Social Media Use to Enhance Internal Communication: Course Design for Business Students

ERIC Educational Resources Information Center

Young, Amy M.; Hinesly, Mary D.

2014-01-01

Organizations are increasingly using social media to improve their internal communication. When successfully implemented, such initiatives can have a dramatic impact on internal efficiency, team collaboration, innovation, organizational alignment, and cultural transformation. This article describes a course offered by the Ross School of Business,…

The Hybrid Automobile and the Atkinson Cycle

ERIC Educational Resources Information Center

Feldman, Bernard J.

2008-01-01

The hybrid automobile is a strikingly new automobile technology with a number of new technological features that dramatically improve energy efficiency. This paper will briefly describe how hybrid automobiles work; what are these new technological features; why the Toyota Prius hybrid internal combustion engine operates on the Atkinson cycle…

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

PubMed Central

Telang, Nakul S; Kong, Caleb J; Verghese, Jenson; Gilliland III, Stanley E; Ahmad, Saeed; Dominey, Raymond N

2018-01-01

Numerous synthetic methods for the continuous preparation of fine chemicals and active pharmaceutical ingredients (API’s) have been reported in recent years resulting in a dramatic improvement in process efficiencies. Herein we report a highly efficient continuous synthesis of the antimalarial drug hydroxychloroquine (HCQ). Key improvements in the new process include the elimination of protecting groups with an overall yield improvement of 52% over the current commercial process. The continuous process employs a combination of packed bed reactors with continuous stirred tank reactors for the direct conversion of the starting materials to the product. This high-yielding, multigram-scale continuous synthesis provides an opportunity to achieve increase global access to hydroxychloroquine for treatment of malaria. PMID:29623120

Driving R&D for the Next Generation Work Truck; NREL (National Renewable Energy Laboratory)

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

Melendez, M.

2015-03-04

Improvements in medium- and heavy-duty work truck energy efficiency can dramatically reduce the use of petroleum-based fuels and the emissions of greenhouse gases. The National Renewable Energy Laboratory (NREL) is working with industry partners to develop fuel-saving, high-performance vehicle technologies, while examining fleet operational practices that can simulateneously improve fuel economy, decrease emissions, and support bottom-line goals.

NREL, SPI Solar and Trimark Optimize Parabolic Trough Receiver Performance

Science.gov Websites

(CSP) plants. Photo of parabolic trough receiver equipment in a laboratory Photo by Dennis Schroeder Receivers in CSP plants take a lot of abuse, from dramatic temperature changes to numerous mechanical conditions can lead to big improvements in the overall efficiency of CSP plants

Chiller plant design rules...Have they changed?

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

Eppelheimer, D.

1995-09-01

Chilled water plants are often viewed as energy consumers, actually they are only energy movers. In just the simple process of chilling water, there are four discrete energy moving functions. The chilled water pumps, condenser water pumps, and cooling tower fans are all forms of transport energy. The chiller is a heat pump where energy is consumed to raise the temperature of the heat stream. Insight into improved chiller plant performance can be obtained by tracking the power consumption of these four functions. The performance of centrifugal chillers has improved dramatically in the past 25 years. Certainly some of thismore » improvement is due to technology improvements in heat transfer and compressor efficiency. However, the lion`s share of gain in chiller efficiency is a result of chiller owners budgeting more funds to energy conservation and purchasing more efficient chillers. Since 1970, the efficiency of electric water chillers has improved by nearly 4 percent! The intent of this presentation is to review the energy cost associated with central chilled water plants and identify opportunities in design that may reduce energy costs.« less

Enhanced Charge Extraction of Li-Doped TiO₂ for Efficient Thermal-Evaporated Sb₂S₃ Thin Film Solar Cells.

PubMed

Lan, Chunfeng; Luo, Jingting; Lan, Huabin; Fan, Bo; Peng, Huanxin; Zhao, Jun; Sun, Huibin; Zheng, Zhuanghao; Liang, Guangxing; Fan, Ping

2018-02-28

We provided a new method to improve the efficiency of Sb₂S₃ thin film solar cells. The TiO₂ electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb₂S₃ solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO₂ films. Compared with the undoped TiO₂, Li-doped mesoporous TiO₂ dramatically improved the photo-voltaic performance of the thermal-evaporated Sb₂S₃ thin film solar cells, with the average power conversion efficiency ( PCE ) increasing from 1.79% to 4.03%, as well as the improved open-voltage ( V oc ), short-circuit current ( J sc ) and fill factors. The best device based on Li-doped TiO₂ achieved a power conversion efficiency up to 4.42% as well as a V oc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb₂S₃ solar cells. This study showed that Li-doping on TiO₂ can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb₂S₃-based solar cells.

Energy Projects for Young Scientists.

ERIC Educational Resources Information Center

Gardner, Robert

Energy is a vital topic. Energy costs have risen dramatically during the last decade and home owners are concerned about their energy bills and the costs associated with heating or cooling their homes. An understanding of energy, its sources and ways to reduce its use or improve the efficiency with which people use it will become more important as…

Edge-Hydroxylated Boron Nitride Nanosheets as an Effective Additive to Improve the Thermal Response of Hydrogels.

PubMed

Xiao, Feng; Naficy, Sina; Casillas, Gilberto; Khan, Majharul H; Katkus, Tomas; Jiang, Lei; Liu, Huakun; Li, Huijun; Huang, Zhenguo

2015-11-25

Upon flowing hot steam over hexagonal boron nitride (h-BN) bulk powder, efficient exfoliation and hydroxylation of BN occur simultaneously. Through effective hydrogen bonding with water and N-isopropylacrylamide, edge-hydroxylated BN nanosheets dramatically improve the dimensional change and dye release of this temperature-sensitive hydrogel and thereby enhance its efficacy in bionic, soft robotic, and drug-delivery applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Germline Cas9 expression yields highly efficient genome engineering in a major worldwide disease vector, Aedes aegypti

PubMed Central

Li, Ming; Bui, Michelle; Yang, Ting; Bowman, Christian S.; White, Bradley J.; Akbari, Omar S.

2017-01-01

The development of CRISPR/Cas9 technologies has dramatically increased the accessibility and efficiency of genome editing in many organisms. In general, in vivo germline expression of Cas9 results in substantially higher activity than embryonic injection. However, no transgenic lines expressing Cas9 have been developed for the major mosquito disease vector Aedes aegypti. Here, we describe the generation of multiple stable, transgenic Ae. aegypti strains expressing Cas9 in the germline, resulting in dramatic improvements in both the consistency and efficiency of genome modifications using CRISPR. Using these strains, we disrupted numerous genes important for normal morphological development, and even generated triple mutants from a single injection. We have also managed to increase the rates of homology-directed repair by more than an order of magnitude. Given the exceptional mutagenic efficiency and specificity of the Cas9 strains we engineered, they can be used for high-throughput reverse genetic screens to help functionally annotate the Ae. aegypti genome. Additionally, these strains represent a step toward the development of novel population control technologies targeting Ae. aegypti that rely on Cas9-based gene drives. PMID:29138316

Germline Cas9 expression yields highly efficient genome engineering in a major worldwide disease vector, Aedes aegypti.

PubMed

Li, Ming; Bui, Michelle; Yang, Ting; Bowman, Christian S; White, Bradley J; Akbari, Omar S

2017-12-05

The development of CRISPR/Cas9 technologies has dramatically increased the accessibility and efficiency of genome editing in many organisms. In general, in vivo germline expression of Cas9 results in substantially higher activity than embryonic injection. However, no transgenic lines expressing Cas9 have been developed for the major mosquito disease vector Aedes aegypti Here, we describe the generation of multiple stable, transgenic Ae. aegypti strains expressing Cas9 in the germline, resulting in dramatic improvements in both the consistency and efficiency of genome modifications using CRISPR. Using these strains, we disrupted numerous genes important for normal morphological development, and even generated triple mutants from a single injection. We have also managed to increase the rates of homology-directed repair by more than an order of magnitude. Given the exceptional mutagenic efficiency and specificity of the Cas9 strains we engineered, they can be used for high-throughput reverse genetic screens to help functionally annotate the Ae. aegypti genome. Additionally, these strains represent a step toward the development of novel population control technologies targeting Ae. aegypti that rely on Cas9-based gene drives. Copyright © 2017 the Author(s). Published by PNAS.

Analysis of Technological Innovation and Environmental Performance Improvement in Aviation Sector

PubMed Central

Lee, Joosung; Mo, Jeonghoon

2011-01-01

The past oil crises have caused dramatic improvements in fuel efficiency in all industrial sectors. The aviation sector—aircraft manufacturers and airlines—has also made significant efforts to improve the fuel efficiency through more advanced jet engines, high-lift wing designs, and lighter airframe materials. However, the innovations in energy-saving aircraft technologies do not coincide with the oil crisis periods. The largest improvement in aircraft fuel efficiency took place in the 1960s while the high oil prices in the 1970s and on did not induce manufacturers or airlines to achieve a faster rate of innovation. In this paper, we employ a historical analysis to examine the socio-economic reasons behind the relatively slow technological innovation in aircraft fuel efficiency over the last 40 years. Based on the industry and passenger behaviors studied and prospects for alternative fuel options, this paper offers insights for the aviation sector to shift toward more sustainable technological options in the medium term. Second-generation biofuels could be the feasible option with a meaningful reduction in aviation’s lifecycle environmental impact if they can achieve sufficient economies of scale. PMID:22016716

Analysis of technological innovation and environmental performance improvement in aviation sector.

PubMed

Lee, Joosung; Mo, Jeonghoon

2011-09-01

The past oil crises have caused dramatic improvements in fuel efficiency in all industrial sectors. The aviation sector-aircraft manufacturers and airlines-has also made significant efforts to improve the fuel efficiency through more advanced jet engines, high-lift wing designs, and lighter airframe materials. However, the innovations in energy-saving aircraft technologies do not coincide with the oil crisis periods. The largest improvement in aircraft fuel efficiency took place in the 1960s while the high oil prices in the 1970s and on did not induce manufacturers or airlines to achieve a faster rate of innovation. In this paper, we employ a historical analysis to examine the socio-economic reasons behind the relatively slow technological innovation in aircraft fuel efficiency over the last 40 years. Based on the industry and passenger behaviors studied and prospects for alternative fuel options, this paper offers insights for the aviation sector to shift toward more sustainable technological options in the medium term. Second-generation biofuels could be the feasible option with a meaningful reduction in aviation's lifecycle environmental impact if they can achieve sufficient economies of scale.

Enhanced Charge Extraction of Li-Doped TiO2 for Efficient Thermal-Evaporated Sb2S3 Thin Film Solar Cells

PubMed Central

Lan, Chunfeng; Luo, Jingting; Lan, Huabin; Fan, Bo; Peng, Huanxin; Zhao, Jun; Sun, Huibin; Zheng, Zhuanghao; Liang, Guangxing; Fan, Ping

2018-01-01

We provided a new method to improve the efficiency of Sb2S3 thin film solar cells. The TiO2 electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb2S3 solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO2 films. Compared with the undoped TiO2, Li-doped mesoporous TiO2 dramatically improved the photo-voltaic performance of the thermal-evaporated Sb2S3 thin film solar cells, with the average power conversion efficiency (PCE) increasing from 1.79% to 4.03%, as well as the improved open-voltage (Voc), short-circuit current (Jsc) and fill factors. The best device based on Li-doped TiO2 achieved a power conversion efficiency up to 4.42% as well as a Voc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb2S3 solar cells. This study showed that Li-doping on TiO2 can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb2S3-based solar cells. PMID:29495612

Fixed Wing Project: Technologies for Advanced Air Transports

NASA Technical Reports Server (NTRS)

Del Rosario, Ruben; Koudelka, John M.; Wahls, Richard A.; Madavan, Nateri

2014-01-01

The NASA Fundamental Aeronautics Fixed Wing (FW) Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. Multidisciplinary advances are required in aerodynamic efficiency to reduce drag, structural efficiency to reduce aircraft empty weight, and propulsive and thermal efficiency to reduce thrust-specific energy consumption (TSEC) for overall system benefit. Additionally, advances are required to reduce perceived noise without adversely affecting drag, weight, or TSEC, and to reduce harmful emissions without adversely affecting energy efficiency or noise.The presentation will highlight the Fixed Wing project vision of revolutionary systems and technologies needed to achieve these challenging goals. Specifically, the primary focus of the FW Project is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe.

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

Romm, J.J.

Many American companies have found that saving energy and cutting pollution dramatically improves the bottom line. But beyond these gains, businesses that launch energy efficiency programs to save money are often astonished to discover unforeseen benefits: energy efficient lighting, heating, cooling, motors, and industrial processes can increase worker productivity, decrease absenteeism, and improve the quality of work performed. Profits created by the jump in worker productivity can exceed energy savings by a factor of ten. Energy efficiency and pollution prevention represent the next wave in manufacturing, following the quality revolution launched by the Japanese in the 1960s. Unless America leadsmore » the lean and clean revolution, economic health will be undermined as other countries develop clean processes and products and US companies suffer competitively. Also, developing countries will leapfrog their wasteful model and buy products and manufacturing processes from foreign firms already practicing lean and clean.« less

Modular Chemical Process Intensification: A Review.

PubMed

Kim, Yong-Ha; Park, Lydia K; Yiacoumi, Sotira; Tsouris, Costas

2017-06-07

Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. These dramatic improvements lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. This article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.

Directed evolution of an ultrastable carbonic anhydrase for highly efficient carbon capture from flue gas

DOE PAGES

Alvizo, Oscar; Nguyen, Luan J.; Savile, Christopher K.; ...

2014-11-03

Carbonic anhydrase (CA) is one of nature’s fastest enzymes and can dramatically improve the economics of carbon capture under demanding environments such as coal-fired power plants. The use of CA to accelerate carbon capture is limited by the enzyme’s sensitivity to the harsh process conditions. Using directed evolution, the properties of a β-class CA from Desulfovibrio vulgaris were dramatically enhanced. Iterative rounds of library design, library generation, and high-throughput screening identified highly stable CA variants that tolerate temperatures of up to 107 °C in the presence of 4.2 M alkaline amine solvent at pH >10.0. This increase in thermostability andmore » alkali tolerance translates to a 4,000,000-fold improvement over the natural enzyme. In conclusion, at pilot scale, the evolved catalyst enhanced the rate of CO2 absorption 25-fold compared with the noncatalyzed reaction.« less

Modular Chemical Process Intensification: A Review

DOE PAGES

Kim, Yong-ha; Park, Lydia K.; Yiacoumi, Sotira; ...

2016-06-24

Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. Dramatic improvements such as these lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. Thismore » article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.« less

Directed evolution of an ultrastable carbonic anhydrase for highly efficient carbon capture from flue gas

PubMed Central

Alvizo, Oscar; Nguyen, Luan J.; Savile, Christopher K.; Bresson, Jamie A.; Lakhapatri, Satish L.; Solis, Earl O. P.; Fox, Richard J.; Broering, James M.; Benoit, Michael R.; Zimmerman, Sabrina A.; Novick, Scott J.; Liang, Jack; Lalonde, James J.

2014-01-01

Carbonic anhydrase (CA) is one of nature’s fastest enzymes and can dramatically improve the economics of carbon capture under demanding environments such as coal-fired power plants. The use of CA to accelerate carbon capture is limited by the enzyme’s sensitivity to the harsh process conditions. Using directed evolution, the properties of a β-class CA from Desulfovibrio vulgaris were dramatically enhanced. Iterative rounds of library design, library generation, and high-throughput screening identified highly stable CA variants that tolerate temperatures of up to 107 °C in the presence of 4.2 M alkaline amine solvent at pH >10.0. This increase in thermostability and alkali tolerance translates to a 4,000,000-fold improvement over the natural enzyme. At pilot scale, the evolved catalyst enhanced the rate of CO2 absorption 25-fold compared with the noncatalyzed reaction. PMID:25368146

Predicting stem total and assortment volumes in an industrial Pinus taeda L. forest plantation using airborne laser scanning data and random forest

Treesearch

Carlos Alberto Silva; Carine Klauberg; Andrew Thomas Hudak; Lee Alexander Vierling; Wan Shafrina Wan Mohd Jaafar; Midhun Mohan; Mariano Garcia; Antonio Ferraz; Adrian Cardil; Sassan Saatchi

2017-01-01

Improvements in the management of pine plantations result in multiple industrial and environmental benefits. Remote sensing techniques can dramatically increase the efficiency of plantation management by reducing or replacing time-consuming field sampling. We tested the utility and accuracy of combining field and airborne lidar data with Random Forest, a supervised...

Influence of computational fluid dynamics on experimental aerospace facilities: A fifteen year projection

NASA Technical Reports Server (NTRS)

1983-01-01

An assessment was made of the impact of developments in computational fluid dynamics (CFD) on the traditional role of aerospace ground test facilities over the next fifteen years. With improvements in CFD and more powerful scientific computers projected over this period it is expected to have the capability to compute the flow over a complete aircraft at a unit cost three orders of magnitude lower than presently possible. Over the same period improvements in ground test facilities will progress by application of computational techniques including CFD to data acquisition, facility operational efficiency, and simulation of the light envelope; however, no dramatic change in unit cost is expected as greater efficiency will be countered by higher energy and labor costs.

Content-based management service for medical videos.

PubMed

Mendi, Engin; Bayrak, Coskun; Cecen, Songul; Ermisoglu, Emre

2013-01-01

Development of health information technology has had a dramatic impact to improve the efficiency and quality of medical care. Developing interoperable health information systems for healthcare providers has the potential to improve the quality and equitability of patient-centered healthcare. In this article, we describe an automated content-based medical video analysis and management service that provides convenience and ease in accessing the relevant medical video content without sequential scanning. The system facilitates effective temporal video segmentation and content-based visual information retrieval that enable a more reliable understanding of medical video content. The system is implemented as a Web- and mobile-based service and has the potential to offer a knowledge-sharing platform for the purpose of efficient medical video content access.

Expanding the substrate scope of chitooligosaccharide oxidase from Fusarium graminearum by structure-inspired mutagenesis.

PubMed

Ferrari, Alessandro R; Lee, Misun; Fraaije, Marco W

2015-06-01

Chitooligosaccharide oxidase from Fusarium graminearum (ChitO) oxidizes N-acetyl-D-glucosamine (GlcNAc) and its oligomers with high efficiency at the C1-hydroxyl moiety while it shows poor or no activity with other carbohydrates. By sequence and structural comparison with other known carbohydrate oxidases (glucooligosaccharide oxidase from Acremonium strictum and lactose oxidase from Microdochium nivale) eleven mutants were designed to redirect the catalytic scope of ChitO for improved oxidation of lactose, cellobiose and maltose. The catalytic properties of the most interesting mutants were further improved by combining single mutations. This has resulted in the creation of a set of ChitO variants that display totally different substrate tolerances. One ChitO variant shows a dramatic improvement in catalytic efficiency towards oxidation of glucose, cellobiose, lactose, and maltose. We also describe a ChitO variant with the highest catalytic efficiency in GlcNAc oxidation so far reported in the literature. © 2015 Wiley Periodicals, Inc.

Accelerated simulation of stochastic particle removal processes in particle-resolved aerosol models

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

Curtis, J.H.; Michelotti, M.D.; Riemer, N.

2016-10-01

Stochastic particle-resolved methods have proven useful for simulating multi-dimensional systems such as composition-resolved aerosol size distributions. While particle-resolved methods have substantial benefits for highly detailed simulations, these techniques suffer from high computational cost, motivating efforts to improve their algorithmic efficiency. Here we formulate an algorithm for accelerating particle removal processes by aggregating particles of similar size into bins. We present the Binned Algorithm for particle removal processes and analyze its performance with application to the atmospherically relevant process of aerosol dry deposition. We show that the Binned Algorithm can dramatically improve the efficiency of particle removals, particularly for low removalmore » rates, and that computational cost is reduced without introducing additional error. In simulations of aerosol particle removal by dry deposition in atmospherically relevant conditions, we demonstrate about 50-times increase in algorithm efficiency.« less

Efficient Suppression of Electron–Hole Recombination in Oxygen-Deficient Hydrogen-Treated TiO2 Nanowires for Photoelectrochemical Water Splitting

PubMed Central

2013-01-01

There is an increasing level of interest in the use of black TiO2 prepared by thermal hydrogen treatments (H:TiO2) due to the potential to enhance both the photocatalytic and the light-harvesting properties of TiO2. Here, we examine oxygen-deficient H:TiO2 nanotube arrays that have previously achieved very high solar-to-hydrogen (STH) efficiencies due to incident photon-to-current efficiency (IPCE) values of >90% for photoelectrochemical water splitting at only 0.4 V vs RHE under UV illumination. Our transient absorption (TA) mechanistic study provides strong evidence that the improved electrical properties of oxygen-deficient TiO2 enables remarkably efficient spatial separation of electron–hole pairs on the submicrosecond time scale at moderate applied bias, and this coupled to effective suppression of microsecond to seconds charge carrier recombination is the primary factor behind the dramatically improved photoelectrochemical activity. PMID:24376902

Multiscale Modeling of Plasmon-Enhanced Power Conversion Efficiency in Nanostructured Solar Cells.

PubMed

Meng, Lingyi; Yam, ChiYung; Zhang, Yu; Wang, Rulin; Chen, GuanHua

2015-11-05

The unique optical properties of nanometallic structures can be exploited to confine light at subwavelength scales. This excellent light trapping is critical to improve light absorption efficiency in nanoscale photovoltaic devices. Here, we apply a multiscale quantum mechanics/electromagnetics (QM/EM) method to model the current-voltage characteristics and optical properties of plasmonic nanowire-based solar cells. The QM/EM method features a combination of first-principles quantum mechanical treatment of the photoactive component and classical description of electromagnetic environment. The coupled optical-electrical QM/EM simulations demonstrate a dramatic enhancement for power conversion efficiency of nanowire solar cells due to the surface plasmon effect of nanometallic structures. The improvement is attributed to the enhanced scattering of light into the photoactive layer. We further investigate the optimal configuration of the nanostructured solar cell. Our QM/EM simulation result demonstrates that a further increase of internal quantum efficiency can be achieved by scattering light into the n-doped region of the device.

High-efficiency and air-stable P3HT-based polymer solar cells with a new non-fullerene acceptor

PubMed Central

Holliday, Sarah; Ashraf, Raja Shahid; Wadsworth, Andrew; Baran, Derya; Yousaf, Syeda Amber; Nielsen, Christian B.; Tan, Ching-Hong; Dimitrov, Stoichko D.; Shang, Zhengrong; Gasparini, Nicola; Alamoudi, Maha; Laquai, Frédéric; Brabec, Christoph J.; Salleo, Alberto; Durrant, James R.; McCulloch, Iain

2016-01-01

Solution-processed organic photovoltaics (OPV) offer the attractive prospect of low-cost, light-weight and environmentally benign solar energy production. The highest efficiency OPV at present use low-bandgap donor polymers, many of which suffer from problems with stability and synthetic scalability. They also rely on fullerene-based acceptors, which themselves have issues with cost, stability and limited spectral absorption. Here we present a new non-fullerene acceptor that has been specifically designed to give improved performance alongside the wide bandgap donor poly(3-hexylthiophene), a polymer with significantly better prospects for commercial OPV due to its relative scalability and stability. Thanks to the well-matched optoelectronic and morphological properties of these materials, efficiencies of 6.4% are achieved which is the highest reported for fullerene-free P3HT devices. In addition, dramatically improved air stability is demonstrated relative to other high-efficiency OPV, showing the excellent potential of this new material combination for future technological applications. PMID:27279376

Privatization of municipal waste management services in Virginia

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

Arner, R.

As the cost of waste management has increased dramatically in recent years, public works and environmental services officials in Virginia responsible for waste management are exploring how various delivery systems can enhance the efficiency and effectiveness of these services. Shifting some service delivery from the public to the private sector, or vice versa, are approaches that may have the potential to improve efficiency. However, each jurisdiction's waste management requirements differ, and there is no cookie-cutter approach. The following discusses various privatization/publicization opportunities and under what conditions these strategies may be developed to the benefit of localities.

Algorithms and analyses for stochastic optimization for turbofan noise reduction using parallel reduced-order modeling

NASA Astrophysics Data System (ADS)

Yang, Huanhuan; Gunzburger, Max

2017-06-01

Simulation-based optimization of acoustic liner design in a turbofan engine nacelle for noise reduction purposes can dramatically reduce the cost and time needed for experimental designs. Because uncertainties are inevitable in the design process, a stochastic optimization algorithm is posed based on the conditional value-at-risk measure so that an ideal acoustic liner impedance is determined that is robust in the presence of uncertainties. A parallel reduced-order modeling framework is developed that dramatically improves the computational efficiency of the stochastic optimization solver for a realistic nacelle geometry. The reduced stochastic optimization solver takes less than 500 seconds to execute. In addition, well-posedness and finite element error analyses of the state system and optimization problem are provided.

Rho kinase inhibitor Y-27632 and Accutase dramatically increase mouse embryonic stem cell derivation.

PubMed

Zhang, Peng; Wu, Xinglong; Hu, Chunchao; Wang, Pengbo; Li, Xiangyun

2012-01-01

Although it has been 30 yr since the development of derivation methods for mouse embryonic stem (ES) cells, the biology of derivation of ES cells is poorly understood and the efficiency varies dramatically between cell lines. Recently, the Rho kinase inhibitor Y-27632 and the cell dissociation reagent Accutase were reported to significantly inhibit apoptosis of human ES cells during passaging. Therefore, in the current study, C57BL/6×129/Sv mouse blastocysts were used to evaluate the effect of the combination of the two reagents instead of using the conventional 129 line in mouse ES cell derivation. The data presented in this study suggests that the combination of Y-27632 and Accutase significantly increases the efficiency of mouse ES cell derivation; furthermore, no negative side effects were observed with Y-27632 and Accutase treatment. The newly established ES cell lines retain stable karyotype, surface markers expression, formed teratomas, and contributed to viable chimeras and germline transmission by tetraploid complementation assay. In addition, Y-27632 improved embryoid body formation of ES cells. During ES cell microinjection, Y-27632 prevented the formation of dissociation-induced cell blebs and facilitates the selection and the capture of intact cells. The methods presented in this study clearly demonstrate that inhibition of Rho kinase with Y-27632 and Accutase dissociation improve the derivation efficiently and reproducibility of mouse ES cell generation which is essential for reducing variability in the results obtained from different cell lines.

Dynamic views of living cell fine structure revealed by birefringence imaging

NASA Astrophysics Data System (ADS)

Oldenbourg, Rudolf

2001-11-01

We have been developing and applying a new type of polarized light microscope, the new Pol-Scope, which dramatically enhances the unique capabilities of the traditional polarizing microscope. In living cells, without applying exogenous dyes or florescent labels, we have studied the dynamic organization of filamentous actin in neuronal growth cones and improved the efficiency of spindle imaging for in-vitro fertilization and enucleation procedures.

Oligovalent Fab display on M13 phage improved by directed evolution.

PubMed

Huovinen, Tuomas; Sanmark, Hanna; Ylä-Pelto, Jani; Vehniäinen, Markus; Lamminmäki, Urpo

2010-03-01

Efficient display of antibody on filamentous phage M13 coat is crucial for successful biopanning selections. We applied a directed evolution strategy to improve the oligovalent display of a poorly behaving Fab fragment fused to phage gene-3 for minor coat protein (g3p). The Fab displaying clones were enriched from a randomly mutated Fab gene library with polyclonal anti-mouse IgG antibodies. Contribution of each mutation to the improved phenotype of one selected mutant was studied. It was found out that two point mutations had significant contribution to the display efficiency of Fab clones superinfected with hyperphage. The most dramatic effect was connected to a start codon mutation, from AUG to GUG, of the PelB signal sequence preceding the heavy chain. The clone carrying this mutation, FabM(GUG), displayed Fab 19-fold better and yielded twofold higher phage titers than the original Fab.

A synthetic design environment for ship design

NASA Technical Reports Server (NTRS)

Chipman, Richard R.

1995-01-01

Rapid advances in computer science and information system technology have made possible the creation of synthetic design environments (SDE) which use virtual prototypes to increase the efficiency and agility of the design process. This next generation of computer-based design tools will rely heavily on simulation and advanced visualization techniques to enable integrated product and process teams to concurrently conceptualize, design, and test a product and its fabrication processes. This paper summarizes a successful demonstration of the feasibility of using a simulation based design environment in the shipbuilding industry. As computer science and information science technologies have evolved, there have been many attempts to apply and integrate the new capabilities into systems for the improvement of the process of design. We see the benefits of those efforts in the abundance of highly reliable, technologically complex products and services in the modern marketplace. Furthermore, the computer-based technologies have been so cost effective that the improvements embodied in modern products have been accompanied by lowered costs. Today the state-of-the-art in computerized design has advanced so dramatically that the focus is no longer on merely improving design methodology; rather the goal is to revolutionize the entire process by which complex products are conceived, designed, fabricated, tested, deployed, operated, maintained, refurbished and eventually decommissioned. By concurrently addressing all life-cycle issues, the basic decision making process within an enterprise will be improved dramatically, leading to new levels of quality, innovation, efficiency, and customer responsiveness. By integrating functions and people with an enterprise, such systems will change the fundamental way American industries are organized, creating companies that are more competitive, creative, and productive.

Green Propulsion Technologies for Advanced Air Transports

NASA Technical Reports Server (NTRS)

Del Rosario, Ruben

2015-01-01

Air transportation is critical to U.S. and Global economic vitality. However, energy and climate issues challenge aviations ability to be sustainable in the long term. Aviation must dramatically reduce fuel use and related emissions. Energy costs to U.S. airlines nearly tripled between 1995 and 2011, and continue to be the highest percentage of operating costs. The NASA Advanced Air Transports Technology Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. The presentation will highlight the NASA vision of revolutionary systems and propulsion technologies needed to achieve these challenging goals. Specifically, the primary focus is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe, which are envisioned as being powered by Hybrid Electric Propulsion Systems.

Green Propulsion Technologies for Advanced Air Transports

NASA Technical Reports Server (NTRS)

Del Rosario, Ruben

2015-01-01

Air transportation is critical to U.S. and Global economic vitality. However, energy and climate issues challenge aviation's ability to be sustainable in the long term. Aviation must dramatically reduce fuel use and related emissions. Energy costs to U.S. airlines nearly tripled between 1995 and 2011, and continue to be the highest percentage of operating costs. The NASA Advanced Air Transports Technology Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. The presentation will highlight the NASA vision of revolutionary systems and propulsion technologies needed to achieve these challenging goals. Specifically, the primary focus is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe.

Analyzing Vehicle Fuel Saving Opportunities through Intelligent Driver Feedback

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

Gonder, J.; Earleywine, M.; Sparks, W.

2012-06-01

Driving style changes, e.g., improving driver efficiency and motivating driver behavior changes, could deliver significant petroleum savings. This project examines eliminating stop-and-go driving and unnecessary idling, and also adjusting acceleration rates and cruising speeds to ideal levels to quantify fuel savings. Such extreme adjustments can result in dramatic fuel savings of over 30%, but would in reality only be achievable through automated control of vehicles and traffic flow. In real-world driving, efficient driving behaviors could reduce fuel use by 20% on aggressively driven cycles and by 5-10% on more moderately driven trips. A literature survey was conducted of driver behaviormore » influences, and pertinent factors from on-road experiments with different driving styles were observed. This effort highlighted important driver influences such as surrounding vehicle behavior, anxiety over trying to get somewhere quickly, and the power/torque available from the vehicle. Existing feedback approaches often deliver efficiency information and instruction. Three recommendations for maximizing fuel savings from potential drive cycle improvement are: (1) leveraging applications with enhanced incentives, (2) using an approach that is easy and widely deployable to motivate drivers, and (3) utilizing connected vehicle and automation technologies to achieve large and widespread efficiency improvements.« less

Improving efficiency and access to mental health care: combining integrated care and advanced access.

PubMed

Pomerantz, Andrew; Cole, Brady H; Watts, Bradley V; Weeks, William B

2008-01-01

To provide an example of implementation of a new program that enhances access to mental health care in primary care. A general and specialized mental health service was redesigned to introduce open access to comprehensive mental health care in a primary care clinic. Key variables measured before and after implementation of the clinic included numbers of completed referrals, waiting time for appointments and clinic productivity. Workload and pre/post-implementation waiting time data were gathered through a computerized electronic monitoring system. Waiting time for new appointments was shortened from a mean of 33 days to 19 min. Clinician productivity and evaluations of new referrals more than doubled. These improvements have been sustained for 4 years. Moving mental health services into primary care, initiating open access and increasing use of technological aids led to dramatic improvements in access to mental health care and efficient use of resources. Implementation and sustainability of the program were enhanced by using a quality improvement approach.

Molecular approaches to third generation photovoltaics: photochemical up-conversion

NASA Astrophysics Data System (ADS)

Cheng, Yuen Yap; Fückel, Burkhard; Roberts, Derrick A.; Khoury, Tony; Clady, Rapha"l. G. C. R.; Tayebjee, Murad J. Y.; Piper, Roland; Ekins-Daukes, N. J.; Crossley, Maxwell J.; Schmidt, Timothy W.

2010-08-01

We have investigated a photochemical up-conversion system comprising a molecular mixture of a palladium porphyrin to harvest light, and a polycyclic aromatic hydrocarbon to emit light. The energy of harvested photons is stored as molecular triplet states which then annihilate to bring about up-converted fluorescence. The limiting efficiency of such triplet-triplet annihilation up-conversion has been believed to be 11% for some time. However, by rigorously investigating the kinetics of delayed fluorescence following pulsed excitation, we demonstrate instantaneous annihilation efficiencies exceeding 40%, and limiting efficiencies for the current system of ~60%. We attribute the high efficiencies obtained to the electronic structure of the emitting molecule, which exhibits an exceptionally high T2 molecular state. We utilize the kinetic data obtained to model an up-converting layer irradiated with broadband sunlight, finding that ~3% efficiencies can be obtained with the current system, with this improving dramatically upon optimization of various parameters.

Organic light-emitting diodes with a spacer enhanced exciplex emission

NASA Astrophysics Data System (ADS)

Yan, Fei; Chen, Rui; Sun, Handong; Wei Sun, Xiao

2014-04-01

By introducing a spacer molecule into the blended exciplex emissive layer, the performance of the bulk heterojunction exciplex organic light-emitting diodes (OLEDs) was improved dramatically; the maximum luminous efficiency was enhanced by about 22% from 7.9 cd/A to 9.7 cd/A, and the luminous efficiency drop was reduced by 28% at 400 mA/cm2. Besides the suppressed annihilation of exciton, the time-resolved photoluminescence measurements indicated that the spacer enhanced the delayed fluorescence through increasing the backward intersystem crossing rate from the triplet to singlet exciplex state. This method is useful for developing high performance exciplex OLEDs.

NASA Fixed Wing Project: Green Technologies for Future Aircraft Generation

NASA Technical Reports Server (NTRS)

Del Rosario, Ruben; Koudelka, John M.; Wahls, Rich; Madavan, Nateri

2014-01-01

Commercial aviation relies almost entirely on subsonic fixed wing aircraft to constantly move people and goods from one place to another across the globe. While air travel is an effective means of transportation providing an unmatched combination of speed and range, future subsonic aircraft must improve substantially to meet efficiency and environmental targets.The NASA Fundamental Aeronautics Fixed Wing (FW) Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. Multidisciplinary advances are required in aerodynamic efficiency to reduce drag, structural efficiency to reduce aircraft empty weight, and propulsive and thermal efficiency to reduce thrust-specific energy consumption (TSEC) for overall system benefit. Additionally, advances are required to reduce perceived noise without adversely affecting drag, weight, or TSEC, and to reduce harmful emissions without adversely affecting energy efficiency or noise.The paper will highlight the Fixed Wing project vision of revolutionary systems and technologies needed to achieve these challenging goals. Specifically, the primary focus of the FW Project is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe

Highly efficient organic electroluminescent diodes realized by efficient charge balance with optimized electron and hole transport layers

NASA Astrophysics Data System (ADS)

Khan, M. A.; Xu, Wei; Wei, Fuxiang; Bai, Yu; Jiang, X. Y.; Zhang, Z. L.; Zhu, W. Q.

2007-11-01

Highly efficient organic electroluminescent devices (OLEDs) were developed based on 4,7-diphenyl-1, 10-phenanthroline (BPhen) as the electron transport layer (ETL), tris-(8-hydroxyquinoline) aluminum (Alq 3) as the emission layer (EML) and N,Ń-bis-[1-naphthy(-N,Ńdiphenyl-1,1'-biphenyl-4,4'-diamine)] (NPB) as the hole transport layer (HTL). The typical device structure was glass substrate/ ITO/ NPB/ Alq 3/ BPhen/ LiF/ Al. Since BPhen possesses a considerable high electron mobility of 5×10 -4 cm 2 V -1 s -1, devices with BPhen as ETL can realize an extremely high luminous efficiency. By optimizing the thickness of both HTL and ETL, we obtained a highly efficient OLED with a current efficiency of 6.80 cd/A and luminance of 1361 cd/m 2 at a current density of 20 mA/cm 2. This dramatic improvement in the current efficiency has been explained on the principle of charge balance.

A study on improvement of discharge characteristic by using a transformer in a capacitively coupled plasma

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

Kim, Young-Cheol; Kim, Hyun-Jun; Lee, Hyo-Chang

In a plasma discharge system, the power loss at powered line, matching network, and other transmission line can affect the discharge characteristics such as the power transfer efficiency, voltage and current at powered electrode, and plasma density. In this paper, we propose a method to reduce power loss by using a step down transformer mounted between the matching network and the powered electrode in a capacitively coupled argon plasma. This step down transformer decreases the power loss by reducing the current flowing through the matching network and transmission line. As a result, the power transfer efficiency was increased about 5%–10%more » by using a step down transformer. However, the plasma density was dramatically increased compared to no transformer. This can be understood by the increase in ohmic heating and the decrease in dc-self bias. By simply mounting a transformer, improvement of discharge efficiency can be achieved in capacitively coupled plasmas.« less

A modified culture method significantly improves the development of mouse somatic cell nuclear transfer embryos.

PubMed

Dai, Xiangpeng; Hao, Jie; Zhou, Qi

2009-08-01

Many strategies have been established to improve the efficiency of somatic cell nuclear transfer (SCNT), but relatively few focused on improving culture conditions. The effect of different culture media on preimplantation development of mouse nuclear transfer embryos was investigated. A modified sequential media method, named D media (M16/KSOM and CZB-EG/KSOM), was successfully established that significantly improves SCNT embryo development. Our result demonstrated that while lacking any adverse effect on in vivo fertilized embryos, the D media dramatically improves the blastocyst development of SCNT embryos compared with other commonly used media, including KSOM, M16, CZB, and alphaMEM. Specifically, the rate of blastocyst formation was 62.3% for D1 (M16/KSOM) versus 10-30% for the other media. An analysis of media components indicated that removing EDTA and glutamine from the media can be beneficial for early SCNT embryo development. Our results suggest that in vitro culture environment plays an important role in somatic cell reprogramming, and D media represent the most efficient culture method reported to date to support mouse SCNT early embryo development in vitro.

Improved stability and efficiency of perovskite solar cells with submicron flexible barrier films deposited in air

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

Rolston, Nicholas; Printz, Adam D.; Hilt, Florian

Here in this paper, we report on submicron organosilicate barrier films produced rapidly in air by a scalable spray plasma process that improves both the stability and efficiency of perovskite solar cells. The plasma is at sufficiently low temperature to prevent damage to the underlying layers. Oxidizing species and heat from the plasma improve device performance by enhancing both interfacial contact and the conductivity of the hole transporting layer. The thickness of the barrier films is tunable and transparent over the entire visible spectrum. The morphology and density of the barrier are shown to improve with the addition of amore » fluorine-based precursor. Devices with submicron coatings exhibited significant improvements in stability, maintaining 92% of their initial power conversion efficiencies after more than 3000 h in dry heat (85 °C, 25% RH) while also being resistant to degradation under simulated operational conditions of continuous exposure to light, heat, and moisture. X-ray diffraction measurements performed while heating showed the barrier film dramatically slows the formation of PbI 2. The barrier films also are compatible with flexible devices, exhibiting no signs of cracking or delamination after 10000 bending cycles on a 127 μm substrate with a bending radius of 1 cm.« less

Improved stability and efficiency of perovskite solar cells with submicron flexible barrier films deposited in air

DOE PAGES

Rolston, Nicholas; Printz, Adam D.; Hilt, Florian; ...

2017-10-27

Here in this paper, we report on submicron organosilicate barrier films produced rapidly in air by a scalable spray plasma process that improves both the stability and efficiency of perovskite solar cells. The plasma is at sufficiently low temperature to prevent damage to the underlying layers. Oxidizing species and heat from the plasma improve device performance by enhancing both interfacial contact and the conductivity of the hole transporting layer. The thickness of the barrier films is tunable and transparent over the entire visible spectrum. The morphology and density of the barrier are shown to improve with the addition of amore » fluorine-based precursor. Devices with submicron coatings exhibited significant improvements in stability, maintaining 92% of their initial power conversion efficiencies after more than 3000 h in dry heat (85 °C, 25% RH) while also being resistant to degradation under simulated operational conditions of continuous exposure to light, heat, and moisture. X-ray diffraction measurements performed while heating showed the barrier film dramatically slows the formation of PbI 2. The barrier films also are compatible with flexible devices, exhibiting no signs of cracking or delamination after 10000 bending cycles on a 127 μm substrate with a bending radius of 1 cm.« less

FY 2007 Progress Report for Advanced Combustion Engine Technologies

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

None, None

2007-12-01

Advanced combustion engines have great potential for achieving dramatic energy efficiency improvements in light-duty vehicle applications, where it is suited to both conventional and hybrid- electric powertrain configurations. Light-duty vehicles with advanced combustion engines can compete directly with gasoline engine hybrid vehicles in terms of fuel economy and consumer-friendly driving characteristics; also, they are projected to have energy efficiencies that are competitive with hydrogen fuel cell vehicles when used in hybrid applications.Advanced engine technologies being researched and developed by the Advanced Combustion Engine R&D Sub-Program will also allow the use of hydrogen as a fuel in ICEs and will providemore » an energy-efficient interim hydrogen-based powertrain technology during the transition to hydrogen/fuelcell-powered transportation vehicles.« less

On the Minimum Induced Drag of Wings

NASA Technical Reports Server (NTRS)

Bowers, Albion H.

2015-01-01

Birds do not require the use of vertical tails. They do not appear to have any mechanism by which to control their yaw. As an example the albatross is notable in this regard. The authors believe this is possible because of a unique adaptation by which there exists a triple-optimal solution that provides the maximum aerodynamic efficiency, the minimum structural weight, and it provides for coordination of control in roll and yaw. Until now, this solution has eluded researchers, and remained unknown. Here it is shown that the correct specification of spanload provides for all three solutions at once, maximum aerodynamic efficiency, minimum structural weight, and coordinated control. The implications of this result has far reaching effects on the design of aircraft, as well as dramatic efficiency improvement.

Improving Efficiency of III-N Quantum Well Based Optoelectronic Devices through Active Region Design and Growth Techniques

NASA Astrophysics Data System (ADS)

Young, Nathan Garrett

The III-Nitride materials system provides a fascinating platform for developing optoelectronic devices, such as solar cells and LEDs, which have the power to dramatically improve the efficiency of our power consumption and reduce our environmental footprint. Finding ways to make these devices more efficient is key to driving their widespread adoption. This dissertation focuses on the intersection of challenges in physics and metalorganic chemical vapor deposition (MOCVD) growth at the nanoscale when designing for device efficiency. In order to create the best possible InGaN solar cell, a multiple quantum well (MQW) active region design had to be employed to prevent strain relaxation related degradation. There were two competing challenges for MQW active region design and growth. First, it was observed current collection efficiency improved with thinner quantum barriers, which promoted efficient tunneling transport instead of inefficiency thermally activated escape. Second, GaN barriers could planarize surface defects in the MQW region under the right conditions and when grown thick enough. A two-step growth method for thinner quantum barriers was developed that simultaneously allowed for tunneling transport and planarized V-defects. Barriers as thin as 4 nm were employed in MQW active regions with up to 30 periods without structural or electrical degradation, leading to record performance. Application of dielectric optical coatings greatly reduced surface reflections and allowed a second pass of light through the device. This both demonstrated the feasibility of multijunction solar integration and boosted conversion efficiency to record levels for an InGaN solar cell. III-N LEDs have achieved state-of-the-art performance for decades, but still suffer from the phenomena of efficiency droop, where device efficiency drops dramatically at high power operation. Droop is exacerbated by the polarization-induced electric fields in InGaN quantum wells, which originate from a lack of inversion symmetry in GaN's wurtzite crystal structure. These fields can be screened by using highly doped layers, but the extreme dopant densities predicted by simulation for complete screening may require using Ge as an alternative n-type dopant to Si. GaN:Ge layers with excellent electrical characteristics were grown by MOCVD with doping densities exceeding 1020 cm -3. However, their surface morphologies were very poor and they proved a poor screening dopant in LED structures. Using Si as the n-type screening dopant, LEDs with single QW active regions were grown, packaged, and tested. Biased photoluminescence showed strong evidence of complete polarization screening. The LEDs had low droop, but also low peak efficiencies. Possible explanations for trends in efficiency with varying QW width and field screening will be discussed.

A new cooperative MIMO scheme based on SM for energy-efficiency improvement in wireless sensor network.

PubMed

Peng, Yuyang; Choi, Jaeho

2014-01-01

Improving the energy efficiency in wireless sensor networks (WSN) has attracted considerable attention nowadays. The multiple-input multiple-output (MIMO) technique has been proved as a good candidate for improving the energy efficiency, but it may not be feasible in WSN which is due to the size limitation of the sensor node. As a solution, the cooperative multiple-input multiple-output (CMIMO) technique overcomes this constraint and shows a dramatically good performance. In this paper, a new CMIMO scheme based on the spatial modulation (SM) technique named CMIMO-SM is proposed for energy-efficiency improvement. We first establish the system model of CMIMO-SM. Based on this model, the transmission approach is introduced graphically. In order to evaluate the performance of the proposed scheme, a detailed analysis in terms of energy consumption per bit of the proposed scheme compared with the conventional CMIMO is presented. Later, under the guide of this new scheme we extend our proposed CMIMO-SM to a multihop clustered WSN for further achieving energy efficiency by finding an optimal hop-length. Equidistant hop as the traditional scheme will be compared in this paper. Results from the simulations and numerical experiments indicate that by the use of the proposed scheme, significant savings in terms of total energy consumption can be achieved. Combining the proposed scheme with monitoring sensor node will provide a good performance in arbitrary deployed WSN such as forest fire detection system.

Efficient perovskite light-emitting diodes featuring nanometre-sized crystallites

NASA Astrophysics Data System (ADS)

Xiao, Zhengguo; Kerner, Ross A.; Zhao, Lianfeng; Tran, Nhu L.; Lee, Kyung Min; Koh, Tae-Wook; Scholes, Gregory D.; Rand, Barry P.

2017-01-01

Organic-inorganic hybrid perovskite materials are emerging as highly attractive semiconductors for use in optoelectronics. In addition to their use in photovoltaics, perovskites are promising for realizing light-emitting diodes (LEDs) due to their high colour purity, low non-radiative recombination rates and tunable bandgap. Here, we report highly efficient perovskite LEDs enabled through the formation of self-assembled, nanometre-sized crystallites. Large-group ammonium halides added to the perovskite precursor solution act as a surfactant that dramatically constrains the growth of 3D perovskite grains during film forming, producing crystallites with dimensions as small as 10 nm and film roughness of less than 1 nm. Coating these nanometre-sized perovskite grains with longer-chain organic cations yields highly efficient emitters, resulting in LEDs that operate with external quantum efficiencies of 10.4% for the methylammonium lead iodide system and 9.3% for the methylammonium lead bromide system, with significantly improved shelf and operational stability.

Improving nitrogen utilization efficiency of aquaponics by introducing algal-bacterial consortia.

PubMed

Fang, Yingke; Hu, Zhen; Zou, Yina; Zhang, Jian; Zhu, Zhuoran; Zhang, Jianda; Nie, Lichao

2017-12-01

Aquaponics is a promising technology combining aquaculture with hydroponics. In this study, algal-bacterial consortia were introduced into aquaponics, i.e., algal-bacterial based aquaponics (AA), to improve the nitrogen utilization efficiency (NUE) of aquaponics. The results showed that the NUE of AA was 13.79% higher than that of media-based aquaponics (MA). In addition, higher NO 3 - removal by microalgae assimilation led to better water quality in AA, which made up for the deficiencies of poor aquaponic management of nitrate. As a result of lower NO 3 - concentrations and dramatically higher dissolved oxygen (DO) concentrations caused by microalgae photosynthesis in the photobioreactor, the N 2 O emission of AA was 89.89% lower than that of MA, although nosZ gene abundance in MA's hydroponic bed was approximately 30 times over that in AA. Considering the factors mentioned above, AA would improve the sustainability of aquaponics and have a good application foreground. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mixed polyanion glass cathodes: Effect of polyanion content

DOE PAGES

Kercher, Andrew K.; Kolopus, James A.; Sacci, Robert L.; ...

2017-02-18

Mixed polyanion glass cathodes in lithium-ion batteries have very high capacities (200-500 mAh/g), but currently these materials have fundamental problems with 1 st-cycle irreversible loss, cycling efficiency, and capacity fade. It is well established that polyanion substitutions into glasses can dramatically affect their physical properties, but the effect of polyanion content on the electrochemical performance has not been previously established. The proper amount of lithium and borate substitution in copper phosphate/vanadate glasses was shown to nearly eliminate 1 st-cycle irreversible loss and improve cycling efficiency. As a result, Raman and IR spectroscopy were used to identify polyanions that correlated withmore » electrochemical performance changes.« less

The Position and Attitude of Sub-reflector Modeling for TM65 m Radio Telescope

NASA Astrophysics Data System (ADS)

Sun, Z. X.; Chen, L.; Wang, J. Q.

2016-01-01

In the course of astronomical observations, with changes in angle of pitch, the large radio telescope will have different degrees of deformation in the sub-reflector support, back frame, main reflector etc, which will lead to the dramatic decline of antenna efficiency in both high and low elevation. A sub-reflector system of the Tian Ma 65 m radio telescope has been installed in order to compensate for the gravitational deformations of the sub-reflector support and the main reflector. The position and attitude of the sub-reflector are variable in order to improve the pointing performance and the efficiency at different elevations. In this paper, it is studied that the changes of position and attitude of the sub-reflector have influence on the efficiency of antenna in the X band and Ku band. A model has been constructed to determine the position and attitude of the sub-reflector with elevation, as well as the point compensation model, by observing the radio source. In addition, antenna efficiency was tested with sub-reflector position adjusted and fixed. The results show that the model of sub-reflector can effectively improve the efficiency of the 65 m radio telescope. In X band, the aperture efficiency of the radio telescope reaches more than 60% over the entire elevation range.

Optimizing sgRNA structure to improve CRISPR-Cas9 knockout efficiency.

PubMed

Dang, Ying; Jia, Gengxiang; Choi, Jennie; Ma, Hongming; Anaya, Edgar; Ye, Chunting; Shankar, Premlata; Wu, Haoquan

2015-12-15

Single-guide RNA (sgRNA) is one of the two key components of the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 genome-editing system. The current commonly used sgRNA structure has a shortened duplex compared with the native bacterial CRISPR RNA (crRNA)-transactivating crRNA (tracrRNA) duplex and contains a continuous sequence of thymines, which is the pause signal for RNA polymerase III and thus could potentially reduce transcription efficiency. Here, we systematically investigate the effect of these two elements on knockout efficiency and showed that modifying the sgRNA structure by extending the duplex length and mutating the fourth thymine of the continuous sequence of thymines to cytosine or guanine significantly, and sometimes dramatically, improves knockout efficiency in cells. In addition, the optimized sgRNA structure also significantly increases the efficiency of more challenging genome-editing procedures, such as gene deletion, which is important for inducing a loss of function in non-coding genes. By a systematic investigation of sgRNA structure we find that extending the duplex by approximately 5 bp combined with mutating the continuous sequence of thymines at position 4 to cytosine or guanine significantly increases gene knockout efficiency in CRISPR-Cas9-based genome editing experiments.

Giving them a good start: informatics support of newborn screening and clinical care.

PubMed

Wetter, T; Haschler, I; Ho, S; Hoffmann, G F; Linderkamp, O; Philipp, F; Skonetzki, S

2005-01-01

Newborns are a vulnerable population: Exposed to dramatically changing environmental conditions, potentially suffering from impairments that cannot realistically be diagnosed during pregnancy, with the risk that unfavorable conditions escalate fast. We have investigated informatics methods and tools to make screening for congenital diseases and containment of critical processes that start in the first days safer and more efficient. This poster present a set of three different methodological approaches that all aim at comprehensive improvement of neonatal care.

The Hybrid Automobile and the Atkinson Cycle

NASA Astrophysics Data System (ADS)

Feldman, Bernard J.

2008-10-01

The hybrid automobile is a strikingly new automobile technology with a number of new technological features that dramatically improve energy efficiency. This paper will briefly describe how hybrid automobiles work; what are these new technological features; why the Toyota Prius hybrid internal combustion engine operates on the Atkinson cycle instead of the Otto cycle; and what are the advantages and disadvantages of the hybrid automobile. This is a follow-up to my two previous papers on the physics of automobile engines.1,2

2015 Summer Series - Lee Stone - Brain Function Through the Eyes of the Beholder

NASA Image and Video Library

2015-06-09

The Visuomotor Control Laboratory (VCL) at NASA Ames conducts neuroscience research on the link between eye movements and brain function to provide an efficient and quantitative means of monitoring human perceptual performance. The VCL aims to make dramatic improvements in mission success through analysis, experimentation, and modeling of human performance and human-automation interaction. Dr. Lee Stone elaborates on how this research is conducted and how it contributes to NASA's mission and advances human-centered design and operations of complex aerospace systems.

Carbon quantum dots coated BiVO{sub 4} inverse opals for enhanced photoelectrochemical hydrogen generation

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

Nan, Feng; Shen, Mingrong; Fang, Liang, E-mail: zhkang@suda.edu.cn, E-mail: lfang@suda.edu.cn

Carbon quantum dots (CQDs) coated BiVO{sub 4} inverse opal (io-BiVO{sub 4}) structure that shows dramatic improvement of photoelectrochemical hydrogen generation has been fabricated using electrodeposition with a template. The io-BiVO{sub 4} maximizes photon trapping through slow light effect, while maintaining adequate surface area for effective redox reactions. CQDs are then incorporated to the io-BiVO{sub 4} to further improve the photoconversion efficiency. Due to the strong visible light absorption property of CQDs and enhanced separation of the photoexcited electrons, the CQDs coated io-BiVO{sub 4} exhibit a maximum photo-to-hydrogen conversion efficiency of 0.35%, which is 6 times higher than that of themore » pure BiVO{sub 4} thin films. This work is a good example of designing composite photoelectrode by combining quantum dots and photonic crystal.« less

Redesigned PDC bit solves low hydraulic hp problems

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

NONE

1996-06-01

A new PDC bit design was created to solve a problem a drilling contractor had due to hydraulic horsepower limitations on rigs used in a particular geographical area. The new bit design, which arose from a formal alliance between Exeter Drilling Co. and Hughes Christensen Co. has greatly improved bit cleaning and overall drilling efficiency in applications where only low hydraulic hp is available. The new design has been run successfully in the Denver-Julesburg (D-J) basin of Colorado. The development was described in detail in paper IADC/SPE 35109, ``Unique PDC bit configuration dramatically improves hole cleaning, drilling efficiency in lowmore » hydraulic applications,`` presented by G.J. Hertzler III, Exeter Drilling Co. and J.T. Wankier, Hughes Christensen Co., at the 1996 IADC/SPE Drilling Conference, New Orleans, La., March 12--15. This article is an abstract of that paper, which contains significantly more technical data.« less

Development of 8-hydroxyquinoline metal based organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Feng, Xiaodong

Because of its potential application for flat panel displays, solid-state lighting and 1.5 mum emitter for fiber optical communications, organic light-emitting diodes (OLEDs) have been intensively researched. One of the major problems with current OLED technology relates to inefficient electron injection at the cathode interface, which causes high driving voltage and poor device stability. Making a low resistance cathode contact for electron injection is critical to device performance. This work mainly focuses on cathode interface design and engineering. The Ohmic contact using a structure of C60/LiF/Al has been developed in electron only devices. It is found that application of the C60/LiF/Al contact to Alq based OLEDs leads to a dramatic reduction in driving voltages, a significant improvement in power efficiency, and a much slower aging process. A new cathode structure based on metal-organic-metal (MOM) tri-layer films has been developed. It is found that MOM cathodes reduce reflection by deconstructive optical interference from two metal films. The absolute reflectance from the MOM tr-ilayer films can be reduced to as low as 7% in the visible light spectrum. In actual working devices, the reflectance can be reduced from ˜80% to ˜20%. MOM cathodes provide a potential low-cost solution for high contrast full-color OLED displays. Low voltage Erq based OLEDs at 1.5 mum emission have been developed. The Erq/Ag cathode interface has been found to be efficient for electron injection. Dramatic improvement in driving voltage and power efficiency has been realized by implementing Bphen and C60 into Erq devices as an electron transport layer. Integration of Erq devices on Si wafers has also been demonstrated.

Reprogramming towards totipotency is greatly facilitated by synergistic effects of small molecules

PubMed Central

Tajima, Yosuke; Yoshida, Koki; Oikawa, Mami; Azuma, Rika; Allen, George E.; Tsujikawa, Tomomi; Tsukaguchi, Tomomasa; Bradshaw, Charles R.; Jullien, Jerome; Yamagata, Kazuo; Matsumoto, Kazuya; Anzai, Masayuki; Imai, Hiroshi; Gurdon, John B.; Yamada, Masayasu

2017-01-01

ABSTRACT Animal cloning has been achieved in many species by transplanting differentiated cell nuclei to unfertilized oocytes. However, the low efficiencies of cloning have remained an unresolved issue. Here we find that the combination of two small molecules, trichostatin A (TSA) and vitamin C (VC), under culture condition with bovine serum albumin deionized by ion-exchange resins, dramatically improves the cloning efficiency in mice and 15% of cloned embryos develop to term by means of somatic cell nuclear transfer (SCNT). The improvement was not observed by adding the non-treated, rather than deionized, bovine serum. RNA-seq analyses of SCNT embryos at the two-cell stage revealed that the treatment with TSA and VC resulted in the upregulated expression of previously identified reprogramming-resistant genes. Moreover, the expression of early-embryo-specific retroelements was upregulated by the TSA and VC treatment. The enhanced gene expression was relevant to the VC-mediated reduction of histone H3 lysine 9 methylation in SCNT embryos. Our study thus shows a simply applicable method to greatly improve mouse cloning efficiency, and furthers our understanding of how somatic nuclei acquire totipotency. PMID:28412714

Toward allocative efficiency in the prescription drug industry.

PubMed

Guell, R C; Fischbaum, M

1995-01-01

Traditionally, monopoly power in the pharmaceutical industry has been measured by profits. An alternative method estimates the deadweight loss of consumer surplus associated with the exercise of monopoly power. Although upper and lower bound estimates for this inefficiency are far apart, they at least suggest a dramatically greater welfare loss than measures of industry profitability would imply. A proposed system would have the U.S. government employing its power of eminent domain to "take" and distribute pharmaceutical patents, providing as "just compensation" the present value of the patent's expected future monopoly profits. Given the allocative inefficiency of raising taxes to pay for the program, the impact of the proposal on allocative efficiency would be at least as good at our lower bound estimate of monopoly costs while substantially improving efficiency at or near our upper bound estimate.

Chitosan-based water-propelled micromotors with strong antibacterial activity.

PubMed

Delezuk, Jorge A M; Ramírez-Herrera, Doris E; Esteban-Fernández de Ávila, Berta; Wang, Joseph

2017-02-09

A rapid and efficient micromotor-based bacteria killing strategy is described. The new antibacterial approach couples the attractive antibacterial properties of chitosan with the efficient water-powered propulsion of magnesium (Mg) micromotors. These Janus micromotors consist of Mg microparticles coated with the biodegradable and biocompatible polymers poly(lactic-co-glycolic acid) (PLGA), alginate (Alg) and chitosan (Chi), with the latter responsible for the antibacterial properties of the micromotor. The distinct speed and efficiency advantages of the new micromotor-based environmentally friendly antibacterial approach have been demonstrated in various control experiments by treating drinking water contaminated with model Escherichia coli (E. coli) bacteria. The new dynamic antibacterial strategy offers dramatic improvements in the antibacterial efficiency, compared to static chitosan-coated microparticles (e.g., 27-fold enhancement), with a 96% killing efficiency within 10 min. Potential real-life applications of these chitosan-based micromotors for environmental remediation have been demonstrated by the efficient treatment of seawater and fresh water samples contaminated with unknown bacteria. Coupling the efficient water-driven propulsion of such biodegradable and biocompatible micromotors with the antibacterial properties of chitosan holds great considerable promise for advanced antimicrobial water treatment operation.

Insights into the Influence of Work Functions of Cathodes on Efficiencies of Perovskite Solar Cells.

PubMed

Yue, Shizhong; Lu, Shudi; Ren, Kuankuan; Liu, Kong; Azam, Muhammad; Cao, Dawei; Wang, Zhijie; Lei, Yong; Qu, Shengchun; Wang, Zhanguo

2017-05-01

Though various efforts on modification of electrodes are still undertaken to improve the efficiency of perovskite solar cells, attributing to the large scope of these methods, it is of significance to unveil the working principle systematically. Herein, inverted perovskite solar cells based on indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/CH 3 NH 3 PbI 3 /phenyl-C61-butyric acid methyl ester (PC 61 BM)/buffer metal/Al are constructed. Through the choice of different buffer metals to tune work function of the cathode, the contact nature of the active layer with the cathode could be manipulated well. In comparison with the device using Au/Al as the electrode that shows an unfavorable band bending for conducting the excited electrons to the cathode, the one with Ca/Al presents a dramatically improved efficiency over 17.1%, ascribed to the favorable band bending at the interface of the cathode with the active layer. Details for tuning the band bending and the corresponding charge transfer mechanism are given in a systematic manner. Thus, a general guideline for constructing perovskite photovoltaic devices efficiently is provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Abnormal crystal growth in CH 3NH 3PbI 3-xCl x using a multi-cycle solution coating process

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

Dong, Qingfeng; Yuan, Yongbo; Shao, Yuchuan

2015-06-23

Recently, the efficiency of organolead trihalide perovskite solar cells has improved greatly because of improved material qualities with longer carrier diffusion lengths. Mixing chlorine in the precursor for mixed halide films has been reported to dramatically enhance the diffusion lengths of mixed halide perovskite films, mainly as a result of a much longer carrier recombination lifetime. Here we report that adding Cl containing precursor for mixed halide perovskite formation can induce the abnormal grain growth behavior that yields well-oriented grains accompanied by the appearance of some very large size grains. The abnormal grain growth becomes prominent only after multi-cycle coatingmore » of MAI : MACl blend precursor. The large grain size is found mainly to contribute to a longer carrier charge recombination lifetime, and thus increases the device efficiency to 18.9%, but without significantly impacting the carrier transport property. As a result, the strong correlation identified between material process and morphology provides guidelines for future material optimization and device efficiency enhancement.« less

Advantages of Crystallographic Fragment Screening: Functional and Mechanistic Insights from a Powerful Platform for Efficient Drug Discovery

PubMed Central

Patel, Disha; Bauman, Joseph D.; Arnold, Eddy

2015-01-01

X-ray crystallography has been an under-appreciated screening tool for fragment-based drug discovery due to the perception of low throughput and technical difficulty. Investigators in industry and academia have overcome these challenges by taking advantage of key factors that contribute to a successful crystallographic screening campaign. Efficient cocktail design and soaking methodologies have evolved to maximize throughput while minimizing false positives/negatives. In addition, technical improvements at synchrotron beamlines have dramatically increased data collection rates thus enabling screening on a timescale comparable to other techniques. The combination of available resources and efficient experimental design has resulted in many successful crystallographic screening campaigns. The three-dimensional crystal structure of the bound fragment complexed to its target, a direct result of the screening effort, enables structure-based drug design while revealing insights regarding protein dynamics and function not readily obtained through other experimental approaches. Furthermore, this “chemical interrogation” of the target protein crystals can lead to the identification of useful reagents for improving diffraction resolution or compound solubility. PMID:25117499

Advantages of crystallographic fragment screening: functional and mechanistic insights from a powerful platform for efficient drug discovery.

PubMed

Patel, Disha; Bauman, Joseph D; Arnold, Eddy

2014-01-01

X-ray crystallography has been an under-appreciated screening tool for fragment-based drug discovery due to the perception of low throughput and technical difficulty. Investigators in industry and academia have overcome these challenges by taking advantage of key factors that contribute to a successful crystallographic screening campaign. Efficient cocktail design and soaking methodologies have evolved to maximize throughput while minimizing false positives/negatives. In addition, technical improvements at synchrotron beamlines have dramatically increased data collection rates thus enabling screening on a timescale comparable to other techniques. The combination of available resources and efficient experimental design has resulted in many successful crystallographic screening campaigns. The three-dimensional crystal structure of the bound fragment complexed to its target, a direct result of the screening effort, enables structure-based drug design while revealing insights regarding protein dynamics and function not readily obtained through other experimental approaches. Furthermore, this "chemical interrogation" of the target protein crystals can lead to the identification of useful reagents for improving diffraction resolution or compound solubility. Copyright © 2014. Published by Elsevier Ltd.

Expansion of environmental impact assessment for eco-efficiency evaluation of China's economic sectors: An economic input-output based frontier approach.

PubMed

Xing, Zhencheng; Wang, Jigan; Zhang, Jie

2018-09-01

Due to the increasing environmental burdens caused by dramatic economic expansion, eco-efficiency indicating how efficient the economic activity is with respect to its environmental impacts has become a topic of considerable interest in China. In this context, Economic Input-output Life Cycle Assessment (EIO-LCA) and Data Envelopment Analysis (DEA) are combined to assess the environmental impacts and eco-efficiency of China's 26 economic sectors. The EIO-LCA results indicate that Electricity Production and Supply sector is the largest net exporter in energy usage, CO 2 emission and exhaust emission categories, while Construction sector is the largest net importer for five impact categories except for water withdrawal. Moreover, Construction sector is found to be the destination of the largest sector-to-sector environmental impact flows for the five impact categories and make the most contributions to the total environmental impacts. Another key finding is that Agriculture sector is both the largest net exporter and the greatest contributor for water withdrawal category. DEA results indicate that seven sectors are eco-efficient while over 70% of China's economic sectors are inefficient and require significant improvements. The average target improvements range between 23.30% and 35.06% depending on the impact category. Further sensitivity analysis reveals that the average sensitivity ratios vary from 7.7% to 15.7% among the six impact categories, which are found to be negatively correlated with their improvement potentials. Finally, several policy recommendations are made to mitigate environmental impacts of China's economic sectors and improve their eco-efficiency levels. Copyright © 2018 Elsevier B.V. All rights reserved.

Improvement of radiological penumbra using intermediate energy photons (IEP) for stereotactic radiosurgery.

PubMed

O'Malley, Lauren; Pignol, Jean-Philippe; Beachey, David J; Keller, Brian M; Presutti, Joseph; Sharpe, Michael

2006-05-21

Using efficient immobilization and dedicated beam collimation devices, stereotactic radiosurgery ensures highly conformal treatment of small tumours with limited microscopic extension. One contribution to normal tissue irradiation remains the radiological penumbra. This work aims at demonstrating that intermediate energy photons (IEP), above orthovoltage but below megavoltage, improve dose distribution for stereotactic radiosurgery for small irradiation field sizes due to a dramatic reduction of radiological penumbra. Two different simulation systems were used: (i) Monte Carlo simulation to investigate the dose distribution of monoenergetic IEP between 100 keV and 1 MeV in water phantom; (ii) the Pinnacle3 TPS including a virtual IEP unit to investigate the dosimetry benefit of treating with 11 non-coplanar beams a 2 cm tumour in the middle of a brain adjacent to a 1 mm critical structure. Radiological penumbrae below 300 microm are generated for field size below 2 x 2 cm2 using monoenergetic IEP beams between 200 and 400 keV. An 800 kV beam generated in a 0.5 mm tungsten target maximizes the photon intensity in this range. Pinnacle3 confirms the dramatic reduction in penumbra size. DVHs show for a constant dose distribution conformality, improved dose distribution homogeneity and better sparing of critical structures using a 800 kV beam compared to a 6 MV beam.

Improvement of radiological penumbra using intermediate energy photons (IEP) for stereotactic radiosurgery

NASA Astrophysics Data System (ADS)

O'Malley, Lauren; Pignol, Jean-Philippe; Beachey, David J.; Keller, Brian M.; Presutti, Joseph; Sharpe, Michael

2006-05-01

Using efficient immobilization and dedicated beam collimation devices, stereotactic radiosurgery ensures highly conformal treatment of small tumours with limited microscopic extension. One contribution to normal tissue irradiation remains the radiological penumbra. This work aims at demonstrating that intermediate energy photons (IEP), above orthovoltage but below megavoltage, improve dose distribution for stereotactic radiosurgery for small irradiation field sizes due to a dramatic reduction of radiological penumbra. Two different simulation systems were used: (i) Monte Carlo simulation to investigate the dose distribution of monoenergetic IEP between 100 keV and 1 MeV in water phantom; (ii) the Pinnacle3 TPS including a virtual IEP unit to investigate the dosimetry benefit of treating with 11 non-coplanar beams a 2 cm tumour in the middle of a brain adjacent to a 1 mm critical structure. Radiological penumbrae below 300 µm are generated for field size below 2 × 2 cm2 using monoenergetic IEP beams between 200 and 400 keV. An 800 kV beam generated in a 0.5 mm tungsten target maximizes the photon intensity in this range. Pinnacle3 confirms the dramatic reduction in penumbra size. DVHs show for a constant dose distribution conformality, improved dose distribution homogeneity and better sparing of critical structures using a 800 kV beam compared to a 6 MV beam.

Economic analysis of greenhouse lighting: light emitting diodes vs. high intensity discharge fixtures.

PubMed

Nelson, Jacob A; Bugbee, Bruce

2014-01-01

Lighting technologies for plant growth are improving rapidly, providing numerous options for supplemental lighting in greenhouses. Here we report the photosynthetic (400-700 nm) photon efficiency and photon distribution pattern of two double-ended HPS fixtures, five mogul-base HPS fixtures, ten LED fixtures, three ceramic metal halide fixtures, and two fluorescent fixtures. The two most efficient LED and the two most efficient double-ended HPS fixtures had nearly identical efficiencies at 1.66 to 1.70 micromoles per joule. These four fixtures represent a dramatic improvement over the 1.02 micromoles per joule efficiency of the mogul-base HPS fixtures that are in common use. The best ceramic metal halide and fluorescent fixtures had efficiencies of 1.46 and 0.95 micromoles per joule, respectively. We also calculated the initial capital cost of fixtures per photon delivered and determined that LED fixtures cost five to ten times more than HPS fixtures. The five-year electric plus fixture cost per mole of photons is thus 2.3 times higher for LED fixtures, due to high capital costs. Compared to electric costs, our analysis indicates that the long-term maintenance costs are small for both technologies. If widely spaced benches are a necessary part of a production system, the unique ability of LED fixtures to efficiently focus photons on specific areas can be used to improve the photon capture by plant canopies. Our analysis demonstrates, however, that the cost per photon delivered is higher in these systems, regardless of fixture category. The lowest lighting system costs are realized when an efficient fixture is coupled with effective canopy photon capture.

Hybrid electro-optics and chipscale integration of electronics and photonics

NASA Astrophysics Data System (ADS)

Dalton, L. R.; Robinson, B. H.; Elder, D. L.; Tillack, A. F.; Johnson, L. E.

2017-08-01

Taken together, theory-guided nano-engineering of organic electro-optic materials and hybrid device architectures have permitted dramatic improvement of the performance of electro-optic devices. For example, the voltage-length product has been improved by nearly a factor of 104 , bandwidths have been extended to nearly 200 GHz, device footprints reduced to less than 200 μm2 , and femtojoule energy efficiency achieved. This presentation discusses the utilization of new coarse-grained theoretical methods and advanced quantum mechanical methods to quantitatively simulate the physical properties of new classes of organic electro-optic materials and to evaluate their performance in nanoscopic device architectures, accounting for the effect on chromophore ordering at interfaces in nanoscopic waveguides.

NASA Fixed Wing Project: Green Technologies for Future Aircraft Generation

NASA Technical Reports Server (NTRS)

DelRosario, Ruben

2014-01-01

The NASA Fundamental Aeronautics Fixed Wing (FW) Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advances in multidisciplinary technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. The presentation will highlight the FW Project vision of revolutionary systems and technologies needed to achieve the challenging goals of aviation. Specifically, the primary focus of the FW Project is on the N+3 generation that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe.

Variation of the Side Chain Branch Position Leads to Vastly Improved Molecular Weight and OPV Performance in 4,8-dialkoxybenzo[1,2-b:4,5-b′]dithiophene/2,1,3-benzothiadiazole Copolymers

DOE PAGES

Coffin, Robert C.; MacNeill, Christopher M.; Peterson, Eric D.; ...

2011-01-01

Tmore » hrough manipulation of the solubilizing side chains, we were able to dramatically improve the molecular weight ( M w ) of 4,8-dialkoxybenzo[1,2- b :4,5- b ′ ]dithiophene (BD)/2,1,3-benzothiadiazole (B) copolymers. When dodecyl side chains ( P1 ) are employed at the 4- and 8-positions of the BD unit, we obtain a chloroform-soluble copolymer fraction with M w of 6.3 kg/mol. Surprisingly, by moving to the commonly employed 2-ethylhexyl branch ( P2 ), M w decreases to 3.4 kg/mol. his is despite numerous reports that this side chain increases solubility and M w . By moving the ethyl branch in one position relative to the polymer backbone (1-ethylhexyl, P3 ), M w is dramatically increased to 68.8 kg/mol. As a result of this M w increase, the shape of the absorption profile is dramatically altered, with λ max = 637 nm compared with 598 nm for P1 and 579 nm for P2 . he hole mobility as determined by thin film transistor (F) measurements is improved from ~ 1 × 10 − 6  cm 2 /Vs for P1 and P2 to 7 × 10 − 4  cm 2 /Vs for P3 , while solar cell power conversion efficiency in increased to 2.91 % for P3 relative to 0.31 % and 0.19 % for P1 and P2 , respectively.« less

Enhancement of the inverted polymer solar cells via ZnO doped with CTAB

NASA Astrophysics Data System (ADS)

Sivashnamugan, Kundan; Guo, Tzung-Fang; Hsu, Yao-Jane; Wen, Ten-Chin

2018-02-01

A facile approach enhancing electron extraction in zinc oxide (ZnO) electron transfer interlayer and improving performance of bulk-heterojunction (BHJ) polymer solar cells (PSCs) by adding cetyltrimethylammonium bromide (CTAB) into sol-gel ZnO precursor solution was demonstrated in this work. The power conversion efficiency (PCE) has a 24.1% increment after modification. Our results show that CTAB can dramatically influence optical, electrical and morphological properties of ZnO electron transfer layer, and work as effective additive to enhance the performance of bulk- heterojunction polymer solar cells.

Creating a high-value delivery system for health care.

PubMed

Teisberg, Elizabeth O; Wallace, Scott

2009-01-01

Health care reform that focuses on improving value enhances both the well-being of patients and the professional satisfaction of physicians. Value in health care is the improvement in health outcomes achieved for patients relative to the money spent. Dramatic and ongoing improvement in the value of health care delivered will require fundamental restructuring of the system. Current efforts to improve safety and reduce waste are truly important but not sufficient. The following three structural changes will drive simultaneous improvement in outcomes and efficiency: (1) reorganizing care delivery into clinically integrated teams defined by patient needs over the full cycle of care; (2) measuring and reporting patient outcomes by clinical teams, across the cycle of care and for identified clusters of medical circumstances; and (3) enabling reimbursement tied to value rather than to quantity of services. Many of these changes require physician leadership. We discuss steps on the journey to value-based care delivery.

Vacuum-free laminated top electrode with conductive tapes for scalable manufacturing of efficient perovskite solar cells

DOE PAGES

Shao, Yuchuan; Wang, Qi; Dong, Qingfeng; ...

2015-06-25

The efficiency of organometal trihalide perovskites (OTP) solar cells have reached that parity of single crystal silicon, and its nature abundant raw material and solution-process capability promise a bright future for commercialization. However, the vacuum based techniques for metal electrode deposition and additional encapsulation layer increase the cost of the perovskite solar cells dramatically and impede their commercialization process. Here, we report a vacuum-free low temperature lamination technique to fabricate the top electrode by commercial conductive tapes (C-tape). The simple fabrication method yields good quality contact and high efficiency device of 12.7%. The C-tapes also encapsulated the devices effectively, resultingmore » in greatly improved device stability. As a result, the combination of lamination of electrodes and encapsulation layers into a single step significantly reduce the cost of device fabrication.« less

Enhancing the transmission efficiency by edge deletion in scale-free networks

NASA Astrophysics Data System (ADS)

Zhang, Guo-Qing; Wang, Di; Li, Guo-Jie

2007-07-01

How to improve the transmission efficiency of Internet-like packet switching networks is one of the most important problems in complex networks as well as for the Internet research community. In this paper we propose a convenient method to enhance the transmission efficiency of scale-free networks dramatically by kicking out the edges linking to nodes with large betweenness, which we called the “black sheep.” The advantages of our method are of facility and practical importance. Since the black sheep edges are very costly due to their large bandwidth, our method could decrease the cost as well as gain higher throughput of networks. Moreover, we analyze the curve of the largest betweenness on deleting more and more black sheep edges and find that there is a sharp transition at the critical point where the average degree of the nodes ⟨k⟩→2 .

Effects of local structural transformation of lipid-like compounds on delivery of messenger RNA

NASA Astrophysics Data System (ADS)

Li, Bin; Luo, Xiao; Deng, Binbin; Giancola, Jolynn B.; McComb, David W.; Schmittgen, Thomas D.; Dong, Yizhou

2016-02-01

Lipid-like nanoparticles (LLNs) have shown great potential for RNA delivery. Lipid-like compounds are key components in LLNs. In this study, we investigated the effects of local structural transformation of lipid-like compounds on delivery of messenger RNA. Our results showed that position change of functional groups on lipid-like compounds can dramatically improve delivery efficiency. We then optimized formulation ratios of TNT-b10 LLNs, a lead material, increasing delivery efficiency over 2-fold. More importantly, pegylated TNT-b10 LLNs is stable for over four weeks and is over 10-fold more efficient than that of its counterpart TNT-a10 LLNs. Additionally, the optimal formulation O-TNT-b10 LLNs is capable of delivering mRNA encoding luciferase in vivo. These results provide useful insights into the design of next generation LLNs for mRNA delivery.

Built-in potential shift and Schottky-barrier narrowing in organic solar cells with UV-sensitive electron transport layers.

PubMed

Li, Cheng; Credgington, Dan; Ko, Doo-Hyun; Rong, Zhuxia; Wang, Jianpu; Greenham, Neil C

2014-06-28

The performance of organic solar cells incorporating solution-processed titanium suboxide (TiOx) as electron-collecting layers can be improved by UV illumination. We study the mechanism of this improvement using electrical measurements and electroabsorption spectroscopy. We propose a model in which UV illumination modifies the effective work function of the oxide layer through a significant increase in its free electron density. This leads to a dramatic improvement in device power conversion efficiency through several mechanisms - increasing the built-in potential by 0.3 V, increasing the conductivity of the TiOx layer and narrowing the interfacial Schottky barrier between the suboxide and the underlying transparent electrode. This work highlights the importance of considering Fermi-level equilibration when designing multi-layer transparent electrodes.

Hartmann characterization of the PEEM-3 aberration-corrected X-ray photoemission electron microscope.

PubMed

Scholl, A; Marcus, M A; Doran, A; Nasiatka, J R; Young, A T; MacDowell, A A; Streubel, R; Kent, N; Feng, J; Wan, W; Padmore, H A

2018-05-01

Aberration correction by an electron mirror dramatically improves the spatial resolution and transmission of photoemission electron microscopes. We will review the performance of the recently installed aberration corrector of the X-ray Photoemission Electron Microscope PEEM-3 and show a large improvement in the efficiency of the electron optics. Hartmann testing is introduced as a quantitative method to measure the geometrical aberrations of a cathode lens electron microscope. We find that aberration correction leads to an order of magnitude reduction of the spherical aberrations, suggesting that a spatial resolution of below 100 nm is possible at 100% transmission of the optics when using x-rays. We demonstrate this improved performance by imaging test patterns employing element and magnetic contrast. Published by Elsevier B.V.

Polymer solar cells with enhanced open-circuit voltage and efficiency

NASA Astrophysics Data System (ADS)

Chen, Hsiang-Yu; Hou, Jianhui; Zhang, Shaoqing; Liang, Yongye; Yang, Guanwen; Yang, Yang; Yu, Luping; Wu, Yue; Li, Gang

2009-11-01

Following the development of the bulk heterojunction structure, recent years have seen a dramatic improvement in the efficiency of polymer solar cells. Maximizing the open-circuit voltage in a low-bandgap polymer is one of the critical factors towards enabling high-efficiency solar cells. Study of the relation between open-circuit voltage and the energy levels of the donor/acceptor in bulk heterojunction polymer solar cells has stimulated interest in modifying the open-circuit voltage by tuning the energy levels of polymers. Here, we show that the open-circuit voltage of polymer solar cells constructed based on the structure of a low-bandgap polymer, PBDTTT, can be tuned, step by step, using different functional groups, to achieve values as high as 0.76 V. This increased open-circuit voltage combined with a high short-circuit current density results in a polymer solar cell with a power conversion efficiency as high as 6.77%, as certified by the National Renewable Energy Laboratory.

Flexible, highly efficient all-polymer solar cells

PubMed Central

Kim, Taesu; Kim, Jae-Han; Kang, Tae Eui; Lee, Changyeon; Kang, Hyunbum; Shin, Minkwan; Wang, Cheng; Ma, Biwu; Jeong, Unyong; Kim, Taek-Soo; Kim, Bumjoon J.

2015-01-01

All-polymer solar cells have shown great potential as flexible and portable power generators. These devices should offer good mechanical endurance with high power-conversion efficiency for viability in commercial applications. In this work, we develop highly efficient and mechanically robust all-polymer solar cells that are based on the PBDTTTPD polymer donor and the P(NDI2HD-T) polymer acceptor. These systems exhibit high power-conversion efficiency of 6.64%. Also, the proposed all-polymer solar cells have even better performance than the control polymer-fullerene devices with phenyl-C61-butyric acid methyl ester (PCBM) as the electron acceptor (6.12%). More importantly, our all-polymer solar cells exhibit dramatically enhanced strength and flexibility compared with polymer/PCBM devices, with 60- and 470-fold improvements in elongation at break and toughness, respectively. The superior mechanical properties of all-polymer solar cells afford greater tolerance to severe deformations than conventional polymer-fullerene solar cells, making them much better candidates for applications in flexible and portable devices. PMID:26449658

Computational efficiency for the surface renewal method

NASA Astrophysics Data System (ADS)

Kelley, Jason; Higgins, Chad

2018-04-01

Measuring surface fluxes using the surface renewal (SR) method requires programmatic algorithms for tabulation, algebraic calculation, and data quality control. A number of different methods have been published describing automated calibration of SR parameters. Because the SR method utilizes high-frequency (10 Hz+) measurements, some steps in the flux calculation are computationally expensive, especially when automating SR to perform many iterations of these calculations. Several new algorithms were written that perform the required calculations more efficiently and rapidly, and that tested for sensitivity to length of flux averaging period, ability to measure over a large range of lag timescales, and overall computational efficiency. These algorithms utilize signal processing techniques and algebraic simplifications that demonstrate simple modifications that dramatically improve computational efficiency. The results here complement efforts by other authors to standardize a robust and accurate computational SR method. Increased speed of computation time grants flexibility to implementing the SR method, opening new avenues for SR to be used in research, for applied monitoring, and in novel field deployments.

Expanding primary care capacity by reducing waste and improving the efficiency of care.

PubMed

Shipman, Scott A; Sinsky, Christine A

2013-11-01

Most solutions proposed for the looming shortage of primary care physicians entail strategies that fall into one of three categories: train more, lose fewer, or find someone else. A fourth strategy deserves more attention: waste less. This article examines the remarkable inefficiency and waste in primary care today and highlights practices that have addressed these problems. For example, delegating certain administrative tasks such as managing task lists in the electronic health record can give physicians more time to see additional patients. Flow managers who guide physicians from task to task throughout the clinical day have been shown to improve physicians' efficiency and capacity. Even something as simple as placing a printer in every exam room can save each physician twenty minutes per day. Modest but systemwide improvements could yield dramatic gains in physician capacity while potentially reducing physician burnout and its implications for the quality of care. If widely adopted, small efforts to empower nonphysicians, reengineer workflows, exploit technology, and update policies to eliminate wasted effort could yield the capacity for millions of additional patient visits per year in the United States.

High-Performance Ultrathin Organic-Inorganic Hybrid Silicon Solar Cells via Solution-Processed Interface Modification.

PubMed

Zhang, Jie; Zhang, Yinan; Song, Tao; Shen, Xinlei; Yu, Xuegong; Lee, Shuit-Tong; Sun, Baoquan; Jia, Baohua

2017-07-05

Organic-inorganic hybrid solar cells based on n-type crystalline silicon and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) exhibited promising efficiency along with a low-cost fabrication process. In this work, ultrathin flexible silicon substrates, with a thickness as low as tens of micrometers, were employed to fabricate hybrid solar cells to reduce the use of silicon materials. To improve the light-trapping ability, nanostructures were built on the thin silicon substrates by a metal-assisted chemical etching method (MACE). However, nanostructured silicon resulted in a large amount of surface-defect states, causing detrimental charge recombination. Here, the surface was smoothed by solution-processed chemical treatment to reduce the surface/volume ratio of nanostructured silicon. Surface-charge recombination was dramatically suppressed after surface modification with a chemical, associated with improved minority charge-carrier lifetime. As a result, a power conversion efficiency of 9.1% was achieved in the flexible hybrid silicon solar cells, with a substrate thickness as low as ∼14 μm, indicating that interface engineering was essential to improve the hybrid junction quality and photovoltaic characteristics of the hybrid devices.

Improved Operating Room Efficiency via Constraint Management: Experience of a Tertiary-Care Academic Medical Center.

PubMed

Kimbrough, Charles W; McMasters, Kelly M; Canary, Jeff; Jackson, Lisa; Farah, Ian; Boswell, Mark V; Kim, Daniel; Scoggins, Charles R

2015-07-01

Suboptimal operating room (OR) efficiency is a universal complaint among surgeons. Nonetheless, maximizing efficiency is critical to institutional success. Here, we report improvement achieved from low-cost, low-technology measures instituted within a tertiary-care academic medical center/Level I trauma center. Improvements in preadmission testing and OR scheduling, including appointing a senior nurse anesthetist to help direct OR use, were instituted in March 2012. A retrospective review of prospectively maintained OR case data was performed to evaluate time periods before and after program implementation, as well as to assess trends over time. Operating room performance metrics were compared using Mann-Whitney and chi-squared tests. Changes over time were analyzed using linear regression. Data including all surgical cases were available for a 36-month period; 10 months (6,581 cases) before program implementation and 26 months afterward (17,574 cases). Dramatic improvement was seen in first-case on-time starts, which increased from 39.3% to 83.8% (p < 0.0001). Additionally, the percent utilization of available OR time demonstrated a steady increase (p < 0.001). After an initial lag, case volume also improved, evident by an increase observed in the 12-month rolling average of cases per month (p < 0.001). The increase in case volume occurred during peak OR time (7 am to 5 pm), and did not result from adding cases after hours (5 pm to 11 pm). After many years of what seemed an insoluble problem, simple changes fostering collaboration among services, including active management of the OR schedule and transparent data, have resulted in substantial improvement in OR efficiency and case volume. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Mild Deoxygenation of Sulfoxides over Plasmonic Molybdenum Oxide Hybrid with Dramatic Activity Enhancement under Visible Light.

PubMed

Kuwahara, Yasutaka; Yoshimura, Yukihiro; Haematsu, Kohei; Yamashita, Hiromi

2018-06-17

Harvesting solar light to boost commercially important organic synthesis still remains a challenge. Coupling of conventional noble metal catalysts with plasmonic oxide materials which exhibit intense plasmon absorption in the visible light region is a promising option for efficient solar energy utilization in catalysis. Herein we for the first time demonstrate that plasmonic hydrogen molybdenum bronze coupled with Pt nanoparticles (Pt/H x MoO 3-y ) shows a high catalytic performance in the deoxygenation of sulfoxides with 1 atm H 2 at room temperature, with dramatic activity enhancement under visible light irradiation relative to dark condition. The plasmonic molybdenum oxide hybrids with strong plasmon resonance peaks pinning at around 556 nm are obtained via a facile H-spillover process. Pt/H x MoO 3-y hybrid provides excellent selectivity for the deoxygenation of various sulfoxides as well as pyridine N-oxides, in which drastically improved catalytic efficiencies are obtained under the irradiation of visible light. Comprehensive analyses reveal that oxygen vacancies massively introduced via a H-spillover process are the main active sites, and reversible redox property of Mo atoms and strong plasmonic absorption play key roles in this reaction. The catalytic system works under extremely mild conditions and can boost the reaction by the assist of visible light, offering an ultimately greener protocol to produce sulfides from sulfoxides. Our findings may open up a new strategy for designing plasmon-based catalytic systems that can harness visible light efficiently.

RAMAN spectroscopy imaging improves the diagnosis of papillary thyroid carcinoma

NASA Astrophysics Data System (ADS)

Rau, Julietta V.; Graziani, Valerio; Fosca, Marco; Taffon, Chiara; Rocchia, Massimiliano; Crucitti, Pierfilippo; Pozzilli, Paolo; Onetti Muda, Andrea; Caricato, Marco; Crescenzi, Anna

2016-10-01

Recent investigations strongly suggest that Raman spectroscopy (RS) can be used as a clinical tool in cancer diagnosis to improve diagnostic accuracy. In this study, we evaluated the efficiency of Raman imaging microscopy to discriminate between healthy and neoplastic thyroid tissue, by analyzing main variants of Papillary Thyroid Carcinoma (PTC), the most common type of thyroid cancer. We performed Raman imaging of large tissue areas (from 100 × 100 μm2 up to 1 × 1 mm2), collecting 38 maps containing about 9000 Raman spectra. Multivariate statistical methods, including Linear Discriminant Analysis (LDA), were applied to translate Raman spectra differences between healthy and PTC tissues into diagnostically useful information for a reliable tissue classification. Our study is the first demonstration of specific biochemical features of the PTC profile, characterized by significant presence of carotenoids with respect to the healthy tissue. Moreover, this is the first evidence of Raman spectra differentiation between classical and follicular variant of PTC, discriminated by LDA with high efficiency. The combined histological and Raman microscopy analyses allow clear-cut integration of morphological and biochemical observations, with dramatic improvement of efficiency and reliability in the differential diagnosis of neoplastic thyroid nodules, paving the way to integrative findings for tumorigenesis and novel therapeutic strategies.

[Treatment of early-onset generalized dystonia by chronic bilateral stimulation of the internal globus pallidus. Apropos of a case].

PubMed

Coubes, P; Echenne, B; Roubertie, A; Vayssière, N; Tuffery, S; Humbertclaude, V; Cambonie, G; Claustres, M; Frerebeau, P

1999-05-01

Dystonia musculorum deformans is an inherited severe disease, with a wide clinical polymorphism. The most severe clinical forms with early onset carry a high risk of life-threatening complications. In the absence of any efficient medical treatment, bilateral pallidotomy has previously been reported to be of value in the management of this disease. We report the first clinical case of a severe early-onset generalized dystonia dramatically improved by a bilateral stimulation of the internal globus pallidus. In November 1996, we proposed this neurosurgical procedure for a 8-year-old girl, who had suffered since the age of 3 from severe generalized dystonia, and who progressively became totally dependent and bedridden. She had been under sedation and permanent controlled respiratory assistance for the last two months. The etiology of the disease remained unknown (the DYT1 mutation was absent). Under general anesthesia, we bilaterally implanted a four-contacts electrode in the internal globus pallidus, using the Leksell's stereotactic frame and a 1.5 tesla MRI control. A dramatic improvement was noted 6 weeks later and led us to connect the two electrodes to neurostimulators inserted under the abdominal skin.

An Efficient Extraction Method for Fragrant Volatiles from Jasminum sambac (L.) Ait.

PubMed

Ye, Qiuping; Jin, Xinyi; Zhu, Xinliang; Lin, Tongxiang; Hao, Zhilong; Yang, Qian

2015-01-01

The sweet smell of aroma of Jasminum sambac (L.) Ait. is releasing while the flowers are blooming. Although components of volatile oil have been extensively studied, there are problematic issues, such as low efficiency of yield, flavour distortion. Here, the subcritical fluid extraction (SFE) was performed to extract fragrant volatiles from activated carbon that had absorbed the aroma of jasmine flowers. This novel method could effectively obtain main aromatic compounds with quality significantly better than solvent extraction (SE). Based on the analysis data with response surface methodology (RSM), we optimized the extraction conditions which consisted of a temperature of 44°C, a solvent-to-material ratio of 3.5:1, and an extraction time of 53 min. Under these conditions, the extraction yield was 4.91%. Furthermore, the key jasmine essence oil components, benzyl acetate and linalool, increase 7 fold and 2 fold respectively which lead to strong typical smell of the jasmine oil. The new method can reduce spicy components which lead to the essential oils smelling sweeter. Thus, the quality of the jasmine essence oil was dramatically improved and yields based on the key component increased dramatically. Our results provide a new effective technique for extracting fragrant volatiles from jasmine flowers.

The CRISPR-Cas9 technology: Closer to the ultimate toolkit for targeted genome editing.

PubMed

Quétier, Francis

2016-01-01

The first period of plant genome editing was based on Agrobacterium; chemical mutagenesis by EMS (ethyl methanesulfonate) and ionizing radiations; each of these technologies led to randomly distributed genome modifications. The second period is associated with the discoveries of homing and meganuclease enzymes during the 80s and 90s, which were then engineered to provide efficient tools for targeted editing. From 2006 to 2012, a few crop plants were successfully and precisely modified using zinc-finger nucleases. A third wave of improvement in genome editing, which led to a dramatic decrease in off-target events, was achieved in 2009-2011 with the TALEN technology. The latest revolution surfaced in 2013 with the CRISPR-Cas9 system, whose high efficiency and technical ease of use is really impressive; scientists can use in-house kits or commercially available kits; the only two requirements are to carefully choose the location of the DNA double strand breaks to be induced and then to order an oligonucleotide. While this close-to- ultimate toolkit for targeted editing of genomes represents dramatic scientific progress which allows the development of more complex useful agronomic traits through synthetic biology, the social acceptance of genome editing remains regularly questioned by anti-GMO citizens and organizations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Thermal Management and Reliability of Power Electronics and Electric Machines

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

Narumanchi, Sreekant

2016-09-19

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.« less

Techno-economic feasibility and life cycle assessment of dairy effluent to renewable diesel via hydrothermal liquefaction.

PubMed

Summers, Hailey M; Ledbetter, Rhesa N; McCurdy, Alex T; Morgan, Michael R; Seefeldt, Lance C; Jena, Umakanta; Hoekman, S Kent; Quinn, Jason C

2015-11-01

The economic feasibility and environmental impact is investigated for the conversion of agricultural waste, delactosed whey permeate, through yeast fermentation to a renewable diesel via hydrothermal liquefaction. Process feasibility was demonstrated at laboratory-scale with data leveraged to validate systems models used to perform industrial-scale economic and environmental impact analyses. Results show a minimum fuel selling price of $4.78 per gallon of renewable diesel, a net energy ratio of 0.81, and greenhouse gas emissions of 30.0g-CO2-eqMJ(-1). High production costs and greenhouse gas emissions can be attributed to operational temperatures and durations of both fermentation and hydrothermal liquefaction. However, high lipid yields of the yeast counter these operational demands, resulting in a favorable net energy ratio. Results are presented on the optimization of the process based on economy of scale and a sensitivity analysis highlights improvements in conversion efficiency, yeast biomass productivity and hydrotreating efficiency can dramatically improve commercial feasibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ion implantation enhanced metal-Si-metal photodetectors

NASA Astrophysics Data System (ADS)

Sharma, A. K.; Scott, K. A. M.; Brueck, S. R. J.; Zolper, J. C.; Myers, D. R.

1994-05-01

The quantum efficiency and frequency response of simple Ni-Si-Ni metal-semiconductor-metal (MSM) photodetectors at long wavelengths are significantly enhanced with a simple, ion-implantation step to create a highly absorbing region approx. 1 micron below the Si surface. The internal quantum efficiency is improved by a factor of approx. 3 at 860 nm (to 64%) and a full factor of ten at 1.06 microns (to 23%) as compared with otherwise identical unimplanted devices. Dark currents are only slightly affected by the implantation process and are as low as 630 pA for a 4.5-micron gap device at 10-V bias. Dramatic improvement in the impulse response is observed, 100 ps vs. 600 ps, also at 10-V bias and 4.5-micron gap, due to the elimination of carrier diffusion tails in the implanted devices. Due to its planar structure, this device is fully VLSI compatible. Potential applications include optical interconnections for local area networks and multi-chip modules.

Assessment of end-of-life design in solid-state lighting

NASA Astrophysics Data System (ADS)

Dzombak, Rachel; Padon, Jack; Salsbury, Josh; Dillon, Heather

2017-08-01

Consumers in the US market and across the globe are beginning to widely adopt light emitting diode (LED) lighting products while the technology continues to undergo significant changes. While LED products are evolving to consume less energy, they are also more complex than traditional lighting products with a higher number of parts and a larger number of electronic components. Enthusiasm around the efficiency and long expected life span of LED lighting products is valid, but research to optimize product characteristics and design is needed. This study seeks to address that gap by characterizing LED lighting products' suitability for end of life (EOL) recycling and disposal. The authors disassembled and assessed 17 different lighting products to understand how designs differ between brands and manufacture year. Products were evaluated based on six parameters to quantify the design. The analysis indicates that while the efficiency of LED products has improved dramatically in the recent past, product designers and manufacturers could incorporate design strategies to improve environmental performance of lighting products at end-of-life.

A Hybrid Approach for Efficient Modeling of Medium-Frequency Propagation in Coal Mines

PubMed Central

Brocker, Donovan E.; Sieber, Peter E.; Waynert, Joseph A.; Li, Jingcheng; Werner, Pingjuan L.; Werner, Douglas H.

2015-01-01

An efficient procedure for modeling medium frequency (MF) communications in coal mines is introduced. In particular, a hybrid approach is formulated and demonstrated utilizing ideal transmission line equations to model MF propagation in combination with full-wave sections used for accurate simulation of local antenna-line coupling and other near-field effects. This work confirms that the hybrid method accurately models signal propagation from a source to a load for various system geometries and material compositions, while significantly reducing computation time. With such dramatic improvement to solution times, it becomes feasible to perform large-scale optimizations with the primary motivation of improving communications in coal mines both for daily operations and emergency response. Furthermore, it is demonstrated that the hybrid approach is suitable for modeling and optimizing large communication networks in coal mines that may otherwise be intractable to simulate using traditional full-wave techniques such as moment methods or finite-element analysis. PMID:26478686

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

Narumanchi, Sreekant

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.« less

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

Narumanchi, Sreekant

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil -- by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines will be presented.« less

A dramatic, objective antiandrogen withdrawal response: case report and review of the literature.

PubMed

Lau, Yiu-Keung; Chadha, Manpreet K; Litwin, Alan; Trump, Donald L

2008-11-05

Antiandrogen withdrawal response is an increasingly recognized entity in patients with metastatic prostate cancer. To our knowledge, there have been no reports describing a durable radiologic improvement along with prostate-specific antigen (PSA) with discontinuation of the antiandrogen agent bicalutamide. We report a case in which a dramatic decline of serum PSA levels associated with a dramatic improvement in radiologic disease was achieved with bicalutamide discontinuation.

Bleomycin in Octaarginine-modified Fusogenic Liposomes Results in Improved Tumor Growth Inhibition

PubMed Central

Koshkaryev, Alexander; Piroyan, Aleksandr; Torchilin, Vladimir P.

2012-01-01

Bleomycin (BLM) is an example of an anticancer drug that should be delivered into cytosol for its efficient therapeutic action. With this in mind, we developed octaarginine (R8)-modified fusogenic DOPE-liposomes (R8-DOPE-BLM). R8-modification dramatically increased (up to 50-fold) the cell-liposome interaction. R8-DOPE-liposomes were internalized via macropinocytosis and did not end up in the lysosomes. R8-DOPE-BLM led to a significantly stronger cell death and DNA damage in vitro relative to all controls. R8-DOPE-BLM demonstrated a prominent anticancer effect in the BALB/c mice bearing 4T1 tumors. Thus, R8-DOPE-BLM provided efficient intracellular delivery of BLM leading to strong tumor growth inhibition in vivo. PMID:22743614

Gene delivery by microfluidic flow-through electroporation based on constant DC and AC field.

PubMed

Geng, Tao; Zhan, Yihong; Lu, Chang

2012-01-01

Electroporation is one of the most widely used physical methods to deliver exogenous nucleic acids into cells with high efficiency and low toxicity. Conventional electroporation systems typically require expensive pulse generators to provide short electrical pulses at high voltage. In this work, we demonstrate a flow-through electroporation method for continuous transfection of cells based on disposable chips, a syringe pump, and a low-cost power supply that provides a constant voltage. We successfully transfect cells using either DC or AC voltage with high flow rates (ranging from 40 µl/min to 20 ml/min) and high efficiency (up to 75%). We also enable the entire cell membrane to be uniformly permeabilized and dramatically improve gene delivery by inducing complex migrations of cells during the flow.

Method can improve efficiency of heli-portable seismic operations

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

Kingsbury, O.J.

1995-11-13

There are regions of the world where the only viable means of conducting a seismic survey on land must involve helicopters as a primary means of transport. The high operating cost of helicopters means that such heliportable work is expensive compared with the more common land and marine surveys. This article is addressed to exploration companies contemplating heliportable seismic surveys. Its aim is to show how these operations work and to enable a dramatic reduction in the cost and timescale of future operations compared with numerous operations this writer has witnessed and been involved with in recent years. The coremore » of this article concerns distinct designs of drilling machinery used in these activities and the most efficient ways of configuring this machinery in the field.« less

Enhanced UV light detection using a p-terphenyl wavelength shifter

NASA Astrophysics Data System (ADS)

Joosten, S.; Kaczanowicz, E.; Ungaro, M.; Rehfuss, M.; Johnston, K.; Meziani, Z.-E.

2017-10-01

UV-glass photomultiplier tubes (PMTs) have poor photon detection efficiency for wavelengths below 300 nm due to the opaqueness of the window material. Costly quartz PMTs could be used to enhance the efficiency below 300 nm. A less expensive solution that dramatically improves this efficiency is the application of a thin film of a p-terphenyl (PT) wavelength shifter on UV-glass PMTs. This improvement was quantified for Photonis XP4500B PMTs for wavelengths between 200 nm and 400 nm. The gain factor ranges up to 5 . 4 ± 0 . 5 at a wavelength of 215 nm, with a material load of 110 ± 10 μg /cm2 (894 nm). The wavelength shifter was found to be fully transparent for wavelengths greater than 300 nm. The resulting gain in detection efficiency, when used in a typical C̆erenkov counter, was estimated to be of the order of 40%. Consistent coating quality was assured by a rapid gain testing procedure using narrow-band UV LEDs. Based on these results, 200 Photonis XP4500B PMTs were treated with PT for the upgraded low-threshold C̆erenkov counter (LTCC) to be used in the CEBAF Large Acceptance Spectrometer upgraded detector (CLAS12) at the Thomas Jefferson National Accelerator Facility.

Parallel elastic elements improve energy efficiency on the STEPPR bipedal walking robot

DOE PAGES

Mazumdar, Anirban; Spencer, Steven J.; Hobart, Clinton; ...

2016-11-23

This study describes how parallel elastic elements can be used to reduce energy consumption in the electric motor driven, fully-actuated, STEPPR bipedal walking robot without compromising or significantly limiting locomotive behaviors. A physically motivated approach is used to illustrate how selectively-engaging springs for hip adduction and ankle flexion predict benefits for three different flat ground walking gaits: human walking, human-like robot walking and crouched robot walking. Based on locomotion data, springs are designed and substantial reductions in power consumption are demonstrated using a bench dynamometer. These lessons are then applied to STEPPR (Sandia Transmission-Efficient Prototype Promoting Research), a fully actuatedmore » bipedal robot designed to explore the impact of tailored joint mechanisms on walking efficiency. Featuring high-torque brushless DC motors, efficient low-ratio transmissions, and high fidelity torque control, STEPPR provides the ability to incorporate novel joint-level mechanisms without dramatically altering high level control. Unique parallel elastic designs are incorporated into STEPPR, and walking data shows that hip adduction and ankle flexion springs significantly reduce the required actuator energy at those joints for several gaits. These results suggest that parallel joint springs offer a promising means of supporting quasi-static joint torques due to body mass during walking, relieving motors of the need to support these torques and substantially improving locomotive energy efficiency.« less

Parallel elastic elements improve energy efficiency on the STEPPR bipedal walking robot

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

Mazumdar, Anirban; Spencer, Steven J.; Hobart, Clinton

This study describes how parallel elastic elements can be used to reduce energy consumption in the electric motor driven, fully-actuated, STEPPR bipedal walking robot without compromising or significantly limiting locomotive behaviors. A physically motivated approach is used to illustrate how selectively-engaging springs for hip adduction and ankle flexion predict benefits for three different flat ground walking gaits: human walking, human-like robot walking and crouched robot walking. Based on locomotion data, springs are designed and substantial reductions in power consumption are demonstrated using a bench dynamometer. These lessons are then applied to STEPPR (Sandia Transmission-Efficient Prototype Promoting Research), a fully actuatedmore » bipedal robot designed to explore the impact of tailored joint mechanisms on walking efficiency. Featuring high-torque brushless DC motors, efficient low-ratio transmissions, and high fidelity torque control, STEPPR provides the ability to incorporate novel joint-level mechanisms without dramatically altering high level control. Unique parallel elastic designs are incorporated into STEPPR, and walking data shows that hip adduction and ankle flexion springs significantly reduce the required actuator energy at those joints for several gaits. These results suggest that parallel joint springs offer a promising means of supporting quasi-static joint torques due to body mass during walking, relieving motors of the need to support these torques and substantially improving locomotive energy efficiency.« less

Preliminary Studies of a Pulsed Detonation Rocket Engine

NASA Technical Reports Server (NTRS)

Cambier, Jean-Luc; Adelman, H. G.; Menees, G. P.; Edwards, Thomas A. (Technical Monitor)

1995-01-01

In the new era of space exploration, there is a strong need for more efficient, cheaper and more reliable propulsion devices. With dramatic increase in specific impulse, the overall mass of fuel to be lifted into orbit is decreased, and this leads, in turn, to much lower mass requirements at lift-off, higher payload ratios and lower launch costs. The Pulsed Detonation engine (PDE) has received much attention lately due to its unique combination of simplicity, light-weight and efficiency. Current investigations focus principally on its use as a low speed, airbreathing engine, although other applications have also been proposed. Its use as a rocket propulsion device was first proposed in 1988 by the present authors. The superior efficiency of the Pulsed Detonation Rocket Engine (PDRE) is due to the near constant volume combustion process of a detonation wave. Our preliminary estimates suggest that the PDRE is theoretically capable of achieving specific impulses as high as 720 sec, a dramatic improvement over the current 480 sec of conventional rocket engines, making it competitive with nuclear thermal rockets. In addition to this remarkable efficiency, the PDRE may eliminate the need for high pressure cryogenic turbopumps, a principal source of failures. The heat transfer rates are also much lower, eliminating the need for nozzle cooling. Overall, the engine is more reliable and has a much lower weight. This paper will describe in detail the operation of the PDRE and calculate its performance, through numerical simulations. Engineering issues will be addressed and discussed, and the impact on mission profiles will also be presented. Finally, the performance of the PDRE using in-situ resources, such as CO and O2 from the martian atmosphere, will also be computed.

Monolayer graphene-insulator-semiconductor emitter for large-area electron lithography

NASA Astrophysics Data System (ADS)

Kirley, Matthew P.; Aloui, Tanouir; Glass, Jeffrey T.

2017-06-01

The rapid adoption of nanotechnology in fields as varied as semiconductors, energy, and medicine requires the continual improvement of nanopatterning tools. Lithography is central to this evolving nanotechnology landscape, but current production systems are subject to high costs, low throughput, or low resolution. Herein, we present a solution to these problems with the use of monolayer graphene in a graphene-insulator-semiconductor (GIS) electron emitter device for large-area electron lithography. Our GIS device displayed high emission efficiency (up to 13%) and transferred large patterns (500 × 500 μm) with high fidelity (<50% spread). The performance of our device demonstrates a feasible path to dramatic improvements in lithographic patterning systems, enabling continued progress in existing industries and opening opportunities in nanomanufacturing.

A dramatic, objective antiandrogen withdrawal response: case report and review of the literature

PubMed Central

Lau, Yiu-Keung; Chadha, Manpreet K; Litwin, Alan; Trump, Donald L

2008-01-01

Antiandrogen withdrawal response is an increasingly recognized entity in patients with metastatic prostate cancer. To our knowledge, there have been no reports describing a durable radiologic improvement along with prostate-specific antigen (PSA) with discontinuation of the antiandrogen agent bicalutamide. We report a case in which a dramatic decline of serum PSA levels associated with a dramatic improvement in radiologic disease was achieved with bicalutamide discontinuation. PMID:18986533

Dramatic pretend play games uniquely improve emotional control in young children.

PubMed

Goldstein, Thalia R; Lerner, Matthew D

2017-09-15

Pretense is a naturally occurring, apparently universal activity for typically developing children. Yet its function and effects remain unclear. One theorized possibility is that pretense activities, such as dramatic pretend play games, are a possible causal path to improve children's emotional development. Social and emotional skills, particularly emotional control, are critically important for social development, as well as academic performance and later life success. However, the study of such approaches has been criticized for potential bias and lack of rigor, precluding the ability to make strong causal claims. We conducted a randomized, component control (dismantling) trial of dramatic pretend play games with a low-SES group of 4-year-old children (N = 97) to test whether such practice yields generalized improvements in multiple social and emotional outcomes. We found specific effects of dramatic play games only on emotional self-control. Results suggest that dramatic pretend play games involving physicalizing emotional states and traits, pretending to be animals and human characters, and engaging in pretend scenarios in a small group may improve children's emotional control. These findings have implications for the function of pretense and design of interventions to improve emotional control in typical and atypical populations. Further, they provide support for the unique role of dramatic pretend play games for young children, particularly those from low-income backgrounds. A video abstract of this article can be viewed at: https://youtu.be/2GVNcWKRHPk. © 2017 John Wiley & Sons Ltd.

Maximizing recovery of water-soluble proteins through acetone precipitation.

PubMed

Crowell, Andrew M J; Wall, Mark J; Doucette, Alan A

2013-09-24

Solvent precipitation is commonly used to purify protein samples, as seen with the removal of sodium dodecyl sulfate through acetone precipitation. However, in its current practice, protein loss is believed to be an inevitable consequence of acetone precipitation. We herein provide an in depth characterization of protein recovery through acetone precipitation. In 80% acetone, the precipitation efficiency for six of 10 protein standards was poor (ca. ≤15%). Poor recovery was also observed for proteome extracts, including bacterial and mammalian cells. As shown in this work, increasing the ionic strength of the solution dramatically improves the precipitation efficiency of individual proteins, and proteome mixtures (ca. 80-100% yield). This is obtained by including 1-30 mM NaCl, together with acetone (50-80%) which maximizes protein precipitation efficiency. The amount of salt required to restore the recovery correlates with the amount of protein in the sample, as well as the intrinsic protein charge, and the dielectric strength of the solution. This synergistic approach to protein precipitation in acetone with salt is consistent with a model of ion pairing in organic solvent, and establishes an improved method to recover proteins and proteome mixtures in high yield. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparing memory-efficient genome assemblers on stand-alone and cloud infrastructures.

PubMed

Kleftogiannis, Dimitrios; Kalnis, Panos; Bajic, Vladimir B

2013-01-01

A fundamental problem in bioinformatics is genome assembly. Next-generation sequencing (NGS) technologies produce large volumes of fragmented genome reads, which require large amounts of memory to assemble the complete genome efficiently. With recent improvements in DNA sequencing technologies, it is expected that the memory footprint required for the assembly process will increase dramatically and will emerge as a limiting factor in processing widely available NGS-generated reads. In this report, we compare current memory-efficient techniques for genome assembly with respect to quality, memory consumption and execution time. Our experiments prove that it is possible to generate draft assemblies of reasonable quality on conventional multi-purpose computers with very limited available memory by choosing suitable assembly methods. Our study reveals the minimum memory requirements for different assembly programs even when data volume exceeds memory capacity by orders of magnitude. By combining existing methodologies, we propose two general assembly strategies that can improve short-read assembly approaches and result in reduction of the memory footprint. Finally, we discuss the possibility of utilizing cloud infrastructures for genome assembly and we comment on some findings regarding suitable computational resources for assembly.

Dramatic Improvement of CRISPR/Cas9 Editing in Candida albicans by Increased Single Guide RNA Expression.

PubMed

Ng, Henry; Dean, Neta

2017-01-01

The clustered regularly interspaced short palindromic repeat system with CRISPR-associated protein 9 nuclease (CRISPR/Cas9) has emerged as a versatile tool for genome editing in Candida albicans . Mounting evidence from other model systems suggests that the intracellular levels of single guide RNA (sgRNA) limit the efficiency of Cas9-dependent DNA cleavage. Here, we tested this idea and describe a new means of sgRNA delivery that improves previously described methods by ~10-fold. The efficiency of Cas9/sgRNA-dependent cleavage and repair of a single-copy yeast enhanced monomeric red fluorescent protein ( RFP ) gene was measured as a function of various parameters that are hypothesized to affect sgRNA accumulation, including transcriptional and posttranscriptional processing. We analyzed different promoters ( SNR52 , ADH1 , and tRNA ), as well as different posttranscriptional RNA processing schemes that serve to generate or stabilize mature sgRNA with precise 5' and 3' ends. We compared the effects of flanking sgRNA with self-cleaving ribozymes or by tRNA, which is processed by endogenous RNases. These studies demonstrated that sgRNA flanked by a 5' tRNA and transcribed by a strong RNA polymerase II ADH1 promoter increased Cas9-dependent RFP mutations by 10-fold. Examination of double-strand-break (DSB) repair in strains hemizygous for RFP demonstrated that both homology-directed and nonhomologous end-joining pathways were used to repair breaks. Together, these results support the model that gRNA expression can be rate limiting for efficient CRISPR/Cas mutagenesis in C. albicans . IMPORTANCE Candida albicans is an important human fungal pathogen. An understanding of fungal virulence factors has been slow because C. albicans is genetically intractable. The recent development of CRISPR/Cas in C. albicans (V. K. Vyas, M. I. Barrasa, G. R. Fink, Sci Adv 1:e1500248, 2015, https://doi.org/10.1126/sciadv.1500248) has the potential to circumvent this problem. However, as has been found in other organisms, CRISPR/Cas mutagenesis efficiency can be frustratingly variable. Here, we systematically examined parameters hypothesized to alter sgRNA intracellular levels in order to optimize CRISPR/Cas in C. albicans . Our most important conclusion is that increased sgRNA expression and maturation dramatically improve efficiency of CRISPR/Cas mutagenesis in C. albicans by ~10-fold. Thus, we anticipate that the modifications described here will further advance the application of CRISPR/Cas for genome editing in C. albicans .

Integrated, Reactor Relevant Solutions for Lower Hybrid Range of Frequencies Actuators

NASA Astrophysics Data System (ADS)

Shiraiwa, S.; Bonoli, P. T.; Lin, Y.; Wallace, G. M.; Wukitch, S. J.

2017-10-01

RF (radiofrequency) actuators with high system efficiency (wall-plug to plasma) and ability for continuous operation have long be recognized as essential tools for realizing a steady state tokamak. A number of physics and technological challenges to utilization remain including current drive efficiency and location, efficient coupling, and impurity contamination. In a reactor environment, plasma material interaction (PMI) issues associated with coupling structures are similar to the first wall and have been identified as a potential show-stopper. High field side (HFS) launch of LHRF power represents an integrated solution that both improves core wave physics and mitigates PMI/coupling issues. For HFS LHRF, wave penetration is vastly improves because wave accessibility scales as 1/B allowing for launching the wave at lower n|| (parallel refractive index). The lower n|| penetrate to higher electron temperature resulting in higher current drive efficiency (1/n||2). HFS RF launch also provides for a means to dramatically improve launcher robustness in a reactor environment. On the HFS, the SOL is quiescent; local density profile is steep and controlled through magnetic shape; fast particle, neutron, turbulent heat and particle fluxes are eliminated or minim Work supported by the U.S. DoE, Office of Science, Office of Fusion Energy Sciences, User Facility Alcator C-Mod under DE-FC02-99ER54512 and US DoE Contract No. DE-FC02-01ER54648 under a Scientific Discovery through Advanced Computing Initiative.

How Energy Efficiency is Adding Jobs in St. Paul, Minnesota

ScienceCinema

Hannigan, Jim; Coleman, Chris; Oliver, LeAnn; Jambois, Louis

2018-02-07

Saint Paul, Minnesota is using an energy efficiency grant to provide commercial retrofits that will allow a local produce distribution company to dramatically reduce its energy costs and add dozens of new workers.

How Energy Efficiency is Adding Jobs in St. Paul, Minnesota

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

Hannigan, Jim; Coleman, Chris; Oliver, LeAnn

2011-01-01

Saint Paul, Minnesota is using an energy efficiency grant to provide commercial retrofits that will allow a local produce distribution company to dramatically reduce its energy costs and add dozens of new workers.

The Future of Satellite-based Lightning Detection

NASA Technical Reports Server (NTRS)

Bocippio, Dennis J.; Christian, Hugh J.; Arnold, James E. (Technical Monitor)

2001-01-01

The future of satellite-based optical lightning detection, beyond the end of the current TRMM mission, is discussed. Opportunities for new low-earth orbit missions are reviewed. The potential for geostationary observations is significant; such observations provide order-of-magnitude gains in sampling and data efficiency over existing satellite convective observations. The feasibility and performance (resolution, sensitivity) of geostationary measurements using current technology is discussed. In addition to direct and continuous hemispheric observation of lighting, geostationary measurements have the potential (through data assimilation) to dramatically improve short and medium range forecasts, offering benefits to prediction of NOx productions and/or vertical transport.

Tunable solid-state lasers - An emerging technology for remote sensing of planetary atmospheres

NASA Technical Reports Server (NTRS)

Barnes, Norman P.; Allario, Frank

1988-01-01

The present development status and prospective (1990s) performance-improvement evaluation of tunable solid-state laser technology notes recent trends toward spectrum coverage over the 0.20-14.0 microns range, in addition to dramatic increases in efficiency, service life, and reliability. It is judged that the Ti:Al2O3 laser and the AgGaSe2 optical parametric oscillator pumped by a Ho:YAG laser could cover the near-IR and mid-IR regions of the spectrum. Laser diodes operating at 0.78 microns should provide an excellent pump for a Ho:YAG laser.

Water/alcohol soluble conjugated polymers as highly efficient electron transporting/injection layer in optoelectronic devices.

PubMed

Huang, Fei; Wu, Hongbin; Cao, Yong

2010-07-01

Water/alcohol soluble conjugated polymers (WSCPs) can be processed from water or other polar solvents, which offer good opportunities to avoid interfacial mixing upon fabrication of multilayer polymer optoelectronic devices by solution processing, and can dramatically improve charge injection from high work-function metal cathode resulting in greatly enhancement of the device performance. In this critical review, the authors provide a brief review of recent developments in this field, including the materials design, functional principles, and their unique applications as interface modification layer in solution-processable multilayer optoelectronic devices (135 references).

Efficiency dilution: long-term exergy conversion trends in Japan.

PubMed

Williams, Eric; Warr, Benjamin; Ayres, Robert U

2008-07-01

This analysis characterizes century-scale trends in exergy efficiency in Japan. Exergy efficiency captures the degree to which energy inputs (such as coal) are converted into useful work (such as electricity or power to move a vehicle). This approach enables the estimation of net efficiencies which aggregate different technologies. Sectors specifically analyzed are electricity generation, transport, steel production, and residential space heating. One result is that the aggregate exergy efficiency of the Japanese economy declined slightly over the last half of the 20th century, reaching a high of around 38% in the late 1970s and falling to around 33% by 1998. The explanation for this is that while individual technologies improved dramatically over the century, less exergy-efficient ones were progressively adopted, yielding a net stabilization or decline. In the electricity sector, for instance, adoption of hydropower was followed by fossil-fired plants and then by nuclear power, each technology being successively less efficient from an exergy perspective. The underlying dynamic of this trend is analogous to declining ore grades in the mining sector. Increasing demand for exergy services requires expended utilization of resources from which it is more difficult to extract utility (e.g., falling water versus coal). We term this phenomenon efficiency dilution.

Improving the sweeping efficiency of permanganate into low permeable zones to treat TCE: experimental results and model development.

PubMed

Chokejaroenrat, Chanat; Kananizadeh, Negin; Sakulthaew, Chainarong; Comfort, Steve; Li, Yusong

2013-11-19

The residual buildup and treatment of dissolved contaminants in low permeable zones (LPZs) is a particularly challenging issue for injection-based remedial treatments. Our objective was to improve the sweeping efficiency of permanganate into LPZs to treat dissolved-phase TCE. This was accomplished by conducting transport experiments that quantified the ability of xanthan-MnO4(-) solutions to penetrate and cover (i.e., sweep) an LPZ that was surrounded by transmissive sands. By incorporating the non-Newtonian fluid xanthan with MnO4(-), penetration of MnO4(-) into the LPZ improved dramatically and sweeping efficiency reached 100% in fewer pore volumes. To quantify how xanthan improved TCE removal, we spiked the LPZ and surrounding sands with (14)C-lableled TCE and used a multistep flooding procedure that quantified the mass of (14)C-TCE oxidized and bypassed during treatment. Results showed that TCE mass removal was 1.4 times greater in experiments where xanthan was employed. Combining xanthan with MnO4(-) also reduced the mass of TCE in the LPZ that was potentially available for rebound. By coupling a multiple species reactive transport model with the Brinkman equation for non-Newtonian flow, the simulated amount of (14)C-TCE oxidized during transport matched experimental results. These observations support the use of xanthan as a means of enhancing MnO4(-) delivery into LPZs for the treatment of dissolved-phase TCE.

Development of Highly Fluorescent Materials Based on Thiophenylimidazole Dyes

NASA Technical Reports Server (NTRS)

Santos, Javier; Bu, Xiu R.; Mintz, Eric A.; Meador, Michael A. (Technical Monitor)

2000-01-01

Organic fluorescent materials are expected to find many potential applications in optical devices and photo-functionalized materials. Although many investigations have been focused on heterocyclic compounds such as coumarins, bipyridines, rhodamines, and pyrrole derivatives, little is known for fluorescent imidazole materials. We discovered that one particular class of imidazole derivatives is highly fluorescent. A series of monomeric and polymeric based fluorescent dyes were prepared containing a thiophene unit at the second position of the imidazole ring. Dependence of fluorescence efficiency on parameters such as solvent polarity and substituent groups has been investigated. It was found that a formyl group at the 2-position of the thiophene ring dramatically enhance fluorescence properties. Ion recognition probes indicated their potential as sensor materials. These fluorophores have flexibility for introduction of versatile substituent groups that could improve the fluorescence efficiency and sensor properties.

Space Photovoltaic Research and Technology, 1988. High Efficiency, Space Environment, and Array Technology

NASA Technical Reports Server (NTRS)

1989-01-01

The 9th Space Photovoltaic Research and Technology conference was held at the NASA Lewis Research Center from April 19 to 21, 1988. The papers and workshop summaries report remarkable progress on a wide variety of approaches in space photovoltaics, for both near and far term applications. Among the former is the recently developed high efficiency GaAs/Ge cell, which formed the focus of a workshop discussion on heteroepitaxial cells. Still aimed at the long term, but with a significant payoff in a new mission capability, are InP cells, with their potentially dramatic improvement in radiation resistance. Approaches to near term, array specific powers exceeding 130 W/kg are also reported, and advanced concentrator panel technology with the potential to achieve over 250 W/sq m is beginning to take shape.

[Cleanliness in the operating room].

PubMed

Suzuki, Toshiyasu

2010-05-01

With regard to recent findings in the cleanliness of the operating room, concerning handwashing and performing operations, the traditional method of excessive scrubbing using a brush is not effective, and handwashing using only an alcohol-containing antiseptic hand rub (rubbing method) has become common practice. Use of a brush has already been abolished in some medical institutions. In addition, sterilized water used for handwashing when performing operations has no scientific basis and use of tap water is considered sufficient. Furthermore, the concept of operating room zoning has also undergone a dramatic change. It was discovered that a layout focusing on work efficiency is more desirable than the one that follows an excessively rigid zoning pattern. One-footwear System not requiring change of shoes also has various advantages in improving the efficiency of the operation room, and this is thought to become commonplace in the future.

Numerical simulation of supersonic and hypersonic inlet flow fields

NASA Technical Reports Server (NTRS)

Mcrae, D. Scott; Kontinos, Dean A.

1995-01-01

This report summarizes the research performed by North Carolina State University and NASA Ames Research Center under Cooperative Agreement NCA2-719, 'Numerical Simulation of Supersonic and Hypersonic Inlet Flow Fields". Four distinct rotated upwind schemes were developed and investigated to determine accuracy and practicality. The scheme found to have the best combination of attributes, including reduction to grid alignment with no rotation, was the cell centered non-orthogonal (CCNO) scheme. In 2D, the CCNO scheme improved rotation when flux interpolation was extended to second order. In 3D, improvements were less dramatic in all cases, with second order flux interpolation showing the least improvement over grid aligned upwinding. The reduction in improvement is attributed to uncertainty in determining optimum rotation angle and difficulty in performing accurate and efficient interpolation of the angle in 3D. The CCNO rotational technique will prove very useful for increasing accuracy when second order interpolation is not appropriate and will materially improve inlet flow solutions.

An integrated approach to realizing high-performance liquid-junction quantum dot sensitized solar cells

PubMed Central

McDaniel, Hunter; Fuke, Nobuhiro; Makarov, Nikolay S.; Pietryga, Jeffrey M.; Klimov, Victor I.

2013-01-01

Solution-processed semiconductor quantum dot solar cells offer a path towards both reduced fabrication cost and higher efficiency enabled by novel processes such as hot-electron extraction and carrier multiplication. Here we use a new class of low-cost, low-toxicity CuInSexS2−x quantum dots to demonstrate sensitized solar cells with certified efficiencies exceeding 5%. Among other material and device design improvements studied, use of a methanol-based polysulfide electrolyte results in a particularly dramatic enhancement in photocurrent and reduced series resistance. Despite the high vapour pressure of methanol, the solar cells are stable for months under ambient conditions, which is much longer than any previously reported quantum dot sensitized solar cell. This study demonstrates the large potential of CuInSexS2−x quantum dots as active materials for the realization of low-cost, robust and efficient photovoltaics as well as a platform for investigating various advanced concepts derived from the unique physics of the nanoscale size regime. PMID:24322379

Synthesis of CdS/BiOBr nanosheets composites with efficient visible-light photocatalytic activity

NASA Astrophysics Data System (ADS)

Cui, Haojie; Zhou, Yawen; Mei, Jinfeng; Li, Zhongyu; Xu, Song; Yao, Chao

2018-01-01

The efficient charge separation action and visible-light responding could enhance the photocatalytic property of photocatalysts. In the present study, novel CdS/BiOBr nanosheets composites were synthesized by a three-step process. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (FE-SEM), diffuse reflection spectroscopy (DRS), Raman spectroscopy and photoluminescence (PL). Under visible-light irradiation, the as-prepared CdS nanoparticles decorated BiOBr nanosheets exhibited the excellent photocatalytic activity and high stability for malachite green (MG) degradation. The photodegradation achieved maximum degradation efficiency (99%) using CdS/BiOBr-3 composites as photocatalyst. Furthermore, the possible photocatalytic mechanism upon CdS/BiOBr composites was also discussed through radical and holes trapping experiments. The heterostructure between CdS and BiOBr improved photocatalytic activity dramatically, which greatly promoted migration rate of the photoinduced electrons besides limiting the recombination of photogenerated electron-hole pairs.

Structural tests and development of a laminar flow control wing surface composite chordwise joint

NASA Technical Reports Server (NTRS)

Lineberger, L. B.

1984-01-01

The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program beginning in 1976 to develop technologies to improve fuel efficiency. The Lockheed-Georgia Company accomplished under NAS1-16235 Laminar-Flow-Control (LFC) Wing Panel Structural Design and Development (WSSD); design, manufacturing, and testing activities. An in-depth preliminary design of the baseline 1993 LFC wing was accomplished. A surface panel using the Lockheed graphite/epoxy integrated LFC wing box structural concept was designed. The concept was shown by analysis to be structurally efficient and cost effective. Critical details of the surface and surface joint was demonstrated by fabricating and testing complex, concept selection specimens. The Lockheed-Georgia Company accomplishments, Development of LFC Wind Surface Composite Structures (WSCS), are documented. Tests were conducted on two CV2 panels to verify the static tension and fatigue strength of LFC wing surface chordwise joints.

Broadly tunable terahertz generation in mid-infrared quantum cascade lasers.

PubMed

Vijayraghavan, Karun; Jiang, Yifan; Jang, Min; Jiang, Aiting; Choutagunta, Karthik; Vizbaras, Augustinas; Demmerle, Frederic; Boehm, Gerhard; Amann, Markus C; Belkin, Mikhail A

2013-01-01

Room temperature, broadly tunable, electrically pumped semiconductor sources in the terahertz spectral range, similar in operation simplicity to diode lasers, are highly desired for applications. An emerging technology in this area are sources based on intracavity difference-frequency generation in dual-wavelength mid-infrared quantum cascade lasers. Here we report terahertz quantum cascade laser sources based on an optimized non-collinear Cherenkov difference-frequency generation scheme that demonstrates dramatic improvements in performance. Devices emitting at 4 THz display a mid-infrared-to-terahertz conversion efficiency in excess of 0.6 mW W(-2) and provide nearly 0.12 mW of peak power output. Devices emitting at 2 and 3 THz fabricated on the same chip display 0.09 and 0.4 mW W(-2) conversion efficiencies at room temperature, respectively. High terahertz-generation efficiency and relaxed phase-matching conditions offered by the Cherenkov scheme allowed us to demonstrate, for the first time, an external-cavity terahertz quantum cascade laser source tunable between 1.70 and 5.25 THz.

Synthesis of hierarchical porous δ-MnO2 nanoboxes as an efficient catalyst for rechargeable Li-O2 batteries

NASA Astrophysics Data System (ADS)

Zhang, Jian; Luan, Yanping; Lyu, Zhiyang; Wang, Liangjun; Xu, Leilei; Yuan, Kaidi; Pan, Feng; Lai, Min; Liu, Zhaolin; Chen, Wei

2015-09-01

A rechargeable lithium-oxygen (Li-O2) battery with a remarkably high theoretical energy storage capacity has attracted enormous research attention. However, the poor oxygen reduction and oxygen evolution reaction (ORR and OER) activities in discharge and charge processes cause low energy efficiency, poor electrolyte stability and short cycle life. This requires the development of efficient cathode catalysts to dramatically improve the Li-O2 battery performances. MnO2-based materials are recognized as efficient and low-cost catalysts for a Li-O2 battery cathode. Here, we report a controllable approach to synthesize hierarchical porous δ-MnO2 nanoboxes by using Prussian blue analogues as the precursors. The obtained products possess hierarchical pore size and an extremely large surface area (249.3 m2 g-1), which would favour oxygen transportation and provide more catalytically active sites to promote ORR and OER as the Li-O2 battery cathode. The battery shows enhanced discharge capacity (4368 mA h g-1@0.08 mA cm-2), reduced overpotential (270 mV), improved rate performance and excellent cycle stability (248 cycles@500 mA h g-1 and 112 cycles@1000 mA h g-1), in comparison with the battery with a VX-72 carbon cathode. The superb performance of the hierarchical porous δ-MnO2 nanoboxes, together with a convenient fabrication method, presents an alternative to develop advanced cathode catalysts for the Li-O2 battery.A rechargeable lithium-oxygen (Li-O2) battery with a remarkably high theoretical energy storage capacity has attracted enormous research attention. However, the poor oxygen reduction and oxygen evolution reaction (ORR and OER) activities in discharge and charge processes cause low energy efficiency, poor electrolyte stability and short cycle life. This requires the development of efficient cathode catalysts to dramatically improve the Li-O2 battery performances. MnO2-based materials are recognized as efficient and low-cost catalysts for a Li-O2 battery cathode. Here, we report a controllable approach to synthesize hierarchical porous δ-MnO2 nanoboxes by using Prussian blue analogues as the precursors. The obtained products possess hierarchical pore size and an extremely large surface area (249.3 m2 g-1), which would favour oxygen transportation and provide more catalytically active sites to promote ORR and OER as the Li-O2 battery cathode. The battery shows enhanced discharge capacity (4368 mA h g-1@0.08 mA cm-2), reduced overpotential (270 mV), improved rate performance and excellent cycle stability (248 cycles@500 mA h g-1 and 112 cycles@1000 mA h g-1), in comparison with the battery with a VX-72 carbon cathode. The superb performance of the hierarchical porous δ-MnO2 nanoboxes, together with a convenient fabrication method, presents an alternative to develop advanced cathode catalysts for the Li-O2 battery. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02983j

Physics of Quantum Structures in Photovoltaic Devices

NASA Technical Reports Server (NTRS)

Raffaelle, Ryne P.; Andersen, John D.

2005-01-01

There has been considerable activity recently regarding the possibilities of using various nanostructures and nanomaterials to improve photovoltaic conversion of solar energy. Recent theoretical results indicate that dramatic improvements in device efficiency may be attainable through the use of three-dimensional arrays of zero-dimensional conductors (i.e., quantum dots) in an ordinary p-i-n solar cell structure. Quantum dots and other nanostructured materials may also prove to have some benefits in terms of temperature coefficients and radiation degradation associated with space solar cells. Two-dimensional semiconductor superlattices have already demonstrated some advantages in this regard. It has also recently been demonstrated that semiconducting quantum dots can also be used to improve conversion efficiencies in polymeric thin film solar cells. Improvement in thin film cells utilizing conjugated polymers has also be achieved through the use of one-dimensional quantum structures such as carbon nanotubes. It is believed that carbon nanotubes may contribute to both the disassociation as well as the carrier transport in the conjugated polymers used in certain thin film photovoltaic cells. In this paper we will review the underlying physics governing some of the new photovoltaic nanostructures being pursued, as well as the the current methods being employed to produce III-V, II-VI, and even chalcopyrite-based nanomaterials and nanostructures for solar cells.

Hidden Markov induced Dynamic Bayesian Network for recovering time evolving gene regulatory networks

NASA Astrophysics Data System (ADS)

Zhu, Shijia; Wang, Yadong

2015-12-01

Dynamic Bayesian Networks (DBN) have been widely used to recover gene regulatory relationships from time-series data in computational systems biology. Its standard assumption is ‘stationarity’, and therefore, several research efforts have been recently proposed to relax this restriction. However, those methods suffer from three challenges: long running time, low accuracy and reliance on parameter settings. To address these problems, we propose a novel non-stationary DBN model by extending each hidden node of Hidden Markov Model into a DBN (called HMDBN), which properly handles the underlying time-evolving networks. Correspondingly, an improved structural EM algorithm is proposed to learn the HMDBN. It dramatically reduces searching space, thereby substantially improving computational efficiency. Additionally, we derived a novel generalized Bayesian Information Criterion under the non-stationary assumption (called BWBIC), which can help significantly improve the reconstruction accuracy and largely reduce over-fitting. Moreover, the re-estimation formulas for all parameters of our model are derived, enabling us to avoid reliance on parameter settings. Compared to the state-of-the-art methods, the experimental evaluation of our proposed method on both synthetic and real biological data demonstrates more stably high prediction accuracy and significantly improved computation efficiency, even with no prior knowledge and parameter settings.

Error-free pathology: applying lean production methods to anatomic pathology.

PubMed

Condel, Jennifer L; Sharbaugh, David T; Raab, Stephen S

2004-12-01

The current state of our health care system calls for dramatic changes. In their pathology department, the authors believe these changes may be accomplished by accepting the long-term commitment of applying a lean production system. The ideal state of zero pathology errors is one that should be pursued by consistently asking, "Why can't we?" The philosophy of lean production systems began in the manufacturing industry: "All we are doing is looking at the time from the moment the customer gives us an order to the point when we collect the cash. And we are reducing that time line by removing non-value added wastes". The ultimate goals in pathology and overall health care are not so different. The authors' intention is to provide the patient (customer) with the most accurate diagnostic information in a timely and efficient manner. Their lead histotechnologist recently summarized this philosophy: she indicated that she felt she could sleep better at night knowing she truly did the best job she could. Her chances of making an error (in cutting or labeling) were dramatically decreased in the one-by-one continuous flow work process compared with previous practices. By designing a system that enables employees to be successful in meeting customer demand, and by empowering the frontline staff in the development and problem solving processes, one can meet the challenges of eliminating waste and build an improved, efficient system.

Wide speed range turboshaft study

NASA Technical Reports Server (NTRS)

Dangelo, Martin

1995-01-01

NASA-Lewis and NASA-Ames have sponsored a series of studies over the last few years to identify key high speed rotorcraft propulsion and airframe technologies. NASA concluded from these studies that for near term aircraft with cruise speeds up to 450 kt, tilting rotor rotorcraft concepts are the most economical and technologically viable. The propulsion issues critical to tilting rotor rotorcraft are: (1) high speed cruise propulsion system efficiency and (2) adequate power to hover safely with one engine inoperative. High speed cruise propeller efficiency can be dramatically improved by reducing rotor speed, yet high rotor speed is critical for good hover performance. With a conventional turboshaft, this wide range of power turbine operating speeds would result in poor engine performance at one or more of these critical operating conditions. This study identifies several wide speed range turboshaft concepts, and analyzes their potential to improve performance at the diverse cruise and hover operating conditions. Many unique concepts were examined, and the selected concepts are simple, low cost, relatively low risk, and entirely contained within the power turbine. These power turbine concepts contain unique, incidence tolerant airfoil designs that allow the engine to cruise efficiently at 51 percent of the hover rotor speed. Overall propulsion system efficiency in cruise is improved as much as 14 percent, with similar improvements in engine weight and cost. The study is composed of a propulsion requirement survey, a concept screening study, a preliminary definition and evaluation of selected concepts, and identification of key technologies and development needs. In addition, a civil transport tilting rotor rotorcraft mission analysis was performed to show the benefit of these concepts versus a conventional turboshaft. Other potential applications for this technology are discussed.

Improved operating scenarios of the DIII-D tokamak as a result of the addition of UNIX computer systems

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

Henline, P.A.

1995-12-31

The increased use of UNIX based computer systems for machine control, data handling and analysis has greatly enhanced the operating scenarios and operating efficiency of the DIII-D tokamak. This paper will describe some of these UNIX systems and their specific uses. These include the plasma control system, the electron cyclotron heating control system, the analysis of electron temperature and density measurements and the general data acquisition system (which is collecting over 130 Mbytes of data). The speed and total capability of these systems has dramatically affected the ability to operate DIII-D. The improved operating scenarios include better plasma shape controlmore » due to the more thorough MHD calculations done between shots and the new ability to see the time dependence of profile data as it relates across different spatial locations in the tokamak. Other analysis which engenders improved operating abilities will be described.« less

Improved operating scenarios of the DIII-D tokamak as a result of the addition of UNIX computer systems

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

Henline, P.A.

1995-10-01

The increased use of UNIX based computer systems for machine control, data handling and analysis has greatly enhanced the operating scenarios and operating efficiency of the DRI-D tokamak. This paper will describe some of these UNIX systems and their specific uses. These include the plasma control system, the electron cyclotron heating control system, the analysis of electron temperature and density measurements and the general data acquisition system (which is collecting over 130 Mbytes of data). The speed and total capability of these systems has dramatically affected the ability to operate DIII-D. The improved operating scenarios include better plasma shape controlmore » due to the more thorough MHD calculations done between shots and the new ability to see the time dependence of profile data as it relates across different spatial locations in the tokamak. Other analysis which engenders improved operating abilities will be described.« less

Dramatically Improve How and Where Academic Content Is Taught

ERIC Educational Resources Information Center

Hyslop, Alisha

2007-01-01

The fourth recommendation in ACTE's high school reform position statement is to dramatically improve how and where academic content is taught. Even as advanced academic course-taking and high school graduation requirements have increased, student achievement on national benchmarks has remained flat, and college remediation rates continue to…

Enhanced UV light detection using a p-terphenyl wavelength shifter

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

Joosten, Sylvester J.; Kaczanowicz, Ed; Ungaro, Maurizio

Here, UV-glass photomultiplier tubes (PMTs) have poor photon detection efficiency for wavelengths belowmore » $$300\\,\\text{nm}$$ due to the opaqueness of the window material. Costly quartz PMTs could be used to enhance the efficiency below $$300\\,\\text{nm}$$. A less expensive solution that dramatically improves this efficiency is the application of a thin film of a p-terphenyl (PT) wavelength shifter on UV-glass PMTs. This improvement was quantified for Photonis XP4500B PMTs for wavelengths between $$200\\,\\text{nm}$$ and $$400\\,\\text{nm}$$. The gain factor ranges up to 5.4 $$\\pm$$ 0.5 at a wavelength of $$215\\,\\text{nm}$$, with a material load of $$110\\pm10\\,\\mu\\text{g}/\\text{cm}^2$$ ($$894\\,\\text{nm}$$). The wavelength shifter was found to be fully transparent for wavelengths greater than $$300\\,\\text{nm}$$. The resulting gain in detection efficiency, when used in a typical Cherenkov counter, was estimated to be of the order of 40%. Consistent coating quality was assured by a rapid gain testing procedure using narrow-band UV LEDs. Based on these results, 200 Photonis XP4500B PMTs were treated with PT for the upgraded low-threshold Cherenkov counter (LTCC) to be used in the CEBAF Large Acceptance Spectrometer upgraded detector (CLAS12) at the Thomas Jefferson National Accelerator Facility.« less

Evaluation of Emerging Energy-Efficient Heterogeneous Computing Platforms for Biomolecular and Cellular Simulation Workloads.

PubMed

Stone, John E; Hallock, Michael J; Phillips, James C; Peterson, Joseph R; Luthey-Schulten, Zaida; Schulten, Klaus

2016-05-01

Many of the continuing scientific advances achieved through computational biology are predicated on the availability of ongoing increases in computational power required for detailed simulation and analysis of cellular processes on biologically-relevant timescales. A critical challenge facing the development of future exascale supercomputer systems is the development of new computing hardware and associated scientific applications that dramatically improve upon the energy efficiency of existing solutions, while providing increased simulation, analysis, and visualization performance. Mobile computing platforms have recently become powerful enough to support interactive molecular visualization tasks that were previously only possible on laptops and workstations, creating future opportunities for their convenient use for meetings, remote collaboration, and as head mounted displays for immersive stereoscopic viewing. We describe early experiences adapting several biomolecular simulation and analysis applications for emerging heterogeneous computing platforms that combine power-efficient system-on-chip multi-core CPUs with high-performance massively parallel GPUs. We present low-cost power monitoring instrumentation that provides sufficient temporal resolution to evaluate the power consumption of individual CPU algorithms and GPU kernels. We compare the performance and energy efficiency of scientific applications running on emerging platforms with results obtained on traditional platforms, identify hardware and algorithmic performance bottlenecks that affect the usability of these platforms, and describe avenues for improving both the hardware and applications in pursuit of the needs of molecular modeling tasks on mobile devices and future exascale computers.

Enhanced UV light detection using a p-terphenyl wavelength shifter

DOE PAGES

Joosten, Sylvester J.; Kaczanowicz, Ed; Ungaro, Maurizio; ...

2017-07-25

Here, UV-glass photomultiplier tubes (PMTs) have poor photon detection efficiency for wavelengths belowmore » $$300\\,\\text{nm}$$ due to the opaqueness of the window material. Costly quartz PMTs could be used to enhance the efficiency below $$300\\,\\text{nm}$$. A less expensive solution that dramatically improves this efficiency is the application of a thin film of a p-terphenyl (PT) wavelength shifter on UV-glass PMTs. This improvement was quantified for Photonis XP4500B PMTs for wavelengths between $$200\\,\\text{nm}$$ and $$400\\,\\text{nm}$$. The gain factor ranges up to 5.4 $$\\pm$$ 0.5 at a wavelength of $$215\\,\\text{nm}$$, with a material load of $$110\\pm10\\,\\mu\\text{g}/\\text{cm}^2$$ ($$894\\,\\text{nm}$$). The wavelength shifter was found to be fully transparent for wavelengths greater than $$300\\,\\text{nm}$$. The resulting gain in detection efficiency, when used in a typical Cherenkov counter, was estimated to be of the order of 40%. Consistent coating quality was assured by a rapid gain testing procedure using narrow-band UV LEDs. Based on these results, 200 Photonis XP4500B PMTs were treated with PT for the upgraded low-threshold Cherenkov counter (LTCC) to be used in the CEBAF Large Acceptance Spectrometer upgraded detector (CLAS12) at the Thomas Jefferson National Accelerator Facility.« less

Electricity generation and nutrients removal from high-strength liquid manure by air-cathode microbial fuel cells.

PubMed

Lin, Hongjian; Wu, Xiao; Nelson, Chad; Miller, Curtis; Zhu, Jun

2016-01-01

Air-cathode microbial fuel cells (MFCs) are widely tested to recover electrical energy from waste streams containing organic matter. When high-strength wastewater, such as liquid animal manure, is used as a medium, inhibition on anode and cathode catalysts potentially impairs the effectiveness of MFC performance in power generation and pollutant removal. This study evaluated possible inhibitive effects of liquid swine manure components on MFC power generation, improved liquid manure-fed MFCs performance by pretreatment (dilution and selective adsorption), and modeled the kinetics of organic matter and nutrients removal kinetics. Parameters monitored included pH, conductivity, chemical oxygen demand (COD), volatile fatty acids (VFAs), total ammoniacal nitrogen (TAN), nitrite, nitrate, and phosphate concentrations. The removals of VFA and TAN were efficient, indicated by the short half-life times of 4.99 and 7.84 d, respectively. The mechanism for phosphate decrease was principally the salt precipitation on cathode, but the removal was incomplete after 42-d operation. MFC with an external resistor of 2.2 kΩ and fed with swine wastewater generated relatively small power (28.2 μW), energy efficiency (0.37%) and Coulombic efficiency (1.5%). Dilution of swine wastewater dramatically improved the power generation as the inhibitory effect was decreased. Zeolite and granular activated carbon were effective in the selective adsorption of ammonia or organic matter in swine wastewater, and so substantially improved the power generation, energy efficiency, and Coulombic efficiency. A smaller external resistor in the circuit was also observed to promote the organic matter degradation and thus to shorten the treatment time. Overall, air-cathode MFCs are promising for generating electrical power from livestock wastewater and meanwhile reducing the level of organic matter and nutrients.

Polymer bulk heterojunction solar cells with PEDOT:PSS bilayer structure as hole extraction layer.

PubMed

Kim, Wanjung; Kim, Namhun; Kim, Jung Kyu; Park, Insun; Choi, Yeong Suk; Wang, Dong Hwan; Chae, Heeyeop; Park, Jong Hyeok

2013-06-01

A high current density obtained in a limited, nanometer-thick region is important for high efficiency polymer solar cells (PSCs). The conversion of incident photons to charge carriers only occurs in confined active layers; therefore, charge-carrier extraction from the active layer within the device by using solar light has an important impact on the current density and the related to power conversion efficiency. In this study, we observed a surprising result, that is, extracting the charge carrier generated in the active layer of a PSC device, with a thickness-controlled PEDOT:PSS bilayer that acted as a hole extraction layer (HEL), yielded a dramatically improved power conversion efficiency in two different model systems (P3HT:PC₆₀BM and PCDTBT:PC₇₀BM). To understand this phenomenon, we conducted optical strength simulation, photocurrent-voltage measurements, incident photon to charge carrier efficiency measurements, ultraviolet photoelectron spectroscopy, and AFM studies. The results revealed that approximately 60 nm was the optimum PEDOT:PSS bilayer HEL thickness in PSCs for producing the maximum power conversion efficiency. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dramatic Developments in the Neurosciences Challenge Educators.

ERIC Educational Resources Information Center

Sylwester, Robert

1986-01-01

Recent dramatic developments in brain research and technology suggest that a comprehensive understanding of how the human brain works may soon be within reach. Just as the ability of the medical profession to treat patients improved dramatically with the advent of effective research skills and technology concerning the structure, biochemistry, and…

Engineering the N-terminal end of CelA results in improved performance and growth of Caldicellulosiruptor bescii on crystalline cellulose

DOE PAGES

Kim, Sun -Ki; Chung, Daehwan; Himmel, Michael E.; ...

2016-12-26

Here, CelA is the most abundant enzyme secreted by Caldicellulosiruptor bescii and has been shown to outperform mixtures of commercially available exo- and endoglucanases in vitro. CelA contains both a glycoside hydrolase family 9 endoglucanase and a glycoside hydrolase family 48 exoglucanase known to be synergistic in their activity, connected by three cellulose-binding domains via linker peptides. Here, repeated aspartate residues were introduced into the N-terminal ends of CelA GH9 and GH48 domains to improve secretion efficiency and/or catalytic efficiency of CelA. Among several constructs, the highest activity on carboxymethylcellulose (CMC), 0.81 ± 0.03 mg/mL was observed for the C.more » bescii strain containing CelA with 5-aspartate tag at the N-terminal end of GH9 domain – an 82% increase over wild type CelA. In addition, Expression of CelA with N-terminal repeated aspartate residues in C. bescii results in a dramatic increase in its ability to grow on Avicel.« less

Clinical image processing engine

NASA Astrophysics Data System (ADS)

Han, Wei; Yao, Jianhua; Chen, Jeremy; Summers, Ronald

2009-02-01

Our group provides clinical image processing services to various institutes at NIH. We develop or adapt image processing programs for a variety of applications. However, each program requires a human operator to select a specific set of images and execute the program, as well as store the results appropriately for later use. To improve efficiency, we design a parallelized clinical image processing engine (CIPE) to streamline and parallelize our service. The engine takes DICOM images from a PACS server, sorts and distributes the images to different applications, multithreads the execution of applications, and collects results from the applications. The engine consists of four modules: a listener, a router, a job manager and a data manager. A template filter in XML format is defined to specify the image specification for each application. A MySQL database is created to store and manage the incoming DICOM images and application results. The engine achieves two important goals: reduce the amount of time and manpower required to process medical images, and reduce the turnaround time for responding. We tested our engine on three different applications with 12 datasets and demonstrated that the engine improved the efficiency dramatically.

Perspectives: parity--prelude to a fifth cycle of reform.

PubMed

Goldman, Howard H

2002-09-01

Based on 2000 Carl Taube Lecture at the NIMH Mental Health Economics Meeting. This perspective article examines the relationship between a policy of parity in financing mental health services and the future of reform in service delivery. Applying theories of static and dynamic efficiency to an understanding of parity and the evolution of mental health services, drawing upon Burton Weisbrod s concept of the health care quadrilemma . Each of four cycles of reform in mental health services have contended with issues of static and dynamic efficiency. Each cycle was associated with static efficiency in the management and financing of services, and each was associated with a set of new treatment technologies intended to improve dynamic efficiency. Each reform proved ultimately unsuccessful primarily because of the failure of the treatment technologies to prevent future patient chronicity or to achieve sustained recovery. Recent advances in treatment technology and management of care can permit an unprecedented level of efficiency consistent with a policy of improved access to mainstream health and social welfare resources, including insurance coverage. This policy of so-called financing parity can improve current mental health service delivery, but it may also portend a future fifth cycle of reform. If new technologies continue to advance as full technologies - simple to deliver and producing true recovery - and mainstream resources are made available, then the specialty mental health services may contract dramatically in favor of effective care and treatment of mental illness in primary care and other mainstream settings. Predicting the future of health care is speculative, but it may be easier using the Weisbrod formulation to understand the process of mental health reform. Over-reliance on administrative techniques for building static efficiency and false optimism about dynamic efficiency from new technology have stymied previous reforms. All the same, a fifth cycle of reform could succeed, if the right conditions are met and mainstream resources are available.

PD2P: PanDA Dynamic Data Placement for ATLAS

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

Maeno, T.; De, K.; Panitkin, S.

2012-12-13

The PanDA (Production and Distributed Analysis) system plays a key role in the ATLAS distributed computing infrastructure. PanDA is the ATLAS workload management system for processing all Monte-Carlo (MC) simulation and data reprocessing jobs in addition to user and group analysis jobs. The PanDA Dynamic Data Placement (PD2P) system has been developed to cope with difficulties of data placement for ATLAS. We will describe the design of the new system, its performance during the past year of data taking, dramatic improvements it has brought about in the efficient use of storage and processing resources, and plans for the future.

The synergistic effect in the Fe-Co bimetallic catalyst system for the growth of carbon nanotube forests

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

Hardeman, D.; Esconjauregui, S., E-mail: cse28@cam.ac.uk; Cartwright, R.

2015-01-28

We report the growth of multi-walled carbon nanotube forests employing an active-active bimetallic Fe-Co catalyst. Using this catalyst system, we observe a synergistic effect by which—in comparison to pure Fe or Co—the height of the forests increases significantly. The homogeneity in the as-grown nanotubes is also improved. By both energy dispersive spectroscopy and in-situ x-ray photoelectron spectroscopy, we show that the catalyst particles consist of Fe and Co, and this dramatically increases the growth rate of the tubes. Bimetallic catalysts are thus potentially useful for synthesising nanotube forests more efficiently.

Ion microscopy with resonant ionization mass spectrometry : time-of-flight depth profiling with improved isotopic precision.

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

Pellin, M. J.; Veryovkin, I. V.; Levine, J.

2010-01-01

There are four generally mutually exclusive requirements that plague many mass spectrometric measurements of trace constituents: (1) the small size (limited by the depth probed) of many interesting materials requires high useful yields to simply detect some trace elements, (2) the low concentrations of interesting elements require efficient discrimination from isobaric interferences, (3) it is often necessary to measure the depth distribution of elements with high surface and low bulk contributions, and (4) many applications require precise isotopic analysis. Resonant ionization mass spectrometry has made dramatic progress in addressing these difficulties over the past five years.

Health resources and Internet with reference to HealthNet Nepal.

PubMed

Pradhan, Mohan Raj

2003-01-01

Technologies with the ability to send information in a fast, efficient and cheap fashion, such as the Internet--can provide dramatic improvements in access to information, advice and care. This article discusses importance of Internet, applications of Internet in providing information services in the health field. The Internet was developed in western countries and the information flow is from North to South. But for decision making within a country, information generated within a country is needed. For this, an organization like HealthNet Nepal is developed. The article discusses the various services of HealthNet Nepal and discusses about its unique features as compared to commercial ISPs.

Development trends for new cancer therapeutics and vaccines.

PubMed

Reichert, Janice M; Wenger, Julia B

2008-01-01

Global commercial development of cancer treatments has dramatically increased over the past 15 years. To assess trends in the process, we analyzed data for 1111 candidates that entered clinical study during 1990-2006. Our results show that although the average number of therapeutic candidates entering clinical study per year more than doubled, the US approval success rate was low (8%) during the period. The therapeutics took seven years on average to go through the clinical and US approval phases, but cancer vaccines have yet to gain any US approvals. These results indicate that improvement in the efficiency of the development process for innovative cancer treatments is needed.

Microchannel plate special nuclear materials sensor

NASA Astrophysics Data System (ADS)

Feller, W. B.; White, P. L.; White, P. B.; Siegmund, O. H. W.; Martin, A. P.; Vallerga, J. V.

2011-10-01

Nova Scientific Inc., is developing for the Domestic Nuclear Detection Office (DNDO SBIR #HSHQDC-08-C-00190), a solid-state, high-efficiency neutron detection alternative to 3He gas tubes, using neutron-sensitive microchannel plates (MCPs) containing 10B and/or Gd. This work directly supports DNDO development of technologies designed to detect and interdict nuclear weapons or illicit nuclear materials. Neutron-sensitized MCPs have been shown theoretically and more recently experimentally, to be capable of thermal neutron detection efficiencies equivalent to 3He gas tubes. Although typical solid-state neutron detectors typically have an intrinsic gamma sensitivity orders of magnitude higher than that of 3He gas detectors, we dramatically reduce gamma sensitivity by combining a novel electronic coincidence rejection scheme, employing a separate but enveloping gamma scintillator. This has already resulted in a measured gamma rejection ratio equal to a small 3He tube, without in principle sacrificing neutron detection efficiency. Ongoing improvements to the MCP performance as well as the coincidence counting geometry will be described. Repeated testing and validation with a 252Cf source has been underway throughout the Phase II SBIR program, with ongoing comparisons to a small commercial 3He gas tube. Finally, further component improvements and efforts toward integration maturity are underway, with the goal of establishing functional prototypes for SNM field testing.

LFC leading edge glove flight: Aircraft modification design, test article development and systems integration

NASA Technical Reports Server (NTRS)

Etchberger, F. R.

1983-01-01

Reduction of skin friction drag by suction of boundary layer air to maintain laminar flow has been known since Prandtl's published work in 1904. The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program in 1976 to develop technologies to improve fuel efficiency. This report documents the Lockheed-Georgia Company accomplishments in designing and fabricating a leading-edge flight test article incorporating boundary layer suction slots to be flown by NASA on their modified JetStar aircraft. Lockheed-Georgia Company performed as the integration contractor to design the JetStar aircraft modification to accept both a Lockheed and a McDonnell Douglas flight test article. McDonnell Douglas uses a porous skin concept. The report describes aerodynamic analyses, fabrication techniques, JetStar modifications, instrumentation requirements, and structural analyses and testing for the Lockheed test article. NASA will flight test the two LFC leading-edge test articles in a simulated commercial environment over a 6 to 8 month period in 1984. The objective of the flight test program is to evaluate the effectiveness of LFC leading-edge systems in reducing skin friction drag and consequently improving fuel efficiency.

Improving the efficiency and environmental stability of inverted planar perovskite solar cells via silver-doped nickel oxide hole-transporting layer

NASA Astrophysics Data System (ADS)

Wei, Ying; Yao, Kai; Wang, Xiaofeng; Jiang, Yihua; Liu, Xueyuan; Zhou, Naigen; Li, Fan

2018-01-01

In this paper, we demonstrate the high-performance inverted planar heterojunction perovskite solar cells (PeSCs) based on the novel inorganic hole-transporting layer (HTL) of silver (Ag)-doped NiOx (Ag:NiOx). Density-functional theory (DFT) calculation reveals that Ag prefers to occupy the substitutional Ni site (AgNi) and behaves as an acceptor in NiO lattice. Compared with the pristine NiOx films, appropriate Ag doping can increase the optical transparency, work function, electrical conductivity and hole mobility of NiOx films. Moreover, the CH3NH3PbI3 perovskite films grown on Ag:NiOx exhibit better crystallinity, higher coverage and smoother surface with densely packed larger grains than those grown on the pristine NiOx film. Consequently, the Ag:NiOx HTL boosts the efficiency of the inverted planar heterojunction PeSCs from 13.46% (for the pristine NiOx-based device) to 16.86% (for the 2 at.% Ag:NiOx-based device). Furthermore, the environmental stability of PeSCs based on Ag:NiOx HTL is dramatically improved compared to devices based on organic HTLs and pristine NiOx HTLs. This work provides a simple and effective HTL material system for high-efficient and stable PeSCs.

Giant photocurrent enhancement by transition metal doping in quantum dot sensitized solar cells

NASA Astrophysics Data System (ADS)

Rimal, Gaurab; Pimachev, Artem K.; Yost, Andrew J.; Poudyal, Uma; Maloney, Scott; Wang, Wenyong; Chien, TeYu; Dahnovsky, Yuri; Tang, Jinke

2016-09-01

A huge enhancement in the incident photon-to-current efficiency of PbS quantum dot (QD) sensitized solar cells by manganese doping is observed. In the presence of Mn dopants with relatively small concentration (4 at. %), the photoelectric current increases by an average of 300% (up to 700%). This effect cannot be explained by the light absorption mechanism because both the experimental and theoretical absorption spectra demonstrate several times decreases in the absorption coefficient. To explain such dramatic increase in the photocurrent we propose the electron tunneling mechanism from the LUMO of the QD excited state to the Zn2SnO4 (ZTO) semiconductor photoanode. This change is due to the presence of the Mn instead of Pb atom at the QD/ZTO interface. The ab initio calculations confirm this mechanism. This work proposes an alternative route for a significant improvement of the efficiency for quantum dot sensitized solar cells.

Laser Direct Writing of Tree-Shaped Hierarchical Cones on a Superhydrophobic Film for High-Efficiency Water Collection.

PubMed

Wang, Meng; Liu, Qian; Zhang, Haoran; Wang, Chuang; Wang, Lei; Xiang, Bingxi; Fan, Yongtao; Guo, Chuan Fei; Ruan, Shuangchen

2017-08-30

Directional water collection has stimulated a great deal of interest because of its potential applications in the field of microfluidics, liquid transportation, fog harvesting, and so forth. There have been some bio or bioinspired structures for directional water collection, from one-dimensional spider silk to two-dimensional star-like patterns to three-dimensional Nepenthes alata. Here we present a simple way for the accurate design and highly controllable driving of tiny droplets: by laser direct writing of hierarchical patterns with modified wettability and desired geometry on a superhydrophobic film, the patterned film can precisely and directionally drive tiny water droplets and dramatically improve the efficiency of water collection with a factor of ∼36 compared with the original superhydrophobic film. Such a patterned film might be an ideal platform for water collection from humid air and for planar microfluidics without tunnels.

Low temperature effects on nitrification and nitrifier community structure in V-ASP for decentralized wastewater treatment and its improvement by bio-augmentation.

PubMed

Yuan, Jiajia; Dong, Wenyi; Sun, Feiyun; Zhao, Ke

2018-03-01

The vegetation-activated sludge process (V-ASP) has been proved to be an environment-friendly decentralized wastewater treatment system with extra esthetic function and less footprint. However, the effects of low temperature on the treatment performance of V-ASP and related improvement methods are rarely investigated, up to now. In this work, the effect of low temperature on nitrification in V-ASP was comprehensively investigated from overall nitrification performance, substrate utilization kinetics, functional enzymatic activities, and microbial community structure shift by comparison with conventional ASP. Bio-augmentation methods in terms of single-time nitrifier-enriched biomass dosage were employed to improve nitrification efficiency in bench- and full-scale systems. The experiment results demonstrated that the NH 4 + -N removal efficiency in V-ASP system decreased when the operational temperature decreased from 30 to 15 °C, and the decreasing extent was rather smaller compared to ASP, as well as ammonium and nitrite oxidation rates and enzymatic activities, which indicated the V-ASP system possesses high resistance to low temperature. With direct dosage of 1.6 mg nitrifier/gSS sludge, the nitrification efficiency in V-ASP was enhanced dramatically from below 50% to above 90%, implying that bio-augmentation was effective for V-ASP whose enzymatic activities and microbial communities were both also improved. The feasibility and effectiveness of bio-augmentation was further confirmed in a full-scale V-ASP system after a long-term experiment which is instructive for the practical application.

Toyota's tips drive dramatic ED improvements.

PubMed

2002-11-01

The Toyota Motor Corp.'s key concepts of allowing workers to make changes, putting the customer first, and reducing waste can have a dramatic impact when implemented in emergency departments. Staff should be empowered to make changes to improve quality. A chain of events should be set in motion for each customer request. Identify and eliminate roadblocks that cause delays.

Solution processable mixed-solvent exfoliated MoS2 nanosheets for efficient and robust organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Liu, Chia-Wei; Wang, Chia; Liao, Chia-Wei; Golder, Jan; Tsai, Ming-Chih; Young, Hong-Tsu; Chen, Chin-Ti; Wu, Chih-I.

2018-04-01

We demonstrate the use of solution-processed molybdenum trioxide (MoO3) nanoparticle-decorated molybdenum disulfide (MoS2) nanosheets (MoS2/MoO3) as hole injection layer (HIL) in organic lighting diodes (OLEDs). The device performance is shown to be significantly improved by the introduction of such MoS2/MoO3 HIL without any post-ultraviolet-ozone treatment, and is shown to better the performance of devices fabricated using conventional poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and MoO3 nanoparticle HILs. The MoS2/MoO3 nanosheets form a compact film, as smooth as PEDOT:PSS films and smoother than MoO3 nanoparticle films, when simply spin-coated on indium tin oxide substrates. The improvement in device efficiency can be attributed to the smooth surface of the nanostructured MoS2/MoO3 HIL and the excellent conductivity characteristics of the two-dimensional (2D) layered material (MoS2), which facilitate carrier transport in the device and reduce the sheet resistance. Moreover, the long-term stability of OLED devices that use such MoS2/MoO3 layers is shown to be improved dramatically compared with hygroscopic and acidic PEDOT:PSS-based devices.

Use of a Novel Fluidics Microbead Trap/Flow-cell Enhances Speed and Sensitivity of Bead-Based Bioassays

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

Ozanich, Rich M.; Antolick, Kathryn C.; Bruckner-Lea, Cindy J.

2007-09-15

Automated devices and methods for biological sample preparation often utilize surface functionalized microbeads (superparamagnetic or non-magnetic) to allow capture, purification and pre-concentration of trace amounts of proteins, cells, or nucleic acids (DNA/RNA) from complex samples. We have developed unique methods and hardware for trapping either magnetic or non-magnetic functionalized beads that allow samples and reagents to be efficiently perfused over a micro-column of beads. This approach yields enhanced mass transport and up to 5-fold improvements in assay sensitivity or speed, dramatically improving assay capability relative to assays conducted in more traditional “batch modes” (i.e., in tubes or microplate wells). Summarymore » results are given that highlight the analytical performance improvements obtained for automated microbead processing systems utilizing novel microbead trap/flow-cells for various applications, including: 1) simultaneous capture of multiple cytokines using an antibody-coupled polystyrene bead assay with subsequent flow cytometry detection; 2) capture of nucleic acids using oligonucleotide coupled polystyrene beads with flow cytometry detection; and 3) capture of Escherichia coli 0157:H7 (E. coli) from 50 mL sample volumes using antibody-coupled superparamagnetic microbeads with subsequent culturing to assess capture efficiency.« less

Influence of photo-generated carriers on current spreading in double diode structures for electroluminescent cooling

NASA Astrophysics Data System (ADS)

Radevici, Ivan; Tiira, Jonna; Sadi, Toufik; Oksanen, Jani

2018-05-01

Current crowding close to electrical contacts is a common challenge in all optoelectronic devices containing thin current spreading layers (CSLs). We analyze the effects of current spreading on the operation of the so-called double diode structure (DDS), consisting of a light emitting diode (LED) and a photodiode (PD) fabricated within the same epitaxial growth process, and providing an attractive platform for studying electroluminescent (EL) cooling under high bias conditions. We show that current spreading in the common n-type layer between the LED and the PD can be dramatically improved by the strong optical coupling between the diodes, as the coupling enables a photo-generated current through the PD. This reduces the current in the DDS CSL and enables the study of EL cooling using structures that are not limited by the conventional light extraction challenges encountered in normal LEDs. The current spreading in the structures is studied using optical imaging techniques, electrical measurements, simulations, as well as simple equivalent circuit models developed for this purpose. The improved current spreading leads further to a mutual dependence with the coupling efficiency, which is expected to facilitate the process of optimizing the DDS. We also report a new improved value of 63% for the DDS coupling quantum efficiency.

Designing Strategies for an Efficient Language MOOC

ERIC Educational Resources Information Center

Perifanou, Maria

2016-01-01

The advent of Massive Open Online Courses (MOOCs) has dramatically changed the way people learn a language. But how can we design an efficient language learning environment for a massive number of learners? Are there any good practices that showcase successful Massive Open Online Language Course (MOOLC) design strategies? According to recent…

Staggered Mesh Ewald: An extension of the Smooth Particle-Mesh Ewald method adding great versatility

PubMed Central

Cerutti, David S.; Duke, Robert E.; Darden, Thomas A.; Lybrand, Terry P.

2009-01-01

We draw on an old technique for improving the accuracy of mesh-based field calculations to extend the popular Smooth Particle Mesh Ewald (SPME) algorithm as the Staggered Mesh Ewald (StME) algorithm. StME improves the accuracy of computed forces by up to 1.2 orders of magnitude and also reduces the drift in system momentum inherent in the SPME method by averaging the results of two separate reciprocal space calculations. StME can use charge mesh spacings roughly 1.5× larger than SPME to obtain comparable levels of accuracy; the one mesh in an SPME calculation can therefore be replaced with two separate meshes, each less than one third of the original size. Coarsening the charge mesh can be balanced with reductions in the direct space cutoff to optimize performance: the efficiency of StME rivals or exceeds that of SPME calculations with similarly optimized parameters. StME may also offer advantages for parallel molecular dynamics simulations because it permits the use of coarser meshes without requiring higher orders of charge interpolation and also because the two reciprocal space calculations can be run independently if that is most suitable for the machine architecture. We are planning other improvements to the standard SPME algorithm, and anticipate that StME will work synergistically will all of them to dramatically improve the efficiency and parallel scaling of molecular simulations. PMID:20174456

Improving Survival and Promoting Respiratory Motor Function After Cervical Spinal Cord Injury

DTIC Science & Technology

2017-09-01

ventilator in order to survive. Use of the ventilator severely limits the quality of life of those injured and dramatically increases the demand for health...care for cervical SCI patients so as to lead to an improved quality of life , better-quality health care management, and improved functional outcomes...mechanical ventilator in order to survive. Use of the ventilator severely limits the quality of life of those injured and dramatically increases the

Implementation of Hospital Computerized Physician Order Entry Systems in a Rural State: Feasibility and Financial Impact

PubMed Central

Ohsfeldt, Robert L.; Ward, Marcia M.; Schneider, John E.; Jaana, Mirou; Miller, Thomas R.; Lei, Yang; Wakefield, Douglas S.

2005-01-01

Objective The aim of this study was to estimate the costs of implementing computerized physician order entry (CPOE) systems in hospitals in a rural state and to evaluate the financial implications of statewide CPOE implementation. Methods A simulation model was constructed using estimates of initial and ongoing CPOE costs mapped onto all general hospitals in Iowa by bed quantity and current clinical information system (CIS) status. CPOE cost estimates were obtained from a leading CPOE vendor. Current CIS status was determined through mail survey of Iowa hospitals. Patient care revenue and operating cost data published by the Iowa Hospital Association were used to simulate the financial impact of CPOE adoption on hospitals. Results CPOE implementation would dramatically increase operating costs for rural and critical access hospitals in the absence of substantial costs savings associated with improved efficiency or improved patient safety. For urban and rural referral hospitals, the cost impact is less dramatic but still substantial. However, relatively modest benefits in the form of patient care cost savings or revenue enhancement would be sufficient to offset CPOE costs for these larger hospitals. Conclusion Implementation of CPOE in rural or critical access hospitals may depend on net increase in operating costs. Adoption of CPOE may be financially infeasible for these small hospitals in the absence of increases in hospital payments or ongoing subsidies from third parties. PMID:15492033

The effect of the number of transferred embryos, the interval between nuclear transfer and embryo transfer, and the transfer pattern on pig cloning efficiency.

PubMed

Rim, Chol Ho; Fu, Zhixin; Bao, Lei; Chen, Haide; Zhang, Dan; Luo, Qiong; Ri, Hak Chol; Huang, Hefeng; Luan, Zhidong; Zhang, Yan; Cui, Chun; Xiao, Lei; Jong, Ui Myong

2013-12-01

To improve the efficiency of producing cloned pigs, we investigated the influence of the number of transferred embryos, the culturing interval between nuclear transfer (NT) and embryo transfer, and the transfer pattern (single oviduct or double oviduct) on cloning efficiency. The results demonstrated that transfer of either 150-200 or more than 200NT embryos compared to transfer of 100-150 embryos resulted in a significantly higher pregnancy rate (48 ± 16, 50 ± 16 vs. 29 ± 5%, p<0.05) and average litter size (4.1 ± 2.3, 7 ± 3.6 vs. 2.5 ± 0.5). In vitro culture of reconstructed embryos for a longer time (40 h vs. 20 h) resulted in higher (p<0.05) pregnancy rate (44 ± 9 vs. 31 ± 3%) and delivery rate (44 ± 9 vs. 25 ± 9%). Furthermore, double oviductal transfer dramatically increased pregnancy rate (83 ± 6 vs. 27+8%, p<0.05), delivery rate (75 ± 2 vs. 27+8%, p<0.05) and average litter size (6.5 ± 2.8 vs. 2.6 ± 1.2) compared to single oviductal transfer. Our study demonstrated that an improvement in pig cloning efficiency is achieved by adjusting the number and in vitro culture time of reconstructed embryos as well as the embryo transfer pattern. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of Emerging Energy-Efficient Heterogeneous Computing Platforms for Biomolecular and Cellular Simulation Workloads

PubMed Central

Stone, John E.; Hallock, Michael J.; Phillips, James C.; Peterson, Joseph R.; Luthey-Schulten, Zaida; Schulten, Klaus

2016-01-01

Many of the continuing scientific advances achieved through computational biology are predicated on the availability of ongoing increases in computational power required for detailed simulation and analysis of cellular processes on biologically-relevant timescales. A critical challenge facing the development of future exascale supercomputer systems is the development of new computing hardware and associated scientific applications that dramatically improve upon the energy efficiency of existing solutions, while providing increased simulation, analysis, and visualization performance. Mobile computing platforms have recently become powerful enough to support interactive molecular visualization tasks that were previously only possible on laptops and workstations, creating future opportunities for their convenient use for meetings, remote collaboration, and as head mounted displays for immersive stereoscopic viewing. We describe early experiences adapting several biomolecular simulation and analysis applications for emerging heterogeneous computing platforms that combine power-efficient system-on-chip multi-core CPUs with high-performance massively parallel GPUs. We present low-cost power monitoring instrumentation that provides sufficient temporal resolution to evaluate the power consumption of individual CPU algorithms and GPU kernels. We compare the performance and energy efficiency of scientific applications running on emerging platforms with results obtained on traditional platforms, identify hardware and algorithmic performance bottlenecks that affect the usability of these platforms, and describe avenues for improving both the hardware and applications in pursuit of the needs of molecular modeling tasks on mobile devices and future exascale computers. PMID:27516922

Reaction chemistry and collisional processes in multiple devices for resolving isobaric interferences in ICP-MS.

PubMed

Bandura, D R; Baranov, V I; Tanner, S D

2001-07-01

A low-level review of the fundamentals of ion-molecule interactions is presented. These interactions are used to predict the efficiencies of collisional fragmentation, energy damping and reaction for a variety of neutral gases as a function of pressure in a rf-driven collision/reaction cell. It is shown that the number of collisions increases dramatically when the ion energies are reduced to near-thermal (< 0.1 eV), because of the ion-induced dipole and ion-dipole interaction. These considerations suggest that chemical reaction can be orders of magnitude more efficient at improving the analyte signal/background ratio than can collisional fragmentation. Considerations that lead to an appropriate selection of type of gas, operating pressure, and ion energies for efficient operation of the cell for the alleviation of spectral interferences are discussed. High efficiency (large differences between reaction efficiencies of the analyte and interference ions, and concomitant suppression of secondary chemistry) might be required to optimize the chemical resolution (determination of an analyte in the presence of an isobaric interference) when using ion-molecule chemistry to suppress the interfering ion. In many instances atom transfer to the analyte, which shifts the analytical m/z by the mass of the atom transferred, provides high chemical resolution, even when the efficiency of reaction is relatively low. Examples are given of oxidation, hydroxylation, and chlorination of analyte ions (V+, Fe+, As+, Se+, Sr+, Y+, and Zr+) to improve the capability of determination of complex samples. Preliminary results are given showing O-atom abstraction by CO from CaO+ to enable the determination of Fe in high-Ca samples.

Alleviation of carbon catabolite repression in Enterobacter aerogenes for efficient utilization of sugarcane molasses for 2,3-butanediol production.

PubMed

Jung, Moo-Young; Jung, Hwi-Min; Lee, Jinwon; Oh, Min-Kyu

2015-01-01

Due to its cost-effectiveness and rich sugar composition, sugarcane molasses is considered to be a promising carbon source for biorefinery. However, the sugar mixture in sugarcane molasses is not consumed as efficiently as glucose in microbial fermentation due to complex interactions among their utilizing pathways, such as carbon catabolite repression (CCR). In this study, 2,3-butanediol-producing Enterobacter aerogenes was engineered to alleviate CCR and improve sugar utilization by modulating its carbon preference. The gene encoding catabolite repressor/activator (Cra) was deleted in the genome of E. aerogenes to increase the fructose consumption rate. However, the deletion mutation repressed sucrose utilization, resulting in the accumulation of sucrose in the fermentation medium. Cra regulation on expression of the scrAB operon involved in sucrose catabolism was verified by reverse transcription and real-time PCR, and the efficiency of sucrose utilization was restored by disrupting the scrR gene and overexpressing the scrAB operon. In addition, overexpression of the ptsG gene involved in glucose utilization enhanced the glucose preference among mixed sugars, which relieved glucose accumulation in fed-batch fermentation. In fed-batch fermentation using sugarcane molasses, the maximum titer of 2,3-butanediol production by the mutant reached 140.0 g/L at 54 h, which was by far the highest titer of 2,3-butanediol with E. aerogenes achieved through genetic engineering. We have developed genetically engineered E. aerogenes as a 2,3-butanediol producer that efficiently utilizes sugarcane molasses. The fermentation efficiency was dramatically improved by the alleviation of CCR and modulation of carbon preference. These results offer a metabolic engineering approach for achieving highly efficient utilization of mixed sugars for the biorefinery industry.

Sensor-Based Vibration Signal Feature Extraction Using an Improved Composite Dictionary Matching Pursuit Algorithm

PubMed Central

Cui, Lingli; Wu, Na; Wang, Wenjing; Kang, Chenhui

2014-01-01

This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP) algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP) is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and reconstruction algorithm is feasible and effective. PMID:25207870

Sensor-based vibration signal feature extraction using an improved composite dictionary matching pursuit algorithm.

PubMed

Cui, Lingli; Wu, Na; Wang, Wenjing; Kang, Chenhui

2014-09-09

This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP) algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP) is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and reconstruction algorithm is feasible and effective.

Effectively Transparent Front Contacts for Optoelectronic Devices

DOE PAGES

Saive, Rebecca; Borsuk, Aleca M.; Emmer, Hal S.; ...

2016-06-10

Effectively transparent front contacts for optoelectronic devices achieve a measured transparency of up to 99.9% and a measured sheet resistance of 4.8 Ω sq-1. These 3D microscale triangular cross-section grid fingers redirect incoming photons efficiently to the active semiconductor area and can replace standard grid fingers as well as transparent conductive oxide layers in optoelectronic devices. Optoelectronic devices such as light emitting diodes, photodiodes, and solar cells play an important and expanding role in modern technology. Photovoltaics is one of the largest optoelectronic industry sectors and an ever-increasing component of the world's rapidly growing renewable carbon-free electricity generation infrastructure. Inmore » recent years, the photovoltaics field has dramatically expanded owing to the large-scale manufacture of inexpensive crystalline Si and thin film cells and modules. The current record efficiency (η = 25.6%) Si solar cell utilizes a heterostructure intrinsic thin layer (HIT) design[1] to enable increased open circuit voltage, while more mass-manufacturable solar cell architectures feature front contacts.[2, 3] Thus improved solar cell front contact designs are important for future large-scale photovoltaics with even higher efficiency.« less

The future challenge for aeropropulsion

NASA Technical Reports Server (NTRS)

Rosen, Robert; Bowditch, David N.

1992-01-01

NASA's research in aeropropulsion is focused on improving the efficiency, capability, and environmental compatibility for all classes of future aircraft. The development of innovative concepts, and theoretical, experimental, and computational tools provide the knowledge base for continued propulsion system advances. Key enabling technologies include advances in internal fluid mechanics, structures, light-weight high-strength composite materials, and advanced sensors and controls. Recent emphasis has been on the development of advanced computational tools in internal fluid mechanics, structural mechanics, reacting flows, and computational chemistry. For subsonic transport applications, very high bypass ratio turbofans with increased engine pressure ratio are being investigated to increase fuel efficiency and reduce airport noise levels. In a joint supersonic cruise propulsion program with industry, the critical environmental concerns of emissions and community noise are being addressed. NASA is also providing key technologies for the National Aerospaceplane, and is studying propulsion systems that provide the capability for aircraft to accelerate to and cruise in the Mach 4-6 speed range. The combination of fundamental, component, and focused technology development underway at NASA will make possible dramatic advances in aeropropulsion efficiency and environmental compatibility for future aeronautical vehicles.

Organic-Inorganic Hybrid Perovskite with Controlled Dopant Modification and Application in Photovoltaic Device.

PubMed

Zhao, Wangen; Yang, Dong; Liu, Shengzhong Frank

2017-07-01

Organic-inorganic hybrid perovskite as a kind of promising photovoltaic material is booming due to its low-cost, high defect tolerance, and easy fabrication, which result in the huge potential in industrial production. In the pursuit of high efficiency photovoltaic devices, high-quality absorbing layer is essential. Therefore, developing organic-inorganic hybrid perovskite thin films with good coverage, improved uniformity, and crystalline in a single pass deposition is of great concern in realizing good performance of perovskite thin-film solar cell. Here, it is found that the introduction of suitable amounts of LiI plays a dramatically positive role in enlarging the grain size and reducing the grain boundaries of absorbing layer. In addition, the carrier lifetime and built-in potential of the LiI doped perovskite device are observed to increase. Thus, it leads to about 15% gain in solar cell efficiency comparing to that without the LiI doping. Meanwhile, a hysteresis reduction is observed and 18.16% power conversion efficiency is achieved in LiI doped perovskite device, as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improving the fiber coupling efficiency for DARWIN by loss-less shaping of the receive beams

NASA Astrophysics Data System (ADS)

Voland, Ch.; Weigel, Th.; Dreischer, Th.; Wallner, O.; Ergenzinger, K.; Ries, H.; Jetter, R.; Vosteen, A.

2017-11-01

For the DARWIN mission the extremely low planet signal levels require an optical instrument design with utmost efficiency to guarantee the required science performance. By shaping the transverse amplitude and phase distributions of the receive beams, the singlemode fibre coupling efficiency can be increased to almost 100%, thus allowing for a gain of more than 20% compared to conventional designs. We show that the use of "tailored freeform surfaces" for purpose of beam shaping dramatically reduces the coupling degradations, which otherwise result from mode mismatch between the Airy pattern of the image and the fibre mode, and therefore allows for achieving a performance close to the physical limitations. We present an application of tailored surfaces for building a beam shaping optics that shall enhance fibre coupling performance as core part of a space based interferometer in the future DARWIN mission and present performance predictions by wave-optical simulations. We assess the feasibility of manufacturing the corresponding tailored surfaces and describe the proof of concept demonstrator we use for experimental performance verification.

Highly Efficient, All-Dielectric Huygens Metasurfaces

NASA Astrophysics Data System (ADS)

Ollanik, Adam; Farrar-Foley, Nick; Smith, Jake; Escarra, Matthew

Demonstration of the control of light by the introduction of abrupt phase discontinuities across a subwavelength scale has opened the doors to a new level of wavefront control. All-dielectric Huygens metasurfaces hold significant promise due to their dramatically improved efficiency over plasmonic approaches. We present the successful design, computational modeling, and experimental realization of all-dielectric transmissive Huygens metasurfaces capable of deflection efficiency >90%. Dielectric Huygens sources, taking advantage of spectrally aligned electric and magnetic dipole resonances, are capable of tunable phase delay for transmitted light with near unity efficiency of forward scattering. Using ellipsoidal cylinder nanoantennas, we are able to manipulate the phase response and engineer a metasurface with a spatially gradient phase profile. Through careful design and optimization we mitigate the effects of inter-antenna coupling. We have designed and modeled metasurfaces demonstrating anomalous refraction with very high efficiency (>80%) for wavelength bands from the UV to the near-IR. These surfaces were designed using three distinct nanoantenna materials, Si, TiO2, and GaP, to demonstrate the flexibility of the technique. Experimentally, Si nanoantennas are fabricated using a combination of electron beam lithography and ICP/RIE-etching. Metasurfaces are characterized using a goniospectrometer capable of mapping light intensity on a cylindrical shell surrounding the metasurface.

The Dynamic Process of Drug-GPCR Binding at Either Orthosteric or Allosteric Sites Evaluated by Metadynamics

PubMed Central

Schneider, Sebastian; Provasi, Davide; Filizola, Marta

2015-01-01

Major advances in G Protein-Coupled Receptor (GPCR) structural biology over the past few years have yielded a significant number of high-resolution crystal structures for several different receptor subtypes. This dramatic increase in GPCR structural information has underscored the use of automated docking algorithms for the discovery of novel ligands that can eventually be developed into improved therapeutics. However, these algorithms are often unable to discriminate between different, yet energetically similar, poses because of their relatively simple scoring functions. Here, we describe a metadynamics-based approach to study the dynamic process of ligand binding to/unbinding from GPCRs with a higher level of accuracy and yet satisfying efficiency. PMID:26260607

An evaluation of NASA's program in human factors research: Aircrew-vehicle system interaction

NASA Technical Reports Server (NTRS)

1982-01-01

Research in human factors in the aircraft cockpit and a proposed program augmentation were reviewed. The dramatic growth of microprocessor technology makes it entirely feasible to automate increasingly more functions in the aircraft cockpit; the promise of improved vehicle performance, efficiency, and safety through automation makes highly automated flight inevitable. An organized data base and validated methodology for predicting the effects of automation on human performance and thus on safety are lacking and without such a data base and validated methodology for analyzing human performance, increased automation may introduce new risks. Efforts should be concentrated on developing methods and techniques for analyzing man machine interactions, including human workload and prediction of performance.

Topographic mapping

USGS Publications Warehouse

,

2008-01-01

The U.S. Geological Survey (USGS) produced its first topographic map in 1879, the same year it was established. Today, more than 100 years and millions of map copies later, topographic mapping is still a central activity for the USGS. The topographic map remains an indispensable tool for government, science, industry, and leisure. Much has changed since early topographers traveled the unsettled West and carefully plotted the first USGS maps by hand. Advances in survey techniques, instrumentation, and design and printing technologies, as well as the use of aerial photography and satellite data, have dramatically improved mapping coverage, accuracy, and efficiency. Yet cartography, the art and science of mapping, may never before have undergone change more profound than today.

Low joining efficiency and non-conservative repair of two distant double-strand breaks in mouse embryonic stem cells.

PubMed

Boubakour-Azzouz, Imenne; Ricchetti, Miria

2008-02-01

Efficient and faithful repair of DNA double-strand breaks (DSBs) is critical for genome stability. To understand whether cells carrying a functional repair apparatus are able to efficiently heal two distant chromosome ends and whether this DNA lesion might result in genome rearrangements, we induced DSBs in genetically modified mouse embryonic stem cells carrying two I-SceI sites in cis separated by a distance of 9 kbp. We show that in this context non-homologous end-joining (NHEJ) can repair using standard DNA pairing of the broken ends, but it also joins 3' non-complementary overhangs that require unusual joining intermediates. The repair efficiency of this lesion appears to be dramatically low and the extent of genome alterations was high in striking contrast with the spectra of repair events reported for two collinear DSBs in other experimental systems. The dramatic decline in accuracy suggests that significant constraints operate in the repair process of these distant DSBs, which may also control the low efficiency of this process. These findings provide important insights into the mechanism of repair by NHEJ and how this process may protect the genome from large rearrangements.

Dramatically accelerated growth and extraordinary gigantism of transgenic mud loach Misgurnus mizolepis.

PubMed

Nam, Y K; Noh, J K; Cho, Y S; Cho, H J; Cho, K N; Kim, C G; Kim, D S

2001-08-01

Transgenic mud loaches (Misgurnus mizolepis), in which the entire transgene originated from the same species, have been generated by microinjecting the mud loach growth hormone (mlGH) gene fused to the mud loach beta-actin promoter. Out of 4,100 eggs injected, 7.5% fish derived from the injected eggs showed dramatically accelerated growth, with a maximum of 35-fold faster growth than their non-transgenic siblings. Many fast-growing transgenic individuals showed extraordinary gigantism: their body weight and total length (largest fish attained to 413 g and 41.5 cm) were larger and longer than even those of 12-year-old normal broodstock (maximum size reached to 89 g and 28 cm). Of 46 transgenic founders tested, 30 individuals transmitted the transgene to next generation with a wide range of germ-line transmission frequencies ranging from 2% to 33%. The growth performance of the subsequent generation (F1) was also dramatically accelerated up to 35-fold, although the levels of enhanced growth were variable among transgenic lines. Three transgenic germ-lines up to F4 were established, showing the expected Mendelian inheritance of the transgene. Expression of GH mRNA in many tissues was detected by RT-PCR analyses. The time required to attain marketable size (10 g) in these transgenic lines was only 30-50 days after fertilization, while at least 6 months in non-transgenic fish. Besides growth enhancement, significantly improved feed-conversion efficiency up to 1.9-fold was also observed.

Training for Efficiency: Work, Time, and Systems-Based Practice in Medical Residency

ERIC Educational Resources Information Center

Szymczak, Julia E.; Bosk, Charles L.

2012-01-01

Medical residency is a period of intense socialization with a heavy workload. Previous sociological studies have identified efficiency as a practical skill necessary for success. However, many contextual features of the training environment have undergone dramatic change since these studies were conducted. What are the consequences of these…

Order of magnitude improvement of nano-contact spin torque nano-oscillator performance.

PubMed

Banuazizi, Seyed Amir Hossein; Sani, Sohrab R; Eklund, Anders; Naiini, Maziar M; Mohseni, Seyed Majid; Chung, Sunjae; Dürrenfeld, Philipp; Malm, B Gunnar; Åkerman, Johan

2017-02-02

Spin torque nano-oscillators (STNO) represent a unique class of nano-scale microwave signal generators and offer a combination of intriguing properties, such as nano sized footprint, ultrafast modulation rates, and highly tunable microwave frequencies from 100 MHz to close to 100 GHz. However, their low output power and relatively high threshold current still limit their applicability and must be improved. In this study, we investigate the influence of the bottom Cu electrode thickness (t Cu ) in nano-contact STNOs based on Co/Cu/NiFe GMR stacks and with nano-contact diameters ranging from 60 to 500 nm. Increasing t Cu from 10 to 70 nm results in a 40% reduction of the threshold current, an order of magnitude higher microwave output power, and close to two orders of magnitude better power conversion efficiency. Numerical simulations of the current distribution suggest that these dramatic improvements originate from a strongly reduced lateral current spread in the magneto-dynamically active region.

Experimental study of a passive thermal management system for high-powered lithium ion batteries using porous metal foam saturated with phase change materials

NASA Astrophysics Data System (ADS)

Li, W. Q.; Qu, Z. G.; He, Y. L.; Tao, Y. B.

2014-06-01

A highly efficient thermal strategy to manage a high-powered Li-ion battery package within the required safe temperature range is of great demand for electric vehicles (EVs) applications. A sandwiched cooling structure using copper metal foam saturated with phase change materials was designed. The thermal efficiency of the system was experimentally evaluated and compared with two control cases: a cooling mode with pure phase change materials and an air-cooling mode. The results showed that the thermal management with air natural convection cannot fulfill the safety demand of the Li-ion battery. The use of pure PCM can dramatically reduce the surface temperature and maintain the temperature within an allowable range due to the latent heat absorption and the natural convection of the melted PCM during the melting process. The foam-paraffin composite further reduced the battery's surface temperature and improved the uniformity of the temperature distribution caused by the improvement of the effective thermal conductivity. Additionally, the battery surface temperature increased with an increase in the porosity and the pore density of the metal foam.

Scaling Optimization of the SIESTA MHD Code

NASA Astrophysics Data System (ADS)

Seal, Sudip; Hirshman, Steven; Perumalla, Kalyan

2013-10-01

SIESTA is a parallel three-dimensional plasma equilibrium code capable of resolving magnetic islands at high spatial resolutions for toroidal plasmas. Originally designed to exploit small-scale parallelism, SIESTA has now been scaled to execute efficiently over several thousands of processors P. This scaling improvement was accomplished with minimal intrusion to the execution flow of the original version. First, the efficiency of the iterative solutions was improved by integrating the parallel tridiagonal block solver code BCYCLIC. Krylov-space generation in GMRES was then accelerated using a customized parallel matrix-vector multiplication algorithm. Novel parallel Hessian generation algorithms were integrated and memory access latencies were dramatically reduced through loop nest optimizations and data layout rearrangement. These optimizations sped up equilibria calculations by factors of 30-50. It is possible to compute solutions with granularity N/P near unity on extremely fine radial meshes (N > 1024 points). Grid separation in SIESTA, which manifests itself primarily in the resonant components of the pressure far from rational surfaces, is strongly suppressed by finer meshes. Large problem sizes of up to 300 K simultaneous non-linear coupled equations have been solved on the NERSC supercomputers. Work supported by U.S. DOE under Contract DE-AC05-00OR22725 with UT-Battelle, LLC.

Magnetic Enrichment of Dendritic Cell Vaccine in Lymph Node with Fluorescent-Magnetic Nanoparticles Enhanced Cancer Immunotherapy

PubMed Central

Jin, Honglin; Qian, Yuan; Dai, Yanfeng; Qiao, Sha; Huang, Chuan; Lu, Lisen; Luo, Qingming; Chen, Jing; Zhang, Zhihong

2016-01-01

Dendritic cell (DC) migration to the lymph node is a key component of DC-based immunotherapy. However, the DC homing rate to the lymphoid tissues is poor, thus hindering the DC-mediated activation of antigen-specific T cells. Here, we developed a system using fluorescent magnetic nanoparticles (α-AP-fmNPs; loaded with antigen peptide, iron oxide nanoparticles, and indocyanine green) in combination with magnetic pull force (MPF) to successfully manipulate DC migration in vitro and in vivo. α-AP-fmNPs endowed DCs with MPF-responsiveness, antigen presentation, and simultaneous optical and magnetic resonance imaging detectability. We showed for the first time that α-AP-fmNP-loaded DCs were sensitive to MPF, and their migration efficiency could be dramatically improved both in vitro and in vivo through MPF treatment. Due to the enhanced migration of DCs, MPF treatment significantly augmented antitumor efficacy of the nanoparticle-loaded DCs. Therefore, we have developed a biocompatible approach with which to improve the homing efficiency of DCs and subsequent anti-tumor efficacy, and track their migration by multi-modality imaging, with great potential applications for DC-based cancer immunotherapy. PMID:27698936

Intensive Study on the Catalytical Behavior of N-Methylphenothiazine as a Soluble Mediator to Oxidize the Li2O2 Cathode of the Li-O2 Battery.

PubMed

Feng, Ningning; Mu, Xiaowei; Zhang, Xueping; He, Ping; Zhou, Haoshen

2017-02-01

Aprotic Li-O 2 batteries have attracted worldwide interest owing to their ultrahigh theoretical energy density. However, the practical Li-O 2 batteries still suffer from high charge overpotential and low energy efficiency resulting from the sluggish kinetics in electrochemically oxidizing the insulating lithium peroxide (Li 2 O 2 ). Recently, dissolved redox mediators in the electrolyte have enabled the effective catalytic oxidation of Li 2 O 2 at the liquid-solid interface. Here, we report that the incorporation of N-methylphenothiazine (MPT), as a redox shuttle in Li-O 2 batteries, provides a dramatic reduction in charge overpotential to 0.67 V and an improved round-trip efficiency close to 76%. Moreover, the efficacy of MPT in Li-O 2 cells was further investigated by various characterizations. On charging, MPT + cations are first generated electrochemically at the cathode surface and subsequently oxidize the solid discharge products Li 2 O 2 through a chemical reaction. Furthermore, the presence of MPT has been demonstrated to improve the cycling stability of the cells and suppress side reactions arising from carbon and electrolytes at high potentials.

Some historical trends in the research and development of aircraft

NASA Technical Reports Server (NTRS)

Spearman, M. L.

1983-01-01

A survey of some trends in aircraft design was made in an effort to determine the relation between research, development, test, and evaluation (RDT and E) and aircraft mission capability, requirements, and objectives. Driving forces in the history of aircraft include the quest for speed which involved design concepts incorporating jet propulsion systems and low drag features. The study of high speed design concepts promoted new experimental and analytical research techniques. These research techniques, in turn, have lead to concepts offering new performance potential. Design trends were directed toward increased speed, efficiency, productivity, and safety. Generally speaking, the research and development effort has been evolutionary in nature and, with the exception of the transition to supersonic flight, little has occurred since the origin of flight that has drastically changed the basic design fundamentals of aircraft. However, this does not preclude the possibility of dramatic changes in the future since the products of research are frequently unpredictable. Advances should be expected and sought in improved aerodynamics (reduced drag, enhanced lift, flow field exploitation); propulsion (improved engine cycles, multimode engines, alternate fuels, alternate power sources); structures (new materials, manufacturing techniques); all with a view toward increased efficiency and utility.

Improving multi-objective reservoir operation optimization with sensitivity-informed dimension reduction

NASA Astrophysics Data System (ADS)

Chu, J.; Zhang, C.; Fu, G.; Li, Y.; Zhou, H.

2015-08-01

This study investigates the effectiveness of a sensitivity-informed method for multi-objective operation of reservoir systems, which uses global sensitivity analysis as a screening tool to reduce computational demands. Sobol's method is used to screen insensitive decision variables and guide the formulation of the optimization problems with a significantly reduced number of decision variables. This sensitivity-informed method dramatically reduces the computational demands required for attaining high-quality approximations of optimal trade-off relationships between conflicting design objectives. The search results obtained from the reduced complexity multi-objective reservoir operation problems are then used to pre-condition the full search of the original optimization problem. In two case studies, the Dahuofang reservoir and the inter-basin multi-reservoir system in Liaoning province, China, sensitivity analysis results show that reservoir performance is strongly controlled by a small proportion of decision variables. Sensitivity-informed dimension reduction and pre-conditioning are evaluated in their ability to improve the efficiency and effectiveness of multi-objective evolutionary optimization. Overall, this study illustrates the efficiency and effectiveness of the sensitivity-informed method and the use of global sensitivity analysis to inform dimension reduction of optimization problems when solving complex multi-objective reservoir operation problems.

Improving multi-objective reservoir operation optimization with sensitivity-informed problem decomposition

NASA Astrophysics Data System (ADS)

Chu, J. G.; Zhang, C.; Fu, G. T.; Li, Y.; Zhou, H. C.

2015-04-01

This study investigates the effectiveness of a sensitivity-informed method for multi-objective operation of reservoir systems, which uses global sensitivity analysis as a screening tool to reduce the computational demands. Sobol's method is used to screen insensitive decision variables and guide the formulation of the optimization problems with a significantly reduced number of decision variables. This sensitivity-informed problem decomposition dramatically reduces the computational demands required for attaining high quality approximations of optimal tradeoff relationships between conflicting design objectives. The search results obtained from the reduced complexity multi-objective reservoir operation problems are then used to pre-condition the full search of the original optimization problem. In two case studies, the Dahuofang reservoir and the inter-basin multi-reservoir system in Liaoning province, China, sensitivity analysis results show that reservoir performance is strongly controlled by a small proportion of decision variables. Sensitivity-informed problem decomposition and pre-conditioning are evaluated in their ability to improve the efficiency and effectiveness of multi-objective evolutionary optimization. Overall, this study illustrates the efficiency and effectiveness of the sensitivity-informed method and the use of global sensitivity analysis to inform problem decomposition when solving the complex multi-objective reservoir operation problems.

Facile route to versatile nanoplatforms for drug delivery by one-pot self-assembly.

PubMed

Zhou, Xing; Che, Ling; Wei, Yanling; Dou, Yin; Chen, Sha; He, Hongmei; Gong, Hao; Li, Xiaohui; Zhang, Jianxiang

2014-06-01

There is still unmet demand for developing powerful approaches to produce polymeric nanoplatforms with versatile functions and broad applications, which are essential for the successful bench-to-bedside translation of polymeric nanotherapeutics developed in the laboratory. We have discovered a facile, convenient, cost-effective and easily scalable one-pot strategy to assemble various lipophilic therapeutics bearing carboxyl groups into nanomedicines, through which highly effective cargo loading and nanoparticle formation can be achieved simultaneously. Besides dramatically improving water solubility, the assembled nanopharmaceuticals showed significantly higher bioavailability and much better therapeutic activity. These one-pot assemblies may also serve as nanocontainers to effectively accommodate other highly hydrophobic drugs such as paclitaxel (PTX). PTX nanomedicines thus formulated display strikingly enhanced in vitro antitumor activity and can reverse the multidrug resistance of tumor cells to PTX therapy. The special surface chemistry offers these assembled entities the additional capability of efficiently packaging and efficaciously transfecting plasmid DNA, with a transfection efficiency markedly higher than that of commonly used positive controls. Consequently, this one-pot assembly approach provides a facile route to multifunctional nanoplatforms for simultaneous delivery of multiple therapeutics with improved therapeutic significance. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Drive cycle simulation of high efficiency combustions on fuel economy and exhaust properties in light-duty vehicles

DOE PAGES

Gao, Zhiming; Curran, Scott J.; Parks, James E.; ...

2015-04-06

We present fuel economy and engine-out emissions for light-duty (LD) conventional and hybrid vehicles powered by conventional and high-efficiency combustion engines. Engine technologies include port fuel-injected (PFI), direct gasoline injection (GDI), reactivity controlled compression ignition (RCCI) and conventional diesel combustion (CDC). In the case of RCCI, the engine utilized CDC combustion at speed/load points not feasible with RCCI. The results, without emissions considered, show that the best fuel economies can be achieved with CDC/RCCI, with CDC/RCCI, CDC-only, and lean GDI all surpassing PFI fuel economy significantly. In all cases, hybridization significantly improved fuel economy. The engine-out hydrocarbon (HC), carbon monoxidemore » (CO), nitrogen oxides (NOx), and particulate matter (PM) emissions varied remarkably with combustion mode. The simulated engine-out CO and HC emissions from RCCI are significantly higher than CDC, but RCCI makes less NOx and PM emissions. Hybridization can improve lean GDI and RCCI cases by increasing time percentage for these more fuel efficient modes. Moreover, hybridization can dramatically decreases the lean GDI and RCCI engine out emissions. Importantly, lean GDI and RCCI combustion modes decrease exhaust temperatures, especially for RCCI, which limits aftertreatment performance to control tailpipe emissions. Overall, the combination of engine and hybrid drivetrain selected greatly affects the emissions challenges required to meet emission regulations.« less

Processing of Cryo-EM Movie Data.

PubMed

Ripstein, Z A; Rubinstein, J L

2016-01-01

Direct detector device (DDD) cameras dramatically enhance the capabilities of electron cryomicroscopy (cryo-EM) due to their improved detective quantum efficiency (DQE) relative to other detectors. DDDs use semiconductor technology that allows micrographs to be recorded as movies rather than integrated individual exposures. Movies from DDDs improve cryo-EM in another, more surprising, way. DDD movies revealed beam-induced specimen movement as a major source of image degradation and provide a way to partially correct the problem by aligning frames or regions of frames to account for this specimen movement. In this chapter, we use a self-consistent mathematical notation to explain, compare, and contrast several of the most popular existing algorithms for computationally correcting specimen movement in DDD movies. We conclude by discussing future developments in algorithms for processing DDD movies that would extend the capabilities of cryo-EM even further. © 2016 Elsevier Inc. All rights reserved.

Deep learning with coherent nanophotonic circuits

NASA Astrophysics Data System (ADS)

Shen, Yichen; Harris, Nicholas C.; Skirlo, Scott; Prabhu, Mihika; Baehr-Jones, Tom; Hochberg, Michael; Sun, Xin; Zhao, Shijie; Larochelle, Hugo; Englund, Dirk; Soljačić, Marin

2017-07-01

Artificial neural networks are computational network models inspired by signal processing in the brain. These models have dramatically improved performance for many machine-learning tasks, including speech and image recognition. However, today's computing hardware is inefficient at implementing neural networks, in large part because much of it was designed for von Neumann computing schemes. Significant effort has been made towards developing electronic architectures tuned to implement artificial neural networks that exhibit improved computational speed and accuracy. Here, we propose a new architecture for a fully optical neural network that, in principle, could offer an enhancement in computational speed and power efficiency over state-of-the-art electronics for conventional inference tasks. We experimentally demonstrate the essential part of the concept using a programmable nanophotonic processor featuring a cascaded array of 56 programmable Mach-Zehnder interferometers in a silicon photonic integrated circuit and show its utility for vowel recognition.

Effect of an Electronic Health Record on the Culture of an Outpatient Medical Oncology Practice in a Four-Hospital Integrated Health Care System: 5-Year Experience

PubMed Central

Brockstein, Bruce; Hensing, Thomas; Carro, George W.; Obel, Jennifer; Khandekar, Janardan; Kaminer, Lynne; Van De Wege, Christine; de Wilton Marsh, Robert

2011-01-01

The electronic health record (EHR) was adopted into the NorthShore University HealthSystem, a four-hospital integrated health system located in suburban Chicago, in 2003. By 2005, all chemotherapy and medicine order entry was conducted through the EHR, completing the incorporation of a fully paperless EHR in our hospital-based oncology practice in both the inpatient and outpatient settings. The use of the EHR has dramatically changed our practice environment by improving efficiency, patient safety, research productivity, and operations, while allowing evaluation of adherence to established quality measures and incorporation of new quality improvement initiatives. The reach of the EHR has been substantial and has influenced every aspect of care at our institution over the short period since its implementation. In this article, we describe subjective and objective measures, outcomes, and achievements of our 5-year EHR experience. PMID:22043197

Navier-Stokes calculations on multi-element airfoils using a chimera-based solver

NASA Technical Reports Server (NTRS)

Jasper, Donald W.; Agrawal, Shreekant; Robinson, Brian A.

1993-01-01

A study of Navier-Stokes calculations of flows about multielement airfoils using a chimera grid approach is presented. The chimera approach utilizes structured, overlapped grids which allow great flexibility of grid arrangement and simplifies grid generation. Calculations are made for two-, three-, and four-element airfoils, and modeling of the effect of gap distance between elements is demonstrated for a two element case. Solutions are obtained using the thin-layer form of the Reynolds averaged Navier-Stokes equations with turbulence closure provided by the Baldwin-Lomax algebraic model or the Baldwin-Barth one equation model. The Baldwin-Barth turbulence model is shown to provide better agreement with experimental data and to dramatically improve convergence rates for some cases. Recently developed, improved farfield boundary conditions are incorporated into the solver for greater efficiency. Computed results show good comparison with experimental data which include aerodynamic forces, surface pressures, and boundary layer velocity profiles.

Observer efficiency in free-localization tasks with correlated noise.

PubMed

Abbey, Craig K; Eckstein, Miguel P

2014-01-01

The efficiency of visual tasks involving localization has traditionally been evaluated using forced choice experiments that capitalize on independence across locations to simplify the performance of the ideal observer. However, developments in ideal observer analysis have shown how an ideal observer can be defined for free-localization tasks, where a target can appear anywhere in a defined search region and subjects respond by localizing the target. Since these tasks are representative of many real-world search tasks, it is of interest to evaluate the efficiency of observer performance in them. The central question of this work is whether humans are able to effectively use the information in a free-localization task relative to a similar task where target location is fixed. We use a yes-no detection task at a cued location as the reference for this comparison. Each of the tasks is evaluated using a Gaussian target profile embedded in four different Gaussian noise backgrounds having power-law noise power spectra with exponents ranging from 0 to 3. The free localization task had a square 6.7° search region. We report on two follow-up studies investigating efficiency in a detect-and-localize task, and the effect of processing the white-noise backgrounds. In the fixed-location detection task, we find average observer efficiency ranges from 35 to 59% for the different noise backgrounds. Observer efficiency improves dramatically in the tasks involving localization, ranging from 63 to 82% in the forced localization tasks and from 78 to 92% in the detect-and- localize tasks. Performance in white noise, the lowest efficiency condition, was improved by filtering to give them a power-law exponent of 2. Classification images, used to examine spatial frequency weights for the tasks, show better tuning to ideal weights in the free-localization tasks. The high absolute levels of efficiency suggest that observers are well-adapted to free-localization tasks.

Observer efficiency in free-localization tasks with correlated noise

PubMed Central

Abbey, Craig K.; Eckstein, Miguel P.

2014-01-01

The efficiency of visual tasks involving localization has traditionally been evaluated using forced choice experiments that capitalize on independence across locations to simplify the performance of the ideal observer. However, developments in ideal observer analysis have shown how an ideal observer can be defined for free-localization tasks, where a target can appear anywhere in a defined search region and subjects respond by localizing the target. Since these tasks are representative of many real-world search tasks, it is of interest to evaluate the efficiency of observer performance in them. The central question of this work is whether humans are able to effectively use the information in a free-localization task relative to a similar task where target location is fixed. We use a yes-no detection task at a cued location as the reference for this comparison. Each of the tasks is evaluated using a Gaussian target profile embedded in four different Gaussian noise backgrounds having power-law noise power spectra with exponents ranging from 0 to 3. The free localization task had a square 6.7° search region. We report on two follow-up studies investigating efficiency in a detect-and-localize task, and the effect of processing the white-noise backgrounds. In the fixed-location detection task, we find average observer efficiency ranges from 35 to 59% for the different noise backgrounds. Observer efficiency improves dramatically in the tasks involving localization, ranging from 63 to 82% in the forced localization tasks and from 78 to 92% in the detect-and- localize tasks. Performance in white noise, the lowest efficiency condition, was improved by filtering to give them a power-law exponent of 2. Classification images, used to examine spatial frequency weights for the tasks, show better tuning to ideal weights in the free-localization tasks. The high absolute levels of efficiency suggest that observers are well-adapted to free-localization tasks. PMID:24817854

An improved state-parameter analysis of ecosystem models using data assimilation

USGS Publications Warehouse

Chen, M.; Liu, S.; Tieszen, L.L.; Hollinger, D.Y.

2008-01-01

Much of the effort spent in developing data assimilation methods for carbon dynamics analysis has focused on estimating optimal values for either model parameters or state variables. The main weakness of estimating parameter values alone (i.e., without considering state variables) is that all errors from input, output, and model structure are attributed to model parameter uncertainties. On the other hand, the accuracy of estimating state variables may be lowered if the temporal evolution of parameter values is not incorporated. This research develops a smoothed ensemble Kalman filter (SEnKF) by combining ensemble Kalman filter with kernel smoothing technique. SEnKF has following characteristics: (1) to estimate simultaneously the model states and parameters through concatenating unknown parameters and state variables into a joint state vector; (2) to mitigate dramatic, sudden changes of parameter values in parameter sampling and parameter evolution process, and control narrowing of parameter variance which results in filter divergence through adjusting smoothing factor in kernel smoothing algorithm; (3) to assimilate recursively data into the model and thus detect possible time variation of parameters; and (4) to address properly various sources of uncertainties stemming from input, output and parameter uncertainties. The SEnKF is tested by assimilating observed fluxes of carbon dioxide and environmental driving factor data from an AmeriFlux forest station located near Howland, Maine, USA, into a partition eddy flux model. Our analysis demonstrates that model parameters, such as light use efficiency, respiration coefficients, minimum and optimum temperatures for photosynthetic activity, and others, are highly constrained by eddy flux data at daily-to-seasonal time scales. The SEnKF stabilizes parameter values quickly regardless of the initial values of the parameters. Potential ecosystem light use efficiency demonstrates a strong seasonality. Results show that the simultaneous parameter estimation procedure significantly improves model predictions. Results also show that the SEnKF can dramatically reduce the variance in state variables stemming from the uncertainty of parameters and driving variables. The SEnKF is a robust and effective algorithm in evaluating and developing ecosystem models and in improving the understanding and quantification of carbon cycle parameters and processes. ?? 2008 Elsevier B.V.

Concerns about irrigation efficiency as an adaptation measure to cope with droughts and climate change in semi-arid basins

NASA Astrophysics Data System (ADS)

Vicuna, S.; Henriquez, L.; Melo, O.

2016-12-01

As expected in the late 1960s, the Paloma reservoir was built in the Limari basin in the semi-arid region in central Chile with the premise that climate conditions of the past, including the recurrence of dry and wet periods, were going to repeat in the future. That was in fact the case for almost 30 years after the reservoir was built. During this period water supplies from the reservoir were reliable and irrigation efficiency was improved with the result of irrigated land in the basin increasing four times especially with high value-permanent-water-consumption crops (fruits, orchards). Since 2003, during a mega-drought that has affected large proportions of central Chile, inflows to the Paloma reservoir have never again equaled or surpassed average historic flows. The refill of the reservoir, an event that happened every 3-4 years has not occurred in the last 13 years. And the capacity of the basin to accommodate to such a drastic reduction in water availability is no longer present because of the already large "efficient" and permanent use of water. The results in terms of agriculture losses and runoff at the outlet of the basin have been dramatic. Some 400 kms. south of the Limari basin, with higher precipitation levels but still in the semi-arid region in Chile is located the Maipo basin home to the 6 million people city of Santiago and around 250,000 has of irrigated land. Irrigation efficiency is also improving in this basin with savings being used mostly to supply drinking water supply shortages via transfer of water rights. Considering costly infrastructure alternatives, adaptation to climate change projections in this basin will likely extend the improvements in irrigation efficiency most likely affecting downstream environmental uses and reducing overall resilience of the basin to cope with droughts.

Learning efficient visual search for stimuli containing diagnostic spatial configurations and color-shape conjunctions.

PubMed

Reavis, Eric A; Frank, Sebastian M; Tse, Peter U

2018-04-12

Visual search is often slow and difficult for complex stimuli such as feature conjunctions. Search efficiency, however, can improve with training. Search for stimuli that can be identified by the spatial configuration of two elements (e.g., the relative position of two colored shapes) improves dramatically within a few hundred trials of practice. Several recent imaging studies have identified neural correlates of this learning, but it remains unclear what stimulus properties participants learn to use to search efficiently. Influential models, such as reverse hierarchy theory, propose two major possibilities: learning to use information contained in low-level image statistics (e.g., single features at particular retinotopic locations) or in high-level characteristics (e.g., feature conjunctions) of the task-relevant stimuli. In a series of experiments, we tested these two hypotheses, which make different predictions about the effect of various stimulus manipulations after training. We find relatively small effects of manipulating low-level properties of the stimuli (e.g., changing their retinotopic location) and some conjunctive properties (e.g., color-position), whereas the effects of manipulating other conjunctive properties (e.g., color-shape) are larger. Overall, the findings suggest conjunction learning involving such stimuli might be an emergent phenomenon that reflects multiple different learning processes, each of which capitalizes on different types of information contained in the stimuli. We also show that both targets and distractors are learned, and that reversing learned target and distractor identities impairs performance. This suggests that participants do not merely learn to discriminate target and distractor stimuli, they also learn stimulus identity mappings that contribute to performance improvements.

Redirecting intracellular trafficking and the secretion pattern of FSH dramatically enhances ovarian function in mice.

PubMed

Wang, Huizhen; Larson, Melissa; Jablonka-Shariff, Albina; Pearl, Christopher A; Miller, William L; Conn, P Michael; Boime, Irving; Kumar, T Rajendra

2014-04-15

FSH and luteinizing hormone (LH) are secreted constitutively or in pulses, respectively, from pituitary gonadotropes in many vertebrates, and regulate ovarian function. The molecular basis for this evolutionarily conserved gonadotropin-specific secretion pattern is not understood. Here, we show that the carboxyterminal heptapeptide in LH is a gonadotropin-sorting determinant in vivo that directs pulsatile secretion. FSH containing this heptapeptide enters the regulated pathway in gonadotropes of transgenic mice, and is released in response to gonadotropin-releasing hormone, similar to LH. FSH released from the LH secretory pathway rescued ovarian defects in Fshb-null mice as efficiently as constitutively secreted FSH. Interestingly, the rerouted FSH enhanced ovarian follicle survival, caused a dramatic increase in number of ovulations, and prolonged female reproductive lifespan. Furthermore, the rerouted FSH vastly improved the in vivo fertilization competency of eggs, their subsequent development in vitro and when transplanted, the ability to produce offspring. Our study demonstrates the feasibility to fine-tune the target tissue responses by modifying the intracellular trafficking and secretory fate of a pituitary trophic hormone. The approach to interconvert the secretory fate of proteins in vivo has pathophysiological significance, and could explain the etiology of several hormone hyperstimulation and resistance syndromes.

Meshfree and efficient modeling of swimming cells

NASA Astrophysics Data System (ADS)

Gallagher, Meurig T.; Smith, David J.

2018-05-01

Locomotion in Stokes flow is an intensively studied problem because it describes important biological phenomena such as the motility of many species' sperm, bacteria, algae, and protozoa. Numerical computations can be challenging, particularly in three dimensions, due to the presence of moving boundaries and complex geometries; methods which combine ease of implementation and computational efficiency are therefore needed. A recently proposed method to discretize the regularized Stokeslet boundary integral equation without the need for a connected mesh is applied to the inertialess locomotion problem in Stokes flow. The mathematical formulation and key aspects of the computational implementation in matlab® or GNU Octave are described, followed by numerical experiments with biflagellate algae and multiple uniflagellate sperm swimming between no-slip surfaces, for which both swimming trajectories and flow fields are calculated. These computational experiments required minutes of time on modest hardware; an extensible implementation is provided in a GitHub repository. The nearest-neighbor discretization dramatically improves convergence and robustness, a key challenge in extending the regularized Stokeslet method to complicated three-dimensional biological fluid problems.

pyRMSD: a Python package for efficient pairwise RMSD matrix calculation and handling.

PubMed

Gil, Víctor A; Guallar, Víctor

2013-09-15

We introduce pyRMSD, an open source standalone Python package that aims at offering an integrative and efficient way of performing Root Mean Square Deviation (RMSD)-related calculations of large sets of structures. It is specially tuned to do fast collective RMSD calculations, as pairwise RMSD matrices, implementing up to three well-known superposition algorithms. pyRMSD provides its own symmetric distance matrix class that, besides the fact that it can be used as a regular matrix, helps to save memory and increases memory access speed. This last feature can dramatically improve the overall performance of any Python algorithm using it. In addition, its extensibility, testing suites and documentation make it a good choice to those in need of a workbench for developing or testing new algorithms. The source code (under MIT license), installer, test suites and benchmarks can be found at https://pele.bsc.es/ under the tools section. victor.guallar@bsc.es Supplementary data are available at Bioinformatics online.

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

Kim, Sun -Ki; Chung, Daehwan; Himmel, Michael E.

Here, CelA is the most abundant enzyme secreted by Caldicellulosiruptor bescii and has been shown to outperform mixtures of commercially available exo- and endoglucanases in vitro. CelA contains both a glycoside hydrolase family 9 endoglucanase and a glycoside hydrolase family 48 exoglucanase known to be synergistic in their activity, connected by three cellulose-binding domains via linker peptides. Here, repeated aspartate residues were introduced into the N-terminal ends of CelA GH9 and GH48 domains to improve secretion efficiency and/or catalytic efficiency of CelA. Among several constructs, the highest activity on carboxymethylcellulose (CMC), 0.81 ± 0.03 mg/mL was observed for the C.more » bescii strain containing CelA with 5-aspartate tag at the N-terminal end of GH9 domain – an 82% increase over wild type CelA. In addition, Expression of CelA with N-terminal repeated aspartate residues in C. bescii results in a dramatic increase in its ability to grow on Avicel.« less

Surface Plasmon Resonance Effect in Inverted Perovskite Solar Cells.

PubMed

Cui, Jin; Chen, Cheng; Han, Junbo; Cao, Kun; Zhang, Wenjun; Shen, Yan; Wang, Mingkui

2016-03-01

This work reports on incorporation of spectrally tuned gold/silica (Au/SiO 2 ) core/shell nanospheres and nanorods into the inverted perovskite solar cells (PVSC). The band gap of hybrid lead halide iodide (CH 3 NH 3 PbI 3 ) can be gradually increased by replacing iodide with increasing amounts of bromide, which can not only offer an appreciate solar radiation window for the surface plasmon resonance effect utilization, but also potentially result in a large open circuit voltage. The introduction of localized surface plasmons in CH 3 NH 3 PbI 2.85 Br 0.15 -based photovoltaic system, which occur in response to electromagnetic radiation, has shown dramatic enhancement of exciton dissociation. The synchronized improvement in photovoltage and photocurrent leads to an inverted CH 3 NH 3 PbI 2.85 Br 0.15 planar PVSC device with power conversion efficiency of 13.7%. The spectral response characterization, time resolved photoluminescence, and transient photovoltage decay measurements highlight the efficient and simple method for perovskite devices.

A 7T Spine Array Based on Electric Dipole Transmitters

PubMed Central

Duan, Qi; Nair, Govind; Gudino, Natalia; de Zwart, Jacco A.; van Gelderen, Peter; Murphy-Boesch, Joe; Reich, Daniel S.; Duyn, Jeff H.; Merkle, Hellmut

2015-01-01

Purpose In this work the feasibility of using an array of electric dipole antennas for RF transmission in spine MRI at high field is explored. Method A 2-channel transmit array based on an electric dipole design was quantitatively optimized for 7T spine imaging and integrated with a receive array combining 8 loop coils. Using B1+ mapping, the transmit efficiency of the dipole array was compared to a design using quadrature loop pairs. The radio-frequency (RF) energy deposition for each array was measured using a home-built dielectric phantom and MR thermometry. The performance of the proposed array was qualitatively demonstrated in human studies. Results The results indicate dramatically improved transmit efficiency for the dipole design as compared to the loop excitation. Up to 76% gain was achieved within the spinal region. Conclusion For imaging of the spine, electric-dipole based transmitters provided an attractive alternative to the traditional loop-based design. Easy integration with existing receive array technology facilitates practical use at high field. PMID:26190585

Sandwiched confinement of quantum dots in graphene matrix for efficient electron transfer and photocurrent production

PubMed Central

Zhu, Nan; Zheng, Kaibo; Karki, Khadga J.; Abdellah, Mohamed; Zhu, Qiushi; Carlson, Stefan; Haase, Dörthe; Žídek, Karel; Ulstrup, Jens; Canton, Sophie E.; Pullerits, Tõnu; Chi, Qijin

2015-01-01

Quantum dots (QDs) and graphene are both promising materials for the development of new-generation optoelectronic devices. Towards this end, synergic assembly of these two building blocks is a key step but remains a challenge. Here, we show a one-step strategy for organizing QDs in a graphene matrix via interfacial self-assembly, leading to the formation of sandwiched hybrid QD-graphene nanofilms. We have explored structural features, electron transfer kinetics and photocurrent generation capacity of such hybrid nanofilms using a wide variety of advanced techniques. Graphene nanosheets interlink QDs and significantly improve electronic coupling, resulting in fast electron transfer from photoexcited QDs to graphene with a rate constant of 1.3 × 109 s−1. Efficient electron transfer dramatically enhances photocurrent generation in a liquid-junction QD-sensitized solar cell where the hybrid nanofilm acts as a photoanode. We thereby demonstrate a cost-effective method to construct large-area QD-graphene hybrid nanofilms with straightforward scale-up potential for optoelectronic applications. PMID:25996307

Visual saliency-based fast intracoding algorithm for high efficiency video coding

NASA Astrophysics Data System (ADS)

Zhou, Xin; Shi, Guangming; Zhou, Wei; Duan, Zhemin

2017-01-01

Intraprediction has been significantly improved in high efficiency video coding over H.264/AVC with quad-tree-based coding unit (CU) structure from size 64×64 to 8×8 and more prediction modes. However, these techniques cause a dramatic increase in computational complexity. An intracoding algorithm is proposed that consists of perceptual fast CU size decision algorithm and fast intraprediction mode decision algorithm. First, based on the visual saliency detection, an adaptive and fast CU size decision method is proposed to alleviate intraencoding complexity. Furthermore, a fast intraprediction mode decision algorithm with step halving rough mode decision method and early modes pruning algorithm is presented to selectively check the potential modes and effectively reduce the complexity of computation. Experimental results show that our proposed fast method reduces the computational complexity of the current HM to about 57% in encoding time with only 0.37% increases in BD rate. Meanwhile, the proposed fast algorithm has reasonable peak signal-to-noise ratio losses and nearly the same subjective perceptual quality.

Carbon dot/polyvinylpyrrolidone hybrid nanofibers with efficient solid-state photoluminescence constructed using an electrospinning technique

NASA Astrophysics Data System (ADS)

Zhai, Yue; Bai, Xue; Cui, Haining; Zhu, Jinyang; Liu, Wei; Zhang, Tianxiang; Dong, Biao; Pan, Gencai; Xu, Lin; Zhang, Shuang; Song, Hongwei

2018-01-01

Carbon dots (CDs) are the promising candidates for application in optoelectronic and biological areas due to their excellent photostability, unique photoluminescence, good biocompatibility, low toxicity and chemical inertness. However, the self-quenching of photoluminescence as they are dried into the solid state dramatically limits their further application. Therefore, realizing efficient photoluminescence and large-scale production of CDs in the solid state is an urgent challenge. Herein, solid-state hybrid nanofibers based on CDs and polyvinylpyrrolidone (PVP) are constructed through an electrospinning process. The resulting solid-state hybrid PVP/CD nanofibers present much enhanced photoluminescence performance compared to the corresponding pristine colloidal CDs due to the decrease in non-radiative recombination of electron-holes. Owing to the suppressed self-quenching of CDs, the photoluminescence quantum yield is considerably improved from 42.9% of pristine CDs to 83.5% of nanofibers under the excitation wavelength of 360 nm. This has great application potential in optical or optoelectronic devices.

Solution of nonlinear time-dependent PDEs through componentwise approximation of matrix functions

NASA Astrophysics Data System (ADS)

Cibotarica, Alexandru; Lambers, James V.; Palchak, Elisabeth M.

2016-09-01

Exponential propagation iterative (EPI) methods provide an efficient approach to the solution of large stiff systems of ODEs, compared to standard integrators. However, the bulk of the computational effort in these methods is due to products of matrix functions and vectors, which can become very costly at high resolution due to an increase in the number of Krylov projection steps needed to maintain accuracy. In this paper, it is proposed to modify EPI methods by using Krylov subspace spectral (KSS) methods, instead of standard Krylov projection methods, to compute products of matrix functions and vectors. Numerical experiments demonstrate that this modification causes the number of Krylov projection steps to become bounded independently of the grid size, thus dramatically improving efficiency and scalability. As a result, for each test problem featured, as the total number of grid points increases, the growth in computation time is just below linear, while other methods achieved this only on selected test problems or not at all.

Sandwiched confinement of quantum dots in graphene matrix for efficient electron transfer and photocurrent production

NASA Astrophysics Data System (ADS)

Zhu, Nan; Zheng, Kaibo; Karki, Khadga J.; Abdellah, Mohamed; Zhu, Qiushi; Carlson, Stefan; Haase, Dörthe; Žídek, Karel; Ulstrup, Jens; Canton, Sophie E.; Pullerits, Tõnu; Chi, Qijin

2015-05-01

Quantum dots (QDs) and graphene are both promising materials for the development of new-generation optoelectronic devices. Towards this end, synergic assembly of these two building blocks is a key step but remains a challenge. Here, we show a one-step strategy for organizing QDs in a graphene matrix via interfacial self-assembly, leading to the formation of sandwiched hybrid QD-graphene nanofilms. We have explored structural features, electron transfer kinetics and photocurrent generation capacity of such hybrid nanofilms using a wide variety of advanced techniques. Graphene nanosheets interlink QDs and significantly improve electronic coupling, resulting in fast electron transfer from photoexcited QDs to graphene with a rate constant of 1.3 × 109 s-1. Efficient electron transfer dramatically enhances photocurrent generation in a liquid-junction QD-sensitized solar cell where the hybrid nanofilm acts as a photoanode. We thereby demonstrate a cost-effective method to construct large-area QD-graphene hybrid nanofilms with straightforward scale-up potential for optoelectronic applications.

A non-covalent peptide-based carrier for in vivo delivery of DNA mimics.

PubMed

Morris, May C; Gros, Edwige; Aldrian-Herrada, Gudrun; Choob, Michael; Archdeacon, John; Heitz, Frederic; Divita, Gilles

2007-01-01

The dramatic acceleration in identification of new nucleic-acid-based therapeutic molecules has provided new perspectives in pharmaceutical research. However, their development is limited by their poor cellular uptake and inefficient trafficking. Here we describe a short amphipathic peptide, Pep-3, that combines a tryptophan/phenylalanine domain with a lysine/arginine-rich hydrophilic motif. Pep-3 forms stable nano-size complexes with peptide-nucleic acid analogues and promotes their efficient delivery into a wide variety of cell lines, including primary and suspension lines, without any associated cytotoxicity. We demonstrate that Pep-3-mediated delivery of antisense-cyclin B1-charged-PNA blocks tumour growth in vivo upon intratumoral and intravenous injection. Moreover, we show that PEGylation of Pep-3 significantly improves complex stability in vivo and consequently the efficiency of antisense cyclin B1 administered intravenously. Given the biological characteristics of these vectors, we believe that peptide-based delivery technologies hold a true promise for therapeutic applications of DNA mimics.

A non-covalent peptide-based carrier for in vivo delivery of DNA mimics

PubMed Central

Morris, May C.; Gros, Edwige; Aldrian-Herrada, Gudrun; Choob, Michael; Archdeacon, John; Heitz, Frederic; Divita, Gilles

2007-01-01

The dramatic acceleration in identification of new nucleic-acid-based therapeutic molecules has provided new perspectives in pharmaceutical research. However, their development is limited by their poor cellular uptake and inefficient trafficking. Here we describe a short amphipathic peptide, Pep-3, that combines a tryptophan/phenylalanine domain with a lysine/arginine-rich hydrophilic motif. Pep-3 forms stable nano-size complexes with peptide-nucleic acid analogues and promotes their efficient delivery into a wide variety of cell lines, including primary and suspension lines, without any associated cytotoxicity. We demonstrate that Pep-3-mediated delivery of antisense-cyclin B1-charged-PNA blocks tumour growth in vivo upon intratumoral and intravenous injection. Moreover, we show that PEGylation of Pep-3 significantly improves complex stability in vivo and consequently the efficiency of antisense cyclin B1 administered intravenously. Given the biological characteristics of these vectors, we believe that peptide-based delivery technologies hold a true promise for therapeutic applications of DNA mimics. PMID:17341467

Effect of inner guide on performances of cross flow turbine

NASA Astrophysics Data System (ADS)

Kokubu, K.; Yamasaki, K.; Honda, H.; Kanemoto, T.

2012-11-01

To get the sustainable society, the hydropower with not only the large but also the mini/micro capacity has been paid attention to the power generation. The cross-flow turbines can work efficiently at the comparatively low head and/or low discharge in the onshore and the offshore, and the runner and the casing profiles have been optimizing. In this paper, the turbine composed of the optimal profiles has prepared to provide for the mini/micro hydropower, and the performances have been investigated at the low head. The hydraulic efficiency is maximal at the normal guide vane opening and deteriorates at the lower and the higher discharge than the normal discharge. Such deteriorations are brought from the unacceptable flow conditions crossing in the runner, that is, the flow direction does not meet the setting angle of the blade at the inner radius. To improve dramatically the performances, the inner guide, which guards the shaft from the water jet and adjusts the flow direction, was installed in the runner.

Enhancing Cell Nucleus Accumulation and DNA Cleavage Activity of Anti-Cancer Drug via Graphene Quantum Dots

NASA Astrophysics Data System (ADS)

Wang, Chong; Wu, Congyu; Zhou, Xuejiao; Han, Ting; Xin, Xiaozhen; Wu, Jiaying; Zhang, Jingyan; Guo, Shouwu

2013-10-01

Graphene quantum dots (GQDs) maintain the intrinsic layered structural motif of graphene but with smaller lateral size and abundant periphery carboxylic groups, and are more compatible with biological system, thus are promising nanomaterials for therapeutic applications. Here we show that GQDs have a superb ability in drug delivery and anti-cancer activity boost without any pre-modification due to their unique structural properties. They could efficiently deliver doxorubicin (DOX) to the nucleus through DOX/GQD conjugates, because the conjugates assume different cellular and nuclear internalization pathways comparing to free DOX. Also, the conjugates could enhance DNA cleavage activity of DOX markedly. This enhancement combining with efficient nuclear delivery improved cytotoxicity of DOX dramatically. Furthermore, the DOX/GQD conjugates could also increase the nuclear uptake and cytotoxicity of DOX to drug-resistant cancer cells indicating that the conjugates may be capable to increase chemotherapy efficacy of anti-cancer drugs that are suboptimal due to the drug resistance.

Increasing magnetite contents of polymeric magnetic particles dramatically improves labeling of neural stem cell transplant populations.

PubMed

Adams, Christopher F; Rai, Ahmad; Sneddon, Gregor; Yiu, Humphrey H P; Polyak, Boris; Chari, Divya M

2015-01-01

Safe and efficient delivery of therapeutic cells to sites of injury/disease in the central nervous system is a key goal for the translation of clinical cell transplantation therapies. Recently, 'magnetic cell localization strategies' have emerged as a promising and safe approach for targeted delivery of magnetic particle (MP) labeled stem cells to pathology sites. For neuroregenerative applications, this approach is limited by the lack of available neurocompatible MPs, and low cell labeling achieved in neural stem/precursor populations. We demonstrate that high magnetite content, self-sedimenting polymeric MPs [unfunctionalized poly(lactic acid) coated, without a transfecting component] achieve efficient labeling (≥90%) of primary neural stem cells (NSCs)-a 'hard-to-label' transplant population of major clinical relevance. Our protocols showed high safety with respect to key stem cell regenerative parameters. Critically, labeled cells were effectively localized in an in vitro flow system by magnetic force highlighting the translational potential of the methods used. Copyright © 2015 Elsevier Inc. All rights reserved.

Land and Resource Management Issues Relevant to Deploying In-Situ Thermal Technologies

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

Keiter, Robert; Ruple, John; Tanana, Heather

2011-01-01

Utah is home to oil shale resources containing roughly 1.3 trillion barrels of oil equivalent and our nation’s richest oil sands resources. If economically feasible and environmentally responsible means of tapping these resources can be developed, these resources could provide a safe and stable domestic energy source for decades to come. In Utah, oil shale and oil sands resources underlay a patchwork of federal, state, private, and tribal lands that are subject to different regulatory schemes and conflicting management objectives. Evaluating the development potential of Utah’s oil shale and oil sands resources requires an understanding of jurisdictional issues and themore » challenges they present to deployment and efficient utilization of emerging technologies. The jurisdictional patchwork and divergent management requirements inhibit efficient, economic, and environmentally sustainable development. This report examines these barriers to resource development, methods of obtaining access to landlocked resources, and options for consolidating resource ownership. This report also examines recent legislative efforts to wrest control of western public lands from the federal government. If successful, these efforts could dramatically reshape resource control and access, though these efforts appear to fall far short of their stated goals. The unintended consequences of adversarial approaches to obtaining resource access may outweigh their benefits, hardening positions and increasing tensions to the detriment of overall coordination between resource managers. Federal land exchanges represent a more efficient and mutually beneficial means of consolidating management control and improving management efficiency. Independent of exchange proposals, resource managers must improve coordination, moving beyond mere consultation with neighboring landowners and sister agencies to coordinating actions with them.« less

Phenformin-Induced Mitochondrial Dysfunction Sensitizes Hepatocellular Carcinoma for Dual Inhibition of mTOR.

PubMed

Veiga, Sonia Rosa; Ge, Xuemei; Mercer, Carol A; Hernández-Alvarez, María Isabel; Thomas, Hala Elnakat; Hernández-Losa, Javier; Ramón Y Cajal, Santiago; Zorzano, Antonio; Thomas, George; Kozma, Sara C

2018-04-24

Hepatocellular carcinoma (HCC) ranks second in cancer mortality and has limited therapeutic options. We recently described the synergistic effect of allosteric and ATP-site competitive inhibitors against the mammalian target of rapamycin (mTOR) for the treatment of HCC. However, such inhibitors induce glycemia and increase mitochondrial efficiency. Here we determined whether the mitochondrial complex I inhibitor Phenformin could reverse both side effects, impose an energetic-stress on cancer cells and suppress the growth of HCC. Human HCC cell lines were used in vitro to access the signaling and energetic impact of mTOR inhibitors and Phenformin, either alone or in combination. Next, the therapeutic utility of these drugs alone or in combination was investigated pre-clinically in human orthotopic tumors implanted in mice, by analyzing their impact on the tumor burden and overall survival. We found Phenformin caused mitochondrial dysfunction and fragmentation, inducing a compensatory shift to glycolysis. In contrast, dual inhibition of mTOR impaired cell growth and glycolysis, while increasing mitochondrial fusion and efficiency. In a mouse model of human HCC, dual inhibition of mTOR, together with Phenformin, was highly efficacious in controlling tumor burden. However, more striking, pretreatment with Phenformin sensitized tumors to dual inhibition of mTOR, leading to a dramatic improvement in survival. Treatment of HCC cells in vitro with the biguanide Phenformin causes a metabolic shift to glycolysis, mitochondrial dysfunction and fragmentation, and dramatically sensitizes orthotopic liver tumors to dual inhibition of mTOR. We therefore propose this therapeutic approach should be tested clinically in HCC. Copyright ©2018, American Association for Cancer Research.

The potential for modification in cloning and vitrification technology to enhance genetic progress in beef cattle in Northern Australia.

PubMed

Taylor-Robinson, Andrew W; Walton, Simon; Swain, David L; Walsh, Kerry B; Vajta, Gábor

2014-08-01

Recent advances in embryology and related research offer considerable possibilities to accelerate genetic improvement in cattle breeding. Such progress includes optimization and standardization of laboratory embryo production (in vitro fertilization - IVF), introduction of a highly efficient method for cryopreservation (vitrification), and dramatic improvement in the efficiency of somatic cell nuclear transfer (cloning) in terms of required effort, cost, and overall outcome. Handmade cloning (HMC), a simplified version of somatic cell nuclear transfer, offers the potential for relatively easy and low-cost production of clones. A potentially modified method of vitrification used at a centrally located laboratory facility could result in cloned offspring that are economically competitive with elite animals produced by more traditional means. Apart from routine legal and intellectual property issues, the main obstacle that hampers rapid uptake of these technologies by the beef cattle industry is a lack of confidence from scientific and commercial sources. Once stakeholder support is increased, the combined application of these methods makes a rapid advance toward desirable traits (rapid growth, high-quality beef, optimized reproductive performance) a realistic goal. The potential impact of these technologies on genetic advancement in beef cattle herds in which improvement of stock is sought, such as in northern Australia, is hard to overestimate. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Enhancing ecosystem restoration efficiency through spatial and temporal coordination.

PubMed

Neeson, Thomas M; Ferris, Michael C; Diebel, Matthew W; Doran, Patrick J; O'Hanley, Jesse R; McIntyre, Peter B

2015-05-12

In many large ecosystems, conservation projects are selected by a diverse set of actors operating independently at spatial scales ranging from local to international. Although small-scale decision making can leverage local expert knowledge, it also may be an inefficient means of achieving large-scale objectives if piecemeal efforts are poorly coordinated. Here, we assess the value of coordinating efforts in both space and time to maximize the restoration of aquatic ecosystem connectivity. Habitat fragmentation is a leading driver of declining biodiversity and ecosystem services in rivers worldwide, and we simultaneously evaluate optimal barrier removal strategies for 661 tributary rivers of the Laurentian Great Lakes, which are fragmented by at least 6,692 dams and 232,068 road crossings. We find that coordinating barrier removals across the entire basin is nine times more efficient at reconnecting fish to headwater breeding grounds than optimizing independently for each watershed. Similarly, a one-time pulse of restoration investment is up to 10 times more efficient than annual allocations totaling the same amount. Despite widespread emphasis on dams as key barriers in river networks, improving road culvert passability is also essential for efficiently restoring connectivity to the Great Lakes. Our results highlight the dramatic economic and ecological advantages of coordinating efforts in both space and time during restoration of large ecosystems.

Conservation of quantum efficiency in quantum well intermixing by stress engineering with dielectric bilayers

NASA Astrophysics Data System (ADS)

Arslan, Seval; Demir, Abdullah; Şahin, Seval; Aydınlı, Atilla

2018-02-01

In semiconductor lasers, quantum well intermixing (QWI) with high selectivity using dielectrics often results in lower quantum efficiency. In this paper, we report on an investigation regarding the effect of thermally induced dielectric stress on the quantum efficiency of quantum well structures in impurity-free vacancy disordering (IFVD) process using photoluminescence and device characterization in conjunction with microscopy. SiO2 and Si x O2/SrF2 (versus SrF2) films were employed for the enhancement and suppression of QWI, respectively. Large intermixing selectivity of 75 nm (125 meV), consistent with the theoretical modeling results, with negligible effect on the suppression region characteristics, was obtained. Si x O2 layer compensates for the large thermal expansion coefficient mismatch of SrF2 with the semiconductor and mitigates the detrimental effects of SrF2 without sacrificing its QWI benefits. The bilayer dielectric approach dramatically improved the dielectric-semiconductor interface quality. Fabricated high power semiconductor lasers demonstrated high quantum efficiency in the lasing region using the bilayer dielectric film during the intermixing process. Our results reveal that stress engineering in IFVD is essential and the thermal stress can be controlled by engineering the dielectric strain opening new perspectives for QWI of photonic devices.

High throughput sequencing analysis of RNA libraries reveals the influences of initial library and PCR methods on SELEX efficiency.

PubMed

Takahashi, Mayumi; Wu, Xiwei; Ho, Michelle; Chomchan, Pritsana; Rossi, John J; Burnett, John C; Zhou, Jiehua

2016-09-22

The systemic evolution of ligands by exponential enrichment (SELEX) technique is a powerful and effective aptamer-selection procedure. However, modifications to the process can dramatically improve selection efficiency and aptamer performance. For example, droplet digital PCR (ddPCR) has been recently incorporated into SELEX selection protocols to putatively reduce the propagation of byproducts and avoid selection bias that result from differences in PCR efficiency of sequences within the random library. However, a detailed, parallel comparison of the efficacy of conventional solution PCR versus the ddPCR modification in the RNA aptamer-selection process is needed to understand effects on overall SELEX performance. In the present study, we took advantage of powerful high throughput sequencing technology and bioinformatics analysis coupled with SELEX (HT-SELEX) to thoroughly investigate the effects of initial library and PCR methods in the RNA aptamer identification. Our analysis revealed that distinct "biased sequences" and nucleotide composition existed in the initial, unselected libraries purchased from two different manufacturers and that the fate of the "biased sequences" was target-dependent during selection. Our comparison of solution PCR- and ddPCR-driven HT-SELEX demonstrated that PCR method affected not only the nucleotide composition of the enriched sequences, but also the overall SELEX efficiency and aptamer efficacy.

Efficient Cargo Delivery into Adult Brain Tissue Using Short Cell-Penetrating Peptides.

PubMed

Kizil, Caghan; Iltzsche, Anne; Thomas, Alvin Kuriakose; Bhattarai, Prabesh; Zhang, Yixin; Brand, Michael

2015-01-01

Zebrafish brains can regenerate lost neurons upon neurogenic activity of the radial glial progenitor cells (RGCs) that reside at the ventricular region. Understanding the molecular events underlying this ability is of great interest for translational studies of regenerative medicine. Therefore, functional analyses of gene function in RGCs and neurons are essential. Using cerebroventricular microinjection (CVMI), RGCs can be targeted efficiently but the penetration capacity of the injected molecules reduces dramatically in deeper parts of the brain tissue, such as the parenchymal regions that contain the neurons. In this report, we tested the penetration efficiency of five known cell-penetrating peptides (CPPs) and identified two- polyR and Trans - that efficiently penetrate the brain tissue without overt toxicity in a dose-dependent manner as determined by TUNEL staining and L-Plastin immunohistochemistry. We also found that polyR peptide can help carry plasmid DNA several cell diameters into the brain tissue after a series of coupling reactions using DBCO-PEG4-maleimide-based Michael's addition and azide-mediated copper-free click reaction. Combined with the advantages of CVMI, such as rapidness, reproducibility, and ability to be used in adult animals, CPPs improve the applicability of the CVMI technique to deeper parts of the central nervous system tissues.

High throughput sequencing analysis of RNA libraries reveals the influences of initial library and PCR methods on SELEX efficiency

PubMed Central

Takahashi, Mayumi; Wu, Xiwei; Ho, Michelle; Chomchan, Pritsana; Rossi, John J.; Burnett, John C.; Zhou, Jiehua

2016-01-01

The systemic evolution of ligands by exponential enrichment (SELEX) technique is a powerful and effective aptamer-selection procedure. However, modifications to the process can dramatically improve selection efficiency and aptamer performance. For example, droplet digital PCR (ddPCR) has been recently incorporated into SELEX selection protocols to putatively reduce the propagation of byproducts and avoid selection bias that result from differences in PCR efficiency of sequences within the random library. However, a detailed, parallel comparison of the efficacy of conventional solution PCR versus the ddPCR modification in the RNA aptamer-selection process is needed to understand effects on overall SELEX performance. In the present study, we took advantage of powerful high throughput sequencing technology and bioinformatics analysis coupled with SELEX (HT-SELEX) to thoroughly investigate the effects of initial library and PCR methods in the RNA aptamer identification. Our analysis revealed that distinct “biased sequences” and nucleotide composition existed in the initial, unselected libraries purchased from two different manufacturers and that the fate of the “biased sequences” was target-dependent during selection. Our comparison of solution PCR- and ddPCR-driven HT-SELEX demonstrated that PCR method affected not only the nucleotide composition of the enriched sequences, but also the overall SELEX efficiency and aptamer efficacy. PMID:27652575

Low-Energy Ions Injection and Acceleration at Oblique Shocks with Focused Transport Model

NASA Astrophysics Data System (ADS)

Zuo, P.; Zhang, M.; Feng, X. S.

2017-12-01

There is strong evidence that a small portion of suprathermal particles from hot coronal material or remnants of previous solar energetic particle (SEP) events serve as the source of large SEP events. Here we present a test particle simulation on the injection and acceleration of low-energy suprathermal particles by Laminar nonrelativistic oblique shocks in the framework of the focused transport theory, which is proved to contain all necessary physics of shock acceleration, but avoid the limitation of diffusive shock acceleration (DSA). We first characterize the role of cross-shock potential (CSP) on pickup ions (PUIs) acceleration. The CSP can affect the shape of the spectrum segment at lower energies, but it does not change the spectral index of the final power-law spectrum at high energies. It is found that a stronger CSP jump results in a dramatically improved injection efficiency. Our simulation results also show that the injection efficiency of PUIs is mass-dependent, which is lower for species with a higher mass. The injection efficiency as the function of Mach number, obliquity, injection speed, and shock strength is also calculated. It can be proved that the focused transport theory is an extension of DSA theory with the capability of predicting the efficiency of source particle injection.

Enhancing ecosystem restoration efficiency through spatial and temporal coordination

PubMed Central

Neeson, Thomas M.; Ferris, Michael C.; Diebel, Matthew W.; Doran, Patrick J.; O’Hanley, Jesse R.; McIntyre, Peter B.

2015-01-01

In many large ecosystems, conservation projects are selected by a diverse set of actors operating independently at spatial scales ranging from local to international. Although small-scale decision making can leverage local expert knowledge, it also may be an inefficient means of achieving large-scale objectives if piecemeal efforts are poorly coordinated. Here, we assess the value of coordinating efforts in both space and time to maximize the restoration of aquatic ecosystem connectivity. Habitat fragmentation is a leading driver of declining biodiversity and ecosystem services in rivers worldwide, and we simultaneously evaluate optimal barrier removal strategies for 661 tributary rivers of the Laurentian Great Lakes, which are fragmented by at least 6,692 dams and 232,068 road crossings. We find that coordinating barrier removals across the entire basin is nine times more efficient at reconnecting fish to headwater breeding grounds than optimizing independently for each watershed. Similarly, a one-time pulse of restoration investment is up to 10 times more efficient than annual allocations totaling the same amount. Despite widespread emphasis on dams as key barriers in river networks, improving road culvert passability is also essential for efficiently restoring connectivity to the Great Lakes. Our results highlight the dramatic economic and ecological advantages of coordinating efforts in both space and time during restoration of large ecosystems. PMID:25918378

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

Barroo, Cedric; Janvelyan, Nare; Zugic, Branko

To improve the understanding of catalytic processes, the surface structure and composition of the active materials need to be determined before and after reaction. Morphological changes may occur under reaction conditions and can dramatically influence the reactivity and/or selectivity of a catalyst. Goldbased catalysts with different architectures are currently being developed for selective oxidation reactions at low temperatures. Specifically, nanoporous Au (npAu) with a composition of Au 97-Ag 3 is obtained by dealloying a Ag 70-Au 30 bulk alloy. Recent studies highlight the efficiency of npAu catalysts for methanol oxidation using ozone to activate the catalysts before methanol oxidation. Inmore » this paper, we studied the morphological and compositional changes occurring at the surface of Au-based catalysts in certain conditions.« less

A continuum theory for multicomponent chromatography modeling.

PubMed

Pfister, David; Morbidelli, Massimo; Nicoud, Roger-Marc

2016-05-13

A continuum theory is proposed for modeling multicomponent chromatographic systems under linear conditions. The model is based on the description of complex mixtures, possibly involving tens or hundreds of solutes, by a continuum. The present approach is shown to be very efficient when dealing with a large number of similar components presenting close elution behaviors and whose individual analytical characterization is impossible. Moreover, approximating complex mixtures by continuous distributions of solutes reduces the required number of model parameters to the few ones specific to the characterization of the selected continuous distributions. Therefore, in the frame of the continuum theory, the simulation of large multicomponent systems gets simplified and the computational effectiveness of the chromatographic model is thus dramatically improved. Copyright © 2016 Elsevier B.V. All rights reserved.

Monte Carlo Sampling in Fractal Landscapes

NASA Astrophysics Data System (ADS)

Leitão, Jorge C.; Lopes, J. M. Viana Parente; Altmann, Eduardo G.

2013-05-01

We design a random walk to explore fractal landscapes such as those describing chaotic transients in dynamical systems. We show that the random walk moves efficiently only when its step length depends on the height of the landscape via the largest Lyapunov exponent of the chaotic system. We propose a generalization of the Wang-Landau algorithm which constructs not only the density of states (transient time distribution) but also the correct step length. As a result, we obtain a flat-histogram Monte Carlo method which samples fractal landscapes in polynomial time, a dramatic improvement over the exponential scaling of traditional uniform-sampling methods. Our results are not limited by the dimensionality of the landscape and are confirmed numerically in chaotic systems with up to 30 dimensions.

Bandwidth efficient coding: Theoretical limits and real achievements. Error control techniques for satellite and space communications

NASA Technical Reports Server (NTRS)

Costello, Daniel J., Jr.; Courturier, Servanne; Levy, Yannick; Mills, Diane G.; Perez, Lance C.; Wang, Fu-Quan

1993-01-01

In his seminal 1948 paper 'The Mathematical Theory of Communication,' Claude E. Shannon derived the 'channel coding theorem' which has an explicit upper bound, called the channel capacity, on the rate at which 'information' could be transmitted reliably on a given communication channel. Shannon's result was an existence theorem and did not give specific codes to achieve the bound. Some skeptics have claimed that the dramatic performance improvements predicted by Shannon are not achievable in practice. The advances made in the area of coded modulation in the past decade have made communications engineers optimistic about the possibility of achieving or at least coming close to channel capacity. Here we consider the possibility in the light of current research results.

Three-Dimensional Inverse Opal Photonic Crystal Substrates toward Efficient Capture of Circulating Tumor Cells.

PubMed

Xu, Hongwei; Dong, Biao; Xiao, Qiaoqin; Sun, Xueke; Zhang, Xinran; Lyu, Jiekai; Yang, Yudan; Xu, Lin; Bai, Xue; Zhang, Shuang; Song, Hongwei

2017-09-13

Artificial fractal structures have attracted considerable scientific interest in circulating tumor cells (CTCs) detection and capture, which plays a pivotal role in the diagnosis and prognosis of cancer. Herein, we designed a bionic TiO 2 inverse opal photonic crystal (IOPC) structure for highly efficient immunocapture of CTCs by combination of a magnetic Fe 3 O 4 @C6@silane nanoparticles with anti-EpCAM (antiepithelial cell adhesion molecule) and microchannel structure. Porous structure and dimension of IOPC TiO 2 can be precisely controlled for mimicking cellular components, and anti-EpCAM antibody was further modified on IOPC interface by conjugating with polydopamine (PDA). The improvement of CTCs capture efficiency reaches a surprising factor of 20 for the IOPC interface compared to that on flat glass, suggesting that the IOPCs are responsible for the dramatic enhancement of the capture efficiency of MCF-7 cells. IOPC substrate with pore size of 415 nm leads to the optimal CTCs capture efficiency of 92% with 1 mL/h. Besides the cell affinity, IOPCs also have the advantage of light scattering property which can enhance the excitation and emission light of fluorescence labels, facilitating the real-time monitoring of CTCs capture. The IOPC-based platform demonstrates excellent performance in CTCs capture, which will take an important step toward specific recognition of disease-related rare cells.

The quality case for information technology in healthcare

PubMed Central

Bates, David W

2002-01-01

Background As described in the Institute of Medicine's Crossing the Quality Chasm report, the quality of health care in the U.S. today leaves much to be desired. Discussion One major opportunity for improving quality relates to increasing the use of information technology, or IT. Health care organizations currently invest less in IT than in any other information-intensive industry, and not surprisingly current systems are relatively primitive, compared with industries such as banking or aviation. Nonetheless, a number of organizations have demonstrated that quality can be substantially improved in a variety of ways if IT use is increased in ways that improve care. Specifically, computerization of processes that are error-prone and computerized decision support may substantially improve both efficiency and quality, as well as dramatically facilitate quality measurement. This report discusses the current levels of IT and quality in health care, how quality improvement and management are currently done, the evidence that more IT might be helpful, a vision of the future, and the barriers to getting there. Summary This report suggests that there are five key policy domains that need to be addressed: standards, incentives, security and confidentiality, professional involvement, and research, with financial incentives representing the single most important lever. PMID:12396233

Development of Ultra-Efficient Electric Motors Final Technical Report Covering work from April 2002 through September 2007

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

Rich Schiferl

2008-05-30

High temperature superconducting (HTS) motors offer the potential for dramatic volume and loss reduction compared to conventional, high horspower, industrial motors. This report is the final report on the results of eight research tasks that address some of the issues related to HTS motor development that affect motor efficiency, cost, and reliability.

Efficient wireless power charging of electric vehicle by modifying the magnetic characteristics of the medium

NASA Astrophysics Data System (ADS)

Mahmud, Mohammad Hazzaz

There is a developing enthusiasm for electric vehicle (EV) innovations as a result of their lessened fuel utilization and greenhouse emission especially through wireless power transfer (WPT) due to the convenience and continuous charging. Numerous research initiatives target on wireless power transfer (WPT) system in the attempt to improve the transportation for last few decades. But several problems like less efficiency, high frequency, long distance energy transfer etc. were always been occupied by the wireless power transfer system. Two ideas have been developed in this research to resolve the two main problems of WPT for electric vehicles which are low efficiency due to large distance between the two coils and slow charging time. As the first phase of study, a proper model, including the coils and cores were required. The selected model was a finite element (FE) modeling. Another part of this study was to create a modified cement that will act as a semi-conductive material for covering the transmitting antenna area. A high frequency wide band gap switch will be used for transferring high amount of power in a very short time. More over this research also proves that, if cores could be added with the transmitter coil and receiver coil then the output efficiency dramatically increased comparing with without core model of transmitter and receiver. The wireless charging is not restricted to parking lot, since it's planned to be embedded into parking space concrete or roadway concrete or asphalt. Therefore, it can also be installed at junctions (behind red lights), stop signs or any spot that the vehicle might stop for several moments. This technology will become more feasible, if the charging time decreases. Therefore, a new model of for wireless power transfer has been proposed in this study which has shown significant improvement. Another motive of this study was to improve the conductivity and permeability in such a way that the medium that is on the top of the transmitting antenna can transfer the power efficiently to the receiving antenna. The best efficiency of 83% was achieved by using this model and the medium.

Core-shell AgSiO2-protoporphyrin IX nanoparticle: Effect of the Ag core on reactive oxygen species generation

NASA Astrophysics Data System (ADS)

Lismont, M.; Pá; ez-Martinez, C.; Dreesen, L.

2015-03-01

Photodynamic therapy (PDT) for cancer is based on the use of a light sensitive molecule to produce, under specific irradiation, toxic reactive oxygen species (ROS). A way to improve the therapy efficiency is to increase the amount of produced ROS near cancer cells. This aim can be achieved by using a metal enhanced process arising when an optically active molecule is located near a metallic nanoparticle (NP). Here, the coupling effect between silver (Ag) NPs and protoporphyrin IX (PpIX) molecules, a clinically approved photosensitizer, is studied compared first, to PpIX fluorescence yield and second, to ROS production efficiency. By applying a modified Stöber process, PpIX was encapsulated into a silica (SiO2) shell, surrounding a 60 nm sized Ag core. We showed that, compared to SiO2-PpIX NPs, Ag coated SiO2-PpIX NPs dramatically decreased PpIX fluorescence together with singlet oxygen production efficiency. However, after incubation time in the dark, the amount of superoxide anions generated by the Ag doped sample was higher than the control sample one.

Efficient traffic grooming with dynamic ONU grouping for multiple-OLT-based access network

NASA Astrophysics Data System (ADS)

Zhang, Shizong; Gu, Rentao; Ji, Yuefeng; Wang, Hongxiang

2015-12-01

Fast bandwidth growth urges large-scale high-density access scenarios, where the multiple Passive Optical Networking (PON) system clustered deployment can be adopted as an appropriate solution to fulfill the huge bandwidth demands, especially for a future 5G mobile network. However, the lack of interaction between different optical line terminals (OLTs) results in part of the bandwidth resources waste. To increase the bandwidth efficiency, as well as reduce bandwidth pressure at the edge of a network, we propose a centralized flexible PON architecture based on Time- and Wavelength-Division Multiplexing PON (TWDM PON). It can provide flexible affiliation for optical network units (ONUs) and different OLTs to support access network traffic localization. Specifically, a dynamic ONU grouping algorithm (DGA) is provided to obtain the minimal OLT outbound traffic. Simulation results show that DGA obtains an average 25.23% traffic gain increment under different OLT numbers within a small ONU number situation, and the traffic gain will increase dramatically with the increment of the ONU number. As the DGA can be deployed easily as an application running above the centralized control plane, the proposed architecture can be helpful to improve the network efficiency for future traffic-intensive access scenarios.

Synthesis of β-cyclodextrin hydrogel nanoparticles for improving the solubility of dexibuprofen: characterization and toxicity evaluation.

PubMed

Khalid, Qandeel; Ahmad, Mahmood; Minhas, Muhammad Usman

2017-11-01

This study was aimed to enhance aqueous solubility of dexibuprofen through designing β-cyclodextrin (βCD) hydrogel nanoparticles and to evaluate toxicological potential through acute toxicity studies in rats. Dexibuprofen is a non-steroidal analgesic and anti-inflammatory drug that is one of safest over the counter medications. However, its clinical effectiveness is hampered due to poor aqueous solubility. βCD hydrogel nanoparticles were prepared and characterized by percent yield, drug loading, solubilization efficiency, FTIR, XRD, DSC, FESEM and in-vitro dissolution studies. Acute oral toxicity study was conducted to assess safety of oral administration of prepared βCD hydrogel nanoparticles. βCD hydrogel nanoparticles dramatically enhanced the drug loading and solubilization efficiency of dexibuprofen in aqueous media. FTIR, TGA and DSC studies confirmed the formation of new and a stable nano-polymeric network and interactions of dexibuprofen with these nanoparticles. Resulting nanoparticles were highly porous with 287 nm in size. XRD analysis revealed pronounced reduction in crystalline nature of dexibuprofen within nanoparticles. Release of dexibuprofen in βCD hydrogel nanoparticles was significantly higher compared with dexibuprofen tablet at pH 1.2 and 6.8. In acute toxicity studies, no significant changes in behavioral, physiological, biochemical or histopathologic parameters of animals were observed. The efficient preparation, high solubility, excellent physicochemical characteristics, improved dissolution and non-toxic βCD hydrogel nanoparticles may be a promising approach for oral delivery of lipophilic drugs.

Automatic detection of animals in mowing operations using thermal cameras.

PubMed

Steen, Kim Arild; Villa-Henriksen, Andrés; Therkildsen, Ole Roland; Green, Ole

2012-01-01

During the last decades, high-efficiency farming equipment has been developed in the agricultural sector. This has also included efficiency improvement of moving techniques, which include increased working speeds and widths. Therefore, the risk of wild animals being accidentally injured or killed during routine farming operations has increased dramatically over the years. In particular, the nests of ground nesting bird species like grey partridge (Perdix perdix) or pheasant (Phasianus colchicus) are vulnerable to farming operations in their breeding habitat, whereas in mammals, the natural instinct of e.g., leverets of brown hare (Lepus europaeus) and fawns of roe deer (Capreolus capreolus) to lay low and still in the vegetation to avoid predators increase their risk of being killed or injured in farming operations. Various methods and approaches have been used to reduce wildlife mortality resulting from farming operations. However, since wildlife-friendly farming often results in lower efficiency, attempts have been made to develop automatic systems capable of detecting wild animals in the crop. Here we assessed the suitability of thermal imaging in combination with digital image processing to automatically detect a chicken (Gallus domesticus) and a rabbit (Oryctolagus cuniculus) in a grassland habitat. Throughout the different test scenarios, our study animals were detected with a high precision, although the most dense grass cover reduced the detection rate. We conclude that thermal imaging and digital imaging processing may be an important tool for the improvement of wildlife-friendly farming practices in the future.

A dramatic increase in the positive blood culture rates of Helicobacter cinaedi: the evidence of differential detection abilities between the Bactec and BacT/Alert systems.

PubMed

Miyake, Noriko; Chong, Yong; Nishida, Ruriko; Nagasaki, Yoji; Kibe, Yasushi; Kiyosuke, Makiko; Shimomura, Takeshi; Shimono, Nobuyuki; Shimoda, Shinji; Akashi, Koichi

2015-11-01

In our hospital, positive blood culture rates of Helicobacter cinaedi dramatically increased after introducing the Bactec system. A simulated culture model of H. cinaedi bacteremia demonstrated no positive signals using the BacT/Alert system, despite efficient growth in bottles. Clinically suspected H. cinaedi bacteremia should be monitored more closely when using the BacT/Alert system, preferably with subcultivation after 7days of incubation. Copyright © 2015 Elsevier Inc. All rights reserved.

Radiation efficiency of earthquake sources at different hierarchical levels

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

Kocharyan, G. G., E-mail: gevorgkidg@mail.ru; Moscow Institute of Physics and Technology

Such factors as earthquake size and its mechanism define common trends in alteration of radiation efficiency. The macroscopic parameter that controls the efficiency of a seismic source is stiffness of fault or fracture. The regularities of this parameter alteration with scale define several hierarchical levels, within which earthquake characteristics obey different laws. Small variations of physical and mechanical properties of the fault principal slip zone can lead to dramatic differences both in the amplitude of released stress and in the amount of radiated energy.

FMLRC: Hybrid long read error correction using an FM-index.

PubMed

Wang, Jeremy R; Holt, James; McMillan, Leonard; Jones, Corbin D

2018-02-09

Long read sequencing is changing the landscape of genomic research, especially de novo assembly. Despite the high error rate inherent to long read technologies, increased read lengths dramatically improve the continuity and accuracy of genome assemblies. However, the cost and throughput of these technologies limits their application to complex genomes. One solution is to decrease the cost and time to assemble novel genomes by leveraging "hybrid" assemblies that use long reads for scaffolding and short reads for accuracy. We describe a novel method leveraging a multi-string Burrows-Wheeler Transform with auxiliary FM-index to correct errors in long read sequences using a set of complementary short reads. We demonstrate that our method efficiently produces significantly more high quality corrected sequence than existing hybrid error-correction methods. We also show that our method produces more contiguous assemblies, in many cases, than existing state-of-the-art hybrid and long-read only de novo assembly methods. Our method accurately corrects long read sequence data using complementary short reads. We demonstrate higher total throughput of corrected long reads and a corresponding increase in contiguity of the resulting de novo assemblies. Improved throughput and computational efficiency than existing methods will help better economically utilize emerging long read sequencing technologies.

Stable Graphene-Two-Dimensional Multiphase Perovskite Heterostructure Phototransistors with High Gain.

PubMed

Shao, Yuchuan; Liu, Ye; Chen, Xiaolong; Chen, Chen; Sarpkaya, Ibrahim; Chen, Zhaolai; Fang, Yanjun; Kong, Jaemin; Watanabe, Kenji; Taniguchi, Takashi; Taylor, André; Huang, Jinsong; Xia, Fengnian

2017-12-13

Recently, two-dimensional (2D) organic-inorganic perovskites emerged as an alternative material for their three-dimensional (3D) counterparts in photovoltaic applications with improved moisture resistance. Here, we report a stable, high-gain phototransistor consisting of a monolayer graphene on hexagonal boron nitride (hBN) covered by a 2D multiphase perovskite heterostructure, which was realized using a newly developed two-step ligand exchange method. In this phototransistor, the multiple phases with varying bandgap in 2D perovskite thin films are aligned for the efficient electron-hole pair separation, leading to a high responsivity of ∼10 5 A W -1 at 532 nm. Moreover, the designed phase alignment method aggregates more hydrophobic butylammonium cations close to the upper surface of the 2D perovskite thin film, preventing the permeation of moisture and enhancing the device stability dramatically. In addition, faster photoresponse and smaller 1/f noise observed in the 2D perovskite phototransistors indicate a smaller density of deep hole traps in the 2D perovskite thin film compared with their 3D counterparts. These desirable properties not only improve the performance of the phototransistor, but also provide a new direction for the future enhancement of the efficiency of 2D perovskite photovoltaics.

Graphene-Reinforced Metal and Polymer Matrix Composites

NASA Astrophysics Data System (ADS)

Kasar, Ashish K.; Xiong, Guoping; Menezes, Pradeep L.

2018-03-01

Composites have tremendous applicability due to their excellent capabilities. The performance of composites mainly depends on the reinforcing material applied. Graphene is successful as an efficient reinforcing material due to its versatile as well as superior properties. Even at very low content, graphene can dramatically improve the properties of polymer and metal matrix composites. This article reviews the fabrication followed by mechanical and tribological properties of metal and polymer matrix composites filled with different kinds of graphene, including single-layer, multilayer, and functionalized graphene. Results reported to date in literature indicate that functionalized graphene or graphene oxide-polymer composites are promising materials offering significantly improved strength and frictional properties. A similar trend of improved properties has been observed in case of graphene-metal matrix composites. However, achieving higher graphene loading with uniform dispersion in metal matrix composites remains a challenge. Although graphene-reinforced composites face some challenges, such as understanding the graphene-matrix interaction or fabrication techniques, graphene-reinforced polymer and metal matrix composites have great potential for application in various fields due to their outstanding properties.

Graphene-Reinforced Metal and Polymer Matrix Composites

NASA Astrophysics Data System (ADS)

Kasar, Ashish K.; Xiong, Guoping; Menezes, Pradeep L.

2018-06-01

Composites have tremendous applicability due to their excellent capabilities. The performance of composites mainly depends on the reinforcing material applied. Graphene is successful as an efficient reinforcing material due to its versatile as well as superior properties. Even at very low content, graphene can dramatically improve the properties of polymer and metal matrix composites. This article reviews the fabrication followed by mechanical and tribological properties of metal and polymer matrix composites filled with different kinds of graphene, including single-layer, multilayer, and functionalized graphene. Results reported to date in literature indicate that functionalized graphene or graphene oxide-polymer composites are promising materials offering significantly improved strength and frictional properties. A similar trend of improved properties has been observed in case of graphene-metal matrix composites. However, achieving higher graphene loading with uniform dispersion in metal matrix composites remains a challenge. Although graphene-reinforced composites face some challenges, such as understanding the graphene-matrix interaction or fabrication techniques, graphene-reinforced polymer and metal matrix composites have great potential for application in various fields due to their outstanding properties.

Guanidinium ionic liquid-controlled synthesis of zeolitic imidazolate framework for improving its adsorption property.

PubMed

Fan, Chen; Liang, You; Dong, Hongqiang; Yang, Jiale; Tang, Gang; Zhang, Wenbing; Kong, Dandan; Li, Jianqiang; Cao, Yongsong

2018-05-30

The massive release of rhodamine B (RhB) to water system is an emerging problem, which dramatically threaten environment and human health. The development of an adsorbent with enhanced removal efficiency for RhB is urgently needed. Herein, we report an environment-friendly synthesis of high quality zeolitic imidazolate framework-8 (ZIF-8) and functional ionic liquid@ZIF-8 in water-based system without heat treatment for improving its adsorption property. Guanidinium ionic liquids (ILs) could not only act as greener agents instead of volatile bases and toxic surfactants to efficiently control the nucleation and growth rate of ZIF-8, but also were incorporated as shell material to add specific adsorption sites. The relationship between nanoparticle structure and adsorption performance for RhB was systematically investigated. Due to high surface area (1167 m 2  g -1 ), high porosity (0.79 cm 3  g -1 ), high crystallinity, nano size (about 100 nm) and monodispersity, the as-obtained ZIF-8 showed improved adsorption capacity toward RhB (80% removal efficiency). Heteropolyanion-based guanidinium IL@meso-ZIF-8 (HPAIL@meso-ZIF-8) exhibited the high RhB uptake capacity of 278 mg g -1 (higher than most of the reported adsorbents) and effectively removed 99% of RhB within 15 min. The results showed that the adsorption process of prepared materials fitted well with pseudo-second-order kinetics and Langmuir isotherm model. The existence of mesopores in ZIF-8 facilitated the diffusion of RhB and the incorporated guanidinium IL played a significant role in enhancing the adsorption affinity. Moreover, the reusability results revealed the HPAIL@meso-ZIF-8 as a highly efficient adsorbent for RhB removal with satisfactory performance and structural stability. Therefore, HPAIL@meso-ZIF-8 is one of the most promising adsorbents for organic dye removal from water. Copyright © 2018 Elsevier B.V. All rights reserved.

Zooniverse: Combining Human and Machine Classifiers for the Big Survey Era

NASA Astrophysics Data System (ADS)

Fortson, Lucy; Wright, Darryl; Beck, Melanie; Lintott, Chris; Scarlata, Claudia; Dickinson, Hugh; Trouille, Laura; Willi, Marco; Laraia, Michael; Boyer, Amy; Veldhuis, Marten; Zooniverse

2018-01-01

Many analyses of astronomical data sets, ranging from morphological classification of galaxies to identification of supernova candidates, have relied on humans to classify data into distinct categories. Crowdsourced galaxy classifications via the Galaxy Zoo project provided a solution that scaled visual classification for extant surveys by harnessing the combined power of thousands of volunteers. However, the much larger data sets anticipated from upcoming surveys will require a different approach. Automated classifiers using supervised machine learning have improved considerably over the past decade but their increasing sophistication comes at the expense of needing ever more training data. Crowdsourced classification by human volunteers is a critical technique for obtaining these training data. But several improvements can be made on this zeroth order solution. Efficiency gains can be achieved by implementing a “cascade filtering” approach whereby the task structure is reduced to a set of binary questions that are more suited to simpler machines while demanding lower cognitive loads for humans.Intelligent subject retirement based on quantitative metrics of volunteer skill and subject label reliability also leads to dramatic improvements in efficiency. We note that human and machine classifiers may retire subjects differently leading to trade-offs in performance space. Drawing on work with several Zooniverse projects including Galaxy Zoo and Supernova Hunter, we will present recent findings from experiments that combine cohorts of human and machine classifiers. We show that the most efficient system results when appropriate subsets of the data are intelligently assigned to each group according to their particular capabilities.With sufficient online training, simple machines can quickly classify “easy” subjects, leaving more difficult (and discovery-oriented) tasks for volunteers. We also find humans achieve higher classification purity while samples produced by machines are typically more complete. These findings set the stage for further investigations, with the ultimate goal of efficiently and accurately labeling the wide range of data classes that will arise from the planned large astronomical surveys.

Evaluation of three high abundance protein depletion kits for umbilical cord serum proteomics

PubMed Central

2011-01-01

Background High abundance protein depletion is a major challenge in the study of serum/plasma proteomics. Prior to this study, most commercially available kits for depletion of highly abundant proteins had only been tested and evaluated in adult serum/plasma, while the depletion efficiency on umbilical cord serum/plasma had not been clarified. Structural differences between some adult and fetal proteins (such as albumin) make it likely that depletion approaches for adult and umbilical cord serum/plasma will be variable. Therefore, the primary purposes of the present study are to investigate the efficiencies of several commonly-used commercial kits during high abundance protein depletion from umbilical cord serum and to determine which kit yields the most effective and reproducible results for further proteomics research on umbilical cord serum. Results The immunoaffinity based kits (PROTIA-Sigma and 5185-Agilent) displayed higher depletion efficiency than the immobilized dye based kit (PROTBA-Sigma) in umbilical cord serum samples. Both the PROTIA-Sigma and 5185-Agilent kit maintained high depletion efficiency when used three consecutive times. Depletion by the PROTIA-Sigma Kit improved 2DE gel quality by reducing smeared bands produced by the presence of high abundance proteins and increasing the intensity of other protein spots. During image analysis using the identical detection parameters, 411 ± 18 spots were detected in crude serum gels, while 757 ± 43 spots were detected in depleted serum gels. Eight spots unique to depleted serum gels were identified by MALDI- TOF/TOF MS, seven of which were low abundance proteins. Conclusions The immunoaffinity based kits exceeded the immobilized dye based kit in high abundance protein depletion of umbilical cord serum samples and dramatically improved 2DE gel quality for detection of trace biomarkers. PMID:21554704

Significant Improvement in Cloning Efficiency of an Inbred Miniature Pig by Histone Deacetylase Inhibitor Treatment after Somatic Cell Nuclear Transfer1

PubMed Central

Zhao, Jianguo; Ross, Jason W.; Hao, Yanhong; Spate, Lee D.; Walters, Eric M.; Samuel, Melissa S.; Rieke, August; Murphy, Clifton N.; Prather, Randall S.

2009-01-01

The National Institutes of Health (NIH) miniature pig was developed specifically for xenotransplantation and has been extensively used as a large-animal model in many other biomedical experiments. However, the cloning efficiency of this pig is very low (<0.2%), and this has been an obstacle to the promising application of these inbred swine genetics for biomedical research. It has been demonstrated that increased histone acetylation in somatic cell nuclear transfer (SCNT) embryos, by applying a histone deacetylase (HDAC) inhibitor such as trichostatin A (TSA), significantly enhances the developmental competence in several species. However, some researchers also reported that TSA treatment had various detrimental effects on the in vitro and in vivo development of the SCNT embryos. Herein, we report that treatment with 500 nM 6-(1,3-dioxo-1H, 3H-benzo[de]isoquinolin-2-yl)-hexanoic acid hydroxyamide (termed scriptaid), a novel HDAC inhibitor, significantly enhanced the development of SCNT embryos to the blastocyst stage when NIH inbred fetal fibroblast cells (FFCs) were used as donors compared with the untreated group (21% vs. 9%, P < 0.05). Scriptaid treatment resulted in eight pregnancies from 10 embryo transfers (ETs) and 14 healthy NIH miniature pigs from eight litters, while no viable piglets (only three mummies) were obtained from nine ETs in the untreated group. Thus, scriptaid dramatically increased the cloning efficiency when using inbred genetics from 0.0% to 1.3%. In contrast, scriptaid treatment decreased the blastocyst rate in in vitro fertilization embryos (from 37% to 26%, P < 0.05). In conclusion, the extremely low cloning efficiency in the NIH miniature pig may be caused by its inbred genetic background and can be improved by alteration of genomic histone acetylation patterns. PMID:19386991

Significant improvement in cloning efficiency of an inbred miniature pig by histone deacetylase inhibitor treatment after somatic cell nuclear transfer.

PubMed

Zhao, Jianguo; Ross, Jason W; Hao, Yanhong; Spate, Lee D; Walters, Eric M; Samuel, Melissa S; Rieke, August; Murphy, Clifton N; Prather, Randall S

2009-09-01

The National Institutes of Health (NIH) miniature pig was developed specifically for xenotransplantation and has been extensively used as a large-animal model in many other biomedical experiments. However, the cloning efficiency of this pig is very low (<0.2%), and this has been an obstacle to the promising application of these inbred swine genetics for biomedical research. It has been demonstrated that increased histone acetylation in somatic cell nuclear transfer (SCNT) embryos, by applying a histone deacetylase (HDAC) inhibitor such as trichostatin A (TSA), significantly enhances the developmental competence in several species. However, some researchers also reported that TSA treatment had various detrimental effects on the in vitro and in vivo development of the SCNT embryos. Herein, we report that treatment with 500 nM 6-(1,3-dioxo-1H, 3H-benzo[de]isoquinolin-2-yl)-hexanoic acid hydroxyamide (termed scriptaid), a novel HDAC inhibitor, significantly enhanced the development of SCNT embryos to the blastocyst stage when NIH inbred fetal fibroblast cells (FFCs) were used as donors compared with the untreated group (21% vs. 9%, P < 0.05). Scriptaid treatment resulted in eight pregnancies from 10 embryo transfers (ETs) and 14 healthy NIH miniature pigs from eight litters, while no viable piglets (only three mummies) were obtained from nine ETs in the untreated group. Thus, scriptaid dramatically increased the cloning efficiency when using inbred genetics from 0.0% to 1.3%. In contrast, scriptaid treatment decreased the blastocyst rate in in vitro fertilization embryos (from 37% to 26%, P < 0.05). In conclusion, the extremely low cloning efficiency in the NIH miniature pig may be caused by its inbred genetic background and can be improved by alteration of genomic histone acetylation patterns.

Spraying Brassinolide improves Sigma Broad tolerance in foxtail millet (Setaria italica L.) through modulation of antioxidant activity and photosynthetic capacity.

PubMed

Yuan, Xiang-Yang; Zhang, Li-Guang; Huang, Lei; Yang, Hui-Jie; Zhong, Yan-Ting; Ning, Na; Wen, Yin-Yuan; Dong, Shu-Qi; Song, Xi-E; Wang, Hong-Fu; Guo, Ping-Yi

2017-09-11

To explore the role of Brassinolide (BR) in improving the tolerance of Sigma Broad in foxtail millet (Setaria italica L.), effects of 0.1 mg/L of BR foliar application 24 h before 3.37 g/ha of Sigma Broad treatment at five-leaf stage of foxtail millet on growth parameters, antioxidant enzymes, malondialdehyde (MDA), chlorophyll, net photosynthetic rate (P N ), chlorophyll fluorescence and P 700 parameters were studied 7 and 15 d after herbicide treatment, respectively. Results showed that Sigma Broad significantly decreased plant height, activities of superoxide dismutase (SOD), chlorophyll content, P N , PS II effective quantum yield (Y (II)), PS II electron transport rate (ETR (II)), photochemical quantum yield of PSI(Y (I)) and PS I electron transport rate ETR (I), but significantly increased MDA. Compared to herbicide treatment, BR dramatically increased plant height, activities of SOD, Y (II), ETR (II), Y (I) and ETR (I). This study showed BR pretreatment could improve the tolerance of Sigma Broad in foxtail millet through improving the activity of antioxidant enzymes, keeping electron transport smooth, and enhancing actual photochemical efficiency of PS II and PSI.

Enhanced photothermal therapy of biomimetic polypyrrole nanoparticles through improving blood flow perfusion.

PubMed

Wang, Xuejun; Li, Haichun; Liu, Xianping; Tian, Ye; Guo, Huishu; Jiang, Ting; Luo, Zimiao; Jin, Kai; Kuai, Xinping; Liu, Yao; Pang, Zhiqing; Yang, Wuli; Shen, Shun

2017-10-01

In this study, we reported a strategy to improve delivery efficiency of a long-circulation biomimetic photothermal nanoagent for enhanced photothermal therapy through selectively dilating tumor vasculature. By using a simply nanocoating technology, a biomimetic layer of natural red blood cell (RBC) membranes was camouflaged on the surface of photothermal polypyrrole nanoparticles (PPy@RBC NPs). The erythrocyte-mimicking PPy NPs inherited the immune evasion ability from natural RBC resulting in superior prolonged blood retention time. Additionally, excellent photothermal and photoacoustic imaging functionalities were all retained attributing to PPy NPs cores. To further improve the photothermal outcome, the endothelin A (ET A ) receptor antagonist BQ123 was jointly employed to regulate tumor microenvironment. The BQ123 could induce tumor vascular relaxation and increase blood flow perfusion through modulating an ET-1/ET A transduction pathway and blocking the ET A receptor, whereas the vessel perfusion of normal tissues was not altered. Through our well-designed tactic, the concentration of biomimetic PPy NPs in tumor site was significantly improved when administered systematically. The study documented that the antitumor efficiency of biomimetic PPy NPs combined with specific antagonist BQ123 was particularly prominent and was superior to biomimetic PPy NPs (P < 0.05) and PEGylated PPy NPs with BQ123 (P < 0.01), showing that the greatly enhanced photothermal treatment could be achieved with low-dose administration of photothermal agents. Our findings would provide a promising procedure for other similar enhanced photothermal treatment by blocking ET A receptor to dramatically increase the delivery of biomimetic photothermal nanomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Good response of low-fat/high-protein diet in a patient with chyluria.

PubMed

Triffoni-Melo, Andresa T; Diez-Garcia, Rosa Wanda; Barros Silva, Gyl Eanes; Garcia Caldas, Fernando de Freitas; Wichert-Ana, Lauro; Corte Denardi, Rafaela; Kato, Mery; Júnior Lucca, Leandro; Dantas, Márcio

2014-04-01

Chyluria is an inappropriate urinary excretion of chyle that turns the urine milky. A nutritional approach based on low-fat/high-protein content diet associated or not with medium-chain triglyceride (MCT) showed to be an efficient conservative treatment to improve the milky urine appearance in a patient with chyluria. A 30-year-old female patient was admitted with chyluria of unknown etiology. An ureteropyeloscopy revealed a single lesion in each kidney, both with linear aspect and measuring 5 mm in extension. These lesions were located close to the renal papillae and were leaking a cloudy and milky fluid. Both lesions were laser cauterized followed by improvement of the milky urine. However, the chyluria relapsed after few months and a low-fat/high-protein content diet with 10 g of soybean oil to meet the requirements essential fatty acids (EFA) and with MCT from coconut oil as alternative to prepare foods was started. Few weeks later the patient returned reporting consistent improvement of the milky urine appearance related with the use of the diet. However since the diet was tasteless and time consuming to prepare, she reported low compliance to diet with MCT and the milky urine relapsed. The MCT was discontinued and the diet with EFA source was maintained with better compliance. Since then the chyluria remains in remission. In conclusion, the dramatic improvement of the milky urine with low-fat/high-protein diet with EFA source observed in our patient demonstrates that this nutritional approach is efficient with fast results to treat chyluria during long term.

Impact of swine reproductive technologies on pig and global food production.

PubMed

Knox, Robert V

2014-01-01

Reproductive technologies have dramatically changed the way pigs are raised for pork production in developed and developing countries. This has involved such areas as pigs produced/sow, more consistent pig flow to market, pig growth rate and feed efficiency, carcass yield and quality, labor efficiency, and pig health. Some reproductive technologies are in widespread use for commercial pork operations [Riesenbeck, Reprod Domest Anim 46:1-3, 2011] while others are in limited use in specific segments of the industry [Knox, Reprod Domest Anim 46:4-6, 2011]. Significant changes in the efficiency of pork production have occurred as a direct result of the use of reproductive technologies that were intended to improve the transfer of genes important for food production [Gerrits et al., Theriogenology 63:283-299, 2005]. While some technologies focused on the efficiency of gene transfer, others addressed fertility and labor issues. Among livestock species, pig reproductive efficiency appears to have achieved exceptionally high rates of performance (PigCHAMP 2011) [Benchmark 2011, Ames, IA, 12-16]. From the maternal side, this includes pigs born per litter, farrowing rate, as well as litters per sow per year. On the male side, boar fertility, sperm production, and sows served per sire have improved as well [Knox et al., Theriogenology, 70:1202-1208, 2008]. These shifts in the efficiency of swine fertility have resulted in the modern pig as one of the most efficient livestock species for global food production. These reproductive changes have predominantly occurred in developed countries, but data suggests transfer and adoption of these in developing countries as well (FAO STAT 2009; FAS 2006) [World pig meat production: food and agriculture organization of the United Nations, 2009; FAS, 2006) Worldwide Pork Production, 2006]. Technological advancements in swine reproduction have had profound effects on industry structure, production, efficiency, quality, and profitability. In all cases, the adoption of these technologies has aided in the creation of a sustainable supply of safe and affordable pork for consumers around the world [den Hartog, Adv Pork Prod 15:17-24, 2004].

Negotiating for Change: Modifying Collective Bargaining Agreements for School Turnaround

ERIC Educational Resources Information Center

Weinberg, Rebecca

2011-01-01

Dramatically improving student achievement in a school that has been failing for many years requires dramatically different conditions. Only the most effective teachers and leaders should be in the building, and the leadership must have the flexibility to respond strategically to the needs of the students, with regular input from teachers.…

Fulcrum of Change: Leveraging 50 States to Turn around 5000 Schools

ERIC Educational Resources Information Center

Rhim, Lauren Morando; Redding, Sam

2011-01-01

In 2010, unprecedented levels of resources began to flow through state education agencies (SEAs) to support dramatic change in persistently low-performing schools under the expanded federal School Improvement Grant (SIG) program. The challenge for states is to leverage the federal investment to drive dramatic and sustainable change efforts in…

Turbine Engine Clearance Control Systems: Current Practices and Future Directions

NASA Astrophysics Data System (ADS)

Lattime, Scott B.; Steinetz, Bruce M.

2002-09-01

Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed 1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

Risk intelligence: making profit from uncertainty in data processing system.

PubMed

Zheng, Si; Liao, Xiangke; Liu, Xiaodong

2014-01-01

In extreme scale data processing systems, fault tolerance is an essential and indispensable part. Proactive fault tolerance scheme (such as the speculative execution in MapReduce framework) is introduced to dramatically improve the response time of job executions when the failure becomes a norm rather than an exception. Efficient proactive fault tolerance schemes require precise knowledge on the task executions, which has been an open challenge for decades. To well address the issue, in this paper we design and implement RiskI, a profile-based prediction algorithm in conjunction with a riskaware task assignment algorithm, to accelerate task executions, taking the uncertainty nature of tasks into account. Our design demonstrates that the nature uncertainty brings not only great challenges, but also new opportunities. With a careful design, we can benefit from such uncertainties. We implement the idea in Hadoop 0.21.0 systems and the experimental results show that, compared with the traditional LATE algorithm, the response time can be improved by 46% with the same system throughput.

The GBS code for tokamak scrape-off layer simulations

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

Halpern, F.D., E-mail: federico.halpern@epfl.ch; Ricci, P.; Jolliet, S.

2016-06-15

We describe a new version of GBS, a 3D global, flux-driven plasma turbulence code to simulate the turbulent dynamics in the tokamak scrape-off layer (SOL), superseding the code presented by Ricci et al. (2012) [14]. The present work is driven by the objective of studying SOL turbulent dynamics in medium size tokamaks and beyond with a high-fidelity physics model. We emphasize an intertwining framework of improved physics models and the computational improvements that allow them. The model extensions include neutral atom physics, finite ion temperature, the addition of a closed field line region, and a non-Boussinesq treatment of the polarizationmore » drift. GBS has been completely refactored with the introduction of a 3-D Cartesian communicator and a scalable parallel multigrid solver. We report dramatically enhanced parallel scalability, with the possibility of treating electromagnetic fluctuations very efficiently. The method of manufactured solutions as a verification process has been carried out for this new code version, demonstrating the correct implementation of the physical model.« less

Turbine Engine Clearance Control Systems: Current Practices and Future Directions

NASA Technical Reports Server (NTRS)

Lattime, Scott B.; Steinetz, Bruce M.

2002-01-01

Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

Thermoelectrics. Dense dislocation arrays embedded in grain boundaries for high-performance bulk thermoelectrics.

PubMed

Kim, Sang Il; Lee, Kyu Hyoung; Mun, Hyeon A; Kim, Hyun Sik; Hwang, Sung Woo; Roh, Jong Wook; Yang, Dae Jin; Shin, Weon Ho; Li, Xiang Shu; Lee, Young Hee; Snyder, G Jeffrey; Kim, Sung Wng

2015-04-03

The widespread use of thermoelectric technology is constrained by a relatively low conversion efficiency of the bulk alloys, which is evaluated in terms of a dimensionless figure of merit (zT). The zT of bulk alloys can be improved by reducing lattice thermal conductivity through grain boundary and point-defect scattering, which target low- and high-frequency phonons. Dense dislocation arrays formed at low-energy grain boundaries by liquid-phase compaction in Bi(0.5)Sb(1.5)Te3 (bismuth antimony telluride) effectively scatter midfrequency phonons, leading to a substantially lower lattice thermal conductivity. Full-spectrum phonon scattering with minimal charge-carrier scattering dramatically improved the zT to 1.86 ± 0.15 at 320 kelvin (K). Further, a thermoelectric cooler confirmed the performance with a maximum temperature difference of 81 K, which is much higher than current commercial Peltier cooling devices. Copyright © 2015, American Association for the Advancement of Science.

Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization

PubMed Central

Barnes, Alexander B.; Mak-Jurkauskas, Melody L.; Matsuki, Yoh; Bajaj, Vikram S.; van der Wel, Patrick C. A.; DeRocher, Ronald; Bryant, Jeffrey; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Lugtenburg, Johan; Herzfeld, Judith; Griffin, Robert G.

2009-01-01

We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by improving long-term instrument stability. Changing samples in conventional cryogenic MAS DNP/NMR experiments involves warming the probe to room temperature, detaching all cryogenic, RF, and microwave connections, removing the probe from the magnet, replacing the sample, and reversing all the previous steps, with the entire cycle requiring a few hours. The sample exchange system described here — which relies on an eject pipe attached to the front of the MAS stator and a vacuum jacketed dewar with a bellowed hole — circumvents these procedures. To demonstrate the excellent sensitivity, resolution, and stability achieved with this quadruple resonance sample exchange probe, we have performed high precision distance measurements on the active site of the membrane protein bacteriorhodopsin. We also include a spectrum of the tripeptide N-f-MLF-OH at 100 K which shows 30 Hz linewidths. PMID:19356957

Risk Intelligence: Making Profit from Uncertainty in Data Processing System

PubMed Central

Liao, Xiangke; Liu, Xiaodong

2014-01-01

In extreme scale data processing systems, fault tolerance is an essential and indispensable part. Proactive fault tolerance scheme (such as the speculative execution in MapReduce framework) is introduced to dramatically improve the response time of job executions when the failure becomes a norm rather than an exception. Efficient proactive fault tolerance schemes require precise knowledge on the task executions, which has been an open challenge for decades. To well address the issue, in this paper we design and implement RiskI, a profile-based prediction algorithm in conjunction with a riskaware task assignment algorithm, to accelerate task executions, taking the uncertainty nature of tasks into account. Our design demonstrates that the nature uncertainty brings not only great challenges, but also new opportunities. With a careful design, we can benefit from such uncertainties. We implement the idea in Hadoop 0.21.0 systems and the experimental results show that, compared with the traditional LATE algorithm, the response time can be improved by 46% with the same system throughput. PMID:24883392

Enhancing fullerene-based solar cell lifetimes by addition of a fullerene dumbbell.

PubMed

Schroeder, Bob C; Li, Zhe; Brady, Michael A; Faria, Gregório Couto; Ashraf, Raja Shahid; Takacs, Christopher J; Cowart, John S; Duong, Duc T; Chiu, Kar Ho; Tan, Ching-Hong; Cabral, João T; Salleo, Alberto; Chabinyc, Michael L; Durrant, James R; McCulloch, Iain

2014-11-17

Cost-effective, solution-processable organic photovoltaics (OPV) present an interesting alternative to inorganic silicon-based solar cells. However, one of the major remaining challenges of OPV devices is their lack of long-term operational stability, especially at elevated temperatures. The synthesis of a fullerene dumbbell and its use as an additive in the active layer of a PCDTBT:PCBM-based OPV device is reported. The addition of only 20 % of this novel fullerene not only leads to improved device efficiencies, but more importantly also to a dramatic increase in morphological stability under simulated operating conditions. Dynamic secondary ion mass spectrometry (DSIMS) and TEM are used, amongst other techniques, to elucidate the origins of the improved morphological stability. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Performance analysis of distributed applications using automatic classification of communication inefficiencies

DOEpatents

Vetter, Jeffrey S.

2005-02-01

The method and system described herein presents a technique for performance analysis that helps users understand the communication behavior of their message passing applications. The method and system described herein may automatically classifies individual communication operations and reveal the cause of communication inefficiencies in the application. This classification allows the developer to quickly focus on the culprits of truly inefficient behavior, rather than manually foraging through massive amounts of performance data. Specifically, the method and system described herein trace the message operations of Message Passing Interface (MPI) applications and then classify each individual communication event using a supervised learning technique: decision tree classification. The decision tree may be trained using microbenchmarks that demonstrate both efficient and inefficient communication. Since the method and system described herein adapt to the target system's configuration through these microbenchmarks, they simultaneously automate the performance analysis process and improve classification accuracy. The method and system described herein may improve the accuracy of performance analysis and dramatically reduce the amount of data that users must encounter.

Computational Image Analysis Reveals Intrinsic Multigenerational Differences between Anterior and Posterior Cerebral Cortex Neural Progenitor Cells

PubMed Central

Winter, Mark R.; Liu, Mo; Monteleone, David; Melunis, Justin; Hershberg, Uri; Goderie, Susan K.; Temple, Sally; Cohen, Andrew R.

2015-01-01

Summary Time-lapse microscopy can capture patterns of development through multiple divisions for an entire clone of proliferating cells. Images are taken every few minutes over many days, generating data too vast to process completely by hand. Computational analysis of this data can benefit from occasional human guidance. Here we combine improved automated algorithms with minimized human validation to produce fully corrected segmentation, tracking, and lineaging results with dramatic reduction in effort. A web-based viewer provides access to data and results. The improved approach allows efficient analysis of large numbers of clones. Using this method, we studied populations of progenitor cells derived from the anterior and posterior embryonic mouse cerebral cortex, each growing in a standardized culture environment. Progenitors from the anterior cortex were smaller, less motile, and produced smaller clones compared to those from the posterior cortex, demonstrating cell-intrinsic differences that may contribute to the areal organization of the cerebral cortex. PMID:26344906

Fourier Transfrom Ion Cyclotron Resonance Mass Spectrometry at High Magnetic Field

NASA Astrophysics Data System (ADS)

Marshall, Alan G.

1998-03-01

At high magnetic field (9.4 tesla at NHMFL), Fourier transform ion cyclotron resonance mass spectrometry performance improves dramatically: mass resolving power, axialization efficiency, and scan speed (each proportional to B), maximum ion mass, dynamic range, ion trapping period, kinetic energy, and electron self-cooling rate for sympathetic cooling (each proportional to B^2), and ion coalescence tendency (proportional 1/B^2). These advantages may apply singly (e.g., unit mass resolution for proteins of >100,000 Da), or compound (e.g., 10-fold improvement in S/N ratio for 9.4 T vs. 6 T at the same resolving power). Examples range from direct determination of molecular formulas of diesel fuel components by accurate mass measurement (=B10.1 ppm) to protein structure and dynamics probed by H/D exchange. This work was supported by N.S.F. (CHE-93-22824; CHE-94-13008), N.I.H. (GM-31683), Florida State University, and the National High Magnetic Field Laboratory in Tallahassee, FL.

Workflow in interventional radiology: nerve blocks and facet blocks

NASA Astrophysics Data System (ADS)

Siddoway, Donald; Ingeholm, Mary Lou; Burgert, Oliver; Neumuth, Thomas; Watson, Vance; Cleary, Kevin

2006-03-01

Workflow analysis has the potential to dramatically improve the efficiency and clinical outcomes of medical procedures. In this study, we recorded the workflow for nerve block and facet block procedures in the interventional radiology suite at Georgetown University Hospital in Washington, DC, USA. We employed a custom client/server software architecture developed by the Innovation Center for Computer Assisted Surgery (ICCAS) at the University of Leipzig, Germany. This software runs in an internet browser, and allows the user to record the actions taken by the physician during a procedure. The data recorded during the procedure is stored as an XML document, which can then be further processed. We have successfully gathered data on a number if cases using a tablet PC, and these preliminary results show the feasibility of using this software in an interventional radiology setting. We are currently accruing additional cases and when more data has been collected we will analyze the workflow of these procedures to look for inefficiencies and potential improvements.

MCTDH on-the-fly: Efficient grid-based quantum dynamics without pre-computed potential energy surfaces

NASA Astrophysics Data System (ADS)

Richings, Gareth W.; Habershon, Scott

2018-04-01

We present significant algorithmic improvements to a recently proposed direct quantum dynamics method, based upon combining well established grid-based quantum dynamics approaches and expansions of the potential energy operator in terms of a weighted sum of Gaussian functions. Specifically, using a sum of low-dimensional Gaussian functions to represent the potential energy surface (PES), combined with a secondary fitting of the PES using singular value decomposition, we show how standard grid-based quantum dynamics methods can be dramatically accelerated without loss of accuracy. This is demonstrated by on-the-fly simulations (using both standard grid-based methods and multi-configuration time-dependent Hartree) of both proton transfer on the electronic ground state of salicylaldimine and the non-adiabatic dynamics of pyrazine.

Quantum error correction assisted by two-way noisy communication

PubMed Central

Wang, Zhuo; Yu, Sixia; Fan, Heng; Oh, C. H.

2014-01-01

Pre-shared non-local entanglement dramatically simplifies and improves the performance of quantum error correction via entanglement-assisted quantum error-correcting codes (EAQECCs). However, even considering the noise in quantum communication only, the non-local sharing of a perfectly entangled pair is technically impossible unless additional resources are consumed, such as entanglement distillation, which actually compromises the efficiency of the codes. Here we propose an error-correcting protocol assisted by two-way noisy communication that is more easily realisable: all quantum communication is subjected to general noise and all entanglement is created locally without additional resources consumed. In our protocol the pre-shared noisy entangled pairs are purified simultaneously by the decoding process. For demonstration, we first present an easier implementation of the well-known EAQECC [[4, 1, 3; 1

Quantum error correction assisted by two-way noisy communication.

PubMed

Wang, Zhuo; Yu, Sixia; Fan, Heng; Oh, C H

2014-11-26

Pre-shared non-local entanglement dramatically simplifies and improves the performance of quantum error correction via entanglement-assisted quantum error-correcting codes (EAQECCs). However, even considering the noise in quantum communication only, the non-local sharing of a perfectly entangled pair is technically impossible unless additional resources are consumed, such as entanglement distillation, which actually compromises the efficiency of the codes. Here we propose an error-correcting protocol assisted by two-way noisy communication that is more easily realisable: all quantum communication is subjected to general noise and all entanglement is created locally without additional resources consumed. In our protocol the pre-shared noisy entangled pairs are purified simultaneously by the decoding process. For demonstration, we first present an easier implementation of the well-known EAQECC [[4, 1, 3; 1

Nanoplasmonics: a frontier of photovoltaic solar cells

NASA Astrophysics Data System (ADS)

Gu, Min; Ouyang, Zi; Jia, Baohua; Stokes, Nicholas; Chen, Xi; Fahim, Narges; Li, Xiangping; Ventura, Michael James; Shi, Zhengrong

2012-12-01

Nanoplasmonics recently has emerged as a new frontier of photovoltaic research. Noble metal nanostructures that can concentrate and guide light have demonstrated great capability for dramatically improving the energy conversion efficiency of both laboratory and industrial solar cells, providing an innovative pathway potentially transforming the solar industry. However, to make the nanoplasmonic technology fully appreciated by the solar industry, key challenges need to be addressed; including the detrimental absorption of metals, broadband light trapping mechanisms, cost of plasmonic nanomaterials, simple and inexpensive fabrication and integration methods of the plasmonic nanostructures, which are scalable for full size manufacture. This article reviews the recent progress of plasmonic solar cells including the fundamental mechanisms, material fabrication, theoretical modelling and emerging directions with a distinct emphasis on solutions tackling the above-mentioned challenges for industrial relevant applications.

Emerging model systems for functional genomics analysis of Crassulacean acid metabolism

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

Hartwell, James; Dever, Louisa V.; Boxall, Susanna F.

Crassulacean acid metabolism (CAM) is one of three main pathways of photosynthetic carbon dioxide fixation found in higher plants. It stands out for its ability to underpin dramatic improvements in plant water use efficiency, which in turn has led to a recent renaissance in CAM research. The current ease with which candidate CAM-associated genes and proteins can be identified through high-throughput sequencing has opened up a new horizon for the development of diverse model CAM species that are amenable to genetic manipulations. The adoption of these model CAM species is underpinning rapid advances in our understanding of the complete genemore » set for CAM. Here, we highlight recent breakthroughs in the functional characterisation of CAM genes that have been achieved through transgenic approaches.« less

ZnO Hierarchical Nanostructure Photoanode in a CdS Quantum Dot-Sensitized Solar Cell

PubMed Central

Liu, Huan; Zhang, Gengmin; Sun, Wentao; Shen, Ziyong; Shi, Mingji

2015-01-01

A hierarchical array of ZnO nanocones covered with ZnO nanospikes was hydrothermally fabricated and employed as the photoanode in a CdS quantum dot-sensitized solar cell (QDSSC). This QDSSC outperformed the QDSSC based on a simple ZnO nanocone photoanode in all the four principal photovoltaic parameters. Using the hierarchical photoanode dramatically increased the short circuit current density and also slightly raised the open circuit voltage and the fill factor. As a result, the conversion efficiency of the QDSSC based on the hierarchical photoanode was more than twice that of the QDSSC based on the simple ZnO nanocone photoanode. This improvement is attributable to both the enlarged specific area of the photoanode and the reduction in the recombination of the photoexcited electrons. PMID:26379268

A History of the Chemical Innovations in Silver-Halide Materials for Color PhotographyII. Color-Forming Development, Part 5. Coupler Innovations after the 1970's—Two-Equivalent Coupler and DIR Coupler

NASA Astrophysics Data System (ADS)

Oishi, Yasushi

After the 1970's on, several manufacturers including Fuji Film, Konica and Agfa-Gevaert participated in innovating color photographic materials by adding their own coupler chemistry to the technological architecture built by Kodak before then. One area of their major advances was development of the couplers having a coupling-off organic group. One of their functional forms was two-equivalent coupler which made the dye-forming process efficient and made the photosensitive layers slim. And another was DIR coupler which improved dramatically the image quality of color negative materials. In this paper a historical overview of these innovations is constructed from the technical documents, mainly patents.

Emerging model systems for functional genomics analysis of Crassulacean acid metabolism

DOE PAGES

Hartwell, James; Dever, Louisa V.; Boxall, Susanna F.

2016-04-12

Crassulacean acid metabolism (CAM) is one of three main pathways of photosynthetic carbon dioxide fixation found in higher plants. It stands out for its ability to underpin dramatic improvements in plant water use efficiency, which in turn has led to a recent renaissance in CAM research. The current ease with which candidate CAM-associated genes and proteins can be identified through high-throughput sequencing has opened up a new horizon for the development of diverse model CAM species that are amenable to genetic manipulations. The adoption of these model CAM species is underpinning rapid advances in our understanding of the complete genemore » set for CAM. Here, we highlight recent breakthroughs in the functional characterisation of CAM genes that have been achieved through transgenic approaches.« less

Continuous Succinic Acid Production by Actinobacillus succinogenes on Xylose-Enriched Hydrolysate

DOE PAGES

Bradfield, Michael F. A.; Mohagheghi, Ali; Salvachua, Davinia; ...

2015-11-14

Bio-manufacturing of high-value chemicals in parallel to renewable biofuels has the potential to dramatically improve the overall economic landscape of integrated lignocellulosic biorefineries. However, this will require the generation of carbohydrate streams from lignocellulose in a form suitable for efficient microbial conversion and downstream processing appropriate to the desired end use, making overall process development, along with selection of appropriate target molecules, crucial to the integrated biorefinery. Succinic acid (SA), a high-value target molecule, can be biologically produced from sugars and has the potential to serve as a platform chemical for various chemical and polymer applications. However, the feasibility ofmore » microbial SA production at industrially relevant productivities and yields from lignocellulosic biorefinery streams has not yet been reported.« less

Nutrient-enhanced n-alkanes biodegradation and succession of bacterial communities

NASA Astrophysics Data System (ADS)

Sun, Yanyu; Wang, Hui; Li, Junde; Wang, Bin; Qi, Cancan; Hu, Xiaoke

2017-11-01

Bioremediation, is an effective and environment-friendly method of cleaning up crude oil pollution after an oil spill. However, the in situ bioremediation of crude oil is usually inhibited by deficiency of inorganic nutrients. To understand the effects of nutrient addition on the bioremediation of crude oil and the succession of bacterial communities during process of bioremediation, microcosms containing oil-contaminated sediments were constructed and biodegradation of crude oil was assessed based on the depletion of different ingredients. We used two culture-independent methods, denaturing gradient gel electrophoresis and a 16S rRNA gene based clone library, to analyze the succession of bacterial communities. The results suggested n-alkanes were degraded after 30 days and that nutrient amendments significantly improved the efficiency of their biodegradation. Moreover, oil contamination and nutrient amendments could dramatically change bacterial community structures. Lower diversity was detected after being contaminated with oil. For instance, bacterial clones affiliated with the phylum Armatimonadetes, Firmicutes, Gemmatimonadetes, and Planctomycetes and the class Deltaproteobacteria and Epsilonproteobacteria could not be identified after 30 days of incubation with crude oil. However, "professional hydrocarbonocastic bacteria" became abundant in samples treated with oil during the bioremediation period, while these clones were almost completely absent from the control plots. Interestingly, bioinformatics analysis showed that even when dramatic differences in oil biodegradation efficiency were observed, bacterial communities in the plots with nutrient amendments were not significantly different from those in plots treated with oil alone. These findings indicated that nutrient amendments could stimulate the process of biodegradation but had less impact on bacterial communities. Overall, nutrient amendments might be able to stimulate the growth of n-alkane degrading bacteria.

Limiting technologies for particle beams and high energy physics

NASA Astrophysics Data System (ADS)

Panofsky, W. K. H.

1985-07-01

Since 1930 the energy of accelerators had grown by an order of magnitude roughly every 7 years. Like all exponential growths, be they human population, the size of computers, or anything else, this eventually will have to come to an end. When will this happen to the growth of the energy of particle accelerators and colliders? Fortunately, as the energy of accelerators has grown the cost per unit energy has decreased almost as fast as has the increase in energy. The result is that while the energy has increased so dramatically the cost per new installation has increased only by roughly an order of magnitude since the 1930's (corrected for inflation), while the number of accelerators operating at the frontier of the field has shrunk. As is shown in the by now familiar Livingston chart this dramatic decrease in cost has been achieved largely by a succession of new technologies, in addition to the more moderate gains in efficiency due to improved design, economies of scale, etc. We are therefore facing two questions: (1) Is there good reason scientifically to maintain the exponential growth, and (2) Are there new technologies in sight which promise continued decreases in unit costs. The answer to the first question is definitely yes; the answer to the second question is maybe.

Silica sol-gel encapsulation of cyanobacteria: lessons for academic and applied research.

PubMed

Dickson, David J; Ely, Roger L

2013-03-01

Cyanobacteria inhabit nearly every ecosystem on earth, play a vital role in nutrient cycling, and are useful as model organisms for fundamental research in photosynthesis and carbon and nitrogen fixation. In addition, they are important for several established biotechnologies for producing food additives, nutritional and pharmaceutical compounds, and pigments, as well as emerging biotechnologies for biofuels and other products. Encapsulation of living cyanobacteria into a porous silica gel matrix is a recent approach that may dramatically improve the efficiency of certain production processes by retaining the biomass within the reactor and modifying cellular metabolism in helpful ways. Although encapsulation has been explored empirically in the last two decades for a variety of cell types, many challenges remain to achieving optimal encapsulation of cyanobacteria in silica gel. Recent evidence with Synechocystis sp. PCC 6803, for example, suggests that several unknown or uncharacterized proteins are dramatically upregulated as a result of encapsulation. Also, additives commonly used to ease stresses of encapsulating living cells, such as glycerol, have detrimental impacts on photosynthesis in cyanobacteria. This mini-review is intended to address the current status of research on silica sol-gel encapsulation of cyanobacteria and research areas that may further the development of this approach for biotechnology applications.

Private tollways : how states can leverage federal highway funds

DOT National Transportation Integrated Search

1992-02-01

Congress has dramatically changed the rules on highway finance in enacting the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA). Reversing 70 years of federal opposition to toll roads, the new law encourages state governments to make ...

Polymerase ribozyme efficiency increased by G/T-rich DNA oligonucleotides

PubMed Central

Yao, Chengguo; Müller, Ulrich F.

2011-01-01

The RNA world hypothesis states that the early evolution of life went through a stage where RNA served as genome and as catalyst. The replication of RNA world organisms would have been facilitated by ribozymes that catalyze RNA polymerization. To recapitulate an RNA world in the laboratory, a series of RNA polymerase ribozymes was developed previously. However, these ribozymes have a polymerization efficiency that is too low for self-replication, and the most efficient ribozymes prefer one specific template sequence. The limiting factor for polymerization efficiency is the weak sequence-independent binding to its primer/template substrate. Most of the known polymerase ribozymes bind an RNA heptanucleotide to form the P2 duplex on the ribozyme. By modifying this heptanucleotide, we were able to significantly increase polymerization efficiency. Truncations at the 3′-terminus of this heptanucleotide increased full-length primer extension by 10-fold, on a specific template sequence. In contrast, polymerization on several different template sequences was improved dramatically by replacing the RNA heptanucleotide with DNA oligomers containing randomized sequences of 15 nt. The presence of G and T in the random sequences was sufficient for this effect, with an optimal composition of 60% G and 40% T. Our results indicate that these DNA sequences function by establishing many weak and nonspecific base-pairing interactions to the single-stranded portion of the template. Such low-specificity interactions could have had important functions in an RNA world. PMID:21622900

Sustainable IT and IT for Sustainability

NASA Astrophysics Data System (ADS)

Liu, Zhenhua

Energy and sustainability have become one of the most critical issues of our generation. While the abundant potential of renewable energy such as solar and wind provides a real opportunity for sustainability, their intermittency and uncertainty present a daunting operating challenge. This thesis aims to develop analytical models, deployable algorithms, and real systems to enable efficient integration of renewable energy into complex distributed systems with limited information. The first thrust of the thesis is to make IT systems more sustainable by facilitating the integration of renewable energy into these systems. IT represents the fastest growing sectors in energy usage and greenhouse gas pollution. Over the last decade there are dramatic improvements in the energy efficiency of IT systems, but the efficiency improvements do not necessarily lead to reduction in energy consumption because more servers are demanded. Further, little effort has been put in making IT more sustainable, and most of the improvements are from improved "engineering" rather than improved "algorithms". In contrast, my work focuses on developing algorithms with rigorous theoretical analysis that improve the sustainability of IT. In particular, this thesis seeks to exploit the flexibilities of cloud workloads both (i) in time by scheduling delay-tolerant workloads and (ii) in space by routing requests to geographically diverse data centers. These opportunities allow data centers to adaptively respond to renewable availability, varying cooling efficiency, and fluctuating energy prices, while still meeting performance requirements. The design of the enabling algorithms is however very challenging because of limited information, non-smooth objective functions and the need for distributed control. Novel distributed algorithms are developed with theoretically provable guarantees to enable the "follow the renewables" routing. Moving from theory to practice, I helped HP design and implement industry's first Net-zero Energy Data Center. The second thrust of this thesis is to use IT systems to improve the sustainability and efficiency of our energy infrastructure through data center demand response. The main challenges as we integrate more renewable sources to the existing power grid come from the fluctuation and unpredictability of renewable generation. Although energy storage and reserves can potentially solve the issues, they are very costly. One promising alternative is to make the cloud data centers demand responsive. The potential of such an approach is huge. To realize this potential, we need adaptive and distributed control of cloud data centers and new electricity market designs for distributed electricity resources. My work is progressing in both directions. In particular, I have designed online algorithms with theoretically guaranteed performance for data center operators to deal with uncertainties under popular demand response programs. Based on local control rules of customers, I have further designed new pricing schemes for demand response to align the interests of customers, utility companies, and the society to improve social welfare.

Effects of pyrite and sphalerite on population compositions, dynamics and copper extraction efficiency in chalcopyrite bioleaching process.

PubMed

Xiao, Yunhua; Liu, Xueduan; Dong, Weiling; Liang, Yili; Niu, Jiaojiao; Gu, Yabing; Ma, Liyuan; Hao, Xiaodong; Zhang, Xian; Xu, Zhen; Yin, Huaqun

2017-07-01

This study used an artificial microbial community with four known moderately thermophilic acidophiles (three bacteria including Acidithiobacillus caldus S1, Sulfobacillus thermosulfidooxidans ST and Leptospirillum ferriphilum YSK, and one archaea, Ferroplasma thermophilum L1) to explore the variation of microbial community structure, composition, dynamics and function (e.g., copper extraction efficiency) in chalcopyrite bioleaching (C) systems with additions of pyrite (CP) or sphalerite (CS). The community compositions and dynamics in the solution and on the ore surface were investigated by real-time quantitative PCR (qPCR). The results showed that the addition of pyrite or sphalerite changed the microbial community composition and dynamics dramatically during the chalcopyrite bioleaching process. For example, A. caldus (above 60%) was the dominant species at the initial stage in three groups, and at the middle stage, still dominated C group (above 70%), but it was replaced by L. ferriphilum (above 60%) in CP and CS groups; at the final stage, L. ferriphilum dominated C group, while F. thermophilum dominated CP group on the ore surface. Furthermore, the additions of pyrite or sphalerite both made the increase of redox potential (ORP) and the concentrations of Fe 3+ and H + , which would affect the microbial community compositions and copper extraction efficiency. Additionally, pyrite could enhance copper extraction efficiency (e.g., improving around 13.2% on day 6) during chalcopyrite bioleaching; on the contrary, sphalerite restrained it.

Depth-color fusion strategy for 3-D scene modeling with Kinect.

PubMed

Camplani, Massimo; Mantecon, Tomas; Salgado, Luis

2013-12-01

Low-cost depth cameras, such as Microsoft Kinect, have completely changed the world of human-computer interaction through controller-free gaming applications. Depth data provided by the Kinect sensor presents several noise-related problems that have to be tackled to improve the accuracy of the depth data, thus obtaining more reliable game control platforms and broadening its applicability. In this paper, we present a depth-color fusion strategy for 3-D modeling of indoor scenes with Kinect. Accurate depth and color models of the background elements are iteratively built, and used to detect moving objects in the scene. Kinect depth data is processed with an innovative adaptive joint-bilateral filter that efficiently combines depth and color by analyzing an edge-uncertainty map and the detected foreground regions. Results show that the proposed approach efficiently tackles main Kinect data problems: distance-dependent depth maps, spatial noise, and temporal random fluctuations are dramatically reduced; objects depth boundaries are refined, and nonmeasured depth pixels are interpolated. Moreover, a robust depth and color background model and accurate moving objects silhouette are generated.

An Efficient Correction Algorithm for Eliminating Image Misalignment Effects on Co-Phasing Measurement Accuracy for Segmented Active Optics Systems

PubMed Central

Yue, Dan; Xu, Shuyan; Nie, Haitao; Wang, Zongyang

2016-01-01

The misalignment between recorded in-focus and out-of-focus images using the Phase Diversity (PD) algorithm leads to a dramatic decline in wavefront detection accuracy and image recovery quality for segmented active optics systems. This paper demonstrates the theoretical relationship between the image misalignment and tip-tilt terms in Zernike polynomials of the wavefront phase for the first time, and an efficient two-step alignment correction algorithm is proposed to eliminate these misalignment effects. This algorithm processes a spatial 2-D cross-correlation of the misaligned images, revising the offset to 1 or 2 pixels and narrowing the search range for alignment. Then, it eliminates the need for subpixel fine alignment to achieve adaptive correction by adding additional tip-tilt terms to the Optical Transfer Function (OTF) of the out-of-focus channel. The experimental results demonstrate the feasibility and validity of the proposed correction algorithm to improve the measurement accuracy during the co-phasing of segmented mirrors. With this alignment correction, the reconstructed wavefront is more accurate, and the recovered image is of higher quality. PMID:26934045

A 7T spine array based on electric dipole transmitters.

PubMed

Duan, Qi; Nair, Govind; Gudino, Natalia; de Zwart, Jacco A; van Gelderen, Peter; Murphy-Boesch, Joe; Reich, Daniel S; Duyn, Jeff H; Merkle, Hellmut

2015-10-01

The goal of this study was to explore the feasibility of using an array of electric dipole antennas for RF transmission in spine MRI at high fields. A two-channel transmit array based on an electric dipole design was quantitatively optimized for 7T spine imaging and integrated with a receive array combining eight loop coils. Using B1+ mapping, the transmit efficiency of the dipole array was compared with a design using quadrature loop pairs. The radiofrequency energy deposition for each array was measured using a home-built dielectric phantom and MR thermometry. The performance of the proposed array was qualitatively demonstrated in human studies. The results indicate dramatically improved transmit efficiency for the dipole design compared with the loop excitation. A gain of up to 76% was achieved within the spinal region. For imaging of the spine, electric dipole-based transmitters provide an attractive alternative to the traditional loop-based design. Easy integration with existing receive array technology facilitates practical use at high fields. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Non-wetting surface-driven high-aspect-ratio crystalline grain growth for efficient hybrid perovskite solar cells

DOE PAGES

Bi, Cheng; Wang, Qi; Shao, Yuchuan; ...

2015-07-20

Large-aspect-ratio grains are needed in polycrystalline thin-film solar cells for reduced charge recombination at grain boundaries; however, the grain size in organolead trihalide perovskite (OTP) films is generally limited by the film thickness. Here we report the growth of OTP grains with high average aspect ratio of 2.3–7.9 on a wide range of non-wetting hole transport layers (HTLs), which increase nucleus spacing by suppressing heterogeneous nucleation and facilitate grain boundary migration in grain growth by imposing less drag force. The reduced grain boundary area and improved crystallinity dramatically reduce the charge recombination in OTP thin films to the level inmore » OTP single crystals. Combining the high work function of several HTLs, a high stabilized device efficiency of 18.3% in low-temperature-processed planar-heterojunction OTP devices under 1 sun illumination is achieved. As a result, this simple method in enhancing OTP morphology paves the way for its application in other optoelectronic devices for enhanced performance.« less

Matrix product operators, matrix product states, and ab initio density matrix renormalization group algorithms

NASA Astrophysics Data System (ADS)

Chan, Garnet Kin-Lic; Keselman, Anna; Nakatani, Naoki; Li, Zhendong; White, Steven R.

2016-07-01

Current descriptions of the ab initio density matrix renormalization group (DMRG) algorithm use two superficially different languages: an older language of the renormalization group and renormalized operators, and a more recent language of matrix product states and matrix product operators. The same algorithm can appear dramatically different when written in the two different vocabularies. In this work, we carefully describe the translation between the two languages in several contexts. First, we describe how to efficiently implement the ab initio DMRG sweep using a matrix product operator based code, and the equivalence to the original renormalized operator implementation. Next we describe how to implement the general matrix product operator/matrix product state algebra within a pure renormalized operator-based DMRG code. Finally, we discuss two improvements of the ab initio DMRG sweep algorithm motivated by matrix product operator language: Hamiltonian compression, and a sum over operators representation that allows for perfect computational parallelism. The connections and correspondences described here serve to link the future developments with the past and are important in the efficient implementation of continuing advances in ab initio DMRG and related algorithms.

Efficient Multi-Dimensional Simulation of Quantum Confinement Effects in Advanced MOS Devices

NASA Technical Reports Server (NTRS)

Biegel, Bryan A.; Rafferty, Conor S.; Ancona, Mario G.; Yu, Zhi-Ping

2000-01-01

We investigate the density-gradient (DG) transport model for efficient multi-dimensional simulation of quantum confinement effects in advanced MOS devices. The formulation of the DG model is described as a quantum correction to the classical drift-diffusion model. Quantum confinement effects are shown to be significant in sub-100nm MOSFETs. In thin-oxide MOS capacitors, quantum effects may reduce gate capacitance by 25% or more. As a result, the inclusion or quantum effects in simulations dramatically improves the match between C-V simulations and measurements for oxide thickness down to 2 nm. Significant quantum corrections also occur in the I-V characteristics of short-channel (30 to 100 nm) n-MOSFETs, with current drive reduced by up to 70%. This effect is shown to result from reduced inversion charge due to quantum confinement of electrons in the channel. Also, subthreshold slope is degraded by 15 to 20 mV/decade with the inclusion of quantum effects via the density-gradient model, and short channel effects (in particular, drain-induced barrier lowering) are noticeably increased.

Matrix product operators, matrix product states, and ab initio density matrix renormalization group algorithms.

PubMed

Chan, Garnet Kin-Lic; Keselman, Anna; Nakatani, Naoki; Li, Zhendong; White, Steven R

2016-07-07

Current descriptions of the ab initio density matrix renormalization group (DMRG) algorithm use two superficially different languages: an older language of the renormalization group and renormalized operators, and a more recent language of matrix product states and matrix product operators. The same algorithm can appear dramatically different when written in the two different vocabularies. In this work, we carefully describe the translation between the two languages in several contexts. First, we describe how to efficiently implement the ab initio DMRG sweep using a matrix product operator based code, and the equivalence to the original renormalized operator implementation. Next we describe how to implement the general matrix product operator/matrix product state algebra within a pure renormalized operator-based DMRG code. Finally, we discuss two improvements of the ab initio DMRG sweep algorithm motivated by matrix product operator language: Hamiltonian compression, and a sum over operators representation that allows for perfect computational parallelism. The connections and correspondences described here serve to link the future developments with the past and are important in the efficient implementation of continuing advances in ab initio DMRG and related algorithms.

Energy-level alignment and open-circuit voltage at graphene/polymer interfaces: theory and experiment

NASA Astrophysics Data System (ADS)

Noori, Keian; Konios, Dimitrios; Stylianakis, Minas M.; Kymakis, Emmanuel; Giustino, Feliciano

2016-03-01

Functionalized graphene promises to become a key component of novel solar cell architectures, owing to its versatile ability to act either as transparent conductor, electron acceptor, or buffer layer. In spite of this promise, the solar energy conversion efficiency of graphene-based devices falls short of the performance of competing solution-processable photovoltaic technologies. Here we address the question of the maximum achievable open-circuit voltage of all-organic graphene: polymer solar cells using a combined theoretical/experimental approach, going from the atomic scale level to the device level. Our calculations on very large atomistic models of the graphene/polymer interface indicate that the ideal open-circuit voltage approaches one volt, and that epoxide functional groups can have a dramatic effect on the photovoltage. Our predictions are confirmed by direct measurements on complete devices where we control the concentration of functional groups via chemical reduction. Our findings indicate that the selective removal of epoxide groups and the use of ultradisperse polymers are key to achieving graphene solar cells with improved energy conversion efficiency.

The Histone Acetyltransferase MOF Promotes Induces Generation of Pluripotent Stem Cells.

PubMed

Mu, Xupeng; Yan, Shaohua; Fu, Changhao; Wei, Anhui

2015-08-01

Histone modification plays an important role in maintaining pluripotency and self-renewal of embryonic stem cells (ESCs). The histone acetyltransferase MOF is a key regulator of ESCs; however, the role of MOF in the process of reprogramming back to induced pluripotent stem cells (iPSCs) remains unclear. In this study, we investigated the function of MOF on the generation of iPSCs. We show that iPSCs contain high levels of MOF mRNA, and the expression level of MOF protein is dramatically upregulated following reprogramming. Most importantly, overexpression of MOF improves reprogramming efficiency and facilitates the formation of iPSCs, whereas small hairpin RNA (shRNA)-mediated knockdown of MOF impairs iPSCs generation during reprogramming. Further investigation reveals that MOF interacts with the H3K4 methyltransferase Wdr5 to promote endogenous Oct4 expression during the reprogramming process. Knockdown of MOF reduces H4K16ac and H3K4me3 modification at the Oct4 promoter. In conclusion, our data indicate that MOF is an important epigenetic regulator that is critical for efficient reprogramming.

The Big Glamorous Monster (or Lady Gaga's Adventures at Sea): Improving Student Writing through Dramatic Approaches in Schools

ERIC Educational Resources Information Center

Lee, Bridget Kiger; Enciso, Patricia

2017-01-01

Drawing on assets-oriented, sociocultural theories of imagination and learning, the authors argue that the improvisational qualities and expanded resources of dramatic approaches to teaching make a positive difference in the quality of and persistence in students' story writing. The authors describe findings from a controlled quasi-experimental…

How to Know when Dramatic Change Is on Track: Leading Indicators of School Turnarounds

ERIC Educational Resources Information Center

Kowal, Julie; Ableidinger, Joe

2011-01-01

In recent years, national policymakers have placed new emphasis on "school turnarounds" as a strategy for rapid, dramatic improvement in chronically failing schools, calling on education leaders to turn around performance in the 5,000 lowest-achieving schools nationwide. This goal may seem daunting, given the dismal success rates of…

Strategies toward High Performance Organic Photovoltaic Cell: Material and Process

NASA Astrophysics Data System (ADS)

Kim, Bong Gi

The power conversion efficiency of organic photovoltaic (OPV) cells has been rapidly improved during the last few years and currently reaches around 10 %. The performance is evenly governed by absorption, exciton diffusion, exciton dissociation, carrier transfer, and collection efficiencies. Establishing a better understanding of OPV device physics combined with the development of new materials for each executive step contributes to this dramatic improvement. This dissertation focuses mainly on material design and development to correlate the intrinsic properties of organic semiconductors and the OPV performance. The introductory Chapter 1 briefly reviews the motivation of OPV research, its working mechanism, and representative organic materials for OPV application. Chapter 2 discusses the modulation of conjugated polymer's (CP's) absorption behavior and an efficient semi-empirical approach to predict CP's energy levels from its constituent monomers' HOMO/LUMO values. A strong acceptor lowered both the HOMO and LUMO levels of the CP, but the LUMO dropped more rapidly which ultimately produced a narrowed band-gap in the electron donating/accepting alternating copolymer system. In addition, the energy level difference between the CP and the constituent monomers converged to a constant value, providing an energy level prediction tool. Chapter 3 illustrates the systematic investigation on the relationship between the molecular structure of an energy harvesting organic dye and the exciton dissociation efficiency. The study showed that the quantum yield decreased as the exciton binding energy increases, and dipole moment direction should be properly oriented in the dye framework in order to improve photo-current generation when used in a dye sensitized photovoltaic device. Chapter 4 demonstrates the ultrasonic-assisted self-assembly of CPs in solution, rapidly and efficiently. Ultrasonication combined with dipolar media accelerated CP's aggregation, and the effect of CP's aggregation on the enhancement of OPV performance by promoting photo-current generation and increasing carrier mobility was systematically investigated. The correlation between the chemical structure of a CP and it aggregation behavior is further described in Chapter 5. To promote CP aggregate, a planar chain conformation was advantageous and CP aggregation improved hole mobility in the OPV device. However, thermally induced CP aggregates caused strong charge recombination, resulting in open circuit voltage drop. In Chapter 6, a novel polymer design principle to enable directed CP alignment is discussed. Regulating chain planarity and preventing massive crystallization of CP achieved by the developed molecular design principle allowed directed CP alignment under small shear flow.

In vitro porcine blastocyst development in three-dimentional alginate hydrogels

USDA-ARS?s Scientific Manuscript database

Appropriate embryonic and fetal development significantly impact pregnancy success and, therefore, the efficiency of swine production. The pre-implantation period of porcine pregnancy is characterized by several developmental hallmarks, which are initiated by the dramatic morphological change that o...

Building a sustainable GIS framework for supporting a tribal transportation problem.

DOT National Transportation Integrated Search

2017-03-01

Due to the recent oil boom, the Fort Berthold Reservation has experienced a dramatic increase in highway and local traffic. To support energy transportation and provide safe roads, the reservation needs cost-efficient and effective transportation pla...

NASA Puffin Electric Tailsitter VTOL Concept

NASA Technical Reports Server (NTRS)

Moore, Mark D.

2010-01-01

Electric propulsion offers dramatic new vehicle mission capabilities, not possible with turbine or reciprocating engines; including high reliability and efficiency, low engine weight and maintenance, low cooling drag and volume required, very low noise and vibration, and zero emissions. The only penalizing characteristic of electric propulsion is the current energy storage technology level, which is set to triple over the next 5-10 years through huge new investments in this field. Most importantly, electric propulsion offers incredible new degrees of freedom in aircraft system integration to achieve unprecedented levels of aerodynamic, propulsive, control, and structural synergistic coupling. A unique characteristic of electric propulsion is that the technology is nearly scale-free, permitting small motors to be parallelized for fail-safe redundancy, or distributed across the airframe for tightly coupled interdisciplinary functionality without significant impacts in motor-controller efficiency or specific weight. Maximizing the potential benefit of electric propulsion is dependent on applying this technology to synergistic mission concepts. The vehicle missions with the most benefit include those which constrain environmental impact (or limit noise, exhaust, or emission signatures) are short range, or where large differences exist in the propulsion system sizing between takeoff and cruise conditions. Electric propulsion offers the following unique capabilities that other propulsion systems can t provide for short range Vertical Takeoff and Landing (VTOL) aircraft; elimination of engine noise and emissions, drastic reduction in engine cooling and radiated heat, drastic reduction in vehicle vibration levels, drastic improvement in reliability and operating costs, variable speed output at full power, for improved cruise efficiency at low tip-speed, elimination of high/hot sizing penalty, and reduction of engine-out penalties.

The zinc finger E-box-binding homeobox 1 (Zeb1) promotes the conversion of mouse fibroblasts into functional neurons.

PubMed

Yan, Long; Li, Yue; Shi, Zixiao; Lu, Xiaoyin; Ma, Jiao; Hu, Baoyang; Jiao, Jianwei; Wang, Hongmei

2017-08-04

The zinc finger E-box-binding transcription factor Zeb1 plays a pivotal role in the epithelial-mesenchymal transition. Numerous studies have focused on the molecular mechanisms by which Zeb1 contributes to this process. However, the functions of Zeb1 beyond the epithelial-mesenchymal transition remain largely elusive. Using a transdifferentiation system to convert mouse embryonic fibroblasts (MEFs) into functional neurons via the neuronal transcription factors achaete-scute family bHLH (basic helix-loop-helix) transcription factor1 ( Ascl1 ), POU class 3 homeobox 2 (POU3F2/ Brn2 ), and neurogenin 2 (Neurog2, Ngn2 ) (ABN), we found that Zeb1 was up-regulated during the early stages of transdifferentiation. Knocking down Zeb1 dramatically attenuated the transdifferentiation efficiency, whereas Zeb1 overexpression obviously increased the efficiency of transdifferentiation from MEFs to neurons. Interestingly, Zeb1 improved the transdifferentiation efficiency induced by even a single transcription factor ( e.g. Asc1 or Ngn2 ). Zeb1 also rapidly promoted the maturation of induced neuron cells to functional neurons and improved the formation of neuronal patterns and electrophysiological characteristics. Induced neuron cells could form functional synapse in vivo after transplantation. Genome-wide RNA arrays showed that Zeb1 overexpression up-regulated the expression of neuron-specific genes and down-regulated the expression of epithelial-specific genes during conversion. Taken together, our results reveal a new role for Zeb1 in the transdifferentiation of MEFs into neurons. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Rapid brain MRI acquisition techniques at ultra-high fields

PubMed Central

Setsompop, Kawin; Feinberg, David A.; Polimeni, Jonathan R.

2017-01-01

Ultra-high-field MRI provides large increases in signal-to-noise ratio as well as enhancement of several contrast mechanisms in both structural and functional imaging. Combined, these gains result in a substantial boost in contrast-to-noise ratio that can be exploited for higher spatial resolution imaging to extract finer-scale information about the brain. With increased spatial resolution, however, is a concurrent increased image encoding burden that can cause unacceptably long scan times for structural imaging and slow temporal sampling of the hemodynamic response in functional MRI—particularly when whole-brain imaging is desired. To address this issue, new directions of imaging technology development—such as the move from conventional 2D slice-by-slice imaging to more efficient Simultaneous MultiSlice (SMS) or MultiBand imaging (which can be viewed as “pseudo-3D” encoding) as well as full 3D imaging—have provided dramatic improvements in acquisition speed. Such imaging paradigms provide higher SNR efficiency as well as improved encoding efficiency. Moreover, SMS and 3D imaging can make better use of coil sensitivity information in multi-channel receiver arrays used for parallel imaging acquisitions through controlled aliasing in multiple spatial directions. This has enabled unprecedented acceleration factors of an order of magnitude or higher in these imaging acquisition schemes, with low image artifact levels and high SNR. Here we review the latest developments of SMS and 3D imaging methods and related technologies at ultra-high field for rapid high-resolution functional and structural imaging of the brain. PMID:26835884

High efficiency labeling of glycoproteins on living cells

PubMed Central

Zeng, Ying; Ramya, T. N. C.; Dirksen, Anouk; Dawson, Philip E.; Paulson, James C.

2010-01-01

We describe a simple method for efficiently labeling cell surface glycans on virtually any living animal cell. The method employs mild Periodate oxidation to generate an aldehyde on sialic acids, followed by Aniline-catalyzed oxime Ligation with a suitable tag (PAL). Aniline catalysis dramatically accelerates oxime ligation, allowing use of low concentrations of aminooxy-biotin at neutral pH to label the majority of cell surface glycoproteins while maintaining high cell viability. PMID:19234450

Socio-dramatic affective-relational intervention for adolescents with asperger syndrome & high functioning autism: pilot study.

PubMed

Lerner, Matthew D; Mikami, Amori Yee; Levine, Karen

2011-01-01

This study examined the effectiveness of a novel intervention called 'socio-dramatic affective-relational intervention' (SDARI), intended to improve social skills among adolescents with Asperger syndrome and high functioning autism diagnoses. SDARI adapts dramatic training activities to focus on in vivo practice of areas of social skill deficit among this population. SDARI was administered as a six-week summer program in a community human service agency. Nine SDARI participants and eight age- and diagnosis-group matched adolescents not receiving SDARI were compared on child- and parent-report of social functioning at three week intervals beginning six weeks prior to intervention and ending six weeks post-intervention. Hierarchical Linear Modeling (HLM) was used to estimate growth trends between groups to assess treatment outcomes and post-treatment maintenance. Results indicated significant improvement and post-treatment maintenance among SDARI participants on several measures of child social functioning. Implications for practice and research are discussed.

Tumor-targeting delivery of herb-based drugs with cell-penetrating/tumor-targeting peptide-modified nanocarriers

PubMed Central

Kebebe, Dereje; Liu, Yuanyuan; Wu, Yumei; Vilakhamxay, Maikhone; Liu, Zhidong; Li, Jiawei

2018-01-01

Cancer has become one of the leading causes of mortality globally. The major challenges of conventional cancer therapy are the failure of most chemotherapeutic agents to accumulate selectively in tumor cells and their severe systemic side effects. In the past three decades, a number of drug delivery approaches have been discovered to overwhelm the obstacles. Among these, nanocarriers have gained much attention for their excellent and efficient drug delivery systems to improve specific tissue/organ/cell targeting. In order to enhance targeting efficiency further and reduce limitations of nanocarriers, nanoparticle surfaces are functionalized with different ligands. Several kinds of ligand-modified nanomedicines have been reported. Cell-penetrating peptides (CPPs) are promising ligands, attracting the attention of researchers due to their efficiency to transport bioactive molecules intracellularly. However, their lack of specificity and in vivo degradation led to the development of newer types of CPP. Currently, activable CPP and tumor-targeting peptide (TTP)-modified nanocarriers have shown dramatically superior cellular specific uptake, cytotoxicity, and tumor growth inhibition. In this review, we discuss recent advances in tumor-targeting strategies using CPPs and their limitations in tumor delivery systems. Special emphasis is given to activable CPPs and TTPs. Finally, we address the application of CPPs and/or TTPs in the delivery of plant-derived chemotherapeutic agents. PMID:29563797

Twin Neurons for Efficient Real-World Data Distribution in Networks of Neural Cliques: Applications in Power Management in Electronic Circuits.

PubMed

Boguslawski, Bartosz; Gripon, Vincent; Seguin, Fabrice; Heitzmann, Frédéric

2016-02-01

Associative memories are data structures that allow retrieval of previously stored messages given part of their content. They, thus, behave similarly to the human brain's memory that is capable, for instance, of retrieving the end of a song, given its beginning. Among different families of associative memories, sparse ones are known to provide the best efficiency (ratio of the number of bits stored to that of the bits used). Recently, a new family of sparse associative memories achieving almost optimal efficiency has been proposed. Their structure, relying on binary connections and neurons, induces a direct mapping between input messages and stored patterns. Nevertheless, it is well known that nonuniformity of the stored messages can lead to a dramatic decrease in performance. In this paper, we show the impact of nonuniformity on the performance of this recent model, and we exploit the structure of the model to improve its performance in practical applications, where data are not necessarily uniform. In order to approach the performance of networks with uniformly distributed messages presented in theoretical studies, twin neurons are introduced. To assess the adapted model, twin neurons are used with the real-world data to optimize power consumption of electronic circuits in practical test cases.

Single-mode light source fabrication based on colloidal quantum dots

NASA Astrophysics Data System (ADS)

Xu, Jianfeng; Chen, Bing; Baig, Sarfaraz; Wang, Michael R.

2009-02-01

There are huge market demands for innovative, cheap and efficient light sources, including light emitting devices, such as LEDs and lasers. However, the light source development in the visible spectral range encounters significant difficulties these years. The available visible wavelength LEDs or lasers are few, large and expensive. The main challenge lies at the lack of efficient light media. Semiconductor nanocrystal quantum dots (QDs) have recently commanded considerable attention. As a result of quantum confinement effect, the emission color of these QDs covers the whole visible spectral range and can be modified dramatically by simply changing their size. Such spectral tunability, together with large photoluminescence quantum yield and photostability, make QDs attractive for potential applications in a variety of light emitting technologies. However, there are still several technical problems that hinder their application as light sources. One main issue is how to fabricate these QDs into a solid state device while still retaining their original optical emission properties. A vacuum assisted micro-fluidic fabrication of guided wave devices has demonstrated low waveguide propagation loss, lower crosstalk, and improved waveguide structures. We report herein the combination of the excellent emission properties of QDs and novel vacuum assisted micro-fluidic photonic structure fabrication technique to realize single-mode efficient light sources.

The short-term effects of merger on hospital operations.

PubMed Central

Alexander, J A; Halpern, M T; Lee, S Y

1996-01-01

OBJECTIVE: The short-term effects of merger on three areas of hospital operations - scale of activity, personnel/staffing practices, and operating efficiency - is examined. DATA SOURCES: Secondary data obtained from the AHA Annual Surveys (1980-1990) were applied to analyze 92 hospital mergers over the period 1982-1989. STUDY DESIGN: The study employed a multiple time-series design involving a six-year longitudinal assessment of change in hospital operating characteristics before and after merger, and a parallel analysis of change in a randomly selected group of nonmerging hospitals. DATA COLLECTION: Pooled, cross-sectional data files were constructed. Comparisons were evaluated using paired and two-sample t-tests. PRINCIPAL FINDINGS: General merger effects occurred primarily in areas related to operating efficiency. Merger resulted in slowing rates of preexisting trends, rather than dramatic improvements in operating practices. CONCLUSIONS: The short-term impact of merger was generally modest but differed by the conditions under which the merger occurred. Specifically, mergers occurring later in the study period and mergers between similarly sized hospitals displayed greater change in operating characteristics than those occurring earlier in the study period and those between hospitals of dissimilar size. Such differences are attributed respectively to increased competitive pressures after PPS and to greater opportunities for consolidation and efficiencies in mergers involving similarly sized hospitals. PMID:8591932

Development of versatile non-homologous end joining-based knock-in module for genome editing.

PubMed

Sawatsubashi, Shun; Joko, Yudai; Fukumoto, Seiji; Matsumoto, Toshio; Sugano, Shigeo S

2018-01-12

CRISPR/Cas9-based genome editing has dramatically accelerated genome engineering. An important aspect of genome engineering is efficient knock-in technology. For improved knock-in efficiency, the non-homologous end joining (NHEJ) repair pathway has been used over the homology-dependent repair pathway, but there remains a need to reduce the complexity of the preparation of donor vectors. We developed the versatile NHEJ-based knock-in module for genome editing (VIKING). Using the consensus sequence of the time-honored pUC vector to cut donor vectors, any vector with a pUC backbone could be used as the donor vector without customization. Conditions required to minimize random integration rates of the donor vector were also investigated. We attempted to isolate null lines of the VDR gene in human HaCaT keratinocytes using knock-in/knock-out with a selection marker cassette, and found 75% of clones isolated were successfully knocked-in. Although HaCaT cells have hypotetraploid genome composition, the results suggest multiple clones have VDR null phenotypes. VIKING modules enabled highly efficient knock-in of any vectors harboring pUC vectors. Users now can insert various existing vectors into an arbitrary locus in the genome. VIKING will contribute to low-cost genome engineering.

Correcting Gravitational Deformation at the Tianma Radio Telescope

NASA Astrophysics Data System (ADS)

Dong, Jian; Zhong, Weiye; Wang, Jinqing; Liu, Qinghui; Shen, Zhiqiang

2018-04-01

The primary reflector of the Tianma Radio Telescope (TMRT) distorts due to gravity, which dramatically reduces the aperture efficiency of high-frequency observations. A technique known as outof-focus holography (OOF) has been developed to measure gravitational deformation. However, the TMRT has a shaped dual-reflector optical system, so the OOF technique cannot be used directly. An extended OOF (e-OOF) technique that can be used for a shaped telescope is proposed. A new calculation method is developed to calculate the extra phase and illumination. A new measurement strategy is proposed that uses only one feed, reduces the length of the scan pattern, and allows the telescope to scan smoothly at low speed. At the TMRT, the time required for each measurement is under 20 min, the achieved accuracy is approximately 50 μm, and the repeatability is sufficient. We have acquired a model for the gravitational deformation of the TMRT. After applying the model, there is a 150%-400% improvement in the aperture efficiency at low and high elevations. The model flattens the gain curve between 15°-80° elevations with an aperture efficiency of approximately 52%. The final weighted root-mean-square error is approximately 270 μm. The e-OOF technique reduces the constraints on the telescopes.

Thin-film semiconductor perspective of organometal trihalide perovskite materials for high-efficiency solar cells

DOE PAGES

Xiao, Zhengguo; Yuan, Yongbo; Wang, Qi; ...

2016-02-19

Organolead trihalide perovskites (OTPs) are arising as a new generation of low-cost active materials for solar cells with efficiency rocketing from 3.5% to over 20% within only five years. From “dye” in dye sensitized solar cells to “hole conductors” and “electron conductors” in mesoscopic heterojunction solar cells, there has been a dramatic conceptual evolution on the function of OTPs in photovoltaic devices. OTPs were originally used as dyes in Gratzel cells, achieving a high efficiency above 15% which, however, did not manifest the excellent charge transport properties of OTPs. An analogy of OTPs to traditional semiconductors was drawn after themore » demonstration of highly efficient planar heterojunction structure OTP devices and the observation of their excellent bipolar transport properties with a large diffusion length exceeding 100 nm in CH 3NH 3PbI 3 (MAPbI 3) polycrystalline thin films. Here, this review aims to provide the most recent advances in the understanding of the origin of the high OTP device efficiency. Specifically we will focus on reviewing the progress in understanding 1) the characterization of fantastic optoelectronic property of OTPs, 2) the unusual defect physics that originate the optoelectronic property; 3) morphology control of the perovskite film from fabrication process and film post-treatment, and 4) device interface and charge transport layers that dramatically impact device efficiency in the OTP thin film devices; 5) photocurrent hysteresis; 6) tandem solar cells; 7) stability of the perovskite materials and solar cell devices.« less

Correcting Inadequate Model Snow Process Descriptions Dramatically Improves Mountain Hydrology Simulations

NASA Astrophysics Data System (ADS)

Pomeroy, J. W.; Fang, X.

2014-12-01

The vast effort in hydrology devoted to parameter calibration as a means to improve model performance assumes that the models concerned are not fundamentally wrong. By focussing on finding optimal parameter sets and ascribing poor model performance to parameter or data uncertainty, these efforts may fail to consider the need to improve models with more intelligent descriptions of hydrological processes. To test this hypothesis, a flexible physically based hydrological model including a full suite of snow hydrology processes as well as warm season, hillslope and groundwater hydrology was applied to Marmot Creek Research Basin, Canadian Rocky Mountains where excellent driving meteorology and basin biophysical descriptions exist. Model parameters were set from values found in the basin or from similar environments; no parameters were calibrated. The model was tested against snow surveys and streamflow observations. The model used algorithms that describe snow redistribution, sublimation and forest canopy effects on snowmelt and evaporative processes that are rarely implemented in hydrological models. To investigate the contribution of these processes to model predictive capability, the model was "falsified" by deleting parameterisations for forest canopy snow mass and energy, blowing snow, intercepted rain evaporation, and sublimation. Model falsification by ignoring forest canopy processes contributed to a large increase in SWE errors for forested portions of the research basin with RMSE increasing from 19 to 55 mm and mean bias (MB) increasing from 0.004 to 0.62. In the alpine tundra portion, removing blowing processes resulted in an increase in model SWE MB from 0.04 to 2.55 on north-facing slopes and -0.006 to -0.48 on south-facing slopes. Eliminating these algorithms degraded streamflow prediction with the Nash Sutcliffe efficiency dropping from 0.58 to 0.22 and MB increasing from 0.01 to 0.09. These results show dramatic model improvements by including snow redistribution and melt processes associated with wind transport and forest canopies. As most hydrological models do not currently include these processes, it is suggested that modellers first improve the realism of model structures before trying to optimise what are inherently inadequate simulations of hydrology.

Innovative Solutions to Challenges in Pupil Transportation.

ERIC Educational Resources Information Center

Ross, Jonathan; Burkybile, Sharon

2000-01-01

States have had to budget increasing amounts for mandated pupil-transportation services as their state transportation aid has been slashed dramatically. Among school districts, cooperation and coordination through shared services (consortia) have resulted in safer, more reliable, and more efficient transportation. Implementation advice is…

Evolution and devolution : a national perspective on the changing role of metropolitan planning organizations in areawide intermodal planning.

DOT National Transportation Integrated Search

1997-01-01

The Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) dramatically changed the metropolitan planning process by presenting new opportunities and responsibilities to the institutions in charge of metropolitan planning. The legislation f...

An Evaluation of Ecotoxicity Test Guidelines: Their Adequacy for Nanomaterials

EPA Science Inventory

Advances in nanotechnology are resulting in the production of new nanomaterials at a rapid pace. Driving the dramatic development of new materials and products is the prospect of stronger and lighter materials, better and more efficient energy systems, potential tremendous benefi...

Epileptic seizures as condensed sleep: an analysis of network dynamics from electroencephalogram signals.

PubMed

Gast, Heidemarie; Müller, Markus; Rummel, Christian; Roth, Corinne; Mathis, Johannes; Schindler, Kaspar; Bassetti, Claudio L

2014-06-01

Both deepening sleep and evolving epileptic seizures are associated with increasing slow-wave activity. Larger-scale functional networks derived from electroencephalogram indicate that in both transitions dramatic changes of communication between brain areas occur. During seizures these changes seem to be 'condensed', because they evolve more rapidly than during deepening sleep. Here we set out to assess quantitatively functional network dynamics derived from electroencephalogram signals during seizures and normal sleep. Functional networks were derived from electroencephalogram signals from wakefulness, light and deep sleep of 12 volunteers, and from pre-seizure, seizure and post-seizure time periods of 10 patients suffering from focal onset pharmaco-resistant epilepsy. Nodes of the functional network represented electrical signals recorded by single electrodes and were linked if there was non-random cross-correlation between the two corresponding electroencephalogram signals. Network dynamics were then characterized by the evolution of global efficiency, which measures ease of information transmission. Global efficiency was compared with relative delta power. Global efficiency significantly decreased both between light and deep sleep, and between pre-seizure, seizure and post-seizure time periods. The decrease of global efficiency was due to a loss of functional links. While global efficiency decreased significantly, relative delta power increased except between the time periods wakefulness and light sleep, and pre-seizure and seizure. Our results demonstrate that both epileptic seizures and deepening sleep are characterized by dramatic fragmentation of larger-scale functional networks, and further support the similarities between sleep and seizures. © 2013 European Sleep Research Society.

A Rural School/Community: A Case Study of a Dramatic Turnaround & Its Implications for School Improvement.

ERIC Educational Resources Information Center

Carlson, Robert V.

This paper presents a case study of a rural community exhibiting a dramatic turnaround in community support for a new school bond issue. Demographic change was partly responsible for the change in community attitudes, with two waves of immigration altering the long-term conservative orientation of this community. After a series of failed…

ZnO-based microrockets with light-enhanced propulsion.

PubMed

Dong, Renfeng; Wang, Chun; Wang, Qinglong; Pei, Allen; She, Xueling; Zhang, Yuxian; Cai, Yuepeng

2017-10-12

Improving the propulsion of artificial micro-nanomotors represents an exciting nanotechnology challenge, especially considering their cargo delivery ability and fuel efficiency. In light of the excellent photocatalytic performance of zinc oxide (ZnO) and chemical catalytic properties of platinum (Pt), ZnO-Pt microrockets with light-enhanced propulsion have been developed by atomic layer deposition (ALD) technology. The velocity of such microrockets is dramatically doubled upon irradiation by 77 mW cm -2 ultraviolet (UV) light in 10% H 2 O 2 and is almost 3 times higher than the classic poly(3,4-ethylenedioxythiophene)-Pt microrockets (PEDOT-Pt microrockets) even in 6% H 2 O 2 under the same UV light. In addition, such micromotors not only retain the standard approach to improve propulsion by varying the fuel concentration, but also demonstrate a simple way to enhance the movement velocity by adjusting the UV light intensity. High reversibility and controllable "weak/strong" propulsion can be easily achieved by switching the UV irradiation on or off. Finally, light-enhanced propulsion has been investigated by electrochemical measurements which further confirm the enhanced photocatalytic properties of ZnO and Pt. The successful demonstration of ZnO-based microrockets with excellent light-enhanced propulsion is significant for developing highly efficient synthetic micro-nanomotors which have strong delivery ability and economic fuel requirements for future practical applications in the micro-nanoscale world.

The assessment of engine losses due to friction and lubricant limitations. Final report May 80-Mar 81

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

Taylor, C.F.; Taylor, T. Jr; Kallin, R.L.

A major area for improving the efficiency of spark ignition and diesel engines is a reduction of frictional losses. Existing literature on engine friction was used as a basis for estimating possible gains in engine fuel economy which look promising within the constraints of modern practice. The means considered include reduction in oil viscosity, increase in bearing and piston clearances, possible changes in piston and valve gear design, and reduction of pumping losses. Estimates indicate potential fuel consumption improvements of 3 to 4% for Otto-Cycle at wide open throttle, 7 to 9% for Otto-Cycle at road load, 4 to 5%more » for diesel at wide open throttle, and 6% for diesel at road-load. Much larger gains at road load could be obtained by using a stratified charge system which requires no air throttling. A literature search on techniques for measuring engine friction under firing conditions was also performed and various concepts employing Pressure-Volume Indicator Diagrams were assessed. Balanced pressure and direct pressure measurement in concert with instantaneous measurement of piston position provide the most reliable and repeatable assessment of engine efficiency. Pressure measurements in the range of 1/2 to 1% are achievable with digital processing techniques reducing dramatically the time and effort to generate P-V Indicator Diagrams.« less

Eu(III) Complexes of Octadentate 1-Hydroxy-2-pyridinones: Stability and Improved Photophysical Performance[].

PubMed

Moore, Evan G; D'Aléo, Anthony; Xu, Jide; Raymond, Kenneth N

2009-10-13

The luminescence properties of lanthanoid ions can be dramatically enhanced by coupling them to antenna ligands that absorb light in the UV/visible and then efficiently transfer the energy to the lanthanoid center. The synthesis and the complexation of Ln(III) cations (Ln=Eu; Gd) for a ligand based on four 1-hydroxy-2-pyridinone (1,2-HOPO) chelators appended to a ligand backbone derived by linking two L-lysine units (3LI-bis-LYS) is described. This octadentate Eu(III) complex ([Eu(3LI-bis-LYS-1,2-HOPO)](-)) has been evaluated in terms of its thermodynamic stability, UV/visible absorption and luminescence properties. For this complex the conditional stability constant (pM) is 19.9, which is an order of magnitude higher than diethylenetriaminepentacetic acid (DTPA) at pH= 7.4. This Eu(III) complex also shows an almost two-fold increase in its luminescence quantum yield in aqueous solution (pH= 7.4) when compared to other octadentate ligands. Hence, despite a slight decrease of the molar absorption coefficient, a much higher brightness is obtained for [Eu(3LI-bis-LYS-1,2-HOPO)](-). This overall improvement was achieved by saturating the coordination sphere of the Eu(III) cation, yielding an increased metal centered efficiency by excluding solvent water molecules from the metal's inner sphere.

Permanent magnets for vehicle-propulsion motors: Cost/availability

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

Oman, H.; Simpson-Clark, R.

1996-12-31

Alternating-current induction motors have been used for fuel-pumping and air-conditioning in airplanes. Series and shunt dc motors have propelled vehicles. The power received by motors goes into producing output torque and magnetic fields. Today these fields can be produced with rare-earth permanent magnets which do not consume input power. Dramatic improvements in motor efficiency can result. Furthermore, with efficient variable-speed controllers using MOSFET and IGBT semiconductors, electric motors can replace the hydraulic actuators that move aircraft surfaces and retract landing gear. The 1993 cost for the magnets in a 100 kW motor was $1,500. Improved production processes are expected tomore » drop this cost to around $400. However, today`s rare-earth magnet-materials are by-products of mines that produce other metals and minerals. The authors explore the effect on cost of increased demand for the pertinent rare-earth elements, neodymium, cobalt, and samarium. A higher price will cause more elements to be extracted from existing mines. The opening of new rare-earth-element mines is another possibility. In 1993 the $250-per-kg cost for neodymium-iron-boron magnets included $190 for processing. Processing cost can drop to $30 per kg of magnet when production reaches 60 tons per month. The cost of the raw material for the magnets will be affected by man factors in a complex scenario.« less

Efficient Implementation of MrBayes on Multi-GPU

PubMed Central

Zhou, Jianfu; Liu, Xiaoguang; Wang, Gang

2013-01-01

MrBayes, using Metropolis-coupled Markov chain Monte Carlo (MCMCMC or (MC)3), is a popular program for Bayesian inference. As a leading method of using DNA data to infer phylogeny, the (MC)3 Bayesian algorithm and its improved and parallel versions are now not fast enough for biologists to analyze massive real-world DNA data. Recently, graphics processor unit (GPU) has shown its power as a coprocessor (or rather, an accelerator) in many fields. This article describes an efficient implementation a(MC)3 (aMCMCMC) for MrBayes (MC)3 on compute unified device architecture. By dynamically adjusting the task granularity to adapt to input data size and hardware configuration, it makes full use of GPU cores with different data sets. An adaptive method is also developed to split and combine DNA sequences to make full use of a large number of GPU cards. Furthermore, a new “node-by-node” task scheduling strategy is developed to improve concurrency, and several optimizing methods are used to reduce extra overhead. Experimental results show that a(MC)3 achieves up to 63× speedup over serial MrBayes on a single machine with one GPU card, and up to 170× speedup with four GPU cards, and up to 478× speedup with a 32-node GPU cluster. a(MC)3 is dramatically faster than all the previous (MC)3 algorithms and scales well to large GPU clusters. PMID:23493260

Efficient implementation of MrBayes on multi-GPU.

PubMed

Bao, Jie; Xia, Hongju; Zhou, Jianfu; Liu, Xiaoguang; Wang, Gang

2013-06-01

MrBayes, using Metropolis-coupled Markov chain Monte Carlo (MCMCMC or (MC)(3)), is a popular program for Bayesian inference. As a leading method of using DNA data to infer phylogeny, the (MC)(3) Bayesian algorithm and its improved and parallel versions are now not fast enough for biologists to analyze massive real-world DNA data. Recently, graphics processor unit (GPU) has shown its power as a coprocessor (or rather, an accelerator) in many fields. This article describes an efficient implementation a(MC)(3) (aMCMCMC) for MrBayes (MC)(3) on compute unified device architecture. By dynamically adjusting the task granularity to adapt to input data size and hardware configuration, it makes full use of GPU cores with different data sets. An adaptive method is also developed to split and combine DNA sequences to make full use of a large number of GPU cards. Furthermore, a new "node-by-node" task scheduling strategy is developed to improve concurrency, and several optimizing methods are used to reduce extra overhead. Experimental results show that a(MC)(3) achieves up to 63× speedup over serial MrBayes on a single machine with one GPU card, and up to 170× speedup with four GPU cards, and up to 478× speedup with a 32-node GPU cluster. a(MC)(3) is dramatically faster than all the previous (MC)(3) algorithms and scales well to large GPU clusters.

Influence of the Metal-MoS2 interface on MoS2 Transistor Performance

NASA Astrophysics Data System (ADS)

Yuan, Hui; Cheng, Guangjun; Hight Walker, Angela; You, Lin; Kopanski, Joseph J.; Li, Qiliang; Richter, Curt A.

2015-03-01

We compare the electrical characteristics of MoS2 field-effect transistors (FETS) with Ag source/drain contacts with transistors with Ti contacts, and we demonstrate that the metal-MoS2 interface is crucial to the final device performance. The topography of 5nm Au/5nm Ag (contact layer) and 5nm Au/5nm Ti metal films deposited onto mono- and few-layer MoS2 was characterized by using scanning electron microscopy and atomic force microscopy. The surface morphology of the Au/Ti films on MoS2 shows a rough, dewetting pattern while Au/Ag forms smooth, dense films. These smoother and denser Au/Ag contacts lead to improved carrier transport efficiency. FETs with Ag contacts show more than 60 times higher on-state current and a steeper subthreshold slope. Raman spectroscopy of MoS2 covered with Au/Ag or Au/Ti films revealed that the contact layer is Ag or Ti, respectively. In addition, there is a dramatic difference in the heat transfer between the MoS2 and the two metals: while laser heating is observed in Au/Ti covered MoS2, no heating effects are seen in Au/Ag covered MoS2. It is reasonable to conclude that the smoother and denser Ag contact leads to higher carrier transport efficiency and contributes to the improved thermal properties.

Specific removal of autoantibodies by extracorporeal immunoadsorption ameliorates experimental autoimmune myasthenia gravis.

PubMed

Lazaridis, Konstantinos; Dalianoudis, Ioannis; Baltatzidi, Vasiliki; Tzartos, Socrates J

2017-11-15

Myasthenia gravis (MG) is caused by autoantibodies, the majority of which target the muscle acetylcholine receptor (AChR). Plasmapheresis and IgG-immunoadsorption are useful therapy options, but are highly non-specific. Antigen-specific immunoadsorption would remove only the pathogenic autoantibodies, reducing the possibility of side effects while maximizing the benefit. We have extensively characterized such adsorbents, but in vivo studies are missing. We used rats with experimental autoimmune MG to perform antigen-specific immunoadsorptions over three weeks, regularly monitoring symptoms and autoantibody titers. Immunoadsorption was effective, resulting in a marked autoantibody titer decrease while the immunoadsorbed, but not the mock-treated, animals showed a dramatic symptom improvement. Overall, the procedure was found to be efficient, suggesting the subsequent initiation of clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

Emerging model systems for functional genomics analysis of Crassulacean acid metabolism.

PubMed

Hartwell, James; Dever, Louisa V; Boxall, Susanna F

2016-06-01

Crassulacean acid metabolism (CAM) is one of three main pathways of photosynthetic carbon dioxide fixation found in higher plants. It stands out for its ability to underpin dramatic improvements in plant water use efficiency, which in turn has led to a recent renaissance in CAM research. The current ease with which candidate CAM-associated genes and proteins can be identified through high-throughput sequencing has opened up a new horizon for the development of diverse model CAM species that are amenable to genetic manipulations. The adoption of these model CAM species is underpinning rapid advances in our understanding of the complete gene set for CAM. We highlight recent breakthroughs in the functional characterisation of CAM genes that have been achieved through transgenic approaches. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Surface Modifications during a Catalytic Reaction: A Combined APT and FIB/SEM Analysis of Surface Segregation

DOE PAGES

Barroo, Cedric; Janvelyan, Nare; Zugic, Branko; ...

2016-07-25

To improve the understanding of catalytic processes, the surface structure and composition of the active materials need to be determined before and after reaction. Morphological changes may occur under reaction conditions and can dramatically influence the reactivity and/or selectivity of a catalyst. Goldbased catalysts with different architectures are currently being developed for selective oxidation reactions at low temperatures. Specifically, nanoporous Au (npAu) with a composition of Au 97-Ag 3 is obtained by dealloying a Ag 70-Au 30 bulk alloy. Recent studies highlight the efficiency of npAu catalysts for methanol oxidation using ozone to activate the catalysts before methanol oxidation. Inmore » this paper, we studied the morphological and compositional changes occurring at the surface of Au-based catalysts in certain conditions.« less

Building electronic data infrastructure for comparative effectiveness research: accomplishments, lessons learned and future steps.

PubMed

Randhawa, Gurvaneet S

2014-11-01

There are large gaps in our knowledge on the potential impact of diagnostics and therapeutics on outcomes of patients treated in the real world. Comparative effectiveness research aims to fill these gaps to maximize effectiveness of these interventions. Health information technology has the potential to dramatically improve the practice of medicine and of research. This is an overview of about US$100 million of American Recovery and Reinvestment Act investment in 12 projects managed by the Agency for Healthcare Research and Quality to build an electronic clinical data infrastructure that connects research with healthcare delivery. The achievements and lessons learned from these projects provided a foundation for the National Patient-Centered Clinical Research Network (PCORnet)and will help to guide future infrastructure development needed to build an efficient, scalable and sustainable learning health system.

Adaptive Development

NASA Technical Reports Server (NTRS)

2005-01-01

The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

Stochastic coupled cluster theory: Efficient sampling of the coupled cluster expansion

NASA Astrophysics Data System (ADS)

Scott, Charles J. C.; Thom, Alex J. W.

2017-09-01

We consider the sampling of the coupled cluster expansion within stochastic coupled cluster theory. Observing the limitations of previous approaches due to the inherently non-linear behavior of a coupled cluster wavefunction representation, we propose new approaches based on an intuitive, well-defined condition for sampling weights and on sampling the expansion in cluster operators of different excitation levels. We term these modifications even and truncated selections, respectively. Utilising both approaches demonstrates dramatically improved calculation stability as well as reduced computational and memory costs. These modifications are particularly effective at higher truncation levels owing to the large number of terms within the cluster expansion that can be neglected, as demonstrated by the reduction of the number of terms to be sampled when truncating at triple excitations by 77% and hextuple excitations by 98%.

Wheat seed transcriptome reveals genes controlling key traits for human preference and crop adaptation.

PubMed

Henry, Robert J; Furtado, Agnelo; Rangan, Parimalan

2018-05-17

Analysis of the transcriptome of the developing wheat grain has associated expression of genes with traits involving production (e.g. yield) and quality (e.g. bread quality). Photosynthesis in the grain may be important in retaining carbon that would be lost in respiration during grain filling and may contribute to yield in the late stages of seed formation under warm and dry environments. A small number of genes have been identified as having been selected by humans to optimize the performance of wheat for foods such as bread. Genes determining flour yield in milling have been discovered. Hardness is explained by variations in expression of pin genes. Knowledge of these genes should dramatically improve the efficiency of breeding better climate adapted wheat genotypes. Copyright © 2018. Published by Elsevier Ltd.

Supplementation of methionine to a low soybean protein diet strikingly increases pancreatic amylase activity in rats.

PubMed

Hara, H; Kiriyama, S; Kasai, T

1997-02-01

Feed efficiency in rats fed a low soybean protein isolate (SPI) diet (100 g/kg diet) was dramatically improved with the supplementation of L-methionine (3 g/kg diet). Pancreatic amylase activity was low in rats fed a low SPI diet, and was much higher in the supplemented group than in the non-supplemented group. Pancreatic trypsinogen and chymotrypsinogen contents (as activities of trypsin and chymotrypsin) were not changed with the methionine supplementation. In the small intestine, sucrase and leucine aminopeptidase in the jejunum and ileum were not clearly changed. In conclusion, a small amount of methionine supplemented to a low SPI diet especially induced pancreatic amylase among digestive enzymes. The factor involved in nutritional status, not the physiological action of methionine itself, may contribute the induction of amylase.

Heterogenised Molecular Catalysts for the Reduction of CO₂ to Fuels.

PubMed

Windle, Christopher D; Reisner, Erwin

2015-08-19

CO2 conversion provides a possible solution to curtail the growing CO2 levels in our atmosphere and reduce dependence on fossil fuels. To this end, it is essential to develop efficient catalysts for the reduction of CO2. The structure and activity of molecular CO2 reduction catalysts can be tuned and they offer good selectivity with reasonable stability. Heterogenisation of these molecules reduces solvent restrictions, facilitates recyclability and can dramatically improve activity by preventing catalyst inactivation and perturbing the kinetics of intermediates. The nature and morphology of the solid-state material upon which the catalyst is immobilised can significantly influence the activity of the hybrid assembly. Although work in this area began forty years ago, it has only drawn substantial attention in recent years. This review article gives an overview of the historical development of the field.

Heterogenised Molecular Catalysts for the Reduction of CO2 to Fuels.

PubMed

Windle, Christopher D; Reisner, Erwin

2015-01-01

CO(2) conversion provides a possible solution to curtail the growing CO(2) levels in our atmosphere and reduce dependence on fossil fuels. To this end, it is essential to develop efficient catalysts for the reduction of CO(2). The structure and activity of molecular CO(2) reduction catalysts can be tuned and they offer good selectivity with reasonable stability. Heterogenisation of these molecules reduces solvent restrictions, facilitates recyclability and can dramatically improve activity by preventing catalyst inactivation and perturbing the kinetics of intermediates. The nature and morphology of the solid-state material upon which the catalyst is immobilised can significantly influence the activity of the hybrid assembly. Although work in this area began forty years ago, it has only drawn substantial attention in recent years. This review article gives an overview of the historical development of the field.

A Web Based Collaborative Design Environment for Spacecraft

NASA Technical Reports Server (NTRS)

Dunphy, Julia

1998-01-01

In this era of shrinking federal budgets in the USA we need to dramatically improve our efficiency in the spacecraft engineering design process. We have come up with a method which captures much of the experts' expertise in a dataflow design graph: Seamlessly connectable set of local and remote design tools; Seamlessly connectable web based design tools; and Web browser interface to the developing spacecraft design. We have recently completed our first web browser interface and demonstrated its utility in the design of an aeroshell using design tools located at web sites at three NASA facilities. Multiple design engineers and managers are now able to interrogate the design engine simultaneously and find out what the design looks like at any point in the design cycle, what its parameters are, and how it reacts to adverse space environments.

In situ precision electrospinning as an effective delivery technique for cyanoacrylate medical glue with high efficiency and low toxicity.

PubMed

Dong, R H; Qin, C C; Qiu, X; Yan, X; Yu, M; Cui, L; Zhou, Y; Zhang, H D; Jiang, X Y; Long, Y Z

2015-12-14

The side effects or toxicity of cyanoacrylate used in vivo have been argued since its first application in wound closure. We propose an airflow-assisted in situ precision electrospinning apparatus as an applicator and make a detailed comparison with traditional spraying via in vitro and in vivo experiments. This novel method can not only improve operational performance and safety by precisely depositing cyanoacrylate fibers onto a wound, but significantly reduce the dosage of cyanoacrylate by almost 80%. A white blood cell count, liver function test and histological analysis prove that the in situ precision electrospinning applicator produces a better postoperative outcome, e.g., minor hepatocyte injury, moderate inflammation and the significant ability for liver regeneration. This in situ precision electrospinning method may thus dramatically broaden both civilian and military applications of cyanoacrylates.

Biobutanol production in a Clostridium acetobutylicum biofilm reactor integrated with simultaneous product recovery by adsorption

PubMed Central

2014-01-01

Background Clostridium acetobutylicum can propagate on fibrous matrices and form biofilms that have improved butanol tolerance and a high fermentation rate and can be repeatedly used. Previously, a novel macroporous resin, KA-I, was synthesized in our laboratory and was demonstrated to be a good adsorbent with high selectivity and capacity for butanol recovery from a model solution. Based on these results, we aimed to develop a process integrating a biofilm reactor with simultaneous product recovery using the KA-I resin to maximize the production efficiency of biobutanol. Results KA-I showed great affinity for butanol and butyrate and could selectively enhance acetoin production at the expense of acetone during the fermentation. The biofilm reactor exhibited high productivity with considerably low broth turbidity during repeated batch fermentations. By maintaining the butanol level above 6.5 g/L in the biofilm reactor, butyrate adsorption by the KA-I resin was effectively reduced. Co-adsorption of acetone by the resin improved the fermentation performance. By redox modulation with methyl viologen (MV), the butanol-acetone ratio and the total product yield increased. An equivalent solvent titer of 96.5 to 130.7 g/L was achieved with a productivity of 1.0 to 1.5 g · L-1 · h-1. The solvent concentration and productivity increased by 4 to 6-fold and 3 to 5-fold, respectively, compared to traditional batch fermentation using planktonic culture. Conclusions Compared to the conventional process, the integrated process dramatically improved the productivity and reduced the energy consumption as well as water usage in biobutanol production. While genetic engineering focuses on strain improvement to enhance butanol production, process development can fully exploit the productivity of a strain and maximize the production efficiency. PMID:24401161

Theoretical investigation of the charge-transfer properties in different meso-linked zinc porphyrins for highly efficient dye-sensitized solar cells.

PubMed

Namuangruk, Supawadee; Sirithip, Kanokkorn; Rattanatwan, Rattanawelee; Keawin, Tinnagon; Kungwan, Nawee; Sudyodsuk, Taweesak; Promarak, Vinich; Surakhot, Yaowarat; Jungsuttiwong, Siriporn

2014-06-28

The charge transfer effect of different meso-substituted linkages on porphyrin analogue 1 (A1, B1 and C1) was theoretically investigated using density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. The calculated geometry parameters and natural bond orbital analysis reveal that the twisted conformation between porphyrin macrocycle and meso-substituted linkages leads to blocking of the conjugation of the conjugated backbone, and the frontier molecular orbital plot shows that the intramolecular charge transfer of A1, B1 and C1 hardly takes place. In an attempt to improve the photoinduced intramolecular charge transfer ability of the meso-linked zinc porphyrin sensitizer, a strong electron-withdrawing group (CN) was introduced into the anchoring group of analogue 1 forming analogue 2 (A2, B2 and C2). The density difference plot of A2, B2 and C2 shows that the charge transfer properties dramatically improved. The electron injection process has been performed using TDDFT; the direct charge-transfer transition in the A2-(TiO2)38 interacting system takes place; our results strongly indicated that introducing electron-withdrawing groups into the acceptor part of porphyrin dyes can fine-tune the effective conjugation length of the π-spacer and improve intramolecular charge transfer properties, consequently inducing the electron injection process from the anchoring group of the porphyrin dye to the (TiO2)38 surface which may improve the conversion efficiency of the DSSCs. Our calculated results can provide valuable information and a promising outlook for computation-aided sensitizer design with anticipated good properties in further experimental synthesis.

The effect of organic amendments on microbial nitrogen cycling in orchard soils

USDA-ARS?s Scientific Manuscript database

Soil microorganisms have the potential to dramatically alter the nitrogen (N) availability in agricultural systems. It is unclear whether manipulation of microbes to enhance soil N availability and increase agricultural efficiency is possible. Ideally, a management strategy would maximize the amount...

Academic Freedom.

ERIC Educational Resources Information Center

Ouchi, William G.

2004-01-01

Argues that school systems are so centralized that they waste money on bureaucratic operations and lack the capacity to respond rapidly to changing circumstances. A study of nine school systems that vary dramatically in their degree of decentralization demonstrates that true decentralization yields benefits in both efficiency and performance. (MLF)

Impacts of land use and climate change on carbon dynamics in south-central Senegal

USGS Publications Warehouse

Liu, Shu-Guang; Kaire, M.; Wood, Eric C.; Diallo, O.; Tieszen, Larry L.

2004-01-01

Total carbon stock in vegetation and soils was reduced 37% in south-central Senegal from 1900 to 2000. The decreasing trend will continue during the 21st century unless forest clearing is stopped, selective logging dramatically reduced, and climate change, if any, relatively small. Developing a sustainable fuelwood and charcoal production system could be the most feasible and significant carbon sequestration project in the region. If future climate changes dramatically as some models have predicted, cropland productivity will drop more than 65% around 2100, posing a serious threat to food security and the efficiency of carbon sequestration projects.

Interface design principles for high-performance organic semiconductor devices

DOE PAGES

Nie, Wanyi; Gupta, Gautam; Crone, Brian K.; ...

2015-03-23

Organic solar cells (OSCs) are a promising cost-effective candidate in next generation photovoltaic technology. However, a critical bottleneck for OSCs is the electron/hole recombination loss through charge transfer state at the interface, which greatly limits the power conversion efficiency. W. Nie, A. Mohite, and co-workers demonstrate a simple strategy of suppressing the recombination rate by inserting a spacer layer at the donor-acceptor interface, resulting in a dramatic increase in power conversion efficiency.

Efficient Direct Lineage Reprogramming of Fibroblasts into Induced Cardiomyocytes Using Nanotopographical Cues.

PubMed

Yoo, Junsang; Chang, Yujung; Kim, Hongwon; Baek, Soonbong; Choi, Hwan; Jeong, Gun-Jae; Shin, Jaein; Kim, Hongnam; Kim, Byung-Soo; Kim, Jongpil

2017-03-01

Induced cardiomyocytes (iCMs) generated via direct lineage reprogramming offer a novel therapeutic target for the study and treatment of cardiac diseases. However, the efficiency of iCM generation is significantly low for therapeutic applications. Here, we show an efficient direct conversion of somatic fibroblasts into iCMs using nanotopographic cues. Compared with flat substrates, the direct conversion of fibroblasts into iCMs on nanopatterned substrates resulted in a dramatic increase in the reprogramming efficiency and maturation of iCM phenotypes. Additionally, enhanced reprogramming by substrate nanotopography was due to changes in the activation of focal adhesion kinase and specific histone modifications. Taken together, these results suggest that nanotopographic cues can serve as an efficient stimulant for direct lineage reprogramming into iCMs.

Decoration of mesoporous Co3O4 nanospheres assembled by monocrystal nanodots on g-C3N4 to construct Z-scheme system for improving photocatalytic performance

NASA Astrophysics Data System (ADS)

Wu, Haijun; Li, Chunmei; Che, Huinan; Hu, Hao; Hu, Wei; Liu, Chunbo; Ai, Junzhe; Dong, Hongjun

2018-05-01

The Co3O4/g-C3N4 Z-scheme system is constructed by decoration of mesoporous Co3O4 nanospheres assembled by monocrystal nanodots on the surface of g-C3N4, which dramatically improves the photocatalytic activity for degrading tetracycline hydrochloride (TC) compared with single g-C3N4. The microstructure investigations evidence the mesoporous structure and enlarged specific surface area of Co3O4/g-C3N4 Z-scheme system, which implies the increase of surface active sites and adsorption ability for reactant molecules. Moreover, by virtue of analyzing physical and photoelectrochemical properties, it evidences that the decoration effect of mesoporous Co3O4 nanospheres on the surface of g-C3N4 obviously improves the transfer and separation efficiency of charge carriers between two phase interfaces and broadens light harvest range. These important factors are beneficial to enhancing photocatalytic activity of Co3O4/g-C3N4 Z-scheme system. In addition, the photocatalityc reaction mechanism is also revealed in depth.

White butterflies as solar photovoltaic concentrators.

PubMed

Shanks, Katie; Senthilarasu, S; Ffrench-Constant, Richard H; Mallick, Tapas K

2015-07-31

Man's harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies' wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies' thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

White butterflies as solar photovoltaic concentrators

NASA Astrophysics Data System (ADS)

Shanks, Katie; Senthilarasu, S.; Ffrench-Constant, Richard H.; Mallick, Tapas K.

2015-07-01

Man’s harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies’ wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies’ thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

Clinical Information Systems - From Yesterday to Tomorrow.

PubMed

Gardner, R M

2016-06-30

To review the history of clinical information systems over the past twenty-five years and project anticipated changes to those systems over the next twenty-five years. Over 250 Medline references about clinical information systems, quality of patient care, and patient safety were reviewed. Books, Web resources, and the author's personal experience with developing the HELP system were also used. There have been dramatic improvements in the use and acceptance of clinical computing systems and Electronic Health Records (EHRs), especially in the United States. Although there are still challenges with the implementation of such systems, the rate of progress has been remarkable. Over the next twenty-five years, there will remain many important opportunities and challenges. These opportunities include understanding complex clinical computing issues that must be studied, understood and optimized. Dramatic improvements in quality of care and patient safety must be anticipated as a result of the use of clinical information systems. These improvements will result from a closer involvement of clinical informaticians in the optimization of patient care processes. Clinical information systems and computerized clinical decision support have made contributions to medicine in the past. Therefore, by using better medical knowledge, optimized clinical information systems, and computerized clinical decision, we will enable dramatic improvements in both the quality and safety of patient care in the next twenty-five years.

The use of Electrolyte Additives to Improve the High Temperature Resilience of Li-Ion Cells

NASA Technical Reports Server (NTRS)

Smart, Marshall C.; Lucht, B. L.; Ratnakumar, Bugga V.

2007-01-01

This viewgraph presentation reviews the use of electrolyte additves to improve the resillience of Lithium ion cells. The objective of this work is to identify lithium-ion electrolytes, which will lead to Li-ion cells with a wide operational temperature range (+60 to -60 C), and to develop Li-ion electrolytes which result in cells that display improved high temperature resilience. Significant improvement in the high temperature resilience of Li-ion cells containing these additives was observed, with the most dramatic benefit being displayed by addition of DMAc. When the electrochemical properties of the individual electrodes were analyzed, the degradation of the anode kinetics was slowed most dramatically by the incorporation of DMAc into the electrolytes. Whereas, the greatest retention in the cathode kinetics was observed in the cell containing the electrolyte with VC added.

More efficient evolutionary strategies for model calibration with watershed model for demonstration

NASA Astrophysics Data System (ADS)

Baggett, J. S.; Skahill, B. E.

2008-12-01

Evolutionary strategies allow automatic calibration of more complex models than traditional gradient based approaches, but they are more computationally intensive. We present several efficiency enhancements for evolution strategies, many of which are not new, but when combined have been shown to dramatically decrease the number of model runs required for calibration of synthetic problems. To reduce the number of expensive model runs we employ a surrogate objective function for an adaptively determined fraction of the population at each generation (Kern et al., 2006). We demonstrate improvements to the adaptive ranking strategy that increase its efficiency while sacrificing little reliability and further reduce the number of model runs required in densely sampled parts of parameter space. Furthermore, we include a gradient individual in each generation that is usually not selected when the search is in a global phase or when the derivatives are poorly approximated, but when selected near a smooth local minimum can dramatically increase convergence speed (Tahk et al., 2007). Finally, the selection of the gradient individual is used to adapt the size of the population near local minima. We show, by incorporating these enhancements into the Covariance Matrix Adaption Evolution Strategy (CMAES; Hansen, 2006), that their synergetic effect is greater than their individual parts. This hybrid evolutionary strategy exploits smooth structure when it is present but degrades to an ordinary evolutionary strategy, at worst, if smoothness is not present. Calibration of 2D-3D synthetic models with the modified CMAES requires approximately 10%-25% of the model runs of ordinary CMAES. Preliminary demonstration of this hybrid strategy will be shown for watershed model calibration problems. Hansen, N. (2006). The CMA Evolution Strategy: A Comparing Review. In J.A. Lozano, P. Larrañga, I. Inza and E. Bengoetxea (Eds.). Towards a new evolutionary computation. Advances in estimation of distribution algorithms. pp. 75-102, Springer Kern, S., N. Hansen and P. Koumoutsakos (2006). Local Meta-Models for Optimization Using Evolution Strategies. In Ninth International Conference on Parallel Problem Solving from Nature PPSN IX, Proceedings, pp.939-948, Berlin: Springer. Tahk, M., Woo, H., and Park. M, (2007). A hybrid optimization of evolutionary and gradient search. Engineering Optimization, (39), 87-104.

Misconceptions of Electric Propulsion Aircraft and Their Emergent Aviation Markets

NASA Technical Reports Server (NTRS)

Moore, Mark D.; Fredericks, Bill

2014-01-01

Over the past several years there have been aircraft conceptual design and system studies that have reached conflicting conclusions relating to the feasibility of full and hybrid electric aircraft. Some studies and propulsion discipline experts have claimed that battery technologies will need to improve by 10 to 20 times before electric aircraft can effectively compete with reciprocating or turbine engines. However, such studies have approached comparative assessments without understanding the compelling differences that electric propulsion offers, how these technologies will fundamentally alter the way propulsion integration is approached, or how these new technologies can not only compete but far exceed existing propulsion solutions in many ways at battery specific energy densities of only 400 watt hours per kilogram. Electric propulsion characteristics offer the opportunity to achieve 4 to 8 time improvements in energy costs with dramatically lower total operating costs, while dramatically improving efficiency, community noise, propulsion system reliability and safety through redundancy, as well as life cycle Green House Gas emissions. Integration of electric propulsion will involve far greater degrees of distribution than existing propulsion solutions due to their compact and scale-free nature to achieve multi-disciplinary coupling and synergistic integration with the aerodynamics, highlift system, acoustics, vehicle control, balance, and aeroelasticity. Appropriate metrics of comparison and differences in analysis/design tools are discussed while comparing electric propulsion to other disruptive technologies. For several initial applications, battery energy density is already sufficient for competitive products, and for many additional markets energy densities will likely be adequate within the next 7 years for vibrant introduction. Market evolution and early adopter markets are discussed, along with the investment areas that will fill technology gaps and create opportunities for the effective, near-term electric aircraft products. Without understanding both the context of how electric propulsion will integrate into the vehicle system, and evolve into the market place it is likely that electric propulsion will continue to be misunderstood.

Prescribers' expectations and barriers to electronic prescribing of controlled substances

PubMed Central

Kim, Meelee; McDonald, Ann; Kreiner, Peter; Kelleher, Stephen J; Blackman, Michael B; Kaufman, Peter N; Carrow, Grant M

2011-01-01

Objective To better understand barriers associated with the adoption and use of electronic prescribing of controlled substances (EPCS), a practice recently established by US Drug Enforcement Administration regulation. Materials and methods Prescribers of controlled substances affiliated with a regional health system were surveyed regarding current electronic prescribing (e-prescribing) activities, current prescribing of controlled substances, and expectations and barriers to the adoption of EPCS. Results 246 prescribers (response rate of 64%) represented a range of medical specialties, with 43.1% of these prescribers current users of e-prescribing for non-controlled substances. Reported issues with controlled substances included errors, pharmacy call-backs, and diversion; most prescribers expected EPCS to address many of these problems, specifically reduce medical errors, improve work flow and efficiency of practice, help identify prescription diversion or misuse, and improve patient treatment management. Prescribers expected, however, that it would be disruptive to practice, and over one-third of respondents reported that carrying a security authentication token at all times would be so burdensome as to discourage adoption. Discussion Although adoption of e-prescribing has been shown to dramatically reduce medication errors, challenges to efficient processes and errors still persist from the perspective of the prescriber, that may interfere with the adoption of EPCS. Most prescribers regarded EPCS security measures as a small or moderate inconvenience (other than carrying a security token), with advantages outweighing the burden. Conclusion Prescribers are optimistic about the potential for EPCS to improve practice, but view certain security measures as a burden and potential barrier. PMID:21946239

A Method on Dynamic Path Planning for Robotic Manipulator Autonomous Obstacle Avoidance Based on an Improved RRT Algorithm.

PubMed

Wei, Kun; Ren, Bingyin

2018-02-13

In a future intelligent factory, a robotic manipulator must work efficiently and safely in a Human-Robot collaborative and dynamic unstructured environment. Autonomous path planning is the most important issue which must be resolved first in the process of improving robotic manipulator intelligence. Among the path-planning methods, the Rapidly Exploring Random Tree (RRT) algorithm based on random sampling has been widely applied in dynamic path planning for a high-dimensional robotic manipulator, especially in a complex environment because of its probability completeness, perfect expansion, and fast exploring speed over other planning methods. However, the existing RRT algorithm has a limitation in path planning for a robotic manipulator in a dynamic unstructured environment. Therefore, an autonomous obstacle avoidance dynamic path-planning method for a robotic manipulator based on an improved RRT algorithm, called Smoothly RRT (S-RRT), is proposed. This method that targets a directional node extends and can increase the sampling speed and efficiency of RRT dramatically. A path optimization strategy based on the maximum curvature constraint is presented to generate a smooth and curved continuous executable path for a robotic manipulator. Finally, the correctness, effectiveness, and practicability of the proposed method are demonstrated and validated via a MATLAB static simulation and a Robot Operating System (ROS) dynamic simulation environment as well as a real autonomous obstacle avoidance experiment in a dynamic unstructured environment for a robotic manipulator. The proposed method not only provides great practical engineering significance for a robotic manipulator's obstacle avoidance in an intelligent factory, but also theoretical reference value for other type of robots' path planning.

Reconstitution of UCP1 using CRISPR/Cas9 in the white adipose tissue of pigs decreases fat deposition and improves thermogenic capacity

PubMed Central

Zheng, Qiantao; Lin, Jun; Huang, Jiaojiao; Zhang, Hongyong; Zhang, Rui; Zhang, Xueying; Cao, Chunwei; Hambly, Catherine; Qin, Guosong; Yao, Jing; Song, Ruigao; Jia, Qitao; Wang, Xiao; Li, Yongshun; Zhang, Nan; Piao, Zhengyu; Ye, Rongcai; Speakman, John R.; Wang, Hongmei; Zhou, Qi; Wang, Yanfang; Jin, Wanzhu

2017-01-01

Uncoupling protein 1 (UCP1) is localized on the inner mitochondrial membrane and generates heat by uncoupling ATP synthesis from proton transit across the inner membrane. UCP1 is a key element of nonshivering thermogenesis and is most likely important in the regulation of body adiposity. Pigs (Artiodactyl family Suidae) lack a functional UCP1 gene, resulting in poor thermoregulation and susceptibility to cold, which is an economic and pig welfare issue owing to neonatal mortality. Pigs also have a tendency toward fat accumulation, which may be linked to their lack of UCP1, and thus influences the efficiency of pig production. Here, we report application of a CRISPR/Cas9-mediated, homologous recombination (HR)-independent approach to efficiently insert mouse adiponectin-UCP1 into the porcine endogenous UCP1 locus. The resultant UCP1 knock-in (KI) pigs showed an improved ability to maintain body temperature during acute cold exposure, but they did not have alterations in physical activity levels or total daily energy expenditure (DEE). Furthermore, ectopic UCP1 expression in white adipose tissue (WAT) dramatically decreased fat deposition by 4.89% (P < 0.01), consequently increasing carcass lean percentage (CLP; P < 0.05). Mechanism studies indicated that the loss of fat upon UCP1 activation in WAT was linked to elevated lipolysis. UCP1 KI pigs are a potentially valuable resource for agricultural production through their combination of cold adaptation, which improves pig welfare and reduces economic losses, with reduced fat deposition and increased lean meat production. PMID:29078316

3D shape reconstruction of specular surfaces by using phase measuring deflectometry

NASA Astrophysics Data System (ADS)

Zhou, Tian; Chen, Kun; Wei, Haoyun; Li, Yan

2016-10-01

The existing estimation methods for recovering height information from surface gradient are mainly divided into Modal and Zonal techniques. Since specular surfaces used in the industry always have complex and large areas, considerations must be given to both the improvement of measurement accuracy and the acceleration of on-line processing speed, which beyond the capacity of existing estimations. Incorporating the Modal and Zonal approaches into a unifying scheme, we introduce an improved 3D shape reconstruction version of specular surfaces based on Phase Measuring Deflectometry in this paper. The Modal estimation is firstly implemented to derive the coarse height information of the measured surface as initial iteration values. Then the real shape can be recovered utilizing a modified Zonal wave-front reconstruction algorithm. By combining the advantages of Modal and Zonal estimations, the proposed method simultaneously achieves consistently high accuracy and dramatically rapid convergence. Moreover, the iterative process based on an advanced successive overrelaxation technique shows a consistent rejection of measurement errors, guaranteeing the stability and robustness in practical applications. Both simulation and experimentally measurement demonstrate the validity and efficiency of the proposed improved method. According to the experimental result, the computation time decreases approximately 74.92% in contrast to the Zonal estimation and the surface error is about 6.68 μm with reconstruction points of 391×529 pixels of an experimentally measured sphere mirror. In general, this method can be conducted with fast convergence speed and high accuracy, providing an efficient, stable and real-time approach for the shape reconstruction of specular surfaces in practical situations.

Internal quantum efficiency in yellow-amber light emitting AlGaN-InGaN-GaN heterostructures

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

Ngo, Thi Huong; Gil, Bernard; Valvin, Pierre

2015-09-21

We determine the internal quantum efficiency of strain-balanced AlGaN-InGaN-GaN hetero-structures designed for yellow-amber light emission, by using a recent model based on the kinetics of the photoluminescence decay initiated by Iwata et al. [J. Appl. Phys. 117, 075701 (2015)]. Our results indicate that low temperature internal quantum efficiencies sit in the 50% range and we measure that adding an AlGaN layer increases the internal quantum efficiency from 50% up to 57% with respect to the GaN-InGaN case. More dramatic, it almost doubles from 2.5% up to 4.3% at room temperature.

Geothermal Energy: Tapping the Potential

ERIC Educational Resources Information Center

Johnson, Bill

2008-01-01

Ground source geothermal energy enables one to tap into the earth's stored renewable energy for heating and cooling facilities. Proper application of ground-source geothermal technology can have a dramatic impact on the efficiency and financial performance of building energy utilization (30%+). At the same time, using this alternative energy…

Engineered Nanomaterial Ecological Effects Research within ORD's National Health and Environmental Effects Laboratory

EPA Science Inventory

Advances in nanotechnology are resulting in the production of new nanomaterials at a rapid pace. Driving the dramatic development of new materials and products is the prospect of stronger and lighter materials, better and more efficient energy systems, potential tremendous benefi...

Rapid-fire improvement with short-cycle kaizen.

PubMed

Heard, E

1999-05-01

Continuous improvement is an attractive idea, but it is typically more myth than reality. SCK is no myth. It delivers dramatic improvements in traditional measures quickly. SCK accomplishes this via kaizens: rapid, repeated, time-compressed changes for the better in bite-sized chunks of the business.

Maine PACE Program Final Technical Report

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

Fischer, Dana; Adamson, Joy M

The ARRA EECBG BetterBuilding helped augment the existing Home Energy Savings Programs (HESP) and incentives with financing through a subordinate lien PACE and HUD PowerSaver programs. The program was designed to document innovative techniques to dramatically increase the number of homes participating in weatherization programs in participating towns. Maine will support new energy efficiency retrofit pilots throughout the state, designed to motivate a large number of homeowners to invest in comprehensive home energy efficiency upgrades to bring real solutions to market.

A Study on the Effect on Scheduling and Management of Surgeries with the Introduction of Excellent Medical Information.

PubMed

Mei, Tsai Ching

2016-01-01

The services of OR play an important role in the medical business for department of surgery. The most important issue for OR is about the scheduling and management of surgeries. Good surgery schedule could elevate the utilization efficiency of OR. Therefore, the introduction of excellent medical information can both dramatically elevate the work efficiency of health care employees and reduce workload to reach win-win benefits in both management and performance.

Fault tolerant operation of switched reluctance machine

NASA Astrophysics Data System (ADS)

Wang, Wei

The energy crisis and environmental challenges have driven industry towards more energy efficient solutions. With nearly 60% of electricity consumed by various electric machines in industry sector, advancement in the efficiency of the electric drive system is of vital importance. Adjustable speed drive system (ASDS) provides excellent speed regulation and dynamic performance as well as dramatically improved system efficiency compared with conventional motors without electronics drives. Industry has witnessed tremendous grow in ASDS applications not only as a driving force but also as an electric auxiliary system for replacing bulky and low efficiency auxiliary hydraulic and mechanical systems. With the vast penetration of ASDS, its fault tolerant operation capability is more widely recognized as an important feature of drive performance especially for aerospace, automotive applications and other industrial drive applications demanding high reliability. The Switched Reluctance Machine (SRM), a low cost, highly reliable electric machine with fault tolerant operation capability, has drawn substantial attention in the past three decades. Nevertheless, SRM is not free of fault. Certain faults such as converter faults, sensor faults, winding shorts, eccentricity and position sensor faults are commonly shared among all ASDS. In this dissertation, a thorough understanding of various faults and their influence on transient and steady state performance of SRM is developed via simulation and experimental study, providing necessary knowledge for fault detection and post fault management. Lumped parameter models are established for fast real time simulation and drive control. Based on the behavior of the faults, a fault detection scheme is developed for the purpose of fast and reliable fault diagnosis. In order to improve the SRM power and torque capacity under faults, the maximum torque per ampere excitation are conceptualized and validated through theoretical analysis and experiments. With the proposed optimal waveform, torque production is greatly improved under the same Root Mean Square (RMS) current constraint. Additionally, position sensorless operation methods under phase faults are investigated to account for the combination of physical position sensor and phase winding faults. A comprehensive solution for position sensorless operation under single and multiple phases fault are proposed and validated through experiments. Continuous position sensorless operation with seamless transition between various numbers of phase fault is achieved.

Improvement of cellulose catabolism in Clostridium cellulolyticum by sporulation abolishment and carbon alleviation

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

Li, Yongchao; Xu, Tao; Tschaplinski, Timothy J

2014-01-01

Background Clostridium cellulolyticum can degrade lignocellulosic biomass, and ferment the soluble sugars to produce valuable chemicals such as lactate, acetate, ethanol and hydrogen. However, the cellulose utilization efficiency of C. cellulolyticum still remains very low, impeding its application in consolidated bioprocessing for biofuels production. In this study, two metabolic engineering strategies were exploited to improve cellulose utilization efficiency, including sporulation abolishment and carbon overload alleviation. Results The spo0A gene at locus Ccel_1894, which encodes a master sporulation regulator was inactivated. The spo0A mutant abolished the sporulation ability. In a high concentration of cellulose (50 g/l), the performance of the spo0Amore » mutant increased dramatically in terms of maximum growth, final concentrations of three major metabolic products, and cellulose catabolism. The microarray and gas chromatography mass spectrometry (GC-MS) analyses showed that the valine, leucine and isoleucine biosynthesis pathways were up-regulated in the spo0A mutant. Based on this information, a partial isobutanol producing pathway modified from valine biosynthesis was introduced into C. cellulolyticum strains to further increase cellulose consumption by alleviating excessive carbon load. The introduction of this synthetic pathway to the wild-type strain improved cellulose consumption from 17.6 g/l to 28.7 g/l with a production of 0.42 g/l isobutanol in the 50 g/l cellulose medium. However, the spo0A mutant strain did not appreciably benefit from introduction of this synthetic pathway and the cellulose utilization efficiency did not further increase. A technical highlight in this study was that an in vivo promoter strength evaluation protocol was developed using anaerobic fluorescent protein and flow cytometry for C. cellulolyticum. Conclusions In this study, we inactivated the spo0A gene and introduced a heterologous synthetic pathway to manipulate the stress response to heavy carbon load and accumulation of metabolic products. These findings provide new perspectives to enhance the ability of cellulolytic bacteria to produce biofuels and biocommodities with high efficiency and at low cost directly from lignocellulosic biomass.« less

On the Improvement of Convergence Performance for Integrated Design of Wind Turbine Blade Using a Vector Dominating Multi-objective Evolution Algorithm

NASA Astrophysics Data System (ADS)

Wang, L.; Wang, T. G.; Wu, J. H.; Cheng, G. P.

2016-09-01

A novel multi-objective optimization algorithm incorporating evolution strategies and vector mechanisms, referred as VD-MOEA, is proposed and applied in aerodynamic- structural integrated design of wind turbine blade. In the algorithm, a set of uniformly distributed vectors is constructed to guide population in moving forward to the Pareto front rapidly and maintain population diversity with high efficiency. For example, two- and three- objective designs of 1.5MW wind turbine blade are subsequently carried out for the optimization objectives of maximum annual energy production, minimum blade mass, and minimum extreme root thrust. The results show that the Pareto optimal solutions can be obtained in one single simulation run and uniformly distributed in the objective space, maximally maintaining the population diversity. In comparison to conventional evolution algorithms, VD-MOEA displays dramatic improvement of algorithm performance in both convergence and diversity preservation for handling complex problems of multi-variables, multi-objectives and multi-constraints. This provides a reliable high-performance optimization approach for the aerodynamic-structural integrated design of wind turbine blade.

Efficient phytoremediation of organic contaminants in soils using plant-endophyte partnerships.

PubMed

Feng, Nai-Xian; Yu, Jiao; Zhao, Hai-Ming; Cheng, Yu-Ting; Mo, Ce-Hui; Cai, Quan-Ying; Li, Yan-Wen; Li, Hui; Wong, Ming-Hung

2017-04-01

Soil pollution with organic contaminants is one of the most intractable environmental problems today, posing serious threats to humans and the environment. Innovative strategies for remediating organic-contaminated soils are critically needed. Phytoremediation, based on the synergistic actions of plants and their associated microorganisms, has been recognized as a powerful in situ approach to soil remediation. Suitable combinations of plants and their associated endophytes can improve plant growth and enhance the biodegradation of organic contaminants in the rhizosphere and/or endosphere, dramatically expediting the removal of organic pollutants from soils. However, for phytoremediation to become a more widely accepted and predictable alternative, a thorough understanding of plant-endophyte interactions is needed. Many studies have recently been conducted on the mechanisms of endophyte-assisted phytoremediation of organic contaminants in soils. In this review, we highlight the superiority of organic pollutant-degrading endophytes for practical applications in phytoremediation, summarize alternative strategies for improving phytoremediation, discuss the fundamental mechanisms of endophyte-assisted phytoremediation, and present updated information regarding the advances, challenges, and new directions in the field of endophyte-assisted phytoremediation technology. Copyright © 2017 Elsevier B.V. All rights reserved.

Physician-Pharmacist collaboration in a pay for performance healthcare environment.

PubMed

Farley, T M; Izakovic, M

2015-01-01

Healthcare is becoming more complex and costly in both European (Slovak) and American models. Healthcare in the United States (U.S.) is undergoing a particularly dramatic change. Physician and hospital reimbursement are becoming less procedure focused and increasingly outcome focused. Efforts at Mercy Hospital have shown promise in terms of collaborative team based care improving performance on glucose control outcome metrics, linked to reimbursement. Our performance on the Centers for Medicare and Medicaid Services (CMS) post-operative glucose control metric for cardiac surgery patients increased from a 63.6% pass rate to a 95.1% pass rate after implementing interventions involving physician-pharmacist team based care.Having a multidisciplinary team that is able to adapt quickly to changing expectations in the healthcare environment has aided our institution. As healthcare becomes increasingly saturated with technology, data and quality metrics, collaborative efforts resulting in increased quality and physician efficiency are desirable. Multidisciplinary collaboration (including physician-pharmacist collaboration) appears to be a viable route to improved performance in an outcome based healthcare system (Fig. 2, Ref. 12).

Pulmonary parenchyma segmentation in thin CT image sequences with spectral clustering and geodesic active contour model based on similarity

NASA Astrophysics Data System (ADS)

He, Nana; Zhang, Xiaolong; Zhao, Juanjuan; Zhao, Huilan; Qiang, Yan

2017-07-01

While the popular thin layer scanning technology of spiral CT has helped to improve diagnoses of lung diseases, the large volumes of scanning images produced by the technology also dramatically increase the load of physicians in lesion detection. Computer-aided diagnosis techniques like lesions segmentation in thin CT sequences have been developed to address this issue, but it remains a challenge to achieve high segmentation efficiency and accuracy without much involvement of human manual intervention. In this paper, we present our research on automated segmentation of lung parenchyma with an improved geodesic active contour model that is geodesic active contour model based on similarity (GACBS). Combining spectral clustering algorithm based on Nystrom (SCN) with GACBS, this algorithm first extracts key image slices, then uses these slices to generate an initial contour of pulmonary parenchyma of un-segmented slices with an interpolation algorithm, and finally segments lung parenchyma of un-segmented slices. Experimental results show that the segmentation results generated by our method are close to what manual segmentation can produce, with an average volume overlap ratio of 91.48%.

Software engineering the mixed model for genome-wide association studies on large samples.

PubMed

Zhang, Zhiwu; Buckler, Edward S; Casstevens, Terry M; Bradbury, Peter J

2009-11-01

Mixed models improve the ability to detect phenotype-genotype associations in the presence of population stratification and multiple levels of relatedness in genome-wide association studies (GWAS), but for large data sets the resource consumption becomes impractical. At the same time, the sample size and number of markers used for GWAS is increasing dramatically, resulting in greater statistical power to detect those associations. The use of mixed models with increasingly large data sets depends on the availability of software for analyzing those models. While multiple software packages implement the mixed model method, no single package provides the best combination of fast computation, ability to handle large samples, flexible modeling and ease of use. Key elements of association analysis with mixed models are reviewed, including modeling phenotype-genotype associations using mixed models, population stratification, kinship and its estimation, variance component estimation, use of best linear unbiased predictors or residuals in place of raw phenotype, improving efficiency and software-user interaction. The available software packages are evaluated, and suggestions made for future software development.

Throwing computing into reverse

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

Frank, Michael P.

For more than 50 years, computers have made steady and dramatic improvements, all thanks to Moore’s Law—the exponential increase over time in the number of transistors that can be fabricated on an integrated circuit of a given size. Moore’s Law owed its success to the fact that as transistors were made smaller, they became simultaneously cheaper, faster, and more energy efficient. The payoff from this win-win-win scenario enabled reinvestment in semiconductor fabrication technology that could make even smaller, more densely-packed transistors. And so this virtuous cycle continued, decade after decade. Now though, experts in industry, academia, and government laboratories anticipatemore » that semiconductor miniaturization won’t continue much longer—maybe 10 years or so, at best. Making transistors smaller no longer yields the improvements it used to. The physical characteristics of small transistors forced clock speeds to cease getting faster more than a decade ago, which drove the industry to start building chips with multiple cores. But even multi-core architectures must contend with increasing amounts of “dark silicon,” areas of the chip that must be powered off to avoid overheating.« less

Nano Copper Oxide-Modified Carbon Cloth as Cathode for a Two-Chamber Microbial Fuel Cell

PubMed Central

Dong, Feng; Zhang, Peng; Li, Kexun; Liu, Xianhua; Zhang, Pingping

2016-01-01

In this work, Cu2O nanoparticles were deposited on a carbon cloth cathode using a facile electrochemical method. The morphology of the modified cathode, which was characterized by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) tests, showed that the porosity and specific surface area of the cathode improved with longer deposition times. X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) results showed that cupric oxide and cuprous oxide coexisted on the carbon cloth, which improved the electrochemical activity of cathode. The cathode with a deposition time of 100 s showed the best performance, with a power density twice that of bare carbon cloth. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) results revealed that moderate deposition of nano copper oxide on carbon cloth could dramatically reduce the charge transfer resistance, which contributed to the enhanced electrochemical performance. The mediation mechanism of copper oxide nanocatalyst was illustrated by the fact that the recycled conversion between cupric oxide and cuprous oxide accelerated the electron transfer efficiency on the cathode. PMID:28335366

Nano Copper Oxide-Modified Carbon Cloth as Cathode for a Two-Chamber Microbial Fuel Cell.

PubMed

Dong, Feng; Zhang, Peng; Li, Kexun; Liu, Xianhua; Zhang, Pingping

2016-12-09

In this work, Cu₂O nanoparticles were deposited on a carbon cloth cathode using a facile electrochemical method. The morphology of the modified cathode, which was characterized by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) tests, showed that the porosity and specific surface area of the cathode improved with longer deposition times. X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) results showed that cupric oxide and cuprous oxide coexisted on the carbon cloth, which improved the electrochemical activity of cathode. The cathode with a deposition time of 100 s showed the best performance, with a power density twice that of bare carbon cloth. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) results revealed that moderate deposition of nano copper oxide on carbon cloth could dramatically reduce the charge transfer resistance, which contributed to the enhanced electrochemical performance. The mediation mechanism of copper oxide nanocatalyst was illustrated by the fact that the recycled conversion between cupric oxide and cuprous oxide accelerated the electron transfer efficiency on the cathode.

Surface nanocrystalline and hardening effects of Ti-Al-V alloy by electropulsing ultrasonic shock

NASA Astrophysics Data System (ADS)

Ye, Xiaoxin

2015-04-01

The effect of electropulsing ultrasonic shock (EUS) on the surface hardening and microstructure of Ti6Al4V alloy was studied. It was found that electropulsing improved the microhardness dramatically both in the influential depth and maximum value, compared with the only ultrasonic-shocked sample. It's indicated that refined surface layer with nanocrystalline and improved microhardness were obtained on account of surface severe plastic deformation, dynamic recrystallization (DRX) and phase change, which was implemented at relative low temperature and high strain rate/capacity due to the coupling of the thermal and athermal effects of EUS. It's different from conventional experiments and theory. It's discussed that the positive contributions of EPT in the thermodynamics and kinetics of microstructure and properties change were attributed to the reduction of nucleation energy barrier and acceleration of atomic diffusion. Therefore, it's supposed that EUS is an energy-saving and high-efficiency method of surface treatment technique with the help of high-energy electropulses, which is promising in cost reduction of the surface engineering and energy management.

Examining the Effects of Distractive Multitasking with Peripheral Computing in the Classroom

ERIC Educational Resources Information Center

Puente, Jaime E.

2017-01-01

The growing use of information and communication technologies (ICTs) in college campuses has dramatically increased the potential for multitasking among students who have to juggle classes, school assignments, work, and recreational activities. These students believe that they have become more efficient by performing two or more tasks…

The response of ammonia-oxidizer activity and community structure to fertilizer amendment of orchard soils

USDA-ARS?s Scientific Manuscript database

Soil microorganisms have the potential to dramatically alter the nitrogen (N) availability in agricultural systems, and therefore affect the efficiency of fertilizer application. Data regarding the effects of cereal management systems on the soil microbiology functional to N cycling have yielded var...

This School Is about Kids

ERIC Educational Resources Information Center

Rooney, Joanne

2009-01-01

Principals talk about children in their schools, noting that their essence cannot be condensed into efficiently scored, disaggregated data. Data tools are useful. But even a dramatic increase in test scores headlined in the newspaper must not become the end product of principals' educational endeavors. What's going on in the hearts and minds of…

Engineering the Ideal Array (BRIEFING CHARTS)

DTIC Science & Technology

2007-03-05

48 V, f = 10 GHz GaN HEMT Transistor i t Dramatically higher: • Output power • Efficiency • Bandwidth GaN HEMT Power Amplifier lifi ...functions – RF amplifiers – 4-bit phase shifters – Amplitude controllers – Summing network – Power control – Latches for phase state – Address

A novel approach to leveraging electronic health record data to enhance pediatric surgical quality improvement bundle process compliance.

PubMed

Fisher, Jason C; Godfried, David H; Lighter-Fisher, Jennifer; Pratko, Joseph; Sheldon, Mary Ellen; Diago, Thelma; Kuenzler, Keith A; Tomita, Sandra S; Ginsburg, Howard B

2016-06-01

Quality improvement (QI) bundles have been widely adopted to reduce surgical site infections (SSI). Improvement science suggests when organizations achieve high-reliability to QI processes, outcomes dramatically improve. However, measuring QI process compliance is poorly supported by electronic health record (EHR) systems. We developed a custom EHR tool to facilitate capture of process data for SSI prevention with the aim of increasing bundle compliance and reducing adverse events. Ten SSI prevention bundle processes were linked to EHR data elements that were then aggregated into a snapshot display superimposed on weekly case-log reports. The data aggregation and user interface facilitated efficient review of all SSI bundle elements, providing an exact bundle compliance rate without random sampling or chart review. Nine months after implementation of our custom EHR tool, we observed centerline shifts in median SSI bundle compliance (46% to 72%). Additionally, as predicted by high reliability principles, we began to see a trend toward improvement in SSI rates (1.68 to 0.87 per 100 operations), but a discrete centerline shift was not detected. Simple informatics solutions can facilitate extraction of QI process data from the EHR without relying on adjunctive systems. Analyses of these data may drive reductions in adverse events. Pediatric surgical departments should consider leveraging the EHR to enhance bundle compliance as they implement QI strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

Improving the cost-effectiveness of IRS with climate informed health surveillance systems

PubMed Central

Worrall, Eve; Connor, Stephen J; Thomson, Madeleine C

2008-01-01

Background This paper examines how the cost-effectiveness of IRS varies depending on the severity of transmission and level of programme coverage and how efficiency could be improved by incorporating climate information into decision making for malaria control programmes as part of an integrated Malaria Early Warning and Response System (MEWS). Methods A climate driven model of malaria transmission was used to simulate cost-effectiveness of alternative IRS coverage levels over six epidemic and non-epidemic years. Decision rules for a potential MEWS system that triggers different IRS coverage are described. The average and marginal cost per case averted with baseline IRS coverage (24%) and under varying IRS coverage levels (50%, 75% and 100%) were calculated. Results Average cost-effectiveness of 24% coverage varies dramatically between years, from US$108 per case prevented in low transmission to US$0.42 in epidemic years. Similarly for higher coverage (24–100%) cost per case prevented is far higher in low than high transmission years ($108–$267 to $0.88–$2.26). Discussion Efficiency and health benefit gains could be achieved by implementing MEWS that provides timely, accurate information. Evidence from southern Africa, (especially Botswana) supports this. Conclusion Advance knowledge of transmission severity can help managers make coverage decisions which optimise resource use and exploit efficiency gains if a fully integrated MEWS is in place alongside a health system with sufficient flexibility to modify control plans in response to information. More countries and programmes should be supported to use the best available evidence and science to integrate climate informed MEWS into decision making within malaria control programmes. PMID:19108723

In Search of the Perfect Photocage: Structure-Reactivity Relationships in meso-Methyl BODIPY Photoremovable Protecting Groups.

PubMed

Slanina, Tomáš; Shrestha, Pradeep; Palao, Eduardo; Kand, Dnyaneshwar; Peterson, Julie A; Dutton, Andrew S; Rubinstein, Naama; Weinstain, Roy; Winter, Arthur H; Klán, Petr

2017-10-25

A detailed investigation of the photophysical parameters and photochemical reactivity of meso-methyl BODIPY photoremovable protecting groups was accomplished through systematic variation of the leaving group (LG) and core substituents as well as substitutions at boron. Efficiencies of the LG release were evaluated using both steady-state and transient absorption spectroscopies as well as computational analyses to identify the optimal structural features. We find that the quantum yields for photorelease with this photocage are highly sensitive to substituent effects. In particular, we find that the quantum yields of photorelease are improved with derivatives with higher intersystem crossing quantum yields, which can be promoted by core heavy atoms. Moreover, release quantum yields are dramatically improved by boron alkylation, whereas alkylation in the meso-methyl position has no effect. Better LGs are released considerably more efficiently than poorer LGs. We find that these substituent effects are additive, for example, a 2,6-diiodo-B-dimethyl BODIPY photocage features quantum yields of 28% for the mediocre LG acetate and a 95% quantum yield of release for chloride. The high chemical and quantum yields combined with the outstanding absorption properties of BODIPY dyes lead to photocages with uncaging cross sections over 10 000 M -1 cm -1 , values that surpass cross sections of related photocages absorbing visible light. These new photocages, which absorb strongly near the second harmonic of an Nd:YAG laser (532 nm), hold promise for manipulating and interrogating biological and material systems with the high spatiotemporal control provided by pulsed laser irradiation, while avoiding the phototoxicity problems encountered with many UV-absorbing photocages. More generally, the insights gained from this structure-reactivity relationship may aid in the development of new highly efficient photoreactions.

Operational Merits of Maritime Superconductivity

NASA Astrophysics Data System (ADS)

Ross, R.; Bosklopper, J. J.; van der Meij, K. H.

The perspective of superconductivity to transfer currents without loss is very appealing in high power applications. In the maritime sector many machines and systems exist in the roughly 1-100 MW range and the losses are well over 50%, which calls for dramatic efficiency improvements. This paper reports on three studies that aimed at the perspectives of superconductivity in the maritime sector. It is important to realize that the introduction of superconductivity comprises two technology transitions namely firstly electrification i.e. the transition from mechanical drives to electric drives and secondly the transition from normal to superconductive electrical machinery. It is concluded that superconductivity does reduce losses, but its impact on the total energy chain is of little significance compared to the investments and the risk of introducing a very promising but as yet not proven technology in the harsh maritime environment. The main reason of the little impact is that the largest losses are imposed on the system by the fossil fueled generators as prime movers that generate the electricity through mechanical torque. Unless electric power is supplied by an efficient and reliable technology that does not involve mechanical torque with the present losses both normal as well as superconductive electrification of the propulsion will hardly improve energy efficiency or may even reduce it. One exception may be the application of degaussing coils. Still appealing merits of superconductivity do exist, but they are rather related to the behavior of superconductive machines and strong magnetic fields and consequently reduction in volume and mass of machinery or (sometimes radically) better performance. The merits are rather convenience, design flexibility as well as novel applications and capabilities which together yield more adequate systems. These may yield lower operational costs in the long run, but at present the added value of superconductivity rather seems more adequate than cheaper systems.

Formation of Nanosized Defective Lithium Peroxides through Si-Coated Carbon Nanotube Cathodes for High Energy Efficiency Li-O2 Batteries.

PubMed

Lin, Qi; Cui, Zhonghui; Sun, Jiyang; Huo, Hanyu; Chen, Cheng; Guo, Xiangxin

2018-06-06

The formation and decomposition of lithium peroxides (Li 2 O 2 ) during cycling is the key process for the reversible operation of lithium-oxygen batteries. The manipulation of such products from the large toroidal particles about hundreds of nanometers to the ones in the scale of tens of nanometers can improve the energy efficiency and the cycle life of the batteries. In this work, we carry out an in situ morphology tuning of Li 2 O 2 by virtue of the surface properties of the n-type Si-modified aligned carbon nanotube (CNT) cathodes. With the introduction of an n-type Si coating layer on the CNT surface, the morphology of Li 2 O 2 formed by discharge changes from large toroidal particles (∼300 nm) deposited on the pristine CNT cathodes to nanoparticles (10-20 nm) with poor crystallinity and plenty of lithium vacancies. Beneficial from such changes, the charge overpotential dramatically decreases to 0.55 V, with the charge plateau lying at 3.5 V even in the case of a high discharge capacity (3450 mA h g -1 ) being delivered, resulting in the high electrical energy efficiency approaching 80%. Such an improvement is attributed to the fact that the introduction of the n-type Si coating layer changes the surface properties of CNTs and guides the formation of nanosized amorphous-like lithium peroxides with plenty of defects. These results demonstrate that the cathode surface properties play an important role in the formation of products formed during the cycle, providing inspiration to design superior cathodes for the Li-O 2 cells.

30% CPV Module Milestone

NASA Astrophysics Data System (ADS)

Gordon, Robert; Kinsey, Geoff; Nayaak, Adi; Garboushian, Vahan

2010-10-01

Concentrating Photovoltaics has held out the promise of low cost solar electricity for now several decades. Steady progress towards this goal in the 80's and 90's gradually produced more efficient and reliable systems. System efficiency is regarded as the largest factor in lowering the electricity cost and the relatively recent advent of the terrestrial multi-junction solar cell has pressed this race forward dramatically. CPV systems are now exhibiting impressive AC field efficiencies of 25% and more, approximately twice that of the best flat plate systems available today. Amonix inc. has just tested their latest generation multi-junction module design, achieving over 31% DC efficiency at near PVUSA test conditions. Inculcating this design into their next MegaModule is forthcoming, but the expected AC system field efficiency should be significantly higher than current 25% levels.

Thermal conductivity engineering in width-modulated silicon nanowires and thermoelectric efficiency enhancement

NASA Astrophysics Data System (ADS)

Zianni, Xanthippi

2018-03-01

Width-modulated nanowires have been proposed as efficient thermoelectric materials. Here, the electron and phonon transport properties and the thermoelectric efficiency are discussed for dimensions above the quantum confinement regime. The thermal conductivity decreases dramatically in the presence of thin constrictions due to their ballistic thermal resistance. It shows a scaling behavior upon the width-modulation rate that allows for thermal conductivity engineering. The electron conductivity also decreases due to enhanced boundary scattering by the constrictions. The effect of boundary scattering is weaker for electrons than for phonons and the overall thermoelectric efficiency is enhanced. A ZT enhancement by a factor of 20-30 is predicted for width-modulated nanowires compared to bulk silicon. Our findings indicate that width-modulated nanostructures are promising for developing silicon nanostructures with high thermoelectric efficiency.

Sleep and circadian rhythms

NASA Technical Reports Server (NTRS)

Monk, Timothy H.

1991-01-01

Three interacting processes are involved in the preservation of circadian rhythms: (1) endogenous rhythm generation mechanisms, (2) entrainment mechanisms to keep these rhythms 'on track', and (3) exogenous masking processes stemming from changes in environment and bahavior. These processes, particularly the latter two, can be dramatically affected in individuals of advanced age and in space travelers, with a consequent disruption in sleep and daytime functioning. This paper presents results of a phase-shift experiment investigating the age-related effects of the exogeneous component of circadian rhythms in various physiological and psychological functions by comparing these functions in middle aged and old subjects. Dramatic differences were found between the two age groups in measures of sleep, mood, activation, and performance efficiency.

Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%.

PubMed

Kim, Hui-Seon; Lee, Chang-Ryul; Im, Jeong-Hyeok; Lee, Ki-Beom; Moehl, Thomas; Marchioro, Arianna; Moon, Soo-Jin; Humphry-Baker, Robin; Yum, Jun-Ho; Moser, Jacques E; Grätzel, Michael; Park, Nam-Gyu

2012-01-01

We report on solid-state mesoscopic heterojunction solar cells employing nanoparticles (NPs) of methyl ammonium lead iodide (CH(3)NH(3))PbI(3) as light harvesters. The perovskite NPs were produced by reaction of methylammonium iodide with PbI(2) and deposited onto a submicron-thick mesoscopic TiO(2) film, whose pores were infiltrated with the hole-conductor spiro-MeOTAD. Illumination with standard AM-1.5 sunlight generated large photocurrents (J(SC)) exceeding 17 mA/cm(2), an open circuit photovoltage (V(OC)) of 0.888 V and a fill factor (FF) of 0.62 yielding a power conversion efficiency (PCE) of 9.7%, the highest reported to date for such cells. Femto second laser studies combined with photo-induced absorption measurements showed charge separation to proceed via hole injection from the excited (CH(3)NH(3))PbI(3) NPs into the spiro-MeOTAD followed by electron transfer to the mesoscopic TiO(2) film. The use of a solid hole conductor dramatically improved the device stability compared to (CH(3)NH(3))PbI(3) -sensitized liquid junction cells.

Cell surface engineering of Bacillus subtilis improves production yields of heterologously expressed α-amylases.

PubMed

Cao, Haojie; van Heel, Auke J; Ahmed, Hifza; Mols, Maarten; Kuipers, Oscar P

2017-04-04

Bacillus subtilis is widely used as a cell factory for numerous heterologous proteins of commercial value and medical interest. To explore the possibility of further enhancing the secretion potential of this model bacterium, a library of engineered strains with modified cell surface components was constructed, and the corresponding influences on protein secretion were investigated by analyzing the secretion of α-amylase variants with either low-, neutral- or high- isoelectric points (pI). Relative to the wild-type strain, the presence of overall anionic membrane phospholipids (phosphatidylglycerol and cardiolipin) increased dramatically in the PssA-, ClsA- and double KO mutants, which resulted in an up to 47% higher secretion of α-amylase. Additionally, we demonstrated that the appropriate net charge of secreted targets (AmyTS-23, AmyBs and AmyBm) was beneficial for secretion efficiency as well. In B. subtilis, the characteristics of cell membrane phospholipid bilayer and the pIs of heterologous α-amylases appear to be important for their secretion efficiency. These two factors can be engineered to reduce the electrostatic interaction between each other during the secretion process, which finally leads to a better secretion yield of α-amylases.

Charge carrier transport and photogeneration in P3HT:PCBM photovoltaic blends.

PubMed

Laquai, Frédéric; Andrienko, Denis; Mauer, Ralf; Blom, Paul W M

2015-06-01

This article reviews the charge transport and photogeneration in bulk-heterojunction solar cells made from blend films of regioregular poly(3-hexylthiophene) (RR-P3HT) and methano-fullerene (PCBM). The charge transport, specifically the hole mobility in the RR-P3HT phase of the polymer:fullerene photovoltaic blend, is dramatically affected by thermal annealing. The hole mobility increases more than three orders of magnitude and reaches a value of up to 2 × 10(-4) cm(2) V(-1) s(-1) after the thermal annealing process as a result of an improved semi-crystallinity of the film. This significant increase of the hole mobility balances the electron and hole mobilities in a photovoltaic blend in turn reducing space-charge formation, and this is the most important factor for the strong enhancement of the photovoltaic efficiency compared to an as cast, that is, non-annealed device. In fact, the balanced charge carrier mobility in RR-P3HT:PCBM blends in combination with a field- and temperature-independent charge carrier generation and greatly reduced non-geminate recombination explains the large quantum efficiencies mea-sured in P3HT:PCBM photovoltaic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Innovation in the collective brain

PubMed Central

Muthukrishna, Michael; Henrich, Joseph

2016-01-01

Innovation is often assumed to be the work of a talented few, whose products are passed on to the masses. Here, we argue that innovations are instead an emergent property of our species' cultural learning abilities, applied within our societies and social networks. Our societies and social networks act as collective brains. We outline how many human brains, which evolved primarily for the acquisition of culture, together beget a collective brain. Within these collective brains, the three main sources of innovation are serendipity, recombination and incremental improvement. We argue that rates of innovation are heavily influenced by (i) sociality, (ii) transmission fidelity, and (iii) cultural variance. We discuss some of the forces that affect these factors. These factors can also shape each other. For example, we provide preliminary evidence that transmission efficiency is affected by sociality—languages with more speakers are more efficient. We argue that collective brains can make each of their constituent cultural brains more innovative. This perspective sheds light on traits, such as IQ, that have been implicated in innovation. A collective brain perspective can help us understand otherwise puzzling findings in the IQ literature, including group differences, heritability differences and the dramatic increase in IQ test scores over time. PMID:26926282

Metal-organic frameworks derived platinum-cobalt bimetallic nanoparticles in nitrogen-doped hollow porous carbon capsules as a highly active and durable catalyst for oxygen reduction reaction

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

Ying, Jie; Li, Jing; Jiang, Gaopeng

Pt-based nanomaterials are regarded as the most efficient electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, widespread adoption of PEMFCs requires solutions to major challenges encountered with ORR catalysts, namely high cost, sluggish kinetics, and low durability. In this paper, a new efficient method utilizing Co-based metal-organic frameworks is developed to produce PtCo bimetallic nanoparticles embedded in unique nitrogen-doped hollow porous carbon capsules. The obtained catalyst demonstrates an outstanding ORR performance, with a mass activity that is 5.5 and 13.5 times greater than that of commercial Pt/C and Pt black, respectively. Most importantly,more » the product exhibits dramatically improved durability in terms of both electrochemically active surface area (ECAS) and mass activity compared to commercial Pt/C and Pt black catalysts. Finally, the remarkable ORR performance demonstrated here can be attributed to the structural features of the catalyst (its alloy structure, high dispersion and fine particle size) and the carbon support (its nitrogen dopant, large surface area and hollow porous structure).« less

White OLED devices and processes for lighting applications

NASA Astrophysics Data System (ADS)

Ide, Nobuhiro; Tsuji, Hiroya; Ito, Norihiro; Matsuhisa, Yuko; Houzumi, Shingo; Nishimori, Taisuke

2010-05-01

In these days, the basic performances of white OLEDs are dramatically improved and application of OLEDs to "Lighting" is expected to be true in the near future. We have developed various technologies for OLED lighting with the aid of the Japanese governmental project, "High-efficiency lighting based on the organic light-emitting mechanism." In this project, a white OLED with high efficiency (37 lm/W) and high quality emission characteristics (CRI of 95 with a small variation of chromaticity in different directions and chromaticity just on the black-body radiation curve) applicable to "Lighting" was realized by a two-unit structure with a fluorescent deep blue emissive unit and a phosphorescent green and red emissive unit. Half-decay lifetime of this white OLED at 1,000 cd/m2 was over 40,000 h. A heat radiative, thin encapsulation structure (less than 1 mm) realized a very stable emission at high luminance of over 3,000 cd/m2. A new deposition source with a hot-wall and a rate controllable valve was developed. Thickness uniformity within +/- 3% at high deposition rate of over 8 nm/s, high material utilization of over 70 %, and repeatable deposition rate controllability were confirmed.

Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%

PubMed Central

Kim, Hui-Seon; Lee, Chang-Ryul; Im, Jeong-Hyeok; Lee, Ki-Beom; Moehl, Thomas; Marchioro, Arianna; Moon, Soo-Jin; Humphry-Baker, Robin; Yum, Jun-Ho; Moser, Jacques E.; Grätzel, Michael; Park, Nam-Gyu

2012-01-01

We report on solid-state mesoscopic heterojunction solar cells employing nanoparticles (NPs) of methyl ammonium lead iodide (CH3NH3)PbI3 as light harvesters. The perovskite NPs were produced by reaction of methylammonium iodide with PbI2 and deposited onto a submicron-thick mesoscopic TiO2 film, whose pores were infiltrated with the hole-conductor spiro-MeOTAD. Illumination with standard AM-1.5 sunlight generated large photocurrents (JSC) exceeding 17 mA/cm2, an open circuit photovoltage (VOC) of 0.888 V and a fill factor (FF) of 0.62 yielding a power conversion efficiency (PCE) of 9.7%, the highest reported to date for such cells. Femto second laser studies combined with photo-induced absorption measurements showed charge separation to proceed via hole injection from the excited (CH3NH3)PbI3 NPs into the spiro-MeOTAD followed by electron transfer to the mesoscopic TiO2 film. The use of a solid hole conductor dramatically improved the device stability compared to (CH3NH3)PbI3 -sensitized liquid junction cells. PMID:22912919

Covalent Attachment of the Water-insoluble Ni(P Cy 2 N Phe 2 ) 2 Electrocatalyst to Electrodes Showing Reversible Catalysis in Aqueous Solution

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

Rodríguez-Maciá, Patricia; Priyadarshani, Nilusha; Dutta, Arnab

Hydrogenases are a diverse group of metalloenzymes which catalyze the reversible conversion between molecular hydrogen and protons at high rates. The catalytic activity of these enzymes does not require overpotential because their active site has been evolutionarily optimized to operate fast and efficiently. These enzymes have inspired the development of molecular catalysts, which have dramatically improved in efficiency in recent years, to the point that some synthetic catalysts even outperform hydrogenases under certain conditions. In this work, we use a reversible noble-metal-free homogeneous catalyst, the [Ni(PCy2NPhe2)2]2+ complex, and we covalently immobilize it on a functionalized highly oriented pyrolytic graphite “edge”more » (HOPGe) electrode surface. This catalyst is not water soluble, but once it is surface-confined on the electrode, it maintains its catalytic properties in aqueous solutions, showing reversibility for H2 oxidation/reduction. Immobilization of the [Ni(PCy2NPhe2)2]2+ complex onto a multi-walled carbon nanotubes coated electrode leads to even higher catalytic current densities and enhanced stability.« less

Ensuring the Environmental and Industrial Safety in Solid Mineral Deposit Surface Mining

NASA Astrophysics Data System (ADS)

Trubetskoy, Kliment; Rylnikova, Marina; Esina, Ekaterina

2017-11-01

The growing environmental pressure of mineral deposit surface mining and severization of industrial safety requirements dictate the necessity of refining the regulatory framework governing safe and efficient development of underground resources. The applicable regulatory documentation governing the procedure of ore open-pit wall and bench stability design for the stage of pit reaching its final boundary was issued several decades ago. Over recent decades, mining and geomechanical conditions have changed significantly in surface mining operations, numerous new software packages and computer developments have appeared, opportunities of experimental methods of source data collection and processing, grounding of the permissible parameters of open pit walls have changed dramatically, and, thus, methods of risk assessment have been perfected [10-13]. IPKON RAS, with the support of the Federal Service for Environmental Supervision, assumed the role of the initiator of the project for the development of Federal norms and regulations of industrial safety "Rules for ensuring the stability of walls and benches of open pits, open-cast mines and spoil banks", which contribute to the improvement of economic efficiency and safety of mineral deposit surface mining and enhancement of the competitiveness of Russian mines at the international level that is very important in the current situation.

Efficient Multi-Dimensional Simulation of Quantum Confinement Effects in Advanced MOS Devices

NASA Technical Reports Server (NTRS)

Biegel, Bryan A.; Ancona, Mario G.; Rafferty, Conor S.; Yu, Zhiping

2000-01-01

We investigate the density-gradient (DG) transport model for efficient multi-dimensional simulation of quantum confinement effects in advanced MOS devices. The formulation of the DG model is described as a quantum correction ot the classical drift-diffusion model. Quantum confinement effects are shown to be significant in sub-100nm MOSFETs. In thin-oxide MOS capacitors, quantum effects may reduce gate capacitance by 25% or more. As a result, the inclusion of quantum effects may reduce gate capacitance by 25% or more. As a result, the inclusion of quantum effects in simulations dramatically improves the match between C-V simulations and measurements for oxide thickness down to 2 nm. Significant quantum corrections also occur in the I-V characteristics of short-channel (30 to 100 nm) n-MOSFETs, with current drive reduced by up to 70%. This effect is shown to result from reduced inversion charge due to quantum confinement of electrons in the channel. Also, subthreshold slope is degraded by 15 to 20 mV/decade with the inclusion of quantum effects via the density-gradient model, and short channel effects (in particular, drain-induced barrier lowering) are noticeably increased.

Innovation in the collective brain.

PubMed

Muthukrishna, Michael; Henrich, Joseph

2016-03-19

Innovation is often assumed to be the work of a talented few, whose products are passed on to the masses. Here, we argue that innovations are instead an emergent property of our species' cultural learning abilities, applied within our societies and social networks. Our societies and social networks act as collective brains. We outline how many human brains, which evolved primarily for the acquisition of culture, together beget a collective brain. Within these collective brains, the three main sources of innovation are serendipity, recombination and incremental improvement. We argue that rates of innovation are heavily influenced by (i) sociality, (ii) transmission fidelity, and (iii) cultural variance. We discuss some of the forces that affect these factors. These factors can also shape each other. For example, we provide preliminary evidence that transmission efficiency is affected by sociality--languages with more speakers are more efficient. We argue that collective brains can make each of their constituent cultural brains more innovative. This perspective sheds light on traits, such as IQ, that have been implicated in innovation. A collective brain perspective can help us understand otherwise puzzling findings in the IQ literature, including group differences, heritability differences and the dramatic increase in IQ test scores over time. © 2016 The Author(s).

Access to Cancer Therapeutics in Low- and Middle-Income Countries.

PubMed

Ruff, Paul; Al-Sukhun, Sana; Blanchard, Charmaine; Shulman, Lawrence N

2016-01-01

Cancer is rapidly becoming a major health care problem, especially in developing countries, where 60% of the world's total new cases are diagnosed. The success of new antineoplastic medicines and modern radiation devices to cure a good proportion of patients with cancer and to alleviate the suffering of many more has been achieved at a dramatic cost. Therefore, it has become mandatory for health care authorities and pharmaceutical companies to cooperate to use and develop resources in an efficient manner to improve health care delivery to patients with cancer worldwide. Regulatory harmonization is an important key to overcome delays in the approval process, whether for antineoplastic and pain control medicines or for essential medical devices. More emphasis on the significant role of opiates in pain control among patients with cancer is needed to overcome the ingrained belief in their potential for addiction. The World Health Organization (WHO) serves an important role in guiding priorities for health care and efficiently allocating resources by providing essential medicine lists (EMLs) and device lists. However, the financial challenge for access to health care is multi-tiered and requires collaboration between key stakeholders including pharmaceutical industry, local national health authorities, WHO, and other nonprofit, patient-oriented organizations.

Ga-Doping-Induced Carrier Tuning and Multiphase Engineering in n-type PbTe with Enhanced Thermoelectric Performance.

PubMed

Wang, Zhengshang; Wang, Guoyu; Wang, Ruifeng; Zhou, Xiaoyuan; Chen, Zhiyu; Yin, Cong; Tang, Mingjing; Hu, Qing; Tang, Jun; Ang, Ran

2018-06-22

P-type lead telluride (PbTe) emerged as a promising thermoelectric material for intermediate-temperature waste-heat-energy harvesting. However, n-type PbTe still confronted with a considerable challenge owing to its relatively low figure of merit ZT and conversion efficiency η, limiting widespread thermoelectric applications. Here, we report that Ga-doping in n-type PbTe can optimize carrier concentration and thus improve the power factor. Moreover, further experimental and theoretical evidence reveals that Ga-doping-induced multiphase structures with nano- to micrometer size can simultaneously modulate phonon transport, leading to dramatic reduction of lattice thermal conductivity. As a consequence, a tremendous enhancement of ZT value at 823 K reaches ∼1.3 for n-type Pb 0.97 Ga 0.03 Te. In particular, in a wide temperature range from 323 to 823 K, the average ZT ave value of ∼0.9 and the calculated conversion efficiency η of ∼13% are achieved by Ga doping. The present findings demonstrate the great potential in Ga-doped PbTe thermoelectric materials through a synergetic carrier tuning and multiphase engineering strategy.

Metal-organic frameworks derived platinum-cobalt bimetallic nanoparticles in nitrogen-doped hollow porous carbon capsules as a highly active and durable catalyst for oxygen reduction reaction

DOE PAGES

Ying, Jie; Li, Jing; Jiang, Gaopeng; ...

2017-11-29

Pt-based nanomaterials are regarded as the most efficient electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, widespread adoption of PEMFCs requires solutions to major challenges encountered with ORR catalysts, namely high cost, sluggish kinetics, and low durability. In this paper, a new efficient method utilizing Co-based metal-organic frameworks is developed to produce PtCo bimetallic nanoparticles embedded in unique nitrogen-doped hollow porous carbon capsules. The obtained catalyst demonstrates an outstanding ORR performance, with a mass activity that is 5.5 and 13.5 times greater than that of commercial Pt/C and Pt black, respectively. Most importantly,more » the product exhibits dramatically improved durability in terms of both electrochemically active surface area (ECAS) and mass activity compared to commercial Pt/C and Pt black catalysts. Finally, the remarkable ORR performance demonstrated here can be attributed to the structural features of the catalyst (its alloy structure, high dispersion and fine particle size) and the carbon support (its nitrogen dopant, large surface area and hollow porous structure).« less

Aerodynamic shape optimization using preconditioned conjugate gradient methods

NASA Technical Reports Server (NTRS)

Burgreen, Greg W.; Baysal, Oktay

1993-01-01

In an effort to further improve upon the latest advancements made in aerodynamic shape optimization procedures, a systematic study is performed to examine several current solution methodologies as applied to various aspects of the optimization procedure. It is demonstrated that preconditioned conjugate gradient-like methodologies dramatically decrease the computational efforts required for such procedures. The design problem investigated is the shape optimization of the upper and lower surfaces of an initially symmetric (NACA-012) airfoil in inviscid transonic flow and at zero degree angle-of-attack. The complete surface shape is represented using a Bezier-Bernstein polynomial. The present optimization method then automatically obtains supercritical airfoil shapes over a variety of freestream Mach numbers. Furthermore, the best optimization strategy examined resulted in a factor of 8 decrease in computational time as well as a factor of 4 decrease in memory over the most efficient strategies in current use.

Operation and design selection of high temperature superconducting magnetic bearings

NASA Astrophysics Data System (ADS)

Werfel, F. N.; Floegel-Delor, U.; Riedel, T.; Rothfeld, R.; Wippich, D.; Goebel, B.

2004-10-01

Axial and radial high temperature superconducting (HTS) magnetic bearings are evaluated by their parameters. Journal bearings possess advantages over thrust bearings. High magnetic gradients in a multi-pole permanent magnet (PM) configuration, the surrounding melt textured YBCO stator and adequate designs are the key features for increasing the overall bearing stiffness. The gap distance between rotor and stator determines the specific forces and has a strong impact on the PM rotor design. We report on the designing, building and measuring of a 200 mm prototype 100 kg HTS bearing with an encapsulated and thermally insulated melt textured YBCO ring stator. The encapsulation requires a magnetically large-gap (4-5 mm) operation but reduces the cryogenic effort substantially. The bearing requires 3 l of LN2 for cooling down, and about 0.2 l LN2 h-1 under operation. This is a dramatic improvement of the efficiency and in the practical usage of HTS magnetic bearings.

Fast and efficient STT switching in MTJ using additional transient pulse current

NASA Astrophysics Data System (ADS)

Pathak, Sachin; Cha, Jongin; Jo, Kangwook; Yoon, Hongil; Hong, Jongill

2017-06-01

We propose a profile of write pulse current-density to switch magnetization in a perpendicular magnetic tunnel junction to reduce switching time and write energy as well. Our simulated results show that an overshoot transient pulse current-density (current spike) imposed to conventional rectangular-shaped pulse current-density (main pulse) significantly improves switching speed that yields the reduction in write energy accordingly. For example, we could dramatically reduce the switching time by 80% and thereby reduce the write energy over 9% in comparison to the switching without current spike. The current spike affects the spin dynamics of the free layer and reduces the switching time mainly due to spin torque induced. On the other hand, the large Oersted field induced causes changes in spin texture. We believe our proposed write scheme can make a breakthrough in magnetic random access memory technology seeking both high speed operation and low energy consumption.

Graphene nanoplatelets induced heterogeneous bimodal structural magnesium matrix composites with enhanced mechanical properties

PubMed Central

Xiang, Shulin; Wang, Xiaojun; Gupta, Manoj; Wu, Kun; Hu, Xiaoshi; Zheng, Mingyi

2016-01-01

In this work, graphene nanoplatelets (GNPs) reinforced magnesium (Mg) matrix composites were synthesised using the multi-step dispersion route. Well-dispersed but inhomogeneously distributed GNPs were obtained in the matrix. Compared with the monolithic alloy, the nanocomposites exhibited dramatically enhanced Young’s modulus, yield strength and ultimate tensile strength and relatively high plasticity, which mainly attributed to the significant heterogeneous laminated microstructure induced by the addition of GNPs. With increasing of the concentration of GNPs, mechanical properties of the composites were gradually improved. Especially, the strengthening efficiency of all the composites exceeded 100%, which was significantly higher than that of carbon nanotubes reinforced Mg matrix composites. The grain refinement and load transfer provided by the two-dimensional and wrinkled surface structure of GNPs were the dominated strengthening mechanisms of the composites. This investigation develops a new method for incorporating GNPs in metals for fabricating high-performance composites. PMID:27941839

Parallel implementation of an adaptive scheme for 3D unstructured grids on the SP2

NASA Technical Reports Server (NTRS)

Strawn, Roger C.; Oliker, Leonid; Biswas, Rupak

1996-01-01

Dynamic mesh adaption on unstructured grids is a powerful tool for computing unsteady flows that require local grid modifications to efficiently resolve solution features. For this work, we consider an edge-based adaption scheme that has shown good single-processor performance on the C90. We report on our experience parallelizing this code for the SP2. Results show a 47.0X speedup on 64 processors when 10 percent of the mesh is randomly refined. Performance deteriorates to 7.7X when the same number of edges are refined in a highly-localized region. This is because almost all the mesh adaption is confined to a single processor. However, this problem can be remedied by repartitioning the mesh immediately after targeting edges for refinement but before the actual adaption takes place. With this change, the speedup improves dramatically to 43.6X.

Parallel Implementation of an Adaptive Scheme for 3D Unstructured Grids on the SP2

NASA Technical Reports Server (NTRS)

Oliker, Leonid; Biswas, Rupak; Strawn, Roger C.

1996-01-01

Dynamic mesh adaption on unstructured grids is a powerful tool for computing unsteady flows that require local grid modifications to efficiently resolve solution features. For this work, we consider an edge-based adaption scheme that has shown good single-processor performance on the C90. We report on our experience parallelizing this code for the SP2. Results show a 47.OX speedup on 64 processors when 10% of the mesh is randomly refined. Performance deteriorates to 7.7X when the same number of edges are refined in a highly-localized region. This is because almost all mesh adaption is confined to a single processor. However, this problem can be remedied by repartitioning the mesh immediately after targeting edges for refinement but before the actual adaption takes place. With this change, the speedup improves dramatically to 43.6X.

Graphene nanoplatelets induced heterogeneous bimodal structural magnesium matrix composites with enhanced mechanical properties

NASA Astrophysics Data System (ADS)

Xiang, Shulin; Wang, Xiaojun; Gupta, Manoj; Wu, Kun; Hu, Xiaoshi; Zheng, Mingyi

2016-12-01

In this work, graphene nanoplatelets (GNPs) reinforced magnesium (Mg) matrix composites were synthesised using the multi-step dispersion route. Well-dispersed but inhomogeneously distributed GNPs were obtained in the matrix. Compared with the monolithic alloy, the nanocomposites exhibited dramatically enhanced Young’s modulus, yield strength and ultimate tensile strength and relatively high plasticity, which mainly attributed to the significant heterogeneous laminated microstructure induced by the addition of GNPs. With increasing of the concentration of GNPs, mechanical properties of the composites were gradually improved. Especially, the strengthening efficiency of all the composites exceeded 100%, which was significantly higher than that of carbon nanotubes reinforced Mg matrix composites. The grain refinement and load transfer provided by the two-dimensional and wrinkled surface structure of GNPs were the dominated strengthening mechanisms of the composites. This investigation develops a new method for incorporating GNPs in metals for fabricating high-performance composites.

The design and test of collecting device and film purge device joint work of residual film recovery machine based on Solidworks & Adams

NASA Astrophysics Data System (ADS)

Zhai, Haozhou; Jian, Jianming; Hou, Shulin; San, Yunlong; Guo, Wensong; Sun, Yue; Gao, Mingqing

2018-03-01

The twine of residual film is an essential issue in the process of remnant residue recovery of the residual film recovery machine. It is difficult to clean up the residual film in the residual film recovery operation and to influence the subsequent film efficiency. Therefore, in response to this problem a composite tooth pocket residual film recovery device was designed. In this paper, the structure of the film recovery device design, theoretical analysis, simulation experiments, get the most appropriate film recovery device parameters. In addition, the residual film rate of the membrane is dramatically low, reaching about 1.3% only, and the operation of the whole machine is smoother, and the stability of the work is promoted. The operation of the film recovery device is very obvious. Lifting, in addition to the film rate has also been significantly improved to 93.88%

Brain-Computer Symbiosis

PubMed Central

Schalk, Gerwin

2009-01-01

The theoretical groundwork of the 1930’s and 1940’s and the technical advance of computers in the following decades provided the basis for dramatic increases in human efficiency. While computers continue to evolve, and we can still expect increasing benefits from their use, the interface between humans and computers has begun to present a serious impediment to full realization of the potential payoff. This article is about the theoretical and practical possibility that direct communication between the brain and the computer can be used to overcome this impediment by improving or augmenting conventional forms of human communication. It is about the opportunity that the limitations of our body’s input and output capacities can be overcome using direct interaction with the brain, and it discusses the assumptions, possible limitations, and implications of a technology that I anticipate will be a major source of pervasive changes in the coming decades. PMID:18310804

New Treatment of Strongly Anisotropic Scattering Phase Functions: The Delta-M+ Method

NASA Astrophysics Data System (ADS)

Stamnes, K. H.; Lin, Z.; Chen, N.; Fan, Y.; Li, W.; Stamnes, S.

2017-12-01

The treatment of strongly anisotropic scattering phase functions is still a challenge for accurate radiance computations. The new Delta-M+ method resolves this problem by introducing a reliable, fast, accurate, and easy-to-use Legendre expansion of the scattering phase function with modified moments. Delta-M+ is an upgrade of the widely-used Delta-M method that truncates the forward scattering cone into a Dirac-delta-function (a direct beam), where the + symbol indicates that it essentially matches moments above the first 2M terms. Compared with the original Delta-M method, Delta-M+ has the same computational efficiency, but the accuracy has been increased dramatically. Tests show that the errors for strongly forward-peaked scattering phase functions are greatly reduced. Furthermore, the accuracy and stability of radiance computations are also significantly improved by applying the new Delta-M+ method.

An Approach to Data Center-Based KDD of Remote Sensing Datasets

NASA Technical Reports Server (NTRS)

Lynnes, Christopher; Mack, Robert; Wharton, Stephen W. (Technical Monitor)

2001-01-01

The data explosion in remote sensing is straining the ability of data centers to deliver the data to the user community, yet many large-volume users actually seek a relatively small information component within the data, which they extract at their sites using Knowledge Discovery in Databases (KDD) techniques. To improve the efficiency of this process, the Goddard Earth Sciences Distributed Active Archive Center (GES DAAC) has implemented a KDD subsystem that supports execution of the user's KDD algorithm at the data center, dramatically reducing the volume that is sent to the user. The data are extracted from the archive in a planned, organized "campaign"; the algorithms are executed, and the output products sent to the users over the network. The first campaign, now complete, has resulted in overall reductions in shipped volume from 3.3 TB to 0.4 TB.

21. century customers: Volume 1 -- Industry and manufacturing. Final report

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

Hanley, P.H.; Asfour, A.; Tripp, S.

1998-12-01

The arrival of 21st century information technologies has compelled traditional heavy industries such as steel, chemicals, and paper/pulp to invest in new plants and technologies, efficiency moves, globalization of sourcing, and aggressive pursuit of foreign direct investment. This report will assist strategic planners and marketing executives charged with identifying the needs of the widely dispersed industrial sector and provide insights regarding how to improve long-term profitability. Understanding and meeting the evolving needs of industrial customers could be critical to the future prosperity of energy enterprises. This report examines five significant industries that are undergoing dramatic changes in their markets andmore » relationships to buyers of their products--steel and aluminum, paper and pulp, chemicals, plastics, and food processing. The report provides a companion to Volume 2, ``21st Century Customers: Volume 2: Business and Commerce``, covering the evolving needs of five commercial sector businesses.« less

High performance aluminum–cerium alloys for high-temperature applications

DOE PAGES

Sims, Zachary C.; Rios, Orlando R.; Weiss, David; ...

2017-08-01

Light-weight high-temperature alloys are important to the transportation industry where weight, cost, and operating temperature are major factors in the design of energy efficient vehicles. Aluminum alloys fill this gap economically but lack high-temperature mechanical performance. Alloying aluminum with cerium creates a highly castable alloy, compatible with traditional aluminum alloy additions, that exhibits dramatically improved high-temperature performance. These compositions display a room temperature ultimate tensile strength of 400 MPa and yield strength of 320 MPa, with 80% mechanical property retention at 240 °C. A mechanism is identified that addresses the mechanical property stability of the Al-alloys to at least 300more » °C and their microstructural stability to above 500 °C which may enable applications without the need for heat treatment. Lastly, neutron diffraction under load provides insight into the unusual mechanisms driving the mechanical strength.« less

Advances in solid dosage form manufacturing technology.

PubMed

Andrews, Gavin P

2007-12-15

Currently, the pharmaceutical and healthcare industries are moving through a period of unparalleled change. Major multinational pharmaceutical companies are restructuring, consolidating, merging and more importantly critically assessing their competitiveness to ensure constant growth in an ever-more demanding market where the cost of developing novel products is continuously increasing. The pharmaceutical manufacturing processes currently in existence for the production of solid oral dosage forms are associated with significant disadvantages and in many instances provide many processing problems. Therefore, it is well accepted that there is an increasing need for alternative processes to dramatically improve powder processing, and more importantly to ensure that acceptable, reproducible solid dosage forms can be manufactured. Consequently, pharmaceutical companies are beginning to invest in innovative processes capable of producing solid dosage forms that better meet the needs of the patient while providing efficient manufacturing operations. This article discusses two emerging solid dosage form manufacturing technologies, namely hot-melt extrusion and fluidized hot-melt granulation.

Polymeric efficiency in remove impurities during cottonseed biodiesel production

NASA Astrophysics Data System (ADS)

Lin, H. L.; Liang, Y. H.; Yan, J.; Lin, H. D.; Espinosa, A. R.

2016-07-01

This paper describes a new process for developing biodiesel by polymer from crude cottonseed oil. The study was conducted to examine the effectiveness of the alkali transesterification-flocculation-sedimentation process on fast glycerol and other impurities in the separation from biodiesel by using quaternary polyamine-based cationic polymers SL2700 and polyacylamide cationic polymer SAL1100. The settling velocity of glycerol and other impurities in biodiesel was investigated through settling test experiments; the quality of the biodiesel was investigated by evaluating the viscosity and density. The results revealed that SL2700, SAL1100 and their combination dramatically improved the settling velocity of glycerol and other impurities materials than traditional method. SL 2700 with molecular weight of 0.2 million Da and charge density of 50% then plus SAL1100 with molecular weight of 11 million Da and charge density of 10% induced observable particle aggregation with the best settling performance.

Significant improvement in Mn2O3 transition metal oxide electrical conductivity via high pressure

PubMed Central

Hong, Fang; Yue, Binbin; Hirao, Naohisa; Liu, Zhenxian; Chen, Bin

2017-01-01

Highly efficient energy storage is in high demand for next-generation clean energy applications. As a promising energy storage material, the application of Mn2O3 is limited due to its poor electrical conductivity. Here, high-pressure techniques enhanced the electrical conductivity of Mn2O3 significantly. In situ synchrotron micro X-Ray diffraction, Raman spectroscopy and resistivity measurement revealed that resistivity decreased with pressure and dramatically dropped near the phase transition. At the highest pressure, resistivity reduced by five orders of magnitude and the sample showed metal-like behavior. More importantly, resistivity remained much lower than its original value, even when the pressure was fully released. This work provides a new method to enhance the electronic properties of Mn2O3 using high-pressure treatment, benefiting its applications in energy-related fields. PMID:28276479

A Domain Analysis Model for eIRB Systems: Addressing the Weak Link in Clinical Research Informatics

PubMed Central

He, Shan; Narus, Scott P.; Facelli, Julio C.; Lau, Lee Min; Botkin, Jefferey R.; Hurdle, John F.

2014-01-01

Institutional Review Boards (IRBs) are a critical component of clinical research and can become a significant bottleneck due to the dramatic increase, in both volume and complexity of clinical research. Despite the interest in developing clinical research informatics (CRI) systems and supporting data standards to increase clinical research efficiency and interoperability, informatics research in the IRB domain has not attracted much attention in the scientific community. The lack of standardized and structured application forms across different IRBs causes inefficient and inconsistent proposal reviews and cumbersome workflows. These issues are even more prominent in multi-institutional clinical research that is rapidly becoming the norm. This paper proposes and evaluates a domain analysis model for electronic IRB (eIRB) systems, paving the way for streamlined clinical research workflow via integration with other CRI systems and improved IRB application throughput via computer-assisted decision support. PMID:24929181

Segmentation and classification of cell cycle phases in fluorescence imaging.

PubMed

Ersoy, Ilker; Bunyak, Filiz; Chagin, Vadim; Cardoso, M Christina; Palaniappan, Kannappan

2009-01-01

Current chemical biology methods for studying spatiotemporal correlation between biochemical networks and cell cycle phase progression in live-cells typically use fluorescence-based imaging of fusion proteins. Stable cell lines expressing fluorescently tagged protein GFP-PCNA produce rich, dynamically varying sub-cellular foci patterns characterizing the cell cycle phases, including the progress during the S-phase. Variable fluorescence patterns, drastic changes in SNR, shape and position changes and abundance of touching cells require sophisticated algorithms for reliable automatic segmentation and cell cycle classification. We extend the recently proposed graph partitioning active contours (GPAC) for fluorescence-based nucleus segmentation using regional density functions and dramatically improve its efficiency, making it scalable for high content microscopy imaging. We utilize surface shape properties of GFP-PCNA intensity field to obtain descriptors of foci patterns and perform automated cell cycle phase classification, and give quantitative performance by comparing our results to manually labeled data.

Cell segmentation in time-lapse fluorescence microscopy with temporally varying sub-cellular fusion protein patterns.

PubMed

Bunyak, Filiz; Palaniappan, Kannappan; Chagin, Vadim; Cardoso, M

2009-01-01

Fluorescently tagged proteins such as GFP-PCNA produce rich dynamically varying textural patterns of foci distributed in the nucleus. This enables the behavioral study of sub-cellular structures during different phases of the cell cycle. The varying punctuate patterns of fluorescence, drastic changes in SNR, shape and position during mitosis and abundance of touching cells, however, require more sophisticated algorithms for reliable automatic cell segmentation and lineage analysis. Since the cell nuclei are non-uniform in appearance, a distribution-based modeling of foreground classes is essential. The recently proposed graph partitioning active contours (GPAC) algorithm supports region descriptors and flexible distance metrics. We extend GPAC for fluorescence-based cell segmentation using regional density functions and dramatically improve its efficiency for segmentation from O(N(4)) to O(N(2)), for an image with N(2) pixels, making it practical and scalable for high throughput microscopy imaging studies.

Low-energy hydraulic fracturing wastewater treatment via AC powered electrocoagulation with biochar.

PubMed

Lobo, Fernanda Leite; Wang, Heming; Huggins, Tyler; Rosenblum, James; Linden, Karl G; Ren, Zhiyong Jason

2016-05-15

Produced and flowback waters are the largest byproducts associated with unconventional oil and gas exploration and production. Sustainable and low cost technologies are needed to treat and reuse this wastewater to avoid the environmental problems associated with current management practices (i.e., deep well injection). This study presents a new process to integrate AC-powered electrocoagulation (EC) with granular biochar to dramatically reduce energy use and electrode passivation while achieving high treatment efficiency. Results show achieving a 99% turbidity and TSS removal for the AC-EC-biochar system only used 0.079 kWh/m(3) or 0.15 kWh/kg TSS, which is 70% lower than traditional DC-EC systems and orders of magnitude lower than previous studies. The amount of biochar added positively correlates with energy saving, and further studies are needed to improve organic carbon and salt removal through system integration. Copyright © 2016 Elsevier B.V. All rights reserved.

The Interlibrary Loan Transaction

PubMed Central

Pings, Vern M.

1965-01-01

Although the number of items borrowed through interlibrary loan may not increase as dramatically as it has in the past ten years, the trend can be expected to continue because of the growing interdisciplinary nature of biomedical research and because of the anticipated improved bibliographic control of biomedical literature. To provide a framework for collecting data on volume of flow between institutions, on time requirements for processing operations, on cost of interlibrary transactions, on the efficiency of communication channels, and on alternative procedures for performing the transaction, block diagrams were prepared to show the flow of information and materials between individuals and institutions. These diagrams show the interinstitutional dependence; any alterations in procedures in one institution affect other institutions. Even though it can be clearly shown where alterations in the flow pattern can be effected, there are little quantitative data available to serve as a justification for maintaining or modifying existing procedures. PMID:14271114

The enhancement of visuospatial processing efficiency through Buddhist Deity meditation.

PubMed

Kozhevnikov, Maria; Louchakova, Olga; Josipovic, Zoran; Motes, Michael A

2009-05-01

This study examined the effects of meditation on mental imagery, evaluating Buddhist monks' reports concerning their extraordinary imagery skills. Practitioners of Buddhist meditation were divided into two groups according to their preferred meditation style: Deity Yoga (focused attention on an internal visual image) or Open Presence (evenly distributed attention, not directed to any particular object). Both groups of meditators completed computerized mental-imagery tasks before and after meditation. Their performance was compared with that of control groups, who either rested or performed other visuospatial tasks between testing sessions. The results indicate that all the groups performed at the same baseline level, but after meditation, Deity Yoga practitioners demonstrated a dramatic increase in performance on imagery tasks compared with the other groups. The results suggest that Deity meditation specifically trains one's capacity to access heightened visuospatial processing resources, rather than generally improving visuospatial imagery abilities.

Transforming physics educator identities: TAs help TAs become teaching professionals

NASA Astrophysics Data System (ADS)

Gretton, Anneke L.; Bridges, Terry; Fraser, James M.

2017-05-01

Research-based instructional strategies have been shown to dramatically improve student learning, but widespread adoption of these pedagogies remains limited. Post-secondary teaching assistants (TAs), with their current positions in course delivery and future roles as academic leaders, are an essential target group for teacher training. However, the literature suggests that successful TA professional development must address not only pedagogical practices but also the cultivation of physics educator identity. The primary goal of this study is to build a framework for TA professional development that strengthens the TA's identity as a physics educator. We base this framework on Etienne Wenger's model for communities of practice and Côté and Levine's personality and social structure identity perspective. We explore this framework in the context of a 12-week, low-cost, TA-led and TA-centered professional development intervention. Our qualitative and quantitative data suggest that this efficient community-based intervention strengthened TAs' identification as physics educators.

Sustainable energy, economic growth and public health.

PubMed

Haines, A

2001-01-01

Dramatic economic growth over the last 50 years has been accompanied by widening inequalities world-wide in wealth and energy consumption, diminished life expectancy in some countries, and deteriorating indices of environmental sustainability including loss of bio-diversity. Raised output of carbon dioxide (CO2) and other greenhouse gases due to increased economic and industrial activity is causing progressive climate change, leading in turn to direct and indirect adverse effects on health. Emissions of greenhouse gases can be lowered by increased use of renewable energy sources, for example, wind power in the United Kingdom (UK), greater energy efficiency and other measures to promote sustainability. The experience of some developing countries shows that favourable indicators of health and development can accompany a low output of greenhouse gases. It is unclear whether contemporary political and social systems can deliver improved human development without increased use of fossil fuels and other resources.

Insulin oedema and treatment-induced neuropathy occurring in a 20-year-old patient with Type 1 diabetes commenced on an insulin pump.

PubMed

Rothacker, K M; Kaye, J

2014-01-01

Oedema may occur following initiation or intensification of insulin therapy in patients with Type 1 and Type 2 diabetes. Mild oedema is thought to be not uncommon, but under-reported, whilst generalized oedema with involvement of serous cavities has rarely been described. Multiple pathogenic mechanisms have been proposed, including insulin-induced sodium and water retention. Patients at greater risk for insulin oedema include those with poor glycaemic control. Dramatic improvement in glycaemic control is also associated with sensory and autonomic neuropathy. We describe a case of generalized oedema occurring in a 20-year-old, low body weight patient with Type 1 diabetes with poor glycaemic control 3 days following commencement of an insulin pump; blood sugars had dramatically improved with this treatment. Alternative causes for oedema were excluded. Oedema slowly improved with insulin dose reduction with higher blood sugar targets plus frusemide treatment. Subsequent to oedema resolution, the patient unfortunately developed generalized neuropathic pain, thought to be another manifestation of rapid improvement in glycaemic control. Caution should be taken when a patient with diabetes that is poorly controlled has an escalation in therapy that may dramatically improve their blood sugar levels; this includes the initiation of an insulin pump. Clinicians and patients should be aware of the potential risk of insulin oedema, treatment-induced neuropathy and worsening of diabetic retinopathy in the setting of rapid improvement in glycaemic control. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.

BiVO4 Photoanode with Exposed (040) Facets for Enhanced Photoelectrochemical Performance

NASA Astrophysics Data System (ADS)

Xia, Ligang; Li, Jinhua; Bai, Jing; Li, Linsen; Chen, Shuai; Zhou, Baoxue

2018-03-01

A BiVO4 photoanode with exposed (040) facets was prepared to enhance its photoelectrochemical performance. The exposure of the (040) crystal planes of the BiVO4 film was induced by adding NaCl to the precursor solution. The as-prepared BiVO4 photoanode exhibits higher solar-light absorption and charge-separation efficiency compared to those of an anode prepared without adding NaCl. To our knowledge, the photocurrent density (1.26 mA cm-2 at 1.23 V vs. RHE) of as-prepared BiVO4 photoanode is the highest according to the reports for bare BiVO4 films under simulated AM1.5G solar light, and the incident photon-to-current conversion efficiency is above 35% at 400 nm. The photoelectrochemical (PEC) water-splitting performance was also dramatically improved with a hydrogen evolution rate of 9.11 μmol cm-2 h-1, which is five times compared with the BiVO4 photoanode prepared without NaCl (1.82 μmol cm-2 h-1). Intensity-modulated photocurrent spectroscopy and transient photocurrent measurements show a higher charge-carrier-transfer rate for this photoanode. These results demonstrate a promising approach for the development of high-performance BiVO4 photoanodes which can be used for efficient PEC water splitting and degradation of organic pollutants. [Figure not available: see fulltext.

VOCs elimination and health risk reduction in e-waste dismantling workshop using integrated techniques of electrostatic precipitation with advanced oxidation technologies.

PubMed

Chen, Jiangyao; Huang, Yong; Li, Guiying; An, Taicheng; Hu, Yunkun; Li, Yunlu

2016-01-25

Volatile organic compounds (VOCs) emitted during the electronic waste dismantling process (EWDP) were treated at a pilot scale, using integrated electrostatic precipitation (EP)-advanced oxidation technologies (AOTs, subsequent photocatalysis (PC) and ozonation). Although no obvious alteration was seen in VOC concentration and composition, EP technology removed 47.2% of total suspended particles, greatly reducing the negative effect of particles on subsequent AOTs. After the AOT treatment, average removal efficiencies of 95.7%, 95.4%, 87.4%, and 97.5% were achieved for aromatic hydrocarbons, aliphatic hydrocarbons, halogenated hydrocarbons, as well as nitrogen- and oxygen-containing compounds, respectively, over 60-day treatment period. Furthermore, high elimination capacities were also seen using hybrid technique of PC with ozonation; this was due to the PC unit's high loading rates and excellent pre-treatment abilities, and the ozonation unit's high elimination capacity. In addition, the non-cancer and cancer risks, as well as the occupational exposure cancer risk, for workers exposed to emitted VOCs in workshop were reduced dramatically after the integrated technique treatment. Results demonstrated that the integrated technique led to highly efficient and stable VOC removal from EWDP emissions at a pilot scale. This study points to an efficient approach for atmospheric purification and improving human health in e-waste recycling regions. Copyright © 2015 Elsevier B.V. All rights reserved.

β-Cell–Specific Protein Kinase A Activation Enhances the Efficiency of Glucose Control by Increasing Acute-Phase Insulin Secretion

PubMed Central

Kaihara, Kelly A.; Dickson, Lorna M.; Jacobson, David A.; Tamarina, Natalia; Roe, Michael W.; Philipson, Louis H.; Wicksteed, Barton

2013-01-01

Acute insulin secretion determines the efficiency of glucose clearance. Moreover, impaired acute insulin release is characteristic of reduced glucose control in the prediabetic state. Incretin hormones, which increase β-cell cAMP, restore acute-phase insulin secretion and improve glucose control. To determine the physiological role of the cAMP-dependent protein kinase (PKA), a mouse model was developed to increase PKA activity specifically in the pancreatic β-cells. In response to sustained hyperglycemia, PKA activity potentiated both acute and sustained insulin release. In contrast, a glucose bolus enhanced acute-phase insulin secretion alone. Acute-phase insulin secretion was increased 3.5-fold, reducing circulating glucose to 58% of levels in controls. Exendin-4 increased acute-phase insulin release to a similar degree as PKA activation. However, incretins did not augment the effects of PKA on acute-phase insulin secretion, consistent with incretins acting primarily via PKA to potentiate acute-phase insulin secretion. Intracellular calcium signaling was unaffected by PKA activation, suggesting that the effects of PKA on acute-phase insulin secretion are mediated by the phosphorylation of proteins involved in β-cell exocytosis. Thus, β-cell PKA activity transduces the cAMP signal to dramatically increase acute-phase insulin secretion, thereby enhancing the efficiency of insulin to control circulating glucose. PMID:23349500

Design principle for efficient charge separation at the donor-acceptor interface for high performance organic solar cell device

NASA Astrophysics Data System (ADS)

Nie, Wanyi; Gupta, Gautam; Crone, Brian; Wang, Hsing-Lin; Mohite, Aditya; MPA-11 Material synthesis and integrated device Team; MPA-chemistry Team

2014-03-01

The performance of donor (D) /acceptor (A) structure based organic electronic devices, such as solar cell, light emitting devices etc., relays on the charge transfer process at the interface dramatically. In organic solar cell, the photo-induced electron-hole pair is tightly bonded and will form a charge transfer (CT) state at the D/A interface after dissociation. There is a large chance for them to recombine through CT state and thus is a major loss that limit the overall performance. Here, we report three different strategies that allow us to completely suppress the exciplex (or charge transfer state) recombination between any D/A system. We observe that the photocurrent increases by 300% and the power conversion efficiency increases by 4-5 times simply by inserting a spacer layer in the form of an a) insulator b) Oliogomer or using a c) heavy atom at the donor-acceptor interface in a P3HT/C60 bilayer device. By using those different functional mono layers, we successfully suppressed the exciplex recombination in evidence of increased photocurrent and open circuit voltage. Moreover, these strategies are applicable universally to any donor-acceptor interface. And we demonstrated such strategies in a bulk-heterojunction device which improved the power conversion efficiency from 3.5% up to 4.6%.

Evaluation of novel PMTs of worldwide best parameters for the CTA project

NASA Astrophysics Data System (ADS)

Mirzoyan, R.; Müller, D.; Hose, J.; Menzel, U.; Nakajima, D.; Takahashi, M.; Teshima, M.; Toyama, T.; Yamamoto, T.

2017-02-01

Photomultiplier Tubes (PMT) are the most widespread detectors for measuring fast and faint light signals. About six years ago, we started an improvement program for the PMT candidates for the Cherenkov Telescope Array (CTA) project in cooperation with the companies Hamamatsu Photonics K.K. (Japan) and Electron Tubes Enterprises Ltd. (England). CTA is the next major Imaging Atmospheric Cherenkov Telescopes array for ground-based high energy gamma-ray astrophysics. A total of ∼ 100 telescopes of sizes of 23 m, 12 m and 4 m in diameter will be built in northern and southern hemispheres. For CTA we need PMTs with the highest quantum efficiency and photoelectron collection efficiency, short pulse width of a few ns, low transit time spread and very low afterpulsing. The manufacturers were able to produce 1.5‧ PMTs of enhanced peak quantum efficiency of ∼ 40 % . These collect up to 95-98% of photoelectrons onto the first dynode for the wavelengths ≥ 400 nm . A pulse width of ≤ 3 ns has been achieved at the selected operational gain of 40k. The afterpulsing for a threshold of ≥ 4 photoelectrons is dramatically reduced, down to the level of 0.02%. We will report on the measurements of 1.5‧ PMTs from Hamamatsu and Electron Tubes Enterprises as candidate PMTs for the CTA project. The novel 1.5‧ PMTs have the worldwide best parameters.

Clinical Information Systems – From Yesterday to Tomorrow

PubMed Central

2016-01-01

Summary Objectives To review the history of clinical information systems over the past twenty-five years and project anticipated changes to those systems over the next twenty-five years. Methods Over 250 Medline references about clinical information systems, quality of patient care, and patient safety were reviewed. Books, Web resources, and the author’s personal experience with developing the HELP system were also used. Results There have been dramatic improvements in the use and acceptance of clinical computing systems and Electronic Health Records (EHRs), especially in the United States. Although there are still challenges with the implementation of such systems, the rate of progress has been remarkable. Over the next twenty-five years, there will remain many important opportunities and challenges. These opportunities include understanding complex clinical computing issues that must be studied, understood and optimized. Dramatic improvements in quality of care and patient safety must be anticipated as a result of the use of clinical information systems. These improvements will result from a closer involvement of clinical informaticians in the optimization of patient care processes. Conclusions Clinical information systems and computerized clinical decision support have made contributions to medicine in the past. Therefore, by using better medical knowledge, optimized clinical information systems, and computerized clinical decision, we will enable dramatic improvements in both the quality and safety of patient care in the next twenty-five years. PMID:27362589

Continuous Quality Improvement: A Roadmap for Rural School Improvement.

ERIC Educational Resources Information Center

Kilmer, Lloyd C.

A case study documented a continuous quality improvement approach to school improvement in a rural Nebraska high school over a 2-year period. Data gathered from surveys, portfolios, pilot results, and test scores indicated that the changes during the 2-year period were not dramatic, but significant and consistent with the Total Quality literature.…

Rectal cancer surgery: a brief history.

PubMed

Galler, Avi S; Petrelli, Nicholas J; Shakamuri, Shanthi P

2011-12-01

In the last 250 years, the treatment of rectal cancer has changed dramatically. Once considered an incurable disease, combined modality therapy has improved mortality from 100% to less than 4% for locally advanced rectal cancer. This dramatic reduction paralleled surgical techniques based on a growing understanding of anatomy and disease pathology. In order to understand modern treatment, it is necessary to recognize the achievements of preceding surgeons. Copyright © 2010 Elsevier Ltd. All rights reserved.

Dramatic reduction of culture time of Mycobacterium tuberculosis

NASA Astrophysics Data System (ADS)

Ghodbane, Ramzi; Raoult, Didier; Drancourt, Michel

2014-02-01

Mycobacterium tuberculosis culture, a critical technique for routine diagnosis of tuberculosis, takes more than two weeks. Here, step-by-step improvements in the protocol including a new medium, microaerophlic atmosphere or ascorbic-acid supplement and autofluorescence detection dramatically shortened this delay. In the best case, primary culture and rifampicin susceptibility testing were achieved in 72 hours when specimens were inoculated directly on the medium supplemented by antibiotic at the beginning of the culture.

Development of a Passively Varying Pitch Propeller

NASA Astrophysics Data System (ADS)

Heinzen, Stearns Beamon

Small general aviation aircraft and unmanned aerial systems are often equipped with sophisticated navigation, control, and other avionics, but retain propulsion systems consisting of retrofitted radio control and ultralight equipment. Consequently, new high performance airframes often rely on relatively primitive propulsive technology. This trend is beginning to shift with recent advances in small turboprop engines, fuel injected reciprocating engines, and improved electric technologies. Although these systems are technologically advanced, they are often paired with standard fixed pitch propellers. To fully realize the potential of these aircraft and the new generation of engines, small propellers which can efficiently transmit power over wide flight envelopes and a variety of power settings must be developed. This work demonstrates a propeller which passively adjusts to incoming airflow at a low penalty to aircraft weight and complexity. This allows the propeller to operate in an efficient configuration over a wide flight envelope, and can prevent blade stall in low-velocity / highly-loaded thrust cases and over-speeding at high flight speeds. The propeller incorporates blades which pivot freely on a radial axis and are aerodynamically tailored to attain and maintain a pitch angle yielding favorable local blade angles of attack, matched to changing inflow conditions. This blade angle is achieved through the use of reflexed airfoils designed for a positive pitching moment, comparable to those used on many tailless flying wings. By setting the axis of rotation at a point forward of the blade aerodynamic center, the blades will naturally adjust to a predetermined positive lift 'trim' condition. Then, as inflow conditions change, the blade angle will automatically pivot to maintain the same angle with respect to incoming air. Computational, wind tunnel, and flight test results indicate that the extent of efficient propeller operation can be increased dramatically as compared to the fixed pitch propellers currently used on most light aircraft and small unmanned systems, making significant improvements in aircraft performance possible. These improvements may yield aircraft with reduced takeoff distances, improved climb rates, increased range and endurance, and higher top speeds, without sacrificing on-design performance.

Hematopoietic Stem Cell Transplantation—50 Years of Evolution and Future Perspectives

PubMed Central

Henig, Israel; Zuckerman, Tsila

2014-01-01

Hematopoietic stem cell transplantation is a highly specialized and unique medical procedure. Autologous transplantation allows the administration of high-dose chemotherapy without prolonged bone marrow aplasia. In allogeneic transplantation, donor-derived stem cells provide alloimmunity that enables a graft-versus-tumor effect to eradicate residual disease and prevent relapse. The first allogeneic transplantation was performed by E. Donnall Thomas in 1957. Since then the field has evolved and expanded worldwide. New indications beside acute leukemia and aplastic anemia have been constantly explored and now include congenital disorders of the hematopoietic system, metabolic disorders, and autoimmune disease. The use of matched unrelated donors, umbilical cord blood units, and partially matched related donors has dramatically extended the availability of allogeneic transplantation. Transplant-related mortality has decreased due to improved supportive care, including better strategies to prevent severe infections and with the incorporation of reduced-intensity conditioning protocols that lowered the toxicity and allowed for transplantation in older patients. However, disease relapse and graft-versus-host disease remain the two major causes of mortality with unsatisfactory progress. Intense research aiming to improve adoptive immunotherapy and increase graft-versus-leukemia response while decreasing graft-versus-host response might bring the next breakthrough in allogeneic transplantation. Strategies of graft manipulation, tumor-associated antigen vaccinations, monoclonal antibodies, and adoptive cellular immunotherapy have already proved clinically efficient. In the following years, allogeneic transplantation is likely to become more complex, more individualized, and more efficient. PMID:25386344

Albumin nanoparticles coated with polysorbate 80 as a novel drug carrier for the delivery of antiretroviral drug—Efavirenz

PubMed Central

Jenita, Josephine Leno; Chocalingam, Vijaya; Wilson, Barnabas

2014-01-01

Purpose of the study: The antiretroviral therapy (ART) has dramatically improved human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) treatment, prevention and also has been found to increase the lifespan of HIV/AIDS patients by providing durable control of the HIV replication in patients. Efavirenz is a non-nucleoside reverse transcriptase inhibitor of HIV-1. The purpose of this study is to formulate efavirenz-loaded bovine serum albumin nanoparticles to improve efavirenz delivery into various organs. Materials and Methods: Nanoparticles were prepared by desolvation technique and coated with polysorbate 80. Ethanol, glutaraldehyde, and mannitol were used as desolvating, cross linking agent, and cryoprotectant, respectively. Drug to polymer ratio was chosen at five levels from 1:2, 1:3, 1:4, 1:5, and 1:6 (by weight). The formulated nanoparticles were characterized for Fourier Transform Infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) studies, entrapment efficiency, particle size, surface charge, surface morphology, in vitro drug release, release kinetics, stability studies, and biodistribution studies. Results and Major Conclusion: The particle size of the prepared formulations was found below 250nm with narrow size distribution, spherical in shape and showed good entrapment efficiency (45.62-72.49%). The in vitro drug release indicated biphasic release and its data were fitted to release kinetics models and release pattern was Fickian diffusion controlled release profile. The prepared nanoparticles increased efavirenz delivery into various organs by several fold in comparison with the free drug. PMID:25126528

Intravenous immunoglobulin therapy leading to dramatic improvement in a patient with systemic juvenile idiopathic arthritis and severe pericarditis resistant to steroid pulse therapy.

PubMed

Aizawa-Yashiro, Tomomi; Oki, Eishin; Tsuruga, Kazushi; Nakahata, Tohru; Ito, Etsuro; Tanaka, Hiroshi

2012-05-01

A 7-year-old Japanese boy with a 4-month history of systemic juvenile idiopathic arthritis (s-JIA) experienced disease flare with spiking fever, exanthema and arthralgia. He then developed progressive dyspnea due to severe pericarditis, and proinflammatory hypercytokinemia was suspected. Methylprednisolone pulse therapy was ineffective and echocardiography showed massive pericardial effusion had persisted. Alternatively, subsequent intravenous immunoglobulin (IVIG) therapy resulted in dramatic resolution of the pericardial effusion, and his general condition significantly improved within a few days. This case report may lend further support the use of IVIG for selected patients with s-JIA and severe pericarditis.

Multi-scale theory-assisted nano-engineering of plasmonic-organic hybrid electro-optic device performance

NASA Astrophysics Data System (ADS)

Elder, Delwin L.; Johnson, Lewis E.; Tillack, Andreas F.; Robinson, Bruce H.; Haffner, Christian; Heni, Wolfgang; Hoessbacher, Claudia; Fedoryshyn, Yuriy; Salamin, Yannick; Baeuerle, Benedikt; Josten, Arne; Ayata, Masafumi; Koch, Ueli; Leuthold, Juerg; Dalton, Larry R.

2018-02-01

Multi-scale (correlated quantum and statistical mechanics) modeling methods have been advanced and employed to guide the improvement of organic electro-optic (OEO) materials, including by analyzing electric field poling induced electro-optic activity in nanoscopic plasmonic-organic hybrid (POH) waveguide devices. The analysis of in-device electro-optic activity emphasizes the importance of considering both the details of intermolecular interactions within organic electro-optic materials and interactions at interfaces between OEO materials and device architectures. Dramatic improvement in electro-optic device performance-including voltage-length performance, bandwidth, energy efficiency, and lower optical losses have been realized. These improvements are critical to applications in telecommunications, computing, sensor technology, and metrology. Multi-scale modeling methods illustrate the complexity of improving the electro-optic activity of organic materials, including the necessity of considering the trade-off between improving poling-induced acentric order through chromophore modification and the reduction of chromophore number density associated with such modification. Computational simulations also emphasize the importance of developing chromophore modifications that serve multiple purposes including matrix hardening for enhanced thermal and photochemical stability, control of matrix dimensionality, influence on material viscoelasticity, improvement of chromophore molecular hyperpolarizability, control of material dielectric permittivity and index of refraction properties, and control of material conductance. Consideration of new device architectures is critical to the implementation of chipscale integration of electronics and photonics and achieving the high bandwidths for applications such as next generation (e.g., 5G) telecommunications.

A case of organic brain syndrome following head injury successfully treated with carbamazepine.

PubMed

Bouvy, P F; van de Wetering, B J; Meerwaldt, J D; Bruijn, J B

1988-03-01

A case of organic brain syndrome occurring in relation to psychological stress 2 years after a severe head injury is described. Treatment with haloperidol resulted only in slight improvement. A dramatic improvement was achieved with carbamazepine.

SOCR "Motion Charts": An Efficient, Open-Source, Interactive and Dynamic Applet for Visualizing Longitudinal Multivariate Data

ERIC Educational Resources Information Center

Al-Aziz, Jameel; Christou, Nicolas; Dinov, Ivo D.

2010-01-01

The amount, complexity and provenance of data have dramatically increased in the past five years. Visualization of observed and simulated data is a critical component of any social, environmental, biomedical or scientific quest. Dynamic, exploratory and interactive visualization of multivariate data, without preprocessing by dimensionality…

Hierarchically structured catalysts for cascade and selective steam reforming/hydrodeoxygenation reactions.

PubMed

Sun, Junming; Karim, Ayman M; Li, Xiaohong Shari; Rainbolt, James; Kovarik, Libor; Shin, Yongsoon; Wang, Yong

2015-12-04

We report a hierarchically structured catalyst with steam reforming and hydrodeoxygenation functionalities being deposited in the micropores and macropores, respectively. The catalyst is highly efficient to upgrade the pyrolysis vapors of pine forest product residual, resulting in a dramatically decreased acid content and increased hydrocarbon yield without external H2 supply.

Web-Based Analysis of Internationalization in Israeli Teaching Colleges

ERIC Educational Resources Information Center

Cohen, Anat; Yemini, Miri; Sadeh, Efrat

2014-01-01

The international activities of academic institutions dramatically expanded in volume, scope, and complexity during the past three decades. This expansion raised the need to monitor and assess the process at various levels and ensure the effectiveness and efficiency of internationalization. This study has two main aims: first, to present a model…

Hierarchically structured catalysts for cascade and selective steam reforming/hydrodeoxygenation reactions

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

Sun, Junming; Karim, Ayman M.; Li, Xiaohong S.

2015-09-29

We report a hierarchically structured catalyst with steam reforming and hydrodeoxygenation functionalities being deposited in the micropores and macropores, respectively. The catalyst is highly efficient to upgrade the pyrolysis vapors of pine forest product residual, resulting in a dramatically decreased acid content and increased hydrocarbon yield without external H2 supply.

Highly Efficient Generation of Transgenic Sheep by Lentivirus Accompanying the Alteration of Methylation Status

PubMed Central

Liu, Chenxi; Wang, Liqin; Li, Wenrong; Zhang, Xuemei; Tian, Yongzhi; Zhang, Ning; He, Sangang; Chen, Tong; Huang, Juncheng; Liu, Mingjun

2013-01-01

Background Low efficiency of gene transfer and silence of transgene expression are the critical factors hampering the development of transgenic livestock. Recently, transfer of recombinant lentivirus has been demonstrated to be an efficient transgene delivery method in various animals. However, the lentiviral transgenesis and the methylation status of transgene in sheep have not been well addressed. Methodology/Principle Findings EGFP transgenic sheep were generated by injecting recombinant lentivirus into zygotes. Of the 13 lambs born, 8 carried the EGFP transgene, and its chromosomal integration was identified in all tested tissues. Western blotting showed that GFP was expressed in all transgenic founders and their various tissues. Analysis of CpG methylation status of CMV promoter by bisulfate sequencing unraveled remarkable variation of methylation levels in transgenic sheep. The average methylation levels ranged from 37.6% to 79.1% in the transgenic individuals and 34.7% to 83% in the tested tissues. Correlative analysis of methylation status with GFP expression revealed that the GFP expression level was inversely correlated with methylation density. The similar phenomenon was also observed in tested tissues. Transgene integration determined by Southern blotting presented multiple integrants ranging from 2 to 6 copies in the genome of transgenic sheep. Conclusions/Significance Injection of lentiviral transgene into zygotes could be a promising efficient gene delivery system to generate transgenic sheep and achieved widespread transgene expression. The promoter of integrants transferred by lentiviral vector was subjected to dramatic alteration of methylation status and the transgene expression level was inversely correlative with promoter methylation density. Our work illustrated for the first time that generation of transgenic sheep by injecting recombinant lentivirus into zygote could be an efficient tool to improve sheep performance by genetic modification. PMID:23382924

Mechanisms Affecting Performance of the BaBar Resistive Plate Chambers and Searches for Remediation

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

Lu, Changguo

2003-09-19

The BaBar experiment at PEPII relies on the Instrumentation of the Flux Return (IFR) for both muon identification and KL detection. The active detector is composed of Resistive Plate Chambers (RPC's) operated in streamer mode. Since the start of operation the RPC's have suffered persistent efficiency deterioration and dark current increase problems. The ''autopsy'' of bad BaBar RPC's revealed that in many cases uncured Linseed oil droplets had formed on the inner surface of the Bakelite plates, leading to current paths from oil ''stalagmites'' bridging the 2 mm gap. In this paper a possible model of this ''stalagmite'' formation andmore » its effect on the dark current and efficiency of RPC chambers is presented. Laboratory test results strongly support this model. Based upon this model we are searching for solutions to eliminate the unfavorable effect of the oil stalagmites. The lab tests show that the stalagmite resistivity increases dramatically if exposed to the air, an observation that points to a possible way to remedy the damage and increase the efficiency. We have seen that flowing an oxygen gas mixture into the chamber helps to polymerize the uncured linseed oil. Consequently the resistivity of the bridged oil stalagmites increases, as does that of the oil coating on the frame edges and spacers, significantly reducing the RPC dark currents and low-efficiency regions. We have tested this idea on two chambers removed from BaBar because of their low efficiency and high dark current. These test results are reported in the paper, and two other remediation methods also mentioned. We continue to study this problem, and try to find new treatments with permanent improvement.« less

Teacher Evaluation: Principals' Insights and Suggestions for Improvement

ERIC Educational Resources Information Center

Kersten, Thomas A.; Israel, Marla S.

2005-01-01

In the twenty-first century, school improvement is the focal point for educational leadership, in which the school building administrator is recognized as the catalyst for this necessary improvement. Within the area of teacher evaluation, the evaluation tools, along with the amount of time, format, and feedback, have changed dramatically from the…

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

Lherbier, Louis, W.; Novotnak, David, J.; Herling, Darrell, R.

Hot forming processes such as forging, die casting and glass forming require tooling that is subjected to high temperatures during the manufacturing of components. Current tooling is adversely affected by prolonged exposure at high temperatures. Initial studies were conducted to determine the root cause of tool failures in a number of applications. Results show that tool failures vary and depend on the operating environment under which they are used. Major root cause failures include (1) thermal softening, (2) fatigue and (3) tool erosion, all of which are affected by process boundary conditions such as lubrication, cooling, process speed, etc. Whilemore » thermal management is a key to addressing tooling failures, it was clear that new tooling materials with superior high temperature strength could provide improved manufacturing efficiencies. These efficiencies are based on the use of functionally graded materials (FGM), a new subset of hybrid tools with customizable properties that can be fabricated using advanced powder metallurgy manufacturing technologies. Modeling studies of the various hot forming processes helped identify the effect of key variables such as stress, temperature and cooling rate and aid in the selection of tooling materials for specific applications. To address the problem of high temperature strength, several advanced powder metallurgy nickel and cobalt based alloys were selected for evaluation. These materials were manufactured into tooling using two relatively new consolidation processes. One process involved laser powder deposition (LPD) and the second involved a solid state dynamic powder consolidation (SSDPC) process. These processes made possible functionally graded materials (FGM) that resulted in shaped tooling that was monolithic, bi-metallic or substrate coated. Manufacturing of tooling with these processes was determined to be robust and consistent for a variety of materials. Prototype and production testing of FGM tooling showed the benefits of the nickel and cobalt based powder metallurgy alloys in a number of applications evaluated. Improvements in tool life ranged from three (3) to twenty (20) or more times than currently used tooling. Improvements were most dramatic where tool softening and deformation were the major cause of tool failures in hot/warm forging applications. Significant improvement was also noted in erosion of aluminum die casting tooling. Cost and energy savings can be realized as a result of increased tooling life, increased productivity and a reduction in scrap because of improved dimensional controls. Although LPD and SSDPC tooling usually have higher acquisition costs, net tooling costs per component produced drops dramatically with superior tool performance. Less energy is used to manufacture the tooling because fewer tools are required and less recycling of used tools are needed for the hot forming process. Energy is saved during the component manufacturing cycle because more parts can be produced in shorter periods of time. Energy is also saved by minimizing heating furnace idling time because of less downtime for tooling changes.« less

Effect of organic solar cells using various power O2 plasma treatments on the indium tin oxide substrate.

PubMed

Ke, Jhong-Ciao; Wang, Yeong-Her; Chen, Kan-Lin; Huang, Chien-Jung

2016-03-01

The effect of organic solar cells (OSCs) by using different power O2 plasma treatments on indium tin oxide (ITO) substrate was studied. The power of O2 plasma treatment on ITO substrate was varied from 20W to 80W, and the power conversion efficiency of device was improved from 1.18% to 1.93% at 20W O2 plasma treatment. The function of O2 plasma treatment on ITO substrate was to remove the surface impurity and to improve the work function of ITO, which can reduce the energy offset between the ITO and SubPc layer and depress the leakage current of device, leading to the shunt resistance increased from 897 to 1100Ωcm(2). The surface roughness of ITO decreased from 3.81 to 3.33nm and the work function of ITO increased from 4.75 to 5.2eV after 20W O2 plasma treatment on ITO substrate. As a result, the open circuit voltage and the fill factor were improved from 0.46 to 0.70V and from 0.56 to 0.61, respectively. However, the series resistance of device was dramatically increased as the power of O2 plasma treatment exceeds 40W, leading to the efficiency reduction. The result is attributed to the variation of oxygen vacancies in ITO film after the 60, 80W O2 plasma treatment. As a consequence, the power of O2 plasma treatment on ITO substrate for the OSCs application should be controlled below 40W to avoid affecting the electricity of ITO film. Copyright © 2015 Elsevier Inc. All rights reserved.

High-efficiency perovskite solar cells prepared by using a sandwich structure MAI-PbI2-MAI precursor film.

PubMed

Zhang, Xuhui; Ye, Jiajiu; Zhu, Liangzheng; Zheng, Haiying; Liu, Guozhen; Liu, Xuepeng; Duan, Bin; Pan, Xu; Dai, Songyuan

2017-04-06

Two-step deposition has been widely used in the perovskite layer preparation for perovskite solar cells due to its attractive morphology controllability. However, the limited diffusivity of CH 3 NH 3 I (MAI) might cause some PbI 2 to remain in the perovskite film. The residual PbI 2 in the perovskite film would lead to inferior performance of devices, such as, low power conversion efficiency (PCE), poor reproducibility and weak air stability. In this work, we developed a sandwich structure MAI-PbI 2 -MAI precursor film to prepare a PbI 2 -free CH 3 NH 3 PbI 3 perovskite film. In comparison to the two-step approach, the MAI-PbI 2 -MAI precursor film with a typical sandwich structure formed a uniform and pinhole-free perovskite film without any PbI 2 residue, which could significantly improve the performance of the devices. Moreover, the bottom MAI layer of the MAI-PbI 2 -MAI precursor film could improve the interfacial contact of the porous TiO 2 layer, leading to the promotion of the charge transfer and reduction of the recombination rate. Therefore, the devices fabricated from the sandwich structure MAI-PbI 2 -MAI precursor films showed dramatic improvements of open-circuit voltage (V oc ), short-circuit current density (J sc ), fill factor (FF) and PCE. As a result, a promising PCE of 17.8% with good long-term air stability was achieved for the MAI-PbI 2 -MAI precursor film based PSC, which is better than that prepared by a two-step approach.

Dual-Functionalized Graphene Oxide Based siRNA Delivery System for Implant Surface Biomodification with Enhanced Osteogenesis.

PubMed

Zhang, Li; Zhou, Qing; Song, Wen; Wu, Kaimin; Zhang, Yumei; Zhao, Yimin

2017-10-11

Surface functionalization by small interfering RNA (siRNA) is a novel strategy for improved implant osseointegration. A gene delivery system with safety and high transfection activity is a crucial factor for an siRNA-functionalized implant to exert its biological function. To this end, polyethylene glycol (PEG) and polyethylenimine (PEI) dual-functionalized graphene oxide (GO; nGO-PEG-PEI) may present a promising siRNA vector. In this study, nanosized nGO-PEG-PEI was prepared and optimized for siRNA delivery. Titania nanotubes (NTs) fabricated by anodic oxidation were biomodified with nGO-PEG-PEI/siRNA by cathodic electrodeposition, designated as NT-GPP/siRNA. NT-GPP/siRNA possessed benign cytocompatibility, as evaluated by cell adhesion and proliferation. Cellular uptake and knockdown efficiency of the NT-GPP/siRNA were assessed by MC3T3-E1 cells, which exhibited high siRNA delivery efficiency and sustained target gene silencing. Casein kinase-2 interacting protein-1 (Ckip-1) is a negative regulator of bone formation. siRNA-targeting Ckip-1 (siCkip-1) was introduced to the implant, and a series of in vitro and in vivo experiments were carried out to evaluate the osteogenic capacity of NT-GPP/siCkip-1. NT-GPP/siCkip-1 dramatically improved the in vitro osteogenic differentiation of MC3T3-E1 cells in terms of improved osteogenesis-related gene expression, and increased alkaline phosphatase (ALP) production, collagen secretion, and extracellular matrix (ECM) mineralization. Moreover, NT-GPP/siCkip-1 led to apparently enhanced in vivo osseointegration, as indicated by histological staining and EDX line scanning. Collectively, these findings suggest that NT-GPP/siRNA represents a practicable and promising approach for implant functionalization, showing clinical potential for dental and orthopedic applications.

Semiconducting Nanocrystals in Mesostructured Thin Films for Optical and Opto-Electronic Device Applications

DTIC Science & Technology

2007-03-01

with HF in methanol. For example, for 4.5 nm In0.91Ga0.09P nanoparticles in toluene, there is a dramatic increase in PL quantum efficiency from 8...opto-electronic device applications, for which quantum efficiencies above 50% are typically required for commercial cost-effectiveness. For the...InGaP nanocrystals……… 14 Figure 4: 2D double- quantum 31P NMR spectrum, 4.5 nm InGaP nanocrystals………….…… 15 Figure 5: TEM of of 10 nm, 5 nm

Achieving Dramatic School Improvement: An Exploratory Study. A Cross-Site Analysis from the Evaluation of Comprehensive School Reform Program Implementation and Outcomes Study

ERIC Educational Resources Information Center

Aladjem, Daniel K.; Birman, Beatrice F.; Orland, Martin; Harr-Robins, Jenifer; Heredia, Alberto; Parrish, Thomas B.; Ruffini, Stephen J.

2010-01-01

This exploratory study describes approaches to improving schools through retrospective, in-depth qualitative case studies. To select schools to be examined, the authors sought to identify Comprehensive School Reform (CSR) schools demonstrating two distinctive patterns of improved student achievement between 2000 and 2005, rapid-improvement (i.e.,…

Capped antigenomic RNA transcript facilitates rescue of a plant rhabdovirus.

PubMed

Qian, Shasha; Chen, Xiaolan; Sun, Kai; Zhang, Yang; Li, Zhenghe

2017-06-13

Recovery of recombinant negative-stranded RNA viruses from cloned cDNAs is an inefficient process as multiple viral components need to be delivered into cells for reconstitution of infectious entities. Previously studies have shown that authentic viral RNA termini are essential for efficient virus rescue. However, little is known about the activity of viral RNAs processed by different strategies in supporting recovery of plant negative-stranded RNA virus. In this study, we used several versions of hammerhead ribozymes and a truncated cauliflower mosaic virus 35S promoter to generate precise 5' termini of sonchus yellow net rhabdovirus (SYNV) antigenomic RNA (agRNA) derivatives. These agRNAs were co-expressed with the SYNV core proteins in Nicotiana benthamiana leaves to evaluate their efficiency in supporting fluorescent reporter gene expression from an SYNV minireplicon (MR) and rescue of full-length virus. Optimization of hammerhead ribozyme cleavage activities led to improved SYNV MR reporter gene expression. Although the MR agRNA processed by the most active hammerhead variants is comparable to the capped, precisely transcribed agRNA in supporting MR activity, efficient recovery of recombinant SYNV was only achieved with capped agRNA. Further studies showed that the capped SYNV agRNA permitted transient expression of the nucleocapsid (N) protein, and an agRNA derivatives unable to express the N protein in cis exhibited dramatically reduced rescue efficiency. Our study reveals superior activity of precisely transcribed, capped SYNV agRNAs to uncapped, hammerhead ribozyme-processed agRNAs, and suggests a cis-acting function for the N protein expressed from the capped agRNA during recovery of SYNV from plasmids.

Silver Nanoparticles with Surface-Bonded Oxygen for Highly Selective CO 2 Reduction

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

Jiang, Kun; Kharel, Priti; Peng, Yande

Here, the surface electronic structures of catalysts need to be carefully engineered in CO 2 reduction reaction (CO 2RR), where the hydrogen evolution side reaction usually takes over under a significant overpotential, and thus dramatically lows the reaction selectivity. Surface oxides can play a critical role in tuning the surface oxidation state of metal catalysts for a proper binding with CO 2RR reaction intermediates, which may significantly improve the catalyst activity and selectivity. Here, we demonstrate the importance of surface-bonded oxygen on silver nanoparticles in altering the reaction pathways and improving the CO 2RR performances. A comparative investigation on air-annealedmore » Ag (Air-Ag) catalyst with or without the post-treatment of H 2 thermal annealing (H 2-Ag) was performed. In Air-Ag, the subsurface chemically bonded O species (O-Ag δ+) was identified by angle resolved X-ray photoelectron spectroscopy and X-ray absorption spectroscopy techniques, and contributed to the improved CO selectivity rather than H 2 in CO 2RR electrolysis. As a result, while the maximal CO Faradaic efficiency of H 2-Ag is at ~ 30 %, the Air-Ag catalyst presented a high CO selectivity of more than 90 % under a current density of ~ 21 mA/cm 2.« less

Persufflation Improves Pancreas Preservation When Compared With the Two-Layer Method

PubMed Central

Scott, W.E.; O'Brien, T.D.; Ferrer-Fabrega, J.; Avgoustiniatos, E.S.; Weegman, B.P.; Anazawa, T.; Matsumoto, S.; Kirchner, V.A.; Rizzari, M.D.; Murtaugh, M.P.; Suszynski, T.M.; Aasheim, T.; Kidder, L.S.; Hammer, B.E.; Stone, S.G.; Tempelman, L.; Sutherland, D.E.R.; Hering, B.J.; Papas, K.K.

2010-01-01

Islet transplantation is emerging as a promising treatment for patients with type 1 diabetes. It is important to maximize viable islet yield for each organ due to scarcity of suitable human donor pancreata, high cost, and the high dose of islets required for insulin independence. However, organ transport for 8 hours using the two-layer method (TLM) frequently results in lower islet yields. Since efficient oxygenation of the core of larger organs (eg, pig, human) in TLM has recently come under question, we investigated oxygen persufflation as an alternative way to supply the pancreas with oxygen during preservation. Porcine pancreata were procured from non–heart-beating donors and preserved by either TLM or persufflation for 24 hours and fixed. Biopsies were collected from several regions of the pancreas, sectioned, stained with hematoxylin and eosin, and evaluated by a histologist. Persufflated tissues exhibited distended capillaries due to gas perfusion and significantly less autolysis/cell death than regions not exposed to persufflation or tissues exposed to TLM. The histology presented here suggests that after 24 hours of preservation, persufflation dramatically improves tissue health when compared with TLM. These results indicate the potential for persufflation to improve viable islet yields and extend the duration of preservation, allowing more donor organs to be utilized. PMID:20692396

White butterflies as solar photovoltaic concentrators

PubMed Central

Shanks, Katie; Senthilarasu, S.; ffrench-Constant, Richard H.; Mallick, Tapas K.

2015-01-01

Man’s harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies’ wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies’ thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off. PMID:26227341

Silver Nanoparticles with Surface-Bonded Oxygen for Highly Selective CO 2 Reduction

DOE PAGES

Jiang, Kun; Kharel, Priti; Peng, Yande; ...

2017-09-12

Here, the surface electronic structures of catalysts need to be carefully engineered in CO 2 reduction reaction (CO 2RR), where the hydrogen evolution side reaction usually takes over under a significant overpotential, and thus dramatically lows the reaction selectivity. Surface oxides can play a critical role in tuning the surface oxidation state of metal catalysts for a proper binding with CO 2RR reaction intermediates, which may significantly improve the catalyst activity and selectivity. Here, we demonstrate the importance of surface-bonded oxygen on silver nanoparticles in altering the reaction pathways and improving the CO 2RR performances. A comparative investigation on air-annealedmore » Ag (Air-Ag) catalyst with or without the post-treatment of H 2 thermal annealing (H 2-Ag) was performed. In Air-Ag, the subsurface chemically bonded O species (O-Ag δ+) was identified by angle resolved X-ray photoelectron spectroscopy and X-ray absorption spectroscopy techniques, and contributed to the improved CO selectivity rather than H 2 in CO 2RR electrolysis. As a result, while the maximal CO Faradaic efficiency of H 2-Ag is at ~ 30 %, the Air-Ag catalyst presented a high CO selectivity of more than 90 % under a current density of ~ 21 mA/cm 2.« less

Efficient sintering of nanocrystalline titanium dioxide films for dye solar cells via raster scanning laser

NASA Astrophysics Data System (ADS)

Mincuzzi, Girolamo; Vesce, Luigi; Reale, Andrea; Di Carlo, Aldo; Brown, Thomas M.

2009-09-01

By identifying the right combination of laser parameters, in particular the integrated laser fluence Φ, we fabricated dye solar cells (DSCs) with UV laser-sintered TiO2 films exhibiting a power conversion efficiency η =5.2%, the highest reported for laser-sintered devices. η is dramatically affected by Φ and a clear trend is reported. Significantly, DSCs fabricated by raster scanning the laser beam to sinter the TiO2 films are made as efficient as those with oven-sintered ones. These results, confirmed on three batches of cells, demonstrate the remarkable potential (noncontact, local, low cost, rapid, selective, and scalable) of scanning laser processing applied to DSC technology.

Diffused holographic information storage and retrieval using photorefractive optical materials

NASA Astrophysics Data System (ADS)

McMillen, Deanna Kay

Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and procured for this research. Transmission spectra and diffraction efficiencies were measured for each of the crystals using wavelengths in the visible spectrum. The diffraction efficiency was increased by as much as two orders of magnitude by using a new dopant combination. A new optical diffuser was designed, modeled, fabricated, and tested as a means of improving storage capacity for angularly multiplexed holograms in photorefractive crystals. The diffuser reduced the dynamic range requirement by over three orders of magnitude, increased the storage capacity by more than 400%, and dramatically improved the correlation signals.

Design of Refractory Linings for Balanced Energy Efficiency, Uptime, and Capacity in Lime Kilns

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

Gorog, John Peter; Hemrick, James Gordon; Walker, Harold

2014-01-01

The rotary kilns used by the pulp and paper industry to regenerate lime in the Kraft process are very energy intensive. Throughout the 90 s, in response to increasing fuel prices, the industry used back up insulation in conjunction with the high alumina brick used to line the burning zones of their kilns. While this improved energy efficiency, the practice of installing insulating brick behind the working lining increased the inner wall temperatures. In the worst case, due to the increased temperatures, rapid brick failures occurred causing unscheduled outages and expensive repairs. Despite these issues, for the most part, themore » industry continued to use insulating refractory linings in that the energy savings were large enough to offset any increase in the cost of maintaining the refractory lining. Due to the dramatic decline in the price of natural gas in some areas combined with mounting pressures to increasing production of existing assets, over the last decade, many mills are focusing more on increasing the uptime of their kilns as opposed to energy savings. To this end, a growing number of mills are using basic (magnesia based) brick instead of high alumina brick to line the burning zone of the kiln since the lime mud does not react with these bricks at the operating temperatures of the burning zone of the kiln. In the extreme case, a few mills have chosen to install basic brick in the front end of the kiln running a length equivalent to 10 diameters. While the use of basic brick can increase the uptime of the kiln and reduce the cost to maintain the refractory lining, it does dramatically increase the heat losses resulting from the increased operating temperatures of the shell. Also, over long periods of time operating at these high temperatures, damage can occur in the shell. There are tradeoffs between energy efficiency, capacity and uptime. When fuel prices are very high, it makes sense to insulate the lining. When fuel prices are lower, trading some thermal efficiency for increased uptime and capacity seems reasonable. This paper considers a number of refractory linings in an effort to develop optimized operating strategies that balance these factors. In addition to considering a range of refractory materials, the paper examines other factors such as the chain area, discharge dams and other operating variables that impact the service life of the refractory lining. The paper provides recommendations that will help mill personnel develop a strategy to select a refractory lining that is optimized for their specific situation.« less

Implementing Innovative Elementary Literacy Programs. Program Report.

ERIC Educational Resources Information Center

Schwab, R. G. Jerry; And Others

This four-document collection describes the implementation processes of dramatically improved literacy programs in elementary schools which are leading the move to restructure literacy education in the Northwest (Alaska, Idaho, Montana, Oregon, and Washington). The first document in the collection, "Strategies for Improving School-Wide…

Dramatic Improvements in Beach Water Quality Following Gull Removal

EPA Science Inventory

Gulls are often cited as important contributors of fecal contamination to surface waters, and some recreational beaches have used gull control measures to improve microbial water quality. In this study, gulls were chased from a Lake Michigan beach using specially trained dogs, a...

Wood adhesives : vital for producing most wood products

Treesearch

Charles R. Frihart

2011-01-01

A main route for the efficient utilization of wood resources is to reduce wood to small pieces and then bond them together (Frihart and Hunt 2010). Although humankind has been bonding wood since early Egyptian civilizations, the quality and quantity of bonded wood products has increased dramatically over the past 100 years with the development of new adhesives and...

Exploring the Potential Rationale for the Privatization of Higher Education in China

ERIC Educational Resources Information Center

Wang, Li

2011-01-01

The last three decades have witnessed great social, political and economic change in China since the market reforms in the late 1970s. A market economy was adopted as a replacement to the planned economy in order to allocate resources more efficiently. Consequently, higher education in China has undergone dramatic reforms to adapt to this…

A Method for Improving the Pose Accuracy of a Robot Manipulator Based on Multi-Sensor Combined Measurement and Data Fusion

PubMed Central

Liu, Bailing; Zhang, Fumin; Qu, Xinghua

2015-01-01

An improvement method for the pose accuracy of a robot manipulator by using a multiple-sensor combination measuring system (MCMS) is presented. It is composed of a visual sensor, an angle sensor and a series robot. The visual sensor is utilized to measure the position of the manipulator in real time, and the angle sensor is rigidly attached to the manipulator to obtain its orientation. Due to the higher accuracy of the multi-sensor, two efficient data fusion approaches, the Kalman filter (KF) and multi-sensor optimal information fusion algorithm (MOIFA), are used to fuse the position and orientation of the manipulator. The simulation and experimental results show that the pose accuracy of the robot manipulator is improved dramatically by 38%∼78% with the multi-sensor data fusion. Comparing with reported pose accuracy improvement methods, the primary advantage of this method is that it does not require the complex solution of the kinematics parameter equations, increase of the motion constraints and the complicated procedures of the traditional vision-based methods. It makes the robot processing more autonomous and accurate. To improve the reliability and accuracy of the pose measurements of MCMS, the visual sensor repeatability is experimentally studied. An optimal range of 1 × 0.8 × 1 ∼ 2 × 0.8 × 1 m in the field of view (FOV) is indicated by the experimental results. PMID:25850067

Hierarchical Graphene Foam for Efficient Omnidirectional Solar-Thermal Energy Conversion.

PubMed

Ren, Huaying; Tang, Miao; Guan, Baolu; Wang, Kexin; Yang, Jiawei; Wang, Feifan; Wang, Mingzhan; Shan, Jingyuan; Chen, Zhaolong; Wei, Di; Peng, Hailin; Liu, Zhongfan

2017-10-01

Efficient solar-thermal energy conversion is essential for the harvesting and transformation of abundant solar energy, leading to the exploration and design of efficient solar-thermal materials. Carbon-based materials, especially graphene, have the advantages of broadband absorption and excellent photothermal properties, and hold promise for solar-thermal energy conversion. However, to date, graphene-based solar-thermal materials with superior omnidirectional light harvesting performances remain elusive. Herein, hierarchical graphene foam (h-G foam) with continuous porosity grown via plasma-enhanced chemical vapor deposition is reported, showing dramatic enhancement of broadband and omnidirectional absorption of sunlight, which thereby can enable a considerable elevation of temperature. Used as a heating material, the external solar-thermal energy conversion efficiency of the h-G foam impressively reaches up to ≈93.4%, and the solar-vapor conversion efficiency exceeds 90% for seawater desalination with high endurance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Primary focal hyperhidrosis: diagnosis and management. .

PubMed

Wang, Rena; Solish, Nowell; Murray, Christian A

2008-12-01

Primary focal hyperhidrosis is a common and serious medical condition that causes considerable psychosocial morbidity. Diagnostic and effective management strategies can improve patients' quality of living dramatically.

Non-Traditional Methods of Improving the Communication Skills of Disadvantaged Students

ERIC Educational Resources Information Center

Wilson, Brenda M.; Power, Marian E.

1978-01-01

Educators are encouraged to use some of the non-traditional student-centered methods for improving the communication skills of disadvantaged students, including technological aids such as books, tapes, cable T.V., video tapes, computers, etc., and devices such as role playing and dramatizations. (AM)

Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE)

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

Eckerle, Wayne; Rutland, Chris; Rohlfing, Eric

This report is based on a SC/EERE Workshop to Identify Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE), held March 3, 2011, to determine strategic focus areas that will accelerate innovation in engine design to meet national goals in transportation efficiency. The U.S. has reached a pivotal moment when pressures of energy security, climate change, and economic competitiveness converge. Oil prices remain volatile and have exceeded $100 per barrel twice in five years. At these prices, the U.S. spends $1 billion per day on imported oil to meet our energy demands. Because the transportation sector accountsmore » for two-thirds of our petroleum use, energy security is deeply entangled with our transportation needs. At the same time, transportation produces one-quarter of the nation’s carbon dioxide output. Increasing the efficiency of internal combustion engines is a technologically proven and cost-effective approach to dramatically improving the fuel economy of the nation’s fleet of vehicles in the near- to mid-term, with the corresponding benefits of reducing our dependence on foreign oil and reducing carbon emissions. Because of their relatively low cost, high performance, and ability to utilize renewable fuels, internal combustion engines—including those in hybrid vehicles—will continue to be critical to our transportation infrastructure for decades. Achievable advances in engine technology can improve the fuel economy of automobiles by over 50% and trucks by over 30%. Achieving these goals will require the transportation sector to compress its product development cycle for cleaner, more efficient engine technologies by 50% while simultaneously exploring innovative design space. Concurrently, fuels will also be evolving, adding another layer of complexity and further highlighting the need for efficient product development cycles. Current design processes, using “build and test” prototype engineering, will not suffice. Current market penetration of new engine technologies is simply too slow—it must be dramatically accelerated. These challenges present a unique opportunity to marshal U.S. leadership in science-based simulation to develop predictive computational design tools for use by the transportation industry. The use of predictive simulation tools for enhancing combustion engine performance will shrink engine development timescales, accelerate time to market, and reduce development costs, while ensuring the timely achievement of energy security and emissions targets and enhancing U.S. industrial competitiveness. In 2007 Cummins achieved a milestone in engine design by bringing a diesel engine to market solely with computer modeling and analysis tools. The only testing was after the fact to confirm performance. Cummins achieved a reduction in development time and cost. As important, they realized a more robust design, improved fuel economy, and met all environmental and customer constraints. This important first step demonstrates the potential for computational engine design. But, the daunting complexity of engine combustion and the revolutionary increases in efficiency needed require the development of simulation codes and computation platforms far more advanced than those available today. Based on these needs, a Workshop to Identify Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE) convened over 60 U.S. leaders in the engine combustion field from industry, academia, and national laboratories to focus on two critical areas of advanced simulation, as identified by the U.S. automotive and engine industries. First, modern engines require precise control of the injection of a broad variety of fuels that is far more subtle than achievable to date and that can be obtained only through predictive modeling and simulation. Second, the simulation, understanding, and control of these stochastic in-cylinder combustion processes lie on the critical path to realizing more efficient engines with greater power density. Fuel sprays set the initial conditions for combustion in essentially all future transportation engines; yet today designers primarily use empirical methods that limit the efficiency achievable. Three primary spray topics were identified as focus areas in the workshop: The fuel delivery system, which includes fuel manifolds and internal injector flow, The multi-phase fuel–air mixing in the combustion chamber of the engine, and The heat transfer and fluid interactions with cylinder walls. Current understanding and modeling capability of stochastic processes in engines remains limited and prevents designers from achieving significantly higher fuel economy. To improve this situation, the workshop participants identified three focus areas for stochastic processes: Improve fundamental understanding that will help to establish and characterize the physical causes of stochastic events, Develop physics-based simulation models that are accurate and sensitive enough to capture performance-limiting variability, and Quantify and manage uncertainty in model parameters and boundary conditions. Improved models and understanding in these areas will allow designers to develop engines with reduced design margins and that operate reliably in more efficient regimes. All of these areas require improved basic understanding, high-fidelity model development, and rigorous model validation. These advances will greatly reduce the uncertainties in current models and improve understanding of sprays and fuel–air mixture preparation that limit the investigation and development of advanced combustion technologies. The two strategic focus areas have distinctive characteristics but are inherently coupled. Coordinated activities in basic experiments, fundamental simulations, and engineering-level model development and validation can be used to successfully address all of the topics identified in the PreSICE workshop. The outcome will be: New and deeper understanding of the relevant fundamental physical and chemical processes in advanced combustion technologies, Implementation of this understanding into models and simulation tools appropriate for both exploration and design, and Sufficient validation with uncertainty quantification to provide confidence in the simulation results. These outcomes will provide the design tools for industry to reduce development time by up to 30% and improve engine efficiencies by 30% to 50%. The improved efficiencies applied to the national mix of transportation applications have the potential to save over 5 million barrels of oil per day, a current cost savings of $500 million per day.« less

Application of acclimated sewage sludge as a bio-augmentation/bio-stimulation strategy for remediating chlorpyrifos contamination in soil with/without cadmium.

PubMed

Wang, Can; Zhou, Zhiren; Liu, Hongdan; Li, Junjie; Wang, Ying; Xu, Heng

2017-02-01

This experiment was performed to investigate the effects of acclimated sewage sludge (ASS) and sterilized ASS on the fates of chlorpyrifos (CP) in soil with or without cadmium (Cd), as well as the improvement of soil biochemical properties. Results showed that both ASS and sterilized ASS could significantly promote CP dissipation, and the groups with ASS had the highest efficiency on CP removal, whose degradation rates reached 71.3%-85.9% at the 30th day (40.4%-50.2% higher than non-sludge groups). Besides, the degradation rate of CP was not severely influenced by the existence of Cd, and the population of soil microorganism dramatically increased after adding sludge. The soil enzyme activities (dehydrogenase, acid phosphatase and FDA hydrolase activities) ranked from high to low were as follows: groups with sterilized ASS>groups with ASS>groups without sludge. Simultaneously, 16S rRNA gene sequencing revealed that ASS changed bacterial community structure and diversity in soil. In addition, alkali-hydrolyzable nitrogen and Olsen- phosphorus increased after application of sludge, indicating that the addition of ASS (or sterilized ASS) could effectively improve soil fertility. Copyright © 2016 Elsevier B.V. All rights reserved.

Integrated Intermodal Passenger Transportation System

NASA Technical Reports Server (NTRS)

Klock, Ryan; Owens, David; Schwartz, Henry; Plencner, Robert

2012-01-01

Modern transportation consists of many unique modes of travel. Each of these modes and their respective industries has evolved independently over time, forming a largely incoherent and inefficient overall transportation system. Travelers today are forced to spend unnecessary time and efforts planning a trip through varying modes of travel each with their own scheduling, pricing, and services; causing many travelers to simply rely on their relatively inefficient and expensive personal automobile. This paper presents a demonstration program system to not only collect and format many different sources of trip planning information, but also combine these independent modes of travel in order to form optimal routes and itineraries of travel. The results of this system show a mean decrease in inter-city travel time of 10 percent and a 25 percent reduction in carbon dioxide emissions over personal automobiles. Additionally, a 55 percent reduction in carbon dioxide emissions is observed for intra-city travel. A conclusion is that current resources are available, if somewhat hidden, to drastically improve point to point transportation in terms of time spent traveling, the cost of travel, and the ecological impact of a trip. Finally, future concepts are considered which could dramatically improve the interoperability and efficiency of the transportation infrastructure.

Improving detection of low SNR targets using moment-based detection

NASA Astrophysics Data System (ADS)

Young, Shannon R.; Steward, Bryan J.; Hawks, Michael; Gross, Kevin C.

2016-05-01

Increases in the number of cameras deployed, frame rate, and detector array sizes have led to a dramatic increase in the volume of motion imagery data that is collected. Without a corresponding increase in analytical manpower, much of the data is not analyzed to full potential. This creates a need for fast, automated, and robust methods for detecting signals of interest. Current approaches fall into two categories: detect-before-track (DBT), which are fast but often poor at detecting dim targets, and track-before-detect (TBD) methods which can offer better performance but are typically much slower. This research seeks to contribute to the near real time detection of low SNR, unresolved moving targets through an extension of earlier work on higher order moments anomaly detection, a method that exploits both spatial and temporal information but is still computationally efficient and massively parallelizable. It was found that intelligent selection of parameters can improve probability of detection by as much as 25% compared to earlier work with higherorder moments. The present method can reduce detection thresholds by 40% compared to the Reed-Xiaoli anomaly detector for low SNR targets (for a given probability of detection and false alarm).

Optimizing groundwater development strategies by genetic algorithm: a case study for balancing the needs for agricultural irrigation and environmental protection in northern China

NASA Astrophysics Data System (ADS)

Wu, Jianfeng; Zheng, Li; Liu, Depeng

2007-11-01

Gaoqing Plain is a major agriculture center of Shandong Province in northern China. Over the last 30 years, the diversion of Yellow River water for intensive irrigation in Gaoqing Plain has led to elevation of the water table and increased evaporation, and subsequently, a dramatic increase in salt content in soil and rapid degradation of crop productivity. Optimal strategies have been explored, that will balance the need to extract sufficient groundwater for irrigation (to ease the pressure on diverting Yellow River water) with the need to improve the local environment by appropriately lowering the water table. Two simulation-optimization models have been formulated and a genetic algorithm (GA) is applied to search for the optimal groundwater development strategies in Gaoqing Plain, while keeping the adverse environmental impacts in check. Compared with the trial-and-error approach of previous studies, the optimization results demonstrate that using an optimization model coupled with a GA search is both effective and efficient. The optimal solutions identified by the GA will provide Gaoqing Plain with the blueprints for developing sustainable groundwater abstraction plans to support local economic development and improve its environmental quality.

Microbial transformation of ginsenoside Rb1, Re and Rg1 and its contribution to the improved anti-inflammatory activity of ginseng.

PubMed

Yu, Shanshan; Zhou, Xiaoli; Li, Fan; Xu, Chunchun; Zheng, Fei; Li, Jing; Zhao, Huanxi; Dai, Yulin; Liu, Shuying; Feng, Yan

2017-03-10

Microbial transformation of ginsenosides to increase its pharmaceutical effect is gaining increasing attention in recent years. In this study, Cellulosimicrobium sp. TH-20, which was isolated from soil samples on which ginseng grown, exhibited effective ginsenoside-transforming activity. After protopanaxadiol (PPD)-type ginsenoside (Rb1) and protopanaxatriol (PPT)-type ginsenosides (Re and Rg1) were fed to C. sp. TH20, a total of 12 metabolites, including 6 new intermediate metabolites, were identified. Stepwise deglycosylation and dehydrogenation on the feeding precursors have been observed. The final products were confirmed to be rare ginsenosides Rd, GypXVII, Rg2 and PPT after 96 h transformation with 38-96% yields. The four products showed improved anti-inflammatory activities by using lipopolysaccharide (LPS)-induced murine RAW 264.7 macrophages and the xylene-induced acute inflammatory model of mouse ear edema. The results indicated that they could dramatically attenuate the production of TNF-α more effectively than the precursors. Our study would provide an example of a unique and powerful microbial cell factory for efficiently converting both PPD-type and PPT-type ginsenosides to rare natural products, which extends the drug candidates as novel anti-inflammatory remedies.

Surface nanocrystalline and hardening effects of Ti-Al-V alloy by electropulsing ultrasonic shock

NASA Astrophysics Data System (ADS)

Ye, Xiaoxin; Tang, Guoyi

2015-03-01

The effect of electropulsing ultrasonic shock (EUS) on the surface hardening and microstructure of Ti6Al4V alloy was studied. It was found that electropulsing improved the microhardness dramatically both in the influential depth and maximum value, compared with the only ultrasonic-shocked sample. It's indicated that refined surface layer with nanocrystalline and improved microhardness were obtained on account of surface severe plastic deformation, dynamic recrystallization (DRX) and phase change, which was implemented at relative low temperature and high strain rate/capacity due to the coupling of the thermal and athermal effects of EUS. It's different from conventional experiments and theory. It's discussed that the positive contributions of EPT in the thermodynamics and kinetics of microstructure and properties change were attributed to the reduction of nucleation energy barrier and acceleration of atomic diffusion. Therefore, it's supposed that EUS is an energy-saving and high-efficiency method of surface treatment technique with the help of high-energy electropulses, which is promising in cost reduction of the surface engineering and energy management. The work is supported by National Natural Science Foundation of China (No. 50571048) and Shenzhen science and technology research funding project of China (No. SGLH20121008144756946).

Sequential application of chelating agents and innovative surfactants for the enhanced electroremediation of real sediments from toxic metals and PAHs.

PubMed

Hahladakis, John N; Lekkas, Nikolaos; Smponias, Andreas; Gidarakos, Evangelos

2014-06-01

This study focused on the sequential application of a chelating agent (citric acid) followed by a surfactant in the simultaneous electroremediation of real contaminated sediments from toxic metals and Polycyclic Aromatic Hydrocarbons (PAHs). Furthermore, the efficiency evaluation of two innovative non-ionic surfactants, commercially known as Poloxamer 407 and Nonidet P40, was investigated. The results indicated a removal efficacy of approximately 43% and 48% for the summation of PAHs (SUM PAHs), respectively for the aforementioned surfactants, much better than the one obtained by the use of Tween 80 (nearly 21%). Individual PAHs (e.g. fluorene) were removed in percentages that reached almost 84% and 92% in the respective electrokinetic experiments when these new surfactants were introduced. In addition, the combined-enhanced sequential electrokinetic treatment with citric acid improved dramatically the removal of Zn and As, compared to the unenhanced run, but did not favor the other toxic metals examined. Since no improvement in metal removal percentages occurred when Tween 80 was used, significant contribution to this matter should also be attributed to the solubilization capacity of these innovative, in electrokinetic remediation, non-ionic surfactants. Copyright © 2013 Elsevier Ltd. All rights reserved.

The role of cross-shock potential on pickup ion shock acceleration in the framework of focused transport theory

DOE PAGES

Zuo, Pingbing; Zhang, Ming; Rassoul, Hamid K.

2013-10-03

The focused transport theory is appropriate to describe the injection and acceleration of low-energy particles at shocks as an extension of diffusive shock acceleration (DSA). In this investigation, we aim to characterize the role of cross-shock potential (CSP) originated in the charge separation across the shock ramp on pickup ion (PUI) acceleration at various types of shocks with a focused transport model. The simulation results of energy spectrum and spatial density distribution for the cases with and without CSP added in the model are compared. With sufficient acceleration time, the focused transport acceleration finally falls into the DSA regime withmore » the power-law spectral index equal to the solution of the DSA theory. The CSP can affect the shape of the spectrum segment at lower energies, but it does not change the spectral index of the final power-law spectrum at high energies. It is found that the CSP controls the injection efficiency which is the fraction of PUIs reaching the DSA regime. A stronger CSP jump results in a dramatically improved injection efficiency. Our simulation results also show that the injection efficiency of PUIs is mass-dependent, which is lower for species with a higher mass. Additionally, the CSP is able to enhance the particle reflection upstream to produce a stronger intensity spike at the shock front. Lastly, we conclude that the CSP is a non-negligible factor that affects the dynamics of PUIs at shocks.« less

Low-Flow Liquid Desiccant Air-Conditioning: Demonstrated Performance and Cost Implications

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

Kozubal, E.; Herrmann, L.; Deru, M.

2014-09-01

Cooling loads must be dramatically reduced when designing net-zero energy buildings or other highly efficient facilities. Advances in this area have focused primarily on reducing a building's sensible cooling loads by improving the envelope, integrating properly sized daylighting systems, adding exterior solar shading devices, and reducing internal heat gains. As sensible loads decrease, however, latent loads remain relatively constant, and thus become a greater fraction of the overall cooling requirement in highly efficient building designs, particularly in humid climates. This shift toward latent cooling is a challenge for heating, ventilation, and air-conditioning (HVAC) systems. Traditional systems typically dehumidify by firstmore » overcooling air below the dew-point temperature and then reheating it to an appropriate supply temperature, which requires an excessive amount of energy. Another dehumidification strategy incorporates solid desiccant rotors that remove water from air more efficiently; however, these systems are large and increase fan energy consumption due to the increased airside pressure drop of solid desiccant rotors. A third dehumidification strategy involves high flow liquid desiccant systems. These systems require a high maintenance separator to protect the air distribution system from corrosive desiccant droplet carryover and so are more commonly used in industrial applications and rarely in commercial buildings. Both solid desiccant systems and most high-flow liquid desiccant systems (if not internally cooled) add sensible energy which must later be removed to the air stream during dehumidification, through the release of sensible heat during the sorption process.« less

Terahertz difference frequency generation in quantum cascade lasers on silicon

NASA Astrophysics Data System (ADS)

Jung, Seungyong; Kim, Jae Hyun; Jiang, Yifan; Vijayraghavan, Karun; Belkin, Mikhail A.

2017-02-01

We demonstrate that an application of a III-V-on-silicon hybrid concept to terahertz (THz) Cherenkov difference frequency generation (DFG) quantum cascade laser (QCL) sources (THz DFG-QCLs) can dramatically improve THz output power and mid-infrared-to-THz conversion efficiency. Completely processed THz DFG-QCLs grown on a 660-μm-thick native InP substrate are transfer-printed onto a 1-mm-thick high-resistive Si substrate using a 100-nm-thick SU-8 as an adhesive layer. Room temperature device performance of the reference InP and hybrid Si THz DFG-QCLs of the same ridge width (22 μm) and cavity length (4.2 mm) have been experimentally compared. The target THz frequency of 3.5 THz is selected for both devices using the dual-period first order surface gratings to select the mid-infrared pump wavelength of 994 cm-1 and 1110 cm-1. At the maximum bias current, the reference InP and hybrid Si devices produced THz power of 50 μW and 270 μW, respectively. The mid-infrared-to-THz conversion efficiency corresponds to 60 μW/W2 and 480 μW/W2, respectively, resulting in 5 times higher THz power and 8 times higher conversion efficiency from the best-performing hybrid devices. A hybrid Si device integrated in a Littrow external-cavity setup showed wavelength tuning from 1.3 THz to 4.3 THz with beam-steering free operation.

Effect of extra-column volume on practical chromatographic parameters of sub-2-μm particle-packed columns in ultra-high pressure liquid chromatography.

PubMed

Wu, Naijun; Bradley, Ashley C; Welch, Christopher J; Zhang, Li

2012-08-01

Effects of extra-column volume on apparent separation parameters were studied in ultra-high pressure liquid chromatography with columns and inlet connection tubings of various internal diameters (id) using 50-mm long columns packed with 1.8-μm particles under isocratic conditions. The results showed that apparent retention factors were on average 5, 11, 18, and 41% lower than those corrected with extra-column volumes for 4.6-, 3.0-, 2.1-, and 1.0-mm id columns, respectively, when the extra-column volume (11.3 μL) was kept constant. Also, apparent pressures were 31, 16, 12, and 10% higher than those corrected with pressures from extra-column volumes for 4.6-, 3.0-, 2.1-, and 1.0-mm id columns at the respective optimum flow rate for a typical ultra-high pressure liquid chromatography system. The loss in apparent efficiency increased dramatically from 4.6- to 3.0- to 2.1- to 1.0-mm id columns, less significantly as retention factors increased. The column efficiency was significantly improved as the inlet tubing id was decreased for a given column. The results suggest that maximum ratio of extra-column volume to column void volume should be approximately 1:10 for column porosity more than 0.6 and a retention factor more than 5, where 80% or higher of theoretically predicted efficiency could be achieved. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exceptional Children Conference Papers: Gifted and Talented.

ERIC Educational Resources Information Center

Council for Exceptional Children, Arlington, VA.

Educators concerned with improving educational opportunities for the gifted need to consider ways to achieve their ends within the realities of the political system. Federal programs cannot be expected to provide ideas which will dramatically improve education for the gifted nor to provide large quantities of money. The federal government can…

Using JournalMap to improve discovery and visualization of rangeland scientific knowledge

USDA-ARS?s Scientific Manuscript database

Most of the ecological research conducted around the world is tied to specific places; however, that location information is locked up in the text and figures of scientific articles in myriad forms that are not easily searchable. While access to ecological literature has improved dramatically in the...