Successful strategies for improving operating room efficiency at academic institutions.

PubMed

Overdyk, F J; Harvey, S C; Fishman, R L; Shippey, F

1998-04-01

In this prospective study, we evaluated the etiology of operating room (OR) delays in an academic institution, examined the impact of multidisciplinary strategies to improve OR efficiency, and established OR timing benchmarks for use in future OR efficiency studies. OR times and delay etiologies were collected for 94 cases during the initial phase of the study. Timing data and delay etiologies were analyzed, and 2 wk of multidisciplinary OR efficiency awareness education was conducted for the nursing, surgical, and anesthesia staff. After the education period, timing data were collected from 1787 cases, and monthly reports listing individual case delays and timing data were sent to the Chiefs of Service. For the first case of the day, patient in room, anesthesia ready, surgical preparation start, and procedure start time were significantly earlier (P < 0.01) in the posteducation period compared with the preeducation period, and the procedure start time for the first case of the day occurred, on average, 22 min earlier than all other procedures. For all cases combined, turnover time decreased, on average, by 16 min. Unavailability of surgeons, anesthesiologists, and residents decreased significantly (P < 0.05) as causes of OR delays. Anesthesia induction times were consistently longer for the vascular and cardiothoracic services, whereas surgical preparation time was increased for the neurosurgical and orthopedic services (P < 0.05). Identification of the etiology of OR inefficiency, combined with multidisciplinary awareness training and personal accountability, can improve OR efficiency. The time savings realized are probably most cost-effective when combined with more flexible OR staffing and improved OR scheduling. We achieved significant improvements in operating room efficiency by analyzing operating room data on causes of delays, devising strategies for minimizing the most common delays, and subsequently measuring delay data. Personal accountability, streamlining of procedures, interdisciplinary team work, and accurate data collection were all important contributors to improved efficiency.

Does Competition Improve Public School Efficiency? A Spatial Analysis

ERIC Educational Resources Information Center

Misra, Kaustav

2010-01-01

Proponents of educational reform often call for policies to increase competition between schools. It is argued that market forces naturally lead to greater efficiencies, including improved student learning, when schools face competition. In many parts of the country, public schools experience significant competition from private schools; however,…

Optimum outlier model for potential improvement of environmental cleaning and disinfection.

PubMed

Rupp, Mark E; Huerta, Tomas; Cavalieri, R J; Lyden, Elizabeth; Van Schooneveld, Trevor; Carling, Philip; Smith, Philip W

2014-06-01

The effectiveness and efficiency of 17 housekeepers in terminal cleaning 292 hospital rooms was evaluated through adenosine triphosphate detection. A subgroup of housekeepers was identified who were significantly more effective and efficient than their coworkers. These optimum outliers may be used in performance improvement to optimize environmental cleaning.

Structure-guided systems-level engineering of oxidation-prone methionine residues in catalytic domain of an alkaline α-amylase from Alkalimonas amylolytica for significant improvement of both oxidative stability and catalytic efficiency.

PubMed

Yang, Haiquan; Liu, Long; Shin, Hyun-dong; Li, Jianghua; Du, Guocheng; Chen, Jian

2013-01-01

High oxidative stability and catalytic efficiency are required for the alkaline α-amylases to keep the enzymatic performance under the harsh conditions in detergent industries. In this work, we attempted to significantly improve both the oxidative stability and catalytic efficiency of an alkaline α-amylase from Alkalimonas amylolytica by engineering the five oxidation-prone methionine residues around the catalytic domain via a systematic approach. Specifically, based on the tertiary structure analysis, five methionines (Met 145, Met 214, Met 229, Met 247 and Met 317) were individually substituted with oxidation-resistant threonine, isoleucine and alaline, respectively. Among the created 15 mutants, 7 mutants M145A, M145I, M214A, M229A, M229T, M247T and M317I showed significantly enhanced oxidative stability or catalytic efficiency. In previous work, we found that the replacement of M247 with leucine could significantly improve the oxidative stability. Thus, these 8 positive mutants (M145A, M145I, M214A, M229A, M229T, M247T, M247L and M317I) were used to conduct the second round of combinational mutations. Among the constructed 85 mutants (25 two-point mutants, 36 three-point mutants, 16 four-point mutants and 8 five-point mutants), the mutant M145I-214A-229T-247T-317I showed a 5.4-fold increase in oxidative stability and a 3.0-fold increase in catalytic efficiency. Interestingly, the specific activity, alkaline stability and thermal stability of this mutant were also increased. The increase of salt bridge and hydrogen bonds around the catalytic domain contributed to the significantly improved catalytic efficiency and stability, as revealed by the three-dimensional structure model of wild-type alkaline α-amylase and its mutant M145I-214A-229T-247T-317I. With the significantly improved oxidative stability and catalytic efficiency, the mutant M145I-214A-229T-247T-317I has a great potential as a detergent additive, and this structure-guided systems engineering strategy may be useful for the protein engineering of the other microbial enzymes to fulfill industrial requirements.

Efficiency improvement of GaN-on-silicon thin-film light-emitting diodes with optimized via-like n-electrodes

NASA Astrophysics Data System (ADS)

Feng, Bo; Deng, Biao; Fu, Yi; Liu, Le Gong; Li, Zeng Cheng; Feng, Mei Xin; Zhao, Han Min; Sun, Qian

2017-07-01

This work reports a significant improvement in efficiency by optimizing the via-like n-electrode architecture design of a GaN-based thin-film LED grown on a 6-inch silicon substrate. The external quantum efficiency of the as-fabricated 1.1 mm × 1.1 mm via-thin-film LED chip at 350 mA was increased by 11.3% compared to that of a vertical thin-film LED chip with a conventional finger-like n-electrode. Detailed analysis of encapsulation gain and false color emission patterns illustrated that the significantly improved LED performance was due to enhanced light extraction efficiency and more uniform current spreading, both of which can be attributed to the optimized via-thin-film chip structure. Minimizing the light loss at the periphery of the Ag mirror was demonstrated to be a critical factor for improving light extraction, rather than simply replacing the finger-like n-electrodes with via-like ones. After encapsulation, the median blue lamp power and the wall-plug efficiency of the via-thin-film LED at 350 mA reached 659 mW and 63.7%, respectively.

Flexible deep-ultraviolet light-emitting diodes for significant improvement of quantum efficiencies by external bending

NASA Astrophysics Data System (ADS)

Shervin, Shahab; Oh, Seung Kyu; Park, Hyun Jung; Lee, Keon-Hwa; Asadirad, Mojtaba; Kim, Seung-Hwan; Kim, Jeomoh; Pouladi, Sara; Lee, Sung-Nam; Li, Xiaohang; Kwak, Joon Seop; Ryou, Jae-Hyun

2018-03-01

We report a new route to improve quantum efficiencies of AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) using mechanical flexibility of recently developed bendable thin-film structures. Numerical studies show that electronic band structures of AlGaN heterostructures and resulting optical and electrical characteristics of the devices can be significantly modified by external bending through active control of piezoelectric polarization. Internal quantum efficiency is enhanced higher than three times, when the DUV LEDs are moderately bent with concave curvatures. Furthermore, an efficiency droop at high injection currents is mitigated and turn-on voltage of diodes decreases with the same bending condition. The concept of bendable DUV LEDs with a controlled external strain can provide a new path for high-output-power and high-efficiency devices.

Utilization of Portable Radios to Improve Ophthalmology Clinic Efficiency in an Academic Setting.

PubMed

Davis, Alexander S; Elkeeb, Ahmed M; Vizzeri, Gianmarco; Godley, Bernard F

2016-03-01

Improvement in clinic efficiency in the ambulatory setting is often looked at as an area for development of lean management strategies to deliver a higher quality of healthcare while reducing errors, costs, and delays. To examine the benefits of improving team communication and its impact on clinic flow and efficiency, we describe a time-motion study performed in an academic outpatient Ophthalmology clinic and its objective and subjective results. Compared to clinic encounters without the use of the portable radios, objective data demonstrated an overall significant decreases in mean workup time (15.18 vs. 13.10), room wait (13.10 vs. 10.47), and decreased the total time needed with an MD per encounter (9.45 vs. 6.63). Subjectively, significant improvements were seen in careprovider scores for patient flow (60.78 vs. 84.29), getting assistance (61.89 vs. 88.57), moving patient charts (54.44 vs. 85.71), teamwork (69.56 vs. 91.0), communications (62.33 vs. 90.43), providing quality patient care (76.22 vs. 89.57), and receiving input on the ability to see walk-in patients (80.11 vs. 90.43). For academic purposes, an improvement in engagement in patient care and learning opportunities was noted by the clinic resident-in-training during the pilot study. Portable radios in our pilot study were preferred over the previous method of communication and demonstrates significant improvements in certain areas of clinical efficiency, subjective perception of teamwork and communications, and academic learning.

Holographic heat engine within the framework of massive gravity

NASA Astrophysics Data System (ADS)

Mo, Jie-Xiong; Li, Gu-Qiang

2018-05-01

Heat engine models are constructed within the framework of massive gravity in this paper. For the four-dimensional charged black holes in massive gravity, it is shown that the existence of graviton mass improves the heat engine efficiency significantly. The situation is more complicated for the five-dimensional neutral black holes since the constant which corresponds to the third massive potential also contributes to the efficiency. It is also shown that the existence of graviton mass can improve the heat engine efficiency. Moreover, we probe how the massive gravity influences the behavior of the heat engine efficiency approaching the Carnot efficiency.

Air transportation energy efficiency - Alternatives and implications

NASA Technical Reports Server (NTRS)

Williams, L. J.

1976-01-01

Results from recent studies of air transportation energy efficiency alternatives are discussed, along with some of the implications of these alternatives. The fuel-saving alternatives considered include aircraft operation, aircraft modification, derivative aircraft, and new aircraft. In the near-term, energy efficiency improvements should be possible through small improvements in fuel-saving flight procedures, higher density seating, and higher load factors. Additional small near-term improvements could be obtained through aircraft modifications, such as the relatively inexpensive drag reduction modifications. Derivatives of existing aircraft could meet the requirements for new aircraft and provide energy improvements until advanced technology is available to justify the cost of a completely new design. In order to obtain significant improvements in energy efficiency, new aircraft must truly exploit advanced technology in such areas as aerodynamics, composite structures, active controls, and advanced propulsion.

Hyperaccumulator straw improves the cadmium phytoextraction efficiency of emergent plant Nasturtium officinale.

PubMed

Li, Keqiang; Lin, Lijin; Wang, Jin; Xia, Hui; Liang, Dong; Wang, Xun; Liao, Ming'an; Wang, Li; Liu, Li; Chen, Cheng; Tang, Yi

2017-08-01

With the development of economy, the heavy metal contamination has become an increasingly serious problem, especially the cadmium (Cd) contamination. The emergent plant Nasturtium officinale R. Br. is a Cd-accumulator with low phytoremediation ability. To improve Cd phytoextraction efficiency of N. officinale, the straw from Cd-hyperaccumulator plants Youngia erythrocarpa, Galinsoga parviflora, Siegesbeckia orientalis, and Bidens pilosa was applied to Cd-contaminated soil and N. officinale was then planted; the study assessed the effect of hyperaccumulator straw on the growth and Cd accumulation of N. officinale. The results showed that application of hyperaccumulator species straws increased the biomass and photosynthetic pigment content and reduced the root/shoot ratio of N. officinale. All straw treatments significantly increased Cd content in roots, but significantly decreased Cd content in shoots of N. officinale. Applying hyperaccumulator straw significantly increased the total Cd accumulation in the roots, shoots, and whole plants of N. officinale. Therefore, application of straw from four hyperaccumulator species promoted the growth of N. officinale and improved the phytoextraction efficiency of N. officinale in Cd-contaminated paddy field soil; the straw of Y. erythrocarpa provided the most improvement.

Voluntary Medical Male Circumcision Scale-Up in Nyanza, Kenya: Evaluating Technical Efficiency and Productivity of Service Delivery

PubMed Central

Omondi Aduda, Dickens S.; Ouma, Collins; Onyango, Rosebella; Onyango, Mathews; Bertrand, Jane

2015-01-01

Background Voluntary medical male circumcision (VMMC) service delivery is complex and resource-intensive. In Kenya’s context there is still paucity of information on resource use vis-à-vis outputs as programs scale up. Knowledge of technical efficiency, productivity and potential sources of constraints is desirable to improve decision-making. Objective To evaluate technical efficiency and productivity of VMMC service delivery in Nyanza in 2011/2012 using data envelopment analysis. Design Comparative process evaluation of facilities providing VMMC in Nyanza in 2011/2012 using output orientated data envelopment analysis. Results Twenty one facilities were evaluated. Only 1 of 7 variables considered (total elapsed operation time) significantly improved from 32.8 minutes (SD 8.8) in 2011 to 30 minutes (SD 6.6) in 2012 (95%CI = 0.0350–5.2488; p = 0.047). Mean scale technical efficiency significantly improved from 91% (SD 19.8) in 2011 to 99% (SD 4.0) in 2012 particularly among outreach compared to fixed service delivery facilities (CI -31.47959–4.698508; p = 0.005). Increase in mean VRS technical efficiency from 84% (SD 25.3) in 2011 and 89% (SD 25.1) in 2012 was not statistically significant. Benchmark facilities were #119 and #125 in 2011 and #103 in 2012. Malmquist Productivity Index (MPI) at fixed facilities declined by 2.5% but gained by 4.9% at outreach ones by 2012. Total factor productivity improved by 83% (p = 0.032) in 2012, largely due to progress in technological efficiency by 79% (p = 0.008). Conclusions Significant improvement in scale technical efficiency among outreach facilities in 2012 was attributable to accelerated activities. However, ongoing pure technical inefficiency requires concerted attention. Technological progress was the key driver of service productivity growth in Nyanza. Incorporating service-quality dimensions and using stepwise-multiple criteria in performance evaluation enhances comprehensiveness and validity. These findings highlight site-level resource use and sources of variations in VMMC service productivity, which are important for program planning. PMID:25706119

Perceptual learning improves visual performance in juvenile amblyopia.

PubMed

Li, Roger W; Young, Karen G; Hoenig, Pia; Levi, Dennis M

2005-09-01

To determine whether practicing a position-discrimination task improves visual performance in children with amblyopia and to determine the mechanism(s) of improvement. Five children (age range, 7-10 years) with amblyopia practiced a positional acuity task in which they had to judge which of three pairs of lines was misaligned. Positional noise was produced by distributing the individual patches of each line segment according to a Gaussian probability function. Observers were trained at three noise levels (including 0), with each observer performing between 3000 and 4000 responses in 7 to 10 sessions. Trial-by-trial feedback was provided. Four of the five observers showed significant improvement in positional acuity. In those four observers, on average, positional acuity with no noise improved by approximately 32% and with high noise by approximately 26%. A position-averaging model was used to parse the improvement into an increase in efficiency or a decrease in equivalent input noise. Two observers showed increased efficiency (51% and 117% improvements) with no significant change in equivalent input noise across sessions. The other two observers showed both a decrease in equivalent input noise (18% and 29%) and an increase in efficiency (17% and 71%). All five observers showed substantial improvement in Snellen acuity (approximately 26%) after practice. Perceptual learning can improve visual performance in amblyopic children. The improvement can be parsed into two important factors: decreased equivalent input noise and increased efficiency. Perceptual learning techniques may add an effective new method to the armamentarium of amblyopia treatments.

Electronic and mechanical improvement of the receiving terminal of a free-space microwave power transmission system

NASA Technical Reports Server (NTRS)

Brown, W. C.

1977-01-01

Significant advancements were made in a number of areas: improved efficiency of basic receiving element at low power density levels, improved resolution and confidence in efficiency measurements mathematical modelling and computer simulation of the receiving element and the design, construction, and testing of an environmentally protected two-plane construction suitable for low cost, highly automated construction of large receiving arrays.

An Adaptive Evolutionary Algorithm for Traveling Salesman Problem with Precedence Constraints

PubMed Central

Sung, Jinmo; Jeong, Bongju

2014-01-01

Traveling sales man problem with precedence constraints is one of the most notorious problems in terms of the efficiency of its solution approach, even though it has very wide range of industrial applications. We propose a new evolutionary algorithm to efficiently obtain good solutions by improving the search process. Our genetic operators guarantee the feasibility of solutions over the generations of population, which significantly improves the computational efficiency even when it is combined with our flexible adaptive searching strategy. The efficiency of the algorithm is investigated by computational experiments. PMID:24701158

An adaptive evolutionary algorithm for traveling salesman problem with precedence constraints.

PubMed

Sung, Jinmo; Jeong, Bongju

2014-01-01

Traveling sales man problem with precedence constraints is one of the most notorious problems in terms of the efficiency of its solution approach, even though it has very wide range of industrial applications. We propose a new evolutionary algorithm to efficiently obtain good solutions by improving the search process. Our genetic operators guarantee the feasibility of solutions over the generations of population, which significantly improves the computational efficiency even when it is combined with our flexible adaptive searching strategy. The efficiency of the algorithm is investigated by computational experiments.

Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-temperature Season

PubMed Central

Sun, Jin; Lu, Na; Xu, Hongjia; Maruo, Toru; Guo, Shirong

2016-01-01

Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C) and exogenous spermidine (Spd) root-pretreatment (SRP, 0.1 mM) on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C) were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (Gs) to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII), rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved PN of lettuce plants in a high-temperature season by both improvement of Gs to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation. PMID:27047532

Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-temperature Season.

PubMed

Sun, Jin; Lu, Na; Xu, Hongjia; Maruo, Toru; Guo, Shirong

2016-01-01

Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C) and exogenous spermidine (Spd) root-pretreatment (SRP, 0.1 mM) on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C) were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (G s) to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII), rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved P N of lettuce plants in a high-temperature season by both improvement of G s to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation.

Measuring and Benchmarking Technical Efficiency of Public Hospitals in Tianjin, China

PubMed Central

Li, Hao; Dong, Siping

2015-01-01

China has long been stuck in applying traditional data envelopment analysis (DEA) models to measure technical efficiency of public hospitals without bias correction of efficiency scores. In this article, we have introduced the Bootstrap-DEA approach from the international literature to analyze the technical efficiency of public hospitals in Tianjin (China) and tried to improve the application of this method for benchmarking and inter-organizational learning. It is found that the bias corrected efficiency scores of Bootstrap-DEA differ significantly from those of the traditional Banker, Charnes, and Cooper (BCC) model, which means that Chinese researchers need to update their DEA models for more scientific calculation of hospital efficiency scores. Our research has helped shorten the gap between China and the international world in relative efficiency measurement and improvement of hospitals. It is suggested that Bootstrap-DEA be widely applied into afterward research to measure relative efficiency and productivity of Chinese hospitals so as to better serve for efficiency improvement and related decision making. PMID:26396090

A novel technique based on in vitro oocyte injection to improve CRISPR/Cas9 gene editing in zebrafish

PubMed Central

Xie, Shao-Lin; Bian, Wan-Ping; Wang, Chao; Junaid, Muhammad; Zou, Ji-Xing; Pei, De-Sheng

2016-01-01

Contemporary improvements in the type II clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system offer a convenient way for genome editing in zebrafish. However, the low efficiencies of genome editing and germline transmission require a time-intensive and laborious screening work. Here, we reported a method based on in vitro oocyte storage by injecting oocytes in advance and incubating them in oocyte storage medium to significantly improve the efficiencies of genome editing and germline transmission by in vitro fertilization (IVF) in zebrafish. Compared to conventional methods, the prior micro-injection of zebrafish oocytes improved the efficiency of genome editing, especially for the sgRNAs with low targeting efficiency. Due to high throughputs, simplicity and flexible design, this novel strategy will provide an efficient alternative to increase the speed of generating heritable mutants in zebrafish by using CRISPR/Cas9 system. PMID:27680290

Efficient amplitude-modulated pulses for triple- to single-quantum coherence conversion in MQMAS NMR.

PubMed

Colaux, Henri; Dawson, Daniel M; Ashbrook, Sharon E

2014-08-07

The conversion between multiple- and single-quantum coherences is integral to many nuclear magnetic resonance (NMR) experiments of quadrupolar nuclei. This conversion is relatively inefficient when effected by a single pulse, and many composite pulse schemes have been developed to improve this efficiency. To provide the maximum improvement, such schemes typically require time-consuming experimental optimization. Here, we demonstrate an approach for generating amplitude-modulated pulses to enhance the efficiency of the triple- to single-quantum conversion. The optimization is performed using the SIMPSON and MATLAB packages and results in efficient pulses that can be used without experimental reoptimisation. Most significant signal enhancements are obtained when good estimates of the inherent radio-frequency nutation rate and the magnitude of the quadrupolar coupling are used as input to the optimization, but the pulses appear robust to reasonable variations in either parameter, producing significant enhancements compared to a single-pulse conversion, and also comparable or improved efficiency over other commonly used approaches. In all cases, the ease of implementation of our method is advantageous, particularly for cases with low sensitivity, where the improvement is most needed (e.g., low gyromagnetic ratio or high quadrupolar coupling). Our approach offers the potential to routinely improve the sensitivity of high-resolution NMR spectra of nuclei and systems that would, perhaps, otherwise be deemed "too challenging".

Efficient Amplitude-Modulated Pulses for Triple- to Single-Quantum Coherence Conversion in MQMAS NMR

PubMed Central

2014-01-01

The conversion between multiple- and single-quantum coherences is integral to many nuclear magnetic resonance (NMR) experiments of quadrupolar nuclei. This conversion is relatively inefficient when effected by a single pulse, and many composite pulse schemes have been developed to improve this efficiency. To provide the maximum improvement, such schemes typically require time-consuming experimental optimization. Here, we demonstrate an approach for generating amplitude-modulated pulses to enhance the efficiency of the triple- to single-quantum conversion. The optimization is performed using the SIMPSON and MATLAB packages and results in efficient pulses that can be used without experimental reoptimisation. Most significant signal enhancements are obtained when good estimates of the inherent radio-frequency nutation rate and the magnitude of the quadrupolar coupling are used as input to the optimization, but the pulses appear robust to reasonable variations in either parameter, producing significant enhancements compared to a single-pulse conversion, and also comparable or improved efficiency over other commonly used approaches. In all cases, the ease of implementation of our method is advantageous, particularly for cases with low sensitivity, where the improvement is most needed (e.g., low gyromagnetic ratio or high quadrupolar coupling). Our approach offers the potential to routinely improve the sensitivity of high-resolution NMR spectra of nuclei and systems that would, perhaps, otherwise be deemed “too challenging”. PMID:25047226

Parallel AFSA algorithm accelerating based on MIC architecture

NASA Astrophysics Data System (ADS)

Zhou, Junhao; Xiao, Hong; Huang, Yifan; Li, Yongzhao; Xu, Yuanrui

2017-05-01

Analysis AFSA past for solving the traveling salesman problem, the algorithm efficiency is often a big problem, and the algorithm processing method, it does not fully responsive to the characteristics of the traveling salesman problem to deal with, and therefore proposes a parallel join improved AFSA process. The simulation with the current TSP known optimal solutions were analyzed, the results showed that the AFSA iterations improved less, on the MIC cards doubled operating efficiency, efficiency significantly.

An Improved Syringe Agroinfiltration Protocol to Enhance Transformation Efficiency by Combinative Use of 5-Azacytidine, Ascorbate Acid and Tween-20.

PubMed

Zhao, Huimin; Tan, Zilong; Wen, Xuejing; Wang, Yucheng

2017-02-14

Syringe infiltration is an important transient transformation method that is widely used in many molecular studies. Owing to the wide use of syringe agroinfiltration, it is important and necessary to improve its transformation efficiency. Here, we studied the factors influencing the transformation efficiency of syringe agroinfiltration. The pCAMBIA1301 was transformed into Nicotiana benthamiana leaves for investigation. The effects of 5-azacytidine (AzaC), Ascorbate acid (ASC) and Tween-20 on transformation were studied. The β-glucuronidase ( GUS ) expression and GUS activity were respectively measured to determine the transformation efficiency. AzaC, ASC and Tween-20 all significantly affected the transformation efficiency of agroinfiltration, and the optimal concentrations of AzaC, ASC and Tween-20 for the transgene expression were identified. Our results showed that 20 μM AzaC, 0.56 mM ASC and 0.03% ( v / v ) Tween-20 is the optimal concentration that could significantly improve the transformation efficiency of agroinfiltration. Furthermore, a combined supplement of 20 μM AzaC, 0.56 mM ASC and 0.03% Tween-20 improves the expression of transgene better than any one factor alone, increasing the transgene expression by more than 6-fold. Thus, an optimized syringe agroinfiltration was developed here, which might be a powerful method in transient transformation analysis.

New Source Review (NSR) Air Permitting and Energy Efficiency for Industrial Projects, IECA Manufacturers for Energy Efficiency Coalition Meeting (Presentation) – April 18, 2012

EPA Pesticide Factsheets

This presentation provides information about major new source review (NSR), including recent improvement changes and court rulings, flexible air permits rule, significant deterioration rules, and energy efficiency considerations.

Ergonomics and simulation-based approach in improving facility layout

NASA Astrophysics Data System (ADS)

Abad, Jocelyn D.

2018-02-01

The use of the simulation-based technique in facility layout has been a choice in the industry due to its convenience and efficient generation of results. Nevertheless, the solutions generated are not capable of addressing delays due to worker's health and safety which significantly impact overall operational efficiency. It is, therefore, critical to incorporate ergonomics in facility design. In this study, workstation analysis was incorporated into Promodel simulation to improve the facility layout of a garment manufacturing. To test the effectiveness of the method, existing and improved facility designs were measured using comprehensive risk level, efficiency, and productivity. Results indicated that the improved facility layout generated a decrease in comprehensive risk level and rapid upper limb assessment score; an increase of 78% in efficiency and 194% increase in productivity compared to existing design and thus proved that the approach is effective in attaining overall facility design improvement.

Scope for improved eco-efficiency varies among diverse cropping systems.

PubMed

Carberry, Peter S; Liang, Wei-li; Twomlow, Stephen; Holzworth, Dean P; Dimes, John P; McClelland, Tim; Huth, Neil I; Chen, Fu; Hochman, Zvi; Keating, Brian A

2013-05-21

Global food security requires eco-efficient agriculture to produce the required food and fiber products concomitant with ecologically efficient use of resources. This eco-efficiency concept is used to diagnose the state of agricultural production in China (irrigated wheat-maize double-cropping systems), Zimbabwe (rainfed maize systems), and Australia (rainfed wheat systems). More than 3,000 surveyed crop yields in these three countries were compared against simulated grain yields at farmer-specified levels of nitrogen (N) input. Many Australian commercial wheat farmers are both close to existing production frontiers and gain little prospective return from increasing their N input. Significant losses of N from their systems, either as nitrous oxide emissions or as nitrate leached from the soil profile, are infrequent and at low intensities relative to their level of grain production. These Australian farmers operate close to eco-efficient frontiers in regard to N, and so innovations in technologies and practices are essential to increasing their production without added economic or environmental risks. In contrast, many Chinese farmers can reduce N input without sacrificing production through more efficient use of their fertilizer input. In fact, there are real prospects for the double-cropping systems on the North China Plain to achieve both production increases and reduced environmental risks. Zimbabwean farmers have the opportunity for significant production increases by both improving their technical efficiency and increasing their level of input; however, doing so will require improved management expertise and greater access to institutional support for addressing the higher risks. This paper shows that pathways for achieving improved eco-efficiency will differ among diverse cropping systems.

Scope for improved eco-efficiency varies among diverse cropping systems

PubMed Central

Carberry, Peter S.; Liang, Wei-li; Twomlow, Stephen; Holzworth, Dean P.; Dimes, John P.; McClelland, Tim; Huth, Neil I.; Chen, Fu; Hochman, Zvi; Keating, Brian A.

2013-01-01

Global food security requires eco-efficient agriculture to produce the required food and fiber products concomitant with ecologically efficient use of resources. This eco-efficiency concept is used to diagnose the state of agricultural production in China (irrigated wheat–maize double-cropping systems), Zimbabwe (rainfed maize systems), and Australia (rainfed wheat systems). More than 3,000 surveyed crop yields in these three countries were compared against simulated grain yields at farmer-specified levels of nitrogen (N) input. Many Australian commercial wheat farmers are both close to existing production frontiers and gain little prospective return from increasing their N input. Significant losses of N from their systems, either as nitrous oxide emissions or as nitrate leached from the soil profile, are infrequent and at low intensities relative to their level of grain production. These Australian farmers operate close to eco-efficient frontiers in regard to N, and so innovations in technologies and practices are essential to increasing their production without added economic or environmental risks. In contrast, many Chinese farmers can reduce N input without sacrificing production through more efficient use of their fertilizer input. In fact, there are real prospects for the double-cropping systems on the North China Plain to achieve both production increases and reduced environmental risks. Zimbabwean farmers have the opportunity for significant production increases by both improving their technical efficiency and increasing their level of input; however, doing so will require improved management expertise and greater access to institutional support for addressing the higher risks. This paper shows that pathways for achieving improved eco-efficiency will differ among diverse cropping systems. PMID:23671071

Determinants of eco-efficiency in the Chinese industrial sector.

PubMed

Fujii, Hidemichi; Managi, Shunsuke

2013-12-01

This study measures productive inefficiency within the context of multi-environmental pollution (eco-efficiency) in the Chinese industrial sector. The weighted Russell directional distance model is applied to measure eco-efficiency using production technology. The objective is to clarify how external factors affect eco-efficiency. The major findings are that both foreign direct investment and investment for pollution abatement improve eco-efficiency as measured by air pollutant substances. A levy system for wastewater discharge improves eco-efficiency as measured by wastewater pollutant substances. However, an air pollutant levy does not significantly affect eco-efficiency as measured by air pollutants. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Efficient, flexible and mechanically robust perovskite solar cells on inverted nanocone plastic substrates.

PubMed

Tavakoli, Mohammad Mahdi; Lin, Qingfeng; Leung, Siu-Fung; Lui, Ga Ching; Lu, Hao; Li, Liang; Xiang, Bin; Fan, Zhiyong

2016-02-21

Utilization of nanostructures on photovoltaic devices can significantly improve the device energy conversion efficiency by enhancing the device light harvesting capability as well as carrier collection efficiency. However, improvements in device mechanical robustness and reliability, particularly for flexible devices, have rarely been reported with in-depth understanding. In this work, we fabricated efficient, flexible and mechanically robust organometallic perovskite solar cells on plastic substrates with inverted nanocone (i-cone) structures. Compared with the reference cell that was fabricated on a flat substrate, it was shown that the device power conversion efficiency could be improved by 37%, and reached up to 11.29% on i-cone substrates. More interestingly, it was discovered that the performance of an i-cone device remained more than 90% of the initial value even after 200 mechanical bending cycles, which is remarkably better than for the flat reference device, which degraded down to only 60% in the same test. Our experiments, coupled with mechanical simulation, demonstrated that a nanostructured template can greatly help in relaxing stress and strain upon device bending, which suppresses crack nucleation in different layers of a perovskite solar cell. This essentially leads to much improved device reliability and robustness and will have significant impact on practical applications.

Assessing global resource utilization efficiency in the industrial sector.

PubMed

Rosen, Marc A

2013-09-01

Designing efficient energy systems, which also meet economic, environmental and other objectives and constraints, is a significant challenge. In a world with finite natural resources and large energy demands, it is important to understand not just actual efficiencies, but also limits to efficiency, as the latter identify margins for efficiency improvement. Energy analysis alone is inadequate, e.g., it yields energy efficiencies that do not provide limits to efficiency. To obtain meaningful and useful efficiencies for energy systems, and to clarify losses, exergy analysis is a beneficial and useful tool. Here, the global industrial sector and industries within it are assessed by using energy and exergy methods. The objective is to improve the understanding of the efficiency of global resource use in the industrial sector and, with this information, to facilitate the development, prioritization and ultimate implementation of rational improvement options. Global energy and exergy flow diagrams for the industrial sector are developed and overall efficiencies for the global industrial sector evaluated as 51% based on energy and 30% based on exergy. Consequently, exergy analysis indicates a less efficient picture of energy use in the global industrial sector than does energy analysis. A larger margin for improvement exists from an exergy perspective, compared to the overly optimistic margin indicated by energy. Copyright © 2012 Elsevier B.V. All rights reserved.

Improving paddling efficiency through raising sitting height in female white water kayakers.

PubMed

Broomfield, Shelley A L; Lauder, Mike

2015-01-01

The study compared female white water paddlers over two conditions: with seat raise and with no seat raise. The aim was to determine whether raising the sitting height would improve paddling efficiency. Sitting height of each participant was recorded in order to calculate the seat raise height required and three-dimensional kinematic data was collected for six participants over both conditions. Twelve measures of efficiency were utilised. The efficiency of all participants improved on the seat condition for ≥4 of the measures, with three participants showing improvement for ≥6 of the measures. The stern snaking measure had the highest value of significance (P = 0.1455) and showed an average of 11.98% reduction in movement between no seat and seat conditions. The results indicate that improvements were seen although these were individualistic. Therefore it can be concluded that it is worth experimenting with a seat raise for a female kayaker who is lacking efficiency, noting, however, that improvements might depend on anthropometrics and the seat height selected, and therefore could elicit differing results.

Energy efficiency of mobile soft robots.

PubMed

Shui, Langquan; Zhu, Liangliang; Yang, Zhe; Liu, Yilun; Chen, Xi

2017-11-15

The performance of mobile soft robots is usually characterized by their locomotion/velocity efficiency, whereas the energy efficiency is a more intrinsic and fundamental criterion for the performance evaluation of independent or integrated soft robots. In this work, a general framework is established to evaluate the energy efficiency of mobile soft robots by considering the efficiency of the energy source, actuator and locomotion, and some insights for improving the efficiency of soft robotic systems are presented. Proposed as the ratio of the desired locomotion kinetic energy to the input mechanical energy, the energy efficiency of locomotion is found to play a critical role in determining the overall energy efficiency of soft robots. Four key factors related to the locomotion energy efficiency are identified, that is, the locomotion modes, material properties, geometric sizes, and actuation states. It is found that the energy efficiency of most mobile soft robots reported in the literature is surprisingly low (mostly below 0.1%), due to the inefficient mechanical energy that essentially does not contribute to the desired locomotion. A comparison of the locomotion energy efficiency for several representative locomotion modes in the literature is presented, showing a descending ranking as: jumping ≫ fish-like swimming > snake-like slithering > rolling > rising/turning over > inchworm-like inching > quadruped gait > earthworm-like squirming. Besides, considering the same locomotion mode, soft robots with lower stiffness, higher density and larger size tend to have higher locomotion energy efficiency. Moreover, a periodic pulse actuation instead of a continuous actuation mode may significantly reduce the input mechanical energy, thus improving the locomotion energy efficiency, especially when the pulse actuation matches the resonant states of the soft robots. The results presented herein indicate a large and necessary space for improving the locomotion energy efficiency, which is of practical significance for the future development and application of soft robots.

Newly formulated, protein quality-enhanced, extruded sorghum-, cowpea-, corn-, soya-, sugar- and oil-containing fortified-blended foods lead to adequate vitamin A and iron outcomes and improved growth compared with non-extruded CSB+ in rats.

PubMed

Delimont, Nicole M; Fiorentino, Nicole M; Opoku-Acheampong, Alexander B; Joseph, Michael V; Guo, Qingbin; Alavi, Sajid; Lindshield, Brian L

2017-01-01

Corn and soyabean micronutrient-fortified-blended foods (FBF) are commonly used for food aid. Sorghum and cowpeas have been suggested as alternative commodities because they are drought tolerant, can be grown in many localities, and are not genetically modified. Change in formulation of blends may improve protein quality, vitamin A and Fe availability of FBF. The primary objective of this study was to compare protein efficiency, Fe and vitamin A availability of newly formulated extruded sorghum-, cowpea-, soya- and corn-based FBF, along with a current, non-extruded United States Agency for International Development (USAID) corn and soya blend FBF (CSB+). A second objective was to compare protein efficiency of whey protein concentrate (WPC) and soya protein isolate (SPI) containing FBF to determine whether WPC inclusion improved outcomes. Eight groups of growing rats ( n 10) consumed two white and one red sorghum-cowpea (WSC1 + WPC, WSC2 + WPC, RSC + WPC), white sorghum-soya (WSS + WPC) and corn-soya (CSB14 + WPC) extruded WPC-containing FBF, an extruded white sorghum-cowpea with SPI (WSC1 + SPI), non-extruded CSB+, and American Institute of Nutrition (AIN)-93G, a weanling rat diet, for 4 weeks. There were no significant differences in protein efficiency, Fe or vitamin A outcomes between WPC FBF groups. The CSB+ group consumed significantly less food, gained significantly less weight, and had significantly lower energy efficiency, protein efficiency and length, compared with all other groups. Compared with WSC1 + WPC, the WSC1 + SPI FBF group had significantly lower energy efficiency, protein efficiency and weight gain. These results suggest that a variety of commodities can be used in the formulation of FBF, and that newly formulated extruded FBF are of better nutritional quality than non-extruded CSB+.

Coal-Powered Electric Generating Unit Efficiency and Reliability Dialogue: Summary Report

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

Taylor, Emmanuel

Coal continues to play a critical role in powering the Nation’s electricity generation, especially for baseload power plants. With aging coal generation assets facing decreased performance due to the state of the equipment, and with challenges exacerbated by the current market pressures on the coal sector, there are opportunities to advance early-stage technologies that can retrofit or replace equipment components. These changes will eventually result in significant improvements in plant performance once further developed and deployed by industry. Research and development in areas such as materials, fluid dynamics, fuel properties and preparation characteristics, and a new generation of plant controlsmore » can lead to new components and systems that can help improve the efficiency and reliability of coal-fired power plants significantly, allowing these assets to continue to provide baseload power. Coal stockpiles at electricity generation plants are typically large enough to provide 30 to 60 days of power prior to resupply—significantly enhancing the stability and reliability of the U.S. electricity sector. Falling prices for non-dispatchable renewable energy and mounting environmental regulations, among other factors, have stimulated efforts to improve the efficiency of these coal-fired electric generating units (EGUs). In addition, increased reliance on natural gas and non-dispatchable energy sources has spurred efforts to further increase the reliability of coal EGUs. The Coal Powered EGU Efficiency and Reliability Dialogue brought together stakeholders from across the coal EGU industry to discuss methods for improvement. Participants at the event reviewed performance-enhancing innovations in coal EGUs, discussed the potential for data-driven management practices to increase efficiency and reliability, investigated the impacts of regulatory compliance on coal EGU performance, and discussed upcoming challenges for the coal industry. This report documents the key findings and research suggestions discussed at the event. Discussions at the workshop will aid DOE in developing a set of distinct initiatives that can be pursued by government and industry to realize promising technological pursuits. DOE plans to use the results of the Dialogue coupled with ongoing technical analysis of efficiency opportunities within the coal-fired fleet, and additional studies to develop a comprehensive strategy for capitalizing on thermal efficiency improvements. Expected Power Plant Efficiency Improvements include developing cost-effective, efficient, and reliable technologies for boilers, turbines, and sensors and controls to improve the reliability and efficiency of existing coal-based power plants. The Office of Fossil Energy at DOE plans to work with industry to develop knowledge pertaining to advanced technologies and systems that industry can subsequently develop. These technologies and systems will increase reliability, add operational flexibility and improve efficiency, thereby providing more robust power generation infrastructure. The following table lists the research suggestions and questions for further investigation that were identified by participants in each session of the dialogue.« less

Surface passivation of InP solar cells with InAlAs layers

NASA Technical Reports Server (NTRS)

Jain, Raj K.; Flood, Dennis J.; Landis, Geoffrey A.

1993-01-01

The efficiency of indium phosphide solar cells is limited by high values of surface recombination. The effect of a lattice-matched In(0.52)Al(0.48)As window layer material for InP solar cells, using the numerical code PC-1D is investigated. It was found that the use of InAlAs layer significantly enhances the p(+)n cell efficiency, while no appreciable improvement is seen for n(+)p cells. The conduction band energy discontinuity at the heterojunction helps in improving the surface recombination. An optimally designed InP cell efficiency improves from 15.4 percent to 23 percent AMO for a 10 nm thick InAlAs layer. The efficiency improvement reduces with increase in InAlAs layer thickness, due to light absorption in the window layer.

The moderating effect of leadership on the relationship between personality and performance.

PubMed

Yeh, Shu-Chuan Jennifer; Yuan, Kuo-Shu; Chen, Shih-Hua Sarah; Lo, Ying-Ying; Chou, Hsueh-Chih; Huang, Shan; Chiu, Herng-Chia; Wan, Thomas T H

2016-10-01

To examine how personality and leadership influence efficiency in the nursing service environment. Leadership and personality contribute to the success and failure of a unit. However, how they interact to influence performance is still understudied. We used matched pairs sample design to survey 135 head nurses and 1353 registered nurses on validated instruments of demographic characteristics, leadership styles and personality during June and July of 2014. Efficiency was calculated using Data Envelopment Analysis. Tobit regression was used for analysis. High conscientiousness and low neuroticism were significantly associated with higher efficiency. Particularly, under the initiating structure leadership style, high conscientiousness, high extraversion, high agreeableness, high openness and low neuroticism were related to higher efficiency. Openness would improve efficiency under a low consideration leadership style. Most personality traits were related to higher efficiency under the initiating leadership style. Only openness would improve leaders' efficiency under a high initiating structure and a low consideration leadership style. Considering personality as one factor of selecting head nurses, selecting the right person can improve the fit between individuals and organisations, which in turn, improves job performance. Training head nurses to develop better leadership styles in nurses is another way to enhance efficiency. © 2016 John Wiley & Sons Ltd.

Improving efficiency, reducing infection, and enhancing experience.

PubMed

Massa, Judith

For health professionals to make an informed choice and tailor each bed bath to the individual needs of the patient, they must firstly understand the different bed bath options available, their impact on skin integrity, and any associated risks they may pose to the patient in terms of cross-infection. Only with this knowledge can health professionals determine the appropriate form and frequency of the bed bath. Specialist wipes offer significant improvements in skin care and a reduced risk of cross-infection, compared with the traditional soap and water bed bath. Use of these wipes also improves the efficiency of the process, which links to the Productive Ward Initiative and results in clinical staff (i.e. nursing staff, healthcare assistants) having more time available to undertake additional patient care activities. This product focus highlights the benefits of moving to a wipe-based bed bath method, and the significant efficiency savings that can be realized as a result.

Measuring and Benchmarking Technical Efficiency of Public Hospitals in Tianjin, China: A Bootstrap-Data Envelopment Analysis Approach.

PubMed

Li, Hao; Dong, Siping

2015-01-01

China has long been stuck in applying traditional data envelopment analysis (DEA) models to measure technical efficiency of public hospitals without bias correction of efficiency scores. In this article, we have introduced the Bootstrap-DEA approach from the international literature to analyze the technical efficiency of public hospitals in Tianjin (China) and tried to improve the application of this method for benchmarking and inter-organizational learning. It is found that the bias corrected efficiency scores of Bootstrap-DEA differ significantly from those of the traditional Banker, Charnes, and Cooper (BCC) model, which means that Chinese researchers need to update their DEA models for more scientific calculation of hospital efficiency scores. Our research has helped shorten the gap between China and the international world in relative efficiency measurement and improvement of hospitals. It is suggested that Bootstrap-DEA be widely applied into afterward research to measure relative efficiency and productivity of Chinese hospitals so as to better serve for efficiency improvement and related decision making. © The Author(s) 2015.

Efficient preloading of the ventricles by a properly timed atrial contraction underlies stroke work improvement in the acute response to cardiac resynchronization therapy

PubMed Central

Hu, Yuxuan; Gurev, Viatcheslav; Constantino, Jason; Trayanova, Natalia

2013-01-01

Background The acute response to cardiac resynchronization therapy (CRT) has been shown to be due to three mechanisms: resynchronization of ventricular contraction, efficient preloading of the ventricles by a properly timed atrial contraction, and mitral regurgitation reduction. However, the contribution of each of the three mechanisms to the acute response of CRT, specifically stroke work improvement, has not been quantified. Objective The goal of this study was to use an MRI-based anatomically accurate 3D model of failing canine ventricular electromechanics to quantify the contribution of each of the three mechanisms to stroke work improvement and identify the predominant mechanisms. Methods An MRI-based electromechanical model of the failing canine ventricles assembled previously by our group was further developed and modified. Three different protocols were used to dissect the contribution of each of the three mechanisms to stroke work improvement. Results Resynchronization of ventricular contraction did not lead to significant stroke work improvement. Efficient preloading of the ventricles by a properly timed atrial contraction was the predominant mechanism underlying stroke work improvement. Stroke work improvement peaked at an intermediate AV delay, as it allowed ventricular filling by atrial contraction to occur at a low diastolic LV pressure but also provided adequate time for ventricular filling before ventricular contraction. Diminution of mitral regurgitation by CRT led to stroke work worsening instead of improvement. Conclusion Efficient preloading of the ventricles by a properly timed atrial contraction is responsible for significant stroke work improvement in the acute CRT response. PMID:23928177

Valuing Residential Energy Efficiency in Two Alaska Real Estate Markets: A Hedonic Approach

NASA Astrophysics Data System (ADS)

Pride, Dominique J.

Alaska households have high home energy consumption and expenditures. Improving the energy efficiency of the housing stock can reduce home energy consumption, thereby reducing home energy expenditures and CO2 emissions. Improving the energy efficiency of a home may also increase its transaction price if the energy efficiency improvements are capitalized into the value of the home. The relationship between energy efficiency and transaction prices in the Fairbanks and Anchorage, Alaska residential real estate markets is examined. Using a hedonic pricing framework and difference-in-differences analysis, the impact of the Alaska Home Energy Rebate program on the transaction prices of single-family homes in the Fairbanks and Anchorage housing markets from 2008 through 2015 is examined. The results indicate that compared to homes that did not complete the program, homes that completed the program sell for a statistically significant price premium between 15.1% and 15.5% in the Fairbanks market and between 5% and 11% in the Anchorage market. A hedonic pricing framework is used to relate energy efficiency ratings and transaction prices of homes in the Fairbanks and Anchorage residential real estate markets from 2008 through 2015. The results indicate that homes with above-average energy efficiency ratings sell for a statistically significant price premium between 6.9% and 17.5% in the Fairbanks market and between 1.8% and 6.0% in the Anchorage market.

[Effects of postponed basal nitrogen application with reduced nitrogen rate on grain yield and nitrogen use efficiency of south winter wheat].

PubMed

Zhang, Lei; Shao, Yu Hang; Gu, Shi Lu; Hu, Hang; Zhang, Wei Wei; Tian, Zhong Wei; Jiang, Dong; Dai, Ting Bo

2016-12-01

Excessive nitrogen (N) fertilizer application has led to a reduction of nitrogen use efficiency and environmental problems. It was of great significance for high-yield and high-efficiency cultivation to reduce N fertilizer application with modified application strategies. A two-year field experiment was conducted to study effects of different N application rates at basal and seedling application stages on grain yield and nitrogen use efficiency. Taking the conventional nitrogen application practice (240 kg N·hm -2 with application at basal, jointing, and booting stages at ratios of 5:3:2, respectively) as control, a field trial was conducted at different N application rates (240, 180 and 150 kg N·hm -2 , N 240 , N 180 and N 150 , respectively) and different application times [basal (L 0 ), fourth (L 4 ) and sixth leaf stage (L 6 )] to investigate the effects on grain yield and nitrogen use efficiency. The results indicated that grain yield decreased along with reducing the N application rate, but it had no significant difference between N 240 and N 180 while decreased significantly under N 150 . Nitrogen agronomy and recovery efficiency were all highest under N 180 . Among different N application stages, grain yield and nitrogen use efficiency were highest under L 4 . N 180 L 4 had no signifi-cant difference with control in grain yield, but its nitrogen use efficiency was significantly higher. The leaf area index, flag leaf photosynthesis rate, leaf nitrogen content, activity of nitrogen reductase and glutamine synthase in flag leaf, dry matter and N accumulation after jointing of N 180 L 4 had no significant difference with control. In an overall view, postponing basal N fertilizer application at reduced nitrogen rate could maintain high yield and improve nitrogen use efficiency through improving photosynthetic production capacity and promoting nitrogen uptake and assimilation.

Does integration of HIV and sexual and reproductive health services improve technical efficiency in Kenya and Swaziland? An application of a two-stage semi parametric approach incorporating quality measures

PubMed Central

Obure, Carol Dayo; Jacobs, Rowena; Guinness, Lorna; Mayhew, Susannah; Vassall, Anna

2016-01-01

Theoretically, integration of vertically organized services is seen as an important approach to improving the efficiency of health service delivery. However, there is a dearth of evidence on the effect of integration on the technical efficiency of health service delivery. Furthermore, where technical efficiency has been assessed, there have been few attempts to incorporate quality measures within efficiency measurement models particularly in sub-Saharan African settings. This paper investigates the technical efficiency and the determinants of technical efficiency of integrated HIV and sexual and reproductive health (SRH) services using data collected from 40 health facilities in Kenya and Swaziland for 2008/2009 and 2010/2011. Incorporating a measure of quality, we estimate the technical efficiency of health facilities and explore the effect of integration and other environmental factors on technical efficiency using a two-stage semi-parametric double bootstrap approach. The empirical results reveal a high degree of inefficiency in the health facilities studied. The mean bias corrected technical efficiency scores taking quality into consideration varied between 22% and 65% depending on the data envelopment analysis (DEA) model specification. The number of additional HIV services in the maternal and child health unit, public ownership and facility type, have a positive and significant effect on technical efficiency. However, number of additional HIV and STI services provided in the same clinical room, proportion of clinical staff to overall staff, proportion of HIV services provided, and rural location had a negative and significant effect on technical efficiency. The low estimates of technical efficiency and mixed effects of the measures of integration on efficiency challenge the notion that integration of HIV and SRH services may substantially improve the technical efficiency of health facilities. The analysis of quality and efficiency as separate dimensions of performance suggest that efficiency may be achieved without sacrificing quality. PMID:26803655

Does integration of HIV and sexual and reproductive health services improve technical efficiency in Kenya and Swaziland? An application of a two-stage semi parametric approach incorporating quality measures.

PubMed

Obure, Carol Dayo; Jacobs, Rowena; Guinness, Lorna; Mayhew, Susannah; Vassall, Anna

2016-02-01

Theoretically, integration of vertically organized services is seen as an important approach to improving the efficiency of health service delivery. However, there is a dearth of evidence on the effect of integration on the technical efficiency of health service delivery. Furthermore, where technical efficiency has been assessed, there have been few attempts to incorporate quality measures within efficiency measurement models particularly in sub-Saharan African settings. This paper investigates the technical efficiency and the determinants of technical efficiency of integrated HIV and sexual and reproductive health (SRH) services using data collected from 40 health facilities in Kenya and Swaziland for 2008/2009 and 2010/2011. Incorporating a measure of quality, we estimate the technical efficiency of health facilities and explore the effect of integration and other environmental factors on technical efficiency using a two-stage semi-parametric double bootstrap approach. The empirical results reveal a high degree of inefficiency in the health facilities studied. The mean bias corrected technical efficiency scores taking quality into consideration varied between 22% and 65% depending on the data envelopment analysis (DEA) model specification. The number of additional HIV services in the maternal and child health unit, public ownership and facility type, have a positive and significant effect on technical efficiency. However, number of additional HIV and STI services provided in the same clinical room, proportion of clinical staff to overall staff, proportion of HIV services provided, and rural location had a negative and significant effect on technical efficiency. The low estimates of technical efficiency and mixed effects of the measures of integration on efficiency challenge the notion that integration of HIV and SRH services may substantially improve the technical efficiency of health facilities. The analysis of quality and efficiency as separate dimensions of performance suggest that efficiency may be achieved without sacrificing quality. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Survey of Architectural Techniques For Improving Cache Power Efficiency

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

Mittal, Sparsh

Modern processors are using increasingly larger sized on-chip caches. Also, with each CMOS technology generation, there has been a significant increase in their leakage energy consumption. For this reason, cache power management has become a crucial research issue in modern processor design. To address this challenge and also meet the goals of sustainable computing, researchers have proposed several techniques for improving energy efficiency of cache architectures. This paper surveys recent architectural techniques for improving cache power efficiency and also presents a classification of these techniques based on their characteristics. For providing an application perspective, this paper also reviews several real-worldmore » processor chips that employ cache energy saving techniques. The aim of this survey is to enable engineers and researchers to get insights into the techniques for improving cache power efficiency and motivate them to invent novel solutions for enabling low-power operation of caches.« less

Labor productivity, perceived effectiveness, and sustainability of innovative projects.

PubMed

Makai, Peter; Cramm, Jane M; van Grotel, Marloes; Nieboer, Anna P

2014-01-01

To assess labor productivity, perceived effectiveness, and sustainability of a national quality program that sought to stimulate efficiency gains through increased labor productivity while maintaining quality through implementing small-scale innovation projects. Longitudinal measures of labor productivity and quality were collected at baseline and after completion of the innovation projects. Perceived effectiveness and sustainability (measured by routinization) were assessed cross-sectionally after project completion. This study was conducted in The Netherlands. Ninety-eight improvement projects in long-term care organizations. A national quality program to stimulate innovative approaches in long-term care. Labor productivity, perceived effectiveness, and sustainability were the main outcome measures. Labor productivity data were available for only 37 (38%) of the 98 projects, 33 (89%) of which demonstrated significantly improved efficiency. Perceived effectiveness was significantly associated with sustainability (0.29; p < .05), but not labor productivity. To achieve sustainability in long-term care, developers of innovative projects must collect better quality information on efficiency gains in terms of labor productivity and focus more on efficiency improvement. More research is necessary to explore relationships between labor productivity, perceived effectiveness, and sustainability. © 2012 National Association for Healthcare Quality.

Improving operating theatre efficiency: an intervention to significantly reduce changeover time.

PubMed

Soliman, Bishoy A B; Stanton, Raymond; Sowter, Steven; Rozen, Warren Matthew; Shahbaz, Shekib

2013-07-01

Operating theatre inefficiency and changeover delays are not only a significant source of wasted resources, but also a familiar source of frustration to patients and health-care providers. This study aimed to prove that the surgical registrar through active involvement in patient changeover can significantly improve operating room efficiency and minimize delays. A two-phase prospective cohort study was undertaken, conducted over the course of 4 weeks at a single institution. The only inclusion criteria comprised patients to undertake endoscopic urological day surgery cases and require general anaesthesia. There were no exclusions. In the first phase (observational, with no intervention), changeover times between cases were documented. The second phase followed a structured intervention, involving the surgical registrar being actively involved in the patient's operative journey. Outcome measures were qualitative measures of operative efficiency. Statistical analysis was undertaken. There were 42 patients included in this study, with 21 patients in each of its arms. A 48% (P-value < 0.01) reduction in overall case changeover times was demonstrated with the utilization of a structured intervention from 27.7 min (95% confidence interval (CI) 22.8-32.7%) to 15.7 min (95% CI 13.2-18.2%). The intervention results were statistically significant (P-value < 0.05) for all markers of efficiency except for the waiting time in the anaesthetic holding bay (P-value 0.13). The surgical registrar can improve operating room efficiency by using a structured intervention, ultimately reducing patient changeover times. © 2012 The Authors. ANZ Journal of Surgery © 2012 Royal Australasian College of Surgeons.

A Metamaterial-Inspired Approach to RF Energy Harvesting

NASA Astrophysics Data System (ADS)

Fowler, Clayton; Zhou, Jiangfeng

2016-03-01

We demonstrate an RF energy harvesting rectenna design based on a metamaterial perfect absorber (MPA). With the embedded Schottky diodes, the rectenna converts captured RF energy to DC currents. The Fabry-Perot cavity resonance of the MPA greatly improves the amount of energy captured and hence improves the rectification efficiency. Furthermore, the FP resonance exhibits a high Q-factor and significantly increases the voltage across the Schottky diodes. This leads to a factor of 16 improvement of RF-DC conversion efficiency at ambient intensity level.

A Metamaterial-Inspired Approach to RF Energy Harvesting

NASA Astrophysics Data System (ADS)

Fowler, Clayton; Zhou, Jiangfeng

We demonstrate an RF energy harvesting rectenna design based on a metamaterial perfect absorber (MPA). With the embedded Schottky diodes, the rectenna converts captured RF energy to DC currents. The Fabry-Perot cavity resonance of the MPA greatly improves the amount of energy captured and hence improves the rectification efficiency. Furthermore, the FP resonance exhibits high Q-factor and significantly increases the voltage across the Schottky diodes. This leads to a factor of 16 improvement of RF-DC conversion efficiency at ambient intensity level.

Quantifying and improving the efficiency of Gamma Knife treatment plans for brain metastases: results of a 1-year audit.

PubMed

Wright, Gavin; Hatfield, Paul; Loughrey, Carmel; Reiner, Beatrice; Bownes, Peter

2014-12-01

A method for quantifying the efficiency of Gamma Knife treatment plans for metastases was previously implemented by the authors to retrospectively identify the least efficient plans and has provided insights into improved planning strategies. The aim of the current work was to ascertain whether those insights led to improved treatment plans. Following completion of the initial study, a 1-year audit of metastasis plans created at St. James's Institute of Oncology was carried out. Audited recent plans were compared with the earlier plans of the initial study, in terms of their efficiency and dosimetric quality. The statistical significance of any differences between relevant plan parameters was quantified by Mann-Whitney U-tests. Comparisons were made between all plans and repeated for a reduced set of plans from which the smallest lesions treated with a single 4-mm shot were excluded. The plan parameters compared were a plan efficiency index (PEI), the number of shots, Paddick conformity index (PCI), gradient index (GI), and percent coverage (of the lesion by the prescription isodose). A total of 157 metastatic lesions were included in the audit and were compared with 241 in the initial study. In a comparison of all cases, the audited plans achieved a higher median PEI score than did the earlier plans from the initial study (1.08 vs 1.02), indicating improved efficiency of the audited plans. When the smallest lesions (for which there was little scope for varying plan strategy) were discounted, the improvement in median PEI score was greater (1.23 vs 1.03, p < 0.001). This improvement in efficiency corresponds to an estimated mean (maximum) time saving of 15% (66%) per lesion (11 minutes [64 minutes] on the day of treatment). The modified planning strategy yielding these efficiency improvements did not rely on the use of significantly fewer shots (median 11 vs 11 shots, p = 0.924), nor did it result in significant detriment to dosimetric quality (median coverage 99% vs 99%, median PCI 0.84 vs 0.83, p = 0.449, and median GI 2.72 vs 2.67, p = 0.701, audited plans vs initial plans, respectively). Choice of planning strategy can substantially affect plan efficiency and thus strongly influence treatment time. Through increased emphasis on efficiency, resulting from the introduction of PEI combined with a modified planning strategy informed by previous work, it has been possible to reduce times for metastatic plans without compromising their dosimetric quality. Although the average time savings achieved per lesion are moderate, the potential benefits per patient are greater for those with multiple metastases. Reducing treatment times has clear benefits with regard to patient comfort and throughput. In addition, optimization of plan efficiency may potentially affect the biologically effective dose from Gamma Knife treatments and offers opportunity for further work.

Intelligent single switch wheelchair navigation.

PubMed

Ka, Hyun W; Simpson, Richard; Chung, Younghyun

2012-11-01

We have developed an intelligent single switch scanning interface and wheelchair navigation assistance system, called intelligent single switch wheelchair navigation (ISSWN), to improve driving safety, comfort and efficiency for individuals who rely on single switch scanning as a control method. ISSWN combines a standard powered wheelchair with a laser rangefinder, a single switch scanning interface and a computer. It provides the user with context sensitive and task specific scanning options that reduce driving effort based on an interpretation of sensor data together with user input. Trials performed by 9 able-bodied participants showed that the system significantly improved driving safety and efficiency in a navigation task by significantly reducing the number of switch presses to 43.5% of traditional single switch wheelchair navigation (p < 0.001). All participants made a significant improvement (39.1%; p < 0.001) in completion time after only two trials.

Reducing the efficiency-stability-cost gap of organic photovoltaics with highly efficient and stable small molecule acceptor ternary solar cells

NASA Astrophysics Data System (ADS)

Baran, Derya; Ashraf, Raja Shahid; Hanifi, David A.; Abdelsamie, Maged; Gasparini, Nicola; Röhr, Jason A.; Holliday, Sarah; Wadsworth, Andrew; Lockett, Sarah; Neophytou, Marios; Emmott, Christopher J. M.; Nelson, Jenny; Brabec, Christoph J.; Amassian, Aram; Salleo, Alberto; Kirchartz, Thomas; Durrant, James R.; McCulloch, Iain

2017-03-01

Technological deployment of organic photovoltaic modules requires improvements in device light-conversion efficiency and stability while keeping material costs low. Here we demonstrate highly efficient and stable solar cells using a ternary approach, wherein two non-fullerene acceptors are combined with both a scalable and affordable donor polymer, poly(3-hexylthiophene) (P3HT), and a high-efficiency, low-bandgap polymer in a single-layer bulk-heterojunction device. The addition of a strongly absorbing small molecule acceptor into a P3HT-based non-fullerene blend increases the device efficiency up to 7.7 +/- 0.1% without any solvent additives. The improvement is assigned to changes in microstructure that reduce charge recombination and increase the photovoltage, and to improved light harvesting across the visible region. The stability of P3HT-based devices in ambient conditions is also significantly improved relative to polymer:fullerene devices. Combined with a low-bandgap donor polymer (PBDTTT-EFT, also known as PCE10), the two mixed acceptors also lead to solar cells with 11.0 +/- 0.4% efficiency and a high open-circuit voltage of 1.03 +/- 0.01 V.

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.

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

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

Schoenbauer, Ben

High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency watermore » heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.« less

The Use of Hypnosis in Improving Reading Performance.

ERIC Educational Resources Information Center

Fillmer, H. Thompson; And Others

1983-01-01

Describes a study investigating the effects of group hypnosis on the reading improvement of university students. Finds marginally significant improvement in total vocabulary and comprehension scores and greatest improvement in students with initially low reading scores. Sees group hypnosis as an efficient and economically feasible instructional…

Improving primary health care facility performance in Ghana: efficiency analysis and fiscal space implications.

PubMed

Novignon, Jacob; Nonvignon, Justice

2017-06-12

Health centers in Ghana play an important role in health care delivery especially in deprived communities. They usually serve as the first line of service and meet basic health care needs. Unfortunately, these facilities are faced with inadequate resources. While health policy makers seek to increase resources committed to primary healthcare, it is important to understand the nature of inefficiencies that exist in these facilities. Therefore, the objectives of this study are threefold; (i) estimate efficiency among primary health facilities (health centers), (ii) examine the potential fiscal space from improved efficiency and (iii) investigate the efficiency disparities in public and private facilities. Data was from the 2015 Access Bottlenecks, Cost and Equity (ABCE) project conducted by the Institute for Health Metrics and Evaluation. The Stochastic Frontier Analysis (SFA) was used to estimate efficiency of health facilities. Efficiency scores were then used to compute potential savings from improved efficiency. Outpatient visits was used as output while number of personnel, hospital beds, expenditure on other capital items and administration were used as inputs. Disparities in efficiency between public and private facilities was estimated using the Nopo matching decomposition procedure. Average efficiency score across all health centers included in the sample was estimated to be 0.51. Also, average efficiency was estimated to be about 0.65 and 0.50 for private and public facilities, respectively. Significant disparities in efficiency were identified across the various administrative regions. With regards to potential fiscal space, we found that, on average, facilities could save about GH₵11,450.70 (US$7633.80) if efficiency was improved. We also found that fiscal space from efficiency gains varies across rural/urban as well as private/public facilities, if best practices are followed. The matching decomposition showed an efficiency gap of 0.29 between private and public facilities. There is need for primary health facility managers to improve productivity via effective and efficient resource use. Efforts to improve efficiency should focus on training health workers and improving facility environment alongside effective monitoring and evaluation exercises.

Tuning the relative concentration ratio of bulk defects to surface defects in TiO2 nanocrystals leads to high photocatalytic efficiency.

PubMed

Kong, Ming; Li, Yuanzhi; Chen, Xiong; Tian, Tingting; Fang, Pengfei; Zheng, Feng; Zhao, Xiujian

2011-10-19

TiO(2) nanocrystals with tunable bulk/surface defects were synthesized and characterized with TEM, XRD, BET, positron annihilation, and photocurrent measurements. The effect of defects on photocatalytic activity was studied. It was found for the first time that decreasing the relative concentration ratio of bulk defects to surface defects in TiO(2) nanocrystals could significantly improve the separation efficiency of photogenerated electrons and holes, thus significantly enhancing the photocatalytic efficiency.

Efficiency of bulk-heterojunction organic solar cells

PubMed Central

Scharber, M.C.; Sariciftci, N.S.

2013-01-01

During the last years the performance of bulk heterojunction solar cells has been improved significantly. For a large-scale application of this technology further improvements are required. This article reviews the basic working principles and the state of the art device design of bulk heterojunction solar cells. The importance of high power conversion efficiencies for the commercial exploitation is outlined and different efficiency models for bulk heterojunction solar cells are discussed. Assuming state of the art materials and device architectures several models predict power conversion efficiencies in the range of 10–15%. A more general approach assuming device operation close to the Shockley–Queisser-limit leads to even higher efficiencies. Bulk heterojunction devices exhibiting only radiative recombination of charge carriers could be as efficient as ideal inorganic photovoltaic devices. PMID:24302787

Biomass recycle as a means to improve the energy efficiency of CELSS algal culture systems

NASA Technical Reports Server (NTRS)

Radmer, R.; Cox, J.; Lieberman, D.; Behrens, P.; Arnett, K.

1987-01-01

Algal cultures can be very rapid and efficient means to generate biomass and regenerate the atmosphere for closed environmental life support systems. However, as in the case of most higher plants, a significant fraction of the biomass produced by most algae cannot be directly converted to a useful food product by standard food technology procedures. This waste biomass will serve as an energy drain on the overall system unless it can be efficiently recycled without a significant loss of its energy content. Experiments are reported in which cultures of the alga Scenedesmus obliquus were grown in the light and at the expense of an added carbon source, which either replaced or supplemented the actinic light. As part of these experiments, hydrolyzed waste biomass from these same algae were tested to determine whether the algae themselves could be made part of the biological recycling process. Results indicate that hydrolyzed algal (and plant) biomass can serve as carbon and energy sources for the growth of these algae, suggesting that the efficiency of the closed system could be significantly improved using this recycling process.

High performance cryogenic turboexpanders

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

Agahi, R.R.; Ershaghi, B.; Lin, M.C.

1996-12-31

The use of turboexpanders for deep cryogenic temperatures has been constrained because of thermal efficiency limitations. This limited thermal efficiency was mostly due to mechanical constraints. Recent improvements in analytical techniques, bearing technology, and design features have made it possible to design and operate turboexpanders at more favorable conditions, such as of higher rotational speeds. Several turboexpander installations in helium and hydrogen processes have shown a significant improvement in plant performance over non-turboexpander options.

Applying Lean Six Sigma methodologies to improve efficiency, timeliness of care, and quality of care in an internal medicine residency clinic.

PubMed

Fischman, Daniel

2010-01-01

Patients' connectedness to their providers has been shown to influence the success of preventive health and disease management programs. Lean Six Sigma methodologies were employed to study workflow processes, patient-physician familiarity, and appointment compliance to improve continuity of care in an internal medicine residency clinic. We used a rapid-cycle test to evaluate proposed improvements to the baseline-identified factors impeding efficient clinic visits. Time-study, no-show, and patient-physician familiarity data were collected to evaluate the effect of interventions to improve clinic efficiency and continuity of medical care. Forty-seven patients were seen in each of the intervention and control groups. The wait duration between the end of triage and the resident-patient encounter was statistically shorter for the intervention group. Trends toward shorter wait times for medical assistant triage and total encounter were also seen in the intervention group. On all measures of connectedness, both the physicians and patients in the intervention group showed a statistically significant increased familiarity with each other. This study shows that incremental changes in workflow processes in a residency clinic can have a significant impact on practice efficiency and adherence to scheduled visits for preventive health care and chronic disease management. This project used a structured "Plan-Do-Study-Act" approach.

Improving Operating Room Efficiency: First Case On-Time Start Project.

PubMed

Phieffer, Laura; Hefner, Jennifer L; Rahmanian, Armin; Swartz, Jason; Ellison, Christopher E; Harter, Ronald; Lumbley, Joshua; Moffatt-Bruce, Susan D

Operating rooms (ORs) are costly to run, and multiple factors influence efficiency. The first case on-time start (FCOS) of an OR is viewed as a harbinger of efficiency for the daily schedule. Across 26 ORs of a large, academic medical center, only 49% of cases started on time in October 2011. The Perioperative Services Department engaged an interdisciplinary Operating Room Committee to apply Six Sigma tools to this problem. The steps of this project included (1) problem mapping, (2) process improvements to preoperative readiness, (3) informatics support improvements, and (4) continuous measurement and feedback. By June 2013, there was a peak of 92% first case on-time starts across service lines, decreasing to 78% through 2014, still significantly above the preintervention level of 49% (p = .000). Delay minutes also significantly decreased through the study period (p = .000). Across 2013, the most common delay owners were the patient, the surgeon, the facility, and the anesthesia department. Continuous and sustained improvement of first case on-time starts is attributed to tracking the FCOS metric, establishing embedded process improvement resources and creating transparency of data. This article highlights success factors and barriers to program success and sustainability.

Improving transmission efficiency of large sequence alignment/map (SAM) files.

PubMed

Sakib, Muhammad Nazmus; Tang, Jijun; Zheng, W Jim; Huang, Chin-Tser

2011-01-01

Research in bioinformatics primarily involves collection and analysis of a large volume of genomic data. Naturally, it demands efficient storage and transfer of this huge amount of data. In recent years, some research has been done to find efficient compression algorithms to reduce the size of various sequencing data. One way to improve the transmission time of large files is to apply a maximum lossless compression on them. In this paper, we present SAMZIP, a specialized encoding scheme, for sequence alignment data in SAM (Sequence Alignment/Map) format, which improves the compression ratio of existing compression tools available. In order to achieve this, we exploit the prior knowledge of the file format and specifications. Our experimental results show that our encoding scheme improves compression ratio, thereby reducing overall transmission time significantly.

An efficient optimization method to improve the measuring accuracy of oxygen saturation by using triangular wave optical signal

NASA Astrophysics Data System (ADS)

Li, Gang; Yu, Yue; Zhang, Cui; Lin, Ling

2017-09-01

The oxygen saturation is one of the important parameters to evaluate human health. This paper presents an efficient optimization method that can improve the accuracy of oxygen saturation measurement, which employs an optical frequency division triangular wave signal as the excitation signal to obtain dynamic spectrum and calculate oxygen saturation. In comparison to the traditional method measured RMSE (root mean square error) of SpO2 which is 0.1705, this proposed method significantly reduced the measured RMSE which is 0.0965. It is notable that the accuracy of oxygen saturation measurement has been improved significantly. The method can simplify the circuit and bring down the demand of elements. Furthermore, it has a great reference value on improving the signal to noise ratio of other physiological signals.

Application of carbon nanotubes in perovskite solar cells: A review

NASA Astrophysics Data System (ADS)

Oo, Thet Tin; Debnath, Sujan

2017-11-01

Solar power, as alternative renewable energy source, has gained momentum in global energy generation in recent time. Solar photovoltaics (PV) systems now fulfill a significant portion of electricity demand and the capacity of solar PV capacity is growing every year. PV cells efficiency has improved significantly following decades of research, evolving into third generations of PV cells. These third generation PV cells are set out to provide low-cost and efficient PV systems, further improving the commercial competitiveness of solar energy generation. Among these latest generations of PV cells, perovskite solar cells have gained attraction due to the simple manufacturing process and the immense growth in PV efficiency in a short period of research and development. Despite these advantages, perovskite solar cells are known for the weak stability and decomposition in exposure to humidity and high temperature, hindering the possibility of commercialization. This paper will discuss the role of carbon nanotubes (CNTs) in improving the efficiency and stability of perovskite solar cells, in various components such as perovskite layer and hole transport layer, as well as the application of CNTs in unique aspects. These includes the use of CNTs fiber in making the perovskite solar cells flexible, as well as simplification of perovskite PV production by using CNT flash evaporation printing process. Despite these advances, challenges remain in incorporation CNTs into perovskite such as lower conversion efficiency compared to rare earth metals and improvements need to be made. Thus, the paper will be also highlighting the CNTs materials suggested for further research and improvement of perovskite solar cells.

Simultaneous heavy metals removal and municipal sewage sludge dewaterability improvement in bioleaching processes by various inoculums.

PubMed

Shi, Chaohong; Zhu, Nengwu; Shang, Ru; Kang, Naixin; Wu, Pingxiao

2015-11-01

The heavy metals content and dewaterability of municipal sewage sludge (MSS) are important parameters affecting its subsequent disposal and land application. Six kinds of inoculums were prepared to examine the characteristics of heavy metals removal and MSS dewaterability improvement in bioleaching processes. The results showed that Cu, Zn and Cd bioleaching efficiencies (12 days) were 81-91, 87-93 and 81-89%, respectively, which were significantly higher than those of Fe-S control (P < 0.05) and blank control (P < 0.01). The bioleaching boosted by the prepared inoculums could also significantly enhance MSS dewaterability (P < 0.01). The centrifugal dehydration efficiency of MSS rose from 73.00 to 90.00% at day 12. Microscopic observations and energy dispersive spectrum analysis demonstrated that the dewaterability improvement might be attributed to the changes of sludge structure from flocculent to obvious granular and the formation of secondary minerals mainly consisting of iron, oxygen and sulfur elements. The results above demonstrated that bacterial consortium enriched from acid mine drainage (AMD) was suitable to boost sludge bioleaching for heavy metals removal and dewaterability improvement. It also suggested that the synergy of sulfur/ferrous-oxidizing bacteria (SFOB) enriched from AMD and the cooperation of exogenous and indigenous SFOB significantly promoted bioleaching efficiencies.

Measuring Efficiency in the Community College Sector. CCRC Working Paper No. 43

ERIC Educational Resources Information Center

Belfield, Clive R.

2012-01-01

Community colleges are increasingly being pressed to demonstrate efficiency and improve productivity even as these concepts are not clearly defined and require a significant set of assumptions to determine. This paper sets out a preferred economic definition of efficiency: fiscal and social cost per degree. It then assesses the validity of using…

Patient satisfaction and masticatory efficiency of single implant-retained mandibular overdentures using the stud and magnetic attachments.

PubMed

Cheng, Tao; Sun, Guifeng; Huo, Jingyu; He, Xiaoji; Wang, Yining; Ren, Yan-Fang

2012-11-01

To study patient satisfaction and masticatory efficiency of single implant-retained mandibular overdentures using the stud and magnetic attachments in a randomized clinical trial with a crossover design. Patients received a single implant placed in the midline of the mandible and either a stud (Locator) or a magnetic (Magfit) attachment, assigned at random. Patient satisfaction, including patient comfort, speech, chewing ability and retention, and masticatory efficiency measured by chewing peanuts, were assessed before and 3 months after attachment insertion. Patient satisfaction and masticatory efficiency were evaluated again 3 months after insertion of the alternate attachment bodies. The outcomes were compared before and after insertion of the attachments and between the two types of attachments using Wilcoxon signed rank tests. Patient overall satisfaction, comfort, speech, chewing ability, and retention improved significantly after insertion of both types of attachment bodies (p<0.05). Masticatory efficiencies also increased in both the Locator and the Magfit groups (p<0.05). There were no statistically significant differences in patient overall satisfaction, comfort, speech, and retention between the two types of attachments (p>0.05). The Locator attachments performed better in perceived chewing ability than the Magfit (p<0.05), but there was no statistically significant difference in masticatory efficiency between the two attachment types (p>0.05). Clinical outcomes were significantly improved in single implant-retained mandibular overdentures using either the Locator or the Magfit magnetic attachments. There was no difference in masticatory efficiency between the two attachment types. Copyright © 2012 Elsevier Ltd. All rights reserved.

Advanced Hydrogen Liquefaction Process

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

Schwartz, Joseph; Kromer, Brian; Neu, Ben

2011-09-28

The project identified and quantified ways to reduce the cost of hydrogen liquefaction, and reduce the cost of hydrogen distribution. The goal was to reduce the power consumption by 20% and then to reduce the capital cost. Optimizing the process, improving process equipment, and improving ortho-para conversion significantly reduced the power consumption of liquefaction, but by less than 20%. Because the efficiency improvement was less than the target, the program was stopped before the capital cost was addressed. These efficiency improvements could provide a benefit to the public to improve the design of future hydrogen liquefiers. The project increased themore » understanding of hydrogen liquefaction by modeling different processes and thoroughly examining ortho-para separation and conversion. The process modeling provided a benefit to the public because the project incorporated para hydrogen into the process modeling software, so liquefaction processes can be modeled more accurately than using only normal hydrogen. Adding catalyst to the first heat exchanger, a simple method to reduce liquefaction power, was identified, analyzed, and quantified. The demonstrated performance of ortho-para separation is sufficient for at least one identified process concept to show reduced power cost when compared to hydrogen liquefaction processes using conventional ortho-para conversion. The impact of improved ortho-para conversion can be significant because ortho para conversion uses about 20-25% of the total liquefaction power, but performance improvement is necessary to realize a substantial benefit. Most of the energy used in liquefaction is for gas compression. Improvements in hydrogen compression will have a significant impact on overall liquefier efficiency. Improvements to turbines, heat exchangers, and other process equipment will have less impact.« less

Mitochondrial efficiency and exercise economy following heat stress: a potential role of uncoupling protein 3.

PubMed

Salgado, Roy M; Sheard, Ailish C; Vaughan, Roger A; Parker, Daryl L; Schneider, Suzanne M; Kenefick, Robert W; McCormick, James J; Gannon, Nicholas P; Van Dusseldorp, Trisha A; Kravitz, Len R; Mermier, Christine M

2017-02-01

Heat stress has been reported to reduce uncoupling proteins (UCP) expression, which in turn should improve mitochondrial efficiency. Such an improvement in efficiency may translate to the systemic level as greater exercise economy. However, neither the heat-induced improvement in mitochondrial efficiency (due to decrease in UCP), nor its potential to improve economy has been studied. Determine: (i) if heat stress in vitro lowers UCP3 thereby improving mitochondrial efficiency in C2C12 myocytes; (ii) whether heat acclimation (HA) in vivo improves exercise economy in trained individuals; and (iii) the potential improved economy during exercise at altitude. In vitro, myocytes were heat stressed for 24 h (40°C), followed by measurements of UCP3, mitochondrial uncoupling, and efficiency. In vivo, eight trained males completed: (i) pre-HA testing; (ii) 10 days of HA (40°C, 20% RH); and (iii) post-HA testing. Pre- and posttesting consisted of maximal exercise test and submaximal exercise at two intensities to assess exercise economy at 1600 m (Albuquerque, NM) and 4350 m. Heat-stressed myocytes displayed significantly reduced UCP3 mRNA expression and, mitochondrial uncoupling (77.1 ± 1.2%, P < 0.0001) and improved mitochondrial efficiency (62.9 ± 4.1%, P < 0.0001) compared to control. In humans, at both 1600 m and 4350 m, following HA, submaximal exercise economy did not change at low and moderate exercise intensities. Our findings indicate that while heat-induced reduction in UCP3 improves mitochondrial efficiency in vitro, this is not translated to in vivo improvement of exercise economy at 1600 m or 4350 m. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Design of Spur Gears for Improved Efficiency

NASA Technical Reports Server (NTRS)

Anderson, N. E.; Loewenthal, S. H.

1981-01-01

A method to calculate spur gear system loss for a wide range of gear geometries and operating conditions was used to determine design requirements for an efficient gearset. The effects of spur gear size, pitch, ratio, pitch line velocity and load on efficiency were determined. Peak efficiencies were found to be greater for large diameter and fine pitched gears and tare (no-load) losses were found to be significant.

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

Brown, K. A.; Schoefer, V.; Tomizawa, M.

The new accelerator complex at J-PARC will operate with both high energy and very high intensity proton beams. With a design slow extraction efficiency of greater than 99% this facility will still be depositing significant beam power onto accelerator components [2]. To achieve even higher efficiencies requires some new ideas. The design of the extraction system and the accelerator lattice structure leaves little room for improvement using conventional techniques. In this report we will present one method for improving the slow extraction efficiency at J-PARC by adding duodecapoles or octupoles to the slow extraction system. We will review the theorymore » of resonant extraction, describe simulation methods, and present the results of detailed simulations. From our investigations we find that we can improve extraction efficiency and thereby reduce the level of residual activation in the accelerator components and surrounding shielding.« less

Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

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

High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiencymore » water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.« less

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

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

Schoenbauer, Ben

High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiencymore » water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.« less

Improving quality and patient satisfaction in a pediatric resident continuity clinic through advanced access scheduling.

PubMed

Tuli, Sanjeev Y; Thompson, Lindsay A; Ryan, Kathleen A; Srinivas, Ganga L; Fillipps, Donald J; Young, Christopher M; Tuli, Sonal S

2010-06-01

To evaluate the impact of advanced access scheduling in a pediatric residency clinic on resident and patient satisfaction, medical education, practice quality, and efficiency. Residents were assigned to either the advanced access template (10 appointments available to patients and 2 physician overbooks) or the prior template (5 available and 8 overbooks). Outcomes included resident and patient satisfaction, appointment availability, and continuity of care and clinic costs. Patient satisfaction improved in 7 areas (P < .001). Residents in either template did not report an impact on medical education experiences. Significant increases were realized with appointment availability and the number of patients seen. Continuity also increased as the overflow/acute visits decreased (P < .001). Overall costs per visit decreased 22%. Because of the significant improvements in access, continuity, and efficiency, all residents were switched to the advanced access template after completion of the study. Improvement in access to the primary physician has a significant impact on patient satisfaction with health care delivery. This model optimizes the limited time that residents have in continuity clinic, and it has implications for health care delivery quality improvement.

Speech recognition-based and automaticity programs to help students with severe reading and spelling problems.

PubMed

Higgins, Eleanor L; Raskind, Marshall H

2004-12-01

This study was conducted to assess the effectiveness of two programs developed by the Frostig Center Research Department to improve the reading and spelling of students with learning disabilities (LD): a computer Speech Recognition-based Program (SRBP) and a computer and text-based Automaticity Program (AP). Twenty-eight LD students with reading and spelling difficulties (aged 8 to 18) received each program for 17 weeks and were compared with 16 students in a contrast group who did not receive either program. After adjusting for age and IQ, both the SRBP and AP groups showed significant differences over the contrast group in improving word recognition and reading comprehension. Neither program showed significant differences over contrasts in spelling. The SRBP also improved the performance of the target group when compared with the contrast group on phonological elision and nonword reading efficiency tasks. The AP showed significant differences in all process and reading efficiency measures.

Contribution of village cooperation unit in improving farmers incomes

NASA Astrophysics Data System (ADS)

Sibuea, M. B.; Sibuea, F. A.

2018-02-01

One of the government and private efforts to improve people’s welfare particularly to improve farmer’s income is to activate the Village Cooperation Unit (KUD). The objective of research was to know the efficiency level of farming organized by farmers together with cooperative. Theoretically some social economic variables have been known influences the rate of farmer’s income, therefore three social variables, such us the level of cooperation services, members participation and friendship among farmers with cooperation were studied. List of questions divided into forty family’s leader members of KUD which become samples. Analysis models were used production function of Cob-Douglass and Output Input Ratio models. It was concluded that level of participation and friendship partially were significantly to the income’s rate meanwhile variable of cooperation services level were not significant. Simultaneously, three factors gave very significant contribution, where R-square was 0.97 so that very significant. It’s also concluded that the biggest contribution given by the friendship level. Efficiency level or farming efforts of the farmers is very well and feasible with the average of OIR rate 19.23. This research recommended that this effort could be improved from friendship process among institution since the contribution was significantly improving the farmer’s income.

An improved method to detect correct protein folds using partial clustering.

PubMed

Zhou, Jianjun; Wishart, David S

2013-01-16

Structure-based clustering is commonly used to identify correct protein folds among candidate folds (also called decoys) generated by protein structure prediction programs. However, traditional clustering methods exhibit a poor runtime performance on large decoy sets. We hypothesized that a more efficient "partial" clustering approach in combination with an improved scoring scheme could significantly improve both the speed and performance of existing candidate selection methods. We propose a new scheme that performs rapid but incomplete clustering on protein decoys. Our method detects structurally similar decoys (measured using either C(α) RMSD or GDT-TS score) and extracts representatives from them without assigning every decoy to a cluster. We integrated our new clustering strategy with several different scoring functions to assess both the performance and speed in identifying correct or near-correct folds. Experimental results on 35 Rosetta decoy sets and 40 I-TASSER decoy sets show that our method can improve the correct fold detection rate as assessed by two different quality criteria. This improvement is significantly better than two recently published clustering methods, Durandal and Calibur-lite. Speed and efficiency testing shows that our method can handle much larger decoy sets and is up to 22 times faster than Durandal and Calibur-lite. The new method, named HS-Forest, avoids the computationally expensive task of clustering every decoy, yet still allows superior correct-fold selection. Its improved speed, efficiency and decoy-selection performance should enable structure prediction researchers to work with larger decoy sets and significantly improve their ab initio structure prediction performance.

An improved method to detect correct protein folds using partial clustering

PubMed Central

2013-01-01

Background Structure-based clustering is commonly used to identify correct protein folds among candidate folds (also called decoys) generated by protein structure prediction programs. However, traditional clustering methods exhibit a poor runtime performance on large decoy sets. We hypothesized that a more efficient “partial“ clustering approach in combination with an improved scoring scheme could significantly improve both the speed and performance of existing candidate selection methods. Results We propose a new scheme that performs rapid but incomplete clustering on protein decoys. Our method detects structurally similar decoys (measured using either Cα RMSD or GDT-TS score) and extracts representatives from them without assigning every decoy to a cluster. We integrated our new clustering strategy with several different scoring functions to assess both the performance and speed in identifying correct or near-correct folds. Experimental results on 35 Rosetta decoy sets and 40 I-TASSER decoy sets show that our method can improve the correct fold detection rate as assessed by two different quality criteria. This improvement is significantly better than two recently published clustering methods, Durandal and Calibur-lite. Speed and efficiency testing shows that our method can handle much larger decoy sets and is up to 22 times faster than Durandal and Calibur-lite. Conclusions The new method, named HS-Forest, avoids the computationally expensive task of clustering every decoy, yet still allows superior correct-fold selection. Its improved speed, efficiency and decoy-selection performance should enable structure prediction researchers to work with larger decoy sets and significantly improve their ab initio structure prediction performance. PMID:23323835

[Environmental efficiency evaluation under carbon emission constraint in Western China].

PubMed

Rong, Jian-bo; Yan, Li-jiao; Huang, Shao-rong; Zhang, Ge

2015-06-01

This research used the SBM model based on undesirable outputs to measure the static environmental efficiency of Western China under carbon emission constraint from 2000 to 2012. The researchers also utilized the Malmquist index to further analyze the change tendency of environmental efficiency. Additionally, Tobit regression analysis was used to study the factors relevant to environmental efficiency. Practical solutions to improve environmental quality in Western China were put forward. The study showed that in Western China, environmental efficiency with carbon emission constraint was significantly lower than that without carbon emission constraint, and the difference could be described as an inverse U-shaped curve which increased at first and then decreased. Guang-xi and Inner Mongolia, the two provinces met the effective environmental efficiency levels all the time under carbon emission constraint. However, the five provinces of Guizhou, Gansu, Qinghai, Ningxia and Xinjiang did not. Furthermore, Ningxia had the lowest level of environmental efficiency, with a score between 0.281-0.386. Although the environmental efficiency of most provinces was currently at an ineffective level, the environmental efficiency quality was gradually improving at an average speed of 6.6%. Excessive CO2 emission and a large amount of energy consumption were the primary factors causing environmental inefficiency in Western China, and energy intensity had the most negative impact on the environmental efficiency. The increase of import and export trade reduced the environmental efficiency significantly in Western China, while the increase of foreign direct investment had a positive effect on its environmental efficiency.

Materials Approach to Fuel Efficient Tires

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

Votruba-Drzal, Peter; Kornish, Brian

2015-06-30

The objective of this project was to design, develop, and demonstrate fuel efficient and safety regulation compliant tire filler and barrier coating technologies that will improve overall fuel efficiency by at least 2%. The program developed and validated two complementary approaches to improving fuel efficiency through tire improvements. The first technology was a modified silica-based product that is 15% lower in cost and/or enables a 10% improvement in tread wear while maintaining the already demonstrated minimum of 2% improvement in average fuel efficiency. The second technology was a barrier coating with reduced oxygen transmission rate compared to the state-of-the-art halobutylmore » rubber inner liners that will provide extended placarded tire pressure retention at significantly reduced material usage. A lower-permeance, thinner inner liner coating which retains tire pressure was expected to deliver the additional 2% reduction in fleet fuel consumption. From the 2006 Transportation Research Board Report1, a 10 percent reduction in rolling resistance can reduce consumer fuel expenditures by 1 to 2 percent for typical vehicles. This savings is equivalent to 6 to 12 gallons per year. A 1 psi drop in inflation pressure increases the tire's rolling resistance by about 1.4 percent.« less

Engagement with the auditory processing system during targeted auditory cognitive training mediates changes in cognitive outcomes in individuals with schizophrenia.

PubMed

Biagianti, Bruno; Fisher, Melissa; Neilands, Torsten B; Loewy, Rachel; Vinogradov, Sophia

2016-11-01

Individuals with schizophrenia who engage in targeted cognitive training (TCT) of the auditory system show generalized cognitive improvements. The high degree of variability in cognitive gains maybe due to individual differences in the level of engagement of the underlying neural system target. 131 individuals with schizophrenia underwent 40 hours of TCT. We identified target engagement of auditory system processing efficiency by modeling subject-specific trajectories of auditory processing speed (APS) over time. Lowess analysis, mixed models repeated measures analysis, and latent growth curve modeling were used to examine whether APS trajectories were moderated by age and illness duration, and mediated improvements in cognitive outcome measures. We observed significant improvements in APS from baseline to 20 hours of training (initial change), followed by a flat APS trajectory (plateau) at subsequent time-points. Participants showed interindividual variability in the steepness of the initial APS change and in the APS plateau achieved and sustained between 20 and 40 hours. We found that participants who achieved the fastest APS plateau, showed the greatest transfer effects to untrained cognitive domains. There is a significant association between an individual's ability to generate and sustain auditory processing efficiency and their degree of cognitive improvement after TCT, independent of baseline neurocognition. APS plateau may therefore represent a behavioral measure of target engagement mediating treatment response. Future studies should examine the optimal plateau of auditory processing efficiency required to induce significant cognitive improvements, in the context of interindividual differences in neural plasticity and sensory system efficiency that characterize schizophrenia. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The AMOS cell - An improved metal-semiconductor solar cell. [Antireflection coated Metal Oxide Semiconductor

NASA Technical Reports Server (NTRS)

Stirn, R. J.; Yeh, Y.-C. M.

1975-01-01

A new fabrication process is being developed which significantly improves the efficiency of metal-semiconductor solar cells. The resultant effect, a marked increase in the open-circuit voltage, is produced by the addition of an interfacial layer oxide on the semiconductor. Cells using gold on n-type gallium arsenide have been made in small areas (0.17 sq cm) with conversion efficiencies of 15% in terrestrial sunlight.

Transfection efficiency of chitosan and thiolated chitosan in retinal pigment epithelium cells: A comparative study

PubMed Central

Oliveira, Ana V.; Silva, Andreia P.; Bitoque, Diogo B.; Silva, Gabriela A.; Rosa da Costa, Ana M.

2013-01-01

OBJECTIVE: Gene therapy relies on efficient vector for a therapeutic effect. Efficient non-viral vectors are sought as an alternative to viral vectors. Chitosan, a cationic polymer, has been studied for its gene delivery potential. In this work, disulfide bond containing groups were covalently added to chitosan to improve the transfection efficiency. These bonds can be cleaved by cytoplasmic glutathione, thus, releasing the DNA load more efficiently. MATERIALS AND METHODS: Chitosan and thiolated chitosan nanoparticles (NPs) were prepared in order to obtain a NH3+:PO4− ratio of 5:1 and characterized for plasmid DNA complexation and release efficiency. Cytotoxicity and gene delivery studies were carried out on retinal pigment epithelial cells. RESULTS: In this work, we show that chitosan was effectively modified to incorporate a disulfide bond. The transfection efficiency of chitosan and thiolated chitosan varied according to the cell line used, however, thiolation did not seem to significantly improve transfection efficiency. CONCLUSION: The apparent lack of improvement in transfection efficiency of the thiolated chitosan NPs is most likely due to its size increase and charge inversion relatively to chitosan. Therefore, for retinal cells, thiolated chitosan does not seem to constitute an efficient strategy for gene delivery. PMID:23833516

Beneficial aerodynamic effect of wing scales on the climbing flight of butterflies.

PubMed

Slegers, Nathan; Heilman, Michael; Cranford, Jacob; Lang, Amy; Yoder, John; Habegger, Maria Laura

2017-01-30

It is hypothesized that butterfly wing scale geometry and surface patterning may function to improve aerodynamic efficiency. In order to investigate this hypothesis, a method to measure butterfly flapping kinematics optically over long uninhibited flapping sequences was developed. Statistical results for the climbing flight flapping kinematics of 11 butterflies, based on a total of 236 individual flights, both with and without their wing scales, are presented. Results show, that for each of the 11 butterflies, the mean climbing efficiency decreased after scales were removed. Data was reduced to a single set of differences of climbing efficiency using are paired t-test. Results show a mean decrease in climbing efficiency of 32.2% occurred with a 95% confidence interval of 45.6%-18.8%. Similar analysis showed that the flapping amplitude decreased by 7% while the flapping frequency did not show a significant difference. Results provide strong evidence that butterfly wing scale geometry and surface patterning improve butterfly climbing efficiency. The authors hypothesize that the wing scale's effect in measured climbing efficiency may be due to an improved aerodynamic efficiency of the butterfly and could similarly be used on flapping wing micro air vehicles to potentially achieve similar gains in efficiency.

Potential use and the energy conversion efficiency analysis of fermentation effluents from photo and dark fermentative bio-hydrogen production.

PubMed

Zhang, Zhiping; Li, Yameng; Zhang, Huan; He, Chao; Zhang, Quanguo

2017-12-01

Effluent of bio-hydrogen production system also can be adopted to produce methane for further fermentation, cogeneration of hydrogen and methane will significantly improve the energy conversion efficiency. Platanus Orientalis leaves were taken as the raw material for photo- and dark-fermentation bio-hydrogen production. The resulting concentrations of acetic, butyric, and propionic acids and ethanol in the photo- and dark-fermentation effluents were 2966mg/L and 624mg/L, 422mg/L and 1624mg/L, 1365mg/L and 558mg/L, and 866mg/L and 1352mg/L, respectively. Subsequently, we calculated the energy conversion efficiency according to the organic contents of the effluents and their energy output when used as raw material for methane production. The overall energy conversion efficiencies increased by 15.17% and 22.28%, respectively, when using the effluents of photo and dark fermentation. This two-step bio-hydrogen and methane production system can significantly improve the energy conversion efficiency of anaerobic biological treatment plants. Copyright © 2017. Published by Elsevier Ltd.

Polymer-Polymer Förster Resonance Energy Transfer Significantly Boosts the Power Conversion Efficiency of Bulk-Heterojunction Solar Cells.

PubMed

Gupta, Vinay; Bharti, Vishal; Kumar, Mahesh; Chand, Suresh; Heeger, Alan J

2015-08-01

Optically resonant donor polymers can exploit a wider range of the solar spectrum effectively without a complicated tandem design in an organic solar cell. Ultrafast Förster resonance energy transfer (FRET) in a polymer-polymer system that significantly improves the power conversion efficiency in bulk heterojunction polymer solar cells from 6.8% to 8.9% is demonstrated, thus paving the way to achieving 15% efficient solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A multi-environmental study of recent breeding progress on nitrogen use efficiency in wheat (Triticum aestivum L.).

PubMed

Cormier, Fabien; Faure, Sébastien; Dubreuil, Pierre; Heumez, Emmanuel; Beauchêne, Katia; Lafarge, Stéphane; Praud, Sébastien; Le Gouis, Jacques

2013-12-01

By comparing 195 varieties in eight trials, this study assesses nitrogen use efficiency improvement in high and low nitrogen conditions in European winter wheat over the last 25 years. In a context where European agriculture practices have to deal with environmental concerns and nitrogen (N) fertiliser cost, nitrogen use efficiency (NUE) has to be improved. This study assessed genetic progress in winter wheat (Triticum aestivum L.) NUE. Two hundred and twenty-five European elite varieties were tested in four environments under two levels of N. Global genetic progress was assessed on additive genetic values and on genotype × N interaction, covering 25 years of European breeding. To avoid sampling bias, quality, precocity and plant height were added as covariates in the analyses when needed. Genotype × environment interactions were highly significant for all the traits studied to such an extent that no additive genetic effect was detected on N uptake. Genotype × N interactions were significant for yield, grain protein content (GPC), N concentration in straw, N utilisation, and NUE. Grain yield improvement (+0.45 % year(-1)) was independent of the N treatment. GPC was stable, thus grain nitrogen yield was improved (+0.39 % year(-1)). Genetic progress on N harvest index (+0.12 % year(-1)) and on N concentration in straw (-0.52 % year(-1)) possibly revealed improvement in N remobilisation. There has been an improvement of NUE additive genetic value (+0.33 % year(-1)) linked to better N utilisation (+0.20 % year(-1)). Improved yield stability was detected as a significant improvement of NUE in low compared to high N conditions. The application of these results to breeding programs is discussed.

Effects of simultaneous and optimized sequential cardiac resynchronization therapy on myocardial oxidative metabolism and efficiency.

PubMed

Christenson, Stuart D; Chareonthaitawee, Panithaya; Burnes, John E; Hill, Michael R S; Kemp, Brad J; Khandheria, Bijoy K; Hayes, David L; Gibbons, Raymond J

2008-02-01

Cardiac resynchronization therapy (CRT) can improve left ventricular (LV) hemodynamics and function. Recent data suggest the energy cost of such improvement is favorable. The effects of sequential CRT on myocardial oxidative metabolism (MVO(2)) and efficiency have not been previously assessed. Eight patients with NYHA class III heart failure were studied 196 +/- 180 days after CRT implant. Dynamic [(11)C]acetate positron emission tomography (PET) and echocardiography were performed after 1 hour of: 1) AAI pacing, 2) simultaneous CRT, and 3) sequential CRT. MVO(2) was calculated using the monoexponential clearance rate of [(11)C]acetate (k(mono)). Myocardial efficiency was expressed in terms of the work metabolic index (WMI). P values represent overall significance from repeated measures analysis. Global LV and right ventricular (RV) MVO(2) were not significantly different between pacing modes, but the septal/lateral MVO(2) ratio differed significantly with the change in pacing mode (AAI pacing = 0.696 +/- 0.094 min(-1), simultaneous CRT = 0.975 +/- 0.143 min(-1), and sequential CRT = 0.938 +/- 0.189 min(-1); overall P = 0.001). Stroke volume index (SVI) (AAI pacing = 26.7 +/- 10.4 mL/m(2), simultaneous CRT = 30.6 +/- 11.2 mL/m(2), sequential CRT = 33.5 +/- 12.2 mL/m(2); overall P < 0.001) and WMI (AAI pacing = 3.29 +/- 1.34 mmHg*mL/m(2)*10(6), simultaneous CRT = 4.29 +/- 1.72 mmHg*mL/m(2)*10(6), sequential CRT = 4.79 +/- 1.92 mmHg*mL/m(2)*10(6); overall P = 0.002) also differed between pacing modes. Compared with simultaneous CRT, additional changes in septal/lateral MVO(2), SVI, and WMI with sequential CRT were not statistically significant on post hoc analysis. In this small selected population, CRT increases LV SVI without increasing MVO(2), resulting in improved myocardial efficiency. Additional improvements in LV work, oxidative metabolism, and efficiency from simultaneous to sequential CRT were not significant.

CH3NH3I post-treatment improves the performance of perovskite solar cells via eliminating the impure phases

NASA Astrophysics Data System (ADS)

Liang, Jingjing; Liang, Chunjun; Zhang, Huimin; Sun, Mengjie; Liu, Hong; Ji, Chao; Zhang, Xuewen; Li, Dan; He, Zhiqun

Organic-inorganic halide perovskites are currently generating extensive interest for applications in solar cells. The perovskite morphology and composition have significant roles in solar cells. Impure phases, which will influence the performance of solar cells, are inevitably present in the film of perovskite. We found that another MAI deposition on the previous perovskite could ameliorate the film. The post-deposited MAI participates in the reconstruction of the perovskite, leading to reduced amount of impure phase, increased grain size, increased absorption and significantly improved power conversion efficiency. The results demonstrate a treatment approach to fabricate efficient planar heterojunction perovskite solar cells.

Cash efficiency for bank branches.

PubMed

Cabello, Julia García

2013-01-01

Bank liquidity management has become a major issue during the financial crisis as liquidity shortages have intensified and have put pressure on banks to diversity and improve their liquidity sources. While a significant strand of the literature concentrates on wholesale liquidity generation and on the alternative to deposit funding, the management of an inventory of cash holdings within the banks' branches is also a relevant issue as any significant improvement in cash management at the bank distribution channels may have a positive effect in reducing liquidity tensions. In this paper, we propose a simple programme of cash efficiency for the banks' branches, very easy to implement, which conform to a set of instructions to be imposed from the bank to their branches. This model proves to significantly reduce cash holdings at branches thereby providing efficiency improvements in liquidity management. The methodology we propose is based on the definition of some stochastic processes combined with renewal processes, which capture the random elements of the cash flow, before applying suitable optimization programmes to all the costs involved in cash movements. The classical issue of the Transaction Demand for the Cash and some aspects of Inventory Theory are also present. Mathematics Subject Classification (2000) C02, C60, E50.

[Effects of a non-face-to-face behavioral intervention on poor sleepers and factors affecting improvement of sleep].

PubMed

Amamoto, Yuko; Adachi, Yoshiko; Kunituka, Kouko; Kumagai, Shuzo

2010-03-01

The purposes of this study were 1) to re-examine effects obtained from previous research of a non-face-to-face behavioral intervention in poorer sleepers and 2) to examine the factors impacting on improvement of sleep. The subjects were 178 poor sleepers who participated in an intervention for sleep improvement. The educational procedures comprised a minimal behavioral self-help package for one month that featured self- learning and self- monitoring of practical target habits for change. It was non face-to-face program conducted by only one member of staff. Subjects were asked to answer a questionnaire before and after the intervention. To reexamine the effects of this program found in our previous research, 9 sleep indices, sleep quality, and sleep-related behaviors were compared between before and after intervention. The sleep indices were total sleep time, sleep onset latency, sleep efficiency etc. Subjects were divided into an improvement group (n = 63) and a non-improvement group (n = 115) using a cutoff value for average change in sleep onset latency and sleep efficiency. After comparison of sleep and behavior between the two groups, logistic regression analysis was conducted to select parameters affecting improvement with this program. Total sleep time was significantly increased from 5.7 h to 6.1 h, sleep onset time decreased 18 minutes, and sleep efficiency improved 5.6 points. With 8 of 9 sleep-related behaviors, the proportion of subjects having an undesirable habit significantly decreased. The mean total number of desirable habit' changes was 2.63 in the improvement group and significantly higher than the 2.06 in the non-improvement group. Logistic regression analysis demonstrated that large sleep onset latency at baseline and beginning of regular exercise significantly affected the improvement of sleep in the subjects, after adjusting for all other parameters. The effects revealed by our previous research were reconfirmed. It is suggested that this program is more useful for persons having severe sleep onset difficulties, and regular exercise is particularly important in improvement of sleep. It is possible that even simple behavioral intervention is feasible with many subjects to improve sleep and related habits in poor sleepers.

[Effects of ridge and furrow rain harvesting with supplemental irrigation on winter wheat photosynthetic characteristics, yield and water use efficiency in Guanzhong irrigation district].

PubMed

Zhang, Yu; Han, Qing-fang; Cheng, Xue-feng; Yang, Shan-shan; Jia, Zhi-kuan; Ding, Rui-xia; Ren, Xiao-long; Nie, Jun-feng

2015-05-01

A field experiment was conducted to determine the regulation of crop photosynthesis and output and water saving effect under ridge and furrow rain harvesting with supplemental irrigation in Guanzhong irrigation district. The experiment was set with 5 treatments with irrigation at returning green stage, and the widths of both ridge and furrow being 60 cm. T1, T2 and T3 were in the ridge and furrow rain harvesting planting pattern, with the irrigation volumes being 0, 375 and 750 m3 · hm(-2) respectively, T4 was flat planting with irrigation (border irrigation) of 750 m3 · hm(-2) and CK was flat planting without irrigation. Effects on winter wheat photosynthetic organs, photosynthetic rate, yield and water use efficiency, etc. were tested. The results showed that compared with T4, T1, T2 and T3 treatments increased the grain yield by 2.8%, 9.6% and 18.9%, improved the harvest index by 2.0% to 8.5%, advanced the flag leaf chlorophyll content by 41.9% to 64.4% significantly, and improved the 0-40 cm layer soil moisture content by 0.1%-4.6% during the whole growth period. Photosynthetic rates at the flowering and filling stages also increased by 22.3% to 54.2% and -4.3% to 67.2%, respectively. Total water use efficiencies (WUEy) were 17.9%, 10.4% and 15.4% higher than that of T4, and 69.3%, 58.6% and 65.7% higher than that of CK (P < 0.05), respectively, and enhanced precipitation utilization efficiency ( PUE ) by 94.3%-124.5% than CK. Leaf areas of T2 and T3 treatments at each growth stage were significantly higher than that of T4 and CK, irrigation water use efficiencies (IUE) were 119.1% and 18.8% higher than that of T4, respectively. Therefore, it was concluded that ridge and furrow rain harvesting cultivation could maintain higher grain yield than border irrigation without irrigation or with irrigation reduction by 50%. The utilization efficiency of irrigation water under the condition of irrigation reduction by 50% was improved significantly, and the ridge and furrow rain harvesting could significantly improve whole cropland water use efficiency in the year of less rainfall.

Improvement of density resolution in short-pulse hard x-ray radiographic imaging using detector stacks

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

Borm, B.; Gärtner, F.; Khaghani, D.

2016-09-15

We demonstrate that stacking several imaging plates (IPs) constitutes an easy method to increase hard x-ray detection efficiency. Used to record x-ray radiographic images produced by an intense-laser driven hard x-ray backlighter source, the IP stacks resulted in a significant improvement of the radiograph density resolution. We attribute this to the higher quantum efficiency of the combined detectors, leading to a reduced photon noise. Electron-photon transport simulations of the interaction processes in the detector reproduce the observed contrast improvement. Increasing the detection efficiency to enhance radiographic imaging capabilities is equally effective as increasing the x-ray source yield, e.g., by amore » larger drive laser energy.« less

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

NASA Astrophysics Data System (ADS)

Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

2013-11-01

This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

Irregular large-scale computed tomography on multiple graphics processors improves energy-efficiency metrics for industrial applications

NASA Astrophysics Data System (ADS)

Jimenez, Edward S.; Goodman, Eric L.; Park, Ryeojin; Orr, Laurel J.; Thompson, Kyle R.

2014-09-01

This paper will investigate energy-efficiency for various real-world industrial computed-tomography reconstruction algorithms, both CPU- and GPU-based implementations. This work shows that the energy required for a given reconstruction is based on performance and problem size. There are many ways to describe performance and energy efficiency, thus this work will investigate multiple metrics including performance-per-watt, energy-delay product, and energy consumption. This work found that irregular GPU-based approaches1 realized tremendous savings in energy consumption when compared to CPU implementations while also significantly improving the performance-per- watt and energy-delay product metrics. Additional energy savings and other metric improvement was realized on the GPU-based reconstructions by improving storage I/O by implementing a parallel MIMD-like modularization of the compute and I/O tasks.

Lubricant Formulations to Enhance Engine Efficiency in Modern Internal Combustion Engines

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

Cheng, Wai; Wong, Victor; Plumley, Michael

2017-04-19

The research program presented aimed to investigate, develop, and demonstrate low-friction, environmentally-friendly and commercially-feasible lubricant formulations that would significantly improve the mechanical efficiency of modern engines without incurring increased wear, emissions or deterioration of the emission-aftertreatment system.

Environmental sustainability of bioethanol produced from sweet sorghum stem on saline-alkali land.

PubMed

Wang, Mingxin; Pan, Xinxing; Xia, Xunfeng; Xi, Beidou; Wang, Lijun

2015-01-01

Life cycle assessment was conducted to evaluate the energy efficiency and environmental impacts of a bioethanol production system that uses sweet sorghum stem on saline-alkali land as feedstock. The system comprises a plant cultivation unit, a feedstock transport unit, and a bioethanol conversion unit, with 1000L of bioethanol as a functional unit. The net energy ratio is 3.84, and the net energy gain is 17.21MJ/L. Agrochemical production consumes 76.58% of the life cycle fossil energy. The category with the most significant impact on the environment is eutrophication, followed by acidification, fresh water aquatic ecotoxicity, human toxicity, and global warming. Allocation method, waste recycling approach, and soil salinity significantly influence the results. Using vinasse to produce pellet fuel for steam generation significantly improves energy efficiency and decreases negative environmental impacts. Promoting reasonable management practices to alleviate saline stress and increasing agrochemical utilization efficiency can further improve environmental sustainability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fabrication of Sb₂S₃ Hybrid Solar Cells Based on Embedded Photoelectrodes of Ag Nanowires-Au Nanoparticles Composite.

PubMed

Kim, Kang-Pil; Hwang, Dae-Kue; Woo, Sung-Ho; Kim, Dae-Hwan

2018-09-01

The Ag nanowire (NW) + Au nanoparticle (NP)-embedded TiO2 photoelectrodes were adopted for conventional planar TiO2-based Sb2S3 hybrid solar cells to improve the cell efficiency. Compared to conventional planar TiO2-based Sb2S3 hybrid solar cells, the Ag NW + Au NP/TiO2-based Sb2S3 hybrid solar cells exhibited an improvement of approximately 40% in the cell efficiency due to the significant increase in both Jsc and Voc. These enhanced Jsc and Voc were attributed to the increased surface area, charge-collection efficiency, and light absorption by embedding the Ag NWs + Au NPs composite. The Ag NW + Au NP/TiO2-based Sb2S3 hybrid solar cells showed the highest efficiency of 2.17%, demonstrating that the Ag NW + Au NP-embedded TiO2 photoelectrode was a suitable photoelectrode structure to improve the power conversion efficiency in the Sb2S3 hybrid solar cells.

Improving the sampling efficiency of Monte Carlo molecular simulations: an evolutionary approach

NASA Astrophysics Data System (ADS)

Leblanc, Benoit; Braunschweig, Bertrand; Toulhoat, Hervé; Lutton, Evelyne

We present a new approach in order to improve the convergence of Monte Carlo (MC) simulations of molecular systems belonging to complex energetic landscapes: the problem is redefined in terms of the dynamic allocation of MC move frequencies depending on their past efficiency, measured with respect to a relevant sampling criterion. We introduce various empirical criteria with the aim of accounting for the proper convergence in phase space sampling. The dynamic allocation is performed over parallel simulations by means of a new evolutionary algorithm involving 'immortal' individuals. The method is bench marked with respect to conventional procedures on a model for melt linear polyethylene. We record significant improvement in sampling efficiencies, thus in computational load, while the optimal sets of move frequencies are liable to allow interesting physical insights into the particular systems simulated. This last aspect should provide a new tool for designing more efficient new MC moves.

Final Report: Utilizing Alternative Fuel Ignition Properties to Improve SI and CI Engine Efficiency

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

Wooldridge, Margaret; Boehman, Andre; Lavoie, George

Experimental and modeling studies were completed to explore leveraging physical and chemical fuel properties for improved thermal efficiency of internal combustion engines. Fundamental studies of the ignition chemistry of ethanol and iso-octane blends and constant volume spray chamber studies of gasoline and diesel sprays supported the core research effort which used several reciprocating engine platforms. Single cylinder spark ignition (SI) engine studies were carried out to characterize the impact of ethanol/gasoline, syngas (H 2 and CO)/gasoline and other oxygenate/gasoline blends on engine performance. The results of the single-cylinder engine experiments and other data from the literature were used to trainmore » a GT Power model and to develop a knock criteria based on reaction chemistry. The models were used to interpret the experimental results and project future performance. Studies were also carried out using a state of the art, direct injection (DI) turbocharged multi- cylinder engine with piezo-actuated fuel injectors to demonstrate the promising spray and spark timing strategies from single-cylinder engine studies on the multi-cylinder engine. Key outcomes and conclusions of the studies were: 1. Efficiency benefits of ethanol and gasoline fuel blends were consistent and substantial (e.g. 5-8% absolute improvement in gross indicated thermal efficiency (GITE)). 2. The best ethanol/gasoline blend (based on maximum thermal efficiency) was determined by the engine hardware and limits based on component protection (e.g. peak in-cylinder pressure or maximum turbocharger inlet temperature) – and not by knock limits. Blends with <50% ethanol delivered significant thermal efficiency gains with conventional SI hardware while maintain good safety integrity to the engine hardware. 3. Other compositions of fuel blends including syngas (H 2 and CO) and other dilution strategies provided significant efficiency gains as well (e.g. 5% absolute improvement in ITE). 4. When the combination of engine and fuel system is not knock limited, multiple fuel injection events maintain thermal efficiency while improving engine-out emissions (e.g. CO, UHC, and particulate number).« less

Biasing anisotropic scattering kernels for deep-penetration Monte Carlo calculations

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

Carter, L.L.; Hendricks, J.S.

1983-01-01

The exponential transform is often used to improve the efficiency of deep-penetration Monte Carlo calculations. This technique is usually implemented by biasing the distance-to-collision kernel of the transport equation, but leaving the scattering kernel unchanged. Dwivedi obtained significant improvements in efficiency by biasing an isotropic scattering kernel as well as the distance-to-collision kernel. This idea is extended to anisotropic scattering, particularly the highly forward Klein-Nishina scattering of gamma rays.

Technical Quality of Complete Dentures: Influence on Masticatory Efficiency and Quality of Life.

PubMed

Tôrres, Ana Clara Soares Paiva; Maciel, Amanda de Queiroz; de Farias, Danielle Bezerra; de Medeiros, Annie Karoline Bezerra; Vieira, Flávia Patrícia Tavares Veras; Carreiro, Adriana da Fonte Porto

2017-11-09

To evaluate the effect of the technical quality of conventional complete dentures (CD) on masticatory efficiency and quality of life (QoL) of denture wearers during a 1-year follow-up. A prospective clinical trial with 32 edentulous patients (mean age of 60.2 years) wearing mandibular and maxillary dentures was conducted. All patients were evaluated wearing their preexisting dentures and after 3, 6, and 12 months postinsertion of new dentures. A reproducible method for objective evaluation of the technical quality of CDs was employed. Masticatory efficiency was evaluated by the colorimetric method using beads as artificial testing food. The oral health impact on patient QoL was measured using the OHIP-EDENT (Oral Health Impact Profile in Edentulous Adults) questionnaire. The nonparametric Wilcoxon test was applied to reveal any differences in technical quality between the preexisting and new dentures. The Friedman test was used to detect differences in masticatory efficiency and oral health impact on QoL. Spearman's correlation was applied to reveal correlation between the variables. Comparing preexisting and new dentures, significant improvement was found in technical quality between the dentures (p < 0.001). There was no statistically significant difference in masticatory efficiency. A significant decrease was found in the total OHIP-EDENT scores after denture replacement. A positive correlation was found between technical quality and OHIP in the new denture wearers (p = 0.011). According to the results of this study, denture quality significantly improved patients' oral health-related QoL; however, insertion of new dentures did not influence masticatory efficiency. © 2017 by the American College of Prosthodontists.

Widely Applicable n-Type Molecular Doping for Enhanced Photovoltaic Performance of All-Polymer Solar Cells.

PubMed

Xu, Yalong; Yuan, Jianyu; Sun, Jianxia; Zhang, Yannan; Ling, Xufeng; Wu, Haihua; Zhang, Guobing; Chen, Junmei; Wang, Yongjie; Ma, Wanli

2018-01-24

A widely applicable doping design for emerging nonfullerene solar cells would be an efficient strategy in order to further improve device photovoltaic performance. Herein, a family of compound TBAX (TBA= tetrabutylammonium, X = F, Cl, Br, or I, containing Lewis base anions are considered as efficient n-dopants for improving polymer-polymer solar cells (all-PSCs) performance. In all cases, significantly increased fill factor (FF) and slightly increased short-circuit current density (J sc ) are observed, leading to a best PCE of 7.0% for all-PSCs compared to that of 5.8% in undoped devices. The improvement may be attributed to interaction between different anions X - (X = F, Cl, Br, and I) in TBAX with the polymer acceptor. We reveal that adding TBAX at relatively low content does not have a significantly impact on blend morphology, while it can reduce the work function (WF) of the electron acceptor. We find this simple and solution processable n-type doping can efficiently restrain charge recombination in all-polymer solar cell devices, resulting in improved FF and J sc. More importantly, our findings may provide new protocles and insights using n-type molecular dopants in improving the performance of current polymer-polymer solar cells.

Efficiency of endoscopy units can be improved with use of discrete event simulation modeling.

PubMed

Sauer, Bryan G; Singh, Kanwar P; Wagner, Barry L; Vanden Hoek, Matthew S; Twilley, Katherine; Cohn, Steven M; Shami, Vanessa M; Wang, Andrew Y

2016-11-01

Background and study aims: The projected increased demand for health services obligates healthcare organizations to operate efficiently. Discrete event simulation (DES) is a modeling method that allows for optimization of systems through virtual testing of different configurations before implementation. The objective of this study was to identify strategies to improve the daily efficiencies of an endoscopy center with the use of DES. Methods: We built a DES model of a five procedure room endoscopy unit at a tertiary-care university medical center. After validating the baseline model, we tested alternate configurations to run the endoscopy suite and evaluated outcomes associated with each change. The main outcome measures included adequate number of preparation and recovery rooms, blocked inflow, delay times, blocked outflows, and patient cycle time. Results: Based on a sensitivity analysis, the adequate number of preparation rooms is eight and recovery rooms is nine for a five procedure room unit (total 3.4 preparation and recovery rooms per procedure room). Simple changes to procedure scheduling and patient arrival times led to a modest improvement in efficiency. Increasing the preparation/recovery rooms based on the sensitivity analysis led to significant improvements in efficiency. Conclusions: By applying tools such as DES, we can model changes in an environment with complex interactions and find ways to improve the medical care we provide. DES is applicable to any endoscopy unit and would be particularly valuable to those who are trying to improve on the efficiency of care and patient experience.

Efficiency of endoscopy units can be improved with use of discrete event simulation modeling

PubMed Central

Sauer, Bryan G.; Singh, Kanwar P.; Wagner, Barry L.; Vanden Hoek, Matthew S.; Twilley, Katherine; Cohn, Steven M.; Shami, Vanessa M.; Wang, Andrew Y.

2016-01-01

Background and study aims: The projected increased demand for health services obligates healthcare organizations to operate efficiently. Discrete event simulation (DES) is a modeling method that allows for optimization of systems through virtual testing of different configurations before implementation. The objective of this study was to identify strategies to improve the daily efficiencies of an endoscopy center with the use of DES. Methods: We built a DES model of a five procedure room endoscopy unit at a tertiary-care university medical center. After validating the baseline model, we tested alternate configurations to run the endoscopy suite and evaluated outcomes associated with each change. The main outcome measures included adequate number of preparation and recovery rooms, blocked inflow, delay times, blocked outflows, and patient cycle time. Results: Based on a sensitivity analysis, the adequate number of preparation rooms is eight and recovery rooms is nine for a five procedure room unit (total 3.4 preparation and recovery rooms per procedure room). Simple changes to procedure scheduling and patient arrival times led to a modest improvement in efficiency. Increasing the preparation/recovery rooms based on the sensitivity analysis led to significant improvements in efficiency. Conclusions: By applying tools such as DES, we can model changes in an environment with complex interactions and find ways to improve the medical care we provide. DES is applicable to any endoscopy unit and would be particularly valuable to those who are trying to improve on the efficiency of care and patient experience. PMID:27853739

The Economic Efficiency of European Football Clubs--Data Envelopment Analysis (DEA) Approach

ERIC Educational Resources Information Center

Pyatunin, Aleksey V.; Vishnyakova, Angelina B.; Sherstneva, Natalia L.; Mironova, Svetlana P.; Dneprov, Sergey A.; Grabozdin, Yuriy P.

2016-01-01

The relevance of this paper lies in the fact that football business has grown significantly in the past 20 years and football clubs have become large companies, which in an effort to be profitable and successful on the field need to improve the efficiency of their business. The aim of this article is to measure economic efficiency of 48 big…

Training directionally selective motion pathways can significantly improve reading efficiency

NASA Astrophysics Data System (ADS)

Lawton, Teri

2004-06-01

This study examined whether perceptual learning at early levels of visual processing would facilitate learning at higher levels of processing. This was examined by determining whether training the motion pathways by practicing leftright movement discrimination, as found previously, would improve the reading skills of inefficient readers significantly more than another computer game, a word discrimination game, or the reading program offered by the school. This controlled validation study found that practicing left-right movement discrimination 5-10 minutes twice a week (rapidly) for 15 weeks doubled reading fluency, and significantly improved all reading skills by more than one grade level, whereas inefficient readers in the control groups barely improved on these reading skills. In contrast to previous studies of perceptual learning, these experiments show that perceptual learning of direction discrimination significantly improved reading skills determined at higher levels of cognitive processing, thereby being generalized to a new task. The deficits in reading performance and attentional focus experienced by the person who struggles when reading are suggested to result from an information overload, resulting from timing deficits in the direction-selectivity network proposed by Russell De Valois et al. (2000), that following practice on direction discrimination goes away. This study found that practicing direction discrimination rapidly transitions the inefficient 7-year-old reader to an efficient reader.

Reducing Vehicle Weight and Improving U.S. Energy Efficiency Using Integrated Computational Materials Engineering

NASA Astrophysics Data System (ADS)

Joost, William J.

2012-09-01

Transportation accounts for approximately 28% of U.S. energy consumption with the majority of transportation energy derived from petroleum sources. Many technologies such as vehicle electrification, advanced combustion, and advanced fuels can reduce transportation energy consumption by improving the efficiency of cars and trucks. Lightweight materials are another important technology that can improve passenger vehicle fuel efficiency by 6-8% for each 10% reduction in weight while also making electric and alternative vehicles more competitive. Despite the opportunities for improved efficiency, widespread deployment of lightweight materials for automotive structures is hampered by technology gaps most often associated with performance, manufacturability, and cost. In this report, the impact of reduced vehicle weight on energy efficiency is discussed with a particular emphasis on quantitative relationships determined by several researchers. The most promising lightweight materials systems are described along with a brief review of the most significant technical barriers to their implementation. For each material system, the development of accurate material models is critical to support simulation-intensive processing and structural design for vehicles; improved models also contribute to an integrated computational materials engineering (ICME) approach for addressing technical barriers and accelerating deployment. The value of computational techniques is described by considering recent ICME and computational materials science success stories with an emphasis on applying problem-specific methods.

Industrial Energy Audit Guidebook: Guidelines for Conducting an Energy Audit in Industrial Facilities

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

Hasanbeigi, Ali; Price, Lynn

Various studies in different countries have shown that significant energy-efficiency improvement opportunities exist in the industrial sector, many of which are cost-effective. These energy-efficiency options include both cross-cutting as well as sector-specific measures. However, industrial plants are not always aware of energy-efficiency improvement potentials. Conducting an energy audit is one of the first steps in identifying these potentials. Even so, many plants do not have the capacity to conduct an effective energy audit. In some countries, government policies and programs aim to assist industry to improve competitiveness through increased energy efficiency. However, usually only limited technical and financial resources formore » improving energy efficiency are available, especially for small and medium-sized enterprises. Information on energy auditing and practices should, therefore, be prepared and disseminated to industrial plants. This guidebook provides guidelines for energy auditors regarding the key elements for preparing for an energy audit, conducting an inventory and measuring energy use, analyzing energy bills, benchmarking, analyzing energy use patterns, identifying energy-efficiency opportunities, conducting cost-benefit analysis, preparing energy audit reports, and undertaking post-audit activities. The purpose of this guidebook is to assist energy auditors and engineers in the plant to conduct a well-structured and effective energy audit.« less

Improving Plant Nitrogen Use Efficiency through Alteration of Amino Acid Transport Processes1[OPEN

PubMed Central

Perchlik, Molly

2017-01-01

Improving the efficiency of nitrogen (N) uptake and utilization in plants could potentially increase crop yields while reducing N fertilization and, subsequently, environmental pollution. Within most plants, N is transported primarily as amino acids. In this study, pea (Pisum sativum) plants overexpressing AMINO ACID PERMEASE1 (AAP1) were used to determine if and how genetic manipulation of amino acid transport from source to sink affects plant N use efficiency. The modified plants were grown under low, moderate, or high N fertilization regimes. The results showed that, independent of the N nutrition, the engineered plants allocate more N via the vasculature to the shoot and seeds and produce more biomass and higher seed yields than wild-type plants. Dependent on the amount of N supplied, the AAP1-overexpressing plants displayed improved N uptake or utilization efficiency, or a combination of the two. They also showed significantly increased N use efficiency in N-deficient as well as in N-rich soils and, impressively, required half the amount of N to produce as many fruits and seeds as control plants. Together, these data support that engineering N allocation from source to sink presents an effective strategy to produce crop plants with improved productivity as well as N use efficiency in a range of N environments. PMID:28733388

Cognitive Load Theory vs. Constructivist Approaches: Which Best Leads to Efficient, Deep Learning?

ERIC Educational Resources Information Center

Vogel-Walcutt, J. J.; Gebrim, J. B.; Bowers, C.; Carper, T. M.; Nicholson, D.

2011-01-01

Computer-assisted learning, in the form of simulation-based training, is heavily focused upon by the military. Because computer-based learning offers highly portable, reusable, and cost-efficient training options, the military has dedicated significant resources to the investigation of instructional strategies that improve learning efficiency…

Improving the Efficiency of Dialogue in Tutoring

ERIC Educational Resources Information Center

Kopp, Kristopher J.; Britt, M. Anne; Millis, Keith; Graesser, Arthur C.

2012-01-01

The current studies investigated the efficient use of dialogue in intelligent tutoring systems that use natural language interaction. Such dialogues can be relatively time-consuming. This work addresses the question of how much dialogue is needed to produce significant learning gains. In Experiment 1, a full dialogue condition and a read-only…

Considerably improved photovoltaic performance of carbon nanotube-based solar cells using metal oxide layers.

PubMed

Wang, Feijiu; Kozawa, Daichi; Miyauchi, Yuhei; Hiraoka, Kazushi; Mouri, Shinichiro; Ohno, Yutaka; Matsuda, Kazunari

2015-02-18

Carbon nanotube-based solar cells have been extensively studied from the perspective of potential application. Here we demonstrated a significant improvement of the carbon nanotube solar cells by the use of metal oxide layers for efficient carrier transport. The metal oxides also serve as an antireflection layer and an efficient carrier dopant, leading to a reduction in the loss of the incident solar light and an increase in the photocurrent, respectively. As a consequence, the photovoltaic performance of both p-single-walled carbon nanotube (SWNT)/n-Si and n-SWNT/p-Si heterojunction solar cells using MoOx and ZnO layers is improved, resulting in very high photovoltaic conversion efficiencies of 17.0 and 4.0%, respectively. These findings regarding the use of metal oxides as multifunctional layers suggest that metal oxide layers could improve the performance of various electronic devices based on carbon nanotubes.

[TSA improve transgenic porcine cloned embryo development and transgene expression].

PubMed

Kong, Qing-Ran; Zhu, Jiang; Huang, Bo; Huan, Yan-Jun; Wang, Feng; Shi, Yong-Qian; Liu, Zhong-Feng; Wu, Mei-Ling; Liu, Zhong-Hua

2011-07-01

Uncompleted epigenetic reprogramming is attributed to the low efficiency of producing transgenic cloned animals. Histone modification associated with epigenetics can directly influence the embryo development and transgene expression. Trichostatin A (TSA), as an inhibitor of histone deacetylase, can change the status of histone acetylation, improve somatic cell reprogramming, and enhance cloning efficiency. TSA prevents the chromatin structure from being condensed, so that transcription factor could binds to DNA sequence easily and enhance transgene expression. Our study established the optimal TSA treatment on porcine donor cells and cloned embryos, 250 nmol/L, 24 h and 40 nmol/L, 24 h, respectively. Furthermore, we found that both the cloned embryo and the donor cell treated by TSA resulted in the highest development efficiency. Meanwhile, TSA can improve transgene expression in donor cell and cloned embryo. In summary, TSA can significantly improve porcine reconstructed embryo development and transgene expression.

Considerably improved photovoltaic performance of carbon nanotube-based solar cells using metal oxide layers

NASA Astrophysics Data System (ADS)

Wang, Feijiu; Kozawa, Daichi; Miyauchi, Yuhei; Hiraoka, Kazushi; Mouri, Shinichiro; Ohno, Yutaka; Matsuda, Kazunari

2015-02-01

Carbon nanotube-based solar cells have been extensively studied from the perspective of potential application. Here we demonstrated a significant improvement of the carbon nanotube solar cells by the use of metal oxide layers for efficient carrier transport. The metal oxides also serve as an antireflection layer and an efficient carrier dopant, leading to a reduction in the loss of the incident solar light and an increase in the photocurrent, respectively. As a consequence, the photovoltaic performance of both p-single-walled carbon nanotube (SWNT)/n-Si and n-SWNT/p-Si heterojunction solar cells using MoOx and ZnO layers is improved, resulting in very high photovoltaic conversion efficiencies of 17.0 and 4.0%, respectively. These findings regarding the use of metal oxides as multifunctional layers suggest that metal oxide layers could improve the performance of various electronic devices based on carbon nanotubes.

Development of a 402.5 MHz 140 kW Inductive Output Tube

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

R. Lawrence Ives; Michael Read, Robert Jackson

2012-05-09

This report contains the results of Phase I of an SBIR to develop a Pulsed Inductive Output Tube (IOT) with 140 kW at 400 MHz for powering H-proton beams. A number of sources, including single beam and multiple beam klystrons, can provide this power, but the IOT provides higher efficiency. Efficiencies exceeding 70% are routinely achieved. The gain is typically limited to approximately 24 dB; however, the availability of highly efficient, solid state drivers reduces the significance of this limitation, particularly at lower frequencies. This program initially focused on developing a 402 MHz IOT; however, the DOE requirement for thismore » device was terminated during the program. The SBIR effort was refocused on improving the IOT design codes to more accurately simulate the time dependent behavior of the input cavity, electron gun, output cavity, and collector. Significant improvement was achieved in modeling capability and simulation accuracy.« less

An optimal routing strategy on scale-free networks

NASA Astrophysics Data System (ADS)

Yang, Yibo; Zhao, Honglin; Ma, Jinlong; Qi, Zhaohui; Zhao, Yongbin

Traffic is one of the most fundamental dynamical processes in networked systems. With the traditional shortest path routing (SPR) protocol, traffic congestion is likely to occur on the hub nodes on scale-free networks. In this paper, we propose an improved optimal routing (IOR) strategy which is based on the betweenness centrality and the degree centrality of nodes in the scale-free networks. With the proposed strategy, the routing paths can accurately bypass hub nodes in the network to enhance the transport efficiency. Simulation results show that the traffic capacity as well as some other indexes reflecting transportation efficiency are further improved with the IOR strategy. Owing to the significantly improved traffic performance, this study is helpful to design more efficient routing strategies in communication or transportation systems.

Eco-efficiency improvements in industrial water-service systems: assessing options with stakeholders.

PubMed

Levidow, Les; Lindgaard-Jørgensen, Palle; Nilsson, Asa; Skenhall, Sara Alongi; Assimacopoulos, Dionysis

2014-01-01

The well-known eco-efficiency concept helps to assess the economic value and resource burdens of potential improvements by comparison with the baseline situation. But eco-efficiency assessments have generally focused on a specific site, while neglecting wider effects, for example, through interactions between water users and wastewater treatment (WWT) providers. To address the methodological gap, the EcoWater project has developed a method and online tools for meso-level analysis of the entire water-service value chain. This study investigated improvement options in two large manufacturing companies which have significant potential for eco-efficiency gains. They have been considering investment in extra processes which can lower resource burdens from inputs and wastewater, as well as internalising WWT processes. In developing its methodology, the EcoWater project obtained the necessary information from many agents, involved them in the meso-level assessment and facilitated their discussion on alternative options. Prior discussions with stakeholders stimulated their attendance at a workshop to discuss a comparative eco-efficiency assessment for whole-system improvement. Stakeholders expressed interest in jointly extending the EcoWater method to more options and in discussing investment strategies. In such ways, optimal solutions will depend on stakeholders overcoming fragmentation by sharing responsibility and knowledge.

Applying Lean principles and Kaizen rapid improvement events in public health practice.

PubMed

Smith, Gene; Poteat-Godwin, Annah; Harrison, Lisa Macon; Randolph, Greg D

2012-01-01

This case study describes a local home health and hospice agency's effort to implement Lean principles and Kaizen methodology as a rapid improvement approach to quality improvement. The agency created a cross-functional team, followed Lean Kaizen methodology, and made significant improvements in scheduling time for home health nurses that resulted in reduced operational costs, improved working conditions, and multiple organizational efficiencies.

Artificial Intelligence in Medicine and Radiation Oncology

PubMed Central

Weidlich, Vincent

2018-01-01

Artifical Intelligence (AI) was reviewed with a focus on its potential applicability to radiation oncology. The improvement of process efficiencies and the prevention of errors were found to be the most significant contributions of AI to radiation oncology. It was found that the prevention of errors is most effective when data transfer processes were automated and operational decisions were based on logical or learned evaluations by the system. It was concluded that AI could greatly improve the efficiency and accuracy of radiation oncology operations. PMID:29904616

Artificial Intelligence in Medicine and Radiation Oncology.

PubMed

Weidlich, Vincent; Weidlich, Georg A

2018-04-13

Artifical Intelligence (AI) was reviewed with a focus on its potential applicability to radiation oncology. The improvement of process efficiencies and the prevention of errors were found to be the most significant contributions of AI to radiation oncology. It was found that the prevention of errors is most effective when data transfer processes were automated and operational decisions were based on logical or learned evaluations by the system. It was concluded that AI could greatly improve the efficiency and accuracy of radiation oncology operations.

Coapplication of Chicken Litter Biochar and Urea Only to Improve Nutrients Use Efficiency and Yield of Oryza sativa L. Cultivation on a Tropical Acid Soil

PubMed Central

Maru, Ali; Haruna, Osumanu Ahmed; Charles Primus, Walter

2015-01-01

The excessive use of nitrogen (N) fertilizers in sustaining high rice yields due to N dynamics in tropical acid soils not only is economically unsustainable but also causes environmental pollution. The objective of this study was to coapply biochar and urea to improve soil chemical properties and productivity of rice. Biochar (5 t ha−1) and different rates of urea (100%, 75%, 50%, 25%, and 0% of recommended N application) were evaluated in both pot and field trials. Selected soil chemical properties, rice plants growth variables, nutrient use efficiency, and yield were determined using standard procedures. Coapplication of biochar with 100% and 75% urea recommendation rates significantly increased nutrients availability (especially P and K) and their use efficiency in both pot and field trials. These treatments also significantly increased rice growth variables and grain yield. Coapplication of biochar and urea application at 75% of the recommended rate can be used to improve soil chemical properties and productivity and reduce urea use by 25%. PMID:26273698

Impact of lean six sigma process improvement methodology on cardiac catheterization laboratory efficiency.

PubMed

Agarwal, Shikhar; Gallo, Justin J; Parashar, Akhil; Agarwal, Kanika K; Ellis, Stephen G; Khot, Umesh N; Spooner, Robin; Murat Tuzcu, Emin; Kapadia, Samir R

2016-03-01

Operational inefficiencies are ubiquitous in several healthcare processes. To improve the operational efficiency of our catheterization laboratory (Cath Lab), we implemented a lean six sigma process improvement initiative, starting in June 2010. We aimed to study the impact of lean six sigma implementation on improving the efficiency and the patient throughput in our Cath Lab. All elective and urgent cardiac catheterization procedures including diagnostic coronary angiography, percutaneous coronary interventions, structural interventions and peripheral interventions performed between June 2009 and December 2012 were included in the study. Performance metrics utilized for analysis included turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start and manual sheath-pulls inside the Cath Lab. After implementation of lean six sigma in the Cath Lab, we observed a significant improvement in turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. The percentage of cases with optimal turn-time increased from 43.6% in 2009 to 56.6% in 2012 (p-trend<0.001). Similarly, the percentage of cases with an aggregate on-time start increased from 41.7% in 2009 to 62.8% in 2012 (p-trend<0.001). In addition, the percentage of manual sheath-pulls performed in the Cath Lab decreased from 60.7% in 2009 to 22.7% in 2012 (p-trend<0.001). The current longitudinal study illustrates the impact of successful implementation of a well-known process improvement initiative, lean six sigma, on improving and sustaining efficiency of our Cath Lab operation. After the successful implementation of this continuous quality improvement initiative, there was a significant improvement in the selected performance metrics namely turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. Copyright © 2016 Elsevier Inc. All rights reserved.

Advanced Power Electronics Components

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2004-01-01

This paper will give a description and status of the Advanced Power Electronics Materials and Components Technology program being conducted by the NASA Glenn Research Center for future aerospace power applications. The focus of this research program is on the following: 1) New and/or significantly improved dielectric materials for the development of power capacitors with increased volumetric efficiency, energy density, and operating temperature. Materials being investigated include nanocrystalline and composite ceramic dielectrics and diamond-like carbon films; 2) New and/or significantly improved high frequency, high temperature, low loss soft magnetic materials for the development of transformers/inductors with increased power/energy density, electrical efficiency, and operating temperature. Materials being investigated include nanocrystalline and nanocomposite soft magnetic materials; 3) Packaged high temperature, high power density, high voltage, and low loss SiC diodes and switches. Development of high quality 4H- and 6H- SiC atomically smooth substrates to significantly improve device performance is a major emphasis of the SiC materials program; 4) Demonstration of high temperature (> 200 C) circuits using the components developed above.

Options to improve energy efficiency for educational building

NASA Astrophysics Data System (ADS)

Jahan, Mafruha

The cost of energy is a major factor that must be considered for educational facility budget planning purpose. The analysis of energy related issues and options can be complex and requires significant time and detailed effort. One way to facilitate the inclusion of energy option planning in facility planning efforts is to utilize a tool that allows for quick appraisal of the facility energy profile. Once such an appraisal is accomplished, it is then possible to rank energy improvement options consistently with other facility needs and requirements. After an energy efficiency option has been determined to have meaningful value in comparison with other facility planning options, it is then possible to utilize the initial appraisal as the basis for an expanded consideration of additional facility and energy use detail using the same analytic system used for the initial appraisal. This thesis has developed a methodology and an associated analytic model to assist in these tasks and thereby improve the energy efficiency of educational facilities. A detailed energy efficiency and analysis tool is described that utilizes specific university building characteristics such as size, architecture, envelop, lighting, occupancy, thermal design which allows reducing the annual energy consumption. Improving the energy efficiency of various aspects of an educational building's energy performance can be complex and can require significant time and experience to make decisions. The approach developed in this thesis initially assesses the energy design for a university building. This initial appraisal is intended to assist administrators in assessing the potential value of energy efficiency options for their particular facility. Subsequently this scoping design can then be extended as another stage of the model by local facility or planning personnel to add more details and engineering aspects to the initial screening model. This approach can assist university planning efforts to identify the most cost effective combinations of energy efficiency strategies. The model analyzes and compares the payback periods of all proposed Energy Performance Measures (EPMs) to determine which has the greatest potential value.

Design of spur gears for improved efficiency

NASA Technical Reports Server (NTRS)

Anderson, N. E.; Loewenthal, S. H.

1981-01-01

A method to calculate spur gear system power loss for a wide range of gear geometries and operating conditions is used to determine design requirements for an efficient gearset. The effects of spur gear size, pitch, ratio, pitch-line-velocity and load on efficiency are shown. A design example is given to illustrate how the method is to be applied. In general, peak efficiencies were found to be greater for larger diameter and fine pitched gears and tare (no-load) losses were found to be significant.

Photosynthesis, Light Use Efficiency, and Yield of Reduced-Chlorophyll Soybean Mutants in Field Conditions.

PubMed

Slattery, Rebecca A; VanLoocke, Andy; Bernacchi, Carl J; Zhu, Xin-Guang; Ort, Donald R

2017-01-01

Reducing chlorophyll (chl) content may improve the conversion efficiency of absorbed photosynthetically active radiation into biomass and therefore yield in dense monoculture crops by improving light penetration and distribution within the canopy. The effects of reduced chl on leaf and canopy photosynthesis and photosynthetic efficiency were studied in two reportedly robust reduced-chl soybean mutants, Y11y11 and y9y9 , in comparison to the wild-type (WT) "Clark" cultivar. Both mutants were characterized during the 2012 growing season whereas only the Y11y11 mutant was characterized during the 2013 growing season. Chl deficiency led to greater rates of leaf-level photosynthesis per absorbed photon early in the growing season when mutant chl content was ∼35% of the WT, but there was no effect on photosynthesis later in the season when mutant leaf chl approached 50% of the WT. Transient benefits of reduced chl at the leaf level did not translate to improvements in canopy-level processes. Reduced pigmentation in these mutants was linked to lower water use efficiency, which may have dampened any photosynthetic benefits of reduced chl, especially since both growing seasons experienced significant drought conditions. These results, while not confirming our hypothesis or an earlier published study in which the Y11y11 mutant significantly outyielded the WT, do demonstrate that soybean significantly overinvests in chl. Despite a >50% chl reduction, there was little negative impact on biomass accumulation or yield, and the small negative effects present were likely due to pleiotropic effects of the mutation. This outcome points to an opportunity to reinvest nitrogen and energy resources that would otherwise be used in pigment-proteins into increasing biochemical photosynthetic capacity, thereby improving canopy photosynthesis and biomass production.

Photosynthesis, Light Use Efficiency, and Yield of Reduced-Chlorophyll Soybean Mutants in Field Conditions

PubMed Central

Slattery, Rebecca A.; VanLoocke, Andy; Bernacchi, Carl J.; Zhu, Xin-Guang; Ort, Donald R.

2017-01-01

Reducing chlorophyll (chl) content may improve the conversion efficiency of absorbed photosynthetically active radiation into biomass and therefore yield in dense monoculture crops by improving light penetration and distribution within the canopy. The effects of reduced chl on leaf and canopy photosynthesis and photosynthetic efficiency were studied in two reportedly robust reduced-chl soybean mutants, Y11y11 and y9y9, in comparison to the wild-type (WT) “Clark” cultivar. Both mutants were characterized during the 2012 growing season whereas only the Y11y11 mutant was characterized during the 2013 growing season. Chl deficiency led to greater rates of leaf-level photosynthesis per absorbed photon early in the growing season when mutant chl content was ∼35% of the WT, but there was no effect on photosynthesis later in the season when mutant leaf chl approached 50% of the WT. Transient benefits of reduced chl at the leaf level did not translate to improvements in canopy-level processes. Reduced pigmentation in these mutants was linked to lower water use efficiency, which may have dampened any photosynthetic benefits of reduced chl, especially since both growing seasons experienced significant drought conditions. These results, while not confirming our hypothesis or an earlier published study in which the Y11y11 mutant significantly outyielded the WT, do demonstrate that soybean significantly overinvests in chl. Despite a >50% chl reduction, there was little negative impact on biomass accumulation or yield, and the small negative effects present were likely due to pleiotropic effects of the mutation. This outcome points to an opportunity to reinvest nitrogen and energy resources that would otherwise be used in pigment-proteins into increasing biochemical photosynthetic capacity, thereby improving canopy photosynthesis and biomass production. PMID:28458677

Effects of noninvasive ventilation on sleep outcomes in amyotrophic lateral sclerosis.

PubMed

Katzberg, Hans D; Selegiman, Adam; Guion, Lee; Yuan, Nancy; Cho, Sungho C; Katz, Jonathan S; Miller, Robert G; So, Yuen T

2013-04-15

The objective was to study the effects on noninvasive ventilation on sleep outcomes in patient with ALS, specifically oxygenation and overall sleep quality. Patients with ALS who met criteria for initiation of NIV were studied with a series of 2 home PSG studies, one without NIV and a follow-up study while using NIV. Primary outcome was a change in the maximum overnight oxygen saturation; secondary outcomes included change in mean overnight oxygen saturation, apnea and hypopnea indexes, sleep latency, sleep efficiency, sleep arousals, and sleep architecture. A total of 94 patients with ALS were screened for eligibility; 15 were enrolled; and 12 completed study procedures. Maximum overnight oxygen saturation improved by 7.0% (p = 0.01) and by 6.7% during REM sleep (p = 0.02) with NIV. Time spent below 90% oxygen saturation was also significant-ly better with NIV (30% vs 19%, p < 0.01), and there was trend for improvement in mean overnight saturation (1.5%, p = 0.06). Apnea index (3.7 to 0.7), hypopnea index (6.2 to 5.7), and apnea hypopnea index (9.8 to 6.3) did not significantly improve after introducing NIV. NIV had no effect on sleep efficiency (mean change 10%), arousal index (7 to 12), or sleep stage distribution (Friedman chi-squared = 0.40). NIV improved oxygenation but showed no significant effects on sleep efficiency, sleep arousals, restful sleep, or sleep architecture. The net impact of these changes for patients deserves further study in a larger group of ALS patients.

Engagement with the auditory processing system during targeted auditory cognitive training mediates changes in cognitive outcomes in individuals with schizophrenia

PubMed Central

Biagianti, Bruno; Fisher, Melissa; Neilands, Torsten B.; Loewy, Rachel; Vinogradov, Sophia

2016-01-01

BACKGROUND Individuals with schizophrenia who engage in targeted cognitive training (TCT) of the auditory system show generalized cognitive improvements. The high degree of variability in cognitive gains maybe due to individual differences in the level of engagement of the underlying neural system target. METHODS 131 individuals with schizophrenia underwent 40 hours of TCT. We identified target engagement of auditory system processing efficiency by modeling subject-specific trajectories of auditory processing speed (APS) over time. Lowess analysis, mixed models repeated measures analysis, and latent growth curve modeling were used to examine whether APS trajectories were moderated by age and illness duration, and mediated improvements in cognitive outcome measures. RESULTS We observed signifcant improvements in APS from baseline to 20 hours of training (initial change), followed by a flat APS trajectory (plateau) at subsequent time-points. Participants showed inter-individual variability in the steepness of the initial APS change and in the APS plateau achieved and sustained between 20–40 hours. We found that participants who achieved the fastest APS plateau, showed the greatest transfer effects to untrained cognitive domains. CONCLUSIONS There is a significant association between an individual's ability to generate and sustain auditory processing efficiency and their degree of cognitive improvement after TCT, independent of baseline neurocognition. APS plateau may therefore represent a behavioral measure of target engagement mediating treatment response. Future studies should examine the optimal plateau of auditory processing efficiency required to induce significant cognitive improvements, in the context of inter-individual differences in neural plasticity and sensory system efficiency that characterize schizophrenia. PMID:27617637

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.

Accelerating Improvements in the Energy Efficiency of Room Air Conditioners (RACs) in India: Potential, Cost-Benefit, and Policies (Interim Assessment)

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

Abhyankar, Nikit; Shah, Nihar; Park, Won Young

Falling AC prices, increasing incomes, increasing urbanization, and high cooling requirements due to hot climate are all driving increasing uptake of Room Air Conditioners (RACs) in the Indian market. Air conditioning already comprises 40-60% of summer peak load in large metropolitan Indian cities such as Delhi and is likely to contribute 150 GW to the peak demand in 2030. Standards and labeling policies have contributed to improving the efficiency of RACs in India by about 2.5% in the last 10 years (2.5% per year) while inflation adjusted RAC prices have continued to decline. In this paper, we assess the technicalmore » feasibility, cost-benefit, and required policy enhancements by further accelerating the efficiency improvement of RACs in India. We find that there are examples of significantly more accelerated improvements such as those in Japan and Korea where AC efficiency improved by more than 7% per year resulting in almost a doubling of energy efficiency in 7 to 10 years while inflation adjusted AC prices continued to decline. We find that the most efficient RAC sold on the Indian market is almost twice as efficient as the typical AC sold on the market and hence see no technology constraints in a similar acceleration of improvement of efficiency. If starting 2018, AC efficiency improves at a rate of 6% instead of 3%, 40-60 GW of peak load (equivalent to connected load of 5-6 billion LED bulbs), and over 75 TWh/yr (equivalent to 60 million consumers consuming 100 kWh/month) will be saved by 2030; total peak load reduction would be as high as 50 GW. The net present value (NPV) of the consumer benefit between 2018-2030 will range from Rs 18,000 Cr in the most conservative case (in which prices don’t continue to decline and increase based estimates of today’s cost of efficiency improvement) to 140,000 Cr in a more realistic case (in which prices are not affected by accelerated efficiency improvement as shown by historical experience). This benefit is achievable by ratcheting up the 1 star level for fixed and inverter ACs to the level of today’s five star rating for inverter ACs by 2022. Bulk procurement (similar to the Domestic Efficient Lighting Program) and incentive programs can complement the accelerated ratcheting up of star levels. Similar programs can also be implemented for other types of ACs.« less

Enhanced conversion efficiency in Si solar cells employing photoluminescent down-shifting CdSe/CdS core/shell quantum dots.

PubMed

Lopez-Delgado, R; Zhou, Y; Zazueta-Raynaud, A; Zhao, H; Pelayo, J E; Vomiero, A; Álvarez-Ramos, M E; Rosei, F; Ayon, A

2017-10-26

Silicon solar cells have captured a large portion of the total market of photovoltaic devices mostly due to their relatively high efficiency. However, Silicon exhibits limitations in ultraviolet absorption because high-energy photons are absorbed at the surface of the solar cell, in the heavily doped region, and the photo-generated electron-hole pairs need to diffuse into the junction region, resulting in significant carrier recombination. One of the alternatives to improve the absorption range involves the use of down-shifting nano-structures able to interact with the aforementioned high energy photons. Here, as a proof of concept, we use downshifting CdSe/CdS quantum dots to improve the performance of a silicon solar cell. The incorporation of these nanostructures triggered improvements in the short circuit current density (J sc , from 32.5 to 37.0 mA/cm 2 ). This improvement led to a ∼13% increase in the power conversion efficiency (PCE), from 12.0 to 13.5%. Our results demonstrate that the application of down-shifting materials is a viable strategy to improve the efficiency of Silicon solar cells with mass-compatible techniques that could serve to promote their widespread utilization.

Improving health and energy efficiency through community-based housing interventions.

PubMed

Howden-Chapman, Philippa; Crane, Julian; Chapman, Ralph; Fougere, Geoff

2011-12-01

Houses designed for one climate and cultural group may not be appropriate for other places and people. Our aim is to find cost-effective ways to improve the characteristics of older homes, ill-fitted for New Zealand's climate, in order to improve the occupants' health. We have carried out two community randomised trials, in partnership with local communities, which have focused on retrofitted insulation and more effective heating and have two other studies under way, one which focuses on electricity vouchers and the other on housing hazard remediation. The Housing, Insulation and Health Study showed that insulating 1,350 houses, built before insulation was required, improved the occupants' health and well being as well as household energy efficiency. In the Housing, Heating and Health Study we investigated the impact of installing more effective heating in insulated houses for 409 households, where there was a child with doctor-diagnosed asthma. Again, the study showed significant results in the intervention group; indoor temperatures increased and levels of NO(2) were halved. Children reported less poor health, lower levels of asthma symptoms and sleep disturbances by wheeze and dry cough. Children also had fewer days off school. Improving the energy efficiency of older housing leads to health improvements and energy efficiency improvements. Multidisciplinary studies of housing interventions can create compelling evidence to support policies for sustainable housing developments which improve health.

Genetic variation in transpiration efficiency and relationships between whole plant and leaf gas exchange measurements in Saccharum spp. and related germplasm.

PubMed

Jackson, Phillip; Basnayake, Jaya; Inman-Bamber, Geoff; Lakshmanan, Prakash; Natarajan, Sijesh; Stokes, Chris

2016-02-01

Fifty-one genotypes of sugarcane (Saccharum spp.) or closely related germplasm were evaluated in a pot experiment to examine genetic variation in transpiration efficiency. Significant variation in whole plant transpiration efficiency was observed, with the difference between lowest and highest genotypes being about 40% of the mean. Leaf gas exchange measurements were made across a wide range of conditions. There was significant genetic variation in intrinsic transpiration efficiency at a leaf level as measured by leaf internal CO2 (Ci) levels. Significant genetic variation in Ci was also observed within subsets of data representing narrow ranges of stomatal conductance. Ci had a low broad sense heritability (Hb = 0.11) on the basis of single measurements made at particular dates, because of high error variation and genotype × date interaction, but broad sense heritability for mean Ci across all dates was high (Hb = 0.81) because of the large number of measurements taken at different dates. Ci levels among genotypes at mid-range levels of conductance had a strong genetic correlation (-0.92 ± 0.30) with whole plant transpiration efficiency but genetic correlations between Ci and whole plant transpiration efficiency were weaker or not significant at higher and lower levels of conductance. Reduced Ci levels at any given level of conductance may result in improved yields in water-limited environments without trade-offs in rates of water use and growth. Targeted selection and improvement of lowered Ci per unit conductance via breeding may provide longer-term benefits for water-limited environments but the challenge will be to identify a low-cost screening methodology. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

ZnO/ZnSxSe1-x core/shell nanowire arrays as photoelectrodes with efficient visible light absorption

NASA Astrophysics Data System (ADS)

Wang, Zhenxing; Zhan, Xueying; Wang, Yajun; Safdar, Muhammad; Niu, Mutong; Zhang, Jinping; Huang, Ying; He, Jun

2012-08-01

ZnO/ZnSxSe1-x core/shell nanowires have been synthesized on n+-type silicon substrate via a two-step chemical vapor deposition method. Transmission electron microscopy reveals that ZnSxSe1-x can be deposited on the entire surface of ZnO nanowire, forming coaxial heterojunction along ZnO nanowire with very smooth shell surface and high shell thickness uniformity. The photoelectrode after deposition of the ternary alloy shell significantly improves visible light absorption efficiency. Electrochemical impedance spectroscopy results explicitly indicate that the introduction of ZnSxSe1-x shell to ZnO nanowires effectively improves the photogenerated charge separation process. Our finding opens up an efficient means for achieving high efficient energy conversion devices.

Trends in Department of Defense hospital efficiency.

PubMed

Ozcan, Y A; Bannick, R R

1994-04-01

This study employs a simple cross sectional design using longitudinal data to explore the underlying factors associated with differences in hospital technical efficiency using data envelopment analysis (DEA) in the Department of Defense (DOD) sector across three service components, the Army, Air Force and Navy. The results suggest that the services do not differ significantly in hospital efficiency. Nor does hospital efficiency appear to differ over time. With respect to the efficient use of input resources, the services experienced a general decline in excessive usage of various inputs over the three years. Analysis of the returns to scale captures opportunities for planners of changing the relative mix of output to input slacks for increasing a hospital's efficiency. That is, policy makers would get more immediate "bang per buck" with emphasis on improving the efficiencies of hospitals with higher returns to scale than other hospitals. Findings also suggest a significant degree of comparability between the DEA measure and these measures often used to indicate efficiency.

Wideband piezoelectric energy harvester for low-frequency application with plucking mechanism

NASA Astrophysics Data System (ADS)

Hiraki, Yasuhiro; Masuda, Arata; Ikeda, Naoto; Katsumura, Hidenori; Kagata, Hiroshi; Okumura, Hidenori

2015-04-01

Wireless sensor networks need energy harvesting from vibrational environment for their power supply. The conventional resonance type vibration energy harvesters, however, are not always effective for low frequency application. The purpose of this paper is to propose a high efficiency energy harvester for low frequency application by utilizing plucking and SSHI techniques, and to investigate the effects of applying those techniques in terms of the energy harvesting efficiency. First, we derived an approximate formulation of energy harvesting efficiency of the plucking device by theoretical analysis. Next, it was confirmed that the improved efficiency agreed with numerical and experimental results. Also, a parallel SSHI, a switching circuit technique to improve the performance of the harvester was introduced and examined by numerical simulations and experiments. Contrary to the simulated results in which the efficiency was improved from 13.1% to 22.6% by introducing the SSHI circuit, the efficiency obtained in the experiment was only 7.43%. This would due to the internal resistance of the inductors and photo MOS relays on the switching circuit and the simulation including this factor revealed large negative influence of it. This result suggested that the reduction of the switching resistance was significantly important to the implementation of SSHI.

Tuning Monotonic Basin Hopping: Improving the Efficiency of Stochastic Search as Applied to Low-Thrust Trajectory Optimization

NASA Technical Reports Server (NTRS)

Englander, Jacob; Englander, Arnold

2014-01-01

Trajectory optimization methods using MBH have become well developed during the past decade. An essential component of MBH is a controlled random search through the multi-dimensional space of possible solutions. Historically, the randomness has been generated by drawing RVs from a uniform probability distribution. Here, we investigate the generating the randomness by drawing the RVs from Cauchy and Pareto distributions, chosen because of their characteristic long tails. We demonstrate that using Cauchy distributions (as first suggested by Englander significantly improves MBH performance, and that Pareto distributions provide even greater improvements. Improved performance is defined in terms of efficiency and robustness, where efficiency is finding better solutions in less time, and robustness is efficiency that is undiminished by (a) the boundary conditions and internal constraints of the optimization problem being solved, and (b) by variations in the parameters of the probability distribution. Robustness is important for achieving performance improvements that are not problem specific. In this work we show that the performance improvements are the result of how these long-tailed distributions enable MBH to search the solution space faster and more thoroughly. In developing this explanation, we use the concepts of sub-diffusive, normally-diffusive, and super-diffusive RWs originally developed in the field of statistical physics.

Thermodynamic analysis of performance improvement by reheat on the CO2 transcritical power cycle

NASA Astrophysics Data System (ADS)

Tuo, Hanfei

2012-06-01

The CO2 transcritical rankine power cycle has been widely investigated recently, because of its better temperature glide matching between sensible heat source and working fluid in vapor generator, and its desirable qualities, such as moderate critical point, little environment impact and low cost. A reheat CO2 transcritical power cycle with two stage expansion is presented to improve baseline cycle performance in this paper. Energy and exergy analysis are carried out to investigate effects of important parameters on cycle performance. The main results show that reheat cycle performance is sensitive to the variation of medium pressures and the optimum medium pressures exist for maximizing work output and thermal efficiency, respectively. Reheat cycle is compared to baseline cycle under the same conditions. More significant improvements by reheat are obtained at lower turbine inlet temperatures and larger high cycle pressure. Work output improvement is much higher than thermal efficiency improvement, because extra waste heat is required to reheat CO2. Based on second law analysis, exergy efficiency of reheat cycle is also higher than that of baseline cycle, because more useful work is converted from waste heat. Reheat with two stage expansion has great potential to improve thermal efficiency and especially net work output of a CO2 transcritical power cycle using a low-grade heat source.

Zinc-rich oysters as well as zinc-yeast- and astaxanthin-enriched food improved sleep efficiency and sleep onset in a randomized controlled trial of healthy individuals.

PubMed

Saito, Hitomi; Cherasse, Yoan; Suzuki, Rina; Mitarai, Makoto; Ueda, Fumitaka; Urade, Yoshihiro

2017-05-01

Zinc is an essential mineral that plays an important role in the body. We previously reported that orally feeding zinc-enriched yeast to mice induces nonrapid-eye-movement sleep. In addition, astaxanthin, an antioxidant abundant in seafood such as salmon and krill, is able to chelate minerals and may promote zinc absorption, which in return may also improve sleep. The purpose of our study was to examine the effect of zinc-rich and astaxanthin-containing food on sleep in humans. We conducted a randomized, double-blinded, placebo-controlled parallel group trial of 120 healthy subjects and recorded their night activity by actigraphy for 12 weeks. These subjects were divided into four groups: placebo, zinc-rich food, zinc-, and astaxanthin-rich food, and placebo supplemented with zinc-enriched yeast and astaxanthin oil. Compared with the placebo group, the zinc-rich food group efficiently decreased the time necessary to fall asleep and improved sleep efficiency, whereas the group that ingested zinc-enriched yeast and astaxanthin oil significantly improved the sleep onset latency. Actigraphic sleep monitoring demonstrated that eating zinc-rich food improved sleep onset latency as well as improved the sleep efficiency in healthy individuals. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low-Cost CdTe/Silicon Tandem Solar Cells

DOE PAGES

Tamboli, Adele C.; Bobela, David C.; Kanevce, Ana; ...

2017-09-06

Achieving higher photovoltaic efficiency in single-junction devices is becoming increasingly difficult, but tandem modules offer the possibility of significant efficiency improvements. By device modeling we show that four-terminal CdTe/Si tandem solar modules offer the prospect of 25%-30% module efficiency, and technoeconomic analysis predicts that these efficiency gains can be realized at costs per Watt that are competitive with CdTe and Si single junction alternatives. The cost per Watt of the modeled tandems is lower than crystalline silicon, but slightly higher than CdTe alone. But, these higher power modules reduce area-related balance of system costs, providing increased value especially in area-constrainedmore » applications. This avenue for high-efficiency photovoltaics enables improved performance on a near-term timeframe, as well as a path to further reduced levelized cost of electricity as module and cell processes continue to advance.« less

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

Zhou, Kun; Ikeda, Masao, E-mail: mikeda2013@sinano.ac.cn, E-mail: jpliu2010@sinano.ac.cn; Liu, Jianping, E-mail: mikeda2013@sinano.ac.cn, E-mail: jpliu2010@sinano.ac.cn

The efficiency droop of InGaN/GaN(InGaN) multiple quantum well (MQW) light emitting diodes (LEDs) with thin quantum barriers (QB) is studied. With thin GaN QB (3 nm–6 nm thickness), the efficiency droop is not improved, which indicates that hole transport cannot be significantly enhanced by the thin GaN QBs. On the contrary, the efficiency droop was remarkably reduced by using a InGaN staircase QB (InGaN SC-QB) MQWs structure where InGaN SC-QBs lower the transport energy barrier of holes. The efficiency droop ratio was as low as 3.3% up to 200 A/cm{sup 2} for the InGaN SC-QB LED. By using monitoring QW with longer wavelengthmore » we observe a much uniform carrier distribution in the InGaN SC-QB LEDs, which reveals the mechanism of improvement in the efficiency droop.« less

Low-Cost CdTe/Silicon Tandem Solar Cells

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

Tamboli, Adele C.; Bobela, David C.; Kanevce, Ana

Achieving higher photovoltaic efficiency in single-junction devices is becoming increasingly difficult, but tandem modules offer the possibility of significant efficiency improvements. By device modeling we show that four-terminal CdTe/Si tandem solar modules offer the prospect of 25%-30% module efficiency, and technoeconomic analysis predicts that these efficiency gains can be realized at costs per Watt that are competitive with CdTe and Si single junction alternatives. The cost per Watt of the modeled tandems is lower than crystalline silicon, but slightly higher than CdTe alone. But, these higher power modules reduce area-related balance of system costs, providing increased value especially in area-constrainedmore » applications. This avenue for high-efficiency photovoltaics enables improved performance on a near-term timeframe, as well as a path to further reduced levelized cost of electricity as module and cell processes continue to advance.« less

Effect of co-crystallization on singlet fission efficiency in pentacene derivatives

NASA Astrophysics Data System (ADS)

Wang, Xiaopeng; Sanders, Samuel; Campos, Luis; Sfeir, Matthew; Marom, Noa

Singlet fission (SF), the conversion of one singlet exciton into two triplet excitons, may lead to a twofold increase in the efficiency of organic photovoltaics. Since SF has been observed in crystalline pentacene, this material has drawn interest both experimentally and theoretically. Recently, it has been shown that SF efficiency in rubrene may be improved by modifying the crystal packing. Here, we study the effect of co-crystallization with small molecule H-bond donors on SF efficiency in pentacene derivatives. Five co-crystals are synthetized and their photoluminescence (PL) and absorption spectra are measured. First-principles calculations based on many-body perturbation theory (MBPT) are then employed to study their excitonic properties. By combining experiment and theory, we demonsrate that excitonic properties, including singlet-triplet gaps, exciton binding energies, and exciton localization, are significantly modulated in pentacene co-crystals. Consequently, co-crystallization becomes an effective strategy for improving SF efficiency in molecular crystals of organic semiconductors.

Role of irrigation and irrigation automation in improving crop water use efficiency

USDA-ARS?s Scientific Manuscript database

In arid climates, irrigation is required for significant agricultural production. In subhumid and semiarid climates, supplemental irrigation is recognized as both economically necessary (prevention of crop losses in periodic droughts) and as a means to improve overall crop water use effi...

Recent advances in SPE (tm) water electrolyzer

NASA Technical Reports Server (NTRS)

Mcelroy, James F.

1993-01-01

A new cell structure has been introduced into the SPE Water Electrolyzer which has improved overall characteristics significantly. Weight, reliability, and efficiency are the characteristics that are improved the most, with volume having a second order improvement. This paper discusses the capabilities of the new cell structure and the impact it would have in various space applications.

Extremely Low Roll-Off and High Efficiency Achieved by Strategic Exciton Management in Organic Light-Emitting Diodes with Simple Ultrathin Emitting Layer Structure.

PubMed

Zhang, Tianmu; Shi, Changsheng; Zhao, Chenyang; Wu, Zhongbin; Chen, Jiangshan; Xie, Zhiyuan; Ma, Dongge

2018-03-07

Phosphorescent organic light-emitting diodes (OLEDs) possess the property of high efficiency but have serious efficiency roll-off at high luminance. Herein, we manufactured high-efficiency phosphorescent OLEDs with extremely low roll-off by effectively locating the ultrathin emitting layer (UEML) away from the high-concentration exciton formation region. The strategic exciton management in this simple UEML architecture greatly suppressed the exciton annihilation due to the expansion of the exciton diffusion region; thus, this efficiency roll-off at high luminance was significantly improved. The resulting green phosphorescent OLEDs exhibited the maximum external quantum efficiency of 25.5%, current efficiency of 98.0 cd A -1 , and power efficiency of 85.4 lm W -1 and still had 25.1%, 94.9 cd A -1 , and 55.5 lm W -1 at 5000 cd m -2 luminance, and retained 24.3%, 92.7 cd A -1 , and 49.3 lm W -1 at 10 000 cd m -2 luminance, respectively. Compared with the usual structures, the improvement demonstrated in this work displays potential value in applications.

High-efficiency, radiation-resistant GaAs space cells

NASA Technical Reports Server (NTRS)

Bertness, K. A.; Ristow, M. Ladle; Grounner, M.; Kuryla, M. S.; Werthen, J. G.

1991-01-01

Although many GaAs solar cells are intended for space applicatons, few measurements of cell degradation after radiation are available, particularly for cells with efficiencies exceeding 20 percent (one-sun, AMO). Often the cell performance is optimized for the highest beginning-of-life (BOL) efficiency, despite the unknown effect of such design on end-of-life (EOL) efficiencies. The results of a study of the radiation effects on p-n GaAs cells are presented. The EOL efficiency of GaAs space cell can be increased by adjusting materials growth parameters, resulting in a demonstration of 16 percent EOL efficiency at one-sun, AMO. Reducing base doping levels to below 3 x 10(exp 17)/cu m and decreasing emitter thickness to 0.3 to 0.5 micron for p-n cells led to significant improvements in radiation hardness as measured by EOL/BOL efficiency ratios for irradiation of 10(exp -15)/sq cm electrons at 1 MeV. BOL efficiency was not affected by changes in emitter thickness but did improve with lower base doping.

Effect of the squid viscera hydrolysate on growth performance and digestion in the red sea bream Pagrus major.

PubMed

Kondo, Fumitaka; Ohta, Takashi; Iwai, Toshiharu; Ido, Atsushi; Miura, Chiemi; Miura, Takeshi

2017-12-01

The improvement in feed efficiency is one of the most important subjects in fish culture. The development of feed, in terms of good intake, high growth performance, and high feed efficiency is needed. Squid viscera are one of the candidates for alternative material in improving feed efficiency in fish culture. In the present study, we described the dietary effect of the squid viscera hydrolysate (SVH) on the growth performance of the red sea bream. The addition of SVH to feed caused significant increases in feed intake, fork length, and body weight and produced a marked improvement in feed conversion after 4 weeks of feeding. Furthermore, the results of this feeding revealed that low dietary levels of SVH promote growth performance in the red sea bream. We physiologically analyzed digestion and appetite in fish fed diet containing SVH. SVH promoted the activity of hepatic trypsin and lipase, gene expression of stomach pepsin, hepatic lipase, and pyloric caeca trypsin, thereby improving the nutrient availability in red sea bream. Moreover, the mRNA expression of appetite regulating factor, such as brain NPY and stomach ghrelin was significantly improved by dietary SVH. Our current results indicate that dietary SVH as alternative material produced excellent effects on growth performance, which is dependent on the promoting effect on digestion and appetite in red sea bream.

Cost-efficiency trade-off and the design of thermoelectric power generators.

PubMed

Yazawa, Kazuaki; Shakouri, Ali

2011-09-01

The energy conversion efficiency of today's thermoelectric generators is significantly lower than that of conventional mechanical engines. Almost all of the existing research is focused on materials to improve the conversion efficiency. Here we propose a general framework to study the cost-efficiency trade-off for thermoelectric power generation. A key factor is the optimization of thermoelectric modules together with their heat source and heat sinks. Full electrical and thermal co-optimization yield a simple analytical expression for optimum design. Based on this model, power output per unit mass can be maximized. We show that the fractional area coverage of thermoelectric elements in a module could play a significant role in reducing the cost of power generation systems.

Improved efficient routing strategy on two-layer complex networks

NASA Astrophysics Data System (ADS)

Ma, Jinlong; Han, Weizhan; Guo, Qing; Zhang, Shuai; Wang, Junfang; Wang, Zhihao

2016-10-01

The traffic dynamics of multi-layer networks has become a hot research topic since many networks are comprised of two or more layers of subnetworks. Due to its low traffic capacity, the traditional shortest path routing (SPR) protocol is susceptible to congestion on two-layer complex networks. In this paper, we propose an efficient routing strategy named improved global awareness routing (IGAR) strategy which is based on the betweenness centrality of nodes in the two layers. With the proposed strategy, the routing paths can bypass hub nodes of both layers to enhance the transport efficiency. Simulation results show that the IGAR strategy can bring much better traffic capacity than the SPR and the global awareness routing (GAR) strategies. Because of the significantly improved traffic performance, this study is helpful to alleviate congestion of the two-layer complex networks.

Efficient carbon dots/NiFe-layered double hydroxide/BiVO4 photoanodes for photoelectrochemical water splitting

NASA Astrophysics Data System (ADS)

Lv, Xiaowei; Xiao, Xin; Cao, Minglei; Bu, Yi; Wang, Chuanqing; Wang, Mingkui; Shen, Yan

2018-05-01

Modification of semiconductor photoanodes with oxygen evolution catalyst (OEC) is an effective approach for improving photoelectrochemical (PEC) water splitting efficiency. In the configuration, how to increase the activity of OEC is crucial to further improve PEC performance. Herein, a ternary photoanode system was designed to enhance PEC efficiency of photoelectrodes through introducing carbon dots (CDs), NiFe-layered double hydroxide (NiFe-LDH) nanosheets on BiVO4 particles. Systematic research shows that NiFe-LDH serves as an OEC which accelerates oxygen evolution kinetics, while the introduction of CDs can further reduce charge transfer resistance and overpotential for oxygen evolution. Under the synergistic effect of NiFe-LDH and CDs, the photocurrent and incident photon to current conversion efficiency (IPCE) of the resulting CDs/NiFe-LDH/BiVO4 photoanode is improved significantly than those of the NiFe-LDH/BiVO4 electrode. Consequently, such a ternary heterostructure could be an alternative way to further enhance PEC water splitting performance.

Study of relationships of material properties and high efficiency solar cell performance on material composition

NASA Technical Reports Server (NTRS)

Sah, C. T.

1983-01-01

The performance improvements obtainable from extending the traditionally thin back-surface-field (BSF) layer deep into the base of silicon solar cells under terrestrial solar illumination (AM1) are analyzed. This extended BSF cell is also known as the back-drift-field cell. About 100 silicon cells were analyzed, each with a different emitter or base dopant impurity distribution whose selection was based on physically anticipated improvements. The four principal performance parameters (the open-circuit voltage, the short-circuit current, the fill factor, and the maximum efficiency) are computed using a FORTRAN program, called Circuit Technique for Semiconductor-device Analysis, CTSA, which numerically solves the six Shockley Equations under AM1 solar illumination at 88.92 mW/cm, at an optimum cell thickness of 50 um. The results show that very significant performance improvements can be realized by extending the BSF layer thickness from 2 um (18% efficiency) to 40 um (20% efficiency).

Induction-heating MOCVD reactor with significantly improved heating efficiency and reduced harmful magnetic coupling

NASA Astrophysics Data System (ADS)

Li, Kuang-Hui; Alotaibi, Hamad S.; Sun, Haiding; Lin, Ronghui; Guo, Wenzhe; Torres-Castanedo, Carlos G.; Liu, Kaikai; Valdes-Galán, Sergio; Li, Xiaohang

2018-04-01

In a conventional induction-heating III-nitride metalorganic chemical vapor deposition (MOCVD) reactor, the induction coil is outside the chamber. Therefore, the magnetic field does not couple with the susceptor well, leading to compromised heating efficiency and harmful coupling with the gas inlet and thus possible overheating. Hence, the gas inlet has to be at a minimum distance away from the susceptor. Because of the elongated flow path, premature reactions can be more severe, particularly between Al- and B-containing precursors and NH3. Here, we propose a structure that can significantly improve the heating efficiency and allow the gas inlet to be closer to the susceptor. Specifically, the induction coil is designed to surround the vertical cylinder of a T-shaped susceptor comprising the cylinder and a top horizontal plate holding the wafer substrate within the reactor. Therefore, the cylinder coupled most magnetic field to serve as the thermal source for the plate. Furthermore, the plate can block and thus significantly reduce the uncoupled magnetic field above the susceptor, thereby allowing the gas inlet to be closer. The results show approximately 140% and 2.6 times increase in the heating and susceptor coupling efficiencies, respectively, as well as a 90% reduction in the harmful magnetic flux on the gas inlet.

Improved performance of organic light-emitting diodes with MoO3 interlayer by oblique angle deposition.

PubMed

Liu, S W; Divayana, Y; Sun, X W; Wang, Y; Leck, K S; Demir, H V

2011-02-28

We fabricated and demonstrated improved organic light emitting diodes (OLEDs) in a thin film architecture of indium tin oxide (ITO)/ molybdenum trioxide (MoO3) (20 nm)/N,N'-Di(naphth-2-yl)-N,N'-diphenyl-benzidine (NPB) (50 nm)/ tris-(8-hydroxyquinoline) (Alq3) (70 nm)/Mg:Ag (200 nm) using an oblique angle deposition technique by which MoO3 was deposited at oblique angles (θ) with respect to the surface normal. It was found that, without sacrificing the power efficiency of the device, the device current efficiency and external quantum efficiency were significantly enhanced at an oblique deposition angle of θ=60° for MoO3.

Root carboxylate exudation capacity under phosphorus stress does not improve grain yield in green gram.

PubMed

Pandey, Renu; Meena, Surendra Kumar; Krishnapriya, Vengavasi; Ahmad, Altaf; Kishora, Naval

2014-06-01

Genetic variability in carboxylate exudation capacity along with improved root traits was a key mechanism for P-efficient green gram genotype to cope with P-stress but it did not increase grain yield. This study evaluates genotypic variability in green gram for total root carbon exudation under low phosphorus (P) using (14)C and its relationship with root exuded carboxylates, growth and yield potential in contrasting genotypes. Forty-four genotypes grown hydroponically with low (2 μM) and sufficient (100 μM) P concentrations were exposed to (14)CO2 to screen for total root carbon exudation. Contrasting genotypes were employed to study carboxylate exudation and their performance in soil at two P levels. Based on relative (14)C exudation and biomass, genotypes were categorized. Carboxylic acids were measured in exudates and root apices of contrasting genotypes belonging to efficient and inefficient categories. Oxalic and citric acids were released into the medium under low-P. PDM-139 (efficient) was highly efficient in carboxylate exudation as compared to ML-818 (inefficient). In low soil P, the reduction in biomass was higher in ML-818 as compared to PDM-139. Total leaf area and photosynthetic rate averaged for genotypes increased by 71 and 41 %, respectively, with P fertilization. Significantly, higher root surface area and volume were observed in PDM-139 under low soil P. Though the grain yield was higher in ML-818, the total plant biomass was significantly higher in PDM-139 indicating improved P uptake and its efficient translation into biomass. The higher carboxylate exudation capacity and improved root traits in the later genotype might be the possible adaptive mechanisms to cope with P-stress. However, it is not necessary that higher root exudation would result in higher grain yield.

Improvement Photocatalytic Activity of P25 by Modification with a Rare Earth-Free Upconversion Nanocrystal.

PubMed

Yin, Dongguang; Liu, Yumin; Zhao, Feifei; Zhang, Xinyu; Zhang, Tingting; Wu, Chenglong; Chang, Na; Chen, Zhiwen

2018-05-01

It has been reported that coupling TiO2 with rare earth upconversion nanocrystals (UCNCs) is an efficient strategy to significantly improve photocatalytic activity of TiO2. However, the rare earth materials are scarcity and cost, and the synthesis process of UCNCs using the rare earth materials is complicated. In the present study, we have designed a new approach using a rare earth-free upconversion nanocrystal (REF-UCNCs) as upconversion luminescent material to replace the rare earth UCNCs. A novel nanocomposite photocatalyst of REF-UCNCs@P25: Mo/GN was developed for the first time. Based on the designed structure, the REF-UCNCs, Mo-doping, and GN (graphene) have a synergistic effect that can improve catalytic activity of P25 significantly. The results of photocatalytic experiments using RhB as a model pollutant under simulated solar light irradiation show that the photocatalytic efficiency of the as-prepared catalyst is 3-folds higher than that of benchmark substance P25. This work provides a new strategy for efficiently improving catalytic activity of semiconductor photocatalysts by coupling with REF-UCNCs. This approach is facile and low-cost which can be widely applied for modification of semiconductor photocatalysts and facilitates their applications in environmental protection issues using solar light.

Pt nanoparticles residing in the pores of porous LaNiO₃ nanocubes as high-efficiency electrocatalyst for direct methanol fuel cells.

PubMed

Yu, Nan; Kuai, Long; Wang, Qing; Geng, Baoyou

2012-09-07

Pt-filled porous LaNiO₃ cubes are prepared through a facile route. The characterizations reveal that large numbers of pores (9-10 nm) are distributed homogeneously in porous LaNiO₃ cubes. The Pt nanoparticles residing in the pores of porous LaNiO₃ cubes are about 5 nm in size. The investigation on the electrocatalytic activity reveals that electrocatalytic activity of the obtained Pt loaded porous LaNiO₃ nanocubes exhibit a significantly improved electrochemical active surface area (EASA) and a remarkably enhanced electrocatalytic performance toward methanol oxidation. The results are significant for improving the efficiency of Pt-based catalysts for DMFCs as well as the applications of perovskite compounds.

Low-temperature operation of a Buck DC/DC converter

NASA Technical Reports Server (NTRS)

Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

1995-01-01

Low-temperature (77 K) operation of a 42/28 V, 175 W, 50 kHz PWM Buck DC/DC converter designed with commercially available components is reported. Overall, the converter losses decreased at 77 K compared to room temperature operation. A full-load efficiency of 97 percent was recorded at liquid-nitrogen temperature, compared to 95.8 percent at room temperature. Power MOSFET operation improved significantly where as the output rectifier operation deteriorated at low-temperature. The performance of the output filter inductor and capacitor did not change significantly at 77 K compared to room temperature performance. It is possible to achieve high-density and high efficiency power conversion at low-temperatures due to improved electronic, electrical and thermal properties of materials.

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.

Metamorphic III–V Solar Cells: Recent Progress and Potential

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

Garcia, Ivan; France, Ryan M.; Geisz, John F.

Inverted metamorphic multijunction solar cells have been demonstrated to be a pathway to achieve the highest photovoltaic (PV) conversion efficiencies. Attaining high-quality lattice-mismatched (metamorphic) semiconductor devices is challenging. However, recent improvements to compositionally graded buffer epitaxy and junction structures have led to the achievement of high-quality metamorphic solar cells exhibiting internal luminescence efficiencies over 90%. For this high material quality, photon recycling is significant, and therefore, the optical environment of the solar cell becomes important. In this paper, we first present recent progress and performance results for 1- and 0.7-eV GaInAs solar cells grown on GaAs substrates. Then, an electroopticalmore » model is used to assess the potential performance improvements in current metamorphic solar cells under different realizable design scenarios. The results show that the quality of 1-eV subcells is such that further improving its electronic quality does not produce significant Voc increases in the four-junction inverted metamorphic subcells, unless a back reflector is used to enhance photon recycling, which would significantly complicate the structure. Conversely, improving the electronic quality of the 0.7-eV subcell would lead to significant Voc boosts, driving the progress of four-junction inverted metamorphic solar cells.« less

Effect of external applied electric field on the silicon solar cell's thermodynamic efficiency

NASA Astrophysics Data System (ADS)

Zieba Falama, R.; Mibaile, Justin; Guemene Dountio, E.; Djongyang, Noël; Doka, Serge Y.; Kofane, Timoleon C.

2017-03-01

This paper presents a possible solution to improve the efficiency of photovoltaic solar cells. An external electric field is applied on a silicon photovoltaic solar cell, inducing band-trap ionization of charge carriers. Output current is then monitored and the thermodynamic efficiency is calculated. Results show on the one hand a significant increase in efficiency for a certain margin of applied electric field, and on the another hand the instabilities of efficiency. A simple approach is then suggested for the implementation of these results. An efficiency of 67% has been reached for an applied electric of 1586 V/Cm.

Predictors of surgeons' efficiency in the operating rooms.

PubMed

Nakata, Yoshinori; Watanabe, Yuichi; Narimatsu, Hiroto; Yoshimura, Tatsuya; Otake, Hiroshi; Sawa, Tomohiro

2017-02-01

The sustainability of the Japanese healthcare system is questionable because of a huge fiscal debt. One of the solutions is to improve the efficiency of healthcare. The purpose of this study is to determine what factors are predictive of surgeons' efficiency scores. The authors collected data from all the surgical procedures performed at Teikyo University Hospital from April 1 through September 30 in 2013-2015. Output-oriented Charnes-Cooper-Rhodes model of data envelopment analysis was employed to calculate each surgeon's efficiency score. Seven independent variables that may predict their efficiency scores were selected: experience, medical school, surgical volume, gender, academic rank, surgical specialty, and the surgical fee schedule. Multiple regression analysis using random-effects Tobit model was used for our panel data. The data from total 8722 surgical cases were obtained in 18-month study period. The authors analyzed 134 surgeons. The only statistically significant coefficients were surgical specialty and surgical fee schedule (p = 0.000 and p = 0.016, respectively). Experience had some positive association with efficiency scores but did not reach statistical significance (p = 0.062). The other coefficients were not statistically significant. These results demonstrated that the surgical reimbursement system, not surgeons' personal characteristics, is a significant predictor of surgeons' efficiency.

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology

NASA Astrophysics Data System (ADS)

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium.

Radiation shielding evaluation of the BNCT treatment room at THOR: a TORT-coupled MCNP Monte Carlo simulation study.

PubMed

Chen, A Y; Liu, Y-W H; Sheu, R J

2008-01-01

This study investigates the radiation shielding design of the treatment room for boron neutron capture therapy at Tsing Hua Open-pool Reactor using "TORT-coupled MCNP" method. With this method, the computational efficiency is improved significantly by two to three orders of magnitude compared to the analog Monte Carlo MCNP calculation. This makes the calculation feasible using a single CPU in less than 1 day. Further optimization of the photon weight windows leads to additional 50-75% improvement in the overall computational efficiency.

[Ubiquitination of recombinant adeno-associated viral vector and its application].

PubMed

Wang, Qi-zhao; Lu, Ying-hui; Diao, Yong; Xu, Rui-an

2012-09-01

Recombinant adeno-associated virus (rAAV) has been widely used as vector for gene therapy. However, the effectiveness of gene therapy based on rAAV needs to be further improved. Enhancement of the transduction efficiency is one of the most important fields for rAAV-based gene therapy. Recent results have showed that the ubiquitin-proteasome system plays an important role in the trafficking of rAAV vector in cytoplasm, and regulation of its function may significantly improve the transduction efficiency of rAAV vector in various types of cells and tissues.

Improving Learning Performance Through Rational Resource Allocation

NASA Technical Reports Server (NTRS)

Gratch, J.; Chien, S.; DeJong, G.

1994-01-01

This article shows how rational analysis can be used to minimize learning cost for a general class of statistical learning problems. We discuss the factors that influence learning cost and show that the problem of efficient learning can be cast as a resource optimization problem. Solutions found in this way can be significantly more efficient than the best solutions that do not account for these factors. We introduce a heuristic learning algorithm that approximately solves this optimization problem and document its performance improvements on synthetic and real-world problems.

Nuclear techniques for the on-line bulk analysis of carbon in coal-fired power stations.

PubMed

Sowerby, B D

2009-09-01

Carbon trading schemes usually require large emitters of CO(2), such as coal-fired power stations, to monitor, report and be audited on their CO(2) emissions. The emission price provides a significant additional incentive for power stations to improve efficiency. In the present paper, previous work on the bulk determination of carbon in coal is reviewed and assessed. The most favourable method is that based on neutron inelastic scattering. The potential role of on-line carbon analysers in improving boiler efficiency and in carbon accounting is discussed.

Overview of CMC Development Activities in NASA's Ultra-Efficient Engine Technology (UEET) Program

NASA Technical Reports Server (NTRS)

Brewer, Dave

2001-01-01

The primary objective of the UEET (Ultra-Efficient Engine Technology) Program is to address two of the most critical propulsion issues: performance/efficiency and reduced emissions. High performance, low emissions engine systems will lead to significant improvement in local air quality, minimum impact on ozone depletion and level to an overall reduction in aviation contribution to global warming. The Materials and Structures for High Performance project will develop and demonstrate advanced high temperature materials to enable high-performance, high efficiency, and environmentally compatible propulsion systems.

Recovery Act: High-Efficiency, Wideband Three-Phase Rectifiers and Adaptive Rectifier Management for Telecomm Central Office and Large Data Center Applications

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

Mark A. Johnson

2012-06-29

Lineage Power and Verizon teamed up to address a DOE funding opportunity focused on improving the power conversion chain in telecommunications facilities and data centers. The project had three significant elements: the design and development of high efficiency and high power three-phase rectifiers by Lineage Power, design and development of software to optimize overall plant energy efficiency by Lineage Power, and a field trial in active Verizon telecommunications facilities where energy consumption was measured before and after efficiency upgrades.

Improving Efficiency and Quality of the Children's ASD Diagnostic Pathway: Lessons Learned from Practice

ERIC Educational Resources Information Center

Rutherford, Marion; Burns, Morag; Gray, Duncan; Bremner, Lynne; Clegg, Sarah; Russell, Lucy; Smith, Charlie; O'Hare, Anne

2018-01-01

The 'autism diagnosis crisis' and long waiting times for assessment are as yet unresolved, leading to undue stress and limiting access to effective support. There is therefore a significant need for evidence to support practitioners in the development of efficient services, delivering acceptable waiting times and effectively meeting guideline…

Potential for Increasing the Output of Existing Hydroelectric Plants.

DTIC Science & Technology

1981-06-01

existing units to higher generating capacity by rehabilitating, modifying or replacing turbines and/or generators; increasing the effective...loss in converting fluid energy (flow and head) to mechanical energy ( turbine output) to electrical energy (generator output). The significant practical...opportunity is improvement of the energy conversion efficiency of the hydraulic turbine since the energy conversion efficiency of electrical

Number and location of drainage catheter side holes: in vitro evaluation.

PubMed

Ballard, D H; Alexander, J S; Weisman, J A; Orchard, M A; Williams, J T; D'Agostino, H B

2015-09-01

To evaluate the influence of number and location of catheter shaft side holes regarding drainage efficiency in an in vitro model. Three different drainage catheter models were constructed: open-ended model with no side holes (one catheter), unilateral side hole model (six catheters with one to six unilateral side holes), and bilateral side hole model (six catheters with one to six bilateral side holes). Catheters were inserted into a drainage output-measuring device with a constant-pressure reservoir of water. The volume of water evacuated by each of the catheters at 10-second intervals was measured. A total of five trials were performed for each catheter. Data were analysed using one-way analysis of variance. The open-ended catheter had a mean drainage volume comparable to the unilateral model catheters with three, four, and five side holes. Unilateral model catheters had significant drainage volume increases up to three side holes; unilateral model catheters with more than three side holes had no significant improvement in drainage volume. All bilateral model catheters had significantly higher mean drainage volumes than their unilateral counterparts. There was no significant difference between the mean drainage volume with one, two, or three pairs of bilateral side holes. Further, there was no drainage improvement by adding additional bilateral side holes. The present in vitro study suggests that beyond a critical side hole number threshold, adding more distal side holes does not improve catheter drainage efficiency. These results may be used to enhance catheter design towards improving their drainage efficiency. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Betavoltaic Battery Conversion Efficiency Improvement Based on Interlayer Structures

NASA Astrophysics Data System (ADS)

Li, Da-Rang; Jiang, Lan; Yin, Jian-Hua; Tan, Yuan-Yuan; Lin, Nai

2012-07-01

Significant differences among the doping densities of PN junctions in semiconductors cause lattice mismatch and lattice defects that increase the recombination current of betavoltaic batteries. This extensively decreases the open circuit voltage and the short current, which results in low conversion efficiency. This study proposes P+PINN+-structure based betavoltaic batteries by adding an interlayer to typical PIN structures to improve conversion efficiency. Numerical simulations are conducted for the energy deposition of beta particles along the thickness direction in semiconductors. Based on this, 63Ni-radiation GaAs batteries with PIN and P+PINN+ structures are designed and fabricated to experimentally verify the proposed design. It turns out that the conversion efficiency of the betavoltaic battery with the proposed P+PINN+ structure is about 1.45 times higher than that with the traditional PIN structure.

The Fabrication of Bulk Heterojunction P3HT: PCBM Organic Photovoltaics

NASA Astrophysics Data System (ADS)

Darwis, D.; Sesa, E.; Farhamza, D.; Iqbal

2018-05-01

Bulk heterojunction Organic photovoltaic (OPV) devices are gaining a lot of interest due to their potential for ease of processing and lower manufacturing cost sustainable energy generation. In consequence, the number of studies into the properties and characteristics of organic solar cell devices has been increased to improving their power conversion. A further advancement over past decade has shown that improved efficiency could be obtained by mixed of poly(3 - hexylthiophene) (P3HT) and [1] – phenyl - C61-butyric acid methyl ester (PCBM) as an active layer. A series of optimizations of this P3HT: PCBM blends, such as the mixture ratio variation, the annealing treatments, and solvent treatment, have been emerged to improve the efficiency of the OPV. As a result, significant improvements were achieved. Here, we report the fabrication heterojunction devices of 2.9 % efficiency. This result has been achieved using the configuration of a typical heterojunction solar cell modules consists of layered glass/ITO/PEDOT: PSS/active layer/cathode interlayer

Stationary statistical theory of two-surface multipactor regarding all impacts for efficient threshold analysis

NASA Astrophysics Data System (ADS)

Lin, Shu; Wang, Rui; Xia, Ning; Li, Yongdong; Liu, Chunliang

2018-01-01

Statistical multipactor theories are critical prediction approaches for multipactor breakdown determination. However, these approaches still require a negotiation between the calculation efficiency and accuracy. This paper presents an improved stationary statistical theory for efficient threshold analysis of two-surface multipactor. A general integral equation over the distribution function of the electron emission phase with both the single-sided and double-sided impacts considered is formulated. The modeling results indicate that the improved stationary statistical theory can not only obtain equally good accuracy of multipactor threshold calculation as the nonstationary statistical theory, but also achieve high calculation efficiency concurrently. By using this improved stationary statistical theory, the total time consumption in calculating full multipactor susceptibility zones of parallel plates can be decreased by as much as a factor of four relative to the nonstationary statistical theory. It also shows that the effect of single-sided impacts is indispensable for accurate multipactor prediction of coaxial lines and also more significant for the high order multipactor. Finally, the influence of secondary emission yield (SEY) properties on the multipactor threshold is further investigated. It is observed that the first cross energy and the energy range between the first cross and the SEY maximum both play a significant role in determining the multipactor threshold, which agrees with the numerical simulation results in the literature.

Quantitative learning strategies based on word networks

NASA Astrophysics Data System (ADS)

Zhao, Yue-Tian-Yi; Jia, Zi-Yang; Tang, Yong; Xiong, Jason Jie; Zhang, Yi-Cheng

2018-02-01

Learning English requires a considerable effort, but the way that vocabulary is introduced in textbooks is not optimized for learning efficiency. With the increasing population of English learners, learning process optimization will have significant impact and improvement towards English learning and teaching. The recent developments of big data analysis and complex network science provide additional opportunities to design and further investigate the strategies in English learning. In this paper, quantitative English learning strategies based on word network and word usage information are proposed. The strategies integrate the words frequency with topological structural information. By analyzing the influence of connected learned words, the learning weights for the unlearned words and dynamically updating of the network are studied and analyzed. The results suggest that quantitative strategies significantly improve learning efficiency while maintaining effectiveness. Especially, the optimized-weight-first strategy and segmented strategies outperform other strategies. The results provide opportunities for researchers and practitioners to reconsider the way of English teaching and designing vocabularies quantitatively by balancing the efficiency and learning costs based on the word network.

“Wine-Dark Sea” in an Organic Flow Battery: Storing Negative Charge in 2,1,3-Benzothiadiazole Radicals Leads to Improved Cyclability

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

Duan, Wentao; Huang, Jinhua; Kowalski, Jeffrey A.

Redox-active organic materials (ROMs) have shown great promise for redox flow battery applications but generally encounter limited cycling efficiency and stability at relevant redox material concentrations in nonaqueous systems. Here we report a new heterocyclic organic anolyte molecule, 2,1,3-benzothiadiazole, that has high solubility, a low redox potential, and fast electrochemical kinetics. Coupling it with a benchmark catholyte ROM, the nonaqueous organic flow battery demonstrated significant improvement in cyclable redox material concentrations and cell efficiencies compared to the state-of-the-art nonaqueous systems. Especially, this system produced exceeding cyclability with relatively stable efficiencies and capacities at high ROM concentrations (>0.5 M), which ismore » ascribed to the highly delocalized charge densities in the radical anions of 2,1,3-benzothiadiazole, leading to good chemical stability. As a result, this material development represents significant progress toward promising next-generation energy storage.« less

Demonstrating a Conceptual Framework to Provide Efficient Wound Management Service for a Wound Care Center in a Tertiary Hospital.

PubMed

Chen, Yu-Tsung; Chang, Chang-Cheng; Shen, Jen-Hsiang; Lin, Wei-Nung; Chen, Mei-Yen

2015-11-01

Although the benefits of wound care services and multidisciplinary team care have been well elaborated on in the literature, there is a gap in the actual practice of wound care and the establishment of an efficient referral system. The conceptual framework for establishing efficient wound management services requires elucidation.A wound care center was established in a tertiary hospital in 2010, staffed by an integrated multidisciplinary team including plastic surgeons, a full-time coordinator, a physical therapist, occupational therapists, and other physician specialists. Referral patients were efficiently managed following a conceptual framework for wound care. This efficient wound management service consists of 3 steps: patient entry and onsite immediate wound debridement, wound re-evaluation, and individual wound bed preparation plan. Wound conditions were documented annually over 4 consecutive years.From January 2011 to December 2014, 1103 patients were recruited from outpatient clinics or inpatient consultations for the 3-step wound management service. Of these, 62% of patients achieved healing or improvement in wounds, 13% of patients experienced no change, and 25% of patients failed to follow-up. The outcome of wound treatment varied by wound type. Sixty-nine percent of diabetic foot ulcer patients were significantly healed or improved. In contrast, pressure ulcers were the most poorly healed wound type, with only 55% of patients achieving significantly healed or improved wounds.The 3-step wound management service in the wound care center efficiently provided onsite screening, timely debridement, and multidisciplinary team care. Patients could schedule appointments instead of waiting indefinitely for care. Further wound condition follow-up, education, and prevention were also continually provided.

High-Dose Neutron Detector Development Using 10B Coated Cells

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

Menlove, Howard Olsen; Henzlova, Daniela

2016-11-08

During FY16 the boron-lined parallel-plate technology was optimized to fully benefit from its fast timing characteristics in order to enhance its high count rate capability. To facilitate high count rate capability, a novel fast amplifier with timing and operating properties matched to the detector characteristics was developed and implemented in the 8” boron plate detector that was purchased from PDT. Each of the 6 sealed-cells was connected to a fast amplifier with corresponding List mode readout from each amplifier. The FY16 work focused on improvements in the boron-10 coating materials and procedures at PDT to significantly improve the neutron detectionmore » efficiency. An improvement in the efficiency of a factor of 1.5 was achieved without increasing the metal backing area for the boron coating. This improvement has allowed us to operate the detector in gamma-ray backgrounds that are four orders of magnitude higher than was previously possible while maintaining a relatively high counting efficiency for neutrons. This improvement in the gamma-ray rejection is a key factor in the development of the high dose neutron detector.« less

A hybrid fuzzy logic and extreme learning machine for improving efficiency of circulating water systems in power generation plant

NASA Astrophysics Data System (ADS)

Aziz, Nur Liyana Afiqah Abdul; Siah Yap, Keem; Afif Bunyamin, Muhammad

2013-06-01

This paper presents a new approach of the fault detection for improving efficiency of circulating water system (CWS) in a power generation plant using a hybrid Fuzzy Logic System (FLS) and Extreme Learning Machine (ELM) neural network. The FLS is a mathematical tool for calculating the uncertainties where precision and significance are applied in the real world. It is based on natural language which has the ability of "computing the word". The ELM is an extremely fast learning algorithm for neural network that can completed the training cycle in a very short time. By combining the FLS and ELM, new hybrid model, i.e., FLS-ELM is developed. The applicability of this proposed hybrid model is validated in fault detection in CWS which may help to improve overall efficiency of power generation plant, hence, consuming less natural recourses and producing less pollutions.

Polymer optical fiber compound parabolic concentrator tip for enhanced coupling efficiency for fluorescence based glucose sensors

PubMed Central

Hassan, Hafeez Ul; Nielsen, Kristian; Aasmul, Soren; Bang, Ole

2015-01-01

We demonstrate that the light excitation and capturing efficiency of fluorescence based fiber-optical sensors can be significantly increased by using a CPC (Compound Parabolic Concentrator) tip instead of the standard plane-cut tip. We use Zemax modelling to find the optimum CPC tip profile and fiber length of a polymer optical fiber diabetes sensor for continuous monitoring of glucose levels. We experimentally verify the improved performance of the CPC tipped sensor and the predicted production tolerances. Due to physical size requirements when the sensor has to be inserted into the body a non-optimal fiber length of 35 mm is chosen. For this length an average improvement in efficiency of a factor of 1.7 is experimentally demonstrated and critically compared to the predicted ideal factor of 3 in terms of parameters that should be improved through production optimization. PMID:26713213

Options for reducing carbon dioxide emissions

NASA Astrophysics Data System (ADS)

Rosenfeld, Arthur H.; Price, Lynn

1992-03-01

Improvements in energy efficiency can significantly reduce the annual growth in greenhouse gas emissions. Such improvements occur when energy intensity is reduced; no reduction in energy services is required. Using the concept of ``cost of conserved energy'' to develop conservation supply curves similar to resource supply curves, researchers consistently find that electricity and natural gas savings of nearly 50% of current consumption are possible for U.S. buildings. Such reductions in energy consumption directly reduce emissions of greenhouse gases. To capture these savings, we must continue to develop energy-efficient technologies and strategies. This paper describes three recent energy-efficient technologies that benefitted from energy conservation research and development (R&D) funding: high-frequency ballasts, compact fluorescent lamps, and low-emissivity windows. Other advanced technologies and strategies of spectrally selective windows, superwindows, electrochromic windows, advanced insulation, low-flow showerheads, improved recessed lamp fixtures, whitening surfaces and planting urban trees, daylighting, and thermal energy storage are also discussed.

Photocatalytic activity of Ti3+ self-doped dark TiO2 ultrafine nanorods, grey SiO2 nanotwin crystalline, and their composite under visible light

NASA Astrophysics Data System (ADS)

Zhang, Renhui; Yang, Yingchang; Leng, Senlin; Wang, Qing

2018-04-01

Efficient electron-holes separation is of crucial importance for the improvement of photocatalytic activity for photocatalytic reaction. In this work, dark TiO2 (D-TiO2) nanorods, grey SiO2 (G-SiO2) and D-TiO2/G-SiO2 composite with surface defects are synthesized. We report that the efficiency of photo-generated electrons and holes separation is well enhanced by introducing G-SiO2 into D-TiO2 lattice. Using first-principles method, we find that surface defects (O or Si vacancy) can be conducive to improving the optical absorption under visible-light region. Combination of the experimental results, for D-TiO2/G-SiO2 composite, the surface defects of TiO2 nanocrystallines can significantly improve the photocatalytic efficiency.

Wicket gate trailing-edge blowing: A method for improving off-design hydroturbine performance by adjusting the runner inlet swirl angle

NASA Astrophysics Data System (ADS)

Lewis, B. J.; Cimbala, J. M.; Wouden, A. M.

2014-03-01

At their best efficiency point (BEP), hydroturbines operate at very high efficiency. However, with the ever-increasing penetration of alternative electricity generation, it has become common to operate hydroturbines at off-design conditions in order to maintain stability in the electric power grid. This paper demonstrates a method for improving hydroturbine performance during off-design operation by injecting water through slots at the trailing edges of the wicket gates. The injected water causes a change in bulk flow direction at the inlet of the runner. This change in flow angle from the wicket gate trailing-edge jets provides the capability of independently varying the flow rate and swirl angle through the runner, which in current designs are both determined by the wicket gate opening angle. When properly tuned, altering the flow angle results in a significant improvement in turbine efficiency during off-design operation.

Polymer optical fiber compound parabolic concentrator tip for enhanced coupling efficiency for fluorescence based glucose sensors.

PubMed

Hassan, Hafeez Ul; Nielsen, Kristian; Aasmul, Soren; Bang, Ole

2015-12-01

We demonstrate that the light excitation and capturing efficiency of fluorescence based fiber-optical sensors can be significantly increased by using a CPC (Compound Parabolic Concentrator) tip instead of the standard plane-cut tip. We use Zemax modelling to find the optimum CPC tip profile and fiber length of a polymer optical fiber diabetes sensor for continuous monitoring of glucose levels. We experimentally verify the improved performance of the CPC tipped sensor and the predicted production tolerances. Due to physical size requirements when the sensor has to be inserted into the body a non-optimal fiber length of 35 mm is chosen. For this length an average improvement in efficiency of a factor of 1.7 is experimentally demonstrated and critically compared to the predicted ideal factor of 3 in terms of parameters that should be improved through production optimization.

Drive Cycle Powertrain Efficiencies and Trends Derived from EPA Vehicle Dynamometer Results

DOE PAGES

Thomas, John

2014-10-13

Vehicle manufacturers among others are putting great emphasis on improving fuel economy (FE) of light-duty vehicles in the U.S. market, with significant FE gains being realized in recent years. The U.S. Environmental Protection Agency (EPA) data indicates that the aggregate FE of vehicles produced for the U.S. market has improved by over 20% from model year (MY) 2005 to 2013. This steep climb in FE includes changes in vehicle choice, improvements in engine and transmission technology, and reducing aerodynamic drag, rolling resistance, and parasitic losses. The powertrain related improvements focus on optimizing in-use efficiency of the transmission and engine asmore » a system, and may make use of what is termed downsizing and/or downspeeding. This study explores quantifying recent improvements in powertrain efficiency, viewed separately from other vehicle alterations and attributes (noting that most vehicle changes are not completely independent). A methodology is outlined to estimate powertrain efficiency for the U.S city and highway cycle tests using data from the EPA vehicle database. Comparisons of common conventional gasoline powertrains for similar MY 2005 and 2013 vehicles are presented, along with results for late-model hybrid electric vehicles, the Nissan Leaf, Chevy Volt and other selected vehicles.« less

Transmission and Distribution Efficiency Improvement Rearch and Development Survey.

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

Brooks, C.L.; Westinghouse Electric Corporation. Advanced Systems Technology.

Purpose of this study was to identify and quantify those technologies for improving transmission and distribution (T and D) system efficiency that could provide the greatest benefits for utility customers in the Pacific Northwest. Improving the efficiency of transmission and distribution systems offers a potential source of conservation within the utility sector. An extensive review of this field resulted in a list of 49 state-of-the-art technologies and 39 future technologies. Of these, 15 from the former list and 7 from the latter were chosen as the most promising and then submitted to an evaluative test - a modeled sample systemmore » for Benton County PUD, a utility with characteristics typical of a BPA customer system. Reducing end-use voltage on secondary distribution systems to decrease the energy consumption of electrical users when possible, called ''Conservation Voltage Reduction,'' was found to be the most cost effective state-of-the-art technology. Voltampere reactive (var) optimization is a similarly cost effective alternative. The most significant reduction in losses on the transmission and distribution system would be achieved through the replacement of standard transformers with high efficiency transformers, such as amorphous steel transformers. Of the future technologies assessed, the ''Distribution Static VAR Generator'' appears to have the greatest potential for technological breakthroughs and, therefore in time, commercialization. ''Improved Dielectric Materials,'' with a relatively low cost and high potential for efficiency improvement, warrant R and D consideration. ''Extruded Three-Conductor Cable'' and ''Six- and Twelve-Phase Transmission'' programs provide only limited gains in efficiency and applicability and are therefore the least cost effective.« less

Hybrid Power Management (HPM)

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.

2007-01-01

The NASA Glenn Research Center s Avionics, Power and Communications Branch of the Engineering and Systems Division initiated the Hybrid Power Management (HPM) Program for the GRC Technology Transfer and Partnership Office. HPM is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors and fuel cells. HPM has extremely wide potential. Applications include power generation, transportation systems, biotechnology systems, and space power systems. HPM has the potential to significantly alleviate global energy concerns, improve the environment, and stimulate the economy. One of the unique power devices being utilized by HPM for energy storage is the ultracapacitor. An ultracapacitor is an electrochemical energy storage device, which has extremely high volumetric capacitance energy due to high surface area electrodes, and very small electrode separation. Ultracapacitors are a reliable, long life, maintenance free, energy storage system. This flexible operating system can be applied to all power systems to significantly improve system efficiency, reliability, and performance. There are many existing and conceptual applications of HPM.

Improving Efficiency and Quality of the Children's ASD Diagnostic Pathway: Lessons Learned from Practice.

PubMed

Rutherford, Marion; Burns, Morag; Gray, Duncan; Bremner, Lynne; Clegg, Sarah; Russell, Lucy; Smith, Charlie; O'Hare, Anne

2018-05-01

The 'autism diagnosis crisis' and long waiting times for assessment are as yet unresolved, leading to undue stress and limiting access to effective support. There is therefore a significant need for evidence to support practitioners in the development of efficient services, delivering acceptable waiting times and effectively meeting guideline standards. This study reports statistically significant reductions in waiting times for autism diagnostic assessment following a children's health service improvement programme. The average wait between referral and first appointment reduced from 14.2 to 10.4 weeks (t(21) = 4.3, p < 0.05) and between referral and diagnosis shared, reduced from 270 to 122.5 days, (t(20) = 5.5, p < 0.05). The proportion of girls identified increased from 5.6 to 2.7:1. Methods reported include: local improvement action planning; evidence based pathways; systematic clinical data gathering and a training plan. This is a highly significant finding for many health services wrestling with the challenges of demand and capacity for autism diagnosis and assessment.

Healthcare Commercialization Programs: Improving the Efficiency of Translating Healthcare Innovations From Academia Into Practice.

PubMed

Collins, John M; Reizes, Ofer; Dempsey, Michael K

2016-01-01

Academic investigators are generating a plethora of insights and technologies that have the potential to significantly improve patient care. However, to address the imperative to improve the quality, cost and access to care with ever more constrained funding, the efficiency and the consistency with which they are translated into cost effective products and/or services need to improve. Healthcare commercialization programs (HCPs) are described and proposed as an option that institutions can add to their portfolio to improve translational research. In helping teams translate specific healthcare innovations into practice, HCPs expand the skillset of investigators and enhance an institution's innovation capacity. Lessons learned are shared from configuring and delivering HCPs, which build on the fundamentals of the National Science Foundation's Innovation Corps program, to address the unique challenges in supporting healthcare innovations and innovators.

High-dose neutron detector project update

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

Menlove, Howard Olsen; Henzlova, Daniela

These are the slides for a progress review meeting by the sponsor. This is an update on the high-dose neutron detector project. In summary, improvements in both boron coating and signal amplification have been achieved; improved boron coating materials and procedures have increased efficiency by ~ 30-40% without the corresponding increase in the detector plate area; low dead-time via thin cell design (~ 4 mm gas gaps) and fast amplifiers; prototype PDT 8” pod has been received and testing is in progress; significant improvements in efficiency and stability have been verified; use commercial PDT 10B design and fabrication to obtainmore » a faster path from the research to practical high-dose neutron detector.« less

Tuning Monotonic Basin Hopping: Improving the Efficiency of Stochastic Search as Applied to Low-Thrust Trajectory Optimization

NASA Technical Reports Server (NTRS)

Englander, Jacob A.; Englander, Arnold C.

2014-01-01

Trajectory optimization methods using monotonic basin hopping (MBH) have become well developed during the past decade [1, 2, 3, 4, 5, 6]. An essential component of MBH is a controlled random search through the multi-dimensional space of possible solutions. Historically, the randomness has been generated by drawing random variable (RV)s from a uniform probability distribution. Here, we investigate the generating the randomness by drawing the RVs from Cauchy and Pareto distributions, chosen because of their characteristic long tails. We demonstrate that using Cauchy distributions (as first suggested by J. Englander [3, 6]) significantly improves monotonic basin hopping (MBH) performance, and that Pareto distributions provide even greater improvements. Improved performance is defined in terms of efficiency and robustness. Efficiency is finding better solutions in less time. Robustness is efficiency that is undiminished by (a) the boundary conditions and internal constraints of the optimization problem being solved, and (b) by variations in the parameters of the probability distribution. Robustness is important for achieving performance improvements that are not problem specific. In this work we show that the performance improvements are the result of how these long-tailed distributions enable MBH to search the solution space faster and more thoroughly. In developing this explanation, we use the concepts of sub-diffusive, normally-diffusive, and super-diffusive random walks (RWs) originally developed in the field of statistical physics.

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Final Summary Report

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

White, Thornton C

2014-03-31

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT) is a balanced portfolio of R&D tasks that address energy-saving opportunities in the metalcasting industry. E-SMARRT was created to: • Improve important capabilities of castings • Reduce carbon footprint of the foundry industry • Develop new job opportunities in manufacturing • Significantly reduce metalcasting process energy consumption and includes R&D in the areas of: • Improvements in Melting Efficiency • Innovative Casting Processes for Yield Improvement/Revert Reduction • Instrumentation and Control Improvement • Material properties for Casting or Tooling Design Improvement The energy savings and process improvements developed under E-SMARRT have been mademore » possible through the unique collaborative structure of the E-SMARRT partnership. The E-SMARRT team consisted of DOE’s Office of Industrial Technology, the three leading metalcasting technical associations in the U.S: the American Foundry Society; the North American Die Casting Association; and the Steel Founders’ Society of America; and SCRA Applied R&D, doing business as the Advanced Technology Institute (ATI), a recognized leader in distributed technology management. This team provided collaborative leadership to a complex industry composed of approximately 2,000 companies, 80% of which employ less than 100 people, and only 4% of which employ more than 250 people. Without collaboration, these new processes and technologies that enable energy efficiencies and environment-friendly improvements would have been slow to develop and had trouble obtaining a broad application. The E-SMARRT R&D tasks featured low-threshold energy efficiency improvements that are attractive to the domestic industry because they do not require major capital investment. The results of this portfolio of projects are significantly reducing metalcasting process energy consumption while improving the important capabilities of metalcastings. Through June 2014, the E-SMARRT program predicts an average annual estimated savings of 59 Trillion BTUs per year over a 10 year period through Advanced Melting Efficiencies and Innovative Casting Processes. Along with these energy savings, an estimated average annual estimate of CO2 reduction per year over a ten year period is 3.56 Million Metric Tons of Carbon Equivalent (MM TCE).« less

Active link selection for efficient semi-supervised community detection

NASA Astrophysics Data System (ADS)

Yang, Liang; Jin, Di; Wang, Xiao; Cao, Xiaochun

2015-03-01

Several semi-supervised community detection algorithms have been proposed recently to improve the performance of traditional topology-based methods. However, most of them focus on how to integrate supervised information with topology information; few of them pay attention to which information is critical for performance improvement. This leads to large amounts of demand for supervised information, which is expensive or difficult to obtain in most fields. For this problem we propose an active link selection framework, that is we actively select the most uncertain and informative links for human labeling for the efficient utilization of the supervised information. We also disconnect the most likely inter-community edges to further improve the efficiency. Our main idea is that, by connecting uncertain nodes to their community hubs and disconnecting the inter-community edges, one can sharpen the block structure of adjacency matrix more efficiently than randomly labeling links as the existing methods did. Experiments on both synthetic and real networks demonstrate that our new approach significantly outperforms the existing methods in terms of the efficiency of using supervised information. It needs ~13% of the supervised information to achieve a performance similar to that of the original semi-supervised approaches.

Active link selection for efficient semi-supervised community detection

PubMed Central

Yang, Liang; Jin, Di; Wang, Xiao; Cao, Xiaochun

2015-01-01

Several semi-supervised community detection algorithms have been proposed recently to improve the performance of traditional topology-based methods. However, most of them focus on how to integrate supervised information with topology information; few of them pay attention to which information is critical for performance improvement. This leads to large amounts of demand for supervised information, which is expensive or difficult to obtain in most fields. For this problem we propose an active link selection framework, that is we actively select the most uncertain and informative links for human labeling for the efficient utilization of the supervised information. We also disconnect the most likely inter-community edges to further improve the efficiency. Our main idea is that, by connecting uncertain nodes to their community hubs and disconnecting the inter-community edges, one can sharpen the block structure of adjacency matrix more efficiently than randomly labeling links as the existing methods did. Experiments on both synthetic and real networks demonstrate that our new approach significantly outperforms the existing methods in terms of the efficiency of using supervised information. It needs ~13% of the supervised information to achieve a performance similar to that of the original semi-supervised approaches. PMID:25761385

Synchronized navigation of current and prior studies using image registration improves radiologist's efficiency.

PubMed

Forsberg, Daniel; Gupta, Amit; Mills, Christopher; MacAdam, Brett; Rosipko, Beverly; Bangert, Barbara A; Coffey, Michael D; Kosmas, Christos; Sunshine, Jeffrey L

2017-03-01

The purpose of this study was to investigate how the use of multi-modal rigid image registration integrated within a standard picture archiving and communication system affects the efficiency of a radiologist while performing routine interpretations of cases including prior examinations. Six radiologists were recruited to read a set of cases (either 16 neuroradiology or 14 musculoskeletal cases) during two crossover reading sessions. Each radiologist read each case twice, one time with synchronized navigation, which enables spatial synchronization across examinations from different study dates, and one time without. Efficiency was evaluated based upon time to read a case and amount of scrolling while browsing a case using Wilcoxon signed rank test. Significant improvements in efficiency were found considering either all radiologists simultaneously, the two sections separately and the majority of individual radiologists for time to read and for amount of scrolling. The relative improvement for each individual radiologist ranged from 4 to 32% for time to read and from 14 to 38% for amount of scrolling. Image registration providing synchronized navigation across examinations from different study dates provides a tool that enables radiologists to work more efficiently while reading cases with one or more prior examinations.

Improving the desulfurization performance of CaCO3 with sodium humate

NASA Astrophysics Data System (ADS)

Feng, Run; Sun, Zhiguo; Zhang, Wenqing; Huang, Hao; Hu, Haihang; Zhang, Li; Xie, Hongyong

2018-02-01

The influence of these factors on desulphurization efficiency was studied by changing the amount of calcium carbonate, the concentration of sulfur dioxide, the liquid flow rate of absorbent and the air flow rate, the optimum working condition was determined by the research of limestone-gypsum desulphurization process commonly used in industry. By changing the amount of calcium carbonate, we conclude that the volume of water in the desulfurization efficiency does not increase with the adding amount of calcium carbonate. The optimum conditions were determined : at the condicion of the concentration of 500ppm of sulfur dioxide, 10g calcium carbonate, 150L/h liquid flow and the minimum air flow rate of 6.75m3/h, the highest desulfurization efficiency was close to 100% when sodium humate was not added, but the holding time was only about 5 minutes. After adding 3g of humic acid, the desulfurization efficiency was improved obviously, and the instantaneous efficiency of 100% lasting for about 40 minutes. It can be seen that, calcium carbonate in the addition of humic acid sodium can significantly improve the absorption of calcium carbonate performance of SO2.

Effects of Thermal Barrier Coatings on Approaches to Turbine Blade Cooling

NASA Technical Reports Server (NTRS)

Boyle, Robert J.

2007-01-01

Reliance on Thermal Barrier Coatings (TBC) to reduce the amount of air used for turbine vane cooling is beneficial both from the standpoint of reduced NOx production, and as a means of improving cycle efficiency through improved component efficiency. It is shown that reducing vane cooling from 10 to 5 percent of mainstream air can lead to NOx reductions of nearly 25 percent while maintaining the same rotor inlet temperature. An analysis is given which shows that, when a TBC is relied upon in the vane thermal design process, significantly less coolant is required using internal cooling alone compared to film cooling. This is especially true for small turbines where internal cooling without film cooling permits the surface boundary layer to remain laminar over a significant fraction of the vane surface.

A Novel Design for Drug-Drug Interaction Alerts Improves Prescribing Efficiency.

PubMed

Russ, Alissa L; Chen, Siying; Melton, Brittany L; Johnson, Elizabette G; Spina, Jeffrey R; Weiner, Michael; Zillich, Alan J

2015-09-01

Drug-drug interactions (DDIs) are common in clinical care and pose serious risks for patients. Electronic health records display DDI alerts that can influence prescribers, but the interface design of DDI alerts has largely been unstudied. In this study, the objective was to apply human factors engineering principles to alert design. It was hypothesized that redesigned DDI alerts would significantly improve prescribers' efficiency and reduce prescribing errors. In a counterbalanced, crossover study with prescribers, two DDI alert designs were evaluated. Department of Veterans Affairs (VA) prescribers were video recorded as they completed fictitious patient scenarios, which included DDI alerts of varying severity. Efficiency was measured from time-stamped recordings. Prescribing errors were evaluated against predefined criteria. Efficiency and prescribing errors were analyzed with the Wilcoxon signed-rank test. Other usability data were collected on the adequacy of alert content, prescribers' use of the DDI monograph, and alert navigation. Twenty prescribers completed patient scenarios for both designs. Prescribers resolved redesigned alerts in about half the time (redesign: 52 seconds versus original design: 97 seconds; p<.001). Prescribing errors were not significantly different between the two designs. Usability results indicate that DDI alerts might be enhanced by facilitating easier access to laboratory data and dosing information and by allowing prescribers to cancel either interacting medication directly from the alert. Results also suggest that neither design provided adequate information for decision making via the primary interface. Applying human factors principles to DDI alerts improved overall efficiency. Aspects of DDI alert design that could be further enhanced prior to implementation were also identified.

Effective suppression of efficiency droop in GaN-based light-emitting diodes: role of significant reduction of carrier density and built-in field.

PubMed

Yoo, Yang-Seok; Na, Jong-Ho; Son, Sung Jin; Cho, Yong-Hoon

2016-10-19

A critical issue in GaN-based high power light-emitting diodes (LEDs) is how to suppress the efficiency droop problem occurred at high current injection while improving overall quantum efficiency, especially in conventional c-plane InGaN/GaN quantum well (QW), without using complicated bandgap engineering or unconventional materials and structures. Although increasing thickness of each QW may decrease carrier density in QWs, formation of additional strain and defects as well as increased built-in field effect due to enlarged QW thickness are unavoidable. Here, we propose a facile and effective method for not only reducing efficiency droop but also improving quantum efficiency by utilizing c-plane InGaN/GaN QWs having thinner barriers and increased QW number while keeping the same single well thickness and total active layer thickness. As the barrier thickness decreases and the QW number increases, both internal electric field and carrier density within QWs are simultaneously reduced without degradation of material quality. Furthermore, we found overall improved efficiency and reduced efficiency droop, which was attributed to the decrease of the built-in field and to less influence by non-radiative recombination processes at high carrier density. This simple and effective approach can be extended further for high power ultraviolet, green, and red LEDs.

Effective suppression of efficiency droop in GaN-based light-emitting diodes: role of significant reduction of carrier density and built-in field

NASA Astrophysics Data System (ADS)

Yoo, Yang-Seok; Na, Jong-Ho; Son, Sung Jin; Cho, Yong-Hoon

2016-10-01

A critical issue in GaN-based high power light-emitting diodes (LEDs) is how to suppress the efficiency droop problem occurred at high current injection while improving overall quantum efficiency, especially in conventional c-plane InGaN/GaN quantum well (QW), without using complicated bandgap engineering or unconventional materials and structures. Although increasing thickness of each QW may decrease carrier density in QWs, formation of additional strain and defects as well as increased built-in field effect due to enlarged QW thickness are unavoidable. Here, we propose a facile and effective method for not only reducing efficiency droop but also improving quantum efficiency by utilizing c-plane InGaN/GaN QWs having thinner barriers and increased QW number while keeping the same single well thickness and total active layer thickness. As the barrier thickness decreases and the QW number increases, both internal electric field and carrier density within QWs are simultaneously reduced without degradation of material quality. Furthermore, we found overall improved efficiency and reduced efficiency droop, which was attributed to the decrease of the built-in field and to less influence by non-radiative recombination processes at high carrier density. This simple and effective approach can be extended further for high power ultraviolet, green, and red LEDs.

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

Yazawa, Kazuaki; Shakouri, Ali

The energy conversion efficiency of today’s thermoelectric generators is significantly lower than that of conventional mechanical engines. Almost all of the existing research is focused on materials to improve the conversion efficiency. Here we propose a general framework to study the cost-efficiency trade-off for thermoelectric power generation. A key factor is the optimization of thermoelectric modules together with their heat source and heat sinks. Full electrical and thermal co-optimization yield a simple analytical expression for optimum design. Based on this model, power output per unit mass can be maximized. We show that the fractional area coverage of thermoelectric elements inmore » a module could play a significant role in reducing the cost of power generation systems.« less

Transcranial direct current stimulation versus user training on improving online myoelectric control for amputees

NASA Astrophysics Data System (ADS)

Pan, Lizhi; Zhang, Dingguo; Jiang, Ning; Sheng, Xinjun; Zhu, Xiangyang

2017-08-01

Objective. Transcranial direct current stimulation (tDCS) and user training (UT) are two types of methods to improve myoelectric control performance for amputees. In this study, we compared the independent effect between tDCS and UT, and investigated the combined effect of tDCS and UT. Approach. An online paradigm of simultaneous and proportional control (SPC) based on electromyography (EMG) was adopted. The proposed experiments were conducted on six naïve unilateral trans-radial amputees. The subjects each received three types of 20 min interventions: active tDCS with motor training (tDCS  +  UT), active tDCS with quiet sitting (tDCS), and sham tDCS with motor training (UT). The interventions were applied at one week intervals in a randomized order. The subjects performed online control of a feedback arrow with two degrees of freedom (DoFs) to accomplish target reaching motor tasks in pre-sessions and post-sessions. We compared the performance, measured by completion rate, completion time, and efficiency coefficient, between pre-sessions and post-sessions. Main results. The results showed that the intervention tDCS  +  UT and tDCS significantly improved the online SPC performance (i.e. improved the completion rate; reduced the completion time; and improved the efficiency coefficient), while intervention UT did not significantly change the performance. The results also showed that the online SPC performance after intervention tDCS  +  UT and tDCS was not significantly different, but both were significantly better than that after intervention UT. Significance. tDCS could be an effective intervention to improve the online SPC performance in a short time.

Efficiency and the proposed reforms to the NHS research ethics system

PubMed Central

Hunter, David

2007-01-01

Significant changes are proposed for the research ethics system governing the review of the conduct of medical research in the UK. This paper examines these changes and whether they will meet the aimed‐for goal of improving the efficiency of the research ethics system. The author concludes that, unfortunately, they will not and thus should be rejected. PMID:17971468

Improving and Evaluating Nested Sampling Algorithm for Marginal Likelihood Estimation

NASA Astrophysics Data System (ADS)

Ye, M.; Zeng, X.; Wu, J.; Wang, D.; Liu, J.

2016-12-01

With the growing impacts of climate change and human activities on the cycle of water resources, an increasing number of researches focus on the quantification of modeling uncertainty. Bayesian model averaging (BMA) provides a popular framework for quantifying conceptual model and parameter uncertainty. The ensemble prediction is generated by combining each plausible model's prediction, and each model is attached with a model weight which is determined by model's prior weight and marginal likelihood. Thus, the estimation of model's marginal likelihood is crucial for reliable and accurate BMA prediction. Nested sampling estimator (NSE) is a new proposed method for marginal likelihood estimation. The process of NSE is accomplished by searching the parameters' space from low likelihood area to high likelihood area gradually, and this evolution is finished iteratively via local sampling procedure. Thus, the efficiency of NSE is dominated by the strength of local sampling procedure. Currently, Metropolis-Hasting (M-H) algorithm is often used for local sampling. However, M-H is not an efficient sampling algorithm for high-dimensional or complicated parameter space. For improving the efficiency of NSE, it could be ideal to incorporate the robust and efficient sampling algorithm - DREAMzs into the local sampling of NSE. The comparison results demonstrated that the improved NSE could improve the efficiency of marginal likelihood estimation significantly. However, both improved and original NSEs suffer from heavy instability. In addition, the heavy computation cost of huge number of model executions is overcome by using an adaptive sparse grid surrogates.

Invited review: improving feed efficiency in dairy production: challenges and possibilities.

PubMed

Connor, E E

2015-03-01

Despite substantial advances in milk production efficiency of dairy cattle over the last 50 years, rising feed costs remain a significant threat to producer profitability. There also is a greater emphasis being placed on reducing the negative impacts of dairy production on the environment; thus means to lower greenhouse gas (GHG) emissions and nutrient losses to the environment associated with cattle production are being sought. Improving feed efficiency among dairy cattle herds offers an opportunity to address both of these issues for the dairy industry. However, the best means to assess feed efficiency and make genetic progress in efficiency-related traits among lactating cows without negatively impacting other economically important traits is not entirely obvious. In this review, multiple measurements of feed efficiency for lactating cows are described, as well as the heritability of the traits and their genetic and phenotypic correlations with other production traits. The measure of feed efficiency, residual feed intake is discussed in detail in terms of the benefits for its selection, how it could be assessed in large commercial populations, as well as biological mechanisms contributing to its variation among cows, as it has become a commonly used method to estimate efficiency in the recent scientific literature.

Phosphorous removal from aqueous solution can be enhanced through the calcination of lime sludge.

PubMed

Bal Krishna, K C; Niaz, Mohamed R; Sarker, Dipok C; Jansen, Troy

2017-09-15

Water treatment plants generate an enormous amount of the sludge which is normally treated as waste. In the recent past, many investigations have been focused on developing an economical adsorbent using water treatment sludge to remove phosphorous (P) from aqueous solutions. However, the great extents of the studies have been limited in the use of alum- and iron-based sludges. This study, therefore, investigated the P removal performance of the calcined lime sludge. Calcined lime sludge at 700 °C significantly enhanced the P removal efficiency whereas marginal improvement was noted when the sludge calcined at 400 °C was tested. With increase P removal efficiency, final pH values of the solution also significantly increased. P removal efficiency of the calcined sludge decreased with increasing the initial P concentrations. However, the removal efficiency could be improved by increasing the weight of the sludge. Further analysis demonstrated that P removal trend followed both pseudo-second order and diffusion-chemisorption kinetics signifying the P removal is potentially due to a multi-mechanistic reaction in which, the process is controlled by intra-particle diffusion followed by chemisorptions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic diversity in Capsicum baccatum is significantly influenced by its ecogeographical distribution

USDA-ARS?s Scientific Manuscript database

The structure of genetic diversity in a plant germplasm collection is significantly influenced by its ecogeographical distribution. Improved understanding of the combined effects of geology, ecology and human intervention is essential for efficient conservation and use of plant germplasm. In the pr...

Investigation of Fluorination on Donor Moiety of Donor-Acceptor 4,7-Dithienylbenzothiadiazole-Based Conjugated Polymers toward Enhanced Photovoltaic Efficiency.

PubMed

Li, Yonghai; Wang, Junyi; Liu, Yan; Qiu, Meng; Wen, Shuguang; Bao, Xichang; Wang, Ning; Sun, Mingliang; Yang, Renqiang

2016-10-05

It is known that fluorination on π-conjugated donor-acceptor (D-A) polymers can significantly affect the optoelectronic properties and fluorination on A moiety has been well established for design of efficient photovoltaic materials. For example, polymers based on 4,7-dithienyl-5,6-difluorobenzothiadiazole (DTffBT) have been intensively investigated and exhibited excellent performance, but the corresponding DTBT-based polymers without fluorine often display an unfavorable efficiency. With the purpose of improving photovoltaic efficiency of DTBT-based D-A polymers, we design three polymers PDTBT-TxfBT (x = 0, 1, 2) with fluorination on D moiety (TxfBT) and systematically investigate fluorination on the photophysical/electrochemical and photovoltaic properties. The results show that polymer solar cells (PSCs) based on PDTBT-TBT exhibit moderate power conversion efficiency (PCE) of 5.84%. However, the bis-fluorination on TffBT moiety (PDTBT-TffBT) can greatly enhance the molecular planarity and intermolecular interaction, improve the charge transport and heterojunction morphology, and further suppress the charge recombination losses. PSCs based on PDTBT-TffBT demonstrate obviously improved photovoltaic efficiency with the best PCE up to 7.53% without any processing additives, which ranks among the top DTBT-based PSCs. However, it should be noted that unsymmetrical fluorination on TfBT moiety (PDTBT-TfBT) impairs the regularity of polymer backbone and intermolecular interaction, increases the recombination losses, and seriously reduces the short-circuit current density and efficiency (5.44%). The results exhibit that fluorination on D moiety is a helpful strategy for design high-performance photovoltaic materials and the regularity of fluorination is crucial to improving efficiencies.

Mn-doped quantum dot sensitized solar cells: a strategy to boost efficiency over 5%.

PubMed

Santra, Pralay K; Kamat, Prashant V

2012-02-08

To make Quantum Dot Sensitized Solar Cells (QDSC) competitive, it is necessary to achieve power conversion efficiencies comparable to other emerging solar cell technologies. By employing Mn(2+) doping of CdS, we have now succeeded in significantly improving QDSC performance. QDSC constructed with Mn-doped-CdS/CdSe deposited on mesoscopic TiO(2) film as photoanode, Cu(2)S/Graphene Oxide composite electrode, and sulfide/polysulfide electrolyte deliver power conversion efficiency of 5.4%.

Laser amplifier chain

DOEpatents

Hackel, Richard P.

1992-01-01

A laser amplifier chain has a plurality of laser amplifiers arranged in a chain to sequentially amplify a low-power signal beam to produce a significantly higher-power output beam. Overall efficiency of such a chain is improved if high-gain, low efficiency amplifiers are placed on the upstream side of the chain where only a very small fraction of the total pumped power is received by the chain and low-gain, high-efficiency amplifiers are placed on the downstream side where a majority of pumping energy is received by the chain.

Effect of steam addition on cycle performance of simple and recuperated gas turbines

NASA Technical Reports Server (NTRS)

Boyle, R. J.

1979-01-01

Results are presented for the cycle efficiency and specific power of simple and recuperated gas turbine cycles in which steam is generated and used to increase turbine flow. Calculations showed significant improvements in cycle efficiency and specific power by adding steam. The calculations were made using component efficiencies and loss assumptions typical of stationary powerplants. These results are presented for a range of operating temperatures and pressures. Relative heat exchanger size and the water use rate are also examined.

Impact of an electronic medication administration record on medication administration efficiency and errors.

PubMed

McComas, Jeffery; Riingen, Michelle; Chae Kim, Son

2014-12-01

The study aims were to evaluate the impact of electronic medication administration record implementation on medication administration efficiency and occurrence of medication errors as well as to identify the predictors of medication administration efficiency in an acute care setting. A prospective, observational study utilizing time-and-motion technique was conducted before and after electronic medication administration record implementation in November 2011. A total of 156 cases of medication administration activities (78 pre- and 78 post-electronic medication administration record) involving 38 nurses were observed at the point of care. A separate retrospective review of the hospital Midas+ medication error database was also performed to collect the rates and origin of medication errors for 6 months before and after electronic medication administration record implementation. The mean medication administration time actually increased from 11.3 to 14.4 minutes post-electronic medication administration record (P = .039). In a multivariate analysis, electronic medication administration record was not a predictor of medication administration time, but the distractions/interruptions during medication administration process were significant predictors. The mean hospital-wide medication errors significantly decreased from 11.0 to 5.3 events per month post-electronic medication administration record (P = .034). Although no improvement in medication administration efficiency was observed, electronic medication administration record improved the quality of care with a significant decrease in medication errors.

Process-based organization design and hospital efficiency.

PubMed

Vera, Antonio; Kuntz, Ludwig

2007-01-01

The central idea of process-based organization design is that organizing a firm around core business processes leads to cost reductions and quality improvements. We investigated theoretically and empirically whether the implementation of a process-based organization design is advisable in hospitals. The data came from a database compiled by the Statistical Office of the German federal state of Rheinland-Pfalz and from a written questionnaire, which was sent to the chief executive officers (CEOs) of all 92 hospitals in this federal state. We used data envelopment analysis (DEA) to measure hospital efficiency, and factor analysis and regression analysis to test our hypothesis. Our principal finding is that a high degree of process-based organization has a moderate but significant positive effect on the efficiency of hospitals. The main implication is that hospitals should implement a process-based organization to improve their efficiency. However, to actually achieve positive effects on efficiency, it is of paramount importance to observe some implementation rules, in particular to mobilize physician participation and to create an adequate organizational culture.

Effect of Epichloë gansuensis Endophyte on the Nitrogen Metabolism, Nitrogen Use Efficiency, and Stoichiometry of Achnatherum inebrians under Nitrogen Limitation.

PubMed

Wang, Jianfeng; Nan, Zhibiao; Christensen, Michael J; Zhang, Xingxu; Tian, Pei; Zhang, Zhixin; Niu, Xueli; Gao, Peng; Chen, Tao; Ma, Lixia

2018-04-25

The systemic fungal endophyte of the grass Achnatherum inebrians, Epichloë gansuensis, has important roles in enhancing resistance to biotic and abiotic stresses. In this work, we first evaluated the effects of E. gansuensis on nitrogen metabolism, nitrogen use efficiency, and stoichiometry of A. inebrians under varying nitrogen concentrations. The results demonstrated that E. gansuensis significantly improved the growth of A. inebrians under low nitrogen conditions. The fresh and dry weights, nitrogen reductase, nitrite reductase, and glutamine synthetase activity, NO 3 - , NH 4 + , N, and P content, and also the total N accumulation, N utilization efficiency, and N uptake efficiency were all higher in leaves of A. inebrians with E. ganusensis (E+) plants than A. inebrians plants without this endophyte (E-) under low nitrogen availability. In conclusion, E. gansuensis has positive effects on improving the growth of A. inebrians under low-nitrogen conditions by modulating the enzymes of nitrogen metabolism and enhancing nitrogen use efficiency.

Optimization of blade motion of vertical axis turbine

NASA Astrophysics Data System (ADS)

Ma, Yong; Zhang, Liang; Zhang, Zhi-yang; Han, Duan-feng

2016-04-01

In this paper, a method is proposed to improve the energy efficiency of the vertical axis turbine. First of all, a single disk multiple stream-tube model is used to calculate individual fitness. Genetic algorithm is adopted to optimize blade pitch motion of vertical axis turbine with the maximum energy efficiency being selected as the optimization objective. Then, a particular data processing method is proposed, fitting the result data into a cosine-like curve. After that, a general formula calculating the blade motion is developed. Finally, CFD simulation is used to validate the blade pitch motion formula. The results show that the turbine's energy efficiency becomes higher after the optimization of blade pitch motion; compared with the fixed pitch turbine, the efficiency of variable-pitch turbine is significantly improved by the active blade pitch control; the energy efficiency declines gradually with the growth of speed ratio; besides, compactness has lager effect on the blade motion while the number of blades has little effect on it.

Kinking and Torsion Can Significantly Improve the Efficiency of Valveless Pumping in Periodically Compressed Tubular Conduits. Implications for Understanding of the Form-Function Relationship of Embryonic Heart Tubes.

PubMed

Hiermeier, Florian; Männer, Jörg

2017-11-19

Valveless pumping phenomena (peristalsis, Liebau-effect) can generate unidirectional fluid flow in periodically compressed tubular conduits. Early embryonic hearts are tubular conduits acting as valveless pumps. It is unclear whether such hearts work as peristaltic or Liebau-effect pumps. During the initial phase of its pumping activity, the originally straight embryonic heart is subjected to deforming forces that produce bending, twisting, kinking, and coiling. This deformation process is called cardiac looping. Its function is traditionally seen as generating a configuration needed for establishment of correct alignments of pulmonary and systemic flow pathways in the mature heart of lung-breathing vertebrates. This idea conflicts with the fact that cardiac looping occurs in all vertebrates, including gill-breathing fishes. We speculate that looping morphogenesis may improve the efficiency of valveless pumping. To test the physical plausibility of this hypothesis, we analyzed the pumping performance of a Liebau-effect pump in straight and looped (kinked) configurations. Compared to the straight configuration, the looped configuration significantly improved the pumping performance of our pump. This shows that looping can improve the efficiency of valveless pumping driven by the Liebau-effect. Further studies are needed to clarify whether this finding may have implications for understanding of the form-function relationship of embryonic hearts.

Kinking and Torsion Can Significantly Improve the Efficiency of Valveless Pumping in Periodically Compressed Tubular Conduits. Implications for Understanding of the Form-Function Relationship of Embryonic Heart Tubes

PubMed Central

Hiermeier, Florian; Männer, Jörg

2017-01-01

Valveless pumping phenomena (peristalsis, Liebau-effect) can generate unidirectional fluid flow in periodically compressed tubular conduits. Early embryonic hearts are tubular conduits acting as valveless pumps. It is unclear whether such hearts work as peristaltic or Liebau-effect pumps. During the initial phase of its pumping activity, the originally straight embryonic heart is subjected to deforming forces that produce bending, twisting, kinking, and coiling. This deformation process is called cardiac looping. Its function is traditionally seen as generating a configuration needed for establishment of correct alignments of pulmonary and systemic flow pathways in the mature heart of lung-breathing vertebrates. This idea conflicts with the fact that cardiac looping occurs in all vertebrates, including gill-breathing fishes. We speculate that looping morphogenesis may improve the efficiency of valveless pumping. To test the physical plausibility of this hypothesis, we analyzed the pumping performance of a Liebau-effect pump in straight and looped (kinked) configurations. Compared to the straight configuration, the looped configuration significantly improved the pumping performance of our pump. This shows that looping can improve the efficiency of valveless pumping driven by the Liebau-effect. Further studies are needed to clarify whether this finding may have implications for understanding of the form-function relationship of embryonic hearts. PMID:29367548

The effect of nursing participation in the design of a critical care information system: a case study in a Chinese hospital.

PubMed

Qin, Yanhong; Zhou, Ranyun; Wu, Qiong; Huang, Xiaodi; Chen, Xinli; Wang, Weiwei; Wang, Xun; Xu, Hua; Zheng, Jing; Qian, Siyu; Bai, Changqing; Yu, Ping

2017-12-06

Intensive care information systems (ICIS) are continuously evolving to meet the ever changing information needs of intensive care units (ICUs), providing the backbone for a safe, intelligent and efficient patient care environment. Although beneficial for the international advancement in building smart environments to transform ICU services, knowledge about the contemporary development of ICIS worldwide, their usage and impacts is limited. This study aimed to fill this knowledge gap by researching the development and implementation of an ICIS in a Chinese hospital, nurses' use of the system, and the impact of system use on critical care nursing processes and outcomes. This descriptive case study was conducted in a 14-bed Respiratory ICU in a tertiary hospital in Beijing. Participative design was the method used for ICU nurses, hospital IT department and a software company to collaboratively research and develop the ICIS. Focus group discussions were conducted to understand the subjective perceptions of the nurses toward the ICIS. Nursing documentation time and quality were compared before and after system implementation. ICU nursing performance was extracted from the annual nursing performance data collected by the hospital. A participative design process was followed by the nurses in the ICU, the hospital IT staff and the software engineers in the company to develop and implement a highly useful ICIS. Nursing documentation was fully digitized and was significantly improved in quality and efficiency. The wrong data, missing data items and calculation errors were significantly reduced. Nurses spent more time on direct patient care after the introduction of the ICIS. The accuracy and efficiency of medication administration was also improved. The outcome was improvement in ward nursing performance as measured by ward management, routine nursing practices, disinfection and isolation, infection rate and mortality rate. Nurses in this ICU unit in China actively participated in the ICIS development and fully used the system to document care. Introduction of the ICIS led to significant improvement in quality and efficiency in nursing documentation, medication order transcription and administration. It allowed nurses to spend more time with patients to improve quality of care. These led to improvement in overall nursing performance. Further study should investigate how the ICIS system contributes to the improvement in decision making of ICU nurses and intensivists.

Exceptionally omnidirectional broadband light harvesting scheme for multi-junction concentrator solar cells achieved via ZnO nanoneedles

NASA Astrophysics Data System (ADS)

Yeh, Li-Ko; Tian, Wei-Cheng; Lai, Kun-Yu; He-Hau, Jr.

2016-12-01

GaInP/GaAs/Ge triple-junction concentrator solar cells with significant efficiency enhancement were demonstrated with antireflective ZnO nanoneedles. The novel nanostructure was attained with a Zn(NO3)2-based solution containing vitamin C. Under one sun AM 1.5G solar spectrum, conversion efficiency of the triple-junction device was improved by 23.7% via broadband improvement in short-circuit currents of 3 sub-cells after the coverage by the nanoneedles with a graded refractive index profile. The efficiency enhancement further went up to 45.8% at 100 suns. The performance boost through the nanoneedles also became increasingly pronounced in the conditions of high incident angles and the cloudy weather, e.g. 220.0% of efficiency enhancement was observed at the incident angle of 60°. These results were attributed to the exceptional broadband omnidirectionality of the antireflective nanoneedles.

Evaluation of food drying with air dehumidification system: a short review

NASA Astrophysics Data System (ADS)

Djaeni, M.; Utari, F. D.; Sasongko, S. B.; Kumoro, A. C.

2018-01-01

Energy efficient drying for food and agriculture products resulting high quality products has been an important issue. Currently, about 50% of total energy for postharvest treatment was used for drying. This paper presents the evaluation of new approach namely air dehumidification system with zeolite for food drying. Zeolite is a material having affinity to water in which reduced the moisture in air. With low moisture content and relative humidity, the air can improve driving force for drying even at low temperature. Thus, the energy efficiency can be potentially enhanced and the product quality can be well retained. For proving the hypothesis, the paddy and onion have been dried using dehumidified air. As performance indicators, the drying time, product quality, and heat efficiency were evaluated. Results indicated that the drying with zeolite improved the performances significantly. At operating temperature ranging 50 - 60°C, the efficiency of drying system can reach 75% with reasonable product quality.

Improving enzymatic hydrolysis efficiency of wheat straw through sequential autohydrolysis and alkaline post-extraction.

PubMed

Wu, Xinxing; Huang, Chen; Zhai, Shengcheng; Liang, Chen; Huang, Caoxing; Lai, Chenhuan; Yong, Qiang

2018-03-01

In this work, a two-step pretreatment process of wheat straw was established by combining autohydrolysis pretreatment and alkaline post-extraction. The results showed that employing alkaline post-extraction to autohydrolyzed wheat straw could significantly improve its enzymatic hydrolysis efficiency from 36.0% to 83.7%. Alkaline post-extraction lead to the changes of the structure characteristics of autohydrolyzed wheat straw. Associations between enzymatic hydrolysis efficiency and structure characteristics were also studied. The results showed that the factors of structure characteristics such as delignification, xylan removal yield, crystallinity, accessibility and hydrophobicity are positively related to enzymatic hydrolysis efficiency within a certain range for alkaline post-extracted wheat straw. The results demonstrated that autohydrolysis coupled with alkaline post-extraction is an effective and promising method to gain fermentable sugars from biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design and Development of a Residential Gas-Fired Heat Pump

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

Vineyard, Edward Allan; Abu-Heiba, Ahmad; Mahderekal, Dr. Isaac

2017-01-01

Heating, ventilating, and air-conditioning equipment consumes 43% of the total primary energy consumption in U.S. households. Presently, conventional gas furnaces have maximum heating efficiencies of 98%. Electric air conditioners used in association with the furnace for cooling have a minimum seasonal energy efficiency ratio (SEER) of 14.0. A residential gas-fired heat pump (RGHP) was developed and tested under standard rating conditions, resulting in a significant increase in heating efficiency of over 40% versus conventional natural gas furnaces. The associated efficiency of the RGHP in cooling mode is comparable in efficiency to an electric air conditioner (14.0 SEER) when compared onmore » a primary energy basis. The RGHP is similar in nature to a conventional heat pump but with two main differences. First, the primary energy savings are higher, based on a site versus source comparison, as the result of using natural gas to supply shaft power to the compressor rather than an electric motor. Second, waste heat is recovered from the engine to supplement space heating and reduce the energy input. It can also be used to provide supplemental water heating. The system utilizes a programmable logic controller that allows variable-speed operation to achieve improved control to meet building loads. RGHPs significantly reduce peak electric use during periods of high demand, especially peak summer loads, as well as peak winter loads in regions with widespread use of electric heating. This contributes to leveling year-round gas loads, with the potential to increase annual gas demand in some regions. The widespread adoption of RGHPs will contribute to significant reductions in primary energy consumption and carbon emissions through improved efficiencies.« less

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology.

PubMed

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium. Copyright © 2017 Elsevier B.V. All rights reserved.

Electronic Medical Records and Same Day Patient Tracing Improves Clinic Efficiency and Adherence to Appointments in a Community Based HIV/AIDS Care Program, in Uganda

PubMed Central

Alamo, Stella T.; Wagner, Glenn J.; Sunday, Pamela; Wanyenze, Rhoda K.; Ouma, Joseph; Kamya, Moses; Colebunders, Robert; Wabwire-Mangen, Fred

2013-01-01

Patients who miss clinic appointments make unscheduled visits which compromise the ability to plan for and deliver quality care. We implemented Electronic Medical Records (EMR) and same day patient tracing to minimize missed appointments in a community-based HIV clinic in Kampala. Missed, early, on-schedule appointments and waiting times were evaluated before (pre-EMR) and 6 months after implementation of EMR and patient tracing (post-EMR). Reasons for missed appointments were documented pre and post-EMR. The mean daily number of missed appointments significantly reduced from 21 pre-EMR to 8 post-EMR. The main reason for missed appointments was forgetting (37%) but reduced significantly by 30% post-EMR. Loss to follow-up (LTFU) also significantly decreased from 10.9 to 4.8% The total median waiting time to see providers significantly decreased from 291 to 94 min. Our findings suggest that EMR and same day patient tracing can significantly reduce missed appointments, and LTFU and improve clinic efficiency. PMID:21739285

Breaking down IT silos: a "connected" way to improve customer experience and the bottom line.

PubMed

Hallowell, Bruce; Turisco, Frances

2009-03-01

Hospitals can provide customer service like Amazon.com without purchasing new technology. Making technology interactive requires sharing patient data across applications and enhancing existing IT with decision support. Breaking down technology silos between hospital and outpatient care provider systems significantly improves efficiency, lowers costs, and speeds care delivery.

Enhancing Scalability and Efficiency of the TOUGH2_MP for LinuxClusters

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

Zhang, Keni; Wu, Yu-Shu

2006-04-17

TOUGH2{_}MP, the parallel version TOUGH2 code, has been enhanced by implementing more efficient communication schemes. This enhancement is achieved through reducing the amount of small-size messages and the volume of large messages. The message exchange speed is further improved by using non-blocking communications for both linear and nonlinear iterations. In addition, we have modified the AZTEC parallel linear-equation solver to nonblocking communication. Through the improvement of code structuring and bug fixing, the new version code is now more stable, while demonstrating similar or even better nonlinear iteration converging speed than the original TOUGH2 code. As a result, the new versionmore » of TOUGH2{_}MP is improved significantly in its efficiency. In this paper, the scalability and efficiency of the parallel code are demonstrated by solving two large-scale problems. The testing results indicate that speedup of the code may depend on both problem size and complexity. In general, the code has excellent scalability in memory requirement as well as computing time.« less

Case study:-calender covers in a hospital laundry. Energy Efficiency Office, Department of Energy.

PubMed

1992-01-01

Whipps Cross Hospital laundry is typical of many laundries, both in the commercial sector and NHS, in that it uses old calenders which are substantially less efficient than more modern machines. Although calendering is a relatively efficient method of moisture removal, the quantity of flatwork processed by this laundry means that the calendering section uses a significant proportion of the total laundry energy consumption. In common with many other laundries, the four calenders were producing a great deal of airborne lint which required expensive cleaning at regular intervals, and made the working environment uncomfortable, reducing the performance and morale of the operators. In an effort to improve this situation, covers were fitted to all the calenders in early 1989. These were claimed to improve energy efficiency by reducing the heat losses from the calender's upper surfaces and to improve the local atmosphere by reducing the quantity of lint and moist air escaping into the laundry. This case study examines the savings (both energy savings and others) achieved by the installation of the covers, and assesses any drawbacks which may have become apparent after extended use.

Efficient Robust Optimization of Metal Forming Processes using a Sequential Metamodel Based Strategy

NASA Astrophysics Data System (ADS)

Wiebenga, J. H.; Klaseboer, G.; van den Boogaard, A. H.

2011-08-01

The coupling of Finite Element (FE) simulations to mathematical optimization techniques has contributed significantly to product improvements and cost reductions in the metal forming industries. The next challenge is to bridge the gap between deterministic optimization techniques and the industrial need for robustness. This paper introduces a new and generally applicable structured methodology for modeling and solving robust optimization problems. Stochastic design variables or noise variables are taken into account explicitly in the optimization procedure. The metamodel-based strategy is combined with a sequential improvement algorithm to efficiently increase the accuracy of the objective function prediction. This is only done at regions of interest containing the optimal robust design. Application of the methodology to an industrial V-bending process resulted in valuable process insights and an improved robust process design. Moreover, a significant improvement of the robustness (>2σ) was obtained by minimizing the deteriorating effects of several noise variables. The robust optimization results demonstrate the general applicability of the robust optimization strategy and underline the importance of including uncertainty and robustness explicitly in the numerical optimization procedure.

Hybrid Power Management Program Continued

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.

2002-01-01

Hybrid Power Management (HPM) is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors and photovoltaics. HPM has extremely wide potential with applications including power-generation, transportation, biotechnology, and space power systems. It may significantly alleviate global energy concerns, improve the environment, and stimulate the economy.

Optical Analysis of Cassegrainian Point Focus Concentrators

NASA Technical Reports Server (NTRS)

Waterbury, S. S.; Schwinkendorf, W. E.

1984-01-01

A Cassegrainian solar concentrator, using a 7-meter diameter primary reflector, was analyzed in three forms: (1) an unmodified Cassegrainian, (2) the Ritchey-Chretien configuration, and (3) the unmodified Cassegrainian with a non-imaging tertiary reflector. Optical performance was not significantly improved with the Ritchey-Chretien; however, the tertiary resulted in significant improvement in intercept factor and optical efficiency. The effects of misalignment of the secondary and tertiary reflectors on the optical performance of the collector were also analyzed.

High-performance and environmentally stable planar heterojunction perovskite solar cells based on a solution-processed copper-doped nickel oxide hole-transporting layer.

PubMed

Kim, Jong H; Liang, Po-Wei; Williams, Spencer T; Cho, Namchul; Chueh, Chu-Chen; Glaz, Micah S; Ginger, David S; Jen, Alex K-Y

2015-01-27

An effective approach to significantly increase the electrical conductivity of a NiOx hole-transporting layer (HTL) to achieve high-efficiency planar heterojunction perovskite solar cells is demonstrated. Perovskite solar cells based on using Cu-doped NiOx HTL show a remarkably improved power conversion efficiency up to 15.40% due to the improved electrical conductivity and enhanced perovskite film quality. General applicability of Cu-doped NiOx to larger bandgap perovskites is also demonstrated in this study. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Longhorn Business Jets

NASA Technical Reports Server (NTRS)

1980-01-01

Developed in NASA's Aircraft Energy Efficiency program and manufactured by Gates Learjet Corporation, the winglet is an aerodynamic innovation designed to reduce fuel consumption and improve airplane performance. Winglets are lifting surfaces designed to operate in the "vortex" or air whirlpool which occurs at an airplane's wingtip. Complex flow of air around wingtip creates drag which retards the plane's progress. Winglet reduces strength of vortex and thereby reduces strength of drag. Additionally, winglet generates its own lift, producing forward thrust in the manner of a boat's sail. Combination of reduced drag and additional thrust adds up to significant improvement in fuel efficiency.

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

Albrecht H. Mayer

Asea Brown Boveri (ABB) has completed its technology based program. The results developed under Work Breakdown Structure (WBS) 8, concentrated on technology development and demonstration have been partially implemented in newer turbine designs. A significant improvement in heat rate and power output has been demonstrated. ABB will use the knowledge gained to further improve the efficiency of its Advanced Cycle System, which has been developed and introduced into the marked out side ABB's Advanced Turbine System (ATS) activities. The technology will lead to a power plant design that meets the ATS performance goals of over 60% plant efficiency, decreased electricitymore » costs to consumers and lowest emissions.« less

The Failure of Eco-Efficiency to Guarantee Sustainability: Future Challenges for Industrial Ecology

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

Huesemann, Michael H.

Western industrialized societies are inherently unsustainable in their present form because they depend almost exclusively on a finite supply of non-renewable minerals and fossil fuels. In addition, the resulting wastes cause various environmental problems ranging from widespread ecosystem disruptions to global warming. The most common response to these problems has been to promote technological improvements in eco-efficiency, which may be defined as ''adding maximum value with minimum resource use and minimum pollution'' (Welford 1997). While constructive, improvements in eco-efficiency alone will not guarantee sustainability of industrialized societies because the limited supplies of non-renewable minerals cannot be extended indefinitely via recyclingmore » and substitution, and a transition to renewable and nuclear energy sources would result in significant negative environmental impacts, particularly if deployed on a large scale. In addition, according to the second law of thermodynamics, industrial production technologies have inherently unavoidable environmental impacts. Finally, any hard won improvements in eco-efficiency will soon be negated if growth in population and consumption is allowed to continue. Consequently, long-term industrial sustainability can only be achieved through a transition to a steady-state economy where the total throughput of matter-energy is kept at a constant and sustainable level. This requires not only improvements in eco-efficiency but also a reassessment of fundamental societal values that erroneously equate material consumption and economic growth with well-being and happiness.« less

Defect-Reduction Mechanism for Improving Radiative Efficiency in InGaN/GaN Light-Emitting Diodes using InGaN Underlayers

DOE PAGES

Armstrong, Andrew M.; Bryant, Benjamin N.; Crawford, Mary H.; ...

2015-04-01

The influence of a dilute In xGa 1-xN (x~0.03) underlayer (UL) grown below a single In 0.16Ga 0.84N quantum well (SQW), within a light-emitting diode(LED), on the radiative efficiency and deep level defect properties was studied using differential carrier lifetime (DCL) measurements and deep level optical spectroscopy (DLOS). DCL measurements found that inclusion of the UL significantly improved LED radiative efficiency. At low current densities, the non-radiative recombination rate of the LED with an UL was found to be 3.9 times lower than theLED without an UL, while the radiative recombination rates were nearly identical. This, then, suggests that themore » improved radiative efficiency resulted from reduced non-radiative defect concentration within the SQW. DLOS measurement found the same type of defects in the InGaN SQWs with and without ULs. However, lighted capacitance-voltage measurements of the LEDs revealed a 3.4 times reduction in a SQW-related near-mid-gap defect state for the LED with an UL. Furthermore, quantitative agreement in the reduction of both the non-radiative recombination rate (3.9×) and deep level density (3.4×) upon insertion of an UL corroborates deep level defect reduction as the mechanism for improved LED efficiency.« less

The Technical Efficiency of Earthquake Medical Rapid Response Teams Following Disasters: The Case of the 2010 Yushu Earthquake in China.

PubMed

Liu, Xu; Tang, Bihan; Yang, Hongyang; Liu, Yuan; Xue, Chen; Zhang, Lulu

2015-12-04

Performance assessments of earthquake medical rapid response teams (EMRRTs), particularly the first responders deployed to the hardest hit areas following major earthquakes, should consider efficient and effective use of resources. This study assesses the daily technical efficiency of EMRRTs in the emergency period immediately following the 2010 Yushu earthquake in China. Data on EMRRTs were obtained from official daily reports of the general headquarters for Yushu earthquake relief, the emergency office of the National Ministry of Health, and the Health Department of Qinghai Province, for a sample of data on 15 EMRRTs over 62 days. Data envelopment analysis was used to examine the technical efficiency in a constant returns to scale model, a variable returns to scale model, and the scale efficiency of EMRRTs. Tobit regression was applied to analyze the effects of corresponding influencing factors. The average technical efficiency scores under constant returns to scale, variable returns to scale, and the scale efficiency scores of the 62 units of analysis were 77.95%, 89.00%, and 87.47%, respectively. The staff-to-bed ratio was significantly related to global technical efficiency. The date of rescue was significantly related to pure technical efficiency. The type of institution to which an EMRRT belonged and the staff-to-bed ratio were significantly related to scale efficiency. This study provides evidence that supports improvements to EMRRT efficiency and serves as a reference for earthquake emergency medical rapid assistance leaders and teams.

Use of Lean methodology to improve operating room efficiency in hospitals across the Kingdom of Saudi Arabia.

PubMed

Hassanain, Mazen; Zamakhshary, Mohammed; Farhat, Ghada; Al-Badr, Ahmed

2017-04-01

The objective of this study was to assess whether an intervention on process efficiency using the Lean methodology leads to improved utilization of the operating room (OR), as measured by key performance metrics of OR efficiency. A quasi-experimental design was used to test the impact of the intervention by comparing pre-intervention and post-intervention data on five key performance indicators. The ORs of 12 hospitals were selected across regions of the Kingdom of Saudi Arabia (KSA). The participants were patients treated at these hospitals during the study period. The intervention comprised the following: (i) creation of visual dashboards that enable starting the first case on time; (ii) use of computerized surgical list management; (iii) optimization of time allocation; (iv) development of an operating model with policies and procedures for the pre-anesthesia clinic; and (iv) creation of a governance structure with policies and procedures for day surgeries. The following were the main outcome measures: on-time start for the first case, room turnover times, percent of overrun cases, average weekly procedure volume and OR utilization. The hospital exhibited statistically significant improvements in the following performance metrics: on-time start for the first case, room turnover times and percent of overrun cases. A statistically significant difference in OR utilization or average weekly procedure volumes was not detected. The implementation of a Lean-based intervention targeting process efficiency applied in ORs across various KSA hospitals resulted in encouraging results on some metrics at some sites, suggesting that the approach has the potential to produce significant benefit in the future. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

DOVIS 2.0: an efficient and easy to use parallel virtual screening tool based on AutoDock 4.0.

PubMed

Jiang, Xiaohui; Kumar, Kamal; Hu, Xin; Wallqvist, Anders; Reifman, Jaques

2008-09-08

Small-molecule docking is an important tool in studying receptor-ligand interactions and in identifying potential drug candidates. Previously, we developed a software tool (DOVIS) to perform large-scale virtual screening of small molecules in parallel on Linux clusters, using AutoDock 3.05 as the docking engine. DOVIS enables the seamless screening of millions of compounds on high-performance computing platforms. In this paper, we report significant advances in the software implementation of DOVIS 2.0, including enhanced screening capability, improved file system efficiency, and extended usability. To keep DOVIS up-to-date, we upgraded the software's docking engine to the more accurate AutoDock 4.0 code. We developed a new parallelization scheme to improve runtime efficiency and modified the AutoDock code to reduce excessive file operations during large-scale virtual screening jobs. We also implemented an algorithm to output docked ligands in an industry standard format, sd-file format, which can be easily interfaced with other modeling programs. Finally, we constructed a wrapper-script interface to enable automatic rescoring of docked ligands by arbitrarily selected third-party scoring programs. The significance of the new DOVIS 2.0 software compared with the previous version lies in its improved performance and usability. The new version makes the computation highly efficient by automating load balancing, significantly reducing excessive file operations by more than 95%, providing outputs that conform to industry standard sd-file format, and providing a general wrapper-script interface for rescoring of docked ligands. The new DOVIS 2.0 package is freely available to the public under the GNU General Public License.

Efficiency of lithium pacemaker batteries as a function of discharge rate and iodine:P2VP cathode composition

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

Helgeson, W.D.; Fester, K.E.

1980-01-01

Electrochemical discharge data for Li/I/sub 2/-P2VP pacemaker batteries at various discharge currents show the efficiency of the battery to be a function of discharge current. Depending on the iodine:P2VP cathode composition, the optimum current drain occurs between discharge currents of 100 to 200 /mu/a. As current drain is reduced to pacemaker application drains, 15-25 /mu/a, the efficiency of the Li/I/sub 2/-P2VP battery decreases. The loss in efficiency at pacemaker rates is attributed primarily to self-discharge. The efficiency of Li/I/sub 2/-P2VP batteries is improved by increasing the percent of iodine in the cathode. I/sub 2/:P2VP weight ratios of 10:1, 15:1 andmore » 20:1 have been discharged at various currents and the data indicate that there is significant improvement in efficiency at pacemaker rate in going from 10:1 to 20:1 cathode weight ratio. 2 refs.« less

Efficient convolutional sparse coding

DOEpatents

Wohlberg, Brendt

2017-06-20

Computationally efficient algorithms may be applied for fast dictionary learning solving the convolutional sparse coding problem in the Fourier domain. More specifically, efficient convolutional sparse coding may be derived within an alternating direction method of multipliers (ADMM) framework that utilizes fast Fourier transforms (FFT) to solve the main linear system in the frequency domain. Such algorithms may enable a significant reduction in computational cost over conventional approaches by implementing a linear solver for the most critical and computationally expensive component of the conventional iterative algorithm. The theoretical computational cost of the algorithm may be reduced from O(M.sup.3N) to O(MN log N), where N is the dimensionality of the data and M is the number of elements in the dictionary. This significant improvement in efficiency may greatly increase the range of problems that can practically be addressed via convolutional sparse representations.

Effects of TiO2 NPs on Silkworm Growth and Feed Efficiency.

PubMed

Li, YangYang; Ni, Min; Li, FanChi; Zhang, Hua; Xu, KaiZun; Zhao, XiaoMing; Tian, JiangHai; Hu, JingSheng; Wang, BinBin; Shen, WeiDe; Li, Bing

2016-02-01

Silkworm (Bombyx mori) (B. mori) is an economically important insect and a model species for Lepidoptera. It has been reported that feeding of low concentrations of titanium dioxide nanoparticles (TiO2 NPs) can improve feed efficiency and increase cocoon mass, cocoon shell mass, and the ratio of cocoon shell. However, high concentrations of TiO2 NPs are toxic. In this study, we fed B. mori with different concentrations of TiO2 NPs (5, 10, 20, 40, 80, and 160 mg/L) and investigated B. mori growth, feed efficiency, and cocoon quality. We found that low concentrations of TiO2 NPs (5 and 10 mg/L) were more effective for weight gains, with significant weight gain being obtained at 72 h (P < 0.05). TiO2 NPs at 20 mg/L or higher had certain inhibitory effects, with significant inhibition to B. mori growth being observed at 48 h. The feed efficiency was significantly improved at low concentrations of 5 and 10 mg/L for 14.6 and 13.1 %, respectively (P < 0.05). All B. mori fed with TiO2 NPs showed increased cocoon mass and cocoon shell mass; at 5 and 10 mg/L TiO2 NPs, cocoon mass was significantly increased by 8.29 and 9.39 %, respectively (P < 0.05). We also found that low concentrations (5 and 10 mg/L) of TiO2 NPs promoted B. mori growth and development, improved feed efficiency, and increased cocoon production, while high concentrations (20 mg/L or higher) of TiO2 NPs showed inhibitory effect to the B. mori. Consecutive feeding of high concentrations of TiO2 NPs led to some degrees of adaptability. This study provides a reference for the research on TiO2 NPs toxicity and the basis for the development of TiO2 NPs as a feed additive for B. mori.

Hybrid Power Management Program Evaluated Fuel Cell/Ultracapacitor Combinations and Developed Other New Applications

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.

2004-01-01

In fiscal year 2003, the continuation of the Hybrid Power Management (HPM) Program through NASA Glenn Research Center's Commercial Technology Office resulted in several new successful applications of this pioneering technology. HPM is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors, fuel cells, and photovoltaics. HPM has extremely wide potential, with applications from nanowatts to megawatts--including power generation, transportation systems, biotechnology systems, and space power systems. HPM has the potential to significantly alleviate global energy concerns, improve the environment, and stimulate the economy. Fuel cells provide excellent efficiency and energy density, but do not have good power density. In contrast, ultracapacitors have excellent power density and virtually unlimited cycle life. To improve the power density of the fuel cell, the combination of fuel cells and ultracapacitors was evaluated.

Health and productivity gains from better indoor environments and their relationship with building energy efficiency

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

Fisk, William J.

2000-04-01

Theoretical considerations and empirical data suggest that existing technologies and procedures can improve indoor environments in a manner that significantly increases productivity and health. Existing literature contains moderate to strong evidence that characteristics of buildings and indoor environments significantly influence rates of communicable respiratory illness, allergy and asthma symptoms, sick building symptoms, and worker performance. While there is considerable uncertainty in the estimates of the magnitudes of productivity gains that may be obtained by providing better indoor environments, the projected gains are very large. For the U.S., the estimated potential annual savings and productivity gains are $6 to $14 billionmore » from reduced respiratory disease, $2 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance that are unrelated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment.« less

Reducing RN Vacancy Rate: A Nursing Recruitment Office Process Improvement Project.

PubMed

Hisgen, Stephanie A; Page, Nancy E; Thornlow, Deirdre K; Merwin, Elizabeth I

2018-06-01

The aim of this study was to reduce the RN vacancy rate at an academic medical center by improving the hiring process in the Nursing Recruitment Office. Inability to fill RN positions can lead to higher vacancy rates and negatively impact staff and patient satisfaction, quality outcomes, and the organization's bottom line. The Model for Improvement was used to design and implement a process improvement project to improve the hiring process from time of interview through the position being filled. Number of days to interview and check references decreased significantly, but no change in overall time to hire and time to fill positions was noted. RN vacancy rate also decreased significantly. Nurse manager satisfaction with the hiring process increased significantly. Redesigning the recruitment process supported operational efficiencies of the organization related to RN recruitment.

Healthcare Commercialization Programs: Improving the Efficiency of Translating Healthcare Innovations From Academia Into Practice

PubMed Central

Reizes, Ofer; Dempsey, Michael K.

2016-01-01

Academic investigators are generating a plethora of insights and technologies that have the potential to significantly improve patient care. However, to address the imperative to improve the quality, cost and access to care with ever more constrained funding, the efficiency and the consistency with which they are translated into cost effective products and/or services need to improve. Healthcare commercialization programs (HCPs) are described and proposed as an option that institutions can add to their portfolio to improve translational research. In helping teams translate specific healthcare innovations into practice, HCPs expand the skillset of investigators and enhance an institution’s innovation capacity. Lessons learned are shared from configuring and delivering HCPs, which build on the fundamentals of the National Science Foundation’s Innovation Corps program, to address the unique challenges in supporting healthcare innovations and innovators. PMID:27766188

Cost per RN hired.

PubMed

Hoffman, F M

1985-02-01

Costs of recruiting, hiring, and training new staff members can be significant. This article demonstrates a method for analyzing the components of these costs to target areas where improved efficiency can lead to lower costs.

Advanced Traffic Signal Control Algorithms

DOT National Transportation Integrated Search

2016-05-01

Vehicle convoys (platoons) hold a promise for significant efficiency improvements of freight and passenger transportation through better system integration. Through the use of advanced driver assistance, vehicles in a convoy can keep shorter distance...

New Developments in Robotics and Single-site Gynecologic Surgery.

PubMed

Matthews, Catherine A

2017-06-01

Within the last 10 years there have been significant advances in minimal-access surgery. Although no emerging technology has demonstrated improved outcomes or fewer complications than standard laparoscopy, the introduction of the robotic surgical platform has significantly lowered abdominal hysterectomy rates. While operative time and cost were higher in robotic-assisted procedures when the technology was first introduced, newer studies demonstrate equivalent or improved robotic surgical efficiency with increased experience. Single-port hysterectomy has not improved postoperative pain or subjective cosmetic results. Emerging platforms with flexible, articulating instruments may increase the uptake of single-port procedures including natural orifice transluminal endoscopic cases.

Hole-Accepting-Ligand-Modified CdSe QDs for Dramatic Enhancement of Photocatalytic and Photoelectrochemical Hydrogen Evolution by Solar Energy.

PubMed

Li, Xu-Bing; Liu, Bin; Wen, Min; Gao, Yu-Ji; Wu, Hao-Lin; Huang, Mao-Yong; Li, Zhi-Jun; Chen, Bin; Tung, Chen-Ho; Wu, Li-Zhu

2016-04-01

Solar H 2 evolution of CdSe QDs can be significantly enhanced simply by introducing a suitable hole-accepting-ligand for achieving efficient hole extraction and transfer at the nanoscale interfaces, which opens an effective pathway for dissociation of excitons to generate long-lived charge separation, thus improving the solar-to-fuel conversion efficiency.

Fuel Efficiencies Through Airframe Improvements

NASA Technical Reports Server (NTRS)

Bezos-O'Connor, Gaudy M.; Mangelsdorf, Mark F.; Maliska, Heather A.; Washburn, Anthony E.; Wahls, Richard A.

2011-01-01

The factors of continuing strong growth in air traffic volume, the vital role of the air transport system on the economy, and concerns about the environmental impact of aviation have added focus to the National Aeronautics Research Policy. To address these concerns in the context of the National Policy, NASA has set aggressive goals in noise reduction, emissions, and energy consumption. With respect to the goal of reducing energy consumption in the fleet, the development of promising airframe technologies is required to realize the significant improvements that are desired. Furthermore, the combination of advances in materials and structures with aerodynamic technologies may lead to a paradigm shift in terms of potential configurations for the future. Some of these promising airframe technologies targeted at improved efficiency are highlighted.

Performance improvement of AlGaN-based deep-ultraviolet light-emitting diodes via Al-composition graded quantum wells

NASA Astrophysics Data System (ADS)

Lu, Lin; Zhang, Yu; Xu, Fujun; Ding, Gege; Liu, Yuhang

2018-06-01

Characteristics of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) with step-like and Al-composition graded quantum wells have been investigated. The simulation results show that compared to DUV-LEDs with the conventional AlGaN multiple quantum wells (MQWs) structure, the light output power (LOP) and efficiency droop of DUV-LEDs with the Al-composition graded wells were remarkably improved. The key factor accounting for the improved performance is ascribed to the better modulation of carrier distribution in the quantum wells to increase the overlap between electron and hole wavefunctions, which contributes to more efficient recombination of electrons and holes, and thereby a significant enhancement in the LOP.

Efficient high-order structure-preserving methods for the generalized Rosenau-type equation with power law nonlinearity

NASA Astrophysics Data System (ADS)

Cai, Jiaxiang; Liang, Hua; Zhang, Chun

2018-06-01

Based on the multi-symplectic Hamiltonian formula of the generalized Rosenau-type equation, a multi-symplectic scheme and an energy-preserving scheme are proposed. To improve the accuracy of the solution, we apply the composition technique to the obtained schemes to develop high-order schemes which are also multi-symplectic and energy-preserving respectively. Discrete fast Fourier transform makes a significant improvement to the computational efficiency of schemes. Numerical results verify that all the proposed schemes have satisfactory performance in providing accurate solution and preserving the discrete mass and energy invariants. Numerical results also show that although each basic time step is divided into several composition steps, the computational efficiency of the composition schemes is much higher than that of the non-composite schemes.

Genetic variation in efficiency to deposit fat and lean meat in Norwegian Landrace and Duroc pigs.

PubMed

Martinsen, K H; Ødegård, J; Olsen, D; Meuwissen, T H E

2015-08-01

Feed costs amount to approximately 70% of the total costs in pork production, and feed efficiency is, therefore, an important trait for improving pork production efficiency. Production efficiency is generally improved by selection for high lean growth rate, reduced backfat, and low feed intake. These traits have given an effective slaughter pig but may cause problems in piglet production due to sows with limited body reserves. The aim of the present study was to develop a measure for feed efficiency that expressed the feed requirements per 1 kg deposited lean meat and fat, which is not improved by depositing less fat. Norwegian Landrace ( = 8,161) and Duroc ( = 7,202) boars from Topigs Norsvin's testing station were computed tomography scanned to determine their deposition of lean meat and fat. The trait was analyzed in a univariate animal model, where total feed intake in the test period was the dependent variable and fat and lean meat were included as random regression cofactors. These cofactors were measures for fat and lean meat efficiencies of individual boars. Estimation of fraction of total genetic variance due to lean meat or fat efficiency was calculated by the ratio between the genetic variance of the random regression cofactor and the total genetic variance in total feed intake during the test period. Genetic variance components suggested there was significant genetic variance among Norwegian Landrace and Duroc boars in efficiency for deposition of lean meat (0.23 ± 0.04 and 0.38 ± 0.06) and fat (0.26 ± 0.03 and 0.17 ± 0.03) during the test period. The fraction of the total genetic variance in feed intake explained by lean meat deposition was 12% for Norwegian Landrace and 15% for Duroc. Genetic fractions explained by fat deposition were 20% for Norwegian Landrace and 10% for Duroc. The results suggested a significant part of the total genetic variance in feed intake in the test period was explained by fat and lean meat efficiency. These new efficiency measures may give the breeders opportunities to select for animals with a genetic potential to deposit lean meat efficiently and at low feed costs in slaughter pigs rather than selecting for reduced the feed intake and backfat.

Solar upconversion with plasmon-enhanced bimolecular complexes

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

Dionne, Jennifer

2017-04-14

Upconversion of sub-bandgap photons is a promising approach to exceed the Shockley-Queisser limit in solar technologies. However, due to the low quantum efficiencies and narrow absorption bandwidths of upconverters, existing systems have only led to fractional percent improvements in photovoltaic devices (~0.01%). In this project, we aimed to develop an efficient upconverting material that could improve cell efficiencies by at least one absolute percent. To achieve this goal, we first used thermodynamic calculations to determine cell efficiencies with realistic upconverting materials. Then, we designed, synthesized, and characterized nanoantennas that promise >100x enhancement in both the upconverter absorption cross-section and emissivemore » radiative rate. Concurrently, we optimized the upconverer by designing new ionic and molecular complexes that promise efficient solid-state upconversion. Lastly, with Bosch, we simulated record-efficiency semi-transparent cells that will allow for ready incorporation of our upconverting materials. While we were not successful in designing record efficiency upconverters during our three years of funding, we gained significant insight into the existing limitations of upconverters and how to best address these challenges. Ongoing work is aimed at addressing these limitations, to make upconversion a cost-competitive solar technology in future years.« less

JT8D-15/17 High Pressure Turbine Root Discharged Blade Performance Improvement. [engine design

NASA Technical Reports Server (NTRS)

Janus, A. S.

1981-01-01

The JT8D high pressure turbine blade and seal were modified, using a more efficient blade cooling system, improved airfoil aerodynamics, more effective control of secondary flows, and improved blade tip sealing. Engine testing was conducted to determine the effect of these improvements on performance. The modified turbine package demonstrated significant thrust specific fuel consumption and exhaust gas temperature improvements in sea level and altitude engine tests. Inspection of the improved blade and seal hardware after testing revealed no unusual wear or degradation.

Integrated Practice Improvement Solutions-Practical Steps to Operating Room Management.

PubMed

Chernov, Mikhail; Pullockaran, Janet; Vick, Angela; Leyvi, Galina; Delphin, Ellise

2016-10-01

Perioperative productivity is a vital concern for surgeons, anesthesiologists, and administrators as the OR is a major source of hospital elective admissions and revenue. Based on elements of existing Practice Improvement Methodologies (PIMs), "Integrated Practice Improvement Solutions" (IPIS) is a practical and simple solution incorporating aspects of multiple management approaches into a single open source framework to increase OR efficiency and productivity by better utilization of existing resources. OR efficiency was measured both before and after IPIS implementation using the total number of cases versus room utilization, OR/anesthesia revenue and staff overtime (OT) costs. Other parameters of efficiency, such as the first case on-time start and the turnover time (TOT) were measured in parallel. IPIS implementation resulted in increased numbers of surgical procedures performed by an average of 10.7%, and OR and anesthesia revenue increases of 18.5% and 6.9%, respectively, with a simultaneous decrease in TOT (15%) and OT for anesthesia staff (26%). The number of perioperative adverse events was stable during the two-year study period which involved a total of 20,378 patients. IPIS, an effective and flexible practice improvement model, was designed to quickly, significantly, and sustainably improve OR efficiency by better utilization of existing resources. Success of its implementation directly correlates with the involvement of and acceptance by the entire OR team and hospital administration.

Predictive control strategy of a gas turbine for improvement of combined cycle power plant dynamic performance and efficiency.

PubMed

Mohamed, Omar; Wang, Jihong; Khalil, Ashraf; Limhabrash, Marwan

2016-01-01

This paper presents a novel strategy for implementing model predictive control (MPC) to a large gas turbine power plant as a part of our research progress in order to improve plant thermal efficiency and load-frequency control performance. A generalized state space model for a large gas turbine covering the whole steady operational range is designed according to subspace identification method with closed loop data as input to the identification algorithm. Then the model is used in developing a MPC and integrated into the plant existing control strategy. The strategy principle is based on feeding the reference signals of the pilot valve, natural gas valve, and the compressor pressure ratio controller with the optimized decisions given by the MPC instead of direct application of the control signals. If the set points for the compressor controller and turbine valves are sent in a timely manner, there will be more kinetic energy in the plant to release faster responses on the output and the overall system efficiency is improved. Simulation results have illustrated the feasibility of the proposed application that has achieved significant improvement in the frequency variations and load following capability which are also translated to be improvements in the overall combined cycle thermal efficiency of around 1.1 % compared to the existing one.

Framework for the Intelligent Transportation System (ITS) Evaluation : ITS Integration Activities

DOT National Transportation Integrated Search

2006-08-01

Intelligent Transportation Systems (ITS) represent a significant opportunity to improve the efficiency and safety of the surface transportation system. ITS includes technologies to support information processing, communications, surveillance and cont...

Identification of barriers and research opportunities to improve the effective and efficient application of adjunct UVC surface disinfection in healthcare

NASA Astrophysics Data System (ADS)

Martinello, Richard A.; Miller, Shelly L.; Fabian, M. Patricia; Peccia, Jordan

2018-02-01

Healthcare associated infections (HAI) affect approximately 1 of every 25 hospitalized patients, lead to substantial morbidity and mortality, degrade patient experience and are costly. Risks for HAI are multifactorial and it is known that microbial contamination of the healthcare environment increases risk for HAI. Portable ultraviolet-C (UVC) surface disinfection as an adjunct to standard hospital disinfection has been shown to decrease both surface microbial contamination and HAI. However, there remain significant gaps in the understanding of the efficient and effective application of UVC in healthcare. Specific barriers identified are: 1) the variability in size, shape, and surface materials of hospital rooms as well as the presence of medical devices and furniture, which impacts the amount of UVC energy delivered to surfaces and its disinfection efficiency; 2) the significant resources needed to acquire and efficiently use UVC equipment and achieve the desired patient benefits- a particular challenge for complex healthcare facilities with limited operating margins; and 3) the lack of implementation guidance and industry standard methods for measuring the UVC output and antimicrobial effects from the multiple commercial UVC options available. An improved understanding of the efficient and effective use of UVC surface disinfection in healthcare and the implementation of standard device industry metrics may lead to increased use and decrease the burden of HAI.

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

Polymeric nano-encapsulation of 5-fluorouracil enhances anti-cancer activity and ameliorates side effects in solid Ehrlich Carcinoma-bearing mice.

PubMed

Haggag, Yusuf A; Osman, Mohamed A; El-Gizawy, Sanaa A; Goda, Ahmed E; Shamloula, Maha M; Faheem, Ahmed M; McCarron, Paul A

2018-05-29

Biodegradable PLGA nanoparticles, loaded with 5-fluorouracil (5FU), were prepared using a double emulsion method and characterised in terms of mean diameter, zeta potential, entrapment efficiency and in vitro release. Poly (vinyl alcohol) was used to modify both internal and external aqueous phases and shown have a significant effect on nanoparticulate size, encapsulation efficiency and the initial burst release. Addition of poly (ethylene glycol) to the particle matrix, as part of the polymeric backbone, improved significantly the encapsulation efficiency. 5FU-loaded NPs were spherical in shape and negatively charged with a size range of 185-350 nm. Biological evaluation was performed in vivo using a solid Ehrlich carcinoma (SEC) murine model. An optimised 5FU-loaded formulation containing PEG as part of a block copolymer induced a pronounced reduction in tumour volume and tumour weight, together with an improved percentage tumour growth inhibition. Drug-loaded nanoparticles showed no significant toxicity or associated changes on liver and kidney function in tested animals, whereas increased alanine aminotransferase, aspartate aminotransferase and serum creatinine were observed in animals treated with free 5FU. Histopathological examination demonstrated enhanced cytotoxic action of 5FU-loaded nanoparticles when compared to the free drug. Based on these findings, it was concluded that nano-encapsulation of 5FU using PEGylated PLGA improved encapsulation and sustained in vitro release. This leads to increased anti-tumour efficacy against SEC, with a reduction in adverse effects. Published by Elsevier Masson SAS.

Measuring the efficiency of Palestinian public hospitals during 2010-2015: an application of a two-stage DEA method.

PubMed

Sultan, Wasim I M; Crispim, José

2018-05-29

While health needs and expenditure in the Occupied Palestinian Territories (OPT) are growing, the international donations are declining and the economic situation is worsening. The purpose of this paper is twofold, to evaluate the productive efficiency of public hospitals in West Bank and to study contextual factors contributing to efficiency differences. This study examined technical efficiency among 11 public hospitals in West Bank from 2010 through 2015 targeting a total of 66 observations. Nationally representative data were extracted from the official annual health reports. We applied input-oriented Data Envelopment Analysis (DEA) models to estimate efficiency scores. To elaborate further on performance, we used Tobit regression to identify contextual factors whose impact on inefficient performance is statistically significant. Despite the increase in efficiency mean scores by 4% from 2010 to 2015, findings show potential savings of 14.5% of resource consumption without reducing the volume of the provided services. The significant Tobit model showed four predictors explaining the inefficient performance of a hospital (p <  0.01) are: bed occupancy rate (BOR); the outpatient-inpatient ratio (OPIPR); hospital's size (SIZE); and the availability of primary healthcare centers within the hospital's catchment area (PRC). There is a strong effect of OPIPR on efficiency differences between hospitals: A one unit increase in OPIPR will lead a decrease of 19.7% in the predicted inefficiency level holding all other factors constant. To date, no previous studies have examined the efficiency of public hospitals in the OPT. Our work identified their efficiency levels for potential improvements and the determinants of efficient performance. Based on the measurement of efficiency, the generated information may guide hospitals' managers, policymakers, and international donors improving the performance of the main national healthcare provider. The scope of this study is limited to public hospitals in West Bank. For a better understanding of the Palestinian market, further research on private hospitals and hospitals in Gaza Strip will be useful.

Energy, cost and design aspects of coarse- and fine-bubble aeration systems in the MBBR IFAS process.

PubMed

Sander, S; Behnisch, J; Wagner, M

2017-02-01

With the MBBR IFAS (moving bed biofilm reactor integrated fixed-film activated sludge) process, the biomass required for biological wastewater treatment is either suspended or fixed on free-moving plastic carriers in the reactor. Coarse- or fine-bubble aeration systems are used in the MBBR IFAS process. In this study, the oxygen transfer efficiency (OTE) of a coarse-bubble aeration system was improved significantly by the addition of the investigated carriers, even in-process (∼1% per vol-% of added carrier material). In a fine-bubble aeration system, the carriers had little or no effect on OTE. The effect of carriers on OTE strongly depends on the properties of the aeration system, the volumetric filling rate of the carriers, the properties of the carrier media, and the reactor geometry. This study shows that the effect of carriers on OTE is less pronounced in-process compared to clean water conditions. When designing new carriers in order to improve their effect on OTE further, suppliers should take this into account. Although the energy efficiency and cost effectiveness of coarse-bubble aeration systems can be improved significantly by the addition of carriers, fine-bubble aeration systems remain the more efficient and cost-effective alternative for aeration when applying the investigated MBBR IFAS process.

The efficacy of unsupervised home-based exercise regimens in comparison to supervised laboratory-based exercise training upon cardio-respiratory health facets.

PubMed

Blackwell, James; Atherton, Philip J; Smith, Kenneth; Doleman, Brett; Williams, John P; Lund, Jonathan N; Phillips, Bethan E

2017-09-01

Supervised high-intensity interval training (HIIT) can rapidly improve cardiorespiratory fitness (CRF). However, the effectiveness of time-efficient unsupervised home-based interventions is unknown. Eighteen volunteers completed either: laboratory-HIIT (L-HIIT); home-HIIT (H-HIIT) or home-isometric hand-grip training (H-IHGT). CRF improved significantly in L-HIIT and H-HIIT groups, with blood pressure improvements in the H-IHGT group only. H-HIIT offers a practical, time-efficient exercise mode to improve CRF, away from the laboratory environment. H-IHGT potentially provides a viable alternative to modify blood pressure in those unable to participate in whole-body exercise. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

High Efficiency, Clean Combustion

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

Donald Stanton

2010-03-31

Energy use in trucks has been increasing at a faster rate than that of automobiles within the U.S. transportation sector. According to the Energy Information Administration (EIA) Annual Energy Outlook (AEO), a 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected between 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow between 2009 and 2050 while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast,more » the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. economy. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. Over 90% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. Given the vital role that the trucking industry plays in the economy, improving the efficiency of the transportation of goods was a central focus of the Cummins High Efficient Clean Combustion (HECC) program. In a commercial vehicle, the diesel engine remains the largest source of fuel efficiency loss, but remains the greatest opportunity for fuel efficiency improvements. In addition to reducing oil consumption and the dependency on foreign oil, this project will mitigate the impact on the environment by meeting US EPA 2010 emissions regulations. Innovation is a key element in sustaining a U.S. trucking industry that is competitive in global markets. Unlike passenger vehicles, the trucking industry cannot simply downsize the vehicle and still transport the freight with improved efficiency. The truck manufacturing and supporting industries are faced with numerous challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. The HECC program successfully reduced engine fuel consumption and greenhouse gases while providing greater customer valve. The US EPA 2010 emissions standard poses a significant challenge for developing clean diesel powertrains that meet the DoE Vehicle Technologies Multi-Year Program Plan (MYPP) for fuel efficiency improvement while remaining affordable. Along with exhaust emissions, an emphasis on heavy duty vehicle fuel efficiency is being driven by increased energy costs as well as the potential regulation of greenhouse gases. An important element of the success of meeting emissions while significantly improving efficiency is leveraging Cummins component technologies such as fuel injection equipment, aftertreatment, turbomahcinery, electronic controls, and combustion systems. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 55% peak brake thermal efficiency for the engine plus aftertreatment system. The first step in developing high efficiency clean products has been supported by the DoE co-sponsored HECC program. The objectives of the HECC program are: (1) To design and develop advanced diesel engine architectures capable of achieving US EPA 2010 emission regulations while improving the brake thermal efficiency by 10% compared to the baseline (a state of the art 2007 production diesel engine). (2) To design and develop components and subsystems (fuel systems, air handling, controls, etc) to enable construction and development of multi-cylinder engines. (3) To perform an assessment of the commercial viability of the newly developed engine technology. (4) To specify fuel properties conducive to improvements in emissions, reliability, and fuel efficiency for engines using high-efficiency clean combustion (HECC) technologies. To demonstrate the technology is compatible with B20 (biodiesel). (5) To further improve the brake thermal efficiency of the engine as integrated into the vehicle. To demonstrate robustness and commercial viability of the HECC engine technology as integrated into the vehicles. The Cummins HECC program supported the Advanced Combustion Engine R&D and Fuels Technology initiatives of the DoE Vehicle Technologies Multi-Year Program Plan (MYPP). In particular, the HECC project goals enabled the DoE Vehicle Technologies Program (VTP) to meet energy-efficiency improvement targets for advanced combustion engines suitable for passenger and commercial vehicles, as well as addressing technology barriers and R&D needs that are common between passenger and commercial vehicle applications of advanced combustion engines.« less

Photonics Research and Development

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

Dickson, Elizabeth

During the period August 2005 through October 2009, the UNLV Research Foundation (UNLVRF), a non-profit affiliate of the University of Nevada, Las Vegas (UNLV), in collaboration with UNLV's Colleges of Science and Engineering; Boston University (BU); Oak Ridge National Laboratory (ORNL); and Sunlight Direct, LLC, has managed and conducted a diverse and comprehensive research and development program focused on light-emitting diode (LED) technologies that provide significantly improved characteristics for lighting and display applications. This final technical report provides detailed information on the nature of the tasks, the results of the research, and the deliverables. It is estimated that about fivemore » percent of the energy used in the nation is for lighting homes, buildings and streets, accounting for some 25 percent of the average home's electric bill. However, the figure is significantly higher for the commercial sector. About 60 percent of the electricity for businesses is for lighting. Thus replacement of current lighting with solid-state lighting technology has the potential to significantly reduce this nation's energy consumption by some estimates, possibly as high as 20%. The primary objective of this multi-year R&D project has been to develop and advance lighting technologies to improve national energy conversion efficiencies; reduce heat load; and significantly lower the cost of conventional lighting technologies. The UNLVRF and its partners have specifically focused these talents on (1) improving LED technologies; (2) optimizing hybrid solar lighting, a technology which potentially offers the benefits of blending natural with artificial lighting systems, thus improving energy efficiency; and (3) building a comprehensive academic infrastructure within UNLV which concentrates on photonics R&D. Task researchers have reported impressive progress in (1) the development of quantum dot laser emitting diodes (QDLEDs) which will ultimately improve energy efficiency and lower costs for display and lighting applications (UNLV College of Engineering); (2) advancing green LED technology based on the Indium-Gallium-Nitride system (BU), thus improving conversion efficiencies; (3) employing unique state-of-the-art X-ray, electron and optical spectroscopies with microscopic techniques to learn more about the electronic structure of materials and contacts in LED devices (UNLV College of Science); (4) establishing a UNLV Display Lighting Laboratory staffed with a specialized team of academic researchers, students and industrial partners focused on identifying and implementing engineering solutions for lighting display-related problems; and (5) conducting research, development and demonstration for HSL essential to the resolution of technological barriers to commercialization.« less

[Treatment of acrylate wastewater by electrocatalytic reduction process].

PubMed

Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

2011-10-01

High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process.

Heavy Atom Effect of Bromine Significantly Enhances Exciton Utilization of Delayed Fluorescence Luminogens.

PubMed

Gan, Shifeng; Hu, Shimin; Li, Xiang-Long; Zeng, Jiajie; Zhang, Dongdong; Huang, Tianyu; Luo, Wenwen; Zhao, Zujin; Duan, Lian; Su, Shi-Jian; Tang, Ben Zhong

2018-05-23

Raising triplet exciton utilization of pure organic luminescent materials is of significant importance for efficiency advancement of organic light-emitting diodes (OLEDs). Herein, by introducing bromine atom(s) onto a typical molecule (bis(carbazol-9-yl)-4,5-dicyanobenzene) with thermally activated delayed fluorescence, we demonstrate that the heavy atom effect of bromine can increase spin-orbit coupling and promote the reverse intersystem crossing, which endow the molecules with more distinct delayed fluorescence. In consequence, the triplet exciton utilization is improved greatly with the increase of bromine atoms, affording apparently advanced external quantum efficiencies of OLEDs. Utilizing the enhancement effect of bromine atoms on delayed fluorescence should be a simple and promising design concept for efficient organic luminogens with high exciton utilization.

Improving the efficiency of cognitive-behavioural therapy by using formal client feedback.

PubMed

Janse, Pauline D; De Jong, Kim; Van Dijk, Maarten K; Hutschemaekers, Giel J M; Verbraak, Marc J P M

2017-09-01

Feedback from clients on their view of progress and the therapeutic relationship can improve effectiveness and efficiency of psychological treatments in general. However, what the added value is of client feedback specifically within cognitive-behavioural therapy (CBT), is not known. Therefore, the extent to which the outcome of CBT can be improved is investigated by providing feedback from clients to therapists using the Outcome Rating Scale (ORS) and Session Rating Scale (SRS). Outpatients (n = 1006) of a Dutch mental health organization either participated in the "treatment as usual" (TAU) condition, or in Feedback condition of the study. Clients were invited to fill in the ORS and SRS and in the Feedback condition therapists were asked to frequently discuss client feedback. Outcome on the SCL-90 was only improved specifically with mood disorders in the Feedback condition. Also, in the Feedback condition, in terms of process, the total number of required treatment sessions was on average two sessions fewer. Frequently asking feedback from clients using the ORS/SRS does not necessarily result in a better treatment outcome in CBT. However, for an equal treatment outcome significantly fewer sessions are needed within the Feedback condition, thus improving efficiency of CBT.

Organic-inorganic hybrid nanostructures for solar cell applications

NASA Astrophysics Data System (ADS)

AbdulAlmohsin, Samir M.

The enticing electro-optical properties of nanostructured materials such as carbon nanotubes, graphene, CdS nanocrystals and ZnO nanowrie bring new vigor into the innovation of photovoltaics. The main purpose of this dissertation is to develop novel nano-structured materials for low cost solar cell applications. Fabrication, characterization, and solar cell application of organic-inorganic hybrid structures are the main focus of this research. Polyaniline (PANI)/multi-walled carbon nanotube (MWNT) composite films were synthesized by an electrochemical polymerization of aniline with airbrushed MWNTs on ITO substrates. It was found that the incorporation of MWNTs in PANI effectively increase the film conductivity with a percolation threshold of 5% of nanotubes in the composite. The solar cell performance strongly depends on the conductivity of the composite films, which can be tuned by adjusting nanotube concentration. A higher conductivity resulted in a better cell performance, resulting from an efficient charge collection. This study indicates that PANI/MWNT composite films with optimized conductivity are potentially useful for low-cost hybrid solar cell applications. CdS nanocrystal-sensitized solar cells (NCSSCs) were investigated by using polyaniline (PANI) as a replacement for conventional platinum counter electrode. The growth time of the nanocrystals significantly affects the solar cell performance. At an optimum growth, the NCSSCs exhibit 0.83% of the conversion efficiency in comparison to 0.13% for the identical cells without CdS nanocrystals. Electrochemical impedance spectroscopy showed that the charge transfer in the solar cells with CdS nanocrystals was improved. The enhanced overall energy conversion efficiency by nanocrystals is attributed to improved light absorption and suppressed recombination rate of interfacial charges at the injection, resulting in significantly improved charge transfer and electron lifetime. In addition, the PANI electrodes with large surface area and ideal corrosion-inertness toward polysulfide redox exhibit promising application potential as a counter electrode for NCSSCs. This study demonstrates that the solution grown CdS nanocrystals and polyaniline are potentially useful for fabricating high performance NCSSCs, which is technically attractive for large scale and economic production. A hybrid structure containing graphene-enriched poly (3-hexylthiophene) (G-P3HT) or poly (3-hexylthiophene):(6, 6)-phenyl C60 butyric acid methyl esterand tetra (4-carboxyphenyle) porphyrin-grafted ZnO nanowire arrays was investigated for nanowire/polymer hybrid solar cells. The vertically aligned nanowires embedded in the organic films act as an active n-type semiconductor and a high-efficiency charge collection electrode. The grafting surface of ZnO nanowires by porphyrin was found to significantly improve the cell efficiency as compared with those using pristine ZnO nanowires. The improvement is attributed to the enhanced light harvesting and charge injection with the presence of porphyrin at the junction interface. A comparison study showed that the use of G-P3HT further increase the efficiency of the nanowire solar cells from 0.09 to 0.4%, benefiting from the improved hole collection with graphene in the polymer. This study indicates that hybrid structure comprising surface modified, vertically aligned ZnO nanowire arrays embedded in G-P3HT is promising for solar cell applications. A combination of bulk heterojunction of P3HT: PCBM with ZnO nanorod arrays was also studied for solar cell applications. In the P3HT: PCBM devices, electron donors such as poly (3-hexythiophene) (P3HT) and acceptors as (6, 6)-phenyl C61 butyric acid methyl ester (PCBM) are blended to form one mixed layer (a bulk heterojunction). The charge separation of photo-induced excitons is greatly enhanced by ultra-fast electron transfer and large interface between the two components. However, the charge collection is one of the main limitations for improving cell efficiency. In this study, ZnO nanowire arrys have been used to facilitate efficient charge collection electrodes for improving the energy conversion efficiency.

Energy Efficiency of the Outotec® Ausmelt Process for Primary Copper Smelting

NASA Astrophysics Data System (ADS)

Wood, Jacob; Hoang, Joey; Hughes, Stephen

2017-03-01

The global, non-ferrous smelting industry has witnessed the continual development and evolution of processing technologies in a bid to reduce operating costs and improve the safety and environmental performance of processing plants. This is particularly true in the copper industry, which has seen a number of bath smelting technologies developed and implemented during the past 30 years. The Outotec® Ausmelt Top Submerged Lance Process is one such example, which has been widely adopted in the modernisation of copper processing facilities in China and Russia. Despite improvements in the energy efficiency of modern copper smelting and converting technologies, additional innovation and development is required to further reduce energy consumption, whilst still complying with stringent environmental regulations. In response to this challenge, the Ausmelt Process has undergone significant change and improvement over the course of its history, in an effort to improve its overall competitiveness, particularly with respect to energy efficiency and operating costs. This paper covers a number of recent advances to the technology and highlights the impacts of these developments in reducing energy consumptions for a range of different copper flowsheets. It also compares the energy efficiency of the Ausmelt Process against the Bottom Blown Smelting process, which has become widely adopted in China over the past 5-10 years.

Serotonin (5-HT)2A/2C receptor agonist (2,5-dimethoxy-4-idophenyl)-2-aminopropane hydrochloride (DOI) improves voiding efficiency in the diabetic rat.

PubMed

Tu, Hongjian; Cao, Nailong; Gu, Baojun; Si, Jiemin; Chen, Zhong; Andersson, Karl-Erik

2015-07-01

To examine the effects of the serotonin (5-HT)2A/2C receptor agonist (2,5-dimethoxy-4-idophenyl)-2-aminopropane hydrochloride (DOI) on micturition in rats with diabetes mellitus (DM). Female Sprague-Dawley rats (n = 16) were divided into two groups: rats with Type 1 DM and age-matched control rats. DM was induced by i.p. injection of streptozotocin (65 mg/kg) and detailed cystometrogram (CMG) studies were performed 8 weeks post-injection in all rats under urethane anaesthesia. The selective 5-HT2A antagonist ketanserin was administered after each DOI dose-response curve was plotted. All drugs were administered i.v. Compared with controls, comprehensive urodynamic studies showed that DM rats had a higher bladder capacity and post-void residual urine volume (PVR), and a markedly lower voiding efficiency. In DM rats, DOI (0.01-0.3 mg/kg) induced significant dose-dependent increases in micturition volume and reductions in PVR, resulting in greater voiding efficiency. CMG measurements showed a dose-dependent increase in high-frequency oscillation (HFO) activity, evidenced by an increased duration of HFOs per voiding. This correlated with the improved voiding efficiency. Ketanserin (0.1 mg/kg) partially or completely reversed the DOI-induced changes. The HFOs observed in the present study seem to correlate with external urethral sphincter bursting activity during voiding. Bladder voiding efficiency was reduced in DM rats. The 5-HT2A receptor agonist can enhance HFO activity and improves voiding efficiency, and so may represent a new strategy to improve voiding efficiency after DM in experimental studies. © 2014 The Authors BJU International © 2014 BJU International Published by John Wiley & Sons Ltd.

ALA Pretreatment Improves Waterlogging Tolerance of Fig Plants

PubMed Central

An, Yuyan; Qi, Lin; Wang, Liangju

2016-01-01

5-aminolevulinic acid (ALA), a natural and environmentally friendly plant growth regulator, can improve plant tolerance to various environmental stresses. However, whether ALA can improve plant waterlogging tolerance is unknown. Here, we investigated the effects of ALA pretreatment on the waterlogging-induced damage of fig (Ficus carica Linn.) plants, which often suffer from waterlogging stress. ALA pretreatment significantly alleviated stress-induced morphological damage, increased leaf relative water content (RWC), and reduced leaf superoxide anion (O2⋅¯) production rate and malonaldehyde (MDA) content in fig leaves, indicating ALA mitigates waterlogging stress of fig plants. We further demonstrated that ALA pretreatment largely promoted leaf chlorophyll content, photosynthetic electron transfer ability, and photosynthetic performance index, indicating ALA significantly improves plant photosynthetic efficiency under waterlogging stress. Moreover, ALA pretreatment significantly increased activities of leaf superoxide dismutase (SOD) and peroxidase (POD), root vigor, and activities of root alcohol dehydrogenase (ADH), and lactate dehydrogenase (LDH), indicating ALA also significantly improves antioxidant ability and root function of fig plants under waterlogging stress. Taken together, ALA pretreatment improves waterlogging tolerance of fig plants significantly, and the promoted root respiration, leaf photosynthesis, and antioxidant ability may contribute greatly to this improvement. Our data firstly shows that ALA can improve plant waterlogging tolerance. PMID:26789407

Study and program plan for improved heavy duty gas turbine engine ceramic component development

NASA Technical Reports Server (NTRS)

Helms, H. E.

1977-01-01

Fuel economy in a commercially viable gas turbine engine was demonstrated through use of ceramic materials. Study results show that increased turbine inlet and generator inlet temperatures, through the use of ceramic materials, contribute the greatest amount to achieving fuel economy goals. Improved component efficiencies show significant additional gains in fuel economy.

77 FR 67057 - Notice of Availability of a Finding of No Significant Impact for the Port of Guam Modernization...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-08

... east of the proposed new break-bulk terminal to improve efficiency and security. New entrance and exit... storm water outfalls into the harbor. New safety and security improvements would be constructed. FOR...) 366-0714; or email: [email protected] . Persons who use a telecommunications device for the deaf...

Improved battery charger for electric vehicles

NASA Technical Reports Server (NTRS)

Rippel, W. E.

1981-01-01

Polyphase version of single-phase "boost chopper" significantly reduces ripple and electromagnetic interference (EMI). Drive circuit of n-phase boost chopper incorporates n-phase duty-cycle generator; inductor, transistor, and diode compose chopper which can run on single-phase or three-phase alternating current or on direct current. Device retains compactness and power factors approaching unity, while improving efficiency.

Initial Skill Acquisition of Handrim Wheelchair Propulsion: A New Perspective.

PubMed

Vegter, Riemer J K; de Groot, Sonja; Lamoth, Claudine J; Veeger, Dirkjan Hej; van der Woude, Lucas H V

2014-01-01

To gain insight into cyclic motor learning processes, hand rim wheelchair propulsion is a suitable cyclic task, to be learned during early rehabilitation and novel to almost every individual. To propel in an energy efficient manner, wheelchair users must learn to control bimanually applied forces onto the rims, preserving both speed and direction of locomotion. The purpose of this study was to evaluate mechanical efficiency and propulsion technique during the initial stage of motor learning. Therefore, 70 naive able-bodied men received 12-min uninstructed wheelchair practice, consisting of three 4-min blocks separated by 2 min rest. Practice was performed on a motor-driven treadmill at a fixed belt speed and constant power output relative to body mass. Energy consumption and the kinetics of propulsion technique were continuously measured. Participants significantly increased their mechanical efficiency and changed their propulsion technique from a high frequency mode with a lot of negative work to a longer-slower movement pattern with less power losses. Furthermore a multi-level model showed propulsion technique to relate to mechanical efficiency. Finally improvers and non-improvers were identified. The non-improving group was already more efficient and had a better propulsion technique in the first block of practice (i.e., the fourth minute). These findings link propulsion technique to mechanical efficiency, support the importance of a correct propulsion technique for wheelchair users and show motor learning differences.

The health sector reforms and the efficiency of public hospitals in Turkey: provincial markets.

PubMed

Sulku, Seher Nur

2012-10-01

Turkey initiated the 'Health Transformation Programme' (HTP) in 2003 to align its health care system with the European Union and OECD countries. This study investigates the impact of these reforms on the efficiency of public hospitals. Our study would contribute to the existing literature with a comprehensive analysis of the health system in a developing country. We employ the data envelopment approach and the Malmquist index to comparatively examine before and after the reform years. Our analyses compare the performances of public hospitals served in provincial markets. Inputs of number of beds, number of primary care physician, and number of specialists, and how they are used to produce outputs of inpatient discharges, outpatient visits and surgical operations are investigated. Indeed, as the performance indicators dead rate, hospital bed occupation rate and average length of stay are considered. The HTP was generally successful in boosting productivity due to advancements in technology and technical efficiency but in the socio-economically disadvantaged provinces productivity gains have not been achieved. The average technical efficiency gains took place because of the significantly improved scale efficiencies, as the average pure technical efficiency slightly improved. Lastly, the hospital performance indicators have not improved in the short run. It appears that the expected benefits from the health reforms in Turkey have been partially achieved in the short run.

Treatment of sleep apnea in chronic heart failure patients with auto-servo ventilation improves sleep fragmentation: a randomized controlled trial.

PubMed

Hetzenecker, Andrea; Escourrou, Pierre; Kuna, Samuel T; Series, Frederic; Lewis, Keir; Birner, Christoph; Pfeifer, Michael; Arzt, Michael

2016-01-01

Impaired sleep efficiency is independently associated with worse prognosis in patients with chronic heart failure (CHF). Therefore, a test was conducted on whether auto-servo ventilation (ASV, biphasic positive airway pressure [BiPAP]-ASV, Philips Respironics) reduces sleep fragmentation and improves sleep efficiency in CHF patients with central sleep apnea (CSA) or obstructive sleep apnea (OSA). In this multicenter, randomized, parallel group trial, a study was conducted on 63 CHF patients (age 64 ± 10 years; left ventricular ejection fraction 29 ± 7%) with CSA or OSA (apnea-hypopnea Index, AHI 47 ± 18/h; 46% CSA) referred to sleep laboratories of the four participating centers. Participants were randomized to either ASV (n = 32) or optimal medical treatment alone (control, n = 31). Polysomnography (PSG) and actigraphy at home (home) with centralized blinded scoring were obtained at baseline and 12 weeks. ASV significantly reduced sleep fragmentation (total arousal indexPSG: -16.4 ± 20.6 vs. -0.6 ± 13.2/h, p = 0.001; sleep fragmentation indexhome: -7.6 ± 15.6 versus 4.3 ± 13.9/h, p = 0.003, respectively) and significantly increased sleep efficiency assessed by actigraphy (SEhome) compared to controls (2.3 ± 10.1 vs. -2.1 ± 6.9%, p = 0.002). Effects of ASV on sleep fragmentation and efficiency were similar in patients suffering from OSA and CSA. At home, ASV treatment modestly improves sleep fragmentation as well as sleep efficiency in CHF patients having either CSA or OSA. Copyright © 2015 Elsevier B.V. All rights reserved.

A Phase II Dose-Ranging Study Evaluating the Efficacy and Safety of the Orexin Receptor Antagonist Filorexant (MK-6096) in Patients with Primary Insomnia

PubMed Central

Mahoney, Erin; Jackson, Saheeda; Hutzelmann, Jill; Zhao, Xin; Jia, Nan; Snyder, Ellen; Snavely, Duane; Michelson, David; Roth, Thomas; Herring, W. Joseph

2016-01-01

Background: Filorexant (MK-6096) is an orexin receptor antagonist; here, we evaluate the efficacy of filorexant in the treatment of insomnia in adults. Methods: A double-blind, placebo-controlled, randomized, two 4-week–period, adaptive crossover polysomnography study was conducted at 51 sites worldwide. Patients (18 to <65 years) with insomnia received 1 of 4 doses of oral filorexant (2.5, 5, 10, 20mg) once daily at bedtime during one period and matching placebo in the other period in 1 of 8 possible treatment sequences. Polysomnography was performed on night 1 and end of week 4 of each period. The primary endpoint was sleep efficiency at night 1 and end of week 4. Secondary endpoints included wakefulness after persistent sleep onset and latency to onset of persistent sleep. Results: A total of 324 patients received study treatment, 315 received ≥1 dose of placebo, and 318 ≥1 dose of filorexant (2.5mg, n=79; 5mg, n=78; 10mg, n=80; 20mg, n=81). All filorexant doses (2.5/5/10/20mg) were significantly superior to placebo in improving sleep among patients with insomnia as measured by sleep efficiency and wakefulness after persistent sleep onset on night 1 and end of week 4. The 2 higher filorexant doses (10/20mg) were also significantly more effective than placebo in improving sleep onset as measured by latency to onset of persistent sleep at night 1 and end of week 4. Filorexant was generally well tolerated. Conclusions: Orexin receptor antagonism by filorexant significantly improved sleep efficiency in nonelderly patients with insomnia. Dose-related improvements in sleep onset and maintenance outcomes were also observed with filorexant. PMID:26979830

Increasing operating room efficiency through electronic medical record analysis.

PubMed

Attaallah, A F; Elzamzamy, O M; Phelps, A L; Ranganthan, P; Vallejo, M C

2016-05-01

We used electronic medical record (EMR) analysis to determine errors in operating room (OR) time utilisation. Over a two year period EMR data of 44,503 surgical procedures was analysed for OR duration, on-time, first case, and add-on time performance, within 19 surgical specialties. Maximal OR time utilisation at our institution could have saved over 302,620 min or 5,044 hours of OR efficiency over a two year period. Most specialties (78.95%) had inaccurately scheduled procedure times and therefore used the OR more than their scheduled allotment time. Significant differences occurred between the mean scheduled surgical durations (101.38 ± 87.11 min) and actual durations (108.18 ± 102.27 min; P < 0.001). Significant differences also occurred between the mean scheduled add-on durations (111.4 ± 75.5 min) and the actual add-on scheduled durations (118.6 ± 90.1 minutes; P < 0.001). EMR quality improvement analysis can be used to determine scheduling error and bias, in order to improve efficiency and increase OR time utilisation.

Does the use of automated fetal biometry improve clinical work flow efficiency?

PubMed

Espinoza, Jimmy; Good, Sara; Russell, Evie; Lee, Wesley

2013-05-01

This study was designed to compare the work flow efficiency of manual measurements of 5 fetal parameters with a novel technique that automatically measures these parameters from 2-dimensional sonograms. This prospective study included 200 singleton pregnancies between 15 and 40 weeks' gestation. Patients were randomly allocated to either manual (n = 100) or automatic (n = 100) fetal biometry. The automatic measurement was performed using a commercially available software application. A digital video recorder captured all on-screen activity associated with the sonographic examination. The examination time and number of steps required to obtain fetal measurements were compared between manual and automatic methods. The mean time required to obtain the biometric measurements was significantly shorter using the automated technique than the manual approach (P < .001 for all comparisons). Similarly, the mean number of steps required to perform these measurements was significantly fewer with automatic measurements compared to the manual technique (P < .001). In summary, automated biometry reduced the examination time required for standard fetal measurements. This approach may improve work flow efficiency in busy obstetric sonography practices.

A splay tree-based approach for efficient resource location in P2P networks.

PubMed

Zhou, Wei; Tan, Zilong; Yao, Shaowen; Wang, Shipu

2014-01-01

Resource location in structured P2P system has a critical influence on the system performance. Existing analytical studies of Chord protocol have shown some potential improvements in performance. In this paper a splay tree-based new Chord structure called SChord is proposed to improve the efficiency of locating resources. We consider a novel implementation of the Chord finger table (routing table) based on the splay tree. This approach extends the Chord finger table with additional routing entries. Adaptive routing algorithm is proposed for implementation, and it can be shown that hop count is significantly minimized without introducing any other protocol overheads. We analyze the hop count of the adaptive routing algorithm, as compared to Chord variants, and demonstrate sharp upper and lower bounds for both worst-case and average case settings. In addition, we theoretically analyze the hop reducing in SChord and derive the fact that SChord can significantly reduce the routing hops as compared to Chord. Several simulations are presented to evaluate the performance of the algorithm and support our analytical findings. The simulation results show the efficiency of SChord.

Contact engineering for efficient charge injection in organic transistors with low-cost metal electrodes

NASA Astrophysics Data System (ADS)

Panigrahi, D.; Kumar, S.; Dhar, A.

2017-10-01

Controlling charge injection at the metal-semiconductor interface is very crucial for organic electronic devices in general as it can significantly influence the overall device performance. Herein, we report a facile, yet efficient contact modification approach, to enhance the hole injection efficiency through the incorporation of a high vacuum deposited TPD [N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine] interlayer between the electrodes and the active semiconducting layer. The device performance parameters such as mobility and on/off ratio improved significantly after the inclusion of the TPD buffer layer, and more interestingly, the devices with cost effective Ag and Cu electrodes were able to exhibit a superior device performance than the typically used Au source-drain devices. We have also observed that this contact modification technique can be even more effective than commonly used metal oxide interface modifying layers. Our investigations demonstrate the efficacy of the TPD interlayer in effectively reducing the interfacial contact resistance through the modification of pentacene energy levels, which consequently results in the substantial improvement in the device performances.

Peer Review of March 2013 LDV Rebound Report By Small ...

EPA Pesticide Factsheets

The regulatory option of encouraging the adoption of advanced technologies for improving vehicle efficiency can result in significant fuel savings and GHG emissions benefits. At the same time, it is possible that some of these benefits might be offset by additional driving that is encouraged by the reduced costs of operating more efficient vehicles. This so called “rebound effect”, the increased driving that results from an improvement in the energy efficiency of a vehicle, must be determined in order to reliably estimate the overall benefits of GHG regulations for light-duty vehicles. Dr. Ken Small, an Economist at the Department of Economics, University of California at Irvine, with contributions by Dr. Kent Hymel, Department of Economics, California State University at Northridge, have developed a methodology to estimate the rebound effect for light-duty vehicles in the U.S. Specifically, rebound is estimated as the change in vehicle miles traveled (VMT) with respect to the change in per mile fuel costs that can occur, for example, when vehicle operating efficiency is improved. The model analyzes aggregate personal motor-vehicle travel within a simultaneous model of aggregate VMT, fleet size, fuel efficiency, and congestion formation. To use the peer review process to help assure that the methodologies considered by the U.S. EPA for estimating VMT rebound have been thoroughly examined.

Does decentralization influence efficiency of health units? A study of opinion and perception of health workers in Odisha.

PubMed

Panda, Bhuputra; Thakur, Harshad P; Zodpey, Sanjay P

2016-10-31

Health systems in low and middle income countries are struggling to improve efficiency in the functioning of health units of which workforce is one of the most critical building blocks. In India, Rogi Kalyan Samiti (RKS) was established at every health unit as institutions of local decision making in order to improve productive efficiency and quality. Measuring efficiency of health units is a complex task. This study aimed at assessing the perception (opinion and satisfaction) of health workers about influence of RKS on improving efficiency of peripheral decision making health units (DMHU); examining differences between priority and non-priority set-ups; identifying predictors of satisfaction at work; and discussing suggestions to improve performance. Following a cross-sectional, comparative study design, 130 health workers from 30 institutions were selected through a multi-stage stratified random sampling. A semi-structured questionnaire was administered to assess perception and opinion of health workers about influence of RKS on efficiency of decision making at local level, motivation and performance of staff, and availability of funds; improvement of quality of services, and coordination among co-workers; and participation of community in local decision making. Three districts with highest infant mortality rate (IMR), one each, from 3 zones of Odisha and 3 with lowest IMR were selected on the basis of IMR estimates of 2011. The former constituted priority districts (PD) and the latter, non-priority districts (NPD). Composite scores were developed and compared between PD and NPD. Adjusted linear regression was conducted to identify predictors of satisfaction at work. A majority of respondents felt that RKS was efficient in decision making that resulted in improvement of all critical parameters of health service delivery, including quality; this was significantly higher in PD. Further, higher proportion of respondents from PD was highly satisfied with the current set of provisions and manners of functioning of the sample health units. Active community engagement, participation of elected representatives, selection of a pro-active Chairman, and training to RKS members were suggested as the immediate priority action points for the state government. Mean scores differed significantly between PD and NPD with regard to: influence of RKS on individual-centric, organizational-centric and patient-centric performance, and the responsibilities to be entrusted with RKS. Absenteeism was strongly associated with satisfaction and local self-governance. Work-related factors, systemic factors, local accountability and patients' involvement were found to be the key predictors of satisfaction of health workforce. The understanding on quality improvement strategies was found to be very poor among the health workers. Tailor-made capacity building measures at district and sub-district levels could be critical to equip the peripheral health units to achieve the universal health coverage goals. Work environment, systemic factors and accountability need to be addressed on priority for retention of health workforce. The hypothesized link between efficient local decision making, perception of health workers about efficiency of health units and the health status of population needs further investigation.

[Effect of soil preparation and fertilization on foliage and shoot growth of Ginkgo biloba and its medicine content].

PubMed

He, Binghui; Zhong, Zhangcheng

2004-06-01

The study showed that the efficiency of various treatments in improving the height growth of Ginkgo biloba was organic fertilizer plus intercropping > soil preparation by blasting plus intercropping > organic fertilizer > soil preparation by blasting > intercropping, and the height growth increased by 14.5%, 8.6%, 5.7%, 3.2% and 0, respectively. The efficiency of the treatments in improving new shoot growth was organic fertilizer plus intercropping > soil preparation by blasting plus intercropping > intercropping > organic fertilizer > soil preparation by blasting, and the new shoot growth increased by 58.1%, 36.6%, 33.1%, 30.2% and 14.0%, respectively. Soil preparation, organic fertilization and intercropping had no different effect on the number of long shoots, but their effect on the numbers of short shoots and leaves was significantly different. The most efficient treatment in improving the medicine content was organic fertilization plus intercropping. Compared with control, the content of quercetin and rutin in Ginkgo biloba leaves increased by 420% and 220%, respectively.

Improving the efficiency of selection to Core Medical Training: a study of the use of multiple assessment stations.

PubMed

Atkinson, J M; Tullo, E; Mitchison, H; Pearce, M S; Kumar, N

2012-06-01

To compare three separate assessment stations used for selection to Core Medical Training (CMT) and to determine the effect of reducing the number from three to two. Quantitative analysis of candidates' assessment station scores, financial analysis of costs of the selection process and quantitative and qualitative surveys of candidates and assessors. The assessment stations used for selection to CMT were reliable and valid for assessing suitability for employment as a CMT trainee. There was no significant difference in candidate ranking if only two assessment stations were used rather than three, i.e. there was no change in the likelihood of receiving a job offer. All of the assessment stations were perceived to have face validity by candidates and assessors. The efficiency of the selection process could be improved without loss of quality if two stations were used rather than three. Using two assessment stations rather than three would appear to improve the efficiency and maintain the quality of the CMT selection process while reducing costs.

InGaN/GaN light-emitting diode having direct hole injection plugs and its high-current operation.

PubMed

Kim, Sungjoon; Cho, Seongjae; Jeong, Jaedeok; Kim, Sungjun; Hwang, Sungmin; Kim, Garam; Yoon, Sukho; Park, Byung-Gook

2017-03-20

The light-emitting diode (LED) with an improved hole injection and straightforward process integration is proposed. p-type GaN direct hole injection plugs (DHIPs) are formed on locally etched multiple-quantum wells (MQWs) by epitaxial lateral overgrowth (ELO) method. We confirm that the optical output power is increased up to 23.2% at an operating current density of 100 A/cm². Furthermore, in order to identify the origin of improvement in optical performance, the transient light decay time and light intensity distribution characteristics were analyzed on the DHIP LED devices. Through the calculation of the electroluminescence (EL) decay time, internal quantum efficiency (IQE) is extracted along with the recombination parameters, which reveals that the DHIPs have a significant effect on enhancement of radiative recombination and reduction of efficiency droop. Furthermore, the mapping PL reveals that the DHIP LED also has a potential to improve the light extraction efficiency by hexagonal pyramid shaped DHIPs.

Modulated CH3NH3PbI3−xBrx film for efficient perovskite solar cells exceeding 18%

PubMed Central

Tu, Yongguang; Wu, Jihuai; Lan, Zhang; He, Xin; Dong, Jia; Jia, Jinbiao; Guo, Panfeng; Lin, Jianming; Huang, Miaoliang; Huang, Yunfang

2017-01-01

The organic-inorganic lead halide perovskite layer is a crucial factor for the high performance perovskite solar cell (PSC). We introduce CH3NH3Br in the precursor solution to prepare CH3NH3PbI3−xBrx hybrid perovskite, and an uniform perovskite layer with improved crystallinity and apparent grain contour is obtained, resulting in the significant improvement of photovoltaic performance of PSCs. The effects of CH3NH3Br on the perovskite morphology, crystallinity, absorption property, charge carrier dynamics and device characteristics are discussed, and the improvement of open circuit voltage of the device depended on Br doping is confirmed. Based on above, the device based on CH3NH3PbI2.86Br0.14 exhibits a champion power conversion efficiency (PCE) of 18.02%. This study represents an efficient method for high-performance perovskite solar cell by modulating CH3NH3PbI3−xBrx film. PMID:28303938

Energy Efficient Engine (E3) controls and accessories detail design report

NASA Technical Reports Server (NTRS)

Beitler, R. S.; Lavash, J. P.

1982-01-01

An Energy Efficient Engine program has been established by NASA to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, a new turbofan engine was designed. This report describes the fuel and control system for this engine. The system design is based on many of the proven concepts and component designs used on the General Electric CF6 family of engines. One significant difference is the incorporation of digital electronic computation in place of the hydromechanical computation currently used.

Effects of Nanoimprinted Structures on the Performance of Organic Solar Cells

DOE PAGES

Gill, Hardeep Singh; Li, Lian; Ren, Haizhou; ...

2018-01-01

The effect of nanoimprinted structures on the performance of organic bulk heterojunction solar cells was investigated. The nanostructures were formed over the active layer employing the soft lithographic technique. The measured incident photon-to-current efficiency revealed that the nanostructured morphology over the active layer can efficiently enhance both light harvesting and charge carrier collection due to improvement of the absorption of incident light and the buried nanostructured cathode, respectively. The devices prepared with the imprinted nanostructures exhibited significantly higher power conversion efficiencies as compared to those of the control cells.

Data compression for satellite images

NASA Technical Reports Server (NTRS)

Chen, P. H.; Wintz, P. A.

1976-01-01

An efficient data compression system is presented for satellite pictures and two grey level pictures derived from satellite pictures. The compression techniques take advantages of the correlation between adjacent picture elements. Several source coding methods are investigated. Double delta coding is presented and shown to be the most efficient. Both predictive differential quantizing technique and double delta coding can be significantly improved by applying a background skipping technique. An extension code is constructed. This code requires very little storage space and operates efficiently. Simulation results are presented for various coding schemes and source codes.

Lightweight, Light-Trapped, Thin GaAs Solar Cells for Spacecraft Applications.

DTIC Science & Technology

1995-10-05

improve the efficiency of this type of cell. 2 The high efficiency and light weight of the cover glass supported GaAs solar cell can have a significant...is a 3-mil cover glass and 1-mil silicone adhesive on the front surface of the GaAs solar cell. Power Output 3000 400 -{ 2400 { N 300 S18200 W/m2...the ultra-thin, light-trapped GaAs solar ceill 3. Incorporate light trapping. 0 external quantum efficiency at 850 nm increased by 5.2% 4. Develop

Effects of Nanoimprinted Structures on the Performance of Organic Solar Cells

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

Gill, Hardeep Singh; Li, Lian; Ren, Haizhou

The effect of nanoimprinted structures on the performance of organic bulk heterojunction solar cells was investigated. The nanostructures were formed over the active layer employing the soft lithographic technique. The measured incident photon-to-current efficiency revealed that the nanostructured morphology over the active layer can efficiently enhance both light harvesting and charge carrier collection due to improvement of the absorption of incident light and the buried nanostructured cathode, respectively. The devices prepared with the imprinted nanostructures exhibited significantly higher power conversion efficiencies as compared to those of the control cells.

Laser amplifier chain

DOEpatents

Hackel, R.P.

1992-10-20

A laser amplifier chain has a plurality of laser amplifiers arranged in a chain to sequentially amplify a low-power signal beam to produce a significantly higher-power output beam. Overall efficiency of such a chain is improved if high-gain, low efficiency amplifiers are placed on the upstream side of the chain where only a very small fraction of the total pumped power is received by the chain and low-gain, high-efficiency amplifiers are placed on the downstream side where a majority of pumping energy is received by the chain. 6 figs.

High efficiency low cost monolithic module for SARSAT distress beacons

NASA Technical Reports Server (NTRS)

Petersen, Wendell C.; Siu, Daniel P.

1992-01-01

The program objectives were to develop a highly efficient, low cost RF module for SARSAT beacons; achieve significantly lower battery current drain, amount of heat generated, and size of battery required; utilize MMIC technology to improve efficiency, reliability, packaging, and cost; and provide a technology database for GaAs based UHF RF circuit architectures. Presented in viewgraph form are functional block diagrams of the SARSAT distress beacon and beacon RF module as well as performance goals, schematic diagrams, predicted performances, and measured performances for the phase modulator and power amplifier.

Vertical waveguides integrated with silicon photodetectors: Towards high efficiency and low cross-talk image sensors

NASA Astrophysics Data System (ADS)

Tut, Turgut; Dan, Yaping; Duane, Peter; Yu, Young; Wober, Munib; Crozier, Kenneth B.

2012-01-01

We describe the experimental realization of vertical silicon nitride waveguides integrated with silicon photodetectors. The waveguides are embedded in a silicon dioxide layer. Scanning photocurrent microscopy is performed on a device containing a waveguide, and on a device containing the silicon dioxide layer, but without the waveguide. The results confirm the waveguide's ability to guide light onto the photodetector with high efficiency. We anticipate that the use of these structures in image sensors, with one waveguide per pixel, would greatly improve efficiency and significantly reduce inter-pixel crosstalk.

An efficient quantum circuit analyser on qubits and qudits

NASA Astrophysics Data System (ADS)

Loke, T.; Wang, J. B.

2011-10-01

This paper presents a highly efficient decomposition scheme and its associated Mathematica notebook for the analysis of complicated quantum circuits comprised of single/multiple qubit and qudit quantum gates. In particular, this scheme reduces the evaluation of multiple unitary gate operations with many conditionals to just two matrix additions, regardless of the number of conditionals or gate dimensions. This improves significantly the capability of a quantum circuit analyser implemented in a classical computer. This is also the first efficient quantum circuit analyser to include qudit quantum logic gates.

A Gossip-based Energy Efficient Protocol for Robust In-network Aggregation in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Fauji, Shantanu

We consider the problem of energy efficient and fault tolerant in--network aggregation for wireless sensor networks (WSNs). In-network aggregation is the process of aggregation while collecting data from sensors to the base station. This process should be energy efficient due to the limited energy at the sensors and tolerant to the high failure rates common in sensor networks. Tree based in--network aggregation protocols, although energy efficient, are not robust to network failures. Multipath routing protocols are robust to failures to a certain degree but are not energy efficient due to the overhead in the maintenance of multiple paths. We propose a new protocol for in-network aggregation in WSNs, which is energy efficient, achieves high lifetime, and is robust to the changes in the network topology. Our protocol, gossip--based protocol for in-network aggregation (GPIA) is based on the spreading of information via gossip. GPIA is not only adaptive to failures and changes in the network topology, but is also energy efficient. Energy efficiency of GPIA comes from all the nodes being capable of selective message reception and detecting convergence of the aggregation early. We experimentally show that GPIA provides significant improvement over some other competitors like the Ridesharing, Synopsis Diffusion and the pure version of gossip. GPIA shows ten fold, five fold and two fold improvement over the pure gossip, the synopsis diffusion and Ridesharing protocols in terms of network lifetime, respectively. Further, GPIA retains gossip's robustness to failures and improves upon the accuracy of synopsis diffusion and Ridesharing.

Does restructuring hospitals result in greater efficiency?--An empirical test using diachronic data.

PubMed

Braithwaite, Jeffrey; Westbrook, Mary T; Hindle, Donald; Iedema, Rick A; Black, Deborah A

2006-02-01

Hospitals are being restructured more frequently. Increased cost efficiency is the usual justification given for such changes. All 20 major teaching hospitals in Australia's two most populous states were investigated by classifying each over a 5-6 year period in terms of their cost efficiency (average cost per case weighted by Australian diagnosis-related group [AN-DRG] data and adjusted for inflation) and structure, categorized as traditional-professional (TP), clinical-divisional (CD), or clinical-institute (CI). In all, 12 hospitals changed structure during the study period. There was slight evidence that CD structures were more efficient than TP structures but this was not supported by other evidence. There were no significant differences in efficiency in the first or second years following changes from either TP to CD or TP to CI structures. All four hospitals changing from CD to CI structure became significantly less efficient. This may be due to frequency rather than type of change as they were the only hospitals that implemented two structural changes. Hospitals that changed or did not change structure were similar in efficiency at the beginning and at the end of the study period, in overall efficiency during the period, and in trends toward efficiency over time. The findings challenge those who advocate restructuring hospitals on the grounds of improving cost efficiency.

Dynamic frame resizing with convolutional neural network for efficient video compression

NASA Astrophysics Data System (ADS)

Kim, Jaehwan; Park, Youngo; Choi, Kwang Pyo; Lee, JongSeok; Jeon, Sunyoung; Park, JeongHoon

2017-09-01

In the past, video codecs such as vc-1 and H.263 used a technique to encode reduced-resolution video and restore original resolution from the decoder for improvement of coding efficiency. The techniques of vc-1 and H.263 Annex Q are called dynamic frame resizing and reduced-resolution update mode, respectively. However, these techniques have not been widely used due to limited performance improvements that operate well only under specific conditions. In this paper, video frame resizing (reduced/restore) technique based on machine learning is proposed for improvement of coding efficiency. The proposed method features video of low resolution made by convolutional neural network (CNN) in encoder and reconstruction of original resolution using CNN in decoder. The proposed method shows improved subjective performance over all the high resolution videos which are dominantly consumed recently. In order to assess subjective quality of the proposed method, Video Multi-method Assessment Fusion (VMAF) which showed high reliability among many subjective measurement tools was used as subjective metric. Moreover, to assess general performance, diverse bitrates are tested. Experimental results showed that BD-rate based on VMAF was improved by about 51% compare to conventional HEVC. Especially, VMAF values were significantly improved in low bitrate. Also, when the method is subjectively tested, it had better subjective visual quality in similar bit rate.

A Mixed-Methods Research Framework for Healthcare Process Improvement.

PubMed

Bastian, Nathaniel D; Munoz, David; Ventura, Marta

2016-01-01

The healthcare system in the United States is spiraling out of control due to ever-increasing costs without significant improvements in quality, access to care, satisfaction, and efficiency. Efficient workflow is paramount to improving healthcare value while maintaining the utmost standards of patient care and provider satisfaction in high stress environments. This article provides healthcare managers and quality engineers with a practical healthcare process improvement framework to assess, measure and improve clinical workflow processes. The proposed mixed-methods research framework integrates qualitative and quantitative tools to foster the improvement of processes and workflow in a systematic way. The framework consists of three distinct phases: 1) stakeholder analysis, 2a) survey design, 2b) time-motion study, and 3) process improvement. The proposed framework is applied to the pediatric intensive care unit of the Penn State Hershey Children's Hospital. The implementation of this methodology led to identification and categorization of different workflow tasks and activities into both value-added and non-value added in an effort to provide more valuable and higher quality patient care. Based upon the lessons learned from the case study, the three-phase methodology provides a better, broader, leaner, and holistic assessment of clinical workflow. The proposed framework can be implemented in various healthcare settings to support continuous improvement efforts in which complexity is a daily element that impacts workflow. We proffer a general methodology for process improvement in a healthcare setting, providing decision makers and stakeholders with a useful framework to help their organizations improve efficiency. Published by Elsevier Inc.

Freedom of Information Act: FOIA Task Force Report

EPA Pesticide Factsheets

FOIA Task Force review of any significant weaknesses, and recommendation for improvements of efficiency and effectiveness of the agency's FOIA operations to ensure that information is provided to the Amercian public in a timely fashion.

High Efficiency Synchronous Rectification in Spacecraft

NASA Technical Reports Server (NTRS)

Krauhamer, S.; Das, R.; Vorperian, V.; White, J.; Bennett, J.; Rogers, D.

1993-01-01

This paper examines the implementaion of MOSFETs as synchronous rectifiers which results in a substantial improvement in power processing efficency and therefore may result in significant reduction of spacecraft mass and volum for the same payload.

Effects of the butyric acid-producing strain Clostridium butyricum MIYAIRI 588 on broiler and piglet zootechnical performance and prevention of necrotic enteritis.

PubMed

Takahashi, Motomichi; McCartney, Elinor; Knox, Anne; Francesch, Maria; Oka, Kentaro; Wada, Kaoruko; Ideno, Marie; Uno, Koji; Kozłowski, Krzysztof; Jankowski, Jan; Gracia, Marta I; Morales, Joaquin; Kritas, Spyridon K; Esteve-Garcia, Enric; Kamiya, Shigeru

2018-06-01

The objective of this study was to assess the effects of a probiotic strain Clostridium butyricumMIYAIRI 588 (CBM588) on broiler and weaned piglet health and zootechnical performance. Five field studies were carried out in broilers and five in weaned piglets under European feed additive guidelines. Each study followed a randomized blocked design with two treatments: Control (basal diet) and CBM588 supplemented groups. The zootechnical performance parameters selected were body weight, daily gain, feed intake and feed efficiency (feed:gain). Broilers fed diets with CBM588 gained significantly more weight (+2%, p < .001) and exhibited significantly better feed efficiency (-1.6%, p < .001) in comparison with Controls. Similarly, analysis of pooled data of weaned piglet trials showed that CBM588-fed piglets were significantly heavier than Controls (+2.6%, p = .014), exhibited significantly higher mean daily gain (+4.7%; p = .004), and significantly improved feed efficiency (-4.2%, p = .001). In addition to the zootechnical efficacy studies, the preventive effect of CBM588 on necrotic enteritis (NE) was assessed in a natural challenge model in broilers where CBM588 reduced the incidence and severity of NE lesions. These data indicate the potential of CBM588 to improve broiler and weaned piglet zootechnical performance, and to make a positive contribution to animal health. © 2018 Japanese Society of Animal Science.

Improved actions and asymptotic scaling in lattice Yang-Mills theory

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

Langfeld, Kurt

2007-11-01

Improved actions in SU(2) and SU(3) lattice gauge theories are investigated with an emphasis on asymptotic scaling. A new scheme for tadpole improvement is proposed. The standard but heuristic tadpole improvement emerges from a mean field approximation from the new approach. Scaling is investigated by means of the large distance static quark potential. Both the generic and the new tadpole scheme yield significant improvements on asymptotic scaling when compared with loop improved actions. A study of the rotational symmetry breaking terms, however, reveals that only the new improvement scheme efficiently eliminates the leading irrelevant term from the action.

On the efficiency of the golf swing

NASA Astrophysics Data System (ADS)

White, Rod

2006-12-01

A non-driven double pendulum model is used to explain the principle underlying the surprising efficiency of the golf swing. The principle can be described as a parametric energy transfer between the arms and the club head due to the changing moment of inertia of the club. The transfer is a consequence of conservation of energy and angular momentum. Because the pendulum is not driven by an external force, it shows that the golfer need do little more than accelerate the arms with the wrists cocked and let the double pendulum transfer kinetic energy to the club head. A driven double pendulum model is used to study factors affecting the efficiency of a real golf swing. It is concluded that the wrist-cock angle is the most significant efficiency-determining parameter under the golfer's control and that improvements in golf technology have had a significant impact on driving distance.

Broadband linearisation of high-efficiency power amplifiers

NASA Technical Reports Server (NTRS)

Kenington, Peter B.; Parsons, Kieran J.; Bennett, David W.

1993-01-01

A feedforward-based amplifier linearization technique is presented which is capable of yielding significant improvements in both linearity and power efficiency over conventional amplifier classes (e.g. class-A or class-AB). Theoretical and practical results are presented showing that class-C stages may be used for both the main and error amplifiers yielding practical efficiencies well in excess of 30 percent, with theoretical efficiencies of much greater than 40 percent being possible. The levels of linearity which may be achieved are required for most satellite systems, however if greater linearity is required, the technique may be used in addition to conventional pre-distortion techniques.

Channel coding and data compression system considerations for efficient communication of planetary imaging data

NASA Technical Reports Server (NTRS)

Rice, R. F.

1974-01-01

End-to-end system considerations involving channel coding and data compression are reported which could drastically improve the efficiency in communicating pictorial information from future planetary spacecraft. In addition to presenting new and potentially significant system considerations, this report attempts to fill a need for a comprehensive tutorial which makes much of this very subject accessible to readers whose disciplines lie outside of communication theory.

Airport security inspection process model and optimization based on GSPN

NASA Astrophysics Data System (ADS)

Mao, Shuainan

2018-04-01

Aiming at the efficiency of airport security inspection process, Generalized Stochastic Petri Net is used to establish the security inspection process model. The model is used to analyze the bottleneck problem of airport security inspection process. The solution to the bottleneck is given, which can significantly improve the efficiency and reduce the waiting time by adding the place for people to remove their clothes and the X-ray detector.

Life cycle energy efficiency and environmental impact assessment of bioethanol production from sweet potato based on different production modes

PubMed Central

Zhang, Jun; Jia, Chunrong; Wu, Yi; Xi, Beidou; Wang, Lijun; Zhai, Youlong

2017-01-01

The bioethanol is playing an increasingly important role in renewable energy in China. Based on the theory of circular economy, integration of different resources by polygeneration is one of the solutions to improve energy efficiency and to reduce environmental impact. In this study, three modes of bioethanol production were selected to evaluate the life cycle energy efficiency and environmental impact of sweet potato-based bioethanol. The results showed that, the net energy ratio was greater than 1 and the value of net energy gain was positive in the three production modes, in which the maximum value appeared in the circular economy mode (CEM). The environment emission mainly occurred to bioethanol conversion unit in the conventional production mode (CPM) and the cogeneration mode (CGM), and eutrophication potential (EP) and global warming potential (GWP) were the most significant environmental impact category. While compared with CPM and CGM, the environmental impact of CEM significantly declined due to increasing recycling, and plant cultivation unit mainly contributed to EP and GWP. And the comprehensive evaluation score of environmental impact decreased by 73.46% and 23.36%. This study showed that CEM was effective in improving energy efficiency, especially in reducing the environmental impact, and it provides a new method for bioethanol production. PMID:28672044

Life cycle energy efficiency and environmental impact assessment of bioethanol production from sweet potato based on different production modes.

PubMed

Zhang, Jun; Jia, Chunrong; Wu, Yi; Xia, Xunfeng; Xi, Beidou; Wang, Lijun; Zhai, Youlong

2017-01-01

The bioethanol is playing an increasingly important role in renewable energy in China. Based on the theory of circular economy, integration of different resources by polygeneration is one of the solutions to improve energy efficiency and to reduce environmental impact. In this study, three modes of bioethanol production were selected to evaluate the life cycle energy efficiency and environmental impact of sweet potato-based bioethanol. The results showed that, the net energy ratio was greater than 1 and the value of net energy gain was positive in the three production modes, in which the maximum value appeared in the circular economy mode (CEM). The environment emission mainly occurred to bioethanol conversion unit in the conventional production mode (CPM) and the cogeneration mode (CGM), and eutrophication potential (EP) and global warming potential (GWP) were the most significant environmental impact category. While compared with CPM and CGM, the environmental impact of CEM significantly declined due to increasing recycling, and plant cultivation unit mainly contributed to EP and GWP. And the comprehensive evaluation score of environmental impact decreased by 73.46% and 23.36%. This study showed that CEM was effective in improving energy efficiency, especially in reducing the environmental impact, and it provides a new method for bioethanol production.

Controllable Spatial Configuration on Cathode Interface for Enhanced Photovoltaic Performance and Device Stability.

PubMed

Li, Jiangsheng; Duan, Chenghao; Wang, Ning; Zhao, Chengjie; Han, Wei; Jiang, Li; Wang, Jizheng; Zhao, Yingjie; Huang, Changshui; Jiu, Tonggang

2018-05-08

The molecular structure of cathode interface modification materials can affect the surface morphology of the active layer and key electron transfer processes occurring at the interface of polymer solar cells in inverted structures mostly due to the change of molecular configuration. To investigate the effects of spatial configuration of the cathode interfacial modification layer on polymer solar cells device performances, we introduced two novel organic ionic salts (linear NS2 and three-dimensional (3D) NS4) combined with the ZnO film to fabricate highly efficient inverted solar cells. Both organic ionic salts successfully decreased the surface traps of the ZnO film and made its work function more compatible. Especially NS4 in three-dimensional configuration increased the electron mobility and extraction efficiency of the interfacial film, leading to a significant improvement of device performance. Power conversion efficiency (PCE) of 10.09% based on NS4 was achieved. Moreover, 3D interfacial modification could retain about 92% of its initial PCE over 160 days. It is proposed that 3D interfacial modification retards the element penetration-induced degradation without impeding the electron transfer from the active layer to the ZnO film, which significantly improves device stability. This indicates that inserting three-dimensional organic ionic salt is an efficient strategy to enhance device performance.

Biodegradation of textile wastewater: enhancement of biodegradability via the addition of co-substrates followed by phytotoxicity analysis of the effluent.

PubMed

Ceretta, María Belén; Durruty, Ignacio; Orozco, Ana Micaela Ferro; González, Jorge Froilán; Wolski, Erika Alejandra

2018-05-01

This work reports on the biodegradation of textile wastewater by three alternative microbial treatments. A bacterial consortium, isolated from a dyeing factory, showed significant efficacy in decolourizing wastewater (77.6 ± 3.0%); the decolourization rate was 5.80 ± 0.31 mg of azo dye·L -1 ·h -1 , without the addition of an ancillary carbon source (W). The degradation was 52% (measured as COD removal) and the products of the treatment showed low biodegradability (COD/BOD 5 = 4.2). When glucose was added to the wastewater, (W + G): the decolourization efficiency increased to 87.24 ± 2.5% and the decolourization rate significantly improved (25.67 ± 3.62 mg·L -1 ·h -1 ), although the COD removal efficiency was only 44%. Finally, the addition of starch (W + S) showed both a similar decolourization rate and efficiency to the W treatment, but a higher COD removal efficiency (72%). In addition, the biodegradability of the treated wastewater was considerably improved (COD/BOD 5 = 1.2) when starch was present. The toxicity of the degradation products was tested on Lactuca sativa seeds. In all treatments, toxicity was reduced with respect to the untreated wastewater. The W + S treatment gave the best performance.

Modified Design of Hydroturbine Wicket Gates to Include Liquid Control Jets

NASA Astrophysics Data System (ADS)

Lewis, Bryan; Cimbala, John; Wouden, Alex

2013-11-01

With the ever-increasing penetration of alternative electricity generation, it is becoming more common to operate hydroturbines under off-design conditions in order to maintain stability in the electric power grid. Improving the off-design performance of these turbines is therefore of significant importance. As the runner blades of a Francis hydroturbine pass though the wakes created by the upstream guide vanes (wicket gates and stay vanes), they experience significant changes in the instantaneous values of absolute velocity, flow angle, and pressure. The concept of adding water jets to the trailing edge of the guide vanes is proposed as a method for reducing the dynamic load on the hydroturbine runner blades, as well as modifying the flow angle of the water entering the runner to improve turbine efficiency during off-design operation. In order to add water jets that are capable of turning the flow, a modified beveled trailing edge design is presented. Computational experiments show that a +/-5° change in swirl angle is achievable with the new design, as well as up to 4% improvement in turbine efficiency during off-design operation. This correlates to an overall improvement in machine efficiency of up to 2%, when the losses through the jet channels are taken into account. Funding for this work was provided by the DOD, through the National Defense Science and Engineering Graduate (NDSEG) Fellowship, and the DOE, through the Penn State Hydropower Research Grant.

Computationally efficient method for Fourier transform of highly chirped pulses for laser and parametric amplifier modeling.

PubMed

Andrianov, Alexey; Szabo, Aron; Sergeev, Alexander; Kim, Arkady; Chvykov, Vladimir; Kalashnikov, Mikhail

2016-11-14

We developed an improved approach to calculate the Fourier transform of signals with arbitrary large quadratic phase which can be efficiently implemented in numerical simulations utilizing Fast Fourier transform. The proposed algorithm significantly reduces the computational cost of Fourier transform of a highly chirped and stretched pulse by splitting it into two separate transforms of almost transform limited pulses, thereby reducing the required grid size roughly by a factor of the pulse stretching. The application of our improved Fourier transform algorithm in the split-step method for numerical modeling of CPA and OPCPA shows excellent agreement with standard algorithms.

Evaluation of a Stirling engine heater bypass with the NASA Lewis nodal-analysis performance code

NASA Technical Reports Server (NTRS)

Sullivan, T. J.

1986-01-01

In support of the U.S. Department of Energy's Stirling Engine Highway Vehicle Systems program, the NASA Lewis Research Center investigated whether bypassing the P-40 Stirling engine heater during regenerative cooling would improve engine performance. The Lewis nodal-analysis Stirling engine computer simulation was used for this investigation. Results for the heater-bypass concept showed no significant improvement in the indicated thermal efficiency for the P-40 Stirling engine operating at full-power and part-power conditions. Optimizing the heater tube length produced a small increase in the indicated thermal efficiency with the heater-bypass concept.

REopt Improves the Operations of Alcatraz's Solar PV-Battery-Diesel Hybrid System

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

Olis, Daniel R; Walker, H. A; Van Geet, Otto D

This poster identifies operations improvement strategies for a photovoltaic (PV)-battery-diesel hybrid system at the National Park Service's Alcatraz Island using NREL's REopt analysis tool. The current 'cycle charging' strategy results in significant curtailing of energy production from the PV array, requiring excessive diesel use, while also incurring high wear on batteries without benefit of improved efficiency. A simple 'load following' strategy results in near optimal operating cost reduction.

Photon enhanced thermionic emission

DOEpatents

Schwede, Jared; Melosh, Nicholas; Shen, Zhixun

2014-10-07

Photon Enhanced Thermionic Emission (PETE) is exploited to provide improved efficiency for radiant energy conversion. A hot (greater than 200.degree. C.) semiconductor cathode is illuminated such that it emits electrons. Because the cathode is hot, significantly more electrons are emitted than would be emitted from a room temperature (or colder) cathode under the same illumination conditions. As a result of this increased electron emission, the energy conversion efficiency can be significantly increased relative to a conventional photovoltaic device. In PETE, the cathode electrons can be (and typically are) thermalized with respect to the cathode. As a result, PETE does not rely on emission of non-thermalized electrons, and is significantly easier to implement than hot-carrier emission approaches.

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.

Empirical Study on the Sustainability of China's Grain Quality Improvement: The Role of Transportation, Labor, and Agricultural Machinery.

PubMed

Zhang, Ming; Duan, Fang; Mao, Zisen

2018-02-05

As a major part of farming sustainability, the issues of grain production and its quality improvement have been important in many countries. This paper aims to address these issues in China. Based on the data from the main production provinces and by applying the stochastic frontier analysis methodology, we find that the improvement of transportation and the use of agricultural machinery have become the main driving forces for grain quality improvement in China. After further studying different provinces' potentials of grain quality improvement, we show that grain quality has increased steadily. Therefore, we can conclude China's grain quality improvement is indeed sustainable. Furthermore, different grains like rice, wheat, and corn share similar characteristics in terms of quality improvement, but the improvement rate for rice is relatively low, while those of corn and wheat are relatively high. Moreover, the overall change of efficiency gain of grain quality improvement is not significant for different provinces. The efficiency gains of the quality improvements for rice and wheat even decrease slightly. In addition, we find that only expanding grain quality improvement potential can simultaneously achieve the dual objectives of improving grain quality and increasing yield.

Empirical Study on the Sustainability of China’s Grain Quality Improvement: The Role of Transportation, Labor, and Agricultural Machinery

PubMed Central

Zhang, Ming; Duan, Fang; Mao, Zisen

2018-01-01

As a major part of farming sustainability, the issues of grain production and its quality improvement have been important in many countries. This paper aims to address these issues in China. Based on the data from the main production provinces and by applying the stochastic frontier analysis methodology, we find that the improvement of transportation and the use of agricultural machinery have become the main driving forces for grain quality improvement in China. After further studying different provinces’ potentials of grain quality improvement, we show that grain quality has increased steadily. Therefore, we can conclude China’s grain quality improvement is indeed sustainable. Furthermore, different grains like rice, wheat, and corn share similar characteristics in terms of quality improvement, but the improvement rate for rice is relatively low, while those of corn and wheat are relatively high. Moreover, the overall change of efficiency gain of grain quality improvement is not significant for different provinces. The efficiency gains of the quality improvements for rice and wheat even decrease slightly. In addition, we find that only expanding grain quality improvement potential can simultaneously achieve the dual objectives of improving grain quality and increasing yield. PMID:29401727

Subsonic Performance of Ejector Systems

NASA Astrophysics Data System (ADS)

Weil, Samuel

Combined cycle engines combining scramjets with turbo jets or rockets can provide efficient hypersonic flight. Ejectors have the potential to increase the thrust and efficiency of combined cycle engines near static conditions. A computer code was developed to support the design of a small-scale, turbine-based combined cycle demonstrator with an ejector, built around a commercially available turbojet engine. This code was used to analyze the performance of an ejector system built around a micro-turbojet. With the use of a simple ejector, net thrust increases as large as 20% over the base engine were predicted. Additionally the specific fuel consumption was lowered by 10%. Increasing the secondary to primary area ratio of the ejector lead to significant improvements in static thrust, specific fuel consumption (SFC), and propulsive efficiency. Further ejector performance improvements can be achieved by using a diffuser. Ejector performance drops off rapidly with increasing Mach number. The ejector has lower thrust and higher SFC than the turbojet core at Mach numbers above 0.2. When the nozzle chokes a significant drop in ejector performance is seen. When a diffuser is used, higher Mach numbers lead to choking in the mixer and a shock in the nozzle causing a significant decrease in ejector performance. Evaluation of different turbo jets shows that ejector performance depends significantly on the properties of the turbojet. Static thrust and SFC improvements can be achieved with increasing ejector area for all engines, but size of increase and change in performance at higher Mach numbers depend heavily on the turbojet. The use of an ejector in a turbine based combined cycle configuration also increases performance at static conditions with a thrust increase of 5% and SFC decrease of 5% for the tested configuration.

Improving Si solar cell performance using Mn:ZnSe quantum dot-doped PLMA thin film

PubMed Central

2013-01-01

Poly(lauryl methacrylate) (PLMA) thin film doped with Mn:ZnSe quantum dots (QDs) was spin-deposited on the front surface of Si solar cell for enhancing the solar cell efficiency via photoluminescence (PL) conversion. Significant solar cell efficiency enhancements (approximately 5% to 10%) under all-solar-spectrum (AM0) condition were observed after QD-doped PLMA coatings. Furthermore, the real contribution of the PL conversion was precisely assessed by investigating the photovoltaic responses of the QD-doped PLMA to monochromatic and AM0 light sources as functions of QD concentration, combined with reflectance and external quantum efficiency measurements. At a QD concentration of 1.6 mg/ml for example, among the efficiency enhancement of 5.96%, about 1.04% was due to the PL conversion, and the rest came from antireflection. Our work indicates that for the practical use of PL conversion in solar cell performance improvement, cautions are to be taken, as the achieved efficiency enhancement might not be wholly due to the PL conversion. PMID:23787125

Spectrum splitting metrics and effect of filter characteristics on photovoltaic system performance.

PubMed

Russo, Juan M; Zhang, Deming; Gordon, Michael; Vorndran, Shelby; Wu, Yuechen; Kostuk, Raymond K

2014-03-10

During the past few years there has been a significant interest in spectrum splitting systems to increase the overall efficiency of photovoltaic solar energy systems. However, methods for comparing the performance of spectrum splitting systems and the effects of optical spectral filter design on system performance are not well developed. This paper addresses these two areas. The system conversion efficiency is examined in detail and the role of optical spectral filters with respect to the efficiency is developed. A new metric termed the Improvement over Best Bandgap is defined which expresses the efficiency gain of the spectrum splitting system with respect to a similar system that contains the highest constituent single bandgap photovoltaic cell. This parameter indicates the benefit of using the more complex spectrum splitting system with respect to a single bandgap photovoltaic system. Metrics are also provided to assess the performance of experimental spectral filters in different spectrum splitting configurations. The paper concludes by using the methodology to evaluate spectrum splitting systems with different filter configurations and indicates the overall efficiency improvement that is possible with ideal and experimental designs.

Study on Laws, Regulations and Standards on Energy Efficiency, Energy Conserving and Emission Reduction of Industrial Boilers in EU

NASA Astrophysics Data System (ADS)

Liu, Ren; Zhao, Yuejin; Chen, Haihong; Liang, Xiuying; Yang, Ming

2017-12-01

Industrial boilers are widely applied in such fields as factory power, building heating, and people’s lives; China is the world’s largest producer and user of industrial boilers, with very high annual energy consumption; clear requirements have been put forward by China on the energy efficiency since the “11th Five-year Plan” with the hope to save energy and reduce emission by means of energy efficiency standards and regulations on the supervision and control of various special equipment. So far, the energy efficiency of industrial boilers in China has been improved significantly but there is still a gap with the EU states. This paper analyzes the policies of energy efficiency, implementation models and methods of supervision and implementation at the EU level from laws, regulations, directives as well as standards; the paper also puts forward suggestions of energy conserving and emission reduction on the improvement of energy conserving capacity of industrial boilers in China through studying the legislations and measures of the developed countries in energy conserving of boilers.

Insight into D-A-π-A Structured Sensitizers: A Promising Route to Highly Efficient and Stable Dye-Sensitized Solar Cells.

PubMed

Wu, Yongzhen; Zhu, Wei-Hong; Zakeeruddin, Shaik M; Grätzel, Michael

2015-05-13

The dye-sensitized solar cell (DSSC) is one of the most promising photovoltaic technologies with potential of low cost, light weight, and good flexibility. The practical application of DSSCs requires further improvement in power conversion efficiency and long-term stability. Recently, significant progress has been witnessed in DSSC research owing to the novel concept of the D-A-π-A motif for the molecular engineering of organic photosensitizers. New organic and porphyrin dyes based on the D-A-π-A motif can not only enhance photovoltaic performance, but also improve durability in DSSC applications. This Spotlight on Applications highlights recent advances in the D-A-π-A-based photosensitizers, specifically focusing on the mechanism of efficiency and stability enhancements. Also, we find insight into the additional acceptor as well as the trade-off of long wavelength response. The basic principles are involved in molecular engineering of efficient D-A-π-A sensitizers, providing a clear road map showing how to modulate the energy bands, rationally extending the response wavelength, and optimizing photovoltaic efficiency step by step.

High-efficiency resonant coupled wireless power transfer via tunable impedance matching

NASA Astrophysics Data System (ADS)

Anowar, Tanbir Ibne; Barman, Surajit Das; Wasif Reza, Ahmed; Kumar, Narendra

2017-10-01

For magnetic resonant coupled wireless power transfer (WPT), the axial movement of near-field coupled coils adversely degrades the power transfer efficiency (PTE) of the system and often creates sub-resonance. This paper presents a tunable impedance matching technique based on optimum coupling tuning to enhance the efficiency of resonant coupled WPT system. The optimum power transfer model is analysed from equivalent circuit model via reflected load principle, and the adequate matching are achieved through the optimum tuning of coupling coefficients at both the transmitting and receiving end of the system. Both simulations and experiments are performed to evaluate the theoretical model of the proposed matching technique, and results in a PTE over 80% at close coil proximity without shifting the original resonant frequency. Compared to the fixed coupled WPT, the extracted efficiency shows 15.1% and 19.9% improvements at the centre-to-centre misalignment of 10 and 70 cm, respectively. Applying this technique, the extracted S21 parameter shows more than 10 dB improvements at both strong and weak couplings. Through the developed model, the optimum coupling tuning also significantly improves the performance over matching techniques using frequency tracking and tunable matching circuits.

Electrified Automotive Powertrain Architecture Using Composite DC–DC Converters

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

Chen, Hua; Kim, Hyeokjin; Erickson, Robert

In a hybrid or electric vehicle powertrain, a boost dc-dc converter enables reduction of the size of the electric machine and optimization of the battery system. Design of the powertrain boost converter is challenging because the converter must be rated at high peak power, while efficiency at medium-to-light load is critical for the vehicle system performance. By addressing only some of the loss mechanisms, previously proposed efficiency improvement approaches offer limited improvements in size, cost, and efficiency tradeoffs. This article shows how all dominant loss mechanisms in automotive powertrain applications can be mitigated using a new boost composite converter approach.more » In the composite dc-dc architecture, the loss mechanisms associated with indirect power conversion are addressed explicitly, resulting in fundamental efficiency improvements over wide ranges of operating conditions. Several composite converter topologies are presented and compared to state-of-the-art boost converter technologies. It is found that the selected boost composite converter results in a decrease in the total loss by a factor of 2-4 for typical drive cycles. Furthermore, the total system capacitor power rating and energy rating are substantially reduced, which implies potentials for significant reductions in system size and cost.« less

Ca/Alq3 hybrid cathode buffer layer for the optimization of organic solar cells based on a planar heterojunction

NASA Astrophysics Data System (ADS)

El Jouad, Z.; Barkat, L.; Stephant, N.; Cattin, L.; Hamzaoui, N.; Khelil, A.; Ghamnia, M.; Addou, M.; Morsli, M.; Béchu, S.; Cabanetos, C.; Richard-Plouet, M.; Blanchard, P.; Bernède, J. C.

2016-11-01

Use of efficient anode cathode buffer layer (CBL) is crucial to improve the efficiency of organic photovoltaic cells. Here we show that using a double CBL, Ca/Alq3, allows improving significantly cell performances. The insertion of Ca layer facilitates electron harvesting and blocks hole collection, leading to improved charge selectivity and reduced leakage current, whereas Alq3 blocks excitons. After optimisation of this Ca/Alq3 CBL using CuPc as electron donor, it is shown that it is also efficient when SubPc is substituted to CuPc in the cells. In that case we show that the morphology of the SubPc layer, and therefore the efficiency of the cells, strongly depends on the deposition rate of the SubPc film. It is necessary to deposit slowly (0.02 nm/s) the SubPc films because at higher deposition rate (0.06 nm/s) the films are porous, which induces leakage currents and deterioration of the cell performances. The SubPc layers whose formations are kinetically driven at low deposition rates are more uniform, whereas those deposited faster exhibit high densities of pinholes.

Advanced treatment of biologically pretreated coal chemical industry wastewater using the catalytic ozonation process combined with a gas-liquid-solid internal circulating fluidized bed reactor.

PubMed

Li, Zhipeng; Liu, Feng; You, Hong; Ding, Yi; Yao, Jie; Jin, Chao

2018-04-01

This paper investigated the performance of the combined system of catalytic ozonation and the gas-liquid-solid internal circulating fluidized bed reactor for the advanced treatment of biologically pretreated coal chemical industry wastewater (CCIW). The results indicated that with ozonation alone for 60min, the removal efficiency of chemical oxygen demand (COD) could reach 34%. The introduction of activated carbon, pumice, γ-Al 2 O 3 carriers improved the removal performance of COD, and the removal efficiency was increased by 8.6%, 4.2%, 2%, respectively. Supported with Mn, the catalytic performance of activated carbon and γ-Al 2 O 3 were improved significantly with COD removal efficiencies of 46.5% and 41.3%, respectively; however, the promotion effect of pumice supported with Mn was insignificant. Activated carbon supported with Mn had the best catalytic performance. The catalytic ozonation combined system of MnO X /activated carbon could keep ozone concentration at a lower level in the liquid phase, and promote the transfer of ozone from the gas phase to the liquid phase to improve ozonation efficiency.

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

A Novel Approach To Improve the Efficiency of Block Freeze Concentration Using Ice Nucleation Proteins with Altered Ice Morphology.

PubMed

Jin, Jue; Yurkow, Edward J; Adler, Derek; Lee, Tung-Ching

2017-03-22

Freeze concentration is a separation process with high success in product quality. The remaining challenge is to achieve high efficiency with low cost. This study aims to evaluate the potential of using ice nucleation proteins (INPs) as an effective method to improve the efficiency of block freeze concentration while also exploring the related mechanism of ice morphology. Our results show that INPs are able to significantly improve the efficiency of block freeze concentration in a desalination model. Using this experimental system, we estimate that approximately 50% of the energy cost can be saved by the inclusion of INPs in desalination cycles while still meeting the EPA standard of drinking water (<500 ppm). Our investigative tools for ice morphology include optical microscopy and X-ray computed tomography imaging analysis. Their use indicates that INPs promote the development of a lamellar structured ice matrix with larger hydraulic diameters, which facilitates brine drainage and contains less brine entrapment as compared to control samples. These results suggest great potential for applying INPs to develop an energy-saving freeze concentration method via the alteration of ice morphology.

Electrified Automotive Powertrain Architecture Using Composite DC–DC Converters

DOE PAGES

Chen, Hua; Kim, Hyeokjin; Erickson, Robert; ...

2017-01-01

In a hybrid or electric vehicle powertrain, a boost dc-dc converter enables reduction of the size of the electric machine and optimization of the battery system. Design of the powertrain boost converter is challenging because the converter must be rated at high peak power, while efficiency at medium-to-light load is critical for the vehicle system performance. By addressing only some of the loss mechanisms, previously proposed efficiency improvement approaches offer limited improvements in size, cost, and efficiency tradeoffs. This article shows how all dominant loss mechanisms in automotive powertrain applications can be mitigated using a new boost composite converter approach.more » In the composite dc-dc architecture, the loss mechanisms associated with indirect power conversion are addressed explicitly, resulting in fundamental efficiency improvements over wide ranges of operating conditions. Several composite converter topologies are presented and compared to state-of-the-art boost converter technologies. It is found that the selected boost composite converter results in a decrease in the total loss by a factor of 2-4 for typical drive cycles. Furthermore, the total system capacitor power rating and energy rating are substantially reduced, which implies potentials for significant reductions in system size and cost.« less

Enhanced efficiency of biological excess sludge hydrolysis under anaerobic digestion by additional enzymes.

PubMed

Yang, Qi; Luo, Kun; Li, Xiao-ming; Wang, Dong-bo; Zheng, Wei; Zeng, Guang-ming; Liu, Jing-jin

2010-05-01

In this investigation, the effects of commercial enzyme preparation containing alpha amylase and neutral protease on hydrolysis of excess sludge and the kinetic analysis of hydrolysis process were evaluated. The results indicated that amylase treatment displayed higher hydrolysis efficiency than that of protease. VSS reduction greatly increased to 39.70% for protease and 54.24% for amylase at the enzyme dosage of 6% (w/w), respectively. The hydrolysis rate of sludge improved with temperature increasing from 40 to 50 degrees Celsius, which could be well described by the amended Arrhenius equation. Mixed-enzyme had great impact on sludge solubilisation than single enzyme. The mixture of two enzymes (protease:amylase=1:3) resulted in optimum hydrolysis efficiency, the efficiency of solids hydrolysis increased from 10% (control test) to 68.43% at the temperature of 50 degrees Celsius. Correspondingly, the concentration of reducing sugar and NH(4)(+)-N improved about 377% and 201%, respectively. According to the kinetic analysis of enzymatic hydrolysis process, VSS solubilisation process within prior 4 h followed first-order kinetics. Compared with control test, the hydrolysis rate improved significantly at 50 degrees Celsius when either single enzyme or mixed-enzyme was added. Copyright 2009. Published by Elsevier Ltd.

Method for improving dissolution efficiency in gas-absorption and liquid extraction processes. [Patent application

DOEpatents

Kanak, B.E.; Stephenson, M.J.

1980-01-11

A method is described for improving dissolution efficiency in processes in which a feed fluid is introduced to a zone where it is contacted with a liquid solvent for preferentially removing a component of the feed and where part of the solvent so contacted undergoes transfer into the feed fluid to saturate the same. It has been found that such transfer significantly impairs dissolution efficiency. In accordance with the invention, an amount of the above-mentioned solvent is added to the feed fluid being introduced to the contact zone, the solvent being added in an amount sufficient to effect reduction or elimination of the above-mentioned transfer. Preferably, the solvent is added to the feed fluid in an amount saturating or supersaturating the feed fluid under the conditions prevailing in the contact zone.

Method for improving dissolution efficiency in gas-absorption and liquid extraction processes

DOEpatents

Kanak, Brant E.; Stephenson, Michael J.

1981-01-01

This invention is a method for improving dissolution efficiency in processes in which a feed fluid is introduced to a zone where it is contacted with a liquid solvent for preferentially removing a component of the feed and where part of the solvent so contacted undergoes transfer into the feed fluid to saturate the same. It has been found that such transfer significantly impairs dissolution efficiency. In accordance with the invention, an amount of the above-mentioned solvent is added to the feed fluid being introduced to the contact zone, the solvent being added in an amount sufficient to effect reduction or elimination of the above-mentioned transfer. Preferably, the solvent is added to the feed fluid in an amount saturating or supersaturating the feed fluid under the conditions prevailing in the contact zone.

Parallel discontinuous Galerkin FEM for computing hyperbolic conservation law on unstructured grids

NASA Astrophysics Data System (ADS)

Ma, Xinrong; Duan, Zhijian

2018-04-01

High-order resolution Discontinuous Galerkin finite element methods (DGFEM) has been known as a good method for solving Euler equations and Navier-Stokes equations on unstructured grid, but it costs too much computational resources. An efficient parallel algorithm was presented for solving the compressible Euler equations. Moreover, the multigrid strategy based on three-stage three-order TVD Runge-Kutta scheme was used in order to improve the computational efficiency of DGFEM and accelerate the convergence of the solution of unsteady compressible Euler equations. In order to make each processor maintain load balancing, the domain decomposition method was employed. Numerical experiment performed for the inviscid transonic flow fluid problems around NACA0012 airfoil and M6 wing. The results indicated that our parallel algorithm can improve acceleration and efficiency significantly, which is suitable for calculating the complex flow fluid.

Biting and chewing in overdentures, full dentures, and natural dentitions.

PubMed

Fontijn-Tekamp, F A; Slagter, A P; Van Der Bilt, A; Van 'T Hof, M A; Witter, D J; Kalk, W; Jansen, J A

2000-07-01

It has been suggested that the provision of dental implants can improve the oral function of subjects with severely resorbed mandibles, possibly restoring function to the level experienced by satisfied wearers of conventional complete dentures. Nevertheless, a quantitative comparison has never been made and can be drawn from the literature only with difficulty, since studies differ greatly in methodology. To make such a comparison, we measured bite force and chewing efficiency by using identical methods in subjects with overdentures, complete full dentures, and natural dentitions. Our results indicated that bite forces achieved with overdentures on dental implants were between those achieved with artificial and natural dentitions. Chewing efficiency was significantly greater than that of subjects with full dentures (low mandible), but was still lower than that of subjects with full dentures (high mandible) and overdentures on bare roots. Differences in the height of the mandible revealed significant differences in chewing efficiency between the two full-denture groups. Furthermore, subjects with a shortened dental arch exerted bite forces similar to those of subjects with a complete-natural dentition, but their chewing efficiency was limited due to the reduced occlusal area. For all groups combined, a significant correlation was found between maximum bite force and chewing efficiency. Nearly half of the variation in chewing efficiency was explained by bite force alone.

Improving the relevance and efficiency of human exposure assessments within the process of regulatory risk assessment.

PubMed

Money, Chris

2018-01-24

The process for undertaking exposure assessments varies dependent on its purpose. But for exposure assessments to be relevant and accurate, they are reliant on access to reliable information on key exposure determinants. Acquiring such information is seldom straightforward and can take significant time and resources. This articles examines how the application of tiered and targeted approaches to information acquisition, within the context of European human health risk assessments, can not only lead to improvements in the efficiency and effectiveness of the process but also in the confidence of stakeholders in its outputs. The article explores how the benefits might be further improved through the coordination of such activities, as well as those areas that represent barriers to wider international harmonisation.

Origins of conductivity improvement in fluoride-enhanced silicon doping of ZnO films.

PubMed

Rashidi, Nazanin; Vai, Alex T; Kuznetsov, Vladimir L; Dilworth, Jonathan R; Edwards, Peter P

2015-06-07

Fluoride in spray pyrolysis precursor solutions for silicon-doped zinc oxide (SiZO) transparent conductor thin films significantly improves their electrical conductivity by enhancing silicon doping efficiency and not, as previously assumed, by fluoride doping. Containing only earth-abundant elements, SiZO thus prepared rivals the best solution-processed indium-doped ZnO in performance.

Throughput of Coded Optical CDMA Systems with AND Detectors

NASA Astrophysics Data System (ADS)

Memon, Kehkashan A.; Umrani, Fahim A.; Umrani, A. W.; Umrani, Naveed A.

2012-09-01

Conventional detection techniques used in optical code-division multiple access (OCDMA) systems are not optimal and result in poor bit error rate performance. This paper analyzes the coded performance of optical CDMA systems with AND detectors for enhanced throughput efficiencies and improved error rate performance. The results show that the use of AND detectors significantly improve the performance of an optical channel.

Improving operating room efficiency in academic children's hospital using Lean Six Sigma methodology.

PubMed

Tagge, Edward P; Thirumoorthi, Arul S; Lenart, John; Garberoglio, Carlos; Mitchell, Kenneth W

2017-06-01

Lean Six Sigma (LSS) is a process improvement methodology that utilizes a collaborative team effort to improve performance by systematically identifying root causes of problems. Our objective was to determine whether application of LSS could improve efficiency when applied simultaneously to all services of an academic children's hospital. In our tertiary academic medical center, a multidisciplinary committee was formed, and the entire perioperative process was mapped, using fishbone diagrams, Pareto analysis, and other process improvement tools. Results for Children's Hospital scheduled main operating room (OR) cases were analyzed, where the surgical attending followed themselves. Six hundred twelve cases were included in the seven Children's Hospital operating rooms (OR) over a 6-month period. Turnover Time (interval between patient OR departure and arrival of the subsequent patient) decreased from a median 41min in the baseline period to 32min in the intervention period (p<0.0001). Turnaround Time (interval between surgical dressing application and subsequent surgical incision) decreased from a median 81.5min in the baseline period to 71min in the intervention period (p<0.0001). These results demonstrate that a coordinated multidisciplinary process improvement redesign can significantly improve efficiency in an academic Children's Hospital without preselecting specific services, removing surgical residents, or incorporating new personnel or technology. Prospective comparative study, Level II. Copyright © 2017 Elsevier Inc. All rights reserved.

Improving first case start times using Lean in an academic medical center.

PubMed

Deldar, Romina; Soleimani, Tahereh; Harmon, Carol; Stevens, Larry H; Sood, Rajiv; Tholpady, Sunil S; Chu, Michael W

2017-06-01

Lean is a process improvement strategy that can improve efficiency of the perioperative process. The purpose of this study was to identify etiologies of late surgery start times, implement Lean interventions, and analyze their effects. A retrospective review of all first-start surgery cases was performed. Lean was implemented in May 2015, and cases 7 months before and after implementation were analyzed. A total of 4,492 first-start cases were included; 2,181 were pre-Lean and 2,311 were post-Lean. The post-Lean group had significantly higher on-time starts than the pre-Lean group (69.0% vs 57.0%, P < .01). The most common delay etiology was surgeon-related for both groups. Delayed post-Lean cases were significantly less likely to be due to preoperative assessment (14.9% vs 9.9%, P < .01) and more likely due to patient-related (16.5% vs 22.3%, P < .01) or chaplain (1.8% vs 4.0%, P < .01) factors. Delayed starts occurred more often on snowy and cold days, and less often on didactic days (P < .01). Modifying preoperative tasks using Lean methods can improve operating room efficiency and increase on-time starts. Copyright © 2016 Elsevier Inc. All rights reserved.

Bayesian logistic regression approaches to predict incorrect DRG assignment.

PubMed

Suleiman, Mani; Demirhan, Haydar; Boyd, Leanne; Girosi, Federico; Aksakalli, Vural

2018-05-07

Episodes of care involving similar diagnoses and treatments and requiring similar levels of resource utilisation are grouped to the same Diagnosis-Related Group (DRG). In jurisdictions which implement DRG based payment systems, DRGs are a major determinant of funding for inpatient care. Hence, service providers often dedicate auditing staff to the task of checking that episodes have been coded to the correct DRG. The use of statistical models to estimate an episode's probability of DRG error can significantly improve the efficiency of clinical coding audits. This study implements Bayesian logistic regression models with weakly informative prior distributions to estimate the likelihood that episodes require a DRG revision, comparing these models with each other and to classical maximum likelihood estimates. All Bayesian approaches had more stable model parameters than maximum likelihood. The best performing Bayesian model improved overall classification per- formance by 6% compared to maximum likelihood, with a 34% gain compared to random classification, respectively. We found that the original DRG, coder and the day of coding all have a significant effect on the likelihood of DRG error. Use of Bayesian approaches has improved model parameter stability and classification accuracy. This method has already lead to improved audit efficiency in an operational capacity.

Masticatory efficiency and oral health-related quality of life with implant-retained mandibular overdentures

PubMed Central

Sun, Xu; Zhai, Jun-Jiang; Liao, Jian; Teng, Min-Hua; Tian, Ai; Liang, Xing

2014-01-01

Objectives: To evaluate masticatory efficiency (ME) and oral health-related quality of life (OHRQoL) in patients rehabilitated with implant-retained mandibular overdentures. Methods: In this randomized controlled clinical trial, 50 edentulous patients visiting the Implant Center and Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu, China between June 2010 and June 2012 were selected and received 2 implant-retained mandibular overdenture treatments. All patients were rehabilitated with maxillary complete dentures. The ME and OHRQoL were determined both one month before the mandibular complete denture was anchored to the osseointegrated implants, and 6 months after anchoring. Paired t-tests were used to compare means of ME, and oral health impact profile-49 (OHIP-49) domains scores between pre- and post-implant. Linear regression models were utilized to seek correlations between ME and OHIP domains scores. Results: The ME increased from pre- to post-implant retained mandibular overdentures significantly (p<0.001). The total OHIP score and 4 subscales scores were changed significantly from pre- to post-implant; namely, functional limitation, psychological discomfort, physical disability, and physical pain. The total OHIP score, functional limitation, physical disability, and physical pain subscale scores were related to ME. Conclusion: Implant-retained mandibular over dentures can significantly improve patients’ ME and OHRQoL. The improvement in OHRQoL is mainly because of the improved ME. An improved chewing experience, and pain relief also contributes to improvement of OHRQoL. PMID:25316463

Effect of non-stoichiometric solution chemistry on improving the performance of wide-bandgap perovskite solar cells

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

Yang, Mengjin; Kim, Dong Hoe; Yu, Yue

A high-efficiency wide-bandgap (WBG) perovskite solar cell is critical for developing perovskite-related (e.g., all-perovskite, perovskite/Si, or perovskite/Cu(In,Ga)Se 2) tandem devices. Here, we demonstrate the use of non-stoichiometric precursor chemistry with excess methylammonium halides (MAX; X = I, Br, or Cl) for preparing high-quality ~1.75-eV FA 0.83Cs 0.17Pb(I 0.6Br 0.4) 3 perovskite solar cells. Among various methylammonium halides, using excess MABr in the non-stoichiometric precursor exhibits the strongest effect on improving perovskite crystallographic properties and device characteristics without affecting the perovskite composition. In contrast, using excess MAI significantly reduces the bandgap of perovskite due to the replacement of Br with I.more » Using 40% excess MABr, we demonstrate a single-junction WBG perovskite solar cell with stabilized efficiency of 16.4%. We further demonstrate a 20.3%-efficient 4-terminal tandem device by using a 14.7%-efficient semi-transparent WBG perovskite top cell and an 18.6%-efficient unfiltered (5.6%-efficient filtered) Si bottom cell.« less

Effect of non-stoichiometric solution chemistry on improving the performance of wide-bandgap perovskite solar cells

DOE PAGES

Yang, Mengjin; Kim, Dong Hoe; Yu, Yue; ...

2017-10-02

A high-efficiency wide-bandgap (WBG) perovskite solar cell is critical for developing perovskite-related (e.g., all-perovskite, perovskite/Si, or perovskite/Cu(In,Ga)Se 2) tandem devices. Here, we demonstrate the use of non-stoichiometric precursor chemistry with excess methylammonium halides (MAX; X = I, Br, or Cl) for preparing high-quality ~1.75-eV FA 0.83Cs 0.17Pb(I 0.6Br 0.4) 3 perovskite solar cells. Among various methylammonium halides, using excess MABr in the non-stoichiometric precursor exhibits the strongest effect on improving perovskite crystallographic properties and device characteristics without affecting the perovskite composition. In contrast, using excess MAI significantly reduces the bandgap of perovskite due to the replacement of Br with I.more » Using 40% excess MABr, we demonstrate a single-junction WBG perovskite solar cell with stabilized efficiency of 16.4%. We further demonstrate a 20.3%-efficient 4-terminal tandem device by using a 14.7%-efficient semi-transparent WBG perovskite top cell and an 18.6%-efficient unfiltered (5.6%-efficient filtered) Si bottom cell.« less

Adaptive beam shaping for improving the power coupling of a two-Cassegrain-telescope

NASA Astrophysics Data System (ADS)

Ma, Haotong; Hu, Haojun; Xie, Wenke; Zhao, Haichuan; Xu, Xiaojun; Chen, Jinbao

2013-08-01

We demonstrate the adaptive beam shaping for improving the power coupling of a two-Cassegrain-telescope based on the stochastic parallel gradient descent (SPGD) algorithm and dual phase only liquid crystal spatial light modulators (LC-SLMs). Adaptive pre-compensation the wavefront of projected laser beam at the transmitter telescope is chosen to improve the power coupling efficiency. One phase only LC-SLM adaptively optimizes phase distribution of the projected laser beam and the other generates turbulence phase screen. The intensity distributions of the dark hollow beam after passing through the turbulent atmosphere with and without adaptive beam shaping are analyzed in detail. The influence of propagation distance and aperture size of the Cassegrain-telescope on coupling efficiency are investigated theoretically and experimentally. These studies show that the power coupling can be significantly improved by adaptive beam shaping. The technique can be used in optical communication, deep space optical communication and relay mirror.

High efficiency and enhanced ESD properties of UV LEDs by inserting p-GaN/p-AlGaN superlattice

NASA Astrophysics Data System (ADS)

Huang, Yong; Li, PeiXian; Yang, Zhuo; Hao, Yue; Wang, XiaoBo

2014-05-01

Significantly improved electrostatic discharge (ESD) properties of InGaN/GaN-based UV light-emitting diode (LED) with inserting p-GaN/p-AlGaN superlattice (p-SLs) layers (instead of p-AlGaN single layer) between multiple quantum wells and Mg-doped GaN layer are reported. The pass yield of the LEDs increased from 73.53% to 93.81% under negative 2000 V ESD pulses. In addition, the light output power (LOP) and efficiency droop at high injection current were also improved. The mechanism of the enhanced ESD properties was then investigated. After excluding the effect of capacitance modulation, high-resolution X-ray diffraction (XRD) and atomic force microscope (AFM) measurements demonstrated that the dominant mechanism of the enhanced ESD properties is the material quality improved by p-SLs, which indicated less leakage paths, rather than the current spreading improved by p-SLs.

Improving the environmental and performance characteristics of vehicles by introducing the surfactant additive into gasoline.

PubMed

Magaril, Elena; Magaril, Romen

2016-09-01

The operation of modern vehicles requires the introduction of package of fuel additives to ensure the required level of operating characteristics, some of which cannot be achieved by current oil refining methods. The use of additives allows flexibility of impact on the properties of the fuel at minimal cost, increasing the efficiency and environmental safety of vehicles. Among the wide assortment of additives available on the world market, many are surfactants. It has been shown that the introduction of some surfactants into gasoline concurrently reduces losses from gasoline evaporation, improves the mixture formation during injection of gasoline into the engine and improves detergent and anticorrosive properties. The surfactant gasoline additive that provides significant improvement in the quality of gasoline used and environmental and operating characteristics of vehicles has been developed and thoroughly investigated. The results of studies confirming the efficiency of the gasoline additive application are herein presented.

Line pilot perspectives on complexity of terminal instrument flight procedures

DOT National Transportation Integrated Search

2016-09-01

Many new Performance Based Navigation (PBN) Instrument Flight Procedures (IFPs) are being developed as the United States transforms its airspace to improve safety and efficiency. Despite significant efforts to prepare for operational implementation o...

Vehicle-to-vehicle communications in mixed passenger-freight convoys : [final report].

DOT National Transportation Integrated Search

2016-09-01

Vehicle convoys (platoons) hold a promise for significant efficiency improvements of freight and : passenger transportation through better system integration. Through the use of advanced driver : assistance, vehicles in a convoy can keep shorter dist...

Arterial intelligent transportation systems : infrastructure elements and traveler information requirements.

DOT National Transportation Integrated Search

2009-08-01

Applying Intelligent Transportation Systems (ITS) to arterial systems allows TxDOT to significantly enhance : transportation system operation efficiency and improve traffic mobility. However, no guidelines are available to : assist TxDOT staff in sel...

Effect of Micro-Bubbles in Water on Beam Patterns of Parametric Array

NASA Astrophysics Data System (ADS)

Hashiba, Kunio; Masuzawa, Hiroshi

2003-05-01

The improvement in efficiency of a parametric array by nonlinear oscillation of micro-bubbles in water is studied in this paper. The micro-bubble oscillation can increase the nonlinear coefficient of the acoustic medium. The amplitude of the difference-frequency wave along the longitudinal axis and its beam patterns in the field including the layer with micro-bubbles were analyzed using a Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. As a result, the largest improvement in efficiency was obtained and a narrow parametric beam was formed by forming a layer with micro-bubbles in front of a parametric sound radiator as thick as about the shock formation distance. If the layer becomes significantly thicker than the distance, the beam of the difference-frequency wave in the far-field will become broader. If the layer is significantly thinner than the distance, the intensity level of the wave in the far-field will be too low.

Current challenges in organic photovoltaic solar energy conversion.

PubMed

Schlenker, Cody W; Thompson, Mark E

2012-01-01

Over the last 10 years, significant interest in utilizing conjugated organic molecules for solid-state solar to electric conversion has produced rapid improvement in device efficiencies. Organic photovoltaic (OPV) devices are attractive for their compatibility with low-cost processing techniques and thin-film applicability to flexible and conformal applications. However, many of the processes that lead to power losses in these systems still remain poorly understood, posing a significant challenge for the future efficiency improvements required to make these devices an attractive solar technology. While semiconductor band models have been employed to describe OPV operation, a more appropriate molecular picture of the pertinent processes is beginning to emerge. This chapter presents mechanisms of OPV device operation, based on the bound molecular nature of the involved transient species. With the intention to underscore the importance of considering both thermodynamic and kinetic factors, recent progress in elucidating molecular characteristics that dictate photovoltage losses in heterojunction organic photovoltaics is also discussed.

Improved electrolyte for zinc-bromine flow batteries

NASA Astrophysics Data System (ADS)

Wu, M. C.; Zhao, T. S.; Wei, L.; Jiang, H. R.; Zhang, R. H.

2018-04-01

Conventional zinc bromide electrolytes offer low ionic conductivity and often trigger severe zinc dendrite growth in zinc-bromine flow batteries. Here we report an improved electrolyte modified with methanesulfonic acid, which not only improves the electrolyte conductivity but also ameliorates zinc dendrite. Experimental results also reveal that the kinetics and reversibility of Zn2+/Zn and Br2/Br- are improved in this modified electrolyte. Moreover, the battery's internal resistance is significantly reduced from 4.9 to 2.0 Ω cm2 after adding 1 M methanesulfonic acid, thus leading to an improved energy efficiency from 64% to 75% at a current density of 40 mA cm-2. More impressively, the battery is capable of delivering an energy efficiency of about 78% at a current density of as high as 80 mA cm-2 when the electrode is replaced by a thermally treated one. Additionally, zinc dendrite growth is found to be effectively suppressed in methanesulfonic acid supported media, which, as a result, enables the battery to be operated for 50 cycles without degradation, whereas the one without methanesulfonic acid suffers from significant decay after only 40 cycles, primarily due to severe zinc dendrite growth. These superior results indicate methanesulfonic acid is a promising supporting electrolyte for zinc-bromine flow batteries.

Design and implementation of priority and time-window based traffic scheduling and routing-spectrum allocation mechanism in elastic optical networks

NASA Astrophysics Data System (ADS)

Wang, Honghuan; Xing, Fangyuan; Yin, Hongxi; Zhao, Nan; Lian, Bizhan

2016-02-01

With the explosive growth of network services, the reasonable traffic scheduling and efficient configuration of network resources have an important significance to increase the efficiency of the network. In this paper, an adaptive traffic scheduling policy based on the priority and time window is proposed and the performance of this algorithm is evaluated in terms of scheduling ratio. The routing and spectrum allocation are achieved by using the Floyd shortest path algorithm and establishing a node spectrum resource allocation model based on greedy algorithm, which is proposed by us. The fairness index is introduced to improve the capability of spectrum configuration. The results show that the designed traffic scheduling strategy can be applied to networks with multicast and broadcast functionalities, and makes them get real-time and efficient response. The scheme of node spectrum configuration improves the frequency resource utilization and gives play to the efficiency of the network.

Failsafe modes in incomplete minority game

NASA Astrophysics Data System (ADS)

Yao, Xiaobo; Wan, Shaolong; Chen, Wen

2009-09-01

We make a failsafe extension to the incomplete minority game model, give a brief analysis on how incompleteness will effect system efficiency. Simulations that limited incompleteness in strategies can improve the system efficiency. Among three failsafe modes, the “Back-to-Best” mode brings most significant improvement and keeps the system efficiency in a long range of incompleteness. A simple analytic formula has a trend which matches simulation results. The IMMG model is used to study the effect of distribution, and we find that there is one junction point in each series of curves, at which system efficiency is not influenced by the distribution of incompleteness. When pIbar > the concentration of incompleteness weakens the effect. On the other side of , concentration will be helpful. When pI is close to zero agents using incomplete strategies have on average better profits than those using standard strategies, and the “Back-to-Best” agents have a wider range of pI to win.

Significant performance enhancement of inverted organic light-emitting diodes by using ZnIx as a hole-blocking layer

NASA Astrophysics Data System (ADS)

Cheng, Chuan-Hui; Zhang, Bi-Long; Sun, Chao; Li, Ruo-Xuan; Wang, Yuan; Tian, Wen-Ming; Zhao, Chun-Yi; Jin, Sheng-Ye; Liu, Wei-Feng; Luo, Ying-Min; Du, Guo-Tong; Cong, Shu-Lin

2017-06-01

A highly efficient inverted organic light emitting diode using 1.0 nm-thick ZnIx as a hole-blocking layer is developed. We fabricate devices with the configuration ITO/ZnIx (1.0 nm)/Alq3 (50 nm)/NPB (50 nm)/MoO3 (6.0 nm)/Al (100 nm). The deposition of a ZnIx layer increases the maximum luminance by two orders of magnitude from 13.4 to 3566.1 cd/m2. In addition, the maximum current efficiency and power efficiency are increased by three orders of magnitude, and the turn-on voltage to reach 1 cd/m2 decreases from 13 to 8 V. The results suggest that the electron injection efficiency is not improved by introducing a ZnIx layer. Instead, the improved device performance originates from the strong hole-blocking ability of ZnIx. This work indicates that layered materials may lead to novel applications in optoelectronic devices.

Effect of powdered activated carbon technology on short-cut nitrogen removal for coal gasification wastewater.

PubMed

Zhao, Qian; Han, Hongjun; Xu, Chunyan; Zhuang, Haifeng; Fang, Fang; Zhang, Linghan

2013-08-01

A combined process consisting of a powdered activated carbon technology (PACT) and short-cut biological nitrogen removal reactor (SBNR) was developed to enhance the removal efficiency of the total nitrogen (TN) from the effluent of an upflow anaerobic sludge bed (UASB) reactor, which was used to treat coal gasification wastewater (CGW). The SBNR performance was improved with the increasing of COD and TP removal efficiency via PACT. The average removal efficiencies of COD and TP in PACT were respectively 85.80% and 90.30%. Meanwhile, the NH3-N to NO2-N conversion rate was achieved 86.89% in SBNR and the total nitrogen (TN) removal efficiency was 75.54%. In contrast, the AOB in SBNR was significantly inhibited without PACT or with poor performance of PACT in advance, which rendered the removal of TN. Furthermore, PAC was demonstrated to remove some refractory compounds, which therefore improved the biodegradability of the coal gasification wastewater. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

Numerical flow simulation and efficiency prediction for axial turbines by advanced turbulence models

NASA Astrophysics Data System (ADS)

Jošt, D.; Škerlavaj, A.; Lipej, A.

2012-11-01

Numerical prediction of an efficiency of a 6-blade Kaplan turbine is presented. At first, the results of steady state analysis performed by different turbulence models for different operating regimes are compared to the measurements. For small and optimal angles of runner blades the efficiency was quite accurately predicted, but for maximal blade angle the discrepancy between calculated and measured values was quite large. By transient analysis, especially when the Scale Adaptive Simulation Shear Stress Transport (SAS SST) model with zonal Large Eddy Simulation (ZLES) in the draft tube was used, the efficiency was significantly improved. The improvement was at all operating points, but it was the largest for maximal discharge. The reason was better flow simulation in the draft tube. Details about turbulent structure in the draft tube obtained by SST, SAS SST and SAS SST with ZLES are illustrated in order to explain the reasons for differences in flow energy losses obtained by different turbulence models.

An interactive videogame designed to improve respiratory navigator efficiency in children undergoing cardiovascular magnetic resonance.

PubMed

Hamlet, Sean M; Haggerty, Christopher M; Suever, Jonathan D; Wehner, Gregory J; Grabau, Jonathan D; Andres, Kristin N; Vandsburger, Moriel H; Powell, David K; Sorrell, Vincent L; Fornwalt, Brandon K

2016-09-06

Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient's breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality. We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The game incentivized children to breathe such that the avatar was positioned within the navigator acceptance window (±3 mm) throughout image acquisition. Using a 3T Siemens Tim Trio, 50 children (Age: 14 ± 3 years, 48 % female) with no significant past medical history underwent a respiratory navigator-gated 2D spiral cine displacement encoding with stimulated echoes (DENSE) CMR acquisition first with no feedback (NF) and then with the feedback game (FG). Thirty of the 50 children were randomized to undergo extensive off-scanner training with the FG using a MRI simulator, or no off-scanner training. Navigator efficiency, signal-to-noise ratio (SNR), and global left-ventricular strains were determined for each participant and compared. Using the FG improved average navigator efficiency from 33 ± 15 to 58 ± 13 % (p < 0.001) and improved SNR by 5 % (p = 0.01) compared to acquisitions with NF. There was no difference in navigator efficiency (p = 0.90) or SNR (p = 0.77) between untrained and trained participants for FG acquisitions. Circumferential and radial strains derived from FG acquisitions were slightly reduced compared to NF acquisitions (-16 ± 2 % vs -17 ± 2 %, p < 0.001; 40 ± 10 % vs 44 ± 11 %, p = 0.005, respectively). There were no differences in longitudinal strain (p = 0.38). Use of a respiratory navigator feedback game during navigator-gated CMR improved navigator efficiency in children from 33 to 58 %. This improved efficiency was associated with a 5 % increase in SNR for spiral cine DENSE. Extensive off-scanner training was not required to achieve the improvement in navigator efficiency.

Factors affecting the technical efficiency of general hospitals in Iran: data envelopment analysis.

PubMed

Kalhor, Rohollah; Amini, Saeed; Sokhanvar, Mobin; Lotfi, Farhad; Sharifi, Marziye; Kakemam, Edris

2016-03-01

Restrictions on resource accessibility and its optimal application is the main challenge in organizations nowadays. The aim of this research was to study the technical efficiency and its related factors in Tehran general hospitals. This descriptive analytical study was conducted retrospectively in 2014. Fifty-four hospitals with private, university, and social security ownerships from the total 110 general hospitals were randomly selected for inclusion into this study on the basis of the share of ownership. Data were collected using a checklist with three sections, including background variables, inputs, and outputs. Seventeen (31.48%) hospitals had an efficiency score of 1 (highest efficiency score). The highest average efficiency score was in social security hospitals (84.32). Private and university hospitals ranked next with an average of 84.29 and 79.64, respectively. Analytical results showed that there was a significant relationship between hospital ownership, hospital type in terms of duty and specialization, educational field of the chief executive officer, and technical efficiency. There was no significant relationship between education level of hospital manager and technical efficiency. Most of the studied hospitals were operating at low efficiency. Therefore, policymakers should plan to improve the hospital operations and promote hospitals to an optimal level of efficiency.

Aerobic and Strength Training in Concomitant Metabolic Syndrome and Type 2 Diabetes

PubMed Central

Earnest, Conrad P.; Johannsen, Neil M.; Swift, Damon L.; Gillison, Fiona B.; Mikus, Catherine R.; Lucia, Alejandro; Kramer, Kimberly; Lavie, Carl J.; Church, Timothy S.

2014-01-01

Purpose Concomitant type 2 diabetes (T2D) and metabolic syndrome exacerbates mortality risk; yet, few studies have examined the effect of combining (AER+RES) aerobic (AER) and resistance (RES) training for individuals with T2D and metabolic syndrome. Methods We examined AER, RES, and AER+RES training (9-months) commensurate with physical activity guidelines in individuals with T2D (N=262, 63% female, 44% black). Primary outcomes were change in, and prevalence of, metabolic syndrome score at follow-up (mean, 95%CI). Secondary outcomes included maximal cardiorespiratory fitness (VO2peak and estimated METs from time-to-exhaustion (TTE), and exercise efficiency calculated as the slope of the line between ventilatory threshold, respiratory compensation, and maximal fitness. General linear models and bootstrapped Spearman correlations were used to examine changes in metabolic syndrome associated with training primary and secondary outcome variables. Results We observed a significant decrease in metabolic syndrome scores (P-for-trend, 0.003) for AER (−0.59, 95%CI, −1.00, −0.21) and AER+RES (−0.79, 95%CI, −1.40, −0.35), both being significant (P < 0.02) vs. Control (0.26, 95%CI, −0.58, 0.40) and RES (−0.13, 95%CI, −1.00, 0.24). This lead to a reduction in metabolic syndrome prevalence for the AER (56% vs. 43%) and AER+RES (55% vs. 46%) groups between baseline and follow-up. The observed decrease in metabolic syndrome was mediated by significant improvements in exercise efficiency for the AER and AER+RES training groups (P<0.05), which was more strongly related to TTE (25–30%; r= −0.38; 95% CI: −0.55, −0.19) than VO2peak (5–6%; r= −0.24; 95% CI: −0.45, −0.01). Conclusion Aerobic and AER+RES training significantly improves metabolic syndrome scores and prevalence in patients with T2D. These improvements appear to be associated with improved exercise efficiency and are more strongly related to improved TTE versus VO2peak. PMID:24389523

Variation in capture efficiency of a beach seine for small fishes

USGS Publications Warehouse

Parsley, M.J.; Palmer, D.E.; Burkhardt, R.W.

1989-01-01

We determined the capture efficiency of a beach seine as a means of improving abundance estimates of small fishes in littoral areas. Capture efficiency for 14 taxa (individual species or species groups) was determined by seining within an enclosure at night over fine and coarse substrates in the John Day Reservoir, Oregon–Washington. Mean efficiency ranged from 12% for prickly sculpin Cottus asper captured over coarse substrates to 96% for peamouth Mylocheilus caurinus captured over fine substrates. Mean capture efficiency for a taxon (genus or species) was generally higher over fine substrates than over coarse substrates, although mean capture efficiencies over fine substrates were significantly greater for only 3 of 10 taxa. Capture efficiency generally was not influenced by fish density or by water temperature (range, 8–26°C). Conclusions about the relative abundance of taxa captured by seining can change substantially after capture efficiencies are taken into account.

Data Center Energy Efficiency Standards in India: Preliminary Findings from Global Practices

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

Raje, Sanyukta; Maan, Hermant; Ganguly, Suprotim

Global data center energy consumption is growing rapidly. In India, information technology industry growth, fossil-fuel generation, and rising energy prices add significant operational costs and carbon emissions from energy-intensive data centers. Adoption of energy-efficient practices can improve the global competitiveness and sustainability of data centers in India. Previous studies have concluded that advancement of energy efficiency standards through policy and regulatory mechanisms is the fastest path to accelerate the adoption of energy-efficient practices in the Indian data centers. In this study, we reviewed data center energy efficiency practices in the United States, Europe, and Asia. Using evaluation metrics, we identifiedmore » an initial set of energy efficiency standards applicable to the Indian context using the existing policy mechanisms. These preliminary findings support next steps to recommend energy efficiency standards and inform policy makers on strategies to adopt energy-efficient technologies and practices in Indian data centers.« less

[Primary care: decentralization and efficiency].

PubMed

Pinillos, M; Antoñanzas, F

2002-01-01

The purpose of this study was to evaluate whether the productive behavior of health centers in autonomous communities with competence in health is more efficient than that among centers belonging to Spanish public health system (INSALUD). The technical efficiency of 66 health centers in Alava, Navarre and La Rioja was analyzed. Centers in autonomous communities that in 1997 had been granted complete authority from the central government to manage their healthcare services were compared with centers whose administration, in the same year, was still in the hands of INSALUD. The method used to measure and quantify the efficiency of these centers was data envelopment analysis. Nonparametric contrast of the health centers' mean efficiency rates revealed no significant differences in the (in)efficiency of centers from La Rioja, Navarre and Alava. The results obtained from the model of efficiency measurement used did not indicate that decentralization improves the productive efficiency of primary care centers.

Research on Evaluation of resource allocation efficiency of transportation system based on DEA

NASA Astrophysics Data System (ADS)

Zhang, Zhehui; Du, Linan

2017-06-01

In this paper, we select the time series data onto 1985-2015 years, construct the land (shoreline) resources, capital and labor as inputs. The index system of the output is freight volume and passenger volume, we use Quantitative analysis based on DEA method evaluated the resource allocation efficiency of railway, highway, water transport and civil aviation in China. Research shows that the resource allocation efficiency of various modes of transport has obvious difference, and the impact on scale efficiency is more significant. The most important two ways to optimize the allocation of resources to improve the efficiency of the combination of various modes of transport is promoting the co-ordination of various modes of transport and constructing integrated transportation system.

Conversion to No-Till Improves Maize Nitrogen Use Efficiency in a Continuous Cover Cropping System

PubMed Central

Habbib, Hazzar; Verzeaux, Julien; Nivelle, Elodie; Roger, David; Lacoux, Jérôme; Catterou, Manuella; Hirel, Bertrand; Dubois, Frédéric; Tétu, Thierry

2016-01-01

A two-year experiment was conducted in the field to measure the combined impact of tilling and N fertilization on various agronomic traits related to nitrogen (N) use efficiency and to grain yield in maize cultivated in the presence of a cover crop. Four years after conversion to no-till, a significant increase in N use efficiency N harvest index, N remobilization and N remobilization efficiency was observed both under no and high N fertilization conditions. Moreover, we observed that grain yield and grain N content were higher under no-till conditions only when N fertilizers were applied. Thus, agronomic practices based on continuous no-till appear to be a promising for increasing N use efficiency in maize. PMID:27711154

Experimental study of hydraulics and sediment capture efficiency in catchbasins.

PubMed

Tang, Yangbo; Zhu, David Z; Rajaratnam, N; van Duin, Bert

2016-12-01

Catchbasins (also known as gully pot in the UK and Australia) are used to receive surface runoff and drain the stormwater into storm sewers. The recent interest in catchbasins is to improve their effectiveness in removing sediments in stormwater. An experimental study was conducted to examine the hydraulic features and sediment capture efficiency in catchbasins, with and without a bottom sump. A sump basin is found to increase the sediment capture efficiency significantly. The effect of inlet control devices, which are commonly used to control the amount of flow into the downstream storm sewer system, is also studied. These devices will increase the water depth in the catchbasin and increase the sediment capture efficiency. Equations are developed for predicting the sediment capture efficiency in catchbasins.

Revealing driving factors of China's PM2.5 pollution

NASA Astrophysics Data System (ADS)

Zheng, Y.; Zhao, H.; Zhang, Q.; Geng, G.; Tong, D.; Peng, L.; He, K.

2017-12-01

China's rapid economic development and intensive energy consumption are deteriorating the air quality significantly. Understanding the key driving factors behind China's growing emissions of air pollutants and the accompanying PM2.5 pollution is critical for the development of China's clean air policies and also provides insight into how other emerging economies may develop a clear sky future. Here we reveal the socioeconomic drivers of the variations of China's PM2.5 concentrations during 2002-2012 by using an interdisciplinary framework that integrates an emission inventory model, an index decomposition analysis model, and a regional air quality model. The decomposition results demostrate that the improvements in emission efficiency and energy efficiency failed to offset the increased emissions of both primary PM2.5 and gaseous PM2.5 precursors (including SO2 NOx, and volatile organic compounds) triggered by the surging economic growth during 2002-2012. During the same time, the effects of energy structure, production structure and population growth were relatively less significant to all pollutants, which indicates the potential of large emission abatements through energy structure and production structure adjustment. Sensitivity simulations by the air quality model based on the provincial decomposition results also show that the economic growth have outpaced efficiency improvements in the increments of PM2.5 concentrations during the study years. As China continues to develop rapidly, future policies should promote further improvements in efficiency and accelerate the adjustments toward clean energy and production structures, which are critical for reducing China's emissions and alleviating the severe PM2.5 pollution.

[Improving the feed conversion rate in the pig fattening industry by optimising hygienic management].

PubMed

Riedl, Antonia M; Völkel, Inger; Schlindwein, Bernhard; Czerny, Claus-Peter

2013-01-01

Considering continuously increasing forage costs, the feed conversion rate has a major impact on the economic efficiency in hog fattening. The influence of hygienic management strategies on animal health and feed efficiency was evaluated by an online-study comprising animal health management data of 202 German pig fatteners. Data analysis included a simple comparison of averages, a linear regression analysis, and a cluster analysis. Due to geographical distribution and size of premises, the random sample was not representative but yielded in significant results. The total impact of hygienic management on feed conversion was calculated to be 23.9 %. Professional performance of rodent control (beta = 0.357; p < or = 0.001), efficient insect larvae control (beta = 0.276; p = 0.008), requiring visitors to wear protective gear (beta = 0.261; p = 0.009), and immediately performed cleaning and disinfection of emptied pens (beta = 0.247; p = 0.017) were top-ranking variables. Furthermore, a significantly better fed efficiency was observed in companies reporting stables in a good state of repair or performing further preventive strategies to control animal health on herd-level (storage of fodder retain samples, health screening based on blood and faecal samples, cross-section to verify unclear death cases). For pig fatteners the benefit resulting from improved feed conversion ranged from Euro 1.15 to and Euro 2.53 per pig. Likewise optimized growth performance as a result of improved hygienic management could partly compensate increasing feed costs. The results of this online-study reveal the need to establish reliable HACCP systems on farm level.

Quantitative photogrammetric analysis of the Klapp method for treating idiopathic scoliosis.

PubMed

Iunes, Denise H; Cecílio, Maria B B; Dozza, Marina A; Almeida, Polyanna R

2010-01-01

Few studies have proved that physical therapy techniques are efficient in the treatment of scoliosis. To analyze the efficiency of the Klapp method for the treatment of scoliosis, through a quantitative analysis using computerized biophotogrammetry. Sixteen participants of a mean age of 15+/-2.61 yrs. with idiopathic scoliosis were treated using the Klapp method. To analyze the results from the treatment, they were all of photographed before and after the treatments, following a standardized photographic method. All of the photographs were analyzed quantitatively by the same examiner using the ALCimagem 2000 software. The statistical analyses were performed using the paired t-test with a significance level of 5%. The treatments showed improvements in the angles which evaluated the symmetry of the shoulders, i.e. the acromioclavicular joint angle (AJ; p=0.00) and sternoclavicular joint angle (SJ; p=0.01). There were also improvements in the angle that evaluated the left Thales triangle (DeltaT; p=0.02). Regarding flexibility, there were improvements in the tibiotarsal angle (TTA; p=0.01) and in the hip joint angles (HJA; p=0.00). There were no changes in the vertebral curvatures and nor improvements in head positioning. Only the lumbar curvature, evaluated by the lumbar lordosis angle (LL; p=0.00), changed after the treatments. The Klapp method was an efficient therapeutic technique for treating asymmetries of the trunk and improving its flexibility. However, it was not efficient for pelvic asymmetry modifications in head positioning, cervical lordosis or thoracic kyphosis.

Improvement in Patient Transfer Process From the Operating Room to the PICU Using a Lean and Six Sigma-Based Quality Improvement Project.

PubMed

Gleich, Stephen J; Nemergut, Michael E; Stans, Anthony A; Haile, Dawit T; Feigal, Scott A; Heinrich, Angela L; Bosley, Christopher L; Tripathi, Sandeep

2016-08-01

Ineffective and inefficient patient transfer processes can increase the chance of medical errors. Improvements in such processes are high-priority local institutional and national patient safety goals. At our institution, nonintubated postoperative pediatric patients are first admitted to the postanesthesia care unit before transfer to the PICU. This quality improvement project was designed to improve the patient transfer process from the operating room (OR) to the PICU. After direct observation of the baseline process, we introduced a structured, direct OR-PICU transfer process for orthopedic spinal fusion patients. We performed value stream mapping of the process to determine error-prone and inefficient areas. We evaluated primary outcome measures of handoff error reduction and the overall efficiency of patient transfer process time. Staff satisfaction was evaluated as a counterbalance measure. With the introduction of the new direct OR-PICU patient transfer process, the handoff communication error rate improved from 1.9 to 0.3 errors per patient handoff (P = .002). Inefficiency (patient wait time and non-value-creating activity) was reduced from 90 to 32 minutes. Handoff content was improved with fewer information omissions (P < .001). Staff satisfaction significantly improved among nearly all PICU providers. By using quality improvement methodology to design and implement a new direct OR-PICU transfer process with a structured multidisciplinary verbal handoff, we achieved sustained improvements in patient safety and efficiency. Handoff communication was enhanced, with fewer errors and content omissions. The new process improved efficiency, with high staff satisfaction. Copyright © 2016 by the American Academy of Pediatrics.

CPAP of 4 cm H(2)O Has no short-term benefit at term in infants with BPD.

PubMed

Sandberg, Kenneth L; Hjalmarson, Ola

2012-01-01

Lung development and function is compromised at term in infants with bronchopulmonary dysplasia (BPD), characterized by reduced functional residual capacity (FRC) and impaired gas-mixing efficiency in distal airways. To determine whether continuous positive airway pressure (CPAP) improves FRC, ventilation, distal airway function, and gas exchange in spontaneously breathing infants with BPD. Twenty-one infants with BPD (median birth weight 0.72 kg (range 0.50-1.27) and median gestational age 26 weeks (range 23-28)) were studied before and after CPAP of 4 cm H(2)O was applied by a facemask system. A multiple-breath nitrogen washout method was used to assess FRC, ventilation, and gas-mixing efficiency. Moment analysis and lung clearance index was calculated from the nitrogen-decay curve for assessment of gas-mixing efficiency. Transcutaneous (Tc) PO(2)/PCO(2) was monitored during stable infant conditions before each washout test. When CPAP was raised from 0 to 4 cm H(2)O, FRC increased significantly together with a significant increase in moment ratios (M(1)/M(0) and M(2)/M(0)). Tc PO(2) decreased significantly and the breathing pattern changed, with significantly reduced respiratory rate, minute ventilation, and alveolar ventilation. There was also an increase in tidal volume and dead space. CPAP of 4 cm H(2)O applied with a facemask at term to infants with BPD did not improve ventilation, gas-mixing efficiency in distal airways, or oxygenation despite an increase in FRC. We speculate that instead of promoting recruitment of unventilated lung volumes, increasing the end-expiratory pressure in infants with BPD may lead to an overexpansion of already ventilated parts of the lung, causing further compromise of lung function. Copyright © 2012 S. Karger AG, Basel.

Improving the efficiency of phytoremediation using electrically charged plant and chelating agents.

PubMed

Tahmasbian, Iman; Safari Sinegani, Ali Akbar

2016-02-01

The low efficiency of phytoremediation is a considerable problem that limits the application of this environmentally friendly method on heavy metal-polluted soils. The combination of chelate-assisted phytoextraction and electrokinetic remediation could offer new opportunities to improve the effectiveness of phytoextraction. The current experiment aims to investigate the effects of electrical fields and chelating agents on phytoremediation efficiency. In a pot experiment using mine soil, poultry manure extract (PME), cow manure extract (CME), and ethylenediaminetetraacetic acid (EDTA) were applied to soil as chelating agents (2 g kg(-1)) at the beginning of the flowering stage. A week later, Helianthus annuus (sunflower) was negatively charged by inserting a stainless steel needle with 10 and 30 V DC electricity in the lowest part of the stems for 1 h each day for a 14-day period. At the end of the experiment, the shoot and root dry weight, lead (Pb) concentration in plant organs, translocation factor (TF), metal uptake index (UI), and soil available Pb (diethylene triamine pentaacetic acid (DTPA) extractable) were detected. Results indicated that the application of electrical fields had no significant impact on the shoot and root dry weights, while Pb concentration and UI increased in the 10-V EDTA treatment by 500 % compared to control. There was no significant difference between UI in 30- and 10-V EDTA treatments. Soil available Pb significantly increased in the 30-V treated soil. A positive correlation was observed between the available Pb in soil near the root and Pb concentration in shoot, its TF, and UI. In conclusion, a negatively charged plant along with the application of EDTA significantly increased the phytoremediation efficiency.

Stabilizing Gas Bearings In Free-Piston Machines

NASA Technical Reports Server (NTRS)

Dhar, Manmohan

1995-01-01

Gas bearings and clearance seals between pistons and cylinders in free-piston machines designed to reduce undesired dynamic forces and torques on pistons, gas bearings, and cylinders. Circumferential grooves and drain galleries added to piston or cylinder in improved design. Provides stabilization without significant reduction in length of seal, or significant increase in leakage and consequent reduction of efficiency.

All-silicon tandem solar cells: Practical limits for energy conversion and possible routes for improvement

NASA Astrophysics Data System (ADS)

Jia, Xuguang; Puthen-Veettil, Binesh; Xia, Hongze; Yang, Terry Chien-Jen; Lin, Ziyun; Zhang, Tian; Wu, Lingfeng; Nomoto, Keita; Conibeer, Gavin; Perez-Wurfl, Ivan

2016-06-01

Silicon nanocrystals (Si NCs) embedded in a dielectric matrix is regarded as one of the most promising materials for the third generation photovoltaics, owing to their tunable bandgap that allows fabrication of optimized tandem devices. Previous work has demonstrated fabrication of Si NCs based tandem solar cells by sputter-annealing of thin multi-layers of silicon rich oxide and SiO2. However, these device efficiencies were much lower than expected given that their theoretical values are much higher. Thus, it is necessary to understand the practical conversion efficiency limits for these devices. In this article, practical efficiency limits of Si NC based double junction tandem cells determined by fundamental material properties such as minority carrier, mobility, and lifetime are investigated. The practical conversion efficiency limits for these devices are significantly different from the reported efficiency limits which use Shockley-Queisser assumptions. Results show that the practical efficiency limit of a double junction cell (1.6 eV Si NC top cell and a 25% efficient c-Si PERL cell as the bottom cell) is 32%. Based on these results suggestions for improvement to the performance of Si nanocrystal based tandem solar cells in terms of the different parameters that were simulated are presented.

Efficiency enhancement of octave-bandwidth traveling wave tubes by use of multistage depressed collectors

NASA Technical Reports Server (NTRS)

Ramins, P.; Fox, T. A.

1979-01-01

Small, three- and five-stage depressed collectors were evaluated in conjunction with a 4.8- to 9.6-GHz TWT of 325- to 675-W power output and a beam of 0.5 microperv. The multistage depressed collector (MDC) performed well even though its design had been optimized for a TWT of identical design but considerably less output power. Despite large, fixed losses significant efficiency enhancement was demonstrated with both the three- and five-stage depressed collectors. At saturated rf power output, the improvement in the overall efficiency ranged from a factor of 2.5 to 3.0 for the three-stage collector and a factor of 3.0 to 3.5 for the five-stage collector. At saturation three-stage collector efficiencies of 77 to 80 percent and five-stage collector efficiencies of 81 to 84 percent were obtained across the frequency band. An overall efficiency of 37.0 to 44.3 percent across the frequency band of 4.8 to 9.6 GHz was demonstrated with the use of harmonic injection. For operation below saturation, even larger relative improvements in the overall TWT efficiency were demonstrated. Collector performance was relatively insensitive to the degree of regulation of the collector power supply.

Effects of donor cell type and genotype on the efficiency of mouse somatic cell cloning.

PubMed

Inoue, Kimiko; Ogonuki, Narumi; Mochida, Keiji; Yamamoto, Yoshie; Takano, Kaoru; Kohda, Takashi; Ishino, Fumitoshi; Ogura, Atsuo

2003-10-01

Although it is widely assumed that the cell type and genotype of the donor cell affect the efficiency of somatic cell cloning, little systematic analysis has been done to verify this assumption. The present study was undertaken to examine whether donor cell type, donor genotype, or a combination thereof increased the efficiency of mouse cloning. Initially we assessed the developmental ability of embryos that were cloned from cumulus or immature Sertoli cells with six different genotypes (i.e., 2 x 6 factorial). Significantly better cleavage rates were obtained with cumulus cells than with Sertoli cells (P < 0.005, two-way ANOVA), which probably was due to the superior cell-cycle synchrony of cumulus cells at G0/G1. After embryo transfer, there was a significant effect of cell type on the birth rate, with Sertoli cells giving the better result (P < 0.005). Furthermore, there was a significant interaction (P < 0.05) between the cell type and genotype, which indicates that cloning efficiency is determined by a combination of these two factors. The highest mean birth rate (10.8 +/- 2.1%) was obtained with (B6 x 129)F1 Sertoli cells. In the second series of experiments, we examined whether the developmental ability of clones with the wild-type genotype (JF1) was improved when combined with the 129 genotype. Normal pups were cloned from cumulus and immature Sertoli cells of the (129 x JF1)F1 and (JF1 x 129)F1 genotypes, whereas no pups were born from cells with the (B6 x JF1)F1 genotype. The present study clearly demonstrates that the efficiency of somatic cell cloning, and in particular fetal survival after embryo transfer, may be improved significantly by choosing the appropriate combinations of cell type and genotype.

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

Kisaki, M., E-mail: kisaki.masashi@LHD.nifs.ac.jp; Ikeda, K.; Osakabe, M.

To improve the performance of negative-ion based neutral beam injection on the Large Helical Device, the accelerator was modified on the basis of numerical investigations. A field limiting ring was installed on the upper side of a grounded grid (GG) support and a multi-slot GG was adopted instead of a multi-aperture GG. As a result, the voltage holding capability is improved and the heat load on the GG decreases by 40%. In addition, the arc efficiency is improved significantly only by replacing the GG.

Development of an external ceramic insulation for the space shuttle orbiter. Part 2: Optimization

NASA Technical Reports Server (NTRS)

Tanzilli, R. A. (Editor)

1973-01-01

The basic insulation improvement study concentrated upon evaluating variables which could result in significant near-term gains in mechanical behavior and insulation effectiveness of the baseline system. The approaches undertaken included: evaluation of small diameter fibers, optimization of binder: slurry characteristics, evaluation of techniques for controlling fiber orientation, optimization of firing cycle, and the evaluation of methods for improving insulation efficiency. A detailed discussion of these basic insulation improvement studies is presented.

Using input feature information to improve ultraviolet retrieval in neural networks

NASA Astrophysics Data System (ADS)

Sun, Zhibin; Chang, Ni-Bin; Gao, Wei; Chen, Maosi; Zempila, Melina

2017-09-01

In neural networks, the training/predicting accuracy and algorithm efficiency can be improved significantly via accurate input feature extraction. In this study, some spatial features of several important factors in retrieving surface ultraviolet (UV) are extracted. An extreme learning machine (ELM) is used to retrieve the surface UV of 2014 in the continental United States, using the extracted features. The results conclude that more input weights can improve the learning capacities of neural networks.

Energy and economic analysis of total energy systems for residential and commercial buildings. [utilizing waste heat recovery techniques

NASA Technical Reports Server (NTRS)

Maag, W. L.; Bollenbacher, G.

1974-01-01

Energy and economic analyses were performed for an on-site power-plant with waste heat recovery. The results show that for any specific application there is a characteristic power conversion efficiency that minimizes fuel consumption, and that efficiencies greater than this do not significantly improve fuel consumption. This type of powerplant appears to be a reasonably attractive investment if higher fuel costs continue.

Development of Low Cost, High Energy-Per-Unit-Area Solar Cell Modules

NASA Technical Reports Server (NTRS)

Jones, G. T.; Chitre, S.

1977-01-01

Work on the development of low cost, high energy per unit area solar cell modules was conducted. Hexagonal solar cell and module efficiencies, module packing ratio, and solar cell design calculations were made. The cell grid structure and interconnection pattern was designed and the module substrates were fabricated for the three modules to be used. It was demonstrated that surface macrostructures significantly improve cell power output and photovoltaic energy conversion efficiency.

Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells

NASA Technical Reports Server (NTRS)

Jain, Raj K.

2005-01-01

Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.

Optical designs for improved solar cell performance

NASA Astrophysics Data System (ADS)

Kosten, Emily Dell

The solar resource is the most abundant renewable resource on earth, yet it is currently exploited with relatively low efficiencies. To make solar energy more affordable, we can either reduce the cost of the cell or increase the efficiency with a similar cost cell. In this thesis, we consider several different optical approaches to achieve these goals. First, we consider a ray optical model for light trapping in silicon microwires. With this approach, much less material can be used, allowing for a cost savings. We next focus on reducing the escape of radiatively emitted and scattered light from the solar cell. With this angle restriction approach, light can only enter and escape the cell near normal incidence, allowing for thinner cells and higher efficiencies. In Auger-limited GaAs, we find that efficiencies greater than 38% may be achievable, a significant improvement over the current world record. To experimentally validate these results, we use a Bragg stack to restrict the angles of emitted light. Our measurements show an increase in voltage and a decrease in dark current, as less radiatively emitted light escapes. While the results in GaAs are interesting as a proof of concept, GaAs solar cells are not currently made on the production scale for terrestrial photovoltaic applications. We therefore explore the application of angle restriction to silicon solar cells. While our calculations show that Auger-limited cells give efficiency increases of up to 3% absolute, we also find that current amorphous silicion-crystalline silicon heterojunction with intrinsic thin layer (HIT) cells give significant efficiency gains with angle restriction of up to 1% absolute. Thus, angle restriction has the potential for unprecedented one sun efficiencies in GaAs, but also may be applicable to current silicon solar cell technology. Finally, we consider spectrum splitting, where optics direct light in different wavelength bands to solar cells with band gaps tuned to those wavelengths. This approach has the potential for very high efficiencies, and excellent annual power production. Using a light-trapping filtered concentrator approach, we design filter elements and find an optimal design. Thus, this thesis explores silicon microwires, angle restriction, and spectral splitting as different optical approaches for improving the cost and efficiency of solar cells.

Environmental policy and technological change: The effects of economic incentives and direct regulation on energy-saving innovation

NASA Astrophysics Data System (ADS)

Newell, Richard G., Jr.

Over the long run, the impacts of environmental policies will be greatly affected by the influence these policies have on the rate and direction of technological change. In particular, the roles played by energy prices and product regulation in energy-saving technology innovation are exceptionally important considerations in modeling climate change and evaluating alternative policy options. We analyze the effects of energy prices and energy-efficiency regulations on the menu of air conditioner and water heater models available on the market over a period of more than three decades, measuring their innovation in terms of improvements in the products' underlying characteristics. Through estimation of a series of "characteristics transformation surfaces," we find that during less than four decades, substantial innovation in these products reduced the total capital and operating costs of air conditioning by one-half and water heating by more than one-fifth. Although the overall rate of innovation in these products appears to be independent of energy prices and regulations, the evidence suggests that the direction of innovation may be responsive to energy price changes. This would imply that energy price increases induced innovation in a direction that lowered the capital cost tradeoffs inherent in producing more energy-efficient products. The evidence supporting "regulation-induced" changes in these tradeoffs is much weaker. Our estimates indicate that about one- to two-fifths of the energy-efficiency improvements in these products from 1973 to 1993 were associated with historical changes in energy prices. We also find that this responsiveness to price changes increased substantially after product labeling requirements came into effect, and that minimum efficiency standards had a significant positive effect on average efficiency levels. Nonetheless, a sizeable portion of historical efficiency improvements in these technologies is associated with the products' overall rate of innovation. Looking forward, we estimate that energy taxes of 10 to 30 percent of retail prices could significantly increase the energy efficiency of the product menu. We predict that such taxes would lead to additional efficiency increases in air conditioners of 6 to 26 percent. We conclude that the price-induced component of energy-efficiency innovation should not be ignored when assessing alternative climate change policies.

[Non-face-to-face sleep improvement program in a workplace: bibliotherapy with and without behavioral self-control procedure].

PubMed

Adachi, Yoshiko; Kunitsuka, Kouko; Taniyama, Katsuko; Hayashi, Chikako; Tanaka, Minori; Sato, Chifumi

2010-01-01

Sleep hygiene education has been important health issue in the health promotion and the prevention of lifestyle-related diseases. A feasible and effective method is necessary for population approach. To evaluate the effects of a non-face-to-face brief behavioral program for a sleep improvement in workplaces. Research design was a cluster control trial. Three hundred and thirty participants were allocated to the bibliotherapy group (BTG; n=130) or self-control group (SCG; n=200). Two groups were recruited from separated local sections of a Japanese company each other. There was no eligibility criteria and the intervention was open to every worker in the workplaces. All participants received a self-help booklet and information on recent topics of insomnia-related health problems. SCG participants set several behaviors for habit improvement and monitored those behaviors for 4 wk additionally. The replies to the questionnaire showed that almost all of them had any sleep disturbances. A total of 158 participants in SCG (79%) and a total of 106 participants in BTG (82%) responded to the post questionnaire. Sleep parameters of pre and post questionnaires were compared between SCG and BTG. Overall, sleep onset latency was reduced and sleep efficiency was improved. The significant changes were found in only SCG. Re-analysis of pre and post 3-days' sleep diaries showed that the subjects in both group improved significantly in the main variables (total sleep time, number of awakenings, time spent awake, sleep efficiency). Sleep onset latency, wake after sleep onset, and daytime sleepiness improved significantly in only SCG. These results suggest that an additional target setting and self-monitoring could promote the effectiveness for sleep improvement of a bibliotherapy.

Hybrid Power Management (HPM) Program Resulted in Several New Applications

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.

2003-01-01

Hybrid Power Management (HPM) is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors, fuel cells, and photovoltaics. HPM has extremely wide potential with applications from nanowatts to megawatts. Applications include power generation, transportation systems, biotechnology systems, and space power systems. HPM has the potential to significantly alleviate global energy concerns, improve the environment, and stimulate the economy.

Development of a Field Demonstration for Cost-Effective Low-Grade Heat Recovery and Use Technology Designed to Improve Efficiency and Reduce Water Usage Rates for a Coal-Fired Power Plant

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

Noble, Russell; Dombrowski, K.; Bernau, M.

Coal-based power generation systems provide reliable, low-cost power to the domestic energy sector. These systems consume large amounts of fuel and water to produce electricity and are the target of pending regulations that may require reductions in water use and improvements in thermal efficiency. While efficiency of coal-based generation has improved over time, coal power plants often do not utilize the low-grade heat contained in the flue gas and require large volumes of water for the steam cycle make-up, environmental controls, and for process cooling and heating. Low-grade heat recovery is particularly challenging for coal-fired applications, due in large partmore » to the condensation of acid as the flue gas cools and the resulting potential corrosion of the heat recovery materials. Such systems have also not been of significant interest as recent investments on coal power plants have primarily been for environmental controls due to more stringent regulations. Also, in many regions, fuel cost is still a pass-through to the consumer, reducing the motivation for efficiency improvements. Therefore, a commercial system combining low-grade heat-recovery technologies and associated end uses to cost effectively improve efficiency and/or reduce water consumption has not yet been widely applied. However, pressures from potential new regulations and from water shortages may drive new interest, particularly in the U.S. In an effort to address this issue, the U.S. Department of Energy (DOE) has sought to identify and promote technologies to achieve this goal.« less

Improvement of chromatographic performances of in-situ synthesized hybrid C8 silica monoliths by reduction of structural radial heterogeneities.

PubMed

Roux, R; Abi Jaoudé, M; Demesmay, C

2009-05-01

Several modifications of a previously described protocol are proposed to improve the performances of in-situ synthesized C(8) hybrid silica monoliths. Our attention was focused on reducing the sources of radial heterogeneity that may be responsible for the poor efficiencies observed in the hydrodynamic elution mode. It was demonstrated that a decrease in the temperature of the capillary during the filling step equally to that of the polymerization mixture (0 degrees C), associated with a decrease of the gelation temperature to 20 degrees C along with a new pre-treatment of the capillary's internal walls [with a mixture of tetraethoxysilane (TEOS)/EtOH (1/3, v/v)] allows (i) increasing the radial homogeneity of the monolith, thus further enhancing the performances in the nano-liquid chromatography (nano-LC) mode, (ii) improving the capillary to capillary reproducibility in terms of permeability and efficiencies. In fact, the average minimum plate height H(min) was lowered from 24 to 14 microm and the capillary-to-capillary reproducibility of the synthesis was widely improved by factors two and three of reduction on the calculated standard deviation, respectively for both the efficiency in the nano-LC mode and the permeability. At last, the improved radial homogeneity and anchoring of the synthesized monoliths allowed increasing the inner diameter of the capillary (up to 150 microm) without any significant loss in efficiency. Finally, long term stability of the as-obtained monolithic stationary phases in terms of retention and efficiency was studied. In addition, the evaluation of their chromatographic behaviour was also achieved with the Tanaka test and the results were compared to those already published for commercial monoliths (Chromolith) as well as for particulate stationary phases.

Impact of Indoor Physical Environment on Learning Efficiency in Different Types of Tasks: A 3 × 4 × 3 Full Factorial Design Analysis.

PubMed

Xiong, Lilin; Huang, Xiao; Li, Jie; Mao, Peng; Wang, Xiang; Wang, Rubing; Tang, Meng

2018-06-13

Indoor physical environments appear to influence learning efficiency nowadays. For improvement in learning efficiency, environmental scenarios need to be designed when occupants engage in different learning tasks. However, how learning efficiency is affected by indoor physical environment based on task types are still not well understood. The present study aims to explore the impacts of three physical environmental factors (i.e., temperature, noise, and illuminance) on learning efficiency according to different types of tasks, including perception, memory, problem-solving, and attention-oriented tasks. A 3 × 4 × 3 full factorial design experiment was employed in a university classroom with 10 subjects recruited. Environmental scenarios were generated based on different levels of temperature (17 °C, 22 °C, and 27 °C), noise (40 dB(A), 50 dB(A), 60 dB(A), and 70 dB(A)) and illuminance (60 lx, 300 lx, and 2200 lx). Accuracy rate (AC), reaction time (RT), and the final performance indicator (PI) were used to quantify learning efficiency. The results showed ambient temperature, noise, and illuminance exerted significant main effect on learning efficiency based on four task types. Significant concurrent effects of the three factors on final learning efficiency was found in all tasks except problem-solving-oriented task. The optimal environmental scenarios for top learning efficiency were further identified under different environmental interactions. The highest learning efficiency came in thermoneutral, relatively quiet, and bright conditions in perception-oriented task. Subjects performed best under warm, relatively quiet, and moderately light exposure when recalling images in the memory-oriented task. Learning efficiency peaked to maxima in thermoneutral, fairly quiet, and moderately light environment in problem-solving process while in cool, fairly quiet and bright environment with regard to attention-oriented task. The study provides guidance for building users to conduct effective environmental intervention with simultaneous controls of ambient temperature, noise, and illuminance. It contributes to creating the most suitable indoor physical environment for improving occupants learning efficiency according to different task types. The findings could further supplement the present indoor environment-related standards or norms with providing empirical reference on environmental interactions.

Polymer-modified halide perovskite films for efficient and stable planar heterojunction solar cells

PubMed Central

Zuo, Lijian; Guo, Hexia; deQuilettes, Dane W.; Jariwala, Sarthak; De Marco, Nicholas; Dong, Shiqi; DeBlock, Ryan; Ginger, David S.; Dunn, Bruce; Wang, Mingkui; Yang, Yang

2017-01-01

The solution processing of polycrystalline perovskite films introduces trap states that can adversely affect their optoelectronic properties. Motivated by the use of small-molecule surfactants to improve the optoelectronic performance of perovskites, we demonstrate the use of polymers with coordinating groups to improve the performance of solution-processed semiconductor films. The use of these polymer modifiers results in a marked change in the electronic properties of the films, as measured by both carrier dynamics and overall device performance. The devices grown with the polymer poly(4-vinylpyridine) (PVP) show significantly enhanced power conversion efficiency from 16.9 ± 0.7% to 18.8 ± 0.8% (champion efficiency, 20.2%) from a reverse scan and stabilized champion efficiency from 17.5 to 19.1% [under a bias of 0.94 V and AM (air mass) 1.5-G, 1-sun illumination over 30 min] compared to controls without any passivation. Treating the perovskite film with PVP enables a VOC of up to 1.16 V, which is among the best reported for a CH3NH3PbI3 perovskite solar cell and one of the lowest voltage deficits reported for any perovskite to date. In addition, perovskite solar cells treated with PVP show a long shelf lifetime of up to 90 days (retaining 85% of the initial efficiency) and increased by a factor of more than 20 compared to those without any polymer (degrading to 85% after ~4 days). Our work opens up a new class of chemical additives for improving perovskite performance and should pave the way toward improving perovskite solar cells for high efficiency and stability. PMID:28845446

New configurations of a heat recovery absorption heat pump integrated with a natural gas boiler for boiler efficiency improvement

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

Qu, Ming; Abdelaziz, Omar; Yin, Hongxi

2014-11-01

Conventional natural gas-fired boilers exhaust flue gas direct to the atmosphere at 150 200 C, which, at such temperatures, contains large amount of energy and results in relatively low thermal efficiency ranging from 70% to 80%. Although condensing boilers for recovering the heat in the flue gas have been developed over the past 40 years, their present market share is still less than 25%. The major reason for this relatively slow acceptance is the limited improvement in the thermal efficiency of condensing boilers. In the condensing boiler, the temperature of the hot water return at the range of 50 60more » C, which is used to cool the flue gas, is very close to the dew point of the water vapor in the flue gas. Therefore, the latent heat, the majority of the waste heat in the flue gas, which is contained in the water vapor, cannot be recovered. This paper presents a new approach to improve boiler thermal efficiency by integrating absorption heat pumps with natural gas boilers for waste heat recovery (HRAHP). Three configurations of HRAHPs are introduced and discussed. The three configurations are modeled in detail to illustrate the significant thermal efficiency improvement they attain. Further, for conceptual proof and validation, an existing hot water-driven absorption chiller is operated as a heat pump at operating conditions similar to one of the devised configurations. An overall system performance and economic analysis are provided for decision-making and as evidence of the potential benefits. These three configurations of HRAHP provide a pathway to achieving realistic high-efficiency natural gas boilers for applications with process fluid return temperatures higher than or close to the dew point of the water vapor in the flue gas.« less

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.

Efficient generation of induced pluripotent stem cells from human bone marrow mesenchymal stem cells.

PubMed

Yulin, X; Lizhen, L; Lifei, Z; Shan, F; Ru, L; Kaimin, H; Huang, H

2012-01-01

Ectopic expression of defined sets of genetic factors can reprogramme somatic cells to induced pluripotent stem cells (iPSCs) that closely resemble embryonic stem cells. However, the low reprogramming efficiency is a significant handicap for mechanistic studies and potential clinical application. In this study, we used human bone marrow-derived mesenchymal stem cells (hBMMSCs) as target cells for reprogramming and investigated efficient iPSC generation from hBMMSCs using the compounds of p53 siRNA, valproic acid (VPA) and vitamin C (Vc) with four transcription factors OCT4, SOX2, KLF4, and c-MYC (compound induction system). The synergetic mechanism of the compounds was studied. Our results showed that the compound induction system could efficiently reprogramme hBMMSCs to iPSCs. hBMMSC-derived iPSC populations expressed pluripotent markers and had multi-potential to differentiate into three germ layer-derived cells. p53 siRNA, VPA and Vc had a synergetic effect on cell reprogramming and the combinatorial use of these substances greatly improved the efficiency of iPSC generation by suppressing the expression of p53, decreasing cell apoptosis, up-regulating the expression of the pluripotent gene OCT4 and modifying the cell cycle. Therefore, our study highlights a straightforward method for improving the speed and efficiency of iPSC generation and provides versatile tools for investigating early developmental processes such as haemopoiesis and relevant diseases. In addition, this study provides a paradigm for the combinatorial use of genetic factors and molecules to improve the efficiency of iPSC generation.

Oxygen-controlled automated neural differentiation of mouse embryonic stem cells.

PubMed

Mondragon-Teran, Paul; Tostoes, Rui; Mason, Chris; Lye, Gary J; Veraitch, Farlan S

2013-03-01

Automation and oxygen tension control are two tools that provide significant improvements to the reproducibility and efficiency of stem cell production processes. the aim of this study was to establish a novel automation platform capable of controlling oxygen tension during both the cell-culture and liquid-handling steps of neural differentiation processes. We built a bespoke automation platform, which enclosed a liquid-handling platform in a sterile, oxygen-controlled environment. An airtight connection was used to transfer cell culture plates to and from an automated oxygen-controlled incubator. Our results demonstrate that our system yielded comparable cell numbers, viabilities, metabolism profiles and differentiation efficiencies when compared with traditional manual processes. Interestingly, eliminating exposure to ambient conditions during the liquid-handling stage resulted in significant improvements in the yield of MAP2-positive neural cells, indicating that this level of control can improve differentiation processes. This article describes, for the first time, an automation platform capable of maintaining oxygen tension control during both the cell-culture and liquid-handling stages of a 2D embryonic stem cell differentiation process.

Multidisciplinary design optimization using multiobjective formulation techniques

NASA Technical Reports Server (NTRS)

Chattopadhyay, Aditi; Pagaldipti, Narayanan S.

1995-01-01

This report addresses the development of a multidisciplinary optimization procedure using an efficient semi-analytical sensitivity analysis technique and multilevel decomposition for the design of aerospace vehicles. A semi-analytical sensitivity analysis procedure is developed for calculating computational grid sensitivities and aerodynamic design sensitivities. Accuracy and efficiency of the sensitivity analysis procedure is established through comparison of the results with those obtained using a finite difference technique. The developed sensitivity analysis technique are then used within a multidisciplinary optimization procedure for designing aerospace vehicles. The optimization problem, with the integration of aerodynamics and structures, is decomposed into two levels. Optimization is performed for improved aerodynamic performance at the first level and improved structural performance at the second level. Aerodynamic analysis is performed by solving the three-dimensional parabolized Navier Stokes equations. A nonlinear programming technique and an approximate analysis procedure are used for optimization. The proceduredeveloped is applied to design the wing of a high speed aircraft. Results obtained show significant improvements in the aircraft aerodynamic and structural performance when compared to a reference or baseline configuration. The use of the semi-analytical sensitivity technique provides significant computational savings.

Implementation of light extraction improvements of GaN-based light-emitting diodes with specific textured sidewalls

NASA Astrophysics Data System (ADS)

Chen, Chun-Yen; Chen, Wei-Cheng; Chang, Ching-Hong; Lee, Yu-Lin; Liu, Wen-Chau

2018-05-01

Textured-sidewall GaN-based light-emitting diodes (LEDs) with various sidewall angles (15-90°) and convex or concave sidewalls prepared using an inductively-coupled-plasma approach are comprehensively fabricated and studied. The device with 45° sidewalls (Device F) and that with convex sidewalls (Device B) show significant improvements in optical properties. Experiments show that, at an injection current of 350 mA, the light output power, external quantum efficiency, wall-plug efficiency, and luminous flux of Device F (Device B) are greatly improved by 18.3% (18.2%), 18.2% (18.2%), 17.3% (19.8%), and 16.6% (18.4%), respectively, compared to those of a conventional LED with flat sidewalls. In addition, negligible degradation in electrical properties is found. The enhanced optical performance is mainly attributed to increased light extraction in the horizontal direction due to a significant reduction in total internal reflection at the textured sidewalls. Therefore, the reported specific textured-sidewall structures (Devices B and F) are promising for high-power GaN-based LED applications.

Radio frequency discharge with control of plasma potential distribution.

PubMed

Dudnikov, Vadim; Dudnikov, A

2012-02-01

A RF discharge plasma generator with additional electrodes for independent control of plasma potential distribution is proposed. With positive biasing of this ring electrode relative end flanges and longitudinal magnetic field a confinement of fast electrons in the discharge will be improved for reliable triggering of pulsed RF discharge at low gas density and rate of ion generation will be enhanced. In the proposed discharge combination, the electron energy is enhanced by RF field and the fast electron confinement is improved by enhanced positive plasma potential which improves the efficiency of plasma generation significantly. This combination creates a synergetic effect with a significantly improving the plasma generation performance at low gas density. The discharge parameters can be optimized for enhance plasma generation with acceptable electrode sputtering.

Development of an activity-directed selection system enabled significant improvement of the carboxylation efficiency of Rubisco.

PubMed

Cai, Zhen; Liu, Guoxia; Zhang, Junli; Li, Yin

2014-07-01

Photosynthetic CO(2) fixation is the ultimate source of organic carbon on earth and thus is essential for crop production and carbon sequestration. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the first step of photosynthetic CO(2) fixation. However, the extreme low carboxylation efficiency of Rubisco makes it the most attractive target for improving photosynthetic efficiency. Extensive studies have focused on re-engineering a more efficient enzyme, but the effort has been impeded by the limited understanding of its structure-function relationships and the lack of an efficient selection system towards its activity. To address the unsuccessful molecular engineering of Rubisco, we developed an Escherichia coli-based activity-directed selection system which links the growth of host cell solely to the Rubisco activity therein. A Synechococcus sp. PCC7002 Rubisco mutant with E49V and D82G substitutions in the small subunit was selected from a total of 15,000 mutants by one round of evolution. This mutant showed an 85% increase in specific carboxylation activity and a 45% improvement in catalytic efficiency towards CO(2). The small-subunit E49V mutation was speculated to influence holoenzyme catalysis through interaction with the large-subunit Q225. This interaction is conserved among various Rubisco from higher plants and Chlamydomonas reinhardtii. Knowledge of these might provide clues for engineering Rubisco from higher plants, with the potential of increasing the crop yield.

Improved Convergence Rate of Multi-Group Scattering Moment Tallies for Monte Carlo Neutron Transport Codes

NASA Astrophysics Data System (ADS)

Nelson, Adam

Multi-group scattering moment matrices are critical to the solution of the multi-group form of the neutron transport equation, as they are responsible for describing the change in direction and energy of neutrons. These matrices, however, are difficult to correctly calculate from the measured nuclear data with both deterministic and stochastic methods. Calculating these parameters when using deterministic methods requires a set of assumptions which do not hold true in all conditions. These quantities can be calculated accurately with stochastic methods, however doing so is computationally expensive due to the poor efficiency of tallying scattering moment matrices. This work presents an improved method of obtaining multi-group scattering moment matrices from a Monte Carlo neutron transport code. This improved method of tallying the scattering moment matrices is based on recognizing that all of the outgoing particle information is known a priori and can be taken advantage of to increase the tallying efficiency (therefore reducing the uncertainty) of the stochastically integrated tallies. In this scheme, the complete outgoing probability distribution is tallied, supplying every one of the scattering moment matrices elements with its share of data. In addition to reducing the uncertainty, this method allows for the use of a track-length estimation process potentially offering even further improvement to the tallying efficiency. Unfortunately, to produce the needed distributions, the probability functions themselves must undergo an integration over the outgoing energy and scattering angle dimensions. This integration is too costly to perform during the Monte Carlo simulation itself and therefore must be performed in advance by way of a pre-processing code. The new method increases the information obtained from tally events and therefore has a significantly higher efficiency than the currently used techniques. The improved method has been implemented in a code system containing a new pre-processor code, NDPP, and a Monte Carlo neutron transport code, OpenMC. This method is then tested in a pin cell problem and a larger problem designed to accentuate the importance of scattering moment matrices. These tests show that accuracy was retained while the figure-of-merit for generating scattering moment matrices and fission energy spectra was significantly improved.

Optimizing The DSSC Fabrication Process Using Lean Six Sigma

NASA Astrophysics Data System (ADS)

Fauss, Brian

Alternative energy technologies must become more cost effective to achieve grid parity with fossil fuels. Dye sensitized solar cells (DSSCs) are an innovative third generation photovoltaic technology, which is demonstrating tremendous potential to become a revolutionary technology due to recent breakthroughs in cost of fabrication. The study here focused on quality improvement measures undertaken to improve fabrication of DSSCs and enhance process efficiency and effectiveness. Several quality improvement methods were implemented to optimize the seven step individual DSSC fabrication processes. Lean Manufacturing's 5S method successfully increased efficiency in all of the processes. Six Sigma's DMAIC methodology was used to identify and eliminate each of the root causes of defects in the critical titanium dioxide deposition process. These optimizations resulted with the following significant improvements in the production process: 1. fabrication time of the DSSCs was reduced by 54 %; 2. fabrication procedures were improved to the extent that all critical defects in the process were eliminated; 3. the quantity of functioning DSSCs fabricated was increased from 17 % to 90 %.

The use of information technology to enhance patient safety and nursing efficiency.

PubMed

Lee, Tso-Ying; Sun, Gi-Tseng; Kou, Li-Tseng; Yeh, Mei-Ling

2017-10-23

Issues in patient safety and nursing efficiency have long been of concern. Advancing the role of nursing informatics is seen as the best way to address this. The aim of this study was to determine if the use, outcomes and satisfaction with a nursing information system (NIS) improved patient safety and the quality of nursing care in a hospital in Taiwan. This study adopts a quasi-experimental design. Nurses and patients were surveyed by questionnaire and data retrieval before and after the implementation of NIS in terms of blood drawing, nursing process, drug administration, bar code scanning, shift handover, and information and communication integration. Physiologic values were easier to read and interpret; it took less time to complete electronic records (3.7 vs. 9.1 min); the number of errors in drug administration was reduced (0.08% vs. 0.39%); bar codes reduced the number of errors in blood drawing (0 vs. 10) and transportation of specimens (0 vs. 0.42%); satisfaction with electronic shift handover increased significantly; there was a reduction in nursing turnover (14.9% vs. 16%); patient satisfaction increased significantly (3.46 vs. 3.34). Introduction of NIS improved patient safety and nursing efficiency and increased nurse and patient satisfaction. Medical organizations must continually improve the nursing information system if they are to provide patients with high quality service in a competitive environment.

Training to acquire psychomotor skills for endoscopic endonasal surgery using a personal webcam trainer.

PubMed

Hirayama, Ryuichi; Fujimoto, Yasunori; Umegaki, Masao; Kagawa, Naoki; Kinoshita, Manabu; Hashimoto, Naoya; Yoshimine, Toshiki

2013-05-01

Existing training methods for neuroendoscopic surgery have mainly emphasized the acquisition of anatomical knowledge and procedures for operating an endoscope and instruments. For laparoscopic surgery, various training systems have been developed to teach handling of an endoscope as well as the manipulation of instruments for speedy and precise endoscopic performance using both hands. In endoscopic endonasal surgery (EES), especially using a binostril approach to the skull base and intradural lesions, the learning of more meticulous manipulation of instruments is mandatory, and it may be necessary to develop another type of training method for acquiring psychomotor skills for EES. Authors of the present study developed an inexpensive, portable personal trainer using a webcam and objectively evaluated its utility. Twenty-five neurosurgeons volunteered for this study and were divided into 2 groups, a novice group (19 neurosurgeons) and an experienced group (6 neurosurgeons). Before and after the exercises of set tasks with a webcam box trainer, the basic endoscopic skills of each participant were objectively assessed using the virtual reality simulator (LapSim) while executing 2 virtual tasks: grasping and instrument navigation. Scores for the following 11 performance variables were recorded: instrument time, instrument misses, instrument path length, and instrument angular path (all of which were measured in both hands), as well as tissue damage, max damage, and finally overall score. Instrument time was indicated as movement speed; instrument path length and instrument angular path as movement efficiency; and instrument misses, tissue damage, and max damage as movement precision. In the novice group, movement speed and efficiency were significantly improved after the training. In the experienced group, significant improvement was not shown in the majority of virtual tasks. Before the training, significantly greater movement speed and efficiency were demonstrated in the experienced group, but no difference in movement precision was shown between the 2 groups. After the training, no significant differences were shown between the 2 groups in the majority of the virtual tasks. Analysis revealed that the webcam trainer improved the basic skills of the novices, increasing movement speed and efficiency without sacrificing movement precision. Novices using this unique webcam trainer showed improvement in psychomotor skills for EES. The authors believe that training in terms of basic endoscopic skills is meaningful and that the webcam training system can play a role in daily off-the-job training for EES.

Improving smallholder cattle reproductive efficiency in Cambodia to address expanding regional beef demand.

PubMed

Olmo, L; Ashley, K; Young, J R; Suon, S; Thomson, P C; Windsor, P A; Bush, R D

2017-01-01

This study aimed to identify factors associated with cattle reproductive output in rural smallholder farms in Cambodia in order to determine the main causes of reproductive failure and design efficient interventions for improvement. The majority of the nation's beef is produced on smallholder farms where productivity is constrained by poor animal reproductivity reflected in the recent livestock population decline of approximately 13 % from 2009 to 2013. Farmers (n = 240) from 16 villages from five provinces were surveyed in mid-2015 to determine their baseline knowledge, attitude and practices (KAP) associated with cattle reproduction. In addition, 16 case studies from three of these provinces were conducted to provide a more detailed assessment of current cattle reproductive husbandry practices. In order to assess the reproductive impact of previously implemented interventions, an endpoint KAP survey and longitudinal health and husbandry study from three Cambodian provinces conducted between 2008 and 2013 were also analysed. Three multivariable prediction models (two KAP and one longitudinal) identified the following significant factors associated with the reproductive outcomes 'number of calves born' or probability that cows 'gave birth': target feeding (P = 0.074), growing vegetables (P = 0.005), attitudes towards cattle vaccination (P = 0.010), improving bull selection (P = 0.032), local breed use (P = 0.005), number of joining attempts (P < 0.001), discontinuation of animal draught practices (P = 0.003) and retention of breeding animals (P < 0.001). The identification of significant factors and interventions in this study has led to intervention recommendations that can potentially improve reproductive efficiency, combat the declining cattle population and improve smallholder capacity to supply to expanding regional meat demand in South-East Asia and China.

Contrast and harmonic imaging improves accuracy and efficiency of novice readers for dobutamine stress echocardiography

NASA Technical Reports Server (NTRS)

Vlassak, Irmien; Rubin, David N.; Odabashian, Jill A.; Garcia, Mario J.; King, Lisa M.; Lin, Steve S.; Drinko, Jeanne K.; Morehead, Annitta J.; Prior, David L.; Asher, Craig R.;

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

Application of Lean Healthcare methodology in a urology department of a tertiary hospital as a tool for improving efficiency.

PubMed

Boronat, F; Budia, A; Broseta, E; Ruiz-Cerdá, J L; Vivas-Consuelo, D

To describe the application of the Lean methodology as a method for continuously improving the efficiency of a urology department in a tertiary hospital. The implementation of the Lean Healthcare methodology in a urology department was conducted in 3 phases: 1) team training and improvement of feedback among the practitioners, 2) management by process and superspecialisation and 3) improvement of indicators (continuous improvement). The indicators were obtained from the Hospital's information systems. The main source of information was the Balanced Scorecard for health systems management (CUIDISS). The comparison with other autonomous and national urology departments was performed through the same platform with the help of the Hospital's records department (IASIST). A baseline was established with the indicators obtained in 2011 for the comparative analysis of the results after implementing the Lean Healthcare methodology. The implementation of this methodology translated into high practitioner satisfaction, improved quality indicators reaching a risk-adjusted complication index (RACI) of 0.59 and a risk-adjusted mortality rate (RAMR) of 0.24 in 4 years. A value of 0.61 was reached with the efficiency indicator (risk-adjusted length of stay [RALOS] index), with a savings of 2869 stays compared with national Benchmarking (IASIST). The risk-adjusted readmissions index (RARI) was the only indicator above the standard, with a value of 1.36 but with progressive annual improvement of the same. The Lean methodology can be effectively applied to a urology department of a tertiary hospital to improve efficiency, obtaining significant and continuous improvements in all its indicators, as well as practitioner satisfaction. Team training, management by process, continuous improvement and delegation of responsibilities has been shown to be the fundamental pillars of this methodology. Copyright © 2017 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Surveying Rubisco Diversity and Temperature Response to Improve Crop Photosynthetic Efficiency.

PubMed

Orr, Douglas J; Alcântara, André; Kapralov, Maxim V; Andralojc, P John; Carmo-Silva, Elizabete; Parry, Martin A J

2016-10-01

The threat to global food security of stagnating yields and population growth makes increasing crop productivity a critical goal over the coming decades. One key target for improving crop productivity and yields is increasing the efficiency of photosynthesis. Central to photosynthesis is Rubisco, which is a critical but often rate-limiting component. Here, we present full Rubisco catalytic properties measured at three temperatures for 75 plants species representing both crops and undomesticated plants from diverse climates. Some newly characterized Rubiscos were naturally "better" compared to crop enzymes and have the potential to improve crop photosynthetic efficiency. The temperature response of the various catalytic parameters was largely consistent across the diverse range of species, though absolute values showed significant variation in Rubisco catalysis, even between closely related species. An analysis of residue differences among the species characterized identified a number of candidate amino acid substitutions that will aid in advancing engineering of improved Rubisco in crop systems. This study provides new insights on the range of Rubisco catalysis and temperature response present in nature, and provides new information to include in models from leaf to canopy and ecosystem scale. © 2016 American Society of Plant Biologists. All Rights Reserved.

TSA and BIX-01294 Induced Normal DNA and Histone Methylation and Increased Protein Expression in Porcine Somatic Cell Nuclear Transfer Embryos

PubMed Central

Ding, Biao; Zuo, Xiaoyuan; Li, Hui; Ding, Jianping; Li, Yunsheng; Huang, Weiping; Zhang, Yunhai

2017-01-01

The poor efficiency of animal cloning is mainly attributed to the defects in epigenetic reprogramming of donor cells’ chromatins during early embryonic development. Previous studies indicated that inhibition of histone deacetylases or methyltransferase, such as G9A, using Trichostatin A (TSA) or BIX-01294 significantly enhanced the developmental efficiency of porcine somatic cell nuclear transfer (SCNT) embryos. However, potential mechanisms underlying the improved early developmental competence of SCNT embryos exposed to TSA and BIX-01294 are largely unclear. Here we found that 50 nM TSA or 1.0 μM BIX-01294 treatment alone for 24 h significantly elevated the blastocyst rate (P < 0.05), while further improvement was not observed under combined treatment condition. Furthermore, co-treatment or TSA treatment alone significantly reduced H3K9me2 level at the 4-cell stage, which is comparable with that in in vivo and in vitro fertilized counterparts. However, only co-treatment significantly decreased the levels of 5mC and H3K9me2 in trophectoderm lineage and subsequently increased the expression of OCT4 and CDX2 associated with ICM and TE lineage differentiation. Altogether, these results demonstrate that co-treatment of TSA and BIX-01294 enhances the early developmental competence of porcine SCNT embryos via improvements in epigenetic status and protein expression. PMID:28114389

TSA and BIX-01294 Induced Normal DNA and Histone Methylation and Increased Protein Expression in Porcine Somatic Cell Nuclear Transfer Embryos.

PubMed

Cao, Zubing; Hong, Renyun; Ding, Biao; Zuo, Xiaoyuan; Li, Hui; Ding, Jianping; Li, Yunsheng; Huang, Weiping; Zhang, Yunhai

2017-01-01

The poor efficiency of animal cloning is mainly attributed to the defects in epigenetic reprogramming of donor cells' chromatins during early embryonic development. Previous studies indicated that inhibition of histone deacetylases or methyltransferase, such as G9A, using Trichostatin A (TSA) or BIX-01294 significantly enhanced the developmental efficiency of porcine somatic cell nuclear transfer (SCNT) embryos. However, potential mechanisms underlying the improved early developmental competence of SCNT embryos exposed to TSA and BIX-01294 are largely unclear. Here we found that 50 nM TSA or 1.0 μM BIX-01294 treatment alone for 24 h significantly elevated the blastocyst rate (P < 0.05), while further improvement was not observed under combined treatment condition. Furthermore, co-treatment or TSA treatment alone significantly reduced H3K9me2 level at the 4-cell stage, which is comparable with that in in vivo and in vitro fertilized counterparts. However, only co-treatment significantly decreased the levels of 5mC and H3K9me2 in trophectoderm lineage and subsequently increased the expression of OCT4 and CDX2 associated with ICM and TE lineage differentiation. Altogether, these results demonstrate that co-treatment of TSA and BIX-01294 enhances the early developmental competence of porcine SCNT embryos via improvements in epigenetic status and protein expression.

75 FR 27341 - Increasing Market and Planning Efficiency Through Improved Software; Notice of Technical...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-14

... Market and Planning Efficiency Through Improved Software; Notice of Technical Conference To Discuss Increasing Market and Planning Efficiency Through Improved Software May 7, 2010. Take notice that Commission... planning efficiency through improved software. [[Page 27342

[Analysis of the technical efficiency of hospitals in the Spanish National Health Service].

PubMed

Pérez-Romero, Carmen; Ortega-Díaz, M Isabel; Ocaña-Riola, Ricardo; Martín-Martín, José Jesús

To analyse the technical efficiency and productivity of general hospitals in the Spanish National Health Service (NHS) (2010-2012) and identify explanatory hospital and regional variables. 230 NHS hospitals were analysed by data envelopment analysis for overall, technical and scale efficiency, and Malmquist index. The robustness of the analysis is contrasted with alternative input-output models. A fixed effects multilevel cross-sectional linear model was used to analyse the explanatory efficiency variables. The average rate of overall technical efficiency (OTE) was 0.736 in 2012; there was considerable variability by region. Malmquist index (2010-2012) is 1.013. A 23% variability in OTE is attributable to the region in question. Statistically significant exogenous variables (residents per 100 physicians, aging index, average annual income per household, essential public service expenditure and public health expenditure per capita) explain 42% of the OTE variability between hospitals and 64% between regions. The number of residents showed a statistically significant relationship. As regards regions, there is a statistically significant direct linear association between OTE and annual income per capita and essential public service expenditure, and an indirect association with the aging index and annual public health expenditure per capita. The significant room for improvement in the efficiency of hospitals is conditioned by region-specific characteristics, specifically aging, wealth and the public expenditure policies of each one. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Direct state tomography using continuous variable measuring device

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

Zhu, Xuanmin, E-mail: zhuxuanmin@xidian.edu.cn; Wei, Qun

Compared with the conventional quantum state tomography (QST), the efficiency of the direct state tomography (DST) using weak value is very low. However, DST is easily manipulated in experiments. We modify the direct state tomography by using coupling-deformed observables. The modified direct state measurement is valid for arbitrarily large measurement strength. The optimal measurement strengths are obtained to attain the highest efficiency. The efficiency of DST is significantly improved in the modified strategy, and the reconstructed state has no inherent bias. The state reconstruction strategy investigated in this paper might be useful in actual experiments.

Research of grasping algorithm based on scara industrial robot

NASA Astrophysics Data System (ADS)

Peng, Tao; Zuo, Ping; Yang, Hai

2018-04-01

As the tobacco industry grows, facing the challenge of the international tobacco giant, efficient logistics service is one of the key factors. How to complete the tobacco sorting task of efficient economy is the goal of tobacco sorting and optimization research. Now the cigarette distribution system uses a single line to carry out the single brand sorting task, this article adopts a single line to realize the cigarette sorting task of different brands. Using scara robot special algorithm for sorting and packaging, the optimization scheme significantly enhances the indicators of smoke sorting system. Saving labor productivity, obviously improve production efficiency.

Energy Efficient Engine: Control system component performance report

NASA Technical Reports Server (NTRS)

Beitler, R. S.; Bennett, G. W.

1984-01-01

An Energy Efficient Engine (E3) program was established to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, General Electric designed and tested a new engine. The design, fabrication, bench and engine testing of the Full Authority Digital Electronic Control (FADEC) system used for controlling the E3 Demonstrator Engine is described. The system design was based on many of the proven concepts and component designs used on the General Electric family of engines. One significant difference is the use of the FADEC in place of hydromechanical computation currently used.

A 25.5 percent AMO gallium arsenide grating solar cell

NASA Technical Reports Server (NTRS)

Weizer, V. G.; Godlewski, M. P.

1985-01-01

Recent calculations have shown that significant open circuit voltage gains are possible with a dot grating junction geometry. The feasibility of applying the dot geometry to the GaAs cell was investigated. This geometry is shown to result in voltages approach 1.120 V and efficiencies well over 25 percent (AMO) if good collection efficiency can be maintained. The latter is shown to be possible if one chooses the proper base resistivity and cell thickness. The above advances in efficiency are shown to be possible in the P-base cell with only minor improvements in existing technology.

A 25.5 percent AM0 gallium arsenide grating solar cell

NASA Technical Reports Server (NTRS)

Weizer, V. G.; Godlewski, M. P.

1985-01-01

Recent calculations have shown that significant open circuit voltage gains are possible with a dot grating junction geometry. The feasibility of applying the dot geometry to the GaAs cell was investigated. This geometry is shown to result in voltage approach 1.120 V and efficiencies well over 25 percent (AM0) if good collection efficiency can be maintained. The latter is shown to be possible if one chooses the proper base resistivity and cell thickness. The above advances in efficiency are shown to be possible in the P-base cell with only minor improvements in existing technology.

Efficiency improvement of green light-emitting diodes by employing all-quaternary active region and electron-blocking layer

NASA Astrophysics Data System (ADS)

Usman, Muhammad; Saba, Kiran; Han, Dong-Pyo; Muhammad, Nazeer

2018-01-01

High efficiency of green GaAlInN-based light-emitting diode (LED) has been proposed with peak emission wavelength of ∼510 nm. By introducing quaternary quantum well (QW) along with the quaternary barrier (QB) and quaternary electron blocking layer (EBL) in a single structure, an efficiency droop reduction of up to 29% has been achieved in comparison to the conventional GaN-based LED. The proposed structure has significantly reduced electrostatic field in the active region. As a result, carrier leakage has been minimized and spontaneous emission rate has been doubled.

An integrated CRISPR Bombyx mori genome editing system with improved efficiency and expanded target sites.

PubMed

Ma, Sanyuan; Liu, Yue; Liu, Yuanyuan; Chang, Jiasong; Zhang, Tong; Wang, Xiaogang; Shi, Run; Lu, Wei; Xia, Xiaojuan; Zhao, Ping; Xia, Qingyou

2017-04-01

Genome editing enabled unprecedented new opportunities for targeted genomic engineering of a wide variety of organisms ranging from microbes, plants, animals and even human embryos. The serial establishing and rapid applications of genome editing tools significantly accelerated Bombyx mori (B. mori) research during the past years. However, the only CRISPR system in B. mori was the commonly used SpCas9, which only recognize target sites containing NGG PAM sequence. In the present study, we first improve the efficiency of our previous established SpCas9 system by 3.5 folds. The improved high efficiency was also observed at several loci in both BmNs cells and B. mori embryos. Then to expand the target sites, we showed that two newly discovered CRISPR system, SaCas9 and AsCpf1, could also induce highly efficient site-specific genome editing in BmNs cells, and constructed an integrated CRISPR system. Genome-wide analysis of targetable sites was further conducted and showed that the integrated system cover 69,144,399 sites in B. mori genome, and one site could be found in every 6.5 bp. The efficiency and resolution of this CRISPR platform will probably accelerate both fundamental researches and applicable studies in B. mori, and perhaps other insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Creating Diverse Ensemble Classifiers to Reduce Supervision

DTIC Science & Technology

2005-12-01

artificial examples. Quite often training with noise improves network generalization (Bishop, 1995; Raviv & Intrator, 1996). Adding noise to training...full training set, as seen by comparing to the to- tal dataset sizes. Hence, improving on the data utilization of DECORATE is a fairly difficult task...prohibitively expensive, except (perhaps) with an incremen- tal learner such as Naive Bayes. Our AFA framework is significantly more efficient because

Enhanced Power Conversion Efficiency of Graphene/Silicon Heterojunction Solar Cells Through NiO Induced Doping.

PubMed

Kuru, Cihan; Yavuz, Serdar; Kargar, Alireza; Choi, Duyoung; Choi, Chulmin; Rustomji, Cyrus; Jin, Sungho; Bandaru, Prabhakar R

2016-01-01

We report a doping strategy, where nickel oxide (NiO) nanoparticle film coating is employed for graphene/Si heterojunction solar cells to improve the power conversion efficiency (PCE). NiO doping has been shown to improve the short circuit current (J(SC)) by 12%, open circuit voltage (V(OC)) by 25% and fill factor (FF) by 145% of the cells, in turn increasing the PCE from 1.37% to 4.91%. Furthermore, NiO doped graphene/Si solar cells don't show any significant performance degradation over 10 days revealing that NiO doping can be a promising approach for practical applications of graphene in solar cells.

Enhanced electrocaloric cooling in ferroelectric single crystals by electric field reversal

NASA Astrophysics Data System (ADS)

Ma, Yang-Bin; Novak, Nikola; Koruza, Jurij; Yang, Tongqing; Albe, Karsten; Xu, Bai-Xiang

2016-09-01

An improved thermodynamic cycle is validated in ferroelectric single crystals, where the cooling effect of an electrocaloric refrigerant is enhanced by applying a reversed electric field. In contrast to the conventional adiabatic heating or cooling by on-off cycles of the external electric field, applying a reversed field is significantly improving the cooling efficiency, since the variation in configurational entropy is increased. By comparing results from computer simulations using Monte Carlo algorithms and experiments using direct electrocaloric measurements, we show that the electrocaloric cooling efficiency can be enhanced by more than 20% in standard ferroelectrics and also relaxor ferroelectrics, like Pb (Mg1 /3 /Nb2 /3)0.71Ti0.29O3 .

Double-flow focused liquid injector for efficient serial femtosecond crystallography

PubMed Central

Oberthuer, Dominik; Knoška, Juraj; Wiedorn, Max O.; Beyerlein, Kenneth R.; Bushnell, David A.; Kovaleva, Elena G.; Heymann, Michael; Gumprecht, Lars; Kirian, Richard A.; Barty, Anton; Mariani, Valerio; Tolstikova, Aleksandra; Adriano, Luigi; Awel, Salah; Barthelmess, Miriam; Dörner, Katerina; Xavier, P. Lourdu; Yefanov, Oleksandr; James, Daniel R.; Nelson, Garrett; Wang, Dingjie; Calvey, George; Chen, Yujie; Schmidt, Andrea; Szczepek, Michael; Frielingsdorf, Stefan; Lenz, Oliver; Snell, Edward; Robinson, Philip J.; Šarler, Božidar; Belšak, Grega; Maček, Marjan; Wilde, Fabian; Aquila, Andrew; Boutet, Sébastien; Liang, Mengning; Hunter, Mark S.; Scheerer, Patrick; Lipscomb, John D.; Weierstall, Uwe; Kornberg, Roger D.; Spence, John C. H.; Pollack, Lois; Chapman, Henry N.; Bajt, Saša

2017-01-01

Serial femtosecond crystallography requires reliable and efficient delivery of fresh crystals across the beam of an X-ray free-electron laser over the course of an experiment. We introduce a double-flow focusing nozzle to meet this challenge, with significantly reduced sample consumption, while improving jet stability over previous generations of nozzles. We demonstrate its use to determine the first room-temperature structure of RNA polymerase II at high resolution, revealing new structural details. Moreover, the double flow-focusing nozzles were successfully tested with three other protein samples and the first room temperature structure of an extradiol ring-cleaving dioxygenase was solved by utilizing the improved operation and characteristics of these devices. PMID:28300169

NASA Fixed Wing Project Propulsion Research and Technology Development Activities to Reduce Thrust Specific Energy Consumption

NASA Technical Reports Server (NTRS)

Hathaway, Michael D.; Rosario, Ruben Del; Madavan, Nateri K.

2013-01-01

This paper presents an overview of the propulsion research and technology portfolio of NASA Fundamental Aeronautics Program Fixed Wing Project. The research is aimed at significantly reducing the thrust specific fuel/energy consumption of notional advanced fixed wing aircraft (by 60 percent relative to a baseline Boeing 737-800 aircraft with CFM56-7B engines) in the 2030 to 2035 time frame. The research investments described herein are aimed at improving propulsive efficiency through higher bypass ratio fans, improving thermal efficiency through compact high overall pressure ratio gas generators, and exploring the potential benefits of boundary layer ingestion propulsion and hybrid gas-electric propulsion concepts.

NASA Fixed Wing Project Propulsion Research and Technology Development Activities to Reduce Thrust Specific Energy Consumption

NASA Technical Reports Server (NTRS)

Hathaway, Michael D.; DelRasario, Ruben; Madavan, Nateri K.

2013-01-01

This paper presents an overview of the propulsion research and technology portfolio of NASA Fundamental Aeronautics Program Fixed Wing Project. The research is aimed at significantly reducing the thrust specific fuel/energy consumption of notional advanced fixed wing aircraft (by 60 % relative to a baseline Boeing 737-800 aircraft with CFM56-7B engines) in the 2030-2035 time frame. The research investments described herein are aimed at improving propulsive efficiency through higher bypass ratio fans, improving thermal efficiency through compact high overall pressure ratio gas generators, and exploring the potential benefits of boundary layer ingestion propulsion and hybrid gas-electric propulsion concepts.

Poly(sodium 4-styrenseulfonate)-modified monolayer graphene for anode applications of organic photovoltaic cells

NASA Astrophysics Data System (ADS)

Zhou, Yongfang; Wang, Min; Wang, Liang; Liu, Shuli; Chen, Shufen; Cao, Kun; Shang, Wenjuan; Mai, Jiangquan; Zhao, Baomin; Feng, Jing; Lu, Xinhui; Huang, Wei

2017-09-01

An insulated poly(sodium 4-styrenseulfonate) (PSS) was used to modify monolayer graphene for anode applications of organic photovoltaics (OPVs). With this PSS interfacial modification layer, the OPVs showed a significant increase of 56.4% in efficiency due to an improved work function and hydrophilic feature of graphene and an enlarged recombination resistance of carriers/excitons. Doping a highly contorted 1,2,5-thiadiazole-fused 12-ring polyaromatic hydrocarbon into the active layer to form ternary blended OPVs further enlarged the recombination resistance of carriers/excitons and improved light absorption of the active layer, with which a high power conversion efficiency of 6.29% was acquired.

Characteristics of a semi-custom library development system

NASA Technical Reports Server (NTRS)

Yancey, M.; Cannon, R.

1990-01-01

Standard cell and gate array macro libraries are in common use with workstation computer aided design (CAD) tools for application specific integrated circuit (ASIC) semi-custom application and have resulted in significant improvements in the overall design efficiencies as contrasted with custom design methodologies. Similar design methodology enhancements in providing for the efficient development of the library cells is an important factor in responding to the need for continuous technology improvement. The characteristics of a library development system that provides design flexibility and productivity enhancements for the library development engineer as he provides libraries in the state-of-the-art process technologies are presented. An overview of Gould's library development system ('Accolade') is also presented.

Enhanced monolayer MoS2/InP heterostructure solar cells by graphene quantum dots

NASA Astrophysics Data System (ADS)

Wang, Peng; Lin, Shisheng; Ding, Guqiao; Li, Xiaoqiang; Wu, Zhiqian; Zhang, Shengjiao; Xu, Zhijuan; Xu, Sen; Lu, Yanghua; Xu, Wenli; Zheng, Zheyang

2016-04-01

We demonstrate significantly improved photovoltaic response of monolayer molybdenum disulfide (MoS2)/indium phosphide (InP) van der Waals heterostructure induced by graphene quantum dots (GQDs). Raman and photoluminescence measurements indicate that effective charge transfer takes place between GQDs and MoS2, which results in n-type doping of MoS2. The doping effect increases the barrier height at the MoS2/InP heterojunction, thus the averaged power conversion efficiency of MoS2/InP solar cells is improved from 2.1% to 4.1%. The light induced doping by GQD provides a feasible way for developing more efficient MoS2 based heterostructure solar cells.

Traveling-Wave Tube Efficiency Enhancement

NASA Technical Reports Server (NTRS)

Dayton, James A., Jr.

2011-01-01

Traveling-wave tubes (TWT's) are used to amplify microwave communication signals on virtually all NASA and commercial spacecraft. Because TWT's are a primary power user, increasing their power efficiency is important for reducing spacecraft weight and cost. NASA Glenn Research Center has played a major role in increasing TWT efficiency over the last thirty years. In particular, two types of efficiency optimization algorithms have been developed for coupled-cavity TWT's. The first is the phase-adjusted taper which was used to increase the RF power from 420 to 1000 watts and the RF efficiency from 9.6% to 22.6% for a Ka-band (29.5 GHz) TWT. This was a record efficiency at this frequency level. The second is an optimization algorithm based on simulated annealing. This improved algorithm is more general and can be used to optimize efficiency over a frequency bandwidth and to provide a robust design for very high frequency TWT's in which dimensional tolerance variations are significant.

Naïve Induced Pluripotent Stem Cells Generated From β-Thalassemia Fibroblasts Allow Efficient Gene Correction With CRISPR/Cas9

PubMed Central

Yang, Yuanyuan; Zhang, Xiaobai; Yi, Li; Hou, Zhenzhen; Chen, Jiayu; Kou, Xiaochen; Zhao, Yanhong; Wang, Hong; Sun, Xiao-Fang; Jiang, Cizhong

2016-01-01

Conventional primed human embryonic stem cells and induced pluripotent stem cells (iPSCs) exhibit molecular and biological characteristics distinct from pluripotent stem cells in the naïve state. Although naïve pluripotent stem cells show much higher levels of self-renewal ability and multidifferentiation capacity, it is unknown whether naïve iPSCs can be generated directly from patient somatic cells and will be superior to primed iPSCs. In the present study, we used an established 5i/L/FA system to directly reprogram fibroblasts of a patient with β-thalassemia into transgene-free naïve iPSCs with molecular signatures of ground-state pluripotency. Furthermore, these naïve iPSCs can efficiently produce cross-species chimeras. Importantly, using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 nuclease genome editing system, these naïve iPSCs exhibit significantly improved gene-correction efficiencies compared with the corresponding primed iPSCs. Furthermore, human naïve iPSCs could be directly generated from noninvasively collected urinary cells, which are easily acquired and thus represent an excellent cell resource for further clinical trials. Therefore, our findings demonstrate the feasibility and superiority of using patient-specific iPSCs in the naïve state for disease modeling, gene editing, and future clinical therapy. Significance In the present study, transgene-free naïve induced pluripotent stem cells (iPSCs) directly converted from the fibroblasts of a patient with β-thalassemia in a defined culture system were generated. These naïve iPSCs, which show ground-state pluripotency, exhibited significantly improved single-cell cloning ability, recovery capacity, and gene-targeting efficiency compared with conventional primed iPSCs. These results provide an improved strategy for personalized treatment of genetic diseases such as β-thalassemia. PMID:26676643

Frequency-dependent ultrasound-induced transformation in E. coli.

PubMed

Deeks, Jeremy; Windmill, James; Agbeze-Onuma, Maduka; Kalin, Robert M; Argondizza, Peter; Knapp, Charles W

2014-12-01

Ultrasound-enhanced gene transfer (UEGT) is continuing to gain interest across many disciplines; however, very few studies investigate UEGT efficiency across a range of frequencies. Using a variable frequency generator, UEGT was tested in E. coli at six ultrasonic frequencies. Results indicate frequency can significantly influence UEGT efficiency positively and negatively. A frequency of 61 kHz improved UEGT efficiency by ~70 % higher, but 99 kHz impeded UEGT to an extent worse than no ultrasound exposure. The other four frequencies (26, 133, 174, and 190 kHz) enhanced transformation compared to no ultrasound, but efficiencies did not vary. The influence of frequency on UEGT efficiency was observed across a range of operating frequencies. It is plausible that frequency-dependent dynamics of mechanical and chemical energies released during cavitational-bubble collapse (CBC) are responsible for observed UEGT efficiencies.

Thermoelectric efficiency enhanced in a quantum dot with polarization leads, spin-flip and external magnetic field

NASA Astrophysics Data System (ADS)

Yao, Hui; Niu, Peng-Bin; Zhang, Chao; Xu, Wei-Ping; Li, Zhi-Jian; Nie, Yi-Hang

2018-03-01

We theoretically study the thermoelectric transport properties in a quantum dot system with two ferromagnetic leads, the spin-flip scattering and the external magnetic field. The results show that the spin polarization of the leads strongly influences thermoelectric coefficients of the device. For the parallel configuration the peak of figure of merit increases with the increase of polarization strength and non-collinear configuration trends to destroy the improvement of figure of merit induced by lead polarization. While the modulation of the spin-flip scattering on the figure of merit is effective only in the absence of external magnetic field or small magnetic field. In terms of improving the thermoelectric efficiency, the external magnetic field plays a more important role than spin-flip scattering. The thermoelectric efficiency can be significantly enhanced by the magnetic field for a given spin-flip scattering strength.

Improvement of efficiency in graphene/gallium nitride nanowire on Silicon photoelectrode for overall water splitting

NASA Astrophysics Data System (ADS)

Bae, Hyojung; Rho, Hokyun; Min, Jung-Wook; Lee, Yong-Tak; Lee, Sang Hyun; Fujii, Katsushi; Lee, Hyo-Jong; Ha, Jun-Seok

2017-11-01

Gallium nitride (GaN) nanowires are one of the most promising photoelectrode materials due to their high stability in acidic and basic electrolytes, and tunable band edge potentials. In this study, GaN nanowire arrays (GaN NWs) were prepared by molecular beam epitaxy (MBE); their large surface area enhanced the solar to hydrogen conversion efficiency. More significantly, graphene was grown by chemical vapor deposition (CVD), which enhanced the electron transfer between NWs for water splitting and protected the GaN NW surface. Structural characterizations of the prepared composite were performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocurrent density of Gr/GaN NWs exhibited a two-fold increase over pristine GaN NWs and sustained water splitting up to 70 min. These improvements may accelerate possible applications for hydrogen generation with high solar to hydrogen conversion efficiency.

Improvement of Energy Efficiency and Environmental Safety of Thermal Energy Through the Implementation of Contact Energy Exchange Processes

NASA Astrophysics Data System (ADS)

Varlamov, Gennadii Borysovich; Romanova, Kateryna Alexandrovna; Nazarova, Iryna; Daschenko, Olga; Kapustiansky, Andry

2017-12-01

Energy efficiency improvement and ecological safety of heat power plants are urgent problems, which require scientifically grounded approaches and solutions. These problems can be solved partly within the presented heat-and-power cycles by including contact energy exchange equipment in the circuits of existing installations. A significant positive effect is obtained in the contact energy exchange installations, such as gas-steam installation `Aquarius' and the contact hydrogen heat generator that also can use hydrogen as a fuel. In these plants, the efficiency increases approximately by 10-12% in comparison with traditional installations, and the concentration of toxic substances, such as nitrogen oxides and carbon monoxide in flue gas can be reduced to 30 mg/m3 and to 5 mg/m3, respectively. Moreover, the plants additionally `generate' the clean water, which can be used for technical purposes.

Highly efficient solution-processed phosphorescent organic light-emitting devices with double-stacked hole injection layers

NASA Astrophysics Data System (ADS)

Chen, Yuehua; Hao, Lin; Zhang, Xinwen; Zhang, Xiaolin; Liu, Mengjiao; Zhang, Mengke; Wang, Jiong; Lai, Wen-Yong; Huang, Wei

2017-08-01

In this paper, solution-processed nickel oxide (NiOx) is used as hole-injection layers (HILs) in solution-processed phosphorescent organic light-emitting diodes (PhOLEDs). Serious exciton quenching is verified at the NiOx/emitting layer (EML) interface, resulting in worse device performance. The device performance is significantly improved by inserting a layer of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) between the EML and NiOx. The solution-processed blue PhOLED with the double-stacked NiOx/PEDOT:PSS HILs shows a maximum current efficiency of 30.5 cd/A, which is 75% and 30% higher than those of the devices with a single NiOx HIL and a PEDOT:PSS HIL, respectively. Improvement of device efficiency can be attributed to reducing exciton quenching of the PEDOT:PSS layer as well as the electron blocking effect of the NiOx layer.

The time resolved SBS and SRS research in heavy water and its application in CARS

NASA Astrophysics Data System (ADS)

Liu, Jinbo; Gai, Baodong; Yuan, Hong; Sun, Jianfeng; Zhou, Xin; Liu, Di; Xia, Xusheng; Wang, Pengyuan; Hu, Shu; Chen, Ying; Guo, Jingwei; Jin, Yuqi; Sang, Fengting

2018-05-01

We present the time-resolved character of stimulated Brillouin scattering (SBS) and backward stimulated Raman scattering (BSRS) in heavy water and its application in Coherent Anti-Stokes Raman Scattering (CARS) technique. A nanosecond laser from a frequency-doubled Nd: YAG laser is introduced into a heavy water cell, to generate SBS and BSRS beams. The SBS and BSRS beams are collinear, and their time resolved characters are studied by a streak camera, experiment show that they are ideal source for an alignment-free CARS system, and the time resolved property of SBS and BSRS beams could affect the CARS efficiency significantly. By inserting a Dye cuvette to the collinear beams, the time-overlapping of SBS and BSRS could be improved, and finally the CARS efficiency is increased, even though the SBS energy is decreased. Possible methods to improve the efficiency of this CARS system are discussed too.

High resolution PET breast imager with improved detection efficiency

DOEpatents

Majewski, Stanislaw

2010-06-08

A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

A generative, probabilistic model of local protein structure.

PubMed

Boomsma, Wouter; Mardia, Kanti V; Taylor, Charles C; Ferkinghoff-Borg, Jesper; Krogh, Anders; Hamelryck, Thomas

2008-07-01

Despite significant progress in recent years, protein structure prediction maintains its status as one of the prime unsolved problems in computational biology. One of the key remaining challenges is an efficient probabilistic exploration of the structural space that correctly reflects the relative conformational stabilities. Here, we present a fully probabilistic, continuous model of local protein structure in atomic detail. The generative model makes efficient conformational sampling possible and provides a framework for the rigorous analysis of local sequence-structure correlations in the native state. Our method represents a significant theoretical and practical improvement over the widely used fragment assembly technique by avoiding the drawbacks associated with a discrete and nonprobabilistic approach.

Research of an emergency medical system for mass casualty incidents in Shanghai, China: a system dynamics model.

PubMed

Yu, Wenya; Lv, Yipeng; Hu, Chaoqun; Liu, Xu; Chen, Haiping; Xue, Chen; Zhang, Lulu

2018-01-01

Emergency medical system for mass casualty incidents (EMS-MCIs) is a global issue. However, China lacks such studies extremely, which cannot meet the requirement of rapid decision-support system. This study aims to realize modeling EMS-MCIs in Shanghai, to improve mass casualty incident (MCI) rescue efficiency in China, and to provide a possible method of making rapid rescue decisions during MCIs. This study established a system dynamics (SD) model of EMS-MCIs using the Vensim DSS program. Intervention scenarios were designed as adjusting scales of MCIs, allocation of ambulances, allocation of emergency medical staff, and efficiency of organization and command. Mortality increased with the increasing scale of MCIs, medical rescue capability of hospitals was relatively good, but the efficiency of organization and command was poor, and the prehospital time was too long. Mortality declined significantly when increasing ambulances and improving the efficiency of organization and command; triage and on-site first-aid time were shortened if increasing the availability of emergency medical staff. The effect was the most evident when 2,000 people were involved in MCIs; however, the influence was very small under the scale of 5,000 people. The keys to decrease the mortality of MCIs were shortening the prehospital time and improving the efficiency of organization and command. For small-scale MCIs, improving the utilization rate of health resources was important in decreasing the mortality. For large-scale MCIs, increasing the number of ambulances and emergency medical professionals was the core to decrease prehospital time and mortality. For super-large-scale MCIs, increasing health resources was the premise.

Distributed renewable power from biomass and other waste fuels

NASA Astrophysics Data System (ADS)

Lyons, Chris

2012-03-01

The world population is continually growing and putting a burden on our fossil fuels. These fossil fuels such as coal, oil and natural gas are used for a variety of critical needs such as power production and transportation. While significant environmental improvements have been made, the uses of these fuels are still causing significant ecological impacts. Coal power production efficiency has not improved over the past thirty years and with relatively cheap petroleum cost, transportation mileage has not improved significantly either. With the demand for these fossil fuels increasing, ultimately price will also have to increase. This presentation will evaluate alternative power production methods using localized distributed generation from biomass, municipal solid waste and other waste sources of organic materials. The presentation will review various gasification processes that produce a synthetic gas that can be utilized as a fuel source in combustion turbines for clean and efficient combined heat and power. This fuel source can produce base load renewable power. In addition tail gases from the production of bio-diesel and methanol fuels can be used to produce renewable power. Being localized can reduce the need for long and costly transmission lines making the production of fuels and power from waste a viable alternative energy source for the future.

A Novel Adjustment Method for Shearer Traction Speed through Integration of T-S Cloud Inference Network and Improved PSO

PubMed Central

Si, Lei; Wang, Zhongbin; Yang, Yinwei

2014-01-01

In order to efficiently and accurately adjust the shearer traction speed, a novel approach based on Takagi-Sugeno (T-S) cloud inference network (CIN) and improved particle swarm optimization (IPSO) is proposed. The T-S CIN is built through the combination of cloud model and T-S fuzzy neural network. Moreover, the IPSO algorithm employs parameter automation adjustment strategy and velocity resetting to significantly improve the performance of basic PSO algorithm in global search and fine-tuning of the solutions, and the flowchart of proposed approach is designed. Furthermore, some simulation examples are carried out and comparison results indicate that the proposed method is feasible, efficient, and is outperforming others. Finally, an industrial application example of coal mining face is demonstrated to specify the effect of proposed system. PMID:25506358

Photonic Crystal Microchip Laser.

PubMed

Gailevicius, Darius; Koliadenko, Volodymyr; Purlys, Vytautas; Peckus, Martynas; Taranenko, Victor; Staliunas, Kestutis

2016-09-29

The microchip lasers, being very compact and efficient sources of coherent light, suffer from one serious drawback: low spatial quality of the beam strongly reducing the brightness of emitted radiation. Attempts to improve the beam quality, such as pump-beam guiding, external feedback, either strongly reduce the emission power, or drastically increase the size and complexity of the lasers. Here it is proposed that specially designed photonic crystal in the cavity of a microchip laser, can significantly improve the beam quality. Experiments show that a microchip laser, due to spatial filtering functionality of intracavity photonic crystal, improves the beam quality factor M 2 reducing it by a factor of 2, and increase the brightness of radiation by a factor of 3. This comprises a new kind of laser, the "photonic crystal microchip laser", a very compact and efficient light source emitting high spatial quality high brightness radiation.

Improved finite element methodology for integrated thermal structural analysis

NASA Technical Reports Server (NTRS)

Dechaumphai, P.; Thornton, E. A.

1982-01-01

An integrated thermal-structural finite element approach for efficient coupling of thermal and structural analysis is presented. New thermal finite elements which yield exact nodal and element temperatures for one dimensional linear steady state heat transfer problems are developed. A nodeless variable formulation is used to establish improved thermal finite elements for one dimensional nonlinear transient and two dimensional linear transient heat transfer problems. The thermal finite elements provide detailed temperature distributions without using additional element nodes and permit a common discretization with lower order congruent structural finite elements. The accuracy of the integrated approach is evaluated by comparisons with analytical solutions and conventional finite element thermal structural analyses for a number of academic and more realistic problems. Results indicate that the approach provides a significant improvement in the accuracy and efficiency of thermal stress analysis for structures with complex temperature distributions.

Improved detection of multiple environmental antibiotics through an optimized sample extraction strategy in liquid chromatography-mass spectrometry analysis.

PubMed

Yi, Xinzhu; Bayen, Stéphane; Kelly, Barry C; Li, Xu; Zhou, Zhi

2015-12-01

A solid-phase extraction/liquid chromatography/electrospray ionization/multi-stage mass spectrometry (SPE-LC-ESI-MS/MS) method was optimized in this study for sensitive and simultaneous detection of multiple antibiotics in urban surface waters and soils. Among the seven classes of tested antibiotics, extraction efficiencies of macrolides, lincosamide, chloramphenicol, and polyether antibiotics were significantly improved under optimized sample extraction pH. Instead of only using acidic extraction in many existing studies, the results indicated that antibiotics with low pK a values (<7) were extracted more efficiently under acidic conditions and antibiotics with high pK a values (>7) were extracted more efficiently under neutral conditions. The effects of pH were more obvious on polar compounds than those on non-polar compounds. Optimization of extraction pH resulted in significantly improved sample recovery and better detection limits. Compared with reported values in the literature, the average reduction of minimal detection limits obtained in this study was 87.6% in surface waters (0.06-2.28 ng/L) and 67.1% in soils (0.01-18.16 ng/g dry wt). This method was subsequently applied to detect antibiotics in environmental samples in a heavily populated urban city, and macrolides, sulfonamides, and lincomycin were frequently detected. Antibiotics with highest detected concentrations were sulfamethazine (82.5 ng/L) in surface waters and erythromycin (6.6 ng/g dry wt) in soils. The optimized sample extraction strategy can be used to improve the detection of a variety of antibiotics in environmental surface waters and soils.

Improving spine surgical access, appropriateness and efficiency in metropolitan, urban and rural settings

PubMed Central

Zarrabian, Mohammad; Bidos, Andrew; Fanti, Caroline; Young, Barry; Drew, Brian; Puskas, David; Rampersaud, Raja

2017-01-01

Background The Inter-professional Spine Assessment and Education Clinics (ISAEC) were developed to improve primary care assessment, education and management of patients with persistent or recurrent low back pain–related symptoms. This study aims to determine the effect of ISAEC on access for surgical assessment, referral appropriateness and efficiency for patients meeting a priori referral criteria in rural, urban and metropolitan settings. Methods We conducted a retrospective review of prospective data from networked ISAEC clinics in Thunder Bay, Hamilton and Toronto, Ontario. For patients meeting surgical referral criteria, wait times for surgical assessment, surgical referral–related magnetic resonance imaging (MRI) scans and appropriateness of referral were recorded. Results Overall 422 patients, representing 10% of all ISAEC patients in the study period, were referred for surgical assessment. The average wait times for surgical assessment were 5.4, 4.3 and 2.2 weeks at the metropolitan, urban and rural centres, respectively. Referral MRI usage for the group decreased by 31%. Of the patients referred for formal surgical assessment, 80% had leg-dominant pain and 96% were deemed appropriate surgical referrals. Conclusion Contrary to geographic concentration of health care resources in metropolitan settings, the greatest decrease in wait times was achieved in the rural setting. A networked, shared-cared model of care for patients with low back pain–related symptoms significantly improved access for surgical assessment despite varying geographic practice settings and barriers. The greatest reductions were noted in the rural setting. In addition, significant improvements in referral appropriateness and efficiency were achieved compared with historical reports across all sites.

Near Zero Emissions at 50 Percent Thermal Efficiency

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

None, None

2012-12-31

Detroit Diesel Corporation (DDC) has successfully completed a 10 year DOE sponsored heavy-duty truck engine program, hereafter referred to as the NZ-50 program. This program was split into two major phases. The first phase was called Near-Zero Emission at 50 Percent Thermal Efficiency, and was completed in 2007. The second phase was initiated in 2006, and this phase was named Advancements in Engine Combustion Systems to Enable High-Efficiency Clean Combustion for Heavy-Duty Engines. This phase was completed in September, 2010. The key objectives of the NZ-50 program for this first phase were to: Quantify thermal efficiency degradation associated with reductionmore » of engine-out NOx emissions to the 2007 regulated level of ~1.1 g/hp-hr. Implement an integrated analytical/experimental development plan for improving subsystem and component capabilities in support of emerging engine technologies for emissions and thermal efficiency goals of the program. Test prototype subsystem hardware featuring technology enhancements and demonstrate effective application on a multi-cylinder, production feasible heavy-duty engine test-bed. Optimize subsystem components and engine controls (calibration) to demonstrate thermal efficiency that is in compliance with the DOE 2005 Joule milestone, meaning greater than 45% thermal efficiency at 2007 emission levels. Develop technology roadmap for meeting emission regulations of 2010 and beyond while mitigating the associated degradation in engine fuel consumption. Ultimately, develop technical prime-path for meeting the overall goal of the NZ-50 program, i.e., 50% thermal efficiency at 2010 regulated emissions. These objectives were successfully met during the course of the NZ-50 program. The most noteworthy achievements in this program are summarized as follows: Demonstrated technologies through advanced integrated experiments and analysis to achieve the technical objectives of the NZ-50 program with 50.2% equivalent thermal efficiency under EPA 2010 emissions regulations. Experimentally demonstrate brake efficiency of 48.5% at EPA 2010 emission level at single steady-state point. Analytically demonstrated additional brake efficiency benefits using advanced aftertreatment configuration concept and air system enhancement including, but not limited to, turbo-compound, variable valve actuator system, and new cylinder head redesign, thus helping to achieve the final program goals. Experimentally demonstrated EPA 2010 emissions over FTP cycles using advanced integrated engine and aftertreatment system. These aggressive thermal efficiency and emissions results were achieved by applying a robust systems technology development methodology. It used integrated analytical and experimental tools for subsystem component optimization encompassing advanced fuel injection system, increased EGR cooling capacity, combustion process optimization, and advanced aftertreatment technologies. Model based controls employing multiple input and output techniques enabled efficient integration of the various subsystems and ensured optimal performance of each system within the total engine package. . The key objective of the NZ-50 program for the second phase was to explore advancements in engine combustion systems using high-efficiency clean combustion (HECC) techniques to minimize cylinder-out emissions, targeting a 10% efficiency improvement. The most noteworthy achievements in this phase of the program are summarized as follows: Experimentally and analytically evaluated numerous air system improvements related to the turbocharger and variable valve actuation. Some of the items tested proved to be very successful and modifications to the turbine discovered in this program have since been incorporated into production hardware. The combustion system development continued with evaluation of various designs of the 2-step piston bowl. Significant improvements in engine emissions have been obtained, but fuel economy improvements have been tougher to realize. Development of a neural network control system progressed to the point that the system was fully functional and showing significant fuel economy gains in transient engine testing. Development of the QuantLogic injector with the capability of both a hollow cone spray during early injection and conventional diesel injection at later injection timings was undertaken and proved to be problematic. This injector was designed to be a key component in a PCCI combustion system, but this innovative fuel injector required significantly more development effort than this programâ's resources or timing would allow.« less

Progress on Fuel Efficiency and Market Adoption - SuperTruck Factsheet

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

None

2016-06-30

The Department of Energy (DOE) launched the SuperTruck initiative in 2009 with the goal of developing and demonstrating a 50 percent improvement in overall freight efficiency (expressed in a ton-mile per gallon metric) for a heavy-duty Class 8 tractor-trailer. To date, the industry teams participating in the initiative have successfully met or are on track to exceed this goal, leveraging suites of technologies that hold significant potential for market success.

Application of selected advanced technologies to high performance, single-engine, business airplanes

NASA Technical Reports Server (NTRS)

Domack, C. S.; Martin, G. L.

1984-01-01

Improvements in performance and fuel efficiency are evaluated for five new configurations of a six place, single turboprop, business airplane derived from a conventional, aluminum construction baseline aircraft. Results show the greatest performance gains for enhancements in natural laminar flow. A conceptual diesel engine provides greater fuel efficiency but reduced performance. Less significant effects are produced by the utilization of composite materials construction or by reconfiguration from tractor to pusher propeller installation.

Multi-Scale Experiments to Evaluate Mobility Control Methods for Enhancing the Sweep Efficiency of Injected Subsurface Remediation Amendments

DTIC Science & Technology

2010-08-01

petroleum industry. Moreover, heterogeneity control strategies can be applied to improve the efficiency of a variety of in situ remediation technologies...conditions that differ significantly from those found in environmental systems . Therefore many of the design criteria used by the petroleum industry for...were helpful in constructing numerical models in up-scaled systems (2-D tanks). The UTCHEM model was able to successfully simulate 2-D experimental

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

Sparn, Bethany; Hunsberger, Randolph

Water and wastewater treatment plants and distribution systems use significant amounts of energy, around 2 - 4% of the total electricity used in the US, and their energy use is projected to increase as populations increase and regulations become more stringent. Water and wastewater systems have largely been disconnected from the electric utilities' efforts to improve energy efficiency and provide energy efficiency and provide grid services, likely because their core mission is to provide clean water and treated wastewater. Energy efficiency has slowly crept into the water and wastewater industry as the economic benefit has become more apparent, but theremore » is still potential for significant improvement. Some of the larger, more progressive water utilities are starting to consider providing grid services; however, it remains a foreign concept to many. This report explores intrinsic mechanisms by which the water and wastewater industries can provide exchangeable services, the benefit to the parties involved, and the barriers to implementation. It also highlights relevant case studies and next steps. Although opportunities for increasing process efficiencies are certainly available, this report focuses on the exchangeable services that water and wastewater loads can provide to help maintain grid reliability, keep overall costs down, and increase the penetration of distributed renewables on the electric grid. These services have potential to provide water utilities additional value streams, using existing equipment with modest or negligible upgrade cost.« less

Group aquatic training improves gait efficiency in adolescents with cerebral palsy.

PubMed

Ballaz, Laurent; Plamondon, Suzanne; Lemay, Martin

2011-01-01

To evaluate the effect and feasibility of a 10-week group aquatic training programme on gait efficiency in adolescents with cerebral palsy (CP). The secondary purpose was to determine the exercise intensity during aquatic training in a heterogeneous group of adolescents with CP and to investigate the impact of the training programme on the musculoskeletal system. Twelve ambulatory adolescents with spastic CP were recruited. They participated in 20 aquatic training sessions (45 min twice a week). Three physical therapists and a sports teacher supervised the training sessions. Participants wore a heart rate monitor to assess sessions' intensity and a floatation device as appropriate. The primary outcome measure was gait efficiency as measured by the gait energy expenditure index (EEI). The secondary measures were (1) gait spatiotemporal parameters, (2) maximal isometric knee strength and (3) gross motor function. Ten adolescents completed the training programme. No adverse effect was reported. Average exercise intensity was mild to moderate for more than half of the training session. A significant reduction of the EEI and the heart rate during walking was observed following the training programme. No significant change was observed on secondary outcome measures. Group aquatic training increases gait efficiency in adolescents with CP. This improvement is related to systemic cardiorespiratory adaptations. Group aquatic training programme is feasible in adolescents presenting CP at different levels of severity.

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

Wierer, Jonathan J.; Tsao, Jeffrey Y.; Sizov, Dmitry S.

Solid-state lighting (SSL) is now the most efficient source of high color quality white light ever created. Nevertheless, the blue InGaN light-emitting diodes (LEDs) that are the light engine of SSL still have significant performance limitations. Foremost among these is the decrease in efficiency at high input current densities widely known as “efficiency droop.” Efficiency droop limits input power densities, contrary to the desire to produce more photons per unit LED chip area and to make SSL more affordable. Pending a solution to efficiency droop, an alternative device could be a blue laser diode (LD). LDs, operated in stimulated emission,more » can have high efficiencies at much higher input power densities than LEDs can. In this article, LEDs and LDs for future SSL are explored by comparing: their current state-of-the-art input-power-density-dependent power-conversion efficiencies; potential improvements both in their peak power-conversion efficiencies and in the input power densities at which those efficiencies peak; and their economics for practical SSL.« less

Eco-efficiency of solid waste management in Welsh SMEs

NASA Astrophysics Data System (ADS)

Sarkis, Joseph; Dijkshoorn, Jeroen

2005-11-01

This paper provides an efficiency analysis of practices in Solid Waste Management of manufacturing companies in Wales. We apply data envelopment analysis (DEA) to a data set compiled during the National Waste Survey Wales 2003. We explore the relative performance of small and medium sized manufacturing enterprises (SME; 10-250 employees) in Wales. We determine the technical and scale environmental and economic efficiencies of these organizations. Our evaluation focuses on empirical data collected from companies in a wide diversity of manufacturing industries throughout Wales. We find significant differences in industry and size efficiencies. We also find correlations that exist among environmental and economic efficiencies. These variations show that improvements can be made using benchmarks from similar and different size industries. Further pursuit of an investigation of possible reasons for these differences is recommended.

Decapitation improves the efficiency of Cd phytoextraction by Celosia argentea Linn.

PubMed

Liu, Jie; Zhang, Xuehong; Mo, Lingyun; Yao, Shiyin; Wang, Yixuan

2017-08-01

The effect of decapitation on enhancing plant growth and Cd accumulation in Celosia argentea Linn. was evaluated using a pot experiment. Decapitation significantly enhanced the growth of C. argentea. The numbers of branch and leaf in the decapitated plants (DP) were significantly higher than those in undecapitated plants (UDP, p < 0.05). Decapitation increased the biomass by 75%-105% for roots, 108%-152% for stems, and 80%-107% for leaves. Although the transpiration and photosynthesis rates were not significantly different between DP and UPD, decapitation significantly increased the total leaf area and total transpiration per plant (p < 0.05). The higher total transpiration per plant resulted in a higher leaf Cd concentration in DP. DP accumulated Cd in shoots (197, 275, and 425 μg plant -1 ) that were 2.5-2.8 times higher than UDP (78, 108, and 152 μg plant -1 ), with the soils containing 1, 5, and 10 mg kg -1 Cd. Results suggested that decapitation is a novel and convenient method to improve the phytoextraction efficiency of C. argentea in Cd contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel Transparent Urinary Tract Simulator Improves Teaching of Urological Operation Skills at a Single Institution.

PubMed

Zhong, Xiao; Wang, Pingxian; Feng, Jiayu; Hu, Wengang; Huang, Chibing

2015-01-01

This randomized controlled study compared a novel transparent urinary tract simulator with the traditional opaque urinary tract simulator as an aid for efficiently teaching urological surgical procedures. Senior medical students were tested on their understanding of urological theory before and after lectures concerning urinary system disease. The students received operative training using the transparent urinary tract simulator (experimental group, n = 80) or the J3311 opaque plastic urinary tract simulator (control, n = 80), specifically in catheterization and retrograde double-J stent implantation. The operative training was followed by a skills test and student satisfaction survey. The test scores for theory were similar between the two groups, before and after training. Students in the experimental group performed significantly better than those in the control group on the procedural skills test, and also had significantly better self-directed learning skills, analytical skills, and greater motivation to learn. During the initial step of training, the novel transparent urinary tract simulator significantly improved the efficiency of teaching urological procedural skills compared with the traditional opaque device. © 2015 S. Karger AG, Basel.

A Coordinated Patient Transport System for ICU Patients Requiring Surgery: Impact on Operating Room Efficiency and ICU Workflow.

PubMed

Brown, Michael J; Kor, Daryl J; Curry, Timothy B; Marmor, Yariv; Rohleder, Thomas R

2015-01-01

Transfer of intensive care unit (ICU) patients to the operating room (OR) is a resource-intensive, time-consuming process that often results in patient throughput inefficiencies, deficiencies in information transfer, and suboptimal nurse to patient ratios. This study evaluates the implementation of a coordinated patient transport system (CPTS) designed to address these issues. Using data from 1,557 patient transfers covering the 2006-2010 period, interrupted time series and before and after designs were used to analyze the effect of implementing a CPTS at Mayo Clinic, Rochester. Using a segmented regression for the interrupted time series, on-time OR start time deviations were found to be significantly lower after the implementation of CPTS (p < .0001). The implementation resulted in a fourfold improvement in on-time OR starts (p < .01) while significantly reducing idle OR time (p < .01). A coordinated patient transfer process for moving patient from ICUs to ORs can significantly improve OR efficiency, reduce nonvalue added time, and ensure quality of care by preserving appropriate care provider to patient ratios.

Efficient exciton generation in atomic passivated CdSe/ZnS quantum dots light-emitting devices

PubMed Central

Kang, Byoung-Ho; Lee, Jae-Sung; Lee, Sang-Won; Kim, Sae-Wan; Lee, Jun-Woo; Gopalan, Sai-Anand; Park, Ji-Sub; Kwon, Dae-Hyuk; Bae, Jin-Hyuk; Kim, Hak-Rin; Kang, Shin-Won

2016-01-01

We demonstrate the first-ever surface modification of green CdSe/ZnS quantum dots (QDs) using bromide anions (Br-) in cetyl trimethylammonium bromide (CTAB). The Br- ions reduced the interparticle spacing between the QDs and induced an effective charge balance in QD light-emitting devices (QLEDs). The fabricated QLEDs exhibited efficient charge injection because of the reduced emission quenching effect and their enhanced thin film morphology. As a result, they exhibited a maximum luminance of 71,000 cd/m2 and an external current efficiency of 6.4 cd/A, both significantly better than those of their counterparts with oleic acid surface ligands. In addition, the lifetime of the Br- treated QD based QLEDs is significantly improved due to ionic passivation at the QDs surface. PMID:27686147

Nicotine increases brain functional network efficiency.

PubMed

Wylie, Korey P; Rojas, Donald C; Tanabe, Jody; Martin, Laura F; Tregellas, Jason R

2012-10-15

Despite the use of cholinergic therapies in Alzheimer's disease and the development of cholinergic strategies for schizophrenia, relatively little is known about how the system modulates the connectivity and structure of large-scale brain networks. To better understand how nicotinic cholinergic systems alter these networks, this study examined the effects of nicotine on measures of whole-brain network communication efficiency. Resting state fMRI was acquired from fifteen healthy subjects before and after the application of nicotine or placebo transdermal patches in a single blind, crossover design. Data, which were previously examined for default network activity, were analyzed with network topology techniques to measure changes in the communication efficiency of whole-brain networks. Nicotine significantly increased local efficiency, a parameter that estimates the network's tolerance to local errors in communication. Nicotine also significantly enhanced the regional efficiency of limbic and paralimbic areas of the brain, areas which are especially altered in diseases such as Alzheimer's disease and schizophrenia. These changes in network topology may be one mechanism by which cholinergic therapies improve brain function. Published by Elsevier Inc.

Nicotine Increases Brain Functional Network Efficiency

PubMed Central

Wylie, Korey P.; Rojas, Donald C.; Tanabe, Jody; Martin, Laura F.; Tregellas, Jason R.

2012-01-01

Despite the use of cholinergic therapies in Alzheimer’s disease and the development of cholinergic strategies for schizophrenia, relatively little is known about how the system modulates the connectivity and structure of large-scale brain networks. To better understand how nicotinic cholinergic systems alter these networks, this study examined the effects of nicotine on measures of whole-brain network communication efficiency. Resting-state fMRI was acquired from fifteen healthy subjects before and after the application of nicotine or placebo transdermal patches in a single blind, crossover design. Data, which were previously examined for default network activity, were analyzed with network topology techniques to measure changes in the communication efficiency of whole-brain networks. Nicotine significantly increased local efficiency, a parameter that estimates the network’s tolerance to local errors in communication. Nicotine also significantly enhanced the regional efficiency of limbic and paralimbic areas of the brain, areas which are especially altered in diseases such as Alzheimer’s disease and schizophrenia. These changes in network topology may be one mechanism by which cholinergic therapies improve brain function. PMID:22796985

Optoelectronic engineering of colloidal quantum-dot solar cells beyond the efficiency black hole: a modeling approach

NASA Astrophysics Data System (ADS)

Mahpeykar, Seyed Milad; Wang, Xihua

2017-02-01

Colloidal quantum dot (CQD) solar cells have been under the spotlight in recent years mainly due to their potential for low-cost solution-processed fabrication and efficient light harvesting through multiple exciton generation (MEG) and tunable absorption spectrum via the quantum size effect. Despite the impressive advances achieved in charge carrier mobility of quantum dot solids and the cells' light trapping capabilities, the recent progress in CQD solar cell efficiencies has been slow, leaving them behind other competing solar cell technologies. In this work, using comprehensive optoelectronic modeling and simulation, we demonstrate the presence of a strong efficiency loss mechanism, here called the "efficiency black hole", that can significantly hold back the improvements achieved by any efficiency enhancement strategy. We prove that this efficiency black hole is the result of sole focus on enhancement of either light absorption or charge extraction capabilities of CQD solar cells. This means that for a given thickness of CQD layer, improvements accomplished exclusively in optic or electronic aspect of CQD solar cells do not necessarily translate into tangible enhancement in their efficiency. The results suggest that in order for CQD solar cells to come out of the mentioned black hole, incorporation of an effective light trapping strategy and a high quality CQD film at the same time is an essential necessity. Using the developed optoelectronic model, the requirements for this incorporation approach and the expected efficiencies after its implementation are predicted as a roadmap for CQD solar cell research community.

Highly Enhanced Photoelectrochemical Water Oxidation Efficiency Based on Triadic Quantum Dot/Layered Double Hydroxide/BiVO 4 Photoanodes

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

Tang, Yanqun; Wang, Ruirui; Yang, Ye

2016-08-03

The water oxidation half-reaction is considered to be a bottleneck for achieving highly efficient solar-driven water splitting due to its multiproton-coupled four-electron process and sluggish kinetics. Herein, a triadic photoanode consisting of dual-sized CdTe quantum dots (QDs), Co-based layered double hydroxide (LDH) nanosheets, and BiVO4 particles, that is, QD@LDH@BiVO4, was designed. Two sets of consecutive Type-II band alignments were constructed to improve photogenerated electron-hole separation in the triadic structure. The efficient charge separation resulted in a 2-fold enhancement of the photocurrent of the QD@LDH@BiVO4 photoanode. A significantly enhanced oxidation efficiency reaching above 90% in the low bias region (i.e., Emore » < 0.8 V vs RHE) could be critical in determining the overall performance of a complete photoelectrochemical cell. The faradaic efficiency for water oxidation was almost 90%. The conduction band energy of QDs is -1.0 V more negative than that of LDH, favorable for the electron injection to LDH and enabling a more efficient hole separation. The enhanced photon-to-current conversion efficiency and improved water oxidation efficiency of the triadic structure may result from the non-negligible contribution of hot electrons or holes generated in QDs. Such a band-matching and multidimensional triadic architecture could be a promising strategy for achieving high-efficiency photoanodes by sufficiently utilizing and maximizing the functionalities of QDs.« less

The impact of healthcare reform on the efficiency of public county hospitals in China.

PubMed

Jiang, Shuai; Min, Rui; Fang, Peng-Qian

2017-12-20

The new round of Healthcare Reform in China has implemented over 3 years since 2009, and promoted greatly the development of public county hospitals. The purpose of this study is to evaluate county hospitals efficiency before and after the healthcare reform, and further assess the reform effectiveness through the comparative analysis of the efficiency. Data envelopment analysis (DEA) was employed to calculate the efficiency of 1105 sample hospitals which were selected from 31 provinces of China, also, Tobit regression was used to regress against those main external environmental factors. Our results show that the scales and amounts of service of hospitals had increased sharply, however, the efficiency was relatively low and decreased slightly from 2008 to 2012. Thirteen (1.18%) in 2008 and six (0.54%) hospitals in 2012 were defined as technically efficient, and the average scores were 0.2916 and 0.2503. The technical efficiency average score of the post-reform was significantly less than that of the pre-reform (p < 0.001), and the score of eastern region was highest and the western was lowest among three regions of China. It suggests the reform had not well improved county hospital efficiency although hospitals have reached a fair developing scale, and the corresponding policies and measures should be put into effect for improving efficiency, especially in the level and structure of health investment, operation and supervision mechanism of county hospitals.

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

Nutritional Improvement Correlates with Recovery of Activities of Daily Living among Malnourished Elderly Stroke Patients in the Convalescent Stage: A Cross-Sectional Study.

PubMed

Nishioka, Shinta; Wakabayashi, Hidetaka; Nishioka, Emi; Yoshida, Tomomi; Mori, Natsumi; Watanabe, Riko

2016-05-01

Whether nutritional improvement correlates with functional recovery in convalescent stroke patients is unclear. This study was conducted to examine the relationship between nutritional improvement and recovery of activities of daily living among malnourished elderly stroke patients in the convalescent stage. This study used a cross-sectional study design. One hundred seventy-eight malnourished stroke patients aged 65 years and older from convalescent rehabilitation wards in Japan between April 2012 and December 2014 were included in the analyses. The participants were classified into three groups according to the Mini Nutritional Assessment Short-Form (MNA-SF) score at discharge (0 to 7 as no improvement, 8 to 11 as lesser improvement, and 12 to 14 as greater improvement). The primary outcome was functional independence measure (FIM) efficiency (FIM gain/length of hospital stay). The secondary outcomes were FIM gain and discharge outcome. One-way analysis of variance, χ(2) test, and Kruskal-Wallis test were performed for univariate analysis. Linear regression analysis was used to adjust for covariates such as age, sex, length of hospital stay, FIM (motor and cognitive) on admission, and lower-order items of MNA-SF. Binomial logistic analysis for discharge outcome (home/others) was performed to adjust for covariates such as age, sex, and FIM. Study participants included 85 men and 93 women with a mean age of 77 years. Based on MNA-SF, 16 were classified as no improvement, 113 as lesser improvement, and 49 as greater improvement. The median FIM efficiency and length of hospital stay were 0.27 points/day and 151.5 days, respectively. The greater improvement group had significantly higher FIM efficiency than the other groups (P<0.001). Home discharge rate was also higher in the GI group (P=0.014). Linear regression analysis for FIM efficiency indicated that mobility, neuropsychological problems, and weight loss, which were lower-order items of MNA-SF at discharge, were independent explanatory variables (R(2)=0.373; P<0.001). These findings suggest that nutritional improvement such as maintenance of body weight is associated with the efficient recovery of activities of daily living among malnourished elderly convalescent stroke patients. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Improving phosphorus uptake and wheat productivity by phosphoric acid application in alkaline calcareous soils.

PubMed

Akhtar, Muhammad; Yaqub, Muhammad; Naeem, Asif; Ashraf, Muhammad; Hernandez, Vicente Espinosa

2016-08-01

Low phosphorus (P) efficiency from existing granular fertilisers necessitates searching for efficient alternatives to improve wheat productivity in calcareous soil. Multi-location trials have shown that phosphoric acid (PA) produced 16% higher wheat grain over commercial P fertilisers, i.e. diammonium phosphate (DAP) and triple superphosphate (TSP). Methods of P application significantly influenced grain yield and the efficiency of methods was observed in the order: PA placement below seed > PA, DAP or TSP fertigation > DAP or TSP broadcast. The sub-surface application of PA produced highest grain yields (mean of all rates), i.e. 4669, 4158 and 3910 kg ha(-1) in Bagh, Bhalwal and Shahpur soil series, respectively. Phosphoric acid at 66 kg P2 O5 ha(-1) was found more effective in increasing gain yield over that of control. Trend in grain P uptake was found similar to that observed for grain yield. Maximum P uptake by grain was recorded at the highest P rate and the lowest at zero P. The significant increase in P uptake with P rates was generally related to the increase in yield rather than its concentration in grain. Phosphorus agronomic efficiency (PAE) and phosphorus recovery efficiency (PRE) were found higher at lower P rate (44 kg P2 O5 ha(-1) ) and decreased with P application. However, PA applied by the either method resulted in higher PAE and PRE compared to DAP and TSP. Phosphoric acid is suggested as an efficient alternative to commercial granular P fertilisers for wheat production in alkaline calcareous soils. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Improving GPU-accelerated adaptive IDW interpolation algorithm using fast kNN search.

PubMed

Mei, Gang; Xu, Nengxiong; Xu, Liangliang

2016-01-01

This paper presents an efficient parallel Adaptive Inverse Distance Weighting (AIDW) interpolation algorithm on modern Graphics Processing Unit (GPU). The presented algorithm is an improvement of our previous GPU-accelerated AIDW algorithm by adopting fast k-nearest neighbors (kNN) search. In AIDW, it needs to find several nearest neighboring data points for each interpolated point to adaptively determine the power parameter; and then the desired prediction value of the interpolated point is obtained by weighted interpolating using the power parameter. In this work, we develop a fast kNN search approach based on the space-partitioning data structure, even grid, to improve the previous GPU-accelerated AIDW algorithm. The improved algorithm is composed of the stages of kNN search and weighted interpolating. To evaluate the performance of the improved algorithm, we perform five groups of experimental tests. The experimental results indicate: (1) the improved algorithm can achieve a speedup of up to 1017 over the corresponding serial algorithm; (2) the improved algorithm is at least two times faster than our previous GPU-accelerated AIDW algorithm; and (3) the utilization of fast kNN search can significantly improve the computational efficiency of the entire GPU-accelerated AIDW algorithm.

Patient-specific instrumentation does not improve radiographic alignment or clinical outcomes after total knee arthroplasty.

PubMed

Huijbregts, Henricus J T A M; Khan, Riaz J K; Sorensen, Emma; Fick, Daniel P; Haebich, Samantha

2016-08-01

Background and purpose - Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) has been introduced to improve alignment and reduce outliers, increase efficiency, and reduce operation time. In order to improve our understanding of the outcomes of patient-specific instrumentation, we conducted a meta-analysis. Patients and methods - We identified randomized and quasi-randomized controlled trials (RCTs) comparing patient-specific and conventional instrumentation in TKA. Weighted mean differences and risk ratios were determined for radiographic accuracy, operation time, hospital stay, blood loss, number of surgical trays required, and patient-reported outcome measures. Results - 21 RCTs involving 1,587 TKAs were included. Patient-specific instrumentation resulted in slightly more accurate hip-knee-ankle axis (0.3°), coronal femoral alignment (0.3°, femoral flexion (0.9°), tibial slope (0.7°), and femoral component rotation (0.5°). The risk ratio of a coronal plane outlier (> 3° deviation of chosen target) for the tibial component was statistically significantly increased in the PSI group (RR =1.64). No significance was found for other radiographic measures. Operation time, blood loss, and transfusion rate were similar. Hospital stay was significantly shortened, by approximately 8 h, and the number of surgical trays used decreased by 4 in the PSI group. Knee Society scores and Oxford knee scores were similar. Interpretation - Patient-specific instrumentation does not result in clinically meaningful improvement in alignment, fewer outliers, or better early patient-reported outcome measures. Efficiency is improved by reducing the number of trays used, but PSI does not reduce operation time.

77 FR 19280 - Increasing Market and Planning Efficiency Through Improved Software; Notice of Technical...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... Market and Planning Efficiency Through Improved Software; Notice of Technical Conference: Increasing Real-Time and Day- Ahead Market Efficiency Through Improved Software Take notice that Commission staff will...-time and day-ahead market efficiency through improved software. A detailed agenda with the list of and...