Sample records for principles underlying efficient

  1. Principles of scarce medical resource allocation in natural disaster relief: a simulation approach.

    PubMed

    Cao, Hui; Huang, Simin

    2012-01-01

    A variety of triage principles have been proposed. The authors sought to evaluate their effects on how many lives can be saved in a hypothetical disaster. To determine an optimal scarce resource-rationing principle in the emergency response domain, considering the trade-off between lifesaving efficiency and ethical issues. A discrete event simulation model is developed to examine the efficiency of four resource-rationing principles: first come-first served, random, most serious first, and least serious first. Seven combinations of available resources are examined in the simulations to evaluate the performance of the principles under different levels of resource scarcity. The simulation results indicate that the performance of the medical resource allocation principles is related to the level of the resource scarcity. When the level of the scarcity is high, the performances of the four principles differ significantly. The least serious first principle performs best, followed by the random principle; the most serious first principle acts worst. However, when the scarcity is relieved, there are no significant differences among the random, first come-first served, and least serious first principles, yet the most serious first principle still performs worst. Although the least serious first principle exhibits the highest efficiency, it is not ethically flawless. Considering the trade off between the lifesaving efficiency and the ethical issues, random selection is a relatively fair and efficient principle for allocating scarce medical resources in natural disaster responses.

  2. Sensitivity to the Sampling Process Emerges From the Principle of Efficiency.

    PubMed

    Jara-Ettinger, Julian; Sun, Felix; Schulz, Laura; Tenenbaum, Joshua B

    2018-05-01

    Humans can seamlessly infer other people's preferences, based on what they do. Broadly, two types of accounts have been proposed to explain different aspects of this ability. The first account focuses on spatial information: Agents' efficient navigation in space reveals what they like. The second account focuses on statistical information: Uncommon choices reveal stronger preferences. Together, these two lines of research suggest that we have two distinct capacities for inferring preferences. Here we propose that this is not the case, and that spatial-based and statistical-based preference inferences can be explained by the assumption that agents are efficient alone. We show that people's sensitivity to spatial and statistical information when they infer preferences is best predicted by a computational model of the principle of efficiency, and that this model outperforms dual-system models, even when the latter are fit to participant judgments. Our results suggest that, as adults, a unified understanding of agency under the principle of efficiency underlies our ability to infer preferences. Copyright © 2018 Cognitive Science Society, Inc.

  3. 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.

  4. Optimality principle for the coupled chemical reactions of ATP synthesis and its molecular interpretation

    NASA Astrophysics Data System (ADS)

    Nath, Sunil

    2018-05-01

    Metabolic energy obtained from the coupled chemical reactions of oxidative phosphorylation (OX PHOS) is harnessed in the form of ATP by cells. We experimentally measured thermodynamic forces and fluxes during ATP synthesis, and calculated the thermodynamic efficiency, η and the rate of free energy dissipation, Φ. We show that the OX PHOS system is tuned such that the coupled nonequilibrium processes operate at optimal η. This state does not coincide with the state of minimum Φ but is compatible with maximum Φ under the imposed constraints. Conditions that must hold for species concentration in order to satisfy the principle of optimal efficiency are derived analytically and a molecular explanation based on Nath's torsional mechanism of energy transduction and ATP synthesis is suggested. Differences of the proposed principle with Prigogine's principle are discussed.

  5. Analysis of ramming settlement based on dissipative principle

    NASA Astrophysics Data System (ADS)

    Fu, Hao; Yu, Kaining; Chen, Changli; Li, Changrong; Wang, Xiuli

    2018-03-01

    The deformation of soil is a kind of dissipative structure under the action of dynamic compaction. The macroscopic performance of soil to steady state evolution is the change of ramming settlement in the process of dynamic compaction. based on the existing solution of dynamic compaction boundary problem, calculated ramming effectiveness (W) and ramming efficiency coefficient( η ). For the same soil, ramming efficiency coefficient is related to ramming factor λ = M/ρr3. By using the dissipative principle to analyze the law between ramming settlements and ramming times under different ramming energy and soil density, come to the conclusion that: Firstly, with the increase of ramming numbers, ramming settlement tends to a stable value, ramming effectiveness coefficient tends to a stable value. Secondly, under the condition of the same single ramming energy, the soil density of before ramming has effect on ramming effectiveness of previous ramming, almost no effect on ramming effectiveness of subsequent ramming. Thirdly, under the condition of the same soil density, different ramming energy correspond to different steady-state, the cumulative ramming settlement and steady-state increase with ramming energy.

  6. A review of selected pumping systems in nature and engineering--potential biomimetic concepts for improving displacement pumps and pulsation damping.

    PubMed

    Bach, D; Schmich, F; Masselter, T; Speck, T

    2015-09-03

    The active transport of fluids by pumps plays an essential role in engineering and biology. Due to increasing energy costs and environmental issues, topics like noise reduction, increase of efficiency and enhanced robustness are of high importance in the development of pumps in engineering. The study compares pumps in biology and engineering and assesses biomimetic potentials for improving man-made pumping systems. To this aim, examples of common challenges, applications and current biomimetic research for state-of-the art pumps are presented. The biomimetic research is helped by the similar configuration of many positive displacement pumping systems in biology and engineering. In contrast, the configuration and underlying pumping principles for fluid dynamic pumps (FDPs) differ to a greater extent in biology and engineering. However, progress has been made for positive displacement as well as for FDPs by developing biomimetic devices with artificial muscles and cilia that improve energetic efficiency and fail-safe operation or reduce noise. The circulatory system of vertebrates holds a high biomimetic potential for the damping of pressure pulsations, a common challenge in engineering. Damping of blood pressure pulsation results from a nonlinear viscoelastic behavior of the artery walls which represent a complex composite material. The transfer of the underlying functional principle could lead to an improvement of existing technical solutions and be used to develop novel biomimetic damping solutions. To enhance efficiency or thrust of man-made fluid transportation systems, research on jet propulsion in biology has shown that a pulsed jet can be tuned to either maximize thrust or efficiency. The underlying principle has already been transferred into biomimetic applications in open channel water systems. Overall there is a high potential to learn from nature in order to improve pumping systems for challenges like the reduction of pressure pulsations, increase of jet propulsion efficiency or the reduction of wear.

  7. Spaceborne receivers: Basic principles

    NASA Technical Reports Server (NTRS)

    Stacey, J. M.

    1984-01-01

    The underlying principles of operation of microwave receivers for space observations of planetary surfaces were examined. The design philosophy of the receiver as it is applied to operate functionally as an efficient receiving system, the principle of operation of the key components of the receiver, and the important differences among receiver types are explained. The operating performance and the sensitivity expectations for both the modulated and total power receiver configurations are outlined. The expressions are derived from first principles and are developed through the important intermediate stages to form practicle and easily applied equations. The transfer of thermodynamic energy from point to point within the receiver is illustrated. The language of microwave receivers is applied statistics.

  8. A new submarine oil-water separation system

    NASA Astrophysics Data System (ADS)

    Cai, Wen-Bin; Liu, Bo-Hong

    2017-12-01

    In order to solve the oil field losses of environmental problems and economic benefit caused by the separation of lifting production liquid to offshore platforms in the current offshore oil production, from the most basic separation principle, a new oil-water separation system has been processed of adsorption and desorption on related materials, achieving high efficiency and separation of oil and water phases. And the submarine oil-water separation device has been designed. The main structure of the device consists of gas-solid phase separation device, period separating device and adsorption device that completed high efficiency separation of oil, gas and water under the adsorption and desorption principle, and the processing capacity of the device is calculated.

  9. A Lens for Evaluating Genetic Information Governance Models: Balancing Equity, Efficiency and Sustainability.

    PubMed

    Skorve, Espen; Vassilakopoulou, Polyxeni; Aanestad, Margunn; Grünfeld, Thomas

    2017-01-01

    This paper draws from the literature on collective action and the governance of the commons to address the governance of genetic data on variants of specific genes. Specifically, the data arrangements under study relate to the BRCA genes (BRCA1 and BRCA2) which are linked to breast and ovarian cancer. These data are stored in global genetic data repositories and accessed by researchers and clinicians, from both public and private institutions. The current BRCA data arrangements are fragmented and politicized as there are multiple tensions around data ownership and sharing. Three key principles are proposed for forming and evaluating data governance arrangements in the field. These principles are: equity, efficiency and sustainability.

  10. Zipf's Law of Abbreviation and the Principle of Least Effort: Language users optimise a miniature lexicon for efficient communication.

    PubMed

    Kanwal, Jasmeen; Smith, Kenny; Culbertson, Jennifer; Kirby, Simon

    2017-08-01

    The linguist George Kingsley Zipf made a now classic observation about the relationship between a word's length and its frequency; the more frequent a word is, the shorter it tends to be. He claimed that this "Law of Abbreviation" is a universal structural property of language. The Law of Abbreviation has since been documented in a wide range of human languages, and extended to animal communication systems and even computer programming languages. Zipf hypothesised that this universal design feature arises as a result of individuals optimising form-meaning mappings under competing pressures to communicate accurately but also efficiently-his famous Principle of Least Effort. In this study, we use a miniature artificial language learning paradigm to provide direct experimental evidence for this explanatory hypothesis. We show that language users optimise form-meaning mappings only when pressures for accuracy and efficiency both operate during a communicative task, supporting Zipf's conjecture that the Principle of Least Effort can explain this universal feature of word length distributions. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Universal Expression of Efficiency at Maximum Power: A Quantum-Mechanical Brayton Engine Working with a Single Particle Confined in a Power-Law Trap

    NASA Astrophysics Data System (ADS)

    Ye, Zhuo-Lin; Li, Wei-Sheng; Lai, Yi-Ming; He, Ji-Zhou; Wang, Jian-Hui

    2015-12-01

    We propose a quantum-mechanical Brayton engine model that works between two superposed states, employing a single particle confined in an arbitrary power-law trap as the working substance. Applying the superposition principle, we obtain the explicit expressions of the power and efficiency, and find that the efficiency at maximum power is bounded from above by the function: η+ = θ/(θ + 1), with θ being a potential-dependent exponent. Supported by the National Natural Science Foundation of China under Grant Nos. 11505091, 11265010, and 11365015, and the Jiangxi Provincial Natural Science Foundation under Grant No. 20132BAB212009

  12. Recent Improvements To the Sieve of Eratosthenes.

    ERIC Educational Resources Information Center

    Quesada, Antonio R.

    1997-01-01

    Presents recently developed generalizations to the sieve of Eratosthenes, showing the principles underlying these improvements, which increase its efficiency without changing too much of its simplicity. Offers several possibilities to propose good investigations for students to explore, find patterns, and make generalizations. (JRH)

  13. Principles for the formation of an effective concept of multifunctional high-rise construction investment projects

    NASA Astrophysics Data System (ADS)

    Beliakov, Sergei

    2018-03-01

    Investment projects of high-rise construction have a number of features that determine specific risks and additional opportunities that require analysis and accounting in the formation of an effective project concept. The most significant features of high-rise construction include long construction time, complexity of technical and technological solutions, complexity of decisions on the organization of construction and operation, high cost of construction and operation, complexity in determining the ratio of areas designed to accommodate different functional areas, when organizing and coordinating the operation of the facility, with internal zoning. Taking into account the specificity of high-rise construction, among the factors determining the effectiveness of projects, it is advisable to consider as key factors: organizational, technological and investment factors. Within the framework of the article, the author singled out key particular functions for each group of factors under consideration, and also developed a system of principles for the formation of an effective concept of multifunctional high-rise construction investment projects, including the principle of logistic efficiency, the principle of optimal functional zoning, the principle of efficiency of equipment use, the principle of optimizing technological processes, the principle maximization of income, the principle of fund management, the principle of risk management . The model of formation of an effective concept of investment projects of multifunctional high-rise construction developed by the author can contribute to the development of methodological tools in the field of managing the implementation of high-rise construction projects, taking into account their specificity in the current economic conditions.

  14. The Design of Airplane-engine Superchargers

    NASA Technical Reports Server (NTRS)

    Von Der Null, Werner

    1937-01-01

    With the forms of superchargers and underlying principles of computation, delivery heads per stage of 7,000 to 8,500 meters (air column) at an effective efficiency, based on the adiabatic process, of 0.7 may be attained, the space and weight requirements being kept within reasonable limits.

  15. 20 CFR 627.435 - Cost principles and allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... PROVISIONS GOVERNING PROGRAMS UNDER TITLES I, II, AND III OF THE ACT Administrative Standards § 627.435 Cost... the proper and efficient administration of the program, be allocable to the program, and, except as... Governor or a governmental subrecipient. Costs charged to the program shall be accorded consistent...

  16. 20 CFR 627.435 - Cost principles and allowable costs.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... PROVISIONS GOVERNING PROGRAMS UNDER TITLES I, II, AND III OF THE ACT Administrative Standards § 627.435 Cost... the proper and efficient administration of the program, be allocable to the program, and, except as... Governor or a governmental subrecipient. Costs charged to the program shall be accorded consistent...

  17. Genomic selection in domestic animals: Principles, applications and perspectives.

    PubMed

    Boichard, Didier; Ducrocq, Vincent; Croiseau, Pascal; Fritz, Sébastien

    2016-01-01

    The principles of genomic selection are described, with the main factors affecting its efficiency and the assumptions underlying the different models proposed. The reasons of its fast adoption in dairy cattle are explained and the conditions of its application to other species are discussed. Perspectives of development include: selection for new traits and new breeding objectives; adoption of more robust approaches based on information on causal variants; predictions of genotype×environment interactions. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  18. Modeling recombination processes and predicting energy conversion efficiency of dye sensitized solar cells from first principles

    NASA Astrophysics Data System (ADS)

    Ma, Wei; Meng, Sheng

    2014-03-01

    We present a set of algorithms based on solo first principles calculations, to accurately calculate key properties of a DSC device including sunlight harvest, electron injection, electron-hole recombination, and open circuit voltages. Two series of D- π-A dyes are adopted as sample dyes. The short circuit current can be predicted by calculating the dyes' photo absorption, and the electron injection and recombination lifetime using real-time time-dependent density functional theory (TDDFT) simulations. Open circuit voltage can be reproduced by calculating energy difference between the quasi-Fermi level of electrons in the semiconductor and the electrolyte redox potential, considering the influence of electron recombination. Based on timescales obtained from real time TDDFT dynamics for excited states, the estimated power conversion efficiency of DSC fits nicely with the experiment, with deviation below 1-2%. Light harvesting efficiency, incident photon-to-electron conversion efficiency and the current-voltage characteristics can also be well reproduced. The predicted efficiency can serve as either an ideal limit for optimizing photovoltaic performance of a given dye, or a virtual device that closely mimicking the performance of a real device under different experimental settings.

  19. How to Compute a Slot Marker - Calculation of Controller Managed Spacing Tools for Efficient Descents with Precision Scheduling

    NASA Technical Reports Server (NTRS)

    Prevot, Thomas

    2012-01-01

    This paper describes the underlying principles and algorithms for computing the primary controller managed spacing (CMS) tools developed at NASA for precisely spacing aircraft along efficient descent paths. The trajectory-based CMS tools include slot markers, delay indications and speed advisories. These tools are one of three core NASA technologies integrated in NASAs ATM technology demonstration-1 (ATD-1) that will operationally demonstrate the feasibility of fuel-efficient, high throughput arrival operations using Automatic Dependent Surveillance Broadcast (ADS-B) and ground-based and airborne NASA technologies for precision scheduling and spacing.

  20. A laboratory facility for research on wind-driven rain intrusion in building envelope assemblies

    Treesearch

    Samuel V. Glass

    2010-01-01

    Moisture management is critical for durable, energy-efficient buildings. To address the need for research on wind-driven rain intrusion in wall assemblies, the U.S. Forest Products Laboratory is developing a new facility. This paper describes the underlying principle of this facility and its capabilities.

  1. System and Method for Obtaining Simultaneous Levitation and Rotation of a Ferromagnetic Object

    NASA Astrophysics Data System (ADS)

    Banerjee, Subrata; Sarkar, Mrinal Kanti; Ghosh, Arnab

    2017-02-01

    In this work a practical demonstration for simultaneous levitation and rotation for a ferromagnetic cylindrical object is presented. A hollow steel cylinder has been arranged to remain suspended stably under I-core electromagnet utilizing dc attraction type levitation principle and then arranged to rotate the levitated object around 1000 rpm speed based on eddy current based energy meter principle. Since the object is to be rotating during levitated condition the device will be frictionless, energy-efficient and robust. This technology may be applied to frictionless energy meter, wind turbine, machine tool applications, precision instruments and many other devices where easy energy-efficient stable rotation will be required. The cascade lead compensation control scheme has been applied for stabilization of unstable levitation system. The proposed device is successfully tested in the laboratory and experimental results have been produced.

  2. Applying human factors principles to alert design increases efficiency and reduces prescribing errors in a scenario-based simulation.

    PubMed

    Russ, Alissa L; Zillich, Alan J; Melton, Brittany L; Russell, Scott A; Chen, Siying; Spina, Jeffrey R; Weiner, Michael; Johnson, Elizabette G; Daggy, Joanne K; McManus, M Sue; Hawsey, Jason M; Puleo, Anthony G; Doebbeling, Bradley N; Saleem, Jason J

    2014-10-01

    To apply human factors engineering principles to improve alert interface design. We hypothesized that incorporating human factors principles into alerts would improve usability, reduce workload for prescribers, and reduce prescribing errors. We performed a scenario-based simulation study using a counterbalanced, crossover design with 20 Veterans Affairs prescribers to compare original versus redesigned alerts. We redesigned drug-allergy, drug-drug interaction, and drug-disease alerts based upon human factors principles. We assessed usability (learnability of redesign, efficiency, satisfaction, and usability errors), perceived workload, and prescribing errors. Although prescribers received no training on the design changes, prescribers were able to resolve redesigned alerts more efficiently (median (IQR): 56 (47) s) compared to the original alerts (85 (71) s; p=0.015). In addition, prescribers rated redesigned alerts significantly higher than original alerts across several dimensions of satisfaction. Redesigned alerts led to a modest but significant reduction in workload (p=0.042) and significantly reduced the number of prescribing errors per prescriber (median (range): 2 (1-5) compared to original alerts: 4 (1-7); p=0.024). Aspects of the redesigned alerts that likely contributed to better prescribing include design modifications that reduced usability-related errors, providing clinical data closer to the point of decision, and displaying alert text in a tabular format. Displaying alert text in a tabular format may help prescribers extract information quickly and thereby increase responsiveness to alerts. This simulation study provides evidence that applying human factors design principles to medication alerts can improve usability and prescribing outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Modeling the allocation system: principles for robust design before restructuring.

    PubMed

    Mehrotra, Sanjay; Kilambi, Vikram; Gilroy, Richard; Ladner, Daniela P; Klintmalm, Goran B; Kaplan, Bruce

    2015-02-01

    The United Network for Organ Sharing is poised to resolve geographic disparity in liver transplantation and promote allocation based on medical urgency. At the time of writing, United Network for Organ Sharing is considering redistricting the organ procurement and transplantation network so that patient model for end-stage liver disease scores at transplant is more uniform across regions.We review the proposal with a systems-engineering focus and find that although the proposal is promising, it currently lacks evidence that it would perform effectively under realistic departures from its underlying data and assumptions. Moreover, we caution against prematurely focusing on redistricting as the only method to mitigate disparity. We describe system modeling principles which, if followed, will ensure that the redesigned allocation system is effective and efficient in achieving the intended goals.

  4. Rational, computer-enabled peptide drug design: principles, methods, applications and future directions.

    PubMed

    Diller, David J; Swanson, Jon; Bayden, Alexander S; Jarosinski, Mark; Audie, Joseph

    2015-01-01

    Peptides provide promising templates for developing drugs to occupy a middle space between small molecules and antibodies and for targeting 'undruggable' intracellular protein-protein interactions. Importantly, rational or in cerebro design, especially when coupled with validated in silico tools, can be used to efficiently explore chemical space and identify islands of 'drug-like' peptides to satisfy diverse drug discovery program objectives. Here, we consider the underlying principles of and recent advances in rational, computer-enabled peptide drug design. In particular, we consider the impact of basic physicochemical properties, potency and ADME/Tox opportunities and challenges, and recently developed computational tools for enabling rational peptide drug design. Key principles and practices are spotlighted by recent case studies. We close with a hypothetical future case study.

  5. A combined thermal dissociation and electron impact ionization source for RIB generation

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

    Alton, G.D.; Williams, C.

    1995-12-31

    The probability for simultaneously dissociating and efficiently ionizing the individual atomic constituents of molecular feed materials with conventional, hot-cathode, electron-impact ion sources is low and consequently, the ion beams from these sources often appear as mixtures of several molecular sideband beams. This fragmentation process leads to dilution of the intensity of the species of interest for RIB applications where beam intensity is at a premium. We have conceived an ion source that combines the excellent molecular dissociation properties of a thermal dissociator and the high ionization efficiency characteristics of an electron impact ionization source that will, in principle, overcome thismore » handicap. The source concept will be evaluated as a potential candidate for use for RIB generation at the Holifield Radioactive Ion Beam Facility (HRIBF), now under construction at the Oak Ridge National Laboratory. The design features and principles of operation of the source are described in this article.« less

  6. Scientometrics: Nature Index and Brazilian science.

    PubMed

    Silva, Valter

    2016-09-01

    A recent published newspaper article commented on the (lack of) quality of Brazilian science and its (in) efficiency. The newspaper article was based on a special issue of Nature and on a new resource for scientometrics called Nature Index. I show here arguments and sources of bias that, under the light of the principle in dubio pro reo, it is questionable to dispute the quality and efficiency of the Brazilian science on these grounds, as it was commented on the referred article. A brief overview of Brazilian science is provided for readers to make their own judgment.

  7. Direct Observation of the Biaxial Stress Effect on Efficiency Droop in GaN-based Light-emitting Diode under Electrical Injection.

    PubMed

    Zheng, Jinjian; Li, Shuiqing; Chou, Chilun; Lin, Wei; Xun, Feilin; Guo, Fei; Zheng, Tongchang; Li, Shuping; Kang, Junyong

    2015-12-04

    Light-emitting diode (LED) efficiency has attracted considerable interest because of the extended use of solid-state lighting. Owing to lack of direct measurement, identification of the reasons for efficiency droop has been restricted. A direct measurement technique is developed in this work for characterization of biaxial stress in GaN-based blue LEDs under electrical injection. The Raman shift of the GaN E2 mode evidently decreases by 4.4 cm(-1) as the driving current on GaN-based LEDs increases to 700 mA. Biaxial compressive stress is released initially and biaxial tensile stress builds up as the current increases with respect to the value of stress-free GaN. First-principles calculations reveal that electron accumulation is responsible for the stress variation in InxGa1-xN/GaN quantum wells, and then reduces the transition probability among quantum levels. This behavior is consistent with the measured current-dependent external quantum efficiency. The rule of biaxial stress-dependent efficiency is further validated by controlling the biaxial stress of GaN-based LEDs with different sapphire substrate thicknesses. This work provides a method for direct observation of the biaxial stress effect on efficiency droop in LEDs under electrical injection.

  8. Direct Observation of the Biaxial Stress Effect on Efficiency Droop in GaN-based Light-emitting Diode under Electrical Injection

    PubMed Central

    Zheng, Jinjian; Li, Shuiqing; Chou, Chilun; Lin, Wei; Xun, Feilin; Guo, Fei; Zheng, Tongchang; Li, Shuping; Kang, Junyong

    2015-01-01

    Light-emitting diode (LED) efficiency has attracted considerable interest because of the extended use of solid-state lighting. Owing to lack of direct measurement, identification of the reasons for efficiency droop has been restricted. A direct measurement technique is developed in this work for characterization of biaxial stress in GaN-based blue LEDs under electrical injection. The Raman shift of the GaN E2 mode evidently decreases by 4.4 cm−1 as the driving current on GaN-based LEDs increases to 700 mA. Biaxial compressive stress is released initially and biaxial tensile stress builds up as the current increases with respect to the value of stress-free GaN. First-principles calculations reveal that electron accumulation is responsible for the stress variation in InxGa1−xN/GaN quantum wells, and then reduces the transition probability among quantum levels. This behavior is consistent with the measured current-dependent external quantum efficiency. The rule of biaxial stress-dependent efficiency is further validated by controlling the biaxial stress of GaN-based LEDs with different sapphire substrate thicknesses. This work provides a method for direct observation of the biaxial stress effect on efficiency droop in LEDs under electrical injection. PMID:26634816

  9. 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.

  10. Predicting the electronic properties of aqueous solutions from first-principles

    NASA Astrophysics Data System (ADS)

    Schwegler, Eric; Pham, Tuan Anh; Govoni, Marco; Seidel, Robert; Bradforth, Stephen; Galli, Giulia

    Predicting the electronic properties of aqueous liquids has been a long-standing challenge for quantum-mechanical methods. Yet it is a crucial step in understanding and predicting the key role played by aqueous solutions and electrolytes in a wide variety of emerging energy and environmental technologies, including battery and photoelectrochemical cell design. Here we propose an efficient and accurate approach to predict the electronic properties of aqueous solutions, based on the combination of first-principles methods and experimental validation using state-of-the-art spectroscopic measurements. We present results for the photoelectron spectra of a broad range of solvated ions, showing that first-principles molecular dynamics simulations and electronic structure calculations using dielectric hybrid functionals provide a quantitative description of their electronic properties, including excitation energies, of the solvent and solutes. The proposed computational framework is general and applicable to other liquids, thereby offering great promise in understanding and engineering solutions and liquid electrolytes for a variety of important energy technologies. Part of this work was performed under the auspices of the U.S. Department of Energy at LLNL under Contract DE-AC52-07A27344.

  11. Analysis of electric power industry restructuring

    NASA Astrophysics Data System (ADS)

    Al-Agtash, Salem Yahya

    1998-10-01

    This thesis evaluates alternative structures of the electric power industry in a competitive environment. One structure is based on the principle of creating a mandatory power pool to foster competition and manage system economics. The structure is PoolCo (pool coordination). A second structure is based on the principle of allowing independent multilateral trading and decentralized market coordination. The structure is DecCo (decentralized coordination). The criteria I use to evaluate these two structures are: economic efficiency, system reliability and freedom of choice. Economic efficiency evaluation considers strategic behavior of individual generators as well as behavioral variations of different classes of consumers. A supply-function equilibria model is characterized for deriving bidding strategies of competing generators under PoolCo. It is shown that asymmetric equilibria can exist within the capacities of generators. An augmented Lagrangian approach is introduced to solve iteratively for global optimal operations schedules. Under DecCo, the process involves solving iteratively for system operations schedules. The schedules reflect generators strategic behavior and brokers' interactions for arranging profitable trades, allocating losses and managing network congestion. In the determination of PoolCo and DecCo operations schedules, overall costs of power generation (start-up and shut-down costs and availability of hydro electric power) as well as losses and costs of transmission network are considered. For system reliability evaluation, I examine the effect of PoolCo and DecCo operating conditions on the system security. Random component failure perturbations are generated to simulate the actual system behavior. This is done using Monte Carlo simulation. Freedom of choice evaluation accounts for schemes' beneficial opportunities and capabilities to respond to consumers expressed preferences. An IEEE 24-bus test system is used to illustrate the concepts developed for economic efficiency evaluation. The system was tested over two years time period. The results indicate 2.6684 and 2.7269 percent of efficiency loss on average for PoolCo and DecCo, respectively. These values, however, do not represent forecasts of efficiency losses of PoolCo- and DecCo-based competitive industries. Rather, they are illustrations of the efficiency losses for the given IEEE test system and based on the modeling assumptions underlying framework development.

  12. Metrological Support in Technosphere Safety

    NASA Astrophysics Data System (ADS)

    Akhobadze, G. N.

    2017-11-01

    The principle of metrological support in technosphere safety is considered. It is based on the practical metrology. The theoretical aspects of accuracy and errors of the measuring instruments intended for diagnostics and control of the technosphere under the influence of factors harmful to human beings are presented. The necessity to choose measuring devices with high metrological characteristics according to the accuracy class and contact of sensitive elements with a medium under control is shown. The types of additional errors in measuring instruments that arise when they are affected by environmental influences are described. A specific example of the analyzers application to control industrial emissions and measure the oil and particulate matter in wastewater is shown; it allows assessing advantages and disadvantages of analyzers. Besides, the recommendations regarding the missing metrological characteristics of the instruments in use are provided. The technosphere continuous monitoring taking into account the metrological principles is expected to efficiently forecast the technosphere development and make appropriate decisions.

  13. Asset Management: Roof Maintenance and Facility Energy Retrofits

    DTIC Science & Technology

    2012-03-01

    vapor low emission coatings. Floor finishes completed in ceramic stone tile were the most efficient floor coverings. Fixed insulated fiberglass window...been coined Asset Management which utilizes organizational levels of service, business case analysis, and risk analysis to address urgent...Force have left a number of facility systems such as roofs at risk to disrepair due to a lack of maintenance. Under the principles of asset

  14. [Evaluation of the efficiency of preventive medical examinations of railway transport workers].

    PubMed

    Pankova, V B; Golysheva, G V; Khvastunov, R M; Makarov, A A

    2006-01-01

    The paper reflects the priority role of preliminary and periodic medical examinations in the system of measures implemented by therapeutic-and-prophylactic institutions of the Ministry of Railway of Russia. It gives a comprehensive assessment of the medical, social, and economic aspects of the efficiency of preventive medical examinations. Emphasis is laid on the necessity of elaborating methods to evaluate the economic efficiency of medical measures under the conditions of market economy. At the same time, light is shed on the difficulties available when a full-scale, within the whole industry, economic evaluation of periodic medical examinations is made. The role of a cost-effect analysis is shown as the most flexible existing principle in the evaluation of the efficiency of medical preventive measures.

  15. Bypassing the malfunction junction in warm dense matter simulations

    NASA Astrophysics Data System (ADS)

    Cangi, Attila; Pribram-Jones, Aurora

    2015-03-01

    Simulation of warm dense matter requires computational methods that capture both quantum and classical behavior efficiently under high-temperature and high-density conditions. The state-of-the-art approach to model electrons and ions under those conditions is density functional theory molecular dynamics, but this method's computational cost skyrockets as temperatures and densities increase. We propose finite-temperature potential functional theory as an in-principle-exact alternative that suffers no such drawback. In analogy to the zero-temperature theory developed previously, we derive an orbital-free free energy approximation through a coupling-constant formalism. Our density approximation and its associated free energy approximation demonstrate the method's accuracy and efficiency. A.C. has been partially supported by NSF Grant CHE-1112442. A.P.J. is supported by DOE Grant DE-FG02-97ER25308.

  16. Essential chemistry for biochemists

    PubMed Central

    Jonsson, Amanda L.; Roberts, Mark A.J.; Kiappes, J.L.; Scott, Kathryn A.

    2017-01-01

    Within every living organism, countless reactions occur every second. These reactions typically occur more rapidly and with greater efficiency than would be possible under the same conditions in the chemical laboratory, and while using only the subset of elements that are readily available in nature. Despite these apparent differences between life and the laboratory, biological reactions are governed by the same rules as any other chemical reaction. Thus, a firm understanding of the fundamentals of chemistry is invaluable in biochemistry. There are entire textbooks devoted to the application of chemical principles in biological systems and so it is not possible to cover all of the relevant topics in depth in this short article. The aim is instead to provide a brief overview of those areas in chemistry that are most relevant to biochemistry. We summarize the basic principles, give examples of how these principles are applied in biological systems and suggest further reading on individual topics. PMID:28951470

  17. Safe use of cellular telephones in hospitals: fundamental principles and case studies.

    PubMed

    Cohen, Ted; Ellis, Willard S; Morrissey, Joseph J; Bakuzonis, Craig; David, Yadin; Paperman, W David

    2005-01-01

    Many industries and individuals have embraced cellular telephones. They provide mobile, synchronous communication, which could hypothetically increase the efficiency and safety of inpatient healthcare. However, reports of early analog cellular telephones interfering with critical life-support machines had led many hospitals to strictly prohibit cellular telephones. A literature search revealed that individual hospitals now are allowing cellular telephone use with various policies to prevent electromagnetic interference with medical devices. The fundamental principles underlying electromagnetic interference are immunity, frequency, modulation technology, distance, and power Electromagnetic interference risk mitigation methods based on these principles have been successfully implemented. In one case study, a minimum distance between cellular telephones and medical devices is maintained, with restrictions in critical areas. In another case study, cellular telephone coverage is augmented to automatically control the power of the cellular telephone. While no uniform safety standard yet exists, cellular telephones can be safely used in hospitals when their use is managed carefully.

  18. Quantitative (13)C Solid-State NMR Spectra by Multiple-Contact Cross-polarization for Drug Delivery: From Active Principles to Excipients and Drug Carriers.

    PubMed

    Saïdi, Fadila; Taulelle, Francis; Martineau, Charlotte

    2016-08-01

    In this contribution, we present an analysis of the main parameters influencing the efficiency of the (1)H → (13)C multiple-contact cross-polarization nuclear magnetic resonance (NMR) experiment in the context of solid pharmaceutical materials. Using the optimum experimental conditions, quantitative (13)C NMR spectra are then obtained for porous metal-organic frameworks (potential drug carriers) and for components present in drug formulations (active principle ingredient and excipients, amorphous or crystalline). Finally, we show that mixtures of components can also be quantified with this method and, hence, that it represents an ideal tool for quantification of pharmaceutical formulations by (13)C cross-polarization under magic-angle spinning NMR in the industry as it is robust and easy to set up, much faster than direct (13)C polarization and is efficient for samples at natural abundance. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  19. A combined thermal dissociation and electron impact ionization source for radioactive ion beam generation{sup a}

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

    Alton, G.D.; Williams, C.

    1996-04-01

    The probability for simultaneously dissociating and efficiently ionizing the individual atomic constituents of molecular feed materials with conventional, hot-cathode, electron-impact ion sources is low and consequently, the ion beams from these sources often appear as mixtures of several molecular sideband beams. This fragmentation process leads to dilution of the intensity of the species of interest for radioactive ion beam (RIB) applications where beam intensity is at a premium. We have conceived an ion source that combines the excellent molecular dissociation properties of a thermal dissociator and the high ionization efficiency characteristics of an electron impact ionization source that will, inmore » principle, overcome this handicap. The source concept will be evaluated as a potential candidate for use for RIB generation at the Holifield Radioactive Ion Beam Facility, now under construction at the Oak Ridge National Laboratory. The design features and principles of operation of the source are described in this article. {copyright} {ital 1996 American Institute of Physics.}« less

  20. A combined thermal dissociation and electron impact ionization source for radioactive ion beam generation (abstract){sup a}

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

    Alton, G.D.; Williams, C.

    1996-03-01

    The probability for simultaneously dissociating and efficiently ionizing the individual atomic constituents of molecular feed materials with conventional, hot-cathode, electron-impact ion sources is low and consequently, the ion beams from these sources often appear as mixtures of several molecular sideband beams. This fragmentation process leads to dilution of the intensity of the species of interest for radioactive ion beam (RIB) applications where beam intensity is at a premium. We have conceived an ion source that combines the excellent molecular dissociation properties of a thermal dissociator and the high ionization efficiency characteristics of an electron impact ionization source that will, inmore » principle, overcome this handicap. The source concept will be evaluated as a potential candidate for use for RIB generation at the Holifield Radioactive Ion Beam Facility, now under construction at the Oak Ridge National Laboratory. The design features and principles of operation of the source are described in this article. {copyright} {ital 1996 American Institute of Physics.}« less

  1. New silicon cell design concepts for 20 percent AMI efficiency

    NASA Technical Reports Server (NTRS)

    Wolf, M.

    1982-01-01

    The basic design principles for obtaining high efficiency in silicon solar cells are reviewed. They critically involve very long minority carrier lifetimes, not so much to attain high collection efficiency, but primarily for increased output voltages. Minority carrier lifetime, however, is sensitive to radiation damage, and particularly in low resistivity silicon, on which the high efficiency design is based. Radiation resistant space cells will therefore have to follow differing design principles than high efficiency terrestrial cells.

  2. Modulation/demodulation techniques for satellite communications. Part 2: Advanced techniques. The linear channel

    NASA Technical Reports Server (NTRS)

    Omura, J. K.; Simon, M. K.

    1982-01-01

    A theory is presented for deducing and predicting the performance of transmitter/receivers for bandwidth efficient modulations suitable for use on the linear satellite channel. The underlying principle used is the development of receiver structures based on the maximum-likelihood decision rule. The application of the performance prediction tools, e.g., channel cutoff rate and bit error probability transfer function bounds to these modulation/demodulation techniques.

  3. A quantitative description for efficient financial markets

    NASA Astrophysics Data System (ADS)

    Immonen, Eero

    2015-09-01

    In this article we develop a control system model for describing efficient financial markets. We define the efficiency of a financial market in quantitative terms by robust asymptotic price-value equality in this model. By invoking the Internal Model Principle of robust output regulation theory we then show that under No Bubble Conditions, in the proposed model, the market is efficient if and only if the following conditions hold true: (1) the traders, as a group, can identify any mispricing in asset value (even if no one single trader can do it accurately), and (2) the traders, as a group, incorporate an internal model of the value process (again, even if no one single trader knows it). This main result of the article, which deliberately avoids the requirement for investor rationality, demonstrates, in quantitative terms, that the more transparent the markets are, the more efficient they are. An extensive example is provided to illustrate the theoretical development.

  4. Thermodynamic framework to assess low abundance DNA mutation detection by hybridization.

    PubMed

    Willems, Hanny; Jacobs, An; Hadiwikarta, Wahyu Wijaya; Venken, Tom; Valkenborg, Dirk; Van Roy, Nadine; Vandesompele, Jo; Hooyberghs, Jef

    2017-01-01

    The knowledge of genomic DNA variations in patient samples has a high and increasing value for human diagnostics in its broadest sense. Although many methods and sensors to detect or quantify these variations are available or under development, the number of underlying physico-chemical detection principles is limited. One of these principles is the hybridization of sample target DNA versus nucleic acid probes. We introduce a novel thermodynamics approach and develop a framework to exploit the specific detection capabilities of nucleic acid hybridization, using generic principles applicable to any platform. As a case study, we detect point mutations in the KRAS oncogene on a microarray platform. For the given platform and hybridization conditions, we demonstrate the multiplex detection capability of hybridization and assess the detection limit using thermodynamic considerations; DNA containing point mutations in a background of wild type sequences can be identified down to at least 1% relative concentration. In order to show the clinical relevance, the detection capabilities are confirmed on challenging formalin-fixed paraffin-embedded clinical tumor samples. This enzyme-free detection framework contains the accuracy and efficiency to screen for hundreds of mutations in a single run with many potential applications in molecular diagnostics and the field of personalised medicine.

  5. An accurate and efficient method for piezoelectric coated functional devices based on the two-dimensional Green’s function for a normal line force and line charge

    NASA Astrophysics Data System (ADS)

    Hou, Peng-Fei; Zhang, Yang

    2017-09-01

    Because most piezoelectric functional devices, including sensors, actuators and energy harvesters, are in the form of a piezoelectric coated structure, it is valuable to present an accurate and efficient method for obtaining the electro-mechanical coupling fields of this coated structure under mechanical and electrical loads. With this aim, the two-dimensional Green’s function for a normal line force and line charge on the surface of coated structure, which is a combination of an orthotropic piezoelectric coating and orthotropic elastic substrate, is presented in the form of elementary functions based on the general solution method. The corresponding electro-mechanical coupling fields of this coated structure under arbitrary mechanical and electrical loads can then be obtained by the superposition principle and Gauss integration. Numerical results show that the presented method has high computational precision, efficiency and stability. It can be used to design the best coating thickness in functional devices, improve the sensitivity of sensors, and improve the efficiency of actuators and energy harvesters. This method could be an efficient tool for engineers in engineering applications.

  6. The Efficiency Challenge: Creating a Transformative Learning Experience in a Principles of Management Course

    ERIC Educational Resources Information Center

    Durant, Rita A.; Carlon, Donna M.; Downs, Alexis

    2017-01-01

    This article describes the results of the "Efficiency Challenge," a 10-week, Principles of Management course activity that uses reflection and goal setting to help students understand the concept of operational efficiency. With transformative learning theory as a lens, we base our report on 4 years' worth of student reflections regarding…

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

    Hourdequin, Marion, E-mail: Marion.Hourdequin@ColoradoCollege.edu; Department of Philosophy, Colorado College, 14 E. Cache La Poudre St., Colorado Springs, CO 80903; Landres, Peter

    Traditional mechanisms for public participation in environmental impact assessment under U.S. federal law have been criticized as ineffective and unable to resolve conflict. As these mechanisms are modified and new approaches developed, we argue that participation should be designed and evaluated not only on practical grounds of cost-effectiveness and efficiency, but also on ethical grounds based on democratic ideals. In this paper, we review and synthesize modern democratic theory to develop and justify four ethical principles for public participation: equal opportunity to participate, equal access to information, genuine deliberation, and shared commitment. We then explore several tensions that are inherentmore » in applying these ethical principles to public participation in EIA. We next examine traditional NEPA processes and newer collaborative approaches in light of these principles. Finally, we explore the circumstances that argue for more in-depth participatory processes. While improved EIA participatory processes do not guarantee improved outcomes in environmental management, processes informed by these four ethical principles derived from democratic theory may lead to increased public engagement and satisfaction with government agency decisions. - Highlights: Black-Right-Pointing-Pointer Four ethical principles based on democratic theory for public participation in EIA. Black-Right-Pointing-Pointer NEPA and collaboration offer different strengths in meeting these principles. Black-Right-Pointing-Pointer We explore tensions inherent in applying these principles. Black-Right-Pointing-Pointer Improved participatory processes may improve public acceptance of agency decisions.« less

  8. Caustic Singularities Of High-Gain, Dual-Shaped Reflectors

    NASA Technical Reports Server (NTRS)

    Galindo, Victor; Veruttipong, Thavath W.; Imbriale, William A.; Rengarajan, Sambiam

    1991-01-01

    Report presents study of some sources of error in analysis, by geometric theory of diffraction (GTD), of performance of high-gain, dual-shaped antenna reflector. Study probes into underlying analytic causes of singularity, with view toward devising and testing practical methods to avoid problems caused by singularity. Hybrid physical optics (PO) approach used to study near-field spillover or noise-temperature characteristics of high-gain relector antenna efficiently and accurately. Report illustrates this approach and underlying principles by presenting numerical results, for both offset and symmetrical reflector systems, computed by GTD, PO, and PO/GO methods.

  9. Conversion efficiency limits and bandgap designs for multi-junction solar cells with internal radiative efficiencies below unity.

    PubMed

    Zhu, Lin; Mochizuki, Toshimitsu; Yoshita, Masahiro; Chen, Shaoqiang; Kim, Changsu; Akiyama, Hidefumi; Kanemitsu, Yoshihiko

    2016-05-16

    We calculated the conversion-efficiency limit ηsc and the optimized subcell bandgap energies of 1 to 5 junction solar cells without and with intermediate reflectors under 1-sun AM1.5G and 1000-sun AM1.5D irradiations, particularly including the impact of internal radiative efficiency (ηint) below unity for realistic subcell materials on the basis of an extended detailed-balance theory. We found that the conversion-efficiency limit ηsc significantly drops when the geometric mean ηint* of all subcell ηint in the stack reduces from 1 to 0.1, and that ηsc degrades linearly to logηint* for ηint* below 0.1. For ηint*<0.1 differences in ηsc due to additional intermediate reflectors became very small if all subcells are optically thick for sun light. We obtained characteristic optimized bandgap energies, which reflect both ηint* decrease and AM1.5 spectral gaps. These results provide realistic efficiency targets and design principles.

  10. 47 CFR 36.2 - Fundamental principles underlying procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Fundamental principles underlying procedures... Fundamental principles underlying procedures. (a) The following general principles underlie the procedures... operating forces on a unit basis (e.g., conversation-minute-kilometers per message, weighted standard work...

  11. Disorder-assisted quantum transport in suboptimal decoherence regimes

    PubMed Central

    Novo, Leonardo; Mohseni, Masoud; Omar, Yasser

    2016-01-01

    We investigate quantum transport in binary tree structures and in hypercubes for the disordered Frenkel-exciton Hamiltonian under pure dephasing noise. We compute the energy transport efficiency as a function of disorder and dephasing rates. We demonstrate that dephasing improves transport efficiency not only in the disordered case, but also in the ordered one. The maximal transport efficiency is obtained when the dephasing timescale matches the hopping timescale, which represent new examples of the Goldilocks principle at the quantum scale. Remarkably, we find that in weak dephasing regimes, away from optimal levels of environmental fluctuations, the average effect of increasing disorder is to improve the transport efficiency until an optimal value for disorder is reached. Our results suggest that rational design of the site energies statistical distributions could lead to better performances in transport systems at nanoscale when their natural environments are far from the optimal dephasing regime. PMID:26726133

  12. An evolutionarily conserved RNase-based mechanism for repression of transcriptional positive autoregulation

    PubMed Central

    Wurtmann, Elisabeth J.; Ratushny, Alexander V.; Pan, Min; Beer, Karlyn D.; Aitchison, John D.; Baliga, Nitin S.

    2014-01-01

    Summary It is known that environmental context influences the degree of regulation at the transcriptional and post-transcriptional levels. However, the principles governing the differential usage and interplay of regulation at these two levels are not clear. Here, we show that the integration of transcriptional and post-transcriptional regulatory mechanisms in a characteristic network motif drives efficient environment-dependent state transitions. Through phenotypic screening, systems analysis, and rigorous experimental validation, we discovered an RNase (VNG2099C) in Halobacterium salinarum that is transcriptionally co-regulated with genes of the aerobic physiologic state but acts on transcripts of the anaerobic state. Through modeling and experimentation we show that this arrangement generates an efficient state-transition switch, within which RNase-repression of a transcriptional positive autoregulation (RPAR) loop is critical for shutting down ATP-consuming active potassium uptake to reserve energy required for salinity adaptation under aerobic, high potassium, or dark conditions. Subsequently, we discovered that many Escherichia coli operons with energy-associated functions are also putatively controlled by RPAR indicating that this network motif may have evolved independently in phylogenetically distant organisms. Thus, our data suggest that interplay of transcriptional and post-transcriptional regulation in the RPAR motifis a generalized principle for efficient environment-dependent state transitions across prokaryotes. PMID:24612392

  13. New insights into designing metallacarborane based room temperature hydrogen storage media.

    PubMed

    Bora, Pankaj Lochan; Singh, Abhishek K

    2013-10-28

    Metallacarboranes are promising towards realizing room temperature hydrogen storage media because of the presence of both transition metal and carbon atoms. In metallacarborane clusters, the transition metal adsorbs hydrogen molecules and carbon can link these clusters to form metal organic framework, which can serve as a complete storage medium. Using first principles density functional calculations, we chalk out the underlying principles of designing an efficient metallacarborane based hydrogen storage media. The storage capacity of hydrogen depends upon the number of available transition metal d-orbitals, number of carbons, and dopant atoms in the cluster. These factors control the amount of charge transfer from metal to the cluster, thereby affecting the number of adsorbed hydrogen molecules. This correlation between the charge transfer and storage capacity is general in nature, and can be applied to designing efficient hydrogen storage systems. Following this strategy, a search for the best metallacarborane was carried out in which Sc based monocarborane was found to be the most promising H2 sorbent material with a 9 wt.% of reversible storage at ambient pressure and temperature.

  14. Heat and moisture exchangers and breathing system filters: their use in anaesthesia and intensive care. Part 1 - history, principles and efficiency.

    PubMed

    Wilkes, A R

    2011-01-01

    Heat and moisture exchangers and breathing system filters are intended to replace the normal warming, humidifying and filtering functions of the upper airways when these structures are bypassed during anaesthesia and intensive care. Guidance on their use continues to evolve. The aim of this part of the review is to describe the principles of their action and efficiency and to summarise the findings from clinical and laboratory studies. Based on previous studies, an appropriate minimum target for moisture output is 30 and 20 g.m⁻³ for long-duration use in intensive care and short-duration use in anaesthesia, respectively. The practice of reusing a breathing system in anaesthesia, provided it is protected by a filter, assumes that the filter is effective. However, there is wide variation in the gas-borne filtration performance, and contaminated condensate can potentially pass through some filters under typical pressures encountered during mechanical ventilation. © 2010 The Author. Anaesthesia © 2010 The Association of Anaesthetists of Great Britain and Ireland.

  15. New insights into designing metallacarborane based room temperature hydrogen storage media

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

    Bora, Pankaj Lochan; Singh, Abhishek K.

    Metallacarboranes are promising towards realizing room temperature hydrogen storage media because of the presence of both transition metal and carbon atoms. In metallacarborane clusters, the transition metal adsorbs hydrogen molecules and carbon can link these clusters to form metal organic framework, which can serve as a complete storage medium. Using first principles density functional calculations, we chalk out the underlying principles of designing an efficient metallacarborane based hydrogen storage media. The storage capacity of hydrogen depends upon the number of available transition metal d-orbitals, number of carbons, and dopant atoms in the cluster. These factors control the amount of chargemore » transfer from metal to the cluster, thereby affecting the number of adsorbed hydrogen molecules. This correlation between the charge transfer and storage capacity is general in nature, and can be applied to designing efficient hydrogen storage systems. Following this strategy, a search for the best metallacarborane was carried out in which Sc based monocarborane was found to be the most promising H{sub 2} sorbent material with a 9 wt.% of reversible storage at ambient pressure and temperature.« less

  16. Radiative Cooling: Principles, Progress, and Potentials

    PubMed Central

    Hossain, Md. Muntasir

    2016-01-01

    The recent progress on radiative cooling reveals its potential for applications in highly efficient passive cooling. This approach utilizes the maximized emission of infrared thermal radiation through the atmospheric window for releasing heat and minimized absorption of incoming atmospheric radiation. These simultaneous processes can lead to a device temperature substantially below the ambient temperature. Although the application of radiative cooling for nighttime cooling was demonstrated a few decades ago, significant cooling under direct sunlight has been achieved only recently, indicating its potential as a practical passive cooler during the day. In this article, the basic principles of radiative cooling and its performance characteristics for nonradiative contributions, solar radiation, and atmospheric conditions are discussed. The recent advancements over the traditional approaches and their material and structural characteristics are outlined. The key characteristics of the thermal radiators and solar reflectors of the current state‐of‐the‐art radiative coolers are evaluated and their benchmarks are remarked for the peak cooling ability. The scopes for further improvements on radiative cooling efficiency for optimized device characteristics are also theoretically estimated. PMID:27812478

  17. A linearly-polarized Nd:YVO4/KTP microchip green laser.

    PubMed

    Jung, C; Yu, B-A; Kim, I-S; Lee, Y L; Yu, N E; Ko, D-K

    2009-10-26

    We described the principle and the fabrication of a Nd:YVO(4)/KTP microchip for the linearly-polarized green laser and verified its availability by manufacturing and characterizing the green laser using the microchip. Under the driving condition having the modulation frequency of 60 Hz and the duty ratio of 25%, the laser showed the stable linear polarization, the maximum average power of 37 mW, yielding the high electrical-to-optical efficiency of 10.9%.

  18. Understanding the Fundamental Principles Underlying the Survival and Efficient Recovery of Multi-Scale Techno-Social Networks Following a WMD Event (A)

    DTIC Science & Technology

    2016-07-01

    Influenza H1N1 modeling working group meeting, European Center for Disease Control ECDC, Stockholm, 19 October 2010 (A.Vespignani, Panelist). We...dynamics and assessing non -pharmaceutical control interventions. METHODS: We modelled the movements of individuals, including patients not infected with...classification of urban areas according to quantitative risk assessment metrics of secondary E-WMD threats. 2. Optimal mobility control strategies informed by

  19. First-principles study on leakage current caused by oxygen vacancies at HfO2/SiO2/Si interface

    NASA Astrophysics Data System (ADS)

    Takagi, Kensuke; Ono, Tomoya

    2018-06-01

    The relationship between the position of oxygen vacancies in HfO2/SiO2/Si gate stacks and the leakage current is studied by first-principles electronic-structure and electron-conduction calculations. We find that the increase in the leakage current due to the creation of oxygen vacancies in the HfO2 layer is much larger than that in the SiO2 interlayer. According to previous first-principles total energy calculations, the formation energy of oxygen vacancies is smaller in the SiO2 interlayer than that in the HfO2 layer under the same conditions. Therefore, oxygen vacancies will be attracted from the SiO2 interlayer to minimize the energy, thermodynamically justifying the scavenging technique. Thus, the scavenging process efficiently improves the dielectric constant of HfO2-based gate stacks without increasing the number of oxygen vacancies, which cause the dielectric breakdown.

  20. Between Efficiency, Capability and Recognition: Competing Epistemes in Global Governance Reforms

    ERIC Educational Resources Information Center

    Chan, Jennifer

    2007-01-01

    This article examines global governance reforms as a site of contestation between three different "truths"/epistemes (the market, human rights principles, and cultural identity) in terms of the competing principles of efficiency, capability, and recognition. Nancy Fraser's conceptions of participation parity and a dialogical approach of…

  1. A Market Failure Approach to Linguistic Justice

    ERIC Educational Resources Information Center

    Robichaud, David

    2017-01-01

    This paper will consider language management from the perspective of efficiency, and will set the grounds for a new approach to linguistic justice: a market failure approach. The principle of efficiency emphasises the need to satisfy individuals' preferences in an optimal way. Applying this principle with regard to language would justify language…

  2. On the Materials Science of Nature's Arms Race.

    PubMed

    Liu, Zengqian; Zhang, Zhefeng; Ritchie, Robert O

    2018-06-05

    Biological material systems have evolved unique combinations of mechanical properties to fulfill their specific function through a series of ingenious designs. Seeking lessons from Nature by replicating the underlying principles of such biological materials offers new promise for creating unique combinations of properties in man-made systems. One case in point is Nature's means of attack and defense. During the long-term evolutionary "arms race," naturally evolved weapons have achieved exceptional mechanical efficiency with a synergy of effective offense and persistence-two characteristics that often tend to be mutually exclusive in many synthetic systems-which may present a notable source of new materials science knowledge and inspiration. This review categorizes Nature's weapons into ten distinct groups, and discusses the unique structural and mechanical designs of each group by taking representative systems as examples. The approach described is to extract the common principles underlying such designs that could be translated into man-made materials. Further, recent advances in replicating the design principles of natural weapons at differing lengthscales in artificial materials, devices and tools to tackle practical problems are revisited, and the challenges associated with biological and bioinspired materials research in terms of both processing and properties are discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Thermodynamic framework to assess low abundance DNA mutation detection by hybridization

    PubMed Central

    Willems, Hanny; Jacobs, An; Hadiwikarta, Wahyu Wijaya; Venken, Tom; Valkenborg, Dirk; Van Roy, Nadine; Vandesompele, Jo; Hooyberghs, Jef

    2017-01-01

    The knowledge of genomic DNA variations in patient samples has a high and increasing value for human diagnostics in its broadest sense. Although many methods and sensors to detect or quantify these variations are available or under development, the number of underlying physico-chemical detection principles is limited. One of these principles is the hybridization of sample target DNA versus nucleic acid probes. We introduce a novel thermodynamics approach and develop a framework to exploit the specific detection capabilities of nucleic acid hybridization, using generic principles applicable to any platform. As a case study, we detect point mutations in the KRAS oncogene on a microarray platform. For the given platform and hybridization conditions, we demonstrate the multiplex detection capability of hybridization and assess the detection limit using thermodynamic considerations; DNA containing point mutations in a background of wild type sequences can be identified down to at least 1% relative concentration. In order to show the clinical relevance, the detection capabilities are confirmed on challenging formalin-fixed paraffin-embedded clinical tumor samples. This enzyme-free detection framework contains the accuracy and efficiency to screen for hundreds of mutations in a single run with many potential applications in molecular diagnostics and the field of personalised medicine. PMID:28542229

  4. Investigations into the design principles in the chemotactic behavior of Escherichia coli.

    PubMed

    Kim, Tae-Hwan; Jung, Sung Hoon; Cho, Kwang-Hyun

    2008-01-01

    Inspired by the recent studies on the analysis of biased random walk behavior of Escherichia coli[Passino, K.M., 2002. Biomimicry of bacterial foraging for distributed optimization and control. IEEE Control Syst. Mag. 22 (3), 52-67; Passino, K.M., 2005. Biomimicry for Optimization, Control and Automation. Springer-Verlag, pp. 768-798; Liu, Y., Passino, K.M., 2002. Biomimicry of social foraging bacteria for distributed optimization: models, principles, and emergent behaviors. J. Optim. Theory Appl. 115 (3), 603-628], we have developed a model describing the motile behavior of E. coli by specifying some simple rules on the chemotaxis. Based on this model, we have analyzed the role of some key parameters involved in the chemotactic behavior to unravel the underlying design principles. By investigating the target tracking capability of E. coli in a maze through computer simulations, we found that E. coli clusters can be controlled as target trackers in a complex micro-scale-environment. In addition, we have explored the dynamical characteristics of this target tracking mechanism through perturbation of parameters under noisy environments. It turns out that the E. coli chemotaxis mechanism might be designed such that it is sensitive enough to efficiently track the target and also robust enough to overcome environmental noises.

  5. An Improved Filtering Method for Quantum Color Image in Frequency Domain

    NASA Astrophysics Data System (ADS)

    Li, Panchi; Xiao, Hong

    2018-01-01

    In this paper we investigate the use of quantum Fourier transform (QFT) in the field of image processing. We consider QFT-based color image filtering operations and their applications in image smoothing, sharpening, and selective filtering using quantum frequency domain filters. The underlying principle used for constructing the proposed quantum filters is to use the principle of the quantum Oracle to implement the filter function. Compared with the existing methods, our method is not only suitable for color images, but also can flexibly design the notch filters. We provide the quantum circuit that implements the filtering task and present the results of several simulation experiments on color images. The major advantages of the quantum frequency filtering lies in the exploitation of the efficient implementation of the quantum Fourier transform.

  6. A Many-Body Formalism of ΔSCF Approach for Simulating X-Ray Spectra from First-Principles

    NASA Astrophysics Data System (ADS)

    Liang, Yufeng; Vinson, John; Pemmaraju, Sri; Drisdell, Walter; Shirley, Eric; Prendegast, David

    Accurately reproducing X-ray spectral fingerprints for materials characterization relies heavily on how to correctly model the many-electron response to the generation of an X-ray core hole. In this talk, we present a novel first-principles theory for simulating X-ray spectra that is based on many-electron wavefunctions. The proposed theory go beyond the electron-hole correlations within the Bethe-Saltpeter Equation and consider higher-order vertex corrections up to the level of Mahan-Noziéres-De Dominicis (MND) theory. An efficient algorithm is invented to incorporate these many-electron processes by using linear algebra rather than iterating over all Feynman diag United States Department of Energy under Contact No. DE-AC02-05CH11231, No. DE-SC0004993.

  7. Integrating Sex and Drugs into the Principles Course: Market-Failures versus Failures-of-Market Outcomes.

    ERIC Educational Resources Information Center

    Colander, David

    2003-01-01

    Argues that microeconomics principles courses are structured around an approach to policy that avoids many controversial but central policy issues including: the interplay of moral issues and efficiency; questions of consumer sovereignty; and questions of the interrelation between measures of efficiency and income distribution. Suggests a dual…

  8. 75 FR 30014 - Office of Energy Efficiency and Renewable Energy; Energy Efficiency and Conservation Block Grant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... submittals for consistency with the requirements of Office of Management and Budget's (OMB) Cost Principles... classes (Basic Financial Assistance and Cost Principles--see the Acquisition Career Management Program... not provided from the National Environmental Policy Act (NEPA) or the Office of Management and Budget...

  9. Perovskites: transforming photovoltaics, a mini-review

    DOE PAGES

    Chilvery, Ashwith Kumar; Batra, Ashok K.; Yang, Bin; ...

    2015-01-06

    The recent power-packed advent of perovskite solar cells is transforming photovoltaics (PV) with their superior efficiencies, ease of fabrication, and cost. This perovskite solar cell further boasts of many unexplored features that can further enhance its PV properties and lead to it being branded as a successful commercial product. This paper provides a detailed insight of the organometal halide based perovskite structure, its unique stoichiometric design, and its underlying principles for PV applications. Finally, the compatibility of various PV layers and its fabrication methods is also discussed.

  10. PAM multiplicity marks genomic target sites as inhibitory to CRISPR-Cas9 editing.

    PubMed

    Malina, Abba; Cameron, Christopher J F; Robert, Francis; Blanchette, Mathieu; Dostie, Josée; Pelletier, Jerry

    2015-12-08

    In CRISPR-Cas9 genome editing, the underlying principles for selecting guide RNA (gRNA) sequences that would ensure for efficient target site modification remain poorly understood. Here we show that target sites harbouring multiple protospacer adjacent motifs (PAMs) are refractory to Cas9-mediated repair in situ. Thus we refine which substrates should be avoided in gRNA design, implicating PAM density as a novel sequence-specific feature that inhibits in vivo Cas9-driven DNA modification.

  11. PAM multiplicity marks genomic target sites as inhibitory to CRISPR-Cas9 editing

    PubMed Central

    Malina, Abba; Cameron, Christopher J. F.; Robert, Francis; Blanchette, Mathieu; Dostie, Josée; Pelletier, Jerry

    2015-01-01

    In CRISPR-Cas9 genome editing, the underlying principles for selecting guide RNA (gRNA) sequences that would ensure for efficient target site modification remain poorly understood. Here we show that target sites harbouring multiple protospacer adjacent motifs (PAMs) are refractory to Cas9-mediated repair in situ. Thus we refine which substrates should be avoided in gRNA design, implicating PAM density as a novel sequence-specific feature that inhibits in vivo Cas9-driven DNA modification. PMID:26644285

  12. Highly Efficient LiYF4:Yb(3+), Er(3+) Upconversion Single Crystal under Solar Cell Spectrum Excitation and Photovoltaic Application.

    PubMed

    Chen, Xu; Xu, Wen; Song, Hongwei; Chen, Cong; Xia, Haiping; Zhu, Yongsheng; Zhou, Donglei; Cui, Shaobo; Dai, Qilin; Zhang, Jiazhong

    2016-04-13

    Luminescent upconversion is a promising way to harvest near-infrared (NIR) sunlight and transforms it into visible light that can be directly absorbed by active materials of solar cells and improve their power conversion efficiency (PCE). However, it is still a great challenge to effectively improve the PCE of solar cells with the assistance of upconversion. In this work, we demonstrate the application of the transparent LiYF4:Yb(3+), Er(3+) single crystal as an independent luminescent upconverter to improve the PCE of perovskite solar cells. The LiYF4:Yb(3+), Er(3+) single crystal is prepared by an improved Bridgman method, and its internal quantum efficiency approached to 5.72% under 6.2 W cm(-2) 980 nm excitation. The power-dependent upconversion luminescence indicated that under the excitation of simulated sunlight the (4)F(9/2)-(4)I(15/2) red emission originally results from the cooperation of a 1540 nm photon and a 980 nm photon. Furthermore, when the single crystal is placed in front of the perovskite solar cells, the PCE is enhanced by 7.9% under the irradiation of simulated sunlight by 7-8 solar constants. This work implies the upconverter not only can serve as proof of principle for improving PCE of solar cells but also is helpful to practical application.

  13. Thermodynamic analysis of the efficiency of high-temperature steam electrolysis system for hydrogen production

    NASA Astrophysics Data System (ADS)

    Mingyi, Liu; Bo, Yu; Jingming, Xu; Jing, Chen

    High-temperature steam electrolysis (HTSE), a reversible process of solid oxide fuel cell (SOFC) in principle, is a promising method for highly efficient large-scale hydrogen production. In our study, the overall efficiency of the HTSE system was calculated through electrochemical and thermodynamic analysis. A thermodynamic model in regards to the efficiency of the HTSE system was established and the quantitative effects of three key parameters, electrical efficiency (η el), electrolysis efficiency (η es), and thermal efficiency (η th) on the overall efficiency (η overall) of the HTSE system were investigated. Results showed that the contribution of η el, η es, η th to the overall efficiency were about 70%, 22%, and 8%, respectively. As temperatures increased from 500 °C to 1000 °C, the effect of η el on η overall decreased gradually and the η es effect remained almost constant, while the η th effect increased gradually. The overall efficiency of the high-temperature gas-cooled reactor (HTGR) coupled with the HTSE system under different conditions was also calculated. With the increase of electrical, electrolysis, and thermal efficiency, the overall efficiencies were anticipated to increase from 33% to a maximum of 59% at 1000 °C, which is over two times higher than that of the conventional alkaline water electrolysis.

  14. Layout and flow of dermatology clinics: principles from operations management.

    PubMed

    Wang, Jordan V

    2018-04-15

    Dermatology is a medical specialty that experiences high patient demand and long patient wait times. Dermatology clinics should look for ways to improve efficiency through the incorporation of principles from operations management. Addressing the layout and flow of a clinic can lead to operational efficiency. An ideal layout may lead to increased patient volume, satisfaction, and retention.

  15. Use of General Principles in Teaching Biochemistry.

    ERIC Educational Resources Information Center

    Fernandez, Rolando Hernandez; Tomey, Agustin Vicedo

    1991-01-01

    Presents Principles of Biochemistry for use as main focus of a biochemistry course. The nine guiding ideas are the principles of continual turnover, macromolecular organization, molecular recognition, multiplicity of utilization, maximum efficiency, gradual change, interrelationship, transformational reciprocity, and information transfer. In use…

  16. Materials and microfluidics: enabling the efficient isolation and analysis of circulating tumour cells.

    PubMed

    Jackson, Joshua M; Witek, Małgorzata A; Kamande, Joyce W; Soper, Steven A

    2017-07-17

    We present a critical review of microfluidic technologies and material effects on the analyses of circulating tumour cells (CTCs) selected from the peripheral blood of cancer patients. CTCs are a minimally invasive source of clinical information that can be used to prognose patient outcome, monitor minimal residual disease, assess tumour resistance to therapeutic agents, and potentially screen individuals for the early diagnosis of cancer. The performance of CTC isolation technologies depends on microfluidic architectures, the underlying principles of isolation, and the choice of materials. We present a critical review of the fundamental principles used in these technologies and discuss their performance. We also give context to how CTC isolation technologies enable downstream analysis of selected CTCs in terms of detecting genetic mutations and gene expression that could be used to gain information that may affect patient outcome.

  17. TARGETED SEQUENTIAL DESIGN FOR TARGETED LEARNING INFERENCE OF THE OPTIMAL TREATMENT RULE AND ITS MEAN REWARD.

    PubMed

    Chambaz, Antoine; Zheng, Wenjing; van der Laan, Mark J

    2017-01-01

    This article studies the targeted sequential inference of an optimal treatment rule (TR) and its mean reward in the non-exceptional case, i.e. , assuming that there is no stratum of the baseline covariates where treatment is neither beneficial nor harmful, and under a companion margin assumption. Our pivotal estimator, whose definition hinges on the targeted minimum loss estimation (TMLE) principle, actually infers the mean reward under the current estimate of the optimal TR. This data-adaptive statistical parameter is worthy of interest on its own. Our main result is a central limit theorem which enables the construction of confidence intervals on both mean rewards under the current estimate of the optimal TR and under the optimal TR itself. The asymptotic variance of the estimator takes the form of the variance of an efficient influence curve at a limiting distribution, allowing to discuss the efficiency of inference. As a by product, we also derive confidence intervals on two cumulated pseudo-regrets, a key notion in the study of bandits problems. A simulation study illustrates the procedure. One of the corner-stones of the theoretical study is a new maximal inequality for martingales with respect to the uniform entropy integral.

  18. Green Engineering Principle #4 Maximize Efficiency

    EPA Science Inventory

    As one reads the twelve principles of Green Engineering, there is one message that stands out and becomes ever increasingly more evident with each principle. Moreover, that message is simplicity! It is simplicity that will allow us, as a society, to become more sustainable.Althou...

  19. Evaluation methodology for query-based scene understanding systems

    NASA Astrophysics Data System (ADS)

    Huster, Todd P.; Ross, Timothy D.; Culbertson, Jared L.

    2015-05-01

    In this paper, we are proposing a method for the principled evaluation of scene understanding systems in a query-based framework. We can think of a query-based scene understanding system as a generalization of typical sensor exploitation systems where instead of performing a narrowly defined task (e.g., detect, track, classify, etc.), the system can perform general user-defined tasks specified in a query language. Examples of this type of system have been developed as part of DARPA's Mathematics of Sensing, Exploitation, and Execution (MSEE) program. There is a body of literature on the evaluation of typical sensor exploitation systems, but the open-ended nature of the query interface introduces new aspects to the evaluation problem that have not been widely considered before. In this paper, we state the evaluation problem and propose an approach to efficiently learn about the quality of the system under test. We consider the objective of the evaluation to be to build a performance model of the system under test, and we rely on the principles of Bayesian experiment design to help construct and select optimal queries for learning about the parameters of that model.

  20. A joint Richardson-Lucy deconvolution algorithm for the reconstruction of multifocal structured illumination microscopy data.

    PubMed

    Ströhl, Florian; Kaminski, Clemens F

    2015-01-16

    We demonstrate the reconstruction of images obtained by multifocal structured illumination microscopy, MSIM, using a joint Richardson-Lucy, jRL-MSIM, deconvolution algorithm, which is based on an underlying widefield image-formation model. The method is efficient in the suppression of out-of-focus light and greatly improves image contrast and resolution. Furthermore, it is particularly well suited for the processing of noise corrupted data. The principle is verified on simulated as well as experimental data and a comparison of the jRL-MSIM approach with the standard reconstruction procedure, which is based on image scanning microscopy, ISM, is made. Our algorithm is efficient and freely available in a user friendly software package.

  1. A joint Richardson—Lucy deconvolution algorithm for the reconstruction of multifocal structured illumination microscopy data

    NASA Astrophysics Data System (ADS)

    Ströhl, Florian; Kaminski, Clemens F.

    2015-03-01

    We demonstrate the reconstruction of images obtained by multifocal structured illumination microscopy, MSIM, using a joint Richardson-Lucy, jRL-MSIM, deconvolution algorithm, which is based on an underlying widefield image-formation model. The method is efficient in the suppression of out-of-focus light and greatly improves image contrast and resolution. Furthermore, it is particularly well suited for the processing of noise corrupted data. The principle is verified on simulated as well as experimental data and a comparison of the jRL-MSIM approach with the standard reconstruction procedure, which is based on image scanning microscopy, ISM, is made. Our algorithm is efficient and freely available in a user friendly software package.

  2. A Green Approach for Allylations of Aldehydes and Ketones: Combining Allylborate, Mechanochemistry and Lanthanide Catalyst.

    PubMed

    de Souza, Viviane P; Oliveira, Cristiane K; de Souza, Thiago M; Menezes, Paulo H; Alves, Severino; Longo, Ricardo L; Malvestiti, Ivani

    2016-11-16

    Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative. The catalyzed reactions can also be performed under mild aqueous stirring conditions. Considering the allylation agent and its by-products, aqueous media, energy efficiency and use of catalyst, the methodology meets most of the green chemistry principles.

  3. Review of nanostructured devices for thermoelectric applications

    PubMed Central

    2014-01-01

    Summary A big research effort is currently dedicated to the development of thermoelectric devices capable of a direct thermal-to-electrical energy conversion, aiming at efficiencies as high as possible. These devices are very attractive for many applications in the fields of energy recovery and green energy harvesting. In this paper, after a quick summary of the fundamental principles of thermoelectricity, the main characteristics of materials needed for high efficiency thermoelectric conversion will be discussed, and a quick review of the most promising materials currently under development will be given. This review paper will put a particular emphasis on nanostructured silicon, which represents a valid compromise between good thermoelectric properties on one side and material availability, sustainability, technological feasibility on the other side. The most important bottom-up and top-down nanofabrication techniques for large area silicon nanowire arrays, to be used for high efficiency thermoelectric devices, will be presented and discussed. PMID:25247111

  4. Efficient Terahertz Wide-Angle NUFFT-Based Inverse Synthetic Aperture Imaging Considering Spherical Wavefront.

    PubMed

    Gao, Jingkun; Deng, Bin; Qin, Yuliang; Wang, Hongqiang; Li, Xiang

    2016-12-14

    An efficient wide-angle inverse synthetic aperture imaging method considering the spherical wavefront effects and suitable for the terahertz band is presented. Firstly, the echo signal model under spherical wave assumption is established, and the detailed wavefront curvature compensation method accelerated by 1D fast Fourier transform (FFT) is discussed. Then, to speed up the reconstruction procedure, the fast Gaussian gridding (FGG)-based nonuniform FFT (NUFFT) is employed to focus the image. Finally, proof-of-principle experiments are carried out and the results are compared with the ones obtained by the convolution back-projection (CBP) algorithm. The results demonstrate the effectiveness and the efficiency of the presented method. This imaging method can be directly used in the field of nondestructive detection and can also be used to provide a solution for the calculation of the far-field RCSs (Radar Cross Section) of targets in the terahertz regime.

  5. Organic Solar Cells beyond One Pair of Donor-Acceptor: Ternary Blends and More.

    PubMed

    Yang, Liqiang; Yan, Liang; You, Wei

    2013-06-06

    Ternary solar cells enjoy both an increased light absorption width, and an easy fabrication process associated with their simple structures. Significant progress has been made for such solar cells with demonstrated efficiencies over 7%; however, their fundamental working principles are still under investigation. This Perspective is intended to offer our insights on the three major governing mechanisms in these intriguing ternary solar cells: charge transfer, energy transfer, and parallel-linkage. Through careful analysis of exemplary cases, we summarize the advantages and limitations of these three major mechanisms and suggest future research directions. For example, incorporating additional singlet fission or upconversion materials into the energy transfer dominant ternary solar cells has the potential to break the theoretical efficiency limit in single junction organic solar cells. Clearly, a feedback loop between fundamental understanding and materials selection is in urgent need to accelerate the efficiency improvement of these ternary solar cells.

  6. BIG DATA AND STATISTICS

    PubMed Central

    Rossell, David

    2016-01-01

    Big Data brings unprecedented power to address scientific, economic and societal issues, but also amplifies the possibility of certain pitfalls. These include using purely data-driven approaches that disregard understanding the phenomenon under study, aiming at a dynamically moving target, ignoring critical data collection issues, summarizing or preprocessing the data inadequately and mistaking noise for signal. We review some success stories and illustrate how statistical principles can help obtain more reliable information from data. We also touch upon current challenges that require active methodological research, such as strategies for efficient computation, integration of heterogeneous data, extending the underlying theory to increasingly complex questions and, perhaps most importantly, training a new generation of scientists to develop and deploy these strategies. PMID:27722040

  7. Investigation of Primary Dew-Point Saturator Efficiency in Two Different Thermal Environments

    NASA Astrophysics Data System (ADS)

    Zvizdic, D.; Heinonen, M.; Sestan, D.

    2015-08-01

    The aim of this paper is to describe the evaluation process of the performance of the low-range saturator (LRS), when exposed to two different thermal environments. The examined saturator was designed, built, and tested at MIKES (Centre for Metrology and Accreditation, Finland), and then transported to the Laboratory for Process Measurement (LPM) in Croatia, where it was implemented in a new dew-point calibration system. The saturator works on a single-pressure-single-pass generation principle in the dew/frost-point temperature range between and . The purpose of the various tests performed at MIKES was to examine the efficiency and non-ideality of the saturator. As a test bath facility in Croatia differs from the one used in Finland, the same tests were repeated at LPM, and the effects of different thermal conditions on saturator performance were examined. Thermometers, pressure gauges, an air preparation system, and water for filling the saturator at LPM were also different than those used at MIKES. Results obtained by both laboratories indicate that the efficiency of the examined saturator was not affected either by the thermal conditions under which it was tested or by equipment used for the tests. Both laboratories concluded that LRS is efficient enough for a primary realization of the dew/frost-point temperature scale in the range from to , with flow rates between and . It is also shown that a considerable difference of the pre-saturator efficiency, indicated by two laboratories, did not have influence to the overall performance of the saturator. The results of the research are presented in graphical and tabular forms. This paper also gives a brief description of the design and operation principle of the investigated low-range saturator.

  8. Achieving Energy Efficiency in Accordance with Bioclimatic Architecture Principles

    NASA Astrophysics Data System (ADS)

    Bajcinovci, Bujar; Jerliu, Florina

    2016-12-01

    By using our natural resources, and through inefficient use of energy, we produce much waste that can be recycled as a useful resource, which further contributes to climate change. This study aims to address energy effective bioclimatic architecture principles, by which we can achieve a potential energy savings, estimated at thirty-three per cent, mainly through environmentally affordable reconstruction, resulting in low negative impact on the environment. The study presented in this paper investigated the Ulpiana neighbourhood of Prishtina City, focusing on urban design challenges, energy efficiency and air pollution issues. The research methods consist of empirical observations through the urban spatial area using a comparative method, in order to receive clearer data and information research is conducted within Ulpiana's urban blocks, shapes of architectural structures, with the objective focusing on bioclimatic features in terms of the morphology and microclimate of Ulpiana. Energy supply plays a key role in the economic development of any country, hence, bioclimatic design principles for sustainable architecture and energy efficiency, present an evolutive integrated strategy for achieving efficiency and healthier conditions for Kosovar communities. Conceptual findings indicate that with the integrated design strategy: energy efficiency, and passive bioclimatic principles will result in a bond of complex interrelation between nature, architecture, and community. The aim of this study is to promote structured organized actions to be taken in Prishtina, and Kosovo, which will result in improved energy efficiency in all sectors, and particularly in the residential housing sector.

  9. Problems of the development of international standards of “green building” in Russia

    NASA Astrophysics Data System (ADS)

    Meshcheryakova, Tatiana

    2017-10-01

    Problems of environmental friendliness and energy efficiency in recent decades have become not only the most important issues of economic development of the main industrial economies, but also the basis for the processes of maintaining the security and relative stability of the global ecosystem. The article presents the results of the study of the status and trends of the development of environmental standards for the construction and maintenance of real estate in the world and particularly in Russia. Special market instruments for assessing the compliance with the quality of real estate projects under construction and modern principles of environmental friendliness and energy efficiency include voluntary building certification systems that are actively used in international practice. In Russia there is active use of the following international systems of certification: BREEAM, LEED, DGNB, HQE. Also in the Russian certification market, the national standard STO NOSTROY 2.35.4-2011 “Residential and public buildings” is being implemented, which summarizes the best international experience of the rating evaluation procedure. Comparative characteristics of the “green” standards and the principles of rating assessments of the ecological compatibility of buildings give an idea of applying these standards in Russia.

  10. Origin of reduced efficiency in high Ga concentration Cu(In,Ga)Se2 solar cell

    NASA Astrophysics Data System (ADS)

    Wei, S.-H.; Huang, B.; Deng, H.; Contreras, M. A.; Noufi, R.; Chen, S.; Wang, L. W.

    2014-03-01

    CuInSe2 (CIS) is one of the most attractive thin-film materials for solar cells. It is well know that alloying Ga into CIS forming Cu(In,Ga)Se2 (CIGS) alloy is crucial to achieve the high efficiency, but adding too much Ga will lead to a decline of the solar cell efficiency. The exact origin of this puzzling phenomenon is currently still under debate. Using first-principles method, we have systemically studied the structural and electronic properties of CIGS alloys. Our phase diagram calculations suggest that increasing growth temperature may not be a critical factor in enhancing the cell performance of CIGS under equilibrium growth condition. On the other hand, our defect calculations identify that high concentration of antisite defects MCu(M =In, Ga) rather than anion defects are the key deep-trap centers in CIGS. The more the Ga concentration in CIGS, the more harmful the deep-trap is. Self-compensation in CIGS, which forms 2VCu + MCudefect complexes, is found to be beneficial to quench the deep-trap levels induced by MCu in CIGS, especially at low Ga concentration. Unfortunately, the density of isolated MCu is quite high and cannot be largely converted into 2VCu + MCu complexes under thermal equilibrium condition. Thus, nonequilibrium growth conditions or low growth temperature that can suppress the formation of the deep-trap centers MCu may be necessary for improving the efficiency of CIGS solar cells with high Ga concentrations.

  11. Efficient and Effective Change Principles in Active Videogames

    PubMed Central

    Fenner, Ashley A.; Howie, Erin K.; Feltz, Deborah L.; Gray, Cindy M.; Lu, Amy Shirong; Mueller, Florian “Floyd”; Simons, Monique; Barnett, Lisa M.

    2015-01-01

    Abstract Active videogames have the potential to enhance population levels of physical activity but have not been successful in achieving this aim to date. This article considers a range of principles that may be important to the design of effective and efficient active videogames from diverse discipline areas, including behavioral sciences (health behavior change, motor learning, and serious games), business production (marketing and sales), and technology engineering and design (human–computer interaction/ergonomics and flow). Both direct and indirect pathways to impact on population levels of habitual physical activity are proposed, along with the concept of a game use lifecycle. Examples of current active and sedentary electronic games are used to understand how such principles may be applied. Furthermore, limitations of the current usage of theoretical principles are discussed. A suggested list of principles for best practice in active videogame design is proposed along with suggested research ideas to inform practice to enhance physical activity. PMID:26181680

  12. Efficient and Effective Change Principles in Active Videogames.

    PubMed

    Straker, Leon M; Fenner, Ashley A; Howie, Erin K; Feltz, Deborah L; Gray, Cindy M; Lu, Amy Shirong; Mueller, Florian Floyd; Simons, Monique; Barnett, Lisa M

    2015-02-01

    Active videogames have the potential to enhance population levels of physical activity but have not been successful in achieving this aim to date. This article considers a range of principles that may be important to the design of effective and efficient active videogames from diverse discipline areas, including behavioral sciences (health behavior change, motor learning, and serious games), business production (marketing and sales), and technology engineering and design (human-computer interaction/ergonomics and flow). Both direct and indirect pathways to impact on population levels of habitual physical activity are proposed, along with the concept of a game use lifecycle. Examples of current active and sedentary electronic games are used to understand how such principles may be applied. Furthermore, limitations of the current usage of theoretical principles are discussed. A suggested list of principles for best practice in active videogame design is proposed along with suggested research ideas to inform practice to enhance physical activity.

  13. Exploration on Bioflocculation of Nannochloropsis oculata Using Response Surface Methodology for Biodiesel Production

    PubMed Central

    Surendhiran, Duraiarasan; Vijay, Mani

    2014-01-01

    Harvesting of algal biomass in biodiesel production involves high energy input and cost incurred process. In order to overcome these problems, bioflocculation process was employed and the efficiency of this process was further improved by the addition of a cationic inducer. In this work marine Bacillus subtilis was used for bioflocculation of Nannochloropsis oculata and ZnCl2 as cationic inducer. This study worked under the principle of divalent cationic bridging (DCB) theory. Under temperature stress and high pH, the bacterium produced exopolysaccharide that bound with microalga Nannochloropsis oculata and flocculated them. A maximum efficiency of 95.43% was observed with the optimised RSM parameters—temperature 30.78°C, pH 10.8, flocculation time 6.7 h, bioflocculant size 0.38 mL, and cationic inducer concentration 0.035 mM. The present investigation focused on the cost effective harvesting of microalga on a larger scale for biodiesel production than using toxic, ecofriendly chemical flocculants. PMID:24683320

  14. Green chemistry approach for the synthesis of ZnO-carbon dots nanocomposites with good photocatalytic properties under visible light.

    PubMed

    Bozetine, Hakima; Wang, Qi; Barras, Alexandre; Li, Musen; Hadjersi, Toufik; Szunerits, Sabine; Boukherroub, Rabah

    2016-03-01

    We report on a simple and one-pot synthetic method to produce ZnO/carbon quantum dots (ZnO/CQDs) nanocomposites. The morphological features and chemical composition of the nanocomposites were characterized using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analyses (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The optical properties of the nanocomposites were examined using UV-visible (UV-vis) spectrophotometry. The photocatalytic activity of the ZnO/CQDs was evaluated for the degradation of a model organic pollutant, rhodamine B, under visible light irradiation at room temperature. The highly efficient photodegradation capability of the nanocomposite was demonstrated by comparison with ZnO particles, prepared using identical experimental conditions. Overall, the present approach adheres to green chemistry principles and the nanocomposite holds promise for the development of remarkably efficient catalytic systems. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Semilocal Exchange Energy Functional for Two-Dimensional Quantum Systems: A Step Beyond Generalized Gradient Approximations.

    PubMed

    Jana, Subrata; Samal, Prasanjit

    2017-06-29

    Semilocal density functionals for the exchange-correlation energy of electrons are extensively used as they produce realistic and accurate results for finite and extended systems. The choice of techniques plays a crucial role in constructing such functionals of improved accuracy and efficiency. An accurate and efficient semilocal exchange energy functional in two dimensions is constructed by making use of the corresponding hole which is derived based on the density matrix expansion. The exchange hole involved is localized under the generalized coordinate transformation and satisfies all the relevant constraints. Comprehensive testing and excellent performance of the functional is demonstrated versus exact exchange results. The accuracy of results obtained by using the newly constructed functional is quite remarkable as it substantially reduces the errors present in the local and nonempirical exchange functionals proposed so far for two-dimensional quantum systems. The underlying principles involved in the functional construction are physically appealing and hold promise for developing range separated and nonlocal exchange functionals in two dimensions.

  16. Bismuth vanadate-based semiconductor photocatalysts: a short critical review on the efficiency and the mechanism of photodegradation of organic pollutants.

    PubMed

    Monfort, Olivier; Plesch, Gustav

    2018-06-02

    The number of publications on photocatalytic bismuth vanadate-based materials is constantly increasing. Indeed, bismuth vanadate is gaining stronger interest in the photochemical community since it is a solar-driven photocatalyst. However, the efficiency of BiVO 4 -based photocatalyst under sunlight is questionable: in most of the studies investigating the photodegradation of organic pollutants, only few works identify the by-products and evaluate the real efficiency of BiVO 4 -based materials. This short review aims to (i) present briefly the principles of photocatalysis and define the photocatalytic efficiency and (ii) discuss the formation of reactive species involved in the photocatalytic degradation process of pollutants and thus the corresponding photodegradation mechanism could be determined. All these points are developed in a comprehensive discussion by focusing especially on pure, doped, and composite BiVO 4 . Therefore, this review exhibits a critical overview on different BiVO 4 -based photocatalytic systems with their real efficiency. This is a necessary knowledge for potential implementation of BiVO 4 materials in environmental applications at larger scale than laboratory conditions.

  17. Efficient full-spectrum utilization, reception and conversion of solar energy by broad-band nanospiral antenna.

    PubMed

    Zhao, Huaqiao; Gao, Huotao; Cao, Ting; Li, Boya

    2018-01-22

    In this work, the collection of solar energy by a broad-band nanospiral antenna is investigated in order to solve the low efficiency of the solar rectenna based on conventional nanoantennas. The antenna impedance, radiation, polarization and effective area are all considered in the efficiency calculation using the finite integral technique. The wavelength range investigated is 300-3000 nm, which corresponds to more than 98% of the solar radiation energy. It's found that the nanospiral has stronger field enhancement in the gap than a nanodipole counterpart. And a maximum harvesting efficiency about 80% is possible in principle for the nanospiral coupled to a rectifier resistance of 200 Ω, while about 10% for the nanodipole under the same conditions. Moreover, the nanospiral could be coupled to a rectifier diode of high resistance more easily than the nanodipole. These results indicate that the efficient full-spectrum utilization, reception and conversion of solar energy can be achieved by the nanospiral antenna, which is expected to promote the solar rectenna to be a promising technology in the clean, renewable energy application.

  18. Basal area increment and growth efficiency as functions of canopy dynamics and stem mechanics

    Treesearch

    Thomas J. Dean

    2004-01-01

    Crown and canopy structurecorrelate with growth efficiency and also determine stem size and taper as described by the uniform stress principle of stem formation. A regression model was derived from this principle that expresses basal area increment in terms of the amount and vertical distribution of leaf area and change in these variables during a growth period. This...

  19. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Sustainable principles for siting, design and construction. [Reserved] 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS...-Rise Residential Buildings. § 435.6 Sustainable principles for siting, design and construction...

  20. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Sustainable principles for siting, design and construction. [Reserved] 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS...-Rise Residential Buildings. § 435.6 Sustainable principles for siting, design and construction...

  1. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Sustainable principles for siting, design and construction. [Reserved] 435.6 Section 435.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS...-Rise Residential Buildings. § 435.6 Sustainable principles for siting, design and construction...

  2. Electron Correlation and Tranport Properties in Nuclear Fuel Materials

    NASA Astrophysics Data System (ADS)

    Yin, Quan; Haule, Kristjan; Kotliar, Gabriel; Savrasov, Sergey; Pickett, Warren

    2011-03-01

    Using first principle LDA+DMFT method, we conduct a systematic study on the correlated electronic structures and transport properties of select actinide carbides, nitrides, and oxides, many of which are nuclear fuel materials. Our results capture the metal--insulator Mott transition within the studied systems, and the appearance of the Zhang-Rice state in uranium dioxide. More importantly, by understanding the physics underlying their transport properties, we suggest ways to improve the efficiency of currently used fuels. This work is supported by the DOE Nuclear Energy University Program, contract No. 00088708.

  3. Stiffness Parameter Design of Suspension Element of Under-Chassis-Equipment for A Rail Vehicle

    NASA Astrophysics Data System (ADS)

    Ma, Menglin; Wang, Chengqiang; Deng, Hai

    2017-06-01

    According to the frequency configuration requirements of the vibration of railway under-chassis-equipment, the three- dimension stiffness of the suspension elements of under-chassis-equipment is designed based on the static principle and dynamics principle. The design results of the concrete engineering case show that, compared with the design method based on the static principle, the three- dimension stiffness of the suspension elements designed by the dynamic principle design method is more uniform. The frequency and decoupling degree analysis show that the calculation frequency of under-chassis-equipment under the two design methods is basically the same as the predetermined frequency. Compared with the design method based on the static principle, the design method based on the dynamic principle is adopted. The decoupling degree can be kept high, and the coupling vibration of the corresponding vibration mode can be reduced effectively, which can effectively reduce the fatigue damage of the key parts of the hanging element.

  4. Cost effectiveness and efficiency in assistive technology service delivery.

    PubMed

    Warren, C G

    1993-01-01

    In order to develop and maintain a viable service delivery program, the realities of cost effectiveness and cost efficiency in providing assistive technology must be addressed. Cost effectiveness relates to value of the outcome compared to the expenditures. Cost efficiency analyzes how a provider uses available resources to supply goods and services. This paper describes how basic business principles of benefit/cost analysis can be used to determine cost effectiveness. In addition, basic accounting principles are used to illustrate methods of evaluating a program's cost efficiency. Service providers are encouraged to measure their own program's effectiveness and efficiency (and potential viability) in light of current trends. This paper is meant to serve as a catalyst for continued dialogue on this topic.

  5. The detailed balance principle and the reciprocity theorem between photocarrier collection and dark carrier distribution in solar cells

    NASA Astrophysics Data System (ADS)

    Rau, Uwe; Brendel, Rolf

    1998-12-01

    It is shown that a recently described general relationship between the local collection efficiency of solar cells and the dark carrier concentration (reciprocity theorem) directly follows from the principle of detailed balance. We derive the relationship for situations where transport of charge carriers occurs between discrete states as well as for the situation where electronic transport is described in terms of continuous functions. Combining both situations allows to extend the range of applicability of the reciprocity theorem to all types of solar cells, including, e.g., metal-insulator-semiconductor-type, electrochemical solar cells, as well as the inclusion of the impurity photovoltaic effect. We generalize the theorem further to situations where the occupation probability of electronic states is governed by Fermi-Dirac statistics instead of Boltzmann statistics as underlying preceding work. In such a situation the reciprocity theorem is restricted to small departures from equilibrium.

  6. 26 CFR 1.671-2 - Applicable principles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Applicable principles. 1.671-2 Section 1.671-2...) INCOME TAXES Grantors and Others Treated As Substantial Owners § 1.671-2 Applicable principles. (a) Under... included in a portion of the trust are set forth in § 1.671-3. (b) Since the principle underlying subpart E...

  7. Polymers in Small-Interfering RNA Delivery

    PubMed Central

    Singha, Kaushik; Namgung, Ran

    2011-01-01

    This review will cover the current strategies that are being adopted to efficiently deliver small interfering RNA using nonviral vectors, including the use of polymers such as polyethylenimine, poly(lactic-co-glycolic acid), polypeptides, chitosan, cyclodextrin, dendrimers, and polymers-containing different nanoparticles. The article will provide a brief and concise account of underlying principle of these polymeric vectors and their structural and functional modifications which were intended to serve different purposes to affect efficient therapeutic outcome of small-interfering RNA delivery. The modifications of these polymeric vectors will be discussed with reference to stimuli-responsiveness, target specific delivery, and incorporation of nanoconstructs such as carbon nanotubes, gold nanoparticles, and silica nanoparticles. The emergence of small-interfering RNA as the potential therapeutic agent and its mode of action will also be mentioned in a nutshell. PMID:21749290

  8. A new controller for battery-powered electric vehicles

    NASA Technical Reports Server (NTRS)

    Belsterling, C. A.; Stone, J.

    1980-01-01

    This paper describes the development, under a NASA/DOE contract, of a new concept for efficient and reliable control of battery-powered vehicles. It avoids the detrimental effects of pulsed-power controllers like the SCR 'chopper' by using rotating machines to meter continuous currents to the traction motor. The concept is validated in a proof-of-principle demonstration system and a complete vehicle is simulated on an analog computer. Test results show exceptional promise for a full-scale system. Optimum control strategies to minimize controller weight are developed by means of the simulated vehicle. The design for an Engineering Model is then prepared in the form of a practical, compact two-bearing package with forced air cooling. Predicted performance is outstanding, with controller efficiency of over 90% at high speed.

  9. Students' Conceptions of Underlying Principles in Medical Physiology: An Interview Study of Medical Students' Understanding in a PBL Curriculum

    ERIC Educational Resources Information Center

    Fyrenius, Anna; Silen, Charlotte; Wirell, Staffan

    2007-01-01

    Medical physiology is known to be a complex area where students develop significant errors in conceptual understanding. Students' knowledge is often bound to situational descriptions rather than underlying principles. This study explores how medical students discern and process underlying principles in physiology. Indepth interviews, where…

  10. Eco-development and energy efficient technologies in Russia: prospects and reality

    NASA Astrophysics Data System (ADS)

    Kurakova, Oksana

    2017-10-01

    The article highlights the concept of eco-standards in Russia, and discusses new technologies that allow to build energy-efficient houses in the form of countryside real estate. Special attention is given to the principle of heat production based on the use of individual facilities, power centers mini thermal power plants, as well as to ways to reduce water consumption at home. Presents analysis of the advantages projects “built-to-suit” for the introduction of the energy efficient technologies. Justified idea and principles of “green construction” in Russia in the real estate market. Conclusion about the effectiveness of the use, opportunities and development of energy efficient technologies.

  11. Maximizing biodiversity co-benefits under REDD+: a decoupled approach

    NASA Astrophysics Data System (ADS)

    Potts, Matthew D.; Kelley, Lisa C.; Doll, Hannah M.

    2013-06-01

    Current debates on biodiversity co-benefits under REDD+ are marked by considerable ambiguity and contention. Nevertheless, REDD+ continues to represent one of the most important opportunities for global biodiversity conservation, and the question of how best to achieve biodiversity co-benefits remains an important one. Thus far, most biodiversity conservation in the context of REDD+ is predicated on the notion that services are co-located on a landscape. In contrast, this letter argues that decoupling biodiversity and carbon services on a landscape through national-level planning is a better approach to biodiversity conservation under REDD+. We discuss the fundamental ecological differences between the two services and use principles of resource economics to demonstrate that a decoupled approach will be more efficient, more flexible, and better able to mobilize sufficient finance for biodiversity conservation than a coupled approach.

  12. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential Buildings. § 435.6 Sustainable principles for siting, design and construction...

  13. 10 CFR 435.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential Buildings. § 435.6 Sustainable principles for siting, design and construction...

  14. Atomic scale morphology, growth behaviour and electronic properties of semipolar {101[overline]3} GaN surfaces.

    PubMed

    Kioseoglou, J; Kalesaki, E; Lymperakis, L; Karakostas, Th; Komninou, Ph

    2013-01-30

    First-principles calculations relating to the atomic structure and electronic properties of {101[overline]3} GaN surfaces reveal significant differentiations between the two polarity orientations. The (101[overline]3) surface exhibits a remarkable morphological stability, stabilizing a metallic structure (Ga adlayer) over the entire range of the Ga chemical potential. In contrast, the semiconducting, cleaved surface is favoured on (101[overline]3[overline]) under extremely and moderately N-rich conditions, a Ga bilayer is stabilized under corresponding Ga-rich conditions and various transitions between metallic reconstructions take place in intermediate growth stoichiometries. Efficient growth schemes for smooth, two-dimensional GaN layers and the isolation of {101[overline]3} material from parasitic orientations are identified.

  15. The design of the automated control system for warehouse equipment under radio-electronic manufacturing

    NASA Astrophysics Data System (ADS)

    Kapulin, D. V.; Chemidov, I. V.; Kazantsev, M. A.

    2017-01-01

    In the paper, the aspects of design, development and implementation of the automated control system for warehousing under the manufacturing process of the radio-electronic enterprise JSC «Radiosvyaz» are discussed. The architecture of the automated control system for warehousing proposed in the paper consists of a server which is connected to the physically separated information networks: the network with a database server, which stores information about the orders for picking, and the network with the automated storage and retrieval system. This principle allows implementing the requirements for differentiation of access, ensuring the information safety and security requirements. Also, the efficiency of the developed automated solutions in terms of optimizing the warehouse’s logistic characteristics is researched.

  16. The time-efficiency principle: time as the key diagnostic strategy in primary care.

    PubMed

    Irving, Greg; Holden, John

    2013-08-01

    The test and retest opportunity afforded by reviewing a patient over time substantially increases the total gain in certainty when making a diagnosis in low-prevalence settings (the time-efficiency principle). This approach safely and efficiently reduces the number of patients who need to be formally tested in order to make a correct diagnosis for a person. Time, in terms of observed disease trajectory, provides a vital mechanism for achieving this task. It remains the best strategy for delivering near-optimal diagnoses in low-prevalence settings and should be used to its full advantage.

  17. Liquid Cooling/Warming Garment

    NASA Technical Reports Server (NTRS)

    Koscheyev, Victor S.; Leon, Gloria R.; Dancisak, Michael J.

    2010-01-01

    The NASA liquid cooling/ventilating garment (LCVG) currently in use was developed over 40 years ago. With the commencement of a greater number of extra-vehicular activity (EVA) procedures with the construction of the International Space Station, problems of astronaut comfort, as well as the reduction of the consumption of energy, became more salient. A shortened liquid cooling/warming garment (SLCWG) has been developed based on physiological principles comparing the efficacy of heat transfer of different body zones; the capability of blood to deliver heat; individual muscle and fat body composition as a basis for individual thermal profiles to customize the zonal sections of the garment; and the development of shunts to minimize or redirect the cooling/warming loop for different environmental conditions, physical activity levels, and emergency situations. The SLCWG has been designed and completed, based on extensive testing in rest, exercise, and antiorthostatic conditions. It is more energy efficient than the LCVG currently used by NASA. The total length of tubing in the SLCWG is approximately 35 percent less and the weight decreased by 20 percent compared to the LCVG. The novel features of the innovation are: 1. The efficiency of the SLCWG to maintain thermal status under extreme changes in body surface temperatures while using significantly less tubing than the LCVG. 2. The construction of the garment based on physiological principles of heat transfer. 3. The identification of the body areas that are most efficient in heat transfer. 4. The inclusion of a hood as part of the garment. 5. The lesser consumption of energy.

  18. A computable expression of closure to efficient causation.

    PubMed

    Mossio, Matteo; Longo, Giuseppe; Stewart, John

    2009-04-07

    In this paper, we propose a mathematical expression of closure to efficient causation in terms of lambda-calculus; we argue that this opens up the perspective of developing principled computer simulations of systems closed to efficient causation in an appropriate programming language. An important implication of our formulation is that, by exhibiting an expression in lambda-calculus, which is a paradigmatic formalism for computability and programming, we show that there are no conceptual or principled problems in realizing a computer simulation or model of closure to efficient causation. We conclude with a brief discussion of the question whether closure to efficient causation captures all relevant properties of living systems. We suggest that it might not be the case, and that more complex definitions could indeed create crucial some obstacles to computability.

  19. 26 CFR 4.954-2 - Foreign personal holding company income; taxable years beginning after December 31, 1986.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...)(3). Except as otherwise provided under this paragraph (b)(3), the principles of section 367(a) and..., the determination of the country in which services are performed shall be made under the principles of... gross income derived by the payor) under the principles of § 1.861-8. (ix) Location of debt instruments...

  20. Resourcing the National Goals for Schooling: An Agreed Framework of Principles for Funding Schools

    ERIC Educational Resources Information Center

    Ministerial Council on Education, Employment, Training and Youth Affairs (NJ1), 2012

    2012-01-01

    Funding for school education in Australia should be on the basis of clear and agreed policy principles for achieving effectiveness, efficiency, equity and a socially and culturally cohesive society. On the basis of these principles a national framework for funding schools will be supported by complementary State and Commonwealth models for funding…

  1. Power and Efficiency.

    ERIC Educational Resources Information Center

    Boyd, James N.

    1991-01-01

    Presents a mathematical problem that, when examined and generalized, develops the relationships between power and efficiency in energy transfer. Offers four examples of simple electrical and mechanical systems to illustrate the principle that maximum power occurs at 50 percent efficiency. (MDH)

  2. Highly Efficient Quantum Sieving in Porous Graphene-like Carbon Nitride for Light Isotopes Separation

    NASA Astrophysics Data System (ADS)

    Qu, Yuanyuan; Li, Feng; Zhou, Hongcai; Zhao, Mingwen

    2016-01-01

    Light isotopes separation, such as 3He/4He, H2/D2, H2/T2, etc., is crucial for various advanced technologies including isotope labeling, nuclear weapons, cryogenics and power generation. However, their nearly identical chemical properties made the separation challenging. The low productivity of the present isotopes separation approaches hinders the relevant applications. An efficient membrane with high performance for isotopes separation is quite appealing. Based on first-principles calculations, we theoretically demonstrated that highly efficient light isotopes separation, such as 3He/4He, can be reached in a porous graphene-like carbon nitride material via quantum sieving effect. Under moderate tensile strain, the quantum sieving of the carbon nitride membrane can be effectively tuned in a continuous way, leading to a temperature window with high 3He/4He selectivity and permeance acceptable for efficient isotopes harvest in industrial application. This mechanism also holds for separation of other light isotopes, such as H2/D2, H2/T2. Such tunable quantum sieving opens a promising avenue for light isotopes separation for industrial application.

  3. Efficient integration method for fictitious domain approaches

    NASA Astrophysics Data System (ADS)

    Duczek, Sascha; Gabbert, Ulrich

    2015-10-01

    In the current article, we present an efficient and accurate numerical method for the integration of the system matrices in fictitious domain approaches such as the finite cell method (FCM). In the framework of the FCM, the physical domain is embedded in a geometrically larger domain of simple shape which is discretized using a regular Cartesian grid of cells. Therefore, a spacetree-based adaptive quadrature technique is normally deployed to resolve the geometry of the structure. Depending on the complexity of the structure under investigation this method accounts for most of the computational effort. To reduce the computational costs for computing the system matrices an efficient quadrature scheme based on the divergence theorem (Gauß-Ostrogradsky theorem) is proposed. Using this theorem the dimension of the integral is reduced by one, i.e. instead of solving the integral for the whole domain only its contour needs to be considered. In the current paper, we present the general principles of the integration method and its implementation. The results to several two-dimensional benchmark problems highlight its properties. The efficiency of the proposed method is compared to conventional spacetree-based integration techniques.

  4. Establishment and verification of three-dimensional dynamic model for heavy-haul train-track coupled system

    NASA Astrophysics Data System (ADS)

    Liu, Pengfei; Zhai, Wanming; Wang, Kaiyun

    2016-11-01

    For the long heavy-haul train, the basic principles of the inter-vehicle interaction and train-track dynamic interaction are analysed firstly. Based on the theories of train longitudinal dynamics and vehicle-track coupled dynamics, a three-dimensional (3-D) dynamic model of the heavy-haul train-track coupled system is established through a modularised method. Specifically, this model includes the subsystems such as the train control, the vehicle, the wheel-rail relation and the line geometries. And for the calculation of the wheel-rail interaction force under the driving or braking conditions, the large creep phenomenon that may occur within the wheel-rail contact patch is considered. For the coupler and draft gear system, the coupler forces in three directions and the coupler lateral tilt angles in curves are calculated. Then, according to the characteristics of the long heavy-haul train, an efficient solving method is developed to improve the computational efficiency for such a large system. Some basic principles which should be followed in order to meet the requirement of calculation accuracy are determined. Finally, the 3-D train-track coupled model is verified by comparing the calculated results with the running test results. It is indicated that the proposed dynamic model could simulate the dynamic performance of the heavy-haul train well.

  5. Improving accuracy of electrochemical capacitance and solvation energetics in first-principles calculations

    NASA Astrophysics Data System (ADS)

    Sundararaman, Ravishankar; Letchworth-Weaver, Kendra; Schwarz, Kathleen A.

    2018-04-01

    Reliable first-principles calculations of electrochemical processes require accurate prediction of the interfacial capacitance, a challenge for current computationally efficient continuum solvation methodologies. We develop a model for the double layer of a metallic electrode that reproduces the features of the experimental capacitance of Ag(100) in a non-adsorbing, aqueous electrolyte, including a broad hump in the capacitance near the potential of zero charge and a dip in the capacitance under conditions of low ionic strength. Using this model, we identify the necessary characteristics of a solvation model suitable for first-principles electrochemistry of metal surfaces in non-adsorbing, aqueous electrolytes: dielectric and ionic nonlinearity, and a dielectric-only region at the interface. The dielectric nonlinearity, caused by the saturation of dipole rotational response in water, creates the capacitance hump, while ionic nonlinearity, caused by the compactness of the diffuse layer, generates the capacitance dip seen at low ionic strength. We show that none of the previously developed solvation models simultaneously meet all these criteria. We design the nonlinear electrochemical soft-sphere solvation model which both captures the capacitance features observed experimentally and serves as a general-purpose continuum solvation model.

  6. Electrostatic engineering of strained ferroelectric perovskites from first principles

    NASA Astrophysics Data System (ADS)

    Cazorla, Claudio; Stengel, Massimiliano

    2015-12-01

    Design of novel artificial materials based on ferroelectric perovskites relies on the basic principles of electrostatic coupling and in-plane lattice matching. These rules state that the out-of-plane component of the electric displacement field and the in-plane components of the strain are preserved across a layered superlattice, provided that certain growth conditions are respected. Intense research is currently directed at optimizing materials functionalities based on these guidelines, often with remarkable success. Such principles, however, are of limited practical use unless one disposes of reliable data on how a given material behaves under arbitrary electrical and mechanical boundary conditions. Here we demonstrate, by focusing on the prototypical ferroelectrics PbTiO3 and BiFeO3 as test cases, how such information can be calculated from first principles in a systematic and efficient way. In particular, we construct a series of two-dimensional maps that describe the behavior of either compound (e.g., concerning the ferroelectric polarization and antiferrodistortive instabilities) at any conceivable choice of the in-plane lattice parameter, a , and out-of-plane electric displacement, D . In addition to being of immediate practical applicability to superlattice design, our results bring new insight into the complex interplay of competing degrees of freedom in perovskite materials and reveal some notable instances where the behavior of these materials depart from what naively is expected.

  7. [Ethics versus economics in public health? On the integration of economic rationality in a discourse of public health ethics].

    PubMed

    Rothgang, H; Staber, J

    2009-05-01

    In the course of establishing the discourse of public health ethics in Germany, we discuss whether economic efficiency should be part of public health ethics and, if necessary, how efficiency should be conceptualized. Based on the welfare economics theory, we build a theoretical framework that demands an integration of economic rationality in public health ethics. Furthermore, we consider the possible implementation of welfare efficiency against the background of current practice in an economic evaluation of health care in Germany. The indifference of the welfare efficiency criterion with respect to distribution leads to the conclusion that efficiency must not be the only criteria of public health ethics. Therefore, an ethical approach of principles should be chosen for public health ethics. Possible conflicts between principles of such an approach are outlined.

  8. A fiber-compatible spectrally encoded imaging system using a 45° tilted fiber grating

    NASA Astrophysics Data System (ADS)

    Wang, Guoqing; Wang, Chao; Yan, Zhijun; Zhang, Lin

    2016-04-01

    We propose and demonstrate, for the first time to our best knowledge, the use of a 45° tilted fiber grating (TFG) as an infiber lateral diffraction element in an efficient and fiber-compatible spectrally encoded imaging (SEI) system. Under proper polarization control, the TFG has significantly enhanced diffraction efficiency (93.5%) due to strong tilted reflection. Our conceptually new fiber-topics-based design eliminates the need for bulky and lossy free-space diffraction gratings, significantly reduces the volume and cost of the imaging system, improves energy efficiency, and increases system stability. As a proof-of-principle experiment, we use the proposed system to perform an one dimensional (1D) line scan imaging of a customer-designed three-slot sample and the results show that the constructed image matches well with the actual sample. The angular dispersion of the 45° TFG is measured to be 0.054°/nm and the lateral resolution of the SEI system is measured to be 28 μm in our experiment.

  9. Enhanced Locomotion Efficiency of a Bio-inspired Walking Robot using Contact Surfaces with Frictional Anisotropy

    NASA Astrophysics Data System (ADS)

    Manoonpong, Poramate; Petersen, Dennis; Kovalev, Alexander; Wörgötter, Florentin; Gorb, Stanislav N.; Spinner, Marlene; Heepe, Lars

    2016-12-01

    Based on the principles of morphological computation, we propose a novel approach that exploits the interaction between a passive anisotropic scale-like material (e.g., shark skin) and a non-smooth substrate to enhance locomotion efficiency of a robot walking on inclines. Real robot experiments show that passive tribologically-enhanced surfaces of the robot belly or foot allow the robot to grip on specific surfaces and move effectively with reduced energy consumption. Supplementing the robot experiments, we investigated tribological properties of the shark skin as well as its mechanical stability. It shows high frictional anisotropy due to an array of sloped denticles. The orientation of the denticles to the underlying collagenous material also strongly influences their mechanical interlocking with the substrate. This study not only opens up a new way of achieving energy-efficient legged robot locomotion but also provides a better understanding of the functionalities and mechanical properties of anisotropic surfaces. That understanding will assist developing new types of material for other real-world applications.

  10. Enhanced Locomotion Efficiency of a Bio-inspired Walking Robot using Contact Surfaces with Frictional Anisotropy

    PubMed Central

    Manoonpong, Poramate; Petersen, Dennis; Kovalev, Alexander; Wörgötter, Florentin; Gorb, Stanislav N.; Spinner, Marlene; Heepe, Lars

    2016-01-01

    Based on the principles of morphological computation, we propose a novel approach that exploits the interaction between a passive anisotropic scale-like material (e.g., shark skin) and a non-smooth substrate to enhance locomotion efficiency of a robot walking on inclines. Real robot experiments show that passive tribologically-enhanced surfaces of the robot belly or foot allow the robot to grip on specific surfaces and move effectively with reduced energy consumption. Supplementing the robot experiments, we investigated tribological properties of the shark skin as well as its mechanical stability. It shows high frictional anisotropy due to an array of sloped denticles. The orientation of the denticles to the underlying collagenous material also strongly influences their mechanical interlocking with the substrate. This study not only opens up a new way of achieving energy-efficient legged robot locomotion but also provides a better understanding of the functionalities and mechanical properties of anisotropic surfaces. That understanding will assist developing new types of material for other real-world applications. PMID:28008936

  11. Mechanism of Electro-Coagulation with Al/Fe Periodically Reversing Treating Berberine Pharmaceutical Wastewater

    NASA Astrophysics Data System (ADS)

    Sun, Zhaonan; Liu, Zheng; Hu, Xiaomin

    2017-05-01

    The method of treating pharmaceutical wastewater by electro-coagulation with Al/Fe periodically reversing (ECPR) was proposed based on traditional electrochemical method. The principle of ECPR was generalized. Mechanism of ECPR to treat berberine pharmaceutical wastewater was investigated. Treatability and mechanism studies were conducted under laboratory conditions. For berberine wastewater (800 mg/L), decolourization efficiency and COD removal efficiency were highest to 98% and 95% respectively when voltage was 8V, reaction time was 60 min, alternating period was 10 S electrolyte concentration was 0.015 mol/L, stirring speed was 750 rpm, pH value was 3-10 and distance between two plates was 0.6 cm. For removal berberine, flocculation, floatation and oxidation provided 73%, 8% and 18% removal efficiency, which can be inferred by analysing UV-visible absorption spectrum, acidification experiment, EDTA shielding experiment, structure-activity relationship, oxidation and floatation. Meanwhile decolourization and COD removal conformed to apparent pseudo-first order and zero-order kinetics for 200mg/L and 400-1000 mg/L berberine wastewater respectively.

  12. Multi-emitter laser multiplexer using a two-mirror beam shaper

    NASA Astrophysics Data System (ADS)

    Cobb, Joshua M.; Brennan, John; Bhatia, Vikram

    2014-12-01

    A system was designed and built to spatially multiplex four broad area laser diodes (BALD) and condense the light into a multi-mode fiber with a core diameter of 105 um and an NA of 0.15. The lasers were efficiently combined with an étendue aspect ratio scaler (EARS) optic. The EARS works under the principle of a two mirror beam shaper. We were able to successfully couple more than 87% of the optical energy into the fiber. The design of the optical system and the results of several built systems are discussed.

  13. Quantum design of photosynthesis for bio-inspired solar-energy conversion.

    PubMed

    Romero, Elisabet; Novoderezhkin, Vladimir I; van Grondelle, Rienk

    2017-03-15

    Photosynthesis is the natural process that converts solar photons into energy-rich products that are needed to drive the biochemistry of life. Two ultrafast processes form the basis of photosynthesis: excitation energy transfer and charge separation. Under optimal conditions, every photon that is absorbed is used by the photosynthetic organism. Fundamental quantum mechanics phenomena, including delocalization, underlie the speed, efficiency and directionality of the charge-separation process. At least four design principles are active in natural photosynthesis, and these can be applied practically to stimulate the development of bio-inspired, human-made energy conversion systems.

  14. Hooke's Law: Applications of a Recurring Principle

    ERIC Educational Resources Information Center

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Briggs, Whitney S.; Palani, Gurunanthan; DiCarlo, Stephen E.

    2009-01-01

    Students generally approach topics in physiology as a series of unrelated phenomena that share few underlying principles. However, if students recognized that the same underlying principles can be used to explain many physiological phenomena, they may gain a more unified understanding of physiological systems. To address this concern, we…

  15. Efficient multidimensional free energy calculations for ab initio molecular dynamics using classical bias potentials

    NASA Astrophysics Data System (ADS)

    VandeVondele, Joost; Rothlisberger, Ursula

    2000-09-01

    We present a method for calculating multidimensional free energy surfaces within the limited time scale of a first-principles molecular dynamics scheme. The sampling efficiency is enhanced using selected terms of a classical force field as a bias potential. This simple procedure yields a very substantial increase in sampling accuracy while retaining the high quality of the underlying ab initio potential surface and can thus be used for a parameter free calculation of free energy surfaces. The success of the method is demonstrated by the applications to two gas phase molecules, ethane and peroxynitrous acid, as test case systems. A statistical analysis of the results shows that the entire free energy landscape is well converged within a 40 ps simulation at 500 K, even for a system with barriers as high as 15 kcal/mol.

  16. Dielectric Meta-Holograms Enabled with Dual Magnetic Resonances in Visible Light.

    PubMed

    Li, Zile; Kim, Inki; Zhang, Lei; Mehmood, Muhammad Q; Anwar, Muhammad S; Saleem, Murtaza; Lee, Dasol; Nam, Ki Tae; Zhang, Shuang; Luk'yanchuk, Boris; Wang, Yu; Zheng, Guoxing; Rho, Junsuk; Qiu, Cheng-Wei

    2017-09-26

    Efficient transmission-type meta-holograms have been demonstrated using high-index dielectric nanostructures based on Huygens' principle. It is crucial that the geometry size of building blocks be judiciously optimized individually for spectral overlap of electric and magnetic dipoles. In contrast, reflection-type meta-holograms using the metal/insulator/metal scheme and geometric phase can be readily achieved with high efficiency and small thickness. Here, we demonstrate a general platform for design of dual magnetic resonance based meta-holograms based on the geometric phase using silicon nanostructures that are quarter wavelength thick for visible light. Significantly, the projected holographic image can be unambiguously observed without a receiving screen even under the illumination of natural light. Within the well-developed semiconductor industry, our ultrathin magnetic resonance-based meta-holograms may have promising applications in anticounterfeiting and information security.

  17. Hooke's law: applications of a recurring principle.

    PubMed

    Giuliodori, Mauricio J; Lujan, Heidi L; Briggs, Whitney S; Palani, Gurunanthan; DiCarlo, Stephen E

    2009-12-01

    Students generally approach topics in physiology as a series of unrelated phenomena that share few underlying principles. However, if students recognized that the same underlying principles can be used to explain many physiological phenomena, they may gain a more unified understanding of physiological systems. To address this concern, we developed a simple, inexpensive, and easy to build model to demonstrate the underlying principles regarding Starling's Law of the Heart as well as lung and arterial elastic recoil. A model was chosen because models significantly enhance student understanding. Working with models also encourages research-oriented learning and helps our students understand complex ideas. Students are drawn into discussion by the power of learning that is associated with manipulating and thinking about objects. Recognizing that the same underlying principles can be used to explain many physiological phenomena may help students gain a more complete understanding of physiological systems.

  18. 42 CFR 440.370 - Economy and efficiency.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Economy and efficiency. 440.370 Section 440.370...-Equivalent Coverage § 440.370 Economy and efficiency. Benchmark and benchmark-equivalent coverage and any... requirements and other economy and efficiency principles that would otherwise be applicable to the services or...

  19. 42 CFR 440.370 - Economy and efficiency.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Economy and efficiency. 440.370 Section 440.370...-Equivalent Coverage § 440.370 Economy and efficiency. Benchmark and benchmark-equivalent coverage and any... requirements and other economy and efficiency principles that would otherwise be applicable to the services or...

  20. 42 CFR 440.370 - Economy and efficiency.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Economy and efficiency. 440.370 Section 440.370...-Equivalent Coverage § 440.370 Economy and efficiency. Benchmark and benchmark-equivalent coverage and any... requirements and other economy and efficiency principles that would otherwise be applicable to the services or...

  1. 42 CFR 440.370 - Economy and efficiency.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Economy and efficiency. 440.370 Section 440.370...-Equivalent Coverage § 440.370 Economy and efficiency. Benchmark and benchmark-equivalent coverage and any... requirements and other economy and efficiency principles that would otherwise be applicable to the services or...

  2. Preferential flow, connectivity and the principle of "minimum time to equilibrium": a new perspective on environmental water flow

    NASA Astrophysics Data System (ADS)

    Zehe, E.; Blume, T.; Bloeschl, G.

    2008-12-01

    Preferential/rapid flow and transport is known as one key process in soil hydrology for more than 20 years. It seems to be rather the rule, than the exception. It occurs in soils, in surface rills and river networks. If connective preferential are present at any scale, they crucially control water flow and solute transport. Why? Is there an underlying principle? If energy is conserved a system follows Fermat's principle of minimum action i.e. it follows the trajectory that minimise the integral of the total energy/ La Grangian over time. Hydrological systems are, however, non-conservative as surface and subsurface water flows dissipate energy. From thermodynamics it is well known that natural processes minimize the free energy of the system. For hydrological systems we suggest, therefore, that flow in a catchment arranges in such a way that time to a minimum of free energy becomes minimal for a given rainfall input (disturbance) and under given constraints. Free energy in a soil is determined by potential energy and capillary energy. The pore size distribution of the soil, soil structures, depth to groundwater and most important vegetation make up the constraints. The pore size distribution determines whether potential energy or capillarity dominates the free energy of the soil system. The first term is minimal when the pore space is completely de-saturated the latter becomes minimal at soil saturation. Hence, the soil determines a) the amount of excess (gravity) water that has to be exported from the soil to reach a minimum state of free energy and b) whether redistribution or groundwater recharge is more efficient to reach that equilibrium. On the other hand, the pore size distribution of the soil and the connectivity of preferential pathways (root channels, worm holes and cracks) determine flow velocities and the redistribution of water within the pore space. As water flow and ground water recharge are fast in sandy soils and capillary energy is of minor importance, connective preferential pathways do not mean any advantage for an efficient transition to an equilibrium in these systems. In fine grained soils Darcy velocities and therefore redistribution of water is 2-4 orders of magnitude slower. As capillary energy dominates in these soils an effective redistribution of water within the pore space is crucial for a fast transition of system to an equilibrium state. Connective preferential pathways ore even cracks allow a faster redistribution of water and seem therefore necessary for a fast transition into a state of minimum free energy. The suggested principle "of minimum time to equilibrium" may explain the "advantage" of preferential flow as a much more efficient dissipation of energy in fine grained soils and therefore why connective preferential pathways control environmental flow. From a fundamental, long term perspective the principle may help us to understand whether and why soil structures and even cracks evolve in different landscapes and climates and b) to link soil hydrology and (landscape) ecology. Along the lines the proposed study will present model results to test the stated hypothesis.

  3. Multi-objective optimization of an arch dam shape under static loads using an evolutionary game method

    NASA Astrophysics Data System (ADS)

    Meng, Rui; Cheong, Kang Hao; Bao, Wei; Wong, Kelvin Kian Loong; Wang, Lu; Xie, Neng-gang

    2018-06-01

    This article attempts to evaluate the safety and economic performance of an arch dam under the action of static loads. The geometric description of a crown cantilever section and the horizontal arch ring is presented. A three-objective optimization model of arch dam shape is established based on the arch dam volume, maximum principal tensile stress and total strain energy. The evolutionary game method is then applied to obtain the optimal solution. In the evolutionary game technique, a novel and more efficient exploration method of the game players' strategy space, named the 'sorting partition method under the threshold limit', is presented, with the game profit functions constructed according to both competitive and cooperative behaviour. By way of example, three optimization goals have all shown improvements over the initial solutions. In particular, the evolutionary game method has potentially faster convergence. This demonstrates the preliminary proof of principle of the evolutionary game method.

  4. 26 CFR 1.338-5 - Adjusted grossed-up basis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... decrease with respect to an element of AGUB is required under general principles of tax law, redetermined... initially determined at the beginning of the day after the acquisition date of target. General principles of..., under general principles of tax law, with respect to an element of AGUB. For example, AGUB is...

  5. Fabrication and characterization of a 3D Positive ion detector and its applications

    NASA Astrophysics Data System (ADS)

    Venkatraman, Pitchaikannu; Sureka, Chandrasekaran Senbagavadivoo

    2017-11-01

    There is a growing interest to experimentally evaluate the track structure induced by ionizing particles in order to characterize the radiobiological quality of ionizing radiation for applications in radiotherapy and radiation protection. To do so, a novel positive ion detector based on the multilayer printed circuit board (PCB) technology has been proposed previously, which works under the principle of ion induced impact ionization. Based on this, an upgraded 3D positive ion detector was fabricated in order to improve its efficiency and use it for various applications. To improve the efficiency of the detector, cathodes with different insulators (Bakelite plate and Steatite Ceramics) and conducting layers (ITO, FTO, and Gold coated cathode) were studied under various gaseous media (methane, nitrogen, and air) using Am-241, Co-60, Co-57, Na-22, Cs-137, and Ba-133 sources. From this study, it is confirmed that the novel 3D positive ion detector that has been upgraded using gold as strip material, tungsten (87%) coated copper (13%) as the core wire, gold coated ceramic as cathode, and thickness of 3.483 mm showed 9.2% efficiency under methane medium at 0.9 Torr pressure using an Am-241 source. It is also confirmed that when the conductivity of the cathode and thickness of the detector is increased, the performance of the detector is improved significantly. Further, the scope of the detector to use in the field of radiation protection, radiation dosimetry, gamma spectrometry, radiation biology, and oncology are reported here.

  6. Strategies of Production Control as Tools of Efficient Management of Production Enterprises

    NASA Astrophysics Data System (ADS)

    Budynek, Mateusz; Celińska, Elżbieta; Dybikowska, Adrianna; Kozak, Monika; Ratajczak, Joanna; Urban, Jagoda; Materne, Karolina

    2016-03-01

    The paper discusses the problem of principle methods of production control as a strategy supporting the production system and stimulating efficient solutions in respect management in production enterprises. The article describes MRP, ERP, JIT, KANBAN and TOC methods and focuses on their main goals, principles of functioning as well as benefits resulting from their application. The methods represent two diverse strategies of production control, i.e. pull and push strategies. Push strategies are used when the plans apply to the first and principle part of production and are based on the demand forecasts. Pull strategies are used when all planning decisions apply to the final stage and depend on the actual demand or orders from customers.

  7. Exploring social welfare functions and violation of monotonicity: an example from inequalities in health.

    PubMed

    Abasolo, Ignacio; Tsuchiya, Aki

    2004-03-01

    The social welfare function (SWF) has been used within the economics literature, to study trade-offs between equality and efficiency. These SWFs are characterised by properties determined by traditional welfare economics. One of these properties, the monotonicity principle is explored in this paper. In the context of health there may be occasions when the monotonicity principle is violated as there may be circumstances where distributional issues dominate efficiency concerns. When this is the case, conventional SWFs are not flexible enough to represent such social preferences. Therefore, we propose a SWF with an alternative specification, which is general enough to accommodate preferences that are not necessarily monotonic. A survey of the Spanish general public was undertaken to estimate preferences regarding equality in health, relative to efficiency in health. The results (with 973 usable responses) give strong support to the existence of public preferences which violate the monotonicity principle, and thus to the usefulness of the alternative specification proposed here.

  8. In-channel electrochemical detection in the middle of microchannel under high electric field.

    PubMed

    Kang, Chung Mu; Joo, Segyeong; Bae, Je Hyun; Kim, Yang-Rae; Kim, Yongseong; Chung, Taek Dong

    2012-01-17

    We propose a new method for performing in-channel electrochemical detection under a high electric field using a polyelectrolytic gel salt bridge (PGSB) integrated in the middle of the electrophoretic separation channel. The finely tuned placement of a gold working electrode and the PGSB on an equipotential surface in the microchannel provided highly sensitive electrochemical detection without any deterioration in the separation efficiency or interference of the applied electric field. To assess the working principle, the open circuit potentials between gold working electrodes and the reference electrode at varying distances were measured in the microchannel under electrophoretic fields using an electrically isolated potentiostat. In addition, "in-channel" cyclic voltammetry confirmed the feasibility of electrochemical detection under various strengths of electric fields (∼400 V/cm). Effective separation on a microchip equipped with a PGSB under high electric fields was demonstrated for the electrochemical detection of biological compounds such as dopamine and catechol. The proposed "in-channel" electrochemical detection under a high electric field enables wider electrochemical detection applications in microchip electrophoresis.

  9. Local efficiency in fluvial systems: Lessons from Icicle Bend

    NASA Astrophysics Data System (ADS)

    Jerin, Tasnuba; Phillips, Jonathan

    2017-04-01

    Development of fluvial systems is often described and modeled in terms of principles related to maxima, minima, or optima of various hydraulic or energy parameters that can generally be encompassed by a principle of efficiency selection (more efficient flow routes tend to be preferentially selected and enhanced). However, efficiency selection is highly localized, and the cumulative effects of these local events may or may not produce more efficient pathways at a broader scale. This is illustrated by the case of Icicle Bend on Shawnee Run, a limestone bedrock stream in central Kentucky. Field evidence indicates that a paleochannel was abandoned during downcutting of the stream, and the relocation was analyzed using a flow partitioning model. The bend represents abandonment of a steeper, straighter, more efficient channel at the reach scale in favor of a longer, currently less steep and less efficient flow path. This apparently occurred owing to capture of Shawnee Run flow by a subsurface karst flow path that was subsequently exhumed. The development of Icicle Bend illustrates the local nature of efficiency selection and the role of historical contingency in geomorphic evolution.

  10. SU-E-T-191: First Principle Calculation of Quantum Yield in Photodynamic Therapy

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

    Abolfath, R; Guo, F; Chen, Z

    Purpose: We present a first-principle method to calculate the spin transfer efficiency in oxygen induced by any photon fields especially in MeV energy range. The optical pumping is mediated through photosensitizers, e.g., porphyrin and/or ensemble of quantum dots. Methods: Under normal conditions, oxygen molecules are in the relatively non-reactive triplet state. In the presence of certain photosensitizer compounds such as porphyrins, electromagnetic radiation of specific wavelengths can excite oxygen to highly reactive singlet state. With selective uptake of photosensitizers by certain malignant cells, photon irradiation of phosensitized tumors can lead to selective killing of cancer cells. This is the basismore » of photodynamic therapy (PDT). Despite several attempts, PDT has not been clinically successful except in limited superficial cancers. Many parameters such as photon energy, conjugation with quantum dots etc. can be potentially combined with PDT in order to extend the role of PDT in cancer management. The key quantity for this optimization is the spin transfer efficiency in oxygen by any photon field. The first principle calculation model presented here, is an attempt to fill this need. We employ stochastic density matrix description of the quantum jumps and the rate equation methods in quantum optics based on Markov/Poisson processes and calculate time evolution of the population of the optically pumped singlet oxygen. Results: The results demonstrate the feasibility of our model in showing the dependence of the optical yield in generating spin-singlet oxygen on the experimental conditions. The adjustable variables can be tuned to maximize the population of the singlet oxygen hence the efficacy of the photodynamic therapy. Conclusion: The present model can be employed to fit and analyze the experimental data and possibly to assist researchers in optimizing the experimental conditions in photodynamic therapy.« less

  11. Visible-light-driven methane formation from CO2 with a molecular iron catalyst.

    PubMed

    Rao, Heng; Schmidt, Luciana C; Bonin, Julien; Robert, Marc

    2017-08-03

    Converting CO 2 into fuel or chemical feedstock compounds could in principle reduce fossil fuel consumption and climate-changing CO 2 emissions. One strategy aims for electrochemical conversions powered by electricity from renewable sources, but photochemical approaches driven by sunlight are also conceivable. A considerable challenge in both approaches is the development of efficient and selective catalysts, ideally based on cheap and Earth-abundant elements rather than expensive precious metals. Of the molecular photo- and electrocatalysts reported, only a few catalysts are stable and selective for CO 2 reduction; moreover, these catalysts produce primarily CO or HCOOH, and catalysts capable of generating even low to moderate yields of highly reduced hydrocarbons remain rare. Here we show that an iron tetraphenylporphyrin complex functionalized with trimethylammonio groups, which is the most efficient and selective molecular electro- catalyst for converting CO 2 to CO known, can also catalyse the eight-electron reduction of CO 2 to methane upon visible light irradiation at ambient temperature and pressure. We find that the catalytic system, operated in an acetonitrile solution containing a photosensitizer and sacrificial electron donor, operates stably over several days. CO is the main product of the direct CO 2 photoreduction reaction, but a two-pot procedure that first reduces CO 2 and then reduces CO generates methane with a selectivity of up to 82 per cent and a quantum yield (light-to-product efficiency) of 0.18 per cent. However, we anticipate that the operating principles of our system may aid the development of other molecular catalysts for the production of solar fuels from CO 2 under mild conditions.

  12. Visible-light-driven methane formation from CO2 with a molecular iron catalyst

    NASA Astrophysics Data System (ADS)

    Rao, Heng; Schmidt, Luciana C.; Bonin, Julien; Robert, Marc

    2017-08-01

    Converting CO2 into fuel or chemical feedstock compounds could in principle reduce fossil fuel consumption and climate-changing CO2 emissions. One strategy aims for electrochemical conversions powered by electricity from renewable sources, but photochemical approaches driven by sunlight are also conceivable. A considerable challenge in both approaches is the development of efficient and selective catalysts, ideally based on cheap and Earth-abundant elements rather than expensive precious metals. Of the molecular photo- and electrocatalysts reported, only a few catalysts are stable and selective for CO2 reduction; moreover, these catalysts produce primarily CO or HCOOH, and catalysts capable of generating even low to moderate yields of highly reduced hydrocarbons remain rare. Here we show that an iron tetraphenylporphyrin complex functionalized with trimethylammonio groups, which is the most efficient and selective molecular electro- catalyst for converting CO2 to CO known, can also catalyse the eight-electron reduction of CO2 to methane upon visible light irradiation at ambient temperature and pressure. We find that the catalytic system, operated in an acetonitrile solution containing a photosensitizer and sacrificial electron donor, operates stably over several days. CO is the main product of the direct CO2 photoreduction reaction, but a two-pot procedure that first reduces CO2 and then reduces CO generates methane with a selectivity of up to 82 per cent and a quantum yield (light-to-product efficiency) of 0.18 per cent. However, we anticipate that the operating principles of our system may aid the development of other molecular catalysts for the production of solar fuels from CO2 under mild conditions.

  13. Design principles for radiation-resistant solid solutions

    NASA Astrophysics Data System (ADS)

    Schuler, Thomas; Trinkle, Dallas R.; Bellon, Pascal; Averback, Robert

    2017-05-01

    We develop a multiscale approach to quantify the increase in the recombined fraction of point defects under irradiation resulting from dilute solute additions to a solid solution. This methodology provides design principles for radiation-resistant materials. Using an existing database of solute diffusivities, we identify Sb as one of the most efficient solutes for this purpose in a Cu matrix. We perform density-functional-theory calculations to obtain binding and migration energies of Sb atoms, vacancies, and self-interstitial atoms in various configurations. The computed data informs the self-consistent mean-field formalism to calculate transport coefficients, allowing us to make quantitative predictions of the recombined fraction of point defects as a function of temperature and irradiation rate using homogeneous rate equations. We identify two different mechanisms according to which solutes lead to an increase in the recombined fraction of point defects; at low temperature, solutes slow down vacancies (kinetic effect), while at high temperature, solutes stabilize vacancies in the solid solution (thermodynamic effect). Extension to other metallic matrices and solutes are discussed.

  14. Optical-domain subsampling for data efficient depth ranging in Fourier-domain optical coherence tomography

    PubMed Central

    Siddiqui, Meena; Vakoc, Benjamin J.

    2012-01-01

    Recent advances in optical coherence tomography (OCT) have led to higher-speed sources that support imaging over longer depth ranges. Limitations in the bandwidth of state-of-the-art acquisition electronics, however, prevent adoption of these advances into the clinical applications. Here, we introduce optical-domain subsampling as a method for imaging at high-speeds and over extended depth ranges but with a lower acquisition bandwidth than that required using conventional approaches. Optically subsampled laser sources utilize a discrete set of wavelengths to alias fringe signals along an extended depth range into a bandwidth limited frequency window. By detecting the complex fringe signals and under the assumption of a depth-constrained signal, optical-domain subsampling enables recovery of the depth-resolved scattering signal without overlapping artifacts from this bandwidth-limited window. We highlight key principles behind optical-domain subsampled imaging, and demonstrate this principle experimentally using a polygon-filter based swept-source laser that includes an intra-cavity Fabry-Perot (FP) etalon. PMID:23038343

  15. Atom-Role-Based Access Control Model

    NASA Astrophysics Data System (ADS)

    Cai, Weihong; Huang, Richeng; Hou, Xiaoli; Wei, Gang; Xiao, Shui; Chen, Yindong

    Role-based access control (RBAC) model has been widely recognized as an efficient access control model and becomes a hot research topic of information security at present. However, in the large-scale enterprise application environments, the traditional RBAC model based on the role hierarchy has the following deficiencies: Firstly, it is unable to reflect the role relationships in complicated cases effectively, which does not accord with practical applications. Secondly, the senior role unconditionally inherits all permissions of the junior role, thus if a user is under the supervisor role, he may accumulate all permissions, and this easily causes the abuse of permission and violates the least privilege principle, which is one of the main security principles. To deal with these problems, we, after analyzing permission types and role relationships, proposed the concept of atom role and built an atom-role-based access control model, called ATRBAC, by dividing the permission set of each regular role based on inheritance path relationships. Through the application-specific analysis, this model can well meet the access control requirements.

  16. Biomagnetic fluid flow in an aneurysm using ferrohydrodynamics principles

    NASA Astrophysics Data System (ADS)

    Tzirtzilakis, E. E.

    2015-06-01

    In this study, the fundamental problem of biomagnetic fluid flow in an aneurysmal geometry under the influence of a steady localized magnetic field is numerically investigated. The mathematical model used to formulate the problem is consistent with the principles of ferrohydrodynamics. Blood is considered to be an electrically non-conducting, homogeneous, non-isothermal Newtonian magnetic fluid. For the numerical solution of the problem, which is described by a coupled, non-linear system of Partial Differential Equations (PDEs), with appropriate boundary conditions, the stream function-vorticity formulation is adopted. The solution is obtained by applying an efficient pseudotransient numerical methodology using finite differences. This methodology is based on the application of a semi-implicit numerical technique, transformations, stretching of the grid, and construction of the boundary conditions for the vorticity. The results regarding the velocity and temperature field, skin friction, and rate of heat transfer indicate that the presence of a magnetic field considerably influences the flow field, particularly in the region of the aneurysm.

  17. Evolutionary mechanics: new engineering principles for the emergence of flexibility in a dynamic and uncertain world.

    PubMed

    Whitacre, James M; Rohlfshagen, Philipp; Bender, Axel; Yao, Xin

    2012-09-01

    Engineered systems are designed to deftly operate under predetermined conditions yet are notoriously fragile when unexpected perturbations arise. In contrast, biological systems operate in a highly flexible manner; learn quickly adequate responses to novel conditions, and evolve new routines and traits to remain competitive under persistent environmental change. A recent theory on the origins of biological flexibility has proposed that degeneracy-the existence of multi-functional components with partially overlapping functions-is a primary determinant of the robustness and adaptability found in evolved systems. While degeneracy's contribution to biological flexibility is well documented, there has been little investigation of degeneracy design principles for achieving flexibility in systems engineering. Actually, the conditions that can lead to degeneracy are routinely eliminated in engineering design. With the planning of transportation vehicle fleets taken as a case study, this article reports evidence that degeneracy improves the robustness and adaptability of a simulated fleet towards unpredicted changes in task requirements without incurring costs to fleet efficiency. We find that degeneracy supports faster rates of design adaptation and ultimately leads to better fleet designs. In investigating the limitations of degeneracy as a design principle, we consider decision-making difficulties that arise from degeneracy's influence on fleet complexity. While global decision-making becomes more challenging, we also find degeneracy accommodates rapid distributed decision-making leading to (near-optimal) robust system performance. Given the range of conditions where favorable short-term and long-term performance outcomes are observed, we propose that degeneracy may fundamentally alter the propensity for adaptation and is useful within different engineering and planning contexts.

  18. 44 CFR 13.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... consolidating or breaking out procurements to obtain a more economical purchase. Where appropriate, an analysis... most economical approach. (5) To foster greater economy and efficiency, grantees and subgrantees are... consistent with Federal cost principles (see § 13.22). Grantees may reference their own cost principles that...

  19. 24 CFR 85.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... consolidating or breaking out procurements to obtain a more economical purchase. Where appropriate, an analysis... most economical approach. (5) To foster greater economy and efficiency, grantees and subgrantees are... consistent with Federal cost principles (see § 85.22). Grantees may reference their own cost principles that...

  20. 29 CFR 97.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... consolidating or breaking out procurements to obtain a more economical purchase. Where appropriate, an analysis... most economical approach. (5) To foster greater economy and efficiency, grantees and subgrantees are... consistent with Federal cost principles (see § 97.22). Grantees may reference their own cost principles that...

  1. Participatory Development Principles and Practice: Reflections of a Western Development Worker.

    ERIC Educational Resources Information Center

    Keough, Noel

    1998-01-01

    Principles for participatory community development are as follows: humility and respect; power of local knowledge; democratic practice; diverse ways of knowing; sustainability; reality before theory; uncertainty; relativity of time and efficiency; holistic approach; and decisions rooted in the community. (SK)

  2. Machines That Teach.

    ERIC Educational Resources Information Center

    Sniecinski, Jozef

    This paper reviews efforts which have been made to improve the effectiveness of teaching through the development of principles of programed teaching and the construction of teaching machines, concluding that a combination of computer technology and programed teaching principles offers an efficient approach to improving teaching. Three different…

  3. Laser-stimulated desorption of organic molecules from surfaces, as a method of increasing the efficiency of ion mobility spectrometry analysis.

    PubMed

    Akmalov, Artem E; Chistyakov, Alexander A; Kotkovskii, Gennadii E

    2017-08-01

    Application of laser-induced desorption was investigated as a method of increasing the efficiency of gas phase analyzers on principles of field asymmetric ion mobility spectrometry. Mass spectrometric data of investigations of laser desorption of pentaerythritoltetranitrate molecules and cyclotetramethylenetetranitramine molecules from quartz substrate under vacuum were obtained. Laser sources a Nd 3+ :YAG with nanosecond pulse duration (λ = 532 nm) and a continuous wave diode laser (λ = 440 nm) were used. It was shown that both laser sources have different desorption abilities. This is expressed in various time of appearance of desorbed products that is caused by different heating mechanisms of surface layer. The desorbed quantity under action of both laser sources exceeds the detection threshold for all modern gas phase analyzers. It should be noted that despite the presence of surface dissociation of explosives under laser radiation, the quantity of nondissociated molecules is large enough for detection by ion mobility and field asymmetric ion mobility spectrometers. The optimal parameters of laser radiation for effective removal (evaporation) molecules of low-volatile compounds from surfaces are defined. The conclusion about preferable use of a Nd 3+ :YAG laser for increasing the detection ability of detectors based on ion mobility spectrometry was made.

  4. Examining the Use of First Principles of Instruction by Instructional Designers in a Short-Term, High Volume, Rapid Production of Online K-12 Teacher Professional Development Modules

    ERIC Educational Resources Information Center

    Mendenhall, Anne M.

    2012-01-01

    Merrill (2002a) created a set of fundamental principles of instruction that can lead to effective, efficient, and engaging (e[superscript 3]) instruction. The First Principles of Instruction (Merrill, 2002a) are a prescriptive set of interrelated instructional design practices that consist of activating prior knowledge, using specific portrayals…

  5. DFT study on bimetallic Pt/Cu(1 1 1) as efficient catalyst for H2 dissociation

    NASA Astrophysics Data System (ADS)

    Liu, Ji; Fan, Xiaofeng; Sun, Chang Q.; Zhu, Weiguang

    2018-05-01

    To design a catalyst for the dissociation of H2 with better CO-tolerance performance is very important for proton exchange membrane fuel cells (PEMFCs) towards high efficiency. With slab model, the catalytic properties of overlayer Pt on Cu substrate (Pt/Cu) are analyzed by first-principle calculations. The CO saturation coverage (40%) on Pt2/Cu is found to be lower than that of pure Pt (about 75%). The dissociation barrier from H2 to H is less than 0.4 eV under the saturation coverage of CO. On the basis of kinetics of proton formation, the CO-tolerance ability on double-layer Pt with Cu is found to be greatly improved compared with that on pure Pt. It is expected that Pt overlayer on Cu(1 1 1) is a potential anode material with lower cost for PEMFCs.

  6. Incentive compatibility in kidney exchange problems.

    PubMed

    Villa, Silvia; Patrone, Fioravante

    2009-12-01

    The problem of kidney exchanges shares common features with the classical problem of exchange of indivisible goods studied in the mechanism design literature, while presenting additional constraints on the size of feasible exchanges. The solution of a kidney exchange problem can be summarized in a mapping from the relevant underlying characteristics of the players (patients and their donors) to the set of matchings. The goal is to select only matchings maximizing a chosen welfare function. Since the final outcome heavily depends on the private information in possess of the players, a basic requirement in order to reach efficiency is the truthful revelation of this information. We show that for the kidney exchange problem, a class of (in principle) efficient mechanisms does not enjoy the incentive compatibility property and therefore is subject to possible manipulations made by the players in order to profit of the misrepresentation of their private information.

  7. Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits.

    PubMed

    Ujfalussy, Balázs B; Makara, Judit K; Branco, Tiago; Lengyel, Máté

    2015-12-24

    Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits.

  8. EQUITY EVALUATION OF PADDY IRRIGATION WATER DISTRIBUTION BY SOCIETY-JUSTICE-WATER DISTRIBUTION RULE HYPOTHESIS

    NASA Astrophysics Data System (ADS)

    Tanji, Hajime; Kiri, Hirohide; Kobayashi, Shintaro

    When total supply is smaller than total demand, it is difficult to apply the paddy irrigation water distribution rule. The gap must be narrowed by decreasing demand. Historically, the upstream served rule, rotation schedule, or central schedule weight to irrigated area was adopted. This paper proposes the hypothesis that these rules are dependent on social justice, a hypothesis called the "Society-Justice-Water Distribution Rule Hypothesis". Justice, which means a balance of efficiency and equity of distribution, is discussed under the political philosophy of utilitarianism, liberalism (Rawls), libertarianism, and communitarianism. The upstream served rule can be derived from libertarianism. The rotation schedule and central schedule can be derived from communitarianism. Liberalism can provide arranged schedule to adjust supply and demand based on "the Difference Principle". The authors conclude that to achieve efficiency and equity, liberalism may provide the best solution after modernization.

  9. Bimetallic Ag-Pt Sub-nanometer Supported Clusters as Highly Efficient and Robust Oxidation Catalysts

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

    Negreiros, Fabio R.; Halder, Avik; Yin, Chunrong

    A combined experimental and theoretical investigation of Ag-Pt sub-nanometer clusters as heterogeneous catalysts in the CO -> CO2 reaction (COox) is presented. Ag9Pt2 and Ag9Pt3 clusters are size-selected in the gas phase, deposited on an ultrathin amorphous alumina support, and tested as catalysts experimentally under realistic conditions and by first-principles simulations at realistic coverage. Insitu GISAXS/TPRx demonstrates that the clusters do not sinter or deactivate even after prolonged exposure to reactants at high temperature, and present comparable, extremely high COox catalytic efficiency. Such high activity and stability are ascribed to a synergic role of Ag and Pt in ultranano-aggregates, inmore » which Pt anchors the clusters to the support and binds and activates two CO molecules, while Ag binds and activates O-2, and Ag/Pt surface proximity disfavors poisoning by CO or oxidized species.« less

  10. 45 CFR 602.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Consideration should be given to consolidating or breaking out procurements to obtain a more economical purchase... appropriate analysis to determine the most economical approach. (5) To foster greater economy and efficiency... consistent with Federal cost principles (see § 602.22). Grantees may reference their own cost principles that...

  11. 45 CFR 1157.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... should be given to consolidating or breaking out procurements to obtain a more economical purchase. Where... analysis to determine the most economical approach. (5) To foster greater economy and efficiency, grantees... consistent with Federal cost principles (see § 1157.22). Grantees may reference their own cost principles...

  12. 34 CFR 80.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... should be given to consolidating or breaking out procurements to obtain a more economical purchase. Where... analysis to determine the most economical approach. (5) To foster greater economy and efficiency, grantees... consistent with Federal cost principles (see § 80.22). Grantees may reference their own cost principles that...

  13. 10 CFR 600.236 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... should be given to consolidating or breaking out procurements to obtain a more economical purchase. Where... analysis to determine the most economical approach. (5) To foster greater economy and efficiency, grantees... consistent with Federal cost principles (see § 600.422). Grantees may reference their own cost principles...

  14. 28 CFR 66.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... should be given to consolidating or breaking out procurements to obtain a more economical purchase. Where... analysis to determine the most economical approach. (5) To foster greater economy and efficiency, grantees... consistent with Federal cost principles (see § 66.22). Grantees may reference their own cost principles that...

  15. 22 CFR 135.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... should be given to consolidating or breaking out procurements to obtain a more economical purchase. Where... analysis to determine the most economical approach. (5) To foster greater economy and efficiency, grantees... consistent with Federal cost principles (see § 135.22). Grantees may reference their own cost principles that...

  16. 21 CFR 1403.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Consideration should be given to consolidating or breaking out procurements to obtain a more economical purchase... appropriate analysis to determine the most economical approach. (5) To foster greater economy and efficiency... consistent with Federal cost principles (see § 1403.22). Grantees may reference their own cost principles...

  17. 49 CFR 18.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... should be given to consolidating or breaking out procurements to obtain a more economical purchase. Where... analysis to determine the most economical approach. (5) To foster greater economy and efficiency, grantees... consistent with Federal cost principles (see § 18.22). Grantees may reference their own cost principles that...

  18. 45 CFR 1174.36 - Procurement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Consideration should be given to consolidating or breaking out procurements to obtain a more economical purchase... appropriate analysis to determine the most economical approach. (5) To foster greater economy and efficiency... consistent with Federal cost principles (see § 1174.22). Grantees may reference their own cost principles...

  19. Efficiently Photocontrollable or not? Biological Activity of Photoisomerizable Diarylethenes.

    PubMed

    Komarov, Igor V; Afonin, Sergii; Babii, Oleg; Schober, Tim; Ulrich, Anne S

    2018-04-06

    Diarylethene derivatives, whose biological activity can be reversibly changed by irradiation with light of different wavelengths, have shown promise as scientific tools and as candidates for photocontrollable drugs. However, examples demonstrating efficient photocontrol of their biological activity are still relatively rare. This concept article discusses the possible reasons for this situation and presents a critical analysis of existing data and hypotheses in this field, in order to extract the design principles enabling the construction of efficient photocontrollable diarylethene-based molecules. Papers addressing biologically relevant interactions between diarylethenes and biomolecules are analyzed; however, in most published cases, the efficiency of photocontrol in living systems remains to be demonstrated. We hope that this article will encourage further discussion of design principles, primarily among pharmacologists and synthetic and medicinal chemists. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Green engineering education through a U.S. EPA/academia collaboration.

    PubMed

    Shonnard, David R; Allen, David T; Nguyen, Nhan; Austin, Sharon Weil; Hesketh, Robert

    2003-12-01

    The need to use resources efficiently and reduce environmental impacts of industrial products and processes is becoming increasingly important in engineering design; therefore, green engineering principles are gaining prominence within engineering education. This paper describes a general framework for incorporating green engineering design principles into engineering curricula, with specific examples for chemical engineering. The framework for teaching green engineering discussed in this paper mirrors the 12 Principles of Green Engineering proposed by Anastas and Zimmerman (Environ. Sci. Technol. 2003, 37, 94A-101A), especially in methods for estimating the hazardous nature of chemicals, strategies for pollution prevention, and approaches leading to efficient energy and material utilization. The key elements in green engineering education, which enlarge the "box" for engineering design, are environmental literacy, environmentally conscious design, and beyond-the-plant boundary considerations.

  1. Photoexcitation and Photochemical Stability of Organic Photovoltaic Materials from First Principles

    NASA Astrophysics Data System (ADS)

    Sai, Na; Leung, Kevin

    2013-03-01

    The development of high efficiency organic photovoltaics (OPV) has recently become enabled by the synthesis of new conjugated polymers with low band gap that allow light absorption over a broader range of the spectrum. Stability of these new polymers, a key requirement for commercialization, has not yet received sufficient attention. Here, we report first-principles theoretical modeling of photo-induced degradation of OPV polymers carried out using ab-initio density functional theory (DFT). We report photooxidation routes and reaction products for reactive species including superoxide oxygen anions and hydroxyl groups interacting with the standard workhorse OPV polymer, poly(3-hexyl-thiophene) (P3HT). We discuss theoretical issues and challenges affecting the modeling such reactions in OPV polymers. We also discuss the application of theoretical methods to low-band-gap polymers, and in particular, the effect of the chemical substitution on the photoexcitation properties of these new polymers. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Deparment of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. This work is supported by the Energy Frontier Research Center funded by the U.S. DOE Office of Basic Energy Sciences under Award number DE-SC0001091.

  2. Performance analysis of a microfluidic mixer based on high gradient magnetic separation principles

    NASA Astrophysics Data System (ADS)

    Liu, Mengyu; Han, Xiaotao; Cao, Quanliang; Li, Liang

    2017-09-01

    To achieve a rapid mixing between a water-based ferrofluid and DI water in a microfluidic environment, a magnetically actuated mixing system based on high gradient magnetic separation principles is proposed in this work. The microfluidic system consists of a T-shaped mirochannel and an array of integrated soft-magnetic elements at the sidewall of the channel. With the aid of an external magnetic bias field, these elements are magnetized to produce a magnetic volume force acting on the fluids containing magnetic nanoparticles, and then to induce additional flows for improving the mixing performance. The mixing process is numerically investigated through analyzing the concentration distribution of magnetic nanoparticles using a coupled particle-fluid transport model, and mixing performances under different parametrical conditions are investigated in detail. Numerical results show that a high mixing efficiency around 97.5% can be achieved within 2 s under an inlet flow rate of 1 mm s-1 and a relatively low magnetic bias field of 50 mT. Meanwhile, it has been found that there is an optimum number of magnetic elements used for obtaining the best mixing performance. These results show the potential of the proposed mixing method in lab-on-a-chip system and could be helpful in designing and optimizing system performance.

  3. Size-tunable band alignment and optoelectronic properties of transition metal dichalcogenide van der Waals heterostructures

    NASA Astrophysics Data System (ADS)

    Zhao, Yipeng; Yu, Wangbing; Ouyang, Gang

    2018-01-01

    2D transition metal dichalcogenide (TMDC)-based heterostructures exhibit several fascinating properties that can address the emerging market of energy conversion and storage devices. Current achievements show that the vertical stacked TMDC heterostructures can form type II band alignment and possess significant optoelectronic properties. However, a detailed analytical understanding of how to quantify the band alignment and band offset as well as the optimized power conversion efficiency (PCE) is still lacking. Herein, we propose an analytical model to exhibit the PCEs of TMDC van der Waals (vdW) heterostructures and explore the intrinsic mechanism of photovoltaic conversion based on the detailed balance principle and atomic-bond-relaxation correlation mechanism. We find that the PCE of monolayer MoS2/WSe2 can be up to 1.70%, and that of the MoS2/WSe2 vdW heterostructures increases with thickness, owing to increasing optical absorption. Moreover, the results are validated by comparing them with the available evidence, providing realistic efficiency targets and design principles. Highlights • Both electronic and optoelectronic models are developed for vertical stacked MoS2/WSe2 heterostructures. • The underlying mechanism on size effect of electronic and optoelectronic properties for vertical stacked MoS2/WSe2 heterostructures is clarified. • The macroscopically measurable quantities and the microscopical bond identities are connected.

  4. [The precautionary principle, research and drugs].

    PubMed

    Joly, P

    2000-01-01

    The research, in general, the medical research and the research of new drugs are following the same rules. To be fruitful, they have not to be "a priori" censured, but they have to be prudent on the means they are using and the aims they are pursuing. It's up to the researcher to explain to the public the necessity of the used means and the utility of his discovery. The public, indeed, may be not significantly informed and can be afraid by what is difficult to understand or by what is changing its customs. At the end of the pre-clinic period of research, the discovered substance has to confirm on human being its innocuity and its efficiency. At this time, the experimentation is controlled by several procedures under the control of French and European administrations. All these procedures have to be conducted according to several "Good Practices". The aims are to protect the human being, to define if the new drug is well-tolerated and efficient and what is the ratio Benefit/Risk. Even after the marketing of the new drug, the usage of the new drug is controlled (Drug Safety). So we can consider that precautionary principle is soon applied to the drug according to a very sophisticated and evolutionary mechanism. But as satisfactory it can appear, we must keep vigilant because the zero risk does not exist.

  5. Research status and evaluation system of heat source evaluation method for central heating

    NASA Astrophysics Data System (ADS)

    Sun, Yutong; Qi, Junfeng; Cao, Yi

    2018-02-01

    The central heating boiler room is a regional heat source heating center. It is also a kind of the urban environment pollution, it is an important section of building energy efficiency. This article through to the evaluation method of central heating boiler room and overviews of the researches during domestic and overseas, summarized the main influence factors affecting energy consumption of industrial boiler under the condition of stable operation. According to the principle of establishing evaluation index system. We can find that is great significance in energy saving and environmental protection for the content of the evaluation index system of the centralized heating system.

  6. Formation of plasmon pulses in the cooperative decay of excitons of quantum dots near a metal surface

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

    Shesterikov, A. B.; Gubin, M. Yu.; Gladush, M. G.

    The formation of pulses of surface electromagnetic waves at a metal–dielectric boundary is considered in the process of cooperative decay of excitons of quantum dots distributed near a metal surface in a dielectric layer. It is shown that the efficiency of exciton energy transfer to excited plasmons can, in principle, be increased by selecting the dielectric material with specified values of the complex permittivity. It is found that in the mean field approximation, the semiclassical model of formation of plasmon pulses in the system under study is reduced to the pendulum equation with the additional term of nonlinear losses.

  7. Exhaust gas oxygen sensors

    NASA Astrophysics Data System (ADS)

    Hetrick, Robert E.; Hohnke, D. K.; Logothetis, E. M.

    1981-01-01

    Ceramic ZrO2, TiO2 and related oxides with suitable O2-sensitive electrical properties have found important applications in devices for measuring exhaust-gas O2 concentration. For example, such devices are key components in feedback control systems that would maintain the intake air-to-fuel ratio near the stoichiometric value where regulated emissions can be minimized. The physical principles underlying the operation of ZrO2 based O2-concentration cells and TiO2-based resistive devices for the stoichiometric application are described. Finally, a device based on electrochemical O2 pumping is discussed which may be useful for A/F control in the fuel-efficient lean region.

  8. The Impact of Multimedia and Redundancy on the Efficiency of History Presentations

    ERIC Educational Resources Information Center

    Leach, Adam

    2012-01-01

    The use of educational technology to create classroom presentations is already commonplace in American history classes. Therefore, this study focuses on how multimedia presentations can promote efficient instruction specifically, can the employment of the multimedia and redundancy principles (Mayer, 2009) improve the efficiency of student learning…

  9. [Organization of clinical emergency units. Mission and environmental factors determine the organizational concept].

    PubMed

    Genewein, U; Jakob, M; Bingisser, R; Burla, S; Heberer, M

    2009-02-01

    Mission and organization of emergency units were analysed to understand the underlying principles and concepts. The recent literature (2000-2007) on organizational structures and functional concepts of clinical emergency units was reviewed. An organizational portfolio based on the criteria specialization (presence of medical specialists on the emergency unit) and integration (integration of the emergency unit into the hospital structure) was established. The resulting organizational archetypes were comparatively assessed based on established efficiency criteria (efficiency of resource utilization, process efficiency, market efficiency). Clinical emergency units differ with regard to autonomy (within the hospital structure), range of services and service depth (horizontal and vertical integration). The "specialization"-"integration"-portfolio enabled the definition of typical organizational patterns (so-called archetypes): profit centres primarily driven by economic objectives, service centres operating on the basis of agreements with the hospital board, functional clinical units integrated into medical specialty units (e.g., surgery, gynaecology) and modular organizations characterized by small emergency teams that would call specialists immediately after triage and initial diagnostic. There is no "one fits all" concept for the organization of clinical emergency units. Instead, a number of well characterized organizational concepts are available enabling a rational choice based on a hospital's mission and demand.

  10. Tension-Enhanced Hydrogen Evolution Reaction on Vanadium Disulfide Monolayer

    NASA Astrophysics Data System (ADS)

    Pan, Hui

    2016-02-01

    Water electrolysis is an efficient way for hydrogen production. Finding efficient, cheap, and eco-friendly electrocatalysts is essential to the development of this technology. In the work, we present a first-principles study on the effects of tension on the hydrogen evolution reaction of a novel electrocatalyst, vanadium disulfide (VS2) monolayer. Two electrocatalytic processes, individual and collective processes, are investigated. We show that the catalytic ability of VS2 monolayer at higher hydrogen coverage can be efficiently improved by escalating tension. We find that the individual process is easier to occur in a wide range of hydrogen coverage and the collective process is possible at a certain hydrogen coverage under the same tension. The best hydrogen evolution reaction with near-zero Gibbs free energy can be achieved by tuning tension. We further show that the change of catalytic activity with tension and hydrogen coverage is induced by the change of free carrier density around the Fermi level, that is, higher carrier density, better catalytic performance. It is expected that tension can be a simple way to improve the catalytic activity, leading to the design of novel electrocatalysts for efficient hydrogen production from water electrolysis.

  11. Design and implementation of an array of micro-electrochemical detectors for two-dimensional liquid chromatography--proof of principle.

    PubMed

    Abia, Jude A; Putnam, Joel; Mriziq, Khaled; Guiochon, Georges A

    2010-03-05

    Simultaneous two-dimensional liquid chromatography (2D-LC) is an implementation of two-dimensional liquid chromatography which has the potential to provide very fast, yet highly efficient separations. It is based on the use of time x space and space x space separation systems. The basic principle of this instrument has been validated long ago by the success of two-dimensional thin layer chromatography. The construction of a pressurized wide and flat column (100 mm x 100 mm x 1 mm) operated under an inlet pressure of up to 50 bar was described previously. However, to become a modern analytical method, simultaneous 2D-LC requires the development of detectors suitable for the monitoring of the composition of the eluent of this pressurized planar, wide column. An array of five equidistant micro-electrochemical sensors was built for this purpose and tested. Each sensor is a three-electrode system, with the working electrode being a 25 microm polished platinum micro-electrode. The auxiliary electrode is a thin platinum wire and the reference electrode an Ag/AgCl (3M sat. KCl) electrode. In this first implementation, proof of principle is demonstrated, but the final instrument will require a much larger array. 2010 Elsevier B.V. All rights reserved.

  12. Principles of a Sound State School Finance System.

    ERIC Educational Resources Information Center

    National Conference of State Legislatures, Denver, CO.

    Funding for public elementary and secondary education is a significant portion of most state budgets, representing on average approximately one-third of general fund appropriations. This booklet provides policymakers with five broad principles for the design of state school funding systems--equity, efficiency, adequacy, accountability, and…

  13. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... safely within traffic laws and regulations and maintain an effective and efficient flow of traffic... 32 National Defense 4 2013-07-01 2013-07-01 false Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic...

  14. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... safely within traffic laws and regulations and maintain an effective and efficient flow of traffic... 32 National Defense 4 2012-07-01 2011-07-01 true Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic...

  15. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... safely within traffic laws and regulations and maintain an effective and efficient flow of traffic... 32 National Defense 4 2014-07-01 2013-07-01 true Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic...

  16. Second principle approach to the analysis of unsteady flow and heat transfer in a tube with arc-shaped corrugation

    NASA Astrophysics Data System (ADS)

    Pagliarini, G.; Vocale, P.; Mocerino, A.; Rainieri, S.

    2017-01-01

    Passive convective heat transfer enhancement techniques are well known and widespread tool for increasing the efficiency of heat transfer equipment. In spite of the ability of the first principle approach to forecast the macroscopic effects of the passive techniques for heat transfer enhancement, namely the increase of both the overall heat exchanged and the head losses, a first principle analysis based on energy, momentum and mass local conservation equations is hardly able to give a comprehensive explanation of how local modifications in the boundary layers contribute to the overall effect. A deeper insight on the heat transfer enhancement mechanisms can be instead obtained within a second principle approach, through the analysis of the local exergy dissipation phenomena which are related to heat transfer and fluid flow. To this aim, the analysis based on the second principle approach implemented through a careful consideration of the local entropy generation rate seems the most suitable, since it allows to identify more precisely the cause of the loss of efficiency in the heat transfer process, thus providing a useful guide in the choice of the most suitable heat transfer enhancement techniques.

  17. The Deformations of Carbon Nanotubes under Cutting.

    PubMed

    Deng, Jue; Wang, Chao; Guan, Guozhen; Wu, Hao; Sun, Hong; Qiu, Longbin; Chen, Peining; Pan, Zhiyong; Sun, Hao; Zhang, Bo; Che, Renchao; Peng, Huisheng

    2017-08-22

    The determination of structural evolution at the atomic level is essential to understanding the intrinsic physics and chemistries of nanomaterials. Mechanochemistry represents a promising method to trace structural evolution, but conventional mechanical tension generates random breaking points, which makes it unavailable for effective analysis. It remains difficult to find an appropriate model to study shear deformations. Here, we synthesize high-modulus carbon nanotubes that can be cut precisely, and the structural evolution is efficiently investigated through a combination of geometry phase analysis and first-principles calculations. The lattice fluctuation depends on the anisotropy, chirality, curvature, and slicing rate. The strain distribution further reveals a plastic breaking mechanism for the conjugated carbon atoms under cutting. The resulting sliced carbon nanotubes with controllable sizes and open ends are promising for various applications, for example, as an anode material for lithium-ion batteries.

  18. Design principles for single standing nanowire solar cells: going beyond the planar efficiency limits.

    PubMed

    Zeng, Yang; Ye, Qinghao; Shen, Wenzhong

    2014-05-09

    Semiconductor nanowires (NWs) have long been used in photovoltaic applications but restricted to approaching the fundamental efficiency limits of the planar devices with less material. However, recent researches on standing NWs have started to reveal their potential of surpassing these limits when their unique optical property is utilized in novel manners. Here, we present a theoretical guideline for maximizing the conversion efficiency of a single standing NW cell based on a detailed study of its optical absorption mechanism. Under normal incidence, a standing NW behaves as a dielectric resonator antenna, and its optical cross-section shows its maximum when the lowest hybrid mode (HE11δ) is excited along with the presence of a back-reflector. The promotion of the cell efficiency beyond the planar limits is attributed to two effects: the built-in concentration caused by the enlarged optical cross-section, and the shifting of the absorption front resulted from the excited mode profile. By choosing an optimal NW radius to support the HE11δ mode within the main absorption spectrum, we demonstrate a relative conversion-efficiency enhancement of 33% above the planar cell limit on the exemplary a-Si solar cells. This work has provided a new basis for designing and analyzing standing NW based solar cells.

  19. Design principles for single standing nanowire solar cells: going beyond the planar efficiency limits

    PubMed Central

    Zeng, Yang; Ye, Qinghao; Shen, Wenzhong

    2014-01-01

    Semiconductor nanowires (NWs) have long been used in photovoltaic applications but restricted to approaching the fundamental efficiency limits of the planar devices with less material. However, recent researches on standing NWs have started to reveal their potential of surpassing these limits when their unique optical property is utilized in novel manners. Here, we present a theoretical guideline for maximizing the conversion efficiency of a single standing NW cell based on a detailed study of its optical absorption mechanism. Under normal incidence, a standing NW behaves as a dielectric resonator antenna, and its optical cross-section shows its maximum when the lowest hybrid mode (HE11δ) is excited along with the presence of a back-reflector. The promotion of the cell efficiency beyond the planar limits is attributed to two effects: the built-in concentration caused by the enlarged optical cross-section, and the shifting of the absorption front resulted from the excited mode profile. By choosing an optimal NW radius to support the HE11δ mode within the main absorption spectrum, we demonstrate a relative conversion-efficiency enhancement of 33% above the planar cell limit on the exemplary a-Si solar cells. This work has provided a new basis for designing and analyzing standing NW based solar cells. PMID:24810591

  20. Efficiency gain of solid oxide fuel cell systems by using anode offgas recycle - Results for a small scale propane driven unit

    NASA Astrophysics Data System (ADS)

    Dietrich, Ralph-Uwe; Oelze, Jana; Lindermeir, Andreas; Spitta, Christian; Steffen, Michael; Küster, Torben; Chen, Shaofei; Schlitzberger, Christian; Leithner, Reinhard

    The transfer of high electrical efficiencies of solid oxide fuel cells (SOFC) into praxis requires appropriate system concepts. One option is the anode-offgas recycling (AOGR) approach, which is based on the integration of waste heat using the principle of a chemical heat pump. The AOGR concept allows a combined steam- and dry-reforming of hydrocarbon fuel using the fuel cell products steam and carbon dioxide. SOFC fuel gas of higher quantity and quality results. In combination with internal reuse of waste heat the system efficiency increases compared to the usual path of partial oxidation (POX). The demonstration of the AOGR concept with a 300 Wel-SOFC stack running on propane required: a combined reformer/burner-reactor operating in POX (start-up) and AOGR modus; a hotgas-injector for anode-offgas recycling to the reformer; a dynamic process model; a multi-variable process controller; full system operation for experimental proof of the efficiency gain. Experimental results proof an efficiency gain of 18 percentage points (η·POX = 23%, η·AOGR = 41%) under idealized lab conditions. Nevertheless, further improvements of injector performance, stack fuel utilization and additional reduction of reformer reformer O/C ratio and system pressure drop are required to bring this approach into self-sustaining operation.

  1. Oscillation-based methods for actuation and manipulation of nano-objects

    NASA Astrophysics Data System (ADS)

    Popov, V. L.

    2017-09-01

    We discuss how oscillations can be used for fixation or manipulation of nano-objects or producing nano-drives. The underlying principles are scale-invariant and principally can be scaled down up to the molecular scale. The main underlying principle of fixation and actuation occurs to be symmetry breaking of an oscillating system. From this unifying standpoint, a series of actuation principles are discussed as dragging, ratchets, micro walking, friction-inertia actuators, oscillation tweezers, flagella motors for propulsion in liquids as well as some recently proposed actuation principles.

  2. Intracellular Peptide Self-Assembly: A Biomimetic Approach for in Situ Nanodrug Preparation.

    PubMed

    Du, Wei; Hu, Xiaomu; Wei, Weichen; Liang, Gaolin

    2018-04-18

    Most nanodrugs are preprepared by encapsulating or loading the drugs with nanocarriers (e.g., dendrimers, liposomes, micelles, and polymeric nanoparticles). However, besides the low bioavailability and fast excretion of the nanodrugs in vivo, nanocarriers often exhibit in vitro and in vivo cytotoxicity, oxidative stress, and inflammation. Self-assembly is a ubiquitous process in biology where it plays important roles and underlies the formation of a wide variety of complex biological structures. Inspired by some cellular nanostructures (e.g., actin filaments, microtubules, vesicles, and micelles) in biological systems which are formed via molecular self-assembly, in recent decades, scientists have utilized self-assembly of oligomeric peptide under specific physiological or pathological environments to in situ construct nanodrugs for lesion-targeted therapies. On one hand, peptide-based nanodrugs always have some excellent intrinsic chemical (specificity, intrinsic bioactivity, biodegradability) and physical (small size, conformation) properties. On the other hand, stimuli-regulated intracellular self-assembly of nanodrugs is quite an efficient way to accumulate the drugs in lesion location and can realize an in situ slow release of the drugs. In this review article, we provided an overview on recent design principles for intracellular peptide self-assembly and illustrate how these principles have been applied for the in situ preparation of nanodrugs at the lesion location. In the last part, we list some challenges underlying this strategy and their possible solutions. Moreover, we envision the future possible theranostic applications of this strategy.

  3. The Neural Mechanism Exploration of Adaptive Motor Control: Dynamical Economic Cell Allocation in the Primary Motor Cortex.

    PubMed

    Li, Wei; Guo, Yangyang; Fan, Jing; Ma, Chaolin; Ma, Xuan; Chen, Xi; He, Jiping

    2017-05-01

    Adaptive flexibility is of significance for the smooth and efficient movements in goal attainment. However, the underlying work mechanism of the cerebral cortex in adaptive motor control still remains unclear. How does the cerebral cortex organize and coordinate the activity of a large population of cells in the implementation of various motor strategies? To explore this issue, single-unit activities from the M1 region and kinematic data were recorded simultaneously in monkeys performing 3D reach-to-grasp tasks with different perturbations. Varying motor control strategies were employed and achieved in different perturbed tasks, via the dynamic allocation of cells to modulate specific movement parameters. An economic principle was proposed for the first time to describe a basic rule for cell allocation in the primary motor cortex. This principle, defined as the Dynamic Economic Cell Allocation Mechanism (DECAM), guarantees benefit maximization in cell allocation under limited neuronal resources, and avoids committing resources to uneconomic investments for unreliable factors with no or little revenue. That is to say, the cells recruited are always preferentially allocated to those factors with reliable return; otherwise, the cells are dispatched to respond to other factors about task. The findings of this study might partially reveal the working mechanisms underlying the role of the cerebral cortex in adaptive motor control, wherein is also of significance for the design of future intelligent brain-machine interfaces and rehabilitation device.

  4. The similia principle: results obtained in a cellular model system.

    PubMed

    Wiegant, Fred; Van Wijk, Roeland

    2010-01-01

    This paper describes the results of a research program focused on the beneficial effect of low dose stress conditions that were applied according to the similia principle to cells previously disturbed by more severe stress conditions. In first instance, we discuss criteria for research on the similia principle at the cellular level. Then, the homologous ('isopathic') approach is reviewed, in which the initial (high dose) stress used to disturb cellular physiology and the subsequent (low dose) stress are identical. Beneficial effects of low dose stress are described in terms of increased cellular survival capacity and at the molecular level as an increase in the synthesis of heat shock proteins (hsps). Both phenomena reflect a stimulation of the endogenous cellular self-recovery capacity. Low dose stress conditions applied in a homologous approach stimulate the synthesis of hsps and enhance survival in comparison with stressed cells that were incubated in the absence of low dose stress conditions. Thirdly, the specificity of the low dose stress condition is described where the initial (high dose) stress is different in nature from the subsequently applied (low dose) stress; the heterologous or 'heteropathic' approach. The results support the similia principle at the cellular level and add to understanding of how low dose stress conditions influence the regulatory processes underlying self-recovery. In addition, the phenomenon of 'symptom aggravation' which is also observed at the cellular level, is discussed in the context of self-recovery. Finally, the difference in efficiency between the homologous and the heterologous approach is discussed; a perspective is indicated for further research; and the relationship between studies on the similia principle and the recently introduced concept of 'postconditioning hormesis' is emphasized. Copyright 2009 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  5. Charting a path to efficiencies following a merger.

    PubMed

    Klar, Brandon; Shufelt, Gregory P

    2015-06-01

    Health systems can access the full range of opportunities for enhanced efficiencies following a merger or an acquisition by pursuing the following five-step process, which constitutes the development of a business plan of operational efficiencies: Secure executive sponsorship and involvement. Establish an integration steering committee. Develop guiding principles. Identify and validate potential efficiencies. Develop an action plan for each department and function.

  6. 10 CFR 433.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Sustainable principles for siting, design and construction. [Reserved] 433.6 Section 433.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND CONSTRUCTION OF NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL...

  7. Efficient Predictions of Excited State for Nanomaterials Using Aces 3 and 4

    DTIC Science & Technology

    2017-12-20

    by first-principle methods in the software package ACES by using large parallel computers, growing tothe exascale. 15. SUBJECT TERMS Computer...modeling, excited states, optical properties, structure, stability, activation barriers first principle methods , parallel computing 16. SECURITY...2 Progress with new density functional methods

  8. 10 CFR 433.6 - Sustainable principles for siting, design and construction. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Sustainable principles for siting, design and construction. [Reserved] 433.6 Section 433.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND CONSTRUCTION OF NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL...

  9. Finding e[superscript 3] (Effective, Efficient, and Engaging) Instruction

    ERIC Educational Resources Information Center

    Merrill, M. David

    2009-01-01

    From a review of instructional design theories, research, and practice, the author has derived his "First Principles of Instruction". In this article, he suggests a rubric for using these principles to evaluate existing instruction. The article presents a Course Evaluation form and accompanying demonstration and application rubrics that enable the…

  10. The Power of “Principles” in a National Pharmaceuticals Strategy

    PubMed Central

    MacPherson, Catherine S.; Kenny, Nuala P.

    2009-01-01

    The role of principles in shaping the development of public policy has garnered increasing attention. The authors explore the role of underlying principles in the development of a Canadian National Pharmaceuticals Strategy (NPS), an area in which practical policy development has been disappointing. In analyzing proposed principles for a NPS identified in government documents and by a set of major stakeholder coalitions, they find broad agreement on principles underlying a NPS, particularly regarding equity, accessibility, safety and effectiveness. However, the identification of principles for a NPS has not motivated practical policy progress in this crucial area. Some reasons for this failure are rooted in the current state of ethics and principles in health policy and some in the value-laden, interest-dominated nature of pharmaceutical policy itself. PMID:19377353

  11. Efficient hybrid metrology for focus, CD, and overlay

    NASA Astrophysics Data System (ADS)

    Tel, W. T.; Segers, B.; Anunciado, R.; Zhang, Y.; Wong, P.; Hasan, T.; Prentice, C.

    2017-03-01

    In the advent of multiple patterning techniques in semiconductor industry, metrology has progressively become a burden. With multiple patterning techniques such as Litho-Etch-Litho-Etch and Sidewall Assisted Double Patterning, the number of processing step have increased significantly and therefore, so as the amount of metrology steps needed for both control and yield monitoring. The amount of metrology needed is increasing in each and every node as more layers needed multiple patterning steps, and more patterning steps per layer. In addition to this, there is that need for guided defect inspection, which in itself requires substantially denser focus, overlay, and CD metrology as before. Metrology efficiency will therefore be cruicial to the next semiconductor nodes. ASML's emulated wafer concept offers a highly efficient method for hybrid metrology for focus, CD, and overlay. In this concept metrology is combined with scanner's sensor data in order to predict the on-product performance. The principle underlying the method is to isolate and estimate individual root-causes which are then combined to compute the on-product performance. The goal is to use all the information available to avoid ever increasing amounts of metrology.

  12. Work extremum principle: structure and function of quantum heat engines.

    PubMed

    Allahverdyan, Armen E; Johal, Ramandeep S; Mahler, Guenter

    2008-04-01

    We consider a class of quantum heat engines consisting of two subsystems interacting with a work-source and coupled to two separate baths at different temperatures Th>Tc. The purpose of the engine is to extract work due to the temperature difference. Its dynamics is not restricted to the near equilibrium regime. The engine structure is determined by maximizing the extracted work under various constraints. When this maximization is carried out at finite power, the engine dynamics is described by well-defined temperatures and satisfies the local version of the second law. In addition, its efficiency is bounded from below by the Curzon-Ahlborn value 1-radical Tc/Th and from above by the Carnot value 1-(Tc/Th). The latter is reached-at finite power--for a macroscopic engine, while the former is achieved in the equilibrium limit Th-->Tc . The efficiency that maximizes the power is strictly larger than the Curzon-Ahloborn value. When the work is maximized at a zero power, even a small (few-level) engine extracts work right at the Carnot efficiency.

  13. Comparison of AGE and Spectral Methods for the Simulation of Far-Wakes

    NASA Technical Reports Server (NTRS)

    Bisset, D. K.; Rogers, M. M.; Kega, Dennis (Technical Monitor)

    1999-01-01

    Turbulent flow simulation methods based on finite differences are attractive for their simplicity, flexibility and efficiency, but not always for accuracy or stability. This report demonstrates that a good compromise is possible with the Advected Grid Explicit (AGE) method. AGE has proven to be both efficient and accurate for simulating turbulent free-shear flows, including planar mixing layers and planar jets. Its efficiency results from its localized fully explicit finite difference formulation (Bisset 1998a,b) that is very straightforward to compute, outweighing the need for a fairly small timestep. Also, most of the successful simulations were slightly under-resolved, and therefore they were, in effect, large-eddy simulations (LES) without a sub-grid-scale (SGS) model, rather than direct numerical simulations (DNS). The principle is that the role of the smallest scales of turbulent motion (when the Reynolds number is not too low) is to dissipate turbulent energy, and therefore they do not have to be simulated when the numerical method is inherently dissipative at its resolution limits. Such simulations are termed 'auto-LES' (LES with automatic SGS modeling) in this report.

  14. 78 FR 4417 - Draft Guidance for Industry and Food and Drug Administration Staff; Submissions for Postapproval...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... intends to provide the underlying principles to determine the type of marketing submission that may be... industry and FDA staff on the underlying principles to determine the type of marketing submission that may... Modifications to a Combination Product Approved Under Certain Marketing Applications; Availability AGENCY: Food...

  15. 48 CFR 252.231-7000 - Supplemental cost principles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... principles. 252.231-7000 Section 252.231-7000 Federal Acquisition Regulations System DEFENSE ACQUISITION... of Provisions And Clauses 252.231-7000 Supplemental cost principles. As prescribed in 231.100-70, use the following clause: Supplemental Cost Principles (DEC 1991) When the allowability of costs under...

  16. A pilot study designed to acquaint medical educators with basic pedagogic principles.

    PubMed

    McLeod, P J; Brawer, J; Steinert, Y; Chalk, C; McLeod, A

    2008-02-01

    Faculty development activities in medical schools regularly target teaching behaviours but rarely address basic pedagogic principles underlying those behaviours. Although many teachers have an intuitive or tacit knowledge of basic pedagogic principles, overt knowledge of fundamental educational principles is rare. We conducted a short-term pilot study designed to transform teachers' tacit knowledge into explicit knowledge of pedagogic principles. We hypothesized that conscious awareness of these principles will positively influence their teaching effectiveness. The intervention included a workshop, provision of a workbook on pedagogic principles and free access to educational consultants. For the intervention, we chose a purposive sample of experienced teachers at our medical school. Evaluation of the impact of the intervention using questionnaires and semi-structured interviews revealed three notable findings; 1. Participants were surprised to discover the existence of an extensive body of pedagogic science underlying teaching and learning. 2. They were enthusiastic about the intervention and expressed interest in learning more about basic pedagogic principles. 3. The knowledge acquired had an immediate impact on their teaching.

  17. Handicap principle implies emergence of dimorphic ornaments

    PubMed Central

    2016-01-01

    Species spanning the animal kingdom have evolved extravagant and costly ornaments to attract mating partners. Zahavi's handicap principle offers an elegant explanation for this: ornaments signal individual quality, and must be costly to ensure honest signalling, making mate selection more efficient. Here, we incorporate the assumptions of the handicap principle into a mathematical model and show that they are sufficient to explain the heretofore puzzling observation of bimodally distributed ornament sizes in a variety of species. PMID:27903876

  18. The Size and Role of Government: Economic Issues

    DTIC Science & Technology

    2009-07-01

    results in a net loss in economic efficiency over time. 32 See, for example, N. Gregory Mankiw , Principles of Microeconomics (Fort Worth: Dryden Press...Act of 1986 (P.L. 99-514) as a good example of a tax reform that followed this principle . The Size and Role of Government: Economic Issues...sacrifice principle that tax rates should be set by income status such that taxes reduce the welfare of all taxpayers equally (so that high income

  19. Beyond Moore’s technologies: operation principles of a superconductor alternative

    PubMed Central

    Klenov, Nikolay V; Bakurskiy, Sergey V; Kupriyanov, Mikhail Yu; Gudkov, Alexander L; Sidorenko, Anatoli S

    2017-01-01

    The predictions of Moore’s law are considered by experts to be valid until 2020 giving rise to “post-Moore’s” technologies afterwards. Energy efficiency is one of the major challenges in high-performance computing that should be answered. Superconductor digital technology is a promising post-Moore’s alternative for the development of supercomputers. In this paper, we consider operation principles of an energy-efficient superconductor logic and memory circuits with a short retrospective review of their evolution. We analyze their shortcomings in respect to computer circuits design. Possible ways of further research are outlined. PMID:29354341

  20. 24 CFR 3282.402 - General principles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false General principles. 3282.402... and Remedial Actions § 3282.402 General principles. (a) Nothing in this subpart or in these... manufactured home manufacturers to provide remedial actions under this subpart is limited by the principle that...

  1. 45 CFR Appendix E to Part 74 - Principles for Determining Costs Applicable to Research and Development Under Grants and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Research and Development Under Grants and Contracts With Hospitals E Appendix E to Part 74 Public Welfare... Research and Development Under Grants and Contracts With Hospitals i. purpose and scope A. Objectives. This appendix provides principles for determining the costs applicable to research and development work...

  2. 45 CFR Appendix E to Part 74 - Principles for Determining Costs Applicable to Research and Development Under Grants and...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Research and Development Under Grants and Contracts With Hospitals E Appendix E to Part 74 Public Welfare... Research and Development Under Grants and Contracts With Hospitals i. purpose and scope A. Objectives. This appendix provides principles for determining the costs applicable to research and development work...

  3. 45 CFR Appendix E to Part 74 - Principles for Determining Costs Applicable to Research and Development Under Grants and...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Research and Development Under Grants and Contracts With Hospitals E Appendix E to Part 74 Public Welfare... Research and Development Under Grants and Contracts With Hospitals i. purpose and scope A. Objectives. This appendix provides principles for determining the costs applicable to research and development work...

  4. 45 CFR Appendix E to Part 74 - Principles for Determining Costs Applicable to Research and Development Under Grants and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Research and Development Under Grants and Contracts With Hospitals E Appendix E to Part 74 Public Welfare... Research and Development Under Grants and Contracts With Hospitals i. purpose and scope A. Objectives. This appendix provides principles for determining the costs applicable to research and development work...

  5. 45 CFR Appendix E to Part 74 - Principles for Determining Costs Applicable to Research and Development Under Grants and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Research and Development Under Grants and Contracts With Hospitals E Appendix E to Part 74 Public Welfare... Research and Development Under Grants and Contracts With Hospitals i. purpose and scope A. Objectives. This appendix provides principles for determining the costs applicable to research and development work...

  6. A Framework for Developing Sustainable E-Learning Programmes

    ERIC Educational Resources Information Center

    Chipere, Ngoni

    2017-01-01

    A framework was created at the University of the West Indies to guide the development of 18 e-learning programmes. The framework is based on three principles for sustainable e-learning design: (1) stakeholder-centredness; (2) cost-effectiveness and (3) high operational efficiency. These principles give rise to nine framework elements: (1) a labour…

  7. Learning with Hyperlinked Videos--Design Criteria and Efficient Strategies for Using Audiovisual Hypermedia

    ERIC Educational Resources Information Center

    Zahn, Carmen; Barquero, Beatriz; Schwan, Stephan

    2004-01-01

    In this article, we discuss the results of an experiment in which we studied two apparently conflicting classes of design principles for instructional hypervideos: (1) those principles derived from work on multimedia learning that emphasize spatio-temporal contiguity and (2) those originating from work on hypermedia learning that favour…

  8. Enhanced Efficiency of Internal Combustion Engines By Employing Spinning Gas

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

    Geyko, Vasily; Fisch, Nathaniel

    2014-02-27

    The efficiency of the internal combustion engine might be enhanced by employing spinning gas. A gas spinning at near sonic velocities has an effectively higher heat capacity, which allows practical fuel cycles, which are far from the Carnot efficiency, to approach more closely the Carnot efficiency. A gain in fuel efficiency of several percent is shown to be theoretically possible for the Otto and Diesel cycles. The use of a flywheel, in principle, could produce even greater increases in the efficiency.

  9. Enhanced efficiency of internal combustion engines by employing spinning gas.

    PubMed

    Geyko, V I; Fisch, N J

    2014-08-01

    The efficiency of the internal combustion engine might be enhanced by employing spinning gas. A gas spinning at near sonic velocities has an effectively higher heat capacity, which allows practical fuel cycles, which are far from the Carnot efficiency, to approach more closely the Carnot efficiency. A remarkable gain in fuel efficiency is shown to be theoretically possible for the Otto and Diesel cycles. The use of a flywheel, in principle, could produce even greater increases in efficiency.

  10. Handicap principle implies emergence of dimorphic ornaments.

    PubMed

    Clifton, Sara M; Braun, Rosemary I; Abrams, Daniel M

    2016-11-30

    Species spanning the animal kingdom have evolved extravagant and costly ornaments to attract mating partners. Zahavi's handicap principle offers an elegant explanation for this: ornaments signal individual quality, and must be costly to ensure honest signalling, making mate selection more efficient. Here, we incorporate the assumptions of the handicap principle into a mathematical model and show that they are sufficient to explain the heretofore puzzling observation of bimodally distributed ornament sizes in a variety of species. © 2016 The Author(s).

  11. Semi-autonomous parking for enhanced safety and efficiency.

    DOT National Transportation Integrated Search

    2017-06-01

    This project focuses on the use of tools from a combination of computer vision and localization based navigation schemes to aid the process of efficient and safe parking of vehicles in high density parking spaces. The principles of collision avoidanc...

  12. Efficient Project Delivery Using Lean Principles - An Indian Case Study

    NASA Astrophysics Data System (ADS)

    Kovvuri, P. Ramachandra Reddy; Sawhney, Anil; Ahuja, Ritu; Sreekumar, Aiswarya

    2016-03-01

    Construction industry in India is growing at a rapid pace. Along with this growth, the industry is facing numerous challenges that are making delivery of projects inefficient. Experts believe that capacity constraints in the industry need to be addressed immediately. Government has recommended `introduction of efficient technologies and modern management techniques' to increase the productivity of the industry. In this context, lean principles can act as a lever to make project delivery more efficient and provide the much needed impetus to the Indian construction sector. Around the globe lean principles are showing positive results on the projects. Project teams are reporting improvements in construction time, cost and quality along with softer benefits of enhanced collaboration, coordination and trust in project teams. Can adoption of lean principles provide similar benefits in the Indian construction sector? This research was conducted to answer this question. Using an action research approach a key lean construction tool called Last Planner System (LPS) was tested on a large Indian construction project. The work described in this work investigates the improvements achieved in project delivery by adopting LPS in Indian construction sector. Comparison in pre- and post-implementation data demonstrates increase in the certainty of work-flow and improves schedule compliance. This is measured through a simple LPS metric called percent plan complete. Explicit improvements in schedule performance are seen during 8 week LPS implementation along with implicit improvements in coordination, collaboration and trust in the project team. This work reports the findings of LPS implementation on the case study project outlining the barriers and drivers to adoption, strategies needed to ensure successful implementation and roadmap for implementation. Based on the findings the authors envision that lean construction can make project delivery more efficient in India.

  13. Unconventional Hamilton-type variational principle in phase space and symplectic algorithm

    NASA Astrophysics Data System (ADS)

    Luo, En; Huang, Weijiang; Zhang, Hexin

    2003-06-01

    By a novel approach proposed by Luo, the unconventional Hamilton-type variational principle in phase space for elastodynamics of multidegree-of-freedom system is established in this paper. It not only can fully characterize the initial-value problem of this dynamic, but also has a natural symplectic structure. Based on this variational principle, a symplectic algorithm which is called a symplectic time-subdomain method is proposed. A non-difference scheme is constructed by applying Lagrange interpolation polynomial to the time subdomain. Furthermore, it is also proved that the presented symplectic algorithm is an unconditionally stable one. From the results of the two numerical examples of different types, it can be seen that the accuracy and the computational efficiency of the new method excel obviously those of widely used Wilson-θ and Newmark-β methods. Therefore, this new algorithm is a highly efficient one with better computational performance.

  14. Open-Shell-Character-Based Molecular Design Principles: Applications to Nonlinear Optics and Singlet Fission.

    PubMed

    Nakano, Masayoshi

    2017-01-01

    Open-shell character, e. g., diradical character, is a quantum chemically well-defined quantity in ground-state molecular systems, which is not an observable but can quantify the degree of effective bond weakness in the chemical sense or electron correlation strength in the physical sense. Because this quantity also correlates to specific excited states, physicochemical properties concerned with those states are expected to strongly correlate to the open-shell character. This feature enables us to open a new path to revealing the mechanism of these properties as well as to realizing new design principles for efficient functional molecular systems. This account explains the open-shell-character-based molecular design principles and introduces their applications to the rational design of highly efficient nonlinear optical and singlet fission molecular systems. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Design Principles for Covalent Organic Frameworks as Efficient Electrocatalysts in Clean Energy Conversion and Green Oxidizer Production.

    PubMed

    Lin, Chun-Yu; Zhang, Lipeng; Zhao, Zhenghang; Xia, Zhenhai

    2017-05-01

    Covalent organic frameworks (COFs), an emerging class of framework materials linked by covalent bonds, hold potential for various applications such as efficient electrocatalysts, photovoltaics, and sensors. To rationally design COF-based electrocatalysts for oxygen reduction and evolution reactions in fuel cells and metal-air batteries, activity descriptors, derived from orbital energy and bonding structures, are identified with the first-principle calculations for the COFs, which correlate COF structures with their catalytic activities. The calculations also predict that alkaline-earth metal-porphyrin COFs could catalyze the direct production of H 2 O 2 , a green oxidizer and an energy carrier. These predictions are supported by experimental data, and the design principles derived from the descriptors provide an approach for rational design of new electrocatalysts for both clean energy conversion and green oxidizer production. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Thermal Performance Testing of Cryogenic Insulation Systems

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.; Augustynowicz, Stan D.; Scholtens, Brekke E.

    2007-01-01

    Efficient methods for characterizing thermal performance of materials under cryogenic and vacuum conditions have been developed. These methods provide thermal conductivity data on materials under actual-use conditions and are complementary to established methods. The actual-use environment of full temperature difference in combination with vacuum-pressure is essential for understanding insulation system performance. Test articles include solids, foams, powders, layered blankets, composite panels, and other materials. Test methodology and apparatus design for several insulation test cryostats are discussed. The measurement principle is liquid nitrogen boil-off calorimetry. Heat flux capability ranges from approximately 0.5 to 500 watts per square meter; corresponding apparent thermal conductivity values range from below 0.01 up to about 60 mW/m- K. Example data for different insulation materials are also presented. Upon further standardization work, these patented insulation test cryostats can be available to industry for a wide range of practical applications.

  17. Cytoskeletal self-organization in neuromorphogenesis.

    PubMed

    Dehmelt, Leif

    2014-01-01

    Self-organization of dynamic microtubules via interactions with associated motors plays a critical role in spindle formation. The microtubule-based mechanisms underlying other aspects of cellular morphogenesis, such as the formation and development of protrusions from neuronal cells is less well understood. In a recent study, we investigated the molecular mechanism that underlies the massive reorganization of microtubules induced in non-neuronal cells by expression of the neuronal microtubule stabilizer MAP2c. In that study we directly observed cortical dynein complexes and how they affect the dynamic behavior of motile microtubules in living cells. We found that stationary dynein complexes transiently associate with motile microtubules near the cell cortex and that their rapid turnover facilitates efficient microtubule transport. Here, we discuss our findings in the larger context of cellular morphogenesis with specific focus on self-organizing principles from which cellular shape patterns such as the thin protrusions of neurons can emerge.

  18. Cytoskeletal self-organization in neuromorphogenesis

    PubMed Central

    Dehmelt, Leif

    2014-01-01

    Self-organization of dynamic microtubules via interactions with associated motors plays a critical role in spindle formation. The microtubule-based mechanisms underlying other aspects of cellular morphogenesis, such as the formation and development of protrusions from neuronal cells is less well understood. In a recent study, we investigated the molecular mechanism that underlies the massive reorganization of microtubules induced in non-neuronal cells by expression of the neuronal microtubule stabilizer MAP2c. In that study we directly observed cortical dynein complexes and how they affect the dynamic behavior of motile microtubules in living cells. We found that stationary dynein complexes transiently associate with motile microtubules near the cell cortex and that their rapid turnover facilitates efficient microtubule transport. Here, we discuss our findings in the larger context of cellular morphogenesis with specific focus on self-organizing principles from which cellular shape patterns such as the thin protrusions of neurons can emerge. PMID:24847718

  19. Applying human factors principles to alert design increases efficiency and reduces prescribing errors in a scenario-based simulation

    PubMed Central

    Russ, Alissa L; Zillich, Alan J; Melton, Brittany L; Russell, Scott A; Chen, Siying; Spina, Jeffrey R; Weiner, Michael; Johnson, Elizabette G; Daggy, Joanne K; McManus, M Sue; Hawsey, Jason M; Puleo, Anthony G; Doebbeling, Bradley N; Saleem, Jason J

    2014-01-01

    Objective To apply human factors engineering principles to improve alert interface design. We hypothesized that incorporating human factors principles into alerts would improve usability, reduce workload for prescribers, and reduce prescribing errors. Materials and methods We performed a scenario-based simulation study using a counterbalanced, crossover design with 20 Veterans Affairs prescribers to compare original versus redesigned alerts. We redesigned drug–allergy, drug–drug interaction, and drug–disease alerts based upon human factors principles. We assessed usability (learnability of redesign, efficiency, satisfaction, and usability errors), perceived workload, and prescribing errors. Results Although prescribers received no training on the design changes, prescribers were able to resolve redesigned alerts more efficiently (median (IQR): 56 (47) s) compared to the original alerts (85 (71) s; p=0.015). In addition, prescribers rated redesigned alerts significantly higher than original alerts across several dimensions of satisfaction. Redesigned alerts led to a modest but significant reduction in workload (p=0.042) and significantly reduced the number of prescribing errors per prescriber (median (range): 2 (1–5) compared to original alerts: 4 (1–7); p=0.024). Discussion Aspects of the redesigned alerts that likely contributed to better prescribing include design modifications that reduced usability-related errors, providing clinical data closer to the point of decision, and displaying alert text in a tabular format. Displaying alert text in a tabular format may help prescribers extract information quickly and thereby increase responsiveness to alerts. Conclusions This simulation study provides evidence that applying human factors design principles to medication alerts can improve usability and prescribing outcomes. PMID:24668841

  20. Reconstruction of interatomic vectors by principle component analysis of nuclear magnetic resonance data in multiple alignments

    NASA Astrophysics Data System (ADS)

    Hus, Jean-Christophe; Bruschweiler, Rafael

    2002-07-01

    A general method is presented for the reconstruction of interatomic vector orientations from nuclear magnetic resonance (NMR) spectroscopic data of tensor interactions of rank 2, such as dipolar coupling and chemical shielding anisotropy interactions, in solids and partially aligned liquid-state systems. The method, called PRIMA, is based on a principal component analysis of the covariance matrix of the NMR parameters collected for multiple alignments. The five nonzero eigenvalues and their eigenvectors efficiently allow the approximate reconstruction of the vector orientations of the underlying interactions. The method is demonstrated for an isotropic distribution of sample orientations as well as for finite sets of orientations and internuclear vectors encountered in protein systems.

  1. Catalytic Conia-ene and related reactions.

    PubMed

    Hack, Daniel; Blümel, Marcus; Chauhan, Pankaj; Philipps, Arne R; Enders, Dieter

    2015-10-07

    Since its initial inception, the Conia-ene reaction, known as the intramolecular addition of enols to alkynes or alkenes, has experienced a tremendous development and appealing catalytic protocols have emerged. This review fathoms the underlying mechanistic principles rationalizing how substrate design, substrate activation, and the nature of the catalyst work hand in hand for the efficient synthesis of carbocycles and heterocycles at mild reaction conditions. Nowadays, Conia-ene reactions can be found as part of tandem reactions, and the road for asymmetric versions has already been paved. Based on their broad applicability, Conia-ene reactions have turned into a highly appreciated synthetic tool with impressive examples in natural product synthesis reported in recent years.

  2. Using Visualization in Cockpit Decision Support Systems

    NASA Technical Reports Server (NTRS)

    Aragon, Cecilia R.

    2005-01-01

    In order to safely operate their aircraft, pilots must make rapid decisions based on integrating and processing large amounts of heterogeneous information. Visual displays are often the most efficient method of presenting safety-critical data to pilots in real time. However, care must be taken to ensure the pilot is provided with the appropriate amount of information to make effective decisions and not become cognitively overloaded. The results of two usability studies of a prototype airflow hazard visualization cockpit decision support system are summarized. The studies demonstrate that such a system significantly improves the performance of helicopter pilots landing under turbulent conditions. Based on these results, design principles and implications for cockpit decision support systems using visualization are presented.

  3. Does the private sector have a role in Canadian healthcare?

    PubMed

    McGowan, Tom

    2004-01-01

    The current system of public pay with primarily public management for essential healthcare services has largely been successful. The Romanow and Kirby reports have made compelling arguments for expanding the definition of essential healthcare services to include, among other things, medications. The problem facing Canadians is that expanding services is not feasible under the current structure, as it is not affordable. The rigid adherence to a 45-year-old definition of system structure is hampering our ability to innovate. In an increasingly unresponsive system, the introduction of private management, through the judicious use of private contracts, can improve efficiency and increase accountability, while maintaining the important principle of public funding.

  4. A simple white noise analysis of neuronal light responses.

    PubMed

    Chichilnisky, E J

    2001-05-01

    A white noise technique is presented for estimating the response properties of spiking visual system neurons. The technique is simple, robust, efficient and well suited to simultaneous recordings from multiple neurons. It provides a complete and easily interpretable model of light responses even for neurons that display a common form of response nonlinearity that precludes classical linear systems analysis. A theoretical justification of the technique is presented that relies only on elementary linear algebra and statistics. Implementation is described with examples. The technique and the underlying model of neural responses are validated using recordings from retinal ganglion cells, and in principle are applicable to other neurons. Advantages and disadvantages of the technique relative to classical approaches are discussed.

  5. Extending the Lifetime of Perovskite Solar Cells using a Perfluorinated Dopant.

    PubMed

    Salado, Manuel; Ramos, F Javier; Manzanares, Valentin M; Gao, Peng; Nazeeruddin, Mohammad Khaja; Dyson, Paul J; Ahmad, Shahzada

    2016-09-22

    The principle limitation of perovskite solar cells is related to their instability and, hence, their limited lifetime. Herein, we employ an imidazolium iodide dopant, 1-methyl-3-(1H,1H,2H,2H-nonafluorohexyl)-imidazolium iodide, containing a perfluorous appendage, which leads to prolonged (unencapsulated, under Ar atmosphere) device activities exceeding 100 days without compromising the power conversion efficiency and other photovoltaic parameters. The extended lifetime of the device can be attributed, at least in part, to the hydrophobic nature of the imidazolium iodide salt. The functionalization of the perovskite material was found to have negligible influence on the perovskite crystal structure. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Representing Medical Knowledge in a Terminological Language is Difficult1

    PubMed Central

    Haimowits, Ira J.; Patil, Ramesh S.; Szolovits, Peter

    1988-01-01

    We report on an experiment to use a modern knowledge representation language, NIKL, to express the knowledge of a sophisticated medical reasoning program, ABEL. We are attempting to put the development of more capable medical programs on firmer representational grounds by moving from the ad hoc representations typical of current programs toward more principled representation languages now in use or under construction. Our experience with the project reported here suggests caution, however. Attempts at cleanliness and efficiency in the design of representation languages lead to a poverty of expressiveness that makes it difficult if not impossible to say in such languages what needs to be stated to support the application.

  7. PACS—Realization of an adaptive concept using pressure actuated cellular structures

    NASA Astrophysics Data System (ADS)

    Gramüller, B.; Boblenz, J.; Hühne, C.

    2014-10-01

    A biologically inspired concept is investigated which can be utilized to develop energy efficient, lightweight and applicational flexible adaptive structures. Building a real life morphing unit is an ambitious task as the numerous works in the particular field show. Summarizing fundamental demands and barriers regarding shape changing structures, the basic challenges of designing morphing structures are listed. The concept of Pressure Actuated Cellular Structures (PACS) is arranged within the recent morphing activities and it is shown that it complies with the underlying demands. Systematically divided into energy-related and structural subcomponents the working principle is illuminated and relationships between basic design parameters are expressed. The analytical background describing the physical mechanisms of PACS is presented in concentrated manner. This work focuses on the procedure of dimensioning, realizing and experimental testing of a single cell and a single row cantilever made of PACS. The experimental outcomes as well as the results from the FEM computations are used for evaluating the analytical methods. The functionality of the basic principle is thus validated and open issues are determined pointing the way ahead.

  8. Second Harmonic Correlation Spectroscopy: Theory and Principles for Determining Surface Binding Kinetics.

    PubMed

    Sly, Krystal L; Conboy, John C

    2017-06-01

    A novel application of second harmonic correlation spectroscopy (SHCS) for the direct determination of molecular adsorption and desorption kinetics to a surface is discussed in detail. The surface-specific nature of second harmonic generation (SHG) provides an efficient means to determine the kinetic rates of adsorption and desorption of molecular species to an interface without interference from bulk diffusion, which is a significant limitation of fluorescence correlation spectroscopy (FCS). The underlying principles of SHCS for the determination of surface binding kinetics are presented, including the role of optical coherence and optical heterodyne mixing. These properties of SHCS are extremely advantageous and lead to an increase in the signal-to-noise (S/N) of the correlation data, increasing the sensitivity of the technique. The influence of experimental parameters, including the uniformity of the TEM00 laser beam, the overall photon flux, and collection time are also discussed, and are shown to significantly affect the S/N of the correlation data. Second harmonic correlation spectroscopy is a powerful, surface-specific, and label-free alternative to other correlation spectroscopic methods for examining surface binding kinetics.

  9. Exciton diffusion in disordered small molecules for organic photovoltaics: insights from first-principles simulations.

    PubMed

    Li, Z; Zhang, X; Lu, G

    2014-05-07

    Exciton diffusion in small molecules 3,6-bis(5-(benzofuran-2-yl)thiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4-dione [DPP(TBFu)2] is studied using first-principles simulations. We have examined dependence of exciton diffusion on structure disorder, temperature and exciton energy. We find that exciton diffusion length and diffusivity increase with structural order, temperature and the initial exciton energy. Compared to conjugated polymer poly(3-hexylthiophene) (P3HT), DPP(TBFu)2 small molecules exhibit a much higher exciton diffusivity, but a shorter lifetime. The exciton diffusion length in DPP(TBFu)2 is 50% longer than that in P3HT, yielding a higher exciton harvesting efficiency; the physical origin behind these differences is discussed. The time evolutions of exciton energy, electron-hole distance, and exciton localization are explored, and the widely speculated exciton diffusion mechanism is confirmed theoretically. The connection between exciton diffusion and carrier mobilities is also studied. Finally we point out the possibility to estimate exciton diffusivity by measuring carrier mobilities under AC electric fields.

  10. The History and Future of Neoliberal Health Reform: Obamacare and Its Predecessors.

    PubMed

    Waitzkin, Howard; Hellander, Ida

    2016-10-01

    The Colombian reform of 1994, through a strange historical sequence, became a model for health reform in Latin America, Europe, and the United States. Officially, the reform aimed to improve access for the uninsured and underinsured, in collaboration with the private, for-profit insurance industry. After several historical attempts at health reform adhering to the neoliberal pattern, favored by international financial institutions and multinational insurance corporations, the Affordable Care Act (ACA) similarly enhanced access by corporations to public-sector trust funds. An ideology favoring for-profit corporations in the marketplace justified these reforms through unproven claims about the efficiency of the private sector and enhanced quality of care under principles of competition and business management. The ACA maintains this historical continuity by dealing with health care as a commodity bought and sold in a marketplace, rather than a fundamental human right to be guaranteed according to principles of social solidarity. As the ACA heads toward probable failure, a space finally will open for a U.S. national health program that does not follow same historical patterns of the neoliberal model. © The Author(s) 2016.

  11. Visual circuits of the avian telencephalon: evolutionary implications

    NASA Technical Reports Server (NTRS)

    Shimizu, T.; Bowers, A. N.

    1999-01-01

    Birds and primates are vertebrates that possess the most advanced, efficient visual systems. Although lineages leading to these two classes were separated about 300 million years ago, there are striking similarities in their underlying neural mechanisms for visual processing. This paper discusses such similarities with special emphasis on the visual circuits in the avian telencephalon. These similarities include: (1) the existence of two parallel visual pathways and their distinct telencephalic targets, (2) anatomical and functional segregation within the visual pathways, (3) laminar organization of the telencephalic targets of the pathways (e.g. striate cortex in primates), and (4) possible interactions between multiple visual areas. Additional extensive analyses are necessary to determine whether these similarities are due to inheritance from a common ancestral stock or the consequences of convergent evolution based on adaptive response to similar selective pressures. Nevertheless, such a comparison is important to identify the general and specific principles of visual processing in amniotes (reptiles, birds, and mammals). Furthermore, these principles in turn will provide a critical foundation for understanding the evolution of the brain in amniotes.

  12. 42 CFR 405.740 - Principles for determining the amount in controversy.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Principles for determining the amount in... Reconsiderations and Appeals Under Medicare Part A § 405.740 Principles for determining the amount in controversy... more appellants, the Secretary may assert that the aggregation principles contained in this subpart may...

  13. Acquisition of the Novel Name-Nameless Category (N3C) Principle.

    ERIC Educational Resources Information Center

    Mervis, Carolyn B.; Bertrand, Jacquelyn

    1994-01-01

    Examined the use by children of the Novel Name-Nameless Category principle, under the framework that lexical principles are acquired in a developmental sequence. Results indicated that the particular principle was not available at the start of lexical acquisition but that exhaustive categorization ability and a vocabulary spurt occur…

  14. 78 FR 47154 - Core Principles and Other Requirements for Swap Execution Facilities; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ... COMMODITY FUTURES TRADING COMMISSION 17 CFR Part 37 RIN 3038-AD18 Core Principles and Other... this chapter. Appendix B to Part 37--Guidance on, and Acceptable Practices in, Compliance With Core Principles [Corrected] 2. On page 33600, in the second column, under the heading Core Principle 3 of Section...

  15. Economics of Agroforestry

    Treesearch

    D. Evan Mercer; Frederick W. Cubbage; Gregory E. Frey

    2014-01-01

    This chapter provides principles, literature and a case study about the economics of agroforestry. We examine necessary conditions for achieving efficiency in agroforestry system design and economic analysis tools for assessing efficiency and adoptability of agroforestry. The tools presented here (capital budgeting, linear progranuning, production frontier analysis...

  16. First-Principles Equation of State and Shock Compression of Warm Dense Aluminum and Hydrocarbons

    NASA Astrophysics Data System (ADS)

    Driver, Kevin; Soubiran, Francois; Zhang, Shuai; Militzer, Burkhard

    2017-10-01

    Theoretical studies of warm dense plasmas are a key component of progress in fusion science, defense science, and astrophysics programs. Path integral Monte Carlo (PIMC) and density functional theory molecular dynamics (DFT-MD), two state-of-the-art, first-principles, electronic-structure simulation methods, provide a consistent description of plasmas over a wide range of density and temperature conditions. Here, we combine high-temperature PIMC data with lower-temperature DFT-MD data to compute coherent equations of state (EOS) for aluminum and hydrocarbon plasmas. Subsequently, we derive shock Hugoniot curves from these EOSs and extract the temperature-density evolution of plasma structure and ionization behavior from pair-correlation function analyses. Since PIMC and DFT-MD accurately treat effects of atomic shell structure, we find compression maxima along Hugoniot curves attributed to K-shell and L-shell ionization, which provide a benchmark for widely-used EOS tables, such as SESAME and LEOS, and more efficient models. LLNL-ABS-734424. Funding provided by the DOE (DE-SC0010517) and in part under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Computational resources provided by Blue Waters (NSF ACI1640776) and NERSC. K. Driver's and S. Zhang's current address is Lawrence Livermore Natl. Lab, Livermore, CA, 94550, USA.

  17. Maximizing root/rhizosphere efficiency to improve crop productivity and nutrient use efficiency in intensive agriculture of China.

    PubMed

    Shen, Jianbo; Li, Chunjian; Mi, Guohua; Li, Long; Yuan, Lixing; Jiang, Rongfeng; Zhang, Fusuo

    2013-03-01

    Root and rhizosphere research has been conducted for many decades, but the underlying strategy of root/rhizosphere processes and management in intensive cropping systems remain largely to be determined. Improved grain production to meet the food demand of an increasing population has been highly dependent on chemical fertilizer input based on the traditionally assumed notion of 'high input, high output', which results in overuse of fertilizers but ignores the biological potential of roots or rhizosphere for efficient mobilization and acquisition of soil nutrients. Root exploration in soil nutrient resources and root-induced rhizosphere processes plays an important role in controlling nutrient transformation, efficient nutrient acquisition and use, and thus crop productivity. The efficiency of root/rhizosphere in terms of improved nutrient mobilization, acquisition, and use can be fully exploited by: (1) manipulating root growth (i.e. root development and size, root system architecture, and distribution); (2) regulating rhizosphere processes (i.e. rhizosphere acidification, organic anion and acid phosphatase exudation, localized application of nutrients, rhizosphere interactions, and use of efficient crop genotypes); and (3) optimizing root zone management to synchronize root growth and soil nutrient supply with demand of nutrients in cropping systems. Experiments have shown that root/rhizosphere management is an effective approach to increase both nutrient use efficiency and crop productivity for sustainable crop production. The objectives of this paper are to summarize the principles of root/rhizosphere management and provide an overview of some successful case studies on how to exploit the biological potential of root system and rhizosphere processes to improve crop productivity and nutrient use efficiency.

  18. The Evolution of the Council of Academic Hospitals of Ontario Statement of Principles--A Successful Harmonization Initiative

    ERIC Educational Resources Information Center

    Porter, Katie; Lampson, Sarah

    2011-01-01

    To improve efficiency, consistency and transparency in clinical trial contract negotiations with industry sponsors, a Council of Academic Hospitals of Ontario (CAHO) committee facilitated the development of standard principles for member hospitals to follow during contract negotiation. Hospitals were encouraged to provide a link to the CAHO…

  19. The Assessment on the Application of School Administrator Selection in Turkey Related to Competency and Career Principles of Human Resource Management

    ERIC Educational Resources Information Center

    Özyildirim, Gülnar; Kayikçi, Kemal

    2017-01-01

    Administrators are the most responsible people for achieving goals of educational institution. That administration fulfills schools' aims effectively and efficiently depends on whether administrative functions are carried out according to scientific principles. The aim of the study was the assessment on school administrators' selection done as…

  20. Does user-centred design affect the efficiency, usability and safety of CPOE order sets?

    PubMed

    Chan, Julie; Shojania, Kaveh G; Easty, Anthony C; Etchells, Edward E

    2011-05-01

    Application of user-centred design principles to Computerized provider order entry (CPOE) systems may improve task efficiency, usability or safety, but there is limited evaluative research of its impact on CPOE systems. We evaluated the task efficiency, usability, and safety of three order set formats: our hospital's planned CPOE order sets (CPOE Test), computer order sets based on user-centred design principles (User Centred Design), and existing pre-printed paper order sets (Paper). 27 staff physicians, residents and medical students. Sunnybrook Health Sciences Centre, an academic hospital in Toronto, Canada. Methods Participants completed four simulated order set tasks with three order set formats (two CPOE Test tasks, one User Centred Design, and one Paper). Order of presentation of order set formats and tasks was randomized. Users received individual training for the CPOE Test format only. Completion time (efficiency), requests for assistance (usability), and errors in the submitted orders (safety). 27 study participants completed 108 order sets. Mean task times were: User Centred Design format 273 s, Paper format 293 s (p=0.73 compared to UCD format), and CPOE Test format 637 s (p<0.0001 compared to UCD format). Users requested assistance in 31% of the CPOE Test format tasks, whereas no assistance was needed for the other formats (p<0.01). There were no significant differences in number of errors between formats. The User Centred Design format was more efficient and usable than the CPOE Test format even though training was provided for the latter. We conclude that application of user-centred design principles can enhance task efficiency and usability, increasing the likelihood of successful implementation.

  1. Does user-centred design affect the efficiency, usability and safety of CPOE order sets?

    PubMed Central

    Chan, Julie; Shojania, Kaveh G; Easty, Anthony C

    2011-01-01

    Background Application of user-centred design principles to Computerized provider order entry (CPOE) systems may improve task efficiency, usability or safety, but there is limited evaluative research of its impact on CPOE systems. Objective We evaluated the task efficiency, usability, and safety of three order set formats: our hospital's planned CPOE order sets (CPOE Test), computer order sets based on user-centred design principles (User Centred Design), and existing pre-printed paper order sets (Paper). Participants 27staff physicians, residents and medical students. Setting Sunnybrook Health Sciences Centre, an academic hospital in Toronto, Canada. Methods Participants completed four simulated order set tasks with three order set formats (two CPOE Test tasks, one User Centred Design, and one Paper). Order of presentation of order set formats and tasks was randomized. Users received individual training for the CPOE Test format only. Main Measures Completion time (efficiency), requests for assistance (usability), and errors in the submitted orders (safety). Results 27 study participants completed 108 order sets. Mean task times were: User Centred Design format 273 s, Paper format 293 s (p=0.73 compared to UCD format), and CPOE Test format 637 s (p<0.0001 compared to UCD format). Users requested assistance in 31% of the CPOE Test format tasks, whereas no assistance was needed for the other formats (p<0.01). There were no significant differences in number of errors between formats. Conclusions The User Centred Design format was more efficient and usable than the CPOE Test format even though training was provided for the latter. We conclude that application of user-centred design principles can enhance task efficiency and usability, increasing the likelihood of successful implementation. PMID:21486886

  2. Efficient Network Coding-Based Loss Recovery for Reliable Multicast in Wireless Networks

    NASA Astrophysics Data System (ADS)

    Chi, Kaikai; Jiang, Xiaohong; Ye, Baoliu; Horiguchi, Susumu

    Recently, network coding has been applied to the loss recovery of reliable multicast in wireless networks [19], where multiple lost packets are XOR-ed together as one packet and forwarded via single retransmission, resulting in a significant reduction of bandwidth consumption. In this paper, we first prove that maximizing the number of lost packets for XOR-ing, which is the key part of the available network coding-based reliable multicast schemes, is actually a complex NP-complete problem. To address this limitation, we then propose an efficient heuristic algorithm for finding an approximately optimal solution of this optimization problem. Furthermore, we show that the packet coding principle of maximizing the number of lost packets for XOR-ing sometimes cannot fully exploit the potential coding opportunities, and we then further propose new heuristic-based schemes with a new coding principle. Simulation results demonstrate that the heuristic-based schemes have very low computational complexity and can achieve almost the same transmission efficiency as the current coding-based high-complexity schemes. Furthermore, the heuristic-based schemes with the new coding principle not only have very low complexity, but also slightly outperform the current high-complexity ones.

  3. Emergent Auditory Feature Tuning in a Real-Time Neuromorphic VLSI System.

    PubMed

    Sheik, Sadique; Coath, Martin; Indiveri, Giacomo; Denham, Susan L; Wennekers, Thomas; Chicca, Elisabetta

    2012-01-01

    Many sounds of ecological importance, such as communication calls, are characterized by time-varying spectra. However, most neuromorphic auditory models to date have focused on distinguishing mainly static patterns, under the assumption that dynamic patterns can be learned as sequences of static ones. In contrast, the emergence of dynamic feature sensitivity through exposure to formative stimuli has been recently modeled in a network of spiking neurons based on the thalamo-cortical architecture. The proposed network models the effect of lateral and recurrent connections between cortical layers, distance-dependent axonal transmission delays, and learning in the form of Spike Timing Dependent Plasticity (STDP), which effects stimulus-driven changes in the pattern of network connectivity. In this paper we demonstrate how these principles can be efficiently implemented in neuromorphic hardware. In doing so we address two principle problems in the design of neuromorphic systems: real-time event-based asynchronous communication in multi-chip systems, and the realization in hybrid analog/digital VLSI technology of neural computational principles that we propose underlie plasticity in neural processing of dynamic stimuli. The result is a hardware neural network that learns in real-time and shows preferential responses, after exposure, to stimuli exhibiting particular spectro-temporal patterns. The availability of hardware on which the model can be implemented, makes this a significant step toward the development of adaptive, neurobiologically plausible, spike-based, artificial sensory systems.

  4. Emergent Auditory Feature Tuning in a Real-Time Neuromorphic VLSI System

    PubMed Central

    Sheik, Sadique; Coath, Martin; Indiveri, Giacomo; Denham, Susan L.; Wennekers, Thomas; Chicca, Elisabetta

    2011-01-01

    Many sounds of ecological importance, such as communication calls, are characterized by time-varying spectra. However, most neuromorphic auditory models to date have focused on distinguishing mainly static patterns, under the assumption that dynamic patterns can be learned as sequences of static ones. In contrast, the emergence of dynamic feature sensitivity through exposure to formative stimuli has been recently modeled in a network of spiking neurons based on the thalamo-cortical architecture. The proposed network models the effect of lateral and recurrent connections between cortical layers, distance-dependent axonal transmission delays, and learning in the form of Spike Timing Dependent Plasticity (STDP), which effects stimulus-driven changes in the pattern of network connectivity. In this paper we demonstrate how these principles can be efficiently implemented in neuromorphic hardware. In doing so we address two principle problems in the design of neuromorphic systems: real-time event-based asynchronous communication in multi-chip systems, and the realization in hybrid analog/digital VLSI technology of neural computational principles that we propose underlie plasticity in neural processing of dynamic stimuli. The result is a hardware neural network that learns in real-time and shows preferential responses, after exposure, to stimuli exhibiting particular spectro-temporal patterns. The availability of hardware on which the model can be implemented, makes this a significant step toward the development of adaptive, neurobiologically plausible, spike-based, artificial sensory systems. PMID:22347163

  5. Double Super-Exchange in Silicon Quantum Dots Connected by Short-Bridged Networks

    NASA Astrophysics Data System (ADS)

    Li, Huashan; Wu, Zhigang; Lusk, Mark

    2013-03-01

    Silicon quantum dots (QDs) with diameters in the range of 1-2 nm are attractive for photovoltaic applications. They absorb photons more readily, transport excitons with greater efficiency, and show greater promise in multiple-exciton generation and hot carrier collection paradigms. However, their high excitonic binding energy makes it difficult to dissociate excitons into separate charge carriers. One possible remedy is to create dot assemblies in which a second material creates a Type-II heterojunction with the dot so that exciton dissociation occurs locally. This talk will focus on such a Type-II heterojunction paradigm in which QDs are connected via covalently bonded, short-bridge molecules. For such interpenetrating networks of dots and molecules, our first principles computational investigation shows that it is possible to rapidly and efficiently separate electrons to QDs and holes to bridge units. The bridge network serves as an efficient mediator of electron superexchange between QDs while the dots themselves play the complimentary role of efficient hole superexchange mediators. Dissociation, photoluminescence and carrier transport rates will be presented for bridge networks of silicon QDs that exhibit such double superexchange. This material is based upon work supported by the Renewable Energy Materials Research Science and Engineering Center (REMRSEC) under Grant No. DMR-0820518 and Golden Energy Computing Organization (GECO).

  6. EDITORIAL: Imaging Systems and Techniques Imaging Systems and Techniques

    NASA Astrophysics Data System (ADS)

    Giakos, George; Yang, Wuqiang; Petrou, M.; Nikita, K. S.; Pastorino, M.; Amanatiadis, A.; Zentai, G.

    2011-10-01

    This special feature on Imaging Systems and Techniques comprises 27 technical papers, covering essential facets in imaging systems and techniques both in theory and applications, from research groups spanning three different continents. It mainly contains peer-reviewed articles from the IEEE International Conference on Imaging Systems and Techniques (IST 2011), held in Thessaloniki, Greece, as well a number of articles relevant to the scope of this issue. The multifaceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment, and the technological revolution; there is an urgent need to address and propose dynamic and innovative solutions to problems that tend to be either complex and static or rapidly evolving with a lot of unknowns. For instance, exploration of the engineering and physical principles of new imaging systems and techniques for medical applications, remote sensing, monitoring of space resources and enhanced awareness, exploration and management of natural resources, and environmental monitoring, are some of the areas that need to be addressed with urgency. Similarly, the development of efficient medical imaging techniques capable of providing physiological information at the molecular level is another important area of research. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, using high resolution and high selectivity nanoimaging techniques, can play an important role in the diagnosis and treatment of cancer, as well as provide efficient drug-delivery imaging solutions for disease treatment with increased sensitivity and specificity. On the other hand, technical advances in the development of efficient digital imaging systems and techniques and tomographic devices operating on electric impedance tomography, computed tomography, single-photon emission and positron emission tomography detection principles are anticipated to have a significant impact on a wide spectrum of technological areas, such as medical imaging, pharmaceutical industry, analytical instrumentation, aerospace, remote sensing, lidars and ladars, surveillance, national defense, corrosion imaging and monitoring, sub-terrestrial and marine imaging. The complexity of the involved imaging scenarios, and demanding design parameters such as speed, signal-to-noise ratio, high specificity, high contrast and spatial resolution, high-scatter rejection, complex background and harsh environment, necessitate the development of a multifunctional, scalable and efficient imaging suite of sensors, solutions driven by innovation, operating on diverse detection and imaging principles. Finally, pattern recognition and image processing algorithms can significantly contribute to enhanced detection and imaging, including object classification, clustering, feature selection, texture analysis, segmentation, image compression and color representation under complex imaging scenarios, with applications in medical imaging, remote sensing, aerospace, radars, defense and homeland security. We feel confident that the exciting new contributions of this special feature on Imaging Systems and Techniques will appeal to the technical community. We would like to thank all authors as well as all anonymous reviewers and the MST Editorial Board, Publisher and staff for their tremendous efforts and invaluable support to enhance the quality of this significant endeavor.

  7. Statutory health insurance in Germany: a health system shaped by 135 years of solidarity, self-governance, and competition.

    PubMed

    Busse, Reinhard; Blümel, Miriam; Knieps, Franz; Bärnighausen, Till

    2017-08-26

    Bismarck's Health Insurance Act of 1883 established the first social health insurance system in the world. The German statutory health insurance system was built on the defining principles of solidarity and self-governance, and these principles have remained at the core of its continuous development for 135 years. A gradual expansion of population and benefits coverage has led to what is, in 2017, universal health coverage with a generous benefits package. Self-governance was initially applied mainly to the payers (the sickness funds) but was extended in 1913 to cover relations between sickness funds and doctors, which in turn led to the right for insured individuals to freely choose their health-care providers. In 1993, the freedom to choose one's sickness fund was formally introduced, and reforms that encourage competition and a strengthened market orientation have gradually gained importance in the past 25 years; these reforms were designed and implemented to protect the principles of solidarity and self-governance. In 2004, self-governance was strengthened through the establishment of the Federal Joint Committee, a major payer-provider structure given the task of defining uniform rules for access to and distribution of health care, benefits coverage, coordination of care across sectors, quality, and efficiency. Under the oversight of the Federal Joint Committee, payer and provider associations have ensured good access to high-quality health care without substantial shortages or waiting times. Self-governance has, however, led to an oversupply of pharmaceutical products, an excess in the number of inpatient cases and hospital stays, and problems with delivering continuity of care across sectoral boundaries. The German health insurance system is not as cost-effective as in some of Germany's neighbouring countries, which, given present expenditure levels, indicates a need to improve efficiency and value for patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Multiple p-n junction subwavelength gratings for transmission-mode electro-optic modulators

    PubMed Central

    Lee, Ki Young; Yoon, Jae Woong; Song, Seok Ho; Magnusson, Robert

    2017-01-01

    We propose a free-space electro-optic transmission modulator based on multiple p-n-junction semiconductor subwavelength gratings. The proposed device operates with a high-Q guided-mode resonance undergoing electro-optic resonance shift due to direct electrical control. Using rigorous electrical and optical modeling methods, we theoretically demonstrate a modulation depth of 84%, on-state efficiency 85%, and on-off extinction ratio of 19 dB at 1,550 nm wavelength under electrical control signals within a favorably low bias voltage range from −4 V to +1 V. This functionality operates in the transmission mode and sustainable in the high-speed operation regime up to a 10-GHz-scale modulation bandwidth in principle. The theoretical performance prediction is remarkably advantageous over plasmonic tunable metasurfaces in the power-efficiency and absolute modulation-depth aspects. Therefore, further experimental study is of great interest for creating practical-level metasurface components in various application areas. PMID:28417962

  9. A rapid, efficient, and facile solution for dental hypersensitivity: The tannin–iron complex

    PubMed Central

    Oh, Dongyeop X.; Prajatelistia, Ekavianty; Ju, Sung-Won; Jeong Kim, Hyo; Baek, Soo-Jin; Joon Cha, Hyung; Ho Jun, Sang; Ahn, Jin-Soo; Soo Hwang, Dong

    2015-01-01

    Dental hypersensitivity due to exposure of dentinal tubules under the enamel layer to saliva is a very popular and highly elusive technology priority in dentistry. Blocking water flow within exposed dentinal tubules is a key principle for curing dental hypersensitivity. Some salts used in “at home” solutions remineralize the tubules inside by concentrating saliva ingredients. An “in-office” option of applying dense resin sealants on the tubule entrance has only localized effects on well-defined sore spots. We report a self-assembled film that was formed by facile, rapid (4 min), and efficient (approximately 0.5 g/L concentration) dip-coating of teeth in an aqueous solution containing a tannic acid–iron(III) complex. It quickly and effectively occluded the dentinal tubules of human teeth. It withstood intense tooth brushing and induced hydroxyapatite remineralisation within the dentinal tubules. This strategy holds great promise for future applications as an effective and user-friendly desensitizer for managing dental hypersensitivity. PMID:26039461

  10. A rapid, efficient, and facile solution for dental hypersensitivity: The tannin-iron complex.

    PubMed

    Oh, Dongyeop X; Prajatelistia, Ekavianty; Ju, Sung-Won; Jeong Kim, Hyo; Baek, Soo-Jin; Joon Cha, Hyung; Ho Jun, Sang; Ahn, Jin-Soo; Soo Hwang, Dong

    2015-06-03

    Dental hypersensitivity due to exposure of dentinal tubules under the enamel layer to saliva is a very popular and highly elusive technology priority in dentistry. Blocking water flow within exposed dentinal tubules is a key principle for curing dental hypersensitivity. Some salts used in "at home" solutions remineralize the tubules inside by concentrating saliva ingredients. An "in-office" option of applying dense resin sealants on the tubule entrance has only localized effects on well-defined sore spots. We report a self-assembled film that was formed by facile, rapid (4 min), and efficient (approximately 0.5 g/L concentration) dip-coating of teeth in an aqueous solution containing a tannic acid-iron(III) complex. It quickly and effectively occluded the dentinal tubules of human teeth. It withstood intense tooth brushing and induced hydroxyapatite remineralisation within the dentinal tubules. This strategy holds great promise for future applications as an effective and user-friendly desensitizer for managing dental hypersensitivity.

  11. An economic framework for preventive care advice.

    PubMed

    Pauly, Mark V; Sloan, Frank A; Sullivan, Sean D

    2014-11-01

    Under the Affordable Care Act, preventive care measures, including vaccinations and screenings, recommended by the Advisory Committee on Immunization Practices and the US Preventive Services Task Force must be covered in full by insurance. These recommendations affect the cost of medical care. Yet neither organization explicitly incorporates measures of efficiency or cost-effectiveness in making its recommendations. To redress this shortcoming, we propose a decision-making framework for these two organizations based on the principles of economic efficiency. Our analysis suggests that routine use of a preventive service should be recommended for full insurance coverage if the service's cost-effectiveness exceeds a socially determined threshold. For less cost-effective services, we suggest that information about effectiveness and cost should be provided to consumers by physicians or government, but the choice of care and insurance coverage for care should be made by individuals. For the least cost-effective services, the two organizations should discourage public and private insurers from covering such services and report their unfavorable cost-effectiveness. Project HOPE—The People-to-People Health Foundation, Inc.

  12. Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits

    PubMed Central

    Ujfalussy, Balázs B; Makara, Judit K; Branco, Tiago; Lengyel, Máté

    2015-01-01

    Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits. DOI: http://dx.doi.org/10.7554/eLife.10056.001 PMID:26705334

  13. Infrared Technology Trends and Implications to Home and Building Energy Use Efficiency

    NASA Astrophysics Data System (ADS)

    Woolaway, James T.

    2008-09-01

    It has long been realized that infrared technology would have applicability in improving the energy efficiency of homes and buildings. Walls that are missing or are poorly insulated can be quickly evaluated by looking at the thermal images of these surfaces. Similarly, air infiltration leaks under doors and around windows leave a telltale thermal signature easily seen in the infrared. The ability to view, evaluate and quickly respond to these images has immediate benefits in addressing and correcting situations where these types of losses are occurring. The principle issue that has been limiting the use of infrared technology in these applications has been the lack of availability and accessibility of infrared technology at a cost point suited to this market. The emergence of low cost microbolometer based infrared cameras, not needing sensor cooling, will greatly increase the accessibility and use of infrared technology for House Doctor inspections. The technology cost for this use is projected to be less than 1 per inspection.

  14. Collective navigation of complex networks: Participatory greedy routing.

    PubMed

    Kleineberg, Kaj-Kolja; Helbing, Dirk

    2017-06-06

    Many networks are used to transfer information or goods, in other words, they are navigated. The larger the network, the more difficult it is to navigate efficiently. Indeed, information routing in the Internet faces serious scalability problems due to its rapid growth, recently accelerated by the rise of the Internet of Things. Large networks like the Internet can be navigated efficiently if nodes, or agents, actively forward information based on hidden maps underlying these systems. However, in reality most agents will deny to forward messages, which has a cost, and navigation is impossible. Can we design appropriate incentives that lead to participation and global navigability? Here, we present an evolutionary game where agents share the value generated by successful delivery of information or goods. We show that global navigability can emerge, but its complete breakdown is possible as well. Furthermore, we show that the system tends to self-organize into local clusters of agents who participate in the navigation. This organizational principle can be exploited to favor the emergence of global navigability in the system.

  15. Clean, fast and preserving normal anatomy: "the Helsinki revolution" in microneurosurgery.

    PubMed

    Velasquez, Joham C; Lau, Jane; Kozyrev, Danil; Sharafeddin, Fransua; Colasanti, Roberto; Luostarinen, Teemu; Hernesniemi, Juha

    2016-03-01

    After the senior author took chairmanship in Helsinki University Hospital in, he led the department into making neurosurgical operations much faster, safer and workflow more efficient, and at the same time maintaining high surgical quality and results. The aim was to describe the philosophies and style of Helsinki Microneurosurgery. The philosophies of Helsinki Neurosurgery are categorized into two concepts: The operation room TEAM concept and the main principle "Simple, clean, fast and respecting the normal anatomy". The way to be efficient is to find good methods based on logic, reason and experience. Specific and systematic procedures before the microneurosurgery followed by high quality skills under the microscope are of utmost importance. Moreover, intraoperatively, neuroanesthesia has to provide good surgical conditions. Today, Helsinki University Central hospital Department of Neurosurgery has an annual workflow 3500 neurosurgical operations. We believe that microneurosurgical treatment remains to be important for years ahead, and neurosurgeons of great hearts, minds and skills are welcomed all over the world.

  16. 26 CFR 1.460-5 - Cost allocation rules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... must be allocated to a long-term contract when dedicated to the contract under principles similar to... component is dedicated, under principles similar to those in § 1.263A-11(b)(2). A taxpayer maintaining... exempt construction contract reported using the CCM— (A) Marketing and selling expenses, including...

  17. The search for underlying principles of health impact assessment: progress and prospects: Comment on "Investigating underlying principles to guide health impact assessment".

    PubMed

    Winkler, Mirko S; Utzinger, Jürg

    2014-07-01

    Health Impact Assessment (HIA) is a relatively young field of endeavour, and hence, future progress will depend on the planning, implementation and rigorous evaluation of additional HIAs of projects, programmes and policies the world over. In the June 2014 issue of the International Journal of Health Policy and Management, Fakhri and colleagues investigated underlying principles of HIA through a comprehensive review of the literature and expert consultation. With an emphasis on the Islamic Republic of Iran, the authors identified multiple issues that are relevant for guiding HIA practice. At the same time, the study unravelled current shortcomings in the understanding and definition of HIA principles and best practice at national, regional, and global levels. In this commentary we scrutinise the research presented, highlight strengths and limitations, and discuss the findings in the context of other recent attempts to guide HIA.

  18. 75 FR 79921 - Fall 2010 Unified Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... securitizations that would be affected by recent changes to generally accepted accounting principles. In effect... generally accepted accounting principles in effect prior to November 15, 2009. The transitional safe harbor... conditions for sale accounting treatment under generally accepted accounting principles as [[Page 79923...

  19. Software development environments: Present and future, appendix D

    NASA Technical Reports Server (NTRS)

    Riddle, W. E.

    1980-01-01

    Computerized environments which facilitate the development of appropriately functioning software systems are discussed. Their current status is reviewed and several trends exhibited by their history are identified. A number of principles, some at (slight) variance with the historical trends, are suggested and it is argued that observance of these principles is critical to achieving truly effective and efficient software development support environments.

  20. Mass Customization of Teaching and Training in Organizations: Design Principles and Prototype Evaluation

    ERIC Educational Resources Information Center

    Nistor, Nicolae; Dehne, Anina; Drews, Frank Thomas

    2010-01-01

    In search of methods that improve the efficiency of teaching and training in organizations, several authors point out that mass customization (MC) is a principle that covers individual needs of knowledge and skills and, at the same time limits the development costs of customized training to those of mass training. MC is proven and established in…

  1. The multilingual matrix test: Principles, applications, and comparison across languages: A review.

    PubMed

    Kollmeier, Birger; Warzybok, Anna; Hochmuth, Sabine; Zokoll, Melanie A; Uslar, Verena; Brand, Thomas; Wagener, Kirsten C

    2015-01-01

    A review of the development, evaluation, and application of the so-called 'matrix sentence test' for speech intelligibility testing in a multilingual society is provided. The format allows for repeated use with the same patient in her or his native language even if the experimenter does not understand the language. Using a closed-set format, the syntactically fixed, semantically unpredictable sentences (e.g. 'Peter bought eight white ships') provide a vocabulary of 50 words (10 alternatives for each position in the sentence). The principles (i.e. construction, optimization, evaluation, and validation) for 14 different languages are reviewed. Studies of the influence of talker, language, noise, the training effect, open vs. closed conduct of the test, and the subjects' language proficiency are reported and application examples are discussed. The optimization principles result in a steep intelligibility function and a high homogeneity of the speech materials presented and test lists employed, yielding a high efficiency and excellent comparability across languages. The characteristics of speakers generally dominate the differences across languages. The matrix test format with the principles outlined here is recommended for producing efficient, reliable, and comparable speech reception thresholds across different languages.

  2. Moss-Burstein shift in La-doped BaSnO3; A novel electron transport layer material for hybrid halide perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Taya, Ankur; Rani, Priti; Kashyap, Manish K.

    2018-04-01

    Highly efficient hybrid (organic-inorganic) halide perovskite solar cells (PSCs) employ TiO2 as electron transport layer (ETL) but it impedes the device stability under solar illumination. Therefore, there is an imperative need to study the materials that can be the ideal replacement for TiO2 as ETL. With its growth at mild conditions recently by Shin et al. [Science, 356, 167 (2017)], La-doped BaSnO3 (LBSO) emerges out as an efficient candidate for ETL in PSCs. In this direction, we represent first-principles electronic properties and optical response of pristine and La-doped BaSnO3 using full potential linear augmented plane wave (FPLAPW) method within time efficient orbital independent modified Becke Johnson (mBJ) approach. Post La-doping, Moss-Burtsein shift is observed in BaSnO3 that establishes it as an excellent n-type transparent conducting oxide. The optical absorption spectra of LBSO has been analyzed to prove almost full transmittivity for energy ≤ 4eV which affirms LBSO as an ideal material for ETL in various PSCs.

  3. Construction and in vivo assembly of a catalytically proficient and hyperthermostable de novo enzyme.

    PubMed

    Watkins, Daniel W; Jenkins, Jonathan M X; Grayson, Katie J; Wood, Nicola; Steventon, Jack W; Le Vay, Kristian K; Goodwin, Matthew I; Mullen, Anna S; Bailey, Henry J; Crump, Matthew P; MacMillan, Fraser; Mulholland, Adrian J; Cameron, Gus; Sessions, Richard B; Mann, Stephen; Anderson, J L Ross

    2017-08-25

    Although catalytic mechanisms in natural enzymes are well understood, achieving the diverse palette of reaction chemistries in re-engineered native proteins has proved challenging. Wholesale modification of natural enzymes is potentially compromised by their intrinsic complexity, which often obscures the underlying principles governing biocatalytic efficiency. The maquette approach can circumvent this complexity by combining a robust de novo designed chassis with a design process that avoids atomistic mimicry of natural proteins. Here, we apply this method to the construction of a highly efficient, promiscuous, and thermostable artificial enzyme that catalyzes a diverse array of substrate oxidations coupled to the reduction of H 2 O 2 . The maquette exhibits kinetics that match and even surpass those of certain natural peroxidases, retains its activity at elevated temperature and in the presence of organic solvents, and provides a simple platform for interrogating catalytic intermediates common to natural heme-containing enzymes.Catalytic mechanisms of enzymes are well understood, but achieving diverse reaction chemistries in re-engineered proteins can be difficult. Here the authors show a highly efficient and thermostable artificial enzyme that catalyzes a diverse array of substrate oxidations coupled to the reduction of H 2 O 2 .

  4. Design principles and optimal performance for molecular motors under realistic constraints

    NASA Astrophysics Data System (ADS)

    Tu, Yuhai; Cao, Yuansheng

    2018-02-01

    The performance of a molecular motor, characterized by its power output and energy efficiency, is investigated in the motor design space spanned by the stepping rate function and the motor-track interaction potential. Analytic results and simulations show that a gating mechanism that restricts forward stepping in a narrow window in configuration space is needed for generating high power at physiologically relevant loads. By deriving general thermodynamics laws for nonequilibrium motors, we find that the maximum torque (force) at stall is less than its theoretical limit for any realistic motor-track interactions due to speed fluctuations. Our study reveals a tradeoff for the motor-track interaction: while a strong interaction generates a high power output for forward steps, it also leads to a higher probability of wasteful spontaneous back steps. Our analysis and simulations show that this tradeoff sets a fundamental limit to the maximum motor efficiency in the presence of spontaneous back steps, i.e., loose-coupling. Balancing this tradeoff leads to an optimal design of the motor-track interaction for achieving a maximum efficiency close to 1 for realistic motors that are not perfectly coupled with the energy source. Comparison with existing data and suggestions for future experiments are discussed.

  5. Response of ammonium removal to growth and transpiration of Juncus effusus during the treatment of artificial sewage in laboratory-scale wetlands.

    PubMed

    Wiessner, A; Kappelmeyer, U; Kaestner, M; Schultze-Nobre, L; Kuschk, P

    2013-09-01

    The correlation between nitrogen removal and the role of the plants in the rhizosphere of constructed wetlands are the subject of continuous discussion, but knowledge is still insufficient. Since the influence of plant growth and physiological activity on ammonium removal has not been well characterized in constructed wetlands so far, this aspect is investigated in more detail in model wetlands under defined laboratory conditions using Juncus effusus for treating an artificial sewage. Growth and physiological activity, such as plant transpiration, have been found to correlate with both the efficiency of ammonium removal within the rhizosphere of J. effusus and the methane formation. The uptake of ammonium by growing plant stocks is within in a range of 45.5%, but under conditions of plant growth stagnation, a further nearly complete removal of the ammonium load points to the likely existence of additional nitrogen removal processes. In this way, a linear correlation between the ammonium concentration inside the rhizosphere and the transpiration of the plant stocks implies that an influence of plant physiological activity on the efficiency of N-removal exists. Furthermore, a linear correlation between methane concentration and plant transpiration has been estimated. The findings indicate a fast response of redox processes to plant activities. Accordingly, not only the influence of plant transpiration activity on the plant-internal convective gas transport, the radial oxygen loss by the plant roots and the efficiency of nitrification within the rhizosphere, but also the nitrogen gas released by phytovolatilization are discussed. The results achieved by using an unplanted control system are different in principle and characterized by a low efficiency of ammonium removal and a high methane enrichment of up to a maximum of 72.7% saturation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Fundamental Tactical Principles of Soccer: A Comparison of Different Age Groups

    PubMed Central

    Guilherme, José; Rechenchosky, Leandro; da Costa, Luciane Cristina Arantes; Rinadi, Wilson

    2017-01-01

    Abstract The fundamental tactical principles of the game of soccer represent a set of action rules that guide behaviours related to the management of game space. The aim of this study was to compare the performance of fundamental offensive and defensive tactical principles among youth soccer players from 12 to 17 years old. The sample consisted of 3689 tactical actions performed by 48 soccer players in three age categories: under 13 (U-13), under 15 (U-15), and under 17 (U-17). Tactical performance was measured using the System of Tactical Assessment in Soccer (FUT-SAT). The Kruskal Wallis, Mann-Whitney U, Friedman, Wilcoxon, and Cohen’s Kappa tests were used in the study analysis. The results showed that the principles of “offensive coverage” (p = 0.01) and “concentration” (p = 0.04) were performed more frequently by the U-17 players than the U-13 players. The tactical principles “width and length” (p < 0.05) and “defensive unit” (p < 0.05) were executed more frequently by younger soccer players. It can be concluded that the frequency with which fundamental tactical principles are performed varies between the gaming categories, which implies that there is valuation of defensive security and a progressive increase in “offensive coverage” caused by increased confidence and security in offensive actions. PMID:28828091

  7. Fundamental Tactical Principles of Soccer: A Comparison of Different Age Groups.

    PubMed

    Borges, Paulo Henrique; Guilherme, José; Rechenchosky, Leandro; da Costa, Luciane Cristina Arantes; Rinadi, Wilson

    2017-09-01

    The fundamental tactical principles of the game of soccer represent a set of action rules that guide behaviours related to the management of game space. The aim of this study was to compare the performance of fundamental offensive and defensive tactical principles among youth soccer players from 12 to 17 years old. The sample consisted of 3689 tactical actions performed by 48 soccer players in three age categories: under 13 (U-13), under 15 (U-15), and under 17 (U-17). Tactical performance was measured using the System of Tactical Assessment in Soccer (FUT-SAT). The Kruskal Wallis, Mann-Whitney U, Friedman, Wilcoxon, and Cohen's Kappa tests were used in the study analysis. The results showed that the principles of "offensive coverage" (p = 0.01) and "concentration" (p = 0.04) were performed more frequently by the U-17 players than the U-13 players. The tactical principles "width and length" (p < 0.05) and "defensive unit" (p < 0.05) were executed more frequently by younger soccer players. It can be concluded that the frequency with which fundamental tactical principles are performed varies between the gaming categories, which implies that there is valuation of defensive security and a progressive increase in "offensive coverage" caused by increased confidence and security in offensive actions.

  8. Application of vacuum metallurgy to separate pure metal from mixed metallic particles of crushed waste printed circuit board scraps.

    PubMed

    Zhan, Lu; Xu, Zhenming

    2008-10-15

    The principle of separating pure metal from mixed metallic particles (MMPs) byvacuum metallurgy is that the vapor pressures of various metals at the same temperature are different As a result, the metal with high vapor pressure and low boiling point can be separated from the mixed metals through distillation or sublimation, and then it can be recycled through condensation under a certain condition. The vacuum metallurgy separation (VMS) of MMPs of crushed waste printed circuit boards (WPCBs) has been studied in this paper. Theoretical analyses show that the MMPs (copper, zinc, bismuth, lead, and indium, for example) can be separated by vacuum metallurgy. The copper particles (0.15-0.20 mm) and zinc particles (<0.30 mm) were chosen to simulate the MMPs of crushed WPCBs. Experimental results show that the separated efficiency of zinc in the copper-rich particles achieves 96.19 wt % when the vacuum pressure is 0.01-0.10 Pa, the heating temperature is 1123 K, and the heating time is 105 min. Under this operation condition, the separated efficiency of zinc in the copper-rich particles from crushed WPCBs achieves 97.00 wt % and the copper purity increases from 90.68 to 99.84 wt %.

  9. Computationally efficient optimization of radiation drives

    NASA Astrophysics Data System (ADS)

    Zimmerman, George; Swift, Damian

    2017-06-01

    For many applications of pulsed radiation, the temporal pulse shape is designed to induce a desired time-history of conditions. This optimization is normally performed using multi-physics simulations of the system, adjusting the shape until the desired response is induced. These simulations may be computationally intensive, and iterative forward optimization is then expensive and slow. In principle, a simulation program could be modified to adjust the radiation drive automatically until the desired instantaneous response is achieved, but this may be impracticable in a complicated multi-physics program. However, the computational time increment is typically much shorter than the time scale of changes in the desired response, so the radiation intensity can be adjusted so that the response tends toward the desired value. This relaxed in-situ optimization method can give an adequate design for a pulse shape in a single forward simulation, giving a typical gain in computational efficiency of tens to thousands. This approach was demonstrated for the design of laser pulse shapes to induce ramp loading to high pressure in target assemblies where different components had significantly different mechanical impedance, requiring careful pulse shaping. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  10. The Principle of Cognitive Consistency and Central American Policy: A Comparison of the Carter and Reagan Administrations.

    ERIC Educational Resources Information Center

    Holland, Lynn

    The principle of cognitive consistency, formulated by Jack Snyder, explains decision-making under stressful conditions. Snyder contends that decision-making under stressful conditions creates a drive toward cognitive consistency and brings into operation tendencies: (1) toward a perception of certainty about an opponent's intention and the…

  11. 78 FR 64064 - Agency Information Collection (Principles of Excellence Complaint System Intake) Activity Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... (Principles of Excellence Complaint System Intake) Activity Under OMB Review AGENCY: Veterans Benefits... to the Office of Management and Budget (OMB) for review and comment. The PRA submission describes the... Information and Regulatory Affairs, Office of Management and Budget, Attn: VA Desk Officer; 725 17th St. NW...

  12. Distribution of active faulting along orogenic wedges: Minimum-work models and natural analogue

    NASA Astrophysics Data System (ADS)

    Yagupsky, Daniel L.; Brooks, Benjamin A.; Whipple, Kelin X.; Duncan, Christopher C.; Bevis, Michael

    2014-09-01

    Numerical 2-D models based on the principle of minimum work were used to examine the space-time distribution of active faulting during the evolution of orogenic wedges. A series of models focused on thin-skinned thrusting illustrates the effects of arid conditions (no erosion), unsteady state conditions (accretionary influx greater than erosional efflux) and steady state conditions (accretionary influx balances erosional efflux), on the distribution of fault activity. For arid settings, a general forward accretion sequence prevails, although a significant amount of internal deformation is registered: the resulting fault pattern is a rather uniform spread along the profile. Under fixed erosional efficiency settings, the frontal advance of the wedge-front is inhibited, reaching a steady state after a given forward propagation. Then, the applied shortening is consumed by surface ruptures over a narrow frontal zone. Under a temporal increase in erosional efficiency (i.e., transient non-steady state mass balance conditions), a narrowing of the synthetic wedge results; a rather diffuse fault activity distribution is observed during the deformation front retreat. Once steady balanced conditions are reached, a single long-lived deformation front prevails. Fault activity distribution produced during the deformation front retreat of the latter scenario, compares well with the structural evolution and hinterlandward deformation migration identified in southern Bolivian Subandes (SSA) from late Miocene to present. This analogy supports the notion that the SSA is not in steady state, but is rather responding to an erosional efficiency increase since late Miocene. The results shed light on the impact of different mass balance conditions on the vastly different kinematics found in mountain ranges, suggesting that those affected by growing erosion under a transient unbalanced mass flux condition tend to distribute deformation along both frontal and internal faults, while others under balanced conditions would display focused deformation on a limited number of steady structures.

  13. Distillation with Vapour Compression. An Undergraduate Experimental Facility.

    ERIC Educational Resources Information Center

    Pritchard, Colin

    1986-01-01

    Discusses the need to design distillation columns that are more energy efficient. Describes a "design and build" project completed by two college students aimed at demonstrating the principles of vapour compression distillation in a more energy efficient way. General design specifications are given, along with suggestions for teaching…

  14. Development of a model to assess environmental performance, concerning HSE-MS principles.

    PubMed

    Abbaspour, M; Hosseinzadeh Lotfi, F; Karbassi, A R; Roayaei, E; Nikoomaram, H

    2010-06-01

    The main objective of the present study was to develop a valid and appropriate model to evaluate companies' efficiency and environmental performance, concerning health, safety, and environmental management system principles. The proposed model overcomes the shortcomings of the previous models developed in this area. This model has been designed on the basis of a mathematical method known as Data Envelopment Analysis (DEA). In order to differentiate high-performing companies from weak ones, one of DEA nonradial models named as enhanced Russell graph efficiency measure has been applied. Since some of the environmental performance indicators cannot be controlled by companies' managers, it was necessary to develop the model in a way that it could be applied when discretionary and/or nondiscretionary factors were involved. The model, then, has been modified on a real case that comprised 12 oil and gas general contractors. The results showed the relative efficiency, inefficiency sources, and the rank of contractors.

  15. Teaching/learning principles

    NASA Technical Reports Server (NTRS)

    Hankins, D. B.; Wake, W. H.

    1981-01-01

    The potential remote sensing user community is enormous, and the teaching and training tasks are even larger; however, some underlying principles may be synthesized and applied at all levels from elementary school children to sophisticated and knowledgeable adults. The basic rules applying to each of the six major elements of any training course and the underlying principle involved in each rule are summarized. The six identified major elements are: (1) field sites for problems and practice; (2) lectures and inside study; (3) learning materials and resources (the kit); (4) the field experience; (5) laboratory sessions; and (6) testing and evaluation.

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

    McDermott, Christa; Malone, Elizabeth L.

    This report assesses the use of institutional change principles and the institutional impact of award-winning projects through interviews with 22 Department of Energy Federal Energy Management Program (DOE FEMP) award winners. Award winners identified institutional facilitators and barriers in their projects and programs as well as factors in their implementation processes, thus providing information that can guide other efforts. We found that award winners do use strategies based on eight principles of institutional change, most frequently in terms of making changes to infrastructure, engaging leadership, and capitalizing on multiple motivations for making an energy efficiency improvement. The principles drawn onmore » the least often were commitment and social empowerment. Award winners also faced five major types of obstacles that were institutional in nature: lack of resources, constraints of rules, psychological barriers, lack of information, and communication problems. We also used the seven categories of Energy Management Excellence (EME) as a lens to interpret the interview data and assess whether these categories relate to established institutional change principles. We found that the eight principles reflect strategies that have been found to be useful in improving energy efficiency in organizations, whereas the EME categories capture more of a blend of social contextual factors and strategies. The EME categories fill in some of the social context gaps that facilitate institutional change and energy management excellence, for example, personal persistence, a culture that supports creativity and innovation, regular engagement with tenants, contractors, and staff at all levels. Taking together the use of principles, EME criteria, and obstacles faced by interviewees, we make recommendations for how FEMP can better foster institutional change in federal agencies.« less

  17. 76 FR 16345 - Net Worth and Equity Ratio

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... acquisition must be measured under generally accepted accounting principles as referenced in the Act. 12 U.S.C... equity or member interest in the acquirer. Generally accepted accounting principles require this excess... generally accepted accounting principles. For low income-designated credit unions, net worth also includes...

  18. 5 CFR 551.401 - Basic principles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Basic principles. 551.401 Section 551.401 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work General Provisions § 551.401 Basic principles. (a) All time...

  19. 77 FR 8879 - Agency Information Collection Activities; Proposed Collection; Comment Request: Guidance for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-15

    ... Separator Device Operating by Centrifugal or Filtration Separation Principle AGENCY: Food and Drug... automated blood cell separator device operating by centrifugal or filtration separation principle. DATES... Filtration Separation Principle (OMB Control Number 0910-0594)--Extension Under the Safe Medical Devices Act...

  20. The Principle of the Fermionic Projector: An Approach for Quantum Gravity?

    NASA Astrophysics Data System (ADS)

    Finster, Felix

    In this short article we introduce the mathematical framework of the principle of the fermionic projector and set up a variational principle in discrete space-time. The underlying physical principles are discussed. We outline the connection to the continuum theory and state recent results. In the last two sections, we speculate on how it might be possible to describe quantum gravity within this framework.

  1. Biocatalytically active silCoat-composites entrapping viable Escherichia coli.

    PubMed

    Findeisen, A; Thum, O; Ansorge-Schumacher, M B

    2014-02-01

    Application of whole cells in industrial processes requires high catalytic activity, manageability, and viability under technical conditions, which can in principle be accomplished by appropriate immobilization. Here, we report the identification of carrier material allowing exceptionally efficient adsorptive binding of Escherichia coli whole cells hosting catalytically active carbonyl reductase from Candida parapsilosis (CPCR2). With the immobilizates, composite formation with both hydrophobic and hydrophilized silicone was achieved, yielding advanced silCoat-material and HYsilCoat-material, respectively. HYsilCoat-whole cells were viable preparations with a cell loading up to 400 mg(E. coli) · g(-1)(carrier) and considerably lower leaching than native immobilizates. SilCoat-whole cells performed particularly well in neat substrate exhibiting distinctly increased catalytic activity.

  2. Team Software Development for Aerothermodynamic and Aerodynamic Analysis and Design

    NASA Technical Reports Server (NTRS)

    Alexandrov, N.; Atkins, H. L.; Bibb, K. L.; Biedron, R. T.; Carpenter, M. H.; Gnoffo, P. A.; Hammond, D. P.; Jones, W. T.; Kleb, W. L.; Lee-Rausch, E. M.

    2003-01-01

    A collaborative approach to software development is described. The approach employs the agile development techniques: project retrospectives, Scrum status meetings, and elements of Extreme Programming to efficiently develop a cohesive and extensible software suite. The software product under development is a fluid dynamics simulator for performing aerodynamic and aerothermodynamic analysis and design. The functionality of the software product is achieved both through the merging, with substantial rewrite, of separate legacy codes and the authorship of new routines. Examples of rapid implementation of new functionality demonstrate the benefits obtained with this agile software development process. The appendix contains a discussion of coding issues encountered while porting legacy Fortran 77 code to Fortran 95, software design principles, and a Fortran 95 coding standard.

  3. Tighten water-chemistry control after boiler layup

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

    Brestel, L.

    1994-01-01

    The potential for internal deposition and corrosion can affect boiler reliability by reducing thermal efficiency, tube integrity, and the time between chemical cleanings. While chemical control specifications for normal operation have been developed by consensus of manufacturers and industry, their impact on shutdowns, layups, and startups is not always appreciated. The discussion of chemical-control options applies to boiler systems operating in the medium- and high-pressure ranges. Identification and correction of root causes underlying the chemistry problems encountered and application of the principles involved should result in shorter startup times, improved control over phosphate hideout, and reduced need for chemical cleaning.more » Each of these has a significant cost impact; together, they are the true measure of a successful chemistry-control program.« less

  4. First-principles investigation on transport properties of NiO monowire-based molecular device

    NASA Astrophysics Data System (ADS)

    Chandiramouli, R.; Sriram, S.

    2014-08-01

    The electronic transport properties of novel NiO monowire connected to the gold electrodes are investigated using density functional theory combined with nonequilibrium Green's functions formalism. The densities of states of the monowire under various bias conditions are discussed. The transport properties are discussed in terms of the transmission spectrum and current-voltage characteristics of NiO monowire. The transmission pathways provide the insight to the transmission of electrons along the monowire. With different bias voltages, current in the order of few microampere flows across the monowire. The applied voltage controls the flow of current through the monowire, which can be used to control the current efficiently in the low order of magnitude in the molecular device.

  5. Optical bistability and multistability via double dark resonance in graphene nanostructure

    NASA Astrophysics Data System (ADS)

    Seyyed, Hossein Asadpour; G, Solookinejad; M, Panahi; E Ahmadi, Sangachin

    2016-06-01

    Electrons in graphene nanoribbons can lead to exceptionally strong optical responses in the infrared and terahertz regions owing to their unusual dispersion relation. Therefore, on the basis of quantum optics and solid-material scientific principles, we show that optical bistability and multistability can be generated in graphene nanostructure under strong magnetic field. We also show that by adjusting the intensity and detuning of infrared laser field, the threshold intensity and hysteresis loop can be manipulated efficiently. The effects of the electronic cooperation parameter which are directly proportional to the electronic number density and the length of the graphene sample are discussed. Our proposed model may be useful for the nextgeneration all-optical systems and information processing based on nano scale devices.

  6. Using lean principles to improve outpatient adult infusion clinic chemotherapy preparation turnaround times.

    PubMed

    Lamm, Matthew H; Eckel, Stephen; Daniels, Rowell; Amerine, Lindsey B

    2015-07-01

    The workflow and chemotherapy preparation turnaround times at an adult infusion clinic were evaluated to identify opportunities to optimize workflow and efficiency. A three-phase study using Lean Six Sigma methodology was conducted. In phase 1, chemotherapy turnaround times in the adult infusion clinic were examined one year after the interim goal of a 45-minute turnaround time was established. Phase 2 implemented various experiments including a five-day Kaizen event, using lean principles in an effort to decrease chemotherapy preparation turnaround times in a controlled setting. Phase 3 included the implementation of process-improvement strategies identified during the Kaizen event, coupled with a final refinement of operational processes. In phase 1, the mean turnaround time for all chemotherapy preparations decreased from 60 to 44 minutes, and a mean of 52 orders for adult outpatient chemotherapy infusions was received each day. After installing new processes, the mean turnaround time had improved to 37 minutes for each chemotherapy preparation in phase 2. In phase 3, the mean turnaround time decreased from 37 to 26 minutes. The overall mean turnaround time was reduced by 26 minutes, representing a 57% decrease in turnaround times in 19 months through the elimination of waste and the implementation of lean principles. This reduction was accomplished through increased efficiencies in the workplace, with no addition of human resources. Implementation of Lean Six Sigma principles improved workflow and efficiency at an adult infusion clinic and reduced the overall chemotherapy turnaround times from 60 to 26 minutes. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  7. Investigating underlying principles to guide health impact assessment.

    PubMed

    Fakhri, Ali; Maleki, Mohammadreza; Gohari, Mahmoodreza; Harris, Patrick

    2014-06-01

    Many countries conduct Health Impact Assessment (HIA) of their projects and policies to predict their positive and negative health impacts. In recent years many guides have been developed to inform HIA practice, largely reflecting local developments in HIA. These guides have often been designed for specific contexts and specific need, making the choice between guides difficult. The objective of the current study is to identify underlying principles in order to guide HIA practice in Iran. This study was conducted in three stages: 1) Studies comparing HIA guidelines were reviewed to identify criteria used for comparison seeking emphasized principles. 2) The HIA characteristics extracted from published papers were categorized in order to determine the principles that could guide HIA practice. 3) Finally, these principles were agreed by experts using nominal group technique. The review of the studies comparing HIA guides demonstrated there are no clear comparison criteria for reviewing HIA guides and no study mentioned HIA principles. Investigating the HIA principles from peer-reviewed papers, we found 14 issues. These were, considering of general features in planning and conducting HIAs such as HIA stream, level, timing and type, considering of the wider socio-political and economic context, considering of economic, technical and legal aspects of HIA and capacities for HIA, rationality and comprehensiveness, using appropriate evidence, elaborating on HIA relation to other forms of Impact Assessment, considering of equity, and encouraging intersectoral and interdisciplinary cooperation, involvement of stakeholders and transparency as underlying principles to guide HIA practice. The results emphasize how critical these technical as well as tactical considerations are in the early scoping step of an HIA which plans the conduct of the HIA in reponse to local contextual issues. Determining the principles of HIA from peer-reviewed papers provides an opportunity for guiding HIA practice comprehensively. It seems to be feasible to develop a universal guide that covers all principles required.

  8. The End of Modernist Approaches to School Funding Policy in Australia: A New Rationale for Funding with Inclusive Implications for All Australian Schools?

    ERIC Educational Resources Information Center

    Furtado, Michael

    2005-01-01

    The Australian Senate Employment, Workplace Relations and Education References Committee has been asked to examine the principles of Commonwealth Funding for schools, with particular emphasis on how these principles apply in meeting the current future needs of government and non-government schools and whether they ensure efficiency in the…

  9. 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.

  10. EDITORIAL: Imaging systems and techniques Imaging systems and techniques

    NASA Astrophysics Data System (ADS)

    Yang, Wuqiang; Giakos, George; Nikita, Konstantina; Pastorino, Matteo; Karras, Dimitrios

    2009-10-01

    The papers in this special issue focus on providing the state-of-the-art approaches and solutions to some of the most challenging imaging areas, such as the design, development, evaluation and applications of imaging systems, measuring techniques, image processing algorithms and instrumentation, with an ultimate aim of enhancing the measurement accuracy and image quality. This special issue explores the principles, engineering developments and applications of new imaging systems and techniques, and encourages broad discussion of imaging methodologies, shaping the future and identifying emerging trends. The multi-faceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment and technological evolution. There is an urgent need to address new problems, which tend to be either static but complex, or dynamic, e.g. rapidly evolving with time, with many unknowns, and to propose innovative solutions. For instance, the battles against cancer and terror, monitoring of space resources and enhanced awareness, management of natural resources and environmental monitoring are some of the areas that need to be addressed. The complexity of the involved imaging scenarios and demanding design parameters, e.g. speed, signal-to-noise ratio (SNR), specificity, contrast, spatial resolution, scatter rejection, complex background and harsh environments, necessitate the development of a multi-functional, scalable and efficient imaging suite of sensors, solutions driven by innovation, and operation on diverse detection and imaging principles. Efficient medical imaging techniques capable of providing physiological information at the molecular level present another important research area. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, and using high-resolution, high-selectivity nano-imaging methods, quantum dots, nanoparticles, biomarkers, nanostructures, nanosensors, micro-array imaging chips and nano-clinics for optical diagnostics and targeted therapy, can play an important role in the diagnosis and treatment of cancer. These techniques can also be used to provide efficient drug delivery for treatment of other diseases, with increased sensitivity and specificity. Similarly, enhanced stand-off detection, classification, identification and surveillance techniques, for comprehensive civilian and military target protection and enhanced space situational awareness can open new frontiers of research and applications in the defence arena and homeland security. For instance, the development of potential imaging sensor architectures, enhanced remote sensing systems, ladars, lidars and radars can provide data capable of ensuring continuous monitoring of various imaging/physical/chemical parameters under different operating conditions, using both active and passive detection principles, reconfigurable and scalable focal plane array architectures, reliable systems for stand-off detection of explosives, and enhanced airport security. The above areas pose challenging problems to the technical community and indicate an ever-growing need for innovative and auspicious solutions. We would like to thank all authors for their valuable contributions, without which this special issue would not have become reality.

  11. Impacts of foreign direct investment on efficiency in Swedish manufacturing.

    PubMed

    Svedin, Dick; Stage, Jesper

    2016-01-01

    A number of studies have found that foreign direct investment (FDI) can have positive impacts on productivity. However, while FDI has clearly positive impacts on technology transfers, its effects on resource use within firms is less clear and, in principle, efficiency losses might offset some of the productivity gains associated with improved technologies. In this paper, we study the impacts of FDI on efficiency in Swedish manufacturing. We find that foreign ownership has positive impacts on efficiency, supporting the earlier findings on productivity.

  12. 75 FR 12962 - Transitional Safe Harbor Protection for Treatment by the Federal Deposit Insurance Corporation as...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... be affected by recent changes to generally accepted accounting principles. In effect, the Final Rule... complied with the preexisting requirements under generally accepted accounting principles in effect prior... accounting principles (``GAAP''). The rule was a clarification, rather than a limitation, of the repudiation...

  13. Can Evolutionary Principles Explain Patterns of Family Violence?

    ERIC Educational Resources Information Center

    Archer, John

    2013-01-01

    The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated…

  14. 32 CFR 32.27 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... contractor receiving a. cost-type contract under an assistance award, there is a set of Federal principles... principles applicable to the entity incurring the costs. (b) Governmental organizations. Allowability of... of OMB Circular A-87, 8 “Cost Principles for State and Local Governments.” 8 See footnote 1 to § 32.1...

  15. The Use of Informational Formats to Implement APA Ethical Principles in Collecting Classroom Data.

    ERIC Educational Resources Information Center

    Dolly, John P.; And Others

    1978-01-01

    Providing more information about experimental studies than required under the ethical principles formulated by the American Psychological Association can result in data bias on a specific task; overall, however, the implementation of ethical principles has little effect on data collected in classroom settings. (RL)

  16. 31 CFR 29.341 - General principle.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false General principle. 29.341 Section 29.341 Money and Finance: Treasury Office of the Secretary of the Treasury FEDERAL BENEFIT PAYMENTS UNDER... Benefit Payments § 29.341 General principle. Except for disability retirements after June 30, 1997, and...

  17. 31 CFR 29.331 - General principle.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false General principle. 29.331 Section 29.331 Money and Finance: Treasury Office of the Secretary of the Treasury FEDERAL BENEFIT PAYMENTS UNDER... Satisfied by June 30, 1997 § 29.331 General principle. To determine whether service is creditable for the...

  18. 31 CFR 29.321 - General principle.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false General principle. 29.321 Section 29.321 Money and Finance: Treasury Office of the Secretary of the Treasury FEDERAL BENEFIT PAYMENTS UNDER....321 General principle. Any service performed after June 30, 1997, may never be credited toward Federal...

  19. New classes of Lorenz curves by maximizing Tsallis entropy under mean and Gini equality and inequality constraints

    NASA Astrophysics Data System (ADS)

    Preda, Vasile; Dedu, Silvia; Gheorghe, Carmen

    2015-10-01

    In this paper, by using the entropy maximization principle with Tsallis entropy, new distribution families for modeling the income distribution are derived. Also, new classes of Lorenz curves are obtained by applying the entropy maximization principle with Tsallis entropy, under mean and Gini index equality and inequality constraints.

  20. 26 CFR 1.367(a)-1T - Transfers to foreign corporations subject to section 367(a): In general (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... share of partnership property shall be determined under the rules and principles of sections 701 through... shall be determined under the rules and principles of sections 701 through 761 and the regulations... in manufacturing activities or in marketing activities. A working interest in oil and gas properties...

  1. Supporting Sustainable Rural Communities

    EPA Pesticide Factsheets

    Presentation about creating sustainable rural communities discussing principles, energy efficiency, water quality, waste, business, building improvements and restoration, transportation, and green building.transportation, and green building.

  2. Diffusion models for innovation: s-curves, networks, power laws, catastrophes, and entropy.

    PubMed

    Jacobsen, Joseph J; Guastello, Stephen J

    2011-04-01

    This article considers models for the diffusion of innovation would be most relevant to the dynamics of early 21st century technologies. The article presents an overview of diffusion models and examines the adoption S-curve, network theories, difference models, influence models, geographical models, a cusp catastrophe model, and self-organizing dynamics that emanate from principles of network configuration and principles of heat diffusion. The diffusion dynamics that are relevant to information technologies and energy-efficient technologies are compared. Finally, principles of nonlinear dynamics for innovation diffusion that could be used to rehabilitate the global economic situation are discussed.

  3. Concept of information technology of monitoring and decision-making support

    NASA Astrophysics Data System (ADS)

    Kovalenko, Aleksandr S.; Tymchyk, Sergey V.; Kostyshyn, Sergey V.; Zlepko, Sergey M.; Wójcik, Waldemar; Kalizhanova, Aliya; Burlibay, Aron; Kozbekova, Ainur

    2017-08-01

    Presented concept of information technology monitoring and decision support to determine the health of students. The preconditions of a concept formulated its goal and purpose. Subject area concepts proposed to consider a set of problems, grouped into 8 categories, which in turn necessitates the application when creating technology basic principles from the principles of "first head" and "systems approach" to the principles of "interoperability" and "system integration ". The content of the information providing IT, its position in the segment of single information space, stages of creation. To evaluate the efficiency of the IT system developed proposed criteria.

  4. Commissioning Education Programs Surveys: Active Duty, Reserve, and Air National Guard Officers in Paygrades O-1 through O-3, Field Grade Officers With 1-60 Months Active Commissioned Service

    DTIC Science & Technology

    1994-09-01

    to insure effective/ 6.80 efficient accomplishment of mission C119 Principles of management 6.80 C121 Role of the NCO-responsibilities and duties of...Budgeting System (PPBS) 7.11 C119 Principles of management 7.06 C 114 Career development-know the general structure and career progression patterns 7.06...communication and give effective 6.23 feedback C1 19 Principles of management 6.23 B49 Group problem solving-understand the positive and negative aspects of

  5. Industrial applications using BASF eco-efficiency analysis: perspectives on green engineering principles.

    PubMed

    Shonnard, David R; Kicherer, Andreas; Saling, Peter

    2003-12-01

    Life without chemicals would be inconceivable, but the potential risks and impacts to the environment associated with chemical production and chemical products are viewed critically. Eco-efficiency analysis considers the economic and life cycle environmental effects of a product or process, giving these equal weighting. The major elements of the environmental assessment include primary energy use, raw materials utilization, emissions to all media, toxicity, safety risk, and land use. The relevance of each environmental category and also for the economic versus the environmental impacts is evaluated using national emissions and economic data. The eco-efficiency analysis method of BASF is briefly presented, and results from three applications to chemical processes and products are summarized. Through these applications, the eco-efficiency analyses mostly confirm the 12 Principles listed in Anastas and Zimmerman (Environ. Sci. Technol. 2003, 37(5), 94A), with the exception that, in one application, production systems based on bio-based feedstocks were not the most eco-efficient as compared to those based on fossil resources. Over 180 eco-efficiency analyses have been conducted at BASF, and their results have been used to support strategic decision-making, marketing, research and development, and communication with external parties. Eco-efficiency analysis, as one important strategy and success factor in sustainable development, will continue to be a very strong operational tool at BASF.

  6. 48 CFR 49.206-1 - Submission of settlement proposals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACT MANAGEMENT TERMINATION OF CONTRACTS Additional Principles for Fixed-Price Contracts Terminated for... settlement proposals if they are determined under generally recognized accounting principles consistently...

  7. Ab initio molecular simulations with numeric atom-centered orbitals

    NASA Astrophysics Data System (ADS)

    Blum, Volker; Gehrke, Ralf; Hanke, Felix; Havu, Paula; Havu, Ville; Ren, Xinguo; Reuter, Karsten; Scheffler, Matthias

    2009-11-01

    We describe a complete set of algorithms for ab initio molecular simulations based on numerically tabulated atom-centered orbitals (NAOs) to capture a wide range of molecular and materials properties from quantum-mechanical first principles. The full algorithmic framework described here is embodied in the Fritz Haber Institute "ab initio molecular simulations" (FHI-aims) computer program package. Its comprehensive description should be relevant to any other first-principles implementation based on NAOs. The focus here is on density-functional theory (DFT) in the local and semilocal (generalized gradient) approximations, but an extension to hybrid functionals, Hartree-Fock theory, and MP2/GW electron self-energies for total energies and excited states is possible within the same underlying algorithms. An all-electron/full-potential treatment that is both computationally efficient and accurate is achieved for periodic and cluster geometries on equal footing, including relaxation and ab initio molecular dynamics. We demonstrate the construction of transferable, hierarchical basis sets, allowing the calculation to range from qualitative tight-binding like accuracy to meV-level total energy convergence with the basis set. Since all basis functions are strictly localized, the otherwise computationally dominant grid-based operations scale as O(N) with system size N. Together with a scalar-relativistic treatment, the basis sets provide access to all elements from light to heavy. Both low-communication parallelization of all real-space grid based algorithms and a ScaLapack-based, customized handling of the linear algebra for all matrix operations are possible, guaranteeing efficient scaling (CPU time and memory) up to massively parallel computer systems with thousands of CPUs.

  8. Understanding how replication processes can maintain systems away from equilibrium using Algorithmic Information Theory.

    PubMed

    Devine, Sean D

    2016-02-01

    Replication can be envisaged as a computational process that is able to generate and maintain order far-from-equilibrium. Replication processes, can self-regulate, as the drive to replicate can counter degradation processes that impact on a system. The capability of replicated structures to access high quality energy and eject disorder allows Landauer's principle, in conjunction with Algorithmic Information Theory, to quantify the entropy requirements to maintain a system far-from-equilibrium. Using Landauer's principle, where destabilising processes, operating under the second law of thermodynamics, change the information content or the algorithmic entropy of a system by ΔH bits, replication processes can access order, eject disorder, and counter the change without outside interventions. Both diversity in replicated structures, and the coupling of different replicated systems, increase the ability of the system (or systems) to self-regulate in a changing environment as adaptation processes select those structures that use resources more efficiently. At the level of the structure, as selection processes minimise the information loss, the irreversibility is minimised. While each structure that emerges can be said to be more entropically efficient, as such replicating structures proliferate, the dissipation of the system as a whole is higher than would be the case for inert or simpler structures. While a detailed application to most real systems would be difficult, the approach may well be useful in understanding incremental changes to real systems and provide broad descriptions of system behaviour. Copyright © 2016 The Author. Published by Elsevier Ireland Ltd.. All rights reserved.

  9. Useful Material Efficiency Green Metrics Problem Set Exercises for Lecture and Laboratory

    ERIC Educational Resources Information Center

    Andraos, John

    2015-01-01

    A series of pedagogical problem set exercises are posed that illustrate the principles behind material efficiency green metrics and their application in developing a deeper understanding of reaction and synthesis plan analysis and strategies to optimize them. Rigorous, yet simple, mathematical proofs are given for some of the fundamental concepts,…

  10. A Study of the Effectiveness of Teaching Listening.

    ERIC Educational Resources Information Center

    Broiles, Mack R.

    Listening, the most efficient means of learning in the early grades, is replaced by reading as an efficient method for learning after the seventh grade. For an investigation of the effectiveness with which college students may be taught listening, lesson plans were developed from a programed instruction book --Principles of Selective Listening--…

  11. Efficient decision-making by volume-conserving physical object

    NASA Astrophysics Data System (ADS)

    Kim, Song-Ju; Aono, Masashi; Nameda, Etsushi

    2015-08-01

    Decision-making is one of the most important intellectual abilities of not only humans but also other biological organisms, helping their survival. This ability, however, may not be limited to biological systems and may be exhibited by physical systems. Here we demonstrate that any physical object, as long as its volume is conserved when coupled with suitable operations, provides a sophisticated decision-making capability. We consider the multi-armed bandit problem (MBP), the problem of finding, as accurately and quickly as possible, the most profitable option from a set of options that gives stochastic rewards. Efficient MBP solvers are useful for many practical applications, because MBP abstracts a variety of decision-making problems in real-world situations in which an efficient trial-and-error is required. These decisions are made as dictated by a physical object, which is moved in a manner similar to the fluctuations of a rigid body in a tug-of-war (TOW) game. This method, called ‘TOW dynamics’, exhibits higher efficiency than conventional reinforcement learning algorithms. We show analytical calculations that validate statistical reasons for TOW dynamics to produce the high performance despite its simplicity. These results imply that various physical systems in which some conservation law holds can be used to implement an efficient ‘decision-making object’. The proposed scheme will provide a new perspective to open up a physics-based analog computing paradigm and to understanding the biological information-processing principles that exploit their underlying physics.

  12. In situ growth of Ag nanoparticles on α-Ag2WO4 under electron irradiation: probing the physical principles

    NASA Astrophysics Data System (ADS)

    San-Miguel, Miguel A.; da Silva, Edison Z.; Zannetti, Sonia M.; Cilense, Mario; Fabbro, Maria T.; Gracia, Lourdes; Andrés, Juan; Longo, Elson

    2016-06-01

    Exploiting the plasmonic behavior of Ag nanoparticles grown on α-Ag2WO4 is a widely employed strategy to produce efficient photocatalysts, ozone sensors, and bactericides. However, a description of the atomic and electronic structure of the semiconductor sites irradiated by electrons is still not available. Such a description is of great importance to understand the mechanisms underlying these physical processes and to improve the design of silver nanoparticles to enhance their activities. Motivated by this, we studied the growth of silver nanoparticles to investigate this novel class of phenomena using both transmission electron microscopy and field emission scanning electron microscopy. A theoretical framework based on density functional theory calculations (DFT), together with experimental analysis and measurements, were developed to examine the changes in the local geometrical and electronic structure of the materials. The physical principles for the formation of Ag nanoparticles on α-Ag2WO4 by electron beam irradiation are described. Quantum mechanical calculations based on DFT show that the (001) of α-Ag2WO4 displays Ag atoms with different coordination numbers. Some of them are able to diffuse out of the surface with a very low energy barrier (less than 0.1 eV), thus, initiating the growth of metallic Ag nanostructures and leaving Ag vacancies in the bulk material. These processes increase the structural disorder of α-Ag2WO4 as well as its electrical resistance as observed in the experimental measurements.

  13. Hospital concessions in Chile: where we are and where we are heading.

    PubMed

    Bachelet, Vivienne C

    2014-11-25

    Public-private partnerships began under President Ricardo Lagos, driven by the need to provide roads and other hard facilities. Over time, they expanded into social concessions such as prisons and hospitals. During the Bachelet administration, the construction of two mid-sized hospitals of Santiago was tendered with private finance initiative. During the government of Sebastián Piñera, three more hospitals were tendered. This article critically examines the grounds on which social concessions have been introduced in different parts of the world. I argue that the there are two main rationales underlying the position of those favorable to concession arrangements: pragmatic reasons and ideological-utopian reasons. I refute the arguments related to closing the infrastructure gap, effect on public debt, transfer of risk to the private sector, greater efficiency of the private sector, freeing-up of public funds and quality of health care. Review of the international literature does not yield evidence in favor of hospital concessions consistent with the principles and drivers that promote them. Quite the contrary, when the “Value for Money” methodology has been used, concessions have proven to decrease the overall capacity of the health system and to negatively affect quality of health care. I also note that there is a potential impact on intergenerational equity with projects that span for long periods, as is the case of hospital concessions. I conclude that, since there is no evidence base grounded on sound technical principles in favor of this policy, the real underlying reasons to promote private financing of public health infrastructure are ideological, and functional to market interests but not to collective preferences.

  14. Comparisons of auction mechanisms in a multiple unit setting: A consideration for restructuring electric power markets

    NASA Astrophysics Data System (ADS)

    Bernard, John Charles

    The objective of this study was to compare the performance of five single sided auctions that could be used in restructured electric power markets across different market sizes in a multiple unit setting. Auction selection would profoundly influence an industry over $200 billion in size in the United States, and the consequences of implementing an inappropriate mechanism would be great. Experimental methods were selected to analyze the auctions. Two rounds of experiments were conducted, the first testing the sealed offer last accepted offer (LAO) and first rejected offer (FRO), and the clock English (ENG) and sealed offer English (SOE) in markets of sizes two and six. The FRO, SOE, and ENG used the same pricing rule. Second round testing was on the LAO, FRO, and the nonuniform price multiple unit Vickrey (MUV) in markets of sizes two, four, and six. Experiments lasted 23 and 75 periods for rounds 1 and 2 respectively. Analysis of variance and contrast analysis were used to examine the data. The four performance measures used were price, efficiency, profits per unit, and supply revelation. Five basic principles were also assessed: no sales at losses, all low cost capacity should be offered and sold, no high cost capacity should sell, and the market should clear. It was expected group size and auction type would affect performance. For all performance measures, group size was a significant variable, with smaller groups showing poorer performance. Auction type was significant only for the efficiency performance measure, where clock auctions outperformed the others. Clock auctions also proved superior for the first four principles. The FRO performed poorly in almost all situations, and should not be a preferred mechanism in any market. The ENG was highly efficient, but expensive for the buyer. The SOE appeared superior to the FRO and ENG. The clock improves efficiency over the FRO while less information kept prices under the ENG. The MUV was superior in revealing costs, but performed less well in other categories. While concerns existed for all the mechanisms investigated, the commonly proposed LAO was the best option for restructured electric power markets.

  15. A principled dimension-reduction method for the population density approach to modeling networks of neurons with synaptic dynamics.

    PubMed

    Ly, Cheng

    2013-10-01

    The population density approach to neural network modeling has been utilized in a variety of contexts. The idea is to group many similar noisy neurons into populations and track the probability density function for each population that encompasses the proportion of neurons with a particular state rather than simulating individual neurons (i.e., Monte Carlo). It is commonly used for both analytic insight and as a time-saving computational tool. The main shortcoming of this method is that when realistic attributes are incorporated in the underlying neuron model, the dimension of the probability density function increases, leading to intractable equations or, at best, computationally intensive simulations. Thus, developing principled dimension-reduction methods is essential for the robustness of these powerful methods. As a more pragmatic tool, it would be of great value for the larger theoretical neuroscience community. For exposition of this method, we consider a single uncoupled population of leaky integrate-and-fire neurons receiving external excitatory synaptic input only. We present a dimension-reduction method that reduces a two-dimensional partial differential-integral equation to a computationally efficient one-dimensional system and gives qualitatively accurate results in both the steady-state and nonequilibrium regimes. The method, termed modified mean-field method, is based entirely on the governing equations and not on any auxiliary variables or parameters, and it does not require fine-tuning. The principles of the modified mean-field method have potential applicability to more realistic (i.e., higher-dimensional) neural networks.

  16. The application of evolutionary medicine principles for sustainable malaria control: a scoping study.

    PubMed

    Ocampo, Denise; Booth, Mark

    2016-07-22

    Current interventions against malaria have significantly reduced the number of people infected and the number of deaths. Concerns about emerging resistance of both mosquitoes and parasites to intervention have been raised, and questions remain about how best to generate wider knowledge of the underlying evolutionary processes. The pedagogical and research principles of evolutionary medicine may provide an answer to this problem. Eight programme managers and five academic researchers were interviewed by telephone or videoconference to elicit their first-hand views and experiences of malaria control given that evolution is a constant threat to sustainable control. Interviewees were asked about their views on the relationship between practit groups and academics and for their thoughts on whether or not evolutionary medicine may provide a solution to reported tensions. There was broad agreement that evolution of both parasites and vectors presents an obstacle to sustainable control. It was also widely agreed that through more efficient monitoring, evolution could be widely monitored. Interviewees also expressed the view that even well planned interventions may fail if the evolutionary biology of the disease is not considered, potentially making current tools redundant. This scoping study suggests that it is important to make research, including evolutionary principles, available and easily applicable for programme managers and key decision-makers, including donors and politicians. The main conclusion is that sharing knowledge through the educational and research processes embedded within evolutionary medicine has potential to relieve tensions and facilitate sustainable control of malaria and other parasitic infections.

  17. Twelve tips for utilizing principles of learning to support medical education.

    PubMed

    Cutting, Maris F; Saks, Norma Susswein

    2012-01-01

    Research in the cognitive sciences on learning and memory conducted across a range of domains, settings, and age groups has resulted in the identification and formulation of a set of generic learning principles. These learning principles have proven relevant and applicable to a wide range of learning situations in a variety of settings, and can be useful in supporting medical education. They can provide guidance to medical students for efficient and effective study, and can be helpful to faculty to support instructional planning and decisions relating to curriculum. This article discusses evidence-based principles of learning and their relationship to effective learning, teaching, pedagogy and curriculum development. We reviewed important principles of learning to determine those most relevant to improving medical student learning, guiding faculty toward more effective teaching, and in designing a curriculum. Our analysis has resulted in the articulation of key learning principles and specific strategies that are broadly applicable to medical school learning, teaching, and instructional planning. The twelve tips highlight principles of learning that can be effectively applied in the complex learning environment of medical education.

  18. Defending the beauty of the Invariance Principle

    NASA Astrophysics Data System (ADS)

    Barkana, Itzhak

    2014-01-01

    Customary stability analysis methods for nonlinear nonautonomous systems seem to require a strict condition of uniform continuity. Although extensions of LaSalle's Invariance Principle to nonautonomous systems that mitigate this condition have been available for a long time, they have remained surprisingly unknown or open to misinterpretations. The large scope of the Principle might have misled the prospective users and its application to Control problems has been received with amazing yet clear uneasiness. Counterexamples have been used in order to claim that the Invariance Principle cannot be applied to nonlinear nonautonomous systems. Because the original formulation of the Invariance Principle still imposes conditions that are not necessarily needed, this paper presents a new Invariance Principle that further mitigates previous conditions and thus further expands the scope of stability analysis. A brief comparative review of various alternatives to stability analysis of nonautonomous nonlinear systems and their implications is also presented in order to illustrate that thorough analysis of same examples may actually confirm the efficiency of the Invariance Principle approach when dealing with stability of nonautonomous nonlinear systems problems that may look difficult or even unsolvable otherwise.

  19. The Perceived Implications of an Outsourcing Model on Governance within British Columbia Provincial Parks in Canada: A Quantitative Study

    NASA Astrophysics Data System (ADS)

    Eagles, Paul; Havitz, Mark; McCutcheon, Bonnie; Buteau-Duitschaever, Windekind; Glover, Troy

    2010-06-01

    Good governance is of paramount importance to the success of parks and protected areas. This research utilized a questionnaire for 10 principles of governance to evaluate the outsourcing model used by British Columbia Provincial Parks, where profit-making corporations provide all front country visitor services. A total of 246 respondents representing five stakeholder groups evaluated the model according to each principle, using an online survey. Principal component analysis resulted in two of the 10 principles (equity and effectiveness) each being split into two categories, leading to 12 governance principles. Five of the 12 criteria received scores towards good governance: effectiveness outcome; equity general; strategic vision; responsiveness; and effectiveness process. One criterion, public participation, was on the neutral point. Six criteria received scores below neutral, more towards weak governance: transparency; rule of law; accountability; efficiency; consensus orientation; and, equity finance. The five stakeholder groups differed significantly on 10 of the 12 principles ( P < .05). The 2 exceptions were for efficiency and effectiveness process. Seven of the 12 criteria followed a pattern wherein government employees and contractors reported positive scores, visitors and representatives of NGOs reported more negative scores, and nearby residents reported mid-range scores. Three criteria had government employees and contractors reporting the most positive scores, residents and visitors the most negative scores, and NGO respondents reporting mid-range scores. This research found evidence that perceptions of governance related to this outsourcing model differed significantly amongst various constituent groups.

  20. Deductive Derivation and Turing-Computerization of Semiparametric Efficient Estimation

    PubMed Central

    Frangakis, Constantine E.; Qian, Tianchen; Wu, Zhenke; Diaz, Ivan

    2015-01-01

    Summary Researchers often seek robust inference for a parameter through semiparametric estimation. Efficient semiparametric estimation currently requires theoretical derivation of the efficient influence function (EIF), which can be a challenging and time-consuming task. If this task can be computerized, it can save dramatic human effort, which can be transferred, for example, to the design of new studies. Although the EIF is, in principle, a derivative, simple numerical differentiation to calculate the EIF by a computer masks the EIF’s functional dependence on the parameter of interest. For this reason, the standard approach to obtaining the EIF relies on the theoretical construction of the space of scores under all possible parametric submodels. This process currently depends on the correctness of conjectures about these spaces, and the correct verification of such conjectures. The correct guessing of such conjectures, though successful in some problems, is a nondeductive process, i.e., is not guaranteed to succeed (e.g., is not computerizable), and the verification of conjectures is generally susceptible to mistakes. We propose a method that can deductively produce semiparametric locally efficient estimators. The proposed method is computerizable, meaning that it does not need either conjecturing, or otherwise theoretically deriving the functional form of the EIF, and is guaranteed to produce the desired estimates even for complex parameters. The method is demonstrated through an example. PMID:26237182

  1. Deductive derivation and turing-computerization of semiparametric efficient estimation.

    PubMed

    Frangakis, Constantine E; Qian, Tianchen; Wu, Zhenke; Diaz, Ivan

    2015-12-01

    Researchers often seek robust inference for a parameter through semiparametric estimation. Efficient semiparametric estimation currently requires theoretical derivation of the efficient influence function (EIF), which can be a challenging and time-consuming task. If this task can be computerized, it can save dramatic human effort, which can be transferred, for example, to the design of new studies. Although the EIF is, in principle, a derivative, simple numerical differentiation to calculate the EIF by a computer masks the EIF's functional dependence on the parameter of interest. For this reason, the standard approach to obtaining the EIF relies on the theoretical construction of the space of scores under all possible parametric submodels. This process currently depends on the correctness of conjectures about these spaces, and the correct verification of such conjectures. The correct guessing of such conjectures, though successful in some problems, is a nondeductive process, i.e., is not guaranteed to succeed (e.g., is not computerizable), and the verification of conjectures is generally susceptible to mistakes. We propose a method that can deductively produce semiparametric locally efficient estimators. The proposed method is computerizable, meaning that it does not need either conjecturing, or otherwise theoretically deriving the functional form of the EIF, and is guaranteed to produce the desired estimates even for complex parameters. The method is demonstrated through an example. © 2015, The International Biometric Society.

  2. Energy efficiency as a unifying principle for human, environmental, and global health

    PubMed Central

    Fontana, Luigi; Atella, Vincenzo; Kammen, Daniel M

    2013-01-01

    A strong analogy exists between over/under consumption of energy at the level of the human body and of the industrial metabolism of humanity. Both forms of energy consumption have profound implications for human, environmental, and global health. Globally, excessive fossil-fuel consumption, and individually, excessive food energy consumption are both responsible for a series of interrelated detrimental effects, including global warming, extreme weather conditions, damage to ecosystems, loss of biodiversity, widespread pollution, obesity, cancer, chronic respiratory disease, and other lethal chronic diseases. In contrast, data show that the efficient use of energy—in the form of food as well as fossil fuels and other resources—is vital for promoting human, environmental, and planetary health and sustainable economic development. While it is not new to highlight how efficient use of energy and food can address some of the key problems our world is facing, little research and no unifying framework exists to harmonize these concepts of sustainable system management across diverse scientific fields into a single theoretical body. Insights beyond reductionist views of efficiency are needed to encourage integrated changes in the use of the world’s natural resources, with the aim of achieving a wiser use of energy, better farming systems, and healthier dietary habits. This perspective highlights a range of scientific-based opportunities for cost-effective pro-growth and pro-health policies while using less energy and natural resources. PMID:24555053

  3. Energy efficiency as a unifying principle for human, environmental, and global health.

    PubMed

    Fontana, Luigi; Atella, Vincenzo; Kammen, Daniel M

    2013-01-01

    A strong analogy exists between over/under consumption of energy at the level of the human body and of the industrial metabolism of humanity. Both forms of energy consumption have profound implications for human, environmental, and global health. Globally, excessive fossil-fuel consumption, and individually, excessive food energy consumption are both responsible for a series of interrelated detrimental effects, including global warming, extreme weather conditions, damage to ecosystems, loss of biodiversity, widespread pollution, obesity, cancer, chronic respiratory disease, and other lethal chronic diseases. In contrast, data show that the efficient use of energy-in the form of food as well as fossil fuels and other resources-is vital for promoting human, environmental, and planetary health and sustainable economic development. While it is not new to highlight how efficient use of energy and food can address some of the key problems our world is facing, little research and no unifying framework exists to harmonize these concepts of sustainable system management across diverse scientific fields into a single theoretical body. Insights beyond reductionist views of efficiency are needed to encourage integrated changes in the use of the world's natural resources, with the aim of achieving a wiser use of energy, better farming systems, and healthier dietary habits. This perspective highlights a range of scientific-based opportunities for cost-effective pro-growth and pro-health policies while using less energy and natural resources.

  4. All-fiber probe for optical coherence tomography with an extended depth of focus by a high-efficient fiber-based filter

    NASA Astrophysics Data System (ADS)

    Qiu, Jianrong; Shen, Yi; Shangguan, Ziwei; Bao, Wen; Yang, Shanshan; Li, Peng; Ding, Zhihua

    2018-04-01

    Although methods have been proposed to maintain high transverse resolution over an increased depth range, it is not straightforward to scale down the bulk-optic solutions to minimized probes of optical coherence tomography (OCT). In this paper, we propose a high-efficient fiber-based filter in an all-fiber OCT probe to realize an extended depth of focus (DOF) while maintaining a high transverse resolution. Mode interference in the probe is exploited to modulate the complex field with controllable radial distribution. The principle of DOF extension by the fiber-based filter is theoretically analyzed. Numerical simulations are conducted to evaluate the performances of the designed probes. A DOF extension ratio of 2.6 over conventional Gaussian beam is obtainable in one proposed probe under a focused beam diameter of 4 . 6 μm. Coupling efficiencies of internal interfaces of the proposed probe are below -40 dB except the last probe-air interface, which can also be depressed to be -44 dB after minor modification in lengths for the filter. Length tolerance of the proposed probe is determined to be - 28 / + 20 μm, which is readily satisfied in fabrication. With the merits of extended-DOF, high-resolution, high-efficiency and easy-fabrication, the proposed probe is promising in endoscopic applications.

  5. A new code for the design and analysis of the heliostat field layout for power tower system

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

    Wei, Xiudong; Lu, Zhenwu; Yu, Weixing

    2010-04-15

    A new code for the design and analysis of the heliostat field layout for power tower system is developed. In the new code, a new method for the heliostat field layout is proposed based on the edge ray principle of nonimaging optics. The heliostat field boundary is constrained by the tower height, the receiver tilt angle and size and the heliostat efficiency factor which is the product of the annual cosine efficiency and the annual atmospheric transmission efficiency. With the new method, the heliostat can be placed with a higher efficiency and a faster response speed of the design andmore » optimization can be obtained. A new module for the analysis of the aspherical heliostat is created in the new code. A new toroidal heliostat field is designed and analyzed by using the new code. Compared with the spherical heliostat, the solar image radius of the field is reduced by about 30% by using the toroidal heliostat if the mirror shape and the tracking are ideal. In addition, to maximize the utilization of land, suitable crops can be considered to be planted under heliostats. To evaluate the feasibility of the crop growth, a method for calculating the annual distribution of sunshine duration on the land surface is developed as well. (author)« less

  6. Advances in first-principles calculations of thermodynamic properties of planetary materials (Invited)

    NASA Astrophysics Data System (ADS)

    Wilson, H. F.

    2013-12-01

    First-principles atomistic simulation is a vital tool for understanding the properties of materials at the high-pressure high-temperature conditions prevalent in giant planet interiors, but properties such as solubility and phase boundaries are dependent on entropy, a quantity not directly accessible in simulation. Determining entropic properties from atomistic simulations is a difficult problem typically requiring a time-consuming integration over molecular dynamics trajectories. Here I will describe recent advances in first-principles thermodynamic calculations which substantially increase the simplicity and efficiency of thermodynamic integration and make entropic properties more readily accessible. I will also describe the use of first-principles thermodynamic calculations for understanding problems including core solubility in gas giants and superionic phase changes in ice giants, as well as future prospects for combining first-principles thermodynamics with planetary-scale models to help us understand the origin and consequences of compositional inhomogeneity in giant planet interiors.

  7. The Hungry Fly: Hydrodynamics of feeding in the common house fly

    NASA Astrophysics Data System (ADS)

    Prakash, Manu; Steele, Miles

    2010-11-01

    A large number of insect species feed primarily on a fluid diet. To do so, they must overcome the numerous challenges that arise in the design of high-efficiency, miniature pumps. Although the morphology of insect feeding structures has been described for decades, their dynamics remain largely unknown even in the most well studied species (e.g. fruit fly). Here, we use invivo imaging and microsurgery to elucidate the design principles of feeding structures of the common house fly. Using high-resolution X-ray microscopy, we record invivo flow of sucrose solutions through the body over many hours during fly feeding. Borrowing from microsurgery techniques common in neurophysiology, we are able to perturb the pump to a stall position and thus evaluate function under load conditions. Furthermore, fluid viscosity-dependent feedback is observed for optimal pump performance. As the gut of the fly starts to fill up, feedback from the stretch receptors in the cuticle dictates the effective flow rate. Finally, via comparative analysis between the house fly, blow fly, fruit fly and bumble bees, we highlight the common design principles and the role of interfacial phenomena in feeding.

  8. Purely substitutional nitrogen on graphene/Pt(111) unveiled by STM and first principles calculations

    NASA Astrophysics Data System (ADS)

    Gomez-Rodriguez, Jose M.; Martin-Recio, Ana; Romero-Muniz, Carlos; Pou, Pablo; Perez, Ruben

    Nitrogen doping of graphene can be an efficient way of tuning its pristine electronic properties. Several techniques have been used to introduce nitrogen atoms on graphene layers. The main problem in most of them is the formation of a variety of C-N species that produce different electronic and structural changes on the 2D layer. Here we report on a method to obtain purely substitutional nitrogen on graphene on Pt(111) surfaces. A detailed experimental study performed in situ, under ultra-high vacuum conditions with scanning tunneling microscopy, low energy electron diffraction and Auger electron spectroscopy of the different steps on the preparation of the sample, has allowed us to gain insight into the optimal parameters for this growth method, that combines ion bombardment and annealing. This experimental work is complemented by first-principles calculations that provide the variation of the projected density of states due to both the metallic substrate and the nitrogen atoms. These calculations enlighten the experimental findings and prove that the species found are graphitic nitrogen. This easy and effective technique leads to the possibility of playing with the amount of dopants and the metallic substrate to obtain the desired doping of the graphene layer.

  9. Large-scale optimization-based non-negative computational framework for diffusion equations: Parallel implementation and performance studies

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

    Chang, Justin; Karra, Satish; Nakshatrala, Kalyana B.

    It is well-known that the standard Galerkin formulation, which is often the formulation of choice under the finite element method for solving self-adjoint diffusion equations, does not meet maximum principles and the non-negative constraint for anisotropic diffusion equations. Recently, optimization-based methodologies that satisfy maximum principles and the non-negative constraint for steady-state and transient diffusion-type equations have been proposed. To date, these methodologies have been tested only on small-scale academic problems. The purpose of this paper is to systematically study the performance of the non-negative methodology in the context of high performance computing (HPC). PETSc and TAO libraries are, respectively, usedmore » for the parallel environment and optimization solvers. For large-scale problems, it is important for computational scientists to understand the computational performance of current algorithms available in these scientific libraries. The numerical experiments are conducted on the state-of-the-art HPC systems, and a single-core performance model is used to better characterize the efficiency of the solvers. Furthermore, our studies indicate that the proposed non-negative computational framework for diffusion-type equations exhibits excellent strong scaling for real-world large-scale problems.« less

  10. Inelastic transport theory from first principles: Methodology and application to nanoscale devices

    NASA Astrophysics Data System (ADS)

    Frederiksen, Thomas; Paulsson, Magnus; Brandbyge, Mads; Jauho, Antti-Pekka

    2007-05-01

    We describe a first-principles method for calculating electronic structure, vibrational modes and frequencies, electron-phonon couplings, and inelastic electron transport properties of an atomic-scale device bridging two metallic contacts under nonequilibrium conditions. The method extends the density-functional codes SIESTA and TRANSIESTA that use atomic basis sets. The inelastic conductance characteristics are calculated using the nonequilibrium Green’s function formalism, and the electron-phonon interaction is addressed with perturbation theory up to the level of the self-consistent Born approximation. While these calculations often are computationally demanding, we show how they can be approximated by a simple and efficient lowest order expansion. Our method also addresses effects of energy dissipation and local heating of the junction via detailed calculations of the power flow. We demonstrate the developed procedures by considering inelastic transport through atomic gold wires of various lengths, thereby extending the results presented in Frederiksen [Phys. Rev. Lett. 93, 256601 (2004)]. To illustrate that the method applies more generally to molecular devices, we also calculate the inelastic current through different hydrocarbon molecules between gold electrodes. Both for the wires and the molecules our theory is in quantitative agreement with experiments, and characterizes the system-specific mode selectivity and local heating.

  11. Practical Approaches to Quality Improvement for Radiologists.

    PubMed

    Kelly, Aine Marie; Cronin, Paul

    2015-10-01

    Continuous quality improvement is a fundamental attribute of high-performing health care systems. Quality improvement is an essential component of health care, with the current emphasis on adding value. It is also a regulatory requirement, with reimbursements increasingly being linked to practice performance metrics. Practice quality improvement efforts must be demonstrated for credentialing purposes and for certification of radiologists in practice. Continuous quality improvement must occur for radiologists to remain competitive in an increasingly diverse health care market. This review provides an introduction to the main approaches available to undertake practice quality improvement, which will be useful for busy radiologists. Quality improvement plays multiple roles in radiology services, including ensuring and improving patient safety, providing a framework for implementing and improving processes to increase efficiency and reduce waste, analyzing and depicting performance data, monitoring performance and implementing change, enabling personnel assessment and development through continued education, and optimizing customer service and patient outcomes. The quality improvement approaches and underlying principles overlap, which is not surprising given that they all align with good patient care. The application of these principles to radiology practices not only benefits patients but also enhances practice performance through promotion of teamwork and achievement of goals. © RSNA, 2015.

  12. Calculation of the Curie temperature of Ni using first principles based Wang-Landau Monte-Carlo

    NASA Astrophysics Data System (ADS)

    Eisenbach, Markus; Yin, Junqi; Li, Ying Wai; Nicholson, Don

    2015-03-01

    We combine constrained first principles density functional with a Wang-Landau Monte Carlo algorithm to calculate the Curie temperature of Ni. Mapping the magnetic interactions in Ni onto a Heisenberg like model to underestimates the Curie temperature. Using a model we show that the addition of the magnitude of the local magnetic moments can account for the difference in the calculated Curie temperature. For ab initio calculations, we have extended our Locally Selfconsistent Multiple Scattering (LSMS) code to constrain the magnitude of the local moments in addition to their direction and apply the Replica Exchange Wang-Landau method to sample the larger phase space efficiently to investigate Ni where the fluctuation in the magnitude of the local magnetic moments is of importance equal to their directional fluctuations. We will present our results for Ni where we compare calculations that consider only the moment directions and those including fluctuations of the magnetic moment magnitude on the Curie temperature. This research was sponsored by the Department of Energy, Offices of Basic Energy Science and Advanced Computing. We used Oak Ridge Leadership Computing Facility resources at Oak Ridge National Laboratory, supported by US DOE under contract DE-AC05-00OR22725.

  13. LANL Multiyear Strategy Performance Improvement (MYSPI), Fiscal Years 2017–2021

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

    Leasure, Craig Scott

    2016-05-03

    Los Alamos National Laboratory (LANL) protects the nation and the world using innovative science, technology, and engineering through an integrated approach that harnesses the strength of our people, capabilities, and operations. The Laboratory’s Strategic Plan and Purpose statement provide the framework for scientific excellence and operational excellence now and in the future. Our Strategic Plan and Purpose help position Los Alamos for continuing mission success that ensures the safety, security, and effectiveness of the nation’s deterrent; protects the nation from nuclear and emerging threats through our larger global security missions; provides energy security to the nation; and ensures that themore » nation’s scientific reputation and capabilities remain robust enough to assure our allies and deter our adversaries. Moreover, we use these principles and guidance to ensure that Los Alamos is successful in attracting, recruiting, and retaining the next generation of world-class talent, while creating an efficient, environmentally responsible workplace that provides our employees with access to modern scientific tools and resources. Using this guidance and its underlying principles, we are continuing to restore credibility and operational effectiveness to the Laboratory, deliver mission success and continuing scientific excellence, and protect our employees and the nation’s secrets.« less

  14. LANL Multiyear Strategy Performance Improvement (MYSPI), Fiscal Years 2018-2022

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

    Leasure, Craig Scott

    Los Alamos National Laboratory (LANL) protects the nation and the world using innovative science, technology, and engineering through an integrated approach that harnesses the strength of our people, capabilities, and operations. The Laboratory’s Strategic Plan and Purpose statement provide the framework for scientific excellence and operational excellence now and in the future. Our Strategic Plan and Purpose help position Los Alamos for continuing mission success that ensures the safety, security, and effectiveness of the nation’s deterrent; protects the nation from nuclear and emerging threats through our larger global security missions; provides energy security to the nation; and ensures that themore » nation’s scientific reputation and capabilities remain robust enough to assure our allies and deter our adversaries. Moreover, we use these principles and guidance to ensure that Los Alamos is successful in attracting, recruiting, and retaining the next generation of excellent talent, while creating an efficient, environmentally responsible workplace that provides our employees with access to modern scientific tools and resources. Using this guidance and its underlying principles, we are continuing to restore credibility and operational effectiveness to the Laboratory, deliver mission success and continuing scientific excellence, and protect our employees and the nation’s secrets.« less

  15. Large-scale optimization-based non-negative computational framework for diffusion equations: Parallel implementation and performance studies

    DOE PAGES

    Chang, Justin; Karra, Satish; Nakshatrala, Kalyana B.

    2016-07-26

    It is well-known that the standard Galerkin formulation, which is often the formulation of choice under the finite element method for solving self-adjoint diffusion equations, does not meet maximum principles and the non-negative constraint for anisotropic diffusion equations. Recently, optimization-based methodologies that satisfy maximum principles and the non-negative constraint for steady-state and transient diffusion-type equations have been proposed. To date, these methodologies have been tested only on small-scale academic problems. The purpose of this paper is to systematically study the performance of the non-negative methodology in the context of high performance computing (HPC). PETSc and TAO libraries are, respectively, usedmore » for the parallel environment and optimization solvers. For large-scale problems, it is important for computational scientists to understand the computational performance of current algorithms available in these scientific libraries. The numerical experiments are conducted on the state-of-the-art HPC systems, and a single-core performance model is used to better characterize the efficiency of the solvers. Furthermore, our studies indicate that the proposed non-negative computational framework for diffusion-type equations exhibits excellent strong scaling for real-world large-scale problems.« less

  16. An Analysis of Viable Financial Negotiations Processes and Related Internal Controls for Procurement in Pakistan

    DTIC Science & Technology

    2016-06-01

    regulations are in accordance with UNCITRAL Model Law and are based on principles of “ accountability , transparency, fairness, efficiency and value for... account certain factors about the firm(s) for pre-qualification. These factors include past performance and experience; financial health; managerial...internal control components, along with associated principles , were discussed in detail to develop a suitable internal control system for the financial

  17. Toward Computational Design of High-Efficiency Photovoltaics from First-Principles

    DTIC Science & Technology

    2016-08-15

    dependence of exciton diffusion in conjugated small molecules, Applied Physics Letters, (04 2014): 0. doi: 10.1063/1.4871303 Guangfen Wu, Zi Li, Xu...principle approach based on the time- dependent density functional theory (TDDFT) to describe exciton states, including energy levels and many-body wave... depends more sensitively on the dimension and crystallinity of the acceptor parallel to the interface than normal to the interface. Reorganization

  18. 32 CFR 11.4 - Applicable principles of law.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Applicable principles of law. 11.4 Section 11.4... ELEMENTS FOR TRIALS BY MILITARY COMMISSION § 11.4 Applicable principles of law. (a) General intent. All... wrongful if it is done without justification or excuse cognizable under applicable law. The element of...

  19. 38 CFR 51.43 - Per diem and drugs and medicines-principles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... medicines-principles. 51.43 Section 51.43 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... Per diem and drugs and medicines—principles. (a) As a condition for receiving payment of per diem... drugs and medicines under this part, the State must submit to the VA medical center of jurisdiction a...

  20. 38 CFR 51.43 - Per diem and drugs and medicines-principles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... medicines-principles. 51.43 Section 51.43 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... Per diem and drugs and medicines—principles. (a) As a condition for receiving payment of per diem... Governments.” (f) As a condition for receiving drugs and medicines under this part, the State must submit to...

  1. 38 CFR 51.43 - Per diem and drugs and medicines-principles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... medicines-principles. 51.43 Section 51.43 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... Per diem and drugs and medicines—principles. (a) As a condition for receiving payment of per diem... Governments.” (f) As a condition for receiving drugs and medicines under this part, the State must submit to...

  2. 38 CFR 51.43 - Per diem and drugs and medicines-principles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... medicines-principles. 51.43 Section 51.43 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... Per diem and drugs and medicines—principles. (a) As a condition for receiving payment of per diem... Governments.” (f) As a condition for receiving drugs and medicines under this part, the State must submit to...

  3. Validation of "Teaching and Learning Guiding Principles Instrument" for Malaysian Higher Learning Institutions

    ERIC Educational Resources Information Center

    Rahman, Nurulhuda Abd; Masuwai, Azwani; Tajudin, Nor'ain Mohd; Tek, Ong Eng; Adnan, Mazlini

    2016-01-01

    Purpose: This study was aimed at establishing, through the validation of the "Teaching and Learning Guiding Principles Instrument" (TLGPI), the validity and reliability of the underlying factor structure of the Teaching and Learning Guiding Principles (TLGP) generated by a previous study. Method: A survey method was used to collect data…

  4. Distinguishing between forensic science and forensic pseudoscience: testing of validity and reliability, and approaches to forensic voice comparison.

    PubMed

    Morrison, Geoffrey Stewart

    2014-05-01

    In this paper it is argued that one should not attempt to directly assess whether a forensic analysis technique is scientifically acceptable. Rather one should first specify what one considers to be appropriate principles governing acceptable practice, then consider any particular approach in light of those principles. This paper focuses on one principle: the validity and reliability of an approach should be empirically tested under conditions reflecting those of the case under investigation using test data drawn from the relevant population. Versions of this principle have been key elements in several reports on forensic science, including forensic voice comparison, published over the last four-and-a-half decades. The aural-spectrographic approach to forensic voice comparison (also known as "voiceprint" or "voicegram" examination) and the currently widely practiced auditory-acoustic-phonetic approach are considered in light of this principle (these two approaches do not appear to be mutually exclusive). Approaches based on data, quantitative measurements, and statistical models are also considered in light of this principle. © 2013.

  5. 48 CFR 1631.200 - Scope of subpart.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... actual costs incurred. ... HEALTH BENEFITS ACQUISITION REGULATION GENERAL CONTRACTING REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 1631.200 Scope of subpart. The cost principles under this...

  6. Cost Reporting at a Navy Branch Clinic

    DTIC Science & Technology

    1993-03-01

    John Wiley & Sons, 1991. 15 Horngren , Charles, Cost Accounting -=A Managerial Emphasis, 5th Edition, Prentice Hall, Inc., Englewood Cliffs, N.J., 1982...traditionally reported under a partial cost reporting system. By applying basic principles of managerial accounting , a full cost reporting system is...traditionally reported under a partial cost reporting system. By applying basic principles of managerial accounting , a proposed full cost reporting

  7. The Experimental Demonstration of High Efficiency Interaction-free Measurement for Quantum Counterfactual-like Communication.

    PubMed

    Liu, Chao; Liu, Jinhong; Zhang, Junxiang; Zhu, Shiyao

    2017-09-07

    We present an interaction-free measurement with quantum Zeno effect and a high efficiency η = 74.6% ± 0.15%. As a proof-of-principle demonstration, this measurement can be used to implement a quantum counterfactual-like communication protocol. Instead of a single photon state, we use a coherent light as the input source and show that the output agrees with the proposed quantum counterfactual communication protocol according to Salih et al. Although the counterfactuality is not achieved due to the presence of a few photons in the public channel, we show that the signal light is nearly absent in the public channel, which exhibits a proof-of-principle quantum counterfactual-like property of communication.

  8. Analysis of a Temperature-Controlled Exhaust Thermoelectric Generator During a Driving Cycle

    NASA Astrophysics Data System (ADS)

    Brito, F. P.; Alves, A.; Pires, J. M.; Martins, L. B.; Martins, J.; Oliveira, J.; Teixeira, J.; Goncalves, L. M.; Hall, M. J.

    2016-03-01

    Thermoelectric generators can be used in automotive exhaust energy recovery. As car engines operate under wide variable loads, it is a challenge to design a system for operating efficiently under these variable conditions. This means being able to avoid excessive thermal dilution under low engine loads and being able to operate under high load, high temperature events without the need to deflect the exhaust gases with bypass systems. The authors have previously proposed a thermoelectric generator (TEG) concept with temperature control based on the operating principle of the variable conductance heat pipe/thermosiphon. This strategy allows the TEG modules’ hot face to work under constant, optimized temperature. The variable engine load will only affect the number of modules exposed to the heat source, not the heat transfer temperature. This prevents module overheating under high engine loads and avoids thermal dilution under low engine loads. The present work assesses the merit of the aforementioned approach by analysing the generator output during driving cycles simulated with an energy model of a light vehicle. For the baseline evaporator and condenser configuration, the driving cycle averaged electrical power outputs were approximately 320 W and 550 W for the type-approval Worldwide harmonized light vehicles test procedure Class 3 driving cycle and for a real-world highway driving cycle, respectively.

  9. Unambiguously identifying spin states of transition-metal ions in the Earth (Invited)

    NASA Astrophysics Data System (ADS)

    Hsu, H.

    2010-12-01

    The spin state of a transition-metal ion in crystalline solids, defined by the number of unpaired electrons in the ion’s incomplete 3d shell, may vary with many factors, such as temperature, pressure, strain, and the local atomic configuration, to name a few. Such a phenomenon, known as spin-state crossover, plays a crucial role in spintronic materials. Recently, the pressure-induced spin-state crossover in iron-bearing minerals has been recognized to affect the minerals’ structural and elastic properties. However, the detailed mechanism of such crossover in iron-bearing magnesium silicate perovskite, the most abundant mineral in the Earth, remains unclear. A significant part of this confusion arises from the difficulty in reliably extracting the spin state from experiments. For the same reason, the thermally-induced spin-state crossover in lanthanum cobaltite (LaCoO3) has been controversial for more than four decades. In this talk, I will discuss how first-principle calculations can help clarifying these long-standing controversies. In addition to the total energy, equation of state, and elastic properties of each spin state, first-principle calculations also predict the electric field gradient (EFG) at the nucleus of each transition-metal ion. Our calculations showed that the nuclear EFG, a quantity that can be measured via Mössbauer or nuclear magnetic resonance (NMR) spectroscopy, depends primarily on the spin state, irrespective of the concentration or configuration of transition-metal ions. Such robustness makes EFG a unique fingerprint to identify the spin state. The combination of first-principle calculations and Mössbauer/NMR spectroscopy can therefore be a reliable and efficient approach in tackling spin-state crossover problems in the Earth. This work was primarily supported by the MRSEC Program of NSF under Awards Number DMR-0212302 and DMR-0819885, and partially supported by NSF under ATM-0428774 (V-Lab), EAR-1019853, and EAR-0810272. The computations were performed mainly at the Minnesota Supercomputing Institute (MSI).

  10. Organic food processing: a framework for concept, starting definitions and evaluation.

    PubMed

    Kahl, Johannes; Alborzi, Farnaz; Beck, Alexander; Bügel, Susanne; Busscher, Nicolaas; Geier, Uwe; Matt, Darja; Meischner, Tabea; Paoletti, Flavio; Pehme, Sirli; Ploeger, Angelika; Rembiałkowska, Ewa; Schmid, Otto; Strassner, Carola; Taupier-Letage, Bruno; Załęcka, Aneta

    2014-10-01

    In 2007 EU Regulation (EC) 834/2007 introduced principles and criteria for organic food processing. These regulations have been analysed and discussed in several scientific publications and research project reports. Recently, organic food quality was described by principles, aspects and criteria. These principles from organic agriculture were verified and adapted for organic food processing. Different levels for evaluation were suggested. In another document, underlying paradigms and consumer perception of organic food were reviewed against functional food, resulting in identifying integral product identity as the underlying paradigm and a holistic quality view connected to naturalness as consumers' perception of organic food quality. In a European study, the quality concept was applied to the organic food chain, resulting in a problem, namely that clear principles and related criteria were missing to evaluate processing methods. Therefore the goal of this paper is to describe and discuss the topic of organic food processing to make it operational. A conceptual background for organic food processing is given by verifying the underlying paradigms and principles of organic farming and organic food as well as on organic processing. The proposed definition connects organic processing to related systems such as minimal, sustainable and careful, gentle processing, and describes clear principles and related criteria. Based on food examples, such as milk with different heat treatments, the concept and definitions were verified. Organic processing can be defined by clear paradigms and principles and evaluated according criteria from a multidimensional approach. Further work has to be done on developing indicators and parameters for assessment of organic food quality. © 2013 Society of Chemical Industry.

  11. Software design and implementation concepts for an interoperable medical communication framework.

    PubMed

    Besting, Andreas; Bürger, Sebastian; Kasparick, Martin; Strathen, Benjamin; Portheine, Frank

    2018-02-23

    The new IEEE 11073 service-oriented device connectivity (SDC) standard proposals for networked point-of-care and surgical devices constitutes the basis for improved interoperability due to its independence of vendors. To accelerate the distribution of the standard a reference implementation is indispensable. However, the implementation of such a framework has to overcome several non-trivial challenges. First, the high level of complexity of the underlying standard must be reflected in the software design. An efficient implementation has to consider the limited resources of the underlying hardware. Moreover, the frameworks purpose of realizing a distributed system demands a high degree of reliability of the framework itself and its internal mechanisms. Additionally, a framework must provide an easy-to-use and fail-safe application programming interface (API). In this work, we address these challenges by discussing suitable software engineering principles and practical coding guidelines. A descriptive model is developed that identifies key strategies. General feasibility is shown by outlining environments in which our implementation has been utilized.

  12. Coherent perfect absorbers: linear control of light with light

    NASA Astrophysics Data System (ADS)

    Baranov, Denis G.; Krasnok, Alex; Shegai, Timur; Alù, Andrea; Chong, Yidong

    2017-12-01

    The absorption of electromagnetic energy by a material is a phenomenon that underlies many applications, including molecular sensing, photocurrent generation and photodetection. Typically, the incident energy is delivered to the system through a single channel, for example, by a plane wave incident on one side of an absorber. However, absorption can be made much more efficient by exploiting wave interference. A coherent perfect absorber is a system in which the complete absorption of electromagnetic radiation is achieved by controlling the interference of multiple incident waves. Here, we review recent advances in the design and applications of such devices. We present the theoretical principles underlying the phenomenon of coherent perfect absorption and give an overview of the photonic structures in which it can be realized, including planar and guided-mode structures, graphene-based systems, parity-symmetric and time-symmetric structures, 3D structures and quantum-mechanical systems. We then discuss possible applications of coherent perfect absorption in nanophotonics, and, finally, we survey the perspectives for the future of this field.

  13. Strategies toward High Performance Organic Photovoltaic Cell: Material and Process

    NASA Astrophysics Data System (ADS)

    Kim, Bong Gi

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

  14. Music-evoked emotions: principles, brain correlates, and implications for therapy.

    PubMed

    Koelsch, Stefan

    2015-03-01

    This paper describes principles underlying the evocation of emotion with music: evaluation, resonance, memory, expectancy/tension, imagination, understanding, and social functions. Each of these principles includes several subprinciples, and the framework on music-evoked emotions emerging from these principles and subprinciples is supposed to provide a starting point for a systematic, coherent, and comprehensive theory on music-evoked emotions that considers both reception and production of music, as well as the relevance of emotion-evoking principles for music therapy. © 2015 New York Academy of Sciences.

  15. Contextualizing ethics: ventilators, H1N1 and marginalized populations.

    PubMed

    Silva, Diego S; Nie, Jason X; Rossiter, Kate; Sahni, Sachin; Upshur, Ross E G

    2010-01-01

    If the H1N1 pandemic worsens, there may not be enough ventilated beds to care for all persons with respiratory failure. To date, researchers who explicitly discuss the ethics of intensive care unit admission and the allocation of ventilators during an influenza pandemic have based criteria predominantly on the principles of utility and efficiency, that is, promoting actions that maximize the greatest good for the greatest number of people. However, haphazardly applying utility and efficiency potentially disadvantages marginalized populations who might be at increased risk of severe reactions to H1N1. In Canada, Aboriginals represent 3% of Canadians, yet 11% of H1N1 cases requiring hospitalization involve Aboriginal persons. Aboriginal persons suffer from high rates of obesity due to socio-economic inequalities. Obesity is also a risk factor for severe H1N1 reactions. Yet, since obesity is found to increase the duration of stay in ventilated beds and a long stay is not considered an optimal use of ventilators, applying the principles of utility and efficiency may magnify existing social inequalities. Although promoting utility and efficiency is important, other ethical principles, such as equity and need, require thoughtful consideration and implementation. Furthermore, since public resources are being used to address a public health hazard, the viewpoints of the public, and specifically stakeholders who will be disproportionately affected, should inform decision-makers. Finally, giving attention to the needs and rights of marginalized populations means that ventilators should not be allocated based on criteria that exacerbate the social injustices faced by these groups of people.

  16. Principles of recruitment and retention in clinical trials.

    PubMed

    Aitken, Leanne; Gallagher, Robyn; Madronio, Christine

    2003-12-01

    Efficient and effective recruitment and retention of participants is the largest single component of the study workload and forms an essential component in the conduct of clinical trials. In this paper, we present five principles to guide the processes of both recruitment and retention. These principles include the selection of an appropriate population to adequately answer the research question, followed by the establishment of a sampling process that accurately represents that population. Creation of systematic and effective recruitment mechanisms should be supported by implementation of follow-up mechanisms that promote participant retention. Finally, all activities related to recruitment and retention must be conducted within the framework of ethics and privacy regulations. Adherence to these principles will assist the researcher in achieving the goals of the study within the available resources.

  17. How efficient is sliding-scale insulin therapy? Problems with a 'cookbook' approach in hospitalized patients.

    PubMed

    Katz, C M

    1991-04-01

    Sliding-scale insulin therapy is seldom the best way to treat hospitalized diabetic patients. In the few clinical situations in which it is appropriate, close attention to details and solidly based scientific principles is absolutely necessary. Well-organized alternative approaches to insulin therapy usually offer greater efficiency and effectiveness.

  18. Funding Universities for Efficiency and Equity: Research Findings versus Petty Politics

    ERIC Educational Resources Information Center

    Psacharopoulos, George

    2008-01-01

    The present paper starts by discussing the principles of public funding of universities. The size of the social returns to investment in education gives an indication regarding the most efficient use of resources, while the difference between the private and the social rates relates to issues of equity. The available evidence is contrasted to…

  19. DESCARTES' RULE OF SIGNS AND THE IDENTIFIABILITY OF POPULATION DEMOGRAPHIC MODELS FROM GENOMIC VARIATION DATA.

    PubMed

    Bhaskar, Anand; Song, Yun S

    2014-01-01

    The sample frequency spectrum (SFS) is a widely-used summary statistic of genomic variation in a sample of homologous DNA sequences. It provides a highly efficient dimensional reduction of large-scale population genomic data and its mathematical dependence on the underlying population demography is well understood, thus enabling the development of efficient inference algorithms. However, it has been recently shown that very different population demographies can actually generate the same SFS for arbitrarily large sample sizes. Although in principle this nonidentifiability issue poses a thorny challenge to statistical inference, the population size functions involved in the counterexamples are arguably not so biologically realistic. Here, we revisit this problem and examine the identifiability of demographic models under the restriction that the population sizes are piecewise-defined where each piece belongs to some family of biologically-motivated functions. Under this assumption, we prove that the expected SFS of a sample uniquely determines the underlying demographic model, provided that the sample is sufficiently large. We obtain a general bound on the sample size sufficient for identifiability; the bound depends on the number of pieces in the demographic model and also on the type of population size function in each piece. In the cases of piecewise-constant, piecewise-exponential and piecewise-generalized-exponential models, which are often assumed in population genomic inferences, we provide explicit formulas for the bounds as simple functions of the number of pieces. Lastly, we obtain analogous results for the "folded" SFS, which is often used when there is ambiguity as to which allelic type is ancestral. Our results are proved using a generalization of Descartes' rule of signs for polynomials to the Laplace transform of piecewise continuous functions.

  20. DESCARTES’ RULE OF SIGNS AND THE IDENTIFIABILITY OF POPULATION DEMOGRAPHIC MODELS FROM GENOMIC VARIATION DATA1

    PubMed Central

    Bhaskar, Anand; Song, Yun S.

    2016-01-01

    The sample frequency spectrum (SFS) is a widely-used summary statistic of genomic variation in a sample of homologous DNA sequences. It provides a highly efficient dimensional reduction of large-scale population genomic data and its mathematical dependence on the underlying population demography is well understood, thus enabling the development of efficient inference algorithms. However, it has been recently shown that very different population demographies can actually generate the same SFS for arbitrarily large sample sizes. Although in principle this nonidentifiability issue poses a thorny challenge to statistical inference, the population size functions involved in the counterexamples are arguably not so biologically realistic. Here, we revisit this problem and examine the identifiability of demographic models under the restriction that the population sizes are piecewise-defined where each piece belongs to some family of biologically-motivated functions. Under this assumption, we prove that the expected SFS of a sample uniquely determines the underlying demographic model, provided that the sample is sufficiently large. We obtain a general bound on the sample size sufficient for identifiability; the bound depends on the number of pieces in the demographic model and also on the type of population size function in each piece. In the cases of piecewise-constant, piecewise-exponential and piecewise-generalized-exponential models, which are often assumed in population genomic inferences, we provide explicit formulas for the bounds as simple functions of the number of pieces. Lastly, we obtain analogous results for the “folded” SFS, which is often used when there is ambiguity as to which allelic type is ancestral. Our results are proved using a generalization of Descartes’ rule of signs for polynomials to the Laplace transform of piecewise continuous functions. PMID:28018011

  1. Use and validity of principles of extremum of entropy production in the study of complex systems

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

    Heitor Reis, A., E-mail: ahr@uevora.pt

    2014-07-15

    It is shown how both the principles of extremum of entropy production, which are often used in the study of complex systems, follow from the maximization of overall system conductivities, under appropriate constraints. In this way, the maximum rate of entropy production (MEP) occurs when all the forces in the system are kept constant. On the other hand, the minimum rate of entropy production (mEP) occurs when all the currents that cross the system are kept constant. A brief discussion on the validity of the application of the mEP and MEP principles in several cases, and in particular to themore » Earth’s climate is also presented. -- Highlights: •The principles of extremum of entropy production are not first principles. •They result from the maximization of conductivities under appropriate constraints. •The conditions of their validity are set explicitly. •Some long-standing controversies are discussed and clarified.« less

  2. Extended Huygens-Fresnel principle and optical waves propagation in turbulence: discussion.

    PubMed

    Charnotskii, Mikhail

    2015-07-01

    Extended Huygens-Fresnel principle (EHF) currently is the most common technique used in theoretical studies of the optical propagation in turbulence. A recent review paper [J. Opt. Soc. Am. A31, 2038 (2014)JOAOD60740-323210.1364/JOSAA.31.002038] cites several dozens of papers that are exclusively based on the EHF principle. We revisit the foundations of the EHF, and show that it is burdened by very restrictive assumptions that make it valid only under weak scintillation conditions. We compare the EHF to the less-restrictive Markov approximation and show that both theories deliver identical results for the second moment of the field, rendering the EHF essentially worthless. For the fourth moment of the field, the EHF principle is accurate under weak scintillation conditions, but is known to provide erroneous results for strong scintillation conditions. In addition, since the EHF does not obey the energy conservation principle, its results cannot be accurate for scintillations of partially coherent beam waves.

  3. A Justification, after the Postmodern Turn, of Universal Ethical Principles and Educational Ideals

    ERIC Educational Resources Information Center

    Mason, Mark

    2005-01-01

    The implementation of education programmes in different cultures invites the question whether we are justified in doing so in cultures that may reject the programmes' underlying principles. Are there indeed ethical principles and educational ideals that can be justified as applicable to all cultures? After a consideration of Zygmunt Bauman's…

  4. Population health management guiding principles to stimulate collaboration and improve pharmaceutical care.

    PubMed

    Steenkamer, Betty; Baan, Caroline; Putters, Kim; van Oers, Hans; Drewes, Hanneke

    2018-04-09

    Purpose A range of strategies to improve pharmaceutical care has been implemented by population health management (PHM) initiatives. However, which strategies generate the desired outcomes is largely unknown. The purpose of this paper is to identify guiding principles underlying collaborative strategies to improve pharmaceutical care and the contextual factors and mechanisms through which these principles operate. Design/methodology/approach The evaluation was informed by a realist methodology examining the links between PHM strategies, their outcomes and the contexts and mechanisms by which these strategies operate. Guiding principles were identified by grouping context-specific strategies with specific outcomes. Findings In total, ten guiding principles were identified: create agreement and commitment based on a long-term vision; foster cooperation and representation at the board level; use layered governance structures; create awareness at all levels; enable interpersonal links at all levels; create learning environments; organize shared responsibility; adjust financial strategies to market contexts; organize mutual gains; and align regional agreements with national policies and regulations. Contextual factors such as shared savings influenced the effectiveness of the guiding principles. Mechanisms by which these guiding principles operate were, for instance, fostering trust and creating a shared sense of the problem. Practical implications The guiding principles highlight how collaboration can be stimulated to improve pharmaceutical care while taking into account local constraints and possibilities. The interdependency of these principles necessitates effectuating them together in order to realize the best possible improvements and outcomes. Originality/value This is the first study using a realist approach to understand the guiding principles underlying collaboration to improve pharmaceutical care.

  5. An Analysis of Ethics Laws, Compliance with Ethical Standards, and Ethical Core Competency within the Department of the Army

    DTIC Science & Technology

    2016-06-15

    laws and ethical principles above private gain. (2) Employees shall not hold financial interests that conflict with the conscientious...applying ethical principles to decision-making. We analyze the DA ethics training courses, policies, and procedures. The project explores the...leveraging the Enterprises buying power to obtain goods and services more efficiently. Ms. Lyons earned her Bachelor of Science degree in Accounting in

  6. A convergent diffusion and social marketing approach for disseminating proven approaches to physical activity promotion.

    PubMed

    Dearing, James W; Maibach, Edward W; Buller, David B

    2006-10-01

    Approaches from diffusion of innovations and social marketing are used here to propose efficient means to promote and enhance the dissemination of evidence-based physical activity programs. While both approaches have traditionally been conceptualized as top-down, center-to-periphery, centralized efforts at social change, their operational methods have usually differed. The operational methods of diffusion theory have a strong relational emphasis, while the operational methods of social marketing have a strong transactional emphasis. Here, we argue for a convergence of diffusion of innovation and social marketing principles to stimulate the efficient dissemination of proven-effective programs. In general terms, we are encouraging a focus on societal sectors as a logical and efficient means for enhancing the impact of dissemination efforts. This requires an understanding of complex organizations and the functional roles played by different individuals in such organizations. In specific terms, ten principles are provided for working effectively within societal sectors and enhancing user involvement in the processes of adoption and implementation.

  7. High frequency x-ray generator basics.

    PubMed

    Sobol, Wlad T

    2002-02-01

    The purpose of this paper is to present basic functional principles of high frequency x-ray generators. The emphasis is put on physical concepts that determine the engineering solutions to the problem of efficient generation and control of high voltage power required to drive the x-ray tube. The physics of magnetically coupled circuits is discussed first, as a background for the discussion of engineering issues related to high-frequency power transformer design. Attention is paid to physical processes that influence such factors as size, efficiency, and reliability of a high voltage power transformer. The basic electrical circuit of a high frequency generator is analyzed next, with focus on functional principles. This section investigates the role and function of basic components, such as power supply, inverter, and voltage doubler. Essential electronic circuits of generator control are then examined, including regulation of voltage, current and timing of electrical power delivery to the x-ray tube. Finally, issues related to efficient feedback control, including basic design of the AEC circuitry are reviewed.

  8. Infrared Dielectric Screening Determines the Low Exciton Binding Energy of Metal-Halide Perovskites.

    PubMed

    Umari, Paolo; Mosconi, Edoardo; De Angelis, Filippo

    2018-02-01

    The performance of lead-halide perovskites in optoelectronic devices is due to a unique combination of factors, including highly efficient generation, transport, and collection of photogenerated charge carriers. The mechanism behind efficient charge generation in lead-halide perovskites is still largely unknown. Here, we investigate the factors that influence the exciton binding energy (E b ) in a series of metal-halide perovskites using accurate first-principles calculations based on solution of the Bethe-Salpeter equation, coupled to ab initio molecular dynamics simulations. We find that E b is strongly modulated by screening from low-energy phonons, which account for a factor ∼2 E b reduction, while dynamic disorder and rotational motion of the organic cations play a minor role. We calculate E b = 15 meV for MAPbI 3 , in excellent agreement with recent experimental estimates. We then explore how different material combinations (e.g., replacing Pb → Pb:Sn→ Sn; and MA → FA → Cs) may lead to different E b values and highlight the mechanisms underlying E b tuning.

  9. Reducing the Ideal Shear Strengths of ZrB2 by High Efficient Alloying Elements (Ag, Au, Pd and Pt)

    NASA Astrophysics Data System (ADS)

    Dai, Fu-Zhi; Zhou, Yanchun

    2017-02-01

    Activating the plasticity of ZrB2 is a promising approach to improve its key properties for applications in hypersonic vehicles, including high temperature strength and thermal shock resistance. The present work demonstrates that ideal shear strength of ZrB2, which is a good indicator of the critical stress for dislocation nucleation, can be significantly reduced by dissolving of appropriate alloying elements. Analyzing on the bonding nature of ZrB2 reveals that choosing alloying elements with low energy valence electrons will prevent electron transferring from alloying element to the electron deficient B-B π orbits, which will reduce the local stability of the region surrounding the alloying element. Under the criterion, elements with d electrons tending to be full-filled (Ag, Au, Pd and Pt, the full-filled state is associated with low energy level) are selected as promising candidates with their prominent efficiency in reducing ideal shear strengths verified by first-principles calculations. The results provide useful guidelines for further designs of ZrB2 based materials, especially for improving their mechanical properties.

  10. Reducing the Ideal Shear Strengths of ZrB2 by High Efficient Alloying Elements (Ag, Au, Pd and Pt)

    PubMed Central

    Dai, Fu-Zhi; Zhou, Yanchun

    2017-01-01

    Activating the plasticity of ZrB2 is a promising approach to improve its key properties for applications in hypersonic vehicles, including high temperature strength and thermal shock resistance. The present work demonstrates that ideal shear strength of ZrB2, which is a good indicator of the critical stress for dislocation nucleation, can be significantly reduced by dissolving of appropriate alloying elements. Analyzing on the bonding nature of ZrB2 reveals that choosing alloying elements with low energy valence electrons will prevent electron transferring from alloying element to the electron deficient B-B π orbits, which will reduce the local stability of the region surrounding the alloying element. Under the criterion, elements with d electrons tending to be full-filled (Ag, Au, Pd and Pt, the full-filled state is associated with low energy level) are selected as promising candidates with their prominent efficiency in reducing ideal shear strengths verified by first-principles calculations. The results provide useful guidelines for further designs of ZrB2 based materials, especially for improving their mechanical properties. PMID:28233838

  11. Reducing the Ideal Shear Strengths of ZrB2 by High Efficient Alloying Elements (Ag, Au, Pd and Pt).

    PubMed

    Dai, Fu-Zhi; Zhou, Yanchun

    2017-02-24

    Activating the plasticity of ZrB 2 is a promising approach to improve its key properties for applications in hypersonic vehicles, including high temperature strength and thermal shock resistance. The present work demonstrates that ideal shear strength of ZrB 2 , which is a good indicator of the critical stress for dislocation nucleation, can be significantly reduced by dissolving of appropriate alloying elements. Analyzing on the bonding nature of ZrB 2 reveals that choosing alloying elements with low energy valence electrons will prevent electron transferring from alloying element to the electron deficient B-B π orbits, which will reduce the local stability of the region surrounding the alloying element. Under the criterion, elements with d electrons tending to be full-filled (Ag, Au, Pd and Pt, the full-filled state is associated with low energy level) are selected as promising candidates with their prominent efficiency in reducing ideal shear strengths verified by first-principles calculations. The results provide useful guidelines for further designs of ZrB 2 based materials, especially for improving their mechanical properties.

  12. Energy harvesting: an integrated view of materials, devices and applications.

    PubMed

    Radousky, H B; Liang, H

    2012-12-21

    Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed.

  13. Energy harvesting: an integrated view of materials, devices and applications

    NASA Astrophysics Data System (ADS)

    Radousky, H. B.; Liang, H.

    2012-12-01

    Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed.

  14. Effect of electron-vibration interactions on the thermoelectric efficiency of molecular junctions.

    PubMed

    Hsu, Bailey C; Chiang, Chi-Wei; Chen, Yu-Chang

    2012-07-11

    From first-principles approaches, we investigate the thermoelectric efficiency of a molecular junction where a benzene molecule is connected directly to the platinum electrodes. We calculate the thermoelectric figure of merit ZT in the presence of electron-vibration interactions with and without local heating under two scenarios: linear response and finite bias regimes. In the linear response regime, ZT saturates around the electrode temperature T(e) = 25 K in the elastic case, while in the inelastic case we observe a non-saturated and a much larger ZT beyond T(e) = 25 K attributed to the tail of the Fermi-Dirac distribution. In the finite bias regime, the inelastic effects reveal the signatures of the molecular vibrations in the low-temperature regime. The normal modes exhibiting structures in the inelastic profile are characterized by large components of atomic vibrations along the current density direction on top of each individual atom. In all cases, the inclusion of local heating leads to a higher wire temperature T(w) and thus magnifies further the influence of the electron-vibration interactions due to the increased number of local phonons.

  15. Design principles for high efficiency small-grain polysilicon solar cells, with supporting experimental studies

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.; Sah, C. T.

    1982-01-01

    Design principles suggested here aim toward high conversion efficiency (greater than 15 percent) in polysilicon cells. The principles seek to decrease the liabilities of both intragranular and grain-boundary-surface defects. The advantages of a phosphorus atom concentration gradient in a thin (less than 50 microns) base of a p(+)/n(x)/n(+) drift-field solar cell, which produces favorable gradients in chemical potential, minority-carrier mobility and diffusivity, and recombination lifetime (via phosphorus gettering) are suggested. The degrading effects of grain boundaries are reduced by these three gradients and by substituting atoms (P, H, F or Li) for vacancies on the grain-boundary surface. From recent experiments comes support for the benefits of P diffusion down grain boundaries and, for quasi-grain-boundary-free and related structures. New analytic solutions for the n(x)-base include the effect of a power-law dependence between P concentration and lifetime. These provide an upper-bound estimate on the open circuit voltage. Finite-difference numerical solutions of the six Shockley equations furnish complete information about all solar-cell parameters and add insight concerning design.

  16. Applying the Principles of Lean Production to Gastrointestinal Biopsy Handling: From the Factory Floor to the Anatomic Pathology Laboratory.

    PubMed

    Sugianto, Jessica Z; Stewart, Brian; Ambruzs, Josephine M; Arista, Amanda; Park, Jason Y; Cope-Yokoyama, Sandy; Luu, Hung S

    2015-01-01

    To implement Lean principles to accommodate expanding volumes of gastrointestinal biopsies and to improve laboratory processes overall. Our continuous improvement (kaizen) project analyzed the current state for gastrointestinal biopsy handling using value-stream mapping for specimens obtained at a 487-bed tertiary care pediatric hospital in Dallas, Texas. We identified non-value-added time within the workflow process, from receipt of the specimen in the histology laboratory to the delivery of slides and paperwork to the pathologist. To eliminate non-value-added steps, we implemented the changes depicted in a revised-state value-stream map. Current-state value-stream mapping identified a total specimen processing time of 507 minutes, of which 358 minutes were non-value-added. This translated to a process cycle efficiency of 29%. Implementation of a revised-state value stream resulted in a total process time reduction to 238 minutes, of which 89 minutes were non-value-added, and an improved process cycle efficiency of 63%. Lean production principles of continuous improvement and waste elimination can be successfully implemented within the clinical laboratory.

  17. Principles of light harvesting from single photosynthetic complexes.

    PubMed

    Schlau-Cohen, G S

    2015-06-06

    Photosynthetic systems harness sunlight to power most life on Earth. In the initial steps of photosynthetic light harvesting, absorbed energy is converted to chemical energy with near-unity quantum efficiency. This is achieved by an efficient, directional and regulated flow of energy through a network of proteins. Here, we discuss the following three key principles of this flow and of photosynthetic light harvesting: thermal fluctuations of the protein structure; intrinsic conformational switches with defined functional consequences; and environmentally triggered conformational switches. Through these principles, photosynthetic systems balance two types of operational costs: metabolic costs, or the cost of maintaining and running the molecular machinery, and opportunity costs, or the cost of losing any operational time. Understanding how the molecular machinery and dynamics are designed to balance these costs may provide a blueprint for improved artificial light-harvesting devices. With a multi-disciplinary approach combining knowledge of biology, this blueprint could lead to low-cost and more effective solar energy conversion. Photosynthetic systems achieve widespread light harvesting across the Earth's surface; in the face of our growing energy needs, this is functionality we need to replicate, and perhaps emulate.

  18. When is good, good enough? Methodological pragmatism for sustainable guideline development.

    PubMed

    Browman, George P; Somerfield, Mark R; Lyman, Gary H; Brouwers, Melissa C

    2015-03-06

    Continuous escalation in methodological and procedural rigor for evidence-based processes in guideline development is associated with increasing costs and production delays that threaten sustainability. While health research methodologists are appropriately responsible for promoting increasing rigor in guideline development, guideline sponsors are responsible for funding such processes. This paper acknowledges that other stakeholders in addition to methodologists should be more involved in negotiating trade-offs between methodological procedures and efficiency in guideline production to produce guidelines that are 'good enough' to be trustworthy and affordable under specific circumstances. The argument for reasonable methodological compromise to meet practical circumstances is consistent with current implicit methodological practice. This paper proposes a conceptual tool as a framework to be used by different stakeholders in negotiating, and explicitly reporting, reasonable compromises for trustworthy as well as cost-worthy guidelines. The framework helps fill a transparency gap in how methodological choices in guideline development are made. The principle, 'when good is good enough' can serve as a basis for this approach. The conceptual tool 'Efficiency-Validity Methodological Continuum' acknowledges trade-offs between validity and efficiency in evidence-based guideline development and allows for negotiation, guided by methodologists, of reasonable methodological compromises among stakeholders. Collaboration among guideline stakeholders in the development process is necessary if evidence-based guideline development is to be sustainable.

  19. Removal of malaria-infected red blood cells using magnetic cell separators: A computational study

    PubMed Central

    Kim, Jeongho; Massoudi, Mehrdad; Antaki, James F.; Gandini, Alberto

    2012-01-01

    High gradient magnetic field separators have been widely used in a variety of biological applications. Recently, the use of magnetic separators to remove malaria-infected red blood cells (pRBCs) from blood circulation in patients with severe malaria has been proposed in a dialysis-like treatment. The capture efficiency of this process depends on many interrelated design variables and constraints such as magnetic pole array pitch, chamber height, and flow rate. In this paper, we model the malaria-infected RBCs (pRBCs) as paramagnetic particles suspended in a Newtonian fluid. Trajectories of the infected cells are numerically calculated inside a micro-channel exposed to a periodic magnetic field gradient. First-order stiff ordinary differential equations (ODEs) governing the trajectory of particles under periodic magnetic fields due to an array of wires are solved numerically using the 1st –5th order adaptive step Runge-Kutta solver. The numerical experiments show that in order to achieve a capture efficiency of 99% for the pRBCs it is required to have a longer length than 80 mm; this implies that in principle, using optimization techniques the length could be adjusted, i.e., shortened to achieve 99% capture efficiency of the pRBCs. PMID:22345827

  20. Spatial Resolution Versus Data Acquisition Efficiency in Mapping an Inhomogeneous System with Species Diffusion

    DOE PAGES

    Chen, Fengxiang; Zhang, Yong; Gfroerer, T. H.; ...

    2015-06-02

    Traditionally, spatially-resolved photoluminescence (PL) has been performed using a point-by-point scan mode with both excitation and detection occurring at the same spatial location. But with the availability of high quality detector arrays like CCDs, an imaging mode has become popular for performing spatially-resolved PL. By illuminating the entire area of interest and collecting the data simultaneously from all spatial locations, the measurement efficiency can be greatly improved. However, this new approach has proceeded under the implicit assumption of comparable spatial resolution. We show here that when carrier diffusion is present, the spatial resolution can actually differ substantially between the twomore » modes, with the less efficient scan mode being far superior. We apply both techniques in investigation of defects in a GaAs epilayer – where isolated singlet and doublet dislocations can be identified. A superposition principle is developed for solving the diffusion equation to extract the intrinsic carrier diffusion length, which can be applied to a system with arbitrarily distributed defects. The understanding derived from this work is significant for a broad range of problems in physics and beyond (for instance biology) – whenever the dynamics of generation, diffusion, and annihilation of species can be probed with either measurement mode.« less

  1. Antibodies, synthetic peptides and related constructs for planetary health based on green chemistry in the Anthropocene.

    PubMed

    Caoili, Salvador Eugenio

    2018-03-01

    The contemporary Anthropocene is characterized by rapidly evolving complex global challenges to planetary health vis-a-vis sustainable development, yet innovation is constrained under the prevailing precautionary regime that regulates technological change. Small-molecule xenobiotic drugs are amenable to efficient large-scale industrial synthesis; but their pharmacokinetics, pharmacodynamics, interactions and ultimate ecological impact are difficult to predict, raising concerns over initial testing and environmental contamination. Antibodies and similar agents can serve as antidotes and drug buffers or vehicles to address patient safety and decrease dosing requirements. More generally, peptidic agents including synthetic peptide-based constructs exemplified by vaccines can be used together with or instead of nonpeptidic xenobiotics, thus enabling advances in planetary health based on principles of green chemistry from manufacturing through final disposition.

  2. Feasibility analysis on the building environment of college dormitories in Baoding

    NASA Astrophysics Data System (ADS)

    Wang, Xinyi

    2018-06-01

    The quality of indoor air greatly affects people's health. As a place where college students live for a long time, the architectural environment is closely related to people's lives. In this paper, two cases of dormitory of the North China Electric Power University in Baoding are selected as the subject investigated. The environmental test and questionnaire method were used to study. The test indexes mainly include temperature, relative humidity and wind speeds. We obtain the basic situation of indoor thermal humidity environment, light environment and air velocity. Based on a series of tests, combined with subjective comfort and comprehensive evaluation, we analyzed the thermal comfort of indoor buildings, and put forward measures to further improve the building environment of College Dormitories under the principle of high efficiency and energy saving.

  3. An artificial transport metabolon facilitates improved substrate utilization in yeast.

    PubMed

    Thomik, Thomas; Wittig, Ilka; Choe, Jun-Yong; Boles, Eckhard; Oreb, Mislav

    2017-11-01

    Efficient substrate utilization is the first and most important prerequisite for economically viable production of biofuels and chemicals by microbial cell factories. However, production rates and yields are often compromised by low transport rates of substrates across biological membranes and their diversion to competing pathways. This is especially true when common chassis organisms are engineered to utilize nonphysiological feedstocks. Here, we addressed this problem by constructing an artificial complex between an endogenous sugar transporter and a heterologous xylose isomerase in Saccharomyces cerevisiae. Direct feeding of the enzyme through the transporter resulted in acceleration of xylose consumption and substantially diminished production of xylitol as an undesired side product, with a concomitant increase in the production of ethanol. This underlying principle could also likely be implemented in other biotechnological applications.

  4. A new site for 85Kr measurements on groundwater samples

    NASA Astrophysics Data System (ADS)

    Lange, T.; Hebert, D.

    2001-06-01

    As a part of a new 85Kr laboratory, which is currently being established at the Institute of Applied Physics in Freiberg, Germany, a modified CO 2 extractor for krypton sampling is used. The operation principle is simple and contamination-safe with a reasonable effort. Continuously pumped under pressure, the water passes a Venturi-type nozzle and degasses due to relaxing. The extracted gas mixture then enters a recirculation system flowing through a CO 2 trap (NaOH), molecular sieves and a cooled charcoal trap, where krypton and other components are adsorbed. Remaining gases reenter the system at the Venturi-type nozzle. To keep the circulation alive an additional helium support is needed. In a simple field experiment, extraction efficiencies up to 0.8 for 222Rn have been measured.

  5. Model-free adaptive speed control on travelling wave ultrasonic motor

    NASA Astrophysics Data System (ADS)

    Di, Sisi; Li, Huafeng

    2018-01-01

    This paper introduced a new data-driven control (DDC) method for the speed control of ultrasonic motor (USM). The model-free adaptive control (MFAC) strategy was presented in terms of its principles, algorithms, and parameter selection. To verify the efficiency of the proposed method, a speed-frequency-time model, which contained all the measurable nonlinearity and uncertainties based on experimental data was established for simulation to mimic the USM operation system. Furthermore, the model was identified using particle swarm optimization (PSO) method. Then, the control of the simulated system using MFAC was evaluated under different expectations in terms of overshoot, rise time and steady-state error. Finally, the MFAC results were compared with that of proportion iteration differentiation (PID) to demonstrate its advantages in controlling general random system.

  6. Higher-dimensional Wannier Interpolation for the Modern Theory of the Dzyaloshinskii-Moriya Interaction: Application to Co-based Trilayers

    NASA Astrophysics Data System (ADS)

    Hanke, Jan-Philipp; Freimuth, Frank; Blügel, Stefan; Mokrousov, Yuriy

    2018-04-01

    We present an advanced first-principles formalism to evaluate the Dzyaloshinskii-Moriya interaction (DMI) in its modern theory as well as Berry curvatures in complex spaces based on a higher-dimensional Wannier interpolation. Our method is applied to the Co-based trilayer systems IrδPt1-δ/Co/Pt and AuγPt1-γ/Co/Pt, where we gain insights into the correlations between the electronic structure and the DMI, and we uncover prominent sign changes of the chiral interaction with the overlayer composition. Beyond the discussed phenomena, the scope of applications of our Wannier-based scheme is particularly broad as it is ideally suited to study efficiently the Hamiltonian evolution under the slow variation of very general parameters.

  7. Multiplexed high resolution soft x-ray RIXS

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

    Chuang, Y.-D.; Voronov, D.; Warwick, T.

    2016-07-27

    High-resolution Resonance Inelastic X-ray Scattering (RIXS) is a technique that allows us to probe the electronic excitations of complex materials with unprecedented precision. However, the RIXS process has a low cross section, compounded by the fact that the optical spectrometers used to analyze the scattered photons can only collect a small solid angle and overall have a small efficiency. Here we present a method to significantly increase the throughput of RIXS systems, by energy multiplexing, so that a complete RIXS map of scattered intensity versus photon energy in and photon energy out can be recorded simultaneously{sup 1}. This parallel acquisitionmore » scheme should provide a gain in throughput of over 100.. A system based on this principle, QERLIN, is under construction at the Advanced Light Source (ALS).« less

  8. Engineering coherence among excited states in synthetic heterodimer systems.

    PubMed

    Hayes, Dugan; Griffin, Graham B; Engel, Gregory S

    2013-06-21

    The design principles that support persistent electronic coherence in biological light-harvesting systems are obscured by the complexity of such systems. Some electronic coherences in these systems survive for hundreds of femtoseconds at physiological temperatures, suggesting that coherent dynamics may play a role in photosynthetic energy transfer. Coherent effects may increase energy transfer efficiency relative to strictly incoherent transfer mechanisms. Simple, tractable, manipulable model systems are required in order to probe the fundamental physics underlying these persistent electronic coherences, but to date, these quantum effects have not been observed in small molecules. We have engineered a series of rigid synthetic heterodimers that can serve as such a model system and observed quantum beating signals in their two-dimensional electronic spectra consistent with the presence of persistent electronic coherences.

  9. Project management process.

    DOT National Transportation Integrated Search

    2007-03-01

    This course provides INDOT staff with foundational knowledge and skills in project management principles and methodologies. INDOTs project management processes provide the tools for interdisciplinary teams to efficiently and effectively deliver pr...

  10. Retrieval of spheroid particle size distribution from spectral extinction data in the independent mode using PCA approach

    NASA Astrophysics Data System (ADS)

    Tang, Hong; Lin, Jian-Zhong

    2013-01-01

    An improved anomalous diffraction approximation (ADA) method is presented for calculating the extinction efficiency of spheroids firstly. In this approach, the extinction efficiency of spheroid particles can be calculated with good accuracy and high efficiency in a wider size range by combining the Latimer method and the ADA theory, and this method can present a more general expression for calculating the extinction efficiency of spheroid particles with various complex refractive indices and aspect ratios. Meanwhile, the visible spectral extinction with varied spheroid particle size distributions and complex refractive indices is surveyed. Furthermore, a selection principle about the spectral extinction data is developed based on PCA (principle component analysis) of first derivative spectral extinction. By calculating the contribution rate of first derivative spectral extinction, the spectral extinction with more significant features can be selected as the input data, and those with less features is removed from the inversion data. In addition, we propose an improved Tikhonov iteration method to retrieve the spheroid particle size distributions in the independent mode. Simulation experiments indicate that the spheroid particle size distributions obtained with the proposed method coincide fairly well with the given distributions, and this inversion method provides a simple, reliable and efficient method to retrieve the spheroid particle size distributions from the spectral extinction data.

  11. Research and emulation of ranging in BPON system

    NASA Astrophysics Data System (ADS)

    Yang, Guangxiang; Tao, Dexin; He, Yan

    2005-12-01

    Ranging is one of the key technologies in Broadband Passive Optical Network based on the ATM (BPON) system. It is complex for software designers and difficult to test. In order to simplify the ranging procedure, enhance its efficiency, and find an appropriate method to verify it, a new ranging procedure that completely satisfies the requirements specified in ITU-T G.983.1 and one verifying method is proposed in this paper. A kind of ranging procedure without serial number (SN) searching function, called one-by-one ranging are developed under the condition of cold PON, cold Optical Network Termination (ONU). The ranging procedure includes the use of OLT and ONU flow charts respectively. By using the network emulation software OPNET, the BPON system is modeled and the ranging procedure is simulated. The emulation experimental results show that the presented ranging procedure can effectively eliminate the collision of burst mode signals between ONUs, which can be ranged one-by-one under the controlling of OLT, while also enhancing the ranging efficiency. As all of the message formats used in this research conform with the ITU-T G.983.1, the ranging procedure can meet the protocol specifications with good interoperability, and is very compatible with products of other manufacturer. According to the present study of ranging procedures, guidelines and principles are provided, Also some design difficulties are eliminated in the software design.

  12. A 21st Century Roadmap for Human Health Risk Assessment ...

    EPA Pesticide Factsheets

    For decades human health risk assessment has depended primarily on animal testing to predict adverse effects in humans, but that paradigm has come under question because of calls for more accurate information, less use of animals, and more efficient use of resources. Moreover, the disproportionate use of hazard information has overshadowed the important role of exposure science in determinations of human safety. In addition, major risk assessments lack the clarity and transparency that hinder an understanding of the analysis and communication of key safety messages. To help answer these challenges, the HESI-managed RISK21 project was initiated to develop a scientific, transparent, and efficient approach to the evolving world of human health risk assessment. RISK21 involved over 120 participants from 12 countries, 15 government institutions, 20 universities, 2 non-governmental organizations, and 12 corporations. RISK21 developed a tiered approach that is problem formulation-based, makes maximum use of prior knowledge, and is led by exposure science to produce a highly transparent and flexible visualization of and approach to assessing human safety and risk. The general principles underlying the RISK21 approach as well as an overview of the RISK21 Roadmap are presented here. This paper will be followed by a series of publications that will articulate the details that comprise this systematic approach. The purpose of this manuscript is to provide an overview

  13. Biofiltration of Chloroform in a Trickle Bed Air Biofilter Under ...

    EPA Pesticide Factsheets

    In this paper, the application of biofiltration is investigated for controlled removal of gas phase chloroform through cometabolic degradation with ethanol. A trickle bed air biofilter (TBAB) operated under acidic pH 4 is subjected to aerobic biodegradation of chloroform and ethanol. The TBAB is composed of pelleted diatomaceous earth filter media inoculated with filamentous fungi species, which served as the principle biodegrading microorganism. The removal efficiencies of 5 ppmv of chloroform mixed with different ratios of ethanol as cometabolite (25, 50, 100, 150, and 200 ppmv) ranged between 69.9 and 80.9%. The removal efficiency, reaction rate kinetics, and the elimination capacity increased proportionately with an increase in the cometabolite concentration. The carbon recovery from the TBAB amounted to 69.6% of the total carbon input. It is postulated that the remaining carbon contributed to excess biomass yield within the system. Biomass control strategies such as starvation and stagnation were employed at different phases of the experiment. The chloroform removal kinetics provided a maximum reaction rate constant of 0.0018 s−1. The highest ratio of chemical oxygen demand (COD)removal/nitrogenutilization was observed at 14.5. This study provides significant evidence that the biodegradation of a highly chlorinated methane can be favored by cometabolism in a fungi-based TBAB. Chloroform is volatile hazardous chemical emitted from publicly owned treatment

  14. Controlling Bottom Hole Flowing Pressure Within a Specific Range for Efficient Coalbed Methane Drainage

    NASA Astrophysics Data System (ADS)

    Zhao, Bin; Wang, Zhi-Yin; Hu, Ai-Mei; Zhai, Yu-Yang

    2013-11-01

    The stress state of coal surrounding a coalbed methane (CBM) production well is affected by the bottom hole flowing pressure (BHFP). The permeability of coal shows a marked change under compression. The BHFP must be restricted to a specific range to favor higher permeability in the surrounding coal and thus higher productivity of the well. A new method to determine this specific range is proposed in this paper. Coal has a rather low tensile strength, which induces tensile failure and rock disintegration. The deformation of coal samples under compression has four main stages: compaction, elastic deformation, strain hardening, and strain softening. Permeability is optimal when the coal samples are in the strain softening stage. The three critical values of BHFP, namely, p wmin, p wmid, and p wupper, which correspond to the occurrence of tensile failure, the start of strain softening, and the beginning of plastic deformation, respectively, are derived from theoretical principles. The permeability of coal is in an optimal state when the BHFP is between p wmin and p wmid. The BHFP should be confined to this specific range for the efficient drainage of CBM wells. This method was applied to field operations in three wells in the Hancheng CBM field in China. A comprehensive analysis of drainage data and of the BHFP indicates that the new method is effective and offers significant improvement to current practices.

  15. Model and Study on Cascade Control System Based on IGBT Chopping Control

    NASA Astrophysics Data System (ADS)

    Niu, Yuxin; Chen, Liangqiao; Wang, Shuwen

    2018-01-01

    Thyristor cascade control system has a wide range of applications in the industrial field, but the traditional cascade control system has some shortcomings, such as a low power factor, serious harmonic pollution. In this paper, not only analyzing its system structure and working principle, but also discussing the two main factors affecting the power factor. Chopping-control cascade control system, adopted a new power switching device IGBT, which could overcome traditional cascade control system’s two main drawbacks efficiently. The basic principle of this cascade control system is discussed in this paper and the model of speed control system is built by using MATLAB/Simulink software. Finally, the simulation results of the system shows that the system works efficiently. This system is worthy to be spread widely in engineering application.

  16. Nearfield acoustic holography. I - Theory of generalized holography and the development of NAH

    NASA Technical Reports Server (NTRS)

    Maynard, J. D.; Williams, E. G.; Lee, Y.

    1985-01-01

    Because its underlying principles are so fundamental, holography has been studied and applied in many areas of science. Recently, a technique has been developed which takes the maximum advantage of the fundamental principles and extracts much more information from a hologram than is customarily associated with such a measurement. In this paper the fundamental principles of holography are reviewed, and a sound radiation measurement system, called nearfield acoustic holography (NAH), which fully exploits the fundamental principles, is described.

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

    Faizal, Mir, E-mail: f2mir@uwaterloo.ca; Majumder, Barun, E-mail: barunbasanta@iitgn.ac.in

    In this paper, we will incorporate the generalized uncertainty principle into field theories with Lifshitz scaling. We will first construct both bosonic and fermionic theories with Lifshitz scaling based on generalized uncertainty principle. After that we will incorporate the generalized uncertainty principle into a non-abelian gauge theory with Lifshitz scaling. We will observe that even though the action for this theory is non-local, it is invariant under local gauge transformations. We will also perform the stochastic quantization of this Lifshitz fermionic theory based generalized uncertainty principle.

  18. The Global Experience of Deployment of Energy-Efficient Technologies in High-Rise Construction

    NASA Astrophysics Data System (ADS)

    Potienko, Natalia D.; Kuznetsova, Anna A.; Solyakova, Darya N.; Klyueva, Yulia E.

    2018-03-01

    The objective of this research is to examine issues related to the increasing importance of energy-efficient technologies in high-rise construction. The aim of the paper is to investigate modern approaches to building design that involve implementation of various energy-saving technologies in diverse climates and at different structural levels, including the levels of urban development, functionality, planning, construction and engineering. The research methodology is based on the comprehensive analysis of the advanced global expertise in the design and construction of energy-efficient high-rise buildings, with the examination of their positive and negative features. The research also defines the basic principles of energy-efficient architecture. Besides, it draws parallels between the climate characteristics of countries that lead in the field of energy-efficient high-rise construction, on the one hand, and the climate in Russia, on the other, which makes it possible to use the vast experience of many countries, wholly or partially. The paper also gives an analytical review of the results arrived at by implementing energy efficiency principles into high-rise architecture. The study findings determine the impact of energy-efficient technologies on high-rise architecture and planning solutions. In conclusion, the research states that, apart from aesthetic and compositional interpretation of architectural forms, an architect nowadays has to address the task of finding a synthesis between technological and architectural solutions, which requires knowledge of advanced technologies. The study findings reveal that the implementation of modern energy-efficient technologies into high-rise construction is of immediate interest and is sure to bring long-term benefits.

  19. Dimensionality in Supergravity Cosmology

    NASA Astrophysics Data System (ADS)

    Wu, Zhong Chao

    2008-01-01

    It is shown that in d = 11 supergravity, under a very reasonable ansatz, the observable spacetime must be 4-dimensional. The spacetime dimensionality, for the first time, is proven from the First Principle, instead of the Anthropic Principle.

  20. Owen Chamberlain, the Antiproton, and Polarized Targets

    Science.gov Websites

    allowed us to test the symmetry principles underlying the physics," [colleague Herbert Steiner] said . Symmetry principles state, for example, that some interactions look the same when reflected in a mirror or

  1. Novel Natural Convection Heat Sink Design Concepts From First Principles

    DTIC Science & Technology

    2016-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited NOVEL NATURAL ...COVERED Master’s Thesis 4. TITLE AND SUBTITLE NOVEL NATURAL CONVECTION HEAT SINK DESIGN CONCEPTS FROM FIRST PRINCIPLES 5. FUNDING NUMBERS 6...geometric structures that incorporate the principles of the stack effect to improve the heat transfer capability of a heat sink under natural convection

  2. Output characteristics of a series three-port axial piston pump

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaogang; Quan, Long; Yang, Yang; Wang, Chengbin; Yao, Liwei

    2012-05-01

    Driving a hydraulic cylinder directly by a closed-loop hydraulic pump is currently a key research area in the field of electro-hydraulic control technology, and it is the most direct means to improve the energy efficiency of an electro-hydraulic control system. So far, this technology has been well applied to the pump-controlled symmetric hydraulic cylinder. However, for the differential cylinder that is widely used in hydraulic technology, satisfactory results have not yet been achieved, due to the asymmetric flow constraint. Therefore, based on the principle of the asymmetric valve controlled asymmetric cylinder in valve controlled cylinder technology, an innovative idea for an asymmetric pump controlled asymmetric cylinder is put forward to address this problem. The scheme proposes to transform the oil suction window of the existing axial piston pump into two series windows. When in use, one window is connected to the rod chamber of the hydraulic cylinder and the other is linked with a low-pressure oil tank. This allows the differential cylinders to be directly controlled by changing the displacement or rotation speed of the pumps. Compared with the loop principle of offsetting the area difference of the differential cylinder through hydraulic valve using existing technology, this method may simplify the circuits and increase the energy efficiency of the system. With the software SimulationX, a hydraulic pump simulation model is set up, which examines the movement characteristics of an individual piston and the compressibility of oil, as well as the flow distribution area as it changes with the rotation angle. The pump structure parameters, especially the size of the unloading groove of the valve plate, are determined through digital simulation. All of the components of the series arranged three distribution-window axial piston pump are designed, based on the simulation analysis of the flow pulse characteristics of the pump, and then the prototype pump is made. The basic characteristics, such as the pressure, flow and noise of the pumps under different rotation speeds, are measured on the test bench. The test results verify the correctness of the principle. The proposed research lays a theoretical foundation for the further development of a new pump-controlled cylinder system.

  3. [Testing method research for key performance indicator of imaging acousto-optic tunable filter (AOTF)].

    PubMed

    Hu, Shan-Zhou; Chen, Fen-Fei; Zeng, Li-Bo; Wu, Qiong-Shui

    2013-01-01

    Imaging AOTF is an important optical filter component for new spectral imaging instruments developed in recent years. The principle of imaging AOTF component was demonstrated, and a set of testing methods for some key performances were studied, such as diffraction efficiency, wavelength shift with temperature, homogeneity in space for diffraction efficiency, imaging shift, etc.

  4. 43 CFR 418.33 - Purpose of the implementation strategy.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... implement through their discretionary actions, operating strategies which achieve the principles of this... project operations, economics, and environmental effects. (c) The efficiency target will be used as a...

  5. High-Efficiency Photovoltaic System Using Partially-Connected DC-DC Converter

    NASA Astrophysics Data System (ADS)

    Uno, Masatoshi; Kukita, Akio; Tanaka, Koji

    Power conversion electronics for photovoltaic (PV) systems are desired to operate as efficiently as possible to exploit the power generated by PV modules. This paper proposes a novel PV system in which a dc-dc converter is partially connected to series-connected PV modules. The proposed system achieves high power-conversion efficiency by reducing the passing power and input/output voltages of the converter. The theoretical operating principle was experimentally validated. Resultant efficiency performances of the proposed and conventional systems demonstrated that the proposed system was more efficient in terms of power conversion though the identical converter was used for the both systems.

  6. Mathematical Optimization Algorithm for Minimizing the Cost Function of GHG Emission in AS/RS Using Positive Selection Based Clonal Selection Principle

    NASA Astrophysics Data System (ADS)

    Mahalakshmi; Murugesan, R.

    2018-04-01

    This paper regards with the minimization of total cost of Greenhouse Gas (GHG) efficiency in Automated Storage and Retrieval System (AS/RS). A mathematical model is constructed based on tax cost, penalty cost and discount cost of GHG emission of AS/RS. A two stage algorithm namely positive selection based clonal selection principle (PSBCSP) is used to find the optimal solution of the constructed model. In the first stage positive selection principle is used to reduce the search space of the optimal solution by fixing a threshold value. In the later stage clonal selection principle is used to generate best solutions. The obtained results are compared with other existing algorithms in the literature, which shows that the proposed algorithm yields a better result compared to others.

  7. Agile: From Software to Mission Systems

    NASA Technical Reports Server (NTRS)

    Trimble, Jay; Shirley, Mark; Hobart, Sarah

    2017-01-01

    To maximize efficiency and flexibility in Mission Operations System (MOS) design, we are evolving principles from agile and lean methods for software, to the complete mission system. This allows for reduced operational risk at reduced cost, and achieves a more effective design through early integration of operations into mission system engineering and flight system design. The core principles are assessment of capability through demonstration, risk reduction through targeted experiments, early test and deployment, and maturation of processes and tools through use.

  8. Absorber for solar power.

    PubMed

    Powell, W R

    1974-10-01

    A simple, economical absorber utilizing a new principle of operation to achieve very low reradiation losses while generating temperatures limited by material properties of quartz is described. Its performance is analyzed and indicates approximately 90% thermal efficiency and 73% conversion efficiency for an earth based unit with moderately concentrated (~tenfold) sunlight incident. It is consequently compatible with the most economic of concentrator mirrors (stamped) or mirrors deployable in space. Space applications are particularly attractive, as temperatures significantly below 300 K are possible and permit even higher conversion efficiency.

  9. Preserved imitation in contrast to limited free application of comfortable hand actions in intellectually able young adults with an autism spectrum disorder.

    PubMed

    Beelen, Caroline; Cuypers, Koen; van Schuerbeeck, Lise; Braeken, Marijke; Ross, Veerle; Jongen, Ellen; Meesen, Raf; Vanvuchelen, Marleen

    2017-06-01

    Imitation problems are commonly reported in children with an autism spectrum disorder. However, it has not yet been determined whether imitation problems persist into young adulthood. In this study, we investigated imitation skills of 20 intellectually able young adults with autism spectrum disorder relative to 19 age-matched neurotypical adults. For this purpose, we used a bar-transport task, which evokes the application of the end-state comfort principle. Specifically, we examined whether young adults with autism spectrum disorder imitated the means-end structure of a demonstrator's bar-transport action with and without application of the end-state comfort principle (imitation task). In addition, we examined whether participants spontaneously applied the end-state comfort principle during a similar bar-transport task (free execution task). Results revealed that young adults with autism spectrum disorder imitated the means-end structure of observed actions to the same degree as neurotypical adults ( p = 0.428). In contrast, they applied the end-state comfort principle less often during free executed actions ( p = 0.035). Moreover, during these actions, they were slower to place the bar into the penholder ( p = 0.023), which contributed to the reduced efficiency of their performance. Findings suggest that imitation abilities of young adults with autism spectrum disorder are preserved and that observing others' actions might promote more efficient action planning in this population.

  10. The effects of model composition design choices on high-fidelity simulations of motoneuron recruitment and firing behaviors

    NASA Astrophysics Data System (ADS)

    Allen, John M.; Elbasiouny, Sherif M.

    2018-06-01

    Objective. Computational models often require tradeoffs, such as balancing detail with efficiency; yet optimal balance should incorporate sound design features that do not bias the results of the specific scientific question under investigation. The present study examines how model design choices impact simulation results. Approach. We developed a rigorously-validated high-fidelity computational model of the spinal motoneuron pool to study three long-standing model design practices which have yet to be examined for their impact on motoneuron recruitment, firing rate, and force simulations. The practices examined were the use of: (1) generic cell models to simulate different motoneuron types, (2) discrete property ranges for different motoneuron types, and (3) biological homogeneity of cell properties within motoneuron types. Main results. Our results show that each of these practices accentuates conditions of motoneuron recruitment based on the size principle, and minimizes conditions of mixed and reversed recruitment orders, which have been observed in animal and human recordings. Specifically, strict motoneuron orderly size recruitment occurs, but in a compressed range, after which mixed and reverse motoneuron recruitment occurs due to the overlap in electrical properties of different motoneuron types. Additionally, these practices underestimate the motoneuron firing rates and force data simulated by existing models. Significance. Our results indicate that current modeling practices increase conditions of motoneuron recruitment based on the size principle, and decrease conditions of mixed and reversed recruitment order, which, in turn, impacts the predictions made by existing models on motoneuron recruitment, firing rate, and force. Additionally, mixed and reverse motoneuron recruitment generated higher muscle force than orderly size motoneuron recruitment in these simulations and represents one potential scheme to increase muscle efficiency. The examined model design practices, as well as the present results, are applicable to neuronal modeling throughout the nervous system.

  11. Global adaptation in networks of selfish components: emergent associative memory at the system scale.

    PubMed

    Watson, Richard A; Mills, Rob; Buckley, C L

    2011-01-01

    In some circumstances complex adaptive systems composed of numerous self-interested agents can self-organize into structures that enhance global adaptation, efficiency, or function. However, the general conditions for such an outcome are poorly understood and present a fundamental open question for domains as varied as ecology, sociology, economics, organismic biology, and technological infrastructure design. In contrast, sufficient conditions for artificial neural networks to form structures that perform collective computational processes such as associative memory/recall, classification, generalization, and optimization are well understood. Such global functions within a single agent or organism are not wholly surprising, since the mechanisms (e.g., Hebbian learning) that create these neural organizations may be selected for this purpose; but agents in a multi-agent system have no obvious reason to adhere to such a structuring protocol or produce such global behaviors when acting from individual self-interest. However, Hebbian learning is actually a very simple and fully distributed habituation or positive feedback principle. Here we show that when self-interested agents can modify how they are affected by other agents (e.g., when they can influence which other agents they interact with), then, in adapting these inter-agent relationships to maximize their own utility, they will necessarily alter them in a manner homologous with Hebbian learning. Multi-agent systems with adaptable relationships will thereby exhibit the same system-level behaviors as neural networks under Hebbian learning. For example, improved global efficiency in multi-agent systems can be explained by the inherent ability of associative memory to generalize by idealizing stored patterns and/or creating new combinations of subpatterns. Thus distributed multi-agent systems can spontaneously exhibit adaptive global behaviors in the same sense, and by the same mechanism, as with the organizational principles familiar in connectionist models of organismic learning.

  12. The effects of model composition design choices on high-fidelity simulations of motoneuron recruitment and firing behaviors.

    PubMed

    Allen, John M; Elbasiouny, Sherif M

    2018-06-01

    Computational models often require tradeoffs, such as balancing detail with efficiency; yet optimal balance should incorporate sound design features that do not bias the results of the specific scientific question under investigation. The present study examines how model design choices impact simulation results. We developed a rigorously-validated high-fidelity computational model of the spinal motoneuron pool to study three long-standing model design practices which have yet to be examined for their impact on motoneuron recruitment, firing rate, and force simulations. The practices examined were the use of: (1) generic cell models to simulate different motoneuron types, (2) discrete property ranges for different motoneuron types, and (3) biological homogeneity of cell properties within motoneuron types. Our results show that each of these practices accentuates conditions of motoneuron recruitment based on the size principle, and minimizes conditions of mixed and reversed recruitment orders, which have been observed in animal and human recordings. Specifically, strict motoneuron orderly size recruitment occurs, but in a compressed range, after which mixed and reverse motoneuron recruitment occurs due to the overlap in electrical properties of different motoneuron types. Additionally, these practices underestimate the motoneuron firing rates and force data simulated by existing models. Our results indicate that current modeling practices increase conditions of motoneuron recruitment based on the size principle, and decrease conditions of mixed and reversed recruitment order, which, in turn, impacts the predictions made by existing models on motoneuron recruitment, firing rate, and force. Additionally, mixed and reverse motoneuron recruitment generated higher muscle force than orderly size motoneuron recruitment in these simulations and represents one potential scheme to increase muscle efficiency. The examined model design practices, as well as the present results, are applicable to neuronal modeling throughout the nervous system.

  13. The Principle-Based Method of Practical Ethics.

    PubMed

    Spielthenner, Georg

    2017-09-01

    This paper is about the methodology of doing practical ethics. There is a variety of methods employed in ethics. One of them is the principle-based approach, which has an established place in ethical reasoning. In everyday life, we often judge the rightness and wrongness of actions by their conformity to principles, and the appeal to principles plays a significant role in practical ethics, too. In this paper, I try to provide a better understanding of the nature of principle-based reasoning. To accomplish this, I show in the first section that these principles can be applied to cases in a meaningful and sufficiently precise way. The second section discusses the question how relevant applying principles is to the resolution of ethical issues. This depends on their nature. I argue that the principles under consideration in this paper should be interpreted as presumptive principles and I conclude that although they cannot be expected to bear the weight of definitely resolving ethical problems, these principles can nevertheless play a considerable role in ethical research.

  14. Some Analogies of the Banach Contraction Principle in Fuzzy Modular Spaces

    PubMed Central

    Wongkum, Kittipong; Chaipunya, Parin; Kumam, Poom

    2013-01-01

    We established some theorems under the aim of deriving variants of the Banach contraction principle, using the classes of inner contractions and outer contractions, on the structure of fuzzy modular spaces. PMID:23766681

  15. [Ethical principles and approaches to health systems governance research: conceptual and methodological implications].

    PubMed

    Flores, Walter

    2010-01-01

    Governance refers to decision-making processes in which power relationships and actors and institutions' particular interests converge. Situations of consensus and conflict are inherent to such processes. Furthermore, decision-making happens within a framework of ethical principles, motivations and incentives which could be explicit or implicit. Health systems in most Latin-American and Caribbean countries take the principles of equity, solidarity, social participation and the right to health as their guiding principles; such principles must thus rule governance processes. However, this is not always the case and this is where the importance of investigating governance in health systems lies. Making advances in investigating governance involves conceptual and methodological implications. Clarifying and integrating normative and analytical approaches is relevant at conceptual level as both are necessary for an approach seeking to investigate and understand social phenomena's complexity. In relation to methodological level, there is a need to expand the range of variables, sources of information and indicators for studying decision-making aimed to greater equity, health citizenship and public policy efficiency.

  16. Dynamics of non-holonomic systems with stochastic transport

    NASA Astrophysics Data System (ADS)

    Holm, D. D.; Putkaradze, V.

    2018-01-01

    This paper formulates a variational approach for treating observational uncertainty and/or computational model errors as stochastic transport in dynamical systems governed by action principles under non-holonomic constraints. For this purpose, we derive, analyse and numerically study the example of an unbalanced spherical ball rolling under gravity along a stochastic path. Our approach uses the Hamilton-Pontryagin variational principle, constrained by a stochastic rolling condition, which we show is equivalent to the corresponding stochastic Lagrange-d'Alembert principle. In the example of the rolling ball, the stochasticity represents uncertainty in the observation and/or error in the computational simulation of the angular velocity of rolling. The influence of the stochasticity on the deterministically conserved quantities is investigated both analytically and numerically. Our approach applies to a wide variety of stochastic, non-holonomically constrained systems, because it preserves the mathematical properties inherited from the variational principle.

  17. Evolving models for medical physics education and training: a global perspective.

    PubMed

    Sprawls, P

    2008-01-01

    There is a significant need for high-quality medical physics education and training in all countries to support effective and safe use of modern medical technology for both diagnostic and treatment purposes. This is, and will continue to be, achieved using appropriate technology to increase both the effectiveness and efficiency of educational activities everywhere in the world. While the applications of technology to education and training are relatively new, the successful applications are based on theories and principles of the learning process developed by two pioneers in the field, Robert Gagne and Edgar Dale.The work of Gagne defines the different levels of learning that can occur and is used to show the types and levels of learning that are required for the application of physics and engineering principles to achieve appropriate diagnostic and therapeutic results from modern technology. The learning outcomes are determined by the effectiveness of the learning activity or experience. The extensive work of Dale as formulated in his Cone of Experience relates the effectiveness to the efficiency of educational activities. A major challenge in education is the development and conduction of learning activities (classroom discussions, laboratory and applied experiences, individual study, etc) that provide an optimum balance between effectiveness and efficiency. New and evolving models of the educational process use technology as the infrastructure to support education that is both more effective and efficient.The goal is to use technology to enhance human performance for both learners (students) and learning facilitators (teachers). A major contribution to global education is the trend in the development of shared educational resources. Two models of programs to support this effort with open and free shared resources are Physical Principles of Medical Imaging Online (http://www.sprawls.org/resources) and AAPM Continuing Education Courses (http://www.aapm.org/international).

  18. Evolving models for medical physics education and training: a global perspective

    PubMed Central

    Sprawls, P

    2008-01-01

    There is a significant need for high-quality medical physics education and training in all countries to support effective and safe use of modern medical technology for both diagnostic and treatment purposes. This is, and will continue to be, achieved using appropriate technology to increase both the effectiveness and efficiency of educational activities everywhere in the world. While the applications of technology to education and training are relatively new, the successful applications are based on theories and principles of the learning process developed by two pioneers in the field, Robert Gagne and Edgar Dale. The work of Gagne defines the different levels of learning that can occur and is used to show the types and levels of learning that are required for the application of physics and engineering principles to achieve appropriate diagnostic and therapeutic results from modern technology. The learning outcomes are determined by the effectiveness of the learning activity or experience. The extensive work of Dale as formulated in his Cone of Experience relates the effectiveness to the efficiency of educational activities. A major challenge in education is the development and conduction of learning activities (classroom discussions, laboratory and applied experiences, individual study, etc) that provide an optimum balance between effectiveness and efficiency. New and evolving models of the educational process use technology as the infrastructure to support education that is both more effective and efficient. The goal is to use technology to enhance human performance for both learners (students) and learning facilitators (teachers). A major contribution to global education is the trend in the development of shared educational resources. Two models of programs to support this effort with open and free shared resources are Physical Principles of Medical Imaging Online (http://www.sprawls.org/resources) and AAPM Continuing Education Courses (http://www.aapm.org/international). PMID:21614309

  19. A Hybrid Algorithm for Period Analysis from Multiband Data with Sparse and Irregular Sampling for Arbitrary Light-curve Shapes

    NASA Astrophysics Data System (ADS)

    Saha, Abhijit; Vivas, A. Katherina

    2017-12-01

    Ongoing and future surveys with repeat imaging in multiple bands are producing (or will produce) time-spaced measurements of brightness, resulting in the identification of large numbers of variable sources in the sky. A large fraction of these are periodic variables: compilations of these are of scientific interest for a variety of purposes. Unavoidably, the data sets from many such surveys not only have sparse sampling, but also have embedded frequencies in the observing cadence that beat against the natural periodicities of any object under investigation. Such limitations can make period determination ambiguous and uncertain. For multiband data sets with asynchronous measurements in multiple passbands, we wish to maximally use the information on periodicity in a manner that is agnostic of differences in the light-curve shapes across the different channels. Given large volumes of data, computational efficiency is also at a premium. This paper develops and presents a computationally economic method for determining periodicity that combines the results from two different classes of period-determination algorithms. The underlying principles are illustrated through examples. The effectiveness of this approach for combining asynchronously sampled measurements in multiple observables that share an underlying fundamental frequency is also demonstrated.

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

    Evans, V.; Foltz, D.

    In 1990, the Clean Air Act was amended amidst a flurry of lobbying. One of the special provisions added was Section 404(d) (see also 40 CFR 72.42) to extend the deadline for compliance under Title IV from 1995 to 1997 for units that committed to install high-efficiency SO{sub 2} scrubbers. Title IV created the Acid Rain Program to reduce emissions of SO{sub 2} and NO{sub x} from electric utility boilers. Section 404(d) was added as a result of the efforts to encourage the continued use of high sulfur coal. Congress allocated 3.5 million allowances for EPA to award under thesemore » provisions. To reduce the uncertainty of being selected to receive extension allowances through EPA`s lottery system, utilities interested in participating in the Program formed the Extension Allowance Pool. The Extension Allowance Pooling Agreement was executed as of March 1992 by 16 utilities. The underlying principle of the Pool is that those utilities whose control units were selected to receive extension allowances would share a portion of those allowances with those Pool participants that were not chosen by EPA. The Pool also provided for the various activities required to implement these arrangements.« less

  1. First-Principles Studies of Structure-Property Relationships: Enabling Design of Functional Materials

    NASA Astrophysics Data System (ADS)

    Zhou, Qunfei

    First-principles calculations based on quantum mechanics have been proved to be powerful for accurately regenerating experimental results, uncovering underlying myths of experimental phenomena, and accelerating the design of innovative materials. This work has been motivated by the demand to design next-generation thermionic emitting cathodes and techniques to allow for synthesis of photo-responsive polymers on complex surfaces with controlled thickness and patterns. For Os-coated tungsten thermionic dispenser cathodes, we used first-principles methods to explore the bulk and surface properties of W-Os alloys in order to explain the previously observed experimental phenomena that thermionic emission varies significantly with W-Os alloy composition. Meanwhile, we have developed a new quantum mechanical approach to quantitatively predict the thermionic emission current density from materials perspective without any semi-empirical approximations or complicated analytical models, which leads to better understanding of thermionic emission mechanism. The methods from this work could be used to accelerate the design of next-generation thermionic cathodes. For photoresponsive materials, we designed a novel type of azobenzene-containing monomer for light-mediated ring-opening metathesis polymerization (ROMP) toward the fabrication of patterned, photo-responsive polymers by controlling ring strain energy (RSE) of the monomer that drives ROMP. This allows for unprecedented remote, noninvasive, instantaneous spatial and temporal control of photo-responsive polymer deposition on complex surfaces.This work on the above two different materials systems showed the power of quantum mechanical calculations on predicting, understanding and discovering the structures and properties of both known and unknown materials in a fast, efficient and reliable way.

  2. Unified reduction principle for the evolution of mutation, migration, and recombination

    PubMed Central

    Altenberg, Lee; Liberman, Uri; Feldman, Marcus W.

    2017-01-01

    Modifier-gene models for the evolution of genetic information transmission between generations of organisms exhibit the reduction principle: Selection favors reduction in the rate of variation production in populations near equilibrium under a balance of constant viability selection and variation production. Whereas this outcome has been proven for a variety of genetic models, it has not been proven in general for multiallelic genetic models of mutation, migration, and recombination modification with arbitrary linkage between the modifier and major genes under viability selection. We show that the reduction principle holds for all of these cases by developing a unifying mathematical framework that characterizes all of these evolutionary models. PMID:28265103

  3. Requirements and principles for the implementation and construction of large-scale geographic information systems

    NASA Technical Reports Server (NTRS)

    Smith, Terence R.; Menon, Sudhakar; Star, Jeffrey L.; Estes, John E.

    1987-01-01

    This paper provides a brief survey of the history, structure and functions of 'traditional' geographic information systems (GIS), and then suggests a set of requirements that large-scale GIS should satisfy, together with a set of principles for their satisfaction. These principles, which include the systematic application of techniques from several subfields of computer science to the design and implementation of GIS and the integration of techniques from computer vision and image processing into standard GIS technology, are discussed in some detail. In particular, the paper provides a detailed discussion of questions relating to appropriate data models, data structures and computational procedures for the efficient storage, retrieval and analysis of spatially-indexed data.

  4. Perceptions of Pre-Service Teachers on the Design of a Learning Environment Based on the Seven Principles of Good Practice

    ERIC Educational Resources Information Center

    Al-Furaih, Suad Abdul Aziz

    2017-01-01

    This study explored the perceptions of 88 pre-service teachers on the design of a learning environment using the Seven Principles of Good Practice and its effect on participants' abilities to create their Cloud Learning Environment (CLE). In designing the learning environment, a conceptual model under the name 7 Principles and Integrated Learning…

  5. Manufacturing Methods and Technology Project Summary Reports

    DTIC Science & Technology

    1981-06-01

    a tough urethane film. The basic principle is to pump two components to a spinning disc, mixing the components just prior to depositing in a well...and check out an electronic target scoring device using developed scientific principles without drastically modifying existing commercial...equipment. The scoring device selected and installed was an Accubar Model ATS-16D using the underlying physics principle of acoustic shock wave propagation

  6. 26 CFR 1.199-5 - Application of section 199 to pass-thru entities for taxable years beginning after May 17, 2006...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... principles of § 1.704-1(b)(1)(vii): Gross income attributable to DPGR ($1,500 (DPGR) − $810 (allocable CGS... Federal income tax items, as determined under the principles of § 1.704-1(b)(1)(vii): Gross income... effect under section 704(b). In the 2010 taxable year, PRS's only wage expense is $2,000 for marketing...

  7. [Changes and establishment of the principle of "Unity of traditional Chinese medicine and western medicine"].

    PubMed

    Li, Jian

    2014-11-01

    "Unity of traditional Chinese and western medicine" was one of the three major health work principles at the early founding of the People's Republic of China. It was not only a choice of political strategy in line with the lack of contemporary health-care resources, but also a part of the revolutionary heritage for more than 20 years in the process of the Chinese Communist Party from the preliminary "application of both traditional and western medicine" to the making of the principles of both "cooperation of traditional Chinese and western medicine" and "unity of traditional Chinese and western medicine". All this was closely related to the concrete environment of the Chinese health work of various stages of Yan'an period with strong revolutionary atmosphere and was not the professional demand of the health workers, rather, this principle set up in 1950 was the result of the careful consideration of Mao Zedong and an adjustment guided under the revolutionary framework of Neo-democracy set up under the guidance of the Common Principle which was a bettered adaptation to the contemporary national condition.

  8. Evolutionary principles and their practical application

    PubMed Central

    Hendry, Andrew P; Kinnison, Michael T; Heino, Mikko; Day, Troy; Smith, Thomas B; Fitt, Gary; Bergstrom, Carl T; Oakeshott, John; Jørgensen, Peter S; Zalucki, Myron P; Gilchrist, George; Southerton, Simon; Sih, Andrew; Strauss, Sharon; Denison, Robert F; Carroll, Scott P

    2011-01-01

    Evolutionary principles are now routinely incorporated into medicine and agriculture. Examples include the design of treatments that slow the evolution of resistance by weeds, pests, and pathogens, and the design of breeding programs that maximize crop yield or quality. Evolutionary principles are also increasingly incorporated into conservation biology, natural resource management, and environmental science. Examples include the protection of small and isolated populations from inbreeding depression, the identification of key traits involved in adaptation to climate change, the design of harvesting regimes that minimize unwanted life-history evolution, and the setting of conservation priorities based on populations, species, or communities that harbor the greatest evolutionary diversity and potential. The adoption of evolutionary principles has proceeded somewhat independently in these different fields, even though the underlying fundamental concepts are the same. We explore these fundamental concepts under four main themes: variation, selection, connectivity, and eco-evolutionary dynamics. Within each theme, we present several key evolutionary principles and illustrate their use in addressing applied problems. We hope that the resulting primer of evolutionary concepts and their practical utility helps to advance a unified multidisciplinary field of applied evolutionary biology. PMID:25567966

  9. Evolutionary principles and their practical application.

    PubMed

    Hendry, Andrew P; Kinnison, Michael T; Heino, Mikko; Day, Troy; Smith, Thomas B; Fitt, Gary; Bergstrom, Carl T; Oakeshott, John; Jørgensen, Peter S; Zalucki, Myron P; Gilchrist, George; Southerton, Simon; Sih, Andrew; Strauss, Sharon; Denison, Robert F; Carroll, Scott P

    2011-03-01

    Evolutionary principles are now routinely incorporated into medicine and agriculture. Examples include the design of treatments that slow the evolution of resistance by weeds, pests, and pathogens, and the design of breeding programs that maximize crop yield or quality. Evolutionary principles are also increasingly incorporated into conservation biology, natural resource management, and environmental science. Examples include the protection of small and isolated populations from inbreeding depression, the identification of key traits involved in adaptation to climate change, the design of harvesting regimes that minimize unwanted life-history evolution, and the setting of conservation priorities based on populations, species, or communities that harbor the greatest evolutionary diversity and potential. The adoption of evolutionary principles has proceeded somewhat independently in these different fields, even though the underlying fundamental concepts are the same. We explore these fundamental concepts under four main themes: variation, selection, connectivity, and eco-evolutionary dynamics. Within each theme, we present several key evolutionary principles and illustrate their use in addressing applied problems. We hope that the resulting primer of evolutionary concepts and their practical utility helps to advance a unified multidisciplinary field of applied evolutionary biology.

  10. 10 CFR 455.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... effectively and efficiently. Marketing means a program or activity managed or performed by the State including... purpose government below the State (determined on the basis of the same principles as are used by the...

  11. Principles of light energy management

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

    Davis, N.

    1994-12-31

    A review is presented on methods to minimize the effects of excess energy associated with lighting systems for plant growth. Information on lamp efficiencies and methods for separating and collecting unwanted heat is included.

  12. Teaching Social Studies in North Korean Schools under Communism

    ERIC Educational Resources Information Center

    Kim, H. C.

    1970-01-01

    The main purpose of social studies instruction in North Korea is to develop in the students a devotion to their country and to the principles of socialism and a concomitant hatred for the West and its principles. (CK)

  13. Can one do good medical ethics without principles?

    PubMed

    Macklin, Ruth

    2015-01-01

    The criteria for determining what it is to do good medical ethics are the quality of ethical analysis and ethical justifications for decisions and actions. Justifications for decisions and actions rely on ethical principles, be they the 'famous four' or subsidiary ethical principles relevant to specific contexts. Examples from clinical ethics, research ethics and public health ethics reveal that even when not stated explicitly, principles are involved in ethical justifications. Principles may come into conflict, however, and the resolution of an ethical dilemma requires providing good reasons for preferring one principle over another. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Physician strives to create lean, clean health care machine. Studies of manufacturing processes may one day help make your practice more efficient.

    PubMed

    Hill, D

    2001-01-01

    Elisabeth Hager, MD, MMM, CPE, is teaming up with scientists and industrialists to teach physicians how to apply principles of lean, total-quality manufacturing to their practices. She believes innovation and efficiencies can help doctors resurrect their profession's image and their control over it--and perhaps even reinvent American health care.

  15. [Genome editing ~Principle and possibility of a novel genetic engineering technology. Basic principles of genome editing.

    PubMed

    Yamamoto, Takashi

    Programmable site-specific nuclease mediated-genome editing is an emerging biotechnology for precise manipulation of target genes. In genome editing, gene-knockout as well as gene-knockin are possible in various organisms and cultured cells. CRISPR-Cas9, which was developed in 2012, is a convenient and efficient programmable site-specific nuclease and the use spreads around the world rapidly. For this, it is important for the progress of life science research to introduce the genome editing technology.

  16. Protection - Principles and practice.

    NASA Technical Reports Server (NTRS)

    Graham, G. S.; Denning, P. J.

    1972-01-01

    The protection mechanisms of computer systems control the access to objects, especially information objects. The principles of protection system design are formalized as a model (theory) of protection. Each process has a unique identification number which is attached by the system to each access attempted by the process. Details of system implementation are discussed, taking into account the storing of the access matrix, aspects of efficiency, and the selection of subjects and objects. Two systems which have protection features incorporating all the elements of the model are described.

  17. Ergonomics and design: its principles applied in the industry.

    PubMed

    Tavares, Ademario Santos; Silva, Francisco Nilson da

    2012-01-01

    Industrial Design encompasses both product development and optimization of production process. In this sense, Ergonomics plays a fundamental role, because its principles, methods and techniques can help operators to carry out their tasks most successfully. A case study carried out in an industry shows that the interaction among Design, Production Engineering and Materials Engineering departments may improve some aspects concerned security, comfort, efficiency and performance. In this process, Ergonomics had shown to be of essential importance to strategic decision making to the improvement of production section.

  18. Cost and efficiency lead to increased value for the patient and bottom line for the practice.

    PubMed

    Dahl, Owen J

    2009-01-01

    Understanding how much it costs to provide a service is a basic premise of any business. In addition, healthcare is in need of improved processes to provide and increase value to the patient. This can be accomplished by the application of principles called Six Sigma and Lean Management. Today's medical practice leader must be aware of the costs of doing business and be able to apply proven management principles to the processes involved in providing patient care.

  19. A generalized theory of chromatography and multistep liquid extraction

    NASA Astrophysics Data System (ADS)

    Chizhkov, V. P.; Boitsov, V. N.

    2017-03-01

    A generalized theory of chromatography and multistep liquid extraction is developed. The principles of highly efficient processes for fine preparative separation of binary mixture components on a fixed sorbent layer are discussed.

  20. LeChâtelier's Principle in the Sciences

    NASA Astrophysics Data System (ADS)

    Thomsen, Volker B. E.

    2000-02-01

    LeChâtelier's principle of chemical equilibrium is actually a very general statement about systems in equilibrium and their behavior when subjected to external force or stress. Although one almost never finds mention of his name or law in other sciences, analogous principles and concepts do exist. In this note we examine some of the similar forms taken by this chemical principle in the fields of physics, geology, biology, and economics. Lenz's law in physics is an example of electromagnetic equilibrium and the geological principle of isostatic uplift concerns mechanical equilibrium. Both are strictly consequences of conservation of energy. LeChâtelier's principle deals with thermodynamic equilibrium and involves both the first and second laws of thermodynamics. The concept of homeostasis in biology and the economic law of supply and demand are both equilibrium-like principles, but involve systems in the steady state. However, all these principles involve the stability of the system under consideration and the analogies presented may be useful in the teaching of LeChâtelier's principle.

  1. Extraction of information on macromolecular interactions from fluorescence micro-spectroscopy measurements in the presence and absence of FRET.

    PubMed

    Raicu, Valerică

    2018-06-15

    Investigations of static or dynamic interactions between proteins or other biological macromolecules in living cells often rely on the use of fluorescent tags with two different colors in conjunction with adequate theoretical descriptions of Förster Resonance Energy Transfer (FRET) and molecular-level micro-spectroscopic technology. One such method based on these general principles is FRET spectrometry, which allows determination of the quaternary structure of biomolecules from cell-level images of the distributions, or spectra of occurrence frequency of FRET efficiencies. Subsequent refinements allowed combining FRET frequency spectra with molecular concentration information, thereby providing the proportion of molecular complexes with various quaternary structures as well as their binding/dissociation energies. In this paper, we build on the mathematical principles underlying FRET spectrometry to propose two new spectrometric methods, which have distinct advantages compared to other methods. One of these methods relies on statistical analysis of color mixing in subpopulations of fluorescently tagged molecules to probe molecular association stoichiometry, while the other exploits the color shift induced by FRET to also derive geometric information in addition to stoichiometry. The appeal of the first method stems from its sheer simplicity, while the strength of the second consists in its ability to provide structural information. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Principles of Dataset Versioning: Exploring the Recreation/Storage Tradeoff

    PubMed Central

    Bhattacherjee, Souvik; Chavan, Amit; Huang, Silu; Deshpande, Amol; Parameswaran, Aditya

    2015-01-01

    The relative ease of collaborative data science and analysis has led to a proliferation of many thousands or millions of versions of the same datasets in many scientific and commercial domains, acquired or constructed at various stages of data analysis across many users, and often over long periods of time. Managing, storing, and recreating these dataset versions is a non-trivial task. The fundamental challenge here is the storage-recreation trade-off: the more storage we use, the faster it is to recreate or retrieve versions, while the less storage we use, the slower it is to recreate or retrieve versions. Despite the fundamental nature of this problem, there has been a surprisingly little amount of work on it. In this paper, we study this trade-off in a principled manner: we formulate six problems under various settings, trading off these quantities in various ways, demonstrate that most of the problems are intractable, and propose a suite of inexpensive heuristics drawing from techniques in delay-constrained scheduling, and spanning tree literature, to solve these problems. We have built a prototype version management system, that aims to serve as a foundation to our DataHub system for facilitating collaborative data science. We demonstrate, via extensive experiments, that our proposed heuristics provide efficient solutions in practical dataset versioning scenarios. PMID:28752014

  3. Extraction of information on macromolecular interactions from fluorescence micro-spectroscopy measurements in the presence and absence of FRET

    NASA Astrophysics Data System (ADS)

    Raicu, Valerică

    2018-06-01

    Investigations of static or dynamic interactions between proteins or other biological macromolecules in living cells often rely on the use of fluorescent tags with two different colors in conjunction with adequate theoretical descriptions of Förster Resonance Energy Transfer (FRET) and molecular-level micro-spectroscopic technology. One such method based on these general principles is FRET spectrometry, which allows determination of the quaternary structure of biomolecules from cell-level images of the distributions, or spectra of occurrence frequency of FRET efficiencies. Subsequent refinements allowed combining FRET frequency spectra with molecular concentration information, thereby providing the proportion of molecular complexes with various quaternary structures as well as their binding/dissociation energies. In this paper, we build on the mathematical principles underlying FRET spectrometry to propose two new spectrometric methods, which have distinct advantages compared to other methods. One of these methods relies on statistical analysis of color mixing in subpopulations of fluorescently tagged molecules to probe molecular association stoichiometry, while the other exploits the color shift induced by FRET to also derive geometric information in addition to stoichiometry. The appeal of the first method stems from its sheer simplicity, while the strength of the second consists in its ability to provide structural information.

  4. Separating and Recycling Plastic, Glass, and Gallium from Waste Solar Cell Modules by Nitrogen Pyrolysis and Vacuum Decomposition.

    PubMed

    Zhang, Lingen; Xu, Zhenming

    2016-09-06

    Many countries have gained benefits through the solar cells industry due to its high efficiency and nonpolluting power generation associated with solar energy. Accordingly, the market of solar cell modules is expanding rapidly in recent decade. However, how to environmentally friendly and effectively recycle waste solar cell modules is seldom concerned. Based on nitrogen pyrolysis and vacuum decomposition, this work can successfully recycle useful organic components, glass, and gallium from solar cell modules. The results were summarized as follows: (i) nitrogen pyrolysis process can effectively decompose plastic. Organic conversion rate approached 100% in the condition of 773 K, 30 min, and 0.5 L/min N2 flow rate. But, it should be noted that pyrolysis temperature should not exceed 773 K, and harmful products would be increased with the increasing of temperature, such as benzene and its derivatives by GC-MS measurement; (ii) separation principle, products analysis, and optimization of vacuum decomposition were discussed. Gallium can be well recycled under temperature of 1123 K, system pressure of 1 Pa and reaction time of 40 min. This technology is quite significant in accordance with the "Reduce, Reuse, and Recycle Principle" for solid waste, and provides an opportunity for sustainable development of photovoltaic industry.

  5. When private water rights become a public asset: Stakeholder perspectives on the fairness of environmental water management

    NASA Astrophysics Data System (ADS)

    Lukasiewicz, Anna; Dare, Melanie (Lain)

    2016-05-01

    This paper explores environmental water management as a social process of navigating conflicting interests through a distributive justice lens. Environmental water management can achieve substantial ecological outcomes and address ongoing river degradation caused by past management and climate change; however it also causes specific and substantial burdens and benefits to different groups of stakeholders. Given that in most developed countries the majority of land is under private tenure, environmental watering must have active cooperation of private landholders to achieve its ecological outcomes and thus it must effectively deal with an array of vested interests. Australia's reforms aimed at reallocating water from production to the environment have resulted in significant considerable volumes of environmental water. In the state of New South Wales, this water is managed by the state and national governments with the help of five Environmental Water Advisory Groups made up of a wide representation of interests. In this paper, we explore the perceptions of environmental, government, irrigator and grazing representatives, which demonstrate conflicting principles over how environmental water should be distributed. We detail how government water managers reconcile competing distributive principles of equity (ensuring that no one is disproportionally affected or benefits unduly), need (achieving environmental outcomes) and efficiency (prioritizing operational feasibility) in order to maintain the social acceptability of environmental water.

  6. Fifth amendment taking and environmental protection under the police power: Historical development and a modest proposal to address the muddle

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

    Root, T.E.; Dotterrer, I.L.

    1995-12-01

    Under its developing {open_quotes}just compensation{close_quotes} jurisprudence, the United States Supreme Court has applied the constitutional requirement (of just compensation for taking private property for public use) to overly intrusive regulations. The application of the just compensation clause to governmental environmental protection activity has pitted the basic principle of protection of private property from government confiscation against another basic principle-the police power (which allows the government to regulate the use of property to protect the health, safety, and welfare of the people). The authors outline the muddle resulting from the conflict of these two constitutional principles after tracing the development ofmore » each. This article first outlines the general trend of increasing regulation of the uses of private property under environmental laws pursuant to the police power, and then outlines the development of Fifth Amendment just compensation jurisprudence (from eminent domain, through inverse condemnation, to regulatory taking). The authors urge Congress to authorize a Commission to review exercise of the police power and environmental protection legislation in light of the Fifth Amendment just compensation provision and to recommend legislation that will reconcile the two principles.« less

  7. Principles for high-quality, high-value testing.

    PubMed

    Power, Michael; Fell, Greg; Wright, Michael

    2013-02-01

    A survey of doctors working in two large NHS hospitals identified over 120 laboratory tests, imaging investigations and investigational procedures that they considered not to be overused. A common suggestion in this survey was that more training was required. And, this prompted the development of a list of core principles for high-quality, high-value testing. The list can be used as a framework for training and as a reference source. The core principles are: (1) Base testing practices on the best available evidence. (2) Apply the evidence on test performance with careful judgement. (3) Test efficiently. (4) Consider the value (and affordability) of a test before requesting it. (5) Be aware of the downsides and drivers of overdiagnosis. (6) Confront uncertainties. (7) Be patient-centred in your approach. (8) Consider ethical issues. (9) Be aware of normal cognitive limitations and biases when testing. (10) Follow the 'knowledge journey' when teaching and learning these core principles.

  8. Principle of relative positioning of structures in the human body☆

    PubMed Central

    Meng, Buliang; Pang, Ailan; Li, Ming

    2013-01-01

    The arrangement of various biological structures should generally ensure the safety of crucial structures and increase their working efficiency; however, other principles governing the relative positions of structures in humans have not been reported. The present study therefore investigated other principles using nerves and their companion vessels in the human body as an example. Nerves and blood vessels usually travel together and in the most direct way towards their targets. Human embryology, histology, and gross anatomy suggest that there are many possible positions for these structures during development. However, for mechanical reasons, tougher or stronger structures should take priority. Nerves are tougher than most other structures, followed by arteries, veins, and lymphatic vessels. Nerves should therefore follow the most direct route, and be followed by the arteries, veins, and lymphatic vessels. This general principle should be applicable to all living things. PMID:25206733

  9. 5 CFR 551.202 - General principles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false General principles. 551.202 Section 551.202 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY... preclude exemption under another category. For example, an engineering technician who fails to meet the...

  10. 5 CFR 551.202 - General principles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false General principles. 551.202 Section 551.202 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY... preclude exemption under another category. For example, an engineering technician who fails to meet the...

  11. 5 CFR 551.202 - General principles.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false General principles. 551.202 Section 551.202 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY... preclude exemption under another category. For example, an engineering technician who fails to meet the...

  12. 5 CFR 551.202 - General principles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false General principles. 551.202 Section 551.202 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY... preclude exemption under another category. For example, an engineering technician who fails to meet the...

  13. 2 CFR 225.15 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR STATE, LOCAL... grant streamlining effort under Public Law 106-107, Federal Financial Award Management Improvement Act... review existing cost principles for Federal awards to State, local, and Indian tribal governments...

  14. 42 CFR 413.170 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PRINCIPLES OF REASONABLE COST REIMBURSEMENT; PAYMENT FOR END-STAGE RENAL DISEASE SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Payment for End-Stage Renal Disease (ESRD... the principles and authorities under which CMS is authorized to establish a prospective payment system...

  15. The Application Potential of Eco-Efficiency for Greening Company

    NASA Astrophysics Data System (ADS)

    Prasaja, Lukman Eka; Hadiyanto

    2018-02-01

    Eco-Efficiency emerged in the 1990s as a measure of "the efficiency that ecological sources use to meet human needs." As a tool in economic and environmental integration, Eco-efficiency needs to be promoted further so that regulation in government and industrial management can include it as an important instrument. This paper provides several approaches that can help various industries to develop effective eco-efficiency principles. The approach used is to maximize the role of the Steering Committee of the company's internal environment. Utilization of natural resources such as water, forests, mines and energy needs need to be balanced with Eco-Efficiency so that natural exploitation can be well controlled so that sustainable development aspired by the world can be realized.

  16. A New Set of Forces

    DTIC Science & Technology

    2012-12-01

    correcting forces is the free market itself. Unfortunately, macroeconomic principles do not always prove useful at the microeconomic level...model for this discussion are not relevant, but the underlying principle of the model is—forces can be self-correcting. Any im- balance in one...Performance-based acqui- sition appears to be one of those principles that looks good on paper and has proved quite successful in private industry but has had

  17. Fermion systems in discrete space-time

    NASA Astrophysics Data System (ADS)

    Finster, Felix

    2007-05-01

    Fermion systems in discrete space-time are introduced as a model for physics on the Planck scale. We set up a variational principle which describes a non-local interaction of all fermions. This variational principle is symmetric under permutations of the discrete space-time points. We explain how for minimizers of the variational principle, the fermions spontaneously break this permutation symmetry and induce on space-time a discrete causal structure.

  18. Air Base Ground Defense Wargame: Study of a Security Police Training Device.

    DTIC Science & Technology

    1987-09-01

    different locations of the air base under siege. Therefore, AFOSP supports the development of a board wargame training device to compensate for the...commercial wargames available on the market . Eight games were identified as having application to this study due to their use of modern weapons and the...operation under his operational control (9:23). Concentration of MIR Efforts. This principle is a restatement of the universally accepted principle of mass (9

  19. Principles of transverse flow fractionation of microparticles in superhydrophobic channels.

    PubMed

    Asmolov, Evgeny S; Dubov, Alexander L; Nizkaya, Tatiana V; Kuehne, Alexander J C; Vinogradova, Olga I

    2015-07-07

    We propose a concept of fractionation of micron-sized particles in a microfluidic device with a bottom wall decorated by superhydrophobic stripes. The stripes are oriented at an angle α to the direction of a driving force, G, which generally includes an applied pressure gradient and gravity. Separation relies on the initial sedimentation of particles under gravity in the main forward flow, and their subsequent lateral deflection near a superhydrophobic wall due to generation of a secondary flow transverse to G. We provide some theoretical arguments allowing us to quantify the transverse displacement of particles in the microfluidic channel, and confirm the validity of theoretical predictions in test experiments with monodisperse fractions of microparticles. Our results can guide the design of superhydrophobic microfluidic devices for efficient sorting of microparticles with a relatively small difference in size and density.

  20. Dodging the crisis of folding proteins with knots

    NASA Astrophysics Data System (ADS)

    Sulkowska, Joanna

    2009-03-01

    Proteins with nontrivial topology, containing knots and slipknots, have the ability to fold to their native states without any additional external forces invoked. A mechanism is suggested for folding of these proteins, such as YibK and YbeA, which involves an intermediate configuration with a slipknot. It elucidates the role of topological barriers and backtracking during the folding event. It also illustrates that native contacts are sufficient to guarantee folding in around 1-2% of the simulations, and how slipknot intermediates are needed to reduce the topological bottlenecks. As expected, simulations of proteins with similar structure but with knot removed fold much more efficiently, clearly demonstrating the origin of these topological barriers. Although these studies are based on a simple coarse-grained model, they are already able to extract some of the underlying principles governing folding in such complex topologies.

  1. Construction of a cost effective optical tweezers for manipulation of birefringent materials using circularly polarized light

    NASA Astrophysics Data System (ADS)

    McMahon, Allison; Sauncy, Toni

    2008-10-01

    Light manipulation is a very powerful tool in physics, biology, and chemistry. There are several physical principles underlying the apparatus known as the ``optical tweezers,'' the term given to using focused light to manipulate and control small objects. By carefully controlling the orientation and position of a focused laser beam, dielectric particles can be effectively trapped and manipulated. We have designed a cost efficient and effective undergraduate optical tweezers apparatus by using standard ``off the shelf'' components and starting with a standard undergraduate laboratory microscope. Images are recorded using a small CCD camera interfaced to a computer and controlled by LabVIEW^TM software. By using wave plates to produce circular polarized light, rotational motion can be induced in small particles of birefringent materials such as calcite and mica.

  2. Stroke rehabilitation in ontario: an opportunity for health care transformation.

    PubMed

    Meyer, Matthew J; Meyer, John P; Foley, Norine; Salter, Katherine; McClure, J Andrew; Teasell, Robert

    2011-11-01

    In this article, Ontario's stroke rehabilitation system is used to exemplify the challenges faced by rehabilitation and healthcare systems across Canada who are attempting to provide quality care to patients in the face of increasing demands. Currently, Ontario's rehabilitation system struggles in its efforts to provide accessible and comprehensive care to patients recovering from stroke. We begin our exploration by identifying both the primary stakeholders and the underlying factors that have contributed to the current challenges. The framework put forward in the Canadian Medical Association's recommendations for transformation is then used to suggest a vision for a more patient-focused system incorporating three key principles: a broader perspective, a patient-first approach, and greater unity. The use of health information technology, proper incentives, and greater accountability are discussed as mechanisms to improve the quality and efficiency of care.

  3. Photocell Optimization Using Dark State Protection.

    PubMed

    Fruchtman, Amir; Gómez-Bombarelli, Rafael; Lovett, Brendon W; Gauger, Erik M

    2016-11-11

    Conventional photocells suffer a fundamental efficiency threshold imposed by the principle of detailed balance, reflecting the fact that good absorbers must necessarily also be fast emitters. This limitation can be overcome by "parking" the energy of an absorbed photon in a dark state which neither absorbs nor emits light. Here we argue that suitable dark states occur naturally as a consequence of the dipole-dipole interaction between two proximal optical dipoles for a wide range of realistic molecular dimers. We develop an intuitive model of a photocell comprising two light-absorbing molecules coupled to an idealized reaction center, showing asymmetric dimers are capable of providing a significant enhancement of light-to-current conversion under ambient conditions. We conclude by describing a road map for identifying suitable molecular dimers for demonstrating this effect by screening a very large set of possible candidate molecules.

  4. Relative Importance Assigned to Health Care Rationing Principles at the Bedside: Evidence From a Portuguese and Bulgarian Survey.

    PubMed

    Pinho, Micaela Moreira; Pinto Borges, Ana

    Activity was undertaken to develop a Prioritization Scoring Index for Portugal and Bulgaria that weights the importance given to ethical rationing principles that should guide decisions at the bedside. Data from two random samples of 355 Portuguese and 298 Bulgarian members of the public were collected from an online questionnaire. Questions asked about the level of importance given to specific issues related to patient's prioritization criteria. Responses were analyzed quantitatively with the SPSS. In the process of selecting the patient to treat, Portuguese and Bulgarian respondents seem unanimous in giving greater importance to (i) the treatment outcomes, (ii) the severity of illness, (iii) children, and (iv) patients' fragility. In general, Portuguese and Bulgarian respondents allocate more than 50% of the prioritization weight to equity considerations, approximately 35% to efficiency considerations, and 5% to lottery selection. Even so, Bulgarian respondents rate highly the equity and less the efficiency consideration than Portuguese respondents. Although the pursuit of efficiency seems to be valued by respondents, their major concern seems to be with the reduction of inequalities in health.

  5. Principles that Govern the Performance of Molecular Motors

    NASA Astrophysics Data System (ADS)

    Eide, Jon; Chakraborty, Arup; Oster, George

    2003-03-01

    We have created a two dimensional polymeric coarse-grained model to simulate the power stroke from the F0F1 ATP synthase class of molecular motors. There has been much work to understand the structure and dynamics of this type of molecular motor using both constrained molecular dynamics and general Markov models but neither of them have been able to elucidate in a qualitative manner how a constant force is created and transferred in the motor at a nearly 100efficiency. Our model is a modified Rouse system using Brownian and Monte Carlo (with solvent) Dynamics, concentrating only on the catalytic site and protein structures that we think are important for motor motion and energy transfer. While modeling the real system as closely as possible, we have determined the optimum characteristics for maximum efficiency. The efficiency depends on the load against the polymer, the polymer flexibility, polymer and surface matching, and solvent interactions. Insight into the basic principles behind the mechanical motion of this system may have implications for many other molecular motors driven by nucleotide hydrolysis and help design synthetic devices that can carry out biomimetic tasks.

  6. Comprehensive Study on Wastages of Supply Chain Information Sharing in Automotive Industries

    NASA Astrophysics Data System (ADS)

    Sendhil Kumar, R.; Pugazhendhi, S.; Muralidharan, C.; Murali, S.

    2017-03-01

    A supply chain is a very extensive concept, which encompasses many problems and features when it comes to controlling. Now a day’s lean concept is a very common method to several areas, such as service sectors and manufacturing. Applying the lean concept to supply chain management is a very popular study part, it has attracted many industrial practices and researchers with different applications. Information sharing and technology remain one of the key factors of integrating the supply chain members. Current scenario the competition is no longer between the competing companies, but it happens between the supply chains. So the efficiency of the supply chain is very important. And the effective sharing of information can enhance the supply chain efficiency through minimizing the inventories and Information sharing can increase supply chain efficiency by reducing inventories and stabilizing the production. This paper describes and discusses about the seven deadly wastes of supply chain information with the comparative principle of Toyota production system (TPS) principle approach. How the TPS can be applied to supply chain information sharing And lean tool of 5S concept possibility improve the information sharing.

  7. How to Present Evidence-Based Usability Design Principles Dedicated to Medication-Related Alerting Systems to Designers and Evaluators? Results from a Workshop.

    PubMed

    Marcilly, Romaric; Monkman, Helen; Villumsen, Sidsel; Kaufman, David; Beuscart-Zephir, Marie-Catherine

    2016-01-01

    Medication alerting system use errors and lack of adoption are often attributed to usability issues. Previous work has used evidence from the literature to reveal usability principles specific to medication alerting systems and identify potential consequences of violating these principles. The current study sought to explore how best to convey these principles to designers and evaluators of these systems to facilitate their work. To this aim, a workshop with 19 participants was used to generate ideas and opinions on how to deliver these topic-specific design principles in a way that would be most helpful for them. Participants generated ideas for how (e.g., a collaborative, continuously updated forum) and what (e.g., illustrations, checklists, evidence sources and strength, consequences of violations) information is most useful to disseminate usability principles for medication alerting systems. Participants, especially designers, expressed desire to use these principles in practice and avoid previously documented mistakes and therefore make design and evaluation of these systems more effective and efficient. Those insights are discussed in terms of feasibility and logistical challenges to developing the proposed documentation). To move this work forward, a more collaborative approach of Human Factors specialists in medical informatics is necessary.

  8. A study of usability principles and interface design for mobile e-books.

    PubMed

    Wang, Chao-Ming; Huang, Ching-Hua

    2015-01-01

    This study examined usability principles and interface designs in order to understand the relationship between the intentions of mobile e-book interface designs and users' perceptions. First, this study summarised 4 usability principles and 16 interface attributes, in order to conduct usability testing and questionnaire survey by referring to Nielsen (1993), Norman (2002), and Yeh (2010), who proposed the usability principles. Second, this study used the interviews to explore the perceptions and behaviours of user operations through senior users of multi-touch prototype devices. The results of this study are as follows: (1) users' behaviour of operating an interactive interface is related to user prior experience; (2) users' rating of the visibility principle is related to users' subjective perception but not related to user prior experience; however, users' ratings of the ease, efficiency, and enjoyment principles are related to user prior experience; (3) the interview survey reveals that the key attributes affecting users' behaviour of operating an interface include aesthetics, achievement, and friendliness. This study conducts experiments to explore the effects of users’ prior multi-touch experience on users’ behaviour of operating a mobile e-book interface and users’ rating of usability principles. Both qualitative and quantitative data analyses were performed. By applying protocol analysis, key attributes affecting users’ behaviour of operation were determined.

  9. Handbook for aquaculture water quality

    USDA-ARS?s Scientific Manuscript database

    Efficient aquaculture production depends upon maintaining acceptable water quality conditions in culture units. This handbook discusses background information from chemistry, physics, biology, and engineering necessary for understanding the principles of water quality management in aquaculture. It a...

  10. 7 CFR 3015.190 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... costs. These cost principles shall apply to transactions and activities conducted under grants... AGRICULTURE UNIFORM FEDERAL ASSISTANCE REGULATIONS Cost Principles § 3015.190 Scope. This subpart makes the allowable costs incurred by the recipient the maximum amount of money a recipient is entitled to receive...

  11. An efficient formulation of robot arm dynamics for control and computer simulation

    NASA Astrophysics Data System (ADS)

    Lee, C. S. G.; Nigam, R.

    This paper describes an efficient formulation of the dynamic equations of motion of industrial robots based on the Lagrange formulation of d'Alembert's principle. This formulation, as applied to a PUMA robot arm, results in a set of closed form second order differential equations with cross product terms. They are not as efficient in computation as those formulated by the Newton-Euler method, but provide a better analytical model for control analysis and computer simulation. Computational complexities of this dynamic model together with other models are tabulated for discussion.

  12. Response to Comment on "Water harvesting from air with metal-organic frameworks powered by natural sunlight".

    PubMed

    Kim, Hyunho; Rao, Sameer R; Narayanan, Shankar; Kapustin, Eugene A; Yang, Sungwoo; Furukawa, Hiroyasu; Umans, Ari S; Yaghi, Omar M; Wang, Evelyn N

    2017-12-01

    In their comment, Bui et al argue that the approach we described in our report is vastly inferior in efficiency to alternative off-the-shelf technologies. Their conclusion is invalid, as they compare efficiencies in completely different operating conditions. Here, using heat transfer and thermodynamics principles, we show how Bui et al 's conclusions about the efficiencies of off-the-shelf technologies are fundamentally flawed and inaccurate for the operating conditions described in our study. Copyright © 2017, American Association for the Advancement of Science.

  13. High-efficiency non-blocking phosphorescent organic light emitting diode with ultrathin emission layer

    NASA Astrophysics Data System (ADS)

    Qiu, Jacky; Helander, Michael G.; Wang, Zhibin; Chang, Yi-Lu; Lu, ZhengHong

    2012-09-01

    Non-blocking Phosphorescent Organic Light Emitting Diode (NB-PHOLED) is a highly simplified device structure that has achieved record high device performance on chlorinated ITO[1], flexible substrates[2], also with Pt based phosphorescent dopants[3] and NB-PHOLED has significantly reduced efficiency roll-off[4]. The principle novel features of NB-PHOLED is the absence of blocking layer in the OLED stack, as well as the absence of organic hole injection layer, this allows for reduction of carrier accumulation in between organic layers and result in higher efficiencies.

  14. Role of Water in the Reversible Optoelectronic Degradation in Hybrid Perovskites at Low Pressure

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

    Hall, Genevieve N.; Stuckelberger, Michael; Nietzold, Tara

    There is no doubt about the potential offered by the low-cost fabrication and high efficiency of hybrid organic–inorganic perovskite solar cells. However, the service lifetimes of these devices must be increased from months to years to capitalize on their potential. The archetypal hybrid perovskite for solar cells, methylammonium lead iodide (CH 3NH 3PbI 3, abbreviated MAPI), readily degrades in ambient atmosphere under standard operating conditions. Understanding the origin and effects of this degradation can pave the way to better engineer photovoltaic devices and the perovskite material itself. Herein we present the effects of varying pressure on the electrical performance ofmore » MAPI solar cells. Solar cell parameters, especially open circuit voltage, are significantly affected by the total ambient pressure and present an unexpected reversible behavior upon pressure cycling. We complement photoluminescence studies as a function of ambient atmosphere and temperature with first-principles density functional theory (DFT) calculations. The results suggest that the reversible intercalation of water in MAPI is a necessary component underlying this behavior.« less

  15. Composition-dependent stability of the medium-range order responsible for metallic glass formation

    DOE PAGES

    Zhang, Feng; Ji, Min; Fang, Xiao-Wei; ...

    2014-09-18

    The competition between the characteristic medium-range order corresponding to amorphous alloys and that in ordered crystalline phases is central to phase selection and morphology evolution under various processing conditions. We examine the stability of a model glass system, Cu–Zr, by comparing the energetics of various medium-range structural motifs over a wide range of compositions using first-principles calculations. Furthermore, we focus specifically on motifs that represent possible building blocks for competing glassy and crystalline phases, and we employ a genetic algorithm to efficiently identify the energetically favored decorations of each motif for specific compositions. These results show that a Bergman-type motifmore » with crystallization-resisting icosahedral symmetry is energetically most favorable in the composition range 0.63 < xCu < 0.68, and is the underlying motif for one of the three optimal glass-forming ranges observed experimentally for this binary system (Li et al., 2008). This work establishes an energy-based methodology to evaluate specific medium-range structural motifs which compete with stable crystalline nuclei in deeply undercooled liquids.« less

  16. On displacement-based plastic design of parallel chord vierendeel girders

    NASA Astrophysics Data System (ADS)

    Grigorian, Mark

    2014-09-01

    The paper introduces the principles of displacement-based plastic design (DBPD) and its applications to the efficient design of parallel chord steel vierendeel girders under normal nodal forces. A simplifying assumption has been made that the mathematical model is composed of imaginary, pin connected modules that fit within the bays of the prototype. The use of this modeling concept in conjunction with the applications of the uniform strength theory leads to the development of an algorithm that is ideally suited for manual, minimum weight design of steel vierendeel girders under any distribution of vertical nodal forces. The resulting solutions are exact and unique and lend themselves well to DBPD and minimum weight treatment. In DBPD which is akin to performance control, member strengths and stiffnesses are assigned rather than tested. Several generic examples have been provided to illustrate the applications of the proposed design procedures. The numerical results of these examples have been verified through long hand and computer methods of analysis. An extensive proof of the proposed method of approach has been provided in the "Appendix".

  17. Digital and biological computing in organizations.

    PubMed

    Kampfner, Roberto R

    2002-01-01

    Michael Conrad unveiled many of the fundamental characteristics of biological computing. Underlying the behavioral variability and the adaptability of biological systems are these characteristics, including the ability of biological information processing to exploit quantum features at the atomic level, the powerful 3-D pattern recognition capabilities of macromolecules, the computational efficiency, and the ability to support biological function. Among many other things, Conrad formalized and explicated the underlying principles of biological adaptability, characterized the differences between biological and digital computing in terms of a fundamental tradeoff between adaptability and programmability of information processing, and discussed the challenges of interfacing digital computers and human society. This paper is about the encounter of biological and digital computing. The focus is on the nature of the biological information processing infrastructure of organizations and how it can be extended effectively with digital computing. In order to achieve this goal effectively, however, we need to embed properly digital computing into the information processing aspects of human and social behavior and intelligence, which are fundamentally biological. Conrad's legacy provides a firm, strong, and inspiring foundation for this endeavor.

  18. Role of Water in the Reversible Optoelectronic Degradation in Hybrid Perovskites at Low Pressure

    DOE PAGES

    Hall, Genevieve N.; Stuckelberger, Michael; Nietzold, Tara; ...

    2017-10-10

    There is no doubt about the potential offered by the low-cost fabrication and high efficiency of hybrid organic–inorganic perovskite solar cells. However, the service lifetimes of these devices must be increased from months to years to capitalize on their potential. The archetypal hybrid perovskite for solar cells, methylammonium lead iodide (CH 3NH 3PbI 3, abbreviated MAPI), readily degrades in ambient atmosphere under standard operating conditions. Understanding the origin and effects of this degradation can pave the way to better engineer photovoltaic devices and the perovskite material itself. Herein we present the effects of varying pressure on the electrical performance ofmore » MAPI solar cells. Solar cell parameters, especially open circuit voltage, are significantly affected by the total ambient pressure and present an unexpected reversible behavior upon pressure cycling. We complement photoluminescence studies as a function of ambient atmosphere and temperature with first-principles density functional theory (DFT) calculations. The results suggest that the reversible intercalation of water in MAPI is a necessary component underlying this behavior.« less

  19. Conformational space annealing scheme in the inverse design of functional materials

    NASA Astrophysics Data System (ADS)

    Kim, Sunghyun; Lee, In-Ho; Lee, Jooyoung; Oh, Young Jun; Chang, Kee Joo

    2015-03-01

    Recently, the so-called inverse method has drawn much attention, in which specific electronic properties are initially assigned and target materials are subsequently searched. In this work, we develop a new scheme for the inverse design of functional materials, in which the conformational space annealing (CSA) algorithm for global optimization is combined with first-principles density functional calculations. To implement the CSA, we need a series of ingredients, (i) an objective function to minimize, (ii) a 'distance' measure between two conformations, (iii) a local enthalpy minimizer of a given conformation, (iv) ways to combine two parent conformations to generate a daughter one, (v) a special conformation update scheme, and (vi) an annealing method in the 'distance' parameter axis. We show the results of applications for searching for Si crystals with direct band gaps and the lowest-enthalpy phase of boron at a finite pressure and discuss the efficiency of the present scheme. This work is supported by the National Research Foundation of Korea (NRF) under Grant No. NRF-2005-0093845 and by Samsung Science and Technology Foundation under Grant No. SSTFBA1401-08.

  20. Electronic Topological Transitions in CuNiMnAl and CuNiMnSn under pressure from first principles study

    NASA Astrophysics Data System (ADS)

    Rambabu, P.; Kanchana, V.

    2018-06-01

    A detailed study on quaternary ordered full Heusler alloys CuNiMnAl and CuNiMnSn at ambient and under different compressions is presented using first principles electronic structure calculations. Both the compounds are found to possess ferromagnetic nature at ambient with magnetic moment of Mn being 3.14 μB and 3.35 μB respectively in CuNiMnAl and CuNiMnSn. The total magnetic moment for both the compounds is found to decrease under compression. Fermi surface (FS) topology change is observed in both compounds under pressure at V/V0 = 0.90, further leading to Electronic Topological Transitions (ETTs) and is evidenced by the anomalies visualized in density of states and elastic constants under compression.

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