save lives, and lower health care costs in the United States to a much greater degree than the approach currently recommended by the College.

Mineral Surface Reactivity in teaching of Science Materials

NASA Astrophysics Data System (ADS)

Del Hoyo Martínez, Carmen

2013-04-01

In the last fifty years, science materials issues has required the study of air pollution, water and soil to prevent and remedy the adverse effects of waste originating from anthropogenic activity and the development of new energies and new materials. The teaching of this discipline has been marked by lectures on general lines, materials, disciplines, who explained biased objects of reality, but often forgot the task of reconstruction and integration of such visions. Moving from that model, otherwise quite static, to a dynamic relational model, would in our view, a real revolution in education. This means taking a systematic approach to complex both in interpreting reality and in favor when learning. Children relationships are as important or more than single objects, and it is to discover fundamental organizational principles of phenomena we seek to interpret or in other words, find the pattern that connects. Thus, we must work on relationships and also take into account the relation between the observer and the observed. Educate about relationships means that studies should always be considered within a framework of probabilities, not absolute certainties. This model of systemic thinking, dealing with complexity, is a possibility to bring coherence to our educational work, because the complexity is not taught, complexity is live, so that complex thinking is extended (and fed) in a form educate complex. It is the task of teaching to help people move from level to level of decision reviews. This means that systems thinking should be extended in a local action, action that engages the individual and the environment. Science Materials has emerged as a discipline of free choice for pupils attending chemical engineering which has been assigned 6.0 credits. The chemical engineer's professional profile within the current framework is defined as a professional knowledge as a specialization technical / functional, working in a learning organization and the formation of which enables him to continuous innovation. Different materials are used in the adsorption and improvement and design of new adsorbents, most of whom remain under patent, so they do not know the procedures and products used, but in all cases the safety and / or biodegradability of materials used is an important issue in their choice for environmental applications. In regard to materials, safe and low cost must be mentioned clays and clay minerals, whose colloidal properties, ease of generating structural changes, abundance in nature, and low cost make them very suitable for adsorption chemical contaminants. We proposed to use these materials to show the different aspects for the study of the Science Materials. References -del Hoyo, C. (2007b). Layered Double Hydroxides and human health: An overview. Applied Clay Science. 36, 103-121. -Konta, J. (1995). Clay and man: Clay raw materials in the service of man. Applied Clay Science. 10, 275-335. -Volzone, C. (2007). Retention of pollutant gases: Comparison between clay minerals and their modified products. Applied Clay Science. 36, 191-196.

Part Count: Monolithic Part Effects On Manufacturing Labor Cost, An Aircraft Applied Model

DTIC Science & Technology

2010-03-01

Fulfillment of the Requirements for the Degree of Master of Science in Financial Analysis Aaron M. Lemke, BS Captain, USAF March 2010... ACCA ), provides substantial support for the impact of part size on life cycle cost for payload aircraft. This research evaluates select methods used...1: Boeing 787 External Skin Materials (Boeing, 2010) ..........................................9 Figure 2: ACCA Task Sequence (Neumeier et al, 2009

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

Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.

We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less

Low-cost solar array project task 1: Silicon material. Gaseous melt replenishment system

NASA Technical Reports Server (NTRS)

Jewett, D. N.; Bates, H. E.; Hill, D. M.

1980-01-01

The operation of a silicon production technique was demonstrated. The essentials of the method comprise chemical vapor deposition of silicon, by hydrogen reduction of chlorosilanes, on the inside of a quartz reaction vessel having large internal surface area. The system was designed to allow successive deposition-melting cycles, with silicon removal being accomplished by discharging the molten silicon. The liquid product would be suitable for transfer to a crystal growth process, casting into solid form, or production of shots. A scaled-down prototype reactor demonstrated single pass conversion efficiency of 20 percent and deposition rates and energy consumption better than conventional Siemens reactors, via deposition rates of 365 microns/hr. and electrical consumption of 35 Kwhr/kg of silicon produced.

Heat exchanger-ingot casting/slicing process, phase 1: Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Schmid, F.; Khattak, C. P.

1977-01-01

A controlled growth, heat-flow and cool-down process is described that yielded silicon with a high degree of single crystallinity. Even when the seed melted out, very large grains formed. Solar cell samples made from cast material yielded conversion efficiency of over 9%. Representative characterizations of grown silicon demonstrated a dislocation density of less than 100/sq cm and a minority carrier diffusion length of 31 micron. The source of silicon carbide in silicon ingots was identified to be from graphite retainers in contact with silica crucibles. Higher growth rates were achieved with the use of a graphite plug at the bottom of the silica crucible.

Comprehensive silicon solar cell computer modeling

NASA Technical Reports Server (NTRS)

Lamorte, M. F.

1984-01-01

The development of an efficient, comprehensive Si solar cell modeling program that has the capability of simulation accuracy of 5 percent or less is examined. A general investigation of computerized simulation is provided. Computer simulation programs are subdivided into a number of major tasks: (1) analytical method used to represent the physical system; (2) phenomena submodels that comprise the simulation of the system; (3) coding of the analysis and the phenomena submodels; (4) coding scheme that results in efficient use of the CPU so that CPU costs are low; and (5) modularized simulation program with respect to structures that may be analyzed, addition and/or modification of phenomena submodels as new experimental data become available, and the addition of other photovoltaic materials.

Development of high-performance concrete mixtures for durable bridge decks in Montana using locally available materials.

DOT National Transportation Integrated Search

2005-03-01

"The Montana Department of Transportation (MDT) is performing research to develop a cost-effective, indigenous highperformance : concrete (HPC) for use in bridge deck applications. The investigation was divided into two tasks: 1) : identification of ...

Low-Cost Inkjet Printing Technology for the Rapid Prototyping of Transducers

PubMed Central

Andò, Bruno; Baglio, Salvatore; Bulsara, Adi R.; Emery, Teresa; Marletta, Vincenzo; Pistorio, Antonio

2017-01-01

Recently, there has been an upsurge in efforts dedicated to developing low-cost flexible electronics by exploiting innovative materials and direct printing technologies. This interest is motivated by the need for low-cost mass-production, shapeable, and disposable devices, and the rapid prototyping of electronics and sensors. This review, following a short overview of main printing processes, reports examples of the development of flexible transducers through low-cost inkjet printing technology. PMID:28368318

Residential Consumption Scheduling Based on Dynamic User Profiling

NASA Astrophysics Data System (ADS)

Mangiatordi, Federica; Pallotti, Emiliano; Del Vecchio, Paolo; Capodiferro, Licia

Deployment of household appliances and of electric vehicles raises the electricity demand in the residential areas and the impact of the building's electrical power. The variations of electricity consumption across the day, may affect both the design of the electrical generation facilities and the electricity bill, mainly when a dynamic pricing is applied. This paper focuses on an energy management system able to control the day-ahead electricity demand in a residential area, taking into account both the variability of the energy production costs and the profiling of the users. The user's behavior is dynamically profiled on the basis of the tasks performed during the previous days and of the tasks foreseen for the current day. Depending on the size and on the flexibility in time of the user tasks, home inhabitants are grouped in, one over N, energy profiles, using a k-means algorithm. For a fixed energy generation cost, each energy profile is associated to a different hourly energy cost. The goal is to identify any bad user profile and to make it pay a highest bill. A bad profile example is when a user applies a lot of consumption tasks and low flexibility in task reallocation time. The proposed energy management system automatically schedules the tasks, solving a multi-objective optimization problem based on an MPSO strategy. The goals, when identifying bad users profiles, are to reduce the peak to average ratio in energy demand, and to minimize the energy costs, promoting virtuous behaviors.

High productivity mould robotic milling in Al-5083

NASA Astrophysics Data System (ADS)

Urresti, Iker; Arrazola, Pedro Jose; Ørskov, Klaus Bonde; Pelegay, Jose Angel

2018-05-01

Industrial serial robots were usually limited to welding, handling or spray painting operations until very recent years. However, some industries have already realized about their important capabilities in terms of flexibility, working space, adaptability and cost. Hence, currently they are seriously being considered to carry out certain metal machining tasks. Therefore, robot based machining is presented as a cost-saving and flexible manufacturing alternative compared to conventional CNC machines especially for roughing or even pre-roughing of large parts. Nevertheless, there are still some drawbacks usually referred as low rigidity, accuracy and repeatability. Thus, the process productivity is usually sacrificed getting low Material Removal Rates (MRR), and consequently not being competitive. Nevertheless, in this paper different techniques to obtain increased productivity are presented, though an appropriate selection of cutting strategies and parameters that are essential for it. During this research some rough milling tests in Al-5083 are presented where High Feed Milling (HFM) is implemented as productive cutting strategy and the experimental modal analysis named Tap-testing is used for the suitable choice of cutting conditions. Competitive productivity rates are experienced while process stability is checked through the cutting forces measurements in order to prove the effectiveness of the experimental modal analysis for robotic machining.

Preparation, characterization and environmental/electrochemical energy storage testing of low-cost biochar from natural chitin obtained via pyrolysis at mild conditions

NASA Astrophysics Data System (ADS)

Magnacca, Giuliana; Guerretta, Federico; Vizintin, Alen; Benzi, Paola; Valsania, Maria C.; Nisticò, Roberto

2018-01-01

Chitin (a biopolymer obtained from shellfish industry) was used as precursor for the production of biochars obtained via pyrolysis treatments performed at mild conditions (in the 290-540 °C range). Biochars were physicochemical characterized in order to evaluate the pyrolysis-induced effects in terms of both functional groups and material structure. Moreover, such carbonaceous materials were tested as adsorbent substrates for the removal of target molecules from aqueous environment as well as in solid-gas experiments, to measure the adsorption capacities and selectivity toward CO2. Lastly, biochars were also investigated as possible cathode materials in sustainable and low-cost electrochemical energy storage devices, such as lithium-sulphur (Li-S) batteries. Interestingly, experimental results evidenced that such chitin-derived biochars obtained via pyrolysis at mild conditions are sustainable, low-cost and easy scalable alternative materials suitable for both environmental and energetic applications.

System Architecture of Explorer Class Spaceborne Telescopes: A look at Optimization of Cost, Testability, Risk and Operational Duty Cycle from the Perspective of Primary Mirror Material Selection

NASA Astrophysics Data System (ADS)

Hull, Anthony B.; Westerhoff, Thomas

2015-01-01

Management of cost and risk have become the key enabling elements for compelling science to be done within Explorer or M-Class Missions. We trace how optimal primary mirror selection may be co-optimized with orbit selection. And then trace the cost and risk implications of selecting a low diffusivity low thermal expansion material for low and medium earth orbits, vs. high diffusivity high thermal expansion materials for the same orbits. We will discuss that ZERODUR®, a material that has been in space for over 30 years, is now available as highly lightweighted open-back mirrors, and the attributes of these mirrors in spaceborne optical telescope assemblies. Lightweight ZERODUR® solutions are practical from mirrors < 0.3m in diameter to >4m in diameter. An example of a 1.2m lightweight ZERODUR® mirror will be discussed.

Health workforce skill mix and task shifting in low income countries: a review of recent evidence

PubMed Central

2011-01-01

Background Health workforce needs-based shortages and skill mix imbalances are significant health workforce challenges. Task shifting, defined as delegating tasks to existing or new cadres with either less training or narrowly tailored training, is a potential strategy to address these challenges. This study uses an economics perspective to review the skill mix literature to determine its strength of the evidence, identify gaps in the evidence, and to propose a research agenda. Methods Studies primarily from low-income countries published between 2006 and September 2010 were found using Google Scholar and PubMed. Keywords included terms such as skill mix, task shifting, assistant medical officer, assistant clinical officer, assistant nurse, assistant pharmacist, and community health worker. Thirty-one studies were selected to analyze, based on the strength of evidence. Results First, the studies provide substantial evidence that task shifting is an important policy option to help alleviate workforce shortages and skill mix imbalances. For example, in Mozambique, surgically trained assistant medical officers, who were the key providers in district hospitals, produced similar patient outcomes at a significantly lower cost as compared to physician obstetricians and gynaecologists. Second, although task shifting is promising, it can present its own challenges. For example, a study analyzing task shifting in HIV/AIDS in sub-Saharan Africa noted quality and safety concerns, professional and institutional resistance, and the need to sustain motivation and performance. Third, most task shifting studies compare the results of the new cadre with the traditional cadre. Studies also need to compare the new cadre's results to the results from the care that would have been provided--if any care at all--had task shifting not occurred. Conclusions Task shifting is a promising policy option to increase the productive efficiency of the delivery of health care services, increasing the number of services provided at a given quality and cost. Future studies should examine the development of new professional cadres that evolve with technology and country-specific labour markets. To strengthen the evidence, skill mix changes need to be evaluated with a rigorous research design to estimate the effect on patient health outcomes, quality of care, and costs. PMID:21223546

A low-cost efficient and durable low-temperature solar collector

NASA Astrophysics Data System (ADS)

Odonnell, T. P.

The considered collector utilizes a material made of ethylene-propylene-diene-monomer (EPDM). This material has been used in solar systems to heat domestic water, pools, spas, and homes by radiant energy. EPDM or ethylene propylene rubber compounds are synthetic elastomers. EPDM elastomers combine superior ozone, good heat and oxygen resistance, and very good low temperature properties to produce a compound with excellent overall age resistance. The material is extruded into 4.4 inch wide mats. Each mat has six small tubes alternating with thin webbing. The absorber mat will adhere to any clean building surface with the use of thermosetting construction-grade mastic adhesive. Carbon black contained in the mat material acts to increase the solar absorptivity. Their low cost makes the elastomers commercially very attractive. The efficiency and durability of the material are discussed.

Low-Cost Educational Materials: How to Make, How to Use, How to Adapt. Inventory. Volume II.

ERIC Educational Resources Information Center

United Nations Educational, Scientific and Cultural Organization, Bangkok (Thailand). Asian Centre for Educational Innovation for Development.

This volume presents instructions for 52 low-cost and indigenous teaching materials and devices developed during a second series of national workshops held in Bangladesh, Indonesia, the Republic of Korea, Papua New Guinea, Sri Lanka, Thailand, and the Socialist Republic of Viet Nam during 1979/1980, and also during the second Sub-Regional Workshop…

MoS2: a two-dimensional hole-transporting material for high-efficiency, low-cost perovskite solar cells

NASA Astrophysics Data System (ADS)

Kohnehpoushi, Saman; Nazari, Pariya; Abdollahi Nejand, Bahram; Eskandari, Mehdi

2018-05-01

In this work MoS2 thin film was studied as a potential two-dimensional (2D) hole-transporting material for fabrication of low-cost, durable and efficient perovskite solar cells. The thickness of MoS2 was studied as a potential factor in reaching high power conversion efficiency in perovskite solar cells. The thickness of the perovskite layer and the different metal back contacts gave distinct photovoltaic properties to the designed cells. The results show that a single sheet of MoS2 could considerably improve the power conversion efficacy of the device from 10.41% for a hole transport material (HTM)-free device to 20.43% for a device prepared with a 0.67 nm thick MoS2 layer as a HTM. On the back, Ag and Al collected the carriers more efficiently than Au due to the value of their metal contact work function with the TiO2 conduction band. The present work proposes a new architecture for the fabrication of low-cost, durable and efficient perovskite solar cells made from a low-cost and robust inorganic HTM and electron transport material.

MoS2: a two-dimensional hole-transporting material for high-efficiency, low-cost perovskite solar cells.

PubMed

Kohnehpoushi, Saman; Nazari, Pariya; Nejand, Bahram Abdollahi; Eskandari, Mehdi

2018-05-18

In this work MoS 2 thin film was studied as a potential two-dimensional (2D) hole-transporting material for fabrication of low-cost, durable and efficient perovskite solar cells. The thickness of MoS 2 was studied as a potential factor in reaching high power conversion efficiency in perovskite solar cells. The thickness of the perovskite layer and the different metal back contacts gave distinct photovoltaic properties to the designed cells. The results show that a single sheet of MoS 2 could considerably improve the power conversion efficacy of the device from 10.41% for a hole transport material (HTM)-free device to 20.43% for a device prepared with a 0.67 nm thick MoS 2 layer as a HTM. On the back, Ag and Al collected the carriers more efficiently than Au due to the value of their metal contact work function with the TiO 2 conduction band. The present work proposes a new architecture for the fabrication of low-cost, durable and efficient perovskite solar cells made from a low-cost and robust inorganic HTM and electron transport material.

Recycled-tire pyrolytic carbon made functional: A high-arsenite [As(III)] uptake material PyrC350®.

PubMed

Mouzourakis, E; Georgiou, Y; Louloudi, M; Konstantinou, I; Deligiannakis, Y

2017-03-15

A novel material, PyrC 350 ® , has been developed from pyrolytic-tire char (PyrC), as an efficient low-cost Arsenite [As(III)] adsorbent from water. PyrC 350 ® achieves 31mgg -1 As(III) uptake, that remains unaltered at pH=4-8.5. A theoretical Surface Complexation Model has been developed that explains the adsorption mechanism, showing that in situ formed Fe 3 C, ZnS particles act cooperatively with the carbon matrix for As(III) adsorption. Addressing the key-issue of cost-effectiveness, we provide a comparison of As(III)-uptake effectiveness in conjunction with a cost analysis, showing that PyrC 350 ® stands in the top of [effectiveness/cost] vs. existing carbon-based, low-cost materials. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessed and Experimentally Provided Social Support.

DTIC Science & Technology

1983-10-18

concerning attachment have encouraged research into the supportive role of social relationships among both adults and children (Bowlby 1969, 1980...irrelevant material than did those low in SSQS. It may be that the task material had less motivating quality for people who feel secure in their social ... relationships . They may have allowed their minds to wander because the task appeared so easy to them. The results concerning the interaction between

Dental amalgam and mercury vapor release.

PubMed

Osborne, J W

1992-09-01

Dental diseases are among the most common ailments, and dentists in the United States spend over 50% of their time in dental practice rebuilding carious, malformed, and traumatically injured teeth. It is logical, therefore, that the majority of the dental school curriculum is devoted to the diagnosis, prevention, and treatment of teeth with anomalies. Dentists have several choices of materials they can use to accomplish the task of rebuilding teeth. Besides amalgam, they have ceramic materials, resin composites, base-metal and noble casting alloys, and glass-ionomer cements to use to restore the posterior dentition. Each of these restorative materials has advantages and disadvantages, and the clinical judgment as to when a particular material should be used is given a high priority in dental education. Amalgam is the most widely used of these restorative materials, with 92% of dentists listing it as the material of choice in the posterior of the mouth (Clinical Research Associates, 1990). Dentists have been placing amalgams for over 150 years in the US. They placed 150 million last year, which represents over 75 tons of amalgam alloy. The reasons that dentists use this restorative material so frequently are its durability, ease of manipulation, and low cost. Numerous clinical studies have been conducted on the serviceability of amalgam. Most of these have been on the old, low-copper alloys, and results indicate that they last from 8 to 15 years (Bailit et al., 1979; Osborne et al., 1980; Qvist et al., 1986). In the past 20 years, vast improvements have been made in amalgams with the development of the high-copper systems.(ABSTRACT TRUNCATED AT 250 WORDS)

Hybrid Solar Cells: Materials, Interfaces, and Devices

NASA Astrophysics Data System (ADS)

Mariani, Giacomo; Wang, Yue; Kaner, Richard B.; Huffaker, Diana L.

Photovoltaic technologies could play a pivotal role in tackling future fossil fuel energy shortages, while significantly reducing our carbon dioxide footprint. Crystalline silicon is pervasively used in single junction solar cells, taking up 80 % of the photovoltaic market. Semiconductor-based inorganic solar cells deliver relatively high conversion efficiencies at the price of high material and manufacturing costs. A great amount of research has been conducted to develop low-cost photovoltaic solutions by incorporating organic materials. Organic semiconductors are conjugated hydrocarbon-based materials that are advantageous because of their low material and processing costs and a nearly unlimited supply. Their mechanical flexibility and tunable electronic properties are among other attractions that their inorganic counterparts lack. Recently, collaborations in nanotechnology research have combined inorganic with organic semiconductors in a "hybrid" effort to provide high conversion efficiencies at low cost. Successful integration of these two classes of materials requires a profound understanding of the material properties and an exquisite control of the morphology, surface properties, ligands, and passivation techniques to ensure an optimal charge carrier generation across the hybrid device. In this chapter, we provide background information of this novel, emerging field, detailing the various approaches for obtaining inorganic nanostructures and organic polymers, introducing a multitude of methods for combining the two components to achieve the desired morphologies, and emphasizing the importance of surface manipulation. We highlight several studies that have fueled new directions for hybrid solar cell research, including approaches for maximizing efficiencies by controlling the morphologies of the inorganic component, and in situ molecular engineering via electrochemical polymerization of a polymer directly onto the inorganic nanowire surfaces. In the end, we provide some possible future directions for advancing the field, with a focus on flexible, lightweight, semitransparent, and low-cost photovoltaics.

Nurse extenders offer a way to trim staff expenses.

PubMed

Eastaugh, S R; Regan-Donovan, M

1990-04-01

Troubles confronting hospital nursing--from a national shortage of nurses to low morale, high turnover, and rising costs of replacing and retaining staff members--require creative approaches and a rethinking of traditional primary care nursing. Nurse extender programs place non-nursing tasks in the hands of technicians trained to deliver meals, transport patients, take vital signs, and perform other patient care tasks.

A Job Aid Solution to the Need for Low Cost, Results Oriented Dental Laboratory Manufacturing Industry Training.

ERIC Educational Resources Information Center

Selg, Timothy E.

A thesis project was conducted to design, develop, implement, and evaluate a job aid used by shipping department employees in a dental laboratory. The job aid was developed in preference to training to solve the organization's performance problem. Task analysis was performed to identify the shipping clerks' duties. These tasks were stated in the…

Nursery Task Force update

Treesearch

Russ Pohl

2007-01-01

The Nursery Task Force was set up at the behest of the Southern Group of State Foresters in the late winter/spring of 2005. Its mission was to assess the condition of state nurseries across the South and to make recommendations to improve their viability. At the time, tree planting cost-share money was diminished; pulpwood prices were low; much of the Southeast had...

Microstructural Properties of Cement Paste and Mortar Modified by Low Cost Nanoplatelets Sourced from Natural Materials.

PubMed

Huang, Piao; Lv, Liming; Liao, Wei; Lu, Chunhua; Xu, Zhongzi

2018-05-11

Nanomaterials have been widely used in cement-based materials. Graphene has excellent properties for improving the durability of cement-based materials. Given its high production budget, it has limited its wide potential for application in the field of engineering. Hence, it is very meaningful to obtain low cost nanoplatelets from natural materials that can replace graphene nanoplatelets (GNPs) The purpose of this paper is to improve the resistance to chloride ion penetration by optimizing the pore structure of cement-based materials, and another point is to reduce investment costs. The results illustrated that low cost CaCO₃ nanoplatelets (CCNPs) were successfully obtained under alkali treatment of seashell powder, and the chloride ion permeability of cement-based materials significantly decreased by 15.7% compared to that of the control samples when CCNPs were incorporated. Furthermore, the compressive strength of cement pastes at the age of 28 days increased by 37.9% than that of the plain sample. Improvement of performance of cement-based materials can be partly attributed to the refinement of the pore structure. In addition, AFM was employed to characterize the nanoplatelet thickness of CCNPs and the pore structures of the cement-based composites were analyzed by MIP, respectively. CCNPs composite cement best performance could lay the foundation for further study of the durability of cement-based materials and the application of decontaminated seashells.

Microstructural Properties of Cement Paste and Mortar Modified by Low Cost Nanoplatelets Sourced from Natural Materials

PubMed Central

Lv, Liming; Liao, Wei; Lu, Chunhua; Xu, Zhongzi

2018-01-01

Nanomaterials have been widely used in cement-based materials. Graphene has excellent properties for improving the durability of cement-based materials. Given its high production budget, it has limited its wide potential for application in the field of engineering. Hence, it is very meaningful to obtain low cost nanoplatelets from natural materials that can replace graphene nanoplatelets (GNPs) The purpose of this paper is to improve the resistance to chloride ion penetration by optimizing the pore structure of cement-based materials, and another point is to reduce investment costs. The results illustrated that low cost CaCO3 nanoplatelets (CCNPs) were successfully obtained under alkali treatment of seashell powder, and the chloride ion permeability of cement-based materials significantly decreased by 15.7% compared to that of the control samples when CCNPs were incorporated. Furthermore, the compressive strength of cement pastes at the age of 28 days increased by 37.9% than that of the plain sample. Improvement of performance of cement-based materials can be partly attributed to the refinement of the pore structure. In addition, AFM was employed to characterize the nanoplatelet thickness of CCNPs and the pore structures of the cement-based composites were analyzed by MIP, respectively. CCNPs composite cement best performance could lay the foundation for further study of the durability of cement-based materials and the application of decontaminated seashells. PMID:29751666

Comparative evaluation of low cost materials as constructed wetland filling media

NASA Astrophysics Data System (ADS)

Pinho, Henrique J. O.; Vaz, Mafalda M.; Mateus, Dina M. R.

2017-11-01

Three waste materials from civil construction activities were assessed as low cost alternative filling materials used in Constructed Wetlands (CW). CW are green processes for wastewater treatment, whose design includes an appropriate selection of vegetation and filling material. The sustainability of such processes may be incremented using recovered wastes as filling materials. The abilities of the materials to support plant growth and to contribute to pollutants removal from wastewater were assessed and compared to expanded clay, a filling usually used in CW design. Statistical analysis, using one-way ANOVA and Welch's ANOVA, demonstrate that limestone fragments are a better choice of filling material than brick fragments and basalt gravel.

Life and stability testing of packaged low-cost energy storage materials

NASA Astrophysics Data System (ADS)

Frysinger, G. R.

1980-07-01

A low-cost laminated plastic film which is used to contain a Glauber's salt-based phase change thermal energy storage material in sausage like containers called Chubs was developed. Results of tests performed on the Chub packages themselves and on the thermal energy storage capacity of the packaged phase change material are described. From the test results, a set of specifications was drawn up for a film material which will satisfactorily contain the phase change material under anticipated operating conditions. Calorimetric testing of the phase change material with thermal cycling indicates that a design capacity of 45 to 50 Btu/lb for a delta T of 30 F can be used for the packaged material.

Distributed computing feasibility in a non-dedicated homogeneous distributed system

NASA Technical Reports Server (NTRS)

Leutenegger, Scott T.; Sun, Xian-He

1993-01-01

The low cost and availability of clusters of workstations have lead researchers to re-explore distributed computing using independent workstations. This approach may provide better cost/performance than tightly coupled multiprocessors. In practice, this approach often utilizes wasted cycles to run parallel jobs. The feasibility of such a non-dedicated parallel processing environment assuming workstation processes have preemptive priority over parallel tasks is addressed. An analytical model is developed to predict parallel job response times. Our model provides insight into how significantly workstation owner interference degrades parallel program performance. A new term task ratio, which relates the parallel task demand to the mean service demand of nonparallel workstation processes, is introduced. It was proposed that task ratio is a useful metric for determining how large the demand of a parallel applications must be in order to make efficient use of a non-dedicated distributed system.

Low-cost exterior insulation process and structure

DOEpatents

Vohra, A.

1999-03-02

A low-cost exterior insulation process of stacking bags of insulating material against a wall and covering them with wire mesh and stucco provides a durable structure with good insulating value. 2 figs.

Array Automated Assembly Task Low Cost Silicon Solar Array Project, Phase 2

NASA Technical Reports Server (NTRS)

Rhee, S. S.; Jones, G. T.; Allison, K. L.

1978-01-01

Progress in the development of solar cells and module process steps for low-cost solar arrays is reported. Specific topics covered include: (1) a system to automatically measure solar cell electrical performance parameters; (2) automation of wafer surface preparation, printing, and plating; (3) laser inspection of mechanical defects of solar cells; and (4) a silicon antireflection coating system. Two solar cell process steps, laser trimming and holing automation and spray-on dopant junction formation, are described.

Automated Array Assembly Task In-depth Study of Silicon Wafer Surface Texturizing

NASA Technical Reports Server (NTRS)

Jones, G. T.; Chitre, S.; Rhee, S. S.; Allison, K. L.

1979-01-01

A low cost wafer surface texturizing process was studied. An investigation of low cost cleaning operations to clean residual wax and organics from the surface of silicon wafers was made. The feasibility of replacing dry nitrogen with clean dry air for drying silicon wafers was examined. The two stage texturizing process was studied for the purpose of characterizing relevant parameters in large volume applications. The effect of gettering solar cells on photovoltaic energy conversion efficiency is described.

A low cost method for hard x-ray grating interferometry.

PubMed

Du, Yang; Lei, Yaohu; Liu, Xin; Huang, Jianheng; Zhao, Zhigang; Guo, Jinchuan; Li, Ji; Niu, Hanben

2016-12-07

Grating interferometry is advantageous over conventional x-ray absorption imaging because it enables the detection of samples constituted by low atomic number elements (low-Z materials). Therefore, it has a potential application in biological science and medical diagnostics. The grating interferometry has some critical optics components such as absorption gratings which are conventionally manufactured by the lithography, electroplating, and molding (LIGA) technique and employing gold as the absorbent material in it. However, great challenge lies in its implementations for practical applications because of the cost and difficulty to achieve high aspect ratio absorbing grating devices. In this paper, we present a low-cost approach that involves using the micro-casting technique with bismuth (Bi) as the absorber in source grating and as well as filling cesium iodide thallium(CsI:Tl) in a periodically structured scintillator. No costly facilities as synchrotron radiation are required and cheap material is used in our approach. Our experiment using these components shows high quality complementary images can be obtained with contrast of absorption, phase and visibility. This alternative method conquers the limitation of costly grating devices for a long time and stands an important step towards the further practical application of grating interferometry.

Design Of Robots For Outer Space

NASA Technical Reports Server (NTRS)

Roston, Gerald P.

1990-01-01

Report discusses design of robots for use in zero gravity and vacuum, with attention to differences between requirements imposed on designs by outer space and by terrestrial applications. Terrestrial robots designed for multiple purposes and for minimal cost. Outer-space robots designed specialized to one task where cost has relatively low priority. Design optimal in one environment unlikely optimal in another.

Cotton yield estimation using very high-resolution digital images acquired on a low-cost small unmanned aerial vehicle

USDA-ARS?s Scientific Manuscript database

Yield estimation is a critical task in crop management. A number of traditional methods are available for crop yield estimation but they are costly, time-consuming and difficult to expand to a relatively large field. Remote sensing provides techniques to develop quick coverage over a field at any sc...

Pay Nothing? Easier Said than Done

ERIC Educational Resources Information Center

Azevedo, Alisha

2013-01-01

Providing college students with free textbooks is no easy task. That seems to be the major lesson from several efforts to produce e-books that are low-cost or free to help reduce students' costs. Money pressures, slow adoption by professors, and quality concerns stand in the way as these projects hope to rival traditional publishing. Take Flat…

State-of-the-Art Review of Low-Cost Collector Technologies

DTIC Science & Technology

1981-06-01

Mobility Low-Cost Parabolic Trough Survivability Light-Weight Thin-Film Reliability Heliostats Polymers Military 20. ABSTRACT (Contine an revers. deo It... heliostats and parabolic dish collectors. In addition several criteria were evaluated with respect to low-cost collector technologies These included...has produced collectors which incorporate sophisticated materials, = Heliostat heavy components, expensive seals and compli- o- (Point Focus) cated

CubeSat mechanical design: creating low mass and durable structures

NASA Astrophysics Data System (ADS)

Fiedler, Gilbert; Straub, Jeremy

2017-05-01

This paper considers the mechanical design of a low-mass, low-cost spacecraft for use in a multi-satellite sensing constellation. For a multi-spacecraft mission, aggregated small mass and cost reductions can have significant impact. One approach to mass reduction is to make cuts into the structure, removing material. Stress analysis is used to determine the level of material reduction possible. Focus areas for this paper include determining areas to make cuts to ensure that a strong shape remains, while considering the comparative cost and skill level of each type of cut. Real-world results for a CubeSat and universally applicable analysis are presented.

Ultra High p-doping Material Research for GaN Based Light Emitters

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

Vladimir Dmitriev

2007-06-30

The main goal of the Project is to investigate doping mechanisms in p-type GaN and AlGaN and controllably fabricate ultra high doped p-GaN materials and epitaxial structures. Highly doped p-type GaN-based materials with low electrical resistivity and abrupt doping profiles are of great importance for efficient light emitters for solid state lighting (SSL) applications. Cost-effective hydride vapor phase epitaxial (HVPE) technology was proposed to investigate and develop p-GaN materials for SSL. High p-type doping is required to improve (i) carrier injection efficiency in light emitting p-n junctions that will result in increasing of light emitting efficiency, (ii) current spreading inmore » light emitting structures that will improve external quantum efficiency, and (iii) parameters of Ohmic contacts to reduce operating voltage and tolerate higher forward currents needed for the high output power operation of light emitters. Highly doped p-type GaN layers and AlGaN/GaN heterostructures with low electrical resistivity will lead to novel device and contact metallization designs for high-power high efficiency GaN-based light emitters. Overall, highly doped p-GaN is a key element to develop light emitting devices for the DOE SSL program. The project was focused on material research for highly doped p-type GaN materials and device structures for applications in high performance light emitters for general illumination P-GaN and p-AlGaN layers and multi-layer structures were grown by HVPE and investigated in terms of surface morphology and structure, doping concentrations and profiles, optical, electrical, and structural properties. Tasks of the project were successfully accomplished. Highly doped GaN materials with p-type conductivity were fabricated. As-grown GaN layers had concentration N{sub a}-N{sub d} as high as 3 x 10{sup 19} cm{sup -3}. Mechanisms of doping were investigated and results of material studies were reported at several International conferences providing better understanding of p-type GaN formation for Solid State Lighting community. Grown p-type GaN layers were used as substrates for blue and green InGaN-based LEDs made by HVPE technology at TDI. These results proved proposed technical approach and facilitate fabrication of highly conductive p-GaN materials by low-cost HVPE technology for solid state lighting applications. TDI has started the commercialization of p-GaN epitaxial materials.« less

Low-weight, low-cost, low-cycle time, replicated glass mirrors

NASA Astrophysics Data System (ADS)

Egerman, Robert; De Smitt, Steven; Strafford, David

2010-07-01

ITT has patented and continues to develop processes to fabricate low-cost borosilicate mirrors that can be used for both ground and space-based optical telescopes. Borosilicate glass is a commodity and is the material of choice for today's flat-panel televisions and monitors. Supply and demand has kept its cost low compared to mirror substrate materials typically found in telescopes. The current technology development is on the path to having the ability to deliver imaging quality optics of up to 1m (scalable to 2m) in diameter in three weeks. For those applications that can accommodate the material properties of borosilicate glasses, this technology has the potential to revolutionize ground and space-based astronomy. ITT Corporation has demonstrated finishing a planar, 0.6m borosilicate, optic to <100 nm-rms. This paper will provide an historical overview of the development in this area with an emphasis on recent technology developments to fabricate a 0.6m parabolic mirror under NASA Earth Science Technology Office (ESTO) grant #NNX09AD61G.

Federal Information Resources for Professional Counselors. A Sourcebook of Free and Low-Cost Resources To Support and Enrich Your Work as a Professional Counselor.

ERIC Educational Resources Information Center

Lum, Christie

This publication is a sourcebook of free and low-cost resources to support the work of professional counselors. The information includes: (1) synthesis of current research, statistics, and research reports; (2) background material about current and emerging policy issues; (3) information about model programs and policies; (4) materials and…

Neural Mechanisms Underlying the Cost of Task Switching: An ERP Study

PubMed Central

Li, Ling; Wang, Meng; Zhao, Qian-Jing; Fogelson, Noa

2012-01-01

Background When switching from one task to a new one, reaction times are prolonged. This phenomenon is called switch cost (SC). Researchers have recently used several kinds of task-switching paradigms to uncover neural mechanisms underlying the SC. Task-set reconfiguration and passive dissipation of a previously relevant task-set have been reported to contribute to the cost of task switching. Methodology/Principal Findings An unpredictable cued task-switching paradigm was used, during which subjects were instructed to switch between a color and an orientation discrimination task. Electroencephalography (EEG) and behavioral measures were recorded in 14 subjects. Response-stimulus interval (RSI) and cue-stimulus interval (CSI) were manipulated with short and long intervals, respectively. Switch trials delayed reaction times (RTs) and increased error rates compared with repeat trials. The SC of RTs was smaller in the long CSI condition. For cue-locked waveforms, switch trials generated a larger parietal positive event-related potential (ERP), and a larger slow parietal positivity compared with repeat trials in the short and long CSI condition. Neural SC of cue-related ERP positivity was smaller in the long RSI condition. For stimulus-locked waveforms, a larger switch-related central negative ERP component was observed, and the neural SC of the ERP negativity was smaller in the long CSI. Results of standardized low resolution electromagnetic tomography (sLORETA) for both ERP positivity and negativity showed that switch trials evoked larger activation than repeat trials in dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC). Conclusions/Significance The results provide evidence that both RSI and CSI modulate the neural activities in the process of task-switching, but that these have a differential role during task-set reconfiguration and passive dissipation of a previously relevant task-set. PMID:22860090

Wireless Sensor Network for Electric Transmission Line Monitoring

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

Alphenaar, Bruce

Generally, federal agencies tasked to oversee power grid reliability are dependent on data from grid infrastructure owners and operators in order to obtain a basic level of situational awareness. Since there are many owners and operators involved in the day-to-day functioning of the power grid, the task of accessing, aggregating and analyzing grid information from these sources is not a trivial one. Seemingly basic tasks such as synchronizing data timestamps between many different data providers and sources can be difficult as evidenced during the post-event analysis of the August 2003 blackout. In this project we investigate the efficacy and costmore » effectiveness of deploying a network of wireless power line monitoring devices as a method of independently monitoring key parts of the power grid as a complement to the data which is currently available to federal agencies from grid system operators. Such a network is modeled on proprietary power line monitoring technologies and networks invented, developed and deployed by Genscape, a Louisville, Kentucky based real-time energy information provider. Genscape measures transmission line power flow using measurements of electromagnetic fields under overhead high voltage transmission power lines in the United States and Europe. Opportunities for optimization of the commercial power line monitoring technology were investigated in this project to enable lower power consumption, lower cost and improvements to measurement methodologies. These optimizations were performed in order to better enable the use of wireless transmission line monitors in large network deployments (perhaps covering several thousand power lines) for federal situational awareness needs. Power consumption and cost reduction were addressed by developing a power line monitor using a low power, low cost wireless telemetry platform known as the ''Mote''. Motes were first developed as smart sensor nodes in wireless mesh networking applications. On such a platform, it has been demonstrated in this project that wireless monitoring units can effectively deliver real-time transmission line power flow information for less than $500 per monitor. The data delivered by such a monitor has during the course of the project been integrated with a national grid situational awareness visualization platform developed by Oak Ridge National Laboratory. Novel vibration energy scavenging methods based on piezoelectric cantilevers were also developed as a proposed method to power such monitors, with a goal of further cost reduction and large-scale deployment. Scavenging methods developed during the project resulted in 50% greater power output than conventional cantilever-based vibrational energy scavenging devices typically used to power smart sensor nodes. Lastly, enhanced and new methods for electromagnetic field sensing using multi-axis magnetometers and infrared reflectometry were investigated for potential monitoring applications in situations with a high density of power lines or high levels of background 60 Hz noise in order to isolate power lines of interest from other power lines in close proximity. The goal of this project was to investigate and demonstrate the feasibility of using small form factor, highly optimized, low cost, low power, non-contact, wireless electric transmission line monitors for delivery of real-time, independent power line monitoring for the US power grid. The project was divided into three main types of activity as follows; (1) Research into expanding the range of applications for non-contact power line monitoring to enable large scale low cost sensor network deployments (Tasks 1, 2); (2) Optimization of individual sensor hardware components to reduce size, cost and power consumption and testing in a pilot field study (Tasks 3,5); and (3) Demonstration of the feasibility of using the data from the network of power line monitors via a range of custom developed alerting and data visualization applications to deliver real-time information to federal agencies and others tasked with grid reliability (Tasks 6,8).« less

Task shifting for non-communicable disease management in low and middle income countries--a systematic review.

PubMed

Joshi, Rohina; Alim, Mohammed; Kengne, Andre Pascal; Jan, Stephen; Maulik, Pallab K; Peiris, David; Patel, Anushka A

2014-01-01

One potential solution to limited healthcare access in low and middle income countries (LMIC) is task-shifting- the training of non-physician healthcare workers (NPHWs) to perform tasks traditionally undertaken by physicians. The aim of this paper is to conduct a systematic review of studies involving task-shifting for the management of non-communicable disease (NCD) in LMIC. A search strategy with the following terms "task-shifting", "non-physician healthcare workers", "community healthcare worker", "hypertension", "diabetes", "cardiovascular disease", "mental health", "depression", "chronic obstructive pulmonary disease", "respiratory disease", "cancer" was conducted using Medline via Pubmed and the Cochrane library. Two reviewers independently reviewed the databases and extracted the data. Our search generated 7176 articles of which 22 were included in the review. Seven studies were randomised controlled trials and 15 were observational studies. Tasks performed by NPHWs included screening for NCDs and providing primary health care. The majority of studies showed improved health outcomes when compared with usual healthcare, including reductions in blood pressure, increased uptake of medications and lower depression scores. Factors such as training of NPHWs, provision of algorithms and protocols for screening, treatment and drug titration were the main enablers of the task-shifting intervention. The main barriers identified were restrictions on prescribing medications and availability of medicines. Only two studies described cost-effective analyses, both of which demonstrated that task-shifting was cost-effective. Task-shifting from physicians to NPHWs, if accompanied by health system re-structuring is a potentially effective and affordable strategy for improving access to healthcare for NCDs. Since the majority of study designs reviewed were of inadequate quality, future research methods should include robust evaluations of such strategies.

A training phantom for ultrasound-guided needle insertion and suturing.

PubMed

Nattagh, Khashayar; Siauw, Timmy; Pouliot, Jean; Hsu, I-Chow; Cunha, J Adam

2014-01-01

During gynecologic brachytherapy (BT), suturing and image-guided needle insertions are highly skill-dependent tasks. Medical residents often have to practice these techniques in the operating room; this is sub-optimal for many reasons. We present a fast and low-cost method of building realistic and disposable gynecologic phantoms, which can be used to train physicians new to gynecologic BT. Phantoms comprised a rectal cavity large enough to accommodate a standard transrectal ultrasound (US) probe, a vaginal cavity, a uterus, a uterine canal, and a cervix, all embedded in a gelatin matrix. The uterus was made of gelatin and coated with rubber to mimic the texture of soft tissue and for computed tomography (CT) and US image contrast. The phantom's durability, longevity, construction times, materials costs, CT, and US image quality were recorded. The speed of sound in the gelatin was measured using pulse echo measurements. Anatomic structures were distinguishable using CT and US. For the first phantom, material costs were under $200, curing time was approximately 48 hours, and active participation time was 3 hours. Reusable parts allowed for reduction in time and cost for subsequent phantoms: under $20, 24 hours curing time, and 1 hour active participation time. The speed of sound in the gelatin ranged from 1495 to 1506 m/s. A method for constructing gelatin gynecologic phantoms was developed. It can be used for training in image-guided BT needle insertion, placing a suture on the vaginal wall, and suturing the cervical lip. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Test Plans. Lightweight Durable TPS: Tasks 1,2,4,5, and 6

NASA Technical Reports Server (NTRS)

Greenberg, H. S.; Tu, Tina

1994-01-01

The objective of this task is to develop the fluted core flexible blankets, also referred to as the Tailorable Advanced Blanket Insulation (TABI), to a technology readiness level (TRL) of 6. This task is one of the six tasks under TA 3, Lightweight Durable TPS study, of the Single Stage to Orbit (SSTO) program. The purpose of this task is to develop a durable and low maintenance flexible TPS blanket material to be implemented on the SSTO vehicle.

Evaluation of low-cost commercial-off-the-shelf autopilot systems for SUAS operations

NASA Astrophysics Data System (ADS)

Brown, Calvin Thomas

With this increase in unmanned aircraft system (UAS) operations, there is a need for a structured process to evaluate different commercially available systems, particularly autopilots. The Remotely Operated Aircraft Management, Interpretation, and Navigation from Ground or ROAMING scale was developed to meet this need. This scale is a modification of the widely accepted Handling Qualities Rating scale developed by George Cooper and Robert Harper Jr. The Cooper-Harper scale allows pilots to rate a vehicle's performance in completing some task. Similarly, the ROAMING scale allows UAS operators to evaluate the management and observability of UAS in completing some task. The standardized evaluative process consists of cost, size, weight, and power (SWAP) analysis, ease of implementation through procedural description of setup, ROAMING scale rating, a slightly modified NASA TLX rating, and comparison of manual operation to autonomous operation of the task. This standard for evaluation of autopilots and their software will lead to better understanding of the workload placed on UAS operators and indicate where improvements to design and operational procedures can be made. An assortment of low-cost commercial-off-the-shelf (COTS) autopilots were selected for use in the development of the evaluation and results of these tests demonstrate the commonalities and differences in these systems.

Increasing patient engagement in rehabilitation exercises using computer-based citizen science.

PubMed

Laut, Jeffrey; Cappa, Francesco; Nov, Oded; Porfiri, Maurizio

2015-01-01

Patient motivation is an important factor to consider when developing rehabilitation programs. Here, we explore the effectiveness of active participation in web-based citizen science activities as a means of increasing participant engagement in rehabilitation exercises, through the use of a low-cost haptic joystick interfaced with a laptop computer. Using the joystick, patients navigate a virtual environment representing the site of a citizen science project situated in a polluted canal. Participants are tasked with following a path on a laptop screen representing the canal. The experiment consists of two conditions: in one condition, a citizen science component where participants classify images from the canal is included; and in the other, the citizen science component is absent. Both conditions are tested on a group of young patients undergoing rehabilitation treatments and a group of healthy subjects. A survey administered at the end of both tasks reveals that participants prefer performing the scientific task, and are more likely to choose to repeat it, even at the cost of increasing the time of their rehabilitation exercise. Furthermore, performance indices based on data collected from the joystick indicate significant differences in the trajectories created by patients and healthy subjects, suggesting that the low-cost device can be used in a rehabilitation setting for gauging patient recovery.

The influence of cue-task association and location on switch cost and alternating-switch cost.

PubMed

Arbuthnott, Katherine D; Woodward, Todd S

2002-03-01

Task-switching performance is strongly influenced by whether the imperative stimulus uniquely specifies which task to perform: Switch cost is substantial with bivalent stimuli but is greatly reduced with univalent stimuli, suggesting that available contextual information influences processing in task-switching situations. The present study examined whether task-relevant information provided by task cues influences the magnitude of switch cost in a parallel manner. Cues presented 500 ms prior to a trivalent stimulus indicated which of three tasks to perform. These cues either had a preexisting association with the to-be-performed task (verbal cues), or a recently learned association with the task (spatial and shape cues). The results paralleled the effects of stimulus bivalence: substantial switch cost with recently learned cue-task associations and greatly reduced switch cost with preexisting cue-task associations. This suggests that both stimulus-based and cue-based information can activate the relevant task set, possibly providing external support to endogenous control processes. Alternating-switch cost, a greater cost for switching back to a recently abandoned task, was also observed with both preexisting and recently learned cue-task associations, but only when all tasks were presented in a consistent spatial location. When spatial location was used to cue the to-be-performed tasks, no alternating-switch cost was observed, suggesting that different processes may be involved when tasks are uniquely located in space. Specification of the nature of these processes may prove to be complex, as post-hoc inspection of the data suggested that for the spatial cue condition, the alternating-switch cost may oscillate between cost and benefit, depending on the relevant task.

Proceedings of the Low-Cost Solar Array Wafering Workshop

NASA Technical Reports Server (NTRS)

Morrison, A. D.

1982-01-01

The technology and economics of silicon ingot wafering for low cost solar arrays were discussed. Fixed and free abrasive sawing wire, ID, and multiblade sawing, materials, mechanisms, characterization, and innovative concepts were considered.

Effects of anxiety on task switching: evidence from the mixed antisaccade task.

PubMed

Ansari, Tahereh L; Derakshan, Nazanin; Richards, Anne

2008-09-01

According to the attentional control theory of anxiety (Eysenck, Derakshan, Santos, & Calvo, 2007), anxiety impairs performance on cognitive tasks that involve the shifting function of working memory. This hypothesis was tested using a mixed antisaccade paradigm, in which participants performed single-task and mixed-task versions of the paradigm. The single task involved the completion of separate blocks of anti- and prosaccade trials, whereas in the mixed task, participants completed anti- and prosaccade trials in a random order within blocks. Analysis of switch costs showed that high-anxious individuals did not exhibit the commonly reported paradoxical improvement in saccade latency, whereas low-anxious individuals did. The findings are discussed within the framework of attentional control theory.

Atomic Oxygen Task

NASA Technical Reports Server (NTRS)

Hadaway, James B.

1997-01-01

This report details work performed by the Center for Applied Optics (CAO) at the University of Alabama in Huntsville (UAH) on the contract entitled 'Atomic Oxygen Task' for NASA's Marshall Space Flight Center (contract NAS8-38609, Delivery Order 109, modification number 1). Atomic oxygen effects on exposed materials remain a critical concern in designing spacecraft to withstand exposure in the Low Earth Orbit (LEO) environment. The basic objective of atomic oxygen research in NASA's Materials & Processes (M&P) Laboratory is to provide the solutions to material problems facing present and future space missions. The objective of this work was to provide the necessary research for the design of specialized experimental test configurations and development of techniques for evaluating in-situ space environmental effects, including the effects of atomic oxygen and electromagnetic radiation on candidate materials. Specific tasks were performed to address materials issues concerning accelerated environmental testing as well as specifically addressing materials issues of particular concern for LDEF analysis and Space Station materials selection.

Method for materials deposition by ablation transfer processing

DOEpatents

Weiner, Kurt H.

1996-01-01

A method in which a thin layer of semiconducting, insulating, or metallic material is transferred by ablation from a source substrate, coated uniformly with a thin layer of said material, to a target substrate, where said material is desired, with a pulsed, high intensity, patternable beam of energy. The use of a patternable beam allows area-selective ablation from the source substrate resulting in additive deposition of the material onto the target substrate which may require a very low percentage of the area to be covered. Since material is placed only where it is required, material waste can be minimized by reusing the source substrate for depositions on multiple target substrates. Due to the use of a pulsed, high intensity energy source the target substrate remains at low temperature during the process, and thus low-temperature, low cost transparent glass or plastic can be used as the target substrate. The method can be carried out atmospheric pressures and at room temperatures, thus eliminating vacuum systems normally required in materials deposition processes. This invention has particular application in the flat panel display industry, as well as minimizing materials waste and associated costs.

Metal-free supercapacitor with aqueous electrolyte and low-cost carbon materials

NASA Astrophysics Data System (ADS)

Blomquist, Nicklas; Wells, Thomas; Andres, Britta; Bäckström, Joakim; Forsberg, Sven; Olin, Håkan

2017-01-01

Electric double-layer capacitors (EDLCs) or supercapacitors (SCs) are fast energy storage devices with high pulse efficiency and superior cyclability, which makes them useful in various applications including electronics, vehicles and grids. Aqueous SCs are considered to be more environmentally friendly than those based on organic electrolytes. Because of the corrosive nature of the aqueous environment, however, expensive electrochemically stable materials are needed for the current collectors and electrodes in aqueous SCs. This results in high costs for a given energy-storage capacity. To address this, we developed a novel low-cost aqueous SC using graphite foil as the current collector and a mix of graphene, nanographite, simple water-purification carbons and nanocellulose as electrodes. The electrodes were coated directly onto the graphite foil by using casting frames and the SCs were assembled in a pouch cell design. With this approach, we achieved a material cost reduction of greater than 90% while maintaining approximately one-half of the specific capacitance of a commercial unit, thus demonstrating that the proposed SC can be an environmentally friendly, low-cost alternative to conventional SCs.

[Improvement in the efficiency of a rehabilitation service using Lean Healthcare methodology].

PubMed

Pineda Dávila, S; Tinoco González, J

2015-01-01

The aim of this study was to evaluate the reduction in costs and the increase in time devoted to the patient, by applying Lean Healthcare methodology. A multidisciplinary team was formed, setting up three potential areas for improvement by performing a diagnostic process, including the storage and standardization of materials, and professional tasks in the therapeutic areas, by implementing three Lean tools: kanban, 5S and 2P. Stored material costs decreased by 43%, the cost of consumables per patient treated by 19%, and time dedicated to patient treatment increased by 7%. The processes were standardized and "muda" (wastefulness) was eliminated, thus reducing costs and increasing the value to the patient. All this demonstrates that it is possible to apply tools of industrial origin to the health sector, with the aim of improving the quality of care and achieve maximum efficiency. Copyright © 2014 SECA. Published by Elsevier Espana. All rights reserved.

Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

NASA Astrophysics Data System (ADS)

Potyrailo, Radislav; Naik, Rajesh R.

2013-07-01

At present, monitoring of air at the workplace, in urban environments, and on battlefields; exhaled air from medical patients; air in packaged food containers; and so forth can be accomplished with different types of analytical instruments. Vapor sensors have their niche in these measurements when an unobtrusive, low-power, and cost-sensitive technical solution is required. Unfortunately, existing vapor sensors often degrade their vapor-quantitation accuracy in the presence of high levels of interferences and cannot quantitate several components in complex gas mixtures. Thus, new sensing approaches with improved sensor selectivity are required. This technological task can be accomplished by the careful design of sensing materials with new performance properties and by coupling these materials with the suitable physical transducers. This review is focused on the assessment of the capabilities of bionanomaterials and bioinspired nanostructures for selective vapor sensing. We demonstrate that these sensing materials can operate with diverse transducers based on electrical, mechanical, and optical readout principles and can provide vapor-response selectivity previously unattainable by using other sensing materials. This ability for selective vapor sensing provides opportunities to significantly impact the major directions in development and application scenarios of vapor sensors.

Low-Cost Composite Materials and Structures for Aircraft Applications

NASA Technical Reports Server (NTRS)

Deo, Ravi B.; Starnes, James H., Jr.; Holzwarth, Richard C.

2003-01-01

A survey of current applications of composite materials and structures in military, transport and General Aviation aircraft is presented to assess the maturity of composites technology, and the payoffs realized. The results of the survey show that performance requirements and the potential to reduce life cycle costs for military aircraft and direct operating costs for transport aircraft are the main reasons for the selection of composite materials for current aircraft applications. Initial acquisition costs of composite airframe components are affected by high material costs and complex certification tests which appear to discourage the widespread use of composite materials for aircraft applications. Material suppliers have performed very well to date in developing resin matrix and fiber systems for improved mechanical, durability and damage tolerance performance. The next challenge for material suppliers is to reduce material costs and to develop materials that are suitable for simplified and inexpensive manufacturing processes. The focus of airframe manufacturers should be on the development of structural designs that reduce assembly costs by the use of large-scale integration of airframe components with unitized structures and manufacturing processes that minimize excessive manual labor.

A noble metal-free proton-exchange membrane fuel cell based on bio-inspired molecular catalysts† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c4sc03774j Click here for additional data file.

PubMed Central

Tran, P. D.; Morozan, A.; Archambault, S.; Heidkamp, J.; Chenevier, P.; Dau, H.; Fontecave, M.

2015-01-01

Hydrogen is a promising energy vector for storing renewable energies: obtained from water-splitting, in electrolysers or photoelectrochemical cells, it can be turned back to electricity on demand in fuel cells (FCs). Proton exchange membrane (PEM) devices with low internal resistance, high compactness and stability are an attractive technology optimized over decades, affording fast start-up times and low operating temperatures. However, they rely on the powerful catalytic properties of noble metals such as platinum, while lower cost, more abundant materials would be needed for economic viability. Replacing these noble metals at both electrodes has long proven to be a difficult task, so far incompatible with PEM technologies. Here we take advantage of newly developed bio-inspired molecular H2 oxidation catalysts and noble metal-free O2-reducing materials, to fabricate a noble metal-free PEMFC, with an 0.74 V open circuit voltage and a 23 μW cm–2 output power under technologically relevant conditions. X-ray absorption spectroscopy measurements confirm that the catalysts are stable and retain their structure during turnover. PMID:29142673

All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications.

PubMed

Tucker, Michael C; Phillips, Adam; Weber, Adam Z

2015-12-07

An all-iron redox flow battery is proposed and developed for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. The design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe2 (SO4 )3 active material and 1.2 m NaCl supporting electrolyte. With these materials, an average power density around 20 mW cm(-2) and a maximum energy density of 11.5 Wh L(-1) are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh(-1) , or only US$0.034 per mobile phone charge. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications

DOE PAGES

Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.

2015-11-20

We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less

Design of sensor node platform for wireless biomedical sensor networks.

PubMed

Xijun, Chen; -H Meng, Max; Hongliang, Ren

2005-01-01

Design of low-cost, miniature, lightweight, ultra low-power, flexible sensor platform capable of customization and seamless integration into a wireless biomedical sensor network(WBSN) for health monitoring applications presents one of the most challenging tasks. In this paper, we propose a WBSN node platform featuring an ultra low-power microcontroller, an IEEE 802.15.4 compatible transceiver, and a flexible expansion connector. The proposed solution promises a cost-effective, flexible platform that allows easy customization, energy-efficient computation and communication. The development of a common platform for multiple physical sensors will increase reuse and alleviate costs of transition to a new generation of sensors. As a case study, we present an implementation of an ECG (Electrocardiogram) sensor.

A Graphical User Interface for the Low Cost Combat Direction System

DTIC Science & Technology

1991-09-16

the same tasks. These shipboard tasks, which include contact management , moving geometry calculations, intelligence compila- tion, area plotting and...Display Defaults Analysis This category covers a wide range of required data input and system configuration issues. To keep the screen display manageable ...parts or dialog boxes. The implementation of an Ada application using STARS is quite straightforward, although knowlede of X Protocol primitives is

Learning in Neural Networks: VLSI Implementation Strategies

NASA Technical Reports Server (NTRS)

Duong, Tuan Anh

1995-01-01

Fully-parallel hardware neural network implementations may be applied to high-speed recognition, classification, and mapping tasks in areas such as vision, or can be used as low-cost self-contained units for tasks such as error detection in mechanical systems (e.g. autos). Learning is required not only to satisfy application requirements, but also to overcome hardware-imposed limitations such as reduced dynamic range of connections.

Expansion-matched passively cooled heatsinks with low thermal resistance for high-power diode laser bars

NASA Astrophysics Data System (ADS)

Leers, Michael; Scholz, Christian; Boucke, Konstantin; Poprawe, Reinhart

2006-02-01

The lifetime of high-power diode lasers, which are cooled by standard copper heatsinks, is limited. The reasons are the aging of the indium solder normally employed as well as the mechanical stress caused by the mismatch between the copper heatsink (16 - 17ppm/K) and the GaAs diode laser bars (6 - 7.5 ppm/K). For micro - channel heatsinks corrosion and erosion of the micro channels limit the lifetime additionally. The different thermal behavior and the resulting stress cannot be compensated totally by the solder. Expansion matched heatsink materials like tungsten-copper or aluminum nitride reduce this stress. A further possible solution is a combination of copper and molybdenum layers, but all these materials have a high thermal resistance in common. For high-power electronic or low cost medical applications novel materials like copper/carbon compound, compound diamond or high-conductivity ceramics were developed during recent years. Based on these novel materials, passively cooled heatsinks are designed, and thermal and mechanical simulations are performed to check their properties. The expansion of the heatsink and the induced mechanical stress between laser bar and heatsink are the main tasks for the simulations. A comparison of the simulation with experimental results for different material combinations illustrates the advantages and disadvantages of the different approaches. Together with the boundary conditions the ideal applications for packaging with these materials are defined. The goal of the development of passively-cooled expansion-matched heatsinks has to be a long-term reliability of several 10.000h and a thermal resistance below 1 K/W.

A Low-Cost, Passive Approach for Bacterial Growth and Distribution for Large-Scale Implementation of Bioaugmentation

DTIC Science & Technology

2012-07-01

technologies with significant capital costs, secondary waste streams, the involvement of hazardous materials, and the potential for additional worker...or environmental exposure. A more ideal technology would involve lower capital costs, would not generate secondary waste streams, would be...of bioaugmentation technology in general include low risk to human health and the environment during implementation, low secondary waste generation

Low Cost Equipment for Science and Technology Education. A Resource Document on Low Cost Equipment That You Can Make and Use.

ERIC Educational Resources Information Center

Lowe, N. K., Ed.

This document provides technical information and simple instructions for constructing 84 different pieces of science equipment. Each entry includes: (1) name of item; (2) purpose of the equipment; (3) person who submitted the information; (4) line drawing of prototype; (5) list of low-cost materials needed; (6) construction procedures; (7)…

Patient-centered technological assessment and monitoring of depression for low-income patients.

PubMed

Wu, Shinyi; Vidyanti, Irene; Liu, Pai; Hawkins, Caitlin; Ramirez, Magaly; Guterman, Jeffrey; Gross-Schulman, Sandra; Sklaroff, Laura Myerchin; Ell, Kathleen

2014-01-01

Depression is a significant challenge for ambulatory care because it worsens health status and outcomes, increases health care utilizations and costs, and elevates suicide risk. An automatic telephonic assessment (ATA) system that links with tasks and alerts to providers may improve quality of depression care and increase provider productivity. We used ATA system in a trial to assess and monitor depressive symptoms of 444 safety-net primary care patients with diabetes. We assessed system properties, evaluated preliminary clinical outcomes, and estimated cost savings. The ATA system is feasible, reliable, valid, safe, and likely cost-effective for depression screening and monitoring for low-income primary care population.

Solar Stirling system development

NASA Technical Reports Server (NTRS)

Stearns, J. W., Jr.; Won, Y. S.; Poon, P. T.; Das, R.; Chow, E. Y.

1979-01-01

A low-cost, high-efficiency dish-Stirling solar thermal-electric power system is being developed for test in 1981. System components are the solar concentrator, receiver, fossil fuel combustor, thermal energy storage (TES), engine-generator, and power processing. System conceptualization is completed and design is in progress. Two receiver alternatives are being evaluated, a direct-coupled receiver-engine configuration with no TES and a heat pipe receiver with TES. System cost projections are being made. Goals for the system development task are (1) to develop an advanced dish-Stirling technology, utilizing a team of industrial contractors, (2) to demonstrate that technology at the system level, and (3) to determine how to achieve low production cost.

The Effect of N-3 on N-2 Repetition Costs in Task Switching

ERIC Educational Resources Information Center

Schuch, Stefanie; Grange, James A.

2015-01-01

N-2 task repetition cost is a response time and error cost returning to a task recently performed after one intervening trial (i.e., an ABA task sequence) compared with returning to a task not recently performed (i.e., a CBA task sequence). This cost is considered a robust measure of inhibitory control during task switching. The present article…

Solar power satellite system definition study, phase 2.

NASA Technical Reports Server (NTRS)

1979-01-01

A program plan for the Solar Power Satellite Program is presented. The plan includes research, development, and evaluation phase, engineering and development and cost verification phase, prototype construction, and commercialization. Cost estimates and task requirements are given for the following technology areas: (1) solar arrays; (2) thermal engines and thermal systems; (3) power transmission (to earth); (4) large space structures; (5) materials technology; (6) system control; (7) space construction; (8) space transportation; (9) power distribution, and space environment effects.

Can Force Feedback and Science Learning Enhance the Effectiveness of Neuro-Rehabilitation? An Experimental Study on Using a Low-Cost 3D Joystick and a Virtual Visit to a Zoo

PubMed Central

Cappa, Paolo; Clerico, Andrea; Nov, Oded; Porfiri, Maurizio

2013-01-01

In this paper, we demonstrate that healthy adults respond differentially to the administration of force feedback and the presentation of scientific content in a virtual environment, where they interact with a low-cost haptic device. Subjects are tasked with controlling the movement of a cursor on a predefined trajectory that is superimposed on a map of New York City’s Bronx Zoo. The system is characterized in terms of a suite of objective indices quantifying the subjects’ dexterity in planning and generating the multijoint visuomotor tasks. We find that force feedback regulates the smoothness, accuracy, and duration of the subject’s movement, whereby converging or diverging force fields influence the range of variations of the hand speed. Finally, our findings provide preliminary evidence that using educational content increases subjects’ satisfaction. Improving the level of interest through the inclusion of learning elements can increase the time spent performing rehabilitation tasks and promote learning in a new context. PMID:24349562

Low cost lab-on-a-chip prototyping with a consumer grade 3D printer.

PubMed

Comina, Germán; Suska, Anke; Filippini, Daniel

2014-08-21

Versatile prototyping of 3D printed lab-on-a-chip devices, supporting different forms of sample delivery, transport, functionalization and readout, is demonstrated with a consumer grade printer, which centralizes all critical fabrication tasks. Devices cost 0.57US$ and are demonstrated in chemical sensing and micromixing examples, which exploit established principles from reference technologies.

Sources and Transportation of Bulk, Low-Cost Lunar Simulant Materials

NASA Technical Reports Server (NTRS)

Rickman, D. L.

2013-01-01

Marshall Space Flight Center (MSFC) has built the Lunar Surface Testbed using 200 tons of volcanic cinder and ash from the same source used for the simulant series JSC-1. This Technical Memorandum examines the alternatives examined for transportation and source. The cost of low-cost lunar simulant is driven by the cost of transportation, which is controlled by distance and, to a lesser extent, quantity. Metabasalts in the eastern United States were evaluated due to their proximity to MSFC. Volcanic cinder deposits in New Mexico, Colorado, and Arizona were recognized as preferred sources. In addition to having fewer green, secondary minerals, they contain vesicular glass, both of which are desirable. Transportation costs were more than 90% of the total procurement costs for the simulant material.

A Cost Analysis of Forward Positioning Material in the Fifth Fleet Area of Responsibility

DTIC Science & Technology

2014-12-01

CTF combined task force CY calendar year DDC defense distribution center DDNB Defense Depot Navy Detachment, Bahrain DHL DHL Airways DLA...items from Bahrain to the requesting unit.  Defense Distribution Center ( DDC )– DDC is concerned with getting the requested national item

Influence of Microstructure on the Fatigue Crack Growth of A516 in Hydrogen

NASA Technical Reports Server (NTRS)

Wachob, Harry F.; Nelson, Howard G.

1980-01-01

Some day hydrogen may be used as a viable energy storage and transport medium within the United States. Hydrogen gas may be used to dilute and extend our present methane supply as a blend or may even be used in its pure elemental form as a primary fuel. Independent of the methods of production, storage, and distribution, the interaction of hydrogen with its containment material will play an integral role in the success of a hydrogen energy program. Presently, the selection of hydrogen containment materials can be made such that the material will remain reasonably free from environmental degradation; however, costly alloying additions are required. Unfortunately, high alloy steels are economically prohibitive when large-scale hydrogen energy storage, transmission, and conversion systems are desired. Therefore, in order to implement such hydrogen energy systems in the future, existing low-cost materials must be improved via mechanical, thermal, or thermo-mechanical processing methods or new low-cost materials which are compatible with hydrogen must be developed. Originally, low strength, low alloy steels at room temperature were thought to be immune to hydrogen gas embrittlement, since no sustained load crack growth is observed. However, results of Clark in HY8O and Nelson in SAE 1020 have shown that the fatigue crack growth rate can be greatly accelerated in the presence of hydrogen gas. In recent results reported by Louthan and Mucci, the smooth bar fatigue life of an A1068 pipeline steel was reduced up to a factor of ten when the tests were performed in a 13.8 MPa hydrogen environment. These results suggest that the selection of material for structures designed to operate in hydrogen under cyclic loads must include consideration of hydrogen/metal fatigue interaction. Although the hydrogen/metal fatigue interaction can be severe in low strength low alloy steels, the degree of degradation may be altered by the underlying ferrous microstructure. At present, no correlation between microstructure and degree of hydrogen susceptibility exists for low strength steels. However, in high strength steels, susceptibility to hydrogen embrittlement has been shown to be strongly sensitive to the metallurgical microstructure. In addition, compositional effects and grain size can 703 Some day hydrogen may be used as a viable energy storage and transport medium within the United States. Hydrogen gas may be used to dilute and extend our present methane supply as a blend or may even be used in its pure elemental form as a primary fuel. Independent of the methods of production, storage, and distribution, the interaction of hydrogen with its containment material will play an integral role in the success of a hydrogen energy program. Presently, the selection of hydrogen containment materials can be made such that the material will remain reasonably free from environmental degradation; however, costly alloying additions are required. Unfortunately, high alloy steels are economically prohibitive when large-scale hydrogen energy storage, transmission, and conversion systems are desired. Therefore, in order to implement such hydrogen energy systems in the future, existing low-cost materials must be improved via mechanical, thermal, or thermo-mechanical processing methods or new low-cost materials which are compatible with hydrogen must be developed.

Dual task cost of walking is related to fall risk in persons with multiple sclerosis.

PubMed

Wajda, Douglas A; Motl, Robert W; Sosnoff, Jacob J

2013-12-15

Persons with multiple sclerosis (MS) commonly have walking and cognitive impairments. While walking with a simultaneous cognitive task, persons with MS experience a greater decline in walking performance than healthy controls. This change in performance is termed dual task cost or dual task interference and has been associated with fall risk in older adults. We examined whether dual task cost during walking was related to fall risk in persons with MS. Thirty-three ambulatory persons with MS performed walking tasks with and without a concurrent cognitive task (dual task condition) as well as underwent a fall risk assessment. Dual task cost was operationalized as the percent change in velocity from normal walking conditions to dual task walking conditions. Fall risk was quantified using the Physiological Profile Assessment. A Spearman correlation analysis revealed a significant positive correlation between dual task cost of walking velocity and fall risk as well as dual task cost of stride length and fall risk. Overall, the findings indicate that dual task cost is associated with fall risk and may be an important target for falls prevention strategies. © 2013.

A curriculum for real-time computer and control systems engineering

NASA Technical Reports Server (NTRS)

Halang, Wolfgang A.

1990-01-01

An outline of a syllabus for the education of real-time-systems engineers is given. This comprises the treatment of basic concepts, real-time software engineering, and programming in high-level real-time languages, real-time operating systems with special emphasis on such topics as task scheduling, hardware architectures, and especially distributed automation structures, process interfacing, system reliability and fault-tolerance, and integrated project development support systems. Accompanying course material and laboratory work are outlined, and suggestions for establishing a laboratory with advanced, but low-cost, hardware and software are provided. How the curriculum can be extended into a second semester is discussed, and areas for possible graduate research are listed. The suitable selection of a high-level real-time language and supporting operating system for teaching purposes is considered.

Slicing of silicon into sheet material. Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Holden, S. C.; Fleming, J. R.

1978-01-01

Fabrication of a prototype large capacity multiple blade slurry saw is considered. Design of the bladehead which will tension up to 1000 blades, and cut a 45 cm long silicon ingot as large as 12 cm in diameter is given. The large blade tensioning force of 270,000 kg is applied through two bolts acting on a pair of scissor toggles, significantly reducing operator set-up time. Tests with an upside-down cutting technique resulted in 100% wafering yields and the highest wafer accuracy yet experienced with MS slicing. Variations in oil and abrasives resulted only in degraded slicing results. A technique of continuous abrasive slurry separation to remove silicon debris is described.

Improving memory after interruption: exploiting soft constraints and manipulating information access cost.

PubMed

Morgan, Phillip L; Patrick, John; Waldron, Samuel M; King, Sophia L; Patrick, Tanya

2009-12-01

Forgetting what one was doing prior to interruption is an everyday problem. The recent soft constraints hypothesis (Gray, Sims, Fu, & Schoelles, 2006) emphasizes the strategic adaptation of information processing strategy to the task environment. It predicts that increasing information access cost (IAC: the time, and physical and mental effort involved in accessing information) encourages a more memory-intensive strategy. Like interruptions, access costs are also intrinsic to most work environments, such as when opening documents and e-mails. Three experiments investigated whether increasing IAC during a simple copying task can be an effective method for reducing forgetting following interruption. IAC was designated Low (all information permanently visible), Medium (a mouse movement to uncover target information), or High (an additional few seconds to uncover such information). Experiment 1 found that recall improved across all three levels of IAC. Subsequent experiments found that High IAC facilitated resumption after interruption, particularly when interruption occurred on half of all trials (Experiment 2), and improved prospective memory following two different interrupting tasks, even when one involved the disruptive effect of using the same type of resource as the primary task (Experiment 3). The improvement of memory after interruption with increased IAC supports the prediction of the soft constraints hypothesis. The main disadvantage of a high access cost was a reduction in speed of task completion. The practicality of manipulating IAC as a design method for inducing a memory-intensive strategy to protect against forgetting is discussed. Copyright 2009 APA

High throughput CIGS solar cell fabrication via ultra-thin absorber layer with optical confinement and (Cd, CBD)-free heterojunction partner

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

Marsillac, Sylvain

2015-11-30

The main objective of this proposal was to use several pathways to reduce the production cost of Cu(In,Ga)Se 2 (CIGS) PV modules and therefore the levelized cost of energy (LCOE) associated with this technology. Three high cost drivers were identified, nominally: 1) Materials cost and availability; 2) Large scale uniformity; 3) Improved throughput These three cost drivers were targeted using the following pathways: 1) Reducing the thickness of the CIGS layer while enhancing materials quality; 2) Developing and applying enhanced in-situ metrology via real time spectroscopic ellipsometry; 3) Looking into alternative heterojunction partner, back contact and anti-reflection (AR) coating Elevenmore » main Tasks were then defined to achieve these goals (5 in Phase 1 and 6 in Phase 2), with 11 Milestones and 2 Go/No-go decision points at the end of Phase 1. The key results are summarized below« less

Carbonaceous materials and their advances as a counter electrode in dye-sensitized solar cells: challenges and prospects.

PubMed

Kouhnavard, Mojgan; Ludin, Norasikin Ahmad; Ghaffari, Babak V; Sopian, Kamarozzaman; Ikeda, Shoichiro

2015-05-11

Dye-sensitized solar cells (DSSCs) serve as low-costing alternatives to silicon solar cells because of their low material and fabrication costs. Usually, they utilize Pt as the counter electrode (CE) to catalyze the iodine redox couple and to complete the electric circuit. Given that Pt is a rare and expensive metal, various carbon materials have been intensively investigated because of their low costs, high surface areas, excellent electrochemical stabilities, reasonable electrochemical activities, and high corrosion resistances. In this feature article, we provide an overview of recent studies on the electrochemical properties and photovoltaic performances of carbon-based CEs (e.g., activated carbon, nanosized carbon, carbon black, graphene, graphite, carbon nanotubes, and composite carbon). We focus on scientific challenges associated with each material and highlight recent advances achieved in overcoming these obstacles. Finally, we discuss possible future directions for this field of research aimed at obtaining highly efficient DSSCs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improving executive function in childhood: evaluation of a training intervention for 5-year-old children

PubMed Central

Traverso, Laura; Viterbori, Paola; Usai, Maria Carmen

2015-01-01

Executive function (EF) refers to a set of higher order cognitive processes that control and modulate cognition under continuously changing and multiple task demands. EF plays a central role in early childhood, is associated and predictive of important cognitive achievements and has been recognized as a significant aspect of school readiness. This study examines the efficacy of a group based intervention for 5-year-old children that focuses on basic components of EF (working memory, inhibitory control, cognitive flexibility). The intervention included 12 sessions, lasted 1 month and used low-cost materials. Seventy-five children took part in the study. The results indicate that the children who attended the intervention outperformed controls in simple and more complex EF tasks. Specifically, these children exhibited increased abilities to delay gratification, to control on-going responses, to process and update information, and to manage high cognitive conflict. These results suggest the possibility that this intervention, which may be easily implemented in educational services, can promote EF during preschool period before the entrance in primary school. PMID:25983706

Improving executive function in childhood: evaluation of a training intervention for 5-year-old children.

PubMed

Traverso, Laura; Viterbori, Paola; Usai, Maria Carmen

2015-01-01

Executive function (EF) refers to a set of higher order cognitive processes that control and modulate cognition under continuously changing and multiple task demands. EF plays a central role in early childhood, is associated and predictive of important cognitive achievements and has been recognized as a significant aspect of school readiness. This study examines the efficacy of a group based intervention for 5-year-old children that focuses on basic components of EF (working memory, inhibitory control, cognitive flexibility). The intervention included 12 sessions, lasted 1 month and used low-cost materials. Seventy-five children took part in the study. The results indicate that the children who attended the intervention outperformed controls in simple and more complex EF tasks. Specifically, these children exhibited increased abilities to delay gratification, to control on-going responses, to process and update information, and to manage high cognitive conflict. These results suggest the possibility that this intervention, which may be easily implemented in educational services, can promote EF during preschool period before the entrance in primary school.

Possible application of laser isotope separation

NASA Technical Reports Server (NTRS)

Delionback, L. M.

1975-01-01

The laser isotope separation process is described and its special economic features discussed. These features are its low cost electric power operation, capital investment costs, and the costs of process materials.

LOW-COST WASTEWATER COLLECTION FOR SMALL COMMUNITIES

EPA Science Inventory

A presentation of previously cleared material on low-cost wastewater collection in small communities will be presented, using slides from previous presentations. The primary thrust of the presentation is to acquaint the audience with all types of alternative wastewater collection...

Visual short-term memory load modulates the early attention and perception of task-irrelevant emotional faces

PubMed Central

Yang, Ping; Wang, Min; Jin, Zhenlan; Li, Ling

2015-01-01

The ability to focus on task-relevant information, while suppressing distraction, is critical for human cognition and behavior. Using a delayed-match-to-sample (DMS) task, we investigated the effects of emotional face distractors (positive, negative, and neutral faces) on early and late phases of visual short-term memory (VSTM) maintenance intervals, using low and high VSTM loads. Behavioral results showed decreased accuracy and delayed reaction times (RTs) for high vs. low VSTM load. Event-related potentials (ERPs) showed enhanced frontal N1 and occipital P1 amplitudes for negative faces vs. neutral or positive faces, implying rapid attentional alerting effects and early perceptual processing of negative distractors. However, high VSTM load appeared to inhibit face processing in general, showing decreased N1 amplitudes and delayed P1 latencies. An inverse correlation between the N1 activation difference (high-load minus low-load) and RT costs (high-load minus low-load) was found at left frontal areas when viewing negative distractors, suggesting that the greater the inhibition the lower the RT cost for negative faces. Emotional interference effect was not found in the late VSTM-related parietal P300, frontal positive slow wave (PSW) and occipital negative slow wave (NSW) components. In general, our findings suggest that the VSTM load modulates the early attention and perception of emotional distractors. PMID:26388763

Low-cost, highly transparent flexible low-e coating film to enable electrochromic windows with increased energy savings

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

Berland, Brian; Hollingsworth, Russell

Five Quads of energy are lost through windows annually in the U.S. Low-e coatings are increasingly employed to reduce the wasted energy. Most commonly, the low-e coating is an oxide material applied directly to the glass at high temperature. With over 100,000,000 existing homes, a retrofit product is crucial to achieve widespread energy savings. Low-e films, i.e. coatings on polymeric substrates, are now also available to meet this need. However, the traditional oxide materials and process is incompatible with low temperature plastics. Alternate high performing low-e films typically incorporate materials that limit visible transmission to 35% or less. Further, themore » cost is high. The objective of this award was to develop a retrofit, integrated low-e/electrochromic window film to dramatically reduce energy lost through windows. While field testing of state-of-the-art electrochromic (EC) windows show the energy savings are maximized if a low-e coating is used in conjunction with the EC, available low-e films have a low visible transmission (~70% or less) that limits the achievable clear state and therefore, appearance and energy savings potential. Comprehensive energy savings models were completed at Lawrence Berkeley National Lab (LBNL). A parametric approach was used to project energy usage for windows with a large range of low-e properties across all U.S. climate zones, without limiting the study to materials that had already been produced commercially or made in a lab. The model enables projection of energy savings for low-e films as well as integrated low-e/EC products. This project developed a novel low-e film, optimized for compatibility with EC windows, using low temperature, high deposition rate processes for the growth of low-e coatings on plastic films by microwave plasma enhanced chemical vapor deposition. Silica films with good density and optical properties were demonstrated at deposition rates as high as 130Å/sec. A simple bi-layer low-e stack of silica and a transparent conductive oxide demonstrated 90% visible transmission with high thermal infrared reflectivity characteristic of conventional low-e coatings. A slightly more complex stack provided high solar infrared reflection without sacrificing visible transmission or thermal infrared reflection. Successful completion of the effort produced a prototype integrated low-e, dynamic window film with characterized energy saving potential. Cost modeling for the passive bi-layer, low-e film projects a manufacturing cost of ~$0.50/ft2 for a plant with 10M ft2/yr capacity. The novel thin film processes developed here enable high deposition rate (low cost), optical quality oxide coatings at low temperatures. When combined with engineered materials, ITN’s coating will result in low-cost, low-e films that reflect a high degree of infrared radiation without substantially reducing the visible transmission. The resultant window film will improve the U-value and achieve SHGC improvements over bare glass. The new low-e coating will be particularly attractive when combined with an electrochromic film. Low-e coating design guided by energy savings modeling allows customization of the product for different climate zones.« less

Engineering a responsive, low cost, tactical satellite, TACSAT-1

NASA Astrophysics Data System (ADS)

Hurley, M.; Duffey, T.; Huffine, Christopher; Weldy, Ken; Clevland, Jeff; Hauser, Joe

2004-11-01

The Secretary of Defense's Office of Force Transformation (OFT) is currently undertaking an initiative to develop a low-cost, responsive, operationally relevant space capability using small satellites. The Naval Research Laboratory (NRL) is tasked to be program manger for this initiative, which seeks to make space assets and capabilities available to operational users. TacSat-1 is the first in a series of small satellites that will result in rapid, tailored, and operationally relevant experimental space capabilities for tactical forces. Components of the resulting tactical architecture include a highly automated small satellite bus, modular payloads, common launch and payload interfaces, tasking and data dissemination using the SIPRNET (Secret Internet Protocol Routing Network), and low cost, rapid response launches. The overall goal of TacSat-1 is to demonstrate the utility of a broader complementary business model and provide a catalyst for energizing DoD and industry in the operational space area. This paper first provides a brief overview of the TacSat- 1 experiment and then discusses the engineering designs and practices used to achieve the aggressive cost and schedule goals. Non-standard approaches and engineering philosophies that allowed the TacSat-1 spacecraft to be finished in twelve months are detailed and compared with "normal" satellite programs where applicable. Specific subsystem design, integration and test techniques, which contributed to the successful completion of the TacSat-1 spacecraft, are reviewed. Finally, lessons learned are discussed.

Processing bulk natural wood into a high-performance structural material

Treesearch

Jianwei Song; Chaoji Chen; Shuze Zhu; Mingwei Zhu; Jiaqi Dai; Upamanyu Ray; Yiju Li; Yudi Kuang; Yongfeng Li; Nelson Quispe; Yonggang Yao; Amy Gong; Ulrich H. Leiste; Hugh A. Bruck; J. Y. Zhu; Azhar Vellore; Heng Li; Marilyn L. Minus; Zheng Jia; Ashlie Martini; Teng Li; Liangbing Hu

2018-01-01

Synthetic structural materials with exceptional mechanical performance suffer from either large weight and adverse environmental impact (for example, steels and alloys) or complex manufacturing processes and thus high cost (for example, polymer-based and biomimetic composites)1–8. Natural wood is a low-cost and abundant material and has been used...

Solution Adsorption Formation of a π-Conjugated Polymer/Graphene Composite for High-Performance Field-Effect Transistors.

PubMed

Liu, Yun; Hao, Wei; Yao, Huiying; Li, Shuzhou; Wu, Yuchen; Zhu, Jia; Jiang, Lei

2018-01-01

Semiconducting polymers with π-conjugated electronic structures have potential application in the large-scale printable fabrication of high-performance electronic and optoelectronic devices. However, owing to their poor environmental stability and high-cost synthesis, polymer semiconductors possess limited device implementation. Here, an approach for constructing a π-conjugated polymer/graphene composite material to circumvent these limitations is provided, and then this material is patterned into 1D arrays. Driven by the π-π interaction, several-layer polymers can be adsorbed onto the graphene planes. The low consumption of the high-cost semiconductor polymers and the mass production of graphene contribute to the low-cost fabrication of the π-conjugated polymer/graphene composite materials. Based on the π-conjugated system, a reduced π-π stacking distance between graphene and the polymer can be achieved, yielding enhanced charge-transport properties. Owing to the incorporation of graphene, the composite material shows improved thermal stability. More generally, it is believed that the construction of the π-conjugated composite shows clear possibility of integrating organic molecules and 2D materials into microstructure arrays for property-by-design fabrication of functional devices with large area, low cost, and high efficiency. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gear materials for high-production light-deputy service

NASA Technical Reports Server (NTRS)

Townsend, D. P.

1973-01-01

The selection of a material for high volume, low cost gears requires careful consideration of all the requirements and the processes used to manufacture the gears. The wrong choice in material selection could very well mean the difference between success and failure. A summary of the cost that might be expected for different materials and processes is presented; it can be seen that the cost can span nearly three order of magnitudes from the molded plastic gear to the machined gear with stamped and powder metal gears falling in between these extremes.

Culture Moderates Biases in Search Decisions.

PubMed

Pattaratanakun, Jake A; Mak, Vincent

2015-08-01

Prior studies suggest that people often search insufficiently in sequential-search tasks compared with the predictions of benchmark optimal strategies that maximize expected payoff. However, those studies were mostly conducted in individualist Western cultures; Easterners from collectivist cultures, with their higher susceptibility to escalation of commitment induced by sunk search costs, could exhibit a reversal of this undersearch bias by searching more than optimally, but only when search costs are high. We tested our theory in four experiments. In our pilot experiment, participants generally undersearched when search cost was low, but only Eastern participants oversearched when search cost was high. In Experiments 1 and 2, we obtained evidence for our hypothesized effects via a cultural-priming manipulation on bicultural participants in which we manipulated the language used in the program interface. We obtained further process evidence for our theory in Experiment 3, in which we made sunk costs nonsalient in the search task-as expected, cross-cultural effects were largely mitigated. © The Author(s) 2015.

Materials for microfluidic chip fabrication.

PubMed

Ren, Kangning; Zhou, Jianhua; Wu, Hongkai

2013-11-19

Through manipulating fluids using microfabricated channel and chamber structures, microfluidics is a powerful tool to realize high sensitive, high speed, high throughput, and low cost analysis. In addition, the method can establish a well-controlled microenivroment for manipulating fluids and particles. It also has rapid growing implementations in both sophisticated chemical/biological analysis and low-cost point-of-care assays. Some unique phenomena emerge at the micrometer scale. For example, reactions are completed in a shorter amount of time as the travel distances of mass and heat are relatively small; the flows are usually laminar; and the capillary effect becomes dominant owing to large surface-to-volume ratios. In the meantime, the surface properties of the device material are greatly amplified, which can lead to either unique functions or problems that we would not encounter at the macroscale. Also, each material inherently corresponds with specific microfabrication strategies and certain native properties of the device. Therefore, the material for making the device plays a dominating role in microfluidic technologies. In this Account, we address the evolution of materials used for fabricating microfluidic chips, and discuss the application-oriented pros and cons of different materials. This Account generally follows the order of the materials introduced to microfluidics. Glass and silicon, the first generation microfluidic device materials, are perfect for capillary electrophoresis and solvent-involved applications but expensive for microfabriaction. Elastomers enable low-cost rapid prototyping and high density integration of valves on chip, allowing complicated and parallel fluid manipulation and in-channel cell culture. Plastics, as competitive alternatives to elastomers, are also rapid and inexpensive to microfabricate. Their broad variety provides flexible choices for different needs. For example, some thermosets support in-situ fabrication of arbitrary 3D structures, while some perfluoropolymers are extremely inert and antifouling. Chemists can use hydrogels as highly permeable structural material, which allows diffusion of molecules without bulk fluid flows. They are used to support 3D cell culture, to form diffusion gradient, and to serve as actuators. Researchers have recently introduced paper-based devices, which are extremely low-cost to prepare and easy to use, thereby promising in commercial point-of-care assays. In general, the evolution of chip materials reflects the two major trends of microfluidic technology: powerful microscale research platforms and low-cost portable analyses. For laboratory research, chemists choosing materials generally need to compromise the ease in prototyping and the performance of the device. However, in commercialization, the major concerns are the cost of production and the ease and reliability in use. There may be new growth in the combination of surface engineering, functional materials, and microfluidics, which is possibly accomplished by the utilization of composite materials or hybrids for advanced device functions. Also, significant expanding of commercial applications can be predicted.

Polycrystalline silicon study: Low-cost silicon refining technology prospects and semiconductor-grade polycrystalline silicon availability through 1988

NASA Technical Reports Server (NTRS)

Costogue, E. N.; Ferber, R.; Lutwack, R.; Lorenz, J. H.; Pellin, R.

1984-01-01

Photovoltaic arrays that convert solar energy into electrical energy can become a cost effective bulk energy generation alternative, provided that an adequate supply of low cost materials is available. One of the key requirements for economic photovoltaic cells is reasonably priced silicon. At present, the photovoltaic industry is dependent upon polycrystalline silicon refined by the Siemens process primarily for integrated circuits, power devices, and discrete semiconductor devices. This dependency is expected to continue until the DOE sponsored low cost silicon refining technology developments have matured to the point where they are in commercial use. The photovoltaic industry can then develop its own source of supply. Silicon material availability and market pricing projections through 1988 are updated based on data collected early in 1984. The silicon refining industry plans to meet the increasing demands of the semiconductor device and photovoltaic product industries are overviewed. In addition, the DOE sponsored technology research for producing low cost polycrystalline silicon, probabilistic cost analysis for the two most promising production processes for achieving the DOE cost goals, and the impacts of the DOE photovoltaics program silicon refining research upon the commercial polycrystalline silicon refining industry are addressed.

Recovery of PET from packaging plastics mixtures by wet shaking table.

PubMed

Carvalho, M T; Agante, E; Durão, F

2007-01-01

Recycling requires the separation of materials appearing in a mass of wastes of heterogeneous composition and characteristics, into single, almost pure, component/material flows. The separation of materials (e.g., some types of plastics) with similar physical properties (e.g., specific gravity) is often accomplished by human sorting. This is the case of the separation of packaging plastics in municipal solid wastes (MSW). The low cost of virgin plastics and low value of recycled plastics necessitate the utilization of low cost techniques and processes in the recycling of packaging plastics. An experimental study was conducted to evaluate the feasibility of production of a PET product, cleaned from PVC and PS, using a wet shaking table. The wet shaking table is an environmentally friendly process, widely used to separate minerals, which has low capital and operational costs. Some operational variables of the equipment, as well as different feed characteristics, were considered. The results show that the separation of these plastics is feasible although, similarly to the mineral field, in somewhat complex flow sheets.

Self-Assembled Carbon-Polyoxometalate Composites for Electrochemical Capacitors

NASA Astrophysics Data System (ADS)

Genovese, Matthew

The development of high performance yet cost effective energy storage devices is critical for enabling the growth of important emerging sectors from the internet of things to grid integration of renewable energy. Material costs are by far the largest contributor to the overall cost of energy storage devices and thus research into cost effective energy storage materials will play an important role in developing technology to meet real world storage demands. In this thesis, low cost high performance composite electrode materials for supercapacitors (SCs) have been developed through the surface modification of electrochemically double layer capacitive (EDLC) carbon substrates with pseudocapacitive Polyoxometalates (POMs). Significant fundamental contributions have been made to the understanding of all components of the composite electrode including the POM active layer, cation linker, and carbon substrate. The interaction of different POM chemistries in solution has been studied to elucidate the novel ways in which these molecules combine and the mechanism underlying this combination. A more thorough understanding regarding the cation linker's role in electrode fabrication has been developed through examining the linker properties which most strongly affect electrode performance. The development of porosity in biomass derived carbon materials has also been examined leading to important insights regarding the effect of substrate porosity on POM modification and electrochemical properties. These fundamental contributions enabled the design and performance optimization of POM-carbon composite SC electrodes. Understanding how POMs combine in solution, allowed for the development of mixed POM molecular coatings with tunable electrochemical properties. These molecular coatings were used to modify low cost biomass derived carbon substrates that had been structurally optimized to accommodate POM molecules. The resulting electrode composites utilizing low cost materials fabricated through simple scalable techniques demonstrated (i) high capacitance (361 F g-1), (ii) close to ideal pseudocapacitive behavior, (iii) stable cycling, and (iv) good rate performance.

Argobots: A Lightweight Low-Level Threading and Tasking Framework

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

Seo, Sangmin; Amer, Abdelhalim; Balaji, Pavan

In the past few decades, a number of user-level threading and tasking models have been proposed in the literature to address the shortcomings of OS-level threads, primarily with respect to cost and flexibility. Current state-of-the-art user-level threading and tasking models, however, are either too specific to applications or architectures or are not as powerful or flexible. In this paper, we present Argobots, a lightweight, low-level threading and tasking framework that is designed as a portable and performant substrate for high-level programming models or runtime systems. Argobots offers a carefully designed execution model that balances generality of functionality with providing amore » rich set of controls to allow specialization by the user or high-level programming model. We describe the design, implementation, and optimization of Argobots and present integrations with three example high-level models: OpenMP, MPI, and co-located I/O service. Evaluations show that (1) Argobots outperforms existing generic threading runtimes; (2) our OpenMP runtime offers more efficient interoperability capabilities than production OpenMP runtimes do; (3) when MPI interoperates with Argobots instead of Pthreads, it enjoys reduced synchronization costs and better latency hiding capabilities; and (4) I/O service with Argobots reduces interference with co-located applications, achieving performance competitive with that of the Pthreads version.« less

Control and Guidance of Low-Cost Robots via Gesture Perception for Monitoring Activities in the Home

PubMed Central

Sempere, Angel D.; Serna-Leon, Arturo; Gil, Pablo; Puente, Santiago; Torres, Fernando

2015-01-01

This paper describes the development of a low-cost mini-robot that is controlled by visual gestures. The prototype allows a person with disabilities to perform visual inspections indoors and in domestic spaces. Such a device could be used as the operator's eyes obviating the need for him to move about. The robot is equipped with a motorised webcam that is also controlled by visual gestures. This camera is used to monitor tasks in the home using the mini-robot while the operator remains quiet and motionless. The prototype was evaluated through several experiments testing the ability to use the mini-robot’s kinematics and communication systems to make it follow certain paths. The mini-robot can be programmed with specific orders and can be tele-operated by means of 3D hand gestures to enable the operator to perform movements and monitor tasks from a distance. PMID:26690448

Sound attenuation and absorption by micro-perforated panels backed by anisotropic fibrous materials: Theoretical and experimental study

NASA Astrophysics Data System (ADS)

Bravo, Teresa; Maury, Cédric

2018-07-01

Enhancing the attenuation or the absorption of low-frequency noise using lightweight bulk-reacting liners is still a demanding task in surface and air transport systems. The aim of this study is to understand the physical mechanisms involved in the attenuation and absorption properties of partitions made up of a thin micro-perforated panel (MPP) rigidly backed by a cavity filled with anisotropic fibrous material. Such a layout is denoted as a MPPF partition. Analytical models are formulated in the flow and no-flow cases to predict the axial damping of the least attenuated wave in a MPPF partition as well as the plane wave absorption coefficient. They account for a rigid or an elastic MPP facing a bulk-reacting fully-anisotropic material. A cost-efficient solution of the propagation constant for the least attenuated mode is obtained using a simulated annealing search method as well as a low-frequency approximation to the axial attenuation. The normal incidence absorption model is assessed in the no-flow case against pressure-velocity measurements of the surface impedance over a MPPF partition filled with fibreglass material. A parametric study is conducted to evaluate the MPP and the cavity constitutive parameters that mostly enhance the axial attenuation and sound absorption properties, with special interest on the MPP airframe relative velocity. This sensitivity study provides guidelines that could be used to further reduce the search space in parametric or impedance optimization studies.

How much does care in palliative care wards cost in Poland?

PubMed Central

Pokropska, Wieslawa; Łuczak, Jacek; Kaptacz, Anna; Stachowiak, Andrzej; Hurich, Krystyna; Koszela, Monika

2016-01-01

Introduction The main task of palliative care units is to provide a dignified life for people with advanced progressive chronic disease through appropriate symptom management, communication between medical specialists and the patient and his family, as well as the coordination of care. Many palliative care units struggle with low incomes from the National Health Fund (NHF), which causes serious economic problems. The aim of the study was to estimate of direct and administrative costs of care and the actual cost per patient per day in selected palliative care units and comparison of the results to the valuation of the NHF. Material and methods The study of the costs of hospitalization of 175 patients was conducted prospectively in five palliative care units (PCUs). The costs directly associated with care were recorded on the specially prepared forms in each unit and also personnel and administrative costs provided by the accounting departments. Results The total costs of analyzed units amounted to 209 002 EUR (898 712 PLN), while the payment for palliative care services from the NHF amounted to 126 010 EUR (541 844 PLN), which accounted for only 60% of the costs incurred by the units. The average cost per person per day of hospitalization, calculated according to the actual duration of hospitalization in the unit, was 83 EUR (357 PLN), and the average payment from the NHF was 52.8 EUR (227 PLN). Underpayment per person per day was approximately 29.2 EUR (125 PLN). Conclusions The study showed a significant difference between the actual cost of palliative care units and the level of refund from the NHF. Based on the analysis of costs, the application has been submitted to the NHF to change the reimbursement amount of palliative care services in 2013. PMID:27186194

A task shifting approach to primary mental health care for adults in South Africa: human resource requirements and costs for rural settings.

PubMed

Petersen, Inge; Lund, Crick; Bhana, Arvin; Flisher, Alan J

2012-01-01

BACKGROUND A recent situational analysis suggests that post-apartheid South Africa has made some gains with respect to the decentralization and integration of mental health into primary health care. However, service gaps within and between provinces remain, with rural areas particularly underserved. Aim This study aims to calculate and cost a hypothetical human resource mix required to populate a framework for district adult mental health services. This framework embraces the concept of task shifting, where dedicated low cost mental health workers at the community and clinic levels supplement integrated care. METHOD The expected number and cost of human resources was based on: (a) assumptions of service provision derived from existing services in a sub-district demonstration site and a literature review of evidence-based packages of care in low- and middle-income countries; and (b) assumptions of service needs derived from other studies. RESULTS For a nominal population of 100 000, minimal service coverage estimates of 50% for schizophrenia, bipolar affective disorder, major depressive disorder and 30% for post-traumatic stress disorder and maternal depression would require that the primary health care staffing package include one post for a mental health counsellor or equivalent and 7.2 community mental health worker posts. The cost of these personnel amounts to £28 457 per 100 000 population. This cost can be offset by a reduction in the number of other specialist and non-specialist health personnel required to close service gaps at primary care level. CONCLUSION The adoption of the concept of task shifting can substantially reduce the expected number of health care providers otherwise needed to close mental health service gaps at primary health care level in South Africa at minimal cost and may serve as a model for other middle-income countries.

Modeling workflow to design machine translation applications for public health practice

PubMed Central

Turner, Anne M.; Brownstein, Megumu K.; Cole, Kate; Karasz, Hilary; Kirchhoff, Katrin

2014-01-01

Objective Provide a detailed understanding of the information workflow processes related to translating health promotion materials for limited English proficiency individuals in order to inform the design of context-driven machine translation (MT) tools for public health (PH). Materials and Methods We applied a cognitive work analysis framework to investigate the translation information workflow processes of two large health departments in Washington State. Researchers conducted interviews, performed a task analysis, and validated results with PH professionals to model translation workflow and identify functional requirements for a translation system for PH. Results The study resulted in a detailed description of work related to translation of PH materials, an information workflow diagram, and a description of attitudes towards MT technology. We identified a number of themes that hold design implications for incorporating MT in PH translation practice. A PH translation tool prototype was designed based on these findings. Discussion This study underscores the importance of understanding the work context and information workflow for which systems will be designed. Based on themes and translation information workflow processes, we identified key design guidelines for incorporating MT into PH translation work. Primary amongst these is that MT should be followed by human review for translations to be of high quality and for the technology to be adopted into practice. Counclusion The time and costs of creating multilingual health promotion materials are barriers to translation. PH personnel were interested in MT's potential to improve access to low-cost translated PH materials, but expressed concerns about ensuring quality. We outline design considerations and a potential machine translation tool to best fit MT systems into PH practice. PMID:25445922

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

Dunn, K.J.; Wales, D.

This document presents a gasket replacement study performed by AAI Corporation for the U.S. Army Chemical Research, Development and Engineering Center. The new gaskets will replace those currently used in the M3A3 Smoke Generator. In accordance with Delivery Order 0002, AAI performed the following tasks: (1) Conducted a literature and industry search for new gasket material, (2) Selected and procured four of the most promising replacement materials, (3) Tested gaskets fabricated from these materials using a GFE M3A3 Smoke Generator, and (4) Recommended final replacement gaskets based on cost, chemical and temperature resistance, and test performance.

Solar energy and conservation technologies for Caribbean Tourist Facilities (CTF)

NASA Astrophysics Data System (ADS)

The primary objectives of the Caribbean Tourist Facilities (CTF) project were to develop and publish materials and conduct workshops on solar energy and conservation technologies that would directly address the needs and interests of tourist facilities in the Caribbean basin. Past contacts with the Caribbean and US tourist industries indicated that decision-makers remained unconvinced that renewable technologies could have a significant impact on development and operation costs or that renewable energy products and services suited their needs. In order to assure that the materials and programs developed were responsive to the Caribbean tourist industry and U.S. conservation and renewable energy industries, marketing research with potential end users and the organizations and associations that serve those users was included as an underlying task in the project. The tasks outlined in the CTF Statement of Work included conference planning, gathering of field data, development of educational materials, and conduct of workshop(s). In addition to providing a chronicle of the fulfillment of those tasks, this final report includes suggestions for distributing the documents developed during the project, venues for future workshops, and other technology transfer and market influence strategies.

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

Not Available

The primary objectives of the Caribbean Tourist Facilities (CTF) project were to develop and publish materials and conduct workshops on solar energy and conservation technologies that would directly address the needs and interests of tourist facilities in the Caribbean basin. Past contacts with the Caribbean and US tourist industries indicated that decision-makers remained unconvinced that renewable technologies could have a significant impact on development and operation costs or that renewable energy products and services suited their needs. In order to assure that the materials and programs developed were responsive to the Caribbean tourist industry and US conservation and renewable energymore » industries, marketing research with potential end users and the organizations and associations that serve those users was included as an underlying task in the project. The tasks outlined in the CTF Statement of Work included conference planning, gathering of field data, development of educational materials, and conduct of workshop(s). In addition to providing a chronicle of the fulfillment of those tasks, this final report includes suggestions for distributing the documents developed during the project, venues for future workshops, and other technology transfer and market influence strategies. 3 refs.« less

Overview of ARPA low-cost ceramic composites (LC{sup 3}) program

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

Adler, P.N.

1996-12-31

Grumman is currently leading an approximate $10M ARPA cost-shared program aimed at developing low-cost fabrication methodology for manufacturing ceramic matrix composite (CMC) structural components. One of the program goals is to demonstrate the effectiveness of an advanced materials partnership. A vertically integrated collaboration now exists that combines the talents of three large private sector organizations, two smaller private sector organizations, three universities, and three federal government laboratories. Work in progress involves preceramic polymer (Blackglas{trademark}) CMC materials technology, RTM and pyrolysis process modeling & simulation, and utilization of low-cost approaches for fabricating a CMC demonstration engine seal component. This paper reviewsmore » the program organization, functioning, and some of the highlights of the technical work, which is of interest to the DoD as well as the commercial sector.« less

NREL to Research Revolutionary Battery Storage Approaches in Support of

Science.gov Websites

adoption by dramatically improving driving range and reliability, and by providing low-cost carbon have the potential to meet the demanding safety, cost and performance levels for EVs set by ARPA-E, but materials to develop a new low-cost battery that operates similar to a flow battery, where chemical energy

Autonomous Wheeled Robot Platform Testbed for Navigation and Mapping Using Low-Cost Sensors

NASA Astrophysics Data System (ADS)

Calero, D.; Fernandez, E.; Parés, M. E.

2017-11-01

This paper presents the concept of an architecture for a wheeled robot system that helps researchers in the field of geomatics to speed up their daily research on kinematic geodesy, indoor navigation and indoor positioning fields. The presented ideas corresponds to an extensible and modular hardware and software system aimed at the development of new low-cost mapping algorithms as well as at the evaluation of the performance of sensors. The concept, already implemented in the CTTC's system ARAS (Autonomous Rover for Automatic Surveying) is generic and extensible. This means that it is possible to incorporate new navigation algorithms or sensors at no maintenance cost. Only the effort related to the development tasks required to either create such algorithms needs to be taken into account. As a consequence, change poses a much small problem for research activities in this specific area. This system includes several standalone sensors that may be combined in different ways to accomplish several goals; that is, this system may be used to perform a variety of tasks, as, for instance evaluates positioning algorithms performance or mapping algorithms performance.

GazeParser: an open-source and multiplatform library for low-cost eye tracking and analysis.

PubMed

Sogo, Hiroyuki

2013-09-01

Eye movement analysis is an effective method for research on visual perception and cognition. However, recordings of eye movements present practical difficulties related to the cost of the recording devices and the programming of device controls for use in experiments. GazeParser is an open-source library for low-cost eye tracking and data analysis; it consists of a video-based eyetracker and libraries for data recording and analysis. The libraries are written in Python and can be used in conjunction with PsychoPy and VisionEgg experimental control libraries. Three eye movement experiments are reported on performance tests of GazeParser. These showed that the means and standard deviations for errors in sampling intervals were less than 1 ms. Spatial accuracy ranged from 0.7° to 1.2°, depending on participant. In gap/overlap tasks and antisaccade tasks, the latency and amplitude of the saccades detected by GazeParser agreed with those detected by a commercial eyetracker. These results showed that the GazeParser demonstrates adequate performance for use in psychological experiments.

IEA Wind Task 26 - Multi-national Case Study of the Financial Cost of Wind Energy; Work Package 1 Final Report

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

Schwabe, P.; Lensink, S.; Hand, M.

2011-03-01

The lifetime cost of wind energy is comprised of a number of components including the investment cost, operation and maintenance costs, financing costs, and annual energy production. Accurate representation of these cost streams is critical in estimating a wind plant's cost of energy. Some of these cost streams will vary over the life of a given project. From the outset of project development, investors in wind energy have relatively certain knowledge of the plant's lifetime cost of wind energy. This is because a wind energy project's installed costs and mean wind speed are known early on, and wind generation generallymore » has low variable operation and maintenance costs, zero fuel cost, and no carbon emissions cost. Despite these inherent characteristics, there are wide variations in the cost of wind energy internationally, which is the focus of this report. Using a multinational case-study approach, this work seeks to understand the sources of wind energy cost differences among seven countries under International Energy Agency (IEA) Wind Task 26 - Cost of Wind Energy. The participating countries in this study include Denmark, Germany, the Netherlands, Spain, Sweden, Switzerland, and the United States. Due to data availability, onshore wind energy is the primary focus of this study, though a small sample of reported offshore cost data is also included.« less

Task-set switching under cue-based versus memory-based switching conditions in younger and older adults.

PubMed

Kray, Jutta

2006-08-11

Adult age differences in task switching and advance preparation were examined by comparing cue-based and memory-based switching conditions. Task switching was assessed by determining two types of costs that occur at the general (mixing costs) and specific (switching costs) level of switching. Advance preparation was investigated by varying the time interval until the next task (short, middle, very long). Results indicated that the implementation of task sets was different for cue-based switching with random task sequences and memory-based switching with predictable task sequences. Switching costs were strongly reduced under cue-based switching conditions, indicating that task-set cues facilitate the retrieval of the next task. Age differences were found for mixing costs and for switching costs only under cue-based conditions in which older adults showed smaller switching costs than younger adults. It is suggested that older adults adopt a less extreme bias between two tasks than younger adults in situations associated with uncertainty. For cue-based switching with random task sequences, older adults are less engaged in a complete reconfiguration of task sets because of the probability of a further task change. Furthermore, the reduction of switching costs was more pronounced for cue- than memory-based switching for short preparation intervals, whereas the reduction of switch costs was more pronounced for memory- than cue-based switching for longer preparation intervals at least for older adults. Together these findings suggest that the implementation of task sets is functionally different for the two types of task-switching conditions.

Method for materials deposition by ablation transfer processing

DOEpatents

Weiner, K.H.

1996-04-16

A method in which a thin layer of semiconducting, insulating, or metallic material is transferred by ablation from a source substrate, coated uniformly with a thin layer of said material, to a target substrate, where said material is desired, with a pulsed, high intensity, patternable beam of energy. The use of a patternable beam allows area-selective ablation from the source substrate resulting in additive deposition of the material onto the target substrate which may require a very low percentage of the area to be covered. Since material is placed only where it is required, material waste can be minimized by reusing the source substrate for depositions on multiple target substrates. Due to the use of a pulsed, high intensity energy source the target substrate remains at low temperature during the process, and thus low-temperature, low cost transparent glass or plastic can be used as the target substrate. The method can be carried out atmospheric pressures and at room temperatures, thus eliminating vacuum systems normally required in materials deposition processes. This invention has particular application in the flat panel display industry, as well as minimizing materials waste and associated costs. 1 fig.

Calibrating the response to health warnings: limiting both overreaction and underreaction with self-affirmation.

PubMed

Griffin, Dale W; Harris, Peter R

2011-05-01

Self-affirmation, reflecting on one's defining personal values, increases acceptance of threatening information, but does it do so at the cost of inducing undue alarm in people at low risk of harm? We contrast an alarm model, wherein self-affirmation simply increases response to threat, with a calibration model, wherein self-affirmation increases sensitivity to the self-relevance of health-risk information. Female seafood consumers (N = 165) completed a values self-affirmation or control task before reading a U.S. Food and Drug Administration brochure on mercury in seafood. Findings support the calibration model: Among frequent seafood consumers, self-affirmation generally increased concern (reports of depth of thought, personal message relevance, perceived risk, and negative affect) for those high in defensiveness and reduced it for those low in defensiveness. Among infrequent consumers of seafood, self-affirmation typically reduced concern. Thus, self-affirmation increased the sensitivity with which women at different levels of risk, and at different levels of defensiveness, responded cognitively and affectively to the materials.

A low-cost, mechanically simple apparatus for measuring eddy current-induced magnetic fields in MRI.

PubMed

Gilbert, Kyle M; Martyn Klassen, L; Menon, Ravi S

2013-10-01

The fidelity of gradient waveforms in MRI pulse sequences is essential to the acquisition of images and spectra with minimal distortion artefacts. Gradient waveforms can become nonideal when eddy currents are created in nearby conducting structures; however, the resultant magnetic fields can be characterised and compensated for by measuring the spatial and temporal field response following a gradient impulse. This can be accomplished using a grid of radiofrequency (RF) coils. The RF coils must adhere to strict performance requirements: they must achieve a high sensitivity and signal-to-noise ratio (SNR), have minimal susceptibility field gradients between the sample and surrounding material interfaces and be highly decoupled from each other. In this study, an apparatus is presented that accomplishes these tasks with a low-cost, mechanically simple solution. The coil system consists of six transmit/receive RF coils immersed in a high-molarity saline solution. The sensitivity and SNR following an excitation pulse are sufficiently high to allow accurate phase measurements during free-induction decays; the intrinsic susceptibility matching of the materials, because of the unique design of the coil system, results in sufficiently narrow spectral line widths (mean of 19 Hz), and adjacent RF coils are highly decoupled (mean S12 of -47 dB). The temporal and spatial distributions of eddy currents following a gradient pulse are measured to validate the efficacy of the design, and the resultant amplitudes and time constants required for zeroth- and first-order compensation are provided. Copyright © 2013 John Wiley & Sons, Ltd.

Distraction by emotional sounds: Disentangling arousal benefits and orienting costs.

PubMed

Max, Caroline; Widmann, Andreas; Kotz, Sonja A; Schröger, Erich; Wetzel, Nicole

2015-08-01

Unexpectedly occurring task-irrelevant stimuli have been shown to impair performance. They capture attention away from the main task leaving fewer resources for target processing. However, the actual distraction effect depends on various variables; for example, only target-informative distractors have been shown to cause costs of attentional orienting. Furthermore, recent studies have shown that high arousing emotional distractors, as compared with low arousing neutral distractors, can improve performance by increasing alertness. We aimed to separate costs of attentional orienting and benefits of arousal by presenting negative and neutral environmental sounds (novels) as oddballs in an auditory-visual distraction paradigm. Participants categorized pictures while task-irrelevant sounds preceded visual targets in two conditions: (a) informative sounds reliably signaled onset and occurrence of visual targets, and (b) noninformative sounds occurred unrelated to visual targets. Results confirmed that only informative novels yield distraction. Importantly, irrespective of sounds' informational value participants responded faster in trials with high arousing negative as compared with moderately arousing neutral novels. That is, costs related to attentional orienting are modulated by information, whereas benefits related to emotional arousal are independent of a sound's informational value. This favors a nonspecific facilitating cross-modal influence of emotional arousal on visual task performance and suggests that behavioral distraction by noninformative novels is controlled after their motivational significance has been determined. (c) 2015 APA, all rights reserved).

Transferring control demands across incidental learning tasks – stronger sequence usage in serial reaction task after shortcut option in letter string checking

PubMed Central

Gaschler, Robert; Marewski, Julian N.; Wenke, Dorit; Frensch, Peter A.

2014-01-01

After incidentally learning about a hidden regularity, participants can either continue to solve the task as instructed or, alternatively, apply a shortcut. Past research suggests that the amount of conflict implied by adopting a shortcut seems to bias the decision for vs. against continuing instruction-coherent task processing. We explored whether this decision might transfer from one incidental learning task to the next. Theories that conceptualize strategy change in incidental learning as a learning-plus-decision phenomenon suggest that high demands to adhere to instruction-coherent task processing in Task 1 will impede shortcut usage in Task 2, whereas low control demands will foster it. We sequentially applied two established incidental learning tasks differing in stimuli, responses and hidden regularity (the alphabet verification task followed by the serial reaction task, SRT). While some participants experienced a complete redundancy in the task material of the alphabet verification task (low demands to adhere to instructions), for others the redundancy was only partial. Thus, shortcut application would have led to errors (high demands to follow instructions). The low control demand condition showed the strongest usage of the fixed and repeating sequence of responses in the SRT. The transfer results are in line with the learning-plus-decision view of strategy change in incidental learning, rather than with resource theories of self-control. PMID:25506336

Low-cost far infrared bolometer camera for automotive use

NASA Astrophysics Data System (ADS)

Vieider, Christian; Wissmar, Stanley; Ericsson, Per; Halldin, Urban; Niklaus, Frank; Stemme, Göran; Källhammer, Jan-Erik; Pettersson, Håkan; Eriksson, Dick; Jakobsen, Henrik; Kvisterøy, Terje; Franks, John; VanNylen, Jan; Vercammen, Hans; VanHulsel, Annick

2007-04-01

A new low-cost long-wavelength infrared bolometer camera system is under development. It is designed for use with an automatic vision algorithm system as a sensor to detect vulnerable road users in traffic. Looking 15 m in front of the vehicle it can in case of an unavoidable impact activate a brake assist system or other deployable protection system. To achieve our cost target below €100 for the sensor system we evaluate the required performance and can reduce the sensitivity to 150 mK and pixel resolution to 80 x 30. We address all the main cost drivers as sensor size and production yield along with vacuum packaging, optical components and large volume manufacturing technologies. The detector array is based on a new type of high performance thermistor material. Very thin Si/SiGe single crystal multi-layers are grown epitaxially. Due to the resulting valence barriers a high temperature coefficient of resistance is achieved (3.3%/K). Simultaneously, the high quality crystalline material provides very low 1/f-noise characteristics and uniform material properties. The thermistor material is transferred from the original substrate wafer to the read-out circuit using adhesive wafer bonding and subsequent thinning. Bolometer arrays can then be fabricated using industry standard MEMS process and materials. The inherently good detector performance allows us to reduce the vacuum requirement and we can implement wafer level vacuum packaging technology used in established automotive sensor fabrication. The optical design is reduced to a single lens camera. We develop a low cost molding process using a novel chalcogenide glass (GASIR®3) and integrate anti-reflective and anti-erosion properties using diamond like carbon coating.

Pizzazz for Pennies: Promoting Alumni Programs the Low-Cost Way.

ERIC Educational Resources Information Center

Cunningham, Earl L.

1983-01-01

Suggestions for producing low-cost promotional materials to attract alumni to alumni programs are provided. Running advertisements in an alumni periodical or promoting all events in one brochure are suggested. Production, paper and printing, and illustrations and photos are discussed. (MLW)

Patient-Centered Technological Assessment and Monitoring of Depression for Low-Income Patients

PubMed Central

Wu, Shinyi; Vidyanti, Irene; Liu, Pai; Hawkins, Caitlin; Ramirez, Magaly; Guterman, Jeffrey; Gross-Schulman, Sandra; Sklaroff, Laura Myerchin; Ell, Kathleen

2014-01-01

Depression is a significant challenge for ambulatory care because it worsens health status and outcomes, increases health care utilizations and costs, and elevates suicide risk. An automatic telephonic assessment (ATA) system that links with tasks and alerts to providers may improve quality of depression care and increase provider productivity. We used ATA system in a trial to assess and monitor depressive symptoms of 444 safety-net primary care patients with diabetes. We assessed system properties, evaluated preliminary clinical outcomes, and estimated cost savings. The ATA system is feasible, reliable, valid, safe, and likely cost-effective for depression screening and monitoring for low-income primary care population. PMID:24525531

Low Cost, Net Shape Fabrication of Rhenium and High Temperature Materials for Rocket Engine Components

DTIC Science & Technology

2001-03-01

tungsten thin wall nozzle liner removed from reusable mandrel. b) W and Re rocket, nozzle inserts (2 inserts per mandrel) for Air Force. Rhenium PPI...compares the fabrication time for the VPS nozzles with equivalent carbon / carbon composite (C/C) and forged tungsten materials. Table 5: Comparison of...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO1 1181 TITLE: Low Cost, Net Shape Fabrication of Rhenium and High

Advanced Materials and Manufacturing for Low-Cost, High-Performance Liquid Rocket Combustion Chambers

NASA Technical Reports Server (NTRS)

Williams, Brian E.; Arrieta, Victor M.

2013-01-01

A document describes the low-cost manufacturing of C103 niobium alloy combustion chambers, and the use of a high-temperature, oxidation-resistant coating that is superior to the standard silicide coating. The manufacturing process involved low-temperature spray deposition of C103 on removable plastic mandrels produced by rapid prototyping. Thin, vapor-deposited platinum-indium coatings were shown to substantially improve oxidation resistance relative to the standard silicide coating. Development of different low-cost plastic thrust chamber mandrel materials and prototyping processes (selective laser sintering and stereolithography) yielded mandrels with good dimensional accuracy (within a couple of mils) for this stage of development. The feasibility of using the kinetic metallization cold-spray process for fabrication of free-standing C1O3 thrusters on removable plastic mandrels was also demonstrated. The ambient and elevated temperature mechanical properties of the material were shown to be reasonably good relative to conventionally processed C103, but the greatest potential benefit is that coldsprayed chambers require minimal post-process machining, resulting in substantially lower machining and material costs. The platinum-iridium coating was shown to provide greatly increased oxidation resistance over the silicide when evaluated through oxyacetylene torch testing to as high as 300 F (= 150 C). The iridium component minimizes reaction with the niobium alloy chamber at high temperatures, and provides the high-temperature oxidation resistance needed at the throat.

Interfering with memory for faces: The cost of doing two things at once.

PubMed

Wammes, Jeffrey D; Fernandes, Myra A

2016-01-01

We inferred the processes critical for episodic retrieval of faces by measuring susceptibility to memory interference from different distracting tasks. Experiment 1 examined recognition of studied faces under full attention (FA) or each of two divided attention (DA) conditions requiring concurrent decisions to auditorily presented letters. Memory was disrupted in both DA relative to FA conditions, a result contrary to a material-specific account of interference effects. Experiment 2 investigated whether the magnitude of interference depended on competition between concurrent tasks for common processing resources. Studied faces were presented either upright (configurally processed) or inverted (featurally processed). Recognition was completed under FA, or DA with one of two face-based distracting tasks requiring either featural or configural processing. We found an interaction: memory for upright faces was lower under DA when the distracting task required configural than featural processing, while the reverse was true for memory of inverted faces. Across experiments, the magnitude of memory interference was similar (a 19% or 20% decline from FA) regardless of whether the materials in the distracting task overlapped with the to-be-remembered information. Importantly, interference was significantly larger (42%) when the processing demands of the distracting and target retrieval task overlapped, suggesting a processing-specific account of memory interference.

A novel low cost pulse excitation source to study trap spectroscopy of persistent luminescent materials

NASA Astrophysics Data System (ADS)

Chandrasekhar, Ngangbam; Singh, Nungleppam Monorajan; Gartia, R. K.

2018-04-01

Luminescent techniques require one or the other source of excitations which may vary from high cost X-rays, γ-rays, β-rays etc. to low cost LED. Persistent luminescent materials or Glow-in-the-Dark phosphors are the optical harvesters which store the optical energy from day light illuminating a whole night. They are so sensitive that they can be excited even with the low light of firefly. Therefore, instead of using a high cost excitation source authors have developed a low cost functioning of excitation source controlling short pulses of LED to excite persistent phosphors with the aid of ExpEYES Junior (Hardware/software framework developed by IUAC, New Delhi). Using this, the authors have excited the sample under investigation upto 10 ms. Trap spectroscopy of the pre-excited sample with LED is studied using Thermoluminescence (TL) technique. In this communication, development of the excitation source is discussed and demonstrate the its usefulness in the study of trap spectroscopy of commercially available CaS:Eu2+, Sm3+. Trapping parameters are also evaluated using Computerized Glow Curve Deconvolution (CGCD) technique.

[Research on the Application of Lean Management in Medical Consumables Material Logistics Management].

PubMed

Yang, Chai; Zhang, Wei; Gu, Wei; Shen, Aizong

2016-11-01

Solve the problems of high cost, low utilization rate of resources, low medical care quality problem in medical consumables material logistics management for scientific of medical consumables management. Analysis of the problems existing in the domestic medical consumables material logistics management in hospital, based on lean management method, SPD(Supply, Processing, Distribution) for specific applications, combined HBOS(Hospital Business Operation System), HIS (Hospital Information System) system for medical consumables material management. Achieve the lean management in medical consumables material purchase, warehouse construction, push, clinical use and retrospect. Lean management in medical consumables material can effectively control the cost in logistics management, optimize the alocation of resources, liberate unnecessary time of medical staff, improve the quality of medical care. It is a scientific management method.

Reconfigurable intelligent sensors for health monitoring: a case study of pulse oximeter sensor.

PubMed

Jovanov, E; Milenkovic, A; Basham, S; Clark, D; Kelley, D

2004-01-01

Design of low-cost, miniature, lightweight, ultra low-power, intelligent sensors capable of customization and seamless integration into a body area network for health monitoring applications presents one of the most challenging tasks for system designers. To answer this challenge we propose a reconfigurable intelligent sensor platform featuring a low-power microcontroller, a low-power programmable logic device, a communication interface, and a signal conditioning circuit. The proposed solution promises a cost-effective, flexible platform that allows easy customization, run-time reconfiguration, and energy-efficient computation and communication. The development of a common platform for multiple physical sensors and a repository of both software procedures and soft intellectual property cores for hardware acceleration will increase reuse and alleviate costs of transition to a new generation of sensors. As a case study, we present an implementation of a reconfigurable pulse oximeter sensor.

Stopping decisions: information order effects on nonfocal evaluations.

PubMed

Yu, Michael; Gonzalez, Cleotilde

2013-08-01

We investigated how the order in which information is presented affects when a person decides to stop performing a task. A stopping decision is a decision to stop performing a task on the basis of a sequence of cues. Previous order-effects models do not account for how these contexts limit available working memory for making such decisions. Participants decided how long to perform a task known as the Work Hazard Game that began by rewarding points but later cost points if work continued after an unannounced "emergency." An additive sequence of cues indicated the probability of an emergency. Study I involved a three-group design with cue sequences that indicated the same risk at each decision point but whose final cue presented a high, medium, or low probability. Study 2 had a 2 x 2 design with high or low final cues and an easy or a challenging task. In Study I, participants stopped sooner when the most recent cue presented a high rather than low probability (p = .09), despite the same emergency risk. In Study 2, participants stopped sooner when the most recent cue presented a high rather than low probability for the challenging task but not for the easy task (p = .08). Stopping decisions appear sensitive to the most recent cue observed while experiencing task load. Participants responded to the same risks differently only on the basis of a change in presentation. Findings may be relevant for research and training for hazardous jobs, such as subsurface coal mining, fishing, and trucking.

Polypyrrole/sargassum activated carbon modified stainless-steel sponge as high-performance and low-cost bioanode for microbial fuel cells

NASA Astrophysics Data System (ADS)

Wu, Gaoming; Bao, Han; Xia, Zheng; Yang, Bin; Lei, Lecheng; Li, Zhongjian; Liu, Chunxian

2018-04-01

Anode materials, as the core component of microbial fuel cells (MFCs), have huge impacts on power generation performance and overall cost. Stainless-steel sponge (SS) can be a promising material for MFC anodes, due to its open continuous three-dimensional structure, high conductivity and low cost. However, poor biocompatibility limits its application. In this paper, a polypyrrole/sargassum activated carbon modified SS anode (Ppy/SAC/SS) is developed by electrochemical polymerization of pyrrole on the SS with the SAC as a dopant. The maximum power density achieved with the Ppy/SAC/SS anode is 45.2 W/m3, which is increased by 2 orders of magnitude and 2.9 times compared with an unmodified SS anode and a solely Ppy modified SS anode (Ppy/SS), respectively. In addition, the Ppy/SAC layer effectively eliminates electrochemical corrosion of the SS substrate. Electrochemical impedance spectroscopy reveals that Ppy/SAC modification decreases electron transfer resistance between the bacteria and the electrode. Furthermore, in vivo fluorescence imaging indicates that a more uniform biofilm is formed on the Ppy/SAC/SS compared to the unmodified SS and Ppy/SS. Due to the low cost of the materials, easy fabrication process and relatively high performance, our developed Ppy/SAC/SS can be a cost efficient anode material for MFCs in practical applications.

An economic analysis of adherence engineering to improve use of best practices during central line maintenance procedures.

PubMed

Nelson, Richard E; Angelovic, Aaron W; Nelson, Scott D; Gleed, Jeremy R; Drews, Frank A

2015-05-01

Adherence engineering applies human factors principles to examine non-adherence within a specific task and to guide the development of materials or equipment to increase protocol adherence and reduce human error. Central line maintenance (CLM) for intensive care unit (ICU) patients is a task through which error or non-adherence to protocols can cause central line-associated bloodstream infections (CLABSIs). We conducted an economic analysis of an adherence engineering CLM kit designed to improve the CLM task and reduce the risk of CLABSI. We constructed a Markov model to compare the cost-effectiveness of the CLM kit, which contains each of the 27 items necessary for performing the CLM procedure, compared with the standard care procedure for CLM, in which each item for dressing maintenance is gathered separately. We estimated the model using the cost of CLABSI overall ($45,685) as well as the excess LOS (6.9 excess ICU days, 3.5 excess general ward days). Assuming the CLM kit reduces the risk of CLABSI by 100% and 50%, this strategy was less costly (cost savings between $306 and $860) and more effective (between 0.05 and 0.13 more quality-adjusted life-years) compared with not using the pre-packaged kit. We identified threshold values for the effectiveness of the kit in reducing CLABSI for which the kit strategy was no longer less costly. An adherence engineering-based intervention to streamline the CLM process can improve patient outcomes and lower costs. Patient safety can be improved by adopting new approaches that are based on human factors principles.

Polycrystalline silicon material availability and market pricing outlook study for 1980 to 88: January 1983 update

NASA Technical Reports Server (NTRS)

Costogue, E.; Pellin, R.

1983-01-01

Photovoltaic solar cell arrays which convert solar energy into electrical energy can become a cost effective, alternative energy source provided that an adequate supply of low priced materials and automated fabrication techniques are available. Presently, silicon is the most promising cell material for achieving the near term cost goals of the Photovoltaics Program. Electronic grade silicon is produced primarily for the semiconductor industry with the photovoltaic industry using, in most cases, the production rejects of slightly lower grade material. Therefore, the future availability of adequate supplies of low cost silicon is one of the major concerns of the Photovoltaic Program. The supply outlook for silicon with emphasis on pricing is updated and is based primarily on an industry survey conducted by a JPL consultant. This survey included interviews with polycrystalline silicon manufacturers, a large cross section of silicon users and silicon solar cell manufacturers.

Low cost carbon fiber technology development for carbon fiber composite applications : phase 1.

DOT National Transportation Integrated Search

2008-01-01

The main goals of this research program at UTSI were: 1) to produce low cost carbon fibers and 2) to develop specific carbonbased : material technologies to meet current and future high performance fiber-reinforced composite needs of FTA and other : ...

Exploring physical exposures and identifying high-risk work tasks within the floor layer trade

PubMed Central

McGaha, Jamie; Miller, Kim; Descatha, Alexis; Welch, Laurie; Buchholz, Bryan; Evanoff, Bradley; Dale, Ann Marie

2014-01-01

Introduction Floor layers have high rates of musculoskeletal disorders yet few studies have examined their work exposures. This study used observational methods to describe physical exposures within floor laying tasks. Methods We analyzed 45 videos from 32 floor layers using Multimedia-Video Task Analysis software to determine the time in task, forces, postures, and repetitive hand movements for installation of four common flooring materials. We used the WISHA checklists to define exposure thresholds. Results Most workers (91%) met the caution threshold for one or more exposures. Workers showed high exposures in multiple body parts with variability in exposures across tasks and for different materials. Prolonged exposures were seen for kneeling, poor neck and low back postures, and intermittent but frequent hand grip forces. Conclusions Floor layers experience prolonged awkward postures and high force physical exposures in multiple body parts, which probably contribute to their high rates of musculoskeletal disorders. PMID:24274895

Foundations of Supply Chain Management for Space Application

NASA Technical Reports Server (NTRS)

Galluzzi, Michael; Zapata, Edgar; Steele, Martin; De Weck, Olivier

2006-01-01

Supply Chain Management (SCM) is a key piece of the framework for America's space technology investment as the National Aeronautics and Space Administration (NASA), the aerospace industry, and international partners embark on a bold new vision of human and robotic space exploration beyond Low-Earth-Orbit (LEO). This type of investment is driven by the Agency's need for cost efficient operational support associated with, processing and operating space vehicles and address many of the biggest operational challenge including extremely tight funding profiles, seamless program-to-program transition activities and the reduction of the time gap with human spaceflight capabilities in the post-Shuttle era. An investment of this magnitude is a multiyear task and must include new patterns of thought within the engineering community to respect the importance of SCM and the integration of the material and information flow. Experience within the Department of Defense and commercial sectors which has shown that support cost reductions and or avoidances of upwards to 35% over business as usual are achievable. It is SCM that will ultimately bring the solar system within the economic sphere of our society.

Changes in reading strategies in school-age children.

PubMed

Sanabria Díaz, Gretel; Torres, María del Rosario; Iglesias, Jorge; Mosquera, Raysil; Reigosa, Vivian; Santos, Elsa; Lage, Agustín; Estévez, Nancy; Galán, Lidice

2009-11-01

Learning to read is one of the most important cognitive milestones in the human social environment. One of the most accepted models explaining such process is the Double-Route Cascaded Model. It suggests the existence of two reading strategies: lexical and sublexical. In the Spanish language there are some contradictions about how these strategies are applied for reading. In addition, there are only a few studies dealing with the analysis of shifts between them, achieving a fluent reading process. In this paper we use a reading task including words and pseudowords for characterizing the cost of shifting between reading strategies in children with developmental dyslexia and normal controls. Our results suggest the presence of both strategies in these two experimental groups. In controls, both strategies become more efficient in correspondence to the increased exposition to written material. However, in children with developmental dyslexia only the lexical strategy exhibits such improvement. Their also point to a low cost for shifting between strategies in controls and a much more significant one in children with developmental dyslexia, differentiating subgroups with distinct shifting patterns.

Effects of redundancy in the comparison of speech and pictorial displays in the cockpit environment.

PubMed

Byblow, W D

1990-06-01

Synthesised speech and pictorial displays were compared in a spatially compatible simulated cockpit environment. Messages of high or low levels of redundancy were presented to subjects in both modality conditions. Subjects responded to warnings presented in a warning-only condition and in a dual-task condition, in which a simulated flight task was performed with visual and manual input/output modalities. Because the amount of information presented in most real-world applications and experimental paradigms is quantifiably large with respect to present guidelines for the use of synthesised speech warnings, the low-redundancy condition was hypothesised to allow for better performance. Results showed that subjects respond quicker to messages of low redundancy in both modalities. It is suggested that speech messages with low-redundancy levels were effective in minimising message length and ensuring that messages did not overload the short-term memory required to process and maintain speech in memory. Manipulation of phrase structure was used to optimise message redundancy and enhance the conceptual compatibility of the message without increasing message length or imposing a perceptual cost or memory overload. The results also suggest that system response times were quicker when synthesised speech warnings were used. This result is consistent with predictions from multiple resource theory which states that the resources required for the perception of verbal warnings are different from those for the flight task. It is also suggested that the perception of a pictorial display requires the same resources used for the perception of the primary flight task. An alternative explanation is that pictorial displays impose a visual scanning cost which is responsible for decreased performance. Based on the findings reported here, it is suggested that speech displays be incorporated in a spatially compatible cockpit environment because they allow equal or better performance when compared with pictorial displays. More importantly, the amount of time that the operator must direct his vision away from information vital to the flight task is decreased.

Test plan. GCPS task 7, subtask 7.1: IHM development

NASA Technical Reports Server (NTRS)

Greenberg, H. S.

1994-01-01

The overall objective of Task 7 is to identify cost-effective life cycle integrated health management (IHM) approaches for a reusable launch vehicle's primary structure. Acceptable IHM approaches must: eliminate and accommodate faults through robust designs, identify optimum inspection/maintenance periods, automate ground and on-board test and check-out, and accommodate and detect structural faults by providing wide and localized area sensor and test coverage as required. These requirements are elements of our targeted primary structure low cost operations approach using airline-like maintenance by exception philosophies. This development plan will follow an evolutionary path paving the way to the ultimate development of flight-quality production, operations, and vehicle systems. This effort will be focused on maturing the recommended sensor technologies required for localized and wide area health monitoring to a technology readiness level (TRL) of 6 and to establish flight ready system design requirements. The following is a brief list of IHM program objectives: design out faults by analyzing material properties, structural geometry, and load and environment variables and identify failure modes and damage tolerance requirements; design in system robustness while meeting performance objectives (weight limitations) of the reusable launch vehicle primary structure; establish structural integrity margins to preclude the need for test and checkout and predict optimum inspection/maintenance periods through life prediction analysis; identify optimum fault protection system concept definitions combining system robustness and integrity margins established above with cost effective health monitoring technologies; and use coupons, panels, and integrated full scale primary structure test articles to identify, evaluate, and characterize the preferred NDE/NDI/IHM sensor technologies that will be a part of the fault protection system.

Low cost composite materials for wind energy conversion systems

NASA Technical Reports Server (NTRS)

Weingart, O.

1980-01-01

A winding process utilizing a low-cost E-glass fabric called transverse-filament tape for low-cost production of wind turbine generators (WTG) is described. The process can be carried out continuously at high speed to produce large one-piece parts with tapered wall thicknesses on a tapered mandrel. It is being used to manufacture blades for the NASA/DOE 200-ft-diameter MOD-1 WTG and Rockwell/DOE 40-kW small wind energy conversion system (SWECS).

Cost Estimate for Molybdenum and Tantalum Refractory Metal Alloy Flow Circuit Concepts

NASA Technical Reports Server (NTRS)

Hickman, Robert R.; Martin, James J.; Schmidt, George R.; Godfroy, Thomas J.; Bryhan, A.J.

2010-01-01

The Early Flight Fission-Test Facilities (EFF-TF) team at NASA Marshall Space Flight Center (MSFC) has been tasked by the Naval Reactors Prime Contract Team (NRPCT) to provide a cost and delivery rough order of magnitude estimate for a refractory metal-based lithium (Li) flow circuit. The design is based on the stainless steel Li flow circuit that is currently being assembled for an NRPCT task underway at the EFF-TF. While geometrically the flow circuit is not representative of a final flight prototype, knowledge has been gained to quantify (time and cost) the materials, manufacturing, fabrication, assembly, and operations to produce a testable configuration. This Technical Memorandum (TM) also identifies the following key issues that need to be addressed by the fabrication process: Alloy selection and forming, cost and availability, welding, bending, machining, assembly, and instrumentation. Several candidate materials were identified by NRPCT including molybdenum (Mo) alloy (Mo-47.5 %Re), tantalum (Ta) alloys (T-111, ASTAR-811C), and niobium (Nb) alloy (Nb-1 %Zr). This TM is focused only on the Mo and Ta alloys, since they are of higher concern to the ongoing effort. The initial estimate to complete a Mo-47%Re system ready for testing is =$9,000k over a period of 30 mo. The initial estimate to complete a T-111 or ASTAR-811C system ready for testing is =$12,000k over a period of 36 mo.

Identification of High Performance, Low Environmental Impact Materials and Processes Using Systematic Substitution (SyS)

NASA Technical Reports Server (NTRS)

Dhooge, P. M.; Nimitz, J. S.

2001-01-01

Process analysis can identify opportunities for efficiency improvement including cost reduction, increased safety, improved quality, and decreased environmental impact. A thorough, systematic approach to materials and process selection is valuable in any analysis. New operations and facilities design offer the best opportunities for proactive cost reduction and environmental improvement, but existing operations and facilities can also benefit greatly. Materials and processes that have been used for many years may be sources of excessive resource use, waste generation, pollution, and cost burden that should be replaced. Operational and purchasing personnel may not recognize some materials and processes as problems. Reasons for materials or process replacement may include quality and efficiency improvements, excessive resource use and waste generation, materials and operational costs, safety (flammability or toxicity), pollution prevention, compatibility with new processes or materials, and new or anticipated regulations.

Outsourcing cognitive control to the environment: adult age differences in the use of task cues.

PubMed

Spieler, Daniel H; Mayr, Ulrich; LaGrone, Susan

2006-10-01

When an initial phase of cued task switching is followed by a phase of single-task trials, older adults show difficulties changing to the more efficient single-task mode of processing (Mayr & Liebscher, 2001). In Experiment 1, we show that these costs follow older adults' continued tendency to inspect task cues even though these provide no new information. In Experiment 2, we included a condition in which task cues were eliminated from the display after the task-switching phase. In this condition, older adults behaved the same as younger adults, suggesting that the presence of the task cue is critical for observing age differences while switching from a "high-control" to a "low-control" mode of processing. We discuss our results in terms of a life-span shift with regard to the reliance on internal versus external sources of information under conditions of high-control demands.

Developmental changes in using verbal self-cueing in task-switching situations: the impact of task practice and task-sequencing demands.

PubMed

Kray, Jutta; Gaspard, Hanna; Karbach, Julia; Blaye, Agnès

2013-01-01

In this study we examined whether developmental changes in using verbal self-cueing for task-goal maintenance are dependent on the amount of task practice and task-sequencing demands. To measure task-goal maintenance we applied a switching paradigm in which children either performed only task A or B in single-task blocks or switched between them on every second trial in mixed-task blocks. Task-goal maintenance was determined by comparing the performance between both blocks (mixing costs). The influence of verbal self-cueing was measured by instructing children to either name the next task aloud or not to verbalize during task preparation. Task-sequencing demands were varied between groups whereas one group received spatial task cues to support keeping track of the task sequence, while the other group did not. We also varied by the amount of prior practice in task switching while one group of participants practiced task switching first, before performing the task naming in addition, and the other group did it vice versa. Results of our study investigating younger (8-10 years) and older children (11-13 years) revealed no age differences in beneficial effects of verbal self-cueing. In line with previous findings, children showed reduced mixing costs under task-naming instructions and under conditions of low task-sequence demands (with the presence of spatial task cues). Our results also indicated that these benefits were only obtained for those groups of children that first received practice in task switching alone with no additional verbalization instruction. These findings suggest that internal task-cueing strategies can be efficiently used in children but only if they received prior practice in the underlying task so that demands on keeping and coordinating various instructions are reduced. Moreover, children benefitted from spatial task cues for better task-goal maintenance only if no verbal task-cueing strategy was introduced first.

Analysis and Evaluation of Processes and Equipment in Tasks 2 and 4 of the Low-cost Solar Array Project

NASA Technical Reports Server (NTRS)

Goldman, H.; Wolf, M.

1978-01-01

The significant economic data for the current production multiblade wafering and inner diameter slicing processes were tabulated and compared to data on the experimental and projected multiblade slurry, STC ID diamond coated blade, multiwire slurry and crystal systems fixed abrasive multiwire slicing methods. Cost calculations were performed for current production processes and for 1982 and 1986 projected wafering techniques.

Silicon Materials Task of the Low Cost Solar Array Project, Phase 3. Effect of Impurities and Processing on Silicon Solar Cells

NASA Technical Reports Server (NTRS)

Hopkins, R. H.; Davis, J. R.; Blais, P. D.; Rohatgi, A.; Campbell, R. B.; Rai-Choudhury, P.; Stapleton, R. E.; Mollenkopf, H. C.; Mccormick, J. R.

1979-01-01

The effects of impurities, various thermochemical processes, and any impurity process interactions on the performance of terrestrial silicon solar cells are defined. Determinations of the segregation coefficients of tungsten, tantalum, and cobalt for the Czochralski pulling of silicon single crystals are reported. Sensitive neutron activation analysis was used to determine the metal impurity content of the silicon while atomic absorption was used to measure the metal content of the residual liquid from which the doped crystals were grown. Gettering of Ti doped silicon wafers improved cell performance by one to two percent for the highest temperatures and longest times. The HCl is more effective than POCl3 treatments for deactivating Ti but POCl3 and HCl produced essentially identical results for Mo or Fe.

Asymmetrical Switch Costs in Children

ERIC Educational Resources Information Center

Ellefson, Michelle R.; Shapiron, Laura R.; Chater, Nick

2006-01-01

Switching between tasks produces decreases in performance as compared to repeating the same task. Asymmetrical switch costs occur when switching between two tasks of unequal difficulty. This asymmetry occurs because the cost is greater when switching to the less difficult task than when switching to the more difficult task. Various theories about…

Automated array assembly task, phase 1

NASA Technical Reports Server (NTRS)

Carbajal, B. G.

1977-01-01

An assessment of state-of-the-art technologies that are applicable to silicon solar cell and solar cell module fabrication is provided. The assessment consists of a technical feasibility evaluation and a cost projection for high-volume production of silicon solar cell modules. The cost projection was approached from two directions; a design-to-cost analysis assigned cost goals to each major process element in the fabrication scheme, and a cost analysis built up projected costs for alternate technologies for each process element. A technical evaluation was used in combination with the cost analysis to identify a baseline low cost process. A novel approach to metal pattern design based on minimum power loss was developed. These design equations were used as a tool in the evaluation of metallization technologies.

RADIOISOTOPE-DRIVEN DUAL-MODE PROPULSION SYSTEM FOR CUBESAT-SCALE PAYLOADS TO THE OUTER PLANETS

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

N. D. Jerred; T. M. Howe; S. D. Howe

It is apparent the cost of planetary exploration is rising as mission budgets declining. Currently small scientific beds geared to performing limited tasks are being developed and launched into low earth orbit (LEO) in the form of small-scale satellite units, i.e., CubeSats. These micro- and nano-satellites are gaining popularity among the university and science communities due to their relatively low cost and design flexibility. To date these small units have been limited to performing tasks in LEO utilizing solar-based power. If a reasonable propulsion system could be developed, these CubeSat platforms could perform exploration of various extra-terrestrial bodies within themore » solar system engaging a broader range of researchers. Additionally, being mindful of mass, smaller cheaper launch vehicles (approximately 1,000 kgs to LEO) can be targeted. Thus, in effect, allows for beneficial exploration to be conducted within limited budgets. Researchers at the Center for Space Nuclear Research (CSNR) are proposing a low mass, radioisotope-based, dual-mode propulsion system capable of extending the exploration realm of these CubeSats out of LEO.« less

A low cost real-time motion tracking approach using webcam technology.

PubMed

Krishnan, Chandramouli; Washabaugh, Edward P; Seetharaman, Yogesh

2015-02-05

Physical therapy is an important component of gait recovery for individuals with locomotor dysfunction. There is a growing body of evidence that suggests that incorporating a motor learning task through visual feedback of movement trajectory is a useful approach to facilitate therapeutic outcomes. Visual feedback is typically provided by recording the subject's limb movement patterns using a three-dimensional motion capture system and displaying it in real-time using customized software. However, this approach can seldom be used in the clinic because of the technical expertise required to operate this device and the cost involved in procuring a three-dimensional motion capture system. In this paper, we describe a low cost two-dimensional real-time motion tracking approach using a simple webcam and an image processing algorithm in LabVIEW Vision Assistant. We also evaluated the accuracy of this approach using a high precision robotic device (Lokomat) across various walking speeds. Further, the reliability and feasibility of real-time motion-tracking were evaluated in healthy human participants. The results indicated that the measurements from the webcam tracking approach were reliable and accurate. Experiments on human subjects also showed that participants could utilize the real-time kinematic feedback generated from this device to successfully perform a motor learning task while walking on a treadmill. These findings suggest that the webcam motion tracking approach is a feasible low cost solution to perform real-time movement analysis and training. Copyright © 2014 Elsevier Ltd. All rights reserved.

A low cost real-time motion tracking approach using webcam technology

PubMed Central

Krishnan, Chandramouli; Washabaugh, Edward P.; Seetharaman, Yogesh

2014-01-01

Physical therapy is an important component of gait recovery for individuals with locomotor dysfunction. There is a growing body of evidence that suggests that incorporating a motor learning task through visual feedback of movement trajectory is a useful approach to facilitate therapeutic outcomes. Visual feedback is typically provided by recording the subject’s limb movement patterns using a three-dimensional motion capture system and displaying it in real-time using customized software. However, this approach can seldom be used in the clinic because of the technical expertise required to operate this device and the cost involved in procuring a three-dimensional motion capture system. In this paper, we describe a low cost two-dimensional real-time motion tracking approach using a simple webcam and an image processing algorithm in LabVIEW Vision Assistant. We also evaluated the accuracy of this approach using a high precision robotic device (Lokomat) across various walking speeds. Further, the reliability and feasibility of real-time motion-tracking were evaluated in healthy human participants. The results indicated that the measurements from the webcam tracking approach were reliable and accurate. Experiments on human subjects also showed that participants could utilize the real-time kinematic feedback generated from this device to successfully perform a motor learning task while walking on a treadmill. These findings suggest that the webcam motion tracking approach is a feasible low cost solution to perform real-time movement analysis and training. PMID:25555306

School-Home Notes with and without Response Cost: Increasing Attention and Academic Performance in Low-Income Children with Attention-Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Jurbergs, Nichole; Palcic, Jennette; Kelley, Mary Lou

2007-01-01

This study evaluates the effectiveness of school-home notes for increasing academic productivity and on-task behavior of low-income, African American children diagnosed with attention-deficit/hyperactivity disorder (ADHD). Using a withdrawal, alternating treatments design, each student received school-home notes with and without a response cost…

Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

DOEpatents

Kuo, L.J.H.; Singh, P.; Ruka, R.J.; Vasilow, T.R.; Bratton, R.J.

1997-11-11

A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators. 4 figs.

Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

DOEpatents

Kuo, Lewis J. H.; Singh, Prabhakar; Ruka, Roswell J.; Vasilow, Theodore R.; Bratton, Raymond J.

1997-01-01

A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators.

What Costs Do Reveal and Moving Beyond the Cost Debate: Reply to Einstein and McDaniel (in press)

PubMed Central

Smith, Rebekah E.

2010-01-01

Einstein et al., (2005) predicted no cost to an ongoing task when a prospective memory task meet certain criteria. Smith et al. (2007) used prospective memory tasks that met these criteria and found a cost to the ongoing task, contrary to Einstein et al.'s prediction. Einstein and McDaniel (in press) correctly note that there are limitations to using ongoing task performance as a measure of the processes that contribute to prospective memory performance, however, the alternatives suggested by Einstein and McDaniel all focus on ongoing task performance and therefore do not move beyond the cost debate. This article describes why the Smith et al. findings are important, provides recommendations for issues to consider when investigating cost, and discusses individual cost measures. Finally, noting the blurry distinction between Einstein and McDaniel's description of the reflexive associative processes and preparatory attentional processes and difficulties in extending the multiprocess view to nonlaboratory tasks, suggestions are made for moving beyond the cost debate. PMID:20852726

Choosing the optimal Pareto composition of the charge material for the manufacture of composite blanks

NASA Astrophysics Data System (ADS)

Zalazinsky, A. G.; Kryuchkov, D. I.; Nesterenko, A. V.; Titov, V. G.

2017-12-01

The results of an experimental study of the mechanical properties of pressed and sintered briquettes consisting of powders obtained from a high-strength VT-22 titanium alloy by plasma spraying with additives of PTM-1 titanium powder obtained by the hydride-calcium method and powder of PV-N70Yu30 nickel-aluminum alloy are presented. The task is set for the choice of an optimal charge material composition of a composite material providing the required mechanical characteristics and cost of semi-finished products and items. Pareto optimal values for the composition of the composite material charge have been obtained.

Development of an improved coating for polybenzimidazole foam. [for space shuttle heat shields

NASA Technical Reports Server (NTRS)

Neuner, G. J.; Delano, C. B.

1976-01-01

An improved coating system was developed for Polybenzimidazole (PBI) foam to provide coating stability, ruggedness, moisture resistance, and to satisfy optical property requirements (alpha sub (s/epsilon) or = 0.4 and epsilon 0.8) for the space shuttle. The effort was performed in five tasks: Task 1 to establish material and process specifications for the PBI foam, and material specifications for the coatings; Task 2 to identify and evaluate promising coatings; Task 3 to establish mechanical and thermophysical properties of the tile components; Task 4 to determine by systems analysis the potential weight trade-offs associated with a coated PBI TPS; and Task 5 to establish a preliminary quality assurance program. The coated PBI tile was, through screening tests, determined to satisfy the design objectives with a reduced system weight over the baseline shuttle silica LRSI TPS. The developed tile provides a thermally stable, extremely rugged, low thermal conductivity insulator with a well characterized optical coating.

Process research of non-CZ silicon material

NASA Technical Reports Server (NTRS)

1983-01-01

High risk, high payoff research areas associated with the Westinghouse process for producing photovoltaic modules using non- CZ sheet material were investigated. All work was performed using dendritic web silicon. The following tasks are discussed and associated technical results are given: (1) determining the technical feasibility of forming front and back junctions in non-CT silicon using dopant techniques; (2) determining the feasibility of forming a liquid applied diffusion mask to replace the more costly chemical vapor deposited SiO2 diffusion mask; (3) determining the feasibility of applying liquid anti-reflective solutions using meniscus coating equipment; (4) studying the production of uniform, high efficiency solar cells using ion implanation junction formation techniques; and (5) quantifying cost improvements associated with process improvements.

Facility for orbital material processing

NASA Astrophysics Data System (ADS)

Starodubov, D.; McCormick, K.; Dellosa, M.; Erdelyi, E.; Volfson, L.

2018-05-01

The sustainable orbital manufacturing with commercially viable and profitable operation has tremendous potential for driving the space exploration industry and human expansion into outer space. This highly challenging task has never been accomplished before. The current relatively high delivery cost of materials represents the business challenge of value proposition for making products in space. FOMS Inc. team identified an opportunity of fluoride optical fiber manufacturing in space that can lead to the first commercial production on orbit. To address continued cost effective International Space Station (ISS) operations FOMS Inc. has developed and demonstrated for the first time a fully operational space facility for orbital remote manufacturing with up to 50 km fiber fabrication capability and strong commercial potential for manufacturing operations on board the ISS.

Performance and cost of materials for lithium-based rechargeable automotive batteries

NASA Astrophysics Data System (ADS)

Schmuch, Richard; Wagner, Ralf; Hörpel, Gerhard; Placke, Tobias; Winter, Martin

2018-04-01

It is widely accepted that for electric vehicles to be accepted by consumers and to achieve wide market penetration, ranges of at least 500 km at an affordable cost are required. Therefore, significant improvements to lithium-ion batteries (LIBs) in terms of energy density and cost along the battery value chain are required, while other key performance indicators, such as lifetime, safety, fast-charging ability and low-temperature performance, need to be enhanced or at least sustained. Here, we review advances and challenges in LIB materials for automotive applications, in particular with respect to cost and performance parameters. The production processes of anode and cathode materials are discussed, focusing on material abundance and cost. Advantages and challenges of different types of electrolyte for automotive batteries are examined. Finally, energy densities and costs of promising battery chemistries are critically evaluated along with an assessment of the potential to fulfil the ambitious targets of electric vehicle propulsion.

Atomic research

NASA Technical Reports Server (NTRS)

Hadaway, James B.; Connatser, Robert; Cothren, Bobby; Johnson, R. B.

1993-01-01

Work performed by the University of Alabama in Huntsville's (UAH) Center for Applied Optics (CAO) entitled Atomic Research is documented. Atomic oxygen (AO) effects on materials have long been a critical concern in designing spacecraft to withstand exposure to the Low Earth Orbit (LEO) environment. The objective of this research effort was to provide technical expertise in the design of instrumentation and experimental techniques for analyzing materials exposed to atomic oxygen in accelerated testing at NASA/MSFC. Such testing was required to answer fundamental questions concerning Space Station Freedom (SSF) candidate materials and materials exposed to atomic oxygen aboard the Long-Duration Exposure Facility (LDEF). The primary UAH task was to provide technical design, review, and analysis to MSFC in the development of a state-of-the-art 5eV atomic oxygen beam facility required to simulate the RAM-induced low earth orbit (LEO) AO environment. This development was to be accomplished primarily at NASA/MSFC. In support of this task, contamination effects and ultraviolet (UV) simulation testing was also to be carried out using NASA/MSFC facilities. Any materials analysis of LDEF samples was to be accomplished at UAH.

Executive Function Skills of 6 to 8 Year Olds: Brain and Behavioral Evidence and Implications for School Achievement

PubMed Central

Molfese, Victoria J.; Molfese, Peter J.; Molfese, Dennis L.; Rudasill, Kathleen M.; Armstrong, Natalie; Starkey, Gillian

2010-01-01

Academic and social success in school has been linked to children’s self-regulation. This study investigated the assessment of the executive function (EF) component of self-regulation using a low-cost, easily administered measure to determine whether scores obtained from the behavioral task would agree with those obtained using a laboratory-based neuropsychological measure of EF skills. The sample included 74 children (37 females; M = 86.2 months) who participated in two assessments of working memory and inhibitory control: Knock-Tap (NEPSY: Korkman, Kirk, and Kemp, 1998), and participation in event-related potential (ERP) testing that included the Directional Stroop Test (Davidson, Cruess, Diamond, O’Craven, & Savoy, 1999). Three main findings emerged. First, children grouped as high versus low performing on the NEPSY Knock-Tap Task were found to performed differently on the more difficult conditions of the DST (the Incongruent and Mixed Conditions), suggesting that the Knock-Tap Task as a low-cost and easy to administer assessment of EF skills may be one way for teachers to identify students with poor inhibitory control skills. Second, children’s performance on the DST was strongly related to their ERP responses, adding to evidence that differences in behavioral performance on the DST as a measure of EF skills reflect corresponding differences in brain processing. Finally, differences in brain processing on the DST task also were found when the children were grouped based on Knock-Tap performance. Simple screening procedures can enable teachers to identify children whose distractibility, inattentiveness, or poor attention spans may interfere with classroom learning. PMID:20798857

Wind turbine generator rotor blade concepts with low cost potential

NASA Technical Reports Server (NTRS)

Sullivan, T. L.; Cahill, T. P.; Griffee, D. G., Jr.; Gewehr, H. W.

1977-01-01

Four processed for producing blades are examined. Two use filament winding techniques and two involve filling a mold or form to produce all or part of a blade. The processes are described and a comparison is made of cost, material properties, design and free vibration characteristics. Conclusions are made regarding the feasibility of each process to produce low cost, structurally adequate blades.

Wind-turbine-generator rotor-blade concepts with low-cost potential

NASA Technical Reports Server (NTRS)

Sullivan, T. L.; Cahill, T. P.; Griffee, D. G., Jr.; Gewehr, H. W.

1978-01-01

Four processes for producing blades are examined. Two use filament winding techniques and two involve filling a mold or form to produce all or part of a blade. The processes are described and a comparison is made of costs, material properties, designs and free vibration characteristics. Conclusions are made regarding the feasibility of each process to produce low-cost, structurally adequate blades.

Additive Manufacturing of Low Cost Upper Stage Propulsion Components

NASA Technical Reports Server (NTRS)

Protz, Christopher; Bowman, Randy; Cooper, Ken; Fikes, John; Taminger, Karen; Wright, Belinda

2014-01-01

NASA is currently developing Additive Manufacturing (AM) technologies and design tools aimed at reducing the costs and manufacturing time of regeneratively cooled rocket engine components. These Low Cost Upper Stage Propulsion (LCUSP) tasks are funded through NASA's Game Changing Development Program in the Space Technology Mission Directorate. The LCUSP project will develop a copper alloy additive manufacturing design process and develop and optimize the Electron Beam Freeform Fabrication (EBF3) manufacturing process to direct deposit a nickel alloy structural jacket and manifolds onto an SLM manufactured GRCop chamber and Ni-alloy nozzle. In order to develop these processes, the project will characterize both the microstructural and mechanical properties of the SLMproduced GRCop-84, and will explore and document novel design techniques specific to AM combustion devices components. These manufacturing technologies will be used to build a 25K-class regenerative chamber and nozzle (to be used with tested DMLS injectors) that will be tested individually and as a system in hot fire tests to demonstrate the applicability of the technologies. These tasks are expected to bring costs and manufacturing time down as spacecraft propulsion systems typically comprise more than 70% of the total vehicle cost and account for a significant portion of the development schedule. Additionally, high pressure/high temperature combustion chambers and nozzles must be regeneratively cooled to survive their operating environment, causing their design to be time consuming and costly to build. LCUSP presents an opportunity to develop and demonstrate a process that can infuse these technologies into industry, build competition, and drive down costs of future engines.

Internet, Multimedia and Virtual Laboratories in a 'Third World' Environment.

ERIC Educational Resources Information Center

Monge-Najera, Julian Antonio; Rivas Rossi, Marta; Mendez-Estrada, Victor Hugo

2001-01-01

Describes the development of low-cost multimedia courses and materials for use on the Internet, as well as virtual laboratories, at the Universidad Estatal a Distancia (Costa Rica). Explains how simultaneous production of traditional printed materials and online courses, outsourcing, and the use of HTML and Java can reduce costs for developing…

Field Testing of a Wet FGD Additive for Enhanced Mercury Control

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

Gary Blythe; MariJon Owens

2007-12-31

This document is the final report for DOE-NETL Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project has been to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project was intended to demonstrate whether such additives can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from themore » FGD liquor and bulk solid byproducts for separate disposal. The project involved pilot- and full-scale tests of the additives in wet FGD absorbers. The tests were intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power provided the Texas lignite/PRB co-fired test site for pilot FGD tests and project cost sharing. Southern Company provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested, and project cost sharing. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation provided the TMT-15 additive, and the Nalco Company provided the Nalco 8034 additive. Both companies also supplied technical support to the test program as in-kind cost sharing. The project was conducted in six tasks. Of the six tasks, Task 1 involved project planning and Task 6 involved management and reporting. The other four tasks involved field testing on FGD systems, either at pilot or full scale. These four tasks included: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests were completed in 2005 and the full-scale test using high-sulfur coal was completed in 2006; only the TMT-15 additive was tested in these efforts. The Task 5 full-scale additive tests conducted at Southern Company's Plant Yates Unit 1 were completed in 2007, and both the TMT-15 and Nalco 8034 additives were tested.« less

Scale-up of Carbon/Carbon Bipolar Plates

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

David P. Haack

2009-04-08

This project was focused upon developing a unique material technology for use in PEM fuel cell bipolar plates. The carbon/carbon composite material developed in this program is uniquely suited for use in fuel cell systems, as it is lightweight, highly conductive and corrosion resistant. The project further focused upon developing the manufacturing methodology to cost-effectively produce this material for use in commercial fuel cell systems. United Technology Fuel Cells Corp., a leading fuel cell developer was a subcontractor to the project was interested in the performance and low-cost potential of the material. The accomplishments of the program included the developmentmore » and testing of a low-cost, fully molded, net-shape carbon-carbon bipolar plate. The process to cost-effectively manufacture these carbon-carbon bipolar plates was focused on extensively in this program. Key areas for cost-reduction that received attention in this program was net-shape molding of the detailed flow structures according to end-user design. Correlations between feature detail and process parameters were formed so that mold tooling could be accurately designed to meet a variety of flow field dimensions. A cost model was developed that predicted the cost of manufacture for the product in near-term volumes and long-term volumes (10+ million units per year). Because the roduct uses lowcost raw materials in quantities that are less than competitive tech, it was found that the cost of the product in high volume can be less than with other plate echnologies, and can meet the DOE goal of $4/kW for transportation applications. The excellent performance of the all-carbon plate in net shape was verified in fuel cell testing. Performance equivalent to much higher cost, fully machined graphite plates was found.« less

Argobots: A Lightweight Low-Level Threading and Tasking Framework

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

Seo, Sangmin; Amer, Abdelhalim; Balaji, Pavan

In the past few decades, a number of user-level threading and tasking models have been proposed in the literature to address the shortcomings of OS-level threads, primarily with respect to cost and flexibility. Current state-of-the-art user-level threading and tasking models, however, either are too specific to applications or architectures or are not as powerful or flexible. In this paper, we present Argobots, a lightweight, low-level threading and tasking framework that is designed as a portable and performant substrate for high-level programming models or runtime systems. Argobots offers a carefully designed execution model that balances generality of functionality with providing amore » rich set of controls to allow specialization by end users or high-level programming models. We describe the design, implementation, and performance characterization of Argobots and present integrations with three high-level models: OpenMP, MPI, and colocated I/O services. Evaluations show that (1) Argobots, while providing richer capabilities, is competitive with existing simpler generic threading runtimes; (2) our OpenMP runtime offers more efficient interoperability capabilities than production OpenMP runtimes do; (3) when MPI interoperates with Argobots instead of Pthreads, it enjoys reduced synchronization costs and better latency-hiding capabilities; and (4) I/O services with Argobots reduce interference with colocated applications while achieving performance competitive with that of a Pthreads approach.« less

Argobots: A Lightweight Low-Level Threading and Tasking Framework

DOE PAGES

Seo, Sangmin; Amer, Abdelhalim; Balaji, Pavan; ...

2017-10-24

In the past few decades, a number of user-level threading and tasking models have been proposed in the literature to address the shortcomings of OS-level threads, primarily with respect to cost and flexibility. Current state-of-the-art user-level threading and tasking models, however, are either too specific to applications or architectures or are not as powerful or flexible. In this article, we present Argobots, a lightweight, low-level threading and tasking framework that is designed as a portable and performant substrate for high-level programming models or runtime systems. Argobots offers a carefully designed execution model that balances generality of functionality with providing amore » rich set of controls to allow specialization by the user or high-level programming model. Here, we describe the design, implementation, and optimization of Argobots and present integrations with three example high-level models: OpenMP, MPI, and co-located I/O service. Evaluations show that (1) Argobots outperforms existing generic threading runtimes; (2) our OpenMP runtime offers more efficient interoperability capabilities than production OpenMP runtimes do; (3) when MPI interoperates with Argobots instead of Pthreads, it enjoys reduced synchronization costs and better latency hiding capabilities; and (4) I/O service with Argobots reduces interference with co-located applications, achieving performance competitive with that of the Pthreads version.« less

Argobots: A Lightweight Low-Level Threading and Tasking Framework

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

Seo, Sangmin; Amer, Abdelhalim; Balaji, Pavan

In the past few decades, a number of user-level threading and tasking models have been proposed in the literature to address the shortcomings of OS-level threads, primarily with respect to cost and flexibility. Current state-of-the-art user-level threading and tasking models, however, are either too specific to applications or architectures or are not as powerful or flexible. In this article, we present Argobots, a lightweight, low-level threading and tasking framework that is designed as a portable and performant substrate for high-level programming models or runtime systems. Argobots offers a carefully designed execution model that balances generality of functionality with providing amore » rich set of controls to allow specialization by the user or high-level programming model. Here, we describe the design, implementation, and optimization of Argobots and present integrations with three example high-level models: OpenMP, MPI, and co-located I/O service. Evaluations show that (1) Argobots outperforms existing generic threading runtimes; (2) our OpenMP runtime offers more efficient interoperability capabilities than production OpenMP runtimes do; (3) when MPI interoperates with Argobots instead of Pthreads, it enjoys reduced synchronization costs and better latency hiding capabilities; and (4) I/O service with Argobots reduces interference with co-located applications, achieving performance competitive with that of the Pthreads version.« less

An aqueous electrolyte, sodium ion functional, large format energy storage device for stationary applications

NASA Astrophysics Data System (ADS)

Whitacre, J. F.; Wiley, T.; Shanbhag, S.; Wenzhuo, Y.; Mohamed, A.; Chun, S. E.; Weber, E.; Blackwood, D.; Lynch-Bell, E.; Gulakowski, J.; Smith, C.; Humphreys, D.

2012-09-01

An approach to making large format economical energy storage devices based on a sodium-interactive set of electrodes in a neutral pH aqueous electrolyte is described. The economics of materials and manufacturing are examined, followed by a description of an asymmetric/hybrid device that has λ-MnO2 positive electrode material and low cost activated carbon as the negative electrode material. Data presented include materials characterization of the active materials, cyclic voltammetry, galvanostatic charge/discharge cycling, and application-specific performance of an 80 V, 2.4 kW h pack. The results indicate that this set of electrochemical couples is stable, low cost, requires minimal battery management control electronics, and therefore has potential for use in stationary applications where device energy density is not a concern.

Can tasks be inherently boring?

PubMed

Charney, Evan

2013-12-01

Kurzban et al. argue that the experiences of "effort," "boredom," and "fatigue" are indications that the costs of a task outweigh its benefits. Reducing the costs of tasks to "opportunity costs" has the effect of rendering tasks costless and of denying that they can be inherently boring or tedious, something that "vigilance tasks" were intentionally designed to be.

Low-cost solar array project and Proceedings of the 15th Project Integration Meeting

NASA Technical Reports Server (NTRS)

1980-01-01

Progress made by the Low-Cost Solar Array Project during the period December 1979 to April 1980 is described. Project analysis and integration, technology development in silicon material, large area silicon sheet and encapsulation, production process and equipment development, engineering, and operation are included.

Vitre-graf Coating on Mullite. Low Cost Silicon Array Project: Large Area Sillicon Sheet Task

NASA Technical Reports Server (NTRS)

Rossi, R. C.

1979-01-01

The processing parameters of the Vitre-Graf coating for optimal performance and economy when applied to mullite and graphite as substrates were presented. A minor effort was also performed on slip-cast fused silica substractes.

Design and evaluation of low-cost stainless steel fiberglass foam blades for large wind driven generating systems

NASA Technical Reports Server (NTRS)

Eggert, W. S.

1982-01-01

A low cost wind turbine blade based on a stainless steel fiberglass foam Budd blade design concept, was evaluated for its principle characteristics, low cost features, and its advantages and disadvantages. A blade structure was designed and construction methods and materials were selected. A complete blade tooling concepts, various technical and economic analysis, and evaluations of the blade design were performed. A comprehensive fatigue test program is conducted to provide data to verify the design stress allowables.

Construction of a low-cost detector to identify dissolved metals in aqueous media by fluorescence spectroscopy: design and perspectives.

NASA Astrophysics Data System (ADS)

González, M.; Montaño, M.; Hoyo, C.

2017-01-01

We have constructed a low cost fluorescence detector model to determine the presence of some heavy metals in an aqueous medium. In particular, we focus on metals which cause public health problems in our country. We did the first tests with standard samples of Hg (II). The innovative features of this instrument are its small dimensions (9 dm3) and the low cost of materials used in its construction.

Design and evaluation of low-cost stainless steel fiberglass foam blades for large wind driven generating systems

NASA Astrophysics Data System (ADS)

Eggert, W. S.

1982-10-01

A low cost wind turbine blade based on a stainless steel fiberglass foam Budd blade design concept, was evaluated for its principle characteristics, low cost features, and its advantages and disadvantages. A blade structure was designed and construction methods and materials were selected. A complete blade tooling concepts, various technical and economic analysis, and evaluations of the blade design were performed. A comprehensive fatigue test program is conducted to provide data to verify the design stress allowables.

General Slowing and Education Mediate Task Switching Performance Across the Life-Span

PubMed Central

Moretti, Luca; Semenza, Carlo; Vallesi, Antonino

2018-01-01

Objective: This study considered the potential role of both protective factors (cognitive reserve, CR) and adverse ones (general slowing) in modulating cognitive flexibility in the adult life-span. Method: Ninety-eight individuals performed a task-switching (TS) paradigm in which we adopted a manipulation concerning the timing between the cue and the target. Working memory demands were minimized by using transparent cues. Additionally, indices of cognitive integrity, depression, processing speed and different CR dimensions were collected and used in linear models accounting for TS performance under the different time constraints. Results: The main results showed similar mixing costs and higher switching costs in older adults, with an overall age-dependent effect of general slowing on these costs. The link between processing speed and TS performance was attenuated when participants had more time to prepare. Among the different CR indices, formal education only was associated with reduced switch costs under time pressure. Discussion: Even though CR is often operationalized as a unitary construct, the present research confirms the benefits of using tools designed to distinguish between different CR dimensions. Furthermore, our results provide empirical support to the assumption that processing speed influence on executive performance depends on time constraints. Finally, it is suggested that whether age differences appear in terms of switch or mixing costs depends on working memory demands (which were low in our tasks with transparent cues). PMID:29780341

Control and Effort Costs Influence the Motivational Consequences of Choice

PubMed Central

Sullivan-Toole, Holly; Richey, John A.; Tricomi, Elizabeth

2017-01-01

The act of making a choice, apart from any outcomes the choice may yield, has, paradoxically, been linked to both the enhancement and the detriment of intrinsic motivation. Research has implicated two factors in potentially mediating these contradictory effects: the personal control conferred by a choice and the costs associated with a choice. Across four experiments, utilizing a physical effort task disguised as a simple video game, we systematically varied costs across two levels of physical effort requirements (Low-Requirement, High-Requirement) and control over effort costs across three levels of choice (Free-Choice, Restricted-Choice, and No-Choice) to disambiguate how these factors affect the motivational consequences of choosing within an effortful task. Together, our results indicated that, in the face of effort requirements, illusory control alone may not sufficiently enhance perceptions of personal control to boost intrinsic motivation; rather, the experience of actual control may be necessary to overcome effort costs and elevate performance. Additionally, we demonstrated that conditions of illusory control, while otherwise unmotivating, can through association with the experience of free-choice, be transformed to have a positive effect on motivation. PMID:28515705

Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy-Efficient Wood-Plastic Composites

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

David N. Thompson, Robert W. Emerick, Alfred B. England, James P. Flanders, Frank J. Loge, Katherine A. Wiedeman, Michael P. Wolcott

The forestry, wood and paper industries in the United States provide thousands of productive well-paying jobs; however, in the face of the recent economic downturn it faces significant challenges in remaining economically viable and competitive. To compete successfully on a global market that is increasingly driven by the need for sustainable products and practices, the industry must improve margins and diversify product lines while continuing to produce the staple products. One approach that can help to accomplish this goal sustainably is the forest biorefinery. In the forest biorefinery, traditional waste streams are utilized singly or in combination to manufacture additionalmore » products in a profitable and environmentally sustainable manner. In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered Wood Products (EWP). Utilizing bio-based thermoplastics for these materials can reduce our dependence on foreign petroleum. Renewable microbial polyesters are not currently used in WFRTCs primarily because their production costs are several times higher than those of conventional petrochemical-derived plastics, limiting their use to small specialty markets. The strategy for this project was to economically produce WFRTCs using microbial polyesters by reducing or eliminating the most costly steps in the bio-plastic production. This would be achieved by producing them in and from waste effluents from the municipal and forest products sectors, and by eliminating the costly purification steps. After production the plasticladen biosolids would be dried and used directly to replace petroleum-derived plastics in WFRTCs. Using this strategy, we could greatly reduce the cost of producing and utilizing these renewable plastics in WFRTCs. This was a collaborative project among the Idaho National Laboratory, Washington State University, the University of California-Davis, Glatfelter Corporation, Strandex Corporation, and ECO:LOGIC Engineering, Inc. The project was comprised of five tasks. The first four tasks addressed PHA production, extrusion, and composite properties. Feedstock performance and compositional properties were determined in the laboratory by WSU. Both pure commercial PHAs (Task 1) and unpurified effluentderived PHAs (Task 4) were used. Results were used to define appropriate effluent feedstocks (Task 2) and optimize supplements (Task 3) to produce biosolids for the preferred composite formulations. Task 5 included a pilot-scale extrusion of wood-PHA-biosolids composites.« less

Choosing MUSE: Validation of a Low-Cost, Portable EEG System for ERP Research

PubMed Central

Krigolson, Olave E.; Williams, Chad C.; Norton, Angela; Hassall, Cameron D.; Colino, Francisco L.

2017-01-01

In recent years there has been an increase in the number of portable low-cost electroencephalographic (EEG) systems available to researchers. However, to date the validation of the use of low-cost EEG systems has focused on continuous recording of EEG data and/or the replication of large system EEG setups reliant on event-markers to afford examination of event-related brain potentials (ERP). Here, we demonstrate that it is possible to conduct ERP research without being reliant on event markers using a portable MUSE EEG system and a single computer. Specifically, we report the results of two experiments using data collected with the MUSE EEG system—one using the well-known visual oddball paradigm and the other using a standard reward-learning task. Our results demonstrate that we could observe and quantify the N200 and P300 ERP components in the visual oddball task and the reward positivity (the mirror opposite component to the feedback-related negativity) in the reward-learning task. Specifically, single sample t-tests of component existence (all p's < 0.05), computation of Bayesian credible intervals, and 95% confidence intervals all statistically verified the existence of the N200, P300, and reward positivity in all analyses. We provide with this research paper an open source website with all the instructions, methods, and software to replicate our findings and to provide researchers with an easy way to use the MUSE EEG system for ERP research. Importantly, our work highlights that with a single computer and a portable EEG system such as the MUSE one can conduct ERP research with ease thus greatly extending the possible use of the ERP methodology to a variety of novel contexts. PMID:28344546

Choosing MUSE: Validation of a Low-Cost, Portable EEG System for ERP Research.

PubMed

Krigolson, Olave E; Williams, Chad C; Norton, Angela; Hassall, Cameron D; Colino, Francisco L

2017-01-01

In recent years there has been an increase in the number of portable low-cost electroencephalographic (EEG) systems available to researchers. However, to date the validation of the use of low-cost EEG systems has focused on continuous recording of EEG data and/or the replication of large system EEG setups reliant on event-markers to afford examination of event-related brain potentials (ERP). Here, we demonstrate that it is possible to conduct ERP research without being reliant on event markers using a portable MUSE EEG system and a single computer. Specifically, we report the results of two experiments using data collected with the MUSE EEG system-one using the well-known visual oddball paradigm and the other using a standard reward-learning task. Our results demonstrate that we could observe and quantify the N200 and P300 ERP components in the visual oddball task and the reward positivity (the mirror opposite component to the feedback-related negativity) in the reward-learning task. Specifically, single sample t -tests of component existence (all p 's < 0.05), computation of Bayesian credible intervals, and 95% confidence intervals all statistically verified the existence of the N200, P300, and reward positivity in all analyses. We provide with this research paper an open source website with all the instructions, methods, and software to replicate our findings and to provide researchers with an easy way to use the MUSE EEG system for ERP research. Importantly, our work highlights that with a single computer and a portable EEG system such as the MUSE one can conduct ERP research with ease thus greatly extending the possible use of the ERP methodology to a variety of novel contexts.

Ultra-low cost and highly stable hydrated FePO4 anodes for aqueous sodium-ion battery

NASA Astrophysics Data System (ADS)

Wang, Yuesheng; Feng, Zimin; Laul, Dharminder; Zhu, Wen; Provencher, Manon; Trudeau, Michel L.; Guerfi, Abdelbast; Zaghib, Karim

2018-01-01

The growing demands for large-scale energy storage devices have put a spotlight on aqueous sodium-ion batteries, which possess a number of highly desirable features, such as sodium abundance, low cost and safety over organic electrolytes. While lots of cathode materials were reported, only few candidate materials like active carbon and NaTi2(PO4)3 were proposed as anodes. It is a long-standing common knowledge that the low cost, non-toxicity, and highly reversible FePO4·2H2O is known as an attractive cathode material for non-aqueous lithium- and sodium-ion batteries, but we demonstrate for the first time that nano-size non-carbon coated amorphous FePO4·2H2O can be used as the anode for an aqueous sodium-ion battery. Its optimum operating voltage (∼2.75 V vs. Na+/Na) avoids hydrogen evolution. The capacity is as high as 80 mAh/g at a rate of 0.5 C in a three-electrode system. The full cell, using the Na0.44MnO2 as cathode, maintained 90% of the capacity at 300 cycles at a rate of 3 C. The calculations also show that its volume change during the intercalation of Na ions is below 2%. Its low cost, high safety, along with its outstanding electrochemical performance makes amorphous FePO4·2H2O a promising anode material for aqueous sodium-ion batteries.

Key issues for low-cost FGD installations

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

DePriest, W.; Mazurek, J.M.

1995-12-01

This paper will discuss various methods for installing low-cost FGD systems. The paper will include a discussion of various types of FGD systems available, both wet and dry, and will compare the relative cost of each type. Important design issues, such as use of spare equipment, materials of construction, etc. will be presented. An overview of various low-cost construction techniques (i.e., modularization) will be included. This paper will draw heavily from Sargent & Lundy`s database of past and current FGD projects together with information we gathered for several Electric Power Research Institute (EPRI) studies on the subject.

Feasibility of adapting the fundamentals of laparoscopic surgery trainer box to endoscopic skills training tool.

PubMed

Crespin, Oscar M; Okrainec, Allan; Kwong, Andrea V; Habaz, Ilay; Jimenez, Maria Carolina; Szasz, Peter; Weiss, Ethan; Gonzalez, Cecilia G; Mosko, Jeffrey D; Liu, Louis W C; Swanstrom, Lee L; Perretta, Silvana; Shlomovitz, Eran

2018-06-01

The fundamentals of laparoscopic surgery (FLS) training box is a validated tool, already accessible to surgical trainees to hone their laparoscopic skills. We aim to investigate the feasibility of adapting the FLS box for the practice and assessment of endoscopic skills. This would allow for a highly available, reusable, low-cost, mechanical trainer. The design and development process was based on a user-centered design, which is a combination of the design thinking method and cognitive task analysis. The process comprises four phases: empathy, cognitive, prototyping/adaptation, and end user testing. The underlying idea was to utilize as many of the existing components of FLS training to maintain simplicity and cost effectiveness while allowing for the practice of clinically relevant endoscopic skills. A sample size of 18 participants was calculated to be sufficient to detect performance differences between experts and trainees using a two tailed t test with alpha set at 0.05, standard deviation of 5.5, and a power of 80%. Adaptation to the FLS box included two fundamental attachments: a front panel with an insertion point for an endoscope and a shaft which provides additional support and limits movement of the scope. The panel also allows for mounting of retroflexion tasks. Six endoscopic tasks inspired by FLS were designed (two of which utilize existing FLS components). Pilot testing with 38 participants showed high user's satisfaction and demonstrated that the trainer was robust and reliable. Task performance times was able to discriminate between trainees and experts for all six tasks. A mechanical, reusable, low-cost adaptation of the FLS training box for endoscopic skills is feasible and has high user satisfaction. Preliminary testing shows that the simulator is able to discriminate between trainees and experts. Following further validation, this adaptation may act as a supplement to the FES program.

Early differential processing of material images: Evidence from ERP classification.

PubMed

Wiebel, Christiane B; Valsecchi, Matteo; Gegenfurtner, Karl R

2014-06-24

Investigating the temporal dynamics of natural image processing using event-related potentials (ERPs) has a long tradition in object recognition research. In a classical Go-NoGo task two characteristic effects have been emphasized: an early task independent category effect and a later task-dependent target effect. Here, we set out to use this well-established Go-NoGo paradigm to study the time course of material categorization. Material perception has gained more and more interest over the years as its importance in natural viewing conditions has been ignored for a long time. In addition to analyzing standard ERPs, we conducted a single trial ERP pattern analysis. To validate this procedure, we also measured ERPs in two object categories (people and animals). Our linear classification procedure was able to largely capture the overall pattern of results from the canonical analysis of the ERPs and even extend it. We replicate the known target effect (differential Go-NoGo potential at frontal sites) for the material images. Furthermore, we observe task-independent differential activity between the two material categories as early as 140 ms after stimulus onset. Using our linear classification approach, we show that material categories can be differentiated consistently based on the ERP pattern in single trials around 100 ms after stimulus onset, independent of the target-related status. This strengthens the idea of early differential visual processing of material categories independent of the task, probably due to differences in low-level image properties and suggests pattern classification of ERP topographies as a strong instrument for investigating electrophysiological brain activity. © 2014 ARVO.

Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

NASA Technical Reports Server (NTRS)

Stearns, M.; Wilbers, L.

1982-01-01

Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems.

Low Budget Biology 3: A Collection of Low Cost Labs and Activities.

ERIC Educational Resources Information Center

Wartski, Bert; Wartski, Lynn Marie

This document contains biology labs, demonstrations, and activities that use low budget materials. The goal is to get students involved in the learning process by experiencing biology. Each lab has a teacher preparation section which outlines the purpose of the lab, some basic information, a list of materials , and how to prepare the different…

Space-based solar power conversion and delivery systems study. Volume 4: Energy conversion systems studies

NASA Technical Reports Server (NTRS)

1977-01-01

Solar cells and optical configurations for the SSPS were examined. In this task, three specific solar cell materials were examined: single crystal silicon, single crystal gallium arsenide, and polycrystalline cadmium sulfide. The comparison of the three different cells on the basis of a subsystem parametric cost per kW of SSPS-generated power at the terrestrial utility interface showed that gallium arsenide was the most promising solar cell material at high concentration ratios. The most promising solar cell material with no concentration, was dependent upon the particular combination of parameters representing cost, mass and performance that were chosen to represent each cell in this deterministic comparative analysis. The potential for mass production, based on the projections of the present state-of-the-art would tend to favor cadmium sulfide in lieu of single crystal silicon or gallium arsenide solar cells.

Stimulus-level interference disrupts repetition benefit during task switching in middle childhood

PubMed Central

Karayanidis, Frini; Jamadar, Sharna; Sanday, Dearne

2013-01-01

The task-switching paradigm provides a powerful tool to measure the development of core cognitive control processes. In this study, we use the alternating runs task-switching paradigm to assess preparatory control processes involved in flexibly preparing for a predictable change in task and stimulus-driven control processes involved in controlling stimulus-level interference. We present three experiments that examine behavioral and event-related potential (ERP) measures of task-switching performance in middle childhood and young adulthood under low and high stimulus interference conditions. Experiment 1 confirms that our new child-friendly tasks produce similar behavioral and electrophysiological findings in young adults as those previously reported. Experiment 2 examines task switching with univalent stimuli across a range of preparation intervals in middle childhood. Experiment 3 compares task switching with bivalent stimuli across the same preparation intervals in children and young adults. Children produced a larger RT switch cost than adults with univalent stimuli and a short preparation interval. Both children and adults showed significant reduction in switch cost with increasing preparation interval, but in children this was caused by greater increase in RT for repeat than switch trials. Response-locked ERPs showed intact preparation for univalent, but less efficient preparation for bivalent stimulus conditions. Stimulus-locked ERPs confirmed that children showed greater stimulus-level interference for repeat trials, especially with bivalent stimuli. We conclude that children show greater stimulus-level interference especially for repeat trials under high interference conditions, suggesting weaker mental representation of the current task set. PMID:24367317

Self-Paced Preparation for a Task Switch Eliminates Attentional Inertia but Not the Performance Switch Cost

ERIC Educational Resources Information Center

Longman, Cai S.; Lavric, Aureliu; Monsell, Stephen

2017-01-01

The performance overhead associated with changing tasks (the "switch cost") usually diminishes when the task is specified in advance but is rarely eliminated by preparation. A popular account of the "residual" (asymptotic) switch cost is that it reflects "task-set inertia": carry-over of task-set parameters from the…

Possibility of material cost reduction toward development of low-cost second-generation superconducting wires

NASA Astrophysics Data System (ADS)

Ichinose, Ataru; Horii, Shigeru; Doi, Toshiya

2017-10-01

Two approaches to reducing the material cost of second-generation superconducting wires are proposed in this paper: (1) instead of the electrical stabilizing layers of silver and copper presently used on the superconducting layer, a Nb-doped SrTiO3 conductive buffer layer and cube-textured Cu are proposed as an advanced architecture, and (2) the use of an electromagnetic (EM) steel tape as a metal substrate of coated conductors in a conventional architecture. In structures fabricated without using electrical stabilizing layers on the superconducting layer, the critical current density achieved at 77 K in a self-field was approximately 2.6 MA/cm2. On the other hand, in the case of using EM steel tapes, although the critical current density was far from practical at the current stage, the biaxial alignment of YBa2Cu3O y (YBCO) and buffer layers was realized without oxidation on the metal surface. In this study, the possibility of material cost reduction has been strongly indicated toward the development of low-cost second-generation superconducting wires in the near future.

Array automated assembly task low cost silicon solar array project, phase 2

NASA Technical Reports Server (NTRS)

Olson, C.

1980-01-01

Analyses of solar cell and module process steps for throughput rate, cost effectiveness, and reproductibility are reported. In addition to the concentration on cell and module processing sequences, an investigation was made into the capability of using microwave energy in the diffusion, sintering, and thick film firing steps of cell processing. Although the entire process sequence was integrated, the steps are treated individually with test and experimental data, conclusions, and recommendations.

Regularization iteration imaging algorithm for electrical capacitance tomography

NASA Astrophysics Data System (ADS)

Tong, Guowei; Liu, Shi; Chen, Hongyan; Wang, Xueyao

2018-03-01

The image reconstruction method plays a crucial role in real-world applications of the electrical capacitance tomography technique. In this study, a new cost function that simultaneously considers the sparsity and low-rank properties of the imaging targets is proposed to improve the quality of the reconstruction images, in which the image reconstruction task is converted into an optimization problem. Within the framework of the split Bregman algorithm, an iterative scheme that splits a complicated optimization problem into several simpler sub-tasks is developed to solve the proposed cost function efficiently, in which the fast-iterative shrinkage thresholding algorithm is introduced to accelerate the convergence. Numerical experiment results verify the effectiveness of the proposed algorithm in improving the reconstruction precision and robustness.

Acquiring research-grade ERPs on a shoestring budget: A comparison of a modified Emotiv and commercial SynAmps EEG system.

PubMed

Barham, Michael P; Clark, Gillian M; Hayden, Melissa J; Enticott, Peter G; Conduit, Russell; Lum, Jarrad A G

2017-09-01

This study compared the performance of a low-cost wireless EEG system to a research-grade EEG system on an auditory oddball task designed to elicit N200 and P300 ERP components. Participants were 15 healthy adults (6 female) aged between 19 and 40 (M = 28.56; SD = 6.38). An auditory oddball task was presented comprising 1,200 presentations of a standard tone interspersed by 300 trials comprising a deviant tone. EEG was simultaneously recorded from a modified Emotiv EPOC and a NeuroScan SynAmps RT EEG system. The modifications made to the Emotiv system included attaching research grade electrodes to the Bluetooth transmitter. Additional modifications enabled the Emotiv system to connect to a portable impedance meter. The cost of these modifications and portable impedance meter approached the purchase value of the Emotiv system. Preliminary analyses revealed significantly more trials were rejected from data acquired by the modified Emotiv compared to the SynAmps system. However, the ERP waveforms captured by the Emotiv system were found to be highly similar to the corresponding waveform from the SynAmps system. The latency and peak amplitude of N200 and P300 components were also found to be similar between systems. Overall, the results indicate that, in the context of an oddball task, the ERP acquired by a low-cost wireless EEG system can be of comparable quality to research-grade EEG acquisition equipment. © 2017 Society for Psychophysiological Research.

Overcoming residual interference in mental set switching: Neural correlates and developmental trajectory

PubMed Central

Witt, Suzanne T.; Stevens, Michael C.

2012-01-01

Mental set switching is a key facet of executive control measured behaviorally through reaction time or accuracy (i.e., ‘switch costs’) when shifting among task types. One of several experimentally-dissociable influences on switch costs is ‘task set inertia’, conceptualized as the residual interference conferred when a previous stimulus-response tendency interferes with subsequent stimulus processing on a new task. Task set inertia is thought to represent the passive decay of the previous stimulus-response set from working memory, and its effects decrease with increased interstimulus interval. Closely spaced trials confer high task set inertia, while sparsely spaced trials confer low task set inertia. This functional magnetic resonance imaging (fMRI) study characterized, for the first time, two opposing brain systems engaged to resolve task set inertia: 1) a frontoparietal ‘cortical control’ network for overcoming high task set inertia interference and 2) a subcortical-motor network more active during trials with low task set inertia. These networks were distinct from brain regions showing general switching effects (i.e., switch > non-switch) and from other previously-characterized interference effects. Moreover, there were ongoing maturational effects throughout adolescence for the brain regions engaged to overcome high task set inertia not seen for generalized switching effects. These novel findings represent a new avenue of exploration of cognitive set switching neural function. PMID:22584223

System identification of a small low-cost unmanned aerial vehicle using flight data from low-cost sensors

NASA Astrophysics Data System (ADS)

Hoffer, Nathan Von

Remote sensing has traditionally been done with satellites and manned aircraft. While. these methods can yield useful scientificc data, satellites and manned aircraft have limitations in data frequency, process time, and real time re-tasking. Small low-cost unmanned aerial vehicles (UAVs) provide greater possibilities for personal scientic research than traditional remote sensing platforms. Precision aerial data requires an accurate vehicle dynamics model for controller development, robust flight characteristics, and fault tolerance. One method of developing a model is system identification (system ID). In this thesis system ID of a small low-cost fixed-wing T-tail UAV is conducted. The linerized longitudinal equations of motion are derived from first principles. Foundations of Recursive Least Squares (RLS) are presented along with RLS with an Error Filtering Online Learning scheme (EFOL). Sensors, data collection, data consistency checking, and data processing are described. Batch least squares (BLS) and BLS with EFOL are used to identify aerodynamic coecoefficients of the UAV. Results of these two methods with flight data are discussed.

Evaluation of target efficiencies for solid-liquid separation steps in biofuels production.

PubMed

Kochergin, Vadim; Miller, Keith

2011-01-01

Development of liquid biofuels has entered a new phase of large scale pilot demonstration. A number of plants that are in operation or under construction face the task of addressing the engineering challenges of creating a viable plant design, scaling up and optimizing various unit operations. It is well-known that separation technologies account for 50-70% of both capital and operating cost. Additionally, reduction of environmental impact creates technological challenges that increase project cost without adding to the bottom line. Different technologies vary in terms of selection of unit operations; however, solid-liquid separations are likely to be a major contributor to the overall project cost. Despite the differences in pretreatment approaches, similar challenges arise for solid-liquid separation unit operations. A typical process for ethanol production from biomass includes several solid-liquid separation steps, depending on which particular stream is targeted for downstream processing. The nature of biomass-derived materials makes it either difficult or uneconomical to accomplish complete separation in a single step. Therefore, setting realistic efficiency targets for solid-liquid separations is an important task that influences overall process recovery and economics. Experimental data will be presented showing typical characteristics for pretreated cane bagasse at various stages of processing into cellulosic ethanol. Results of generic material balance calculations will be presented to illustrate the influence of separation target efficiencies on overall process recoveries and characteristics of waste streams.

Creating TUIs Using RFID Sensors--A Case Study Based on the Literacy Process of Children with Down Syndrome.

PubMed

Jadán-Guerrero, Janio; Guerrero, Luis; López, Gustavo; Cáliz, Doris; Bravo, José

2015-06-24

Teaching children with intellectual disabilities is a big challenge for most parents and educators. Special education teachers use learning strategies to develop and enhance motivation for complex learning tasks. Literacy acquisition is an essential and life-long skill for a child with intellectual disabilities. In this context, technology can support specific strategies that will help children learn to read. This paper introduces a Tangible User Interface (TUI) system based on Radio Frequency Identification (RFID) technology to support literacy for children with Down syndrome. Our proposed system focuses on the integration of RFID tags in 3D printed objects and low cost toys. The paper describes the experience of using some materials covering the tags and the different problems related to the material and distance of radio wave propagation. The results of a preliminary evaluation in a special education institution showed that the system helps to improve the interaction between teachers and children. The use of a TUI seems to give a physical sensory experience to develop literacy skills in children with Down syndrome.

Creating TUIs Using RFID Sensors—A Case Study Based on the Literacy Process of Children with Down Syndrome

PubMed Central

Jadán-Guerrero, Janio; Guerrero, Luis; López, Gustavo; Cáliz, Doris; Bravo, José

2015-01-01

Teaching children with intellectual disabilities is a big challenge for most parents and educators. Special education teachers use learning strategies to develop and enhance motivation for complex learning tasks. Literacy acquisition is an essential and life-long skill for a child with intellectual disabilities. In this context, technology can support specific strategies that will help children learn to read. This paper introduces a Tangible User Interface (TUI) system based on Radio Frequency Identification (RFID) technology to support literacy for children with Down syndrome. Our proposed system focuses on the integration of RFID tags in 3D printed objects and low cost toys. The paper describes the experience of using some materials covering the tags and the different problems related to the material and distance of radio wave propagation. The results of a preliminary evaluation in a special education institution showed that the system helps to improve the interaction between teachers and children. The use of a TUI seems to give a physical sensory experience to develop literacy skills in children with Down syndrome. PMID:26115455

Hot forming of silicon sheet, silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Graham, C. D., Jr.; Pope, D. P.; Kulkarni, S.; Wolf, M.

1978-01-01

The hot workability of polycrystalline silicon was studied. Uniaxail stress-strain curves are given for strain rates in the range of .0001 to .1/sec and temperatures from 1100 to 1380 C. At the highest strain rates at 1380 C axial strains in excess of 20% were easily obtainable without cracking. After deformations of 36%, recrystallization was completed within 0.1 hr at 1380 C. When the recrystallization was complete, there was still a small volume fraction of unrecyrstallized material which appeared very stable and may degrade the electronic properties of the bulk materials. Texture measurements showed that the as-produced vapor deposited polycrystalline rods have a 110 fiber texture with the 110 direction parallel to the growth direction and no preferred orientation about this axis. Upon axial compression perpendicular to the growth direction, the former 110 fiber axis changed to 111 and the compression axis became 110 . Recrystallization changed the texture to 110 along the former fiber axis and to 100 along the compression axis.

Research to Support the Determination of Spacecraft Maximum Acceptable Concentrations of Potential Atmospheric Contaminants

NASA Technical Reports Server (NTRS)

Orr, John L.

1997-01-01

In many ways, the typical approach to the handling of bibliographic material for generating review articles and similar manuscripts has changed little since the use of xerographic reproduction has become widespread. The basic approach is to collect reprints of the relevant material and place it in folders or stacks based on its dominant content. As the amount of information available increases with the passage of time, the viability of this mechanical approach to bibliographic management decreases. The personal computer revolution has changed the way we deal with many familiar tasks. For example, word processing on personal computers has supplanted the typewriter for many applications. Similarly, spreadsheets have not only replaced many routine uses of calculators but have also made possible new applications because the cost of calculation is extremely low. Objective The objective of this research was to use personal computer bibliographic software technology to support the determination of spacecraft maximum acceptable concentration (SMAC) values. Specific Aims The specific aims were to produce draft SMAC documents for hydrogen sulfide and tetrachloroethylene taking maximum advantage of the bibliographic software.

Development of a Benthic Macroinvertebrate Multimetric Index (MMI) for Neotropical Savanna Headwater Streams

EPA Science Inventory

Assessing the ecological impacts of anthropogenic pressures is a key task in environmental management. Multimetric indices (MMIs), based on aquatic assemblage responses to anthropogenic pressures, have been used increasingly throughout the world. The MMI approach is a low-cost, r...

A natural user interface to integrate citizen science and physical exercise.

PubMed

Palermo, Eduardo; Laut, Jeffrey; Nov, Oded; Cappa, Paolo; Porfiri, Maurizio

2017-01-01

Citizen science enables volunteers to contribute to scientific projects, where massive data collection and analysis are often required. Volunteers participate in citizen science activities online from their homes or in the field and are motivated by both intrinsic and extrinsic factors. Here, we investigated the possibility of integrating citizen science tasks within physical exercises envisaged as part of a potential rehabilitation therapy session. The citizen science activity entailed environmental mapping of a polluted body of water using a miniature instrumented boat, which was remotely controlled by the participants through their physical gesture tracked by a low-cost markerless motion capture system. Our findings demonstrate that the natural user interface offers an engaging and effective means for performing environmental monitoring tasks. At the same time, the citizen science activity increases the commitment of the participants, leading to a better motion performance, quantified through an array of objective indices. The study constitutes a first and necessary step toward rehabilitative treatments of the upper limb through citizen science and low-cost markerless optical systems.

Simulative design and process optimization of the two-stage stretch-blow molding process

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

Hopmann, Ch.; Rasche, S.; Windeck, C.

2015-05-22

The total production costs of PET bottles are significantly affected by the costs of raw material. Approximately 70 % of the total costs are spent for the raw material. Therefore, stretch-blow molding industry intends to reduce the total production costs by an optimized material efficiency. However, there is often a trade-off between an optimized material efficiency and required product properties. Due to a multitude of complex boundary conditions, the design process of new stretch-blow molded products is still a challenging task and is often based on empirical knowledge. Application of current CAE-tools supports the design process by reducing development timemore » and costs. This paper describes an approach to determine optimized preform geometry and corresponding process parameters iteratively. The wall thickness distribution and the local stretch ratios of the blown bottle are calculated in a three-dimensional process simulation. Thereby, the wall thickness distribution is correlated with an objective function and preform geometry as well as process parameters are varied by an optimization algorithm. Taking into account the correlation between material usage, process history and resulting product properties, integrative coupled simulation steps, e.g. structural analyses or barrier simulations, are performed. The approach is applied on a 0.5 liter PET bottle of Krones AG, Neutraubling, Germany. The investigations point out that the design process can be supported by applying this simulative optimization approach. In an optimization study the total bottle weight is reduced from 18.5 g to 15.5 g. The validation of the computed results is in progress.« less

Simulative design and process optimization of the two-stage stretch-blow molding process

NASA Astrophysics Data System (ADS)

Hopmann, Ch.; Rasche, S.; Windeck, C.

2015-05-01

The total production costs of PET bottles are significantly affected by the costs of raw material. Approximately 70 % of the total costs are spent for the raw material. Therefore, stretch-blow molding industry intends to reduce the total production costs by an optimized material efficiency. However, there is often a trade-off between an optimized material efficiency and required product properties. Due to a multitude of complex boundary conditions, the design process of new stretch-blow molded products is still a challenging task and is often based on empirical knowledge. Application of current CAE-tools supports the design process by reducing development time and costs. This paper describes an approach to determine optimized preform geometry and corresponding process parameters iteratively. The wall thickness distribution and the local stretch ratios of the blown bottle are calculated in a three-dimensional process simulation. Thereby, the wall thickness distribution is correlated with an objective function and preform geometry as well as process parameters are varied by an optimization algorithm. Taking into account the correlation between material usage, process history and resulting product properties, integrative coupled simulation steps, e.g. structural analyses or barrier simulations, are performed. The approach is applied on a 0.5 liter PET bottle of Krones AG, Neutraubling, Germany. The investigations point out that the design process can be supported by applying this simulative optimization approach. In an optimization study the total bottle weight is reduced from 18.5 g to 15.5 g. The validation of the computed results is in progress.

Boiler materials for ultra supercritical coal power plants

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

Purgert, Robert; Shingledecker, John; Pschirer, James

2015-12-29

The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have undertaken a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of advanced ultrasupercritical (A-USC) steam conditions up to 760°C (1400°F) and 35 MPa (5000 psi). A limiting factor to achieving these higher temperatures and pressures for future A-USC plants are the materials of construction. The goal of this projectmore » is to assess/develop materials technology to build and operate an A-USC boiler capable of delivering steam with conditions up to 760°C (1400°F)/35 MPa (5000 psi). The project has successfully met this goal through a focused long-term public-private consortium partnership. The project was based on an R&D plan developed by the Electric Power Research Institute (EPRI) and an industry consortium that supplemented the recommendations of several DOE workshops on the subject of advanced materials. In view of the variety of skills and expertise required for the successful completion of the proposed work, a consortium led by the Energy Industries of Ohio (EIO) with cost-sharing participation of all the major domestic boiler manufacturers, ALSTOM Power (Alstom), Babcock and Wilcox Power Generation Group, Inc. (B&W), Foster Wheeler (FW), and Riley Power, Inc. (Riley), technical management by EPRI and research conducted by Oak Ridge National Laboratory (ORNL) has been developed. The project has clearly identified and tested materials that can withstand 760°C (1400°F) steam conditions and can also make a 700°C (1300°F) plant more economically attractive. In this project, the maximum temperature capabilities of these and other available high-temperature alloys have been assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. A major effort involving eight tasks was completed in Phase 1. In a subsequent Phase 2 extension, the earlier defined tasks were extended to finish and enhance the Phase 1 activities. This extension included efforts in improved weld/weldment performance, development of longer-term material property databases, additional field (in-plant) corrosion testing, improved understanding of long-term oxidation kinetics and exfoliation, cyclic operation, and fabrication methods for waterwalls. In addition, preliminary work was undertaken to model an oxyfuel boiler to define local environments expected to occur and to study corrosion behavior of alloys under these conditions. This final technical report provides a comprehensive summary of all the work undertaken by the consortium and the research findings from all eight (8) technical tasks including A-USC boiler design and economics (Task 1), long-term materials properties (Task 2), steam- side oxidation (Task 3), Fireside Corrosion (Task 4), Welding (Task 5), Fabricability (Task 6), Coatings (Task 7), and Design Data and Rules (Task 8).« less

Is there a general task switching ability?

PubMed

Yehene, Einat; Meiran, Nachshon

2007-11-01

Participants were tested on two analogous task switching paradigms involving Shape/Size tasks and Vertical/Horizontal tasks, respectively, and three measures of psychometric intelligence, tapping fluid, crystallized and perceptual speed abilities. The paradigms produced similar patterns of group mean reaction times (RTs) and the vast majority of the participants showed switching cost (switch RT minus repeat RT), mixing cost (repeat RT minus single-task RT) and congruency effects. The shared intra-individual variance across paradigms and with psychometric intelligence served as criteria for general ability. Structural equations modeling indicated that switching cost with ample preparation ("residual cost") and mixing cost met these criteria. However, switching cost with little preparation and congruency effects were predominantly paradigm specific.

Citrate-based fluorescent materials for low-cost chloride sensing in the diagnosis of Cystic Fibrosis.

PubMed

Kim, Jimin P; Xie, Zhiwei; Creer, Michael; Liu, Zhiwen; Yang, Jian

2017-01-01

Chloride is an essential electrolyte that maintains homeostasis within the body, where abnormal chloride levels in biological fluids may indicate various diseases such as Cystic Fibrosis. However, current analytical solutions for chloride detection fail to meet the clinical needs of both high performance and low material or labor costs, hindering translation into clinical settings. Here we present a new class of fluorescence chloride sensors derived from a facile citrate -based synthesis platform that utilize dynamic quenching mechanisms. Based on this low-cost platform, we demonstrate for the first time a selective sensing strategy that uses a single fluorophore to detect multiple halides simultaneously, promising both selectivity and automation to improve performance and reduce labor costs. We also demonstrate the clinical utility of citrate-based sensors as a new sweat chloride test method for the diagnosis of Cystic Fibrosis by performing analytical validation with sweat controls and clinical validation with sweat from individuals with or without Cystic Fibrosis. Lastly, molecular modeling studies reveal the structural mechanism behind chloride sensing, serving to expand this class of fluorescence sensors with improved chloride sensitivities. Thus citrate-based fluorescent materials may enable low-cost, automated multi-analysis systems for simpler, yet accurate, point-of-care diagnostics that can be readily translated into clinical settings. More broadly, a wide range of medical, industrial, and environmental applications can be achieved with such a facile synthesis platform, demonstrated in our citrate-based biodegradable polymers with intrinsic fluorescence sensing.

Low-Cost Aids for Elementary Science Teaching in Asia and the Pacific.

ERIC Educational Resources Information Center

National Inst. for Educational Research, Tokyo (Japan).

Regional workshops sponsored by the National Institute for Educational Research (Japan) were held to strengthen national efforts in the development of elementary science aids/materials. This document provides: (1) guidelines for the development of appropriate and low-cost aids for science instruction; (2) inventory of aids; (3) synthesis of…

Affective attention under cognitive load: reduced emotional biases but emergent anxiety-related costs to inhibitory control

PubMed Central

Berggren, Nick; Richards, Anne; Taylor, Joseph; Derakshan, Nazanin

2013-01-01

Trait anxiety is associated with deficits in attentional control, particularly in the ability to inhibit prepotent responses. Here, we investigated this effect while varying the level of cognitive load in a modified antisaccade task that employed emotional facial expressions (neutral, happy, and angry) as targets. Load was manipulated using a secondary auditory task requiring recognition of tones (low load), or recognition of specific tone pitch (high load). Results showed that load increased antisaccade latencies on trials where gaze toward face stimuli should be inhibited. This effect was exacerbated for high anxious individuals. Emotional expression also modulated task performance on antisaccade trials for both high and low anxious participants under low cognitive load, but did not influence performance under high load. Collectively, results (1) suggest that individuals reporting high levels of anxiety are particularly vulnerable to the effects of cognitive load on inhibition, and (2) support recent evidence that loading cognitive processes can reduce emotional influences on attention and cognition. PMID:23717273

A Low-Cost Part-Task Flight Training System: An Application of a Head Mounted Display

DTIC Science & Technology

1990-12-01

architecture. The task at hand was to develop a software emulation libary that would emulate the function calls used within the Flight and Dog programs. This...represented in two hexadecimal digits for each color. The format of the packed long integer looks like aaggbbrr with each color value representing a...Western Digital ethernet card as the cheapest compatible card available. Good fortune arrived, as I was calling to order the card, I saw an unused card

Screening, cataloging and indexing of earth resource aircraft missions

NASA Technical Reports Server (NTRS)

1974-01-01

Data obtained from 30 earth resources aircraft missions, flown between September 1, 1973 and September 1, 1974, were screened, cataloged, and indexed using microfilm copy. The manhours required for completing the task are presented, and problems encountered during the project are reported. It is concluded that a cataloging and indexing report of remote sensor data can be prepared on a timely basis for a relatively low cost from microfilm. Recommendations are given in order to further facilitate the task.

Low cost 3D-printing used in an undergraduate project: an integrating sphere for measurement of photoluminescence quantum yield

NASA Astrophysics Data System (ADS)

Tomes, John J.; Finlayson, Chris E.

2016-09-01

We report upon the exploitation of the latest 3D printing technologies to provide low-cost instrumentation solutions, for use in an undergraduate level final-year project. The project addresses prescient research issues in optoelectronics, which would otherwise be inaccessible to such undergraduate student projects. The experimental use of an integrating sphere in conjunction with a desktop spectrometer presents opportunities to use easily handled, low cost materials as a means to illustrate many areas of physics such as spectroscopy, lasers, optics, simple circuits, black body radiation and data gathering. Presented here is a 3rd year undergraduate physics project which developed a low cost (£25) method to manufacture an experimentally accurate integrating sphere by 3D printing. Details are given of both a homemade internal reflectance coating formulated from readily available materials, and a robust instrument calibration method using a tungsten bulb. The instrument is demonstrated to give accurate and reproducible experimental measurements of luminescence quantum yield of various semiconducting fluorophores, in excellent agreement with literature values.

Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 5 Full-Scale Test Results

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

Gary Blythe; MariJon Owens

2007-12-01

This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulkmore » solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the additives in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power has provided the Texas lignite/PRB co-fired test site for pilot FGD tests and cost sharing. Southern Company has provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation is providing the TMT-15 additive, and the Nalco Company is providing the Nalco 8034 additive. Both companies are also supplying technical support to the test program as in-kind cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests and the full-scale test using high-sulfur coal were completed in 2005 and 2006 and have been previously reported. This topical report presents the results from the Task 5 full-scale additive tests, conducted at Southern Company's Plant Yates Unit 1. Both additives were tested there.« less

Low Angle Silicon Sheet Growth. Large Area Silicon Sheet Task Low Cost Solar Array Project

NASA Technical Reports Server (NTRS)

1982-01-01

The results of a program to demonstrate the feasibility of a low angle silicon ribbon growth process are described. Twenty-six experimental runs were performed. Ribbons were grown at pull rates from 5 to 68 cm/min. Ribbon lengths up to 74 cm were grown while widths varied from 5 to 25 mm. Thicknesses varied from 0.6 to 2.5 mm, with typical values of about 1 mm.

Different Strokes for Different Folks: How Individual Interest Moderates the Effects of Situational Factors on Task Interest

ERIC Educational Resources Information Center

Durik, Amanda M.; Harackiewicz, Judith M.

2007-01-01

Individual interest was examined as a moderator of effects of situational factors designed to catch and hold task interest. In Study 1, 96 college students learned a math technique with materials enhanced with collative features (catch) versus not. Catch promoted motivation among participants with low individual interest in math (IIM) but hampered…

Designer's unified cost model

NASA Technical Reports Server (NTRS)

Freeman, William T.; Ilcewicz, L. B.; Swanson, G. D.; Gutowski, T.

1992-01-01

A conceptual and preliminary designers' cost prediction model has been initiated. The model will provide a technically sound method for evaluating the relative cost of different composite structural designs, fabrication processes, and assembly methods that can be compared to equivalent metallic parts or assemblies. The feasibility of developing cost prediction software in a modular form for interfacing with state of the art preliminary design tools and computer aided design programs is being evaluated. The goal of this task is to establish theoretical cost functions that relate geometric design features to summed material cost and labor content in terms of process mechanics and physics. The output of the designers' present analytical tools will be input for the designers' cost prediction model to provide the designer with a data base and deterministic cost methodology that allows one to trade and synthesize designs with both cost and weight as objective functions for optimization. The approach, goals, plans, and progress is presented for development of COSTADE (Cost Optimization Software for Transport Aircraft Design Evaluation).

Common Low-cost IM Explosive Program. Development of Next Generation Insensitive Munitions: A Success Story

DTIC Science & Technology

2011-11-30

fuze separating from the shell body preventing high order detonations thus saving the lives of the Soldiers. Unit’s SPC Alan Ng  with his father Peter...Sensitive If not fully compliant, must show improvement over Baseline explosive Affordable Artillery Cost Drivers = Steel Body Material & Explosive Fill...Mortar Cost Drivers = Steel Body Material, Fuze & Propelling Charges Producible within the National Technology and Industrial Base Infrastructure

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

NASA Astrophysics Data System (ADS)

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

2012-03-01

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

Low Cost Polymer heat Exchangers for Condensing Boilers

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

Butcher, Thomas; Trojanowski, Rebecca; Wei, George

2015-09-30

Work in this project sought to develop a suitable design for a low cost, corrosion resistant heat exchanger as part of a high efficiency condensing boiler. Based upon the design parameters and cost analysis several geometries and material options were explored. The project also quantified and demonstrated the durability of the selected polymer/filler composite under expected operating conditions. The core material idea included a polymer matrix with fillers for thermal conductivity improvement. While the work focused on conventional heating oil, this concept could also be applicable to natural gas, low sulfur heating oil, and biodiesel- although these are considered tomore » be less challenging environments. An extruded polymer composite heat exchanger was designed, built, and tested during this project, demonstrating technical feasibility of this corrosion-resistant material approach. In such flue gas-to-air heat exchangers, the controlling resistance to heat transfer is in the gas-side convective layer and not in the tube material. For this reason, the lower thermal conductivity polymer composite heat exchanger can achieve overall heat transfer performance comparable to a metal heat exchanger. However, with the polymer composite, the surface temperature on the gas side will be higher, leading to a lower water vapor condensation rate.« less

Low temperature selective absorber research

NASA Astrophysics Data System (ADS)

Herzenberg, S. A.; Silberglitt, R.

1982-04-01

Research carried out since 1979 on selective absorbers is surveyed, with particular attention given to the low-temperature coatings seen as promising for flat plate and evacuated tube applications. The most thoroughly investigated absorber is black chrome, which is highly selective and is the most durable low-temperature absorber. It is believed that other materials, because of their low cost and lower content of strategic materials, may eventually supplant black chrome. Among these candidates are chemically converted black nickel; anodically oxidized nickel, zinc, and copper composites; and nickel or other low-cost multilayer coatings. In reviewing medium and high-temperature research, black chrome, multilayer coatings and black cobalt are seen as best medium-temperature candidates. For high temperatures, an Al2O3/Pt-Al203 multilayer composite or the zirconium diboride coating is preferred.

Inhibition in task switching: The reliability of the n - 2 repetition cost.

PubMed

Kowalczyk, Agnieszka W; Grange, James A

2017-12-01

The n - 2 repetition cost seen in task switching is the effect of slower response times performing a recently completed task (e.g. an ABA sequence) compared to performing a task that was not recently completed (e.g. a CBA sequence). This cost is thought to reflect cognitive inhibition of task representations and as such, the n - 2 repetition cost has begun to be used as an assessment of individual differences in inhibitory control; however, the reliability of this measure has not been investigated in a systematic manner. The current study addressed this important issue. Seventy-two participants performed three task switching paradigms; participants were also assessed on rumination traits and processing speed-measures of individual differences potentially modulating the n - 2 repetition cost. We found significant n - 2 repetition costs for each paradigm. However, split-half reliability tests revealed that this cost was not reliable at the individual-difference level. Neither rumination tendencies nor processing speed predicted this cost. We conclude that the n - 2 repetition cost is not reliable as a measure of individual differences in inhibitory control.

Analysis and evaluation of processes and equipment in tasks 2 and 4 of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Goldman, H.; Wolf, M.

1978-01-01

Several experimental and projected Czochralski crystal growing process methods were studied and compared to available operations and cost-data of recent production Cz-pulling, in order to elucidate the role of the dominant cost contributing factors. From this analysis, it becomes apparent that the specific add-on costs of the Cz-process can be expected to be reduced by about a factor of three by 1982, and about a factor of five by 1986. A format to guide in the accumulation of the data needed for thorough techno-economic analysis of solar cell production processes was developed.

Researchers propose single grade rule for evaluating hardwood pallet cants

Treesearch

Hal Mitchell; Marshall White; Philip Araman; Peter Hamner

2008-01-01

In "price taker" markets, successful businesses are the low cost producers, and pallet manufacturers are no exception. The single largest cost component of pallet manufacturing is raw material costs. Cants and lumber typically account for over 60% of operating costs. In the last three decades, cants have replaced lumber as the primary raw...

What Costs Do Reveal and Moving beyond the Cost Debate: Reply to Einstein and McDaniel (2010)

ERIC Educational Resources Information Center

Smith, Rebekah E.

2010-01-01

Einstein et al. (2005) predicted no cost to an ongoing task when a prospective memory task met certain criteria. Smith, Hunt, McVay, and McConnell (2007) used prospective memory tasks that met these criteria and found a cost to the ongoing task, contrary to Einstein et al.'s prediction. Einstein and McDaniel (2010) correctly noted that there are…

A comparison of human and machine translation of health promotion materials for public health practice: time, costs, and quality.

PubMed

Turner, Anne M; Bergman, Margo; Brownstein, Megumu; Cole, Kate; Kirchhoff, Katrin

2014-01-01

Most local public health departments serve limited English proficiency groups but lack sufficient resources to translate the health promotion materials that they produce into different languages. Machine translation (MT) with human postediting could fill this gap and work toward decreasing health disparities among non-English speakers. (1) To identify the time and costs associated with human translation (HT) of public health documents, (2) determine the time necessary for human postediting of MT, and (3) compare the quality of postedited MT and HT. A quality comparison of 25 MT and HT documents was performed with public health translators. The public health professionals involved were queried about the workflow, costs, and time for HT of 11 English public health documents over a 20-month period. Three recently translated documents of similar size and topic were then machine translated, the time for human postediting was recorded, and a blind quality analysis was performed. Seattle/King County, Washington. Public health professionals. (1) Estimated times for various HT tasks; (2) observed postediting times for MT documents; (3) actual costs for HT; and (4) comparison of quality ratings for HT and MT. Human translation via local health department methods took 17 hours to 6 days. While HT postediting words per minute ranged from 1.58 to 5.88, MT plus human postediting words per minute ranged from 10 to 30. The cost of HT ranged from $130 to $1220; MT required no additional costs. A quality comparison by bilingual public health professionals showed that MT and HT were equivalently preferred. MT with human postediting can reduce the time and costs of translating public health materials while maintaining quality similar to HT. In conjunction with postediting, MT could greatly improve the availability of multilingual public health materials.

Galactic and Solar Cosmic Ray Shielding in Deep Space

NASA Technical Reports Server (NTRS)

Wilson, John W.; Cucinotta, Francis A.; Tai, H.; Simonsen, Lisa C.; Shinn, Judy L.; Thibeault, Shelia; Kim, M. Y.

1997-01-01

An analysis of the radiation hazards in support of NASA deep space exploration activities is presented. The emphasis is on materials required for radiation protection shielding. Aluminum has been found to be a poor shield material when dose equivalent is used with exposure limits for low Earth orbit (LEO) as a guide for shield requirements. Because the radiation issues are cost related-the parasitic shield mass has high launch costs, the use of aluminum as a basic construction material is clearly not cost-effective and alternate materials need to be developed. In this context, polyethylene is examined as a potentially useful material and demonstrates important advantages as an alternative to aluminum construction. Although polyethylene is useful as a shield material, it may not meet other design criteria (strength, stability, thermal); other polymer materials must be examined.

Single String Integration Test of the High Voltage Hall Accelerator System

NASA Technical Reports Server (NTRS)

Kamhawi, Hani; Haag, Thomas W.; Huang, Wensheng; Pinero, Luis; Peterson, Todd; Shastry, Rohit

2013-01-01

HiVHAc Task Objectives:-Develop and demonstrate low-power, long-life Hall thruster technology to enable cost effective EP for Discovery-class missions-Advance the TRL level of potential power processing units and xenon feed systems to integrate with the HiVHAc thruster.

Task switching costs in preschool children and adults.

PubMed

Peng, Anna; Kirkham, Natasha Z; Mareschal, Denis

2018-08-01

Past research investigating cognitive flexibility has shown that preschool children make many perseverative errors in tasks that require switching between different sets of rules. However, this inflexibility might not necessarily hold with easier tasks. The current study investigated the developmental differences in cognitive flexibility using a task-switching procedure that compared reaction times and accuracy in 4- and 6-year-olds with those in adults. The experiment involved simple target detection tasks and was intentionally designed in a way that the stimulus and response conflicts were minimal together with a long preparation window. Global mixing costs (performance costs when multiple tasks are relevant in a context), and local switch costs (performance costs due to switching to an alternative task) are typically thought to engage endogenous control processes. If this is the case, we should observe developmental differences with both of these costs. Our results show, however, that when the accuracy was good, there were no age differences in cognitive flexibility (i.e., the ability to manage multiple tasks and to switch between tasks) between children and adults. Even though preschool children had slower reaction times and were less accurate, the mixing and switch costs associated with task switching were not reliably larger for preschool children. Preschool children did, however, show more commission errors and greater response repetition effects than adults, which may reflect differences in inhibitory control. Copyright © 2018 Elsevier Inc. All rights reserved.

Cost-effective treatment of low-risk carcinoma not invading bladder muscle.

PubMed

Green, David A; Rink, Michael; Cha, Eugene K; Xylinas, Evanguelos; Chughtai, Bilal; Scherr, Douglas S; Shariat, Shahrokh F; Lee, Richard K

2013-03-01

Study Type - Therapy (cost effectiveness analysis) Level of Evidence 2a What's known on the subject? and What does the study add? Bladder cancer is one of the costliest malignancies to treat throughout the life of a patient. The most cost-effective management for low-risk non-muscle-invasive bladder cancer is not known. The current study shows that employing cystoscopic office fulguration for low-risk appearing bladder cancer recurrences can materially impact the cost-effectiveness of therapy. In a follow-up protocol where office fulguration is routinely employed for low-risk bladder cancers, peri-operative intravesical chemotherapy may not provide any additional cost-effectiveness benefit. To examine the cost-effectiveness of fulguration vs transurethral resection of bladder tumour (TURBT) with and without perioperative intravesical chemotherapy (PIC) for managing low-risk carcinoma not invading bladder muscle (NMIBC). Low-risk NMIBC carries a low progression rate, lending support to the use of office-based fulguration for small recurrences rather than traditional TURBT. A Markov state transition model was created to simulate treatment of NMIBC with vs without PIC, with recurrence treated by formal TURBT vs treatment with fulguration. Costing data were obtained from the Medicare Resource Based Relative Value Scale. Data regarding the success of PIC were obtained from the peer-reviewed literature, as were corresponding utilities for bladder cancer-related procedures. Sensitivity analyses were performed. At 5-year follow-up, a strategy of fulguration without PIC was the most cost-effective (mean cost-effectiveness = US $654.8/quality-adjusted life year), despite a lower recurrence rate with PIC. Both fulguration strategies dominated each TURBT strategy. Sensitivity analysis showed that fulguration without PIC dominated all other strategies when the recurrence rate after PIC was increased to ≥14.2% per year. Similarly, the cost-effectiveness of TURBT becomes more competitive with fulguration when the total cost of TURBT declines < US $1175. The present study shows that fulguration without PIC was the most cost-effective strategy for treating low-risk NMIBC. The effectiveness of PIC and the cost of TURBT can materially impact the cost-effectiveness of the different management strategies. These results should be considered in treatment decisions in the context of preserving oncological control. © 2012 BJU INTERNATIONAL.

Effect of feedback mode and task difficulty on quality of timing decisions in a zero-sum game.

PubMed

Tikuisis, Peter; Vartanian, Oshin; Mandel, David R

2014-09-01

The objective was to investigate the interaction between the mode of performance outcome feedback and task difficulty on timing decisions (i.e., when to act). Feedback is widely acknowledged to affect task performance. However, the extent to which feedback display mode and its impact on timing decisions is moderated by task difficulty remains largely unknown. Participants repeatedly engaged a zero-sum game involving silent duels with a computerized opponent and were given visual performance feedback after each engagement. They were sequentially tested on three different levels of task difficulty (low, intermediate, and high) in counterbalanced order. Half received relatively simple "inside view" binary outcome feedback, and the other half received complex "outside view" hit rate probability feedback. The key dependent variables were response time (i.e., time taken to make a decision) and survival outcome. When task difficulty was low to moderate, participants were more likely to learn and perform better from hit rate probability feedback than binary outcome feedback. However, better performance with hit rate feedback exacted a higher cognitive cost manifested by higher decision response time. The beneficial effect of hit rate probability feedback on timing decisions is partially moderated by task difficulty. Performance feedback mode should be judiciously chosen in relation to task difficulty for optimal performance in tasks involving timing decisions.

Using Converter Dust to Produce Low Cost Cementitious Composites by in situ Carbon Nanotube and Nanofiber Synthesis

PubMed Central

Ludvig, Péter; Calixto, José M.; Ladeira, Luiz O.; Gaspar, Ivan C.P.

2011-01-01

Carbon nanotubes (CNTs) and nanofibers (CNFs) were synthesized on clinker and silica fume particles in order to create a low cost cementitious nanostructured material. The synthesis was carried out by an in situ chemical vapor deposition (CVD) process using converter dust, an industrial byproduct, as iron precursor. The use of these materials reduces the cost, with the objective of application in large-scale nanostructured cement production. The resulting products were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) and were found to be polydisperse in size and to have defective microstructure. Some enhancement in the mechanical behavior of cement mortars was observed due to the addition of these nano-size materials. The contribution of these CNTs/CNFs to the mechanical strength of mortar specimens is similar to that of high quality CNTs incorporated in mortars by physical mixture. PMID:28880007

The Role of Working Memory Capacity and Interference Resolution Mechanisms in Task Switching

PubMed Central

Pettigrew, Corinne; Martin, Randi C.

2015-01-01

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response-distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response-distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching. PMID:26594895

The role of working memory capacity and interference resolution mechanisms in task switching.

PubMed

Pettigrew, Corinne; Martin, Randi C

2016-12-01

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response-distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. A total of 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response-distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores, which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching.

Distributive Distillation Enabled by Microchannel Process Technology

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

Arora, Ravi

The application of microchannel technology for distributive distillation was studied to achieve the Grand Challenge goals of 25% energy savings and 10% return on investment. In Task 1, a detailed study was conducted and two distillation systems were identified that would meet the Grand Challenge goals if the microchannel distillation technology was used. Material and heat balance calculations were performed to develop process flow sheet designs for the two distillation systems in Task 2. The process designs were focused on two methods of integrating the microchannel technology 1) Integrating microchannel distillation to an existing conventional column, 2) Microchannel distillation formore » new plants. A design concept for a modular microchannel distillation unit was developed in Task 3. In Task 4, Ultrasonic Additive Machining (UAM) was evaluated as a manufacturing method for microchannel distillation units. However, it was found that a significant development work would be required to develop process parameters to use UAM for commercial distillation manufacturing. Two alternate manufacturing methods were explored. Both manufacturing approaches were experimentally tested to confirm their validity. The conceptual design of the microchannel distillation unit (Task 3) was combined with the manufacturing methods developed in Task 4 and flowsheet designs in Task 2 to estimate the cost of the microchannel distillation unit and this was compared to a conventional distillation column. The best results were for a methanol-water separation unit for the use in a biodiesel facility. For this application microchannel distillation was found to be more cost effective than conventional system and capable of meeting the DOE Grand Challenge performance requirements.« less

Thermal infrared reference sources fabricated from low-cost components and materials

NASA Astrophysics Data System (ADS)

Hovland, Harald; Skauli, Torbjørn

2018-04-01

Mass markets, including mobile phones and automotive sensors, drive rapid developments of imaging technologies toward high performance, low cost sensors, even for the thermal infrared. Good infrared calibration blackbody sources have remained relatively costly, however. Here we demonstrate how to make low-cost reference sources, making quantitative infrared radiometry more accessible to a wider community. Our approach uses ordinary construction materials combined with low cost microcontrollers, digital temperature sensors and foil heater elements from massmarket 3D printers. Blackbodies are constructed from a foil heater of some chosen size and shape, attached to the back of a similarly shaped aluminum plate coated with commercial black paint, which normally exhibits high emissivity. The emissivity can be readily checked by using a thermal imager to view the reflection of a hot object. A digital temperature sensor is attached to the back of the plate. Thermal isolation of the backside minimizes temperature gradients through the plate, ensuring correct readings of the front temperature. The isolation also serves to minimize convection gradients and keeps power consumption low, which is useful for battery powered operation in the field. We demonstrate surface blackbodies (200x200 mm2) with surface homogeneities as low as 0.1°C at 100°C. Homogeneous heating and low thermal mass provides for fast settling time and setup/pack-down time. The approach is scalable to larger sizes by tiling, enabling portable and foldable square-meter-size or larger devices.

Characterization of asphalt treated base course material

DOT National Transportation Integrated Search

2010-06-01

Asphalt-treated bases are often used in new pavements; the materials are available and low-cost, but there is little data on how these materials perform in cold regions. : This study investigated four ATB types (hot asphalt, emulsion, foamed asphalt,...

We Will Find A Way: Understanding the Legacy of Canadian Special Operations Forces

DTIC Science & Technology

2012-02-01

and numerous contemporary English accounts conceded that the Canadian raiders “are well known to be the most dangerous enemy of any... reckoned...of the 1st Canadian Parachute Bat- talion, at great cost and personal sacrifice, pioneered a new innovative form of warfare and demonstrated agility...The MND quickly realized the strategic impact at a relatively low cost , that even a small SOF task force could achieve. As such, he pushed for

Standardizing adult tracheostomy tube styles: what is the clinical and cost-effective impact?

PubMed

Crimlisk, Janet T; O'Donnell, Charles; Grillone, Gregory A

2006-01-01

Tracheostomy tubes are made of a variety of materials, components, and styles. In a recent merger of our hospitals, we noted a large assortment of tubes available for clinicians. The different tubes resulted in complaints from staff, which included confusion, delays in obtaining preferred tubes, and inconsistent shelf stock. A multidisciplinary task force was formed to recommend standardizing the styles of tracheostomy tubes. A comparison of tracheotomy procedures, tracheostomy tube usage, and tube costs were done 6 months before and 6 months after the standardization. The number of tube styles decreased from 9 to 4; specialty extra-long tubes decreased from 3 to 2. There were no cost savings in standardizing the tracheostomy tubes.

Category priming with aliens: analysing the influence of targets' prototypicality on the centre surround inhibition mechanism.

PubMed

Frings, Christian; Göbel, Ariane; Mast, Frank; Sutter, Julia; Bermeitinger, Christina; Wentura, Dirk

2011-08-01

Marginally perceptible prototypes as primes lead to slowed reactions to related category exemplars as compared to unrelated ones. This at first glance counterintuitive finding has been interpreted as evidence for a particular mechanism of lateral inhibition, namely the centre surround inhibition mechanism. We investigated the semantic surround of category labels by experimentally manipulating the prototypicality of stimuli. Participants first learned two new categories of fantasy creatures in a 5-day-long learning phase before they worked through a semantic priming task with the category prototypes as primes and category exemplars as targets. For high-prototypical targets we observed benefit effects from related primes, whereas for low-prototypical targets we observed cost effects. The results define when the centre surround inhibition mechanism is applied, and furthermore might explain why previous studies with word stimuli (i.e., material that prevents experimental manipulation of prototypicality) observed mixed results concerning the prototypicality of targets.

Silicon on Ceramic Process: Silicon Sheet Growth and Device Development for the Large-area Silicon Sheet and Cell Development Tasks of the Low-cost Solar Array Project

NASA Technical Reports Server (NTRS)

Chapman, P. W.; Zook, J. D.; Heaps, J. D.; Pickering, C.; Grung, B. L.; Koepke, B.; Schuldt, S. B.

1979-01-01

The technical and economic feasibility of producing solar cell quality sheet silicon was investigated. It was hoped this could be done by coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. Work was directed towards the solution of unique cell processing/design problems encountered with the silicon-ceramic (SOC) material due to its intimate contact with the ceramic substrate. Significant progress was demonstrated in the following areas; (1) the continuous coater succeeded in producing small-area coatings exhibiting unidirectional solidification and substatial grain size; (2) dip coater succeeded in producing thick (more than 500 micron) dendritic layers at coating speeds of 0.2-0.3 cm/sec; and (3) a standard for producing total area SOC solar cells using slotted ceramic substrates was developed.

Silicon Sheet Growth Development for the Large Area Sheet Task of the Low Cost Solar Array Project. Heat Exchanger Method - Ingot Casting Fixed Abrasive Method - Multi-Wire Slicing

NASA Technical Reports Server (NTRS)

Schmid, F.; Khattak, C. P.

1978-01-01

Solar cells fabricated from HEM cast silicon yielded up to 15% conversion efficiencies. This was achieved in spite of using unpurified graphite parts in the HEM furnace and without optimization of material or cell processing parameters. Molybdenum retainers prevented SiC formation and reduced carbon content by 50%. The oxygen content of vacuum cast HEM silicon is lower than typical Czochralski grown silicon. Impregnation of 45 micrometers diamonds into 7.5 micrometers copper sheath showed distortion of the copper layer. However, 12.5 micrometers and 15 micrometers copper sheath can be impregnated with 45 micrometers diamonds to a high concentration. Electroless nickel plating of wires impregnated only in the cutting edge showed nickel concentration around the diamonds. This has the possibility of reducing kerf. The high speed slicer fabricated can achieve higher speed and longer stroke with vibration isolation.

Silicon-on-ceramic Process: Silicon Sheet Growth and Device Development for the Large-area Silicon Sheet and Cell Development Tasks of the Low-cost Solar Array Project

NASA Technical Reports Server (NTRS)

Chapman, P. W.; Zook, J. D.; Heaps, J. D.; Grung, B. L.; Koepke, B.; Schuldt, S. B.

1979-01-01

Significant progress is reported in fabricating a 4 sq cm cell having a 10.1 percent conversion efficiency and a 10 sq cm cell having a 9.2 percent conversion efficiency. The continuous (SCIM) coater succeeded in producing a 16 sq cm coating exhibiting unidirectional solidification and large grain size. A layer was grown at 0.2 cm/sec in the experimental coater which was partially dendritic but also contained a large smooth area approximately 100 micron m thick. The dark characteristic measurements of a typical SCC solar cell yield shunt resistance values of 10K ohms and series resistance values and 0.4 ohm. The production dip-coater is operating at over 50 percent yield in terms of good cell quality material. The most recent run yielded 13 good substrates out of 15.

Low cost solar array project silicon materials task. Development of a process for high capacity arc heater production of silicon for solar arrays

NASA Technical Reports Server (NTRS)

Fey, M. G.

1981-01-01

The experimental verification system for the production of silicon via the arc heater-sodium reduction of SiCl4 was designed, fabricated, installed, and operated. Each of the attendant subsystems was checked out and operated to insure performance requirements. These subsystems included: the arc heaters/reactor, cooling water system, gas system, power system, Control & Instrumentation system, Na injection system, SiCl4 injection system, effluent disposal system and gas burnoff system. Prior to introducing the reactants (Na and SiCl4) to the arc heater/reactor, a series of gas only-power tests was conducted to establish the operating parameters of the three arc heaters of the system. Following the successful completion of the gas only-power tests and the readiness tests of the sodium and SiCl4 injection systems, a shakedown test of the complete experimental verification system was conducted.

Integrating 3D Flower-Like Hierarchical Cu2NiSnS4 with Reduced Graphene Oxide as Advanced Anode Materials for Na-Ion Batteries.

PubMed

Yuan, Shuang; Wang, Sai; Li, Lin; Zhu, Yun-hai; Zhang, Xin-bo; Yan, Jun-min

2016-04-13

Development of an anode material with high performance and low cost is crucial for implementation of next-generation Na-ion batteries (NIBs) electrode, which is proposed to meet the challenges of large scale renewable energy storage. Metal chalcogenides are considered as promising anode materials for NIBs due to their high theoretical capacity, low cost, and abundant sources. Unfortunately, their practical application in NIBs is still hindered because of low conductivity and morphological collapse caused by their volume expansion and shrinkage during Na(+) intercalation/deintercalation. To solve the daunting challenges, herein, we fabricated novel three-dimensional (3D) Cu2NiSnS4 nanoflowers (CNTSNs) as a proof-of-concept experiment using a facile and low-cost method. Furthermore, homogeneous integration with reduced graphene oxide nanosheets (RGNs) endows intrinsically insulated CNTSNs with superior electrochemical performances, including high specific capacity (up to 837 mAh g(-1)), good rate capability, and long cycling stability, which could be attributed to the unique 3D hierarchical structure providing fast ion diffusion pathway and high contact area at the electrode/electrolyte interface.

Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan.

PubMed

Whitson, Lisa R; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T; Heathcote, Andrew; Hsieh, Shulan

2014-01-01

In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these "mixed" repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility.

Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan

PubMed Central

Whitson, Lisa R.; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T.; Heathcote, Andrew; Hsieh, Shulan

2014-01-01

In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these “mixed” repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility. PMID:24817859

Marketing communications in nonbusiness situations or why it's so hard to sell brotherhood like soap.

PubMed

Rothschild, M L

1979-01-01

Marketing tools, techniques, and theories developed in the private sector can be applied in the public and nonprofit sectors; however, their limitations must be recognized. Nonbusiness communications campaigns should consider the involvedness (high or low) of the situation and the relevant segments, available positive and negative reinforcers, nonmonetary costs, the level of latent demand, and the wide range of communications alternatives. 5 hypotheses can be proposed regarding communications effectiveness outside of the private sector: 1) the lower the perceived personal value to the individual, relative to the cost, the more difficult the behavior change task and the lower the likelihood of success of marketing communications; 2) the lower the latent or pre-existing demand for the object, the more difficult the behavior change task and the lower the likelihood of marketing communications success; 3) the greater the involvement level of the object, situation, or issue, the more difficult the behavior change task and the lower the likelihood of marketing success; 4) the greater the past involvement level of the individual, the more difficult the behavior change task and the lower the likelihood of success; and 5) the greater the level of participation needed within the society, the more difficult the behavior change and the lower the likelihood of sucess of marketing communications. Many nonbusiness issues exist in either very high or very low involvement environments, calling for an enlarged set of communications strategies. More attention should be given to communications alternatives such as movies, television programs, and in-home and in-school educational communications, especially since it appears that public service spots are not very effective. Finally, more research is needed to generate and test the effectiveness of various marketing strategies aimed at overcoming inherent characteristics that suggest a low likelihood of success.

A low cost Doppler system for vascular dialysis access surveillance.

PubMed

Molina, P S C; Moraes, R; Baggio, J F R; Tognon, E A

2004-01-01

The National Kidney Foundation guidelines for vascular access recommend access surveillance to avoid morbidity among patients undergoing hemodialysis. Methods to detect access failure based on CW Doppler system are being proposed to implement surveillance programs at lower cost. This work describes a low cost Doppler system implemented in a PC notebook designed to carry out this task. A Doppler board samples the blood flow velocity and delivers demodulated quadrature Doppler signals. These signals are sampled by a notebook sound card. Software for Windows OS (running at the notebook) applies CFFT to consecutive 11.6 ms intervals of Doppler signals. The sonogram is presented on the screen in real time. The software also calculates the maximum and the intensity weighted mean frequency envelopes. Since similar systems employ DSP boards to process the Doppler signals, cost reduction was achieved. The Doppler board electronic circuits and routines to process the Doppler signals are presented.

A simple, low-cost conductive composite material for 3D printing of electronic sensors.

PubMed

Leigh, Simon J; Bradley, Robert J; Purssell, Christopher P; Billson, Duncan R; Hutchins, David A

2012-01-01

3D printing technology can produce complex objects directly from computer aided digital designs. The technology has traditionally been used by large companies to produce fit and form concept prototypes ('rapid prototyping') before production. In recent years however there has been a move to adopt the technology as full-scale manufacturing solution. The advent of low-cost, desktop 3D printers such as the RepRap and Fab@Home has meant a wider user base are now able to have access to desktop manufacturing platforms enabling them to produce highly customised products for personal use and sale. This uptake in usage has been coupled with a demand for printing technology and materials able to print functional elements such as electronic sensors. Here we present formulation of a simple conductive thermoplastic composite we term 'carbomorph' and demonstrate how it can be used in an unmodified low-cost 3D printer to print electronic sensors able to sense mechanical flexing and capacitance changes. We show how this capability can be used to produce custom sensing devices and user interface devices along with printed objects with embedded sensing capability. This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating additives such as carbon nanotubes.

Distinctive features of high-ash bituminuos coals combution with low milling fineness in furnace chambers with bottom blowing

NASA Astrophysics Data System (ADS)

Zroychikov, N. A.; Kaverin, A. A.; Biryukov, Ya A.

2017-11-01

Nowadays the problem of improvement of pulverized coal combustion schemes is an actual one for national power engineering, especially for combustion of coals with low milling fineness with significant portion of moisture or mineral impurities. In this case a big portion of inert material in the fuel may cause impairment of its ignition and combustion. In addition there are a lot of boiler installations on which nitrogen oxides emission exceeds standard values significantly. Decreasing of milling fineness is not without interest as a way of lowering an electric energy consumption for pulverization, which can reach 30% of power plant’s auxiliary consumption of electricity. Development of a combustion scheme meeting the requirements both for effective coal burning and environmental measures (related to NOx emission) is a complex task and demands compromising between these two factors, because implementation of NOx control by combustion very often leads to rising of carbon-in-ash loss. However widespread occurrence of such modern research technique as computer modeling allows to conduct big amount of variants calculations of combustion schemes with low cost and find an optimum. This paper presents results of numerical research of combined schemes of coal combustion with high portion of inert material based on straight-flow burners and nozzles. Several distinctive features of furnace aerodynamics, heat transfer and combustion has been found. The combined scheme of high-ash bituminouos coals combustion with low milling fineness, which allows effective combustion of pointed type of fuels with nitrogen oxides emission reduction has been proposed.

Effects of automation and task load on task switching during human supervision of multiple semi-autonomous robots in a dynamic environment.

PubMed

Squire, P N; Parasuraman, R

2010-08-01

The present study assessed the impact of task load and level of automation (LOA) on task switching in participants supervising a team of four or eight semi-autonomous robots in a simulated 'capture the flag' game. Participants were faster to perform the same task than when they chose to switch between different task actions. They also took longer to switch between different tasks when supervising the robots at a high compared to a low LOA. Task load, as manipulated by the number of robots to be supervised, did not influence switch costs. The results suggest that the design of future unmanned vehicle (UV) systems should take into account not simply how many UVs an operator can supervise, but also the impact of LOA and task operations on task switching during supervision of multiple UVs. The findings of this study are relevant for the ergonomics practice of UV systems. This research extends the cognitive theory of task switching to inform the design of UV systems and results show that switching between UVs is an important factor to consider.

Integrating the behavioral and neural dynamics of response selection in a dual-task paradigm: a dynamic neural field model of Dux et al. (2009).

PubMed

Buss, Aaron T; Wifall, Tim; Hazeltine, Eliot; Spencer, John P

2014-02-01

People are typically slower when executing two tasks than when only performing a single task. These dual-task costs are initially robust but are reduced with practice. Dux et al. (2009) explored the neural basis of dual-task costs and learning using fMRI. Inferior frontal junction (IFJ) showed a larger hemodynamic response on dual-task trials compared with single-task trial early in learning. As dual-task costs were eliminated, dual-task hemodynamics in IFJ reduced to single-task levels. Dux and colleagues concluded that the reduction of dual-task costs is accomplished through increased efficiency of information processing in IFJ. We present a dynamic field theory of response selection that addresses two questions regarding these results. First, what mechanism leads to the reduction of dual-task costs and associated changes in hemodynamics? We show that a simple Hebbian learning mechanism is able to capture the quantitative details of learning at both the behavioral and neural levels. Second, is efficiency isolated to cognitive control areas such as IFJ, or is it also evident in sensory motor areas? To investigate this, we restrict Hebbian learning to different parts of the neural model. None of the restricted learning models showed the same reductions in dual-task costs as the unrestricted learning model, suggesting that efficiency is distributed across cognitive control and sensory motor processing systems.

Feasibility of using the Sony PlayStation 2 gaming platform for an individual poststroke: a case report.

PubMed

Flynn, Sheryl; Palma, Phyllis; Bender, Anneke

2007-12-01

Many Americans live with physical functional limitations stemming from stroke. These functional limitations can be reduced by task-specific training that is repetitive, motivating, and augmented with feedback. Virtual reality (VR) is reported to offer an engaging environment that is repetitive, safe, motivating, and gives task-specific feedback. The purpose of this case report was to explore the use of a low-cost VR device [Sony PlayStation 2 (PS2) EyeToy] for an individual in the chronic phase of stroke recovery. An individual two years poststroke with residual sensorimotor deficits completed 20 one-hour sessions using the PS2 EyeToy. The game's task requirements included target-based motion, dynamic balance, and motor planning. The feasibility of using the gaming platform was explored and a broad selection of outcomes was used to assess change in performance. Device use was feasible. Clinically relevant improvements were found on the Dynamic Gait Index and trends toward improvement on the Fugl-Meyer Assessment, Berg Balance Scale, UE Functional Index, Motor Activity Log, and Beck Depression Inventory. A low-cost VR system was easily used in the home. In the future it may be used to improve sensory/motor recovery following stroke as an adjunct to standard care physical therapy.

The pharmacology of effort-related choice behavior: Dopamine, depression, and individual differences.

PubMed

Salamone, John D; Correa, Merce; Yohn, Samantha; Lopez Cruz, Laura; San Miguel, Noemi; Alatorre, Luisa

2016-06-01

This review paper is focused upon the involvement of mesolimbic dopamine (DA) and related brain systems in effort-based processes. Interference with DA transmission affects instrumental behavior in a manner that interacts with the response requirements of the task, such that rats with impaired DA transmission show a heightened sensitivity to ratio requirements. Impaired DA transmission also affects effort-related choice behavior, which is assessed by tasks that offer a choice between a preferred reinforcer that has a high work requirement vs. less preferred reinforcer that can be obtained with minimal effort. Rats and mice with impaired DA transmission reallocate instrumental behavior away from food-reinforced tasks with high response costs, and show increased selection of low reinforcement/low cost options. Tests of effort-related choice have been developed into models of pathological symptoms of motivation that are seen in disorders such as depression and schizophrenia. These models are being employed to explore the effects of conditions associated with various psychopathologies, and to assess drugs for their potential utility as treatments for effort-related symptoms. Studies of the pharmacology of effort-based choice may contribute to the development of treatments for symptoms such as psychomotor slowing, fatigue or anergia, which are seen in depression and other disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

Module encapsulation technology

NASA Technical Reports Server (NTRS)

Willis, P.

1986-01-01

The identification and development techniques for low-cost module encapsulation materials were reviewed. Test results were displayed for a variety of materials. The improved prospects for modeling encapsulation systems for life prediction were reported.

Performance of Integrated Fiber Optic, Piezoelectric, and Shape Memory Alloy Actuators/Sensors in Thermoset Composites

NASA Technical Reports Server (NTRS)

Trottier, C. Michael

1996-01-01

Recently, scientists and engineers have investigated the advantages of smart materials and structures by including actuators in material systems for controlling and altering the response of structural environments. Applications of these materials systems include vibration suppression/isolation, precision positioning, damage detection and tunable devices. Some of the embedded materials being investigated for accomplishing these tasks include piezoelectric ceramics, shape memory alloys, and fiber optics. These materials have some benefits and some shortcomings; each is being studied for use in active material design in the SPICES (Synthesis and Processing of Intelligent Cost Effective Structures) Consortium. The focus of this paper concerns the manufacturing aspects of smart structures by incorporating piezoelectric ceramics, shape memory alloys and fiber optics in a reinforced thermoset matrix via resin transfer molding (RTM).

Partially Overlapping Mechanisms of Language and Task Control in Young and Older Bilinguals

PubMed Central

Weissberger, Gali H.; Wierenga, Christina E.; Bondi, Mark W.; Gollan, Tamar H.

2012-01-01

The current study tested the hypothesis that bilinguals rely on domain-general mechanisms of executive control to achieve language control by asking if linguistic and nonlinguistic switching tasks exhibit similar patterns of aging-related decline. Thirty young and 30 aging bilinguals completed a cued language-switching task and a cued color-shape switching task. Both tasks demonstrated significant aging effects, but aging-related slowing and the aging-related increase in errors were significantly larger on the color-shape than on the language task. In the language task, aging increased language-switching costs in both response times and errors, and language-mixing costs only in response times. In contrast, the color-shape task exhibited an aging-related increase in costs only in mixing errors. Additionally, a subset of the older bilinguals could not do the color-shape task, but were able to do the language task, and exhibited significantly larger language-switching costs than matched controls. These differences, and some subtle similarities, in aging effects observed across tasks imply that mechanisms of nonlinguistic task and language control are only partly shared and demonstrate relatively preserved language control in aging. More broadly, these data suggest that age deficits in switching and mixing costs may depend on task expertise, with mixing deficits emerging for less-practiced tasks and switching deficits for highly practiced, possibly “expert” tasks (i.e., language). PMID:22582883

Making a Low Cost Candy Floss Kit Gets Students Excited about Learning Physics

ERIC Educational Resources Information Center

Amir, Nazir; Subramaniam, R.

2009-01-01

An activity to excite kinaesthetically inclined students about learning physics is described in this article. Using only commonly available materials, a low cost candy floss kit is fabricated by students. A number of physics concepts are embedded contextually in the activity so that students get to learn these concepts in a real world setting…

Catadioptric Optics for laser Doppler velocimeter applications

NASA Technical Reports Server (NTRS)

Dunagan, Stephen E.

1989-01-01

In the design of a laser velocimeter system, attention must be given to the performance of the optical elements in their two principal tasks: focusing laser radiation into the probe volume, and collecting the scattered light. For large aperture applications, custom lens design and fabrication costs, long optical path requirements, and chromatic aberration (for two color operation) can be problematic. The adaptation of low cost Schmidt-Cassegrain astronomical telescopes to perform these laser beam manipulation and scattered light collection tasks is examined. A generic telescope design is analyzed using ray tracing and Gaussian beam propagation theory, and a simple modification procedure for converting from infinite to near unity conjugate ratio operation with image quality near the diffraction limit was identified. Modification requirements and performance are predicted for a range of geometries. Finally, a 200-mm-aperture telescope was modified for f/10 operation; performance data for this modified optic for both laser beam focusing and scattered light collection tasks agree well with predictions.

Construction and validation of a low-cost surgical trainer based on iPhone technology for training laparoscopic skills.

PubMed

Pérez Escamirosa, Fernando; Ordorica Flores, Ricardo; Minor Martínez, Arturo

2015-04-01

In this article, we describe the construction and validation of a laparoscopic trainer using an iPhone 5 and a plastic document holder case. The abdominal cavity was simulated with a clear plastic document holder case. On 1 side of the case, 2 holes for entry of laparoscopic instruments were drilled. We added a window to place the camera of the iPhone, which works as our camera of the trainer. Twenty residents carried out 4 tasks using the iPhone Trainer and a physical laparoscopic trainer. The time of all tasks were analyzed with a simple paired t test. The construction of the trainer took 1 hour, with a cost of

Application of vitreous and graphitic large-area carbon surfaces as field-emission cathodes

NASA Astrophysics Data System (ADS)

Hunt, Charles E.; Wang, Yu

2005-09-01

Numerous carbon bulk or thin-film materials have been used as field-emission cathodes. Most of these can be made into large-area and high-current field-emission cathodes without the use of complex IC fabrication techniques. Some of these exhibit low-extraction field, low work-function, high ruggedness, chemical stability, uniform emission, and low-cost manufacturability. A comparison of all of these materials is presented. Two viable cathode materials, reticulated vitreous carbon (RVC) and graphite paste are examined here and compared.

Cost estimating Brayton and Stirling engines

NASA Technical Reports Server (NTRS)

Fortgang, H. R.

1980-01-01

Brayton and Stirling engines were analyzed for cost and selling price for production quantities ranging from 1000 to 400,000 units per year. Parts and components were subjected to indepth scrutiny to determine optimum manufacturing processes coupled with make or buy decisions on materials and small parts. Tooling and capital equipment costs were estimated for each detail and/or assembly. For low annual production volumes, the Brayton engine appears to have a lower cost and selling price than the Stirling Engine. As annual production quantities increase, the Stirling becomes a lower cost engine than the Brayton. Both engines could benefit cost wise if changes were made in materials, design and manufacturing process as annual production quantities increase.

Bolstering Teaching through Online Tools

ERIC Educational Resources Information Center

Singh, Anil; Mangalaraj, George; Taneja, Aakash

2010-01-01

This paper offers a compilation of technologies that provides either free or low-cost solutions to the challenges of teaching online courses. It presents various teaching methods the outlined tools and technologies can support, with emphasis on fit between these tools and the tasks they are meant to serve. In addition, it highlights various…

Quantitative analysis of defects in silicon: Silicon sheet growth development for the large area silicon sheet task of the low cost solar array project

NASA Technical Reports Server (NTRS)

Natesh, R.; Smith, J. M.; Qidwai, H. A.

1978-01-01

The various steps involved in the chemical polishing and etching of silicon samples are described and the data on twins, grain boundaries and dislocation pits from fifty-three (53) samples are discussed.

Estimation of the laser cutting operating cost by support vector regression methodology

NASA Astrophysics Data System (ADS)

Jović, Srđan; Radović, Aleksandar; Šarkoćević, Živče; Petković, Dalibor; Alizamir, Meysam

2016-09-01

Laser cutting is a popular manufacturing process utilized to cut various types of materials economically. The operating cost is affected by laser power, cutting speed, assist gas pressure, nozzle diameter and focus point position as well as the workpiece material. In this article, the process factors investigated were: laser power, cutting speed, air pressure and focal point position. The aim of this work is to relate the operating cost to the process parameters mentioned above. CO2 laser cutting of stainless steel of medical grade AISI316L has been investigated. The main goal was to analyze the operating cost through the laser power, cutting speed, air pressure, focal point position and material thickness. Since the laser operating cost is a complex, non-linear task, soft computing optimization algorithms can be used. Intelligent soft computing scheme support vector regression (SVR) was implemented. The performance of the proposed estimator was confirmed with the simulation results. The SVR results are then compared with artificial neural network and genetic programing. According to the results, a greater improvement in estimation accuracy can be achieved through the SVR compared to other soft computing methodologies. The new optimization methods benefit from the soft computing capabilities of global optimization and multiobjective optimization rather than choosing a starting point by trial and error and combining multiple criteria into a single criterion.

Phosphorus Diffusion Gettering Efficacy in Upgraded Metallurgical-Grade Solar Silicon

NASA Astrophysics Data System (ADS)

Jiménez, A.; del Cañizo, C.; Cid, C.; Peral, A.

2018-05-01

In the context of the continuous price reduction in photovoltaics (PV) in recent years, Si feedstock continues to be a relevant component in the cost breakdown of a PV module, highlighting the need for low-cost, low-capital expenditure (CAPEX) silicon technologies to further reduce this cost component. Upgraded metallurgical-grade silicon (UMG Si) has recently received much attention, improving its quality and even attaining, in some cases, solar cell efficiencies similar to those of conventional material. However, some technical challenges still have to be addressed when processing this material to compensate efficiently for the high content of impurities and contaminants. Adaptation of a conventional solar cell process to monocrystalline UMG Si wafers has been studied in this work. In particular, a tailored phosphorus diffusion gettering step followed by a low-temperature anneal at 700°C was implemented, resulting in enhanced bulk lifetime and emitter recombination properties. In spite of the need for further research and material optimization, UMG Si wafers were successfully processed, achieving efficiencies in the range of 15% for a standard laboratory solar cell process with aluminum back surface field.

Metacognition of Multi-Tasking: How Well Do We Predict the Costs of Divided Attention?

PubMed Central

Finley, Jason R.; Benjamin, Aaron S.; McCarley, Jason S.

2014-01-01

Risky multi-tasking, such as texting while driving, may occur because people misestimate the costs of divided attention. In two experiments, participants performed a computerized visual-manual tracking task in which they attempted to keep a mouse cursor within a small target that moved erratically around a circular track. They then separately performed an auditory n-back task. After practicing both tasks separately, participants received feedback on their single-task tracking performance and predicted their dual-task tracking performance before finally performing the two tasks simultaneously. Most participants correctly predicted reductions in tracking performance under dual-task conditions, with a majority overestimating the costs of dual-tasking. However, the between-subjects correlation between predicted and actual performance decrements was near zero. This combination of results suggests that people do anticipate costs of multi-tasking, but have little metacognitive insight on the extent to which they are personally vulnerable to the risks of divided attention, relative to other people. PMID:24490818

Architectures for Improved Organic Semiconductor Devices

NASA Astrophysics Data System (ADS)

Beck, Jonathan H.

Advancements in the microelectronics industry have brought increasing performance and decreasing prices to a wide range of users. Conventional silicon-based electronics have followed Moore's law to provide an ever-increasing integrated circuit transistor density, which drives processing power, solid-state memory density, and sensor technologies. As shrinking conventional integrated circuits became more challenging, researchers began exploring electronics with the potential to penetrate new applications with a low price of entry: "Electronics everywhere." The new generation of electronics is thin, light, flexible, and inexpensive. Organic electronics are part of the new generation of thin-film electronics, relying on the synthetic flexibility of carbon molecules to create organic semiconductors, absorbers, and emitters which perform useful tasks. Organic electronics can be fabricated with low energy input on a variety of novel substrates, including inexpensive plastic sheets. The potential ease of synthesis and fabrication of organic-based devices means that organic electronics can be made at very low cost. Successfully demonstrated organic semiconductor devices include photovoltaics, photodetectors, transistors, and light emitting diodes. Several challenges that face organic semiconductor devices are low performance relative to conventional devices, long-term device stability, and development of new organic-compatible processes and materials. While the absorption and emission performance of organic materials in photovoltaics and light emitting diodes is extraordinarily high for thin films, the charge conduction mobilities are generally low. Building highly efficient devices with low-mobility materials is one challenge. Many organic semiconductor films are unstable during fabrication, storage, and operation due to reactions with water, oxygen and hydroxide. A final challenge facing organic electronics is the need for new processes and materials for electrodes, semiconductors and substrates compatible with low-temperature, flexible, and oxygenated and aromatic solvent-free fabrication. Materials and processes must be capable of future high volume production in order to enable low costs. In this thesis we explore several techniques to improve organic semiconductor device performance and enable new fabrication processes. In Chapter 2, I describe the integration of sub-optical-wavelength nanostructured electrodes that improve fill factor and power conversion efficiency in organic photovoltaic devices. Photovoltaic fill factor performance is one of the primary challenges facing organic photovoltaics because most organic semiconductors have poor charge mobility. Our electrical and optical measurements and simulations indicate that nanostructured electrodes improve charge extraction in organic photovoltaics. In Chapter 3, I describe a general method for maximizing the efficiency of organic photovoltaic devices by simultaneously optimizing light absorption and charge carrier collection. We analyze the potential benefits of light trapping strategies for maximizing the overall power conversion efficiency of organic photovoltaic devices. This technique may be used to improve organic photovoltaic materials with low absorption, or short exciton diffusion and carrier-recombination lengths, opening up the device design space. In Chapter 4, I describe a process for high-quality graphene transfer onto chemically sensitive, weakly interacting organic semiconductor thin-films. Graphene is a promising flexible and highly transparent electrode for organic electronics; however, transferring graphene films onto organic semiconductor devices was previously impossible. We demonstrate a new transfer technique based on an elastomeric stamp coated with an fluorinated polymer release layer. We fabricate three classes of organic semiconductor devices: field effect transistors without high temperature annealing, transparent organic light-emitting diodes, and transparent small-molecule organic photovoltaic devices.

Advanced, Low/Zero Emission Boiler Design and Operation

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

Babcock /Wilcox; Illinois State Geological; Worley Parsons

2007-06-30

In partnership with the U.S. Department of Energy's National Energy Technology Laboratory, B&W and Air Liquide are developing and optimizing the oxy-combustion process for retrofitting existing boilers as well as new plants. The main objectives of the project is to: (1) demonstrate the feasibility of the oxy-combustion technology with flue gas recycle in a 5-million Btu/hr coal-fired pilot boiler, (2) measure its performances in terms of emissions and boiler efficiency while selecting the right oxygen injection and flue gas recycle strategies, and (3) perform technical and economic feasibility studies for application of the technology in demonstration and commercial scale boilers.more » This document summarizes the work performed during the period of performance of the project (Oct 2002 to June 2007). Detailed technical results are reported in corresponding topical reports that are attached as an appendix to this report. Task 1 (Site Preparation) has been completed in 2003. The experimental pilot-scale O{sub 2}/CO{sub 2} combustion tests of Task 2 (experimental test performance) has been completed in Q2 2004. Process simulation and cost assessment of Task 3 (Techno-Economic Study) has been completed in Q1 2005. The topical report on Task 3 has been finalized and submitted to DOE in Q3 2005. The calculations of Task 4 (Retrofit Recommendation and Preliminary Design of a New Generation Boiler) has been completed in 2004. In Task 6 (engineering study on retrofit applications), the engineering study on 25MW{sub e} unit has been completed in Q2, 2008 along with the corresponding cost assessment. In Task 7 (evaluation of new oxy-fuel power plants concepts), based on the design basis document prepared in 2005, the design and cost estimate of the Air Separation Units, the boiler islands and the CO{sub 2} compression and trains have been completed, for both super and ultra-supercritical case study. Final report of Task-7 is published by DOE in Oct 2007.« less

On the Origins of the Task Mixing Cost in the Cuing Task-Switching Paradigm

ERIC Educational Resources Information Center

Rubin, Orit; Meiran, Nachshon

2005-01-01

Poorer performance in conditions involving task repetition within blocks of mixed tasks relative to task repetition within blocks of single task is called mixing cost (MC). In 2 experiments exploring 2 hypotheses regarding the origins of MC, participants either switched between cued shape and color tasks, or they performed them as single tasks.…

Low-cost, solution processable carbon nanotube supercapacitors and their characterization

NASA Astrophysics Data System (ADS)

Lehtimäki, Suvi; Tuukkanen, Sampo; Pörhönen, Juho; Moilanen, Pasi; Virtanen, Jorma; Honkanen, Mari; Lupo, Donald

2014-06-01

We report ecological and low-cost carbon nanotube (CNT) supercapacitors fabricated using a simple, scalable solution processing method, where the use of a highly porous and electrically conductive active material eliminates the need for a current collector. Electrodes were fabricated on a poly(ethylene terephthalate) substrate from a printable multi-wall CNT ink, where the CNTs are solubilized in water using xylan as a dispersion agent. The dispersion method facilitates a very high concentration of CNTs in the ink. Supercapacitors were assembled using a paper separator and an aqueous NaCl electrolyte and the devices were characterized with a galvanostatic discharge method defined by an industrial standard. The capacitance of the 2 cm^2 devices was 6 mF/cm^2 (2.3 F/g) and equivalent series resistance 80 Ω . Low-cost supercapacitors fabricated from safe and environmentally friendly materials have potential applications as energy storage devices in ubiquitous and autonomous intelligence as well as in disposable low-end products.

Performances of some low-cost counter electrode materials in CdS and CdSe quantum dot-sensitized solar cells.

PubMed

Jun, Hieng Kiat; Careem, Mohamed Abdul; Arof, Abdul Kariem

2014-02-10

Different counter electrode (CE) materials based on carbon and Cu2S were prepared for the application in CdS and CdSe quantum dot-sensitized solar cells (QDSSCs). The CEs were prepared using low-cost and facile methods. Platinum was used as the reference CE material to compare the performances of the other materials. While carbon-based materials produced the best solar cell performance in CdS QDSSCs, platinum and Cu2S were superior in CdSe QDSSCs. Different CE materials have different performance in the two types of QDSSCs employed due to the different type of sensitizers and composition of polysulfide electrolytes used. The poor performance of QDSSCs with some CE materials is largely due to the lower photocurrent density and open-circuit voltage. The electrochemical impedance spectroscopy performed on the cells showed that the poor-performing QDSSCs had higher charge-transfer resistances and CPE values at their CE/electrolyte interfaces.

Carbon-Based Functional Materials Derived from Waste for Water Remediation and Energy Storage.

PubMed

Ma, Qinglang; Yu, Yifu; Sindoro, Melinda; Fane, Anthony G; Wang, Rong; Zhang, Hua

2017-04-01

Carbon-based functional materials hold the key for solving global challenges in the areas of water scarcity and the energy crisis. Although carbon nanotubes (CNTs) and graphene have shown promising results in various fields of application, their high preparation cost and low production yield still dramatically hinder their wide practical applications. Therefore, there is an urgent call for preparing carbon-based functional materials from low-cost, abundant, and sustainable sources. Recent innovative strategies have been developed to convert various waste materials into valuable carbon-based functional materials. These waste-derived carbon-based functional materials have shown great potential in many applications, especially as sorbents for water remediation and electrodes for energy storage. Here, the research progress in the preparation of waste-derived carbon-based functional materials is summarized, along with their applications in water remediation and energy storage; challenges and future research directions in this emerging research field are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The rise of organic electrode materials for energy storage.

PubMed

Schon, Tyler B; McAllister, Bryony T; Li, Peng-Fei; Seferos, Dwight S

2016-11-07

Organic electrode materials are very attractive for electrochemical energy storage devices because they can be flexible, lightweight, low cost, benign to the environment, and used in a variety of device architectures. They are not mere alternatives to more traditional energy storage materials, rather, they have the potential to lead to disruptive technologies. Although organic electrode materials for energy storage have progressed in recent years, there are still significant challenges to overcome before reaching large-scale commercialization. This review provides an overview of energy storage systems as a whole, the metrics that are used to quantify the performance of electrodes, recent strategies that have been investigated to overcome the challenges associated with organic electrode materials, and the use of computational chemistry to design and study new materials and their properties. Design strategies are examined to overcome issues with capacity/capacitance, device voltage, rate capability, and cycling stability in order to guide future work in the area. The use of low cost materials is highlighted as a direction towards commercial realization.

Marshall Space Flight Center solid waste characterization and recycling improvement study

NASA Technical Reports Server (NTRS)

Eley, Michael H.; Crews, Lavonne; Johnston, Ben; Lee, David; Colebaugh, James

1995-01-01

The MSFC Facilities Office, which is responsible for disposing of all waste generated by MSFC, issued a delivery order to the University of Alabama in Huntsville (UAH) to characterize current MSFC waste streams and to evaluate their existing recycling program. The purpose of the study was to define the nature, quantity, and types of waste produced and to generate ideas for improving the present recycling program. Specifically, the following tasks were to be performed: Identify various surplus and waste materials--as identified by the Contracting Officer's Technical Representative (COTR)--by source, location, and type; Analyze MSFC's current methods for handling, storage, transport, and disposition of waste and surplussed materials; Determine the composition of various surplus and waste materials as to type and quantities from various sources and locations; Analyze different methods for the disposition of various surplus and waste materials, including quality, quantity, preparation, transport cost, and value; Study possible alternatives to current methods of handling, storage, transport, and disposition of surplus and waste materials to improve the quality and quantities recycled or sold and to reduce and minimize the quantities of surplus and waste material currently being disposed of or stored; Provide recommendations for source and centralized segregation and aggregation of materials for recycling and/or disposition; and The analysis could include identification and laboratory level evaluation of methods and/or equipment, including capital costs, operating costs, maintenance requirements, life cycle and return on investment for systems to support the waste reduction program mission.

Selecting Tasks for Evaluating Human Performance as a Function of Gravity

NASA Technical Reports Server (NTRS)

Norcross, J. R.; Gernhardt, M. L.

2010-01-01

A challenge in understanding human performance as a function of gravity is determining which tasks to research. Initial studies began with treadmill walking, which was easy to quantify and control. However, with the development of pressurized rovers, it is less important to optimize human performance for ambulation as rovers will likely perform gross translation for them. Future crews are likely to spend much of their extravehicular activity (EVA) performing geology, construction and maintenance type tasks, for which it is difficult to measure steady-state-workloads. To evaluate human performance in reduced gravity, we have collected metabolic, biomechanical and subjective data for different tasks at varied gravity levels. Methods: Ten subjects completed 5 different tasks including weight transfer, shoveling, treadmill walking, treadmill running and treadmill incline walking. All tasks were performed shirt-sleeved at 1-g, 3/8-g and 1/6-g. Off-loaded conditions were achieved via the Active Response Gravity Offload System. Treadmill tasks were performed for 3 minutes with reported oxygen consumption (VO2) averaged over the last 2 minutes. Shoveling was performed for 3 minutes with metabolic cost reported as ml O2 consumed per kg material shoveled. Weight transfer reports metabolic cost as liters O2 consumed to complete the task. Statistical analysis was performed via repeated measures ANOVA. Results: Statistically significant metabolic differences were noted between all 3 gravity levels for treadmill running and incline walking. For the other 3 tasks, there were significant differences between 1-g and each reduced gravity, but not between 1/6-g and 3/8-g. For weight transfer, significant differences were seen between gravities in both trial-average VO2 and time-to-completion with noted differences in strategy for task completion. Conclusion: To determine if gravity has a metabolic effect on human performance, this research may indicate that tasks should be selected that require the subject to work vertically against the force of gravity.