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1

Congestion game model for efficient utilization of spectrum  

NASA Astrophysics Data System (ADS)

Dynamic spectrum access is a way of gaining access to individual frequencies on a temporary basis. This makes use of the frequency assigned to a specific user (primary user) by using specific devices and/or spectrum management techniques. The spectrum management techniques can be done by allocating the spectrum (a) through auctions (market based), (b) using management techniques (c) spectrum sharing (detects and utilizes the unutilized part of the spectrum) (d) command and control, and (e) through opportunistic spectrum access. In opportunistic spectrum access, the secondary or unlicensed user transfers the data with high speed and at short distances with tolerable interference (without disturbing) to the primary signal. Efficient spectrum allocation techniques were discussed using stochastic models, economic models, genetic algorithms, and optimization techniques. The existing models need to be tuned for better performance with optimum utilization of the power. In this paper, we proposed a model that provides access with tolerable interference from secondary users to the primary users while maximizing the spectrum utilization. Furthermore, we designed a congestion game model for efficient utilization of the spectrum by secondary users with minimum interference to primary users. The simulation results show that the congestion game model helps to utilize the spectrum efficiently.

Reddy, Y. B.; Smith, Heather

2010-04-01

2

A New Formulation of Spectrum-Orbit Utilization Efficiency for Satellite Communications in Interference-Limited Situations  

Microsoft Academic Search

The spectrum-orbit utilization efficiency of satellite communications is becoming increasingly important. A first attempt is made in this paper to try to formulate the spectrum-orbit utilization efficiency in interference-limited situations by defining the self-efficiency for a single satellite, and the cross-efficiency and coordination efficiency for each pair of adjacent satellites. The various technical aspects and complicated interference considerations relevant to

Lin-Shan Lee

1984-01-01

3

A new formulation of spectrum-orbit utilization efficiency for satellite communications in interference-limited situations  

Microsoft Academic Search

The spectrum-orbit utilization efficiency of satellite communications is becoming increasingly important. A first attempt is made in this paper to try to formulate the spectrum-orbit utilization efficiency in interference-limited situations by defining the self-efficiency for a single satellite, and the cross-efficiency and coordination efficiency for each pair of adjacent satellites. The various technical aspects and complicated interference considerations relevant to

L.-S. Lee

1984-01-01

4

Improving VHF Spectrum Utilization  

NASA Technical Reports Server (NTRS)

Limited VHF communications system capacity and increasing air traffic results in congestion of the aviation VHF spectrum. The voice communications errors and delayed channel access create system congestion and air traffic delays. Regulatory subdivision of bands for specific functions limits flexibility in the frequency usage. The objective of this viewgraph presentation is to identify near/mid/far term technologies to improve the performance and spectrum efficiency of current and emerging VHF communications systems. Select technologies with the highest potential, perform research and development to bring them to implementation stage.

Andro, Monty; Orr, Richard; Foore, Larry; Sheehe, Charles; Freeman, Mark; Nguyen, Thanh; Bretmersky, Steven; Laberge, Chuck; Buchanan, David

2004-01-01

5

47 CFR 101.521 - Spectrum utilization.  

Code of Federal Regulations, 2010 CFR

...Telecommunication 5 2010-10-01 2010-10-01 false Spectrum utilization. 101.521 Section 101.521 Telecommunication...Service and Digital Electronic Message Service § 101.521 Spectrum utilization. All applicants for DEMS...

2010-10-01

6

47 CFR 101.521 - Spectrum utilization.  

Code of Federal Regulations, 2011 CFR

...Telecommunication 5 2011-10-01 2011-10-01 false Spectrum utilization. 101.521 Section 101.521 Telecommunication...Service and Digital Electronic Message Service § 101.521 Spectrum utilization. All applicants for DEMS...

2011-10-01

7

78 FR 18374 - Promoting Economic Efficiency in Spectrum Use: WSRD SSG Workshop IV  

Federal Register 2010, 2011, 2012, 2013

...FOUNDATION Promoting Economic Efficiency in Spectrum Use: WSRD SSG Workshop IV AGENCY: The...promote progress toward more efficient spectrum utilization and sharing. SUPPLEMENTARY...accelerate the progress toward more efficient spectrum utilization and sharing. The...

2013-03-26

8

Distributed spectrum sensing utilizing heterogeneous wireless devices and measurement equipment  

Microsoft Academic Search

A suitable spectrum policy is essential to allow efficient use of the radio spectrum. The Japanese government currently employs a Command and Control (C&C) regime, but measures must be taken to speed up governmental decisions. The first step is to obtain spectrum utilization data which can form the basis of such decisions. This paper describes the design, implementation and evaluation

Junichi Naganawa; Hojun Kim; Shunsuke Saruwatari; Hisashi Onaga; Hiroyuki Morikawa

2011-01-01

9

Energy Efficiency and Electric Utilities  

SciTech Connect

The report is an overview of electric energy efficiency programs. It takes a concise look at what states are doing to encourage energy efficiency and how it impacts electric utilities. Energy efficiency programs began to be offered by utilities as a response to the energy crises of the 1970s. These regulatory-driven programs peaked in the early-1990s and then tapered off as deregulation took hold. Today, rising electricity prices, environmental concerns, and national security issues have renewed interest in increasing energy efficiency as an alternative to additional supply. In response, new methods for administering, managing, and delivering energy efficiency programs are being implemented. Topics covered in the report include: Analysis of the benefits of energy efficiency and key methods for achieving energy efficiency; evaluation of the business drivers spurring increased energy efficiency; Discussion of the major barriers to expanding energy efficiency programs; evaluation of the economic impacts of energy efficiency; discussion of the history of electric utility energy efficiency efforts; analysis of the impact of energy efficiency on utility profits and methods for protecting profitability; Discussion of non-utility management of energy efficiency programs; evaluation of major methods to spur energy efficiency - systems benefit charges, resource planning, and resource standards; and, analysis of the alternatives for encouraging customer participation in energy efficiency programs.

NONE

2007-11-15

10

75 FR 70725 - Spectrum Policy Seminar for the Utility Sector  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF ENERGY Spectrum Policy Seminar for the Utility Sector...information to the utility sector on spectrum policy issues in light of the role wireless...of smart grid technologies. At this spectrum policy seminar, senior officials...

2010-11-18

11

Towards Cognitive Radio Networks: Spectrum Utilization Measurements in Suburb Environment  

E-print Network

Towards Cognitive Radio Networks: Spectrum Utilization Measurements in Suburb Environment Václav with an overall approach regarding spectrum utilization in the next generation wireless networks. Index Terms or underutilized frequency spectrum from primary licensed networks and consequently solves the spectrum utilization

Paris-Sud XI, Université de

12

Enhancing spectrum utilization through cooperation and cognition in wireless systems  

E-print Network

We have seen a proliferation of wireless technologies and devices in recent years. The resulting explosion of wireless demand has put immense pressure on available spectrum. Improving spectrum utilization is therefore ...

Rahul, Hariharan Shankar, 1975-

2013-01-01

13

Towards cognitive radio networks: Spectrum utilization measurements in suburb environment  

Microsoft Academic Search

This paper deals with spectrum utilization measurements in the frequency band from 100 MHz up to 3 GHz. The measurement is based on the energy detection principle using wideband logarithmically periodic antenna. The results point out the fact, that the frequency spectrum is not utilized in an optimal manner and that there do exist less or more utilized licensed frequency

Václav Valenta; Zbynek Fedra; R. Marsalek; G. Baudoin; M. Villegas

2009-01-01

14

Cutoff wavelength optimization for high-efficiency split spectrum photovoltaics  

NASA Astrophysics Data System (ADS)

Split spectrum photovoltaics, where incident light is divided onto multiple cells on the basis of wavelength, are an exciting recent development in the solar energy field. This technology has the potential to exceed record conversion efficiencies by utilizing a large number of p-n junctions while mitigating the constraints that plague monolithic cells: lattice matching and current matching. Each cell in a split spectrum system can have a different lattice constant (allowing for more combinations of materials) and to have different operating currents (allowing for more combinations of band spacing). In this work, we examine a split spectrum system utilizing a single spectrum splitting device (a dichroic filter) to divide the solar spectrum onto two cells. Whereas many split spectrum designs use numerous filters to direct light onto single junction cells, in this system each cell is composed of multiple active junctions. Each cell is then tailored to absorb a portion of the solar spectrum. The combination of the two cells allows for four, five, or more active junctions while maintaining lattice and current matching conditions in each cell. A number of different cutoff frequencies for the dichroic filter are examined. Each cutoff frequency corresponds to its own combination of ideal band placements for both the shorter and longer wavelength cells. Materials corresponding to those band placements are examined to determine if any combinations can satisfy lattice matching parameters; designs which do are then simulated using TCAD Sentaurus.

Downs, Chandler; Vandervelde, Thomas E.

2014-03-01

15

75 FR 81558 - Promoting More Efficient Use of Spectrum Through Dynamic Spectrum Use Technologies  

Federal Register 2010, 2011, 2012, 2013

...FCC 10-198] Promoting More Efficient Use of Spectrum Through Dynamic Spectrum Use Technologies AGENCY: Federal Communications...innovation to ensure that the promise of dynamic spectrum access technologies can be fully realized...

2010-12-28

16

Efficient cooperative spectrum sensing for Wi-Fi on TV spectrum  

Microsoft Academic Search

Cognitive radio (CR) has become a better way to solve the inefficiency of spectrum usage unlike fixed spectrum assignment. The concept of CR was introduced in [1], where secondary (unlicensed) users utilize the licensed spectrum while primary (licensed) user is absence. To achieve this, secondary users require sensing the spectrum to decide the absence and presence of the primary user.

Chongjoon You; Jaeyoung Lee; Jinyoung Kim; Jun Heo

2011-01-01

17

Energy-efficient spectrum sensing for cognitive sensor networks  

E-print Network

Energy-efficient spectrum sensing for cognitive sensor networks Sina Maleki, Ashish Pandharipande a combined sleeping and censoring scheme for energy-efficient spectrum sensing in cognitive sensor networks for newer wireless net- works and applications. Radio spectrum measurements [13] however indicate that large

Leus, Geert

18

SPARTA: Stable and Efficient Spectrum Access in Next Generation Dynamic Spectrum Networks  

E-print Network

SPARTA: Stable and Efficient Spectrum Access in Next Generation Dynamic Spectrum Networks Lili Cao constraints. We propose SPARTA, a new DSA architecture to provide efficient and stable spectrum usage by integrating proactive planning with reactive adaptation. First, SPARTA introduces a novel statistical

Almeroth, Kevin C.

19

Adaptive Pricing for Efficient Spectrum Sharing in MIMO Systems  

Microsoft Academic Search

The concept of cognitive radio with many promising features like spectrum sensing, dynamic spectrum access has the potential to greatly improve the spectral efficiency. In this paper, we consider the problem of spectrum-hole sharing, i.e., vacant channel and power allocation to multiple cognitive radio (CR) users who coexist in a network. These CR users are equipped with multiple antennas at

Bhargav Kollimarla; Qi Cheng

2010-01-01

20

Utility-subsidized energy-efficiency programs  

SciTech Connect

In the end, the rise of large utility-subsidized energy-efficiency programs in the US in the late 1980s and early 1990s can best be understood from the perspective of political economy rather than from the perspective of neoclassical market economics. These programs represent a partially successful effort to capture the regulatory process and to use the institution of regulated monopoly to raise funds to pursue certain social ends. In the process, many of the interesting issues raised about the imperfections associated with the markets through which energy-efficiency decisions are made, the nature and causes of these imperfections, and the effectiveness of alternative public policies to ameliorate them have largely been ignored. The ability to use utilities in this way depends critically on the continuation of the institution of regulated monopoly electricity suppliers insulated from competition at the retail level. As competition spreads in the electric power sector, it is creating major conflicts between increasing competitive opportunities for customers vs continued reliance on utilities to pursue energy-efficiency programs that raise prices within the context of highly politicized IRP programs that embody a centralized planning philosophy. As competition intensifies, new ways will have to be found to achieve the energy-efficiency and environmental goals that motivate utility-subsidized energy-efficiency programs.

Joskow, P.L. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Economics

1995-11-01

21

Analysis of Spectrum Utilization in Suburb Environment Evaluation of Potentials for Cognitive Radio  

E-print Network

}@feec.vutbr.cz Abstract This paper deals with spectrum utilization measurements in the frequency band from 100 MHz up to 3 with an overall approach regarding spectrum utilization in the next generation wireless networks. 1. Introduction frequency spectrum from primary licensed networks and consequently solves the spectrum utilization problem

Paris-Sud XI, Université de

22

76 FR 18476 - Improving Communications Services for Native Nations by Promoting Greater Utilization of Spectrum...  

Federal Register 2010, 2011, 2012, 2013

...Nations by Promoting Greater Utilization of Spectrum Over Tribal Lands AGENCY: Federal Communications...objective of promoting greater use of spectrum over unserved and underserved Tribal...Telecommunications Bureau, Auctions and Spectrum Access Division: Stephen Johnson,...

2011-04-04

23

Reclaiming the White Spaces: Spectrum Efficient Coexistence with Primary Users  

E-print Network

Reclaiming the White Spaces: Spectrum Efficient Coexistence with Primary Users George Nychis, §Microsoft Research, Microsoft Research Asia, ABSTRACT TV white spaces offer an exciting opportunity for increasing spectrum availability, but white space devices (WSDs) cannot interfere with pri- mary users

Hunt, Galen

24

Reclaiming the White Spaces: Spectrum Efficient Coexistence with Primary Users  

E-print Network

Reclaiming the White Spaces: Spectrum Efficient Coexistence with Primary Users George Nychis, §Microsoft Research, Microsoft Research Asia ABSTRACT TV white spaces offer an exciting opportunity for increasing spectrum availability, but white space devices (WSDs) cannot interfere with pri- mary users

Treuille, Adrien

25

Energy Efficiency in Buildings- the Utilities View  

E-print Network

PAGE 1 Energy Efficiency in Buildings - the Utilities View U. K?nig RWE Energy AG The energy to lead ESL-IC-08-10-27 Proceedings of the Eighth International Conference for Enhanced Building Operations, Berlin, Germany, October 20-22, 2008 RWE... International Conference for Enhanced Building Operations, Berlin, Germany, October 20-22, 2008 RWE Energy / Energieeffizienz bei Immobilien / U. K?nig / ICEBO '08 SEITE 3 RWE ? One of the five leading Energy Companies in Europe > Nr 1 producer of electricity...

Konig, U.

26

47 CFR 90.535 - Modulation and spectrum usage efficiency requirements.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Modulation and spectrum usage efficiency requirements. 90...MHz Bands § 90.535 Modulation and spectrum usage efficiency requirements. ...least one voice path per 6.25 kHz of spectrum bandwidth. (2) Licensees...

2011-10-01

27

47 CFR 90.535 - Modulation and spectrum usage efficiency requirements.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Modulation and spectrum usage efficiency requirements. 90...MHz Bands § 90.535 Modulation and spectrum usage efficiency requirements. ...least one voice path per 6.25 kHz of spectrum bandwidth. (2) Licensees...

2010-10-01

28

Utilization of new attributes for evaluating a flower colour spectrum  

Microsoft Academic Search

Flower colour spectra were initially used in India to characterize the flora of urban localities (Nagrathna, 1968; Oommachan, 1973), but only on a presence-absence basis. In order to have a quantitative appraisal of the flower colour spectrum of the vegetation at a particular locality, the density of the species and the number of flowers on each plant should be taken

Rajani Varma; R. R. Das

1983-01-01

29

Dynamic Spectrum Allocation in Wireless Cognitive Sensor Networks: Improving Fairness and Energy Efficiency  

Microsoft Academic Search

This paper considers the centralized spectrum allo- cations in resource-constrained wireless sensor networks with the following goals: (1) allocate spectrum as fairly as possible, (2) util- ize spectrum resource maximally, (3) reflect the priority among sensor data, and (4) reduce spectrum handoff. The problem is formulated into a multi-objective problem, where we propose a new approach to solve it using

Sang-seon Byun; Ilangko Balasingham; Xuedong Liang

2008-01-01

30

Promoting Energy Efficiency in Industry: Utility Roles and Perspectives  

E-print Network

This paper identifies the factors that influence industrial firms' decisions to invest in energy efficiency and notes how the emerging wave of electric utility 'demand-side' planning and marketing can help industry control costs of production...

Limaye, D. R.; Davis, T. D.

1984-01-01

31

An Efficient Spectrum Sensing Scheme for Cognitive Radio  

E-print Network

co-exist with one another in the same spectrum space. This is achieved by CRs dynamically sensing the spectrum for `unused' or white bands, and `low energy use' or grey bands. In an environment where multiple spectrum holes. Two key issues are high complexity and power consumption of the sensing process, and large

Cheng, Samuel

32

The Utility of Genetically Modified Animals in Modeling OCD-Spectrum Disorders  

E-print Network

, hypochondriasis, self-harm disorders, tic disorders, body dysmorphic disorder, and eating disorders, in addition139 Chapter 7 The Utility of Genetically Modified Animals in Modeling OCD-Spectrum Disorders AmandaPorte, and Allan V. Kalueff Abstract Obsessive-compulsive disorder (OCD) inflicts uncontrollable, intrusive

Kalueff, Allan V.

33

Utility investments in low-income-energy-efficiency programs  

SciTech Connect

The objective of this study is to describe the energy-efficiency programs being operated by utilities for low-income customers. The study focuses, in particular, on programs that install major residential weatherization measures free-of-charge to low-income households. A survey was mailed to a targeted list of 600 utility program managers. Follow-up telephone calls were made to key non- respondents, and a random sample of other non-respondents also was contacted. Completed surveys were received from 180 utilities, 95 of which provided information on one or more of their 1992 low-income energy-efficiency programs for a total of 132 individual programs. These 132 utility programs spent a total of $140.6 million in 1992. This represents 27% of the total program resources available to weatherize the dwellings of low-income households in that year. Both the total funding and the number of programs has grown by 29% since 1989. A majority of the 132 programs are concentrated in a few regions of the country (California, the Pacific Northwest, the Upper Midwest, and the Northeast). Although a majority of the programs are funded by electric utilities, gas utilities have a significantly greater average expenditure per participant ($864 vs. $307 per participant). The most common primary goal of low-income energy-efficiency programs operating in 1992 was {open_quotes}to make energy services more affordable to low-income customers{close_quotes}. Only 44% of the programs were operated primarily to provide a cost-effective energy resource. Based on a review of household and measure selection criteria, equity and not the efficiency of resource acquisition appears to dominate the design of these programs.

Brown, M.A. [Oak Ridge National Lab., TN (United States); Beyer, M.A. [Aspen Systems Corp., Oak Ridge, TN (United States); Eisenberg, J.; Power, M. [Economic Opportunity Research Institute, Washington, DC (United States); Lapsa, E.J. [Manhattan Data Systems, Knoxville, TN (United States)

1994-09-01

34

Network efficiency in autism spectrum disorder and its relation to brain overgrowth  

PubMed Central

A substantial body of evidence links differences in brain size to differences in brain organization. We have hypothesized that the developmental aspect of this relation plays a role in autism spectrum disorder (ASD), a neurodevelopmental disorder which involves abnormalities in brain growth. Children with ASD have abnormally large brains by the second year of life, and for several years thereafter their brain size can be multiple standard deviations above the norm. The greater conduction delays and cellular costs presumably associated with the longer long-distance connections in these larger brains is thought to influence developmental processes, giving rise to an altered brain organization with less communication between spatially distant regions. This has been supported by computational models and by findings linking greater intra-cranial volume, an index of maximum brain-size during development, to reduced inter-hemispheric connectivity in individuals with ASD. In this paper, we further assess this hypothesis via a whole-brain analysis of network efficiency. We utilize diffusion tractography to estimate the strength and length of the connections between all pairs of cortical regions. We compute the efficiency of communication between each network node and all others, and within local neighborhoods; we then assess the relation of these measures to intra-cranial volume, and the differences in these measures between adults with autism and typical controls. Intra-cranial volume is shown to be inversely related to efficiency for wide-spread regions of cortex. Moreover, the spatial patterns of reductions in efficiency in autism bear a striking resemblance to the regional relationships between efficiency and intra-cranial volume, particularly for local efficiency. The results thus provide further support for the hypothesized link between brain overgrowth in children with autism and the efficiency of the organization of the brain in adults with autism. PMID:24368901

Lewis, John D.; Theilmann, Rebecca J.; Townsend, Jeanne; Evans, Alan C.

2013-01-01

35

Development of a gas leak detection method based on infrared spectrum imaging utilizing microbolometer camera  

NASA Astrophysics Data System (ADS)

Development of an early gas leak detection system is essential for safety of energy storage tank fields or chemical plants. Contact-type conventional gas sensors are not suitable for remote surveillance of gas leakage in wide area. Infrared camera has been utilized for gas leak detection, however it is limited only for detecting particular gas. In this study a gas leak identification system, which enables us to detect gas leakage and to identify gas type and density, is developed based on infrared spectrum imaging system utilizing low cost and compact microbolometer infrared camera. Feasibility of the proposed system was demonstrated by experimental results on identification of hydrofluorocarbon gas.

Sakagami, Takahide; Anzai, Hiroaki; Kubo, Shiro

2011-05-01

36

Robust Distributed Spectrum Sensing in Cognitive Radio Networks  

Microsoft Academic Search

Cognitive radio is an enabling technology for efficient utilization of radio spectrum. A key function of cognitive radios is spectrum sensing, which enables secondary users to identify vacant spectrum not used by primary users (a.k.a. spectrum \\

Ruiliang Chen; Jung-Min Park; Kaigui Bian

2008-01-01

37

Multiple access techniques and spectrum utilization of the Globalstar mobile satellite system  

NASA Astrophysics Data System (ADS)

The Globalstar LEO satellite system is described in terms of the commercial application of multiple-access and other technologies for cellular telephones. Attention is given to the simultaneous spectrum usage in several bands and the use of time-domain duplexing to achieve multiple access in both systems A and B. The efficiency of the code-division multiple-access (CDMA) technique employed is demonstrated in a discussion of the total system capacity for the 24-satellite constellation. CDMA is shown to allow frequency reuse of adjacent beams with marginal isolation, capacity increases by means of the voice-activity factor, and spectrum sharing among different operators. Also employed in the system are frequency- and time-division multiple-access technologies which enhance the efficiency of the modulation and multiple-access system.

Louie, Ming; Rouffet, Denis; Gilhousen, Klein S.

1992-03-01

38

Distributed energy efficient spectrum access in cognitive radio wireless ad hoc networks  

Microsoft Academic Search

In this paper, energy efficient spectrum access is considered for a wireless cognitive radio ad hoc network, where each node is equipped with cognitive radio, has limited energy, and the network is an OFDMA system operating on time slots. In each slot, the users with new traffic demand will sense the spectrum and locate the available subcarrier set. Given the

Song Gao; Lijun Qian; Dhadesugoor R. Vaman

2009-01-01

39

Animal production for efficient phosphate utilization: from optimized feed to high efficiency livestock.  

PubMed

Phosphorus (P) is an essential nutrient for livestock but its efficiency of utilization is below 40%, contributing to environmental issues. In this review, we summarize recent approaches to optimize P availability in livestock diets and improve its utilization efficiency. Phase feeding could potentially reduce P excretion by 20%. Addition of phytase enzymes to diets increased P availability from 42 to 95%. Low phytate transgenic plants and transgenic animals increased P availability by 14% and 52-99%, respectively. In practice, a combination of phase feeding and enzymes has the highest potential for P reduction but legislation and ethics implications will prevent using transgenic animals in the short term. Functional and nutritional genomics may provide tools to improve efficiency in the future. PMID:22796051

Kebreab, Ermias; Hansen, Anja V; Strathe, Anders B

2012-12-01

40

Fabrication Infrastructure to Enable Efficient Exploration and Utilization of Space  

NASA Technical Reports Server (NTRS)

Unlike past one-at-a-time mission approaches, system-of-systems infrastructures will be needed to enable ambitious scenarios for sustainable future space exploration and utilization. Fabrication infrastructure will be needed to support habitat structure development, tools and mechanical part fabrication, as well as repair and replacement of ground support and space mission hardware such as life support items, vehicle components and crew systems. The fabrication infrastructure will need the In Situ Fabrication and Repair (ISFR) element, which is working in conjunction with the In Situ Resources Utilization (ISRU) element, to live off the land. The ISFR Element supports the entire life cycle of Exploration by: reducing downtime due to failed components; decreasing risk to crew by recovering quickly from degraded operation of equipment; improving system functionality with advanced geometry capabilities; and enhancing mission safety by reducing assembly part counts of original designs where possible. This paper addresses the fabrication infrastructures that support efficient, affordable, reliable infrastructures for both space exploration systems and logistics; these infrastructures allow sustained, affordable and highly effective operations on the Moon, Mars and beyond.

Howell, Joe T.; Fikes, John C.; McLemore, Carole A.; Manning, Curtis W.; Good, Jim

2007-01-01

41

Efficiency of sunlight utilization: tubular versus flat photobioreactors  

PubMed

The light saturation effect imposes a serious limitation on the efficiency with which solar energy can be utilized in outdoor algal cultures. One solution proposed to reduce the intensity of incident solar radiation and overcome the light saturation effect is "spatial dilution of light" (i.e., distribution of the impinging photon flux on a greater photosynthetic surface area), but consistent experimental data supporting a significant positive influence of spatial light dilution on the productivity and the photosynthetic efficiency of outdoor algal cultures have never been reported. We used a coiled tubular reactor and compared a near-horizontal straight tubular reactor and a near-horizontal flat panel in outdoor cultivation of the cyanobacterium Arthrospira (Spirulina) platensis under defined operating conditions for optimum productivity. The photosynthetic efficiency achieved in the tubular systems was significantly higher because their curved surface "diluted" the impinging solar radiation and thus reduced the light saturation effect. This interpretation was supported by the results of experiments carried out in the laboratory under continuous artificial illumination using both a flat and a curved chamber reactor. The study also showed that, when the effect of light saturation is eliminated or reduced, productivity and solar irradiance are linearly correlated even at very high diurnal irradiance values, and supported findings that outdoor algal cultures are light-limited even during bright summer days. It was also observed that, besides improving the photosynthetic efficiency of the culture, spatial dilution of light also leads to higher growth rates and lowers the cellular content of accessory pigments; that is, it reduces mutual shading in the culture. The inadequacy of using volumetric productivity as the sole criterion for comparing reactors of different surface-to-volume ratio and of the areal productivity for evaluating the performance of elevated photobioreactors operated outdoors is stressed; it is furthermore suggested that the photosynthetic efficiency achieved by the culture also be calculated to provide a suitable parameter for comparison of different algal cultivation systems operated under similar climatic conditions. Copyright 1998 John Wiley & Sons, Inc. PMID:10099193

Tredici; Zittelli

1998-01-20

42

Design of high-resolution and multilevel reference pattern for improvement of both light utilization efficiency and signal-to-noise ratio in coaxial holographic data storage.  

PubMed

A high-resolution and multilevel designed reference pattern (DRP) is presented for improvement of both light utilization efficiency and the signal-to-noise ratio (SNR) of reconstructed images in coaxial holographic data storage. With a DRP, the desired Fourier power spectrum of a reference beam is obtained. Numerical and experimental results show that the DRP increases the SNR compared with that of a random phase mask (RPM). Moreover, the light utilization efficiency of the DRP is higher than that of a high-resolution RPM. In addition, the effect of the phase level and the pixel pitch of DRPs on the SNR and the light utilization efficiency are investigated. PMID:24921144

Nobukawa, Teruyoshi; Nomura, Takanori

2014-06-10

43

The efficient discrete Tchebichef transform for spectrum analysis of speech recognition  

NASA Astrophysics Data System (ADS)

Spectrum analysis is an elementary operation in speech recognition. Fast Fourier Transform (FFT) is a famous technique to analyze frequency spectrum of the signal in speech recognition. The Discrete Tchebichef Transform (DTT) is proposed as possible alternative to the FFT. DTT has lower computational complexity and it does not require complex transform with imaginary numbers. This paper proposes an approach based on 256 discrete orthonormal Tchebichef polynomials for efficient to analyze a vowel and a consonant in spectral frequency of speech recognition. The comparison between 1024 discrete Tchebichef transform and 256 discrete Tchebichef transform has been done. The preliminary experimental results show that 256 DTT has the potential to be efficient to transform time domain into frequency domain for speech recognition. 256 DTT produces simpler output than 1024 DTT in frequency spectrum. The used of 256 Discrete Tchebichef Transform can produce concurrently four formants F1, F2, F3 and F4 for the consonant.

Ernawan, Ferda; Abu, Nur A.; Suryana, Nanna

2013-03-01

44

An efficient multi-resolution spectrum sensing method for cognitive radio  

Microsoft Academic Search

This paper presents a novel energy based multi-resolution spectrum sensing technique. By applying an efficient flexible FFT, the proposed method can focus on a small part of the interested bands with finer resolutions at low computational cost. The hardware implementation of the algorithm has been considered. An experiment on a reconfigurable platform shows that the algorithm is not only computationally

Qiwei Zhang; Andre B. J. Kokkeler; Gerard J. M. Smit

2008-01-01

45

Increasing Instructional Efficiency by Presenting Additional Stimuli in Learning Trials for Children with Autism Spectrum Disorders  

ERIC Educational Resources Information Center

The current study examined the effectiveness and efficiency of presenting secondary targets within learning trials for 4 children with an autism spectrum disorder. Specifically, we compared 4 instructional conditions using a progressive prompt delay. In 3 conditions, we presented secondary targets in the antecedent or consequence portion of…

Vladescu, Jason C.; Kodak, Tiffany M.

2013-01-01

46

Efficiency of Lexical Access in Children with Autism Spectrum Disorders: Does Modality Matter?  

ERIC Educational Resources Information Center

The provision of visual support to individuals with an autism spectrum disorder (ASD) is widely recommended. We explored one mechanism underlying the use of visual supports: efficiency of language processing. Two groups of children, one with and one without an ASD, participated. The groups had comparable oral and written language skills and…

Harper-Hill, Keely; Copland, David; Arnott, Wendy

2014-01-01

47

Protein requirements and ageing: metabolic demand and efficiency of utilization.  

PubMed

The protein requirements of the elderly were investigated with [13C]leucine balance studies of metabolic demand, the efficiency of postprandial protein utilization (PPU) and the consequent apparent protein requirement. Ten elderly subjects aged 68-91 years (five men and five women) and ten young adult subjects aged 21-31 years (five men and five women) were infused with L-[1-13C]leucine for 9 h commencing in the postabsorptive state (0-3 h), continuing during the half-hourly feeding of low-protein meals (LP; protein 3% energy, 3-6 h), and during similar feeding of isoenergetic higher protein meals (HP; protein 15% energy, 6-9 h). Leucine oxidation and balance were determined from plasma [1-13C]-alpha-ketoisocaproate enrichment and expired 13CO2 excretion measured during the 3rd hour of each 3 h period. The protein intake during the HP phase was similar to the habitual intake estimated in the subjects from 24 h urinary N excretion. Metabolic demand was defined as equal to twice the body-protein equivalent of measured postabsorptive leucine oxidation. The efficiency of PPU was calculated from the increased leucine oxidation observed during feeding, and the apparent protein requirement was defined as metabolic demand/PPU and calculated in relation to both body weight (BW) and fat-free mass (FFM) determined by densitometry or bioimpedance. Metabolic demand in the young adults was 0.83 g protein/kg per d; in both elderly groups it was 36% lower when expressed per kg BW and 30% lower when expressed per kg FFM. The apparent protein requirement calculated from metabolic demand and PPU was 0.99 g protein/kg per d in the young adults and this was also lower in the elderly, although this was only significant in the men (0.66 g per kg BW, P = 0.013; 0.79 g per kg FFM, P = 0.02). The results show that in this group of healthy elderly adults protein requirements as assessed from leucine balance studies were either similar to or less than those of younger adults. PMID:9175990

Fereday, A; Gibson, N R; Cox, M; Pacy, P J; Millward, D J

1997-05-01

48

Static efficiency decompositions and capacity utilization: integrating economic and technical capacity notions  

Microsoft Academic Search

Starting from existing static decompositions of overall economic efficiency on nonparametric production and cost frontiers, this article proposes more comprehensive decompositions including several cost-based notions of capacity utilization. Furthermore, in case prices are lacking, we develop additional decompositions of overall technical efficiency integrating a technical concept of capacity utilization. These new efficiency decompositions provide a link between short and long

Bruno De Borger; Kristiaan Kerstens; Diego Prior; Ignace Van de Woestyne

2011-01-01

49

Efficiency of energy utilization of the House Sparrow, Passer domesticus  

Microsoft Academic Search

Multiple regression analyses were made of the effect of food composition upon energetic efficiency and existence energy of House Sparrows, Passer domesticus. Protein content of experimental food is the most important of eleven independent variables tested in the prediction of energetic efficiency. Other variables significantly affecting energetic efficiency are fat content of food, ambient temperature, caloric content per gram of

Charles R. Blem

1976-01-01

50

USpan: An Efficient Algorithm for Mining High Utility Sequential Patterns  

E-print Network

Sequential pattern mining plays an important role in many applications, such as bioinformatics and consumer utility (frequent or infrequent) patterns are mined which ad- dress typical business concerns concatenation mechanisms for calculating the utility of a node and its children with two ef- fective pruning

Cao, Longbing

51

Acoustic Feature Selection Utilizing Multiple Kernel Learning for Classification of Children with Autism Spectrum and Typically  

E-print Network

, elderly people or people with disabilities [1], [2], and research related to autistic spectrum disorders (ASD) has also been focused on. An autistic spectrum obstacle is a congenital cerebral dysfunction, and linguistic functions [3], [4], [5]. Children with autistic spectrum are diagnosed as having less than normal

Takiguchi, Tetsuya

52

Family-Focused Autism Spectrum Disorder Research: A Review of the Utility of Family Systems Approaches  

ERIC Educational Resources Information Center

A family member with an autism spectrum disorder presents pervasive and bidirectional influences on the entire family system, suggesting a need for family-focused autism spectrum disorder research. While there has been increasing interest in this research area, family-focused autism spectrum disorder research can still be considered relatively…

Cridland, Elizabeth K.; Jones, Sandra C.; Magee, Christopher A.; Caputi, Peter

2014-01-01

53

Utilization and Expenditure of Hospital Admission in Patients with Autism Spectrum Disorder: National Health Insurance Claims Database Analysis  

ERIC Educational Resources Information Center

There were not many studies to provide information on health access and health utilization of people with autism spectrum disorders (ASD). The present study describes a general profile of hospital admission and the medical cost among people with ASD, and to analyze the determinants of medical cost. A retrospective study was employed to analyze…

Lin, Jin-Ding; Hung, Wen-Jiu; Lin, Lan-Ping; Lai, Chia-Im

2011-01-01

54

Utilization and expenditure of hospital admission in patients with autism spectrum disorder: National Health Insurance claims database analysis  

Microsoft Academic Search

There were not many studies to provide information on health access and health utilization of people with autism spectrum disorders (ASD). The present study describes a general profile of hospital admission and the medical cost among people with ASD, and to analyze the determinants of medical cost. A retrospective study was employed to analyze medical fee of 397 individuals with

Jin-Ding Lin; Wen-Jiu Hung; Lan-Ping Lin; Chia-Im Lai

2011-01-01

55

Assessment of Global Functioning in Adolescents with Autism Spectrum Disorders: Utility of the Developmental Disability-Child Global Assessment Scale  

ERIC Educational Resources Information Center

Assessment of global functioning is an important consideration in treatment outcome research; yet, there is little guidance on its evidence-based assessment for children with autism spectrum disorders. This study investigated the utility and validity of clinician-rated global functioning using the Developmental Disability-Child Global Assessment…

White, Susan W.; Smith, Laura A.; Schry, Amie R.

2014-01-01

56

An Efficient Moving Target Detection Algorithm Based on Sparsity-Aware Spectrum Estimation  

PubMed Central

In this paper, an efficient direct data domain space-time adaptive processing (STAP) algorithm for moving targets detection is proposed, which is achieved based on the distinct spectrum features of clutter and target signals in the angle-Doppler domain. To reduce the computational complexity, the high-resolution angle-Doppler spectrum is obtained by finding the sparsest coefficients in the angle domain using the reduced-dimension data within each Doppler bin. Moreover, we will then present a knowledge-aided block-size detection algorithm that can discriminate between the moving targets and the clutter based on the extracted spectrum features. The feasibility and effectiveness of the proposed method are validated through both numerical simulations and raw data processing results. PMID:25222035

Shen, Mingwei; Wang, Jie; Wu, Di; Zhu, Daiyin

2014-01-01

57

An efficient moving target detection algorithm based on sparsity-aware spectrum estimation.  

PubMed

In this paper, an efficient direct data domain space-time adaptive processing (STAP) algorithm for moving targets detection is proposed, which is achieved based on the distinct spectrum features of clutter and target signals in the angle-Doppler domain. To reduce the computational complexity, the high-resolution angle-Doppler spectrum is obtained by finding the sparsest coefficients in the angle domain using the reduced-dimension data within each Doppler bin. Moreover, we will then present a knowledge-aided block-size detection algorithm that can discriminate between the moving targets and the clutter based on the extracted spectrum features. The feasibility and effectiveness of the proposed method are validated through both numerical simulations and raw data processing results. PMID:25222035

Shen, Mingwei; Wang, Jie; Wu, Di; Zhu, Daiyin

2014-01-01

58

Encouraging the Construction of Energy Efficient Homes - A Utility Perspective  

E-print Network

Historically an industry with a supply side orientation, electric utilities are becoming increasingly involved with the end usage, or demand side, of their product as a means of effectively managing their systems....

Kimmons, G. H.

1985-01-01

59

Efficient green polymer light-emitting diodes with microcavity effect in electroluminescence spectrum but constant quantum efficiency  

NASA Astrophysics Data System (ADS)

We report the efficient green polymer light-emitting diodes (LEDS) that exhibit a strong microcavity effect in the electroluminescence (EL) spectrum. The LEDs employ a double-layer structure, with poly-(3,4-ethylenedioxythiophene): polystyrene sulfonic acid as the hole-transporting layer and with a highly efficient polyfluorene-based green-emitting polymer as the electron-transporting and emitting layer. The EL spectra of the LEDs demonstrate a strong resonance effect with the thickness of the emitting layer varying from 30 to 280nm. The turn-on voltage of the device increases with the increasing thickness of the emitting layer. However, the brightness and especially the external quantum efficiency of the devices are largely independent of the thickness from 100 to 280nm, when the emitting layer is thick enough to avoid cathode quenching of the electroluminescence.

Jiang, Xuezhong; Herguth, Petra; Sassa, Takafumi; Jen, Alex K.-Y.

2004-09-01

60

Efficient Energy Utilization in the Industrial Sector - Case Studies  

E-print Network

The need for more efficient use of the world's energy resources has become one of the major concerns of technology today. Over the past 50 years, during which our population has doubled, our requirements for energy has quadrupled. Recent figures...

Davis, S. R.

1984-01-01

61

Optimization of gas utilization efficiency for short-pulsed electron cyclotron resonance ion sourcea)  

NASA Astrophysics Data System (ADS)

Numerical analysis of 6He atoms utilizing efficiency in the ion source with powerful gyrotron heating is performed in present work using zero-dimensional balanced model of ECR discharge in a magnetic trap. Two ways of creation of ion source with high gas utilization efficiency (up to 60%-90%) are suggested.

Izotov, I. V.; Skalyga, V. A.; Zorin, V. G.

2012-02-01

62

Molecular Control of Sucrose Utilization in Escherichia coli W, an Efficient Sucrose-Utilizing Strain  

PubMed Central

Sucrose is an industrially important carbon source for microbial fermentation. Sucrose utilization in Escherichia coli, however, is poorly understood, and most industrial strains cannot utilize sucrose. The roles of the chromosomally encoded sucrose catabolism (csc) genes in E. coli W were examined by knockout and overexpression experiments. At low sucrose concentrations, the csc genes are repressed and cells cannot grow. Removal of either the repressor protein (cscR) or the fructokinase (cscK) gene facilitated derepression. Furthermore, combinatorial knockout of cscR and cscK conferred an improved growth rate on low sucrose. The invertase (cscA) and sucrose transporter (cscB) genes are essential for sucrose catabolism in E. coli W, demonstrating that no other genes can provide sucrose transport or inversion activities. However, cscK is not essential for sucrose utilization. Fructose is excreted into the medium by the cscK-knockout strain in the presence of high sucrose, whereas at low sucrose (when carbon availability is limiting), fructose is utilized by the cell. Overexpression of cscA, cscAK, or cscAB could complement the W?cscRKAB knockout mutant or confer growth on a K-12 strain which could not naturally utilize sucrose. However, phenotypic stability and relatively good growth rates were observed in the K-12 strain only when overexpressing cscAB, and full growth rate complementation in W?cscRKAB also required cscAB. Our understanding of sucrose utilization can be used to improve E. coli W and engineer sucrose utilization in strains which do not naturally utilize sucrose, allowing substitution of sucrose for other, less desirable carbon sources in industrial fermentations. PMID:23124236

Sabri, Suriana; Nielsen, Lars K.

2013-01-01

63

Self-optimality and efficiency in utility distortion games  

Microsoft Academic Search

In social choice problems where players may strategically misrepresent their preferences, we call a profile of preferences self-optimal if reporting them is a Nash equilibrium given that they are the true preferences. Self-optimality can be interpreted as a very weak honesty requirement. We apply the self-optimality concept to a utility distortion game in the context of bargaining and obtain a

Hans Peters

1992-01-01

64

Spread spectrum goes commercial  

Microsoft Academic Search

The use of spread-spectrum techniques to achieve more efficient utilization of available frequency spectra is examined. The two main spread-spectrum techniques, direct sequence and frequency hopping, are explained. In frequency hopping, the transmitter repeatedly changes (hops) the carrier frequency from one frequency to another. Direct-sequence transmission spreads the spectrum not by periodically changing the frequency but by modulating the original

D. L. Schilling; R. L. Pickholtz; L. B. Milstein

1990-01-01

65

Air Conditioner Efficiency Under Hot Dry and Hot Humid Conditions - The Utility Perspective  

E-print Network

Air Conditioner Efficiency under Hot Dry and Hot Humid Conditions - The Utility Perspective Ammi Amarnath Technical Leader, Energy Efficiency & Demand Response Program Electric Power Research Institute 3420 Hillview Avenue Palo Alto, CA... 94304 E-mail: aamarnath@epri.com Phone: (650) 855-1007 Energy efficient residential air conditioning is important to utilities and their customers. In almost all parts of the U.S., an air conditioner for a dwelling has a high peak demand...

Amarnath, A.

66

Utilizing Carbon Nanotubes to Improve Efficiency of Organic Solar Cells  

Microsoft Academic Search

The weight, cost, and flexibility of organic photovoltaics have become increasingly applicable for use in bringing power to even the most remote locations. In order for these cells to be successful their efficiency, currently around 1-3% (compared to 20-30% for the traditional cells), needs to be on par with that produced by the traditional cells. Our research team worked in

Richard Elkins; Nathan Fierro; Erin Flanagan; Adam Haughton; Michael Kasser; Matthew Stair

67

Marginal-utility-cost concept helps maximize plant efficiency  

Microsoft Academic Search

Operation conditions often subject industrial powerplants to off-design cyclic and permanent changes, making continual high-efficiency operation a challenge to even the most experienced engineer-especially when he considers the complex interconnections among boiler, turbines and headers at different pressures. In such cases, application of the marginal-cost concept can help in maintaining optimum performance level. It is also useful in evaluating retrofit

S. M. Ranade; W. Robert

1987-01-01

68

HC-MAC: A Hardware-Constrained Cognitive MAC for Efficient Spectrum Management  

Microsoft Academic Search

Radio spectrum resource is of fundamental impor- tance for wireless communication. Recent reports show that most available spectrum has been allocated. While some of the spectrum bands (e.g., unlicensed band, GSM band) have seen increasingly crowded usage, most of the other spectrum resources are underutilized. This drives the emergence of open spectrum and dynamic spectrum access concepts, which allow unlicensed

Juncheng Jia; Qian Zhang; Xuemin Shen

2008-01-01

69

Determination of TFTR far-field neutron detector efficiencies by local neutron flux spectrum measurement  

NASA Astrophysics Data System (ADS)

Neutron detectors have often been located on the tokamak fusion test reactor (TFTR) test cell floor 3 m or more from the vacuum vessel for ease of detector access, to reduce radiation damage, minimize count saturation problems, and to avoid high magnetic fields. These detectors include Si surface-barrier diodes, fission chambers, natural diamond detectors, and T2 production in a moderated 3He cell. To evaluate the performance of these detectors during deuterium-tritium (D-T) operation, we determined the neutron flux spectrum incident on the principal detector enclosure using nuclide sample sets containing Al, Ti, Fe, Co, Cu, Zn, Ni, Zr, Nb, In, and Au activation foils. Foils were installed and then removed after ample exposure to TFTR D-T neutrons. High efficiency, high purity Ge detectors were used for gamma spectroscopy of the irradiated foils. The incident neutron fluence and spectral distribution were unfolded from the measured results, and used to derive absolute detector efficiencies.

Jassby, D. L.; Ascione, G.; Kugel, H. W.; Roquemore, A. L.; Barcelo, T. W.; Kumar, A.

1997-01-01

70

High Efficiency Resonant DC/DC Converter Utilizing a Resistance Compression Network  

E-print Network

This paper presents a new topology for a high-efficiency dc/dc resonant power converter that utilizes a resistance compression network (RCN) to provide simultaneous zero-voltage switching and near-zero-current switching ...

Inam, Wardah

71

High efficiency resonant dc/dc converter utilizing a resistance compression network  

E-print Network

This paper presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across ...

Inam, Wardah

72

Implications of the Public Utility Regulatory Act for Energy Efficiency in Texas  

E-print Network

to prepare energy efficiency plans. In their plans, utilities must consider the potential for economically producing capacity through supply? side and demand-side alternatives to new power plant construction. These alter? natives are identified... in the definition of energy efficiency included in the Rules. Supply-side alternatives are: optimizing existing and planned generation, transmission, and distribution facilities; purchasing power from cogenerators and small power producers; utilizing direct...

Biedrzycki, C. J.

73

UTILITY OF A WIDE SPECTRUM LIGHT METER AS AN UNDERWATER SENSOR OF PHOTOSYNTHETICALLY ACTIVE RADIATION (PAR)  

EPA Science Inventory

The strong attenuation of infra red wavelengths (>700 nm) in coastal waters is suggestive that some instruments with broad spectral responses might be useful, inexpensive substitutes for PAR sensors in studies of estuarine plant dynamics. Wide spectrum (350-1100 nm) light intensi...

74

Interactions between Energy Efficiency Programs funded under the Recovery Act and Utility Customer-Funded Energy Efficiency Programs  

SciTech Connect

Since the spring of 2009, billions of federal dollars have been allocated to state and local governments as grants for energy efficiency and renewable energy projects and programs. The scale of this American Reinvestment and Recovery Act (ARRA) funding, focused on 'shovel-ready' projects to create and retain jobs, is unprecedented. Thousands of newly funded players - cities, counties, states, and tribes - and thousands of programs and projects are entering the existing landscape of energy efficiency programs for the first time or expanding their reach. The nation's experience base with energy efficiency is growing enormously, fed by federal dollars and driven by broader objectives than saving energy alone. State and local officials made countless choices in developing portfolios of ARRA-funded energy efficiency programs and deciding how their programs would relate to existing efficiency programs funded by utility customers. Those choices are worth examining as bellwethers of a future world where there may be multiple program administrators and funding sources in many states. What are the opportunities and challenges of this new environment? What short- and long-term impacts will this large, infusion of funds have on utility customer-funded programs; for example, on infrastructure for delivering energy efficiency services or on customer willingness to invest in energy efficiency? To what extent has the attribution of energy savings been a critical issue, especially where administrators of utility customer-funded energy efficiency programs have performance or shareholder incentives? Do the new ARRA-funded energy efficiency programs provide insights on roles or activities that are particularly well-suited to state and local program administrators vs. administrators or implementers of utility customer-funded programs? The answers could have important implications for the future of U.S. energy efficiency. This report focuses on a selected set of ARRA-funded energy efficiency programs administered by state energy offices: the State Energy Program (SEP) formula grants, the portion of Energy Efficiency and Conservation Block Grant (EECBG) formula funds administered directly by states, and the State Energy Efficient Appliance Rebate Program (SEEARP). Since these ARRA programs devote significant monies to energy efficiency and serve similar markets as utility customer-funded programs, there are frequent interactions between programs. We exclude the DOE low-income weatherization program and EECBG funding awarded directly to the over 2,200 cities, counties and tribes from our study to keep its scope manageable. We summarize the energy efficiency program design and funding choices made by the 50 state energy offices, 5 territories and the District of Columbia. We then focus on the specific choices made in 12 case study states. These states were selected based on the level of utility customer program funding, diversity of program administrator models, and geographic diversity. Based on interviews with more than 80 energy efficiency actors in those 12 states, we draw observations about states strategies for use of Recovery Act funds. We examine interactions between ARRA programs and utility customer-funded energy efficiency programs in terms of program planning, program design and implementation, policy issues, and potential long-term impacts. We consider how the existing regulatory policy framework and energy efficiency programs in these 12 states may have impacted development of these selected ARRA programs. Finally, we summarize key trends and highlight issues that evaluators of these ARRA programs may want to examine in more depth in their process and impact evaluations.

Goldman, Charles A.; Stuart, Elizabeth; Hoffman, Ian; Fuller, Merrian C.; Billingsley, Megan A.

2011-02-25

75

Using utility DSM programs to spur the development of more efficient appliances  

SciTech Connect

This paper describes utility programs that are designed to encourage manufacturers to develop and commercialize highly efficient refrigerators and clothes washers. Opportunities for improving the efficiency of other types of appliances are also discussed. Presented at the International Appliance Technical Conference.

Nadel, S.

1993-12-31

76

High-pressure sodium: economical and energy efficient lighting for utilities  

Microsoft Academic Search

Opportunities exist in indoor and outdoor lighting at electric utilities to reduce energy and maintenance costs by replacing older and\\/or less efficient systems. It is suggested that the Lucalox system should be considered when planning new construction. The high-pressure sodium lamp is the most efficient white light source available for general lighting. Savings in energy costs are significant enough to

1979-01-01

77

Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths  

E-print Network

A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 - 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of Tetraphenyl Butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and reemits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

V. M. Gehman; S. R. Seibert; K. Rielage; A. Hime; Y. Sun; D. -M. Mei; J. Maassen; D. Moore

2011-04-16

78

Promoting high efficiency residential HVAC equipment: Lessons learned from leading utility programs  

SciTech Connect

The Consortium for Energy Efficiency recently sponsored a study of leading electric utility efforts to promote high efficiency residential HVAC equipment. Given growing concerns from some utilities about the level of expenditures associated with rebate programs, special emphasis was placed on assessing the success of financing and other non-rebate options for promoting efficiency. Emphasis was also placed on review of efforts--rebate or otherwise--to push the market to very high levels of efficiency (i.e., SEER 13). This paper presents the results of the study. It includes discussion of key lessons from the utility programs analyzed. It also examines program participation rates and other potential indicators of market impacts. One notable conclusion is that several utility programs have pushed market shares for SEER 12 equipment to about 50% (the national average is less than 20%). At least one utility program has achieved a 50% market share for SEER 13 equipment (the national average is less than 3%). In general, financing does not appear to have as broad an appeal as consumer rebates. However, one unique utility program which combines the other of customer financing with modest incentives to contractors--in the form of frequent seller points that can be redeemed for advertising, technician training, travel and other merchandise--offers some promise that high participation rates can be achieved without customer rebates.

Neme, C.; Peters, J.; Rouleau, D.

1998-07-01

79

A Comparison of Health Care Utilization and Costs of Children with and without Autism Spectrum Disorders in a Large Group-Model Health Plan  

ERIC Educational Resources Information Center

Objective: Data on the current costs of medical services for children with autism spectrum disorders are lacking. Our purpose for this study was to compare health care utilization and costs of children with and without autism spectrum disorders in the same health plan. Patients and Methods: Participants included all 2- to 18-year-old children with…

Croen, Lisa A.; Najjar, Daniel V.; Ray, G. Thomas; Lotspeich, Linda; Bernal, Pilar

2007-01-01

80

Identifying Cost-Effective Residential Energy Efficiency Opportunities for the Kauai Island Utility Cooperative  

SciTech Connect

This analysis is an update to the 2005 Energy Efficiency Potential Study completed by KEMA for the Kauai Island Utility Cooperative (KIUC) and identifies potential energy efficiency opportunities in the residential sector on Kauai (KEMA 2005). The Total Resource Cost (TRC) test is used to determine which of the energy efficiency measures analyzed in the KEMA report are cost effective for KIUC to include in a residential energy efficiency program. This report finds that there remains potential energy efficiency savings that could be cost-effectively incentivized through a utility residential demand-side management program on Kauai if implemented in such a way that the program costs per measure are consistent with the current residential program costs.

Busche, S.; Hockett, S.

2010-06-01

81

Treatment of Organic-Contaminated Mixed Waste Utilizing the Oak Ridge Broad Spectrum Contracts  

SciTech Connect

To meet the requirements of the State of Tennessee's Department of Environment and Conservation Commissioner's Order for treatment of mixed low level wastes, Oak Ridge has utilized commercial treatment companies to treat and dispose mixed waste. Over the past year, Oak Ridge has shipped organic-contaminated mixed waste for treatment to meet milestones under the Site Treatment Plan. Oak Ridge has established contracts with commercial treatment companies accessible by all DOE sites for treatment of a wide range of mixed wastes. The paper will describe and summarize the activities involved in treating and disposing of organic-contaminated mixed waste utilizing DOE complex-wide contracts and the treatment and disposal activities required. This paper will describe the case history of treatment of several organic-contaminated mixed wastes from the Oak Ridge Reservation requiring treatment prior to disposal. The paper will include waste category information, implementation activities, and contract access. The paper will discuss the specifics of the mixed waste treatment including waste characteristics, treatment process and equipment utilized, and treatment results. Additional information will be provided on task order development, waste profiling, treatment pricing, and the disposal process.

Estes, C. H.; Heacker, F. K.; Cunningham, J.; Westich, B.

2003-02-25

82

Determination of desorption efficiency utilizing direct injection: a dynamic calibration system and phase equilibrium  

E-print Network

DETERMINATION OF DESORPTION EFFICIENCY UTILIZING DIRECT INJECTION, A DYNAMIC CALIBRATION SYSTEM AND PHASE EQUILIBRIUM A Thesis by RONALD H. WILLIAMS Submitted to the Graduate College of Texas AFM University in par'tial fulfi' lment of the r... equi. ement for' the degree of MASTER OF SCIENCE August 1979 Major Subject: Industrial Hygiene DETERMINATION OF DESORPTION FFFICIENCY UTILIZING DIRECT INJECTION, A DYNAMIC CALIBRATION SYSTEM AND PHASE EOUILIBRIUM A Thesis by RONALD H. WILLIAMS...

Williams, Ronald H

2012-06-07

83

Economic Efficiency of Residential Water Conservation Programs in a Pennsylvania Public Water Utility  

Microsoft Academic Search

This study examines the economic efficiency of implementing a residential water conservation program in a small Pennsylvania public water utility. Local demographic data and results from similar programs elsewhere were used to estimate potential water conservation for three programs: rebates for low-flow toilets, rebates for high-efficiency washing machines, and in-home water audits. Future water supply and wastewater treatment demand were

Christopher Woltemade; Kurt Fuellhart

2012-01-01

84

Opportunistic Spectrum Sharing in Cognitive MIMO Wireless Networks  

Microsoft Academic Search

Cognitive radio has been recently proposed as a promising technology to improve the spectrum utilization. In this paper, we consider the spectrum sharing between a large number of cognitive radio users and a licensed user in order to enhance the spectrum efficiency. With the deployment of M antennas at the cognitive base station, an opportunistic spectrum sharing approach is proposed

Karama Hamdi; Wei Zhang; Khaled Ben Letaief

2009-01-01

85

Price-Based Spectrum Management in Cognitive Radio Networks  

Microsoft Academic Search

Cognitive radios (CRs) have a great potential to improve spectrum utilization by enabling users to access the spectrum dynamically without disturbing licensed primary radios (PRs). A key challenge in operating these radios as a network is how to implement an efficient medium access control (MAC) mechanism that can adaptively and efficiently allocate transmission powers and spectrum among CRs according to

Fan Wang; Marwan Krunz; Shuguang Cui

2008-01-01

86

Energy and exergy efficiencies in agricultural and utility sectors of Iran compared with other countries  

Microsoft Academic Search

Energy consumption and carbon emissions in Iran have risen rapidly in recent years which is not acceptable regarding environmental regulations. Government officials have been trying to resolve this problem, but so far there has been less success. Exergy analysis method is a powerful tool, which has been successfully used for estimating energy utilization efficiencies of countries. In this study, energy

A. Avara; M. Karami

2010-01-01

87

Using Milk Urea Nitrogen to Predict Nitrogen Excretion and Utilization Efficiency in Lactating Dairy Cows1  

Microsoft Academic Search

Because animal agriculture has been identified as a major source of nonpoint N pollution, ways to reduce the excretion of N by production animals must be examined. The objective of this research was to develop and evaluate a mathematical model that inte- grates milk urea N to predict excretion, intake, and utilization efficiency of N in lactating dairy cows. Three

J. S. Jonker; R. A. Kohn; R. A. Erdman

1998-01-01

88

A bright idea for industry. [demand side management: utilization of energy-efficiency technology  

Microsoft Academic Search

Tucked in the middle of the National Energy Policy Act is a little-noticed program with a big mission: to tap the huge pool of energy-efficiency potential in the industrial sector, and in the process spur industrial competitiveness. The new legislation focuses on one particularly promising strategy: forging a partnership between utilities and their industrial customers. This partnership expands on the

C. Bartsch; D. DeVaul

1993-01-01

89

A Hardware Evaluation of Cache Partitioning to Improve Utilization and Energy-Efficiency  

E-print Network

electricity consumption and operational costs and can significantly impact the capital costs of the infrastrucA Hardware Evaluation of Cache Partitioning to Improve Utilization and Energy-Efficiency while, but this incurs additional energy, power, and capital costs. In this paper, we evaluate the poten- tial

California at Berkeley, University of

90

An Approach to Integrated Spectrum Efficient Network Enhanced Telemetry (iSENET))  

NASA Technical Reports Server (NTRS)

As the integrated Network Enhanced Telemetry (iNET) program moves forward in resolving systems engineering design and architecture definition, critical technology "gaps" and a migration path to realizing the integration of this technology are needed to insure a smooth transition from the current legacy point to point telemetry links to a network oriented telemetry system. Specifically, identified by the DoD aeronautical telemetry community is the need for a migration to a network solution for command, control, and transfer of test data by optimizing the physical, data link, and network layers. In this paper, we present a network-centric telemetry approach based on variants of 802.11 that leverages the open standards as well as the previous Advanced Range Telemetry (ARTM) work on the physical layer waveform. Specifically, we present a burst modem approach based on the recent AOFDM 802.11a work, a TDMA-like MAC layer approach based on 802.11e, and then add additional MAC layer features to allow for the multi-hop aeronautical environment using a variant of the current working standards of 802.11s. The combined benefits of the variants obtained from 802.11a, 802.11e, and 802.11s address the needs for both spectrum efficiency in the aeronautical environment and the iNET program.

Okino, Clayton; Gao, Jay; Clare, Loren; Darden, Scott; Walsh, William; Loh, Kok-kiong

2006-01-01

91

Efficient Single-Mode Photon-Coupling Device Utilizing a Nanofiber Tip  

PubMed Central

Single-photon sources are important elements in quantum optics and quantum information science. It is crucial that such sources be able to couple photons emitted from a single quantum emitter to a single propagating mode, preferably to the guided mode of a single-mode optical fiber, with high efficiency. Various photonic devices have been successfully demonstrated to efficiently couple photons from an emitter to a single mode of a cavity or a waveguide. However, efficient coupling of these devices to optical fibers is sometimes challenging. Here we show that up to 38% of photons from an emitter can be directly coupled to a single-mode optical fiber by utilizing the flat tip of a silica nanofiber. With the aid of a metallic mirror, the efficiency can be increased to 76%. The use of a silicon waveguide further increases the efficiency to 87%. This simple device can be applied to various quantum emitters. PMID:24759303

Chonan, Sho; Kato, Shinya; Aoki, Takao

2014-01-01

92

Efficient Single-Mode Photon-Coupling Device Utilizing a Nanofiber Tip  

NASA Astrophysics Data System (ADS)

Single-photon sources are important elements in quantum optics and quantum information science. It is crucial that such sources be able to couple photons emitted from a single quantum emitter to a single propagating mode, preferably to the guided mode of a single-mode optical fiber, with high efficiency. Various photonic devices have been successfully demonstrated to efficiently couple photons from an emitter to a single mode of a cavity or a waveguide. However, efficient coupling of these devices to optical fibers is sometimes challenging. Here we show that up to 38% of photons from an emitter can be directly coupled to a single-mode optical fiber by utilizing the flat tip of a silica nanofiber. With the aid of a metallic mirror, the efficiency can be increased to 76%. The use of a silicon waveguide further increases the efficiency to 87%. This simple device can be applied to various quantum emitters.

Chonan, Sho; Kato, Shinya; Aoki, Takao

2014-04-01

93

Efficient Discovery of Spectrum Opportunities with MAC-Layer Sensing in Cognitive Radio Networks  

Microsoft Academic Search

Sensing\\/monitoring of spectrum-availability has been identified as a key requirement for dynamic spectrum allocation in cognitive radio networks (CRNs). An important issue associated with MAC-layer sensing in CRNs is how often to sense the availability of licensed channels and in which order to sense those channels. To resolve this issue, we address (1) how to maximize the discovery of spectrum

Hyoil Kim; Kang G. Shin

2008-01-01

94

A scoping study on energy-efficiency market transformation by California Utility DSM Programs  

SciTech Connect

Market transformation has emerged as a central policy objective for future publicly-funded energy-efficiency programs in California. California Public Utilities Commission (CPUC) Decision 95-12-063 calls for public funding to shift to activities designed to transform the energy-efficiency market. The CPUC envisions that funding {open_quotes}would only be needed for specific and limited periods of time to cause the market to be transformed{close_quotes}. At the same time, the CPUC also acknowledges that {open_quotes}there are many definitions of market transformation{close_quotes} ... and does {open_quotes}not attempt to refine those definitions today{close_quotes}. We argue that a definition of market transformation is essential. The literature is now replete with definitions, and an operational definition is needed for the CPUC to decide on which programs should be supported with public funds. The CPUC decision initially indicated a preference for programs that do not provide financial assistance 4-efficiency programs that rely on financial assistance to customers. However, energy customers have traditionally accounted for a substantial portion of California utility`s DSM programs, so the CPUC`s direction to use ratepayer funds to support programs that will transform the market raises critical questions about how to analyze what has happened in order to plan effectively for the future: Which utility energy-efficiency programs, including those that provide financial assistance to customers, have had market transforming effects? To what extent do current regulatory rules and practices encourage or discourage utilities from running programs that are designed to transform the market? Should the rules and programs be modified, and, if so, how, to promote market transformation?

Eto, J.; Prahl, R.; Schlegel, J.

1996-07-01

95

DSM in the broader economy: The economic impacts of utility efficiency programs  

SciTech Connect

The good news is that increased energy efficiency provides benefits to the environment. The better news is that the more efficient use of electricity may also benefit the economy. It`s a classic win-win proposition. Must America choose between a strong economy and a clean environment? Advocates of demand side management (DSM) have argued that programs which provide motion, heat, and light to electric utility customers with fewer kilowatt hours of electricity will both aid the environment and strengthen the economy. To test these claims, three foundations and one public utility jointly sponsored a study to determine the economic and employment impacts of an aggressive program of energy efficiency investments by America`s electric utilities. This article describes the results of that study. New DSM technologies in the areas of lighting, heating, cooling, electric motors, electronic controls, and transportation have the potential to provide electricity users the same comfort, illumination, or industrial power they previously enjoyed with lower electricity inputs. This study looks at the macroeconomic impacts at a national level which an investment efficiency program based on new DSM technologies can offer the economy.

Moscovitch, E.

1994-05-01

96

Decision factors affecting transmission and distribution efficiency improvements by Northwest electric utilities  

SciTech Connect

The principal objective of this report was to assess and document the attitude of Northwest electric utilities toward possible BPA conservation acquisition programs that may provide incentive(s) to reduce losses on T and D lines. Secondary objectives were to examine existing incentives for making such improvements, to categorize prior T and D efficiency improvements, and to examine factors affecting the decision-making process for system improvements. Much of the information presented in the report is derived from a survey administered during personal interviews at 29 Northwest electric utilities between November 1984 and January 1985.

Hendrickson, P.L.; Darwin, R.F.

1986-01-01

97

Efficient Utilization of Crude Glycerol as Fermentation Substrate in the Synthesis of Poly(3-hydroxybutyrate) Biopolymers  

Microsoft Academic Search

One refined and two crude glycerol (from biodiesel production) samples were utilized to produce poly(3-hydroxybutyrate) (PHB)\\u000a by Pseudomonas oleovorans NRRL B-14682. A batch culture fermentation protocol including 1% glycerol and an aeration rate of 3 standard liters per minute\\u000a proved best for PHB synthesis (av. yield = 1.0 ± 0.2 g\\/L at 48 h) and efficient glycerol utilization. PHB molecular weights\\u000a decreased as MeOH concentration increased.

Richard D. AshbyDaniel; Daniel K. Y. Solaiman; Gary D. Strahan

2011-01-01

98

Serving the industrial customer: Emerging directions for utility-related energy efficiency services  

SciTech Connect

The electric utility industry, and utility energy efficiency services, are going through a radical transformation. Traditional regulated monopoly utilities and traditional utility DSM programs will soon be history. In their place will emerge a much more dynamic market. The market is likely to be dominated by price considerations, but quality of service, and providing extra value to the customer will also be important. It is in these latter areas that energy efficiency services will play a significant role. In this market, many new services are starting to emerge including customized packages of services (combining energy efficiency, power quality, pollution prevention, and/or productivity enhancement), engineering assistance, cogeneration and power house management, end-use pricing, and motor and compressed air system management. The variety of these services are likely to grow as boundaries between utilities, power marketers, and energy service companies blur, and all of these players seek to offer power as well as other value-added services. However, market-based efficiency services are unlikely to serve all customers, or to address many barriers inhibiting investments in cost-effective energy saving technologies and practices. In particular, the market is unlikely to adequately serve small customers, including small industrial customers. Add the market-alone is unlikely to be able to transform highly diffuse markets, such as electric motors and distribution transformers, where the actions of thousands of customers are needed to prompt significant change. To fill this gap, some but not all states are likely to offer a variety of programs including market transformation programs (primarily targeting generic equipment such as motors, compressors and transformers that are used by many customers), bidding and standard offer programs, technical and financing assistance (primarily for small- and medium-sized customers), and research, development and demonstrations. The dominant theme of these programs will be market transformation--reducing the barriers inhibiting efficient goods and services, so that in the long term these efficient goods and services become normal practice without continued intervention in the market. In this market transformation context, R and D, education, financing, and other initiatives will all play a role. These public benefit programs will be funded with small public benefit charges on distribution service, just as similar programs are funded through electric and gas rates today. In addition, in some limited geographic areas where distribution capacity is tight, energy efficiency services will be offered to all customers to reduce energy use and demand and defer the need for distribution upgrades. Such programs will be offered where the cost of the programs are less than the cost of distribution upgrades that can be deferred.

Nadel, S.; Elliott, N.; Pye, M.

1997-07-01

99

A Study About Improvement of Efficiency of a Sewage Heat Utilization System  

NASA Astrophysics Data System (ADS)

On the basis of the data analysis of operational performance at the DHC plant in Makuhari HB area, it is examined how the properties of the sewage used as a heat source affect the effectiveness of the system. The result of this study suggests that a sewage heat utilization system is able to perform higher efficiency when it is designed as a distributed system that has separate heat sources than a central system.

Kobayakawa, Tomoaki; Hihara, Eiji; Hanazaki, Hirotaka

100

Utility planning implications of efficient electric cooking in a developing country: Case of Nepal  

Microsoft Academic Search

We examine implications of electric cooking as a demand-side management (DSM) option for power development plans, as well as emission of pollutants, for the predominantly hydroelectric utility of Nepal. Options considered include seasonal and year-round electric cooking with high- and low-efficiency appliances. For both types of appliances, seasonal electric cooking is economically and environmentally attractive. However, substantial reductions in electricity

Ram M. Shrestha; Gopal B. Bhattarai

1995-01-01

101

Energy Efficiency: Marketing and Service Potential for Energy Utilities' Industrial Markets  

E-print Network

may anticipate playing a cooperative role with their respective regulatory agencies in drafting program elements. A simple yet effective plan for satisfying PBF objectives is for the utiLity to promote existing efficiency references provided...://www.oit.doe.gov/bestpractices/compressed_air/ Process Heating The newest DOE-OIT BestPractices effort supports process heating. See http://www.oit.doe.gov/bestpractices/process_heaU Natural Resources Canada has an excellent energy management library for industry. Visit http...

Russel, C.; Tate, R.; Tubiolo, A.

102

Walt Disney World`s utility efficiency awards and environmental circles of excellence  

SciTech Connect

This paper describes an innovative approach to energy conservation that has been started at WALT DISNEY WORLD. The program that was established was designed to heighten the awareness of energy usage in our Management and Cast Members, establish a method for recognizing and rewarding positive energy conservation efforts and, most importantly, keeping the effort simple and fun. Two programs work together to meet this goal: Utility Efficiency Awards and the Environmental Circles of Excellence. The Utility Efficiency Awards are given to the top areas that have demonstrated a reduction in utility consumption relative to the same period in prior years. More importantly, a report is generated that shows a best-to-worst ranking. Relying on the idea that {open_quotes}nobody wants to be on the bottom of the list{close_quotes}, conservation is enhanced by focusing attention on improving efficiency. To encourage direct cast member involvement in our environmental program, the Environmental Circles of Excellence were created. These groups, made up of hourly and salaried cast members, discuss their location`s environmental commitments, set goals and implement programs. This paper describes these initiatives in detail and presents some initial results that have heightened the awareness of energy conservation at WALT DISNEY WORLD.

Allen, P.J.; Kivler, W.B.

1996-05-01

103

The politics of electric utility regulation: Explaining energy efficiency policy in the states  

NASA Astrophysics Data System (ADS)

Even with broad societal pressures to alter the regulatory environment in the states with regard to the efficient use of electricity, many states have not made what some conservation advocates believe are adequate reforms for increasing levels of energy efficiency. While some states have comprehensive policies that require electric utilities to engage in integrated resource planning and demand-side management (DSM), along with providing utilities with a regulatory framework that allows for the recovery of energy efficiency program costs and lost revenues, other states have no such policies. The main purpose of this inquiry is twofold: first, it discusses some of the current regulatory issues being explored at the state level in an attempt to determine how states vary in their development and application of energy efficiency regulations; and second, it attempts to explain why the states differ in their development of energy efficiency regulations. The application of the analytical framework developed in this study proves useful for assessing the various elements that affect state regulatory policy development. Organized interests, state political culture, and various state economic variables tend to exert considerable influence over regulatory policy choice. However, other factors such as government institutions, including state legislatures and regulatory agencies, were not without effect. Though the directions of some of the relationships were unexpected, various logistic regression models show that each of the approaches to the study of regulation is useful in explaining the process of developing and adopting innovative energy efficiency policies. In the area of electric utility regulation, and more specifically energy efficiency regulation, this analysis finds that, in general, the likelihood of a state adopting DSM-related lost revenue recovery and/or sharehoider incentives on DSM programs, as well as stringent cost-effectiveness tests, is greater for states with Republican governors, Democratic and professionalized legislatures, dominant interest groups, higher levels of GSP, greater growth in per capita personal income, traditionalistic political cultures, and lower levels of environmental commitment. Moreover, economics is not always the most influential factor in determining regulatory policy. Rather, political institutions and government bureaucracies make a considerable difference.

Altman, John Arthur

104

Optimal Design of site investigation: Entropy based Utility functions and efficient implementations  

NASA Astrophysics Data System (ADS)

Integrating additional data into (stochastic) hydro-geological models helps to improve prediction quality. For a given modeling task, Optimal Design (OD) of data acquisition is used to search for the most `valuable` set of data, thus providing guidance on how to approach site investigation. The utility of data can be quantified theoretically by Mutual Information (MI), which measures the information content of potential data sets for the prediction quantity of interest. OD requires to evaluate the chosen utility function for all potential design pattern averaged over all possible data values, which makes OD computationally extremely burdening. The computational costs mainly depend on (1) the number of possible designs, (2) the efficiency of the involved search algorithm for high-dimensional optimization, and (3) the precise choice and computational implementation of the utility function. Due to high-computational costs, utility functions are often only approximations of MI, including linearizations (e.g. posterior variances, covariances). In previous work it has been shown, that such linearized analyses lead to a dramatic speedup, however fail to discover non-linear dependencies between possible observations and predictions goals and therefore often lead to suboptimal results. The current study focuses on efficient choices and implementations of utility functions in OD. Growing and cheap computer power nowadays allows direct and more accurate evaluation of MI based on entropy estimates or non-linear Bayesian updating schemes. In particular, because MI is a symmetric information measure several different formulations are possible. The options developed in this study include forward evaluation, reverse evaluation and evaluation based on joint distributions. In addition, many approximation of MI are available, but their behavior and computational requirements are mostly unknown. To allow an informed decision, we compare different approximations and formulations of MI in terms of computational efficiency, accuracy, resulting design quality and feasibility for applications to large data sets. We developed an error estimate to asses accuracy versus efficiency. In addition, the options of linearization are pointed out and discussed for some possible approximations. Finally, we investigated in which cases the improvement of design quality may justify the additional computational costs for switching to more accurate yet slower formulations or implementations.

Geiges, A.; Nowak, W.

2011-12-01

105

[Research practices of conversion efficiency of resources utilization model of castoff from Chinese material medica industrialization].  

PubMed

The industrialization chains and their products, which were formed from the process of the production of medicinal materials-prepared drug in pieces and deep processed product of Chinese material medica (CMM) resources, have generated large benefits of social and economic. However, The large of herb-medicine castoff of "non-medicinal parts" and "rejected materials" produced inevitably during the process of Chinese medicinal resources produce and process, and the residues, waste water and waste gas were produced during the manufactured and deep processed product of CMM. These lead to the waste of resources and environmental pollution. Our previous researches had proposed the "three utilization strategies" and "three types of resources models" of herb-medicine castoff according to the different physicochemical property of resources constitutes, resources potential and utility value of herb-medicine castoff. This article focus on the conversion efficiency of resources model and analysis the ways, technologies, practices, and application in herb-medicine cast off of the conversion efficiency of resources model based on the recycling economy theory of resources and thoughts of resources chemistry of CMM. These data may be promote and resolve the key problems limited the industrialization of Chinese material medica for long time and promote the realization of herb-medicine castoff resources utilization. PMID:24791476

Duan, Jin-Ao; Su, Shu-Lan; Guo, Sheng; Liu, Pei; Qian, Da-Wei; Jiang, Shu; Zhu, Hua-Xu; Tang, Yu-Ping; Wu, Qi-Nan

2013-12-01

106

Engineered Enterobacter aerogenes for efficient utilization of sugarcane molasses in 2,3-butanediol production.  

PubMed

Sugarcane molasses is considered to be a good carbon source for biorefinery due to its high sugar content and low price. Sucrose occupies more than half of the sugar in the molasses. Enterobacter aerogenes is a good host strain for 2,3-butanediol production, but its utilization of sucrose is not very efficient. To improve sucrose utilization in E. aerogenes, a sucrose regulator (ScrR) was disrupted from the genomic DNA. The deletion mutation increased the sucrose consumption rate significantly when sucrose or sugarcane molasses was used as a carbon source. The 2,3-butanediol production from sugarcane molasses by the mutant was enhanced by 60% in batch fermentation compared to that by the wild type strain. In fed-batch fermentation, 98.69 g/L of 2,3-butanediol production was achieved at 36 h. PMID:23644066

Jung, Moo-Young; Park, Bu-Soo; Lee, Jinwon; Oh, Min-Kyu

2013-07-01

107

Arc View/Avenue: Coding styles and utility scripts for efficient development  

SciTech Connect

Effectiveness and efficiency of software development can be greatly increased by writing modularized code using informal (styles) and formal (standards) work approaches. Software development is about connecting pieces into a coherent whole. Thus consistent work approaches provide a structure that allows individuals and teams to minimize the time and thought put into making these connections. These investments in structure return even more benefits in the maintenance phase when old code has to be examined by new programmers, or after time has passed. We present some examples of coding style for Avenue: a simplified form of Hungarian notation (notationHungarian, stringCustomerName, etc.), script naming prefixes and suffixes, and options in script headers. We demonstrate several modular, object-like utility scripts that can be used alone or combined into other utilities. These include developer tools such as a System.Echo substitute for Windows, a Window inspector, and a script for detecting and dealing with multiple display resolutions.

Ganter, J.

1996-05-07

108

An aggregated perylene-based broad-spectrum, efficient and label-free quencher for multiplexed fluorescent bioassays.  

PubMed

Fluorescent sensing systems based on the quenching of fluorophores have found wide applications in bioassays. An efficient quencher will endow the sensing system a high sensitivity. The frequently used quenchers are based on organic molecules or nanomaterials, which usually need tedious synthesizing and modifying steps, and exhibit different quenching efficiencies to different fluorophores. In this work, we for the first time report that aggregated perylene derivative can serve as a broad-spectrum and label-free quencher that is able to efficiently quench a variety of fluorophores, such as green, red and far red dyes labeled on DNA. By choosing nucleases as model biomolecules, such a broad-spectrum quencher was then employed to construct a multiplexed bioassay platform through a label-free manner. Due to the high quenching efficiency of the aggregated perylene, the proposed platform could detect nuclease with high sensitivity, with a detection limit of 0.03U/mL for EcoRV, and 0.05U/mL for EcoRI. The perylene quencher does not affect the activity of nuclease, which makes it possible to design post-addition type bioassay platform. Moreover, the proposed platform allows simultaneous and multicolor analysis of nucleases in homogeneous solution, demonstrating its value of potential application in rapid screening of multiple bio-targets. PMID:24662061

Liu, Tao; Hu, Rong; Lv, Yi-Fan; Wu, Yuan; Liang, Hao; Huan, Shuang-Yan; Zhang, Xiao-Bing; Tan, Weihong; Yu, Ru-Qin

2014-08-15

109

Metabolic and Regulatory Rearrangements Underlying Efficient d-Xylose Utilization in Engineered Pseudomonas putida S12*  

PubMed Central

Previously, an efficient d-xylose utilizing Pseudomonas putida S12 strain was obtained by introducing the d-xylose isomerase pathway from Escherichia coli, followed by evolutionary selection. In the present study, systemic changes associated with the evolved phenotype were identified by transcriptomics, enzyme activity analysis, and inverse engineering. A key element in improving the initially poor d-xylose utilization was the redistribution of 6-phospho-d-gluconate (6-PG) between the Entner-Doudoroff pathway and the oxidative pentose phosphate (PP) pathway. This redistribution increased the availability of 6-PG for oxidative decarboxylation to d-ribose-5-phosphate, which is essential for the utilization of d-xylose via the nonoxidative PP pathway. The metabolic redistribution of 6-PG was procured by modified HexR regulation, which in addition appeared to control periplasmic sugar oxidation. Because the absence of periplasmic d-xylonate formation was previously demonstrated to be essential for achieving a high biomass yield on d-xylose, the aberrant HexR control appeared to underlie both the improved growth rate and biomass yield of the evolved d-xylose utilizing P. putida strain. The increased oxidative PP pathway activity furthermore resulted in an elevated NADH/NAD+ ratio that caused the metabolic flux to be redirected from the TCA cycle to the glyoxylate shunt, which was also activated transcriptionally. Clearly, these findings may serve as an important case in point to engineer and improve the utilization of non-natural carbon sources in a wide range of industrial microorganisms. PMID:22416130

Meijnen, Jean-Paul; de Winde, Johannes H.; Ruijssenaars, Harald J.

2012-01-01

110

Adaptive protocols for energy-efficient spread-spectrum wireless networks  

Microsoft Academic Search

A set of adaptive protocols for mobile wireless frequency-hop spread-spectrum communication networks is described. The primary elements of the protocol suite are the adaptive-transmission protocol, the adaptive-routing protocol, and the adaptive-forwarding protocol. Together, these protocols control the transmission of packets on each link in the network and the routing of packets through the network. Each protocol interacts with the other

Michael Pursley; Harlan Russell; Jeffrey Wysocarski

2002-01-01

111

Industrial Partnerships with a Multi-utilities Firm: An Industrial Tool to Improve Economic and Environmental Efficiency  

Microsoft Academic Search

This paper discusses how competitiveness could be enhanced through a close partnership with an integrated multi-utilities firm, aimed at improving energetic efficiency, reduce polluting emissions, and thereby cut costs. Our case describes how PSA, a car manufacturer, turned the environmental issue into a competitive advantage by externalising to Veolia, a multi-utilities firm, a bundle of on-site utilities and technical services

Géry Deffontaines

112

Rapid Sensing of Underutilized, Wideband Spectrum Using the Random Demodulator  

E-print Network

, Waheed U. Bajwa2, Robert Calderbank3 Department of Electrical Engineering, Princeton University@princeton.edu 2 waheed.bajwa@rutgers.edu 3 robert.calderbank@duke.edu Abstract--Efficient spectrum sensing efficiently use wireless spectrum. The so-called white-space devices are an exam- ple that utilize unused

Bajwa, Waheed U.

113

Optical spectrum of bottom-up graphene nanoribbons: towards efficient atom-thick excitonic solar cells.  

PubMed

Recently, atomically well-defined cove-shaped graphene nanoribbons have been obtained using bottom-up synthesis. These nanoribbons have an optical gap in the visible range of the spectrum which make them candidates for donor materials in photovoltaic devices. From the atomistic point of view, their electronic and optical properties are not clearly understood. Therefore, in this work we carry out ab-initio density functional theory calculations combine with many-body perturbation formalism to study their electronic and optical properties. Through the comparison with experimental measurements, we show that an accurate description of the nanoribbon's optical properties requires the inclusion of electron-hole correlation effects. The energy, binding energy and the corresponding excitonic transitions involved are analyzed. We found that in contrast to zigzag graphene nanoribbons, the excitonic peaks in the absorption spectrum are a consequence of a group of transitions involving the first and second conduction and valence bands. Finally, we estimate some relevant optical properties that strengthen the potential of these nanoribbons for acting as a donor materials in photovoltaic. PMID:25301001

Villegas, Cesar E P; Mendonça, P B; Rocha, A R

2014-01-01

114

Optical spectrum of bottom-up graphene nanoribbons: towards efficient atom-thick excitonic solar cells  

NASA Astrophysics Data System (ADS)

Recently, atomically well-defined cove-shaped graphene nanoribbons have been obtained using bottom-up synthesis. These nanoribbons have an optical gap in the visible range of the spectrum which make them candidates for donor materials in photovoltaic devices. From the atomistic point of view, their electronic and optical properties are not clearly understood. Therefore, in this work we carry out ab-initio density functional theory calculations combine with many-body perturbation formalism to study their electronic and optical properties. Through the comparison with experimental measurements, we show that an accurate description of the nanoribbon's optical properties requires the inclusion of electron-hole correlation effects. The energy, binding energy and the corresponding excitonic transitions involved are analyzed. We found that in contrast to zigzag graphene nanoribbons, the excitonic peaks in the absorption spectrum are a consequence of a group of transitions involving the first and second conduction and valence bands. Finally, we estimate some relevant optical properties that strengthen the potential of these nanoribbons for acting as a donor materials in photovoltaic.

Villegas, Cesar E. P.; Mendonça, P. B.; Rocha, A. R.

2014-10-01

115

Optical spectrum of bottom-up graphene nanoribbons: towards efficient atom-thick excitonic solar cells  

PubMed Central

Recently, atomically well-defined cove-shaped graphene nanoribbons have been obtained using bottom-up synthesis. These nanoribbons have an optical gap in the visible range of the spectrum which make them candidates for donor materials in photovoltaic devices. From the atomistic point of view, their electronic and optical properties are not clearly understood. Therefore, in this work we carry out ab-initio density functional theory calculations combine with many-body perturbation formalism to study their electronic and optical properties. Through the comparison with experimental measurements, we show that an accurate description of the nanoribbon's optical properties requires the inclusion of electron-hole correlation effects. The energy, binding energy and the corresponding excitonic transitions involved are analyzed. We found that in contrast to zigzag graphene nanoribbons, the excitonic peaks in the absorption spectrum are a consequence of a group of transitions involving the first and second conduction and valence bands. Finally, we estimate some relevant optical properties that strengthen the potential of these nanoribbons for acting as a donor materials in photovoltaic. PMID:25301001

Villegas, Cesar E. P.; Mendonça, P. B.; Rocha, A. R.

2014-01-01

116

Bilayer Polymer Solar Cells with Improved Power Conversion Efficiency and Enhanced Spectrum Coverage  

SciTech Connect

We demonstrate the construction of an efficient bilayer polymer solar cell comprising of Poly(3-hexylthiophene)(P3HT) as a p-type semiconductor and asymmetric fullerene (C{sub 70}) as n-type counterparts. The bilayer configuration was very efficient compared to the individual layer performance and it behaved like a regular p-n junction device. The photovoltaic characteristic of the bilayers were studied under AM 1.5 solar radiation and the optimized device parameters are the following: Voc = 0.5V, Jsc = 10.1 mA/cm{sup 2}, FF = 0.60 and power conversion efficiency of 3.6 %. A high fill factor of {approx}0.6 was achieved, which is only slightly reduced at very intense illumination. Balanced mobility between p-and n-layers is achieved which is essential for achieving high device performance. Correlation between the crystallinity, morphology and the transport properties of the active layers is established. The External quantum efficiency (EQE) spectral distribution of the bilayer devices with different processing solvents correlates well with the trends of short circuit current densities (J{sub sc}) measured under illumination. Efficiency of the bilayer devices with rough P3HT layer was found to be about 3 times higher than those with a planar P3HT surface. Hence it is desirable to have a larger grains with a rough surface of P3HT layer for providing larger interfacial area for the exciton dissociation.

Kekuda, Dhananjaya [Department of Physics, Manipal Institute of Technology, Manipal University, Manipal, India 576 104 (India); Chu, Chih-Wei [Research Center for Applied Science, Academia Sinica, Taipei, Taiwan 300 13 (China)

2011-10-20

117

On-Site Fabrication Infrastructure to Enable Efficient Exploration and Utilization of Space  

NASA Technical Reports Server (NTRS)

Unlike past one-at-a-time mission approaches, system-of-systems infrastructures will be needed to enable ambitious scenarios for sustainable future space exploration and utilization. So what do we do when we get to the moon for sustainable exploration. On-site fabrication infrastructure will be needed to support habitat structure development, tools and mechanical part fabrication, as well as repair and replacement of ground support and space mission hardware such as life support items, vehicle components and crew systems. The on-site fabrication infrastructure will need the In Situ Fabrication and Repair (ISFR) element, which is working in conjunction with the In Situ Resources Utilization (ISRU) element, to live off the land. The ISFR element has worked closely with the ISRU element in the past year to assess the ability of using lunar regolith as a viable feedstock for fabrication material. Preliminary work has shown promise and the ISFR Element will continue to concentrate on this activity. Fabrication capabilities have been furthered with the process certification effort that, when completed, will allow for space-qualified hardware to be manufactured. Materials being investigated include titanium and aluminum alloys as well as lunar regolith simulants with binders. This paper addresses the latest advancements made in the fabrication of infrastructures that support efficient, affordable, reliable infrastructures for both space exploration systems and logistics; infrastructures that allow sustained, affordable and highly effective operations on the Moon and beyond.

Howell, Joe T.; Fikes, John C.; McLemore, Carole A.; Good, James E.

2008-01-01

118

Efficient, full-spectrum, long-lived, non-toxic microwave lamp for plant growth  

NASA Technical Reports Server (NTRS)

Fusion Systems Corporation has developed a mercury-free, low infrared, efficient microwave lamp using a benign sulfur based fill optimized for visible light. Our literature search and discussions with researchers directed us to enhance the bulbs red output. We have demonstrated a photosynthetic efficacy of over 2 micro-moles per microwave joule which corresponds to over 1.3 micro-moles per joule at the power main. Recent work has shown we can make additional increases in overall system efficiency. During the next two years, we expect to demonstrate a system capable of producing more than 1.5 micro-moles/joule measured at the power main with significantly less IR than alternative lamp systems. We determined optimal plant growth light requirements via a literature search and researcher input. We surveyed candidate lamp fill materials to be used in combination with sulfur and explored several methods of increasing photosynthetic efficacy.

Maclennan, Donald A.; Turner, Brian P.; Dolan, James T.; Ury, Michael G.; Gustafson, Paul

1994-01-01

119

Revised IR spectrum, radiative efficiency and global warming potential of nitrogen trifluoride  

NASA Astrophysics Data System (ADS)

Nitrogen trifluoride (NF3) is an industrial gas used in the semiconductor industry as a plasma etchant and chamber cleaning gas. NF3 is an alternative to other potent greenhouse gases and its usage has increased markedly over the last decade. In recognition of its increased relevance and to aid planning of future usage we report an updated radiative efficiency and global warming potentials for NF3. Laboratory measurements give an integrated absorption cross section of 7.04 × 10-17 cm2 molecule-1 cm-1 over the spectral region 200-2000 cm-1. The radiative efficiency is calculated to be 0.21 Wm-2 ppbv-1 and the 100 year GWP, relative to carbon dioxide, is 17200. These values are approximately 60% higher than previously published estimates, primarily reflecting the higher infrared absorption cross-sections reported here.

Robson, J. I.; Gohar, L. K.; Hurley, M. D.; Shine, K. P.; Wallington, T. J.

2006-05-01

120

Spectrum efficiency improvement of directly detected OFDM based on balance receiver  

NASA Astrophysics Data System (ADS)

A novel optical single-sideband directly detected orthogonal frequency division multiplexing (DD-OFDM) system based on balance receiver consisting of two PINs is proposed and demonstrated. By introducing phase shift of ? to one arm of the proposed receiver, inter-modulation distortion (IMD) near the optical carrier can be eliminated efficiently. The simulation results show that our system improves spectral efficiency to about 1.54 bps/Hz with 4-quadrature amplitude modulation (4QAM) mapping, and the optical carrier and signal power ratio (CSPR) has negligible impact on the OSNR performance, which can be improved by 3 dB with negligible error vector magnitude (EVM) penalty. Additionally, the optimum CSPR can be controlled by adjusting them respectively. 5 Gbit/s data with 4QAM mapping and 6.25% cyclic prefix (CP) inserted is successfully transmitted over 320 km of standard single mode fiber (SSMF) and our system exhibits a negligible penalty. Higher spectral efficiency can be achieved with more complex modulation formats and polarization multiplexing.

Tang, Chao; Chen, Hongwei; Chen, Minghua; Xie, Shizhong

2009-11-01

121

Utility of the Psychoeducational Profile-3 for Assessing Cognitive and Language Skills of Children with Autism Spectrum Disorders  

ERIC Educational Resources Information Center

The Psychoeducational Profile-3's (PEP-3) ability to estimate cognitive and language skills of 136 children (20-75 months) with autism spectrum disorders (ASDs) across a range of functioning, and the association between the PEP-3 and ASD symptomatology was examined using retrospective data. PEP-3 cognitive and language measures were…

Fulton, Mandy L.; D'Entremont, Barbara

2013-01-01

122

Simian Immunodeficiency Virus Utilizes Human and Sooty Mangabey but Not Rhesus Macaque STRL33 for Efficient Entry  

Microsoft Academic Search

It has been established that many simian immunodeficiency virus (SIV) isolates utilize the orphan receptors GPR15 and STRL33 about as efficiently as the chemokine receptor CCR5 for entry into target cells. Most stud- ies were performed, however, with coreceptors of human origin. We found that SIV from captive rhesus macaques (SIVmac) can utilize both human and simian CCR5 and GPR15

STEFAN POHLMANN; BENHUR LEE; SILKE MEISTER; MANDY KRUMBIEGEL; GEORGE LESLIE; ROBERT W. DOMS; FRANK KIRCHHOFF

2000-01-01

123

Advanced control for photoautotrophic growth and CO2-utilization efficiency using a membrane carbonation photobioreactor (MCPBR).  

PubMed

A membrane carbonation (MC) module uses bubbleless gas-transfer membranes to supply inorganic carbon (C(i)) for photoautotrophic cyanobacterial growth in a photobioreactor (PBR); this creates the novel MCPBR system, which allows precise control of the CO(2)-delivery rate and minimal loss of CO(2) to the atmosphere. Experiments controlled the supply rate of C(i) to the main PBR by regulating the recirculation rate (Q(R)) between the module of MC chamber and the main PBR. The experiments evaluated how Q(R) controls the CO(2) mass transport in MC chamber and how it connects with the biomass production rate, C(i) concentration, pH in the PBR, and CO(2)-utilization efficiency. The biomass production rate and C(i) concentration increased in response to the C(i) supply rate (controlled by Q(R)), but not in linear proportion. The biomass production rate increased less than C(i) due to increased light limitation. Except for the highest Q(R), when the higher C(i) concentration caused the pH to decrease, CO(2) loss to gas ventilation was negligible. The results demonstrate that this MCPBR offers independent control over the growth of photoautotrophic biomass, pH control, and minimal loss of CO(2) to the atmosphere. PMID:21557590

Kim, Hyun Woo; Marcus, Andrew K; Shin, Jeong Hoon; Rittmann, Bruce E

2011-06-01

124

Highly efficient SO? absorption and its subsequent utilization by weak base/polyethylene glycol binary system.  

PubMed

A binary system consisting of polyethylene glycol (PEG, proton donor)/PEG-functionalized base with suitable basicity was developed for efficient gas desulfurization (GDS) and can be regarded as an alternative approach to circumvent the energy penalty problem in the GDS process. High capacity for SO(2) capture up to 4.88 mol of SO(2)/mol of base was achieved even under low partial pressure of SO(2). Furthermore, SO(2) desorption runs smoothly under mild conditions (N(2), 25 °C) and no significant drop in SO(2) absorption was observed after five-successive absorption-desorption cycles. On the other hand, the absorbed SO(2) by PEG(150)MeIm/PEG(150), being considered as the activated form of SO(2), can be directly transformed into value-added chemicals under mild conditions, thus eliminating the energy penalty for SO(2) desorption and simultaneously realizing recycle of the absorbents. Thus, this SO(2) capture and utilization (SCU) process offers an alternative way for GDS and potentially enables the SO(2) conversion from flue gas to useful chemicals as a value-added process. PMID:23323771

Yang, Zhen-Zhen; He, Liang-Nian; Zhao, Ya-Nan; Yu, Bing

2013-02-01

125

Efficient reduction of complex noise in passive millimeter-wavelength video utilizing Bayesian surprise  

NASA Astrophysics Data System (ADS)

Passive millimeter wavelength (PMMW) video holds great promise given its ability to see targets and obstacles through fog, smoke and rain. However, current imagers produce undesirable complex noise. This can come as a mixture of fast shot (snow like) noise and a slower forming circular fixed pattern. Shot noise can be removed by a simple gain style filter. However, this can produce blurring of objects in the scene. To alleviate this, we measure the amount of Bayesian surprise in videos. Bayesian surprise is feature change in time which is abrupt, but cannot be accounted for as shot noise. Surprise is used to attenuate the shot noise filter in locations of high surprise. Since high Bayesian surprise in videos is very salient to observers, this reduces blurring particularly in places where people visually attend. Fixed pattern noise is removed after the shot noise using a combination of Non-uniformity correction (NUC) and Eigen Image Wavelet Transformation. The combination allows for online removal of time varying fixed pattern noise even when background motion may be absent. It also allows for online adaptation to differing intensities of fixed pattern noise. The fixed pattern and shot noise filters are all efficient allowing for real time video processing of PMMW video. We show several examples of PMMW video with complex noise that is much cleaner as a result of the noise removal. Processed video clearly shows cars, houses, trees and utility poles at 20 frames per second.

Mundhenk, T. Nathan; Baron, Josh; Matic, Roy M.

2011-06-01

126

Establishing an Efficient Way to Utilize the Drought Resistance Germplasm Population in Wheat  

PubMed Central

Drought resistance breeding provides a hopeful way to improve yield and quality of wheat in arid and semiarid regions. Constructing core collection is an efficient way to evaluate and utilize drought-resistant germplasm resources in wheat. In the present research, 1,683 wheat varieties were divided into five germplasm groups (high resistant, HR; resistant, R; moderate resistant, MR; susceptible, S; and high susceptible, HS). The least distance stepwise sampling (LDSS) method was adopted to select core accessions. Six commonly used genetic distances (Euclidean distance, Euclid; Standardized Euclidean distance, Seuclid; Mahalanobis distance, Mahal; Manhattan distance, Manhat; Cosine distance, Cosine; and Correlation distance, Correlation) were used to assess genetic distances among accessions. Unweighted pair-group average (UPGMA) method was used to perform hierarchical cluster analysis. Coincidence rate of range (CR) and variable rate of coefficient of variation (VR) were adopted to evaluate the representativeness of the core collection. A method for selecting the ideal constructing strategy was suggested in the present research. A wheat core collection for the drought resistance breeding programs was constructed by the strategy selected in the present research. The principal component analysis showed that the genetic diversity was well preserved in that core collection. PMID:23737717

Wang, Jiancheng; Guan, Yajing; Wang, Yang; Zhu, Liwei; Wang, Qitian; Hu, Qijuan; Hu, Jin

2013-01-01

127

Immune system stimulation reduces the efficiency of tryptophan utilization for body protein deposition in growing pigs.  

PubMed

The effect of immune system stimulation (ISS) on N retention and Trp utilization in pigs fed Trp-limiting diets was evaluated using 36 growing pigs (20.0 ± 1.1 kg BW; 3 blocks of 12 barrows). Pigs were randomly assigned to 1 of 5 diets (Diet 1, 2, 4, and 5, n = 7; Diet 3, n = 8) and fed restrictively at 800 g/d. Diets 1 to 4 were generated by blending Diet 1 with a protein-free supplement and were calculated to contain varying amounts of standardized ileal digestible (SID) Trp (1.31, 1.05, 0.80, and 0.55 g/kg). To confirm that Trp was the first-limiting AA in Diets 1 to 4, an additional diet was used (Diet 5), which was equivalent to Diet 4 and contained 0.34 g/kg of added Trp. After a 5-d adaptation period, pigs were injected every 2 d with increasing amounts of E. coli lipopolysaccharide to induce ISS (initial dose 20 ?g/kg BW, increasing 15% each subsequent injection). Whole body N balance was measured in 3 periods: before immune stimulation (pre-ISS) and during ISS in 2 subsequent periods (ISS-1, 3 d; ISS-2, 4 d). Regression analysis was used to estimate the marginal efficiency of Trp utilization for whole body protein deposition (PD; N retention × 6.25). Plasma concentrations of acute-phase proteins and white blood cell counts increased (P < 0.001) and plasma albumin decreased (P < 0.001) during ISS. Nitrogen retention increased (P < 0.001) as Trp intake increased. Nitrogen retention was numerically greater but not statistically different between Diet 5 (added Trp diet) and Diet 4. Whole body N retention was less (P < 0.05) during ISS due primarily to an increase (P < 0.05) in urinary N excretion. There was a linear response (P < 0.05) in N retention, urinary N, and total excreted N to increasing Trp intake. Protein deposition increased by 88.2 ± 5.2, 82.5 ± 5.1, and 92.5 ± 3.4 g/d for each additional g/d of SID Trp intake during pre-ISS, ISS-1, and ISS-2, respectively, but the intercept was not different (-32.3 g/d). The slope of the response of PD to increasing Trp intake (based on the common intercept) was less during ISS-1 compared with pre-ISS (P = 0.01) or ISS-2 (P = 0.002) but not different between pre-ISS and ISS-2. Immune system stimulation reduced N retention in pigs fed limiting dietary Trp. The efficiency of Trp utilization for protein deposition was also reduced during ISS, indicating that the Trp requirement for PD is increased ?7% during an inflammatory state. PMID:22851250

de Ridder, K; Levesque, C L; Htoo, J K; de Lange, C F M

2012-10-01

128

Genome Sequence of the Thermophilic Strain Bacillus coagulans XZL4, an Efficient Pentose-Utilizing Producer of Chemicals  

PubMed Central

Bacillus coagulans XZL4 is an efficient pentose-utilizing producer of important platform compounds, such as l-lactic acid, 2,3-butanediol, and acetoin. Here we present a 2.8-Mb assembly of its genome. Simple and efficient carbohydrate metabolism systems, especially the transketolase/transaldolase pathway, make it possible to convert pentose sugars to products at high levels. PMID:22038963

Su, Fei; Xu, Ke; Zhao, Bo; Tai, Cui; Tao, Fei; Tang, Hongzhi; Xu, Ping

2011-01-01

129

Energy Efficiency in Western Utility Resource Plans: Impacts onRegional Resources Assessment and Support for WGA Policies  

SciTech Connect

In the aftermath of the consumer price shocks and short-term power shortages of the 2000-01 electricity crisis, policymakers and regulators in Western states are placing increased emphasis on integrated resource planning (IRP), resource adequacy and assessment and a diversified portfolio of resources to meet the needs of electricity consumers. In some states, this has led to a resurgence in state and utility commitments to energy efficiency. Increasing interest in acquiring energy efficiency as a power-system resource is also driven by the desire to dampen high growth rates in electricity demand in some Western states, rapid increases in natural gas prices, concerns about the environmental impacts of electricity generation (e.g. water consumption by power plants, air quality), and the potential of energy efficiency to provide utility bill savings for households and businesses (WGA CDEAC 2006). Recognizing the cost-competitiveness and environmental benefits of energy efficiency, the Western Governor's Association (WGA) has set a high priority for energy efficiency, establishing a goal of reducing projected electricity demand by 20% across the West by 2020 in a policy resolution on Clean and Diversified Energy for the West (WGA 2004). Nationally, the need for improved tracking of demand-side resources in load forecasting is formalized in the North American Electric Reliability Council (NERC)'s recently adopted reliability standards, which utilities and regional reliability organizations will need to comply with (NERC 2005a and 2005b). In this study, we examine the treatment of energy efficiency in recent resource plans issued by fourteen investor-owned utilities (IOUs) in the Western United States and Canada. The goals of this study are to: (1) summarize energy-efficiency resources as represented in a large sample of recent resource plans prepared by Western utilities and identify key issues; (2) evaluate the extent to which the information provided in current resource plans can be used to support region-wide resource assessment and tracking of state/utility progress in meeting the WGA's energy-efficiency goals (WGA 2004); and (3) offer recommendations on information and documentation of energy-efficiency resources that should be included in future resource plans to facilitate comparative review and regional coordination. The scope of this report covers projected electric end-use efficiency investments reported in all Western utility resource plans that were publicly available as of February 2006. While a few utilities included additional demand-side resources, such as demand response, in their plans, we do not report that information. However, many of the issues and recommendations in reference to energy efficiency in this report are relevant to other demand-side resources as well. This report is organized as follows. Section 2 outlines the data sources and approach used in this study and conceptualizes methods and metrics for tracking energy-efficiency resources over time. Section 3 presents results from the review of the utility resource plans. Important issues encountered in reviewing the resource plans are discussed in section 4. Finally, section 5 concludes with recommendations for improving the tracking and reporting of energy efficiency in forthcoming resource plans.

Hopper, Nicole; Goldman, Charles; Schlegal, Jeff

2006-08-01

130

Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines  

SciTech Connect

The purpose of this program was to develop low-emissions, efficient fuel-flexible combustion technology which enables operation of a given gas turbine on a wider range of opportunity fuels that lie outside of current natural gas-centered fuel specifications. The program encompasses a selection of important, representative fuels of opportunity for gas turbines with widely varying fundamental properties of combustion. The research program covers conceptual and detailed combustor design, fabrication, and testing of retrofitable and/or novel fuel-flexible gas turbine combustor hardware, specifically advanced fuel nozzle technology, at full-scale gas turbine combustor conditions. This project was performed over the period of October 2008 through September 2011 under Cooperative Agreement DE-FC26-08NT05868 for the U.S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled "Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines". The overall objective of this program was met with great success. GE was able to successfully demonstrate the operability of two fuel-flexible combustion nozzles over a wide range of opportunity fuels at heavy-duty gas turbine conditions while meeting emissions goals. The GE MS6000B ("6B") gas turbine engine was chosen as the target platform for new fuel-flexible premixer development. Comprehensive conceptual design and analysis of new fuel-flexible premixing nozzles were undertaken. Gas turbine cycle models and detailed flow network models of the combustor provide the premixer conditions (temperature, pressure, pressure drops, velocities, and air flow splits) and illustrate the impact of widely varying fuel flow rates on the combustor. Detailed chemical kinetic mechanisms were employed to compare some fundamental combustion characteristics of the target fuels, including flame speeds and lean blow-out behavior. Perfectly premixed combustion experiments were conducted to provide experimental combustion data of our target fuels at gas turbine conditions. Based on an initial assessment of premixer design requirements and challenges, the most promising sub-scale premixer concepts were evaluated both experimentally and computationally. After comprehensive screening tests, two best performing concepts were scaled up for further development. High pressure single nozzle tests were performed with the scaled premixer concepts at target gas turbine conditions with opportunity fuels. Single-digit NOx emissions were demonstrated for syngas fuels. Plasma-assisted pilot technology was demonstrated to enhance ignition capability and provide additional flame stability margin to a standard premixing fuel nozzle. However, the impact of plasma on NOx emissions was observed to be unacceptable given the goals of this program and difficult to avoid.

Venkatesan, Krishna

2011-11-30

131

Improving yield potential in crops under elevated CO2: Integrating the photosynthetic and nitrogen utilization efficiencies  

PubMed Central

Increasing crop productivity to meet burgeoning human food demand is challenging under changing environmental conditions. Since industrial revolution atmospheric CO2 levels have linearly increased. Developing crop varieties with increased utilization of CO2 for photosynthesis is an urgent requirement to cope with the irreversible rise of atmospheric CO2 and achieve higher food production. The primary effects of elevated CO2 levels in most crop plants, particularly C3 plants, include increased biomass accumulation, although initial stimulation of net photosynthesis rate is only temporal and plants fail to sustain the maximal stimulation, a phenomenon known as photosynthesis acclimation. Despite this acclimation, grain yield is known to marginally increase under elevated CO2. The yield potential of C3 crops is limited by their capacity to exploit sufficient carbon. The “C fertilization” through elevated CO2 levels could potentially be used for substantial yield increase. Rubisco is the rate-limiting enzyme in photosynthesis and its activity is largely affected by atmospheric CO2 and nitrogen availability. In addition, maintenance of the C/N ratio is pivotal for various growth and development processes in plants governing yield and seed quality. For maximizing the benefits of elevated CO2, raising plant nitrogen pools will be necessary as part of maintaining an optimal C/N balance. In this review, we discuss potential causes for the stagnation in yield increases under elevated CO2 levels and explore possibilities to overcome this limitation by improved photosynthetic capacity and enhanced nitrogen use efficiency. Opportunities of engineering nitrogen uptake, assimilatory, and responsive genes are also discussed that could ensure optimal nitrogen allocation toward expanding source and sink tissues. This might avert photosynthetic acclimation partially or completely and drive for improved crop production under elevated CO2 levels. PMID:22833749

Kant, Surya; Seneweera, Saman; Rodin, Joakim; Materne, Michael; Burch, David; Rothstein, Steven J.; Spangenberg, German

2012-01-01

132

Iron(III)-mediated photocatalytic selective substitution of aryl bromine by chlorine with high chloride utilization efficiency.  

PubMed

An iron(iii)-mediated photocatalytic method for the conversion of aryl, heteroaryl and polycyclic aromatic bromides to the corresponding chlorides with high selectivity has been achieved successfully. The mild reaction conditions and high chloride utilization efficiency promise a bright future for chlorination reactions. PMID:24448585

Wang, Ying; Li, Lina; Ji, Hongwei; Ma, Wanhong; Chen, Chuncheng; Zhao, Jincai

2014-03-01

133

A Spectrum Surveying Framework for Dynamic Spectrum Access Networks  

Microsoft Academic Search

Dynamic spectrum access networks and wireless spectrum policy reforms heavily rely on accurate spectrum utilization statistics, which are obtained via spectrum surveys. In this paper, we propose a generic spectrum-surveying framework that introduces both standardization and automation to this process, as well as enables a distributed approach to spectrum surveying. The proposed framework outlines procedures for the collection, analysis, and

Dinesh Datla; Alexander M. Wyglinski; Gary J. Minden

2009-01-01

134

Efficient light emitting devices utilizing CdSe(ZnS) quantum dots in organic host matrices  

E-print Network

We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the ...

Coe-Sullivan, Seth (Seth Alexander)

2002-01-01

135

Efficiency of Photosynthesis in a Chl d-Utilizing Cyanobacterium is Comparable to or Higher than that in Chl a-Utilizing Oxygenic Species  

NASA Technical Reports Server (NTRS)

The cyanobacterium Acaryochloris marina uses chlorophyll d to carry out oxygenic photosynthesis in environments depleted in visible and enhanced in lower-energy, far-red light. However, the extent to which low photon energies limit the efficiency of oxygenic photochemistry in A. marina is not known. Here, we report the first direct measurements of the energy-storage efficiency of the photosynthetic light reactions in A. marina whole cells,and find it is comparable to or higher than that in typical, chlorophyll a-utilizing oxygenic species. This finding indicates that oxygenic photosynthesis is not fundamentally limited at the photon energies employed by A. marina, and therefore is potentially viable in even longer-wavelength light environments.

Mielke, S. P.; Kiang, N. Y.; Blankenship, R. E.; Gunner, M. R.; Mauzerall, D.

2011-01-01

136

Plasticity of rhizosphere hydraulic properties as a key for efficient utilization of scarce resources  

PubMed Central

Background It is known that the soil near roots, the so-called rhizosphere, has physical and chemical properties different from those of the bulk soil. Rhizosphere properties are the result of several processes: root and soil shrinking/swelling during drying/wetting cycles, soil compaction by root growth, mucilage exuded by root caps, interaction of mucilage with soil particles, mucilage shrinking/swelling and mucilage biodegradation. These processes may lead to variable rhizosphere properties, i.e. the presence of air-filled gaps between soil and roots; water repellence in the rhizosphere caused by drying of mucilage around the soil particles; or water accumulation in the rhizosphere due to the high water-holding capacity of mucilage. The resulting properties are not constant in time but they change as a function of soil condition, root growth rate and mucilage age. Scope We consider such a variability as an expression of rhizosphere plasticity, which may be a strategy for plants to control which part of the root system will have a facilitated access to water and which roots will be disconnected from the soil, for instance by air-filled gaps or by rhizosphere hydrophobicity. To describe such a dualism, we suggest classifying rhizosphere into two categories: class A refers to a rhizosphere covered with hydrated mucilage that optimally connects roots to soil and facilitates water uptake from dry soils. Class B refers to the case of air-filled gaps and/or hydrophobic rhizosphere, which isolate roots from the soil and may limit water uptake from the soil as well water loss to the soil. The main function of roots covered by class B will be long-distance transport of water. Outlook This concept has implications for soil and plant water relations at the plant scale. Root water uptake in dry conditions is expected to shift to regions covered with rhizosphere class A. On the other hand, hydraulic lift may be limited in regions covered with rhizosphere class B. New experimental methods need to be developed and applied to different plant species and soil types, in order to understand whether such dualism in rhizosphere properties is an important mechanism for efficient utilization of scarce resources and drought tolerance. PMID:23235697

Carminati, Andrea; Vetterlein, Doris

2013-01-01

137

The cost and performance of utility commercial lighting programs. A report from the Database on Energy Efficiency Programs (DEEP) project  

SciTech Connect

The objective of the Database on Energy Efficiency Programs (DEEP) is to document the measured cost and performance of utility-sponsored, energy-efficiency, demand-side management (DSM) programs. Consistent documentation of DSM programs is a challenging goal because of problems with data consistency, evaluation methodologies, and data reporting formats that continue to limit the usefulness and comparability of individual program results. This first DEEP report investigates the results of 20 recent commercial lighting DSM programs. The report, unlike previous reports of its kind, compares the DSM definitions and methodologies that each utility uses to compute costs and energy savings and then makes adjustments to standardize reported program results. All 20 programs were judged cost-effective when compared to avoided costs in their local areas. At an average cost of 3.9{cents}/kWh, however, utility-sponsored energy efficiency programs are not ``too cheap to meter.`` While it is generally agreed upon that utilities must take active measures to minimize the costs and rate impacts of DSM programs, the authors believe that these activities will be facilitated by industry adoption of standard definitions and reporting formats, so that the best program designs can be readily identified and adopted.

Eto, J.; Vine, E.; Shown, L.; Sonnenblick, R.; Payne, C. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.

1994-05-01

138

Optimal Linear Cooperation for Spectrum Sensing in Cognitive Radio Networks  

Microsoft Academic Search

Cognitive radio technology has been proposed to improve spectrum efficiency by having the cognitive radios act as secondary users to opportunistically access under-utilized frequency bands. Spectrum sensing, as a key enabling functionality in cognitive radio networks, needs to reliably detect signals from licensed primary radios to avoid harmful interference. However, due to the effects of channel fading\\/shadowing, individual cognitive radios

Zhi Quan; Shuguang Cui; Ali H. Sayed

2008-01-01

139

An energy-saving spectrum sensing processor based on partial discrete wavelet packet transform  

Microsoft Academic Search

Cognitive radio draws lots of research attentions in recent years for its efficient spectrum utilization. This research proposes a discrete wavelet packet transform (DWPT)-based spectrum sensing processor for cognitive radio systems. In this processor, this study proposes a partial DWPT spectrum analyzer and a double-threshold energy detection and decision result prediction technique to reduce the computational complexity. Complexity analysis shows

Chi-Kai Yang; Chi-Hsuan Hsieh; Yuan-Hao Huang

2012-01-01

140

Software Radio-Based Decentralized Dynamic Spectrum Access Networks: A Prototype Design and Experimental Results  

Microsoft Academic Search

Significant progress has been made in the past few years on Dynamic Spectrum Access (DSA) wireless networks which seek to use RF spectrum more efficiently and dynamically. For example, many measurements of current spectrum utilization are available and theoretical analyses and computational simulations of DSA networks abound. In sharp contrast, few network systems, particularly those with a decentralized structure, have

Feng Ge; Aravind Radhakrishnan; Mustafa Y. ElNainay; Qinqin Chen; Charles W. Bostian; Allen B. MacKenzie

2010-01-01

141

Increasing Water Utilization Efficiency of a Pasture Grass by Increasing Aftermath through Plant Selection.  

National Technical Information Service (NTIS)

Maximum land utilization requires that maximum production be obtained throughout the growing season. Perennial crops such as forage grasses have the potential for production during an entire grazing season. Cool season grasses now grown in the upper Great...

J. G. Ross

1977-01-01

142

A Study About Improvement of Efficiency of a Sewage Heat Utilization System  

NASA Astrophysics Data System (ADS)

In order to acquire the basis of technical information that will be required for the design and operation of a sewage heat utilization system, this paper discusses the data analysis of operational performance at the DHC plant in Makuhari HB area. The methodology used in this study is to clarify the characteristics of a sewage heat utilization system from compound characteristics of the DHC plant that consists of various heating systems, and evaluate them.

Kobayakawa, Tomoaki; Hihara, Eiji; Hanazaki, Hirotaka

143

Impact of Large Scale Energy Efficiency Programs On Consumer Tariffs and Utility Finances in India  

SciTech Connect

Large-scale EE programs would modestly increase tariffs but reduce consumers' electricity bills significantly. However, the primary benefit of EE programs is a significant reduction in power shortages, which might make these programs politically acceptable even if tariffs increase. To increase political support, utilities could pursue programs that would result in minimal tariff increases. This can be achieved in four ways: (a) focus only on low-cost programs (such as replacing electric water heaters with gas water heaters); (b) sell power conserved through the EE program to the market at a price higher than the cost of peak power purchase; (c) focus on programs where a partial utility subsidy of incremental capital cost might work and (d) increase the number of participant consumers by offering a basket of EE programs to fit all consumer subcategories and tariff tiers. Large scale EE programs can result in consistently negative cash flows and significantly erode the utility's overall profitability. In case the utility is facing shortages, the cash flow is very sensitive to the marginal tariff of the unmet demand. This will have an important bearing on the choice of EE programs in Indian states where low-paying rural and agricultural consumers form the majority of the unmet demand. These findings clearly call for a flexible, sustainable solution to the cash-flow management issue. One option is to include a mechanism like FAC in the utility incentive mechanism. Another sustainable solution might be to have the net program cost and revenue loss built into utility's revenue requirement and thus into consumer tariffs up front. However, the latter approach requires institutionalization of EE as a resource. The utility incentive mechanisms would be able to address the utility disincentive of forgone long-run return but have a minor impact on consumer benefits. Fundamentally, providing incentives for EE programs to make them comparable to supply-side investments is a way of moving the electricity sector toward a model focused on providing energy services rather than providing electricity.

Abhyankar, Nikit; Phadke, Amol

2011-01-20

144

(Energy efficiency of the computerized utilities energy monitor and control system)  

SciTech Connect

The travelers, representing the ORNL Energy Division, Efficiency and Renewables Research Section, conducted an in-depth evaluation of the CUMACS/EMCS installed at the 26th Support Group, USAREUR. This endeavor included an evaluation of the overall performance of this system including operations maintenance and end-user impact. System energy efficiency in terms of projected and actual energy and cost savings were analyzed. Conclusions and preliminary recommendations based on this evaluation were also formulated.

Broders, M.A.; McConnell, B.W.

1990-12-17

145

Utility and State Industrial Efficient Motors Systems Incentives Programs: Experience and Success Factors  

E-print Network

not specifically target industrial customers; instead, industrial customers are combined with commercial and, in two programs surveyed, agricultural customers. 60% of the programs provide incentives for both motors and motor controllers, usually referred... Barriers Many barriers inhibit the implementation f efficient motor systems within industry. Some ~f the more common barriers on the customer's ~ide include I ? higher initial cost: Efficient motor technologies tend to cost more than stand~rd motors...

Roop, J. M.; Stucky, D. J.

146

Genome Sequence of Bacillus cereus Strain A1, an Efficient Starch-Utilizing Producer of Hydrogen  

PubMed Central

Bacillus cereus strain A1 is a newly isolated hydrogen producer capable of utilizing bioresources and biowaste, such as starch and starch wastewater. Here, we present a 5.67-Mb assembly of the genome sequence of strain A1, which may provide insights into the molecular mechanism of hydrogen production from bioresources and biowaste. PMID:24874679

Zhang, Ting; Bao, Meidan; Wang, Yu; Tan, Tianwei

2014-01-01

147

Assessing the effect of fuel adjustment clauses on electric utility efficiency  

Microsoft Academic Search

Fuel adjustment clauses (FACs) have been adopted by state and federal regulatory authorities on a widespread basis to help preserve electric utility revenues during times of rapid, unexpected fuel price inflation. Economic theory suggests, however, that FAC use may generate several inefficiencies. These include a factor bias where fuel is favored relative to other productive inputs, managerial inefficiency, and a

Mahrenholz

1984-01-01

148

Simian immunodeficiency virus utilizes human and sooty mangabey but not rhesus macaque STRL33 for efficient entry.  

PubMed

It has been established that many simian immunodeficiency virus (SIV) isolates utilize the orphan receptors GPR15 and STRL33 about as efficiently as the chemokine receptor CCR5 for entry into target cells. Most studies were performed, however, with coreceptors of human origin. We found that SIV from captive rhesus macaques (SIVmac) can utilize both human and simian CCR5 and GPR15 with comparable efficiencies. Strikingly, however, only human STRL33 (huSTRL33), not rhesus macaque STRL33 (rhSTRL33), functioned efficiently as an entry cofactor for a variety of isolates of SIVmac and SIV from sooty mangabeys. A single amino acid substitution of S30R in huSTRL33 impaired coreceptor activity, and the reverse change in rhSTRL33 greatly increased coreceptor activity. In comparison, species-specific sequence variations in N-terminal tyrosines in STRL33 had only moderate effects on SIV entry. These results show that a serine residue located just outside of the cellular membrane in the N terminus of STRL33 is critical for SIV coreceptor function. Interestingly, STRL33 derived from sooty mangabeys, a natural host of SIV, also contained a serine at the corresponding position and was used efficiently as an entry cofactor. These results suggest that STRL33 is not a relevant coreceptor in the SIV/macaque model but may play a role in SIV replication and transmission in naturally infected sooty mangabeys. PMID:10799581

Pöhlmann, S; Lee, B; Meister, S; Krumbiegel, M; Leslie, G; Doms, R W; Kirchhoff, F

2000-06-01

149

Jicarilla Apache Utility Authority Renewable Energy and Energy Efficiency Strategic Planning  

SciTech Connect

The purpose of this Strategic Plan Report is to provide an introduction and in-depth analysis of the issues and opportunities, resources, and technologies of energy efficiency and renewable energy that have potential beneficial application for the people of the Jicarilla Apache Nation and surrounding communities. The Report seeks to draw on the best available information that existed at the time of writing, and where necessary, draws on new research to assess this potential. This study provides a strategic assessment of opportunities for maximizing the potential for electrical energy efficiency and renewable energy development by the Jicarilla Apache Nation. The report analyzes electricity use on the Jicarilla Apache Reservation in buildings. The report also assesses particular resources and technologies in detail, including energy efficiency, solar, wind, geothermal, biomass, and small hydropower. The closing sections set out the elements of a multi-year, multi-phase strategy for development of resources to the maximum benefit of the Nation.

Rabago, K.R.

2008-06-28

150

Analysis of power sector efficiency improvements for an integrated utility planning process in Costa Rica  

SciTech Connect

In an effort to analyze and document the potential for power sector efficiency improvements from generation to end-use, the Agency for International Development and the Government of Costa Rica are jointly conducting an integrated power sector efficiency analysis. Potential for energy and cost savings in power plants, transmission and distribution, and demand-side management programs are being evaluated. The product of this study will be an integrated investment plan for the Instituto Costarricense de Electricidad, incorporating both supply and demand side investment options. This paper presents the methodology employed in the study, as well as preliminary estimates of the results of the study. 14 refs., 4 figs., 5 tabs.

Waddle, D.B.; MacDonald, J.M.

1990-01-01

151

Utility Goals for the Efficiency Resource: Impact of PUC Rulemaking Project No. 39674 on Future Programs  

E-print Network

NA LM is safe; mandatory transition is not appropriate at this time; no caps applied Preamble Q2: Performance Standards; Equipment Incentives NA NA NA Current standards are approved; util ities should continue to develop own performance standards... rate classes whose base rates provide for demand charges, the EECRF rates shall provide for energy charges or demand charges, but not both. No longer have the choice to recover costs based on a customer charge or an energy charge. EECRF Cost Caps...

Martin, A.

2012-01-01

152

Efficient operation of a chemically pumped oxygen iodine laser utilizing dilute hydrogen peroxide  

Microsoft Academic Search

A chemically pumped oxygen iodine laser system has been operated employing 35 wt pct H2O2 rather than commonly used 90 wt pct H2O2. Laser power as high as 40 W has been extracted. The maximum overall efficiency of 20.7 percent, which is almost 25 percent higher than the previously reported best data, has been achieved.

S. Yoshida; H. Fujii; T. Sawano; M. Endo; T. Fujioka

1987-01-01

153

Efficiency of quantum-utilizing solar energy converters in the absence of intraband thermalization  

Microsoft Academic Search

In some photoelectrical and photochemical devices, energy conversion may occur before thermal equilibrium within the electronic bands of the absorber. A statistical thermodynamic argument shows that such hot-transfer devices cannot have an efficiency greater than that of an ideal device in which thermalization precedes energy conversion.

Robert T. Ross

1979-01-01

154

The Utility of an Efficient Outcomes Assessment System at University Counseling Centers  

ERIC Educational Resources Information Center

Due to increased demands placed on university counseling centers (UCCs) in recent years, there is a need for these centers to enhance the efficiency and effectiveness of their psychological services. Regularly monitoring client progress is one approach to increase the likelihood of positive clinical outcomes. This article describes the use of the…

Kopta, S. Mark; Petrik, Megan L.; Saunders, Stephen M.; Mond, Michael; Hirsch, Glenn; Kadison, Richard; Raymond, Danielle

2014-01-01

155

Utilization of off-peak electric power to improve cycle efficiency during peak demand periods  

Microsoft Academic Search

This paper describes a procedure to use off-peak power to produce ice, which could be melted during peak demand periods to produce a cold heat sink for condensation of the low-pressure steam turbine exhaust at lower temperatures, thereby allowing more expansion in the turbine, ore work output per pound of stem processed, and a higher efficiency. An analysis of this

B. J. Jody; E. J. Daniels

1990-01-01

156

Pumping iron to keep fit: modulation of siderophore secretion helps efficient aromatic utilization in Pseudomonas putida KT2440.  

PubMed

Studies of biotechnology applications of Pseudomonas putida KT2440 have been predominantly focused on regulation and expression of the toluene degradation (TOL) pathway. Unfortunately, there is limited information on the role of other physiological factors influencing aromatic utilization. In this report, we demonstrate that P. putida KT2440 increases its siderophore secretion in response to the availability of benzyl alcohol, a model aromatic substrate. It is argued that accelerated siderophore secretion in response to aromatic substrates provides an iron 'boost' which is required for the effective functioning of the iron-dependent oxygenases responsible for ring opening. Direct evidence for the cardinal role of siderophores in aromatic utilization is provided by evaluation of per capita siderophore secretion and comparative growth assessments of wild-type and siderophore-negative mutant strains grown on an alternative carbon source. Accelerated siderophore secretion can be viewed as a compensatory mechanism in P. putida in the context of its inability to secrete more than one type of siderophore (pyoverdine) or to utilize heterologous siderophores. Stimulated siderophore secretion might be a key factor in successful integration and proliferation of this organism as a bio-augmentation agent for aromatic degradation. It not only facilitates efficient aromatic utilization, but also provides better opportunities for iron assimilation amongst diverse microbial communities, thereby ensuring better survival and proliferation. PMID:24742959

Joshi, Hiren; Dave, Rachna; Venugopalan, V P

2014-07-01

157

Efficient operation of a chemically pumped oxygen iodine laser utilizing dilute hydrogen peroxide  

SciTech Connect

A chemically pumped oxygen iodine laser system has been operated employing 35 wt. % H/sub 2/O/sub 2/ rather than commonly used 90 wt. % H/sub 2/O/sub 2/. Laser power as high as 40 W has been extracted. The maimum overall efficiency of 20.7%, which is almost 25% higher than the previously reported best data, has been achieved.

Yoshida, S.; Fujii, H.; Sawano, T.; Endo, M.; Fujioka, T.

1987-11-09

158

Improving the efficiency, safety, and utility of woodburning units. Volume 3  

Microsoft Academic Search

Since the rapid growth of the domestic wood heating industry in the late 1970's great emphasis has been placed on accurately determining the heating performance and efficiency of wood-fired heating appliances. Starting in early 1983, six laboratories were involved in a test program designed to produce such correlative test results. The same stove, a free standing, airtight-radiant unit was used

T. M. Pruitt; T. T. Maxwell; D. F. Dyer; G. Maples

1984-01-01

159

Sustainable business model for energy-efficient lighting utilizing wireless advances  

Microsoft Academic Search

This paper describes an intelligent energy-efficient street lighting system based on solid-state LED technology. The system integrates wireless networking sub-systems to enable its use as a cost-effective access point for mobile traffic offload and for enhancing remote operational visibility to municipal field staff. We also discuss a new deployment approach that can help Urban Local Bodies to join forces with

Santosh Kesavan

2011-01-01

160

Efficient utilization of short rotation tree biomass for cooking in India  

NASA Astrophysics Data System (ADS)

The human as well as livestock population increase is phenomenal in developing world including India. The survival of this huge population certainly depends on the carrying capacity of the natural systems, which is essentially determined by the nature itself. Present state of the forests can satisfy the needs of certain population and the demand for wood has rapidly outstripped the sustainability of forests. The fuelwood requirements in the developing world is approximately 80 per cent of total wood requirements and is the major cause of forest degradation. Therefore, there is need to maximize the productivity on one hand and protection/extention of the area on another hand. Wood substitution is an option including shifting from fuelwood for cooking to fossil fuels but in the changing climatic situation, this option is short term alternative. There is need to produce more and use the same efficiently to reduce the demands. Millions of households across the country are using crude cooking stoves for their daily needs which are not only energy inefficient but detrimental to women health also. It has been the policy of Government to encourage trees outside forests to minimize the pressure from forests through meeting requirements outside forests, which is possible through intensively managed short rotation forestry and also some initiatives have been taken to increase the fuelwood efficiency through improved cooking stove, which are working successfully. Woodfuel remained the most important source of household energy in India but regular attempts have not been made to improve the efficiency in its use. This paper will focus on potential of short rotation forestry plantations for energy consumption and its efficient use at domestic scale. This has three fold interrelated economic, environmental and social impact. Key words: Short Rotation Forestry, trees outside forests, wood energy, cooking stove

Sharma, R.; Chauhan, S. K.

2012-04-01

161

Light requirement and photosynthetic cell cultivation – Development of processes for efficient light utilization in photobioreactors  

Microsoft Academic Search

Although the potential of photosyntheticmicroorganisms for production of various metabolitesand in environmental bioremediation is recognized,their practical application has been limited by thedifficulty in supplying light efficiently tophotobioreactors. Various types of photobioreactorwith high illumination to volume ratios have beenproposed, but most are limited by cost, mass transfer,contamination, scale-up or a combination of these.The problem of light supply to photobioreactorscan be solved

James C. Ogbonna; Hideo Tanaka

2000-01-01

162

High efficient treatment of citric acid effluent by Chlorella vulgaris and potential biomass utilization.  

PubMed

The efficiency of treating citric acid effluent by green algae Chlorella was investigated. With the highest growth rate, Chlorella vulgaris C9-JN2010 that could efficiently remove nutrients in the citric acid effluent was selected for scale-up batch experiments under the optimal conditions, where its maximum biomass was 1.04 g l(-1) and removal efficiencies of nutrients (nitrogen, phosphorus, total organic carbon, chemical oxygen demand and biochemical oxygen demand) were above 90.0%. Algal lipid and protein contents were around 340.0 and 500.0 mg · g(-1) of the harvested biomass, respectively. Proportions of polyunsaturated fatty acids in the lipids and eight kinds of essential amino acids in algal protein were 74.0% and 40.0%, respectively. Three major fatty acids were hexadecanoic acid, eicosapentaenoic acid and docosadienoic acid. This specific effluent treatment process could be proposed as a dual-beneficial approach, which converts nutrients in the high strength citric acid effluent into profitable byproducts and reduces the contaminations. PMID:23131649

Li, Changling; Yang, Hailin; Xia, Xiaole; Li, Yuji; Chen, Luping; Zhang, Meng; Zhang, Ling; Wang, Wu

2013-01-01

163

Efficiency of phosphorus utilization in phyA-expressing cotton lines.  

PubMed

To evaluate and characterize the stability of traits conferred by phyA from Aspergillus ficuum, we examined expression of phyA in sexually-derived transgenic cotton progeny and assessed the capacity for phytate-utilization in T4 progeny. The gene (phyA) was expressed only in the roots, but not in the stem and leaf tissues. Phytase activity was 2.38-fold higher in transgenic line L2 than in wild-type (WT) plants. The amount of phosphorus in the leaves was also significantly higher in transgenic lines L2, L6 and L9. Among those lines, L2 performed best, showing increase in phosphorus contents of 10.67% (seedling stage), 8.78% (squaring), 11.77% (flowering) and 11.59% (boll-opening). The level of available phosphorus in the rhizosphere was 19% higher in soil containing transgenic plants compared with the WT. When both transgenic and WT were grown in the same type of soil, the number of bacteria, fungi and actinomycetes was not obviously different. These results indicated that although the T4 generation enhanced the utilization of phytate phosphorus, it had no influence on the number of soil microorganisms. Our findings also demonstrated that phytase-expression lines could be used for developing new varieties of cotton having improved phosphorus uptake from the soil. PMID:23077786

Liu, Jianfeng; Wang, Xingfen; Huang, Hui; Wang, Jingjing; Li, Zhikun; Wu, Liqiang; Zhang, Guiyin; Ma, Zhiying

2012-08-01

164

Effects of dietary protein levels on growth, feed utilization, protein retention efficiency and body composition of young Heteropneustes fossilis (Bloch)  

Microsoft Academic Search

An 8-week growth trial was conducted to assess the effect of dietary protein on growth, feed utilization, protein retention\\u000a efficiency, and body composition of young Heteropneustes fossilis (10.02 ± 0.09 g; 9.93 ± 0.07 cm). Isocaloric (4.15 kcal g?1, GE) diets with varying levels of protein (25, 30, 35, 40, 45, and 50% of the diet) were fed near to satiation to triplicate\\u000a groups of fish. Optimum dietary

Tabassum Qamar Siddiqui; Mukhtar A. Khan

2009-01-01

165

Influence of heat recuperation in ORC power plant on efficiency of waste heat utilization  

NASA Astrophysics Data System (ADS)

The present work is devoted to the problem of utilization of the waste heat contained in the exhaust gases having the temperature of 350 °C. Conversion of the waste heat into electricity using a power plant working with organic fluid cycles is considered. Three Organic Rankine Cycle (ORC) power plant solutions are analysed and compared: a solution with the basic, single thermodynamic conversion cycle, one with internal heat recuperation and one with external heat recuperation. It results from the analysis that it is the proper choice of the working fluid evaporation temperature that fundamentally affects the maximum of the ORC plant output power. Application of the internal heat recuperation in the plant basic cycle results in the output power increase of approx. 5%. Addition of the external heat recuperation to the plant basic cycle, in the form of a secondary supercritical ORC power cycle can rise the output power by approx. 2%.

Borsukiewicz-Gozdur, Aleksandra

2010-10-01

166

The utility of available low quantum efficiency detector arrays for tactical imaging  

NASA Astrophysics Data System (ADS)

A mosaic detector array which uses a charge coupled array to integrate and multiplex signals is significantly limited by charge saturation. Detection of warm targets by infrared sensing through the atmosphere tends to be limited more by clutter than by random fluctuations. For missions at television frame rates the important attributes of the detector array are good spatial resolution and uniformity of response. Responsive quantum efficiency is relatively unimportant. Operation at 3 to 4.2 microns offers advantages of resolution and larger rate of change of radiant signal with temperature.

Jamieson, J. A.

1980-01-01

167

Costs and benefits from utility-funded commissioning of energy- efficiency measures in 16 buildings  

SciTech Connect

This paper describes the costs and savings of commissioning of energy- efficiency measures in 16 buildings. A total of 46 EEMs were commissioned for all 16 buildings and 73 deficiencies were corrected. On average, commissioning was marginally cost effective on energy savings alone, although the results were mixed among all 16 buildings. When considered as a stand-alone measure, the median simple payback time of 6.5 years under the low energy prices in the Pacific Northwest. Under national average prices the median payback time is about three years. In estimating the present value of the energy savings from commissioning we considered low and high lifetimes for the persistence of savings from deficiency corrections. Under the low- lifetime case the average present value of the energy savings ($0. 21/ft{sup 2}) were about equal to the average commissioning costs ($0. 23/ft{sup 2}). Under the high-lifetime case the savings ($0.51/ft{sup 2}) were about twice the costs. Again, the savings would be about twice as large under national average prices. The results are subject to significant uncertainty because of the small sample size and lack of metered data in the evaluation. However, the findings suggest that investments in commissioning pay off. Building owners want buildings that work as intended, and are comfortable, healthy, and efficient. It is likely that the non-energy benefits, which are difficult to quantify, are larger than the energy-savings benefits.

Piette, M.A.; Nordman, B.

1995-10-01

168

CD36, but not GPR120, is required for efficient fatty acid utilization during endurance exercise.  

PubMed

Fatty acids (FA) are an important energy source during exercise. In addition to its role as an energy supply for skeletal muscle, FA may activate signaling pathways that regulate gene expression. FA translocase/cluster of differentiation 36 (CD36) and G protein-coupled receptor GPR120 are long-chain FA receptors. In this study, we investigated the impact of CD36 or GPR120 deletion on energy metabolism during exercise. CD36 has been reported to facilitate cellular transport and oxidation of FA during endurance exercise. We show that CD36 deletion decreased exogenous FA oxidation during exercise, using a combination of (13)C-labeled FA oxidation measurement and indirect calorimetry. In contrast, GPR120 deletion had no observable effect on energy metabolism during exercise. Our results further substantiate that CD36-mediated FA transport plays an essential role in efficient FA oxidation during exercise. PMID:25070011

Fujitani, Mina; Matsumura, Shigenobu; Masuda, Daisaku; Yamashita, Shizuya; Fushiki, Tohru; Inoue, Kazuo

2014-11-01

169

Efficient Power Converters for PV Arrays : Scalable Submodule Power Conversion for Utility-Scale Photovoltaics  

SciTech Connect

Solar ADEPT Project: SolarBridge is developing a new power conversion technique to improve the energy output of PV power plants. This new technique is specifically aimed at large plants where many solar panels are connected together. SolarBridge is correcting for the inefficiencies that occur when two solar panels that encounter different amounts of sun are connected together. In most conventional PV system, the weakest panel limits the energy production of the entire system. That’s because all of the energy collected by the PV system feeds into a single collection point where a central inverter then converts it into useable energy for the grid. SolarBridge has found a more efficient and cost-effective way to convert solar energy, correcting these power differences before they reach the grid.

None

2012-02-23

170

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology  

SciTech Connect

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, [approximately] 1 [times] 10[sup 5] cm[sup [minus]5], as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 [times]10[sup 7] cm[sup [minus]2]. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. (Spire Corp., Bedford, MA (United States))

1993-04-01

171

Perspectives on the utilization of aquaculture coproduct in Europe and Asia: prospects for value addition and improved resource efficiency.  

PubMed

Aquaculture has often been criticized for its environmental impacts, especially efficiencies concerning global fisheries resources for use in aquafeeds among others. However, little attention has been paid to the contribution of coproducts from aquaculture, which can vary between 40% and 70% of the production. These have often been underutilized and could be redirected to maximize the efficient use of resource inputs including reducing the burden on fisheries resources. In this review, we identify strategies to enhance the overall value of the harvested yield including noneffluent processing coproducts for three of the most important global aquaculture species, and discuss the current and prospective utilization of these resources for value addition and environmental impact reduction. The review concludes that in Europe coproducts are often underutilized because of logistical reasons such as the disconnected nature of the value chain, and perceived legislative barriers. However, in Asia, most coproducts are used, often innovatively but not to their full economic potential and sometimes with possible human health and biosecurity risks. These include possible spread of diseased material and low traceability in some circumstances. Full economic and environmental appraisal is long overdue for the current and potential strategies available for coproduct utilization. PMID:24237000

Newton, Richard; Telfer, Trevor; Little, Dave

2014-01-01

172

Characteristics of filtering effect for a polarization division multiplexed-quadrature phase shift keying signal with Nyquist and super-Nyquist spectrum efficiency employing various algorithms  

NASA Astrophysics Data System (ADS)

Quadrature duobinary (QDB) spectrum shaping polarization division multiplexed-quadrature phase shift keying (PDM-QPSK) signal with Nyquist and super-Nyquist spectrum efficiency will be a promising candidate for future ultrahigh speed ultrahigh spectrum efficiency coherent optical fiber transmissions systems. Several equalization algorithms including constant modulus algorithm (CMA), CMA plus postfilter, and cascaded multimodulus algorithm (CMMA) have been proposed as effective solutions for QDB-PDM-QPSK signal. For the first time as far as we know, the application conditions and performances for these three algorithms are analyzed and compared. System performances for a 112-Gb/s QDB-PDM-QPSK signal as a function of the optical filtering bandwidth and the optical SNR have been theoretically investigated. The results show that CMA would be the best choice in terms of convergence rate for general filtering. However, CMMA can outperform the other two schemes with a good receiver sensitivity and high-dynamic range of optical signal to noise ratio giving a strong filtering effect of super-Nyquist signaling.

Shi, Jianyang; Zhang, Junwen; Tao, Li; Wang, Yiguang; Wang, Yuanquan; Chi, Nan

2014-07-01

173

Adapting Wave-front Algorithms to Efficiently Utilize Systems with Deep Communication Hierarchies  

SciTech Connect

Large-scale systems increasingly exhibit a differential between intra-chip and inter-chip communication performance especially in hybrid systems using accelerators. Processorcores on the same socket are able to communicate at lower latencies, and with higher bandwidths, than cores on different sockets either within the same node or between nodes. A key challenge is to efficiently use this communication hierarchy and hence optimize performance. We consider here the class of applications that contains wavefront processing. In these applications data can only be processed after their upstream neighbors have been processed. Similar dependencies result between processors in which communication is required to pass boundary data downstream and whose cost is typically impacted by the slowest communication channel in use. In this work we develop a novel hierarchical wave-front approach that reduces the use of slower communications in the hierarchy but at the cost of additional steps in the parallel computation and higher use of on-chip communications. This tradeoff is explored using a performance model. An implementation using the Reverse-acceleration programming model on the petascale Roadrunner system demonstrates a 27% performance improvement at full system-scale on a kernel application. The approach is generally applicable to large-scale multi-core and accelerated systems where a differential in system communication performance exists.

Kerbyson, Darren J.; Lang, Michael; Pakin, Scott

2011-09-30

174

Code-phase-shift keying: a power and bandwidth efficient spread spectrum signaling technique for wireless local area network applications  

Microsoft Academic Search

Code-phase-shift keying (CPSK) is a novel direct-sequence spread-spectrum (DS-SS) signaling system employing M different code phase shifts of a single pseudonoise (PN) code sequence for M-ary signaling. CPSK offers increasing thermal noise immunity as M increases, and totally mitigates the effect of carrier frequency tone interference. It maintains good performance in a Rician fading channel, and a RAKE receiver could

Aries Y.-C. Wong; Victor C. M. Leung

1997-01-01

175

Survivable wavelength-division multiplexing passive optical network system with centralized protection routing scheme and efficient wavelength utilization  

NASA Astrophysics Data System (ADS)

A survivable wavelength-division multiplexing passive optical network (WDM-PON) with centralized protection scheme and colorless optical network units is proposed. The sideband channels generated via optical carrier suppression technique are used to carry both the downstream (DS) and the upstream (US) remodulated signals for two neighboring sub-PONs. By employing alternate path routing of sideband channels, the centralized protection scheme can provide reliable protection against any failure in feed fibers, remote node, and distribution fibers. The number of extra fibers is greatly reduced, and efficient utilization of wavelength resource is achieved. The feasibility of the proposed system is verified by 10-Gb/s DS and 1.25-Gb/s US signals over 25-km single-mode fiber transmission in both working and protection modes.

Zhou, Zhao; Xiao, Shilin; Bi, Meihua; Qi, Tao; Li, Pingqing; Hu, Weisheng

2013-09-01

176

Promoting emerging energy-efficiency technologies and practices by utilities in a restructured energy industry: A report from California  

SciTech Connect

The potential energy savings from emerging technologies (i.e., those technologies emerging from research and development) represent a significant resource to California and the US This paper describes how California's investor-owned utilities (IOUs) have been promoting emerging technologies over the last three years to increase energy efficiency in the buildings sector. During these years, the IOUs have experienced significant changes in their regulatory environment as part of the restructuring of the energy industry in California. These regulatory changes have impacted the way emerging technologies are treated by the regulatory community and the IOUs. After reviewing these changes, the paper concludes by discussing potential opportunities to improve the market penetration of emerging technologies.

Vine, Edward L.

2000-07-01

177

Energy-efficient reference gait generation utilizing variable ZMP and vertical hip motion based on inverted pendulum model for biped robots  

Microsoft Academic Search

Energy-efficient reference gait generation algorithm is suggested utilizing variable ZMP (Zero Moment Point) and vertical hip motion, which maxmizes the energy efficiency for cyclic gaits, based on inverted pendulum model (IPM) for biped robots. As observed in natural human walking, the robot's vertical hip motion (with average height and amplitude of hip ripple) as well as allowing variable ZMP pattern,

Hyeok Ki Shin; Byung Kook Kim

2010-01-01

178

Control of a wind-driven self-excited induction generator water-pumping system for maximum utilization efficiency  

SciTech Connect

This paper analyzes a stand-alone water-pumping system consisting of a motor-pump set supplied by a wind-driven self-excited induction generator. In order to achieve maximum utilization efficiency, the system designer is interested in optimally matching the system components together so that maximum energy available from the wind is absorbed and utilized all the time. Unfortunately, this optimal matching is speed-dependent and hence no single matching is valid for all wind speeds. Therefore the operating point of the system must vary with wind speed. In this paper, a control strategy is formulated which properly adjust the operating point of the system to coincide with the maximum power operating condition. The self-excited induction generator (SEIG) is basically an induction machine which is driven by a prime mover such as a wind turbine while a capacitor is connected across its stator terminals. The SEIG supplies an induction motor which is coupled to a water pump. The system need not operate continuously and water can be used directly for drinking and irrigation or it can be collected in a storage tank for later use. Due to the high cost of the wind turbine and equipment, the system designer is interested in maximizing the amount of pumped water per day. This can be achieved by proper selection and matching of the system components. However, proper matching of the system components together is not sufficient to guarantee maximum utilization since matching is dependent on wind speed. Therefore, certain system components must be controlled according to wind speed, such that matching is achieved all the time. This paper presents a control strategy to control the excitation capacitance of the induction generator such that its generated terminal voltage, which is applied to the induction motor, is kept constant as the rotor speed varies with wind speed.

Alghuwainem, S.M.

1998-07-01

179

Improved efficiency of bulk heterojunction hybrid solar cells by utilizing CdSe quantum dot-graphene nanocomposites.  

PubMed

We present a significant efficiency enhancement of hybrid bulk heterojunction solar cells by utilizing CdSe quantum dots attached to reduced graphene oxide (rGO) as the electron accepting phase, blended with the PCPDTBT polymer. The quantum dot attachment to rGO was achieved following a self-assembly approach, recently developed, using thiolated reduced graphene oxide (TrGO) to form a TrGO-CdSe nanocomposite. Therefore, we are able to obtain TrGO-CdSe quantum dot/PCPDTBT bulk-heterojunction hybrid solar cells with power conversion efficiencies of up to 4.2%, compared with up to 3% for CdSe quantum dot/PCPDTBT devices. The improvement is mainly due to an increase of the open-circuit voltage from 0.55 V to 0.72 V. We found evidence for a significant change in the heterojunction donor-acceptor blend nanomorphology, observable by a more vertical alignment of the TrGO-quantum dot nanocomposites in the z-direction and a different nanophase separation in the x-y direction compared to the quantum dot only containing device. Moreover, an improved charge extraction and trap state reduction were observed for TrGO containing hybrid solar cells. PMID:24820059

Eck, Michael; Pham, Chuyen Van; Züfle, Simon; Neukom, Martin; Sessler, Martin; Scheunemann, Dorothea; Erdem, Emre; Weber, Stefan; Borchert, Holger; Ruhstaller, Beat; Krüger, Michael

2014-06-28

180

Highly efficient SO2 absorption/activation and subsequent utilization by polyethylene glycol-functionalized Lewis basic ionic liquids.  

PubMed

Up to now, flue-gas desulfurization (FGD) is one of the most effective techniques to control SO(2) emission from the combustion of fossil fuels. The conventional technology for FGD poses serious inherent drawbacks such as formation of byproducts and volatilization of solvents. In this work, polyethylene glycol (PEG)-functionalized Lewis basic ionic liquids (ILs) derived from DABCO were proved to be highly efficient absorbents for FGD due to its specific features such as high thermal stability, negligible vapor pressure, high loading capacity. Notably, PEG(150)MeDABCONTf(2) gave an extremely high SO(2) capacity (4.38 mol mol(-1) IL), even under 0.1 bar SO(2) partial pressure (1.01 mol mol(-1) IL), presumably owing to the strong SO(2)-philic characterization of the PEG chain. Furthermore, the absorbed SO(2) could be easy to release by just bubbling N(2) at room temperature, greatly reducing energy requirement for SO(2) desorption. In addition, SO(2)/CO(2) selectivity (110) of PEG(150)MeDABCONTf(2) is two times larger than the non-functionalized imidazolium IL (45). On the other hand, through activation of SO(2) with the tertiary nitrogen in the cation, Lewis basic ILs such as PEG(150)MeDABCOBr proved to be efficient catalysts for the conversion of SO(2) to some value-added chemicals such as cyclic sulfites without utilization of any organic solvent or additive. Thus, this protocol would pave the way for the development of technological innovation towards efficient and low energy demanded practical process for SO(2) absorption and subsequent transformation. PMID:23090138

Yang, Zhen-Zhen; He, Liang-Nian; Song, Qing-Wen; Chen, Kai-Hong; Liu, An-Hua; Liu, Xiang-Ming

2012-12-01

181

A Novel Bargaining Based Dynamic Spectrum Management Scheme in Reconfigurable Systems  

Microsoft Academic Search

B3G wireless networks are expected to be characterized by the pouring of diversified services supported by different operators. In parallel with this, how to efficiently utilize the limited radio spectrum and guarantee the operator¿s profits has become a joint economical and technical problem. As a possible solution, in this paper, we set forth a novel bargaining approach for dynamic spectrum

Miao Pan; Shuo Liang; Haozhi Xiong; Jie Chen; Guangyi Liu

2006-01-01

182

A mechanistic dissection of polyethylenimine mediated transfection of CHO cells: To enhance the efficiency of recombinant DNA utilization.  

PubMed

In this study, we examine the molecular and cellular interactions that underpin efficient internalization and utilization of polyethylenimine (PEI):DNA complexes (polyplexes) by Chinese Hamster Ovary (CHO) cells. Cell surface polyplex binding and internalization was a biphasic process, consisting of an initial rapid Phase (I), lasting approximately 15 min, followed by a slower second Phase (II), saturating at approximately 240 min post transfection. The second Phase accounted for the majority (60-70%) of polyplex internalization. While cell surface heparan sulphate proteoglycans (HSPGs) were rapidly cointernalized with polyplexes during Phase I, cell surface polyplex binding was not dependent on HSPGs. However, Phase II polyplex internalization and HSPG regeneration onto the surface of trypsinized cells occurred at similar rates, suggesting that the rate of recycling of HSPG-containing membrane to the plasma membrane limits Phase II internalization rate. Under optimal transfection conditions, polyplexes had a near neutral surface charge (zeta potential) and cell surface binding was dependent on hydrophobic interactions, being significantly inhibited by both chemical sequestration of cholesterol from the plasma membrane and addition of nonionic surfactant. Induced alterations in polyplex zeta potential, using ferric (III) citrate to decrease surface charge and varying PEI:DNA ratio to increase surface charge, served to inhibit polyplex binding or reduce secreted alkaline phosphatase reporter expression and cell viability, respectively. To increase polyplex hydrophobicity and internalization an alkylated derivative of PEI, propyl-PEI, was chemically synthesized. Using Design of Experiments-Response Surface Modeling to optimize the transfection process, the function of propyl-PEI was compared to that of unmodified PEI in both parental CHO-S cells and a subclone (Clone 4), which exhibited superior transgene expression via an increased resistance to polyplex cytotoxicity. The combination of propyl-PEI and Clone 4 doubled the efficiency of recombinant DNA utilization and reporter protein production. These data show that for maximal efficacy, strategies to increase polyplex internalization into cells must be used in concert with strategies to offset the inherent cytotoxicity of this process. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1161-1170, 2014. PMID:24850296

Mozley, Olivia L; Thompson, Ben C; Fernandez-Martell, Alejandro; James, David C

2014-09-01

183

Genome Sequence of Thermophilic Bacillus licheniformis Strain 3F-3, an Efficient Pentose-Utilizing Producer of 2,3-Butanediol  

PubMed Central

Bacillus licheniformis strain 3F-3 is an efficient pentose-utilizing producer of platform chemical, 2,3-butanediol. Here we present a 4.1-Mb assembly of its genome. The key genes for pentose utilization, regulation, and metabolism of 2,3-butanediol were annotated, which may provide further insights into the molecular mechanism of 2,3-butanediol production from biomass pentose. PMID:24970831

Li, Lixiang; Wang, Yu; Wang, Kai; Li, Kun; Ma, Cuiqing

2014-01-01

184

Spectrum management considerations of adaptive power control in satellite networks  

NASA Technical Reports Server (NTRS)

Adaptive power control concepts for the compensation of rain attenuation are considered for uplinks and downlinks. The performance of example power-controlled and fixed-EIRP uplinks is compared in terms of C/Ns and C/Is. Provisional conclusions are drawn with regard to the efficacy of uplink and downlink power control orbit/spectrum utilization efficiency.

Sawitz, P.; Sullivan, T.

1983-01-01

185

An Assessment Model for Energy Efficiency Program Planning in Electric Utilities: Case of the Pacific of Northwest U.S.A  

NASA Astrophysics Data System (ADS)

Energy efficiency stands out with its potential to address a number of challenges that today's electric utilities face, including increasing and changing electricity demand, shrinking operating capacity, and decreasing system reliability and flexibility. Being the least cost and least risky alternative, the share of energy efficiency programs in utilities' energy portfolios has been on the rise since the 1980s, and their increasing importance is expected to continue in the future. Despite holding great promise, the ability to determine and invest in only the most promising program alternatives plays a key role in the successful use of energy efficiency as a utility-wide resource. This issue becomes even more significant considering the availability of a vast number of potential energy efficiency programs, the rapidly changing business environment, and the existence of multiple stakeholders. This dissertation introduces hierarchical decision modeling as the framework for energy efficiency program planning in electric utilities. The model focuses on the assessment of emerging energy efficiency programs and proposes to bridge the gap between technology screening and cost/benefit evaluation practices. This approach is expected to identify emerging technology alternatives which have the highest potential to pass cost/benefit ratio testing procedures and contribute to the effectiveness of decision practices in energy efficiency program planning. The model also incorporates rank order analysis and sensitivity analysis for testing the robustness of results from different stakeholder perspectives and future uncertainties in an attempt to enable more informed decision-making practices. The model was applied to the case of 13 high priority emerging energy efficiency program alternatives identified in the Pacific Northwest, U.S.A. The results of this study reveal that energy savings potential is the most important program management consideration in selecting emerging energy efficiency programs. Market dissemination potential and program development and implementation potential are the second and third most important, whereas ancillary benefits potential is the least important program management consideration. The results imply that program value considerations, comprised of energy savings potential and ancillary benefits potential; and program feasibility considerations, comprised of program development and implementation potential and market dissemination potential, have almost equal impacts on assessment of emerging energy efficiency programs. Considering the overwhelming number of value-focused studies and the few feasibility-focused studies in the literature, this finding clearly shows that feasibility-focused studies are greatly understudied. The hierarchical decision model developed in this dissertation is generalizable. Thus, other utilities or power systems can adopt the research steps employed in this study as guidelines and conduct similar assessment studies on emerging energy efficiency programs of their interest.

Iskin, Ibrahim

186

Utility of the "Social Communication Questionnaire-Current" and "Social Responsiveness Scale" as Teacher-Report Screening Tools for Autism Spectrum Disorders  

ERIC Educational Resources Information Center

Limited research exists regarding the role of teachers in screening for Autism Spectrum Disorders (ASD). The current study examined the use of the "Social Communication Questionnaire" (SCQ) and "Social Responsiveness Scale" (SRS) as completed by parents and teachers about school-age children from the Simons Simplex Collection. Using the…

Schanding, G. Thomas, Jr.; Nowell, Kerri P.; Goin-Kochel, Robin P.

2012-01-01

187

Free lysine ( l-lysine · HCl) is utilized for growth less efficiently than protein-bound lysine (soybean meal) in practical diets by young channel catfish ( Ictalurus punctatus)  

Microsoft Academic Search

Two 10-week feeding experiments were conducted with channel catfish fingerlings in aquaria to compare the efficiency of utilization for growth of free versus protein bound lysine in practical diets. In experiment 1, a basal, 26% protein diet, deficient only in lysine, was formulated with a combination of peanut meal and corn gluten meal as the primary protein source. The diet

Dannie D. Zarate; Richard T. Lovell

1997-01-01

188

Outage Performance of the Primary Service in Spectrum Sharing Networks  

E-print Network

and utilizes the spectrum holes or white spaces [3], [6]. White spaces are those parts of the spectrum access (OSA) [4], [5]. In the OSA, the SS utilizes spectrum sensing schemes to detect the white spaces

Yanikomeroglu, Halim

189

An Analysis of Learner Efficiency when Individualized and Group-Instructional Formats are Utilized with Disadvantaged Students  

ERIC Educational Resources Information Center

Analyzes four instructional methods used to teach biology to disadvantaged high school students in terms of learning efficiency (net gain mean/total time mean). Concludes that individualized methods are more efficient than group methods. (MLH)

Kahle, Jane B.; And Others

1976-01-01

190

Group-based spectrum assignment in dynamic flex-grid optical networks  

NASA Astrophysics Data System (ADS)

Traditional wavelength switched optical network employing wavelength-division-multiplexing (WDM) technology, allocates constant spectrum band to different kinds of services, which lacks flexibility in spectrum provisioning and thus reduces the resource utilization efficiency. Flex-grid technology, which introduces a finer spectrum granularity and allocates spectrum to different services flexibly according to their required bandwidth, is considered a promising candidate solution to improve the resource utilization efficiency of an optical network. However, since multiple contiguous spectrum granularities are usually assigned to a single service in such flex-grid optical network, the spectrum continuity and contiguity constraints should always be guaranteed, which may induce spectrum fragmentation. With the accumulation of spectrum fragmentation, available spectrum resources decrease, and this will greatly worsen the performance of the whole network, especially in networking. Therefore, spectrum fragmentation is considered a serious problem in flex-grid optical networks and many schemes have been proposed to solve it. These existing schemes, known as defragmentation, can reduce spectrum fragmentation either by rerouting the lightpath or by reallocating the spectrum for a service, which re-optimizes the spectrum resources. However, in the rerouting or reallocation procedure, existing traffic may be disrupted or extra resources, such as alternative spectrum or expensive spectrum convertors, are needed. None of these schemes can solve spectrum fragmentation with both no disrupted traffic and extra resources. It is because all these schemes utilize remedial methods to solve fragmentation problem and either disrupted traffic or extra resources are the cost when they cope with the defragmented spectrum. Different from all the above schemes, we propose a precautionary method to solve fragmentation problem in this paper. By introducing group-based spectrum assignment algorithm into flex-grid optical networks, spectrum resources are sorted into groups and each spectrum group only accommodates one specific kind of services. Since released spectrum can always be reused by the services of the same kind, spectrum fragmentation is prevented from its generation. Simulation results demonstrate that the proposed algorithm induces no spectrum fragmentations and is suitable to accommodate high-speed services.

Qiu, Yang

2013-10-01

191

Optimal Design of the Spectrum Sensing Parameters in the Overlay Spectrum Sharing  

E-print Network

is referred to as spectrum holes or white spaces. The under-utilized portions of the spectrum in a specific related to the sensing mechanism for detecting and monitoring the white spaces [5]. The spectrum sensing

Yanikomeroglu, Halim

192

Development of Technologies for a High Efficiency, Very Low Emission, Diesel Engine for Light Trucks and Sport Utility Vehicles  

SciTech Connect

Cummins Inc., in partnership with the Department of Energy, has developed technology for a new highly efficient, very low emission, diesel engine for light trucks and sport utility vehicles. This work began in April 1997, and started with very aggressive goals for vehicles in the 5751 to 8500 pound GCW weight class. The primary program goals were as follows: (1) EMISSIONS--NO{sub x} = 0.50 g/mi; PM = 0.05 g/mi; CO = 2.8 g/mi; and NMHC = 0.07 g/mi. California decided to issue new and even tougher LEV II light truck regulations late in 1999. EPA also issued its lower Tier 2 regulations late in 2000. The net result was that the targets for this diesel engine project were lowered, and these goals were eventually modified by the publication of Federal Tier 2 emission standards early in 2000 to the following: NO{sub x} = 0.07 g/mi; and PM = 0.01 g/mi. (2) FUEL ECONOMY--The fuel economy goal was 50 percent MPG improvement (combined city/highway) over the 1997 gasoline powered light truck or sport utility vehicle in the vehicle class for which this diesel engine is being designed to replace. The goal for fuel economy remained at 50 percent MPG improvement, even with the emissions goal revisions. (3) COOPERATIVE DEVELOPMENT--Regular design reviews of the engine program will be conducted with a vehicle manufacturer to insure that the concepts and design specifics are commercially feasible. (DaimlerChrysler has provided Cummins with this design review input.) Cummins has essentially completed a demonstration of proof-of-principle for a diesel engine platform using advanced combustion and fuel system technologies. Cummins reported very early progress in this project, evidence that new diesel engine technology had been developed that demonstrated the feasibility of the above emissions goals. Emissions levels of NOx = 0.4 g/mi and PM = 0.06 g/mi were demonstrated for a 5250 lb. test weight vehicle with passive aftertreatment only. These results were achieved using the full chassis dynamometer FTP-75 test procedure that allowed compliance with the Tier 2 Interim Bin 10 Standards and would apply to vehicles in MY2004 through MY2007 timeframe. In further technology development with active aftertreatment management, Cummins has been able to report that the emissions goals for the Tier 2 Bin 5 standards were met on an engine running the full FTP-75 test procedure. The fuel economy on the chassis tests was measured at over 59 percent MPG improvement over the gasoline engines that are offered in typical SUVs and light trucks. The above demonstration used only in-cylinder fueling for management of the aftertreatment system.

John H. Stang

2005-12-31

193

Development of Technologies for a High Efficiency, Very Low Emission, Diesel Engine for Light Trucks and Sport Utility Vehicles  

SciTech Connect

Cummins Inc., in partnership with the Department of Energy, has developed technology for a new highly efficient, very low emission, diesel engine for light trucks and sport utility vehicles. This work began in April 1997, and started with very aggressive goals for vehicles in the 5751 to 8500 pound GCW weight class. The primary program goals were as follows: (1) EMISSIONS -- NOx = 0.50 g/mi; PM = 0.05 g/mi; CO = 2.8 g/mi; and NMHC = 0.07 g/mi. California decided to issue new and even tougher LEV II light truck regulations late in 1999. EPA also issued its lower Tier 2 regulations late in 2000. The net result was that the targets for this diesel engine project were lowered, and these goals were eventually modified by the publication of Federal Tier 2 emission standards early in 2000 to the following: NOx = 0.07 g/mi; and PM = 0.01 g/mi. (2) FUEL ECONOMY -- The fuel economy goal was 50 percent MPG improvement (combined city/highway) over the 1997 gasoline powered light truck or sport utility vehicle in the vehicle class for which this diesel engine is being designed to replace. The goal for fuel economy remained at 50 percent MPG improvement, even with the emissions goal revisions. (3) COOPERATIVE DEVELOPMENT -- Regular design reviews of the engine program will be conducted with a vehicle manufacturer to insure that the concepts and design specifics are commercially feasible. (DaimlerChrysler has provided Cummins with this design review input.) Cummins has essentially completed a demonstration of proof-of-principle for a diesel engine platform using advanced combustion and fuel system technologies. Cummins reported very early progress in this project, evidence that new diesel engine technology had been developed that demonstrated the feasibility of the above emissions goals. Emissions levels of NOx = 0.4 g/mi and PM = 0.06 g/mi were demonstrated for a 5250 lb. test weight vehicle with passive aftertreatment only. These results were achieved using the full chassis dynamometer FTP-75 test procedure that allowed compliance with the Tier 2 Interim Bin 10 Standards and would apply to vehicles in MY2004 through MY2007 timeframe. In further technology development with active aftertreatment management, Cummins has been able to report that the emissions goals for the Tier 2 Bin 5 standards were met on an engine running the full FTP-75 test procedure. The fuel economy on the chassis tests was measured at over 59 percent MPG improvement over the gasoline engines that are offered in typical SUVs and light trucks. The above demonstration used only in-cylinder fueling for management of the aftertreatment system.

Stang, John H.

2005-12-19

194

Utility residential new construction programs: Going beyond the code. A report from the Database on Energy Efficiency Programs (DEEP) Project  

SciTech Connect

Based on an evaluation of 10 residential new construction programs, primarily sponsored by investor-owned utilities in the United States, we find that many of these programs are in dire straits and are in danger of being discontinued because current inclusion of only direct program effects leads to the conclusion that they are not cost-effective. We believe that the cost-effectiveness of residential new construction programs can be improved by: (1) promoting technologies and advanced building design practices that significantly exceed state and federal standards; (2) reducing program marketing costs and developing more effective marketing strategies; (3) recognizing the role of these programs in increasing compliance with existing state building codes; and (4) allowing utilities to obtain an ``energy-savings credit`` from utility regulators for program spillover (market transformation) impacts. Utilities can also leverage their resources in seizing these opportunities by forming strong and trusting partnerships with the building community and with local and state government.

Vine, E.

1995-08-01

195

Improved utilization efficiency of Ga source and flatness of GaN layer by pulsed-GaCl flow modulation on hydride vapor phase epitaxy  

NASA Astrophysics Data System (ADS)

This paper presents the results of pulsed-GaCl flow modulation epitaxy (FME) on hydride vapor phase epitaxy (HVPE) at various interval times, supply times, and V/III ratios under a constant NH3 flow. The best performance was observed at an interval time of 30 s, GaCl gas supply time of 10 s in one cycle and V/III ratio of 10. As compared to the conventional HVPE growth, the utilization efficiency of the GaCl gas improved by 2.5 times in the present method and the root-mean-square (RMS) values reduced to one-fifth of the original, without degradation of crystalline quality. We concluded that the dynamic change in the V/III ratio in one cycle of an FME sequence contributed to a change in the growth mode, resulting in an improved utilization efficiency of the GaCl gas.

Yamane, Keisuke; Hashimoto, Yasuhiro; Okada, Narihito; Tadatomo, Kazuyuki

2014-10-01

196

Effects of photoperiod on the performance of farmed Nile tilapia Oreochromis niloticus: I. Growth, feed utilization efficiency and survival of fry and fingerlings  

Microsoft Academic Search

The effect of photoperiod on survival, growth rates and feed utilization efficiency of Nile tilapia (Oreochromis niloticus L.) fry and fingerlings was investigated in two consecutive experiments. In Experiment 1, triplicate groups of 75 swim-up fry (0.02 g) were stocked in 25-l fiberglass tanks, in recirculating indoor system. The fish were exposed to four photoperiod (light:dark, L:D) cycles (24L:0D, 18L:6D,

Abdel-Fattah M El-Sayed; Mamdouh Kawanna

2004-01-01

197

Blackbody Spectrum  

NSDL National Science Digital Library

How does the blackbody spectrum of the sun compare to visible light? Learn about the blackbody spectrum of the sun, a light bulb, an oven, and the earth. Adjust the temperature to see the wavelength and intensity of the spectrum change. View the color of the peak of the spectral curve.

Simulations, Phet I.; Dubson, Michael; Perkins, Kathy; Adams, Wendy

2004-06-01

198

Achieving spectrum conservation for the minimum-span and minimum-order frequency assignment problems  

NASA Technical Reports Server (NTRS)

Effective and efficient solutions of frequency assignment problems assumes increasing importance as the radiofrequency spectrum experiences ever increasing utilization by diverse communications services, requiring that the most efficient use of this resource be achieved. The research presented explores a general approach to the frequency assignment problem, in which such problems are categorized by the appropriate spectrum conserving objective function, and are each treated as an N-job, M-machine scheduling problem appropriate for the objective. Results obtained and presented illustrate that such an approach presents an effective means of achieving spectrum conserving frequency assignments for communications systems in a variety of environments.

Heyward, Ann O.

1992-01-01

199

Improving the efficiency of feed utilization in poultry by selection. 1. Genetic parameters of anatomy of the gastro-intestinal tract and digestive efficiency  

Microsoft Academic Search

Background  Feed costs represent about 70% of the costs of raising broilers. The main way to decrease these costs is to improve feed efficiency\\u000a by modification of diet formulation, but one other possibility would be to use genetic selection. Understanding the genetic\\u000a architecture of the gastro-intestinal tract (GIT) and the impact of the selection criterion on the GIT would be of

Hugues de Verdal; Agnès Narcy; Denis Bastianelli; Hervé Chapuis; Nathalie Même; Séverine Urvoix; Elisabeth Le Bihan-Duval; Sandrine Mignon-Grasteau

2011-01-01

200

High Prescription Drug Utilization and Associated Costs among Medicaid-eligible Children with Autism Spectrum Disorders Identified by a Population-based Surveillance Network  

PubMed Central

Purpose This study assessed medication use and associated costs among 8- and 15-yearold children with autism spectrum disorders (ASD) identified by the South Carolina Autism and Developmental Disabilities Monitoring (SCADDM) Network. Methods All Medicaid-eligible SCADDM-identified children with ASD from surveillance years 2006 and 2007 were included (n=263). Children were classified as ASD cases when documented behaviors consistent with the DSM-IV-TR criteria for autistic disorder, Asperger disorder, or pervasive developmental disorder- not otherwise specified (PDD-NOS) were present in health and education evaluation records. Medication and cost data were obtained by linking population-based and Medicaid data. Results All 263 SCADDM-identified children had Medicaid data available; 56% (n=147) had a prescription of any type, 40% (n=105) used psychotropic medication, and 20% (n=52) used multiple psychotropic classes over the study period. Common combinations were (1) attention deficit hyperactivity disorder (ADHD) medications and an antihypertensive, antidepressant or antipsychotic; and (2) antidepressants and an antipsychotic. Multiple psychotropic classes were more common among older children. Both the overall distribution of the number of prescription claims and medication costs varied significantly by age. Conclusions Results confirm that medication use in ASD, alone or in combination, is common, costly, and may increase with age. PMID:22153288

Logan, Sarah L.; Nicholas, Joyce S.; Carpenter, Laura A.; King, Lydia B.; Garrett-Mayer, Elizabeth; Charles, Jane M.

2011-01-01

201

Adaptive spectrum sensing for agile cognitive radios  

Microsoft Academic Search

Vast segments of the frequency spectrum are licensed to specific users for particular applications. These legacy users, however, of- ten under-utilize their designated spectrum segments. Unlicensed (secondary) users can benefit from this fact and opportunistically exploit the vacant spectrum segments (spectral holes). Due to the transient nature of the spectrum occupancy it becomes imperative for secondary users to quickly identify

Ali Tajer; Rui Castro; Xiaodong Wang

2010-01-01

202

Development of high-efficiency cost-effective, zinc--chlorine batteries for utility peak-shaving, 1976. Interim report  

Microsoft Academic Search

The two principal thrusts of this program were battery scale-up by a factor of twenty from earlier work and investigation of the economics of zinc--chlorine peak-shaving batteries located at utility substations. Development programs on cell performance, electrode research, and materials of construction were conducted in support of these objectives. A battery was designed, built, and tested which delivered 18 kWh

Symons

1978-01-01

203

High efficiency, quasi-instantaneous steam expansion device utilizing fossil or nuclear fuel as the heat source  

Microsoft Academic Search

Thermal-hydraulic analysis of a specially designed steam expansion device (heat cavity) was performed to prove the feasibility of steam expansions at elevated rates for power generation with higher efficiency. The steam expansion process inside the heat cavity greatly depends on the gap within which the steam expands and accelerates. This system can be seen as a miniaturized boiler integrated inside

Claudio Filippone

1999-01-01

204

HIGH EFFICIENCY, QUASI-INSTANTANEOUS STEAM EXPANSION DEVICE UTILIZING FOSSIL OR NUCLEAR FUEL AS THE HEAT SOURCE  

Microsoft Academic Search

Thermal-hydraulic analysis of a specially designed steam expansion device (heat cavity) was performed to prove the feasibility of steam expansions at elevated rates for power generation with higher efficiency. The steam expansion process inside the heat cavity greatly depends on the gap within which the steam expands and accelerates. This system can be seen as a miniaturized boiler integrated inside

Claudio Filippone

1999-01-01

205

The efficiency and effectiveness of utilizing diagrams in interviews: an assessment of participatory diagramming and graphic elicitation  

PubMed Central

Background This paper focuses on measuring the efficiency and effectiveness of two diagramming methods employed in key informant interviews with clinicians and health care administrators. The two methods are 'participatory diagramming', where the respondent creates a diagram that assists in their communication of answers, and 'graphic elicitation', where a researcher-prepared diagram is used to stimulate data collection. Methods These two diagramming methods were applied in key informant interviews and their value in efficiently and effectively gathering data was assessed based on quantitative measures and qualitative observations. Results Assessment of the two diagramming methods suggests that participatory diagramming is an efficient method for collecting data in graphic form, but may not generate the depth of verbal response that many qualitative researchers seek. In contrast, graphic elicitation was more intuitive, better understood and preferred by most respondents, and often provided more contemplative verbal responses, however this was achieved at the expense of more interview time. Conclusion Diagramming methods are important for eliciting interview data that are often difficult to obtain through traditional verbal exchanges. Subject to the methodological limitations of the study, our findings suggest that while participatory diagramming and graphic elicitation have specific strengths and weaknesses, their combined use can provide complementary information that would not likely occur with the application of only one diagramming method. The methodological insights gained by examining the efficiency and effectiveness of these diagramming methods in our study should be helpful to other researchers considering their incorporation into qualitative research designs. PMID:18691410

Umoquit, Muriah J; Dobrow, Mark J; Lemieux-Charles, Louise; Ritvo, Paul G; Urbach, David R; Wodchis, Walter P

2008-01-01

206

Efficient utilization of complex N-linked glycans is a selective advantage for Bacteroides fragilis in extraintestinal infections.  

PubMed

Bacteroides fragilis is the most common anaerobe isolated from clinical infections, and in this report we demonstrate a characteristic of the species that is critical to their success as an opportunistic pathogen. Among the Bacteroides spp. in the gut, B. fragilis has the unique ability of efficiently harvesting complex N-linked glycans from the glycoproteins common to serum and serous fluid. This activity is mediated by an outer membrane protein complex designated as Don. Using the abundant serum glycoprotein transferrin as a model, it has been shown that B. fragilis alone can rapidly and efficiently deglycosylate this protein in vitro and that transferrin glycans can provide the sole source of carbon and energy for growth in defined media. We then showed that transferrin deglycosylation occurs in vivo when B. fragilis is propagated in the rat tissue cage model of extraintestinal growth, and that this ability provides a competitive advantage in vivo over strains lacking the don locus. PMID:25139987

Cao, Yanlu; Rocha, Edson R; Smith, C Jeffrey

2014-09-01

207

Yield and Resource Utilization Efficiency in Baby Corn—Legume-Intercropping System in the Eastern Plateau of India  

Microsoft Academic Search

Cereal-legume intercropping plays a pivotal role for increasing land use efficiency and atmospheric nitrogen fixation. A field experiment was carried out on a baby corn–legume intercropping system in 2:1 and 2:2 additive series in the eastern plateau region of India over two consecutive rainy seasons (2003\\/2004). The experimental design was a randomized complete block with 13 treatments replicated thrice. Significant

P. Banik; R. C. Sharma

2009-01-01

208

Loss of Glyphosate Efficacy: A Changing Weed Spectrum in Georgia Cotton  

Microsoft Academic Search

Introduction of glyphosate resistance into crops through genetic modification has revolutionized crop protection. Glyphosate is a broad-spectrum herbicide with favorable environmental characteristics and effective broad-spectrum weed control that has greatly improved crop protection efficiency. However, in less than a decade, the utility of this technology is threatened by the occurrence of glyphosate-tolerant and glyphosate-resistant weed species. Factors that have contributed

Theodore M. Webster; Lynn M. Sosnoskie

2010-01-01

209

An Energy and Peak Loads Analysis of the Texas Department of Health Building, Final Report, Prepared for the Energy Efficiency Division, Texas Public Utility Commission  

E-print Network

ESL-TR-86/10-01 AN ENERGY AND PEAK LOADS ANALYSIS OF THE TEXAS DEPARTMENT OF HEALTH BUILDING FINAL REPORT October 1986 Submitted by Srinivas Katipamula Dennis O'Neal Prepared For Energy Efficiency Division Texas Public Utility Commission Austin..., Texas SUMMARY The energy use of the Department of Health Building at Austin, Texas, was analyzed using the DOE 2.1B building energy simulation program. An analysis was made for the building as specified in the building plans and the specifications...

Katipamula, S.; O'Neal, D. L.

1986-01-01

210

Efficient succinic acid production from lignocellulosic biomass by simultaneous utilization of glucose and xylose in engineered Escherichia coli.  

PubMed

To enhance succinic acid formation during xylose fermentation in Escherichia coli, overexpression of ATP-forming phosphoenolpyruvate carboxykinase (PEPCK) from Bacillus subtilis 168 in an ldhA, pflB, and ppc deletion strain resulted in a significant increase in cell mass and succinic acid production. However, BA204 displays a low yield of glucose fermentation and sequential glucose-xylose utilization under regulation by the phosphotransferase system (PTS). To improve the capability of glucose fermentation and simultaneously consume sugar mixture for succinic acid production, a pflB, ldhA, ppc, and ptsG deletion strain overexpressing ATP-forming PEPCK, named E. coli BA305, was constructed. As a result, after 120 h fed-batch fermentation of sugarcane bagasse hydrolysate, the dry cell weight and succinic acid concentration in BA305 were 4.58 g L(-1) and 39.3 g L(-1), respectively. PMID:24096277

Liu, Rongming; Liang, Liya; Li, Feng; Wu, Mingke; Chen, Kequan; Ma, Jiangfeng; Jiang, Min; Wei, Ping; Ouyang, Pingkai

2013-12-01

211

Variation in the apparent sensitivity of the insulin-mediated inhibition of proteolysis to amino acid supply determines the efficiency of protein utilization.  

PubMed

1. The variability between normal individuals in the efficiency of postprandial protein utilization (PPU), a determinant of the apparent protein requirement, was examined in relation to the relative responses of protein synthesis and proteolysis to protein feeding by means of [1-13C]leucine turnover and balance studies.2. Twenty-five healthy adults were infused intravenously with L-[1-13C]leucine continuously for 9 h. This was started in the postabsorptive state (PA, 3 h) and followed by low-protein feeding (LP, 3 h), and then by isoenergetic high-protein feeding (HP, 3 h). This allowed protein intake to be varied against a constant postprandial insulin level so that the extent of any amino-acid-mediated responses which were additional to those exerted by insulin could be investigated. Leucine oxidation, O, and balance (intake-oxidation), protein synthesis, S, and degradation, D, were calculated from plasma [1-13C]alpha-ketoisocaproic acid enrichment and 13CO2 excretion.3.PPUprotein, calculated as change in leucine balance/change in intake (HP-LP), varied from 0.58 to 0.99 (mean=0. 81+/-0.10), independently of age or sex. PPUprotein varied directly with the inhibition of D and inversely with the increase in leucine concentration and stimulation of O and S.4. Efficient PPU, as demonstrated by the top quintile of individuals categorized in terms of PPUprotein, involves maximal inhibition of D by protein feeding with minimal increases in free amino acid concentrations, O and S. Lesser inhibition of D and greater stimulation of S and O characterized the lower, less efficient quintile. This indicates that the efficiency of protein utilization in individuals, and a component of their apparent protein requirement, is determined by the sensitivity of the insulin-mediated inhibition of proteolysis to amino acid supply. PMID:9831698

Fereday, A; Gibson, N R; Cox, M; Pacy, P J; Millward, D J

1998-12-01

212

High efficiency, quasi-instantaneous steam expansion device utilizing fossil or nuclear fuel as the heat source  

SciTech Connect

Thermal-hydraulic analysis of a specially designed steam expansion device (heat cavity) was performed to prove the feasibility of steam expansions at elevated rates for power generation with higher efficiency. The steam expansion process inside the heat cavity greatly depends on the gap within which the steam expands and accelerates. This system can be seen as a miniaturized boiler integrated inside the expander where steam (or the proper fluid) is generated almost instantaneously prior to its expansion in the work-producing unit. Relatively cold water is pulsed inside the heat cavity, where the heat transferred causes the water to flash to steam, thereby increasing its specific volume by a large factor. The gap inside the heat cavity forms a special nozzle-shaped system in which the fluid expands rapidly, accelerating toward the system outlet. The expansion phenomenon is the cause of ever-increasing fluid speed inside the cavity system, eliminating the need for moving parts (pumps, valves, etc.). In fact, the subsequent velocity induced by the sudden fluid expansion causes turbulent conditions, forcing accelerating Reynolds and Nusselt numbers which, in turn, increase the convective heat transfer coefficient. When the combustion of fossil fuels constitutes the heat source, the heat cavity concept can be applied directly inside the stator of conventional turbines, thereby greatly increasing the overall system efficiency.

Claudio Filippone, Ph.D.

1999-06-01

213

Efficient and colour-stable hybrid white organic light-emitting diodes utilizing electron-hole balanced spacers  

NASA Astrophysics Data System (ADS)

High-efficiency two-colour white organic light-emitting diodes (WOLEDs) comprising a newly synthesized iridium complex orange phosphor ((impy)2Ir(acac)) and a blue fluorophor (BD012) have been realized by placing several kinds of thin spacers between two emitters. Hybrid WOLEDs with a spacer composed of a hole-transporting N,N-dicarbazolyl-3,5-benzene (mCP) and an electron-transporting 4,7-diphenyl-1,10-phenanthroline (Bphen) exhibit a high external quantum efficiency (EQE) of up to 8.4% and a negligible colour change (the colour coordinate of (0.39, 0.41) at 1000 cd m-2) with increasing brightness, whereas the device using a hole-transporting mCP spacer shows a relatively low EQE of 6.2% and a large shift of emitting colour with increasing brightness. Device performance is further characterized based on the charge transport behaviour of the spacers inserted between the two emitters.

Leem, Dong-Seok; Kim, Ji Whan; Ouk Jung, Sung; Kim, Seul-Ong; Kim, Se Hoon; Kim, Kee Young; Kim, Yun-Hi; Kwon, Soon-Ki; Kim, Jang-Joo

2010-10-01

214

Evaluation of energy-conversion efficiencies in microbial fuel cells (MFCs) utilizing fermentable and non-fermentable substrates.  

PubMed

We established the first complete electron-equivalent balances in microbial fuel cells (MFCs) fed with non-fermentable (acetate) and fermentable (glucose) electron donors by experimentally quantifying current, biomass, residual organic compounds, H(2), and CH(4) gas. The comparison of the two donors allowed us to objectively evaluate the diversion of electron flow to non-electricity sinks for fermentable donors, leading to different behaviors in energy-conversion efficiency (ECE) and potential efficiency (PE). Electrical current was the most significant electron sink in both MFCs, being 71% and 49%, respectively, of the initial COD applied. Biomass and residual organic compounds, the second and third greatest sinks, respectively, were greater in the glucose-fed MFC than in the acetate-fed MFC. We detected methane gas only in the glucose-fed MFC, and this means that anode-respiring bacteria (ARB) could out-compete acetoclastic methanogens. The ECE was 42% with acetate, but was only 3% with glucose. The very low ECE for glucose was mostly due to a large increase of the anode potential, giving a PE of only 6%. Although the glucose-fed MFC had the higher biomass density on its anode, it had a very low current density, which supports the fact that the density of ARB was very low. This led to slow kinetics for electron transfer to the anode and accentuated loss due to the substrate-concentration gradient in the anode-biofilm. The large drop of PE with low current, probably caused by a low ARB density and electron (e(-)) donor concentration, resulted in a poor maximum power density (9.8mW/m(2)) with glucose. In contrast, PE reached 59% along with high current for acetate and the maximum power density was 360mW/m(2). PMID:18035391

Lee, Hyung-Sool; Parameswaran, Prathap; Kato-Marcus, Andrew; Torres, César I; Rittmann, Bruce E

2008-03-01

215

Myocardial blood flow and its transit time, oxygen utilization, and efficiency of highly endurance-trained human heart.  

PubMed

Highly endurance-trained athlete's heart represents the most extreme form of cardiac adaptation to physical stress, but its circulatory alterations remain obscure. In the present study, myocardial blood flow (MBF), blood mean transit time (MTT), oxygen extraction fraction (OEF) and consumption (MVO2), and efficiency of cardiac work were quantified in highly trained male endurance athletes and control subjects at rest and during supine cycling exercise using [(15)O]-labeled radiotracers and positron emission tomography. Heart rate and MBF were lower in athletes both at rest and during exercise. OEF increased in response to exercise in both groups, but was higher in athletes (70 ± 21 vs. 63 ± 11 % at rest and 86 ± 13 vs. 73 ± 10 % during exercise). MTT was longer and vascular resistance higher in athletes both at rest and during exercise, but arterial content of 2,3-diphosphoglycerate (oxygen affinity) was unchanged. MVO2 per gram of myocardium trended (p = 0.08) lower in athletes both at rest and during exercise, while myocardial efficiency of work and MVO2 per beat were not different between groups. Arterial levels of free fatty acids were ~twofold higher in athletes likely leading to higher myocardial fatty acid oxidation and hence oxygen cost, which may have blunted the bradycardia-induced decrease in MVO2. Finally, the observed group differences in MBF, OEF, MTT and vascular resistance remained significant also after they were controlled for differences in MVO2. In conclusion, in highly endurance-trained human heart, increased myocardial blood transition time enables higher oxygen extraction levels with a lower myocardial blood flow and higher vascular resistance. These physiological adaptations to exercise training occur independently of the level of oxygen consumption and together with training-induced bradycardia may serve as mechanisms to increase functional reserve of the human heart. PMID:24866583

Heinonen, Ilkka; Kudomi, Nobuyuki; Kemppainen, Jukka; Kiviniemi, Antti; Noponen, Tommi; Luotolahti, Matti; Luoto, Pauliina; Oikonen, Vesa; Sipilä, Hannu T; Kopra, Jaakko; Mononen, Ilkka; Duncker, Dirk J; Knuuti, Juhani; Kalliokoski, Kari K

2014-07-01

216

Speed control of a PV powered DC motor driving a self-excited 3-phase induction generator for maximum utilization efficiency  

SciTech Connect

Photovoltaic (PV) powered dc motors driving dedicated loads (e.g., water pumps) are increasingly used in the remote rural areas of may developing countries. The key to their success is simplicity (direct coupling, no dc-ac conversion, no storage batteries, etc.). Because of the relatively high cost of the PV array, the system designer is interested in maximizing its utilization efficiency. A PV powered dc motor can also be used to drive a three-phase self-excited induction generator (SEIG). This arrangement is useful as part of an integrated renewable energy system (IRES), which takes advantage of the inherent diversity of wind and solar energy in most developing countries to improve power quality. The SEIG is driven by a wind-turbine, dc motor, or both. Another advantage of this arrangement is its versatile control characteristics through the dc motor control. This paper describes a technique to maximize the utilization efficiency of the PV array by controlling the field current of the dc motor through a dc chopper.

Alghuwainem, S.M. [King Saud Univ., Riyadh (Saudi Arabia). Electrical Engineering Dept.] [King Saud Univ., Riyadh (Saudi Arabia). Electrical Engineering Dept.

1996-12-01

217

Efficient Production of Pyruvate from DL-Lactate by the Lactate-Utilizing Strain Pseudomonas stutzeri SDM  

PubMed Central

Background The platform chemical lactate is currently produced mainly through the fermentation of sugars presented in biomass. Besides the synthesis of biodegradable polylactate, lactate is also viewed as a feedstock for the green chemistry of the future. Pyruvate, another important platform chemical, can be produced from lactate through biocatalysis. Methodology/Principal Findings It was established that whole cells of Pseudomonas stutzeri SDM catalyze lactate oxidation with lactate-induced NAD-independent lactate dehydrogenases (iLDHs) through the inherent electron transfer chain. Unlike the lactate oxidation processes observed in previous reports, the mechanism underlying lactate oxidation described in the present study excluded the costliness of the cofactor regeneration step and production of the byproduct hydrogen peroxide. Conclusions/Significance Biocatalysis conditions were optimized by using the cheap dl-lactate as the substrate and whole cells of the lactate-utilizing P. stutzeri SDM as catalyst. Under optimal conditions, the biocatalytic process produced pyruvate at a high concentration (48.4 g l?1) and a high yield (98%). The bioconversion system provides a promising alternative for the green production of pyruvate. PMID:22792404

Gao, Chao; Qiu, Jianhua; Ma, Cuiqing; Xu, Ping

2012-01-01

218

Spectrum Clouds: A Session Based Spectrum Trading System for Multi-hop Cognitive Radio Networks  

E-print Network

Spectrum Clouds: A Session Based Spectrum Trading System for Multi-hop Cognitive Radio Networks spectrum bands are extremely under-utilized. Experimental tests in academia [4], [5] and measurements networks (CRNs) and promoted a lot of interesting research on the design of spectrum trading systems [8

Latchman, Haniph A.

219

The Storage Spectrum  

NSDL National Science Digital Library

Virtually every modern computer system incorporates several different storage technologies to process data efficiently. A gentle introduction to data storage is given on this site, part of Red Hat, Inc.'s Linux System Administration Primer. The topics covered include: "The Storage Spectrum," "CPU Registers," "Cache Memory," "Cache Levels," "Main Memory - RAM," "Hard Drives," and "Off-Line Backup Storage."

2008-02-15

220

Utilization of the graded universal testing system to increase the efficiency for assessing aerobic and anaerobic capacity  

NASA Technical Reports Server (NTRS)

The in-flight exercise test performed by cosmonauts as part of the Russian Exercise Countermeasure Program is limited to 5 minutes due to communication restrictions. During a recent graded exercise test on a U.S. Shuttle flight, the test was terminated early due to an upcoming loss of signal (LOS) with the ground. This exercise test was a traditional test where the subject's exercise capacity dictates the length of the test. For example, one crew member may take 15 minutes to complete the test, while another may take 18 minutes. The traditional exercise test limits the flight schedulers to large blocks of space flight time in order to provide medical and research personnel information on the fitness capacity (maximal oxygen uptake: VO2max) of crew members during flight. A graded exercise test that would take a finite amount of time and a set preparation and recovery time would ease this problem by allowing flight schedulers to plan exercise tests in advance of LOS. The Graded Universal Testing System (GUTS) was designed to meet this goal. Fitness testing of astronauts before and after flight provides pertinent data on many variables. The Detailed Supplemental Objective (DSO608) protocol (6) is one of the graded exercise tests (GXT) currently used in astronaut testing before and after flight. Test times for this protocol have lasted from 11 to 18 minutes. Anaerobic capacity is an important variable that is currently not being evaluated before and after flight. Recent reports (1,2,5) from the literature have suggested that the oxygen deficit at supramaximal exercise is a measure of anaerobic capacity. We postulated that the oxygen deficit at maximal exercise would be an indication of anaerobic capacity. If this postulate can be accepted, then the efficiency of acquiring data from a graded exercise test would increase at least twofold. To examine this hypothesis anaerobic capacity was measured using a modified treadmill test (3,4) designed to exhaust the anaerobic systems in approximately 45 to 75 seconds. Lactate concentration in the blood was analyzed after all tests, since lactate is the end-product of anaerobic energy production. Therefore, the peak lactate response is an additional indication of anaerobic capacity. A preliminary comparison of the GUTS and the DSO608 suggests that the GUTS protocol would increase the efficiency of VO2max testing of astronauts before and after flight. Results for anaerobic capacity have not been tabulated.

Rodgers, Sandra L.

1992-01-01

221

ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS CROSS-CUTTING R&D ON ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS FOR MORE EFFICIENT AND AFFORDABLE USE OF SOLAR ENERGY IN BUILDINGS AND HYBRID PHOTOBIOREACTORS  

SciTech Connect

This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports day light from a paraboloidal dish concentrator to a luminaire via a large core polymer fiber optic. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of day lighting and fluorescent lighting for office lighting. In this project, the sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. The secondary mirror consists of eight planar-segmented mirrors that direct the visible part of the spectrum to eight fibers (receiver) and subsequently to eight luminaires. This results in about 8,200 lumens incident at each fiber tip. Each fiber can illuminate about 16.7 m{sup 2} (180 ft{sup 2}) of office space. The IR spectrum is directed to a thermophotovoltaic array to produce electricity. This report describes eleven investigations on various aspects of the system. Taken as a whole, they confirm the technical feasibility of this technology.

Byard D. Wood; Jeff D. Muhs

2002-09-01

222

A novel fermentation strategy for removing the key inhibitor acetic acid and efficiently utilizing the mixed sugars from lignocellulosic hydrolysates  

SciTech Connect

As part of preliminary research efforts, we have completed several experiments which demonstrate 'proof of concept.' These experiments addressed the following three questions: (1) Can a synthetic mixed sugar solution of glucose and xylose be efficiently consumed using the multi-organism approach? (2) Can this approach be used to accumulate a model product? (3) Can this approach be applied to the removal of an inhibitor, acetate, selectively from mixtures of xylose and glucose? To answer the question of whether this multi-organism approach can effectively consume synthetic mixed sugar solutions, we first tested substrate-selective uptake using two strains, one unable to consume glucose and one unable to consume xylose. The xylose-selective strain ALS998 has mutations in the three genes involved in glucose uptake, rendering it unable to consume glucose: ptsG codes for the Enzyme IICB{sup Glc} of the phosphotransferase system (PTS) for carbohydrate transport (Postma et al., 1993), manZ codes for the IID{sup Man} domain of the mannose PTS permease (Huber, 1996), glk codes for glucokinase (Curtis and Epstein 1975) We also constructed strain ALS1008 which has a knockout in the xylA gene encoding for xylose isomerase, rendering ALS1008 unable to consume xylose. Two batch experiments and one continuous bioprocess were completed. In the first experiment, each strain was grown separately in a defined medium of 8 g/L xylose and 15 g/L glucose which represented xylose and glucose concentrations that can be generated by actual biomass. In the second experiment, the two strains were grown together in batch in the same defined, mixed-sugar medium. In a third experiment, we grew the strains continuously in a 'chemostat', except that we shifted the concentrations of glucose and xylose periodically to observe how the system would respond. (For example, we shifted the glucose concentration suddenly from 15 g/L to 30 g/L in the feed).

Mark A. Eiteman PHD; Elliot Altman Phd

2009-02-11

223

Optical performance of dichroic spectrum-splitting filters  

NASA Astrophysics Data System (ADS)

We investigate the optical performance of dichroic filters used in solar spectrum-splitting applications. Photovoltaic (PV) systems utilizing spectrum splitting have higher theoretical conversion efficiency than single-bandgap PV modules. Dichroic filters have been used in several spectrum-splitting optical system designs with success. However, dichroic filters only achieve ideal performance under collimated incident light. With an incident angle constraint the optical concentration ratio is limited. A high-concentration ratio helps to achieve high-conversion efficiency and control cost by reducing the PV cell area. In a dual-junction spectrum-splitting PV configuration with a gallium arsenide (GaAs) PV cell and a 2.1-eV bandgap PV cell, the experimental dichroic filter can provide 86.3% of the ideal designed performance. The filter nonideal performance under focused incident light is simulated with ZEMAX. System efficiency under different F-number and filter refractive index is simulated for dual-junction and three-junction systems to show the performance of dichroic filters. We have found that for a dual-bandgap spectrum-splitting system there is a 0.32% system efficiency gain associated with a filter refractive index increased from 1.5 to 1.95. An efficiency gain of 0.41% is associated with an aperture size reduction from F2.0 to F3.0. In a three-junction configuration, simulation shows that a 0.57% system efficiency gain is possible when the filter refractive index is increased from 1.5 to 1.95. An efficiency gain of 0.63% is associated with an aperture size reduction from F2.0 to F3.0.

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

2014-01-01

224

ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS Cross-Cutting R & D on adaptive full-spectrum solar energy systems for more efficient and affordable use of solar energy in buildings and hybrid photobioreactors  

SciTech Connect

This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports daylight from a paraboloidal dish concentrator to a luminaire via a bundle of polymer fiber optics. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of daylighting and electric lighting for space/task lighting. In this project, the sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. For the third generation (beta) system, the secondary mirror is an ellipsoidal mirror that directs the visible light into a bundle of 3 mm diameter fibers. The IR spectrum is filtered out to minimize unnecessary heating at the fiber entrance region. This report describes the following investigations: Niche applications for HSL technology, Luminaire design characteristics for linear and point lighting fixtures, and Daylight affects on productivity.

Byard D. Wood; David L. Beshears

2006-02-01

225

Broad spectrum solar cell  

DOEpatents

An alloy having a large band gap range is used in a multijunction solar cell to enhance utilization of the solar energy spectrum. In one embodiment, the alloy is In.sub.1-xGa.sub.xN having an energy bandgap range of approximately 0.7 eV to 3.4 eV, providing a good match to the solar energy spectrum. Multiple junctions having different bandgaps are stacked to form a solar cell. Each junction may have different bandgaps (realized by varying the alloy composition), and therefore be responsive to different parts of the spectrum. The junctions are stacked in such a manner that some bands of light pass through upper junctions to lower junctions that are responsive to such bands.

Walukiewicz, Wladyslaw (Kensington, CA); Yu, Kin Man (Lafayette, CA); Wu, Junqiao (Richmond, CA); Schaff, William J. (Ithaca, NY)

2007-05-15

226

Policy-based reasoning for spectrum sharing in radio networks  

Microsoft Academic Search

Regulation of spectrum may undergo revolutionary changes in the near future allowing a less restricted and more flexible access to radio spectrum. Intelligent radios, or so-called cognitive radios, will realize the dynamic usage of frequency bands on an opportunistic basis, by identifying and using under-utilized spectrum. Such a flexible spectrum usage requires changes in regulation towards a more open spectrum.

Lars Berlemann; Stefan Mangold; Bernhard H. Walke

2005-01-01

227

Effects of anaerobic growth conditions on biomass accumulation, root morphology, and efficiencies of nutrient uptake and utilization in seedlings of some southern coastal plain  

SciTech Connect

Seedlings of pond, and loblolly pines were grown in a non-circulating, continuously-flowing solution culture under anaerobic (0.75 mg/1 O/sub 2/) conditions to determine the effects of anaerobiosis on overall growth, root morphology and efficiencies of nutrient uptake and utilization. Although shoot growth of the 11-week old loblolly and pond was not affected by anaerobic treatment, it did significantly reduce root biomass. Sand pine suffered the largest biomass reduction. Flooding tolerance was positively correlated with morphological changes which enhanced root internal aeration. Oxygen transport from shoot to the root was demonstrated via rhizosphere oxidation experiments using indigo-carmine dye solutions and polarography. Stem and root collar lenticels were found to be the major sites of atmospheric O/sub 2/ entry for submerged roots. Longitudinal and radial pathways for gas diffusion via intercellular spaces in the pericycle and ray parenchyma, respectively, were elucidated histologically. Lenticel and aerenchyma development, and rhizosphere oxidation in roots of anaerobically-grown sand pine seedlings were minimal. Elemental analyses showed that anaerobic conditions interfered with nutrient absorption and utilization. Short-term /sup 32/P uptake experiments with intact seedlings indicated that net absorption decreased because of the reduction in root biomass. Phosphorus absorption rates were negatively correlated with internal tissue phosphorus concentrations, and root and shoot biomass. 315 refs., 25 figs., 14 tabs.

Topa, M.A.

1984-01-01

228

Wideband Spectrum Sensing in Cognitive Radio Networks  

Microsoft Academic Search

Spectrum sensing is an essential enabling function- ality for cognitive radio networks to detect spectrum holes and opportunistically use the under-utilized frequency bands without causing harmful interference to legacy networks. This paper introduces a novel wideband spectrum sensing technique, called multiband joint detection, which jointly detects the signal energy levels over multiple frequency bands rather than consider one band at

Zhi Quan; Shuguang Cui; Ali H. Sayed; H. Vincent Poor

2008-01-01

229

Smart Radio Spectrum Management for Cognitive Radio  

E-print Network

Today's wireless networks are characterized by fixed spectrum assignment policy. The limited available spectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm to exploit the existing wireless spectrum opportunistically. Cognitive radio is a paradigm for wireless communication in which either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with licensed or unlicensed users. In this work, a fuzzy logic based system for spectrum management is proposed where the radio can share unused spectrum depending on some parameters like distance, signal strength, node velocity and availability of unused spectrum. The system is simulated and is found to give satisfactory results.

Bhattacharya, Partha Pratim; Gera, Rishita; Agarwal, Anjali

2011-01-01

230

Phosphate Utilization Efficiency Correlates with Expression of Low-Affinity Phosphate Transporters and Noncoding RNA, IPS1, in Barley1[W  

PubMed Central

Genetic variation in phosphorus (P) efficiency exists among wheat (Triticum aestivum) and barley (Hordeum vulgare) genotypes, but the underlying mechanisms for the variation remain elusive. High- and low-affinity phosphate (Pi) PHT1 transporters play an indispensable role in P acquisition and remobilization. However, little is known about genetic variation in PHT1 gene expression and association with P acquisition efficiency (PAE) and P utilization efficiency (PUE). Here, we present quantitative analyses of transcript levels of high- and low-affinity PHT1 Pi transporters in four barley genotypes differing in PAE. The results showed that there was no clear pattern in the expression of four paralogs of the high-affinity Pi transporter HvPHT1;1 among the four barley genotypes, but the expression of a low-affinity Pi transporter, HvPHT1;6, and its close homolog HvHPT1;3 was correlated with the genotypes differing in PUE. Interestingly, the expression of HvPHT1;6 and HvPHT1;3 was correlated with the expression of HvIPS1 (for P starvation inducible; noncoding RNA) but not with HvIPS2, suggesting that HvIPS1 plays a distinct role in the regulation of the low-affinity Pi transporters. In addition, high PUE was found to be associated with high root-shoot ratios in low-P conditions, indicating that high carbohydrate partitioning into roots occurs simultaneously with high PUE. However, high PUE accompanying high carbon partitioning into roots could result in low PAE. Therefore, the optimization of PUE through the modification of low-affinity Pi transporter expression may assist further improvement of PAE for low-input agriculture systems. PMID:21606317

Huang, Chun Y.; Shirley, Neil; Genc, Yusuf; Shi, Bujun; Langridge, Peter

2011-01-01

231

To Preempt or Not: Tackling Bid and Time-based Cheating in Online Spectrum Auctions  

E-print Network

Abstract—Online spectrum auctions offer ample flexibility for bidders to request and obtain spectrum on-the-fly. Such flexibility, however, opens up new vulnerabilities to bidder manipulation. Aside from rigging their bids, selfish bidders can falsely report their arrival time to game the system and obtain unfair advantage over others. Such time-based cheating is easy to perform yet produces severe damage to auction performance. We propose Topaz, a truthful online spectrum auction design that distributes spectrum efficiently while discouraging bidders from misreporting their bids or time report. Topaz makes three key contributions. First, Topaz applies a 3D bin packing mechanism to distribute spectrum across time, space and frequency, exploiting spatial and time reuse to improve allocation efficiency. Second, Topaz enforces truthfulness using a novel temporalsmoothed critical value based pricing. Capturing the temporal and spatial dependency among bidders who arrive subsequently, this pricing effectively diminishes gain from bid and/or timecheating. Finally, Topaz offers a “scalable ” winner preemption to address the uncertainty of future arrivals at each decision time, which significantly boosts auction revenue. We analytically prove Topaz’s truthfulness, which does not require any knowledge of bidder behavior, or an optimal spectrum allocation to enforce truthfulness. Using empirical arrival and bidding models, we perform simulations to demonstrate the efficiency of Topaz. We show that proper winner preemption improves auction revenue by 45-65 % at a minimum cost of spectrum utilization. I.

Lara Deek; Xia Zhou; Kevin Almeroth; Haitao Zheng

232

[Design of concave grating for ultraviolet-spectrum].  

PubMed

Ultraviolet-spectrum technology is a kind of low signal and multianalysis technology. For taking full advantage of spectral information and reducing the volume of spectrometer, we used high efficiency spectroscopy structure based on concave grating. Based on concave grating theory and optic design software ZEMAX, a flat field concave grating for ultraviolet spectrophotometer was designed from primary structure, which relied on global optimization of the software. The contradiction between wide spectrum bound and limited spectrum extension was resolved, aberrations were reduced successfully, spectrum information was utilized fully, and the optic structure of spectrometer was highly efficient. For better preference of this spectrophotometer, after get the structure parameter, combine grating fabrication condition with practice working condition, grating diffractive theory, holographic optics theory and software PCG rate was used for diffraction efficiency design and improve. A paradigm of flat field concave grating is given, it works between 190 nm to 410 nm, the diameter of the concave grating is 20 mm, and F/# is 0.21. The design result was analyzed and evaluated. It was showed that if the slit source, whose width is 50 microm, is used to reconstruction, the theoretic resolution capacity is better than 3 nm. PMID:22870673

Luo, Biao; Wen, Zhi-Yu; Wen, Zhong-Quan; Zeng, Tian-Ling

2012-06-01

233

Joint Spectrum and Power Allocation for Inter-Cell Spectrum Sharing in Cognitive Radio Networks  

Microsoft Academic Search

Cognitive radio (CR) networking achieves high utilization of the scarce spectrum resources without causing any performance degradation to the licensed users. Since the spectrum availability varies over time and space, the infrastructure-based CR networks are required to have a dynamic inter-cell spectrum sharing capability. This allows fair resource allocation as well as capacity maximization and avoids the starvation problems seen

Won-Yeol Lee; Ian F. Akyildiz

2008-01-01

234

Optimization of Spectrum Sensing for Opportunistic Spectrum Access in Cognitive Radio Networks  

Microsoft Academic Search

Motivated by the low utilization of the licensed spectrum across many frequency bands, sensing-based oppor- tunistic spectrum access has recently emerged as an alternative to the outdated exclusive spectrum access policy. Under this new paradigm, a secondary (unlicensed) user monitors a primary (licensed) frequency band for a given time and opportunistically transmits if it does not detect any ongoing licensed

Amir Ghasemi; Elvino S. Sousa

2007-01-01

235

High Throughput Spectrum-aware Routing for Cognitive Radio Networks  

Microsoft Academic Search

Dynamic spectrum networks enable fast deployment of new wireless technologies by effectively utilizing allo cated yet unused wireless spectrum. By sensing and utilizing available wire- less channels, cognitive radio devices can provide high through- put, low latency communication. Existing schemes for channel as- signment suffer drawbacks in throughput and reachability in the presence of location-dependent channel availability. We propose SPEctrum-Aware

Ashwin Sampath; Lei Yang; Lili Cao; Haitao Zheng; Ben Y. Zhao

236

Basic Amino Acid Residues in the V3 Loop of Simian Immunodeficiency Virus Envelope Alter Viral Coreceptor Tropism and Infectivity but Do Not Allow Efficient Utilization of CXCR4 as Entry Cofactor  

Microsoft Academic Search

In contrast to human immunodeficiency viruses type 1 and type 2 (HIV-1 and HIV-2, respectively), simian immunodeficiency virus (SIVmac) rarely uses CXCR4 (X4) for efficient entry into target cells. Basic amino acid residues in the V3 loop of HIV Env allow efficient coreceptor utilization of X4. Therefore, we investigated if similar changes in the SIVmac Env protein also mediate a

Silke Meister; Claas Otto; Armin Papkalla; Mandy Krumbiegel; Stefan Pöhlmann; Frank Kirchhoff

2001-01-01

237

Spectrum sensing and resource allocation for multicarrier cognitive radio systems under interference and power constraints  

NASA Astrophysics Data System (ADS)

Multicarrier waveforms have been commonly recognized as strong candidates for cognitive radio. In this paper, we study the dynamics of spectrum sensing and spectrum allocation functions in cognitive radio context using very practical signal models for the primary users (PUs), including the effects of power amplifier nonlinearities. We start by sensing the spectrum with energy detection-based wideband multichannel spectrum sensing algorithm and continue by investigating optimal resource allocation methods. Along the way, we examine the effects of spectral regrowth due to the inevitable power amplifier nonlinearities of the PU transmitters. The signal model includes frequency selective block-fading channel models for both secondary and primary transmissions. Filter bank-based wideband spectrum sensing techniques are applied for detecting spectral holes and filter bank-based multicarrier (FBMC) modulation is selected for transmission as an alternative multicarrier waveform to avoid the disadvantage of limited spectral containment of orthogonal frequency-division multiplexing (OFDM)-based multicarrier systems. The optimization technique used for the resource allocation approach considered in this study utilizes the information obtained through spectrum sensing and knowledge of spectrum leakage effects of the underlying waveforms, including a practical power amplifier model for the PU transmitter. This study utilizes a computationally efficient algorithm to maximize the SU link capacity with power and interference constraints. It is seen that the SU transmission capacity depends critically on the spectral containment of the PU waveform, and these effects are quantified in a case study using an 802.11-g WLAN scenario.

Dikmese, Sener; Srinivasan, Sudharsan; Shaat, Musbah; Bader, Faouzi; Renfors, Markku

2014-12-01

238

Sequence Detection Algorithms for Dynamic Spectrum Access Networks  

Microsoft Academic Search

Spectrum sensing is a critical function for enabling dynamic spectrum access (DSA) in wireless networks that utilize cognitive radio (CR). In DSA networks, unlicensed secondary users can gain access to a licensed spectrum band as long as they do not interfere with primary users. Spectrum sensing is subject to errors in the form of false alarms and missed detections. False

Zhanwei Sun; J. Nicholas Laneman; Glenn J. Bradford

2010-01-01

239

Throughput-oriented channel assignment for opportunistic spectrum access networks  

Microsoft Academic Search

Cognitive radio (CR) is a revolutionary technology in wireless communications that enhances spectrum utilization by allowing opportunistic and dynamic spectrum access. One of the key challenges in this domain is how CR users cooperate to dynamically access the available spectrum opportunities in order to maximize the overall perceived throughput. In this paper, we consider the coordinated spectrum access problem in

Haythem Ahmad Bany Salameh

2011-01-01

240

Route and Spectrum Selection in Dynamic Spectrum Networks  

E-print Network

conflicts, while promoting utilization and fairness. Existing work in this context took a collaborative and spectrum management makes it important to examine interaction between the two and the corresponding design where these tasks are carried out independently by different protocol layers, and a collaborative

Almeroth, Kevin C.

241

A Novel Spectrum Sharing Algorithm Based on the Throughput in Cognitive Radio Networks  

Microsoft Academic Search

Spectrum sharing is of special significance among all the key technologies in cognitive radio (CR), such as spectrum sensing, spectrum management and power allocation etc. Since all the efforts in CR directly aim at enhancing spectrum utilization and spectrum sharing is the final step of all these key technologies, spectrum sharing completely determines whether CR is just a theoretical topic

Wei Wang; Tiejun Lv; Zhiyuan Ren; Long Gao; Weidong Liu

2009-01-01

242

IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. 13, NO. 9, SEPTEMBER 2014 2071 Optimal Design of the Spectrum Sensing  

E-print Network

service's spectrum [1]. The under-utilized spec- trum is referred to as spectrum holes or white spaces the white spaces [5]. The spectrum sensing evaluates the spectrum status as idle or busy. The secondary

Yanikomeroglu, Halim

243

Fast mixed spectrum reactor concept  

Microsoft Academic Search

The Fast Mixed Spectrum Reactor is a highly promising concept for a fast reactor with improved features of proliferation resistance, and excellent utilization of uranium resources. In technology, it can be considered to be a branch of fast breeder development, though its operation and implications are different from those of FBR'S in important respects. Successful development programs are required in

H. J. C. Kouts; G. J. Fischer; R. J. Cerbone

1979-01-01

244

Improved full spectrum cloudy scene simulation  

NASA Astrophysics Data System (ADS)

This paper will discuss recent improvements made to the MCScene code, a high fidelity model for full optical spectrum (UV through LWIR) hyperspectral image (HSI) simulation. MCScene provides an accurate, robust, and efficient means to generate HSI scenes for algorithm validation. MCScene utilizes a Direct Simulation Monte Carlo approach for modeling 3D atmospheric radiative transfer (RT) including full treatment of molecular absorption and Rayleigh scattering, aerosol absorption and scattering, and multiple scattering and adjacency effects, as well as scattering from spatially inhomogeneous surfaces, including surface BRDF effects. The model includes treatment of land and ocean surfaces, 3D terrain, 3D surface objects, and effects of finite clouds with surface shadowing. This paper will provide an overview of how RT elements are incorporated into the Monte Carlo engine. Several new examples of the capabilities of MCScene to simulate 3-dimensional cloud fields will also be discussed, and sample calculations will be presented.

Sundberg, Robert; Richtsmeier, Steven; Haren, Raymond

2008-10-01

245

Spectrum formation in supernovae - Numerical techniques  

NASA Technical Reports Server (NTRS)

The study combines several novel techniques for spectrum simulation in the Eddington computer program which solves the comoving frame equation of transfer coupled with the statistical and radiative equilibrium equations. One of these is a generalization of the accelerated lambda iteration (ALI) scheme to include an approximate frequency-derivative operator. This greatly enhances the convergence rate of ALI in optically thick, high-velocity shear flows. Another is a partial linearization technique which is capable of efficiently solving a very large number of rate equations on a moderately sized computer. An expansion opacity and emissivity approximation is derived which makes it possible to determine the effect on the transfer and statistical equilibrium of a very large number of lines not explicitly represented in the frequency grid and additionally to treat line-blanketing from species not explicitly included in the rate equations. The utility of these techniques is illustrated with models of two supernovae.

Eastman, Ronald G.; Pinto, Philip A.

1993-01-01

246

Monte Carlo simulation of a PhosWatch detector using Geant4 for xenon isotope beta-gamma coincidence spectrum profile and detection efficiency calculations.  

PubMed

A simulation tool has been developed using the Geant4 Toolkit to simulate a PhosWatch single channel beta-gamma coincidence detection system consisting of a CsI(Tl)/BC404 Phoswich well detector and pulse shape analysis algorithms implemented digital signal processor. The tool can be used to simulate the detector's response for all the gamma rays and beta particles emitted from (135)Xe, (133m)Xe, (133)Xe, (131m)Xe and (214)Pb. Two- and three-dimensional beta-gamma coincidence spectra from the PhosWatch detector can be produced using the simulation tool. The accurately simulated spectra could be used to calculate system coincidence detection efficiency for each xenon isotope, the corrections for the interference from the various spectral components from radon and xenon isotopes, and system gain calibration. Also, it can generate two- and three-dimensional xenon reference spectra to test beta-gamma coincidence spectral deconvolution analysis software. PMID:19647444

Mekarski, P; Zhang, W; Ungar, K; Bean, M; Korpach, E

2009-10-01

247

A discharge flow-photoionization mass spectrometric study of the FO(X 2 Pi i) radical. Photoionization efficiency spectrum and ionization energy  

NASA Technical Reports Server (NTRS)

Photoionization efficiency spectra of FO were measured over the wavelength range 80.0-100.0 nm and in the ionization threshold region, 94.0-100.0 nm, using a discharge flow-photoionization mass spectrometer apparatus coupled to a synchrotron radiation source. FO was generated by the reaction of F2P atoms with NO3 and via a F2O2 discharge. A value of 12.78 +/- 0.03 eV was obtained for the adiabatic ionization energy of FO from photoion thresholds which corresponds to FO(+)(X 3 Sigma -) from FO(X 2 Pi i). These results, which are the first to be obtained by direct Photo-ionization mass spectrometry (PIMS) measurements, corroborate those of a photoelectron spectroscopy (PES) study; however, the ionization energy determined here is free from interferences due to other species which complicated the PES measurement. A value of 109.5 +/- 8.0 kJ/mol for Delta f H 0 298(FO) is computed from the present value of IE(FO) and a previous appearance energy measurement, and a value for the proton affinity of FO is calculated to be 511.5 +/- 10.0 kJ/mol.

Zhang, Zhengyu; Kuo, Szu-Cherng; Klemm, R. Bruce; Monks, Paul S.; Stief, Louis J.

1994-01-01

248

An exploration of an alternative rate structure as a means of integrating equity and efficiency in a municipally owned natural gas distribution utility  

Microsoft Academic Search

After two decades of a somewhat golden age for gas utilities and regulators, the 1970's saw a changing energy market characterized by curtailments and allocations in the natural gas industry. The Natural Gas Policy Act of 1978 provided incentives for new supplies but at increased prices. During a period of rapidly calculating natural gas prices (1979-1984), municipal owned public utility

1989-01-01

249

SALSA: Strategyproof Online Spectrum Admissions for Wireless Networks  

Microsoft Academic Search

It is imperative to design efficient and effective online spectrum allocation methods since requests for spectrums often come in an online fashion. In this paper, we propose SALSA, strategyproof online spectrum admission for wireless networks. We assume that the requests arrival follows the Poisson distribution. Upon receiving an online spectrum request, our protocol will decide immediately whether to grant its

Ping Xu; ShiGuang Wang; Xiang-Yang Li

2010-01-01

250

A Wavelet Approach to Wideband Spectrum Sensing for Cognitive Radios  

Microsoft Academic Search

In cognitive radio networks, the first cognitive task preceding any form of dynamic spectrum management is the sensing and identification of spectrum holes in wireless environments. This paper develops a wavelet approach to efficient spectrum sensing of wideband channels. The signal spectrum over a wide frequency band is decomposed into elementary building blocks of subbands that are well characterized by

Zhi Tian; Georgios B. Giannakis

2006-01-01

251

DYNAMIC SPECTRUM ALLOCATION (DSA) AND RECONFIGURABILITY  

Microsoft Academic Search

In the context of the European research project OverDRiVE (Spectrum Efficient Uni- and Multicast Services Over Dynamic Radio Networks in Vehicular Environments), this paper presents the flexible spectrum management strategy (the dynamic spectrum allocation concept) developed in the project, and discusses OverDRiVE's approach to identify and formalise the impact of DSA on both reconfigurability and SDR equipment, capturing the reconfigurable

David Grandblaise; Didier Bourse; Klaus Moessner; Paul Leaves

2002-01-01

252

NASA technology utilization house  

NASA Technical Reports Server (NTRS)

Following systems and features, which are predicted to save approximately $20,000 in utility costs over twenty year period, are incorporated into single-level, contemporarily designed, energy efficient residential structure: solar heating and cooling; energy efficient appliances; water recycling; security, smoke, and tornado detectors; and flat conductor electrical wiring.

1977-01-01

253

Basic amino acid residues in the V3 loop of simian immunodeficiency virus envelope alter viral coreceptor tropism and infectivity but do not allow efficient utilization of CXCR4 as entry cofactor.  

PubMed

In contrast to human immunodeficiency viruses type 1 and type 2 (HIV-1 and HIV-2, respectively), simian immunodeficiency virus (SIVmac) rarely uses CXCR4 (X4) for efficient entry into target cells. Basic amino acid residues in the V3 loop of HIV Env allow efficient coreceptor utilization of X4. Therefore, we investigated if similar changes in the SIVmac Env protein also mediate a coreceptor switch from CCR5 (R5) to X4. Functional analysis revealed that none of eight SIVmac variants, containing V3 regions with an overall charge between +4 and +10, efficiently utilized X4 as entry cofactor. Nonetheless, these alterations had differential effects on SIV coreceptor tropism and on Env expression levels. A single amino acid substitution of L328R, located near the tip of the V3 loop, resulted in grossly reduced Env expression levels and impaired viral infectivity. Notably, additional basic residues restored efficient Env expression and virion incorporation but not infectivity. In comparison to the L328R mutation, changes of P334K and D337K had little disruptive effects on SIVmac entry and replication. Interestingly, mutation of L320K and P321R disrupted coreceptor usage of GPR15 but not R5. These changes also impaired SIVmac replication in peripheral blood mononuclear cells (PBMC) derived from a Delta32/Delta32 donor but not in R5-expressing human or simian PBMC. Our results show that positively charged amino acid residues in the V3 loop affect SIVmac coreceptor tropism and infectivity but do not allow efficient utilization of X4. PMID:11384227

Meister, S; Otto, C; Papkalla, A; Krumbiegel, M; Pöhlmann, S; Kirchhoff, F

2001-06-01

254

Final Report for DE-FG36-08GO18007 "All-Inorganic, Efficient Photovoltaic Solid State Devices Utilizing Semiconducting Colloidal Nanocrystal Quantum Dots"  

SciTech Connect

We demonstrated robust colloidal quantum dot (QD) photovoltaics with high internal quantum efficiencies. In our structures, device durability is derived from use of all-inorganic atmospherically-stable semiconducting metal-oxide films together with QD photoreceptors. We have shown that both QD and metal-oxide semiconducting films and contacts are amenable to room temperature processing under minimal vacuum conditions, enabling large area processing of PV structures of high internal efficiency. We generated the state of the art devices with power conversion efficiency of more than 4%, and have shown that efficiencies as high as 9% are achievable in the near-term, and as high as 17% in the long-term.

Vladimir Bulovic and Moungi Bawendi

2011-09-30

255

A welfare analysis of spectrum allocation policies  

Microsoft Academic Search

Economic analysis of spectrum policy focuses on government revenues derived via competitive bidding for licenses. Auctions generating high bids are identified as successful and those with lower receipts as fiascoes. Yet spectrum policies that create rents impose social costs. Most obviously, rules favoring monopoly predictably increase license values but reduce welfare. This article attempts to shift analytical focus to efficiency

Thomas W. Hazlett; Roberto E. Muñoz

2009-01-01

256

NeXt generation\\/dynamic spectrum access\\/cognitive radio wireless networks: A survey  

Microsoft Academic Search

Today's wireless networks are characterized by a fixed spectrum assignment policy. However, a large portion of the assigned spectrum is used sporadically and geographical variations in the utilization of assigned spectrum ranges from 15% to 85% with a high variance in time. The limited available spectrum and the inefficiency in the spectrum usage neces- sitate a new communication paradigm to

Ian F. Akyildiz; Won-yeol Lee; Mehmet C. Vuran; Shantidev Mohanty

2006-01-01

257

Dynamic open spectrum sharing MAC protocol for wireless ad hoc networks  

Microsoft Academic Search

In legacy wireless communication systems, spectrum allocation is static, resulting in extremely low spectrum utilization. On the other hand, there is little spectrum left for allocation to an increasing number of emerging wireless applications. A promising approach to solving this paradox is opening up most of the spectrum for unlicensed spectrum users in ways that co-exist with legacy users. Following

Liangping Ma; Xiaofeng Han; Chien-Chung Shen

2005-01-01

258

Genome Sequence of Enterobacter cloacae subsp. dissolvens SDM, an Efficient Biomass-Utilizing Producer of Platform Chemical 2,3-Butanediol  

PubMed Central

Enterobacter cloacae subsp. dissolvens SDM has an extraordinary characteristic of biomass utilization for 2,3-butanediol production. Here we present a 4.9-Mb assembly of its genome. The key genes for regulation and metabolism of 2,3-butanediol production were annotated, which could provide further insights into the molecular mechanism of high-yield production of 2,3-butanediol. PMID:22275097

Xu, Youqiang; Wang, Ailong; Tao, Fei; Su, Fei; Tang, Hongzhi

2012-01-01

259

77 FR 19575 - Promoting Interoperability in the 700 MHz Commercial Spectrum; Interoperability of Mobile User...  

Federal Register 2010, 2011, 2012, 2013

...Interoperability in the 700 MHz Commercial Spectrum; Interoperability of Mobile User Equipment Across Paired Commercial Spectrum Blocks in the 700 MHz Band AGENCY...to encourage the efficient use of spectrum. DATES: Interested parties may...

2012-04-02

260

78 FR 66298 - Promoting Interoperability in the 700 MHz Commercial Spectrum; Requests for Waiver and Extension...  

Federal Register 2010, 2011, 2012, 2013

...Interoperability in the 700 MHz Commercial Spectrum; Requests for Waiver and Extension of...and by encouraging efficient use of spectrum, investment, job creation, and the...primarily of 70 megahertz of commercial spectrum and 34 megahertz of public safety...

2013-11-05

261

A comprehensive review of reported heritable noggin-associated syndromes and proposed clinical utility of one broadly inclusive diagnostic term: NOG-related-symphalangism spectrum disorder (NOG-SSD).  

PubMed

The NOG gene encodes noggin, a secreted polypeptide that is important for regulating multiple signaling pathways during human development, particularly in cartilage and bone. The hallmark of NOG-related syndromes is proximal symphalangism, defined by abnormal fusion of the proximal interphalangeal joints of the hands and feet. Many additional features secondary to NOG mutations are commonly but inconsistently observed, including a characteristic facies with a hemicylindrical nose, congenital conductive hearing loss due to stapes fixation, and hyperopia. The variable clinical presentations led to the designation of five different autosomal dominant syndromes, all subsequently found to have resulted from NOG mutations. These include (1) proximal symphalangism; (2) multiple synostoses syndrome 1; (3) stapes ankylosis with broad thumbs and toes; (4) tarsal-carpal coalition syndrome; and (5) brachydactyly type B2. Herein, we review the phenotypic features associated with mutations in the NOG gene, demonstrating the overlapping characteristics of these syndromes. Due to the variable phenotypic spectrum within families and among families with the same mutation, we propose a unifying term, NOG-related symphalangism spectrum disorder (NOG-SSD), to aid in the clinical recognition and evaluation of all affected individuals with these phenotypes. These NOG gene variants are available in a new locus-specific database (https://NOG.lovd.nl). PMID:21538686

Potti, Tommy A; Petty, Elizabeth M; Lesperance, Marci M

2011-08-01

262

A Survey on Dynamic Spectrum Access Techniques for Cognitive Radio  

E-print Network

Cognitive radio (CR) is a new paradigm that utilizes the available spectrum band. The key characteristic of CR system is to sense the electromagnetic environment to adapt their operation and dynamically vary its radio operating parameters. The technique of dynamically accessing the unused spectrum band is known as Dynamic Spectrum Access (DSA). The dynamic spectrum access technology helps to minimize unused spectrum bands. In this paper, main functions of Cognitive Radio (CR) i.e. spectrum sensing, spectrum management, spectrum mobility and spectrum sharing are discussed. Then DSA models are discussed along with different methods of DSA such as Command and Control, Exclusive-Use, Shared Use of Primary Licensed User and Commons method. Game-theoretic approach using Bertrand game model, Markovian Queuing Model for spectrum allocation in centralized architecture and Fuzzy logic based method are also discussed and result are shown.

Garhwal, Anita

2012-01-01

263

Deficient efficiency  

SciTech Connect

This article is a review of utility policy and public opinion related to energy efficiency. The historical background is presented, and the current socioeconomic status is also presented. Many fallacies of past utility policies intended to promote conservation are noted, and it is demonstrated that past policies have not been effective, i.e. the cost of electricity has increased. Given the failure of past practices, fourteen recommendations for future practices are set forth.

Rudin, A.

1995-05-01

264

High efficiency 2 micrometer laser utilizing wing-pumped Tm.sup.3+ and a laser diode array end-pumping architecture  

DOEpatents

Wing pumping a Tm.sup.3+ doped, end pumped solid state laser generates 2 .mu.m laser radiation at high average powers with high efficiency. Using laser diode arrays to end-pump the laser rod or slab in the wing of the Tm.sup.3+ absorption band near 785 nm results in 2-for-1 quantum efficiency in Tm.sup.3+ because high Tm.sup.3+ concentrations can be used. Wing pumping allows the thermal power generated in the rod or slab to be distributed over a large enough volume to make thermal management practical in the laser gain medium even at high average power operation. The approach is applicable to CW, Q-switched, and rep-pulsed free-laser operation.

Beach, Raymond J. (Livermore, CA)

1997-01-01

265

High efficiency 2 micrometer laser utilizing wing-pumped Tm{sup 3+} and a laser diode array end-pumping architecture  

DOEpatents

Wing pumping a Tm{sup 3+} doped, end pumped solid state laser generates 2 {micro}m laser radiation at high average powers with high efficiency. Using laser diode arrays to end-pump the laser rod or slab in the wing of the Tm{sup 3+} absorption band near 785 nm results in 2-for-1 quantum efficiency in Tm{sup 3+} because high Tm{sup 3+} concentrations can be used. Wing pumping allows the thermal power generated in the rod or slab to be distributed over a large enough volume to make thermal management practical in the laser gain medium even at high average power operation. The approach is applicable to CW, Q-switched, and rep-pulsed free-laser operation. 7 figs.

Beach, R.J.

1997-11-18

266

Bacterial Activity and Bacterioplankton Diversity in the Eutrophic River Warnow—Direct Measurement of Bacterial Growth Efficiency and Its Effect on Carbon Utilization  

Microsoft Academic Search

The influence of bacterial activity and diversity on bacterial growth efficiency was investigated in a flatland river. Eutrophic\\u000a River Warnow drains predominantly agricultural land and is heavily loaded with nutrients, dissolved and particulate organic\\u000a matter (DOM and POM), especially humic substances. Although the water column bacterial community consists of many inactive\\u000a or damaged cells, bacterioplankton sustained a high bacterial secondary

Mareike Warkentin; Heike M. Freese; Rhena Schumann

2011-01-01

267

Security issues in cooperative spectrum sensing for cognitive radio network  

NASA Astrophysics Data System (ADS)

In the CR networks, the unlicensed users can access the idle spectrum when they sense that licensed users are not using this spectrum. Due to the ability of dynamically reusing the spare spectrum resources, there is a remarkable increase of the spectrum utilization. However cognitive radio has brought new problems and concerns, especially in safety. Primary user emulation attack (PUEA) and Spectrum Sensing Data Falsity (SSDF) attack are typical attacks in spectrum sensing. In this paper we will give a detailed introduce of this two threats. Then we will represent some methods to weaken the effectiveness of these attacks.

Du, Jiang; Zhu, Chunjiao; Chen, Zhaohui

2013-03-01

268

Evaluation of Spectrum Occupancy in Indoor and Outdoor Scenario in the Context of Cognitive Radio  

Microsoft Academic Search

Dynamic spectrum access is an integral part of the Cognitive Radio paradigm. However, efficient spectrum sensing techniques are crucial on the way towards systems, which use idle spectrum bands opportunistically and increase the overall spectral efficiency. Current spectrum occupancy was evaluated in few measurement campaigns at different locations mostly located in the USA. In this paper we report about an

Matthias Wellens; Jin Wu; Petri Mahonen

2007-01-01

269

Application of ZnO nanoparticles to enhance photoluminescence in porous silicon and its possible utilization for improving the short wavelength quantum efficiency of silicon solar cell  

NASA Astrophysics Data System (ADS)

We have formed photoluminescent porous silicon (PS) layers and over which a ZnO layer (hereafter called ZnOPS layers) is deposited. We studied the photoluminescent properties of individual layers as well as the composite layer under excitation with 405 nm wavelength. Using the data of PL a theoretical analysis of a solar cell having such a composite layer of a given photoluminescent conversion efficiency ?PL on the front surface has been done. The condition of a photoluminescent composite layer (ZnOPS) useful for enhancing the spectral response of n+-p-p+ structured silicon solar cell has been identified.

Verma, Daisy; Kharkwal, Aneeta; Singh, S. N.; Singh, P. K.; Sharma, S. N.; Mehdi, S. S.; Husain, M.

2014-11-01

270

Genetic variation in feed consumption, growth, nutrient utilization efficiency and mitochondrial function within a farmed population of channel catfish (Ictalurus punctatus).  

PubMed

We evaluated the effects of diets (32/4 or 36/6 percent protein/fat) and six channel catfish families for growth performance characteristics. Two families with fast- (C) and slow- (D) growth rate and with low and high feed efficiency (FE) were selected for analyses of mitochondrial complex enzymatic activities (I, II, III, and IV) and gene expression (ND1, CYTB, COX1, COX2, ATP6) levels in liver, muscle, and intestine. There were significant differences in growth rate and nutrient retention among the families. Mitochondrial enzymatic complex activities (I-V) in the tissues were all lower in family C. Four of the five genes were down-regulated in the liver and up-regulated in the muscle for the fast growing family C. There were significant differences between diets for some mitochondrial respiratory chain enzyme activities and gene expression levels. Significant diet×family interactions were observed for some enzyme activities and gene expression levels. Changes in mitochondrial respiratory chain enzyme activities and gene expression levels provide insight into the cellular mechanisms of fish with differences in growth rate and feed efficiency. Results also suggest that genotype×diet interactions should be accounted for when considering strategies for using mitochondrial function as a criteria in channel catfish selection programs for improved growth performance characteristics. PMID:22691874

Eya, Jonathan C; Ashame, Martha F; Pomeroy, Charles F; Manning, Bruce B; Peterson, Brian C

2012-10-01

271

DISTRIBUTED COGNITIVE MAC FOR ENERGY-CONSTRAINED OPPORTUNISTIC SPECTRUM ACCESS  

E-print Network

existence of spectrum opportunities. Real measurements show that, at any given time and location, a large opportunities among secondary users so that the network-level spectrum efficiency is maximized subject to someDISTRIBUTED COGNITIVE MAC FOR ENERGY-CONSTRAINED OPPORTUNISTIC SPECTRUM ACCESS Yunxia Chen, Qing

Islam, M. Saif

272

Robust Nonparametric Cyclic Correlation Based Spectrum Sensing for Cognitive Radio  

Microsoft Academic Search

Cognitive radios sense the radio spectrum in order to find underutilized spectrum and then exploit it in an agile man- ner. Spectrum sensing has to be performed reliably in challeng- ing propagation environments characterized by shadowing and fading effects as well as heavy-tailed noise distributions. In this paper a robust computationally efficient nonparametric cyclic correlation estimator based on the multivariate

Jarmo Lunden; Saleem A. Kassam; Visa Koivunen

2009-01-01

273

The Electromagnetic Spectrum  

NSDL National Science Digital Library

This web site contains materials about all parts of the electromagnetic spectrum. It describes each space telescope that NASA has launched as well as its observing range in the electromagnetic spectrum.

Astrophysics, Laboratory F.

2004-11-17

274

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology. Annual subcontract report, 1 August 1991--31 July 1992  

SciTech Connect

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, {approximately} 1 {times} 10{sup 5} cm{sup {minus}5}, as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 {times}10{sup 7} cm{sup {minus}2}. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. [Spire Corp., Bedford, MA (United States)

1993-04-01

275

Improvement of Carbon Dioxide Sweep Efficiency by Utilization of Microbial Permeability Profile Modification to Reduce the Amount of Oil Bypassed During Carbon Dioxide Flood  

SciTech Connect

The objective of this project was to couple microbial permeability profile modification (MPPM), with carbon dioxide flooding to improve oil recovery from the Upper Cretaceous Little Creek Oil Field situated in Lincoln and Pike counties, MS. This study determined that MPPM technology, which improves production by utilizing environmentally friendly nutrient solutions to simulate the growth of the indigenous microflora in the most permeable zones of the reservoir thus diverting production to less permeable, previously unswept zones, increased oil production without interfering with the carbon dioxide flooding operation. Laboratory tests determined that no microorganisms were produced in formation waters, but were present in cores. Perhaps the single most significant contribution of this study is the demonstration that microorganisms are active at a formation temperature of 115?C (239?F) by using a specially designed culturing device. Laboratory tests were employed to simulate the MPPM process by demonstrating that microorganisms could be activated with the resulting production of oil in coreflood tests performed in the presence of carbon dioxide at 66?C (the highest temperature that could be employed in the coreflood facility). Geological assessment determined significant heterogeneity in the Eutaw Formation, and documented relatively thin, variably-lithified, well-laminated sandstone interbedded with heavily-bioturbated, clay-rich sandstone and shale. Live core samples of the Upper Cretaceous Eutaw Formation from the Heidelberg Field, MS were quantitatively assessed using SEM, and showed that during MPPM permeability modification occurs ubiquitously within pore and throat spaces of 10-20 ?m diameter. Testing of the MPPM procedure in the Little Creek Field showed a significant increase in production occurred in two of the five production test wells; furthermore, the decline curve in each of the production wells became noticeably less steep. This project greatly extends the number of oil fields in which MPPM can be implemented.

Darrel Schmitz; Lewis Brown F. Leo Lynch; Brenda Kirkland; Krystal Collins; William Funderburk

2010-12-31

276

An efficient and economical way to enhance the performance of present HTS Maglev systems by utilizing the anisotropy property of bulk superconductors  

NASA Astrophysics Data System (ADS)

We report a simple, efficient and economical way to enhance the levitation or guidance performance of present high-temperature superconducting (HTS) Maglev systems by exploring the anisotropic properties of the critical current density in the a-b plane and along the c-axis of bulk superconductors. In the method, the bulk laying mode with different c-axis directions is designed to match with the magnetic field configuration of the applied permanent magnet guideway (PMG). Experimental results indicate that more than a factor of two improvement in the levitation force or guidance force is achieved when changing the laying mode of bulk superconductors from the traditional fashion of keeping the c-axis vertical to the PMG surface to the studied one of keeping the c-axis parallel to the PMG surface, at the maximum horizontal and vertical magnetic field positions of the PMG, respectively. These phenomena resulted from the physical nature of the generated levitation force and guidance force (electromagnetic forces) and the fact that there are different critical current densities in the a-b plane and along the c axis. Based on the experimental results, new HTS Maglev systems can be designed to meet the requirements of practical heavy-load or curved-route applications.

Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

2013-02-01

277

YEAR 2 BIOMASS UTILIZATION  

SciTech Connect

This Energy & Environmental Research Center (EERC) Year 2 Biomass Utilization Final Technical Report summarizes multiple projects in biopower or bioenergy, transportation biofuels, and bioproducts. A prototype of a novel advanced power system, termed the high-temperature air furnace (HITAF), was tested for performance while converting biomass and coal blends to energy. Three biomass fuels--wood residue or hog fuel, corn stover, and switchgrass--and Wyoming subbituminous coal were acquired for combustion tests in the 3-million-Btu/hr system. Blend levels were 20% biomass--80% coal on a heat basis. Hog fuel was prepared for the upcoming combustion test by air-drying and processing through a hammer mill and screen. A K-Tron biomass feeder capable of operating in both gravimetric and volumetric modes was selected as the HITAF feed system. Two oxide dispersion-strengthened (ODS) alloys that would be used in the HITAF high-temperature heat exchanger were tested for slag corrosion rates. An alumina layer formed on one particular alloy, which was more corrosion-resistant than a chromia layer that formed on the other alloy. Research activities were completed in the development of an atmospheric pressure, fluidized-bed pyrolysis-type system called the controlled spontaneous reactor (CSR), which is used to process and condition biomass. Tree trimmings were physically and chemically altered by the CSR process, resulting in a fuel that was very suitable for feeding into a coal combustion or gasification system with little or no feed system modifications required. Experimental procedures were successful for producing hydrogen from biomass using the bacteria Thermotoga, a deep-ocean thermal vent organism. Analytical procedures for hydrogen were evaluated, a gas chromatography (GC) method was derived for measuring hydrogen yields, and adaptation culturing and protocols for mutagenesis were initiated to better develop strains that can use biomass cellulose. Fly ash derived from cofiring coal with waste paper, sunflower hulls, and wood waste showed a broad spectrum of chemical and physical characteristics, according to American Society for Testing and Materials (ASTM) C618 procedures. Higher-than-normal levels of magnesium, sodium, and potassium oxide were observed for the biomass-coal fly ash, which may impact utilization in cement replacement in concrete under ASTM requirements. Other niche markets for biomass-derived fly ash were explored. Research was conducted to develop/optimize a catalytic partial oxidation-based concept for a simple, low-cost fuel processor (reformer). Work progressed to evaluate the effects of temperature and denaturant on ethanol catalytic partial oxidation. A catalyst was isolated that had a yield of 24 mole percent, with catalyst coking limited to less than 15% over a period of 2 hours. In biodiesel research, conversion of vegetable oils to biodiesel using an alternative alkaline catalyst was demonstrated without the need for subsequent water washing. In work related to biorefinery technologies, a continuous-flow reactor was used to react ethanol with lactic acid prepared from an ammonium lactate concentrate produced in fermentations conducted at the EERC. Good yields of ester were obtained even though the concentration of lactic acid in the feed was low with respect to the amount of water present. Esterification gave lower yields of ester, owing to the lowered lactic acid content of the feed. All lactic acid fermentation from amylose hydrolysate test trials was completed. Management activities included a decision to extend several projects to December 31, 2003, because of delays in receiving biomass feedstocks for testing and acquisition of commercial matching funds. In strategic studies, methods for producing acetate esters for high-value fibers, fuel additives, solvents, and chemical intermediates were discussed with several commercial entities. Commercial industries have an interest in efficient biomass gasification designs but are waiting for economic incentives. Utility, biorefinery, pulp and paper, or o

Christopher J. Zygarlicke

2004-11-01

278

A Cell Based Dynamic Spectrum Management Scheme with Interference Mitigation for Cognitive Networks  

Microsoft Academic Search

Future wireless systems are expected to be characterized by the coexistence of different radio access technologies (RATs) resulting in complex heterogeneous wireless environments. In parallel with this, the tremendous demand for spectrum\\u000a has inspired the requirement of dynamic spectrum management (DSM). This paper aims at designing a cell based dynamic spectrum management (CBDSM) scheme to enhance the spectrum utilization and

Vanbien Le; Zhiyong Feng; Didier Bourse; Ping Zhang

2009-01-01

279

Sequence Detection Algorithms for PHY-Layer Sensing in Dynamic Spectrum Access Networks  

Microsoft Academic Search

Spectrum sensing is a critical function for enabling dynamic spectrum access (DSA) in wireless networks that utilize cognitive radio (CR). In DSA networks, unlicensed secondary userscan gainaccessto alicensed spectrumbandaslongastheydo not cause harmful interfere to primary users. Spectrum sensing is subject to errors in the form of false alarms and missed detections. False alarms cause spectrum under-use by secondary users, and

Zhanwei Sun; Glenn J. Bradford; J. Nicholas Laneman

2011-01-01

280

On Spectrum Selection Games in Cognitive Radio Ilaria Malanchini, Matteo Cesana, Nicola Gatti  

E-print Network

On Spectrum Selection Games in Cognitive Radio Networks Ilaria Malanchini, Matteo Cesana, Nicola measures for the spectrum opportunities are considered and evaluated in the game framework, including stems from var- ious measurements of spectrum utilization which generally show that spectrum is under

Gatti, Nicola

281

Vision Utilities  

E-print Network

This paper documents a collection of Lisp utilities which I have written while doing vision programming on a Symbolics Lisp machine. Many of these functions are useful both as interactive commands invoked from the Lisp ...

Voorhees, Harry

282

Accelerating Spectrum Sharing Technologies  

SciTech Connect

Spectrum sharing potentially holds the promise of solving the emerging spectrum crisis. However, technology innovators face the conundrum of developing spectrum sharing technologies without the ability to experiment and test with real incumbent systems. Interference with operational incumbents can prevent critical services, and the cost of deploying and operating an incumbent system can be prohibitive. Thus, the lack of incumbent systems and frequency authorization for technology incubation and demonstration has stymied spectrum sharing research. To this end, industry, academia, and regulators all require a test facility for validating hypotheses and demonstrating functionality without affecting operational incumbent systems. This article proposes a four-phase program supported by our spectrum accountability architecture. We propose that our comprehensive experimentation and testing approach for technology incubation and demonstration will accelerate the development of spectrum sharing technologies.

Juan D. Deaton; Lynda L. Brighton; Rangam Subramanian; Hussein Moradi; Jose Loera

2013-09-01

283

Quantum Spread Spectrum Communication  

SciTech Connect

We show that communication of single-photon quantum states in a multi-user environment is improved by using spread spectrum communication techniques. We describe a framework for spreading, transmitting, despreading, and detecting single-photon spectral states that mimics conventional spread spectrum techniques. We show in the cases of inadvertent detection, unintentional interference, and multi-user management, that quantum spread spectrum communications may minimize receiver errors by managing quantum channel access.

Humble, Travis S [ORNL

2011-01-01

284

Utility Bill Analysis Saves Money.  

ERIC Educational Resources Information Center

Analysis of school utility bills is a good business practice for administrators. Efficient energy management of equipment is measured by the "load factor"--the ratio of average demand to maximum demand. An audit enables control of this factor. (CJH)

Lucht, Ray; Dembowski, Frederick L.

1987-01-01

285

The Electromagnetic Spectrum  

NSDL National Science Digital Library

This is a lesson about the electromagnetic spectrum. Learners will read two pages of information about the electromagnetic spectrum and answer questions in an accompanying worksheet. This activity is from the Stanford Solar Center's All About the Sun: Sun and Stars activity guide for Grades 5-8 and can also accompany the Stanford Solar Center's Build Your Own Spectroscope activity.

286

The Electromagnetic Spectrum  

NSDL National Science Digital Library

This tutorial introduces students to the concepts of electromagnetic waves, wavelength, and the electromagnetic spectrum. Diagrams and written descriptions explain how wavelength is measured and explore the traditional divisions of the spectrum: radio, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

287

Radiation detector spectrum simulator  

DOEpatents

A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

Wolf, M.A.; Crowell, J.M.

1985-04-09

288

Allocating dynamic time-spectrum blocks in cognitive radio networks  

Microsoft Academic Search

A number of studies have shown the abundance of unused spectrum in the TV bands. This is in stark contrast to the overcrowding of wireless devices in the ISM bands. A recent trend to alleviate this disparity is the design of Cog- nitive Radios, which constantly sense the spectrum and op- portunistically utilize unused frequencies in the TV bands. In

Yuan Yuan; Paramvir Bahl; Ranveer Chandra; Thomas Moscibroda; Yunnan Wu

2007-01-01

289

BIOMASS UTILIZATION  

EPA Science Inventory

The biomass utilization task consists of the evaluation of a biomass conversion technology including research and development initiatives. The project is expected to provide information on co-control of pollutants, as well as, to prove the feasibility of biomass conversion techn...

290

Glary Utilities  

NSDL National Science Digital Library

Glary Utilities offers this free application to help users improve their system's performance and also protect their privacy. After installing the application, users can remove and back up faculty registry entries, along with offering a secure file deletion feature. This version is compatible with computers running Windows 98 and newer.

2008-01-01

291

DECENTRALIZED TRANSMISSION STRATEGY FOR DELAY-SENSITIVE APPLICATIONS OVER SPECTRUM AGILE NETWORK  

Microsoft Academic Search

With the growing demand of radio resources, maximiz- ing spectrum efficiency becomes increasingly important. Tra- ditional static spectrum allocation lacks the mechanisms for sharing the spectral resources between different allocated bands. Hence, spectrum agility which allows the radio de- vices to dynamically use the idle spectral band is attracting more and more attention. In this paper, we show how spectrum

Aymeric Larcher; Haitong Sun; Mihaela Van Der Schaar; Zhi Ding

292

Pricing-based Spectrum Access Control in Cognitive Radio Networks with Random Access  

E-print Network

" in the spectrum white space, and to enable spectrum sharing for secondary users (SUs). One challenge is how SUs of PUs. I. INTRODUCTION Cognitive radio (CR) is expected to capture temporal and spatial "spectrum holes can discover spectrum holes and access them efficiently and fairly, without causing interference

Tan, Chee Wei

293

Improving process efficiency by utilizing adaptive control  

SciTech Connect

This paper describes an interesting application of adaptive control. It is presently in use on a process located at a plant in the Standard Oil Company (Indiana) system. The results of this application are the transformation of an uncontrollable process to a controllable one; and a significant economic savings to the corporation. The results also show that a detailed analysis of the mechanical, chemical, and control systems can provide both the basis for revising an existing control system and some of the reasons why that system is inadequate.

Whatley, M.J.; Pott, D.C.

1985-01-01

294

Nitrogen utilization efficiency in sorghum cultivars  

E-print Network

. 20b 0. 07b 0. 12b 0. 0813 0. 1113 0. 14b 0. 10b 0. 151) 0. 12b 0. 12b 0. 0913 M35-1 SC326-6 Tx2817 R8507 R8505 ATx623xRTx430 IS9530 BTx378 0. 15cd 0. 26de 0. 18bcd 0. 47bc 0. 12d 0. 14d 0. 35cde 0. 37cde 0. 15cd 0. 30cde ATx... 8180bcce 9123bcd 7852cde 10713b 9604bc 7876cde 650oe 6678de 9548bc 9744bc 7698cde Table 13. continued. b) Avera e Percent of maximum yield Genot e N=O N=150 unfertilized/fertilized Rio ATx623xRTx430 ATx3197xRTx7000 BTx378 R8507 SC279...

Reed, Stewart Thomas

2012-06-07

295

Parametric Adaptive Spectrum Sensing Framework for Dynamic Spectrum Access Networks  

Microsoft Academic Search

The opportunistic usage of the spectrum must be done without causing any interference to the licensed spectrum users. Conventional non-adaptive wideband spectrum sensing approaches could potentially be inefficient since they generally employ the same scanning resolution, even though the spectrum might contain different types of signals, individually requiring scans with different resolutions. In this paper, we present a novel spectrum

Dinesh Datla; Rakesh Rajbanshi; Alexander M. Wyglinski; Gary J. Minden

2007-01-01

296

Parametric Adaptive Spectrum Sensing Framework for Dynamic Spectrum Access Networks  

E-print Network

Parametric Adaptive Spectrum Sensing Framework for Dynamic Spectrum Access Networks Dinesh Datla-adaptive approach. 1 Introduction Dynamic spectrum access (DSA) networks promise to solve the spectrum scarcity receiver that captures the spectrum measurements, with the signal presence detected using en- ergy

Kansas, University of

297

An Adaptive Spectrum Sensing Architecture for Dynamic Spectrum Access Networks  

Microsoft Academic Search

Dynamic spectrum access networks are expected to operate in a manner that is transparent to the incumbent licensed spectrum users. Conventional non-adaptive wideband spectrum sensing approaches could potentially be inefficient since they employ the same scanning resolution to track signals, even though different signals require spectrum scans with different sensing parameters. In this paper, we present an adaptive spectrum sensing

Dinesh Datla; Rakesh Rajbanshi; Alexander M. Wyglinski; Gary J. Minden

2009-01-01

298

Spectrum Sensing for Dynamic Spectrum Access of TV Bands  

Microsoft Academic Search

In this paper we address the issue of spectrum sensing in cognitive radio based wireless networks. Spectrum sensing is the key enabler for dynamic spectrum access as it can allow secondary networks to reuse spectrum without causing harmful interference to primary users. Here we propose a set of integrated medium access control (MAC) and physical layer (PHY) spectrum sensing techniques

Carlos Cordeiro; Monisha Ghosh; Dave Cavalcanti; Kiran Challapali

2007-01-01

299

Hybrid power control scheme in hierarchical spectrum sharing network for cognitive radio  

Microsoft Academic Search

Recently, Hierarchical Spectrum Sharing Network (HSSN) has been proposed to efficiently and flexibly unitize available spectrum resource in cognitive radio context. In the HSSN, available spectrum bands are classified into two types to support both centralized and distributed communications simultaneously. A stable and efficient power control scheme is required to fully make use of the potential of HSSN. An effective

Yueling Che; Jun Wang; Jie Chen; Wanbin Tang; Shaoqian Li

2009-01-01

300

Office of Spectrum Management  

NSDL National Science Digital Library

Office of Spectrum Management (OSM) is responsible for managing the Federal Government's use of the radio frequency spectrum." There are many informative features on the OSM Web site, most notably a collection of studies and reports about federal policies and regulations. Included in these reports is a long-range plan for accommodating the growing spectrum requirements of the government. Another interesting document is a detailed chart of frequency allocation in the US, which shows the range of frequencies reserved for specific radio services. The site is updated often with national and international news and hot topics.

301

Blackbody Radiation Spectrum Model  

NSDL National Science Digital Library

The Blackbody Radiation Spectrum model shows six fixed-temperature curves between Tmin and Tmax and a red variable-temperature curve that can be adjusted using a slider. The wavelength is measured in nm (nanometer) and the intensity is measured in W.e-5 / (m2.nm). Users can adjust Tmin and Tmax to change the temperature range that is displayed. The Blackbody Radiation Spectrum was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double click the ejs_ntnu_BlackbodyRadiationSpectrum.jar file to run the program if Java is installed.

Hwang, Fu-Kwun

2009-08-22

302

A Comprehensive Book on Autism Spectrum Disorders  

ERIC Educational Resources Information Center

The aim of the book is to serve for clinical, practical, basic and scholarly practices. In twentyfive chapters it covers the most important topics related to Autism Spectrum Disorders in the efficient way and aims to be useful for health professionals in training or clinicians seeking an update. Different people with autism can have very different…

Mohammadi, Mohammad-Reza, Ed.

2011-01-01

303

Spread spectrum for commercial communications  

Microsoft Academic Search

The authors describe how spread spectrum operates and explain why the FCC has allocated several spectral bands for spread spectrum. They examine what is wrong with the spectrum allocations the way they are now. They show who is using and will use spread spectrum and why. In particular, they discuss the use of spread spectrum for mobile cellular communications: the

D. L. Schilling; L. B. Milstein; R. L. Pickholtz; M. Kullback; F. Miller

1991-01-01

304

Spectrum Sensing for Cognitive Radio  

Microsoft Academic Search

Spectrum sensing is the very task upon which the entire operation of cognitive radio rests. For cognitive radio to fulfill the potential it offers to solve the spectrum underutilization problem and do so in a reliable and computationally feasible manner, we require a spectrum sensor that detects spectrum holes (i.e., underutilized subbands of the radio spectrum), provides high spectral-resolution capability,

Simon Haykin; David J. Thomson; Jeffrey H. Reed

2009-01-01

305

The Electromagnetic Spectrum  

NSDL National Science Digital Library

This interactive, online module reviews the basics of the the electromagnetic spectrum and makes the connection between radiation theory and the images we get from weather satellites. Students will learn about: the electromagnetic spectrum; electromagnetic waves; the electromagnetic spectrum and radiation theory; and how satellite radiometers "see" different sections of the spectrum. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

306

Spectrum and Network Analyzers  

Microsoft Academic Search

Spectrum and network analyzers (SPAs and NWAs) are found in every microwave laboratory. This report describes the basic principles of operation of a SPA and NWA and also describes several simple example measurements using each of these instruments.

J. M. BYRD; Friedhelm Caspers

1999-01-01

307

IRIS Spectrum Line Plot  

NASA Video Gallery

This video shows a line plot of the spectrum. The spectra here are shown for various locations on the Sun. The changes in the movie are caused by differing physical conditions in the locations. Cre...

308

Autism Spectrum Disorder (ASD)  

MedlinePLUS

... you’re concerned." Share on Facebook Share on Twitter "Children with autism spectrum disorder are not being ... as they could be. Learn more." Share on Twitter ASD Homepage Facts Signs and Symptoms Screening & Diagnosis ...

309

Autism Spectrum Disorder (ASD)  

MedlinePLUS

... Information Clinical Trials Resources and Publications En Español Autism Spectrum Disorder (ASD): Condition Information Skip sharing on ... Restricted interests and repetitive behaviors Different people with autism can have different symptoms. For this reason, autism ...

310

Synthesis of artificial spectrum-compatible seismic accelerograms  

NASA Astrophysics Data System (ADS)

The Hilbert-Huang transform is used to generate artificial seismic signals compatible with the acceleration spectra of natural seismic records. Artificial spectrum-compatible accelerograms are utilized instead of natural earthquake records for the dynamic response analysis of many critical structures such as hospitals, bridges, and power plants. The realistic estimation of the seismic response of structures involves nonlinear dynamic analysis. Moreover, it requires seismic accelerograms representative of the actual ground acceleration time histories expected at the site of interest. Unfortunately, not many actual records of different seismic intensities are available for many regions. In addition, a large number of seismic accelerograms are required to perform a series of nonlinear dynamic analyses for a reliable statistical investigation of the structural behavior under earthquake excitation. These are the main motivations for generating artificial spectrum-compatible seismic accelerograms and could be useful in earthquake engineering for dynamic analysis and design of buildings. According to the proposed method, a single natural earthquake record is deconstructed into amplitude and frequency components using the Hilbert-Huang transform. The proposed method is illustrated by studying 20 natural seismic records with different characteristics such as different frequency content, amplitude, and duration. Experimental results reveal the efficiency of the proposed method in comparison with well-established and industrial methods in the literature.

Vrochidou, E.; Alvanitopoulos, P. F.; Andreadis, I.; Elenas, A.; Mallousi, K.

2014-08-01

311

Exploring the Electromagnetic Spectrum  

NSDL National Science Digital Library

Students learn the basics of the electromagnetic spectrum and how various types of electromagnetic waves are related in terms of wavelength and energy. In addition, they are introduced to the various types of waves that make up the electromagnetic spectrum including, radio waves, ultraviolet waves, visible light and infrared waves. These topics help inform students before they turn to designing solutions to an overarching engineering challenge question.

Research Experience for Teachers (RET) Program, Center of Advancement of Engineering Fibers and Films,

312

QoS-aware dynamic spectrum access for cognitive radio networks  

NASA Astrophysics Data System (ADS)

Ubiquitous wireless networking requires efficient dynamic spectrum access (DSA) among heterogeneous users with diverse transmission types and bandwidth demands. To meet user-specific quality-of-service (QoS) requirements, the power and spectrum allocated to each user should lie inside a power/spectral-shape bounded region in order to be meaningful for the intended application. Most existing DSA methods aim at enhancing the total system utility. As such, spectrum wastage may arise when the system-wide optimal allocation falls outside individual users' desired regions for QoS provisioning. In this work, novel QoS-aware DSA algorithms are developed for both non-cooperative power allocation (QoSNCPA) and cooperative (QoSCPA) users in cognitive radio (CR) networks. The algorithms maximize the "useful utilities" to the users, and minimize the power consumption and mutual interference within the CR network. Simulations results of the QoSNCPA and QoSCPA for single and multiple channel cases demonstrate the effectiveness of the algorithms for DSA.

Tian, Xin; Tian, Zhi; Pham, Khanh; Blasch, Erik; Chen, Genshe

2013-05-01

313

In situ growth of NiCo2S4 nanotube arrays on Ni foam for supercapacitors: Maximizing utilization efficiency at high mass loading to achieve ultrahigh areal pseudocapacitance  

NASA Astrophysics Data System (ADS)

Self-standing NiCo2S4 nanotube arrays have been in situ grown on Ni foam by the anion-exchange reaction and directly used as the electrode for supercapacitors. The NiCo2S4 nanotube in the arrays effectively reduces the inactive material and increases the electroactive surface area because of the ultrathin wall, which is quite competent to achieve high utilization efficiency at high electroactive materials mass loading. The NiCo2S4 nanotube arrays hybrid electrode exhibits an ultrahigh specific capacitance of 14.39 F cm-2 at 5 mA cm-2 with excellent rate performance (67.7% retention for current increases 30 times) and cycling stability (92% retention after 5000 cycles) at a high mass loading of 6 mg cm-2. High areal capacitance (4.68 F cm-2 at 10 mA cm-2), high energy density (31.5 Wh kg-1 at 156.6 W kg-1) and high power density (2348.5 W kg-1 at 16.6 Wh kg-1) can be achieved by assembling asymmetric supercapacitor with reduced graphene oxide at a total active material mass loading as high as 49.5 mg. This work demonstrates that NiCo2S4 nanotube arrays structure is a superior electroactive material for high-performance supercapacitors even at a mass loading of potential application-specific scale.

Chen, Haichao; Jiang, Jianjun; Zhang, Li; Xia, Dandan; Zhao, Yuandong; Guo, Danqing; Qi, Tong; Wan, Houzhao

2014-05-01

314

Adaptive channel allocation spectrum etiquette for cognitive radio networks  

Microsoft Academic Search

In this work, we propose a game theoretic framework to analyze the behavior of cognitive radios for distributed adaptive channel allocation. We define two different objective functions for the spectrum sharing games, which capture the utility of selfish users and cooperative users, respectively. Based on the utility definition for cooperative users, we show that the channel allocation problem can be

Nie Nie; Cristina Comaniciu

2005-01-01

315

Adaptive Channel Allocation Spectrum Etiquette for Cognitive Radio Networks  

Microsoft Academic Search

In this work, we propose a game theoretic frame- work to analyze the behavior of cognitive radios for distributed adaptive channel allocation. We define two different objective functions for the spectrum sharing games, which capture the utility of selfish users and cooperative users, respectively. Based on the utility definition for cooperative users, we show that the channel allocation problem can

Nie Nie; Cristina Comaniciu

2006-01-01

316

Gender Differences in Symptoms of Autism Spectrum Disorders in Toddlers  

ERIC Educational Resources Information Center

Gender differences in symptoms representing the triad of impairments of Autism Spectrum Disorders remain unclear. To date, the majority of research conducted on this topic has utilized samples of older children. Thus, the purpose of the current study was to utilize a sample of toddlers to investigate gender differences in symptom endorsements of…

Sipes, Megan; Matson, Johnny L.; Worley, Julie A.; Kozlowski, Alison M.

2011-01-01

317

Optical wireless applications: a solution to ease the wireless airwaves spectrum crunch  

NASA Astrophysics Data System (ADS)

Demands by the communications industry for greater and greater bandwidth push the capability of conventional wireless technology. Part of the Radio Spectrum that is suitable for mobility is very limited. Higher frequency waves above 30 GHz tend to travel only a few miles or less and generally do not penetrate solid materials very well. This offers a sustainable solution for the current Spectrum Crunch in the lower microwave bands. One mission of this paper is to demonstrate practical and usable networks that can select a self-limiting link distance, allowing spectrum reuse. The motivation for operators of such bands to actually choose to self-limit is that by doing so, they improve the signal-tonoise against competing users at a lower cost than trying to overcome interference. These characteristics of wave propagation are not necessarily disadvantageous as they enable more densely packed communications links. Thus, high frequencies can provide very efficient spectrum utilization through "selective spectrum reuse", and naturally increase the security of transmissions. Optical systems and networks offer a far greater bandwidth. This means new devices and systems have to be developed. Semiconductor Light Emitting Diode (LED) is considered to be the future primary lighting source for buildings, automobiles and aircrafts. LED provides higher energy efficiency compared to incandescent and fluorescent light sources and it will play a major role in the global reduction of carbon dioxide emissions, as a consequence of the significant energy savings. Lasers are also under investigation for similar applications. These core devices have the potential to revolutionize how we use light, including not only for illumination, but as well; for communications, sensing, navigation, positioning, surveillance, and imaging.

Kavehrad, M.

2013-01-01

318

The research of optical fiber Brillouin spectrum denoising based on wavelet transform and neural network  

NASA Astrophysics Data System (ADS)

The center frequency of Brillouin scattering spectrum is easily influenced by the noise and the measurement accuracy of optical fiber strain is reduced. So a novel denoising method which can be applied in the Brillouin scattering spectrum is developed in this article. The Brillouin scattering spectrum is decomposed into multi-scale detail coefficients and approximation coefficients by using the wavelet transform. The wavelet decomposition detail coefficients are threshold quantified by utilizing the threshold algorithm. At the same time, the wavelet decomposition approximation coefficients are trained and simulated by using the BP neural network in order to remove noise hided in the approximation coefficients. So the novel method can reduce the wavelet decomposition scales. The Brillouin scattering spectrum which has a better denoising effect can be gained by using the inverse wavelet transform, and the measurement accuracy of optical fiber strain is enhanced also. The results of simulation and experiment demonstrate that the proposed method can suppress noise better; accordingly, the new method can gain more precision optical fiber strain and reduce the wavelet decomposition scales effectively than the conventional wavelet denoising method. Theory analysis and experiment show that the method is reasonable and efficient.

Zhang, Zhi-hui; Hu, Wei-liang; Yan, Ji-song; Zhang, Peng

2013-08-01

319

Economic Viability of Dynamic Spectrum Management  

E-print Network

Economic Viability of Dynamic Spectrum Management Jianwei Huang Network Communications, however, is surprisingly low. A recent spectrum measurement in the US showed that the average spectrum Viability of Dynamic Spectrum Management Spectrum resources are scarce, as most spectrums have been

Huang, Jianwei

320

ADAPTIVE SPECTRUM SENSING FOR AGILE COGNITIVE RADIOS Ali Tajer, Rui Castro, and Xiaodong Wang  

E-print Network

ADAPTIVE SPECTRUM SENSING FOR AGILE COGNITIVE RADIOS Ali Tajer, Rui Castro, and Xiaodong Wang of the frequency spectrum are licensed to specific users for particular applications. These legacy users, however that vast segments of the frequency spectrum are often under-utilized, despite being licensed to legacy

Castro, Rui

321

Energizing Efficiency's Potential  

SciTech Connect

Advances such as 'smart' meters, two-way communication, and automation technology are rapidly improving information exchange between utilities and their customers, and enabling further energy efficiency gains. (author)

Kuhn, Thomas R.

2006-10-15

322

Spread spectrum image steganography  

Microsoft Academic Search

In this paper, we present a new method of digitalsteganography, entitled spread spectrum image steganography(SSIS). Steganography, which means "covered writing" in Greek,is the science of communicating in a hidden manner. Followinga discussion of steganographic communication theory and reviewof existing techniques, the new method, SSIS, is introduced. Thissystem hides and recovers a message of substantial length withindigital imagery while maintaining the

Lisa M. Marvel; Charles G. Boncelet Jr.; Charles T. Retter

1999-01-01

323

The Heavy Hadron Spectrum  

E-print Network

I discuss the spectrum of hadrons containing heavy quarks ($b$ or $c$), and how well the experimental results are matched by theoretical ideas. Useful insights come from potential models and applications of Heavy Quark Symmetry and these can be compared with new numerical results from the ab initio methods of Lattice QCD.

C. T. H. Davies

1997-10-17

324

Electromagnetic Spectrum Control Programs  

Microsoft Academic Search

The radio frequency spectrum is becoming increasingly saturated and polluted due to intensified use and unnecessary radiations and is being taxed severely to meet man's communications-electronics needs. Additional corrective measures are necessary-improved standards, increased concern for conservation of the resource, greater emphasis on intersystems compatibility, increased research, better educational and training programs, and the inclusion of economic and social values

Wilfred Dean

1971-01-01

325

Autism Spectrum Disorders  

Microsoft Academic Search

\\u000a Autism spectrum disorders are becoming more recognized in the general population. With increased awareness, primary care physicians\\u000a are diagnosing these disorders at an earlier age. The following is a brief review of the proposed diagnostic changes in DSM-V,\\u000a and recommendations for making a diagnosis and for treatment planning.

Ahsan Nazeer

326

Cloud Spectrum Measurements  

E-print Network

Cloud Seed Techniques (Mali, Saudi Arabia) Basic Cloud Parameter (MPACE) Icing Studies (WISP04` Cloud Spectrum Measurements By David Delene #12;Forward Scattering Spectrometer Probe (FSSP The ¶amount of liquid water for a given volume of air may be determined through mass integration of the cloud

Delene, David J.

327

Cosmic Ray Spectrum in Supernova Remnant Shocks  

NASA Astrophysics Data System (ADS)

We perform kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). Bohm-like diffusion due to self-excited Alfvén waves is assumed,and simple models for Alfvénic drift and dissipation are adopted. Phenomenological models for thermal leakage injection are considered as well. We find that the preshock gas temperature is the primary parameter that governs the cosmic ray (CR) acceleration efficiency and energy spectrum,while the CR injection rate is a secondary parameter. For SNRs in the warm ISM of T_0 ? 10^5K, if the injection fraction is ? ? 10^{-4},the DSA is efficient enough to convert more than 20 % of the SN explosion energy into CRs and the accelerated CR spectrum exhibits a concave curvature flattening to E^{-1.6}, which is characteristic of CR modified shocks. Such a flat source spectrum near the knee energy, however, may not be reconciled with the CR spectrum observed at Earth.On the other hand, SNRs in the hot ISM of T_0? 10^6K with a small injection fraction, ? < 10^{-4}, are inefficient accelerators with less than 10 % of the explosion energy getting converted to CRs. Also the shock structure is almost test-particle like and the ensuing CR spectrum can be steeper than E^{-2}. With amplified magnetic field strength of order of 30?G, Alfvén waves generated by the streaming instability may drift upstream fast enough to make the modified test-particle power-law as steep as E^{-2.3}, which is more consistent with the observed CR spectrum.

Kang, Hyesung

2010-04-01

328

Network inefficiencies in autism spectrum disorder at 24 months  

PubMed Central

Autism spectrum disorder (ASD) is a developmental disorder defined by behavioral symptoms that emerge during the first years of life. Associated with these symptoms are differences in the structure of a wide array of brain regions, and in the connectivity between these regions. However, the use of cohorts with large age variability and participants past the generally recognized age of onset of the defining behaviors means that many of the reported abnormalities may be a result of cascade effects of developmentally earlier deviations. This study assessed differences in connectivity in ASD at the age at which the defining behaviors first become clear. There were 113 24-month-old participants at high risk for ASD, 31 of whom were classified as ASD, and 23 typically developing 24-month-old participants at low risk for ASD. Utilizing diffusion data to obtain measures of the length and strength of connections between anatomical regions, we performed an analysis of network efficiency. Our results showed significantly decreased local and global efficiency over temporal, parietal and occipital lobes in high-risk infants classified as ASD, relative to both low- and high-risk infants not classified as ASD. The frontal lobes showed only a reduction in global efficiency in Broca's area. In addition, these same regions showed an inverse relation between efficiency and symptom severity across the high-risk infants. The results suggest delay or deficits in infants with ASD in the optimization of both local and global aspects of network structure in regions involved in processing auditory and visual stimuli, language and nonlinguistic social stimuli. PMID:24802306

Lewis, J D; Evans, A C; Pruett, J R; Botteron, K; Zwaigenbaum, L; Estes, A; Gerig, G; Collins, L; Kostopoulos, P; McKinstry, R; Dager, S; Paterson, S; Schultz, R T; Styner, M; Hazlett, H; Piven, J

2014-01-01

329

The performance of water utilities in Jordan.  

PubMed

This paper aims to measure the relative performance of Jordan's water utilities for water sector (WS) and wastewater sector (WWS), and to investigate the major factors behind their inefficiencies. DEA (non-parametric method) and Tobit model (parametric method) were used at two stages. At the first stage DEA was used to evaluate the utilities' efficiency and to investigate the utilities' scale effect on efficiency. At the second stage Tobit model (regression) is applied to determine the impact of the non-controllable factors on utilities' inefficiencies where the efficiency score is the dependent variable in the regression. The results of DEA showed that there is a potential to reduce inputs level: water supply and operational expense (OPEX) for WS, and treated wastewater and OPEX for WWS, by around 15-20 and 23-27%, respectively. Aqaba and Jarash utilities are the most efficient utilities in the WS, while it is Amman utility in the WWS. The utility size has relatively moderate effect on the relative performance. It is concluded that the medium utility size for WS and large utility size for WWS is the most appropriate. Tobit model results indicate that commercialization activities have a clear positive impact on efficiency improvement for both sectors. PMID:20729581

Al-Assa'd, Tamer; Sauer, Johannes

2010-01-01

330

Free-form Fresnel RXI Köhler design with spectrum-splitting for photovoltaics  

NASA Astrophysics Data System (ADS)

Here we present a novel optical design of the high concentration photovoltaics (HPCV) nonimaging concentrator (>500x) with built-in spectrum splitting concept. The primary optical element (POE) is a flat Fresnel lens and the secondary optical element (SOE) is a free-form RXI-type concentrator with a band-pass filter embedded in it, both POE and SOE performing Köhler integration to produce light homogenization on the target. It uses the combination of a commercial concentration GaInP/GaInAs/Ge 3J cell and a concentration Back-Point-Contact (BPC) silicon cell for efficient spectral utilization, and external confinement techniques for recovering the 3J cell's reflection. Design targets equivalent cell efficiency ~46% using commercial 39% 3J and 26% Si cells, and CPV module efficiency greater than 38%, achieved at a concentration level larger than 500X and wide acceptance angle (+/-1°). A first proof-of concept receiver prototype has been manufactured using a simpler optical architecture (with a lower concentration, ~100x and lower simulated added efficiency), and experimental measurements have shown up to 39.8% 4J receiver efficiency using a 3J with peak efficiency of 36.9%.

Buljan, M.; Benítez, P.; Mohedano, R.; Miñano, J. C.; Sun, Y.; Falicoff, W.; Vilaplana, J.; Chaves, J.; Biot, G.; López, J.

2011-10-01

331

The spectrum of ?-ray burst: a clue  

NASA Astrophysics Data System (ADS)

In this work, we numerically calculate the thermal radiation efficiency of the baryonic outflow. The possible outflow acceleration in the transparent stage, which lowers thermal radiation efficiency, has been taken into account. In the standard internal shock model for the prompt emission, the fast shells should move with a typical Lorentz factor ~5 ?i otherwise the ?-ray burst (GRB) efficiency will be in disagreement with the observations, where ?i is the bulk Lorentz factor of the shocked/emitting region. The photosphere radius of these fast shells is small and the thermal radiation is too strong to be effectively outshone by the internal shock emission. This is particularly the case for some extremely bright events having ?i ~ 103, like GRBs 080319B and 080916C. The absence of a distinct thermal component in the spectrum of most GRBs challenges the standard internal shock model and may suggest a non-baryonic (magnetic) outflow component. Though the magnetic outflow model seems favoured by more and more data, it can hardly reproduce the typical GRB spectrum. In the photosphere-gradual magnetic dissipation scenario, the spectrum cuts off at ~1 GeV, too low to account for the observations of GRBs 080916C. In the sudden magnetic energy dissipation model, the low-energy spectrum is expected to be F? ~ ?-1/2, too soft to be consistent with the data F? ~ ?0. We speculate that the low-energy spectrum puzzle could be unveiled by the mechanism that particles, in the magnetic dissipation process, are repeatedly accelerated.

Fan, Yi-Zhong

2010-03-01

332

A study analysis of cooperative spectrum sensing in cognitive radio networks  

NASA Astrophysics Data System (ADS)

Cognitive radios (CR) are designed in order to provide highly reliable communication for all users of the network, wherever and whenever needed and to facilitate effective utilization of the radio spectrum. In this paper, we analyzed local spectrum sensing for various fading channel scenario and also analyzed conventional cooperative spectrum sensing. We simulated various performance analysis for Additive White Gaussian Noise (AWGN), Rayleigh fading and cooperative spectrum sensing.

Kalimuthu, K.; Kumar, R.

2013-01-01

333

Evaluating Energy Conversion Efficiency  

NASA Technical Reports Server (NTRS)

Devices that convert solar radiation directly into storable chemical or electrical energy, have characteristic energy absorption spectrum; specifically, each of these devices has energy threshold. The conversion efficiency of generalized system that emcompasses all threshold devices is analyzed, resulting in family of curves for devices of various threshold energies operating at different temperatures.

Byvik, C. E.; Smith, B. T.; Buoncristiani, A. M.

1983-01-01

334

Spread spectrum image steganography.  

PubMed

In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking. PMID:18267522

Marvel, L M; Boncelet, C R; Retter, C T

1999-01-01

335

Multitaper Spectrum Estimates  

NASA Astrophysics Data System (ADS)

Multitapering is a statistical technique developed to improve on the notorious periodogram estimate of the power spectrum (Thomson, 1982; Percival, Walden 1993). We show how to obtain orthogonal tapers for time series observed with gaps, and how to use statistical resampling techniques (Efron, Tibshirani 1993) to calculate realistic uncertainty estimates for multitaper estimates. We introduce multisegment multitapering. Multitapering can also be extended to the 2D case. We indicate how to construct tapers that minimize the spatial leakage in estimates of the spherical harmonic decomposition of the velocity images. Spatial multitapering followed by the temporal tapering of the estimated spherical harmonic time series is expected to result in improved spectrum and subsequent solar oscillation mode parameter estimates.

Fodor, I. K.; Stark, P. B.

336

The Electromagnetic Spectrum  

NSDL National Science Digital Library

In this lesson, students are introduced to the electromagnetic spectrum. They observe a demonstration of the visible light spectrum created by a flashlight and a prism, complete an activity sheet where they identify the wavelength that is involved in technologies used in their communities, and learn about satellite sensors that remotely sense data. Student worksheets, a data sheet, answer keys, and Web links are included. This is Lesson 3 in Understanding Light, part of IMAGERS, Interactive Media Adventures for Grade School Education using Remote Sensing. The website provides hands-on activities in the classroom supporting the science content in two interactive media books, The Adventures of Echo the Bat and Amelia the Pigeon.

337

Exploring the Spectrum  

NSDL National Science Digital Library

This activity introduces students to the visible light spectrum, and demonstrates what happens to the appearance of an image when certain wavelengths of light are blocked by filters or made visible using special tools. Students are lead through experiments with light and filters, demonstrating that the broader the range of the electromagnetic spectrum we can detect, the more information we gather about the universe. By completing this activity, students gain background information that is necessary for activities that follow this one. This activity is part of the "Cosmic Questions: Our Place in Space and Time" educator's guide that was developed to support the Cosmic Questions exhibit. Activities in the guide can be used in conjunction with, or independently of, the exhibt.

338

The Supersymmetric Particle Spectrum  

E-print Network

We examine the spectrum of supersymmetric particles predicted by grand unified theoretical (GUT) models where the electroweak symmetry breaking is accomplished radiatively. We evolve the soft supersymmetry breaking parameters according to the renormalization group equations (RGE). The minimization of the Higgs potential is conveniently described by means of tadpole diagrams. We present complete one-loop expressions for these minimization conditions, including contributions from the matter and the gauge sectors. We concentrate on the low $\\tan \\beta$ fixed point region (that provides a natural explanation of a large top quark mass) for which we find solutions to the RGE satisfying both experimental bounds and fine-tuning criteria. We also find that the constraint from the consideration of the lightest supersymmetric particle as the dark matter of the universe is accommodated in much of parameter space where the lightest neutralino is predominantly gaugino. The supersymmetric mass spectrum displays correlations that are model-independent over much of the GUT parameter space.

V. Barger; M. S. Berger; P. Ohmann

1993-11-11

339

Detecting anomalous spectrum usage in dynamic spectrum access networks  

Microsoft Academic Search

Dynamic spectrum access has been proposed as a means to share scarce radio resources, and requires devices to follow protocols that access spectrum resources in a proper, disciplined manner. For a cognitive radio network to achieve this goal, spectrum policies and the ability to enforce them are necessary. Detection of an unauthorized (anomalous) usage is one of the critical issues

Song Liu; Larry J. Greenstein; Wade Trappe; Yingying Chen

340

DECENTRALIZED TRANSMISSION STRATEGIES FOR DELAY-SENSITIVE APPLICATIONS OVER SPECTRUM AGILE NETWORKS  

Microsoft Academic Search

With the growing demand of radio resources, maximiz- ing spectrum efficiency becomes increasingly important. Tra- ditional static spectrum allocation lacks effective mecha- nisms for sharing spectral resources. Through adaptive re- source allocation, spectrum agility allows the radio devices to dynamically use the idle spectral band and is becoming increasingly attractive because it can provide a large number of resources for

Aymeric Larcher; Haitong Sun; Mihaela van der Schaar; Zhi Ding

2004-01-01

341

Attack Prevention for Collaborative Spectrum Sensing in Cognitive Radio Networks  

E-print Network

Collaborative spectrum sensing can significantly improve the detection performance of secondary unlicensed users (SUs). However, the performance of collaborative sensing is vulnerable to sensing data falsification attacks, where malicious SUs (attackers) submit manipulated sensing reports to mislead the fusion center's decision on spectrum occupancy. Moreover, attackers may not follow the fusion center's decision regarding their spectrum access. This paper considers a challenging attack scenario where multiple rational attackers overhear all honest SUs' sensing reports and cooperatively maximize attackers' aggregate spectrum utilization. We show that, without attack-prevention mechanisms, honest SUs are unable to transmit over the licensed spectrum, and they may further be penalized by the primary user for collisions due to attackers' aggressive transmissions. To prevent such attacks, we propose two novel attack-prevention mechanisms with direct and indirect punishments. The key idea is to identify collisions...

Duan, Lingjie; Huang, Jianwei; Shin, Kang G

2011-01-01

342

Spectrum tailoring of the neutron energy spectrum in the context of delayed neutron detection  

SciTech Connect

For the purpose of measuring plutonium mass in spent fuel, a delayed neutron instrument is of particular interest since, if properly designed, the delayed neutron signal from {sup 235}U is significantly stronger than the signature from {sup 239}Pu or {sup 241}Pu. A key factor in properly designing a delayed neutron instrument is to minimize the fission of {sup 238}U. This minimization is achieved by keeping the interrogating neutron spectrum below {approx} 1 MeV. In the context of spent fuel measurements it is desirable to use a 14 MeV (deuterium and tritium) neutron generator for economic reasons. Spectrum tailoring is the term used to describe the inclusion of material between the 14 MeV neutrons and the interrogated object that lower the neutron energy through nuclear reactions and moderation. This report quantifies the utility of different material combination for spectrum tailoring.

Koehler, William E [Los Alamos National Laboratory; Tobin, Steve J [Los Alamos National Laboratory; Sandoval, Nathan P [Los Alamos National Laboratory; Fensin, Mike L [Los Alamos National Laboratory

2010-01-01

343

Sulforaphane and Autism Spectrum Disorder  

MedlinePLUS

... right-hand corner of the player. Sulforaphane and Autism Spectrum Disorder HealthDay October 14, 2014 Related MedlinePlus Pages Autism Spectrum Disorder Nutrition Transcript Can a chemical found ...

344

On the Spectrum Handoff for Cognitive Radio Ad Hoc Networks without Common Control Channel  

E-print Network

Cognitive radio (CR) technology is a promising solution to enhance the spectrum utilization by enabling unlicensed users to exploit the spectrum in an opportunistic manner. Since unlicensed users are temporary visitors to the licensed spectrum, they are required to vacate the spectrum when a licensed user reclaims it. Due to the randomness of the appearance of licensed users, disruptions to both licensed and unlicensed communications are often difficult to prevent. In this chapter, a proactive spectrum handoff framework for CR ad hoc networks is proposed to address these concerns. In the proposed framework, channel switching policies and a proactive spectrum handoff protocol are proposed to let unlicensed users vacate a channel before a licensed user utilizes it to avoid unwanted interference. Network coordination schemes for unlicensed users are also incorporated into the spectrum handoff protocol design to realize channel rendezvous. Moreover, a distributed channel selection scheme to eliminate collisions a...

Song, Yi

2011-01-01

345

ACBAR CMB Power Spectrum  

NASA Astrophysics Data System (ADS)

We report the first measurements of anisotropy in the cosmic microwave background (CMB) radiation with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). The instrument was installed on the 2.1 m Viper telescope at the South Pole in December 2000; the data presented here are the product of observations up to and including July 2002. The large 3 degree extent of the maps, and small beamsize of the experiment allow the measurement of the CMB anisotropy power spectrum over the range l = 150-3000 with resolution of ? l=150. We discuss the observation strategy, analysis method, and the cosmological implication of the results.

Kuo, C.-L.; Ade, P.; Bock, J. J.; Daub, M. D.; Goldstein, J.; Holzapfel, W. L.; Lange, A. E.; Newcomb, M.; Peterson, J. B.; Ruhl, J.; Runyan, M. C.; Torbet, E.

2002-12-01

346

Psychotropic Medication Use among Children with Autism Spectrum Disorders within the Simons Simplex Collection: Are Core Features of Autism Spectrum Disorder Related?  

ERIC Educational Resources Information Center

Psychotropic medication use and its relationship to autism spectrum core features were examined in a well-characterized but nonstratified North American sample (N = 1605) of children/adolescents diagnosed with autism spectrum disorders utilizing the "Autism Diagnostic Observation Schedule" and the "Autism Diagnostic…

Mire, Sarah S.; Nowell, Kerri P.; Kubiszyn, Thomas; Goin-Kochel, Robin P.

2014-01-01

347

Efficiency Projects and Water Reuse  

E-print Network

Efficiency In A Small Utility Bill Pannell bill.pannell@cleburne.net City of Cleburne ESL-KT-11-11-36 ?Efficiency In A Small Utility Are We As Efficient As We Can Be?? Reduce Water ?Loss? Thru Better Auditing And Metering Improvements...?? ? Where should you focus your capital and effort? ? Routine, meaningful, audits are the first step in answering these critical questions. ? TWDB program is the best proven method, and best of all ? it is free! ? The ?Assessment Scale scores...

Pannell, B.

2011-01-01

348

Efficient Windows Collaborative  

SciTech Connect

The project goals covered both the residential and commercial windows markets and involved a range of audiences such as window manufacturers, builders, homeowners, design professionals, utilities, and public agencies. Essential goals included: (1) Creation of 'Master Toolkits' of information that integrate diverse tools, rating systems, and incentive programs, customized for key audiences such as window manufacturers, design professionals, and utility programs. (2) Delivery of education and outreach programs to multiple audiences through conference presentations, publication of articles for builders and other industry professionals, and targeted dissemination of efficient window curricula to professionals and students. (3) Design and implementation of mechanisms to encourage and track sales of more efficient products through the existing Window Products Database as an incentive for manufacturers to improve products and participate in programs such as NFRC and ENERGY STAR. (4) Development of utility incentive programs to promote more efficient residential and commercial windows. Partnership with regional and local entities on the development of programs and customized information to move the market toward the highest performing products. An overarching project goal was to ensure that different audiences adopt and use the developed information, design and promotion tools and thus increase the market penetration of energy efficient fenestration products. In particular, a crucial success criterion was to move gas and electric utilities to increase the promotion of energy efficient windows through demand side management programs as an important step toward increasing the market share of energy efficient windows.

Nils Petermann

2010-02-28

349

Rotational spectrum of tryptophan  

NASA Astrophysics Data System (ADS)

The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the 14N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O-H...N hydrogen bond in the side chain and a N-H...? interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.

Sanz, M. Eugenia; Cabezas, Carlos; Mata, Santiago; Alonso, Josè L.

2014-05-01

350

Rotational spectrum of paracetamol.  

PubMed

In this paper we report the first rotational spectrum of isolated paracetamol. Solid samples of paracetamol were vaporized by laser ablation, expanded in a supersonic jet and characterized by Fourier transform microwave spectroscopy in the 4-10 GHz frequency range. The spectra of a total of four conformers, two with a trans peptidic -CO-NH- functional group arrangement and two with a cis peptidic group arrangement have been observed for the first time. The identification of all the conformers was based on the comparison of the experimental rotational and (14)N quadrupole coupling constants with those predicted by ab initio calculations, and relative values of their electrical dipole moment components. PMID:23746213

Varela, Marcelino; Cabezas, Carlos; López, Juan C; Alonso, José Luis

2013-12-19

351

Autism Spectrum Disorders  

PubMed Central

Autism spectrum disorders (ASDs) are collectively the most commonly diagnosed pediatric neurodevelopmental condition. ASDs include autism, pervasive developmental disorder-not otherwise specified (PDD-NOS), Rett syndrome and Asperger disorder. ASD is characterized by impaired communication and social interaction and may involve developmental delays and seizure disorders. Recent parent-reported diagnosis of ASD in the United States put it at higher levels (1:91) than previously thought, with its diagnosis in boys occurring 4 to 5 times more frequently than in girls (1:58).1 CDC estimates are currently 1:110;1 up from 1:150 in 2007.2 Annual medical expenditures for those affected are generally four to six times greater than for those without ASD.1 While twin studies demonstrate that genetics play a significant role in ASD, the impact of environment should not be underestimated, given the approximate 20-fold increase in incidence over the last 20 years.3 PMID:24278834

Hyman, Mark; Swift, Kathie

2012-01-01

352

Cross-spectrum Analyzer for Low Frequency Noise Analysis  

E-print Network

The design and performance of a sensitive and reliable cross-correlation spectrum analyzer for studying low frequency transport noise is described in detail. The design makes use of common PC-based data acquisition hardware and preamplifiers to acquire time-based data, along with software we have developed to compute the cross-correlation and noise spectral density. The impedance of device under test may cover four decades from ${100\\,{\\Omega}}$ to ${1\\,{\\mathrm{M}\\Omega}}$. By utilizing a custom developed signal processing program, this system is tested to be accurate and efficient for measuring voltage noise as low as $\\sim\\!10^{-19}\\,\\mathrm{V}^2/\\mathrm{Hz}$ from ${0.001\\,}$Hz to ${100\\,}$kHz within one day's averaging time, comparable with more expensive hardware solutions (bandwidth in real measurements may be limited by the sample impedance and stray capacitance). The time dependence of measurement sensitivity is discussed theoretically and characterized experimentally to optimize between measuring tim...

Zhong, Xing; Jones, Josh; Mewes, Claudia; LeClair, Patrick R

2014-01-01

353

Broad spectrum bioactive sunscreens.  

PubMed

The development of sunscreens containing reduced concentration of chemical UV filters, even though, possessing broad spectrum effectiveness with the use of natural raw materials that improve and infer UV absorption is of great interest. Due to the structural similarities between polyphenolic compounds and organic UV filters, they might exert photoprotection activity. The objective of the present research work was to develop bioactive sunscreen delivery systems containing rutin, Passiflora incarnata L. and Plantago lanceolata extracts associated or not with organic and inorganic UV filters. UV transmission of the sunscreen delivery system films was performed by using diffuse transmittance measurements coupling to an integrating sphere. In vitro photoprotection efficacy was evaluated according to the following parameters: estimated sun protection factor (SPF); Boot's Star Rating category; UVA/UVB ratio; and critical wavelength (lambda(c)). Sunscreen delivery systems obtained SPF values ranging from 0.972+/-0.004 to 28.064+/-2.429 and bioactive compounds interacted with the UV filters positive and negatively. This behavior may be attributed to: the composition of the delivery system; the presence of inorganic UV filter and quantitative composition of the organic UV filters; and the phytochemical composition of the P. incarnata L. and P. lanceolata extracts. Among all associations of bioactive compounds and UV filters, we found that the broad spectrum sunscreen was accomplished when 1.68% (w/w) P. incarnata L. dry extract was in the presence of 7.0% (w/w) ethylhexyl methoxycinnamate, 2.0% (w/w) benzophenone-3 and 2.0% (w/w) TiO(2). It was demonstrated that this association generated estimated SPF of 20.072+/-0.906 and it has improved the protective defense against UVA radiation accompanying augmentation of the UVA/UVB ratio from 0.49 to 0.52 and lambda(c) from 364 to 368.6nm. PMID:18662760

Velasco, Maria Valéria Robles; Sarruf, Fernanda Daud; Salgado-Santos, Idalina Maria Nunes; Haroutiounian-Filho, Carlos Alberto; Kaneko, Telma Mary; Baby, André Rolim

2008-11-01

354

Jupiter's transmission spectrum  

NASA Astrophysics Data System (ADS)

In relation to the gas giants that have been observed, Jupiter is located relatively far from its star. Observing Jupiter as an exoplanet can provide information about what to expect when getting data from similar gas giants around other stars. Even though Jupiter's transmission spectrum can be difficult to observe when looking from the Earth, it is possible to do it by using one of the Moons orbiting the planet as a mirror while in Jupiter's shadow. For example, Formisano et al. (2003) reported the detection of Jupiter's methane absorption bands when the Cassini VIMS experiment observed the occultation of the moon Io during its flyby in December 2000. Here, we present the first detection of Jupiter's transmission spectrum from ground-based observations. The first set of observations were taken from La Palma, Spain on the night of the 6th of October 2012, with the William Herchel Telescope (WHT) using the Long-slit Intermediate Resolution Infrared Spectrograph (LIRIS) instrument, which covers the spectral range of 900- 2400 nm with a spectral resolution, R, around 2000: we used Ganymede as a mirror that night. The second set of observations were taken during the nights of the 10th and 17th of November, 2012 from Cerro Paranal using the Very Large Telescope (VLT) and Xshooter, a multiwavelength spectrograph with three different arms: UVB, with the wavelength range of 300- 559.5 nm and R=9900, VIS for 559.5-1024 nm and R=18200 and NIR, for 1024-2480 nm and R=10500. During the first night, Europa was used as a mirror, while during the second one it was Ganymede again.

González-Merino, B.; Montañes-Rodríguez, P.; Palle, E.

2014-03-01

355

By-Products Utilization  

E-print Network

Center for By-Products Utilization UTILIZATION OF FLY ASH AS A CONSTRUCTION MATERIAL IN CHINA #12;UTILIZATION OF FLY ASH AS A CONSTRUCTION MATERIAL IN CHINA Ljhua Wei, Dean M. Golden and Tarun R utilization of fly ash as construction materials. The technologies established for fly ash utilization

Wisconsin-Milwaukee, University of

356

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 30, NO. 11, DECEMBER 2012 2251 Non-Cooperative Spectrum Access  

E-print Network

) choose to either acquire dedicated spectrum or to use spectrum-holes (white spaces) which belong. An example illustrating Secondary Users (SUs) utilizing white spaces (also known as spectrum holes organizations. Under the basic model of CR networks [10], Secondary Users (SUs) can use white spaces

Jagannathan, Krishna

357

The Utility Battery Storage Systems Program Overview  

SciTech Connect

Utility battery energy storage allows a utility or customer to store electrical energy for dispatch at a time when its use is more economical, strategic, or efficient. The UBS program sponsors systems analyses, technology development of subsystems and systems integration, laboratory and field evaluation, and industry outreach. Achievements and planned activities in each area are discussed.

Not Available

1994-11-01

358

Implementation Science, Professional Development, and Autism Spectrum Disorders  

ERIC Educational Resources Information Center

The increased prevalence of autism spectrum disorders (ASD) has intensified the need for high-quality special education services designed for children and youth with ASD and their families. Implementation science provides guidance for moving innovation, such as utilizing evidence- based practices for students with ASD, into regular practice in…

Odom, Samuel L.; Cox, Ann W.; Brock, Matthew E.

2013-01-01

359

Low-Complexity Approaches to Spectrum Opportunity Tracking  

E-print Network

on the sensing history, achieving this synchrony is nontrivial in the absence of a dedicated control channel the under-utilization of the radio spec- trum as revealed by the measurements of actual spectrum usage [1 exploitation of the entire observation history. This is because sensing outcomes provide statistical knowledge

Islam, M. Saif

360

Developing Mirror Self Awareness in Students with Autism Spectrum Disorder  

ERIC Educational Resources Information Center

A teaching methodology and curriculum was designed to develop and increase positive self-awareness in students diagnosed with autism spectrum disorders (ASD). Joint attention (JA) strategies were first utilized to directly teach students about reflected mirror images, and then subsequently, to indirectly teach students about their reflected image.…

Duff, Christine K.; Flattery, J. J., Jr.

2014-01-01

361

Throughput Enhancing Cooperative Spectrum Sensing Strategies for Cognitive Radios  

E-print Network

Throughput Enhancing Cooperative Spectrum Sensing Strategies for Cognitive Radios Kyounghwan Lee, whenever not in use, can be captured and used by additional users. To this end, cognitive radios which the opportunistic utilization of white spaces in the UHF/VHF TV band [3]. Cognitive radios allow a secondary

Yener, Aylin

362

Improved local spectrum sensing for cognitive radio networks  

NASA Astrophysics Data System (ADS)

The successful deployment of dynamic spectrum access requires cognitive radio (CR) to more accurately find the unoccupied portion of the spectrum. An accurate spectrum sensing technique can reduce the probability of false alarms and misdetection. Cooperative spectrum sensing is usually employed to achieve accuracy and improve reliability, but at the cost of cooperation overhead among CR users. This overhead can be reduced by improving local spectrum sensing accuracy. Several signal processing techniques for transmitter detection have been proposed in the literature but more sophisticated approaches are needed to enhance sensing efficiency. This article proposes a two-stage local spectrum sensing approach. In the first stage, each CR performs existing spectrum sensing techniques, i.e., energy detection, matched filter detection, and cyclostationary detection. In the second stage, the output from each technique is combined using fuzzy logic in order to deduce the presence or absence of a primary transmitter. Simulation results verify that our proposed technique outperforms existing local spectrum sensing techniques. The proposed approach shows significant improvement in sensing accuracy by exhibiting a higher probability of detection and low false alarms. The mean detection time of the proposed scheme is equivalent to that of cyclostationary detection.

Ejaz, Waleed; ul Hasan, Najam; Azam, Muhammad Awais; Kim, Hyung Seok

2012-12-01

363

Supporting Dynamic Spectrum Access in Heterogeneous LTE+ Networks  

SciTech Connect

As early as 2014, mobile network operators’ spectral capac- ity is expected to be overwhelmed by the demand brought on by new devices and applications. With Long Term Evo- lution Advanced (LTE+) networks likely as the future one world 4G standard, network operators may need to deploy a Dynamic Spectrum Access (DSA) overlay in Heterogeneous Networks (HetNets) to extend coverage, increase spectrum efficiency, and increase the capacity of these networks. In this paper, we propose three new management frameworks for DSA in an LTE+ HetNet: Spectrum Accountability Client, Cell Spectrum Management, and Domain Spectrum Man- agement. For these spectrum management frameworks, we define protocol interfaces and operational signaling scenar- ios to support cooperative sensing, spectrum lease manage- ment, and alarm scenarios for rule adjustment. We also quan- tify, through integer programs, the benefits of using DSA in an LTE+ HetNet, that can opportunistically reuse vacant TV and GSM spectrum. Using integer programs, we consider a topology using Geographic Information System data from the Blacksburg, VA metro area to assess the realistic benefits of DSA in an LTE+ HetNet.

Luiz A. DaSilva; Ryan E. Irwin; Mike Benonis

2012-08-01

364

Spectrum Sensing and Reconstruction for Cognitive Radio  

E-print Network

Spectrum Sensing and Reconstruction for Cognitive Radio Amanpreet S Saini, Zhen Hu, Robert Qiu with spectrum sensing and spectrum reconstruction under the umbrella of cognitive radio which is the smart radio to explore and exploit the free spectrum. Spectrum analyzer is used to emulate cognitive radio to do spectrum

Qiu, Robert Caiming

365

Tribal Utility Feasibility Study  

SciTech Connect

The Schatz Energy Research Center (SERC) assisted the Yurok Tribe in investigating the feasibility of creating a permanent energy services program for the Tribe. The original purpose of the DOE grant that funded this project was to determine the feasibility of creating a full-blown Yurok Tribal electric utility to buy and sell electric power and own and maintain all electric power infrastructure on the Reservation. The original project consultant found this opportunity to be infeasible for the Tribe. When SERC took over as project consultant, we took a different approach. We explored opportunities for the Tribe to develop its own renewable energy resources for use on the Reservation and/or off-Reservation sales as a means of generating revenue for the Tribe. We also looked at ways the Tribe can provide energy services to its members and how to fund such efforts. We identified opportunities for the development of renewable energy resources and energy services on the Yurok Reservation that fall into five basic categories: • Demand-side management – This refers to efforts to reduce energy use through energy efficiency and conservation measures. • Off-grid, facility and household scale renewable energy systems – These systems can provide electricity to individual homes and Tribal facilities in areas of the Reservation that do not currently have access to the electric utility grid. • Village scale, micro-grid renewable energy systems - These are larger scale systems that can provide electricity to interconnected groups of homes and Tribal facilities in areas of the Reservation that do not have access to the conventional electric grid. This will require the development of miniature electric grids to serve these interconnected facilities. • Medium to large scale renewable energy development for sale to the grid – In areas where viable renewable energy resources exist and there is access to the conventional electric utility grid, these resources can be developed and sold to the wholesale electricity market. • Facility scale, net metered renewable energy systems – These are renewable energy systems that provide power to individual households or facilities that are connected to conventional electric utility grid.

Engel, R. A.; Zoellick, J. J.

2007-06-30

366

The value and validation of broad spectrum biosensors for diagnosis and biodefense  

PubMed Central

Broad spectrum biosensors capable of identifying diverse organisms are transitioning from the realm of research into the clinic. These technologies simultaneously capture signals from a wide variety of biological entities using universal processes. Specific organisms are then identified through bioinformatic signature-matching processes. This is in contrast to currently accepted molecular diagnostic technologies, which utilize unique reagents and processes to detect each organism of interest. This paradigm shift greatly increases the breadth of molecular diagnostic tools with little increase in biochemical complexity, enabling simultaneous diagnostic, epidemiologic, and biothreat surveillance capabilities at the point of care. This, in turn, offers the promise of increased biosecurity and better antimicrobial stewardship. Efficient realization of these potential gains will require novel regulatory paradigms reflective of the generalized, information-based nature of these assays, allowing extension of empirical data obtained from readily available organisms to support broader reporting of rare, difficult to culture, or extremely hazardous organisms. PMID:24128433

Metzgar, David; Sampath, Rangarajan; Rounds, Megan A; Ecker, David J

2013-01-01

367

Rotational Spectrum of Sarin  

NASA Astrophysics Data System (ADS)

As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C 4H 10FO 2P) was observed in the rotationally cold ( Trot<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1?), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm -1. Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G ** level of theory is consistent with our experimental findings.

Walker, A. R. Hight; Suenram, R. D.; Samuels, Alan; Jensen, James; Ellzy, Michael W.; Lochner, J. Michael; Zeroka, Daniel

2001-05-01

368

The Solar Convection Spectrum  

NASA Technical Reports Server (NTRS)

I helped to complete a research project with NASA scientists Dr. David Hathaway (my mentor), Rick Bogart, and John Beck from the SOHO/SOI collaboration. Our published paper in 'Solar Physics' was titled 'The Solar Convection Spectrum' (April 2000). Two of my undergraduate students were named on the paper--Gavrav Khutri and Josh Petitto. Gavrav also wrote a short paper for the National Conference of Undergraduate Research Proceedings in 1998 using a preliminary result. Our main result was that we show no evidence of a scale of convection named 'mesogranulation'. Instead, we see only direct evidence for the well-known scales of convection known as graduation and supergranulation. We are also completing work on vertical versus horizontal flow fluxes at the solar surface. I continue to work on phase relationships of solar activity indicators, but I have not yet written a paper with my students on this topic. Along with my research results, I have developed and augmented undergraduate courses at Birmingham-Southern College by myself and with other faculty. We have included new labs and observations, speakers from NASA and elsewhere, new subject material related to NASA and space science. I have done a great deal of work in outreach, mostly as President and other offices in the Birmingham Astronomical Society. My work includes speaking, attracting speakers, giving workshops, and governing.

Bachmann, Kurt T.

2000-01-01

369

PINS Spectrum Identification Guide  

SciTech Connect

The Portable Isotopic Neutron Spectroscopy—PINS, for short—system identifies the chemicals inside munitions and containers without opening them, a decided safety advantage if the fill chemical is a hazardous substance like a chemical warfare agent or an explosive. The PINS Spectrum Identification Guide is intended as a reference for technical professionals responsible for the interpretation of PINS gamma-ray spectra. The guide is divided into two parts. The three chapters that constitute Part I cover the science and technology of PINS. Neutron activation analysis is the focus of Chapter 1. Chapter 2 explores PINS hardware, software, and related operational issues. Gamma-ray spectral analysis basics are introduced in Chapter 3. The six chapters of Part II cover the identification of PINS spectra in detail. Like the PINS decision tree logic, these chapters are organized by chemical element: phosphorus-based chemicals, chlorine-based chemicals, etc. These descriptions of hazardous, toxic, and/or explosive chemicals conclude with a chapter on the identification of the inert chemicals, e.g. sand, used to fill practice munitions.

A.J. Caffrey

2012-03-01

370

Fetal alcohol spectrum disorders.  

PubMed

Prenatal alcohol exposure (PAE) is one of the most prevalent and modifiable risk factors for somatic, behavioral, and neurological abnormalities. Affected individuals exhibit a wide range of such features referred to as fetal alcohol spectrum disorders (FASD). These are characterized by a more or less specific pattern of minor facial dysmorphic features, growth deficiency and central nervous system symptoms. Nevertheless, whereas the diagnosis of the full-blown fetal alcohol syndrome does not pose a major challenge, only a tentative diagnosis of FASD can be reached if only mild features are present and/or maternal alcohol consumption during pregnancy cannot be verified. The respective disorders have lifelong implications. The teratogenic mechanisms induced by PAE can lead to various additional somatic findings and structural abnormalities of cerebrum and cerebellum. At the functional level, cognition, motor coordination, attention, language development, executive functions, memory, social perception and emotion processing are impaired to a variable extent. The long-term development is characterized by disruption and failure in many domains; an age-adequate independency is frequently not achieved. In addition to primary prevention, individual therapeutic interventions and tertiary prevention are warranted; provision of extensive education to affected subjects and their caregivers is crucial. Protective environments are often required to prevent negative consequences such as delinquency, indebtedness or experience of physical/sexual abuse. PMID:24965796

Dörrie, Nora; Föcker, Manuel; Freunscht, Inga; Hebebrand, Johannes

2014-10-01

371

Asymptotically efficient multi-channel estimation for opportunistic spectrum access  

Microsoft Academic Search

The problem of estimating the parameters of multiple independent continuous-time Markov onoff processes is considered. The objective is to minimize the total mean square error (MSE) under a constraint on the total sensing time. The Fisher information matrix for the primary traffic model and the maximum likelihood estimator are obtained in closed form. Given that the optimal allocation of the

Pouya Tehrani; Lang Tong; Qing Zhao

2011-01-01

372

Synthesis of power efficient multitone signals with flat amplitude spectrum  

Microsoft Academic Search

It is shown that, generally, any binary or polyphase sequence belonging to a pair of complementary sequences can be used to construct the initial phases of tones forming a multitone signal with the crest factor less than or equal to 6 dB. The previously proposed Shapiro-Rudin sequences are representatives of a much larger family of binary Golay complementary sequences. Numerical

B. M. Popovic

1991-01-01

373

Free-form Fresnel RXI-RR Köhler design for high-concentration photovoltaics with spectrum-splitting  

NASA Astrophysics Data System (ADS)

Development of a novel HCPV nonimaging concentrator with high concentration (>500x) and built-in spectrum splitting concept is presented. It uses the combination of a commercial concentration GaInP/GaInAs/Ge 3J cell and a concentration Back-Point-Contact (BPC) silicon cell for efficient spectral utilization, and external confinement techniques for recovering the 3J cell's reflection. The primary optical element (POE) is a flat Fresnel lens and the secondary optical element (SOE) is a free-form RXI-type concentrator with a band-pass filter embedded in it - Both the POE and SOE performing Köhler integration to produce light homogenization on the receiver. The band-pass filter transmits the IR photons in the 900-1200 nm band to the silicon cell. A design target of an "equivalent" cell efficiency ~46% is predicted using commercial 39% 3J and 26% Si cells. A projected CPV module efficiency of greater than 38% is achievable at a concentration level larger than 500X with a wide acceptance angle of +/-1°. A first proof-of concept receiver prototype has been manufactured using a simpler optical architecture (with a lower concentration, ~100x and lower simulated added efficiency), and experimental measurements have shown up to 39.8% 4J receiver efficiency using a 3J cell with a peak efficiency of 36.9%.

Buljan, M.; Benítez, P.; Mohedano, R.; Miñano, J. C.; Sun, Y.; Falicoff, W.; Vilaplana, J.; Chaves, J.; Biot, G.; López, J.

2011-10-01

374

Equity implications of utility energy conservation programs  

SciTech Connect

This paper uses the Residential Energy Consumption Survey undertaken by the Energy Information Administration in 1990 to estimate the statistical association between household income and participation in electric utility energy conservation programs and the association between participation and the electricity consumption. The results indicate that utility rebates, energy audits, load management programs and other conservation measures tend to be undertaken at greater frequency by high income households than by low income households. Participants in conservation programs tend to occupy relatively new and energy efficient residences and undertake conservation measures other than utility programs, which suggests that utility sponsored programs are substitutes for other conservation investments. Electricity consumption during 1990 is not significantly less for households participating in utility programs than for nonparticipants, which also implies that utility conservation programs are displacing other conservation investments. Apparently, utility programs are not avoiding costs of new construction and instead are transferring wealth, particularly to high income participating households.

Sutherland, R.J.

1994-03-15

375

Expected Utility Distributions for Flexible, Contingent Execution  

NASA Technical Reports Server (NTRS)

This paper presents a method for using expected utility distributions in the execution of flexible, contingent plans. A utility distribution maps the possible start times of an action to the expected utility of the plan suffix starting with that action. The contingent plan encodes a tree of possible courses of action and includes flexible temporal constraints and resource constraints. When execution reaches a branch point, the eligible option with the highest expected utility at that point in time is selected. The utility distributions make this selection sensitive to the runtime context, yet still efficient. Our approach uses predictions of action duration uncertainty as well as expectations of resource usage and availability to determine when an action can execute and with what probability. Execution windows and probabilities inevitably change as execution proceeds, but such changes do not invalidate the cached utility distributions, thus, dynamic updating of utility information is minimized.

Bresina, John L.; Washington, Richard

2000-01-01

376

Catatonia and Autistic Spectrum Disorders  

ERIC Educational Resources Information Center

The phenomenon of catatonic-like states in people with autistic spectrum disorders is discussed in the context of current knowledge about catatonia as it occurs in severe mental illness and, less frequently documented, in conjunction with developmental disorders. The existing literature on catatonic-like states in people with autistic spectrum

Hare, Dougal Julian; Malone, Caroline

2004-01-01

377

A spread spectrum network analyser  

Microsoft Academic Search

The paper describes the realisation of a spread spectrum network analyser using appropriate software to control a PC interface card, like a soundcard. The software generates a digitised time waveform consisting of a spread spectrum signal containing a number of equal amplitude spectral components. The interface card converts this waveform to an analogue signal, which is then passed through the

C. J. Kikkert

1999-01-01

378

Visible spectrum of stable sonoluminescence  

Microsoft Academic Search

Synchronous emissions of picosecond pulses of light are observed to originate from a bubble trapped at the pressure antinode of a resonant sound field. The spectrum has been measured using a single slit spectrometer equipped with a linear array CCD detector. Spectra from differing solutions of water and glycerin are compared to the visible blackbody spectrum distribution. Assuming a blackbody

Joseph T. Carlson

1992-01-01

379

The Electromagnetic Spectrum: Infrared Waves  

NSDL National Science Digital Library

This webpage, part of a NASA site on the electromagnetic spectrum, presents information on infrared light. An explanation of how objects emit infrared is provided, along with a diagram of the electromagnetic spectrum. The site contains a number of photos made with infrared light.

2007-06-24

380

The HIV mental health spectrum  

Microsoft Academic Search

The growing mental health needs that are related to HIV are immense and diverse. The HIV mental health spectrum is a model that identifies and characterizes populations in need of HIV-related services which can be offered by Community Mental Health Centers. The spectrum describes the specialized service requirements for each of these populations, the challenges in providing these services, and

Michael D. Knox; Maryann Davis; Martha A. Friedrich

1994-01-01

381

Spectrum Access Games and Strategic Learning in Cognitive Radio Networks for Delay-Critical Applications  

Microsoft Academic Search

With the current proliferation of high bandwidth and delay-sensitive multimedia applications and services, each wireless user will try to maximize its utility by acquiring as much spectrum resources as possible unless a preemptive mechanism exists in the network. Thus, emerging solutions for dynamic spectrum access in cognitive radio networks will need to adopt market-based approaches in order to effectively regulate

Mihaela van der Schaar; Fangwen Fu

2009-01-01

382

Optimal Multiband Joint Detection for Spectrum Sensing in Cognitive Radio Networks  

Microsoft Academic Search

Spectrum sensing is an essential functionality that enables cognitive radios to detect spectral holes and to opportunistically use under-utilized frequency bands without causing harmful interference to legacy (primary) networks. In this paper, a novel wideband spectrum sensing technique referred to as multiband joint detection is introduced, which jointly detects the primary signals over multiple frequency bands rather than over one

Zhi Quan; Shuguang Cui; Ali H. Sayed; H. Vincent Poor

2009-01-01

383

A Leasing Oriented MAC Protocol for High Spectrum Usage in Cognitive Radio Networks  

Microsoft Academic Search

Cognitive radio (CR) is an emerging technology in wireless access, aiming at vastly improving the way radio spectrum is utilized. Its basic idea is that a secondary user (unlicensed user) can be permitted to use licensed spectrum, provided that it does not interfere with any primary users (licensed users). CR technology enables the development of an intelligent and adaptive wireless

Hua Song; Xiaola Lin

2009-01-01

384

Lottery Dependent Utility  

Microsoft Academic Search

In this paper we propose a model for decision making under risk that is capable of predicting empirically observed preference patterns that have been found to be incompatible with the expected utility model. The model departs from the classical expected utility model by allowing utilities to depend on the lottery. The dependence of utilities on the lottery being evaluated is

Joao L. Becker; Rakesh K. Sarin

1987-01-01

385

Utility Theory Social Intelligence  

E-print Network

of Money II Determining Utility Curve: use test persons facing a gamble, say, ¦ ¥ § © 7 ¥ ¥8 § , eUtility Theory Social Intelligence Daniel Polani Utility Theory ­ p.1/15 Utilities: Motivation currency ("money") to move from selection ¢ to selection . £ ¢ if agent would not pay money to move

Polani, Daniel

386

Increased Photovoltaic Power Output via Diffractive Spectrum Separation  

E-print Network

In this Letter, we report the preliminary demonstration of a new paradigm for photovoltaic power generation that utilizes a broadband diffractive-optical element (BDOE) to efficiently separate sunlight into laterally spaced ...

Kim, Ganghun

387

Spectrum of sprite halos  

NASA Astrophysics Data System (ADS)

Spectra of sprite halos in the spectral ranges 200-500 nm and 640-1065 nm are calculated for different spectral resolutions (between 2 nm and 10 nm), rotational temperatures (220 K and 1000 K) and observation altitudes corresponding to mountain (3 km and 4.3 km), airplane (14 km), balloon (35 km) and space observation platforms. We have calculated the non-equilibrium vibrational distribution functions (VDF) of different excited electronic states of molecular nitrogen (N2) associated to sprite halo optical emissions in the ultraviolet (UV), due to the N2 Lyman-Birge-Hopfield (LBH) and Vegard-Kaplan (VK) band systems, and near UV, visible and near infrared (NIR) due to the first (1PG) and second positive (2PG) bands of N2. Comparison of synthetic sprite halo spectra with the single sprite halo spectrum existing to date shows reasonable agreement after the observed sprite halo spectra was corrected for instrument sensitivity response. Calculated VDFs of the N2(B3?g) and N2(C3?u) states of sprite halos show that the blue and NIR emissions produced through strong N2-1PG (B3?g ? A3?u+) and N2-2PG (C3?u ? B3?g) transitions are generally similar to those of known sprite spectral emission patterns, but differences may be observable at some vibrational levels. The calculated sprite halo spectra can be used as a predictive tool for the expected spectral emissions of sprite halos in different possible scenarios.

Gordillo-Vázquez, F. J.; Luque, A.; Simek, M.

2011-09-01

388

Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment  

SciTech Connect

Criticality benchmark data for intermediate energy spectrum systems does not exist. These systems are dominated by scattering and fission events induced by neutrons with energies between 1 eV and 1 MeV. Nuclear data uncertainties have been reported for such systems which can not be resolved without benchmark critical experiments. Intermediate energy spectrum systems have been proposed for the geological disposition of surplus fissile materials. Without the proper benchmarking of the nuclear data in the intermediate energy spectrum, adequate criticality safety margins can not be guaranteed. The Zeus critical experiment now under construction will provide this necessary benchmark data.

Jaegers, P.J.; Sanchez, R.G.

1996-06-01

389

Efficient conversion of solar energy to biomass and electricity.  

PubMed

The Earth receives around 1000 W.m(-2) of power from the Sun and only a fraction of this light energy is able to be converted to biomass (chemical energy) via the process of photosynthesis. Out of all photosynthetic organisms, microalgae, due to their fast growth rates and their ability to grow on non-arable land using saline water, have been identified as potential source of raw material for chemical energy production. Electrical energy can also be produced from this same solar resource via the use of photovoltaic modules. In this work we propose a novel method of combining both of these energy production processes to make full utilisation of the solar spectrum and increase the productivity of light-limited microalgae systems. These two methods of energy production would appear to compete for use of the same energy resource (sunlight) to produce either chemical or electrical energy. However, some groups of microalgae (i.e. Chlorophyta) only require the blue and red portions of the spectrum whereas photovoltaic devices can absorb strongly over the full range of visible light. This suggests that a combination of the two energy production systems would allow for a full utilization of the solar spectrum allowing both the production of chemical and electrical energy from the one facility making efficient use of available land and solar energy. In this work we propose to introduce a filter above the algae culture to modify the spectrum of light received by the algae and redirect parts of the spectrum to generate electricity. The electrical energy generated by this approach can then be directed to running ancillary systems or producing extra illumination for the growth of microalgae. We have modelled an approach whereby the productivity of light-limited microalgae systems can be improved by at least 4% through using an LED array to increase the total amount of illumination on the microalgae culture. PMID:24976951

Parlevliet, David; Moheimani, Navid Reza

2014-01-01

390

Physical Retrieval of Surface Emissivity Spectrum from Hyperspectral Infrared Radiances  

NASA Technical Reports Server (NTRS)

Retrieval of temperature, moisture profiles and surface skin temperature from hyperspectral infrared (IR) radiances requires spectral information about the surface emissivity. Using constant or inaccurate surface emissivities typically results in large retrieval errors, particularly over semi-arid or arid areas where the variation in emissivity spectrum is large both spectrally and spatially. In this study, a physically based algorithm has been developed to retrieve a hyperspectral IR emissivity spectrum simultaneously with the temperature and moisture profiles, as well as the surface skin temperature. To make the solution stable and efficient, the hyperspectral emissivity spectrum is represented by eigenvectors, derived from the laboratory measured hyperspectral emissivity database, in the retrieval process. Experience with AIRS (Atmospheric InfraRed Sounder) radiances shows that a simultaneous retrieval of the emissivity spectrum and the sounding improves the surface skin temperature as well as temperature and moisture profiles, particularly in the near surface layer.

Li, Jun; Weisz, Elisabeth; Zhou, Daniel K.

2007-01-01

391

Stanford University: Dynamic Spectrum Management  

NSDL National Science Digital Library

Dynamic Spectrum Management (DSM) is a research program within the Space, Telecommunications, and Radioscience (STAR) Laboratory, a research group of the Department of Electrical Engineering of Stanford University. Researchers at DSM are investigating the potential for DSM to be used in multiuser environments, with particular emphasis on DSL and wireless transmission channels. Broadly speaking, topics covered through their research on DSM for DSL include: Channel Identification Methods, Spectrum Balancing, Vectored Transmission Methods, and Multiuser Detection. The website provides information on these different areas and links to related publications. The Tutorials section offers some papers and presentations explaining the basics of Dynamic Spectrum Management. A separate section includes papers on Standards Contributions.

Cioffi, John M.

2005-11-05

392

Visible spectrum of stable sonoluminescence  

NASA Astrophysics Data System (ADS)

Synchronous emissions of picosecond pulses of light are observed to originate from a bubble trapped at the pressure antinode of a resonant sound field. The spectrum has been measured using a single slit spectrometer equipped with a linear array CCD detector. Spectra from differing solutions of water and glycerin are compared to the visible blackbody spectrum distribution. Assuming a blackbody model, apparent temperatures of 18,900 Kelvins are observed in pure water. Increasing glycerin concentration appears to correlate with cooler blackbody temperatures. The spectrum is also found to continually change with time, independent of input parameters.

Carlson, Joseph T.

1992-12-01

393

Compressed Wideband Spectrum Sensing Based on Discrete Cosine Transform  

PubMed Central

Discrete cosine transform (DCT) is a special type of transform which is widely used for compression of speech and image. However, its use for spectrum sensing has not yet received widespread attention. This paper aims to alleviate the sampling requirements of wideband spectrum sensing by utilizing the compressive sampling (CS) principle and exploiting the unique sparsity structure in the DCT domain. Compared with discrete Fourier transform (DFT), wideband communication signal has much sparser representation and easier implementation in DCT domain. Simulation result shows that the proposed DCT-CSS scheme outperforms the conventional DFT-CSS scheme in terms of MSE of reconstruction signal, detection probability, and computational complexity. PMID:24526894

Wang, Yulin; Zhang, Gengxin

2014-01-01

394

Is Emotion Recognition Impaired in Individuals with Autism Spectrum Disorders?  

ERIC Educational Resources Information Center

Researchers have argued that individuals with autism spectrum disorders (ASDs) use an effortful "systematizing" process to recognize emotion expressions, whereas typically developing (TD) individuals use a more holistic process. If this is the case, individuals with ASDs should show slower and less efficient emotion recognition, particularly for…

Tracy, Jessica L.; Robins, Richard W.; Schriber, Roberta A.; Solomon, Marjorie

2011-01-01

395

innovati nThe Spectrum of Clean Energy Innovation  

E-print Network

for Sustainable Energy, LLC. NREL Invents a Superior Diagnostics Tool for Solar Cell Manufacturing A solidinnovati nThe Spectrum of Clean Energy Innovation NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance

396

High Efficiency, Long Life Terrestrial Solar Panel.  

National Technical Information Service (NTIS)

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evalua...

T. Chao, S. Khemthong, R. Ling, S. Olah

1977-01-01

397

Spectrum 2013 Volunteer Training Session  

E-print Network

or dark denim · Parking ­ dress warm! If working multiple shifts, please wear your Spectrum shirt Come will be outside! All parking volunteers will get a toque and hot chocolate/coffee available Direct traffic

Saskatchewan, University of

398

Broad-Spectrum Antiviral Therapeutics  

E-print Network

Currently there are relatively few antiviral therapeutics, and most which do exist are highly pathogen-specific or have other disadvantages. We have developed a new broad-spectrum antiviral approach, dubbed Double-stranded ...

Rider, Todd H.

399

EARS (Enhancing Access to the Radio Spectrum) PROGRAM: The radio spectrum is a finite but exceedingly valuable natural resource that  

E-print Network

for wireless broadband use, and specifically calls on the NSF to work with the Department of Commerce and other, computer science, economics, and public policy. A key objective was to identify the intersections of the individual disciplines relevant to radio spectrum efficiency and access. Secretary of Commerce Gary Locke

Cetiner, Bedri A.

400

Adults with Autism Spectrum Disorders  

Microsoft Academic Search

\\u000a Autism spectrum disorders (ASD), otherwise referred to as pervasive developmental disorders, first appeared in the Diagnostic and Statistical Manual, Third Edition (American Psychiatric Association, 1980). Since the debut of this spectrum of disorders 29 years ago, changes in diagnostic\\u000a criteria as well as increased recognition and available assessments have been thought to increase the prevalence of ASD over\\u000a time (Rutter,

Sara Mahan; Alison M. Kozlowski

401

Electromagnetic Spectrum of Radium D  

Microsoft Academic Search

The electromagnetic spectrum of RaD has been studied by the proportional counter spectrometry technique. The work of the Curie Laboratory on the gamma-ray spectrum has been generally confirmed. However, the presumed K x-ray lines are of much lower intensity and occur at a lower energy than previously reported. The L x-ray intensity is 22 per hundred disintegrations, indicating 0.63 conversion

P. E. Damon; R. R. Edwards

1953-01-01

402

Linearizing the Observed Power Spectrum  

E-print Network

Reconstruction of the linear power spectrum from observational data provides a way to compare cosmological models to a large amount of data, as Peacock & Dodds (1994, 1996) have shown. By applying the appropriate corrections to the observational power spectrum it is possible to recover the underlying linear power spectrum for any cosmological model. Using extensive N-body simulations we demonstrate that the method is applicable to a wide range of cosmological models. However, we find that the recovery of the linear power spectrum from observations following PD94 is misleading because the corrections are model- dependent. When we apply the proper corrections for a given model to the observational power spectrum, we find that no model in our test group recovers the linear power spectrum well for the bias suggested by PD94 between Abell, Radio, Optical, and IRAS catalogs 4.5:1.9:1.3:1, with b_IRAS=1. When we allow b_IRAS to vary we find that: (i)CHDM models give very good fits to observations if optically-selected galaxies are slightly biased b_Opt=1.1 (ii) Most LCDM models give worse but acceptable fits if blue galaxies are considerably antibiased: 0.6spectrum of all LCDM models over their entire range of explored wavenumbers,0.01spectrum at higher k.

Clay Smith; Anatoly Klypin; Michael Gross; Joel Primack; Jon Holtzman

1997-02-12

403

Utilities Expense Report.  

ERIC Educational Resources Information Center

Examines how deregulation has affected school district utility costs. Offers ideas that can help school districts save money and energy. Provides several examples of state-wide initiatives intended to help school districts control utility costs. (GR)

Moore, Deborah P.

2001-01-01

404

Educating Michigan's Students with Autism Spectrum Disorder: Educating Michigan's Students with Autism Spectrum Disorder (ASD)  

E-print Network

.......................................................................................................................... Autism Spectrum Disorders: Characteristics, Diagnosis, Prevalence and Etiology........... Autism Spectrum1 Educating Michigan's Students with Autism Spectrum Disorder: Educating Michigan's Students with Autism Spectrum Disorder (ASD): An Initial Exploration of Programming "The ASD-Michigan Project" August 3

Liu, Taosheng

405

INTRODUCTION Measurements of actual spectrum usage have  

E-print Network

INTRODUCTION Measurements of actual spectrum usage have revealed the pervasiveness of idle observed. These measurements highlight the drawbacks of the current static spectrum allotment policy in conventional wired or wire- less networks. To protect spectrum licensees from interference while providing

Zhao, Qing

406

Language of Fetal Alcohol Spectrum Disorders  

MedlinePLUS

... RS FETAL ALCOHOL SPECTRUM DI HISTORY OF FETAL ALCOHOL SPECTRUM DISORDERS For centuries, people have known that ... fetal alcohol syndrome (FAS). 3 DEFINITION OF FETAL ALCOHOL SPECTRUM DISORDERS Experts now know that the effects ...

407

Utilization of solar thermal sources for thermochemical hydrogen production  

Microsoft Academic Search

The utilization of high temperature solar heat for the production of electricity and\\/or fuels is a popular concept. However, since solar concentrator systems are expensive and solar radiation intermittent, practical utilization requires processes that exhibit high conversion efficiencies and also incorporate energy storage. The production of hydrogen fulfills the requirement for energy storage and can fulfill the requirement for efficient

1980-01-01

408

By-Products Utilization  

E-print Network

Center for By-Products Utilization USE OF CLASS F FLY ASH AND CLEAN-COAL ASH BLENDS FOR CAST OF CLASS F FLY ASH AND CLEAN-COAL ASH BLENDS FOR CAST CONCRETE PRODUCTS Authors: Tarun R. Naik, Director on utilization of conventional Class F fly ash in concrete and concrete products, it's utilization rate is much

Wisconsin-Milwaukee, University of

409

High efficiency elastic convolver using KNbO3 substrate  

Microsoft Academic Search

Elastic convolvers are very important for signal processing devices of the spread spectrum communication (SSC) systems. The better efficient convolvers are required for the application for the spread spectrum and next stage communication systems. A high value of coupling coefficient is very important for wideband and high efficiency SAW devices such as SAW convolvers. Potassium niobate (KNbO3) has large piezoelectric

K. Yamanouchi; H. Odagawa; K. Morozumi; Y. Cho

1997-01-01

410

Efficiency in nuclear power pricing  

Microsoft Academic Search

This study investigates whether the rate structure for electric utilities with nuclear and fossil fuel generation is efficient and perhaps equitable. Data were collected on fossil and nuclear steam generation and transmission to estimate costs. Tests were performed to determine if efficient pricing practices were being followed. The results indicate that the marginal cost of nuclear generated power is less

Herbert G. Thompson; David R. Kamerschen; Albert L. Danielsen

1990-01-01

411

Volume 2 11, number 6 CHEMICAL PHYSICS LETTERS 27 August 1993 Study of the photoabsorption spectrum  

E-print Network

Volume 2 11, number 6 CHEMICAL PHYSICS LETTERS 27 August 1993 Study of the photoabsorption spectrum for efficient and accurate determination of the eigenvalues and the photoabsorption spectrum of Rydberg atoms Hamiltonians; and (c) a new procedure for the calculation of photoabsorption spectra of Rydberg atoms without

Chu, Shih-I

412

Using information theory to more fully exploit the electromagnetic spectrum: lessons for regulators  

Microsoft Academic Search

This paper takes tools arising from information theory, used to analyze modulation and coding trade-offs in digital system design, and extends them to the regulation of the electromagnetic spectrum. The benefits to existing spectrum users under the regulatory regime of technical flexibility are demonstrated in the use of the bandwidth-efficiency plane, which shows that extra communications capabilities can be created

Thomas P. Stanley

2005-01-01

413

Spectrum sensing in cognitive radio networks: requirements, challenges and design trade-offs  

Microsoft Academic Search

Opportunistic unlicensed access to the (temporarily) unused frequency bands across the licensed radio spectrum is currently being investigated as a means to increase the efficiency of spectrum usage. Such opportunistic access calls for implementation of safeguards so that ongoing licensed operations are not compromised. Among different candidates, sensing-based access, where the unlicensed users transmit if they sense the licensed band

Amir Ghasemi; Elvino S. Sousa

2008-01-01

414

Coalitional Games for Distributed Collaborative Spectrum Sensing in Cognitive Radio Networks  

E-print Network

Coalitional Games for Distributed Collaborative Spectrum Sensing in Cognitive Radio Networks Walid for large periods of time [1]. In order to efficiently exploit these spectrum holes, cognitive radio (CR, University of Houston, Houston, USA, Email:hanzhu22@gmail.com 3 Alcatel-Lucent Chair in Flexible Radio, SUP

Paris-Sud XI, Université de

415

Use of an iPad Play Story to Increase Play Dialogue of Preschoolers with Autism Spectrum Disorders  

ERIC Educational Resources Information Center

An iPad play story was utilized to increase the pretend play skills of 4 preschoolers with autism spectrum disorders. The story utilized a series of video clips depicting toy figures producing scripted character dialogue, engaged in a pretend play vignette. A multiple baseline design across participants was utilized with play dialogue as the…

Murdock, Linda C.; Ganz, Jennifer; Crittendon, Jessica

2013-01-01

416

A New Digital Signal Processing Method for Spectrum Interference Monitoring  

NASA Astrophysics Data System (ADS)

Frequency spectrum is a limited shared resource, nowadays interested by an ever growing number of different applications. Generally, the companies providing such services pay to the governments the right of using a limited portion of the spectrum, consequently they would be assured that the licensed radio spectrum resource is not interested by significant external interferences. At the same time, they have to guarantee that their devices make an efficient use of the spectrum and meet the electromagnetic compatibility regulations. Therefore the competent authorities are called to control the access to the spectrum adopting suitable management and monitoring policies, as well as the manufacturers have to periodically verify the correct working of their apparatuses. Several measurement solutions are present on the market. They generally refer to real-time spectrum analyzers and measurement receivers. Both of them are characterized by good metrological accuracies but show costs, dimensions and weights that make no possible a use "on the field". The paper presents a first step in realizing a digital signal processing based measurement instrument able to suitably accomplish for the above mentioned needs. In particular the attention has been given to the DSP based measurement section of the instrument. To these aims an innovative measurement method for spectrum monitoring and management is proposed in this paper. It performs an efficient sequential analysis based on a sample by sample digital processing. Three main issues are in particular pursued: (i) measurement performance comparable to that exhibited by other methods proposed in literature; (ii) fast measurement time, (iii) easy implementation on cost-effective measurement hardware.

Angrisani, L.; Capriglione, D.; Ferrigno, L.; Miele, G.

2011-01-01

417

Optimal linear precoding for opportunistic spectrum sharing under arbitrary input distributions assumption  

NASA Astrophysics Data System (ADS)

Cognitive radio network with multiple-input multiple-output is an effective method to improve not only spectrum efficiency, but also energy efficiency. In this article, a linear precoding matrix optimization algorithm, named gradient-aided mutual information optimization (GAMIO), is designed to maximize the secondary users' spectrum efficiency. Unlike the previous algorithms which were developed under a specific input assumption, the GAMIO algorithm can work without imposing any input assumption. Furthermore, a framework is also proposed to develop the energy-efficient algorithm which can work with arbitrary spectrum-efficient algorithm. In this way, an energy-efficient algorithm, which can work under arbitrary input assumption, be developed based on the GAMIO algorithm (EEGAMIO). Numerical results indicate that either the GAMIO algorithm or the EEGAMIO algorithm shows the best performance at the present time.

Zhu, Rui; Zhao, Yifei; Li, Yunzhou; Wang, Jing; Hong, Hao

2013-12-01

418

Enol ethers as substrates for efficient Z- and enantioselective ring-opening/cross-metathesis reactions promoted by stereogenic-at-Mo complexes: utility in chemical synthesis and mechanistic attributes.  

PubMed

The first examples of catalytic enantioselective ring-opening/cross-metathesis (EROCM) reactions that involve enol ethers are reported. Specifically, we demonstrate that catalytic EROCM of several oxa- and azabicycles, cyclobutenes and a cyclopropene with an alkyl- or aryl-substituted enol ether proceed readily in the presence of a stereogenic-at-Mo monopyrrolide-monoaryloxide. In some instances, as little as 0.15 mol % of the catalytically active alkylidene is sufficient to promote complete conversion within 10 min. The desired products are formed in up to 90% yield and >99:1 enantiomeric ratio (er) with the disubstituted enol ether generated in >90% Z selectivity. The enol ether of the enantiomerically enriched products can be easily differentiated from the terminal alkene through a number of functionalization procedures that lead to the formation of useful intermediates for chemical synthesis (e.g., efficient acid hydrolysis to afford the enantiomerically enriched carboxaldehyde). In certain cases, enantioselectivity is strongly dependent on enol ether concentration: larger equivalents of the cross partner leads to the formation of products of high enantiomeric purity (versus near racemic products with one equivalent). The length of reaction time can be critical to product enantiomeric purity; high enantioselectivity in reactions that proceed to >98% conversion in as brief a reaction time as 30 s can be nearly entirely eroded within 30 min. Mechanistic rationale that accounts for the above characteristics of the catalytic process is provided. PMID:22272931

Yu, Miao; Ibrahem, Ismail; Hasegawa, Masayuki; Schrock, Richard R; Hoveyda, Amir H

2012-02-01

419

Utilization of inverted dispersive liquid-liquid microextraction followed by HPLC-UV as a sensitive and efficient method for the extraction and determination of quercetin in honey and biological samples.  

PubMed

A sensitive, rapid and efficient method for the extraction of quercetin as well as its determination in honey and biological samples was developed using inverted dispersive liquid-liquid microextraction (IDLLME) and HPLC-UV. The extraction method is based on the application of an extracting solvent lighter than water in the ternary component solvent (aqueous solution: extracting solvent: disperser solvent) system. The extraction parameters such as type and volume of extracting and disperser solvent, pH of sample, stirring rate and extraction time were optimized. Under the optimal conditions (extracting solvent: 100 ?L 1-octanol; disperser solvent: 300 ?L acetonitrile; pH of sample: 4.5 and stirring rate: 1000 rpm) a linear calibration curve was obtained in the range of 0.5-1000 ng mL(-1) with R(2)=0.9993 (n=10). The limits of detection and quantification were 0.26 and 0.78 ng mL(-1), respectively. The extraction recovery was 97% and the preconcentration factor was 243. While the relative standard deviation for 25 ng mL(-1) was 3.51 (n=5), it was 2.12 (n=5) for 500 ng mL(-1) of quercetin. The method was successfully applied for the preconcentration and determination of quercetin in honey, urine and plasma samples. PMID:22284468

Ranjbari, Elias; Biparva, Pourya; Hadjmohammadi, Mohammad Reza

2012-01-30

420

High efficiency photoionization detector  

DOEpatents

A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36.+-.0.02 eV, and a vapor pressure of 0.35 torr at 20.degree. C.

Anderson, David F. (3055 Trinity, Los Alamos, NM 87544)

1984-01-01

421

High efficiency photoionization detector  

DOEpatents

A high efficiency photoionization detector is described using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 [+-] 0.02 eV, and a vapor pressure of 0.35 torr at 20 C. 6 figs.

Anderson, D.F.

1984-01-31

422

Thermosynechococcus elongatus DpsA binds Zn(II) at a unique three histidine-containing ferroxidase center and utilizes O2 as iron oxidant with very high efficiency, unlike the typical Dps proteins.  

PubMed

The cyanobacterium Thermosynechococcus elongatus is one the few bacteria to possess two Dps proteins, DpsA-Te and Dps-Te. The present characterization of DpsA-Te reveals unusual structural and functional features that differentiate it from Dps-Te and the other known Dps proteins. Notably, two Zn(II) are bound at the ferroxidase center, owing to the unique substitution of a metal ligand at the A-site (His78 in place of the canonical aspartate) and to the presence of a histidine (His164) in place of a hydrophobic residue at a metal-coordinating distance in the B-site. Only the latter Zn(II) is displaced by incoming iron, such that Zn(II)-Fe(III) complexes are formed upon oxidation, as indicated by absorbance and atomic emission spectroscopy data. In contrast to the typical behavior of Dps proteins, where Fe(II) oxidation by H(2)O(2) is about 100-fold faster than by O(2), in DpsA-Te the ferroxidation efficiency of O(2) is very high and resembles that of H(2)O(2). Oxygraphic experiments show that two Fe(II) are required to reduce O(2), and that H(2)O(2) is not released into solution at the end of the reaction. On this basis, a reaction mechanism is proposed that also takes into account the formation of Zn(II)-Fe(III) complexes. The physiological significance of the DpsA-Te behavior is discussed in the framework of a possible localization of the protein at the thylakoid membranes, where photosynthesis takes place, with the consequent increased formation of reactive oxygen species. PMID:20088882

Alaleona, Flaminia; Franceschini, Stefano; Ceci, Pierpaolo; Ilari, Andrea; Chiancone, Emilia

2010-02-01

423

Efficient Single Tobamoviral Vector-Based Bioproduction of Broadly Neutralizing Anti-HIV-1 Monoclonal Antibody VRC01 in Nicotiana benthamiana Plants and Utility of VRC01 in Combination Microbicides  

PubMed Central

Broadly neutralizing monoclonal antibodies (bnMAbs) may offer powerful tools for HIV-1 preexposure prophylaxis, such as topical microbicides. However, this option is hampered due to expensive MAb biomanufacturing based on mammalian cell culture. To address this issue, we developed a new production system for bnMAb VRC01 in Nicotiana benthamiana plants using a tobamovirus replicon vector. Unlike conventional two-vector-based expression, this system was designed to overexpress full-length IgG1 from a single polypeptide by means of kex2p-like enzyme recognition sites introduced between the heavy and light chains. An enzyme-linked immunosorbent assay (ELISA) revealed that gp120-binding VRC01 IgG1 was maximally accumulated on 5 to 7 days following vector inoculation, yielding ?150 mg of the bnMAb per kg of fresh leaf material. The plant-made VRC01 (VRC01p) was efficiently purified by protein A affinity followed by hydrophobic-interaction chromatography. ELISA, surface plasmon resonance, and an HIV-1 neutralization assay demonstrated that VRC01p has gp120-binding affinity and HIV-1-neutralization capacity virtually identical to the human-cell-produced counterpart. To advance VRC01p's use in topical microbicides, we analyzed combinations of the bnMAb with other microbicide candidates holding distinct antiviral mechanisms in an HIV-1 neutralization assay. VRC01p exhibited clear synergy with the antiviral lectin griffithsin, the CCR5 antagonist maraviroc, and the reverse transcriptase inhibitor tenofovir in multiple CCR5-tropic HIV-1 strains from clades A, B, and C. In summary, VRC01p is amenable to robust, rapid, and large-scale production and may be developed as an active component in combination microbicides with other anti-HIV agents such as antiviral lectins, CCR5 antagonists, and reverse transcriptase inhibitors. PMID:23403432

Hamorsky, Krystal Teasley; Grooms-Williams, Tiffany W.; Husk, Adam S.; Bennett, Lauren J.; Palmer, Kenneth E.

2013-01-01

424

Spectrum allocations above 40 GHz  

NASA Technical Reports Server (NTRS)

The 1979 World Administrative Radio Conference (WARC-79) revised the International Table of Frequency Allocations to reflect increased interest and activity in the region of the EM spectrum above 40 GHz. The total width of the spectrum allocated (235 GHz) in the region above 40 GHz indicates the extent of this new spectrum resource, made accessible by advances in the state-of-the-art of telecommunications equipment. There are some striking differences between the approach to allocation above and below 40 GHz. For example, there are not bands allocated exclusively. This reflects the characteristics of propagation and the small antenna beamwidths achievable at these frequencies. Attention is given to atmospheric window and absorption band limits, allocations to satellite services, allocations to scientific services, allocations to terrestrial services, the future refinement of the radio regulations above 40 GHz, and allocations of WARC-79 and frequency management.

Katzenstein, W. E.; Moore, R. P.; Kimball, H. G.

1981-01-01

425

Observations on Spectrum and Spectrum Histograms in BpmDj  

Microsoft Academic Search

BpmDj Is a program for DJ's. It helps to select songs and play them. To achieve this the program relies on a number of signal processing techniques. One of the available techniques compares song spectra. Both a standard spectrum analysis is performed as well as a distri- bution analysis ('echo' characteristics). In this short article we describe how this property

Werner Van Belle

2005-01-01

426

Introduction to The Electromagnetic Spectrum  

NSDL National Science Digital Library

This NASA-created web site introduces electromagnetic waves and their behaviors to secondary learners. Each region of the spectrum is described, illustrated, and accompanied by video clips. Within each section, the authors explore the relationship between wavelength and wave type and provide information about how scientists detect the various waves and collect images of their emissions. Don't miss the link to NASA's Tour of the Electromagnetic Spectrum, a free set of 24 posters, which can be viewed online or printed for the classroom. This tutorial is part of NASA's Mission: Science website.

2009-10-05

427

Vibrational spectrum of magnesium hydride  

NASA Astrophysics Data System (ADS)

The vibrational spectrum of hydrogen atoms in magnesium hydride has been studied by means of inelastic-neutron and Raman-scattering experiments between 12 and 295 K. After careful evaluation of multiple scattering and multiphonon contributions, we provide a vibrational frequency spectrum up to 180 meV and the mean-square displacement of hydrogen atoms. The inelastic light scattering spectra of MgH2 powders show three Raman allowed modes (A1g, B1g, and Eg) and some smaller features that can be related with second-order and disorder-induced processes.

Santisteban, J. R.; Cuello, G. J.; Dawidowski, J.; Fainstein, A.; Peretti, H. A.; Ivanov, A.; Bermejo, F. J.

2000-07-01

428

TPV efficiency predictions and measurements for a closed cavity geometry  

SciTech Connect

A thermophotovoltaic (TPV) efficiency measurement, within a closed cavity, is an integrated test which incorporates four fundamental parameters of TPV direct energy conversion. These are: (1) the TPV devices, (2) spectral control, (3) a radiation/photon source, and (4) closed cavity geometry affects. The overall efficiency of the TPV device is controlled by the TPV cell performance, the spectral control characteristics, the radiator temperature and the geometric arrangement. Controlled efficiency measurements and predictions provide valuable feedback on all four. This paper describes and compares two computer codes developed to model 16, 1 cm{sup 2} TPV cells (in a 4x4 configuration) in a cavity geometry. The first code subdivides the infrared spectrum into several bands and then numerically integrates over the spectrum to provide absorbed heat flux and cell performance predictions (assuming infinite parallel plates). The second utilizes a Monte Carlo Ray-Tracing code that tracks photons, from birth at the radiation source, until they either escape or are absorbed. Absorption depends upon energy dependent reflection probabilities assigned to every geometrical surface within the cavity. The model also has the capability of tallying above and below bandgap absorptions (as a function of location) and can support various radiator temperature profiles. The arrays are fabricated using 0.55 eV InGaAs cells with Si/SiO interference filters for spectral control and at steady state conditions, array efficiency was calculated as the ratio of the load matched power to its absorbed heat flux. Preliminary experimental results are also compared with predictions.

Gethers, C.K.; Ballinger, C.T.; Postlethwait, M.A.; DePoy, D.M.; Baldasaro, P.F. [Lockheed Martin Corp., Schenectady, NY (United States)

1997-05-01

429

TPV efficiency measurements and predictions for a closed cavity geometry  

SciTech Connect

A thermophotovoltaic (TPV) efficiency measurement, within a closed cavity, is an integrated test which incorporates four fundamental parameters of TPV direct energy conversion. These are: (1) the TPV devices, (2) spectral control, (3) a radiation/photon source, and (4) closed cavity geometry effects. The overall efficiency of the TPV device is controlled by the TP cell performance, the spectral control characteristics, the radiator temperature and the geometric arrangement. Controlled efficiency measurements and predictions provide valuable feedback on all four. This paper describes and compares two computer codes developed to model 16, 1 cm{sup 2} TPV cells (in a 4 x 4 configuration) in a cavity geometry. The first code, subdivides the infrared spectrum into several bands and then numerically integrates over the spectrum to provide absorbed heat flux and cell electrical output performance predictions (assuming infinite parallel plates). The second code, utilizes a Monte Carlo Photon Transport code that tracks photons, from birth at the radiation source, until they either escape or are absorbed. Absorption depends upon energy dependent reflection probabilities assigned to every geometrical surface within the cavity. The model also has the capability of tallying above and below bandgap absorptions (as a function of location) and can support various radiator temperature profiles. The arrays were fabricated using 0.55 eV InGaAs cells with Si/SiO interference filters for spectral control and at steady state conditions, array efficiency was calculated as the ratio of the load matched power to its absorbed heat flux. Preliminary experimental results are also compared with predictions.

Gethers, C.K.; Ballinger, C.T.; Postlethwait, M.A.; DePoy, D.M.; Baldasaro, P.F.

1997-05-01

430

DIRECTIONAL DETECTION OF FISSION-SPECTRUM NEUTRONS.  

SciTech Connect

Conventional neutron detectors consisting of {sup 3}He tubes surrounded by a plastic moderator can be quite efficient in detecting fission spectrum neutrons, but do not indicate the direction of the incident radiation. We have developed a new directional detector based on double proton recoil in two separated planes of plastic scintillators. This method allows the spectrum of the neutrons to be measured by a combination of peak amplitude in the first plane and time of flight to the second plane. It also allows the determination of the angle of scattering in the first plane. If the planes are position-sensitive detectors, then the direction of the scattered neutron is known, and the direction of the incident neutron can be determined to lie on a cone of s fixed angle. The superposition of many such cones generates an image that indicates the presence of a localized source. Typical background neutron fluences from the interaction of cosmic rays with the atmosphere are low and fairly uniformly distributed in angle. Directional detection helps to locate a manmade source in the presence of natural background. Monte Carlo simulations are compared with experimental results.

VANIER,P.E.

2007-05-04

431

Application of the spread-spectrum technique in well logging  

SciTech Connect

This paper presents the novel concept of employing the noise insensitive spread-spectrum technique in well logging. The proposed design of a spread-spectrum device improves the performance of well logging tools, particularly within highly noisy environments. The heart of the device is a shift register which generates a pseudorandom binary code sequence. A coder is connected to the transmitter and codes the probing signal by utilizing the pseudorandom sequence. A decoder is connected to the receiver and correlates the return signal to the same sequence, which is used as a sliding reference. Shifts as small as a fraction of a bit are unambiguously resolvable, and distance resolution of the order of micrometers is achievable. Spread-spectrum well logging tools can operate even with coded signal-to-noise ratio below zero-dB. The spread-spectrum device can be interfaced with any available wave transmitting logging tool. However, tools employing acoustic waves are favorable because the acoustic wave propagation velocity is low and allows the use of inexpensive electronics. The problems associated with high temperatures which are commonly encountered In geothermal reservoirs are bypassed, since the spread-spectrum device can be located either inside the well logging tool or together with the supporting electronics on the surface.

Chrysikopoulos, Constantinos V.; Dadakarides, Simos D.

1988-01-01

432

Spectrum Characterization for Opportunistic Cognitive Radio Systems  

E-print Network

initial network entry is also discussed as a case study. Index Terms-- Cognitive radio, spectrum sensing spectrum is spectrum pooling [2]. In this method, the frequency band is measured and unused part the measurements, the empty frequencies in the spectrum are determined. The OFDM(A) sub-carriers are grouped

Arslan, Hüseyin

433

Opportunistic Spectrum Access in Cognitive Radio Networks  

Microsoft Academic Search

Enabled by regulatory initiatives and radio technol- ogy advances, opportunistic spectrum access has the potential to mitigate spectrum scarcity and satisfy the increasing demand for spectrum. In this paper, we consider a scenario where secondary users can opportunistically access unused spectrum vacated by idle primaries. We introduce two metrics to protect primary performance, namely collision probability and overlapping time. We

Senhua Huang; Xin Liu; Zhi Ding

2008-01-01

434

Cogeneration - A Utility Perspective  

E-print Network

will be successful. A project that benefi s one party at the expense of the other will fail. With or without PURPA, industry and utilities hare the opportunity to benefit from cogeneration. is essential that industry and utilities communi cate on their mutual... will be successful. A project that benefi s one party at the expense of the other will fail. With or without PURPA, industry and utilities hare the opportunity to benefit from cogeneration. is essential that industry and utilities communi cate on their mutual...

Williams, M.

1983-01-01

435

By-Products Utilization  

E-print Network

-Viro Soil process.................................................................. 6 Soil substitute from alkaline stabilization................................................................... 6 Geotechnical evaluation of dredged material from Newark harbor............................ 7 Soil stabilization utilizing

Wisconsin-Milwaukee, University of

436

Energy-efficient appliances  

SciTech Connect

The major issues confronting policy makers in their effort to promote energy-efficiency in the home are: performance testing and ratings, marketing and foreign competition, federal standards and incentives, utility load management and incentives, and consumer education. The report concludes by describing some new directions, some of which are extensions of existing programs. They include taxes on inefficient appliances, utility rebates, programs to replace or to audit and modify equipment, appliance ratings as part of home-efficiency ratings, advertising, and public procurements. A research agenda stresses field performance, analytical work, data gathering, and program evaluation. Economic analyses of return on investment, the cost of conserved energy, and early retirement appear in an appendix. 216 references, 14 figures, 15 tables.

Geller, H.S.

1983-01-01

437

Censored Truncated Sequential Spectrum Sensing for Cognitive Radio Networks  

E-print Network

Reliable spectrum sensing is a key functionality of a cognitive radio network. Cooperative spectrum sensing improves the detection reliability of a cognitive radio system but also increases the system energy consumption which is a critical factor particularly for low-power wireless technologies. A censored truncated sequential spectrum sensing technique is considered as an energy-saving approach. To design the underlying sensing parameters, the maximum energy consumption per sensor is minimized subject to a lower bounded global probability of detection and an upper bounded false alarm rate. This way both the interference to the primary user due to miss detection and the network throughput as a result of a low false alarm rate is controlled. We compare the performance of the proposed scheme with a fixed sample size censoring scheme under different scenarios. It is shown that as the sensing cost of the cognitive radios increases, the energy efficiency of the censored truncated sequential approach grows signific...

Maleki, Sina

2011-01-01

438

Neurofeedback in Autism Spectrum Disorders  

ERIC Educational Resources Information Center

Aim: To review current studies on the effectiveness of neurofeedback as a method of treatment of the core symptoms of autism spectrum disorders (ASD). Method: Studies were selected based on searches in PubMed, Ovid MEDLINE, EMBASE, ERIC, and CINAHL using combinations of the following keywords: "Neurofeedback" OR "EEG Biofeedback" OR "Neurotherapy"…

Holtmann, Martin; Steiner, Sabina; Hohmann, Sarah; Poustka, Luise; Banaschewski, Tobias; Bolte, Sven

2011-01-01

439

The Organizational Communication Consulting Spectrum.  

ERIC Educational Resources Information Center

Surveys of businesses and business managers indicate that developing communication skills within organizations is a priority. Communication consulting exists over a wide spectrum of activities that include guest speaking, conducting workshops, and conducting management training programs. These three processes can include a "canned program" that…

Tubbs, Stewart L.

440

Electromagnetic spectrum and color vision  

Microsoft Academic Search

In most of occasions the maps, drawings and printed images are elaborated thinking that the observer will visualize them with illuminants like the light of the day. With these illuminants, for example the CIE D65, we can distinguish the great quantity of colors that it is capable the human eye. But if the illuminant has a very different spectrum than

J. Irigoyen; J. Herraez

2003-01-01

441

Autism Spectrum Disorders and Epigenetics  

ERIC Educational Resources Information Center

Objective: Current research suggests that the causes of autism spectrum disorders (ASD) are multifactorial and include both genetic and environmental factors. Several lines of evidence suggest that epigenetics also plays an important role in ASD etiology and that it might, in fact, integrate genetic and environmental influences to dysregulate…

Grafodatskaya, Daria; Chung, Brian; Szatmari, Peter; Weksberg, Rosanna

2010-01-01

442

Spectrum sharing for unlicensed bands  

Microsoft Academic Search

We study a spectrum sharing problem in an unlicensed band where multiple systems coexist and interfere with each other. We first analyze a cooperative setting where all the systems collaborate to achieve a common goal. Under the assumptions that the systems communicate with Gaussian signals and treat interference as noise, we study the structure of the optimal power allocations. We

Raul Etkin; Abhay Parekh; David Tse

2007-01-01

443

Spectrum sharing for unlicensed bands  

Microsoft Academic Search

We study a spectrum sharing problem in an unlicensed band where multiple systems coexist and interfere with each other. We first analyze a cooperative setting where all the systems collaborate to achieve a common goal. Under the assumptions that the systems communicate with Gaussian signals and treat interference as noise, we study the structure of the optimal power allocations. We

Raul Etkin; Abhay Parekh; David Tse

2005-01-01

444

Autism Spectrum Disorder (ASD): Treatment  

MedlinePLUS

Start of Search Controls Search Form Controls Autism Autism Search The CDC CDC A-Z Index MENU CDC A-Z SEARCH A B C D E F G H I J ... Z # Start of Search Controls Search Form Controls Autism Autism Search The CDC Autism Spectrum Disorder (ASD) ...

445

Zelscope: Oscilloscope and Spectrum Analyzer  

NSDL National Science Digital Library

This is a Windows application that converts a PC into a dual-trace oscilloscope, using the computer's sound card. It can digitize any input waveform (speech, music, electrical signal, etc.) and present it in real time. It includes a spectrum analyzer showing amplitude and phase.

Zeldovich, Konstantin

2004-11-28

446

How utilizes can revitalize industry  

SciTech Connect

During the first weeks of his presidency, Bill Clinton asserted that the nation`s industries must modernize if Americans are to enjoy a rising standard of living. He noted that inadequate knowledge about new production technologies and inadequate capital for plant improvements were making it hard for manufacturers, particularly small and midsized firms, to improve their productivity and economic competitiveness. And though he said his administration would stress the benefits of government research, technology transfer, and financial assistance, President Clinton acknowledged that Washington needs new partners to help modernize U.S. industrial processes. Electric utilities are likely candidates. They have considerable technical expertise and access to large sums of capital that could help industry improve its productivity. Fortuitously, power companies also would benefit by such a partnership stimulating local economic activity and better managing electricity demands. Although many utilities pursue so-called demand-side management programs for their commercial and residential customers, most have not focused much attention on the industrial sector, in part because achieving industrial energy efficiency requires more specialized expertise than do routine energy audits to improve the insulation and lighting of homes and commercial buildings. Yet the reasons to target industry are compelling: Industrial firms consume more than 35 percent of the electricity in the United States, and investment in retooling manufacturing operations with energy-efficient and productive equipment could help spur economic revitalization.

De Vaul, D.; Bartsch, C. [Northeast Midwest Institute, Washington, DC (United States)

1993-12-31

447

Utility and Happiness  

Microsoft Academic Search

Psychologists have developed effective survey methods of measuring how happy people feel at a given time. The relationship between how happy a person feels and utility is an unresolved question. Existing work in Economics either ignores happiness data or assumes that felt happiness is more or less the same thing as flow utility. The approach we propose in this paper

Miles Kimball; Robert Willis

448

By-Products Utilization  

E-print Network

Center for By-Products Utilization HIGH-STRENGTH CONCRETE CONTAINING LARGE QUANTITIES OF FLY ASH-Strength Concrete Containing Large Quantities of Fly Ash By Tarun R. Naik* and Bruce W. Ramme** ABSTRACT Presents and 28 MPa) structural grade concrete utilizing Class C fly ash. The fly ash was produced at Wisconsin

Wisconsin-Milwaukee, University of

449

By-Products Utilization  

E-print Network

Center for By-Products Utilization GLASS AS AGGREGATES IN FLOWABLE CONCRETE WITH FLY ASH By Tarun R is a member of ACI Committee 232, "Fly Ash and Natural Pozzolans in Concrete", Committee 228, "Nondestructive utilizing post- consumer glass (broken glass or glass cullet) aggregate and fly ash. The flowable concrete

Wisconsin-Milwaukee, University of

450

By-Products Utilization  

E-print Network

UTILIZING FLY ASH, BOTTOM ASH, AND USED FOUNDRY SAND By: Tarun R. Naik, Rudolph N. Kraus, and Bruce W. Ramme PRODUCTS UTILIZING FLY ASH, BOTTOM ASH, AND USED FOUNDRY SAND by Tarun R. Naik, Rudolph N. Kraus, and Bruce-cast concrete products containing fly ash, bottom ash, and used foundry sand. Test specimens for all dry

Wisconsin-Milwaukee, University of

451

International utilization and operations  

NASA Technical Reports Server (NTRS)

The international framework of the Space Station Freedom Program is described. The discussion covers the U.S. space policy, international agreements, international Station elements, overall program management structure, and utilization and operations management. Consideration is also given to Freedom's user community, Freedom's crew, pressurized payload and attached payload accommodations, utilization and operations planning, user integration, and user operations.

Goldberg, Stanley R.

1989-01-01

452

Analysis and Simulation of the Dynamic Spectrum Allocation Based on Parallel Immune Optimization in Cognitive Wireless Networks  

PubMed Central

Spectrum allocation is one of the key issues to improve spectrum efficiency and has become the hot topic in the research of cognitive wireless network. This paper discusses the real-time feature and efficiency of dynamic spectrum allocation and presents a new spectrum allocation algorithm based on the master-slave parallel immune optimization model. The algorithm designs a new encoding scheme for the antibody based on the demand for convergence rate and population diversity. For improving the calculating efficiency, the antibody affinity in the population is calculated in multiple computing nodes at the same time. Simulation results show that the algorithm reduces the total spectrum allocation time and can achieve higher network profits. Compared with traditional serial algorithms, the algorithm proposed in this paper has better speedup ratio and parallel efficiency. PMID:25254255

Huixin, Wu; Duo, Mo; He, Li

2014-01-01

453

Analysis and simulation of the dynamic spectrum allocation based on parallel immune optimization in cognitive wireless networks.  

PubMed

Spectrum allocation is one of the key issues to improve spectrum efficiency and has become the hot topic in the research of cognitive wireless network. This paper discusses the real-time feature and efficiency of dynamic spectrum allocation and presents a new spectrum allocation algorithm based on the master-slave parallel immune optimization model. The algorithm designs a new encoding scheme for the antibody based on the demand for convergence rate and population diversity. For improving the calculating efficiency, the antibody affinity in the population is calculated in multiple computing nodes at the same time. Simulation results show that the algorithm reduces the total spectrum allocation time and can achieve higher network profits. Compared with traditional serial algorithms, the algorithm proposed in this paper has better speedup ratio and parallel efficiency. PMID:25254255

Huixin, Wu; Duo, Mo; He, Li

2014-01-01

454

A plasma generator utilizing the high intensity ASTROMAG magnets  

NASA Technical Reports Server (NTRS)

The magnet configuration for the proposed particle astrophysics magnet facility (ASTROMAG) on the space station includes a cusp magnetic field with an intensity of a few tesla. With these large magnets (or others) located in the outer ionosphere, many quite interesting and unique plasma physics experiments become possible. First there are studies utilizing the magnet alone to examine the supersonic, sub-Alfvenic interaction with the ambient medium; the scale length for the magnet perturbation is approx. 20 m. The magnetic field geometry when combined with the Earth's and their relative motion will give rise to a host of plasma phenomena: ring nulls, x-points, ion-acoustic and lower-hybrid shocks, electron heating (possible shuttle glow without a surface) launching of Alfvenwaves, etc. Second, active experiments are possible for a controlled study of fundamental plasma phenomena. A controlled variable species plasma can be made by using an RF ion source; use of two soft iron rings placed about the line cusp would give an adequate resonance zone (ECH or ICH) and a confining volume suitable for gas efficiency. The emanating plasma can be used to study free expansion of plasma along and across field lines (polar wind), plasma flows around the space platform, turbulent mixing in the wake region, long wavelength spectrum of convecting modes, plasma-dust interactions, etc.

Sullivan, James D.; Post, R. S.; Lane, B. G.; Tarrh, J. M.

1986-01-01

455

Constraints on utilization of energy resources  

Microsoft Academic Search

Currently existing constraints on the adoption and enforcement of energy policies are examined. The aims of these policies are to conserve energy by its more efficient utilization in a productive economy, to replace our current reliance on nonrenewable fossil-fuel resources by new inexhaustible environmentally acceptable energy forms and technologies, and to create, by research and development, renewable energy resources. The

J. N. Nassikas

1976-01-01

456

Efficient Windows  

NSDL National Science Digital Library

The Efficient Windows Collaborative (EWC) operates this informative site about the benefits and energy saving characteristics of efficient windows. A good overview of the various types is given in the How Windows Work section. This explains many different glazings, frames, and operating designs of the windows. The three main technologies used to improve insulating performance are covered, and another section highlights some advantages of efficient windows. The Web site also offers fact sheets with statistics for various cities around the US. If users are interested in switching to efficient windows for their homes, there is plenty of information about how to make the best selection.

1998-01-01

457

Dynamic spectrum access with preemption in open spectrum wireless networks  

Microsoft Academic Search

Analytical formulations of dynamic spectrum access (DSA) with and without preemption for two radio systems are presented. The DSA without preemption model is solved explicitly using a two-dimensional Markov chain while the DSA with preemption models are solved numerically using a two-dimensional Markov chain. Grades of service (GoSs) like system airtime, blocking probabilities and preemption probabilities are considered. The performance

D. Tung Chong Wong; Anh Tuan Hoang; Ying-Chang Liang; F. Chin

2008-01-01

458

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

PubMed

During the past few years there has been a significant interest in spectrum splitting systems to increase the overall efficiency of photovoltaic solar energy systems. However, methods for comparing the performance of spectrum splitting systems and the effects of optical spectral filter design on system performance are not well developed. This paper addresses these two areas. The system conversion efficiency is examined in detail and the role of optical spectral filters with respect to the efficiency is developed. A new metric termed the Improvement over Best Bandgap is defined which expresses the efficiency gain of the spectrum splitting system with respect to a similar system that contains the highest constituent single bandgap photovoltaic cell. This parameter indicates the benefit of using the more complex spectrum splitting system with respect to a single bandgap photovoltaic system. Metrics are also provided to assess the performance of experimental spectral filters in different spectrum splitting configurations. The paper concludes by using the methodology to evaluate spectrum splitting systems with different filter configurations and indicates the overall efficiency improvement that is possible with ideal and experimental designs. PMID:24922262

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

2014-03-10

459

Modelling the TSZ power spectrum  

SciTech Connect

The structure formation in university is a hierarchical process. As universe evolves, tiny density fluctuations that existed in the early universe grows under gravitational instability to form massive large scale structures. The galaxy clusters are the massive viralized objects that forms by accreting smaller clumps of mass until they collapse under their self-gravity. As such galaxy clusters are the youngest objects in the universe which makes their abundance as a function of mass and redshift, very sensitive to dark energy. Galaxy clusters can be detected by measuring the richness in optical waveband, by measuring the X-ray flux, and in the microwave sky using Sunyaev-Zel'dovich (SZ) effect. The Sunyaev-Zel'dovich (SZ) effect has long been recognized as a powerful tool for detecting clusters and probing the physics of the intra-cluster medium. Ongoing and future experiments like Atacama Cosmology Telescope, the South Pole Telescope and Planck survey are currently surveying the microwave sky to develop large catalogs of galaxy clusters that are uniformly selected by the SZ flux. However one major systematic uncertainties that cluster abundance is prone to is the connection between the cluster mass and the SZ flux. As shown by several simulation studies, the scatter and bias in the SZ flux-mass relation can be a potential source of systematic error to using clusters as a cosmology probe. In this study they take a semi-analytic approach for modeling the intra-cluster medium in order to predict the tSZ power spectrum. The advantage of this approach is, being analytic, one can vary the parameters describing gas physics and cosmology simultaneously. The model can be calibrated against X-ray observations of massive, low-z clusters, and using the SZ power spectrum which is sourced by high-z lower mass galaxy groups. This approach allows us to include the uncertainty in gas physics, as dictated by the current observational uncertainties, while measuring the cosmological parameters using the SZ power spectrum data. The paper is organized as follows. In section 2, after a brief review of the halo model description of the SZ power spectrum, they discuss their model for intra-cluster medium explaining various parameters describing gas physics. In section 3, they explore a subset of parameter space using the current low-z X-ray data of galaxy clusters and mass and redshift dependence of our intra-cluster medium model. In section 4, they explore the parameter dependence of SZ power spectrum and show the agreement of the model with the current SZ power spectrum data from SPT survey.

Bhattacharya, Suman [Los Alamos National Laboratory; Shaw, Laurie D [YALE; Nagai, Daisuke [YALE

2010-01-01

460

Efficiency limits of diffusive shock acceleration  

E-print Network

It is well accepted today that diffusive acceleration in shocks results to the cosmic ray spectrum formation. This is in principle true for non-relativistic shocks, since there is a detailed theory covering a large range of their properties and the resulting power-law spectrum, which is nevertheless not as efficient to reach the very high energies observed in the cosmic ray spectrum. On the other hand, the cosmic ray maximum energy and the resulting spectra from relativistic shocks, are still under investigation and debate concerning their contribution to the features of the cosmic ray spectrum and the measured, or implied, cosmic ray radiation from candidate astrophysical sources. Here, we discuss the efficiency of the first order Fermi (diffusive) acceleration mechanism up to relativistic shock speeds, presenting Monte Carlo simulations.

A. Meli; A. Mastichiadis

2007-08-10

461

Energy spectrum of sputtered uranium  

NASA Technical Reports Server (NTRS)

The fission track technique for detecting uranium 235 was used in conjunction with a mechanical time-of-flight spectrometer to measure the energy spectrum in the region 1 eV to 1 keV of material sputtered from a 93% enriched U-235 foil by 80 keV Ar-40(+) ions. The spectrum was found to exhibit a peak in the region 2-4 eV and to decrease approximately as E to the -1.77 power for E is approximately greater than 100 eV. The design, construction and resolution of the mechanical spectrometer are discussed and comparisons are made between the data and the predictions of the ramdom collision cascade model of sputtering.

Weller, R. A.; Tombrello, T. A.

1977-01-01

462

77 FR 40647 - Toward Innovative Spectrum-Sharing Technologies: Wireless Spectrum Research and Development...  

Federal Register 2010, 2011, 2012, 2013

...NATIONAL SCIENCE FOUNDATION Toward Innovative Spectrum-Sharing Technologies: Wireless Spectrum Research and Development Senior Steering Group...testing by researchers to explore innovative spectrum-sharing technologies, including those...

2012-07-10

463

High efficiency, long life terrestrial solar panel  

NASA Technical Reports Server (NTRS)

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

1977-01-01