Science.gov

Sample records for alternative design comparison

  1. Comparison of the FRM-II HEU design with an alternative LEU design

    SciTech Connect

    Mo, S.C.; Hanan, N.A.; Matos, J.E.

    1995-12-01

    The FRM-II reactor design of the Technical University of Munich has a compact core that utilizes fuel plates containing highly-enriched uranium (HEU, 93%). This paper presents an alternative core design utilizing low-enriched uranium (LEU, <20%) silicide fuel with 4.8 g/cm{sup 3} that provides nearly the same neutron flux for experiments as the HEU design, but has a less favorable fuel cycle economy. If an LEU fuel with a uranium density of 6.0 - 6.5 g/cm{sup 3} were developed, the alternative design would provide the same neutron flux and use the same number of cores per year as the HEU design. The results of this study show that there are attractive possibilities for using LEU fuel instead of HEU fuel in the FRM-II. Further optimization of the LEU design and near-term availability of LEU fuel with a uranium density greater than 4.8 g/cm{sup 3} would enhance the performance of the LEU core. The RERTR Program is ready to exchange information with the Technical University of Munich to resolve any differences that may exist and to identify design modifications that would optimize reactor performance utilizing LEU fuel.

  2. Seal design alternatives study

    SciTech Connect

    Van Sambeek, L.L.

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information.

  3. Evaluation and comparison of alternative designs for water/solid-waste processing systems for spacecraft

    NASA Technical Reports Server (NTRS)

    Spurlock, J. M.

    1975-01-01

    Promising candidate designs currently being considered for the management of spacecraft solid waste and waste-water materials were assessed. The candidate processes were: (1) the radioisotope thermal energy evaporation/incinerator process; (2) the dry incineration process; and (3) the wet oxidation process. The types of spacecraft waste materials that were included in the base-line computational input to the candidate systems were feces, urine residues, trash and waste-water concentrates. The performance characteristics and system requirements for each candidate process to handle this input and produce the specified acceptable output (i.e., potable water, a storable dry ash, and vapor phase products that can be handled by a spacecraft atmosphere control system) were estimated and compared. Recommendations are presented.

  4. State alternative route designations

    SciTech Connect

    Not Available

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a ``state routing agency,`` defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  5. State alternative route designations

    SciTech Connect

    Not Available

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a state routing agency,'' defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  6. Enhanced Design Alternative IV

    SciTech Connect

    N. E. Kramer

    1999-05-18

    This report evaluates Enhanced Design Alternative (EDA) IV as part of the second phase of the License Application Design Selection (LADS) effort. The EDA IV concept was compared to the VA reference design using criteria from the ''Design Input Request for LADS Phase II EDA Evaluations'' (CRWMS M&O 1999b) and (CRWMS M&O 1999f). Briefly, the EDA IV concept arranges the waste packages close together in an emplacement configuration known as ''line load''. Continuous pre-closure ventilation keeps the waste packages from exceeding the 350 C cladding and 200 C (4.3.13) drift wall temperature limits. This EDA concept keeps relatively high, uniform emplacement drift temperatures (post-closure) to drive water away from the repository and thus dry out the pillars between emplacement drifts. The waste package is shielded to permit human access to emplacement drifts and includes an integral filler inside the package to reduce the amount of water that can contact the waste form. Closure of the repository is desired 50 years after first waste is emplaced. Both backfill and a drip shields will be emplaced at closure to improve post-closure performance.

  7. Alternative Natural Energy Sources in Building Design.

    ERIC Educational Resources Information Center

    Davis, Albert J.; Schubert, Robert P.

    This publication provides a discussion of various energy conserving building systems and design alternatives. The information presented here covers alternative space and water heating systems, and energy conserving building designs incorporating these systems and other energy conserving techniques. Besides water, wind, solar, and bio conversion…

  8. Alternate Propulsion Subsystem Concepts Tripropellant Comparison Study

    NASA Technical Reports Server (NTRS)

    Levack, Daniel

    1995-01-01

    A study was conducted under MSFC contract NAS8-39210 to compare tripropellant and bipropellant engine configurations for the SSTO mission. The objective was to produce an 'apples-to-apples' comparison to isolate the effects of design implementation, designing company, year of design, or technologies included from the basic tripropellant/bipropellant comparison. Consequently, identical technologies were included (e.g., jet pumps) and the same design groundrules and practices were used. Engine power cycles were examined as were turbomachinery/preburner arrangements for each cycle. The bipropellant approach and two tripropellant approaches were separately optimized in terms of operating parameters: exit pressures, mixture ratios, thrust splits, etc. This briefing presents the results of the study including engine weights for both tripropellant and bipropellant engines; dry vehicle weight performance for a range of engine chamber pressures; discusses the basis for the results; examines vehicle performance due to engine cycles and the margin characteristics of various cycles; and identifies technologies with significant payoffs for this application.

  9. Analysis of Alternative Ring Resonator Designs

    DTIC Science & Technology

    2014-08-01

    the ring strip of the antenna as in the case of the original design. Both the alternative dielectric laminate and the increased thickness laminate...adjustments to the geometry parameters. 2. Ring Resonator Antenna Design The ring resonator is a two port antenna consisting of a ring strip and two...differing thicknesses for resonator antennas of the same design suggests that the RF fields penetrate slightly more or that the resonator can “see” a

  10. Design alternatives report for the cesium removal demonstration

    SciTech Connect

    Walker, J.F. Jr.; Youngblood, E.L.

    1995-09-01

    The Cesium Removal Demonstration (CRD) project will use liquid low-level waste (LLLW) stored in the Oak Ridge National Laboratory Melton Valley Storage Tanks to demonstrate cesium removal from sodium nitrate-based supernates. This report presents the results of a conceptual design study to scope the alternatives for conducting the demonstration at ORNL. Factors considered included (1) sorbent alternatives, (2) facility alternatives, (3) process alternatives, (4) process disposal alternatives, and (5) relative cost comparisons. Recommendations included (1) that design of the CRD system move forward based on information obtained to date from tests with Savannah River Resin, (2) that the CRD system be designed so it could use crystalline silicotitanates (CST) if an engineered form of CST becomes available prior to the CRD, (3) that the system be designed without the capability for resin regeneration, (4) that the LLLW solidification facility be used for the demonstration (5) that vitrification of the loaded resins from the CRD be demonstrated at the Savannah River Site, and (6) that permanent disposal of the loaded and/or vitrified resin at the Nevada Test Site be pursued.

  11. Alternative design concept for the second Glass Waste Storage Building

    SciTech Connect

    Rainisch, R.

    1992-10-01

    This document presents an alternative design concept for storing canisters filled with vitrified waste produced at the Defense Waste Processing Facility (DWPF). The existing Glass Waste Storage Building (GWSB1) has the capacity to store 2,262 canisters and is projected to be completely filled by the year 2000. Current plans for glass waste storage are based on constructing a second Glass Waste Storage Building (GWSB2) once the existing Glass Waste Storage Building (GWSB1) is filled to capacity. The GWSB2 project (Project S-2045) is to provide additional storage capacity for 2,262 canisters. This project was initiated with the issue of a basic data report on March 6, 1989. In response to the basic data report Bechtel National, Inc. (BNI) prepared a draft conceptual design report (CDR) for the GWSB2 project in April 1991. In May 1991 WSRC Systems Engineering issued a revised Functional Design Criteria (FDC), the Rev. I document has not yet been approved by DOE. This document proposes an alternative design for the conceptual design (CDR) completed in April 1991. In June 1992 Project Management Department authorized Systems Engineering to further develop the proposed alternative design. The proposed facility will have a storage capacity for 2,268 canisters and will meet DWPF interim storage requirements for a five-year period. This document contains: a description of the proposed facility; a cost estimate of the proposed design; a cost comparison between the proposed facility and the design outlined in the FDC/CDR; and an overall assessment of the alternative design as compared with the reference FDC/CDR design.

  12. Empirical Comparison of Alternative Instructional TV Technologies.

    ERIC Educational Resources Information Center

    Simpson, Henry; And Others

    1993-01-01

    Describes a study conducted by the U.S. Navy that compared training effectiveness and user acceptance of live instruction and six different alternative instructional television (ITV) technologies that had differing levels of audio and video communication. The ITV laboratory configuration is explained, and instructor preferences and skills are…

  13. Optimization methods for alternative energy system design

    NASA Astrophysics Data System (ADS)

    Reinhardt, Michael Henry

    An electric vehicle heating system and a solar thermal coffee dryer are presented as case studies in alternative energy system design optimization. Design optimization tools are compared using these case studies, including linear programming, integer programming, and fuzzy integer programming. Although most decision variables in the designs of alternative energy systems are generally discrete (e.g., numbers of photovoltaic modules, thermal panels, layers of glazing in windows), the literature shows that the optimization methods used historically for design utilize continuous decision variables. Integer programming, used to find the optimal investment in conservation measures as a function of life cycle cost of an electric vehicle heating system, is compared to linear programming, demonstrating the importance of accounting for the discrete nature of design variables. The electric vehicle study shows that conservation methods similar to those used in building design, that reduce the overall UA of a 22 ft. electric shuttle bus from 488 to 202 (Btu/hr-F), can eliminate the need for fossil fuel heating systems when operating in the northeast United States. Fuzzy integer programming is presented as a means of accounting for imprecise design constraints such as being environmentally friendly in the optimization process. The solar thermal coffee dryer study focuses on a deep-bed design using unglazed thermal collectors (UTC). Experimental data from parchment coffee drying are gathered, including drying constants and equilibrium moisture. In this case, fuzzy linear programming is presented as a means of optimizing experimental procedures to produce the most information under imprecise constraints. Graphical optimization is used to show that for every 1 m2 deep-bed dryer, of 0.4 m depth, a UTC array consisting of 5, 1.1 m 2 panels, and a photovoltaic array consisting of 1, 0.25 m 2 panels produces the most dry coffee per dollar invested in the system. In general this study

  14. A comparison of alternative energy storage systems for automobiles

    NASA Astrophysics Data System (ADS)

    The performance potentials of primary batteries, fuel cells, and flywheel-transmission systems in comparison with secondary batteries as alternates to conventional internal combustion engine automobile power systems are discussed. A number of areas of research that are recommended for attention as part of a well-rounded investigation of alternatives are outlined.

  15. Refuge alternatives relief valve testing and design

    PubMed Central

    Lutz, T.J.; Bissert, P.T.; Homce, G.T.; Yonkey, J.A.

    2016-01-01

    The U.S. National Institute for Occupational Safety and Health (NIOSH) has been researching refuge alternatives (RAs) since 2007. RAs typically have built-in pressure relief valves (PRVs) to prevent the unit from reaching unsafe pressures. The U.S. Mine Safety and Health Administration requires that these valves vent the chamber at a maximum pressure of 1.25 kPa (0.18 psi, 5.0 in. H2O), or as specified by the manufacturer, above mine atmospheric pressure in the RA. To facilitate PRV testing, an instrumented benchtop test fixture was developed using an off-the-shelf centrifugal blower and ductwork. Relief pressures and flow characteristics were measured for three units: (1) a modified polyvinyl chloride check valve, (2) an off-the-shelf brass/cast-iron butterfly check valve and (3) a commercially available valve that was designed specifically for one manufacturer’s steel prefabricated RAs and had been adapted for use in one mine operator’s built-in-place RA. PRVs used in tent-style RAs were not investigated. The units were tested with different modifications and configurations in order to check compliance with Title 30 Code of Federal Regulations, or 30 CFR, regulations. The commercially available relief valve did not meet the 30 CFR relief pressure specification but may meet the manufacturer’s specification. Alternative valve designs were modified to meet the 30 CFR relief pressure specification, but all valve designs will need further design research to examine survivability in the event of a 103 kPa (15.0 psi) impulse overpressure during a disaster. PMID:28018003

  16. Refuge alternatives relief valve testing and design.

    PubMed

    Lutz, T J; Bissert, P T; Homce, G T; Yonkey, J A

    2016-10-01

    The U.S. National Institute for Occupational Safety and Health (NIOSH) has been researching refuge alternatives (RAs) since 2007. RAs typically have built-in pressure relief valves (PRVs) to prevent the unit from reaching unsafe pressures. The U.S. Mine Safety and Health Administration requires that these valves vent the chamber at a maximum pressure of 1.25 kPa (0.18 psi, 5.0 in. H2O), or as specified by the manufacturer, above mine atmospheric pressure in the RA. To facilitate PRV testing, an instrumented benchtop test fixture was developed using an off-the-shelf centrifugal blower and ductwork. Relief pressures and flow characteristics were measured for three units: (1) a modified polyvinyl chloride check valve, (2) an off-the-shelf brass/cast-iron butterfly check valve and (3) a commercially available valve that was designed specifically for one manufacturer's steel prefabricated RAs and had been adapted for use in one mine operator's built-in-place RA. PRVs used in tent-style RAs were not investigated. The units were tested with different modifications and configurations in order to check compliance with Title 30 Code of Federal Regulations, or 30 CFR, regulations. The commercially available relief valve did not meet the 30 CFR relief pressure specification but may meet the manufacturer's specification. Alternative valve designs were modified to meet the 30 CFR relief pressure specification, but all valve designs will need further design research to examine survivability in the event of a 103 kPa (15.0 psi) impulse overpressure during a disaster.

  17. Optimizing Monitoring Designs under Alternative Objectives

    DOE PAGES

    Gastelum, Jason A.; USA, Richland Washington; Porter, Ellen A.; ...

    2014-12-31

    This paper describes an approach to identify monitoring designs that optimize detection of CO2 leakage from a carbon capture and sequestration (CCS) reservoir and compares the results generated under two alternative objective functions. The first objective function minimizes the expected time to first detection of CO2 leakage, the second more conservative objective function minimizes the maximum time to leakage detection across the set of realizations. The approach applies a simulated annealing algorithm that searches the solution space by iteratively mutating the incumbent monitoring design. The approach takes into account uncertainty by evaluating the performance of potential monitoring designs across amore » set of simulated leakage realizations. The approach relies on a flexible two-tiered signature to infer that CO2 leakage has occurred. This research is part of the National Risk Assessment Partnership, a U.S. Department of Energy (DOE) project tasked with conducting risk and uncertainty analysis in the areas of reservoir performance, natural leakage pathways, wellbore integrity, groundwater protection, monitoring, and systems level modeling.« less

  18. Behavioral headache research: methodologic considerations and research design alternatives.

    PubMed

    Hursey, Karl G; Rains, Jeanetta C; Penzien, Donald B; Nash, Justin M; Nicholson, Robert A

    2005-05-01

    Behavioral headache treatments have garnered solid empirical support in recent years, but there is substantial opportunity to strengthen the next generation of studies with improved methods and consistency across studies. Recently, Guidelines for Trials of Behavioral Treatments for Recurrent Headache were published to facilitate the production of high-quality research. The present article compliments the guidelines with a discussion of methodologic and research design considerations. Since there is no research design that is applicable in every situation, selecting an appropriate research design is fundamental to producing meaningful results. Investigators in behavioral headache and other areas of research consider the developmental phase of the research, the principle objectives of the project, and the sources of error or alternative interpretations in selecting a design. Phases of clinical trials typically include pilot studies, efficacy studies, and effectiveness studies. These trials may be categorized as primarily pragmatic or explanatory. The most appropriate research designs for these different phases and different objectives vary on such characteristics as sample size and assignment to condition, types of control conditions, periods or frequency of measurement, and the dimensions along which comparisons are made. A research design also must fit within constraints on available resources. There are a large number of potential research designs that can be used and considering these characteristics allows selection of appropriate research designs.

  19. Designing an Alternate Mission Operations Control Room

    NASA Technical Reports Server (NTRS)

    Montgomery, Patty; Reeves, A. Scott

    2014-01-01

    The Huntsville Operations Support Center (HOSC) is a multi-project facility that is responsible for 24x7 real-time International Space Station (ISS) payload operations management, integration, and control and has the capability to support small satellite projects and will provide real-time support for SLS launches. The HOSC is a service-oriented/ highly available operations center for ISS payloads-directly supporting science teams across the world responsible for the payloads. The HOSC is required to endure an annual 2-day power outage event for facility preventive maintenance and safety inspection of the core electro-mechanical systems. While complete system shut-downs are against the grain of a highly available sub-system, the entire facility must be powered down for a weekend for environmental and safety purposes. The consequence of this ground system outage is far reaching: any science performed on ISS during this outage weekend is lost. Engineering efforts were focused to maximize the ISS investment by engineering a suitable solution capable of continuing HOSC services while supporting safety requirements. The HOSC Power Outage Contingency (HPOC) System is a physically diversified compliment of systems capable of providing identified real-time services for the duration of a planned power outage condition from an alternate control room. HPOC was designed to maintain ISS payload operations for approximately three continuous days during planned HOSC power outages and support a local Payload Operations Team, International Partners, as well as remote users from the alternate control room located in another building.

  20. Model‐Based Assessment of Alternative Study Designs in Pediatric Trials. Part I: Frequentist Approaches

    PubMed Central

    Smania, G; Baiardi, P; Ceci, A; Magni, P

    2016-01-01

    Alternative designs can increase the feasibility of pediatric trials when compared to classical parallel designs (PaD). In this work we present a model‐based approach based on clinical trial simulations for the comparison of PaD with the alternative sequential, crossover, and randomized withdrawal (RWD) designs. Study designs were evaluated in terms of: type I and II errors, sample size per arm (SS), trial duration (TD), treatment exposures, and parameter estimate precision (EP). The crossover requires the lowest SS and TD, although it implies higher placebo and no treatment exposures. RWD maximizes exposure to active treatment while minimizing that to placebo, but requires the largest SS. SS of sequential designs can sometimes be smaller than the crossover one, although with poorer EP. This pharmacometric framework allows a multiscale comparison of alternative study designs that can be used for design selection in future pediatric trials. PMID:27300083

  1. 77 FR 30047 - Petition for Alternative Locomotive Crashworthiness Design

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... Federal Railroad Administration Petition for Alternative Locomotive Crashworthiness Design In accordance... design for an electric locomotive, Model ACS-64, built by Siemens Industry, Inc. This request is made in...-0036. The alternative design incorporates crash energy management features, detailed in the...

  2. 46 CFR 116.340 - Alternate design considerations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Alternate design considerations. 116.340 Section 116.340... ARRANGEMENT Hull Structure § 116.340 Alternate design considerations. The Commanding Officer, Marine Safety Center, may approve the structure of a vessel of novel design, unusual form, or special materials,...

  3. 46 CFR 177.340 - Alternate design considerations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Alternate design considerations. 177.340 Section 177.340... TONS) CONSTRUCTION AND ARRANGEMENT Hull Structure § 177.340 Alternate design considerations. When the structure of vessel is of novel design, unusual form, or special materials, which cannot be reviewed...

  4. 46 CFR 116.340 - Alternate design considerations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Alternate design considerations. 116.340 Section 116.340... ARRANGEMENT Hull Structure § 116.340 Alternate design considerations. The Commanding Officer, Marine Safety Center, may approve the structure of a vessel of novel design, unusual form, or special materials,...

  5. Dynamic Learning Communities: An Alternative to Designed Instructional Systems.

    ERIC Educational Resources Information Center

    Wilson, Brent; Ryder, Martin

    Dynamic Learning Communities (DLCs) offer an alternative approach to the traditional Instructional Design (ID) format for learning. This paper outlines the concept of a dynamic learning community as an alternative to teacher-controlled or pre-designed instructional systems. DLCs are groups of people, who form a learning community generally…

  6. Alternative methods for the design of jet engine control systems

    NASA Technical Reports Server (NTRS)

    Sain, M. K.; Leake, R. J.; Basso, R.; Gejji, R.; Maloney, A.; Seshadri, V.

    1976-01-01

    Various alternatives to linear quadratic design methods for jet engine control systems are discussed. The main alternatives are classified into two broad categories: nonlinear global mathematical programming methods and linear local multivariable frequency domain methods. Specific studies within these categories include model reduction, the eigenvalue locus method, the inverse Nyquist method, polynomial design, dynamic programming, and conjugate gradient approaches.

  7. Designing alternative splicing RNA-seq studies. Beyond generic guidelines

    PubMed Central

    Stephan-Otto Attolini, Camille; Peña, Victor; Rossell, David

    2015-01-01

    Motivation: Designing an RNA-seq study depends critically on its specific goals, technology and underlying biology, which renders general guidelines inadequate. We propose a Bayesian framework to customize experiments so that goals can be attained and resources are not wasted, with a focus on alternative splicing. Results: We studied how read length, sequencing depth, library preparation and the number of replicates affects cost-effectiveness of single-sample and group comparison studies. Optimal settings varied strongly according to the target organism or tissue (potential 50–500% cost cuts) and, interestingly, short reads outperformed long reads for standard analyses. Our framework learns key characteristics for study design from the data, and predicts if and how to continue experimentation. These predictions matched several follow-up experimental datasets that were used for validation. We provide default pipelines, but the framework can be combined with other data analysis methods and can help assess their relative merits. Availability and implementation: casper package at www.bioconductor.org/packages/release/bioc/html/casper.html, Supplementary Manual by typing casperDesign() at the R prompt. Contact: rosselldavid@gmail.com Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26220961

  8. Digital Hardware Design Teaching: An Alternative Approach

    ERIC Educational Resources Information Center

    Benkrid, Khaled; Clayton, Thomas

    2012-01-01

    This article presents the design and implementation of a complete review of undergraduate digital hardware design teaching in the School of Engineering at the University of Edinburgh. Four guiding principles have been used in this exercise: learning-outcome driven teaching, deep learning, affordability, and flexibility. This has identified…

  9. Designing oligo libraries taking alternative splicing into account

    NASA Astrophysics Data System (ADS)

    Shoshan, Avi; Grebinskiy, Vladimir; Magen, Avner; Scolnicov, Ariel; Fink, Eyal; Lehavi, David; Wasserman, Alon

    2001-06-01

    We have designed sequences for DNA microarrays and oligo libraries, taking alternative splicing into account. Alternative splicing is a common phenomenon, occurring in more than 25% of the human genes. In many cases, different splice variants have different functions, are expressed in different tissues or may indicate different stages of disease. When designing sequences for DNA microarrays or oligo libraries, it is very important to take into account the sequence information of all the mRNA transcripts. Therefore, when a gene has more than one transcript (as a result of alternative splicing, alternative promoter sites or alternative poly-adenylation sites), it is very important to take all of them into account in the design. We have used the LEADS transcriptome prediction system to cluster and assemble the human sequences in GenBank and design optimal oligonucleotides for all the human genes with a known mRNA sequence based on the LEADS predictions.

  10. Design Alternative Evaluation No. 3: Post-Closure Ventilation

    SciTech Connect

    Logan, R.C.

    1999-06-22

    The objective of this study is to provide input to the Enhanced Design Alternatives (EDA) for License Application Design Selection (LADS). Its purpose is to develop and evaluate conceptual designs for post-closure ventilation alternatives that enhance repository performance. Post-closure ventilation is expected to enhance repository performance by limiting the amount of water contacting the waste packages. Limiting the amount of water contacting the waste packages will reduce corrosion.

  11. Alternative clinical trial design in neurocritical care.

    PubMed

    Lazaridis, Christos; Maas, Andrew I R; Souter, Michael J; Martin, Renee H; Chesnut, Randal M; DeSantis, Stacia M; Sung, Gene; Leroux, Peter D; Suarez, Jose I

    2015-06-01

    Neurocritical care involves the care of highly complex patients with combinations of physiologic derangements in the brain and in extracranial organs. The level of evidence underpinning treatment recommendations remains low due to a multitude of reasons including an incomplete understanding of the involved physiology; lack of good quality, prospective, standardized data; and the limited success of conventional randomized controlled trials. Comparative effectiveness research can provide alternative perspectives and methods to enhance knowledge and evidence within the field of neurocritical care; these include large international collaborations for generation and maintenance of high quality data, statistical methods that incorporate heterogeneity and individualize outcome prediction, and finally advanced bioinformatics that integrate large amounts of variable-source data into patient-specific phenotypes and trajectories.

  12. 46 CFR 116.340 - Alternate design considerations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Center, may approve the structure of a vessel of novel design, unusual form, or special materials, which... principles that the vessel structure provides adequate safety and strength. An owner seeking approval of an alternate design shall submit detailed plans, material component specifications, and design...

  13. 40 CFR 96.111 - Alternate CAIR designated representative.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR Designated Representative for CAIR NOX Sources § 96.111 Alternate CAIR...

  14. 40 CFR 96.111 - Alternate CAIR designated representative.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR Designated Representative for CAIR NOX Sources § 96.111 Alternate CAIR...

  15. 49 CFR 229.209 - Alternative locomotive crashworthiness designs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Alternative locomotive crashworthiness designs. 229.209 Section 229.209 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY...

  16. Insights Gained from Testing Alternate Cell Designs

    SciTech Connect

    J. E. O'Brien; C. M. Stoots; J. S. Herring; G. K. Housley; M. S. Sohal; D. G. Milobar; Thomas Cable

    2009-09-01

    The Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cell for large-scale hydrogen production from steam over a temperature range of 800 to 900ºC. The INL has been testing various solid oxide cell designs to characterize their electrolytic performance operating in the electrolysis mode for hydrogen production. Some results presented in this report were obtained from cells, initially developed by the Forschungszentrum Jülich and now manufactured by the French ceramics firm St. Gobain. These cells have an active area of 16 cm2 per cell. They were initially developed as fuel cells, but are being tested as electrolytic cells in the INL test stands. The electrolysis cells are electrode-supported, with ~10 µm thick yttria-stabilized zirconia (YSZ) electrolytes, ~1400 µm thick nickel-YSZ steam-hydrogen electrodes, and manganite (LSM) air-oxygen electrodes. The experiments were performed over a range of steam inlet mole fractions (0.1 to 0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented. NASA, in conjunction with the University of Toledo, has developed another fuel cell concept with the goals of reduced weight and high power density. The NASA cell is structurally symmetrical, with both electrodes supporting the thin electrolyte and containing micro-channels for gas diffusion. This configuration is called a bi

  17. Brayton heat exchanger unit development program (alternate design)

    NASA Technical Reports Server (NTRS)

    Duncan, J. D.; Gibson, J. C.; Graves, R. F.; Morse, C. J.; Richard, C. E.

    1973-01-01

    A Brayton Heat Exchanger Unit Alternate Design (BHXU-Alternate) consisting of a recuperator, a heat sink heat exchanger, and a gas ducting system, was designed and fabricated. The design was formulated to provide a high performance unit suitable for use in a long-life Brayton-cycle powerplant. Emphasis was on double containment against external leakage and leakage of the organic coolant into the gas stream. A parametric analysis and design study was performed to establish the optimum component configurations to achieve low weight and size and high reliability, while meeting the requirements of high effectiveness and low pressure drop. Layout studies and detailed mechanical and structural design were performed to obtain a flight-type packaging arrangement, including the close-coupled integration of the BHXU-Alternate with the Brayton Rotating Unit (BRU).

  18. 31 CFR 0.104 - Designated Agency Ethics Official and Alternate Designated Agency Ethics Official.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Designated Agency Ethics Official and Alternate Designated Agency Ethics Official. 0.104 Section 0.104 Money and Finance: Treasury Office of the... Responsibilities § 0.104 Designated Agency Ethics Official and Alternate Designated Agency Ethics Official....

  19. 31 CFR 0.104 - Designated Agency Ethics Official and Alternate Designated Agency Ethics Official.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Designated Agency Ethics Official and Alternate Designated Agency Ethics Official. 0.104 Section 0.104 Money and Finance: Treasury Office of the... Responsibilities § 0.104 Designated Agency Ethics Official and Alternate Designated Agency Ethics Official....

  20. 31 CFR 0.104 - Designated Agency Ethics Official and Alternate Designated Agency Ethics Official.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Designated Agency Ethics Official and Alternate Designated Agency Ethics Official. 0.104 Section 0.104 Money and Finance: Treasury Office of the... Responsibilities § 0.104 Designated Agency Ethics Official and Alternate Designated Agency Ethics Official....

  1. 31 CFR 0.104 - Designated Agency Ethics Official and Alternate Designated Agency Ethics Official.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Designated Agency Ethics Official and Alternate Designated Agency Ethics Official. 0.104 Section 0.104 Money and Finance: Treasury Office of the... Responsibilities § 0.104 Designated Agency Ethics Official and Alternate Designated Agency Ethics Official....

  2. 31 CFR 0.104 - Designated Agency Ethics Official and Alternate Designated Agency Ethics Official.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Designated Agency Ethics Official and Alternate Designated Agency Ethics Official. 0.104 Section 0.104 Money and Finance: Treasury Office of the... Responsibilities § 0.104 Designated Agency Ethics Official and Alternate Designated Agency Ethics Official....

  3. Design of a nonscaling fixed field alternating gradient accelerator

    NASA Astrophysics Data System (ADS)

    Trbojevic, D.; Courant, E. D.; Blaskiewicz, M.

    2005-05-01

    We present a design of nonscaling fixed field alternating gradient accelerators (FFAG) minimizing the dispersion action function H. The design is considered both analytically and via computer modeling. We present the basic principles of a nonscaling FFAG lattice and discuss optimization strategies so that one can accelerate over a broad range of momentum with reasonable apertures. Acceleration schemes for muons are discussed.

  4. 40 CFR 72.22 - Alternate designated representative.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the term “designated representative” is used under the Acid Rain Program, the term shall be construed...), whenever the term “alternate designated representative” is used under the Acid Rain Program, the term shall...” is used under the Acid Rain Program, the term shall be construed to include either of the...

  5. 40 CFR 72.22 - Alternate designated representative.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the term “designated representative” is used under the Acid Rain Program, the term shall be construed...), whenever the term “alternate designated representative” is used under the Acid Rain Program, the term shall...” is used under the Acid Rain Program, the term shall be construed to include either of the...

  6. 40 CFR 72.22 - Alternate designated representative.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the term “designated representative” is used under the Acid Rain Program, the term shall be construed...), whenever the term “alternate designated representative” is used under the Acid Rain Program, the term shall...” is used under the Acid Rain Program, the term shall be construed to include either of the...

  7. 40 CFR 72.22 - Alternate designated representative.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the term “designated representative” is used under the Acid Rain Program, the term shall be construed...), whenever the term “alternate designated representative” is used under the Acid Rain Program, the term shall... used under the Acid Rain Program, the term shall be construed to include either of the...

  8. 40 CFR 72.22 - Alternate designated representative.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the term “designated representative” is used under the Acid Rain Program, the term shall be construed...), whenever the term “alternate designated representative” is used under the Acid Rain Program, the term shall...” is used under the Acid Rain Program, the term shall be construed to include either of the...

  9. Using Corrosion Design Models to Accelerate the Transition of Alternatives

    DTIC Science & Technology

    2012-08-01

    Corrosion Design Models • All moving to incorporate light metals, composites and other aviation materials • Maturation includes effect of...Using Corrosion Design Models to Accelerate the Transition of Alternatives Craig Matzdorf Materials Engineering Division Naval Air...TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Air Warfare Center, Materials Engineering Division,22347

  10. Nonrandom Assignment in ANCOVA: The Alternate Ranks Design

    ERIC Educational Resources Information Center

    Dalton, Starrett; Overall, John E.

    1977-01-01

    A specific form of nonrandom assignment to treatment groups, the "alternate ranks" design, was investigated. This design eliminates the possibility of a correlation between the covariate and the treatment, and rules out experimenter bias in assignment of subjects to groups. (Editor)

  11. Subsurface barrier design alternatives for confinement and controlled advection flow

    SciTech Connect

    Phillips, S.J.; Stewart, W.E.; Alexander, R.G.; Cantrell, K.J.; McLaughlin, T.J.

    1994-02-01

    Various technologies and designs are being considered to serve as subsurface barriers to confine or control contaminant migration from underground waste storage or disposal structures containing radioactive and hazardous wastes. Alternatives including direct-coupled flood and controlled advection designs are described as preconceptual examples. Prototype geotechnical equipment for testing and demonstration of these alternative designs tested at the Hanford Geotechnical Development and Test Facility and the Hanford Small-Tube Lysimeter Facility include mobile high-pressure injectors and pumps, mobile transport and pumping units, vibratory and impact pile drivers, and mobile batching systems. Preliminary laboratory testing of barrier materials and additive sequestering agents have been completed and are described.

  12. The cost of ethanol production from lignocellulosic biomass -- A comparison of selected alternative processes. Final report

    SciTech Connect

    Grethlein, H.E.; Dill, T.

    1993-04-30

    The purpose of this report is to compare the cost of selected alternative processes for the conversion of lignocellulosic biomass to ethanol. In turn, this information will be used by the ARS/USDA to guide the management of research and development programs in biomass conversion. The report will identify where the cost leverages are for the selected alternatives and what performance parameters need to be achieved to improve the economics. The process alternatives considered here are not exhaustive, but are selected on the basis of having a reasonable potential in improving the economics of producing ethanol from biomass. When other alternatives come under consideration, they should be evaluated by the same methodology used in this report to give fair comparisons of opportunities. A generic plant design is developed for an annual production of 25 million gallons of anhydrous ethanol using corn stover as the model substrate at $30/dry ton. Standard chemical engineering techniques are used to give first order estimates of the capital and operating costs. Following the format of the corn to ethanol plant, there are nine sections to the plant; feed preparation, pretreatment, hydrolysis, fermentation, distillation and dehydration, stillage evaporation, storage and denaturation, utilities, and enzyme production. There are three pretreatment alternatives considered: the AFEX process, the modified AFEX process (which is abbreviated as MAFEX), and the STAKETECH process. These all use enzymatic hydrolysis and so an enzyme production section is included in the plant. The STAKETECH is the only commercially available process among the alternative processes.

  13. 29 CFR 2703.2 - Designated agency ethics official and alternate designated agency ethics official.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Designated agency ethics official and alternate designated agency ethics official. 2703.2 Section 2703.2 Labor Regulations Relating to Labor (Continued) FEDERAL... agency ethics official and alternate designated agency ethics official. The Chairman shall appoint...

  14. 29 CFR 2703.2 - Designated agency ethics official and alternate designated agency ethics official.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 9 2012-07-01 2012-07-01 false Designated agency ethics official and alternate designated agency ethics official. 2703.2 Section 2703.2 Labor Regulations Relating to Labor (Continued) FEDERAL... agency ethics official and alternate designated agency ethics official. The Chairman shall appoint...

  15. 29 CFR 2703.2 - Designated agency ethics official and alternate designated agency ethics official.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 9 2013-07-01 2013-07-01 false Designated agency ethics official and alternate designated agency ethics official. 2703.2 Section 2703.2 Labor Regulations Relating to Labor (Continued) FEDERAL... agency ethics official and alternate designated agency ethics official. The Chairman shall appoint...

  16. 29 CFR 2703.2 - Designated agency ethics official and alternate designated agency ethics official.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Designated agency ethics official and alternate designated agency ethics official. 2703.2 Section 2703.2 Labor Regulations Relating to Labor (Continued) FEDERAL... agency ethics official and alternate designated agency ethics official. The Chairman shall appoint...

  17. 29 CFR 2703.2 - Designated agency ethics official and alternate designated agency ethics official.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Designated agency ethics official and alternate designated agency ethics official. 2703.2 Section 2703.2 Labor Regulations Relating to Labor (Continued) FEDERAL... agency ethics official and alternate designated agency ethics official. The Chairman shall appoint...

  18. ENVIRONMENTAL COMPARISON METRICS FOR LIFE CYCLE IMPACT ASSESSMENT AND PROCESS DESIGN

    EPA Science Inventory

    Metrics (potentials, potency factors, equivalency factors or characterization factors) are available to support the environmental comparison of alternatives in application domains like proces design and product life-cycle assessment (LCA). These metrics typically provide relative...

  19. 34. ALTERNATE DESIGN USING BATTERED AND UNSHEATHED LIFT TOWERS, WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. ALTERNATE DESIGN USING BATTERED AND UNSHEATHED LIFT TOWERS, WITH DEEPENED TRUSS ON LIFT SPAN. Pen-and-ink drawing by project architect Alfred Eichler, 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  20. Expert System Approach For Generating And Evaluating Engine Design Alternatives

    NASA Astrophysics Data System (ADS)

    Shen, Stewart N. T.; Chew, Meng-Sang; Issa, Ghassan F.

    1989-03-01

    Artificial intelligence is becoming an increasingly important subject of study for computer scientists, engineering designers, as well as professionals in other fields. Even though AI technology is a relatively new discipline, many of its concepts have already found practical applications. Expert systems, in particular, have made significant contributions to technologies in such fields as business, medicine, engineering design, chemistry, and particle physics. This paper describes an expert system developed to aid the mechanical designer with the preliminary design of variable-stroke internal-combustion engines. The expert system accomplished its task by generating and evaluating a large number of design alternatives represented in the form of graphs. Through the application of structural and design rules directly to the graphs, optimal and near optimal preliminary design configurations of engines are deduced.

  1. Molecular signatures of mammalian hibernation: comparisons with alternative phenotypes

    PubMed Central

    2013-01-01

    Background Mammalian hibernators display phenotypes similar to physiological responses to calorie restriction and fasting, sleep, cold exposure, and ischemia-reperfusion in non-hibernating species. Whether biochemical changes evident during hibernation have parallels in non-hibernating systems on molecular and genetic levels is unclear. Results We identified the molecular signatures of torpor and arousal episodes during hibernation using a custom-designed microarray for the Arctic ground squirrel (Urocitellus parryii) and compared them with molecular signatures of selected mouse phenotypes. Our results indicate that differential gene expression related to metabolism during hibernation is associated with that during calorie restriction and that the nuclear receptor protein PPARα is potentially crucial for metabolic remodeling in torpor. Sleep-wake cycle-related and temperature response genes follow the same expression changes as during the torpor-arousal cycle. Increased fatty acid metabolism occurs during hibernation but not during ischemia-reperfusion injury in mice and, thus, might contribute to protection against ischemia-reperfusion during hibernation. Conclusions In this study, we systematically compared hibernation with alternative phenotypes to reveal novel mechanisms that might be used therapeutically in human pathological conditions. PMID:23957789

  2. A Comparison of State Alternative Education Accountability Policies and Frameworks

    ERIC Educational Resources Information Center

    Schlessman, Amy; Hurtado, Kelly

    2012-01-01

    The purpose of this policy study was to report descriptive research on state-level policy and frameworks for accountability systems of alternative education in the United States. The six states; California, Colorado, Texas, Florida, Oklahoma, and North Carolina; identified in the 2010 Jobs for the Futures policy analysis of alternative education…

  3. A Comparison of Alienation among Alternatively and Traditionally Certified Teachers.

    ERIC Educational Resources Information Center

    Shoho, Alan R.; Martin, Nancy K.

    The purpose of this study was to investigate the perceptions of alienation among alternatively and traditionally certified teachers. A total of 228 teachers in grades K-12 from a public university offering both traditional certification (TC) and cooperative alternative certification (AC) graduate programs were assessed using the School Alienation…

  4. An alternative LEU design for the FRM-II

    SciTech Connect

    Hanan, N.A.; Mo, S.C.; Smith, R.S.; Matos, J.E.

    1997-02-01

    The Alternative LEU Design for the FRM-II proposed by the RERTR Program at Argonne National Laboratory (ANL) has a compact core consisting of a single fuel element that uses LEU silicide fuel with a uranium density of 4.5 g/cm[sup 3] and has a power level of 32 MW. Both the HEU design by the Technical University of Munich (TUM) and the alternative LEU design by ANL have the same fuel lifetime (50 days) and the same neutron flux performance (8 x 10[sup 14] n/cm[sup 2]/s in the reflector). LEU silicide fuel with 4.5 g/cm[sup 3] has been thoroughly tested and is fully-qualified, licensable, and available now for use in a high flux reactor such as the FRM-II. Computer models for the HEU and LEU designs have been exchanged between TUM and ANL and discrepancies have been resolved. The following issues are addressed: qualification of HEU and LEU silicide fuels, stability of the fuel plates, gamma heating in the heavy water reflector, a hypothetical accident involving the configuration of the reflector, a loss of primary coolant flow transient due to an interrupted power supply, the radiological consequences of larger fission product and plutonium inventories in the LEU core, and cost and schedule. Calculations were also done to address the possibility that new high density LEU fuels could be developed that would allow conversion of the TUM HEU design to LEU fuel. Based on the excellent results for the Alternative LEU Design that were obtained in these analyses, the RERTR Program concludes that all of the major technical issues regarding use of LEU fuel instead of HEU fuel in the FRM-II have been successfully resolved and that it is definitely feasible to use LEU fuel in the FRM-II without compromising the safety or performance of the facility.

  5. Electromagnetic interference reduction design of alternating integrator for EAST

    NASA Astrophysics Data System (ADS)

    Liu, D. M.; Wan, B. N.; Li, J.; Wang, Y.; Shen, B.; Gong, X. Z.; He, Y. G.

    2016-11-01

    An alternating integrator has been designed for the Experimental Advanced Superconducting Tokamak that is intended for long pulse operation of up to 1000 s. The electromagnetic operating environment for the device is so complex that it could affect the performance of the integrator. The new integrator system is carefully designed and actualized based on specific reduced electromagnetic interference requirements, which were formulated based on consideration of processing of the input signals, the isolation properties, and the circuit board layout and grounding. The developed integrator shows excellent electromagnetic compatibility and low-drift properties.

  6. Economic evaluation and comparison of alternative limestone-scrubbing options

    SciTech Connect

    Burnett, T.A.; Torstrick, R.L.; Sudhoff, F.A.

    1982-01-01

    The preliminary-grade economics (accuracy: -15%, +30%) of various alternative limestone scrubbing options (absorber type, with and without forced oxidation, and with and without adipic acid enhancement) are examined using the current design and economic premises established for the continuing series of economic evaluations performed by TVA for EPA. The economics are projected using the Shawnee lime/limestone computer model, which is based on long-term operating data from the EPA Alkali Scrubbing Test Facility at the TVA Shawnee Steam Plant near Paducah, Kentucky. The capital investment for the base-case limestone scrubbing process (500 MW, 3.5% sulfur coal, 1979 NSPS, spray tower, forced oxidation, landfill) is $206/kW. The first-year and levelized annual revenue requirements are 10.59 and 15.09 mills/kWh respectively. Costs for the equivalent limestone scrubbing process using a Turbulent Contact Absorber (TCA) are lower while those for the venturi - spray tower absorber are higher. The forced-oxidation landfill disposal option has a lower capital investment than the unoxidized pond disposal option for all cases studied; however, the first-year and levelized annual revenue requirements are slightly higher for the forced-oxidation landfill process for most coal applications. For the spray tower limestone process to achieve a specified SO/sub 2/ removal efficiency, it is more economical to increase the limestone stoichiometry and minimize the absorber L/G. The use of adipic acid or possibly dibasic acid (DBA) as an additive to enhance SO/sub 2/ removal in the limestone scrubbing process is an economically attractive option. The use of adipic acid remains economically attractive even if both a high unit cost and a high degradation factor for adpic acid are assumbed.

  7. Interview Design for Ratio Comparison Tasks

    ERIC Educational Resources Information Center

    Alatorre, Silvia; Figueras, Olimpia

    2003-01-01

    In this article, which is part of an ongoing research, a classification is proposed for ratio comparison problems, according to their context, their quantity type, and their numerical structure. Deriving from this classification, an interview protocol was designed, and guidelines for the interpretation of answers into strategies were decided. A…

  8. An alternative LEU design for the FRM-II

    SciTech Connect

    Hanan, N.A.; Mo, S.C.; Smith, R.S.; Matos, J.E.

    1996-12-01

    The Alternative LEU Design for the FRM-II proposed by the RERTR Program at Argonne National Laboratory (ANL) has a compact core consisting of a single fuel element that uses LEU silicide fuel with a uranium density of 4.5 g/cm{sup 3} and has a power level of 32 MW. Both the HEU design by the Technical University of Munich (TUM) and the alternative LEU design by ANL have the same fuel lifetime (50 days) and the same neutron flux performance. LEU silicide fuel with 4.5 g/cm{sup 3} has been thoroughly tested and is fully-qualified, licensable, and available now for use in a high flux reactor such as the FRM-II. The following issues raised by TUM were addressed in Ref. 1: qualification of HEU and LEU silicide fuels, gamma heating in the heavy water reflector, radiological consequences of larger fission product and plutonium inventories in the LEU core, and cost and schedule. The conclusions of these analyses are summarized below. This paper addresses three additional safety issues that were raised by TUM in Ref. 2: stability of the involute fuel plates, a hypothetical accident involving the configuration of the reflector, and a loss of primary coolant flow transient due to an interrupted power supply. Based on the excellent results for the Alternative LEU Design that were obtained in these analyses, the RERTR Program concludes that all of the major technical issues regarding use of LEU fuel instead of HEU fuel in the FRM-II have been successfully resolved and that it is definitely feasible to use LEU fuel in the FRM-II without compromising the safety or performance of the facility.

  9. Design and application of an alternative groundwater sparging technology

    SciTech Connect

    Schrauf, T.W.; Pennington, L.H.

    1995-12-31

    Density-driven convection, an alternative method of in situ groundwater sparging, is being used to remediate 27 underground storage tank releases involving a wide distillation range of petroleum hydrocarbons (gasoline to waste oil) in a variety of site soils (silty clay to sandy gravel). The described method overcomes many of the inherent disadvantages of air sparging methods currently in use (such as pressurized injection) without additional complexity in design, installation, or operation. The principles of operation and design for density-driven convection are discussed in detail and supported by field and laboratory studies. Primary factors affecting the hydraulic driving force, groundwater circulation patterns around the sparging well, and air stripping performance are identified and related to system design. The effectiveness of the system is demonstrated with results from full-scale system installations.

  10. Arizona Public Service - Alternative Fuel (Hydrogen) Pilot Plant Design Report

    SciTech Connect

    James E. Francfort

    2003-12-01

    Hydrogen has promise to be the fuel of the future. Its use as a chemical reagent and as a rocket propellant has grown to over eight million metric tons per year in the United States. Although use of hydrogen is abundant, it has not been used extensively as a transportation fuel. To assess the viability of hydrogen as a transportation fuel and the viability of producing hydrogen using off-peak electric energy, Pinnacle West Capital Corporation (PNW) and its electric utility subsidiary, Arizona Public Service (APS) designed, constructed, and operates a hydrogen and compressed natural gas fueling station—the APS Alternative Fuel Pilot Plant. This report summarizes the design of the APS Alternative Fuel Pilot Plant and presents lessons learned from its design and construction. Electric Transportation Applications prepared this report under contract to the U.S. Department of Energy’s Advanced Vehicle Testing Activity. The Idaho National Engineering and Environmental Laboratory manages these activities for the Advanced Vehicle Testing Activity.

  11. Numerical simulation in alternating current field measurement inducer design

    NASA Astrophysics Data System (ADS)

    Zhou, Zhixiong; Zheng, Wenpei

    2017-02-01

    The present work develops a numerical simulation model to evaluate the magnetic field perturbation of a twin coil alternating current field measurement (ACFM) inducer passing above a surface-breaking crack for the purpose of enhanced crack detection. Model predictions show good agreement with experimental data, verifying the accuracy of the model. The model includes the influence of various parameters, such as core dimensions and core positions on the perturbed magnetic field above a crack. Optimized design parameters for a twin coil inducer are given according to the analysis results, which provide for a greatly improved detection effect.

  12. An Evaluation of Alternative Designs for a Grid Information Service

    NASA Technical Reports Server (NTRS)

    Smith, Warren; Waheed, Abdul; Meyers, David; Yan, Jerry; Kwak, Dochan (Technical Monitor)

    2001-01-01

    The Globus information service wasn't working well. There were many updates of data from Globus daemons which saturated the single server and users couldn't retrieve information. We created a second server for NASA and Alliance. Things were great on that server, but a bit slow on the other server. We needed to know exactly how the information service was being used. What were the best servers and configurations? This viewgraph presentation gives an overview of the evaluation of alternative designs for a Grid Information Service. Details are given on the workload characterization, methodology used, and the performance evaluation.

  13. Comparison of translation loads for standard and alternative genetic codes

    PubMed Central

    2010-01-01

    Background The (almost) universality of the genetic code is one of the most intriguing properties of cellular life. Nevertheless, several variants of the standard genetic code have been observed, which differ in one or several of 64 codon assignments and occur mainly in mitochondrial genomes and in nuclear genomes of some bacterial and eukaryotic parasites. These variants are usually considered to be the result of non-adaptive evolution. It has been shown that the standard genetic code is preferential to randomly assembled codes for its ability to reduce the effects of errors in protein translation. Results Using a genotype-to-phenotype mapping based on a quantitative model of protein folding, we compare the standard genetic code to seven of its naturally occurring variants with respect to the fitness loss associated to mistranslation and mutation. These fitness losses are computed through computer simulations of protein evolution with mutations that are either neutral or lethal, and different mutation biases, which influence the balance between unfolding and misfolding stability. We show that the alternative codes may produce significantly different mutation and translation loads, particularly for genomes evolving with a rather large mutation bias. Most of the alternative genetic codes are found to be disadvantageous to the standard code, in agreement with the view that the change of genetic code is a mutationally driven event. Nevertheless, one of the studied alternative genetic codes is predicted to be preferable to the standard code for a broad range of mutation biases. Conclusions Our results show that, with one exception, the standard genetic code is generally better able to reduce the translation load than the naturally occurring variants studied here. Besides this exception, some of the other alternative genetic codes are predicted to be better adapted for extreme mutation biases. Hence, the fixation of alternative genetic codes might be a neutral or nearly

  14. 40 CFR 96.312 - Changing CAIR designated representative and alternate CAIR designated representative; changes in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Designated Representative for CAIR NOX Ozone Season Sources § 96.312 Changing CAIR designated representative... CAIR NOX Ozone Season source and the CAIR NOX Ozone Season units at the source. (b) Changing alternate... representative and the owners and operators of the CAIR NOX Ozone Season source and the CAIR NOX Ozone...

  15. 40 CFR 96.312 - Changing CAIR designated representative and alternate CAIR designated representative; changes in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Designated Representative for CAIR NOX Ozone Season Sources § 96.312 Changing CAIR designated representative... CAIR NOX Ozone Season source and the CAIR NOX Ozone Season units at the source. (b) Changing alternate... representative and the owners and operators of the CAIR NOX Ozone Season source and the CAIR NOX Ozone...

  16. 40 CFR 96.312 - Changing CAIR designated representative and alternate CAIR designated representative; changes in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Designated Representative for CAIR NOX Ozone Season Sources § 96.312 Changing CAIR designated representative... CAIR NOX Ozone Season source and the CAIR NOX Ozone Season units at the source. (b) Changing alternate... representative and the owners and operators of the CAIR NOX Ozone Season source and the CAIR NOX Ozone...

  17. 40 CFR 96.312 - Changing CAIR designated representative and alternate CAIR designated representative; changes in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Designated Representative for CAIR NOX Ozone Season Sources § 96.312 Changing CAIR designated representative... CAIR NOX Ozone Season source and the CAIR NOX Ozone Season units at the source. (b) Changing alternate... representative and the owners and operators of the CAIR NOX Ozone Season source and the CAIR NOX Ozone...

  18. 40 CFR 96.312 - Changing CAIR designated representative and alternate CAIR designated representative; changes in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Designated Representative for CAIR NOX Ozone Season Sources § 96.312 Changing CAIR designated representative... CAIR NOX Ozone Season source and the CAIR NOX Ozone Season units at the source. (b) Changing alternate... representative and the owners and operators of the CAIR NOX Ozone Season source and the CAIR NOX Ozone...

  19. Comparison of Alternative Gravity Models in Dwarf Galaxy Rotation Curves

    NASA Astrophysics Data System (ADS)

    Harrington, Justin; Saintable, Taylor; O'Brien, James

    2017-01-01

    Galactic rotation curves have proven to be the testing ground for dark matter bounds in spiral galaxies of all morphologies. Dwarf Galaxies serve as an increasingly interesting testing ground of rotation curve dynamics due to their increased stellar formation and typically rising rotation curve. These galaxies usually are not dominated by typical stellar structure and mostly terminate at small radial distances. This, coupled with the fact that Cold Dark Matter theories such as NFW (∧ CDM) struggle with the universality of galactic rotation curves, allow for exclusive features of alternative gravitational models to be analyzed. Here, we present a thorough application of alternative gravitational models (conformal gravity and MOND) to a 2010 dwarf galaxy sample from Swaters et al. An analysis and discussion of the results of the fitting procedure of the two alternative gravitational models are explored. We posit here that both the Conformal Gravity and MOND can provide an accurate description of the galactic dynamics without the need for copious dark matter.

  20. Alternative comparison, analysis, and evaluation of solid waste and materials system alternatives

    SciTech Connect

    Brothers, A.J.

    1995-09-01

    This paper presents a comprehensive analysis of the impact of solid waste technical options on values and objectives that are important to the public. It is written in support of the Solid Waste and Materials Systems Alternatives Study (WHC, 1995). Described are the values that were identified, the major programmatic risks, how the impacts were measured, the performance of alternatives, the methodology used for the analysis, and the implications of the results. Decision analysis was used to guide the collection and analysis of data and the logic of the evaluation. Decision analysis is a structured process for the analysis and evaluation of alternatives. It is theoretically grounded in a set of axioms that capture the basic principles of decision making (von Neuman and Morgenstern 1947). Decision analysis objectively specifies what factors are to be considered, how they are to be measured and evaluated, and heir relative importance. The result is an analysis in which the underlying rationale or logic upon which the decision is based is made explicit. This makes possible open discussion of the decision basis in which facts and values are clearly distinguished, resulting in a well- documented decision that can be clearly explained and justified. The strategy of decision analysis is to analyze the various components relevant to the decision separately and then integrate the individual judgments to arrive at an overall decision. This assures that all the relevant factors are identified and their relative importance is considered. The procedure for obtaining the individual judgments, and the decision rules, for combining them and evaluating alternatives, have both theoretical and empirical foundation in mathematics, economics, and psychology.

  1. Comparison of alternative parameters to dual polarimetric SAR data

    NASA Astrophysics Data System (ADS)

    Sugimoto, Mitsunobu; Ouchi, Kazuo

    2012-09-01

    The goal of this study is to examine the potential of deriving information comparable to quad-polarization synthetic aperture radar (SAR) data from dual-polarization data. Multi-polarization data have shown the potential to increase further the ability of extracting physical quantities of observation targets. Above all, quad-polarization data have more information than others, but they are relatively few in number compared with single or dual-polarization data. Although there are many SAR systems capable of quad-polarization observation, most of them are operated mainly on single or dual-polarization mode because of limited data transfer rate, area of coverage, required resolution, other system restriction, and so on. Thus, there is a certain trade- off between data availability and multi polarization. Therefore, we focused on dual-polarization as a good compromise between single and quad-polarization data. In this study, we investigated possible alternative parameters that can be derived from HH-VV dual-polarization data and can serve as substitutes for cross-polarization component in quad-polarization data. Experiments are performed using the Advanced Land Observation Satellite-Phased Array L-band SAR (ALOS-PALSAR) quad-polarization data. The cross polarization component in the data is used as benchmark for the alternative parameters.

  2. A Life-Cycle Comparison of Alternative Automobile Fuels.

    PubMed

    MacLean, Heather L; Lave, Lester B; Lankey, Rebecca; Joshi, Satish

    2000-10-01

    We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C2H5OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C2H5OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable, and

  3. A life-cycle comparison of alternative automobile fuels.

    PubMed

    MacLean, H L; Lave, L B; Lankey, R; Joshi, S

    2000-10-01

    We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C2H5OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C2H5OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable, and

  4. A Cost Comparison of Alternative Approaches to Distance Education in Developing Countries

    NASA Technical Reports Server (NTRS)

    Ventre, Gerard G.; Kalu, Alex

    1996-01-01

    This paper presents a cost comparison of three approaches to two-way interactive distance learning systems for developing countries. Included are costs for distance learning hardware, terrestrial and satellite communication links, and designing instruction for two-way interactive courses. As part of this project, FSEC is developing a 30-hour course in photovoltaic system design that will be used in a variety of experiments using the Advanced Communications Technology Satellite (ACTS). A primary goal of the project is to develop an instructional design and delivery model that can be used for other education and training programs. Over two-thirds of the world photovoltaics market is in developing countries. One of the objectives of this NASA-sponsored project was to develop new and better energy education programs that take advantage of advances in telecommunications and computer technology. The combination of desktop video systems and the sharing of computer applications software is of special interest. Research is being performed to evaluate the effectiveness of some of these technologies as part of this project. The design of the distance learning origination and receive sites discussed in this paper were influenced by the educational community's growing interest in distance education. The following approach was used to develop comparative costs for delivering interactive distance education to developing countries: (1) Representative target locations for receive sites were chosen. The originating site was assumed to be Cocoa, Florida, where FSEC is located; (2) A range of course development costs were determined; (3) The cost of equipment for three alternative two-way interactive distance learning system configurations was determined or estimated. The types of system configurations ranged from a PC-based system that allows instructors to originate instruction from their office using desktop video and shared application software, to a high cost system that uses a

  5. Comparison of alternate personality models in psychopathology assessment.

    PubMed

    Floros, Georgios D; Stogiannidou, Ariadni; Giouzepas, Ioannis; Garyfallos, Georgios D

    2014-10-01

    This study assessed the results from the parallel application of two alternate personality models, the Zuckerman-Kuhlman trait model and Bond's Defense Styles, in a sample of 268 Greek medical students (172 women, M age = 22.0 yr., SD = 1.1; 95 men, M age = 22.3 yr., SD = 1.2) in relation to psychopathological symptoms, so as to clarify whether this practice yielded accurate results while avoiding shared variance. Data from both models are cross-checked with canonical correlation analysis to validate whether there was significant conceptual overlap between them that would mean that their parallel use is an ineffective research practice. Following this analysis, factors from both models are utilized to predict variance in sample psychopathology, so as to compare their relative usefulness. Results indicated that the two models did not share a significant amount of variance, while a combination of personality aspects from both models, including Impulsive Sensation-Seeking, Neuroticism-Anxiety, Aggression-Hostility, and Sociability traits and Maladaptive Action, Image Distorting, and Adaptive Action defense styles, predicted high variance in psychopathology symptoms.

  6. Comparison of alternative concepts for lunar surface transportation

    NASA Astrophysics Data System (ADS)

    Apel, Uwe

    The lunar surface transportation system is a key element in lunar development. The decision which means of conveyance should be preferred depends on a lot of influencing factors such as transportation requirements, physical boundary conditions and economics. Starting with a systematic approach to define and structure the problem, a model to compare alternative transportation systems has been built. From the pool of possible means of conveyance, chemical rockets, electric cars, maglev-trains and mass-drivers have been chosen as candidates for investigation. With these candidates five different surface transportation systems were defined. For a reference lunar development scenario the systems were compared on the basis of a cost-to-benefit ratio. Preliminary results indicate that under the assumption that LH2 could be produced on lunar surface, LOX/LH2 propulsed "Hoppers" seem very attractive up to medium transportation demands. For large amounts of bulk cargo, mass driver transportation seems to have advantages, and electric cars should be used for all transportation tasks if the transportation demand is high. Maglev-trains seem to be competitive only for very large transportation demand and long life cycles.

  7. NASA Alternative Orion Small Cell Battery Design Support

    NASA Technical Reports Server (NTRS)

    Haynes, Chuck

    2016-01-01

    and analysis were completed and reviewed for endorsement by NASA Engineering and Safety Center team members. All Key Test Objectives were met and the small cell design alternative was demonstrated and selected to be a feasible drop in replacement for the MPCV Orion CM Battery for EM2 mission.

  8. Valley Fill Design and Construction Alternatives to Improve Ecological Performance

    EPA Pesticide Factsheets

    This presentation discusses; current challenges, comprehensive approaches, BMPs, the Middlefork Development, the Guy Cove project, and a path forward when looking at construction alternatives to improve the ecological performance of valley fills.

  9. Need for alternative trial designs and evaluation strategies for therapeutic studies of invasive mycoses.

    PubMed

    Rex, J H; Walsh, T J; Nettleman, M; Anaissie, E J; Bennett, J E; Bow, E J; Carillo-Munoz, A J; Chavanet, P; Cloud, G A; Denning, D W; de Pauw, B E; Edwards Jr, J E; Hiemenz, J W; Kauffman, C A; Lopez-Berestein, G; Martino, P; Sobel, J D; Stevens, D A; Sylvester, R; Tollemar, J; Viscoli, C; Viviani, M A; Wu, T

    2001-07-01

    Studies of invasive fungal infections have been and remain difficult to implement. Randomized clinical trials of fungal infections are especially slow and expensive to perform because it is difficult to identify eligible patients in a timely fashion, to prove the presence of the fungal infection in an unequivocal fashion, and to evaluate outcome in a convincing fashion. Because of these challenges, licensing decisions for antifungal agents have to date depended heavily on historical control comparisons and secondary advantages of the new agent. Although the availability of newer and potentially more effective agents makes these approaches less desirable, the fundamental difficulties of trials of invasive fungal infections have not changed. Therefore, there is a need for alternative trial designs and evaluation strategies for therapeutic studies of invasive mycoses, and this article summarizes the possible strategies in this area.

  10. An alternative to gamma histograms for ROI-based quantitative dose comparisons.

    PubMed

    Dvorak, P

    2009-06-21

    An alternative to gamma (gamma) histograms for ROI-based quantitative comparisons of dose distributions using the gamma concept is proposed. The method provides minimum values of dose difference and distance-to-agreement such that a pre-set fraction of the region of interest passes the gamma test. Compared to standard gamma histograms, the method provides more information in terms of pass rate per gamma calculation. This is achieved at negligible additional calculation cost and without loss of accuracy. The presented method is proposed as a useful and complementary alternative to standard gamma histograms, increasing both the quantity and quality of information for use in acceptance or rejection decisions.

  11. Modular Design/Phased Construction Alternative Evaluation Report

    SciTech Connect

    Schwartztrauber, K.

    1999-05-28

    Modular design concepts are being considered for the license application during the surface facility design phase of the Monitored Geologic Repository (MGR). The Viability Assessment (VA) design is used as the reference design for the report. The primary objectives are to spread construction of the WHB and the subsurface repository over time to reduce annual project costs, and to provide a cost-effective design for the surface facilities that supports waste emplacement starting in the year 2010.

  12. Drift Eliminating Designs for Non-Simultaneous Comparison Calibrations.

    PubMed

    Doiron, Ted

    1993-01-01

    The effects of drift on calibrations carried out by comparison have been studied at the National Institute of Standards and Technology for many years, and a number of strategies have been introduced to combat these effects. One strategy, the use of comparison designs which are inherently immune to linear drift, was developed specifically for mass comparison measurements. These techniques, developed for simultaneous comparisons, are extended to the case of non-simultaneous comparisons, such as gage block calibrations, where each artifact is measured separately, and the comparison is made mathematically from the individual measurements.

  13. Drift Eliminating Designs for Non-Simultaneous Comparison Calibrations

    PubMed Central

    Doiron, Ted

    1993-01-01

    The effects of drift on calibrations carried out by comparison have been studied at the National Institute of Standards and Technology for many years, and a number of strategies have been introduced to combat these effects. One strategy, the use of comparison designs which are inherently immune to linear drift, was developed specifically for mass comparison measurements. These techniques, developed for simultaneous comparisons, are extended to the case of non-simultaneous comparisons, such as gage block calibrations, where each artifact is measured separately, and the comparison is made mathematically from the individual measurements. PMID:28053468

  14. Alternative positron-target design for electron-positron colliders

    SciTech Connect

    Donahue, R.J. ); Nelson, W.R. )

    1991-04-01

    Current electron-positron linear colliders are limited in luminosity by the number of positrons which can be generated from targets presently used. This paper examines the possibility of using an alternate wire-target geometry for the production of positrons via an electron-induced electromagnetic cascade shower. 39 refs., 38 figs., 5 tabs.

  15. Designing and Implementing Effective In-School Alternatives to Suspension.

    ERIC Educational Resources Information Center

    Mizell, M. Hayes

    Because of widespread disillusion with suspension as a discipline procedure, school officials are developing inschool alternative programs. Institution of such a program must begin with reflection about how current disciplinary programs are succeeding or failing. The primary purposes of the program must include helping the child and identifying…

  16. Alternate space shuttle concepts study: Design requirements and phased programs evaluation

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A study to determine program and technical alternatives to the design of the space shuttle orbiter is described. The alternatives include a phased approach, involving orbiter development and operation with an expendable booster for an interim period, as well as design variations to the basic vehicle. The space shuttle orbiter configurations and predicted performance parameters are presented.

  17. Comparison of oil removal in surfactant alternating gas with water alternating gas, water flooding and gas flooding in secondary oil recovery process

    PubMed Central

    Salehi, Mehdi Mohammad; Safarzadeh, Mohammad Amin; Sahraei, Eghbal; Nejad, Seyyed Alireza Tabatabaei

    2014-01-01

    Growing oil prices coupled with large amounts of residual oil after operating common enhanced oil recovery methods has made using methods with higher operational cost economically feasible. Nitrogen is one of the gases used in both miscible and immiscible gas injection process in oil reservoir. In heterogeneous formations gas tends to breakthrough early in production wells due to overriding, fingering and channeling. Surfactant alternating gas (SAG) injection is one of the methods commonly used to decrease this problem. Foam which is formed on the contact of nitrogen and surfactant increases viscosity of injected gas. This increases the oil–gas contact and sweep efficiency, although adsorption of surfactant on rock surface can causes difficulties and increases costs of process. Many parameters must be considered in design of SAG process. One of the most important parameters is SAG ratio that should be in optimum value to improve the flooding efficiency. In this study, initially the concentration of surfactant was optimized due to minimization of adsorption on rock surface which results in lower cost of surfactant. So, different sodium dodecyl sulfate (SDS) concentrations of 100, 500, 1000, 2000, 3000 and 4000 ppm were used to obtain the optimum concentration at 70 °C and 144.74×105 Pa. A simple, clean and relatively fast spectrophotometric method was used for determination of surfactant which is based on the formation of an ion-pair. Then the effect of surfactant to gas volume ratio on oil recovery in secondary oil recovery process during execution of immiscible surfactant alternating gas injection was examined experimentally. The experiments were performed with sand pack under certain temperature, pressure and constant rate. Experiments were performed with surfactant to gas ratio of 1:1, 1:2, 1:3, 2:1 and 3:1 and 1.2 pore volume injected. Then, comparisons were made between obtained results (SAG) with water flooding, gas flooding and water alternating gas

  18. Comparison of oil removal in surfactant alternating gas with water alternating gas, water flooding and gas flooding in secondary oil recovery process.

    PubMed

    Salehi, Mehdi Mohammad; Safarzadeh, Mohammad Amin; Sahraei, Eghbal; Nejad, Seyyed Alireza Tabatabaei

    2014-08-01

    Growing oil prices coupled with large amounts of residual oil after operating common enhanced oil recovery methods has made using methods with higher operational cost economically feasible. Nitrogen is one of the gases used in both miscible and immiscible gas injection process in oil reservoir. In heterogeneous formations gas tends to breakthrough early in production wells due to overriding, fingering and channeling. Surfactant alternating gas (SAG) injection is one of the methods commonly used to decrease this problem. Foam which is formed on the contact of nitrogen and surfactant increases viscosity of injected gas. This increases the oil-gas contact and sweep efficiency, although adsorption of surfactant on rock surface can causes difficulties and increases costs of process. Many parameters must be considered in design of SAG process. One of the most important parameters is SAG ratio that should be in optimum value to improve the flooding efficiency. In this study, initially the concentration of surfactant was optimized due to minimization of adsorption on rock surface which results in lower cost of surfactant. So, different sodium dodecyl sulfate (SDS) concentrations of 100, 500, 1000, 2000, 3000 and 4000 ppm were used to obtain the optimum concentration at 70 °C and 144.74×10(5) Pa. A simple, clean and relatively fast spectrophotometric method was used for determination of surfactant which is based on the formation of an ion-pair. Then the effect of surfactant to gas volume ratio on oil recovery in secondary oil recovery process during execution of immiscible surfactant alternating gas injection was examined experimentally. The experiments were performed with sand pack under certain temperature, pressure and constant rate. Experiments were performed with surfactant to gas ratio of 1:1, 1:2, 1:3, 2:1 and 3:1 and 1.2 pore volume injected. Then, comparisons were made between obtained results (SAG) with water flooding, gas flooding and water alternating gas

  19. Alternating phase-shifted mask for logic gate levels, design, and mask manufacturing

    NASA Astrophysics Data System (ADS)

    Liebmann, Lars W.; Graur, Ioana C.; Leipold, William C.; Oberschmidt, James M.; O'Grady, David S.; Regaill, Denis

    1999-07-01

    While the benefits of alternating phase shifted masks in improving lithographic process windows at increased resolution are well known throughout the lithography community, broad implementation of this potentially powerful technique has been slow due to the inherent complexity of the layout design and mask manufacturing process. This paper will review a project undertaken at IBM's Semiconductor Research and Development Center and Mask Manufacturing and Development facility to understand the technical and logistical issues associated with the application of alternating phase shifted mask technology to the gate level of a full microprocessor chip. The work presented here depicts an important milestone toward integration of alternating phase shifted masks into the manufacturing process by demonstrating an automated design solution and yielding a functional alternating phase shifted mask. The design conversion of the microprocessor gate level to a conjugate twin shifter alternating phase shift layout was accomplished with IBM's internal design system that automatically scaled the design, added required phase regions, and resolved phase conflicts. The subsequent fabrication of a nearly defect free phase shifted mask, as verified by SEM based die to die inspection, highlights the maturity of the alternating phase shifted mask manufacturing process in IBM's internal mask facility. Well defined and recognized challenges in mask inspection and repair remain and the layout of alternating phase shifted masks present a design and data preparation overhead, but the data presented here demonstrate the feasibility of designing and building manufacturing quality alternating phase shifted masks for the gate level of a microprocessor.

  20. Design Alternatives for a Free Electron Laser Facility

    SciTech Connect

    Jacobs, K; Bosch, R A; Eisert, D; Fisher, M V; Green, M A; Keil, R G; Kleman, K J; Kulpin, J G; Rogers, G C; Wehlitz, R; Chiang, T; Miller, T J; Lawler, J E; Yavuz, D; Legg, R A; York, R C

    2012-07-01

    The University of Wisconsin-Madison is continuing design efforts for a vacuum ultraviolet/X-ray Free Electron Laser facility. The design incorporates seeding the FEL to provide fully coherent photon output at energies up to {approx}1 keV. The focus of the present work is to minimize the cost of the facility while preserving its performance. To achieve this we are exploring variations in the electron beam driver for the FEL, in undulator design, and in the seeding mechanism. Design optimizations and trade-offs between the various technologies and how they affect the FEL scientific program will be presented.

  1. EDIN design study alternate space shuttle booster replacement concepts. Volume 2: Design simulation results

    NASA Technical Reports Server (NTRS)

    Demakes, P. T.; Hirsch, G. N.; Stewart, W. A.; Glatt, C. R.

    1976-01-01

    Historical weight estimating relationships were developed for the liquid rocket booster (LRB) using Saturn technology, and modified as required to support the EDIN05 study. Mission performance was computed using February 1975 shuttle configuration groundrules to allow reasonable comparison of the existing shuttle with the EDIN05 designs. The launch trajectory was constrained to pass through both the RTLS/AOA and main engine cut-off points. Performance analysis was based on a point design trajectory model which optimized initial tilt rate and exo-atmospheric pitch profile. A gravity turn was employed during the boost phase in place of the shuttle angle-of-attack profile. Engine throttling add/or shutdown was used to constrain dynamic pressure and/or longitudinal acceleration where necessary.

  2. 46 CFR 177.340 - Alternate design considerations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... structure of vessel is of novel design, unusual form, or special materials, which cannot be reviewed or... principles that the structure provides adequate safety and strength. The owner shall submit detailed plans, material component specifications, and design criteria, including the expected operating...

  3. 46 CFR 177.340 - Alternate design considerations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... structure of vessel is of novel design, unusual form, or special materials, which cannot be reviewed or... principles that the structure provides adequate safety and strength. The owner shall submit detailed plans, material component specifications, and design criteria, including the expected operating...

  4. 46 CFR 177.340 - Alternate design considerations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... structure of vessel is of novel design, unusual form, or special materials, which cannot be reviewed or... that the structure provides adequate safety and strength. The owner shall submit detailed plans, material component specifications, and design criteria, including the expected operating...

  5. RIP Input Tables from WAPDEG for LA Design Selection: Enhanced Design Alternative II-3

    SciTech Connect

    A.M. Monib

    1999-08-24

    The purpose of this calculation is to document (1) the Waste Package Degradation (WAPDEG) version 3.09 (CRWMS M&O 1998b. ''Software Routine Report for WAPDEG'' (Version 3.09)) simulations used to analyze degradation and failure of 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields (that are placed over waste packages composed of a 2-cm thick Alloy 22 corrosion resistant material (CRM) as the outer barrier and an unspecified material to provide structural support as the inner barrier) as well as degradation and failure of the waste packages themselves, and (2) post-processing of these results into tables of drip shield/waste package degradation time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems (RIP) version 5.19.01 (Golder Associates 1998) computer code. This calculation supports Performance Assessment analysis of the License Application Design Selection (LADS) Enhanced Design Alternative (EDA) II-3. The aging period in the EDA II design (CRWMS M&O 1999f. ''Design Input Request for LADS Phase II EDA Evaluations'', Item 1 Row 9 Column 3) was replaced in the case of EDA II-3 with 25 years preclosure ventilation, leading to a total of 50 years preclosure ventilation. The waste packages are line loaded in the repository and no backfill is used.

  6. Implications of solar energy alternatives for community design

    SciTech Connect

    Santos, A.; Steinitz, C.

    1980-06-01

    A graduate-level studio at the Harvard School of Design explored how a policy of solar-based energy independence will influence the design of a new community of approximately 4500 housing units and other uses. Three large sites outside Tucson (a cooling problem), Atlanta (a humidity problem), and Boston (a heating problem) were selected. Each is typical of its region. A single program was assumed and designed for. Each site had two teams, one following a compact approach and one following a more dispersed approach. Each was free to choose the most appropriate mix of (solar) technology and scale, and was free to integrate energy and community in the design as it saw fit. These choice and integration issues are key areas where our experience may be of interest to those involved in community design and solar energy.

  7. NPS alternate techsat satellite, design project for AE-4871

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This project was completed as part of AE-4871, Advanced Spacecraft Design. The intent of the course is to provide experience in the design of all the major components in a spacecraft system. Team members were given responsibility for the design of one of the six primary subsystems: power, structures, propulsion, attitude control, telemetry, tracking and control (TT&C), and thermal control. In addition, a single member worked on configuration control, launch vehicle integration, and a spacecraft test plan. Given an eleven week time constraint, a preliminary design of each subsystem was completed. Where possible, possible component selections were also made. Assistance for this project came principally from the Naval Research Laboratory's Spacecraft Technology Branch. Specific information on components was solicited from representatives in industry. The design project centers on a general purpose satellite bus that is currently being sought by the Strategic Defense Initiative.

  8. The Validity and Precision of the Comparative Interrupted Time-Series Design: Three Within-Study Comparisons

    ERIC Educational Resources Information Center

    St. Clair, Travis; Hallberg, Kelly; Cook, Thomas D.

    2016-01-01

    We explore the conditions under which short, comparative interrupted time-series (CITS) designs represent valid alternatives to randomized experiments in educational evaluations. To do so, we conduct three within-study comparisons, each of which uses a unique data set to test the validity of the CITS design by comparing its causal estimates to…

  9. An Alternating Treatment Comparison of Minimal and Maximal Opposition Sound Selection in Turkish Phonological Disorders

    ERIC Educational Resources Information Center

    Topbas, Seyhun; Unal, Ozlem

    2010-01-01

    A single-subject alternating treatment design in combination with a staggered multiple baseline model across subjects was implemented with two 6:0 year-old girls, monozygotic twins, who were referred to a university clinic for evaluation and treatment. The treatment programme was structured according to variants of "minimal pair contrast…

  10. Alternative Spring Break at the Savannah College of Art and Design: Engaging Art and Design Students in Community Service

    ERIC Educational Resources Information Center

    Hoey, J. Joseph; Feld-Gore, Jeffrey A.

    2014-01-01

    This chapter describes the impact of an alternative spring break program on students at the Savannah College of Art and Design over a set of years as well as its effectiveness as a service-learning tool.

  11. Design element alternatives for stress-management intervention websites.

    PubMed

    Williams, Reg A; Gatien, Gary; Hagerty, Bonnie

    2011-01-01

    Typical public and military-sponsored websites on stress and depression tend to be prescriptive. Some require users to complete lengthy questionnaires. Others reproduce printed flyers, papers, or educational materials not adapted for online use. Some websites require users to follow a prescribed path through the material. Stress Gym was developed as a first-level, evidence-based, website intervention to help U.S. military members learn how to manage mild to moderate stress and depressive symptoms using a self-help intervention with progress tracking and 24/7 availablility. It was designed using web-based, health-management intervention design elements that have been proven effective and users reported they prefer. These included interactivity, self-pacing, and pleasing aesthetics. Users learned how to manage stress by accessing modules they choose, and by practicing proven stress management strategies interactively immediately after login. Test results of Stress Gym with Navy members demonstrated that it was effective, with significant decreases in reported perceived stress levels from baseline to follow-up assessment. Stress Gym used design elements that may serve as a model for future websites to emulate and improve upon, and as a template against which to compare and contrast the design and functionality of future online, health-intervention websites.

  12. ALTERNATE MATERIALS IN DESIGN OF RADIOACTIVE MATERIAL PACKAGES

    SciTech Connect

    Blanton, P.; Eberl, K.

    2010-07-09

    This paper presents a summary of design and testing of material and composites for use in radioactive material packages. These materials provide thermal protection and provide structural integrity and energy absorption to the package during normal and hypothetical accident condition events as required by Title 10 Part 71 of the Code of Federal Regulations. Testing of packages comprising these materials is summarized.

  13. Alternatives generation and analysis for phase I intermediate waste feed staging system design requirements

    SciTech Connect

    Britton, M.D.

    1996-10-02

    This document provides; a decision analysis summary; problem statement; constraints, requirements, and assumptions; decision criteria; intermediate waste feed staging system options and alternatives generation and screening; intermediate waste feed staging system design concepts; intermediate waste feed staging system alternative evaluation and analysis; and open issues and actions.

  14. Erythropoietin: new approaches to improved molecular designs and therapeutic alternatives.

    PubMed

    Debeljak, N; Sytkowski, A J

    2008-01-01

    Erythropoietin (Epo) is a glycoprotein hormone that is the prime regulator of erythropoiesis. Recombinant Epo is a highly effective pharmaceutical used to correct anemias associated with renal insufficiency, cancer and other diseases. Efforts to increase its efficacy in vivo by manipulating the protein's structure have met with some success, and novel Epo-like agents are in development. Additionally, efforts to create Epo mimetic agents are underway, as is the design of agents to increase endogenous production. Because Epo has tissue protective actions outside of erythropoiesis, other designs have focused on producing erythropoietically inactive molecules that still retain extra-hematopoietic activity. The demonstration that Epo can trigger signaling in some cancer cells with, potentially, adverse effects on patient health has raised warning signs in the medical community and has gained the attention of regulatory authorities.

  15. RIP Input Tables From Wapdeg For La Design Selection: Enhanced Design Alternative Iiib

    SciTech Connect

    K.G. Mon; K.G. Mast; J.H. Lee

    1999-07-01

    The purpose of this calculation is to document the Waste Package Degradation (WAPDEG) version 3.09 (CRWMS M&O 1998b. 'Software Routine Report for WAPDEG' (Version 3.09)) simulations used to analyze degradation and failure of 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields as well as degradation and failure of the waste packages over which they are placed. The waste packages are composed of two corrosion resistant materials (CRM) barriers. The outer barrier is composed of 2 cm of Alloy 22 and the inner barrier is composed of 1.5 cm of titanium grade 7. The WAPDEG simulation results are post-processed into tables of drip shield/waste package degradation time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems (RIP) version 5.19.01 (Golder Associates 1998) computer code. This calculation supports Performance Assessment analysis of the License Application Design Selection (LADS) Enhanced Design Alternative IIIb.

  16. Comparison of US Blast Design Guidance Documents

    DTIC Science & Technology

    2010-07-01

    shear reinforcing steel so that the sum of the concrete and steel shear strengths is equal to the equivalent reaction...rev. 1, SBEDS “calculates the required area of shear reinforcing steel so that the sum of the concrete and steel shear strengths is equal to the...greater than 2-degrees typically have fixed supports. 5 In comparison, SBEDS calculates the direct shear capacity of reinforced concrete

  17. Comparison of LIDAR system performance for alternative single-mode receiver architectures: modeling and experimental validation

    NASA Astrophysics Data System (ADS)

    Toliver, Paul; Ozdur, Ibrahim; Agarwal, Anjali; Woodward, T. K.

    2013-05-01

    In this paper, we describe a detailed performance comparison of alternative single-pixel, single-mode LIDAR architectures including (i) linear-mode APD-based direct-detection, (ii) optically-preamplified PIN receiver, (iii) PINbased coherent-detection, and (iv) Geiger-mode single-photon-APD counting. Such a comparison is useful when considering next-generation LIDAR on a chip, which would allow one to leverage extensive waveguide-based structures and processing elements developed for telecom and apply them to small form-factor sensing applications. Models of four LIDAR transmit and receive systems are described in detail, which include not only the dominant sources of receiver noise commonly assumed in each of the four detection limits, but also additional noise terms present in realistic implementations. These receiver models are validated through the analysis of detection statistics collected from an experimental LIDAR testbed. The receiver is reconfigurable into four modes of operation, while transmit waveforms and channel characteristics are held constant. The use of a diffuse hard target highlights the importance of including speckle noise terms in the overall system analysis. All measurements are done at 1550 nm, which offers multiple system advantages including less stringent eye safety requirements and compatibility with available telecom components, optical amplification, and photonic integration. Ultimately, the experimentally-validated detection statistics can be used as part of an end-to-end system model for projecting rate, range, and resolution performance limits and tradeoffs of alternative integrated LIDAR architectures.

  18. A Comparison of Alternative Distributed Dynamic Cluster Formation Techniques for Industrial Wireless Sensor Networks.

    PubMed

    Gholami, Mohammad; Brennan, Robert W

    2016-01-06

    In this paper, we investigate alternative distributed clustering techniques for wireless sensor node tracking in an industrial environment. The research builds on extant work on wireless sensor node clustering by reporting on: (1) the development of a novel distributed management approach for tracking mobile nodes in an industrial wireless sensor network; and (2) an objective comparison of alternative cluster management approaches for wireless sensor networks. To perform this comparison, we focus on two main clustering approaches proposed in the literature: pre-defined clusters and ad hoc clusters. These approaches are compared in the context of their reconfigurability: more specifically, we investigate the trade-off between the cost and the effectiveness of competing strategies aimed at adapting to changes in the sensing environment. To support this work, we introduce three new metrics: a cost/efficiency measure, a performance measure, and a resource consumption measure. The results of our experiments show that ad hoc clusters adapt more readily to changes in the sensing environment, but this higher level of adaptability is at the cost of overall efficiency.

  19. A Comparison of Alternative Distributed Dynamic Cluster Formation Techniques for Industrial Wireless Sensor Networks

    PubMed Central

    Gholami, Mohammad; Brennan, Robert W.

    2016-01-01

    In this paper, we investigate alternative distributed clustering techniques for wireless sensor node tracking in an industrial environment. The research builds on extant work on wireless sensor node clustering by reporting on: (1) the development of a novel distributed management approach for tracking mobile nodes in an industrial wireless sensor network; and (2) an objective comparison of alternative cluster management approaches for wireless sensor networks. To perform this comparison, we focus on two main clustering approaches proposed in the literature: pre-defined clusters and ad hoc clusters. These approaches are compared in the context of their reconfigurability: more specifically, we investigate the trade-off between the cost and the effectiveness of competing strategies aimed at adapting to changes in the sensing environment. To support this work, we introduce three new metrics: a cost/efficiency measure, a performance measure, and a resource consumption measure. The results of our experiments show that ad hoc clusters adapt more readily to changes in the sensing environment, but this higher level of adaptability is at the cost of overall efficiency. PMID:26751447

  20. Alternative splicing in teleost fish genomes: same-species and cross-species analysis and comparisons.

    PubMed

    Lu, Jianguo; Peatman, Eric; Wang, Wenqi; Yang, Qing; Abernathy, Jason; Wang, Shaolin; Kucuktas, Huseyin; Liu, Zhanjiang

    2010-06-01

    Alternative splicing (AS) is a mechanism by which the coding diversity of the genome can be greatly increased. Rates of AS are known to vary according to the complexity of eukaryotic species potentially explaining the tremendous phenotypic diversity among species with similar numbers of coding genes. Little is known, however, about the nature or rate of AS in teleost fish. Here, we report the characteristics of AS in teleost fish and classification and frequency of five canonical AS types. We conducted both same-species and cross-species analysis utilizing the Genome Mapping and Alignment Program (GMAP) and an AS pipeline (ASpipe) to study AS in four genome-enabled species (Danio rerio, Oryzias latipes, Gasterosteus aculeatus, and Takifugu rubripes) and one species lacking a complete genome sequence, Ictalurus punctatus. AS frequency was lowest in the highly duplicated genome of zebrafish (17% of mapped genes). The compact genome of the pufferfish showed the highest occurrence of AS (approximately 43% of mapped genes). An inverse correlation between AS frequency and genome size was consistent across all analyzed species. Cross-species comparisons utilizing zebrafish as the reference genome allowed the identification of additional putative AS genes not revealed by zebrafish transcripts. Approximately, 50% of AS genes identified by same-species comparisons were shared among two or more species. A searchable website, the Teleost Alternative Splicing Database, was created to allow easy identification and visualization of AS transcripts in the studied teleost genomes. Our results and associated database should further our understanding of alternative splicing as an important functional and evolutionary mechanism in the genomes of teleost fish.

  1. How Can Comparison Groups Strengthen Regression Discontinuity Designs?

    ERIC Educational Resources Information Center

    Wing, Coady; Cook, Thomas D.

    2011-01-01

    In this paper, the authors examine some of the ways that different types of non-equivalent comparison groups can be used to strengthen causal inferences based on regression discontinuity design (RDD). First, they consider a design that incorporates pre-test data on assignment scores and outcomes that were collected either before the treatment…

  2. Structural optimization of an alternate design for the space shuttle solid rocket booster field joint

    NASA Technical Reports Server (NTRS)

    Barthelemy, J.-F. M.; Chang, K. J.; Rogers, J. L., Jr.

    1987-01-01

    A structural optimization procedure is used to determine the shape of an alternate design for the shuttle solid rocket booster field joint. In contrast to the tang and clevis design of the existing joint, this alternate design consists of two flanges bolted together. Configurations with 150 studs of 1 1/8 in. diameter and 135 studs of 1 3/16 in. diameter are considered. Using a nonlinear programming procedure, the joint weight is minimized under constraints on either von Mises or maximum normal stresses, joint opening and geometry. The procedure solves the design problem by replacing it by a sequence of approximate (convex) subproblems; the pattern of contact between the joint halves is determined every few cycles by a nonliner displacement analysis. The minimum weight design has 135 studs of 1 3/16 in. diameter and is designed under constraints on normal stresses. It weighs 1144 lb per joint more than the current tang and clevis design.

  3. Detailed design, fabrication and testing of an engineering prototype compensated pulsed alternator. Final report

    SciTech Connect

    Bird, W.L. Jr.; Woodson, H.H.

    1980-03-01

    The design, fabrication, and test results of a prototype compensated pulsed alternator are discussed. The prototype compulsator is a vertical shaft single phase alternator with a rotating armature and salient pole stator. The machine is designed for low rep rate pulsed duty and is sized to drive a modified 10 cm Beta amplifier. The load consists of sixteen 15 mm x 20 mm x 112 cm long xenon flashlamps connected in parallel. The prototype compulsator generates an open circuit voltage of 6 kV, 180 Hz, at a maximum design speed of 5400 rpm. At maximum speed, the inertial energy stored in the compulsator rotor is 3.4 megajoules.

  4. Comparisons of luminaires: Efficacies and system design

    NASA Astrophysics Data System (ADS)

    Albright, L. D.; Both, A. J.

    1994-03-01

    Lighting designs for architectural (aesthetic) purposes, vision and safety, and plant growth have many features in common but several crucial ones that are not. The human eye is very sensitive to the color (wavelength) of light, whereas plants are less so. There are morphological reactions, particularly to the red and blue portions of the light spectrum but, in general, plants appear to accept and use light for photosynthesis everywhere over the PAR region of the spectrum. In contrast, the human eye interprets light intensity on a logarithmic scale, making people insensitive to significant differences of light intensity. As a rough rule, light intensity must change by 30 to 50% for the human eye to recognize the difference. Plants respond much more linearly to light energy, at least at intensities below photosynthetic saturation. Thus, intensity differences not noticeable to the human eye can have significant effects on total plant growth and yield, and crop timing. These factors make luminaire selection and lighting system design particularly important when designing supplemental lighting systems for plant growth. Supplemental lighting for plant growth on the scale of commercial greenhouses is a relatively expensive undertaking. Light intensities are often much higher than required for task (vision) lighting, which increases both installation and operating costs. However, and especially in the northern regions of the United States (and Canada, Europe, etc.), supplemental lighting during winter may be necessary to produce certain crops (e.g., tomatoes) and very useful to achieve full plant growth potential and crop timing with most other greenhouse crops. Operating costs over the life of a luminaire typically will exceed the initial investment, making lighting efficacy a major consideration. This report reviews tests completed to evaluate the efficiencies of various commercially-available High-Pressure Sodium luminaires, and then describes the results of using a

  5. Comparisons of luminaires: Efficacies and system design

    NASA Technical Reports Server (NTRS)

    Albright, L. D.; Both, A. J.

    1994-01-01

    Lighting designs for architectural (aesthetic) purposes, vision and safety, and plant growth have many features in common but several crucial ones that are not. The human eye is very sensitive to the color (wavelength) of light, whereas plants are less so. There are morphological reactions, particularly to the red and blue portions of the light spectrum but, in general, plants appear to accept and use light for photosynthesis everywhere over the PAR region of the spectrum. In contrast, the human eye interprets light intensity on a logarithmic scale, making people insensitive to significant differences of light intensity. As a rough rule, light intensity must change by 30 to 50% for the human eye to recognize the difference. Plants respond much more linearly to light energy, at least at intensities below photosynthetic saturation. Thus, intensity differences not noticeable to the human eye can have significant effects on total plant growth and yield, and crop timing. These factors make luminaire selection and lighting system design particularly important when designing supplemental lighting systems for plant growth. Supplemental lighting for plant growth on the scale of commercial greenhouses is a relatively expensive undertaking. Light intensities are often much higher than required for task (vision) lighting, which increases both installation and operating costs. However, and especially in the northern regions of the United States (and Canada, Europe, etc.), supplemental lighting during winter may be necessary to produce certain crops (e.g., tomatoes) and very useful to achieve full plant growth potential and crop timing with most other greenhouse crops. Operating costs over the life of a luminaire typically will exceed the initial investment, making lighting efficacy a major consideration. This report reviews tests completed to evaluate the efficiencies of various commercially-available High-Pressure Sodium luminaires, and then describes the results of using a

  6. Preliminary design of a mini-Brayton Compressor-Alternator-Turbine (CAT)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The preliminary design of a mini-Brayton compressor-alternator-turbine system is discussed. The program design goals are listed. The optimum system characteristics over the entire range of power output were determined by performing a wide-range parametric study. The ability to develop the required components to the degree necessary within the limitations of present technology is evaluated. The sensitivity of the system to various individual design parameters was analyzed.

  7. MAASE: An alternative splicing database designed for supporting splicing microarray applications

    PubMed Central

    ZHENG, CHRISTINA L.; KWON, YOUNG-SOO; LI, HAI-RI; ZHANG, KUI; COUTINHO-MANSFIELD, GABRIELA; YANG, CANZHU; NAIR, T. MURLIDHARAN; GRIBSKOV, MICHAEL; FU, XIANG-DONG

    2005-01-01

    Alternative splicing is a prominent feature of higher eukaryotes. Understanding of the function of mRNA isoforms and the regulation of alternative splicing is a major challenge in the post-genomic era. The development of mRNA isoform sensitive microarrays, which requires precise splice-junction sequence information, is a promising approach. Despite the availability of a large number of mRNAs and ESTs in various databases and the efforts made to align transcript sequences to genomic sequences, existing alternative splicing databases do not offer adequate information in an appropriate format to aid in splicing array design. Here we describe our effort in constructing the Manually Annotated Alternatively Spliced Events (MAASE) database system, which is specifically designed to support splicing microarray applications. MAASE comprises two components: (1) a manual/computational annotation tool for the efficient extraction of critical sequence and functional information for alternative splicing events and (2) a user-friendly database of annotated events that allows convenient export of information to aid in microarray design and data analysis. We provide a detailed introduction and a step-by-step user guide to the MAASE database system to facilitate future large-scale annotation efforts, integration with other alternative splicing databases, and splicing array fabrication. PMID:16251387

  8. Intervention Research and Program Evaluation in the School Setting: Issues and Alternative Research Designs

    ERIC Educational Resources Information Center

    de Anda, Diane

    2007-01-01

    This article discusses the difficulties in conducting intervention research or evaluating intervention programs in a school setting. In particular, the problems associated with randomization and obtaining control groups are examined. The use of quasi-experimental designs, specifically a paired comparison design using the individual as his or her…

  9. EDECT: An Energy Design, Evaluation, and Comparison Tool.

    DTIC Science & Technology

    1986-01-01

    medium offices and retail stores , and private clinics are envelope dosinant examples. Conversely, system dominant buildings’ major energy loads come from...AD-A17l 261 EDECT: AN ENERGY DESIGN EVALUATION AND COMPARISON TOOL 1/2 (U) AIR FORCE INST OF TECH &RIGHT-PATTERSON AFS OH Wi D ALLEY 1986 RFIT/CI/NR...TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED EDECT: An Energy Design, Evaluation, and TlESIS/I~$ /r/t N Comparison Tool 6. PERFORMING ORG

  10. Digital-computer program for design analysis of salient, wound pole alternators

    NASA Technical Reports Server (NTRS)

    Repas, D. S.

    1973-01-01

    A digital computer program for analyzing the electromagnetic design of salient, wound pole alternators is presented. The program, which is written in FORTRAN 4, calculates the open-circuit saturation curve, the field-current requirements at rated voltage for various loads and losses, efficiency, reactances, time constants, and weights. The methods used to calculate some of these items are presented or appropriate references are cited. Instructions for using the program and typical program input and output for an alternator design are given, and an alphabetical list of most FORTRAN symbols and the complete program listing with flow charts are included.

  11. Comparison of Alternatives to the 2004 Vacuum Vessel Heat Transfer System

    SciTech Connect

    Yoder Jr, Graydon L; Carbajo, Juan J; Kim, Seokho H

    2010-12-01

    A study comparing different alternatives for the Vacuum Vessel Primary Heat Transfer System has been completed. Three alternatives were proposed in a Project Change Request (PCR-190) by relocating the heat exchangers (HXs) from the roof of the Tokamak building to inside the Vacuum Vessel Pressure Suppression System (VVPSS) tank. The study evaluated the three alternatives and recommended modifications to one of them to arrive at a preferred configuration that included relocating the HXs inside the Tokamak building but outside the VVPSS tank as well as including a small safety-rated pump and HX in parallel to the main circulation pump and HX. The Vacuum Vessel (VV) Primary Heat Transfer System (PHTS) removes heat generated in the VV during normal operation (10 MW, pulsed power) as well as the decay heat from the VV itself and from the structures/components attached to the VV (first wall, blanket, and divertor {approx}0.48 MW peak). Therefore, the VV PHTS has two safety functions: (1) contain contaminated cooling water (similar to the other PHTSs) and (2) provide passive cooling during an accident event. The 2004 design of the VV PHTS consists of two independent loops, each loop cooling half of the 18 VV segments with a nominal flow of 475 kg/s of water at about 1.1 MPa and 100 C. The total flow for both loops is 950 kg/s. Both loops are required to remove the heat load during normal plasma operation. During accident conditions, only one loop is needed to remove by natural convection (no pump needed) the decay heat of the complete VV and attached components. The heat is transferred to heat exchanger (HXs) located on top of the roof, outside the Tokamak building. These HXs are air-to-water (A/W) HXs. Three alternatives have been proposed for this cooling system. For a detailed discussion of these alternatives, please refer to Project Change Request, PCR-190 (Ref. 1). A brief introduction is given here. Alternative 1 includes only one main forced circulation loop with a

  12. Alternative trial design in amyotrophic lateral sclerosis saves time and patients.

    PubMed

    Groeneveld, Geert Jan; Graf, Michael; van der Tweel, Ingeborg; van den Berg, Leonard H; Ludolph, Albert C

    2007-10-01

    A sequential trial design is an alternative for the classical trial design with a fixed sample size, that permits stopping a trial as soon as enough evidence for a treatment effect, or a lack thereof, is obtained. This study aimed to determine the difference in efficiency of time and patient number between a classical trial design and a sequential trial design. In this study we re-analysed a previously published classically designed clinical trial according to a sequential trial design. We subsequently determined the difference in total running time and patient number. We found that the sequential analysis offered a gain in time of 38%. We conclude that the sequential trial design may in certain situations be superior to the classical design.

  13. Comparison of JSFR design with EDF requirements for future SFR

    SciTech Connect

    Uematsu, M. M.; Prele, G.; Mariteau, P.; Sauvage, J. F.; Hayafune, H.; Chikazawa, Y.

    2012-07-01

    A comparison of Japan sodium-cooled fast reactor (JSFR) design with future French SFR concept has been done based on the requirement of EDF, the investor-operator of future French SFR, and the French safety baseline, under the framework of EDF-JAEA bilateral agreement of research and development cooperation on future SFR. (authors)

  14. Cell and stack design alternatives. Final report, August 1, 1978-December 31, 1979

    SciTech Connect

    Hoover, Jr., D. Q.; King, Robert B.

    1980-02-01

    The work described comprised the first phase of a planned six phase program to develop commercially viable phosphoric acid fuel cell (PAFC) driven on-site integrated energy systems (OS/IES). The Phase I effort was organized as three major technical tasks; (1) study of system design alternatives; (2) fuel cell design alternatives; and (3) methane conditioner study. It was decided that comprehensive modeling of one application would most effectively utilize the resources available for the study of systems design alternatives. A 48 unit apartment complex located in Albany, New York and built to HUD minimum standards was selected as being typical of the applications that will be served by the systems. The time varying space conditioning (HVAC) and electrical requirements including the effects of varying weather conditions, living habits and occupancy patterns were modeled. These requirements formed the basis for comparing the performance and cost of the alternative configurations with each other and with a conventional system. Five basic alternative OS/IES configurations plus four variations were selected from a preliminary list of 13 basic configurations for detailed performance nd cost evaluations. Study procedures and results are presented in detail. (WHK)

  15. Alternate design concept for the SSC dipole magnet cryogenic support post

    SciTech Connect

    Lipski, A.; Nicol, T.H.; Richardson, R.

    1991-03-01

    New materials and developments in the field of advanced composites have created the opportunity to take a fresh look into the design of the cryogenic supports for SSC collider dipole cryostats. Although the present reentrant post design meets the structural and thermal requirements, its assembly requires precision and proficiency. The objective of the proposed alternate concept is to reduce the overall cost of the support post by means of simplifying and optimizing its component design and assembly process. The present shrink fitted tube assembly may potentially be replaced by injection molded parts. New resin systems with lower thermal conductivity and high strength properties enable the utilization of automated production techniques such as injection molding and filament winding. This paper will provide analysis and design information for the alternate support post concept and compare its test performance and cost to the present support post. 3 refs., 12 figs., 4 tabs.

  16. Alternatives generation and analysis for the Phase I intermediate waste feed staging system design requirements

    SciTech Connect

    Claghorn, R.D., Fluor Daniel Hanford

    1997-02-06

    This alternatives generation and analysis (AGA) addresses the question: What is the design basis for the facilities required to stage low-level waste (LLW) feed to the Phase I private contractors? Alternative designs for the intermediate waste feed staging system were developed, analyzed, and compared. Based on these analyses, this document recommends installing mixer pumps in the central pump pit of double-shell tanks 241-AP-102 and 241-AP-104. Also recommended is installing decant/transfer pumps at these tanks. These recommendations have clear advantages in that they provide a low shedule impact/risk and the highest operability of all the alternatives investigated. This revision incorporates comments from the decision board.

  17. Alternate Lattice Design for Advanced Photon Source Multi-Bend Achromat Upgrade

    SciTech Connect

    Sun, Yipeng; Borland, Michael

    2015-01-01

    A 67-pm hybrid-seven-bend achromat (H7BA) lattice is proposed for a futureAdvanced Photon Source (APS)multibend- achromat (MBA) upgrade. This lattice requires use of a swap-out (on-axis) injection scheme. Alternate lattice design work has also been performed to achieve better beam dynamics performance than the nominal APS MBA lattice, in order to allow beam accumulation. One of such alternate H7BA lattice designs, which still targets a very low emittance of 76 pm, is discussed in this paper. With these lattices, existing APS injector complex can be employed without the requirement of a very high charge operation. Studies show that an emittance below 76 pm can be achieved with the employment of reverse bends in an alternate lattice. We discuss the predicted performance and requirements for these lattices and compare them to the nominal lattice.

  18. Fast Reactor Alternative Studies: Effects of Transuranic Groupings on Metal and Oxide Sodium Fast Reactor Designs

    SciTech Connect

    R. Ferrer; M. Asgari; S. Bays; B. Forget

    2007-09-01

    A 1000 MWth commercial-scale Sodium Fast Reactor (SFR) design with a conversion ratio (CR) of 0.50 was selected in this study to perform perturbations on the external feed coming from Light Water Reactor Spent Nuclear Fuel (LWR SNF) and separation groupings in the reprocessing scheme. A secondary SFR design with a higher conversion ratio (CR=0.75) was also analyzed as a possible alternative, although no perturbations were applied to this model.

  19. Single-Case Research Design: An Alternative Strategy for Evidence-Based Practice

    ERIC Educational Resources Information Center

    Stapleton, Drue; Hawkins, Andrew

    2015-01-01

    Objective: The trend of utilizing evidence-based practice (EBP) in athletic training is now requiring clinicians, researchers, educators, and students to be equipped to both engage in and make judgments about research evidence. Single-case design (SCD) research may provide an alternative approach to develop such skills and inform clinical and…

  20. Designing Innovative Alternatives to Traditional High Schools: What Leaders Need to Know

    ERIC Educational Resources Information Center

    Edwards, Chester Roy

    2013-01-01

    The need for new and innovative alternatives to traditional high schools has never been greater. Never designed to graduate all students on time, traditional high schools and their high dropout rates have remained unchanged for the last 30 years. Improving secondary schooling for all young people is a worthwhile social and educational objective.…

  1. Mirror fusion propulsion system: A performance comparison with alternate propulsion systems for the manned Mars Mission

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.; Carpenter, Scott A.; Deveny, Marc E.; Oconnell, T.

    1993-01-01

    The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons.

  2. Mirror fusion propulsion system - A performance comparison with alternate propulsion systems for the manned Mars mission

    NASA Technical Reports Server (NTRS)

    Deveny, M.; Carpenter, S.; O'Connell, T.; Schulze, N.

    1993-01-01

    The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons.

  3. Comparison of alternative flue gas dry treatment technologies in waste-to-energy processes.

    PubMed

    Dal Pozzo, Alessandro; Antonioni, Giacomo; Guglielmi, Daniele; Stramigioli, Carlo; Cozzani, Valerio

    2016-05-01

    Acid gases such as HCl and SO2 are harmful both for human health and ecosystem integrity, hence their removal is a key step of the flue gas treatment of Waste-to-Energy (WtE) plants. Methods based on the injection of dry sorbents are among the Best Available Techniques for acid gas removal. In particular, systems based on double reaction and filtration stages represent nowadays an effective technology for emission control. The aim of the present study is the simulation of a reference two-stage (2S) dry treatment system performance and its comparison to three benchmarking alternatives based on single stage sodium bicarbonate injection. A modelling procedure was applied in order to identify the optimal operating configuration of the 2S system for different reference waste compositions, and to determine the total annual cost of operation. Taking into account both operating and capital costs, the 2S system appears the most cost-effective solution for medium to high chlorine content wastes. A Monte Carlo sensitivity analysis was carried out to assess the robustness of the results.

  4. An alternative to Rasch analysis using triadic comparisons and multi-dimensional scaling

    NASA Astrophysics Data System (ADS)

    Bradley, C.; Massof, R. W.

    2016-11-01

    Rasch analysis is a principled approach for estimating the magnitude of some shared property of a set of items when a group of people assign ordinal ratings to them. In the general case, Rasch analysis not only estimates person and item measures on the same invariant scale, but also estimates the average thresholds used by the population to define rating categories. However, Rasch analysis fails when there is insufficient variance in the observed responses because it assumes a probabilistic relationship between person measures, item measures and the rating assigned by a person to an item. When only a single person is rating all items, there may be cases where the person assigns the same rating to many items no matter how many times he rates them. We introduce an alternative to Rasch analysis for precisely these situations. Our approach leverages multi-dimensional scaling (MDS) and requires only rank orderings of items and rank orderings of pairs of distances between items to work. Simulations show one variant of this approach - triadic comparisons with non-metric MDS - provides highly accurate estimates of item measures in realistic situations.

  5. 40 CFR 96.115 - Delegation by CAIR designated representative and alternate CAIR designated representative.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR Designated Representative for CAIR...

  6. 40 CFR 96.115 - Delegation by CAIR designated representative and alternate CAIR designated representative.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR Designated Representative for CAIR...

  7. Comparison of alternative treatment systems for DOE mixed low-level waste

    SciTech Connect

    Schwinkendorf, W.E.

    1997-03-01

    From 1993 to 1996, the Department of Energy, Environmental Management, Office of Science and Technology (OST), has sponsored a series of systems analyses to guide its future research and development (R&D) programs for the treatment of mixed low-level waste (MLLW) stored in the DOE complex. The two original studies were of 20 mature and innovative thermal systems. As a result of a technical review of these thermal system studies, a similar study of five innovative nonthermal systems was conducted in which unit operations are limited to temperatures less than 350{degrees}C to minimize volatilization of heavy metals and radionuclides, and de novo production of dioxins and furans in the offgas. Public involvement in the INTS study was established through a working group of 20 tribal and stakeholder representatives to provide input to the INTS studies and identify principles against which the systems should be designed and evaluated. Pre-conceptual designs were developed for all systems to treat the same waste input (2927 lbs/hr) in a single centralized facility operating 4032 hours per year for 20 years. This inventory consisted of a wide range of combustible and non-combustible materials such as paper, plastics, metals, concrete, soils, sludges, liquids, etc., contaminated with trace quantities of radioactive materials and RCRA regulated wastes. From this inventory, an average waste profile was developed for simulated treatment using ASPEN PLUS{copyright} for mass balance calculations. Seven representative thermal systems were selected for comparison with the five nonthermal systems. This report presents the comparisons against the TSWG principles, of total life cycle cost (TLCC), and of other system performance indicators such as energy requirements, reagent requirements, land use, final waste volume, aqueous and gaseous effluents, etc.

  8. Safety and environmental comparisons of stainless steel with alternative structural materials for fusion reactors

    SciTech Connect

    Kinzig, A.P.; Holdren, J.P.; Hibbard, P.J.

    1994-08-01

    Using the FuseDose II computer code, we calculated and compared several indices of safety and environmental (S&E) hazards for conceptual magnetic-fusion reactor designs based on a variety of structural materials-stainless steel, ferritic steel, vanadium-chromium-titanium alloy, and silicon-carbide-and, for comparison, the fuel of a liquid-metal fast breeder fission reactor. FuseDose II is a second-generation code derived from the Fuse-Dose code used in the U.S. Department of Energy`s Committee on Environmental, Safety, and Economic Aspects of Magnetic Fusion Energy (ESECOM) study in the late 1980s. The comparisons update and extend those of the ESECOM study by adding the stainless-steel case, some new indices, graphical representation of the results, and other refinements. The results of our analysis support earlier conclusions concerning the S&E liabilities of stainless steel: The use of stainless steel would significantly reduce the S&E advantages of fusion over fission that are implied by the indices we consider, compared with the advantages portrayed in the ESECOM results for lower-activation fusion materials. The dose potentials represented by the radioactive materials that conceivably could be mobilized in severe accidents are substantially higher for the stainless steel case than for the lower activation fusion designs analyzed by ESECOM, and the waste disposal burden imposed by a stainless steel fusion reactor, though significantly smaller than that associated with a fission reactor of the same output, is high enough to rule out the chance of qualification for shallow burial under current regulations (in contrast to some of the lower activation fusion cases). This work underscores the conclusion that research to demonstrate the viability of the low-activation materials is essential if fusion is to achieve its potential for large and easily demonstrated S&E advantages over fission. 37 refs., 17 figs., 8 tabs.

  9. Dual angiotensin receptor and neprilysin inhibition as an alternative to angiotensin-converting enzyme inhibition in patients with chronic systolic heart failure: rationale for and design of the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure trial (PARADIGM-HF)

    PubMed Central

    McMurray, John J. V.; Packer, Milton; Desai, Akshay S.; Gong, Jim; Lefkowitz, Martin P.; Rizkala, Adel R.; Rouleau, Jean; Shi, Victor C.; Solomon, Scott D.; Swedberg, Karl; Zile, Michael R.

    2013-01-01

    Aims Although the focus of therapeutic intervention has been on neurohormonal pathways thought to be harmful in heart failure (HF), such as the renin–angiotensin–aldosterone system (RAAS), potentially beneficial counter-regulatory systems are also active in HF. These promote vasodilatation and natriuresis, inhibit abnormal growth, suppress the RAAS and sympathetic nervous system, and augment parasympathetic activity. The best understood of these mediators are the natriuretic peptides which are metabolized by the enzyme neprilysin. LCZ696 belongs to a new class of drugs, the angiotensin receptor neprilysin inhibitors (ARNIs), which both block the RAAS and augment natriuretic peptides. Methods Patients with chronic HF, NYHA class II–IV symptoms, an elevated plasma BNP or NT-proBNP level, and an LVEF of ≤40% were enrolled in the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortailty and morbidity in Heart Failure trial (PARADIGM-HF). Patients entered a single-blind enalapril run-in period (titrated to 10 mg b.i.d.), followed by an LCZ696 run-in period (100 mg titrated to 200 mg b.i.d.). A total of 8436 patients tolerating both periods were randomized 1:1 to either enalapril 10 mg b.i.d. or LCZ696 200 mg b.i.d. The primary outcome is the composite of cardiovascular death or HF hospitalization, although the trial is powered to detect a 15% relative risk reduction in cardiovascular death. Perspectives PARADIGM-HF will determine the place of the ARNI LCZ696 as an alternative to enalapril in patients with systolic HF. PARADIGM-HF may change our approach to neurohormonal modulation in HF. Trial registration NCT01035255 PMID:23563576

  10. Technology Learning Activities. Design Brief--Measuring Inaccessible Distances. Alternative Energy Sources: Designing a Wind Powered Generator. Alternative Energy Sources: Designing a Hot Dog Heater Using Solar Energy.

    ERIC Educational Resources Information Center

    Technology Teacher, 1991

    1991-01-01

    These three learning activities are on measuring accessible distances, designing a wind powered generator, and designing a hot dog heater using solar energy. Each activity includes description of context, objectives, list of materials and equipment, challenge to students, and evaluation questions. (SK)

  11. Performance of R-410A Alternative Refrigerants in a Reciprocating Compressor Designed for Air Conditioning Applications

    SciTech Connect

    Shrestha, Som S; Vineyard, Edward Allan; Mumpower, Kevin

    2016-01-01

    In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. After successfully completing the first phase of the program in December 2013, AHRI launched a second phase of the Low-GWP AREP in 2014 to continue research in areas that were not previously addressed, including refrigerants in high ambient conditions, refrigerants in applications not tested in the first phase, and new refrigerants identified since testing for the program began. Although the Ozone Depletion Potential of R-410A is zero, this refrigerant is under scrutiny due to its high GWP. Several candidate alternative refrigerants have already demonstrated low global warming potential. Performance of these low-GWP alternative refrigerants is being evaluated for Air conditioning and heat pump applications to ensure acceptable system capacity and efficiency. This paper reports the results of a series of compressor calorimeter tests conducted for the second phase of the AREP to evaluate the performance of R-410A alternative refrigerants in a reciprocating compressor designed for air conditioning systems. It compares performance of alternative refrigerants ARM-71A, L41-1, DR-5A, D2Y-60, and R-32 to that of R-410A over a wide range of operating conditions. The tests showed that, in general, cooling capacities were slightly lower (except for the R-32), but energy efficiency ratios (EER) of the alternative refrigerants were comparable to that of R-410A.

  12. Cost-comparison of DDT and alternative insecticides for malaria control.

    PubMed

    Walker, K

    2000-12-01

    In anti-malaria operations the use of DDT for indoor residual spraying has declined substantially over the past 30years, but this insecticide is still considered valuable for malaria control, mainly because of its low cost relative to alternative insecticides. Despite the development of resistance to DDT in some populations of malaria vector Anopheles mosquitoes (Diptera: Culicidae), DDT remains generally effective when used for house-spraying against most species of Anopheles, due to excitorepellency as well as insecticidal effects. A 1990 cost comparison by the World Health Organization (WHO) found DDT to be considerably less expensive than other insecticides, which cost 2 to 23 times more on the basis of cost per house per 6 months of control. To determine whether such a cost advantage still prevails for DDT, this paper compares recent price quotes from manufacturers and WHO suppliers for DDT and appropriate formulations of nine other insecticides (two carbamates, two organophosphates and five pyrethroids) commonly used for residual house-spraying in malaria control programmes. Based on these 'global' price quotes, detailed calculations show that DDT is still the least expensive insecticide on a cost per house basis, although the price appears to be rising as DDT production declines. At the same time, the prices of pyrethroids are declining, making some only slightly more expensive than DDT at low application dosages. Other costs, including operations (labour), transportation and human safety may also increase the price advantages of DDT and some pyrethroids vs. organophosphates and carbamates, although possible environmental impacts from DDT remain a concern. However, a global cost comparison may not realistically reflect local costs or effective application dosages at the country level. Recent data on insecticide prices paid by the health ministries of individual countries showed that prices of particular insecticides can vary substantially in the open market

  13. The Untold Story of Being Designated an Alternate Level of Care Patient

    PubMed Central

    McCloskey, Rose; Jarrett, Pamela; Stewart, Connie

    2015-01-01

    Introduction: Much of the research and policy reports on Alternate Level of Care (ALC) in Canada have focused on the impact ALC has on acute care services. To date, the experiences and opinions of those who must wait in hospital for alternate services have been largely absent from discussions. Method: A qualitative study was conducted with patients and families designated as ALC in one urban and two rural hospitals in Atlantic Canada. Data were analyzed using content analysis. Results: Three themes emerged from the data: a perception of normalcy, being old but not sick and anticipating relocation to another facility. Conclusions: ALC is an important issue for patients and their families. Policy directives aimed at addressing the causes and impacts of ALC, identification and provision of appropriate supportive care in the community and sensitivity to the impact of ALC for individuals designated as ALC are needed. PMID:26571470

  14. Surveillance of Aedes aegypti: Comparison of House Index with Four Alternative Traps

    PubMed Central

    Codeço, Claudia T.; Lima, Arthur W. S.; Araújo, Simone C.; Lima, José Bento P.; Maciel-de-Freitas, Rafael; Honório, Nildimar A.; Galardo, Allan K. R.; Braga, Ima A.; Coelho, Giovanini E.; Valle, Denise

    2015-01-01

    Introduction The mosquito Aedes aegypti, vector of dengue, chikungunya and yellow fever viruses, is an important target of vector control programs in tropical countries. Most mosquito surveillance programs are still based on the traditional household larval surveys, despite the availability of new trapping devices. We report the results of a multicentric entomological survey using four types of traps, besides the larval survey, to compare the entomological indices generated by these different surveillance tools in terms of their sensitivity to detect mosquito density variation. Methods The study was conducted in five mid-sized cities, representing variations of tropical climate regimens. Surveillance schemes using traps for adults (BG-Sentinel, Adultrap and MosquiTRAP) or eggs (ovitraps) were applied monthly to three 1 km2 areas per city. Simultaneously, larval surveys were performed. Trap positivity and density indices in each area were calculated and regressed against meteorological variables to characterize the seasonal pattern of mosquito infestation in all cities, as measured by each of the four traps. Results The House Index was consistently low in most cities, with median always 0. Traps rarely produced null indices, pointing to their greater sensitivity in detecting the presence of Ae. aegypti in comparison to the larval survey. Trap positivity indices tend to plateau at high mosquito densities. Despite this, both indices, positivity and density, agreed on the seasonality of mosquito abundance in all cities. Mosquito seasonality associated preferentially with temperature than with precipitation even in areas where temperature variation is small. Conclusions All investigated traps performed better than the House Index in measuring the seasonal variation in mosquito abundance and should be considered as complements or alternatives to larval surveys. Choice between traps should further consider differences of cost and ease-of-use. PMID:25668559

  15. Alternative routes for highway shipments of radioactive materials and lessons learned from state designations

    SciTech Connect

    Not Available

    1990-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under docket numbers HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select altemative routes. First, the state must establish a ``state routing agency``, defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with DOTs Guidelines for Selecting Preferred Highway Routes for Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice to DOT of any alternative route designation before the routes are deemed effective. The purpose of this report is to discuss the ``lessons learned`` by the five states within the southern region that have designated alternative or preferred routes under the regulations of the Department of Transportation (DOT) established for the transportation of radioactive materials. The document was prepared by reviewing applicable federal laws and regulations, examining state reports and documents and contacting state officials and routing agencies involved in making routing decisions. In undertaking this project, the Southern States Energy Board hopes to reveal the process used by states that have designated alternative routes and thereby share their experiences (i.e., lessons learned) with other southern states that have yet to make designations.

  16. Alternative routes for highway shipments of radioactive materials and lessons learned from state designations

    SciTech Connect

    Not Available

    1990-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under docket numbers HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select altemative routes. First, the state must establish a state routing agency'', defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with DOTs Guidelines for Selecting Preferred Highway Routes for Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice to DOT of any alternative route designation before the routes are deemed effective. The purpose of this report is to discuss the lessons learned'' by the five states within the southern region that have designated alternative or preferred routes under the regulations of the Department of Transportation (DOT) established for the transportation of radioactive materials. The document was prepared by reviewing applicable federal laws and regulations, examining state reports and documents and contacting state officials and routing agencies involved in making routing decisions. In undertaking this project, the Southern States Energy Board hopes to reveal the process used by states that have designated alternative routes and thereby share their experiences (i.e., lessons learned) with other southern states that have yet to make designations.

  17. DOE/ORNL heat pump design model, overview and application to R-22 alternatives

    SciTech Connect

    Rice, C.K.

    1997-12-01

    This computer program is a public-domain system design tool for application to air-to-air heat pumps. The main aspects of the program are reviewed with emphasis on the newest features of the current fifth-generation version (Mark V) and an upcoming more fully HFC-capable release (Mark VI). Current model predictions are compared to test data for a leading HFC alternative to HCFC-22 in heat pumps. Examples are shown of some user interfaces that have been recently developed for the program. To demonstrate the design capabilities of the model for R-22 alternatives, a refrigerant-side optimization was conducted to find the best balance of heat transfer versus pressure drop for HCFC R-22, HFCs R-134a and R-410A, and the natural refrigerant propane. COP was maximized while refrigerant charge and tube size were minimized. Independent design parameters were fraction of total area in the outdoor coil, tube diameter and number of circuits for each heat exchanger, and condenser subcooling. Heat exchanger design tradeoffs are discussed for a heat pump relative to air conditioners and heating-only units. A design optimized for heating-only operation is presented.

  18. Alternate optical designs for head-mounted displays with a wide field of view.

    PubMed

    Chen, Bo; Herkommer, Alois M

    2017-02-01

    The most widely applied design form for mixed reality head-mounted display (HMD) systems is generally a prism with one surface in total internal reflection (TIR). This, however, limits the angle of the incident rays, and thus decreases the design freedom and affects the performance. To obtain better performance of the HMD optics, in this paper two seldom used design forms of HMD systems are presented and compared to the standard TIR HMD optics. One of them is a catadioptric HMD system, consisting of one lens and two mirrors; the other is a prism HMD with a different folding geometry. The designs are compared for a field of view of 40°×30°; however, they are also investigated for an increased field of view of 50°×30°. The evaluation indicates good performance of our systems. In particular, the prism with an alternate folding geometry has advantages in both performance and size.

  19. Formulating appropriate statistical hypotheses for treatment comparison in clinical trial design and analysis.

    PubMed

    Huang, Peng; Ou, Ai-hua; Piantadosi, Steven; Tan, Ming

    2014-11-01

    We discuss the problem of properly defining treatment superiority through the specification of hypotheses in clinical trials. The need to precisely define the notion of superiority in a one-sided hypothesis test problem has been well recognized by many authors. Ideally designed null and alternative hypotheses should correspond to a partition of all possible scenarios of underlying true probability models P={P(ω):ω∈Ω} such that the alternative hypothesis Ha={P(ω):ω∈Ωa} can be inferred upon the rejection of null hypothesis Ho={P(ω):ω∈Ω(o)} However, in many cases, tests are carried out and recommendations are made without a precise definition of superiority or a specification of alternative hypothesis. Moreover, in some applications, the union of probability models specified by the chosen null and alternative hypothesis does not constitute a completed model collection P (i.e., H(o)∪H(a) is smaller than P). This not only imposes a strong non-validated assumption of the underlying true models, but also leads to different superiority claims depending on which test is used instead of scientific plausibility. Different ways to partition P fro testing treatment superiority often have different implications on sample size, power, and significance in both efficacy and comparative effectiveness trial design. Such differences are often overlooked. We provide a theoretical framework for evaluating the statistical properties of different specification of superiority in typical hypothesis testing. This can help investigators to select proper hypotheses for treatment comparison inclinical trial design.

  20. Alternative design of inductive pointing device for oral interface for computers and wheelchairs.

    PubMed

    Lontis, Eugen R; Andreasen Struijk, Lotte N S

    2012-01-01

    An inductive pointing device was designed and implemented successfully in a tongue controlled oral interface. Sensors were manufactured as an assembly of multilayer coils in the printed circuit board technology on two pads. The sensor pads were encapsulated together with electronics and battery in a mouthpiece, placed in the upper palate of the oral cavity. The PCB technology allowed surface activation of one or more sensors by gliding over the surface of the coils assembly of a small cylindrical unit attached to the tongue. The model consisted of 8 sensors and allowed real time proportional control of both speed and direction similar to a joystick. However, the size of the oral cavity, the number and geometry of the coil loops and characteristics of the activation unit impose limits in designing the sensors and call for an alternative layout design. Two alternative sensor designs are proposed in this paper, aiming to reduce the size of the sensor pad by one third, extending the target group, including children, and increasing the easiness of wear of the oral interface.

  1. Comparison of Response Surface and Kriging Models in the Multidisciplinary Design of an Aerospike Nozzle

    NASA Technical Reports Server (NTRS)

    Simpson, Timothy W.

    1998-01-01

    The use of response surface models and kriging models are compared for approximating non-random, deterministic computer analyses. After discussing the traditional response surface approach for constructing polynomial models for approximation, kriging is presented as an alternative statistical-based approximation method for the design and analysis of computer experiments. Both approximation methods are applied to the multidisciplinary design and analysis of an aerospike nozzle which consists of a computational fluid dynamics model and a finite element analysis model. Error analysis of the response surface and kriging models is performed along with a graphical comparison of the approximations. Four optimization problems are formulated and solved using both approximation models. While neither approximation technique consistently outperforms the other in this example, the kriging models using only a constant for the underlying global model and a Gaussian correlation function perform as well as the second order polynomial response surface models.

  2. Comparison of Response Surface and Kriging Models for Multidisciplinary Design Optimization

    NASA Technical Reports Server (NTRS)

    Simpson, Timothy W.; Korte, John J.; Mauery, Timothy M.; Mistree, Farrokh

    1998-01-01

    In this paper, we compare and contrast the use of second-order response surface models and kriging models for approximating non-random, deterministic computer analyses. After reviewing the response surface method for constructing polynomial approximations, kriging is presented as an alternative approximation method for the design and analysis of computer experiments. Both methods are applied to the multidisciplinary design of an aerospike nozzle which consists of a computational fluid dynamics model and a finite-element model. Error analysis of the response surface and kriging models is performed along with a graphical comparison of the approximations, and four optimization problems m formulated and solved using both sets of approximation models. The second-order response surface models and kriging models-using a constant underlying global model and a Gaussian correlation function-yield comparable results.

  3. Comparison of a designed virtual counter with a real counter

    NASA Astrophysics Data System (ADS)

    Tektas, G.; Celiktas, C.

    2017-02-01

    A counter is a device which counts the incident pulses within a fixed time. In this work, a virtual counter was designed by developing a code by LabVIEW software. Generator signals were sent to the virtual counter via a National Instruments multifunction data acquisition device. Analog and PFI (Programmable Function Interface) inputs of the device was used for the process. A real counter was also used for comparison. Counts acquired from both counters in different time intervals were compared with each other. It was concluded from the obtained results that the developed virtual counter could be used as a real counter.

  4. Alternative communication network designs for an operational Plato 4 CAI system

    NASA Technical Reports Server (NTRS)

    Mobley, R. E., Jr.; Eastwood, L. F., Jr.

    1975-01-01

    The cost of alternative communications networks for the dissemination of PLATO IV computer-aided instruction (CAI) was studied. Four communication techniques are compared: leased telephone lines, satellite communication, UHF TV, and low-power microwave radio. For each network design, costs per student contact hour are computed. These costs are derived as functions of student population density, a parameter which can be calculated from census data for one potential market for CAI, the public primary and secondary schools. Calculating costs in this way allows one to determine which of the four communications alternatives can serve this market least expensively for any given area in the U.S. The analysis indicates that radio distribution techniques are cost optimum over a wide range of conditions.

  5. Alternative Certification: A Comparison of Factors Affecting the Motivations of General and Special Educators

    ERIC Educational Resources Information Center

    Hogan, Kathleen Ann

    2010-01-01

    This study was developed to examine the motivations of individuals who chose alternative routes to teacher certification and what they believe were the strengths and weaknesses of their alternative certification preparation (ACP). Data accrued from this study were based on a 55-item online survey and participant information from an online focus…

  6. Exploration of Alternate Catalytic Mechanisms and Optimization Strategies for Retroaldolase Design

    PubMed Central

    Bjelic, Sinisa; Kipnis, Yakov; Wang, Ling; Pianowski, Zbigniew; Vorobiev, Sergey; Su, Min; Seetharaman, Jayaraman; Xiao, Rong; Kornhaber, Gregory; Hunt, John F.; Tong, Liang; Hilvert, Donald; Baker, David

    2014-01-01

    Designed retroaldolases have utilized a nucleophilic lysine to promote carbon–carbon bond cleavage of β-hydroxy-ketones via a covalent Schiff base intermediate. Previous computational designs have incorporated a water molecule to facilitate formation and breakdown of the carbinolamine intermediate to give the Schiff base and to function as a general acid/base. Here we investigate an alternative active-site design in which the catalytic water molecule was replaced by the side chain of a glutamic acid. Five out of seven designs expressed solubly and exhibited catalytic efficiencies similar to previously designed retroaldolases for the conversion of 4-hydro-xy-4-(6-methoxy-2-naphthyl)-2-butanone to 6-methoxy-2-naphthaldehyde and acetone. After one round of site-directed saturation mutagenesis, improved variants of the two best designs, RA114 and RA117, exhibited among the highest kcat (>10−3 s−1) and kcat/KM (11–25 M−1 s−1) values observed for retroaldolase designs prior to comprehensive directed evolution. In both cases, the >105-fold rate accelerations that were achieved are within 1–3 orders of magnitude of the rate enhancements reported for the best catalysts for related reactions, including catalytic antibodies (kcat/kuncat = 106 to 108) and an extensively evolved computational design (kcat/kuncat > 107). The catalytic sites, revealed by X-ray structures of optimized versions of the two active designs, are in close agreement with the design models except for the catalytic lysine in RA114. We further improved the variants by computational remodeling of the loops and yeast display selection for reactivity of the catalytic lysine with a diketone probe, obtaining an additional order of magnitude enhancement in activity with both approaches. PMID:24161950

  7. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design

    PubMed Central

    Bissinger, Alexa; Muller, Mundenga Mutendi; Gebreyesus, Alegnta; Geremew, Haimanot; Wendell, Sarah; Azaza, Aklilu; Salumu, Maurice; Benfield, Nerys

    2015-01-01

    This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania) and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice. PMID:26252003

  8. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design.

    PubMed

    Salmon, Margaret; Salmon, Christian; Bissinger, Alexa; Muller, Mundenga Mutendi; Gebreyesus, Alegnta; Geremew, Haimanot; Wendel, Sarah K; Wendell, Sarah; Azaza, Aklilu; Salumu, Maurice; Benfield, Nerys

    2015-01-01

    This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania) and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice.

  9. Investigating an alternative ring design of transducer arrays for tumor treating fields (TTFields).

    PubMed

    Macedo, Mario; Wenger, Cornelia; Salvador, Ricardo; Fernandes, Sofia R; Miranda, Pedro C

    2016-08-01

    Tumor treating fields (TTFields) is a therapy that inhibits cell proliferation and has been approved by the U.S Food and Drug Administration (FDA) for the treatment of Glioblastoma Multiforme. This anti-mitotic technique works non-invasively and regionally, and is associated with less toxicity and a better quality of life. Currently a device called Optune™ is clinically used which works with two perpendicular and alternating array pairs each consisting of 3×3 transducers. The aim of this study is to investigate a theoretical alternative array design which consists of two rings of 16 transducers and thus permits various field directions. A realistic human head model with isotropic tissues was used to simulate the electric field distribution induced by the two types of array layouts. One virtual tumour was modelled as a sphere in the white matter close to one lateral ventricle. Four alternative ring design directions were evaluated by activating arrays of 2×2 transducers on opposite sides of the head. The same amount of current was passed through active transducer arrays of the Optune system and the ring design. The electric field distribution in the brain differs for the various array configurations, with higher fields between activated transducer pairs and lower values in distant areas. Nonetheless, the average electric field strength values in the tumour are comparable for the various configurations. Values between 1.00 and 1.91 V/cm were recorded, which are above the threshold for effective treatment. Increasing the amount of field directions could possibly also increase treatment efficacy, because TTFields' effect on cancer cells is highest when the randomly distributed cell division axis is aligned with the field. The results further predict that slightly changing transducer positions only has a minor effect on the electric field. Thus patients might have some freedom to adjust array positions without major concern for treatment efficacy.

  10. Environmental and economic comparisons of the satellite power system and six alternative energy technologies

    NASA Astrophysics Data System (ADS)

    Whitfield, R. G.; Habegger, L. J.; Levine, E. P.; Tanzman, E.

    1981-04-01

    The satellite power system (SPS) was compared with alternative systems on life cycle cost and environmental impacts. Environmental and economic effects are evaluated and subdivided into the following issue areas: human health and safety, environmental welfare, resources (land, materials, energy, water, labor), macroeconomics, socioeconomics, and institutional. These evaluations are based on technology characterization data and alternative futures scenarios, developed as part of CDEP. The technologies and the scenarios are described. The cost and performance of the SPS and the alternative technologies provide the basis of the macroeconomic analyses.

  11. DESIGN NOTE: Reduction of uncertainties in temperature calibrations by comparison

    NASA Astrophysics Data System (ADS)

    Drnovsek, Janko; Pusnik, Igor; Bojkovski, Jovan

    1998-11-01

    The objective of this design note is to discuss and define the total uncertainty in temperature calibrations by comparison, by analysing most of the likely error sources. As a result of the proposed and developed uncertainty analysis, further reductions of uncertainties could be realized if/when better equipment becomes available. The analysis is performed as a case study using state-of-the-art calibration equipment described in the design note. This equipment is located in the authors' own secondary temperature calibration laboratory. Accreditation for this laboratory has been granted through The Dutch Council of Accreditation (RVA) for calibrations in the temperature range -55 to 0957-0233/9/11/017/img1C. In temperature calibrations by comparison the four main groups of uncertainties are the reproducibility, uncertainty of a reference thermometer, uncertainty of a calibration bath or a furnace and uncertainty of a measuring device. Special care is taken, using a thorough evaluation procedure, to ensure that the uncertainty contribution of the calibration bath or furnace is as low as possible. This is necessary because the total uncertainty assigned to an instrument under calibration is larger than the largest individual uncertainty contribution. In temperature calibrations the largest uncertainty is most likely to be the uncertainty of the calibration bath or a furnace. Therefore this uncertainty typically represents the lowest limit for further reduction of the total uncertainty of the calibration process. The analysis performed allows optimal use of temperature calibration equipment for calibration of thermometers by comparison. In this way most practical calibration needs are satisfied in a more economical way than by using substantially more expensive fixed point calibrations.

  12. Interdigital H -mode drift-tube linac design with alternative phase focusing for muon linac

    NASA Astrophysics Data System (ADS)

    Otani, M.; Mibe, T.; Yoshida, M.; Hasegawa, K.; Kondo, Y.; Hayashizaki, N.; Iwashita, Y.; Iwata, Y.; Kitamura, R.; Saito, N.

    2016-04-01

    We have developed an interdigital H-mode (IH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The IH-DTL accelerates muons from β =v /c =0.08 to 0.28 at an operational frequency of 324 MHz. The output beam emittances are calculated as 0.315 π and 0.195 π mm mrad in the horizontal and vertical directions, respectively, which satisfies the experimental requirement.

  13. Clearfell controversies and alternative timber harvest designs: how acceptability perceptions vary between Tasmania and the U.S. Pacific Northwest.

    PubMed

    Ribe, Robert G; Ford, Rebecca M; Williams, Kathryn J H

    2013-01-15

    Perceptions of the acceptability of alternative "variable retention" timber harvests, that keep trees standing in harvested areas, were compared between regions beset by major forestry conflicts. Data from similar studies of similar harvest systems were compared between Oregon and Tasmania. These comparisons were related to attitudes and to differences in ecosystems, silvicultural prescriptions, forestry outcomes, aesthetics, and social-political context. Findings showed that perceptions measured in one region cannot be assumed valid in another. Substantial regional differences arose not from general sociological differences but from differences in local forestry outcomes. These largely arose from different regeneration requirements of commercial tree species and consequent differences in the design of otherwise analogous harvests. Comparisons of perceptions by people with similar attitudes yielded substantial regional differences. Those prioritizing ecological conservation were mainly influenced by habitat outcomes, and consequently preferred harvests with aggregated tree retention patterns in Tasmania but not in Oregon. People sympathetic to timber industry interests in both regions showed little association between forestry outcomes and acceptability and favoured more intensive harvests. Tasmanian harvest advocates perceived harvests that keep more standing trees as less acceptable than those in Oregon. This may be due to sampling differences or to greater risk perceptions towards new harvest designs in Tasmania. Tasmanians generally disliked clearfelling more than Oregonians, likely due to different political narratives framing these perceptions or to higher aesthetic impacts in Tasmania due to burning. Dispersed retention was perceived as more acceptable in Oregon than in Tasmania, likely because Oregon had much higher post-harvest tree densities. Regional differences in wildfire-risk and logger-safety were not strongly associated with different acceptability

  14. A Comparison of Candidate Seal Designs for Future Docking Systems

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick, H., Jr.; Steinetz, Bruce, M.

    2012-01-01

    NASA is developing a new docking system to support future space exploration missions to low Earth orbit, the Moon, and other destinations. A key component of this system is the seal at the main docking interface which inhibits the loss of cabin air once docking is complete. Depending on the mission, the seal must be able to dock in either a seal-on-flange or seal-on-seal configuration. Seal-on-flange mating would occur when a docking system equipped with a seal docks to a system with a flat metal flange. This would occur when a vehicle docks to a node on the International Space Station. Seal-on-seal mating would occur when two docking systems equipped with seals dock to each other. Two types of seal designs were identified for this application: Gask-O-seals and multi-piece seals. Both types of seals had a pair of seal bulbs to satisfy the redundancy requirement. A series of performance assessments and comparisons were made between the candidate seal designs indicating that they meet the requirements for leak rate and compression and adhesion loads under a range of operating conditions. Other design factors such as part count, integration into the docking system tunnel, seal-on-seal mating, and cost were also considered leading to the selection of the multi-piece seal design for the new docking system. The results of this study can be used by designers of future docking systems and other habitable volumes to select the seal design best-suited for their particular application.

  15. Preliminary design study of an alternate heat source assembly for a Brayton isotope power system

    NASA Technical Reports Server (NTRS)

    Strumpf, H. J.

    1978-01-01

    Results are presented for a study of the preliminary design of an alternate heat source assembly (HSA) intended for use in the Brayton isotope power system (BIPS). The BIPS converts thermal energy emitted by a radioactive heat source into electrical energy by means of a closed Brayton cycle. A heat source heat exchanger configuration was selected and optimized. The design consists of a 10 turn helically wound Hastelloy X tube. Thermal analyses were performed for various operating conditions to ensure that post impact containment shell (PICS) temperatures remain within specified limits. These limits are essentially satisfied for all modes of operation except for the emergency cooling system for which the PICS temperatures are too high. Neon was found to be the best choice for a fill gas for auxiliary cooling system operation. Low cycle fatigue life, natural frequency, and dynamic loading requirements can be met with minor modifications to the existing HSA.

  16. Using micro-simulation to investigate the safety impacts of transit design alternatives at signalized intersections.

    PubMed

    Li, Lu; Persaud, Bhagwant; Shalaby, Amer

    2017-03-01

    This study investigates the use of crash prediction models and micro-simulation to develop an effective surrogate safety assessment measure at the intersection level. With the use of these tools, hypothetical scenarios can be developed and explored to evaluate the safety impacts of design alternatives in a controlled environment, in which factors not directly associated with the design alternatives can be fixed. Micro-simulation models are developed, calibrated, and validated. Traffic conflicts in the micro-simulation models are estimated and linked with observed crash frequency, which greatly alleviates the lengthy time needed to collect sufficient crash data for evaluating alternatives, due to the rare and infrequent nature of crash events. A set of generalized linear models with negative binomial error structure is developed to correlate the simulated conflicts with the observed crash frequency in Toronto, Ontario, Canada. Crash prediction models are also developed for crashes of different impact types and for transit-involved crashes. The resulting statistical significance and the goodness-of-fit of the models suggest adequate predictive ability. Based on the established correlation between simulated conflicts and observed crashes, scenarios are developed in the micro-simulation models to investigate the safety effects of individual transit line elements by making hypothetical modifications to such elements and estimating changes in crash frequency from the resulting changes in conflicts. The findings imply that the existing transit signal priority schemes can have a negative effect on safety performance, and that the existing near-side stop positioning and streetcar transit type can be safer at their current state than if they were to be replaced by their respective counterparts.

  17. Beyond Fullerenes: Designing Alternative Molecular Electron Acceptors for Solution-Processable Bulk Heterojunction Organic Photovoltaics.

    PubMed

    Sauvé, Geneviève; Fernando, Roshan

    2015-09-17

    Organic photovoltaics (OPVs) are promising candidates for providing a low cost, widespread energy source by converting sunlight into electricity. Solution-processable active layers have predominantly consisted of a conjugated polymer donor blended with a fullerene derivative as the acceptor. Although fullerene derivatives have been the acceptor of choice, they have drawbacks such as weak visible light absorption and poor energy tuning that limit overall efficiencies. This has recently fueled new research to explore alternative acceptors that would overcome those limitations. During this exploration, one question arises: what are the important design principles for developing nonfullerene acceptors? It is generally accepted that acceptors should have high electron affinity, electron mobility, and absorption coefficient in the visible and near-IR region of the spectra. In this Perspective, we argue that alternative molecular acceptors, when blended with a conjugated polymer donor, should also have large nonplanar structures to promote nanoscale phase separation, charge separation and charge transport in blend films. Additionally, new material design should address the low dielectric constant of organic semiconductors that have so far limited their widespread application.

  18. A demonstration of motion base design alternatives for the National Advanced Driving Simulator

    NASA Technical Reports Server (NTRS)

    Mccauley, Michael E.; Sharkey, Thomas J.; Sinacori, John B.; Laforce, Soren; Miller, James C.; Cook, Anthony

    1992-01-01

    A demonstration of the capability of NASA's Vertical Motion Simulator to simulate two alternative motion base designs for the National Advanced Driving simulator (NADS) is reported. The VMS is located at ARC. The motion base conditions used in this demonstration were as follows: (1) a large translational motion base; and (2) a motion base design with limited translational capability. The latter had translational capability representative of a typical synergistic motion platform. These alternatives were selected to test the prediction that large amplitude translational motion would result in a lower incidence or severity of simulator induced sickness (SIS) than would a limited translational motion base. A total of 10 drivers performed two tasks, slaloms and quick-stops, using each of the motion bases. Physiological, objective, and subjective measures were collected. No reliable differences in SIS between the motion base conditions was found in this demonstration. However, in light of the cost considerations and engineering challenges associated with implementing a large translation motion base, performance of a formal study is recommended.

  19. A Visual Analytics Based Decision Support Methodology For Evaluating Low Energy Building Design Alternatives

    NASA Astrophysics Data System (ADS)

    Dutta, Ranojoy

    The ability to design high performance buildings has acquired great importance in recent years due to numerous federal, societal and environmental initiatives. However, this endeavor is much more demanding in terms of designer expertise and time. It requires a whole new level of synergy between automated performance prediction with the human capabilities to perceive, evaluate and ultimately select a suitable solution. While performance prediction can be highly automated through the use of computers, performance evaluation cannot, unless it is with respect to a single criterion. The need to address multi-criteria requirements makes it more valuable for a designer to know the "latitude" or "degrees of freedom" he has in changing certain design variables while achieving preset criteria such as energy performance, life cycle cost, environmental impacts etc. This requirement can be met by a decision support framework based on near-optimal "satisficing" as opposed to purely optimal decision making techniques. Currently, such a comprehensive design framework is lacking, which is the basis for undertaking this research. The primary objective of this research is to facilitate a complementary relationship between designers and computers for Multi-Criterion Decision Making (MCDM) during high performance building design. It is based on the application of Monte Carlo approaches to create a database of solutions using deterministic whole building energy simulations, along with data mining methods to rank variable importance and reduce the multi-dimensionality of the problem. A novel interactive visualization approach is then proposed which uses regression based models to create dynamic interplays of how varying these important variables affect the multiple criteria, while providing a visual range or band of variation of the different design parameters. The MCDM process has been incorporated into an alternative methodology for high performance building design referred to as

  20. Conceptual design of a nonscaling fixed field alternating gradient accelerator for protons and carbon ions for charged particle therapy

    NASA Astrophysics Data System (ADS)

    Peach, K. J.; Aslaninejad, M.; Barlow, R. J.; Beard, C. D.; Bliss, N.; Cobb, J. H.; Easton, M. J.; Edgecock, T. R.; Fenning, R.; Gardner, I. S. K.; Hill, M. A.; Owen, H. L.; Johnstone, C. J.; Jones, B.; Jones, T.; Kelliher, D. J.; Khan, A.; Machida, S.; McIntosh, P. A.; Pattalwar, S.; Pasternak, J.; Pozimski, J.; Prior, C. R.; Rochford, J.; Rogers, C. T.; Seviour, R.; Sheehy, S. L.; Smith, S. L.; Strachan, J.; Tygier, S.; Vojnovic, B.; Wilson, P.; Witte, H.; Yokoi, T.

    2013-03-01

    The conceptual design for a nonscaling fixed field alternating gradient accelerator suitable for charged particle therapy (the use of protons and other light ions to treat some forms of cancer) is described.

  1. Management of radioactive waste gases from the nuclear fuel cycle. Volume I. Comparison of alternatives

    SciTech Connect

    Evans, A.G.; Prout, W.E.; Buckner, J.T.; Buckner, M.R.

    1980-12-01

    Alternatives were compared for collection and fixation of radioactive waste gases released during normal operation of the nuclear fuel cycle, and for transportation and storage/disposal of the resulting waste forms. The study used a numerical rating scheme to evaluate and compare the alternatives for krypton-85, iodine-129, and carbon-14; whereas a subjective evaluation, based on published reports and engineering judgement, was made for transportation and storage/disposal options. Based on these evaluations, certain alternatives are recommended for an integrated scheme for waste management of each of the subject waste gases. Phase II of this project, which is concerned with the development of performance criteria for the waste forms associated with the subject gases, will be completed by the end of 1980. This work will be documented as Volume II of this report.

  2. Two-stage k-sample designs for the ordered alternative problem.

    PubMed

    Shan, Guogen; Hutson, Alan D; Wilding, Gregory E

    2012-01-01

    In preclinical studies and clinical dose-ranging trials, the Jonckheere-Terpstra test is widely used in the assessment of dose-response relationships. Hewett and Spurrier (1979) presented a two-stage analog of the test in the context of large sample sizes. In this paper, we propose an exact test based on Simon's minimax and optimal design criteria originally used in one-arm phase II designs based on binary endpoints. The convergence rate of the joint distribution of the first and second stage test statistics to the limiting distribution is studied, and design parameters are provided for a variety of assumed alternatives. The behavior of the test is also examined in the presence of ties, and the proposed designs are illustrated through application in the planning of a hypercholesterolemia clinical trial. The minimax and optimal two-stage procedures are shown to be preferable as compared with the one-stage procedure because of the associated reduction in expected sample size for given error constraints.

  3. Lithography alternatives meet design style reality: How do they "line" up?

    NASA Astrophysics Data System (ADS)

    Smayling, Michael C.

    2016-03-01

    Optical lithography resolution scaling has stalled, giving innovative alternatives a window of opportunity. One important factor that impacts these lithographic approaches is the transition in design style from 2D to 1D for advanced CMOS logic. Just as the transition from 3D circuits to 2D fabrication 50 years ago created an opportunity for a new breed of electronics companies, the transition today presents exciting and challenging time for lithographers. Today, we are looking at a range of non-optical lithography processes. Those considered here can be broadly categorized: self-aligned lithography, self-assembled lithography, deposition lithography, nano-imprint lithography, pixelated e-beam lithography, shot-based e-beam lithography .Do any of these alternatives benefit from or take advantage of 1D layout? Yes, for example SAPD + CL (Self Aligned Pitch Division combined with Complementary Lithography). This is a widely adopted process for CMOS nodes at 22nm and below. Can there be additional design / process co-optimization? In spite of the simple-looking nature of 1D layout, the placement of "cut" in the lines and "holes" for interlayer connections can be tuned for a given process capability. Examples of such optimization have been presented at this conference, typically showing a reduction of at least one in the number of cut or hole patterns needed.[1,2] Can any of the alternatives complement each other or optical lithography? Yes.[3] For example, DSA (Directed Self Assembly) combines optical lithography with self-assembly. CEBL (Complementary e-Beam Lithography) combines optical lithography with SAPD for lines with shot-based e-beam lithography for cuts and holes. Does one (shrinking) size fit all? No, that's why we have many alternatives. For example NIL (Nano-imprint Lithography) has been introduced for NAND Flash patterning where the (trending lower) defectivity is acceptable for the product. Deposition lithography has been introduced in 3D NAND Flash to

  4. Intramolecular catalytic asymmetric carbon-hydrogen insertion reactions. Synthetic advantages in total synthesis in comparison with alternative approaches.

    PubMed

    Doyle, Michael P; Ratnikov, Maxim; Liu, Yu

    2011-06-07

    The synthetic potential of highly directional formal insertion of a carbene between carbon and hydrogen of a carbon-hydrogen bond has recently been developed for intramolecular reactions that lead to compounds of biological and medicinal interest. Stereoselective and regiocontrolled intramolecular processes from diazoacetate reactants, catalyzed by dirhodium(II) compounds with chiral carboxamidate ligands, provide efficient and selective access to compounds as diverse as enterolactone, baclofen, imperanene, xylolactone, and rolipram. A comparison of the C-H insertion methodology with alternative approaches is presented.

  5. Randomized controlled trials and neuro-oncology: should alternative designs be considered?

    PubMed

    Mansouri, Alireza; Shin, Samuel; Cooper, Benjamin; Srivastava, Archita; Bhandari, Mohit; Kondziolka, Douglas

    2015-09-01

    quality of design/reporting of RCTs in neuro-oncology persist. Quality improvement is necessary. Consideration of alternative strategies should be considered.

  6. Overview On Alternate Asbestos Control Method Research And NESHAP Comparison - Nashville, TN

    EPA Science Inventory

    The alternative asbestos control method (AACM) is an experimental approach to building demolition. Unlike the NESHAP method, the AACM allows some regulated asbestos containing material to remain in the building and a surfactant-water solution is used to suppress asbestos fibers ...

  7. Total Program Efficacy: A Comparison of Traditionally and Alternatively Certified Agriculture Teachers

    ERIC Educational Resources Information Center

    Duncan, Dennis W.; Ricketts, John C.

    2008-01-01

    The purpose of this study was to determine agriculture teachers' perceived levels of efficacy as they relate to managing the total program of agricultural education, both for traditionally and alternatively certified teachers. The constructs used in this study were technical content, FFA/leadership development/SAE, teaching and learning, and…

  8. Teaching Efficacy: A Comparison of Traditionally and Alternatively Certified CTE Teachers in Idaho

    ERIC Educational Resources Information Center

    Duncan, Dennis W.; Cannon, John; Kitchel, Allen

    2013-01-01

    The purpose of this study was to examine Idaho career and technical education (CTE) teachers' perceived levels of efficacy as related to the domain of teaching and learning, both for traditionally and alternatively certified teachers with 10 or less years of teaching experience. Efficacy was examined for early to mid-career CTE teachers across two…

  9. Comparison of Traditional and Alternative Fitness Teaching Formats on Heart Rate Intensity and Perceived Enjoyment.

    ERIC Educational Resources Information Center

    Ha, Amy Sau-ching; Heung-Sang Wong, Stephen

    2002-01-01

    Compared a traditional and an alternative (skill-fitness- music) fitness teaching format to determine whether there would be differences on Hong Kong middle school students' heart rate intensity and perceived enjoyment. Data from heart rate monitors and student surveys indicated that the two formats did not produce differences in heart rates.…

  10. A Comparison of Dense-to-Lean and Fixed Lean Schedules of Alternative Reinforcement and Extinction

    ERIC Educational Resources Information Center

    Hagopian, Louis P.; Toole, Lisa M.; Long, Ethan S.; Bowman, Lynn G.; Lieving, Gregory A.

    2004-01-01

    Behavior-reduction interventions typically employ dense schedules of alternative reinforcement in conjunction with operant extinction for problem behavior. After problem behavior is reduced in the initial treatment stages, schedule thinning is routinely conducted to make the intervention more practical in natural environments. In the current…

  11. Comparison of Health-Risk Behaviors among Students Attending Alternative and Traditional High Schools in Minnesota

    ERIC Educational Resources Information Center

    Johnson, Karen E.; McMorris, Barbara J.; Kubik, Martha Y.

    2013-01-01

    Previous research, over a decade old, suggests students attending alternative high schools (AHS) engage in high levels of health-risk behaviors. Data from the 2007 Minnesota Student Survey for students attending AHS ("n" = 2,847) and traditional high schools (THS; "n" = 87,468) were used for this cross-sectional analysis to…

  12. Certification Requirements and Teacher Quality: A Comparison of Alternative Routes to Teaching. Working Paper 64

    ERIC Educational Resources Information Center

    Sass, Tim R.

    2011-01-01

    Traditionally, states have required individuals complete a program of study in a university-based teacher preparation program in order to be licensed to teach. In recent years, however, various "alternative certification" programs have been developed and the number of teachers obtaining teaching certificates through routes other than…

  13. STATUS REPORT ON THE EVALUATION OF THE ALTERNATIVE ASBESTOS CONTROL METHOD – A COMPARISON TO THE NESHAP METHOD OF DEMOLITION OF ASBESTOS CONTAINING BUILDINGS

    EPA Science Inventory

    Status Report on the Evaluation of the Alternative Asbestos Control Method – A Comparison to the NESHAP Method of Demolition of Asbestos Containing Buildings. This abstract and presentation are based, at least in part, on preliminary data and conclusions. The Alternative Asbestos...

  14. Preliminary Evaluation of Alternate Designs for HFIR Low-Enriched Uranium Fuel

    SciTech Connect

    Renfro, David; Chandler, David; Cook, David; Ilas, Germina; Jain, Prashant; Valentine, Jennifer

    2014-10-30

    Engineering design studies of the feasibility of conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL) as part of an effort sponsored by the U.S. Department of Energy’s Global Threat Reduction Initiative (GTRI)/Reduced Enrichment for Research and Test Reactors (RERTR) program. The fuel type selected by the program for the conversion of the five high-power research reactors in the U.S. that still use HEU fuel is a new U-Mo monolithic fuel. Studies by ORNL have previously indicated that HFIR can be successfully converted using the new fuel provided (1) the reactor power can be increased from 85 MW to 100 MW and (2) the fuel can be fabricated to a specific reference design. Fabrication techniques for the new fuel are under development by the program but are still immature, especially for the “complex” aspects of the HFIR fuel design. In FY 2012, the program underwent a major shift in focus to emphasize developing and qualifying processes for the fabrication of reliable and affordable LEU fuel. In support of this new focus and in an effort to ensure that the HFIR fuel design is as suitable for reliable fabrication as possible, ORNL undertook the present study to propose and evaluate several alternative design features. These features include (1) eliminating the fuel zone axial contouring in the previous reference design by substituting a permanent neutron absorber in the lower unfueled region of all of the fuel plates, (2) relocating the burnable neutron absorber from the fuel plates of the inner fuel element to the side plates of the inner fuel element (the fuel plates of the outer fuel element do not contain a burnable absorber), (3) relocating the fuel zone inside the fuel plate to be centered on the centerline of the depth of the plate, and (4) reshaping the radial contour of the relocated fuel zone to be symmetric about this centerline. The

  15. Preliminary Evaluation of Alternate Designs for HFIR Low-Enriched Uranium Fuel

    SciTech Connect

    Renfro, David G; Chandler, David; Cook, David Howard; Ilas, Germina; Jain, Prashant K; Valentine, Jennifer R

    2014-11-01

    Engineering design studies of the feasibility of conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL) as part of an effort sponsored by the U.S. Department of Energy s Global Threat Reduction Initiative (GTRI)/Reduced Enrichment for Research and Test Reactors (RERTR) program. The fuel type selected by the program for the conversion of the five high-power research reactors in the U.S. that still use HEU fuel is a new U-Mo monolithic fuel. Studies by ORNL have previously indicated that HFIR can be successfully converted using the new fuel provided (1) the reactor power can be increased from 85 MW to 100 MW and (2) the fuel can be fabricated to a specific reference design. Fabrication techniques for the new fuel are under development by the program but are still immature, especially for the complex aspects of the HFIR fuel design. In FY 2012, the program underwent a major shift in focus to emphasize developing and qualifying processes for the fabrication of reliable and affordable LEU fuel. In support of this new focus and in an effort to ensure that the HFIR fuel design is as suitable for reliable fabrication as possible, ORNL undertook the present study to propose and evaluate several alternative design features. These features include (1) eliminating the fuel zone axial contouring in the previous reference design by substituting a permanent neutron absorber in the lower unfueled region of all of the fuel plates, (2) relocating the burnable neutron absorber from the fuel plates of the inner fuel element to the side plates of the inner fuel element (the fuel plates of the outer fuel element do not contain a burnable absorber), (3) relocating the fuel zone inside the fuel plate to be centered on the centerline of the depth of the plate, and (4) reshaping the radial contour of the relocated fuel zone to be symmetric about this centerline. The present

  16. Comparison of coil designs for peripheral magnetic muscle stimulation

    NASA Astrophysics Data System (ADS)

    Goetz, S. M.; Herzog, H.-G.; Gattinger, N.; Gleich, B.

    2011-10-01

    The recent application of magnetic stimulation in rehabilitation is often said to solve key drawbacks of the established electrical method. Magnetic fields cause less pain, allow principally a better penetration of inhomogeneous biologic tissue and do not require skin contact. However, in most studies the evoked muscle force has been disappointing. In this paper, a comparison of a classical round circular geometry, a commercial muscle-stimulation coil and a novel design is presented, with special emphasis on the physical field properties. These systems show markedly different force responses for the same magnetic energy and highlight the enormous potential of different coil geometries. The new design resulted in a slope of the force recruiting curve being more than two and a half times higher than the other coils. The data were analyzed with respect to the underlying physical causes and field conditions. After a parameter-extraction approach, the results for the three coils span a two-dimensional space with clearly distinguishable degrees of freedom, which can be manipulated nearly separately and reflect the two main features of a field; the peak amplitude and its decay with the distance.

  17. Bayesian Comparison of Alternative Graded Response Models for Performance Assessment Applications

    ERIC Educational Resources Information Center

    Zhu, Xiaowen; Stone, Clement A.

    2012-01-01

    This study examined the relative effectiveness of Bayesian model comparison methods in selecting an appropriate graded response (GR) model for performance assessment applications. Three popular methods were considered: deviance information criterion (DIC), conditional predictive ordinate (CPO), and posterior predictive model checking (PPMC). Using…

  18. Comparison of Alternative Methods for Obtaining Severity Scores of the Speech of People Who Stutter

    ERIC Educational Resources Information Center

    Howell, Peter; Soukup-Ascencao, Tajana; Davis, Stephen; Rusbridge, Sarah

    2011-01-01

    Riley's Stuttering Severity Instrument (SSI) is widely used. The manuals allow SSI assessments to be made in different ways (e.g. from digital recordings or whilst listening to speech live). Digital recordings allow segments to be selected and listened to, whereas the entire recording has to be judged when listened to live. Comparison was made…

  19. Composting on Mars or the Moon: I. Comparative evaluation of process design alternatives.

    PubMed

    Finstein, M S; Strom, P F; Hogan, J A; Cowan, R M

    1999-01-01

    As a candidate technology for treating solid wastes and recovering resources in bioregenerative Advanced Life Support, composting potentially offers such advantages as compactness, low mass, near ambient reactor temperatures and pressures, reliability, flexibility, simplicity, and forgiveness of operational error or neglect. Importantly, the interactions among the physical, chemical, and biological factors that govern composting system behavior are well understood. This article comparatively evaluates five Generic Systems that describe the basic alternatives to composting facility design and control. These are: 1) passive aeration; 2) passive aeration abetted by mechanical agitation; 3) forced aeration--O2 feedback control; 4) forced aeration--temperature feedback control; 5) forced aeration--integrated O2 and temperature feedback control. Each of the five has a distinctive pattern of behavior and process performance characteristics. Only Systems 4 and 5 are judged to be viable candidates for ALS on alien worlds, though which is better suited in this application is yet to be determined.

  20. Composting on Mars or the Moon: I. Comparative evaluation of process design alternatives

    NASA Technical Reports Server (NTRS)

    Finstein, M. S.; Strom, P. F.; Hogan, J. A.; Cowan, R. M.; Janes, H. W. (Principal Investigator)

    1999-01-01

    As a candidate technology for treating solid wastes and recovering resources in bioregenerative Advanced Life Support, composting potentially offers such advantages as compactness, low mass, near ambient reactor temperatures and pressures, reliability, flexibility, simplicity, and forgiveness of operational error or neglect. Importantly, the interactions among the physical, chemical, and biological factors that govern composting system behavior are well understood. This article comparatively evaluates five Generic Systems that describe the basic alternatives to composting facility design and control. These are: 1) passive aeration; 2) passive aeration abetted by mechanical agitation; 3) forced aeration--O2 feedback control; 4) forced aeration--temperature feedback control; 5) forced aeration--integrated O2 and temperature feedback control. Each of the five has a distinctive pattern of behavior and process performance characteristics. Only Systems 4 and 5 are judged to be viable candidates for ALS on alien worlds, though which is better suited in this application is yet to be determined.

  1. A comparison of dense-to-lean and fixed lean schedules of alternative reinforcement and extinction.

    PubMed

    Hagopian, Louis P; Toole, Lisa M; Long, Ethan S; Bowman, Lynn G; Lieving, Gregory A

    2004-01-01

    Behavior-reduction interventions typically employ dense schedules of alternative reinforcement in conjunction with operant extinction for problem behavior. After problem behavior is reduced in the initial treatment stages, schedule thinning is routinely conducted to make the intervention more practical in natural environments. In the current investigation, two methods for thinning alternative reinforcement schedules were compared for 3 clients who exhibited severe problem behavior. In the dense-to-lean (DTL) condition, reinforcement was delivered on relatively dense schedules (using noncontingent reinforcement for 1 participant and functional communication training for 2 participants), followed by systematic schedule thinning to progressively leaner schedules. During the fixed lean (FL) condition, reinforcement was delivered on lean schedules (equivalent to the terminal schedule of the DTL condition). The FL condition produced a quicker attainment of individual treatment goals for 2 of the 3 participants. The results are discussed in terms of the potential utility of using relatively lean schedules at treatment outset.

  2. A comparison of dense-to-lean and fixed lean schedules of alternative reinforcement and extinction.

    PubMed Central

    Hagopian, Louis P; Toole, Lisa M; Long, Ethan S; Bowman, Lynn G; Lieving, Gregory A

    2004-01-01

    Behavior-reduction interventions typically employ dense schedules of alternative reinforcement in conjunction with operant extinction for problem behavior. After problem behavior is reduced in the initial treatment stages, schedule thinning is routinely conducted to make the intervention more practical in natural environments. In the current investigation, two methods for thinning alternative reinforcement schedules were compared for 3 clients who exhibited severe problem behavior. In the dense-to-lean (DTL) condition, reinforcement was delivered on relatively dense schedules (using noncontingent reinforcement for 1 participant and functional communication training for 2 participants), followed by systematic schedule thinning to progressively leaner schedules. During the fixed lean (FL) condition, reinforcement was delivered on lean schedules (equivalent to the terminal schedule of the DTL condition). The FL condition produced a quicker attainment of individual treatment goals for 2 of the 3 participants. The results are discussed in terms of the potential utility of using relatively lean schedules at treatment outset. PMID:15529889

  3. An alternative experimental case-control design for genetic association studies on bovine mastitis.

    PubMed

    Biffani, S; Del Corvo, M; Capoferri, R; Pedretti, A; Luini, M; Williams, J L; Pagnacco, G; Minvielle, F; Minozzi, G

    2017-04-01

    The possibility of using genetic control strategies to increase disease resistance to infectious diseases relies on the identification of markers to include in the breeding plans. Possible incomplete exposure of mastitis-free (control) animals, however, is a major issue to find relevant markers in genetic association studies for infectious diseases. Usually, designs based on elite dairy sires are used in association studies, but an epidemiological case-control strategy, based on cows repeatedly field-tested could be an alternative for disease traits. To test this hypothesis, genetic association results obtained in the present work from a cohort of Italian Holstein cows tested for mastitis over time were compared with those from a previous genome-wide scan on Italian Holstein sires genotyped with 50k single nucleotide polymorphisms for de-regressed estimated breeding values for somatic cell counts (SCCs) on Bos taurus autosome (BTA6) and BTA14. A total of 1121 cows were selected for the case-control approach (cases=550, controls=571), on a combination of herd level of SCC incidence and of within herd individual level of SCC. The association study was conducted on nine previously identified markers, six on BTA6 and four on BTA14, using the R statistical environment with the 'qtscore' function of the GenABEL package, on high/low adjusted linear score as a binomial trait. The results obtained in the cow cohort selected on epidemiological information were in agreement with those obtained from the previous sire genome-wide association study (GWAS). Six out of the nine markers showed significant association, four on BTA14 (rs109146371, rs109234250, rs109421300, rs109162116) and two on BTA6 (rs110527224 and rs42766480). Most importantly, using mastitis as a case study, the current work further validated the alternative use of historical field disease data in case-control designs for genetic analysis of infectious diseases in livestock.

  4. On the significance of an alternate pathway of melatonin synthesis via 5-methoxytryptamine: comparisons across species.

    PubMed

    Tan, Dun-Xian; Hardeland, Rüdiger; Back, Kyoungwhan; Manchester, Lucien C; Alatorre-Jimenez, Moises A; Reiter, Russel J

    2016-08-01

    Melatonin is a phylogenetically ancient molecule. It is ubiquitously present in almost all organisms from primitive photosynthetic bacteria to humans. Its original primary function is presumable to be that of an antioxidant with other functions of this molecule having been acquired during evolution. The synthetic pathway of melatonin in vertebrates has been extensively studied. It is common knowledge that serotonin is acetylated to form N-acetylserotonin by arylalkylamine N-acetyltransferase (AANAT) or arylamine N-acetyltransferase (SNAT or NAT) and N-acetylserotonin is, subsequently, methylated to melatonin by N-acetylserotonin O-methyltransferase (ASMT; also known as hydroxyindole-O-methyltransferase, HIOMT). This is referred to as a classic melatonin synthetic pathway. Based on new evidence, we feel that this classic melatonin pathway is not generally the prevailing route of melatonin production. An alternate pathway is known to exist, in which serotonin is first O-methylated to 5-methoxytryptamine (5-MT) and, thereafter, 5-MT is N-acetylated to melatonin. Here, we hypothesize that the alternate melatonin synthetic pathway may be more important in certain organisms and under certain conditions. Evidence strongly supports that this alternate pathway prevails in some plants, bacteria, and, perhaps, yeast and may also occur in animals.

  5. A comparative study of Soviet versus Western helicopters. Part 1: General comparison of designs

    NASA Technical Reports Server (NTRS)

    Stepniewski, W. Z.

    1983-01-01

    This document provides a general comparison of the state of the art of Soviet helicopter design vs. that of the West (U.S. in particular). It includes both commonalities and differences in conceptual design philosophies by addressing design parameters and design effectiveness according to accepted criteria. The baseline for comparison is by design gross weight which is presented in four categories: under 12,000 lb, 30-100,000 lb, and greater than 100,000 lb.

  6. A Dominant Social Comparison Heuristic Unites Alternative Mechanisms for the Evolution of Indirect Reciprocity

    PubMed Central

    Whitaker, Roger M.; Colombo, Gualtiero B.; Allen, Stuart M.; Dunbar, Robin I. M.

    2016-01-01

    Cooperation is a fundamental human trait but our understanding of how it functions remains incomplete. Indirect reciprocity is a particular case in point, where one-shot donations are made to unrelated beneficiaries without any guarantee of payback. Existing insights are largely from two independent perspectives: i) individual-level cognitive behaviour in decision making, and ii) identification of conditions that favour evolution of cooperation. We identify a fundamental connection between these two areas by examining social comparison as a means through which indirect reciprocity can evolve. Social comparison is well established as an inherent human disposition through which humans navigate the social world by self-referential evaluation of others. Donating to those that are at least as reputable as oneself emerges as a dominant heuristic, which represents aspirational homophily. This heuristic is found to be implicitly present in the current knowledge of conditions that favour indirect reciprocity. The effective social norms for updating reputation are also observed to support this heuristic. We hypothesise that the cognitive challenge associated with social comparison has contributed to cerebral expansion and the disproportionate human brain size, consistent with the social complexity hypothesis. The findings have relevance for the evolution of autonomous systems that are characterised by one-shot interactions. PMID:27515119

  7. A Dominant Social Comparison Heuristic Unites Alternative Mechanisms for the Evolution of Indirect Reciprocity

    NASA Astrophysics Data System (ADS)

    Whitaker, Roger M.; Colombo, Gualtiero B.; Allen, Stuart M.; Dunbar, Robin I. M.

    2016-08-01

    Cooperation is a fundamental human trait but our understanding of how it functions remains incomplete. Indirect reciprocity is a particular case in point, where one-shot donations are made to unrelated beneficiaries without any guarantee of payback. Existing insights are largely from two independent perspectives: i) individual-level cognitive behaviour in decision making, and ii) identification of conditions that favour evolution of cooperation. We identify a fundamental connection between these two areas by examining social comparison as a means through which indirect reciprocity can evolve. Social comparison is well established as an inherent human disposition through which humans navigate the social world by self-referential evaluation of others. Donating to those that are at least as reputable as oneself emerges as a dominant heuristic, which represents aspirational homophily. This heuristic is found to be implicitly present in the current knowledge of conditions that favour indirect reciprocity. The effective social norms for updating reputation are also observed to support this heuristic. We hypothesise that the cognitive challenge associated with social comparison has contributed to cerebral expansion and the disproportionate human brain size, consistent with the social complexity hypothesis. The findings have relevance for the evolution of autonomous systems that are characterised by one-shot interactions.

  8. Alternative sanitization methods for minimally processed lettuce in comparison to sodium hypochlorite

    PubMed Central

    Bachelli, Mara Lígia Biazotto; Amaral, Rívia Darla Álvares; Benedetti, Benedito Carlos

    2013-01-01

    Lettuce is a leafy vegetable widely used in industry for minimally processed products, in which the step of sanitization is the crucial moment for ensuring a safe food for consumption. Chlorinated compounds, mainly sodium hypochlorite, are the most used in Brazil, but the formation of trihalomethanes from this sanitizer is a drawback. Then, the search for alternative methods to sodium hypochlorite has been emerging as a matter of great interest. The suitability of chlorine dioxide (60 mg L−1/10 min), peracetic acid (100 mg L−1/15 min) and ozonated water (1.2 mg L−1 /1 min) as alternative sanitizers to sodium hypochlorite (150 mg L−1 free chlorine/15 min) were evaluated. Minimally processed lettuce washed with tap water for 1 min was used as a control. Microbiological analyses were performed in triplicate, before and after sanitization, and at 3, 6, 9 and 12 days of storage at 2 ± 1 °C with the product packaged on LDPE bags of 60 μm. It was evaluated total coliforms, Escherichia coli, Salmonella spp., psicrotrophic and mesophilic bacteria, yeasts and molds. All samples of minimally processed lettuce showed absence of E. coli and Salmonella spp. The treatments of chlorine dioxide, peracetic acid and ozonated water promoted reduction of 2.5, 1.1 and 0.7 log cycle, respectively, on count of microbial load of minimally processed product and can be used as substitutes for sodium hypochlorite. These alternative compounds promoted a shelf-life of six days to minimally processed lettuce, while the shelf-life with sodium hypochlorite was 12 days. PMID:24516433

  9. Alternative sanitization methods for minimally processed lettuce in comparison to sodium hypochlorite.

    PubMed

    Bachelli, Mara Lígia Biazotto; Amaral, Rívia Darla Álvares; Benedetti, Benedito Carlos

    2013-01-01

    Lettuce is a leafy vegetable widely used in industry for minimally processed products, in which the step of sanitization is the crucial moment for ensuring a safe food for consumption. Chlorinated compounds, mainly sodium hypochlorite, are the most used in Brazil, but the formation of trihalomethanes from this sanitizer is a drawback. Then, the search for alternative methods to sodium hypochlorite has been emerging as a matter of great interest. The suitability of chlorine dioxide (60 mg L(-1)/10 min), peracetic acid (100 mg L(-1)/15 min) and ozonated water (1.2 mg L(-1)/1 min) as alternative sanitizers to sodium hypochlorite (150 mg L(-1) free chlorine/15 min) were evaluated. Minimally processed lettuce washed with tap water for 1 min was used as a control. Microbiological analyses were performed in triplicate, before and after sanitization, and at 3, 6, 9 and 12 days of storage at 2 ± 1 °C with the product packaged on LDPE bags of 60 μm. It was evaluated total coliforms, Escherichia coli, Salmonella spp., psicrotrophic and mesophilic bacteria, yeasts and molds. All samples of minimally processed lettuce showed absence of E. coli and Salmonella spp. The treatments of chlorine dioxide, peracetic acid and ozonated water promoted reduction of 2.5, 1.1 and 0.7 log cycle, respectively, on count of microbial load of minimally processed product and can be used as substitutes for sodium hypochlorite. These alternative compounds promoted a shelf-life of six days to minimally processed lettuce, while the shelf-life with sodium hypochlorite was 12 days.

  10. System comparison of hydrogen with other alternative fuels in terms of EPACT requirements

    SciTech Connect

    Barbir, F.; Oezay, K.; Veziroglu, T.N.

    1996-10-01

    The feasibility of several alternative fuels, namely natural gas, methanol, ethanol, hydrogen and electricity, to replace 10% of gasoline by the year 2000 has been investigated. The analysis was divided in two parts: (i) analysis of vehicle technologies, and (ii) analysis of fuel production storage and distribution, from the primary energy sources to the refueling station. Only technologies that are developed to at least demonstration level were considered. The amount and type of the primary energy sources have been determined for each of the fuels being analyzed. A need for a common denominator for different types of energy has been identified.

  11. Reducing motion sickness - A comparison of autogenic-feedback training and an alternative cognitive task

    NASA Technical Reports Server (NTRS)

    Toscano, W. B.; Cowings, P. S.

    1982-01-01

    Eighteen men were randomly assigned to three groups matched for susceptibility to Coriolis motion sickness. All subjects were given six Coriolis Sickness Susceptibility Index (CSSI) tests separated by 5-d intervals. Treatment Group I subjects were taught to control their own autonomic responses before the third, fourth, and fifth CSSI tests (6 h total training). Group II subjects were given 'sham' training in an alternative cognitive task under conditions otherwise identical to those of Group I. Group III subjects received no treatment. Results showed that Group I subjects could withstand the stress of Coriolis acceleration significantly longer after training. Neither of the other two groups changed significantly.

  12. Thermal Alternating Polymer Nanocomposite (TAPNC) Coating Designed to Prevent Aerodynamic Insect Fouling

    NASA Astrophysics Data System (ADS)

    Bayer, Ilker S.; Krishnan, K. Ghokulla; Robison, Robert; Loth, Eric; Berry, Douglas H.; Farrell, Thomas E.; Crouch, Jeffrey D.

    2016-12-01

    Insect residue adhesion to moving surfaces such as turbine blades and aircraft not only causes surface contamination problems but also increases drag on these surfaces. Insect fouling during takeoff, climb and landing can result in increased drag and fuel consumption for aircraft with laminar-flow surfaces. Hence, certain topographical and chemical features of non-wettable surfaces need to be designed properly for preventing insect residue accumulation on surfaces. In this work, we developed a superhydrophobic coating that is able to maintain negligible levels of insect residue after 100 high speed (50 m/s) insect impact events produced in a wind tunnel. The coating comprises alternating layers of a hydrophobic, perfluorinated acrylic copolymer and hydrophobic surface functional silicon dioxide nanoparticles that are infused into one another by successive thermal treatments. The design of this coating was achieved as a result of various experiments conducted in the wind tunnel by using a series of superhydrophobic surfaces made by the combination of the same polymer and nanoparticles in the form of nanocomposites with varying surface texture and self-cleaning hydrophobicity properties. Moreover, the coating demonstrated acceptable levels of wear abrasion and substrate adhesion resistance against pencil hardness, dry/wet scribed tape peel adhesion and 17.5 kPa Taber linear abraser tests.

  13. Thermal Alternating Polymer Nanocomposite (TAPNC) Coating Designed to Prevent Aerodynamic Insect Fouling.

    PubMed

    Bayer, Ilker S; Krishnan, K Ghokulla; Robison, Robert; Loth, Eric; Berry, Douglas H; Farrell, Thomas E; Crouch, Jeffrey D

    2016-12-07

    Insect residue adhesion to moving surfaces such as turbine blades and aircraft not only causes surface contamination problems but also increases drag on these surfaces. Insect fouling during takeoff, climb and landing can result in increased drag and fuel consumption for aircraft with laminar-flow surfaces. Hence, certain topographical and chemical features of non-wettable surfaces need to be designed properly for preventing insect residue accumulation on surfaces. In this work, we developed a superhydrophobic coating that is able to maintain negligible levels of insect residue after 100 high speed (50 m/s) insect impact events produced in a wind tunnel. The coating comprises alternating layers of a hydrophobic, perfluorinated acrylic copolymer and hydrophobic surface functional silicon dioxide nanoparticles that are infused into one another by successive thermal treatments. The design of this coating was achieved as a result of various experiments conducted in the wind tunnel by using a series of superhydrophobic surfaces made by the combination of the same polymer and nanoparticles in the form of nanocomposites with varying surface texture and self-cleaning hydrophobicity properties. Moreover, the coating demonstrated acceptable levels of wear abrasion and substrate adhesion resistance against pencil hardness, dry/wet scribed tape peel adhesion and 17.5 kPa Taber linear abraser tests.

  14. Thermal Alternating Polymer Nanocomposite (TAPNC) Coating Designed to Prevent Aerodynamic Insect Fouling

    PubMed Central

    Bayer, Ilker S.; Krishnan, K. Ghokulla; Robison, Robert; Loth, Eric; Berry, Douglas H.; Farrell, Thomas E.; Crouch, Jeffrey D.

    2016-01-01

    Insect residue adhesion to moving surfaces such as turbine blades and aircraft not only causes surface contamination problems but also increases drag on these surfaces. Insect fouling during takeoff, climb and landing can result in increased drag and fuel consumption for aircraft with laminar-flow surfaces. Hence, certain topographical and chemical features of non-wettable surfaces need to be designed properly for preventing insect residue accumulation on surfaces. In this work, we developed a superhydrophobic coating that is able to maintain negligible levels of insect residue after 100 high speed (50 m/s) insect impact events produced in a wind tunnel. The coating comprises alternating layers of a hydrophobic, perfluorinated acrylic copolymer and hydrophobic surface functional silicon dioxide nanoparticles that are infused into one another by successive thermal treatments. The design of this coating was achieved as a result of various experiments conducted in the wind tunnel by using a series of superhydrophobic surfaces made by the combination of the same polymer and nanoparticles in the form of nanocomposites with varying surface texture and self-cleaning hydrophobicity properties. Moreover, the coating demonstrated acceptable levels of wear abrasion and substrate adhesion resistance against pencil hardness, dry/wet scribed tape peel adhesion and 17.5 kPa Taber linear abraser tests. PMID:27924913

  15. LCA to choose among alternative design solutions: the case study of a new Italian incineration line.

    PubMed

    Scipioni, A; Mazzi, A; Niero, M; Boatto, T

    2009-09-01

    At international level LCA is being increasingly used to objectively evaluate the performances of different Municipal Solid Waste (MSW) management solutions. One of the more important waste management options concerns MSW incineration. LCA is usually applied to existing incineration plants. In this study LCA methodology was applied to a new Italian incineration line, to facilitate the prediction, during the design phase, of its potential environmental impacts in terms of damage to human health, ecosystem quality and consumption of resources. The aim of the study was to analyse three different design alternatives: an incineration system with dry flue gas cleaning (without- and with-energy recovery) and one with wet flue gas cleaning. The last two technological solutions both incorporating facilities for energy recovery were compared. From the results of the study, the system with energy recovery and dry flue gas cleaning revealed lower environmental impacts in relation to the ecosystem quality. As LCA results are greatly affected by uncertainties of different types, the second part of the work provides for an uncertainty analysis aimed at detecting the extent output data from life cycle analysis are influenced by uncertainty of input data, and employs both qualitative (pedigree matrix) and quantitative methods (Monte Carlo analysis).

  16. LCA to choose among alternative design solutions: The case study of a new Italian incineration line

    SciTech Connect

    Scipioni, A. Mazzi, A.; Niero, M.; Boatto, T.

    2009-09-15

    At international level LCA is being increasingly used to objectively evaluate the performances of different Municipal Solid Waste (MSW) management solutions. One of the more important waste management options concerns MSW incineration. LCA is usually applied to existing incineration plants. In this study LCA methodology was applied to a new Italian incineration line, to facilitate the prediction, during the design phase, of its potential environmental impacts in terms of damage to human health, ecosystem quality and consumption of resources. The aim of the study was to analyse three different design alternatives: an incineration system with dry flue gas cleaning (without- and with-energy recovery) and one with wet flue gas cleaning. The last two technological solutions both incorporating facilities for energy recovery were compared. From the results of the study, the system with energy recovery and dry flue gas cleaning revealed lower environmental impacts in relation to the ecosystem quality. As LCA results are greatly affected by uncertainties of different types, the second part of the work provides for an uncertainty analysis aimed at detecting the extent output data from life cycle analysis are influenced by uncertainty of input data, and employs both qualitative (pedigree matrix) and quantitative methods (Monte Carlo analysis)

  17. Life cycle comparison of waste-to-energy alternatives for municipal waste treatment in Chilean Patagonia.

    PubMed

    Bezama, Alberto; Douglas, Carla; Méndez, Jacqueline; Szarka, Nóra; Muñoz, Edmundo; Navia, Rodrigo; Schock, Steffen; Konrad, Odorico; Ulloa, Claudia

    2013-10-01

    The energy system in the Region of Aysén, Chile, is characterized by a strong dependence on fossil fuels, which account for up to 51% of the installed capacity. Although the implementation of waste-to-energy concepts in municipal waste management systems could support the establishment of a more fossil-independent energy system for the region, previous studies have concluded that energy recovery systems are not suitable from an economic perspective in Chile. Therefore, this work intends to evaluate these technical options from an environmental perspective, using life cycle assessment as a tool for a comparative analysis, considering Coyhaique city as a case study. Three technical alternatives were evaluated: (i) landfill gas recovery and flaring without energy recovery; (ii) landfill gas recovery and energy use; and (iii) the implementation of an anaerobic digestion system for the organic waste fraction coupled with energy recovery from the biogas produced. Mass and energy balances of the three analyzed alternatives have been modeled. The comparative LCA considered global warming potential, abiotic depletion and ozone layer depletion as impact categories, as well as required raw energy and produced energy as comparative regional-specific indicators. According to the results, the use of the recovered landfill gas as an energy source can be identified as the most environmentally appropriate solution for Coyhaique, especially when taking into consideration the global impact categories.

  18. Embodied Energy Assessment and Comparisons for a Residential Building Using Conventional and Alternative Materials in Indian Context

    NASA Astrophysics Data System (ADS)

    Naveen Kishore, K.; Chouhan, J. S.

    2014-06-01

    Building sector is responsible for 40 % of the primary energy use and 24 % of carbon dioxide emissions in India. The main source of green house gas emissions from buildings is due to energy consumption. This paper aims to assess the embodied energy index and environmental impact of a two storied residential building. The study proposes various alternative materials which can be used in day to day construction in order to mitigate the environmental impact and climate change due to construction activity in India. Two types of construction techniques have been considered for the study, namely load bearing and reinforced concrete framed construction. Embodied energy and carbon dioxide emissions of walling and roofing components using conventional and alternative materials has also been analyzed and compared. The comparison is done based on two parameters namely, embodied energy/m2 and CO2 emissions per unit of floor area. The study shows that bricks, cement and steel are the three major contributors to the energy cost of constructing a building by conventional methods. A conventional two storied load bearing structure is 22 % more energy efficient when compared to a reinforced concrete structure. It has also been observed from the study that use of alternative material in the building envelope gives embodied energy savings between 50 and 60 % for a two storey load bearing structure and 30-42 % for a two storey reinforced concrete structure. Hence a load bearing construction is certainly a better alternative to RC framed construction for up to two storied structures in terms of embodied energy and environmental impacts.

  19. Passive Samplers for Investigations of Air Quality: Method Description, Implementation, and Comparison to Alternative Sampling Methods

    EPA Science Inventory

    This Paper covers the basics of passive sampler design, compares passive samplers to conventional methods of air sampling, and discusses considerations when implementing a passive sampling program. The Paper also discusses field sampling and sample analysis considerations to ensu...

  20. Comparison: on-design and off-design flow through a high speed turbo pump inducer

    NASA Astrophysics Data System (ADS)

    Cluff, Ryan; Lundgreen, Ryan; Gorrell, Steve; Maynes, Daniel; Oliphant, Kerry

    2012-11-01

    A computational fluid dynamic comparison was performed between on-design and off-design flow rates through a four-bladed axial turbopump inducer. Using CD Adapco's Star-CCM as the CFD package an analysis of the two flow-rate cases was made. The simulations were run time-resolved and with two phases (water and water vapor). Turbulence employed the realizable k-epsilon model and cavitation was predicted using the Rayleigh-Plasset model. The solution discretization is second order accurate in space and first order accurate in time. The results show classical breakdown curves for both flow-rate cases. Breakdown is the condition where the entire flow path in the inducer becomes filled with vapor and the head rise over the inducer is decreased dramatically. Both cases experience breakdown at about the same cavitation number; however, because the off-design case generally has a larger head rise, its breakdown occurs at higher back pressures than the on-design case. Additionally, the off-design case experiences larger amounts of incidence that result in regions of reversed flow along the shroud and an increase of instabilities throughout the machine. Performance maps will be discussed comparing the two cases on head rise and efficiency.

  1. Analytical design of a parasitic-loading digital speed controller for a 400-hertz turbine driven alternator

    NASA Technical Reports Server (NTRS)

    Ingle, B. D.; Ryan, J. P.

    1972-01-01

    A design for a solid-state parasitic speed controller using digital logic was analyzed. Parasitic speed controllers are used in space power electrical generating systems to control the speed of turbine-driven alternators within specified limits. The analysis included the performance characteristics of the speed controller and the generation of timing functions. The speed controller using digital logic applies step loads to the alternator. The step loads conduct for a full half wave starting at either zero or 180 electrical degrees.

  2. Femtosecond laser assisted design of sutureless intrastromal graft as an alternative to partial thickness keratoplasty

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Durkee, Heather; Pini, Roberto; Canovetti, Annalisa; Malandrini, Alex; Lenzetti, Ivo; Rubino, Pierangela; Leaci, Rosachiara; Neri, Alberto; Scaroni, Patrizia; Menabuoni, Luca; Macaluso, Claudio

    2014-02-01

    Minimally invasive laser assisted surgery in ophthalmology is continuously developing in order to find new surgical approaches, preserve patient tissue and improve surgical results in terms of cut precision, restoration of visual acuity, and invasiveness. In order to achieve these goals, the current approach in corneal transplant is lamellar keratoplasty, where only the anterior or posterior part of the patient's cornea is substituted depending on the lesion or pathology. In this work, we present a novel alternative approach: a case study of intrastromal sutureless transplant, where a portion of the anterior stroma of a donor cornea was inserted into the stroma of the recipient cornea, aiming to restore the correct thickness of the patient's cornea. The patient cornea was paracentrally thin, as the result of a trophic ulcer due to ocular pemphigoid. A discoid corneal graft from the anterior stroma of a donor eye was prepared: a femtosecond laser cut with a trapezoidal profile (thickness was 300 μm, minor and major basis were 3.00 and 3.50 mm, respectively). In the recipient eye, an intrastromal cut was also performed with the femtosecond laser using a specifically designed mask; the cut position was 275 μm in depth. The graft was loaded into an injector and inserted as an intrastromal presbyopic implant. The postoperative analysis evidenced a clear and stable graft that selectively restored corneal thickness in the thinned area. Intrastromal corneal transplant surgery is a minimally invasive alternative to anterior or posterior lamellar keratoplasty in select cases. We believe that Sutureless Intrastromal Laser Keratoplasty (SILK) could open up new avenues in the field of corneal transplantation by fully utilizing the potential and precision of existing lasers.

  3. Estimation of magnitude and frequency of floods in Pima County, Arizona, with comparisons of alternative methods

    SciTech Connect

    Eychaner, J.H.

    1984-08-01

    In Pima County, Arizona, a semiarid region of large relief, new regression equations estimate 5- to 100-year flood discharges with standard errors of 42 to 49%. Standard errors for 2- and 500-year discharges are about 60%. Predictor variables are drainage area (0.013 to 4471 square miles), channel slope (0.3 to 13%), and shape factor. Second-order regression models represent the logarithmically nonlinear relations found across the wide range of basin characteristics. Flood estimates are reduced if channel conditions cause large attenuation of peaks. Estimates for gaged sites are a variance-weighted average of estimates from regressions and from gage data. Estimates for the Tucson urban area are based on equations developed in a nationwide study. Research on nonlinear logarithmic regressions and variables that index channel conditions might be useful. Two methods for estimating flood discharges from gage records, two sets of new regressions, and two previously published regional methods are compared. Distribution-free tests against maximum observed floods show differences in accuracy between the methods, and comparisons with base methods show differences in variability. The tests and comparisons indicate that the new equations are more accurate and less variable than methods previously published. 29 refs., 12 figs., 9 tabs.

  4. Is sheep lumbar spine a suitable alternative model for human spinal researches? Morphometrical comparison study

    PubMed Central

    Berner, Dagmar; Jülke, Henriette; Hohaus, Christian; Brehm, Walter; Gerlach, Kerstin

    2013-01-01

    Sheep are commonly used as a model for human spinal orthopaedic research due to their similarity in morphological and biomechanical features. This study aimed to document the volumes of vertebral bodies and compare the generated results as well as morphometry of the sheep lumbar spine to human published data. For this purpose, computed tomography scans were carried out on five adult Merino sheep under general anaesthesia. Transverse 5 mm thick images were acquired from L1 to L6 using a multi-detector-row helical CT scanner. Volume measurements were performed with dedicated software. Four spinal indices and Pavlov's ratio were calculated. Thereafter, the generated data were compared to published literature on humans. The mean vertebral body volume showed an increase towards the caudal vertebrae, but there were no significant differences between the vertebral levels (P>0.05). Compared to humans, sheep vertebral body volumes were 48.6% smaller. The comparison of absolute values between both species revealed that sheep had smaller, longer and narrower vertebral bodies, thinner intervertebral discs, narrower spinal canal, longer transverse processes, shorter dorsal spinous processes and narrower, higher pedicles with more lateral angulations. The comparison of the spinal indices showed a good similarity to human in terms of the vertebral endplates and spinal canal. The results of this study may be helpful for using the sheep as a model for human orthopaedic spinal research if anatomical differences are taken into account. PMID:24396382

  5. Comparison of coating alternatives for US Coast Guard aircraft. Final report for April 1993-August 1994

    SciTech Connect

    Hirst, D.J.; Spadafora, S.J.

    1994-12-12

    Current coatings used on U.S. Coast Guard aircraft contain high volatile organic compound (VOC) contents. Federal, state, and local environmental agencies restrict the amount of VOCs from the use of these materials through legislation such as the Clean Air Act and local Air Quality Management District Rules. At the request of the Coast Guard, the Naval Air Warfare Center Aircraft Division Warminster investigated several low VOC candidate replacements to the current paint scheme. The physical performance properties of these materials (i.e. corrosion resistance, adhesion, etc.) were characterized using standard coatings tests. The results of this program show that there are several acceptable alternatives. Replacement of current coating systems would reduce the total amount of hazardous materials emitted from Coast Guard painting operations and eliminate the need for expensive control equipment which will be required by the Clean Air Act (resulting in substantial future cost savings).

  6. Comparison of two alternative dominant selectable markers for wine yeast transformation.

    PubMed

    Cebollero, Eduardo; Gonzalez, Ramon

    2004-12-01

    Genetic improvement of industrial yeast strains is restricted by the availability of selectable transformation markers. Antibiotic resistance markers have to be avoided for public health reasons, while auxotrophy markers are generally not useful for wine yeast strain transformation because most industrial Saccharomyces cerevisiae strains are prototrophic. For this work, we performed a comparative study of the usefulness of two alternative dominant selectable markers in both episomic and centromeric plasmids. Even though the selection for sulfite resistance conferred by FZF1-4 resulted in a larger number of transformants for a laboratory strain, the p-fluoro-DL-phenylalanine resistance conferred by ARO4-OFP resulted in a more suitable selection marker for all industrial strains tested. Both episomic and centromeric constructions carrying this marker resulted in transformation frequencies close to or above 10(3) transformants per microg of DNA for the three wine yeast strains tested.

  7. Comparison of Two Alternative Dominant Selectable Markers for Wine Yeast Transformation

    PubMed Central

    Cebollero, Eduardo; Gonzalez, Ramon

    2004-01-01

    Genetic improvement of industrial yeast strains is restricted by the availability of selectable transformation markers. Antibiotic resistance markers have to be avoided for public health reasons, while auxotrophy markers are generally not useful for wine yeast strain transformation because most industrial Saccharomyces cerevisiae strains are prototrophic. For this work, we performed a comparative study of the usefulness of two alternative dominant selectable markers in both episomic and centromeric plasmids. Even though the selection for sulfite resistance conferred by FZF1-4 resulted in a larger number of transformants for a laboratory strain, the p-fluoro-dl-phenylalanine resistance conferred by ARO4-OFP resulted in a more suitable selection marker for all industrial strains tested. Both episomic and centromeric constructions carrying this marker resulted in transformation frequencies close to or above 103 transformants per μg of DNA for the three wine yeast strains tested. PMID:15574895

  8. A laboratory fuel efficiency and emissions comparison between Tanzanian traditional and improved biomass cooking stoves and alternative fuels

    NASA Astrophysics Data System (ADS)

    Mitchell, B. R.; Maggio, J. C.; Paterson, K.

    2010-12-01

    Large amounts of aerosols are emitted from domestic biomass burning globally every day. Nearly three billion people cook in their homes using traditional fires and stoves. Biomass is the primary fuel source which results in detrimental levels of indoor air pollution as well as having a strong impact on climate change. Variations in emissions occur depending on the combustion process and stove design as well as the condition and type of fuel used. The three most commonly used fuels for domestic biomass burning are wood, charcoal, and crop residue. In addition to these commonly used fuels and because of the increased difficulty of obtaining charcoal and wood due to a combination of deforestation and new governmental restrictions, alternative fuels are becoming more prevalent. In the Republic of Tanzania a field campaign was executed to test previously adopted and available traditional and improved cooking stoves with various traditional and alternative fuels. The tests were conducted over a two month period and included four styles of improved stoves, two styles of traditional cooking methods, and eight fuel types. The stoves tested include a sawdust stove, ceramic and brick insulated metal stoves, and a mud stove. A traditional three-stone fire was also tested as a benchmark by which to compare the other stoves. Fuel types tested include firewood, charcoal (Acacia), sawdust, pressed briquettes, charcoal dust briquettes, and carbonized crop residue. Water boiling tests were conducted on each stove with associated fuel types during which boiling time, water temperature, CO, CO2, and PM2.5μm emissions were recorded. All tests were conducted on-site in Arusha, Tanzania enabling the use of local materials and fuels under local conditions. It was found that both stove design and fuel type play a critical role in the amount of emissions produced. The most influential design aspect affecting emissions was the size of the combustion chamber in combination with air intake

  9. Experimental investigation on the accuracy of alternative devices to measure DNI in comparison to tracking pyrheliometers

    NASA Astrophysics Data System (ADS)

    Rommel, Matthias; Larcher, Marco

    2016-05-01

    Solar process heat holds a large potential for the application of solar collectors. In the process temperature range above 120°C concentrating collectors such as parabolic trough and liner concentrating Fresnel collectors are used. In order to support the further development of process heat systems with concentrating collectors it is necessary to install, operate and monitor more field systems in which these collectors are operated under real conditions in the industry. A cost-efficient but sufficiently exact measurement of the direct solar irradiation is necessary for the energetic evaluation of system performance and a technical assessment of the collectors. In this paper we report on a comparison of three different possibilities for the measurement of the direct solar irradiation.

  10. Synthesis of Single-Case Experimental Data: A Comparison of Alternative Multilevel Approaches

    ERIC Educational Resources Information Center

    Ferron, John; Van den Noortgate, Wim; Beretvas, Tasha; Moeyaert, Mariola; Ugille, Maaike; Petit-Bois, Merlande; Baek, Eun Kyeng

    2013-01-01

    Single-case or single-subject experimental designs (SSED) are used to evaluate the effect of one or more treatments on a single case. Although SSED studies are growing in popularity, the results are in theory case-specific. One systematic and statistical approach for combining single-case data within and across studies is multilevel modeling. The…

  11. A comparison of methods for estimating climate change impact on design rainfall using a high-resolution RCM

    NASA Astrophysics Data System (ADS)

    Li, Jingwan; Evans, Jason; Johnson, Fiona; Sharma, Ashish

    2017-04-01

    Design rainfall is used to analyse and size water infrastructure and is generally derived from historical rainfall records. Given the expected changes in extreme rainfall due to anthropogenic climate change, future hydrologic design based on historical data may not be appropriate. While a number of studies have assessed the impact of climate change on design rainfall using different methods, to date there has been no comprehensive comparison or examination of the implications of alternative methods on future design rainfall estimates. This study compares the nine methods for estimating the design rainfall for the current climate and the potential changes in the future for the Greater Sydney region. A Monte Carlo cross-validation procedure was employed to evaluate the skill of each method in estimating the design rainfall for the current climate. It was found that bias correcting the annual maximum rainfall based on the empirical distribution combined with regional frequency analysis produces the design rainfall closest to the observations. While regional frequency analysis was found to have limited impact on the design rainfall estimation for the current climate, it provides much more spatially coherent patterns of future change and it is recommended that regionalisation be used in all design rainfall impact assessments. Despite the variations between different methods, a 20-35% increase in design rainfall over the coastal region is consistently projected. This will pose significant challenges for existing infrastructure in that area.

  12. Using pilot test data to refine an alternative cover design in northern California.

    PubMed

    Smesrud, Jason K; Benson, Craig H; Albright, William H; Richards, James H; Wright, Shannon; Israel, Tim; Goodrich, Keith

    2012-01-01

    Two instrumented test sections were constructed in summer 1999 at the Kiefer Landfill near Sacramento, California to test the hydraulic performance of two proposed alternative final covers. Both test sections simulated monolithic evapotranspiration (ET) designs that differed primarily in thickness. Both were seeded with a mix of two perennial and one annual grass species. Oleander seedlings were also planted in the thicker test section. Detailed hydrologic performance monitoring of the covers was conducted from 1999 through 2005, The thicker test section met the performance criterion (average percolation of <3 mm/y). The thinner test section transmitted considerably more percolation (average of 55 mm/y). Both test sections were decommissioned in summer 2005 to investigate changes in soil hydraulic properties, geomorphology, and vegetation and to collect data to support a revised design. Field data from hydrologic monitoring and the decommissioning study were subsequently included in a hydrologic modeling study to estimate the performance of an optimized cover system for full-scale application. The decommissioning study showed that properties of the soils changed over the monitoring period (saturated hydraulic conductivity and water holding capacity increased, density decreased) and that the perennial grasses and shrubs intended for the cover were out-competed by annual species with shallower roots and lesser capacity for water uptake. Of these changes, reduced ET from the shallow-rooted annual vegetation is believed to be the primary cause for the high percolation rate from the thinner test section. Hydrologic modeling suggests that the target hydraulic performance can be achieved using an ET cover with similar thickness to the thin test section if perennial vegetation species observed in surrounding grasslands can be established. This finding underscores the importance of establishing and maintaining the appropriate vegetation on ET covers in this climate.

  13. Alternating iterative regression method for dead time estimation from experimental designs.

    PubMed

    Pous-Torres, S; Torres-Lapasió, J R; Baeza-Baeza, J J; García-Alvarez-Coque, M C

    2009-05-01

    An indirect method for dead time (t (0)) estimation in reversed-phase liquid chromatography, based on a relationship between retention time and organic solvent content, is proposed. The method processes the retention data obtained in experimental designs. In order to get more general validity and enhance the accuracy, the information from several compounds is used altogether in an alternating regression fashion. The method was applied to nitrosamines, alkylbenzenes, phenols, benzene derivatives, polycyclic aromatic hydrocarbons and beta-blockers, among other compounds, chromatographed in a cyano and several C18 columns. A comprehensive validation was carried out by comparing the results with those provided by the injection of markers, the observation of the solvent front and the homologous series method. It was also found that different groups of compounds yielded the same t (0) value with the same column, which was verified in different solvent composition windows. The method allows improved models useful for optimisation or for other purposes, since t (0) can be estimated with the retention data of the target solutes.

  14. Properties of alternative microbial hosts used in synthetic biology: towards the design of a modular chassis

    PubMed Central

    Kim, Juhyun; Salvador, Manuel; Saunders, Elizabeth; González, Jaime; Avignone-Rossa, Claudio

    2016-01-01

    The chassis is the cellular host used as a recipient of engineered biological systems in synthetic biology. They are required to propagate the genetic information and to express the genes encoded in it. Despite being an essential element for the appropriate function of genetic circuits, the chassis is rarely considered in their design phase. Consequently, the circuits are transferred to model organisms commonly used in the laboratory, such as Escherichia coli, that may be suboptimal for a required function. In this review, we discuss some of the properties desirable in a versatile chassis and summarize some examples of alternative hosts for synthetic biology amenable for engineering. These properties include a suitable life style, a robust cell wall, good knowledge of its regulatory network as well as of the interplay of the host components with the exogenous circuits, and the possibility of developing whole-cell models and tuneable metabolic fluxes that could allow a better distribution of cellular resources (metabolites, ATP, nucleotides, amino acids, transcriptional and translational machinery). We highlight Pseudomonas putida, widely used in many different biotechnological applications as a prominent organism for synthetic biology due to its metabolic diversity, robustness and ease of manipulation. PMID:27903818

  15. N-butanol and isobutanol as alternatives to gasoline: Comparison of port fuel injector characteristics

    NASA Astrophysics Data System (ADS)

    Fenkl, Michael; Pechout, Martin; Vojtisek, Michal

    2016-03-01

    The paper reports on an experimental investigation of the relationship between the pulse width of a gasoline engine port fuel injector and the quantity of the fuel injected when butanol is used as a fuel. Two isomers of butanol, n-butanol and isobutanol, are considered as potential candidates for renewable, locally produced fuels capable of serving as a drop-in replacement fuel for gasoline, as an alternative to ethanol which poses material compatibility and other drawbacks. While the injected quantity of fuel is typically a linear function of the time the injector coil is energized, the flow through the port fuel injector is complex, non ideal, and not necessarily laminar, and considering that butanol has much higher viscosity than gasoline, an experimental investigation was conducted. A production injector, coupled to a production fueling system, and driven by a pulse width generator was operated at various pulse lengths and frequencies, covering the range of engine rpm and loads on a car engine. The results suggest that at least at room temperature, the fueling rate remains to be a linear function of the pulse width for both n-butanol and isobutanol, and the volumes of fuel injected are comparable for gasoline and both butanol isomers.

  16. Comparison of health-risk behaviors among students attending alternative and traditional high schools in Minnesota.

    PubMed

    Johnson, Karen E; McMorris, Barbara J; Kubik, Martha Y

    2013-10-01

    Previous research, over a decade old, suggests students attending alternative high schools (AHS) engage in high levels of health-risk behaviors. Data from the 2007 Minnesota Student Survey for students attending AHS (n = 2,847) and traditional high schools (THS; n = 87,468) were used for this cross-sectional analysis to compare prevalence estimates, adjusted for age, race/ethnicity, and free and reduced lunch, for 28 health-risk behaviors. Students attending AHS were significantly more likely than students attending THS to report engaging in all behaviors related to unintentional injury and violence, tobacco use, alcohol and other drug use, and sexual activity, and were significantly less likely to report participating in physical activity, including sports teams. Students attending AHS continue to engage in high levels of health-risk behaviors as compared to their peers in THS. Updated national prevalence data were needed, as well as studies examining the role of protective factors in the lives of students attending AHS.

  17. A Comparison of Alternating Current and Direct Current Electrospray Ionization for Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Sarver, Scott A.; Chetwani, Nishant; Dovichi, Norman J.; Go, David B.; Gartner, Carlos A.

    2014-04-01

    A series of studies comparing the performance of alternating current electrospray ionization (AC ESI) mass spectrometry (MS) and direct current electrospray ionization (DC ESI) MS have been conducted, exploring the absolute signal intensity and signal-to-background ratios produced by both methods using caffeine and a model peptide as targets. Because the high-voltage AC signal was more susceptible to generating gas discharges, the operating voltage range of AC ESI was significantly smaller than that for DC ESI, such that the absolute signal intensities produced by DC ESI at peak voltages were one to two orders of magnitude greater than those for AC ESI. Using an electronegative nebulizing gas, sulfur hexafluoride (SF6), instead of nitrogen (N2) increased the operating range of AC ESI by ~50 %, but did not appreciably improve signal intensities. While DC ESI generated far greater signal intensities, both ionization methods produced comparable signal-to-background noise, with AC ESI spectra appearing qualitatively cleaner. A quantitative calibration analysis was performed for two analytes, caffeine and the peptide MRFA. AC ESI utilizing SF6 outperforms all other techniques for the detection of MRFA, producing chromatographic limits of detection nearly one order of magnitude lower than that of DC ESI utilizing N2, and one-half that of DC ESI utilizing SF6. However, DC ESI outperforms AC ESI for the analysis of caffeine, indicating that improvements in spectral quality may benefit certain compounds or classes of compounds, on an individual basis.

  18. Comparison of recreation use values among alternative reservoir water level management scenarios

    NASA Astrophysics Data System (ADS)

    Cordell, H. Ken; Bergstrom, John C.

    1993-02-01

    Throughout the United States, reservoirs are managed for multiple uses, including hydropower, stream flow regulation, flood control, and recreation. Water level drawdowns for hydropower, stream flow regulation, and flood control often reduce the suitability of reservoirs for water-based recreation. The gain in aggregate economic use value of outdoor recreation under three alternative water level management scenarios was measured for four reservoirs in western North Carolina as part of an interagency policy analysis. Use values were estimated using a contingent valuation survey and expert panel data. The basic question addressed by this study was whether the value recreational users place on higher water levels held longer into the summer and fall is significantly greater than the value of using these reservoirs as they were managed at the time of this study. Maintaining high water levels for longer periods during the summer and fall was found to result in considerable gains in estimated recreational benefits. While not a primary objective of this study, having these estimates provided us an opportunity to compare increased recreational benefits with the value the Tennessee Valley Authority estimated for the reduced production of electricity that would result if the lakes were managed to hold reservoir levels higher, longer into the year.

  19. Comparison of direct current and 50 Hz alternating current microscopic corona characteristics on conductors

    SciTech Connect

    Zhang, Shuai Zhang, Bo He, Jinliang

    2014-06-15

    Corona discharge is one of the major design factors for extra-high voltage and ultra-high voltage DC/AC transmission lines. Under different voltages, corona discharge reveals different characteristics. This paper aims at investigating DC and AC coronas on the microscopic scale. To obtain the specific characteristics of DC and AC coronas, a new measurement approach that utilizes a coaxial wire-cylinder corona cage is designed in this paper, and wires of different diameters are used in the experiment. Based on the measurements, the respective microscopic characteristics of DC and AC coronas are analyzed and compared. With differences in characteristics between DC and AC coronas proposed, this study provides useful insights into DC/AC corona discharges on transmission line applications.

  20. Comparison of direct current and 50 Hz alternating current microscopic corona characteristics on conductors

    NASA Astrophysics Data System (ADS)

    Zhang, Shuai; Zhang, Bo; He, Jinliang

    2014-06-01

    Corona discharge is one of the major design factors for extra-high voltage and ultra-high voltage DC/AC transmission lines. Under different voltages, corona discharge reveals different characteristics. This paper aims at investigating DC and AC coronas on the microscopic scale. To obtain the specific characteristics of DC and AC coronas, a new measurement approach that utilizes a coaxial wire-cylinder corona cage is designed in this paper, and wires of different diameters are used in the experiment. Based on the measurements, the respective microscopic characteristics of DC and AC coronas are analyzed and compared. With differences in characteristics between DC and AC coronas proposed, this study provides useful insights into DC/AC corona discharges on transmission line applications.

  1. A Comparison of Central Composite Design and Taguchi Method for Optimizing Fenton Process

    PubMed Central

    Asghar, Anam; Abdul Raman, Abdul Aziz; Daud, Wan Mohd Ashri Wan

    2014-01-01

    In the present study, a comparison of central composite design (CCD) and Taguchi method was established for Fenton oxidation. [Dye]ini, Dye : Fe+2, H2O2 : Fe+2, and pH were identified control variables while COD and decolorization efficiency were selected responses. L9 orthogonal array and face-centered CCD were used for the experimental design. Maximum 99% decolorization and 80% COD removal efficiency were obtained under optimum conditions. R squared values of 0.97 and 0.95 for CCD and Taguchi method, respectively, indicate that both models are statistically significant and are in well agreement with each other. Furthermore, Prob > F less than 0.0500 and ANOVA results indicate the good fitting of selected model with experimental results. Nevertheless, possibility of ranking of input variables in terms of percent contribution to the response value has made Taguchi method a suitable approach for scrutinizing the operating parameters. For present case, pH with percent contribution of 87.62% and 66.2% was ranked as the most contributing and significant factor. This finding of Taguchi method was also verified by 3D contour plots of CCD. Therefore, from this comparative study, it is concluded that Taguchi method with 9 experimental runs and simple interaction plots is a suitable alternative to CCD for several chemical engineering applications. PMID:25258741

  2. A comparison of central composite design and Taguchi method for optimizing Fenton process.

    PubMed

    Asghar, Anam; Abdul Raman, Abdul Aziz; Daud, Wan Mohd Ashri Wan

    2014-01-01

    In the present study, a comparison of central composite design (CCD) and Taguchi method was established for Fenton oxidation. [Dye]ini, Dye:Fe(+2), H2O2:Fe(+2), and pH were identified control variables while COD and decolorization efficiency were selected responses. L 9 orthogonal array and face-centered CCD were used for the experimental design. Maximum 99% decolorization and 80% COD removal efficiency were obtained under optimum conditions. R squared values of 0.97 and 0.95 for CCD and Taguchi method, respectively, indicate that both models are statistically significant and are in well agreement with each other. Furthermore, Prob > F less than 0.0500 and ANOVA results indicate the good fitting of selected model with experimental results. Nevertheless, possibility of ranking of input variables in terms of percent contribution to the response value has made Taguchi method a suitable approach for scrutinizing the operating parameters. For present case, pH with percent contribution of 87.62% and 66.2% was ranked as the most contributing and significant factor. This finding of Taguchi method was also verified by 3D contour plots of CCD. Therefore, from this comparative study, it is concluded that Taguchi method with 9 experimental runs and simple interaction plots is a suitable alternative to CCD for several chemical engineering applications.

  3. Quantitative comparison of alternative methods for coarse-graining biological networks

    NASA Astrophysics Data System (ADS)

    Bowman, Gregory R.; Meng, Luming; Huang, Xuhui

    2013-09-01

    Markov models and master equations are a powerful means of modeling dynamic processes like protein conformational changes. However, these models are often difficult to understand because of the enormous number of components and connections between them. Therefore, a variety of methods have been developed to facilitate understanding by coarse-graining these complex models. Here, we employ Bayesian model comparison to determine which of these coarse-graining methods provides the models that are most faithful to the original set of states. We find that the Bayesian agglomerative clustering engine and the hierarchical Nyström expansion graph (HNEG) typically provide the best performance. Surprisingly, the original Perron cluster cluster analysis (PCCA) method often provides the next best results, outperforming the newer PCCA+ method and the most probable paths algorithm. We also show that the differences between the models are qualitatively significant, rather than being minor shifts in the boundaries between states. The performance of the methods correlates well with the entropy of the resulting coarse-grainings, suggesting that finding states with more similar populations (i.e., avoiding low population states that may just be noise) gives better results.

  4. A compatibility-based procedure designed to generate potential sanitation system alternatives.

    PubMed

    Maurer, Max; Bufardi, Ahmed; Tilley, Elizabeth; Zurbrügg, Christian; Truffer, Bernhard

    2012-08-15

    Regarding multi-criteria decision analysis (MCDA), the problem of generating alternatives has not received the attention it deserves. Most research is currently devoted to the problem of alternative selection, where it is assumed that a set of appropriate alternatives is already given. This paper addresses the generation of potential alternatives in the domain of sanitation systems planning and decision-making. A compatibility assessment procedure is proposed to determine the set of technically feasible or potential sanitation system alternatives. This is based on a clear definition of such an alternative containing sub-processes that include a user interface, storage, conveyance treatment and reuse/disposal. A newly developed compatibility matrix is applied to identify incompatibilities between the options of the sub-processes. A potential sanitation system alternative is therefore defined by the absence of two-by-two incompatibility between all its options. The compatibility assessment acts as a first filter on the set of sanitation system alternatives to eliminate those that are inoperable before the feasibility assessment. The objective of both steps is to obtain a set of alternatives that are of reasonable and manageable size from which the final solution may be selected.

  5. Comparison between an Alternative and the Classic Definition of Chronic Bronchitis in COPDGene

    PubMed Central

    Crapo, James; Zhao, Huaqing; Jones, Paul W.; Silverman, Edwin K.; Comellas, Alejandro; Make, Barry J.; Criner, Gerard J.

    2015-01-01

    Rationale: Previous studies on chronic bronchitis (CB) have used varying definitions. Objectives: We sought to compare an alternative CB definition, using the St. George’s Respiratory Questionnaire (SGRQ), a commonly used assessment tool, with the classic definition and to investigate if it had independent or additive value. Methods: We analyzed data from 4,513 subjects from Global Initiative for Chronic Obstructive Lung Disease groups 1 to 4 in the COPDGene cohort. We compared the classic definition of CB with the SGRQ definition, defined by their answers to the questions about both cough and phlegm. We compared the Classic CB+ versus CB− groups, and the SGRQ CB+ and CB− groups. We also analyzed the cohort split into four groups: Classic CB+/SGRQ CB+, Classic CB+/SGRQ CB−, Classic CB−/SGRQ CB+, Classic CB−/SGRQ CB−. Measurements and Main Results: A total of 26.1% subjects were Classic CB+, whereas 39.9% were SGRQ CB+. When the SGRQ definition was compared with the Classic CB definition, using this as the gold standard, the SGRQ CB definition had a sensitivity and specificity of 0.87 and 0.77, respectively. The SGRQ CB+ and Classic CB+ groups were strikingly similar, with more respiratory symptoms and exacerbations, worse lung function, and greater airway wall thickness. In addition, the Classic CB+/SGRQ CB+, Classic CB+/SGRQ CB−, and Classic CB−/SGRQ CB+ groups shared similar characteristics as well. Conclusions: The SGRQ CB definition identifies more subjects with chronic cough and sputum who share a similar phenotype identified by the Classic CB definition. The addition of the SGRQ CB definition to the classic one can be used to identify more patients with chronic obstructive pulmonary disease at risk for poor outcomes. PMID:25575351

  6. Comparison of costs for three hypothetical alternative kitchen waste management systems.

    PubMed

    Schiettecatte, Wim; Tize, Ronald; De Wever, Heleen

    2014-11-01

    Urban water and waste management continues to be a major challenge, with the Earth's population projected to rise to 9 billion by 2050, with 70% of this population expected to live in cities. A combined treatment of wastewater and the organic fraction of municipal solid waste offers opportunities for improved environmental protection and energy recovery, but the collection and transport of organic wastes must be cost effective. This study compares three alternative kitchen waste collection and transportation systems for a virtual modern urban area with 300,000 residents and a population density of 10,000 persons per square kilometre. Door-to-door collection, being the standard practice in modern urban centres, remains the most economically advantageous at a cost of 263 euros per tonne of kitchen waste. Important drawbacks are the difficult logistics, increased city traffic, air and noise pollution. The quieter, cleaner and more hygienic vacuum transport of kitchen waste comes with a higher cost of 367 euros per tonne, mainly resulting from a higher initial investment cost for the system installation. The third option includes the well-known use of under-sink food waste disposers (often called garbage grinders) that are connected to the kitchen's wastewater piping system, with a total yearly cost of 392 euros per tonne. Important advantages with this system are the clean operation and the current availability of a city-wide sewage conveyance pipeline system. Further research is recommended, for instance the application of a life cycle assessment approach, to more fully compare the advantages and disadvantages of each option.

  7. Comparison of Marine Spatial Planning Methods in Madagascar Demonstrates Value of Alternative Approaches

    PubMed Central

    Allnutt, Thomas F.; McClanahan, Timothy R.; Andréfouët, Serge; Baker, Merrill; Lagabrielle, Erwann; McClennen, Caleb; Rakotomanjaka, Andry J. M.; Tianarisoa, Tantely F.; Watson, Reg; Kremen, Claire

    2012-01-01

    The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the “strict protection” class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during

  8. Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison.

    PubMed

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

    Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R.

  9. Searching for Controlled Trials of Complementary and Alternative Medicine: A Comparison of 15 Databases

    PubMed Central

    Cogo, Elise; Sampson, Margaret; Ajiferuke, Isola; Manheimer, Eric; Campbell, Kaitryn; Daniel, Raymond; Moher, David

    2011-01-01

    This project aims to assess the utility of bibliographic databases beyond the three major ones (MEDLINE, EMBASE and Cochrane CENTRAL) for finding controlled trials of complementary and alternative medicine (CAM). Fifteen databases were searched to identify controlled clinical trials (CCTs) of CAM not also indexed in MEDLINE. Searches were conducted in May 2006 using the revised Cochrane highly sensitive search strategy (HSSS) and the PubMed CAM Subset. Yield of CAM trials per 100 records was determined, and databases were compared over a standardized period (2005). The Acudoc2 RCT, Acubriefs, Index to Chiropractic Literature (ICL) and Hom-Inform databases had the highest concentrations of non-MEDLINE records, with more than 100 non-MEDLINE records per 500. Other productive databases had ratios between 500 and 1500 records to 100 non-MEDLINE records—these were AMED, MANTIS, PsycINFO, CINAHL, Global Health and Alt HealthWatch. Five databases were found to be unproductive: AGRICOLA, CAIRSS, Datadiwan, Herb Research Foundation and IBIDS. Acudoc2 RCT yielded 100 CAM trials in the most recent 100 records screened. Acubriefs, AMED, Hom-Inform, MANTIS, PsycINFO and CINAHL had more than 25 CAM trials per 100 records screened. Global Health, ICL and Alt HealthWatch were below 25 in yield. There were 255 non-MEDLINE trials from eight databases in 2005, with only 10% indexed in more than one database. Yield varied greatly between databases; the most productive databases from both sampling methods were Acubriefs, Acudoc2 RCT, AMED and CINAHL. Low overlap between databases indicates comprehensive CAM literature searches will require multiple databases. PMID:19468052

  10. Comparison of marine spatial planning methods in Madagascar demonstrates value of alternative approaches.

    PubMed

    Allnutt, Thomas F; McClanahan, Timothy R; Andréfouët, Serge; Baker, Merrill; Lagabrielle, Erwann; McClennen, Caleb; Rakotomanjaka, Andry J M; Tianarisoa, Tantely F; Watson, Reg; Kremen, Claire

    2012-01-01

    The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the "strict protection" class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during

  11. A comparison of estimates of cost-effectiveness of alternative fuels and vehicles for reducing emissions

    SciTech Connect

    Hadder, G.R.

    1995-11-01

    The cost-effectiveness ratio (CER) is a measure of the monetary value of resources expended to obtain reductions in emissions of air pollutants. The CER can lead to selection of the most effective sequence of pollution reduction options. Derived with different methodologies and technical assumptions, CER estimates for alternative fuel vehicles (AFVs) have varied widely among pervious studies. In one of several explanations of LCER differences, this report uses a consistent basis for fuel price to re-estimate CERs for AFVs in reduction of emissions of criteria pollutants, toxics, and greenhouse gases. The re-estimated CERs for a given fuel type have considerable differences due to non-fuel costs and emissions reductions, but the CERs do provide an ordinal sense of cost-effectiveness. The category with CER less than $5,000 per ton includes compressed natural gas and ed Petroleum gas vehicles; and E85 flexible-fueled vehicles (with fuel mixture of 85 percent cellulose-derived ethanol in gasoline). The E85 system would be much less attractive if corn-derived ethanol were used. The CER for E85 (corn-derived) is higher with higher values placed on the reduction of gas emissions. CER estimates are relative to conventional vehicles fueled with Phase 1 California reformulated gasoline (RFG). The California Phase 2 RFG program will be implemented before significant market penetration by AFVs. CERs could be substantially greater if they are calculated incremental to the Phase 2 RFG program. Regression analysis suggests that different assumptions across studies can sometimes have predictable effects on the CER estimate of a particular AFV type. The relative differences in cost and emissions reduction assumptions can be large, and the effect of these differences on the CER estimate is often not predictable. Decomposition of CERs suggests that methodological differences can make large contributions to CER differences among studies.

  12. A comparison of marine protected areas and alternative approaches to coral-reef management.

    PubMed

    McClanahan, Timothy R; Marnane, Michael J; Cinner, Joshua E; Kiene, William E

    2006-07-25

    Marine protected areas (MPAs) have been widely adopted as the leading tool for coral-reef conservation, but resource users seldom accept them , and many have failed to produce tangible conservation benefits [3]. Few studies have objectively and simultaneously examined the types of MPAs that are most effective in conserving reef resources and the socioeconomic factors responsible for effective conservation [4-6]. We simultaneously explored measures of reef and socioeconomic conservation success at four national parks, four comanaged reserves, and three traditionally managed areas in Indonesia and Papua New Guinea. Underwater visual censuses of key ecological indicators [7, 8] revealed that the average size and biomass of fishes were higher in all areas under traditional management and at one comanaged reserve when compared to nearby unmanaged areas. Socioeconomic assessments [6, 9, 10] revealed that this "effective conservation" was positively related to compliance, visibility of the reserve, and length of time the management had been in place but negatively related to market integration, wealth, and village population size. We suggest that in cases where the resources for enforcement are lacking, management regimes that are designed to meet community goals can achieve greater compliance and subsequent conservation success than regimes designed primarily for biodiversity conservation.

  13. Comparison of complementary and alternative medicine use: reasons and motivations between two tertiary children's hospitals

    PubMed Central

    Cincotta, D R; Crawford, N W; Lim, A; Cranswick, N E; Skull, S; South, M; Powell, C V E

    2006-01-01

    Aims To compare prevalence, reasons, motivations, initiation, perceived helpfulness, and communication of complementary and alternative medicine (CAM) use between two tertiary children's hospitals. Methodology A study, using a face‐to‐face questionnaire, of 500 children attending the University Hospital of Wales, Cardiff, UK was compared to an identical study of 503 children attending the Royal Children's Hospital, Melbourne, Australia. Results One year CAM use in Cardiff was lower than Melbourne (41% v 51%; OR = 0.67, 95% CI 0.52–0.85), reflected in non‐medicinal use (OR = 0.41, 95% CI 0.29–0.58) and general paediatric outpatients (OR = 0.38, 95% CI 0.21–0.67). Compared to Melbourne, factors associated with lower CAM use in Cardiff included families born locally (father: OR = 0.58, 95% CI 0.44–0.77) or non‐tertiary educated parents (mother: OR = 0.54, 95% CI 0.38–0.77). Cardiff participants used less vitamin C (OR = 0.31, 95% CI 0.18–0.51) and herbs (OR = 0.49, 95% CI 0.34–0.71), attended less chiropractors (OR = 0.25, 95% CI 0.06–0.37) and naturopaths (OR = 0.08, 95% CI 0.02–0.33), but saw more reflexologists (OR = 3.33, 95% CI 1.08–10.29). In Cardiff, CAM was more popular for relaxation (OR = 1.92, 95% CI 1.03–3.57) but less for colds/coughs (OR = 0.4, 95% CI 0.27–0.73). Most CAM was self‐initiated (by parent) in Cardiff and Melbourne (74% v 70%), but Cardiff CAM users perceived it less helpful (OR = 0.46, 95% CI 0.31–0.68). Non‐disclosure of CAM use was high in Cardiff and Melbourne (66% v 63%); likewise few doctors/nurses documented recent medicinal CAM use in inpatient notes (0/21 v 2/22). Conclusions The differences in CAM use may reflect variation in sociocultural factors influencing reasons, motivations, attitudes, and availability. The regional variation in use and poor communication highlights the importance of local policy development. PMID:16166178

  14. From the Tightrope: Designing, Developing, and Delivering an Alternative Teacher Education Model

    ERIC Educational Resources Information Center

    Yancey, Patty

    2006-01-01

    In the fall of 2003 a number of factors came together to create a fertile environment for developing an alternative, pre-service teacher education model. The overarching goal of the model is to diversify a rural university's credential program(s) by developing and offering alternative paths toward teacher certification within the constraints of a…

  15. Parametric Optimization of Some Critical Operating System Functions--An Alternative Approach to the Study of Operating Systems Design

    ERIC Educational Resources Information Center

    Sobh, Tarek M.; Tibrewal, Abhilasha

    2006-01-01

    Operating systems theory primarily concentrates on the optimal use of computing resources. This paper presents an alternative approach to teaching and studying operating systems design and concepts by way of parametrically optimizing critical operating system functions. Detailed examples of two critical operating systems functions using the…

  16. 20 CFR 645.400 - Under what conditions may the Governor request a waiver to designate an alternate local...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Under what conditions may the Governor request a waiver to designate an alternate local administering agency? 645.400 Section 645.400 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROVISIONS GOVERNING...

  17. A study of alternative designs for a system to concentrate carbon dioxide in a hydrogen-depolarized cell

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Experimental results are presented on alternative designs for a hydrogen depolarized cell to concentrate CO2 in spacecraft atmospheric control systems. Data cover technical problems, methods for solving these problems, and the suitability of such a cell for CO2 removal and control of atmospheric humidity during the flight mode.

  18. Alternative Model-Based and Design-Based Frameworks for Inference from Samples to Populations: From Polarization to Integration

    ERIC Educational Resources Information Center

    Sterba, Sonya K.

    2009-01-01

    A model-based framework, due originally to R. A. Fisher, and a design-based framework, due originally to J. Neyman, offer alternative mechanisms for inference from samples to populations. We show how these frameworks can utilize different types of samples (nonrandom or random vs. only random) and allow different kinds of inference (descriptive vs.…

  19. Conceptual design report: Nuclear materials storage facility renovation. Part 6, Alternatives study

    SciTech Connect

    1995-07-14

    The Nuclear Materials Storage Facility (NMSF) at the Los Alamos National Laboratory (LANL) was a Fiscal Year (FY) 1984 line-item project completed in 1987 that has never been operated because of major design and construction deficiencies. This renovation project, which will correct those deficiencies and allow operation of the facility, is proposed as an FY 97 line item. The mission of the project is to provide centralized intermediate and long-term storage of special nuclear materials (SNM) associated with defined LANL programmatic missions and to establish a centralized SNM shipping and receiving location for Technical Area (TA)-55 at LANL. Based on current projections, existing storage space for SNM at other locations at LANL will be loaded to capacity by approximately 2002. This will adversely affect LANUs ability to meet its mission requirements in the future. The affected missions include LANL`s weapons research, development, and testing (WRD&T) program; special materials recovery; stockpile survelliance/evaluation; advanced fuels and heat sources development and production; and safe, secure storage of existing nuclear materials inventories. The problem is further exacerbated by LANL`s inability to ship any materials offsite because of the lack of receiver sites for material and regulatory issues. Correction of the current deficiencies and enhancement of the facility will provide centralized storage close to a nuclear materials processing facility. The project will enable long-term, cost-effective storage in a secure environment with reduced radiation exposure to workers, and eliminate potential exposures to the public. This report is organized according to the sections and subsections outlined by Attachment 111-2 of DOE Document AL 4700.1, Project Management System. It is organized into seven parts. This document, Part VI - Alternatives Study, presents a study of the different storage/containment options considered for NMSF.

  20. Update and Improve Subsection NH –– Alternative Simplified Creep-Fatigue Design Methods

    SciTech Connect

    Tai Asayama

    2009-10-26

    This report described the results of investigation on Task 10 of DOE/ASME Materials NGNP/Generation IV Project based on a contract between ASME Standards Technology, LLC (ASME ST-LLC) and Japan Atomic Energy Agency (JAEA). Task 10 is to Update and Improve Subsection NH -- Alternative Simplified Creep-Fatigue Design Methods. Five newly proposed promising creep-fatigue evaluation methods were investigated. Those are (1) modified ductility exhaustion method, (2) strain range separation method, (3) approach for pressure vessel application, (4) hybrid method of time fraction and ductility exhaustion, and (5) simplified model test approach. The outlines of those methods are presented first, and predictability of experimental results of these methods is demonstrated using the creep-fatigue data collected in previous Tasks 3 and 5. All the methods (except the simplified model test approach which is not ready for application) predicted experimental results fairly accurately. On the other hand, predicted creep-fatigue life in long-term regions showed considerable differences among the methodologies. These differences come from the concepts each method is based on. All the new methods investigated in this report have advantages over the currently employed time fraction rule and offer technical insights that should be thought much of in the improvement of creep-fatigue evaluation procedures. The main points of the modified ductility exhaustion method, the strain range separation method, the approach for pressure vessel application and the hybrid method can be reflected in the improvement of the current time fraction rule. The simplified mode test approach would offer a whole new advantage including robustness and simplicity which are definitely attractive but this approach is yet to be validated for implementation at this point. Therefore, this report recommends the following two steps as a course of improvement of NH based on newly proposed creep-fatigue evaluation

  1. Consideration of alternative designs for a Percutaneous Endoscopic Gastrostomy feeding tube

    NASA Astrophysics Data System (ADS)

    Yerrabolu, Santosh Rohit

    The inability of some people to chew or swallow foods (but can digest foods) due to problems associated with various diseases and complications leads them to insufficient nutritional intake and loss of quality of life. These individuals are generally provided with nutritional support by means of injecting or infusing food directly into their stomachs or small intestines via feeding tubes. Gastrostomy feeding tubes (G-tubes) are used when such nutritional support is required for over 3-6 weeks. Percutaneous Endoscopic Gastrostomy (PEG) tubes are one of the most widely used G- Tubes and devices which are inserted via an incision through the abdominal wall either through a pull or push method. This investigation proposes conceptual alternative Percutaneous Endoscopy Gastrostomy (PEG) feeding tube designs with optimized materials selection to be used for their construction. The candidate materials were chosen from 18 commercial catheters, 2 reference grade polymers and a commercial polymer; using tissue-catheter-friction testing and surface chemistry characterization (Infrared spectroscopy and Critical Surface Tension approximation). The main objectives considered were to minimize slipping/dislodgement of gastrostomy tube/seal, to reduce peristomal leakage, and to attain size variability of PEG tubes while maintaining a low profile. Scanning Electron Microscope- Energy Dispersive X-ray Spectroscopy was employed to further determine the filler materials used in the samples. Nylon coated with fatty ester and filled with Barium sulphate was determined as the optimum material for the construction of the tube part of the feeding tubes to reduce slipping/dislodgment of gastrostomy tube/seal and to minimize peristomal leakage. Nylon coated with fatty ester and filled with Silica is the suggested as a candidate material for construction of the bumper/mushroom sections of the feeding tubes to avoid the Buried Bumper Syndrome. Fused Deposition Modeling, Selective Laser Sintering

  2. Alternating current dielectrophoresis of core-shell nanoparticles: Experiments and comparison with theory

    NASA Astrophysics Data System (ADS)

    Yang, Chungja

    Nanoparticles are fascinating where physical and optical properties are related to size. Highly controllable synthesis methods and nanoparticle assembly are essential for highly innovative technological applications. Well-defined shaped and sized nanoparticles enable comparisons between experiments, theory and subsequent new models to explain experimentally observed phenomena. Among nanoparticles, nonhomogeneous core-shell nanoparticles (CSnp) have new properties that arise when varying the relative dimensions of the core and the shell. This CSnp structure enables various optical resonances, and engineered energy barriers, in addition to the high charge to surface ratio. Assembly of homogeneous nanoparticles into functional structures has become ubiquitous in biosensors (i.e. optical labeling), nanocoatings, and electrical circuits. Limited nonhomogenous nanoparticle assembly has only been explored. Many conventional nanoparticle assembly methods exist, but this work explores dielectrophoresis (DEP) as a new method. DEP is particle polarization via non-uniform electric fields while suspended in conductive fluids. Most prior DEP efforts involve microscale particles. Prior work on core-shell nanoparticle assemblies and separately, nanoparticle characterizations with dielectrophoresis and electrorotation, did not systematically explore particle size, dielectric properties (permittivity and electrical conductivity), shell thickness, particle concentration, medium conductivity, and frequency. This work is the first, to the best of our knowledge, to systematically examine these dielectrophoretic properties for core-shell nanoparticles. Further, we conduct a parametric fitting to traditional core-shell models. These biocompatible core-shell nanoparticles were studied to fill a knowledge gap in the DEP field. Experimental results (chapter 5) first examine medium conductivity, size and shell material dependencies of dielectrophoretic behaviors of spherical CSnp into 2D and

  3. A comparison of digital flight control design methods

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Parsons, E.; Tashker, M. G.

    1976-01-01

    Many variations in design methods for aircraft digital flight control have been proposed in the literature. In general, the methods fall into two categories: those where the design is done in the continuous domain (or s-plane), and those where the design is done in the discrete domain (or z-plane). This paper evaluates several variations of each category and compares them for various flight control modes of the Langley TCV Boeing 737 aircraft. Design method fidelity is evaluated by examining closed loop root movement and the frequency response of the discretely controlled continuous aircraft. It was found that all methods provided acceptable performance for sample rates greater than 10 cps except the 'uncompensated s-plane design' method which was acceptable above 20 cps. A design procedure based on optimal control methods was proposed that provided the best fidelity at very slow sample rates and required no design iterations for changing sample rates.

  4. Cellulosic fuel ethanol: alternative fermentation process designs with wild-type and recombinant Zymomonas mobilis.

    PubMed

    Lawford, Hugh G; Rousseau, Joyce D

    2003-01-01

    Iogen (Canada) is a major manufacturer of industrial cellulase and hemicellulase enzymes for the textile, pulp and paper, and poultry feed industries. Iogen has recently constructed a 40 t/d biomass-to-ethanol demonstration plant adjacent to its enzyme production facility. The integration of enzyme and ethanol plants results in significant reduction in production costs and offers an alternative use for the sugars generated during biomass conversion. Iogen has partnered with the University of Toronto to test the fermentation performance characteristics of metabolically engineered Zymomonas mobilis created at the National Renewable Energy Laboratory. This study focused on strain AX101, a xylose- and arabinose-fermenting stable genomic integrant that lacks the selection marker gene for antibiotic resistance. The "Iogen Process" for biomass depolymerization consists of a dilute-sulpfuric acid-catalyzed steam explosion, followed by enzymatic hydrolysis. This work examined two process design options for fermentation, first, continuous cofermentation of C5 and C6 sugars by Zm AX101, and second, separate continuous fermentations of prehydrolysate by Zm AX101 and cellulose hydrolysate by either wildtype Z. mobilis ZM4 or an industrial yeast commonly used in the production of fuel ethanol from corn. Iogen uses a proprietary process for conditioning the prehydrolysate to reduce the level of inhibitory acetic acid to at least 2.5 g/L. The pH was controlled at 5.5 and 5.0 for Zymomonas and yeast fermentations, respectively. Neither 2.5 g/L of acetic acid nor the presence of pentose sugars (C6:C5 = 2:1) appreciably affected the high-performance glucose fermentation of wild-type Z. mobilis ZM4. By contrast, 2.5 g/L of acetic acid significantly reduced the rate of pentose fermentation by strain AX101. For single-stage continuous fermentation of pure sugar synthetic cellulose hydrolysate (60 g/L of glucose), wild-type Zymomonas exhibited a four-fold higher volumetric productivity

  5. Comparison of Optimal Design Methods in Inverse Problems.

    PubMed

    Banks, H T; Holm, Kathleen; Kappel, Franz

    2011-07-01

    Typical optimal design methods for inverse or parameter estimation problems are designed to choose optimal sampling distributions through minimization of a specific cost function related to the resulting error in parameter estimates. It is hoped that the inverse problem will produce parameter estimates with increased accuracy using data collected according to the optimal sampling distribution. Here we formulate the classical optimal design problem in the context of general optimization problems over distributions of sampling times. We present a new Prohorov metric based theoretical framework that permits one to treat succinctly and rigorously any optimal design criteria based on the Fisher Information Matrix (FIM). A fundamental approximation theory is also included in this framework. A new optimal design, SE-optimal design (standard error optimal design), is then introduced in the context of this framework. We compare this new design criteria with the more traditional D-optimal and E-optimal designs. The optimal sampling distributions from each design are used to compute and compare standard errors; the standard errors for parameters are computed using asymptotic theory or bootstrapping and the optimal mesh. We use three examples to illustrate ideas: the Verhulst-Pearl logistic population model [13], the standard harmonic oscillator model [13] and a popular glucose regulation model [16, 19, 29].

  6. Radiation Belt Modeling for Spacecraft Design: Model Comparisons for Common Orbits

    NASA Technical Reports Server (NTRS)

    Lauenstein, J.-M.; Barth, J. L.

    2005-01-01

    We present the current status of radiation belt modeling, providing model details and comparisons with AP-8 and AE-8 for commonly used orbits. Improved modeling of the particle environment enables smarter space system design.

  7. Development and Comparison of TACAMO Icon Design Formats

    DTIC Science & Technology

    1992-03-01

    of icons, alphanumeric formats, and labels. While Steiner and Camacho (1989, p. 14) argue that, for large amounts of information, users perform better...superiority of icons over alphanumerics for many applications ( Steiner and Camacho, 1989), an iconic interface is strongly endorsed as an alternative...produce faster search and selection times (Camacho, Steiner , and Berson, 1990) and in some cases they are even preferred by experienced operators

  8. Turbo-alternator-compressor design for supercritical high density working fluids

    SciTech Connect

    Wright, Steven A.; Fuller, Robert L.

    2013-03-19

    Techniques for generating power are provided. Such techniques involve a thermodynamic system including a housing, a turbine positioned in a turbine cavity of the housing, a compressor positioned in a compressor cavity of the housing, and an alternator positioned in a rotor cavity between the turbine and compressor cavities. The compressor has a high-pressure face facing an inlet of the compressor cavity and a low-pressure face on an opposite side thereof. The alternator has a rotor shaft operatively connected to the turbine and compressor, and is supported in the housing by bearings. Ridges extending from the low-pressure face of the compressor may be provided for balancing thrust across the compressor. Seals may be positioned about the alternator for selectively leaking fluid into the rotor cavity to reduce the temperature therein.

  9. M-X Environmental Technical Report. Environmental Characteristics of Alternative Designated Deployment Areas, Power and Energy.

    DTIC Science & Technology

    1980-12-22

    energy impacts of analysis of site-specific impacts for each M-X deployment alternative. Each analysis identifies the cause-and- effect relationships for...Power 70 3.9 Alternative 8 - Coyote Spring Valley; Clovis 70 4.0 Effects on Energy Systevr.s 73 4.1 Energy Supply - Nevada/Utah 73 4.1.1 Fuel Supply...73 4.1.2 Electric Power 73 4.2 Energy Supply - Texas/New Mexico 73 4.2.1 Fuel Supply 73 4.2.2 Electric Power 73 4.3 Effect on Energy Systems near

  10. A comparison of methods for DPLL loop filter design

    NASA Technical Reports Server (NTRS)

    Aguirre, S.; Hurd, W. J.; Kumar, R.; Statman, J.

    1986-01-01

    Four design methodologies for loop filters for a class of digital phase-locked loops (DPLLs) are presented. The first design maps an optimum analog filter into the digital domain; the second approach designs a filter that minimizes in discrete time weighted combination of the variance of the phase error due to noise and the sum square of the deterministic phase error component; the third method uses Kalman filter estimation theory to design a filter composed of a least squares fading memory estimator and a predictor. The last design relies on classical theory, including rules for the design of compensators. Linear analysis is used throughout the article to compare different designs, and includes stability, steady state performance and transient behavior of the loops. Design methodology is not critical when the loop update rate can be made high relative to loop bandwidth, as the performance approaches that of continuous time. For low update rates, however, the miminization method is significantly superior to the other methods.

  11. An International Comparison of Final-Year Design Project Curricula

    ERIC Educational Resources Information Center

    Kentish, Sandra E.; Shallcross, David C.

    2006-01-01

    This paper reviews design teaching at a total of 15 chemical engineering departments across Australia, Singapore, and the United Kingdom. The emphasis is on the capstone Design Project, which can be viewed as a major transition subject for students as they move into the workplace. The study shows that this subject has evolved to act as an…

  12. Financing Alternatives Comparison Tool

    EPA Pesticide Factsheets

    FACT is a financial analysis tool that helps identify the most cost-effective method to fund a wastewater or drinking water management project. It produces a comprehensive analysis that compares various financing options.

  13. A comparison of methods currently used in inclusive design.

    PubMed

    Goodman-Deane, Joy; Ward, James; Hosking, Ian; Clarkson, P John

    2014-07-01

    Inclusive design has unique challenges because it aims to improve usability for a wide range of users. This typically includes people with lower levels of ability, as well as mainstream users. This paper examines the effectiveness of two methods that are used in inclusive design: user trials and exclusion calculations (an inclusive design inspection method). A study examined three autoinjectors using both methods (n=30 for the user trials). The usability issues identified by each method are compared and the effectiveness of the methods is discussed. The study found that each method identified different kinds of issues, all of which are important for inclusive design. We therefore conclude that a combination of methods should be used in inclusive design rather than relying on a single method. Recommendations are also given for how the individual methods can be used more effectively in this context.

  14. Comparison of optimal design methods in inverse problems

    NASA Astrophysics Data System (ADS)

    Banks, H. T.; Holm, K.; Kappel, F.

    2011-07-01

    Typical optimal design methods for inverse or parameter estimation problems are designed to choose optimal sampling distributions through minimization of a specific cost function related to the resulting error in parameter estimates. It is hoped that the inverse problem will produce parameter estimates with increased accuracy using data collected according to the optimal sampling distribution. Here we formulate the classical optimal design problem in the context of general optimization problems over distributions of sampling times. We present a new Prohorov metric-based theoretical framework that permits one to treat succinctly and rigorously any optimal design criteria based on the Fisher information matrix. A fundamental approximation theory is also included in this framework. A new optimal design, SE-optimal design (standard error optimal design), is then introduced in the context of this framework. We compare this new design criterion with the more traditional D-optimal and E-optimal designs. The optimal sampling distributions from each design are used to compute and compare standard errors; the standard errors for parameters are computed using asymptotic theory or bootstrapping and the optimal mesh. We use three examples to illustrate ideas: the Verhulst-Pearl logistic population model (Banks H T and Tran H T 2009 Mathematical and Experimental Modeling of Physical and Biological Processes (Boca Raton, FL: Chapman and Hall/CRC)), the standard harmonic oscillator model (Banks H T and Tran H T 2009) and a popular glucose regulation model (Bergman R N, Ider Y Z, Bowden C R and Cobelli C 1979 Am. J. Physiol. 236 E667-77 De Gaetano A and Arino O 2000 J. Math. Biol. 40 136-68 Toffolo G, Bergman R N, Finegood D T, Bowden C R and Cobelli C 1980 Diabetes 29 979-90).

  15. Can sequential parallel comparison design and two-way enriched design be useful in medical device clinical trials?

    PubMed

    Ivanova, Anastasia; Zhang, Zhiwei; Thompson, Laura; Yang, Ying; Kotz, Richard M; Fang, Xin

    2016-01-01

    Sequential parallel comparison design (SPCD) was proposed for trials with high placebo response. In the first stage of SPCD subjects are randomized between placebo and active treatment. In the second stage placebo nonresponders are re-randomized between placebo and active treatment. Data from the population of "all comers" and the subpopulations of placebo nonresponders then combined to yield a single p-value for treatment comparison. Two-way enriched design (TED) is an extension of SPCD where active treatment responders are also re-randomized between placebo and active treatment in Stage 2. This article investigates the potential uses of SPCD and TED in medical device trials.

  16. An evaluation of the impact of an example of thermal bridging in buildings and a design alternative

    NASA Astrophysics Data System (ADS)

    Kleinfeld, Jack M.

    2012-06-01

    Thermal Bridges act as short circuits for energy flow between conditioned interior space and the outside environment. They readily show up in infrared imaging under appropriate conditions. An example of a thermal bridge in a standard building detail and an alternate design are analyzed to predict the energy impact of the bridge and of removing it. The analysis also provides guidance on whether infrared imaging can detect the thermal bridge.

  17. Examining Our Career Switching Teachers' First Year of Teaching: Implications for Alternative Teacher Education Program Design

    ERIC Educational Resources Information Center

    Wilcox, Dawn Renee; Samaras, Anastasia P.

    2009-01-01

    This study explores the impact of an alternative teacher preparation program development from the "inside out" or through the voices of second career teachers, known as "Career Switchers," at a mid-size state university. The major objective of this study was to probe into their perceptions to inform program development with reporting framed in…

  18. Alternative Fuels and Hybrid Technology: A Classroom Activity Designed to Evaluate a Contemporary Problem

    ERIC Educational Resources Information Center

    Roy MacArthur, Amy H.; Copper, Christine L.

    2009-01-01

    As petroleum reserves are being depleted worldwide and energy costs are increasing, the use of alternative fuels is being more widely considered as a solution to the impending energy crisis. In this classroom activity students are presented with a real-world problem in which they must evaluate the properties and environmental impacts of a variety…

  19. MODELING AND DESIGN STUDY USING HFC-236EA AS AN ALTERNATIVE REFRIGERANT IN A CENTRIFUGAL COMPRESSOR

    EPA Science Inventory

    The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

  20. Alternative Schools.

    ERIC Educational Resources Information Center

    Pritchett, Stanley; Kimsey, Steve

    2002-01-01

    Describes the design of the DeKalb Alternative School in Atlanta, Georgia, located in a renovated shopping center. Purchasing commercial land and renovating the existing building saved the school system time and money. (EV)

  1. An Alternative View of the Instructional Design Process: A Response to Smith and Boling

    ERIC Educational Resources Information Center

    Gibbons, Andrew S.; Yanchar, Stephen C.

    2010-01-01

    A recent literature review by Smith and Boling (2009) critically examines the received view of instructional design in educational technology. Smith and Boling conclude that the foundational literature characterizes design in a way that leads to a constrained understanding of design, especially by novices. They suggest that as a field we move…

  2. SSME Alternate Turbopump Development Program: Design verification specification for high-pressure fuel turbopump

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The design and verification requirements are defined which are appropriate to hardware at the detail, subassembly, component, and engine levels and to correlate these requirements to the development demonstrations which provides verification that design objectives are achieved. The high pressure fuel turbopump requirements verification matrix provides correlation between design requirements and the tests required to verify that the requirement have been met.

  3. Generating Alternative Engineering Designs by Integrating Desktop VR with Genetic Algorithms

    ERIC Educational Resources Information Center

    Chandramouli, Magesh; Bertoline, Gary; Connolly, Patrick

    2009-01-01

    This study proposes an innovative solution to the problem of multiobjective engineering design optimization by integrating desktop VR with genetic computing. Although, this study considers the case of construction design as an example to illustrate the framework, this method can very much be extended to other engineering design problems as well.…

  4. The Civic-Minded Instructional Designers Framework: An Alternative Approach to Contemporary Instructional Designers' Education in Higher Education

    ERIC Educational Resources Information Center

    Yusop, Farrah Dina; Correia, Ana-Paula

    2012-01-01

    This paper argues that an emphasis on training-for-the-job approaches has distracted designers from thinking about the meaning of their profession and the grand purpose of practising instructional design. Drawing from literature in the fields of sociology and educational technology, this paper synthesises discourses on civic professionalism in…

  5. Comparison of soil respiration in typical conventional and new alternative cereal cropping systems on the North China plain.

    PubMed

    Gao, Bing; Ju, Xiaotang; Su, Fang; Gao, Fengbin; Cao, Qingsen; Oenema, Oene; Christie, Peter; Chen, Xinping; Zhang, Fusuo

    2013-01-01

    We monitored soil respiration (Rs), soil temperature (T) and volumetric water content (VWC%) over four years in one typical conventional and four alternative cropping systems to understand Rs in different cropping systems with their respective management practices and environmental conditions. The control was conventional double-cropping system (winter wheat and summer maize in one year--Con.W/M). Four alternative cropping systems were designed with optimum water and N management, i.e. optimized winter wheat and summer maize (Opt.W/M), three harvests every two years (first year, winter wheat and summer maize or soybean; second year, fallow then spring maize--W/M-M and W/S-M), and single spring maize per year (M). Our results show that Rs responded mainly to the seasonal variation in T but was also greatly affected by straw return, root growth and soil moisture changes under different cropping systems. The mean seasonal CO2 emissions in Con.W/M were 16.8 and 15.1 Mg CO2 ha(-1) for summer maize and winter wheat, respectively, without straw return. They increased significantly by 26 and 35% in Opt.W/M, respectively, with straw return. Under the new alternative cropping systems with straw return, W/M-M showed similar Rs to Opt.W/M, but total CO2 emissions of W/S-M decreased sharply relative to Opt.W/M when soybean was planted to replace summer maize. Total CO2 emissions expressed as the complete rotation cycles of W/S-M, Con.W/M and M treatments were not significantly different. Seasonal CO2 emissions were significantly correlated with the sum of carbon inputs of straw return from the previous season and the aboveground biomass in the current season, which explained 60% of seasonal CO2 emissions. T and VWC% explained up to 65% of Rs using the exponential-power and double exponential models, and the impacts of tillage and straw return must therefore be considered for accurate modeling of Rs in this geographical region.

  6. Variance Analysis and Comparison in Computer-Aided Design

    NASA Astrophysics Data System (ADS)

    Ullrich, T.; Schiffer, T.; Schinko, C.; Fellner, D. W.

    2011-09-01

    The need to analyze and visualize differences of very similar objects arises in many research areas: mesh compression, scan alignment, nominal/actual value comparison, quality management, and surface reconstruction to name a few. In computer graphics, for example, differences of surfaces are used for analyzing mesh processing algorithms such as mesh compression. They are also used to validate reconstruction and fitting results of laser scanned surfaces. As laser scanning has become very important for the acquisition and preservation of artifacts, scanned representations are used for documentation as well as analysis of ancient objects. Detailed mesh comparisons can reveal smallest changes and damages. These analysis and documentation tasks are needed not only in the context of cultural heritage but also in engineering and manufacturing. Differences of surfaces are analyzed to check the quality of productions. Our contribution to this problem is a workflow, which compares a reference / nominal surface with an actual, laser-scanned data set. The reference surface is a procedural model whose accuracy and systematics describe the semantic properties of an object; whereas the laser-scanned object is a real-world data set without any additional semantic information.

  7. Comparison of a new flap design with the routinely used triangular flap design in third molar surgery.

    PubMed

    Yolcu, Ü; Acar, A H

    2015-11-01

    The aim of this study is to introduce a new flap design in the surgical removal of impacted mandibular third molars - a lingually based triangular flap - and to compare this flap design with the routinely used triangular flap. This randomized, prospective, split-mouth study involved 22 patients with impacted bilateral mandibular third molars that were symmetrically positioned, mesially angulated, and retained in bone. The impacted teeth were removed in two sessions, using two different flap designs: the new alternative flap and the traditional triangular flap. Postoperative complications (pain, swelling, trismus, alveolar osteitis, and wound dehiscence) were recorded on days 2, 7, 14, and 21. The data obtained were analysed using the χ(2) test, the Mann-Whitney U-test, and Pearson's correlation. In terms of the severity of postoperative facial swelling and trismus, there were no statistically significant differences between the flap designs (P>0.05). The alternative flap exhibited higher pain scores at 12h post-surgery (P<0.05). In addition, the alternative flap group exhibited less wound dehiscence, although this was not statistically significant. Moreover, all wound dehiscence in this group occurred on sound bone. In conclusion, these results show that this new flap design is preferable to the routinely used flap for impacted third molar surgery.

  8. Concept design and alternate arrangements of orbiter mid-deck habitability features

    NASA Technical Reports Server (NTRS)

    Church, R. A.; Ciciora, J. A.; Porter, K. L.; Stevenson, G. E.

    1976-01-01

    The evaluations and recommendations for habitability features in the space shuttle orbiter mid-deck are summarized. The orbiter mission plans, the mid-deck dimensions and baseline arrangements along with crew compliments and typical activities were defined. Female and male anthropometric data based on zero-g operations were also defined. Evaluations of baseline and alternate feasible concepts provided several recommendations which are discussed.

  9. Thermal/mechanical simulation and laboratory fatigue testing of an alternative yttria tetragonal zirconia polycrystal core-veneer all-ceramic layered crown design.

    PubMed

    Bonfante, Estevam A; Rafferty, Brian; Zavanelli, Ricardo A; Silva, Nelson R F A; Rekow, Elizabeth D; Thompson, Van P; Coelho, Paulo G

    2010-04-01

    This study evaluated the stress levels at the core layer and the veneer layer of zirconia crowns (comprising an alternative core design vs. a standard core design) under mechanical/thermal simulation, and subjected simulated models to laboratory mouth-motion fatigue. The dimensions of a mandibular first molar were imported into computer-aided design (CAD) software and a tooth preparation was modeled. A crown was designed using the space between the original tooth and the prepared tooth. The alternative core presented an additional lingual shoulder that lowered the veneer bulk of the cusps. Finite element analyses evaluated the residual maximum principal stresses fields at the core and veneer of both designs under loading and when cooled from 900 degrees C to 25 degrees C. Crowns were fabricated and mouth-motion fatigued, generating master Weibull curves and reliability data. Thermal modeling showed low residual stress fields throughout the bulk of the cusps for both groups. Mechanical simulation depicted a shift in stress levels to the core of the alternative design compared with the standard design. Significantly higher reliability was found for the alternative core. Regardless of the alternative configuration, thermal and mechanical computer simulations showed stress in the alternative core design comparable and higher to that of the standard configuration, respectively. Such a mechanical scenario probably led to the higher reliability of the alternative design under fatigue.

  10. Some comparisons of US and USSR aircraft design developments

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1985-01-01

    A review is given of the design and development of some U.S. and U.S.S.R. aircraft. The emphasis is on the historical development of large aircraft - civil and military transports and bombers. Design trends are somewhat similar for the two countries and indications are that some fundamental characteristics are dictated more by ideological differences rather than technological differences. A brief description is given in a more or less chronological order of the major bomber aircraft, major civil and military transport aircraft, and the development of the air transport systems.

  11. Some comparisons of US and USSR aircraft design developments

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1985-01-01

    A review is given of the design and development of some US and USSR aircraft. The emphasis is on the historical development of large aircraft-civil and military transports and bombers. Design trends are somewhat similar for the two countries and indications are that some fundamental characteristics are dictated more by ideological differences rather than technological differences. A brief description is given in a more or less chronological order of the major bomber aircraft, major civil and military transport aircraft, and the development of the air transport systems.

  12. Comparison of Two Independent LIDAR-Based Pitch Control Designs

    SciTech Connect

    Dunne, F.; Schlipf, D.; Pao, L. Y.

    2012-08-01

    Two different lidar-based feedforward controllers have previously been designed for the NREL 5 MW wind turbine model under separate studies. Feedforward controller A uses a finite-impulse-response design, with 5 seconds of preview, and three rotating lidar measurements. Feedforward controller B uses a static-gain design, with the preview time defined by the pitch actuator dynamics, a simulation of a real nacelle-based scanning lidar system, and a lowpass filter defined by the lidar configuration. These controllers are now directly compared under the same lidar configuration, in terms of fatigue load reduction, rotor speed regulation, and power capture. The various differences in design choices are discussed and compared. We also compare frequency plots of individual pitch feedforward and collective pitch feedforward load reductions, and we see that individual pitch feedforward is effective mainly at the once-per-revolution and twice-per-revolution frequencies. We also explain how to determine the required preview time by breaking it down into separate parts, and we then compare it to the expected preview time available.

  13. Comparison of two approaches to linear collider design

    SciTech Connect

    Schnell, W.

    1987-11-01

    This paper reviews linear collider parameters. It aims at analyzing two specific design approachs - the ones for CLIC at CERN and for a TeV linear collider at SLAC - which appear to lead into remarkably different directions although they start from the same premises and try to respect the same boundary conditions. 19 refs.

  14. Comparison Sensitivity Design of Output Feedback Systems Using State Observers.

    DTIC Science & Technology

    1978-01-01

    of sensitivity reduction in feedback systems which use state observers for dynamic compensation is considered leading to a design procedure which...results developed using state observers in the compensator dynamics. All systems discussed are assumed to be linear time invariant (LTI) systems which are state controllable and state observable. (Author)

  15. Comparison between Kemp, Smith & Ragan, Dick & Carey's Instructional Design Models

    ERIC Educational Resources Information Center

    Birgili, Bengi

    2013-01-01

    Instructional design (ID) is systematic way of suggesting a structure and giving meaning to an instructional problem by helping to visualize the problem and breaking into discrete and manageable units. In addition, ID is a systematic reflective process of applying instructional principles into plans by material, activity, resources and evaluation…

  16. Comparison of Two Independent Lidar-Based Pitch Control Designs

    SciTech Connect

    Dunne, F.; Schlipf, D.; Pao, L. Y.; Wright, A. D.; Jonkman, B.; Kelley, N.; Simley, E.

    2012-01-01

    Two different lidar-based feedforward controllers have previously been designed for the NREL 5 MW wind turbine model under separate studies. One uses a finite-impulse-response design, with 5 seconds of preview, and three rotating lidar measurements. The other uses a static-gain design, with the preview time defined by the pitch actuator dynamics, a simulation of a real nacelle-based scanning lidar system, and a lowpass filter defined by the lidar configuration. These controllers are now directly compared under the same lidar configuration, in terms of fatigue load reduction, rotor speed regulation, and power capture. The various differences in design choices are discussed and compared. We also compare frequency plots of individual pitch feedforward and collective pitch feedforward load reductions, and we see that individual pitch feedforward is effective mainly at the once-per-revolution and twice-per-revolution frequencies. We also explain how to determine the required preview time by breaking it down into separate parts, and we then compare it to the expected preview time available.

  17. Design Approaches and Comparison of TAPS Packages for Engineering

    ERIC Educational Resources Information Center

    Sidhu, S. Manjit

    2007-01-01

    Purpose: The paper's purpose is to promote the use of modern technologies such as multimedia packages to engineering students. The aim is to help them to learning in their learning, visualization, problem solving and understanding engineering concepts such as in mechanics dynamics. Design/methodology/approach: TAPS packages are developed to help…

  18. Weighing Evidence: The Design and Comparison of Probability Thought Experiments.

    DTIC Science & Technology

    1983-06-01

    a belief-function design for the problem. Weighing Evidence 12 The Hominids of East Turkana In the August 1078 issue of Scientific American, Alan...Walker and Richara E. T. Leakey discuss the hominid fossils that have recently been discovered in the region east of Lake Turkana in Kenya. These fossils...the effect that distinct hominid species cannot co-exist after one of them has acquired culture. (ii) Hypotheses I and 4 are doubtful because they

  19. Investigation of Alternative Return Strategies for Orion Trans-earth Injection Design Options

    NASA Technical Reports Server (NTRS)

    Marchand, Belinda G.; Scarritt, Sara K.; Howell, Kathleen C.; Weeks, Michael W.

    2010-01-01

    The purpose of this study is to investigate alternative return strategies for the Orion trans-Earth injection (TEI) phase. A dynamical systems analysis approach considers the structure of the stable and unstable Sun perturbed Earth-Moon manifolds near the Earth-Moon interface region. A hybrid approach, then, combines the results from this analysis with classical two-body methods in a targeting process that seeks to expand the window of return opportunities in a precision entry scenario. The resulting startup arcs can be used, for instance, to enhance the block set of solutions available onboard during an autonomous targeting process.

  20. Impact of Rate Design Alternatives on Residential Solar Customer Bills. Increased Fixed Charges, Minimum Bills and Demand-based Rates

    SciTech Connect

    Bird, Lori; Davidson, Carolyn; McLaren, Joyce; Miller, John

    2015-09-01

    With rapid growth in energy efficiency and distributed generation, electric utilities are anticipating stagnant or decreasing electricity sales, particularly in the residential sector. Utilities are increasingly considering alternative rates structures that are designed to recover fixed costs from residential solar photovoltaic (PV) customers with low net electricity consumption. Proposed structures have included fixed charge increases, minimum bills, and increasingly, demand rates - for net metered customers and all customers. This study examines the electricity bill implications of various residential rate alternatives for multiple locations within the United States. For the locations analyzed, the results suggest that residential PV customers offset, on average, between 60% and 99% of their annual load. However, roughly 65% of a typical customer's electricity demand is non-coincidental with PV generation, so the typical PV customer is generally highly reliant on the grid for pooling services.

  1. Water balance relationships in four alternative cover designs for radioactive and mixed waste landfills

    SciTech Connect

    Warren, R.W.; Hakonson, T.E.; Trujillo, G.

    1994-08-01

    Preliminary results are presented from a field study to evaluate the relative hydrologic performance of various landfill capping technologies installed by the Los Alamos National Laboratory at Hill Air Force Base, Utah. Four cover designs (two Los Alamos capillary barrier designs, one modified EPA RCRA design, and one conventional design) were installed in large lysimeters instrumented to monitor the fate of natural precipitation between 01 January 1990 and 20 September 1993. After 45 months of study, results showed that the cover designs containing barrier layers were effective in reducing deep percolation as compared to a simple soil cap design. The RCRA cover, incorporating a clay hydraulic barrier, was the most effective of all cover designs in controlling percolation but was not 100% effective. Over 90% of all percolation and barrier lateral flow occurred during the months of February through May of each year, primarily as a result of snow melt, early spring rains and low evapotranspiration. Gravel mulch surface treatments (70--80% coverage) were effective in reducing runoff and erosion. The two plots receiving gravel mulch treatments exhibited equal but enhanced amounts of evapotranspiration despite the fact that one plot was planted with additional shrubs.

  2. Assessing the environmental burdens of anaerobic digestion in comparison to alternative options for managing the biodegradable fraction of municipal solid wastes.

    PubMed

    Haight, M

    2005-01-01

    Biological treatment processes including anaerobic digestion (biogasification) and composting are increasingly being considered by waste management officials and planners as alternatives for managing the mainly organic residues of municipal solid wastes (MSW). The integrated waste management model which is based upon the application of life-cycle analysis was employed to compare the environmental burdens of landfilling, composting and anaerobic digestion of MSW at a mid-sized Canadian community. Energy consumption (or recovery), residue recoveries and emissions to air and water were quantified. Scenario comparisons were analyzed to demonstrate that the environmental burdens associated with anaerobic digestion are reduced in comparison with the alternative options. The major benefit occurs as a result of the electricity produced from burning the biogas and then supplying the 'green power' to the local electrical grid.

  3. Comparison of deterministic and Monte Carlo methods in shielding design.

    PubMed

    Oliveira, A D; Oliveira, C

    2005-01-01

    In shielding calculation, deterministic methods have some advantages and also some disadvantages relative to other kind of codes, such as Monte Carlo. The main advantage is the short computer time needed to find solutions while the disadvantages are related to the often-used build-up factor that is extrapolated from high to low energies or with unknown geometrical conditions, which can lead to significant errors in shielding results. The aim of this work is to investigate how good are some deterministic methods to calculating low-energy shielding, using attenuation coefficients and build-up factor corrections. Commercial software MicroShield 5.05 has been used as the deterministic code while MCNP has been used as the Monte Carlo code. Point and cylindrical sources with slab shield have been defined allowing comparison between the capability of both Monte Carlo and deterministic methods in a day-by-day shielding calculation using sensitivity analysis of significant parameters, such as energy and geometrical conditions.

  4. Incremental Testing Design on Slide Board for Speed Skaters: Comparison Between Two Different Protocols.

    PubMed

    Piucco, Tatiane; OʼConnell, Jessica; Stefanyshyn, Darren; de Lucas, Ricardo Dantas

    2016-11-01

    Piucco, T, O'Connell, J, Stefanyshyn, D, and de Lucas, RD. Incremental testing design on slide board for speed skaters: comparison between two different protocols. J Strength Cond Res 30(11): 3116-3121, 2016-The aim of this study was to investigate the effect of stage duration (Long-stage-LS: 3-minute, Short-stage-SS: 1-minute) on maximal and submaximal aerobic physiological variables during a simulated skating test performed on a slide board. Ten well-trained male speed skaters performed 2 maximal incremental tests on slide board until voluntary exhaustion. The second ventilatory threshold (VT2) was determined by the ventilatory equivalent method. All participants reached the criteria for maximal oxygen uptake (V[Combining Dot Above]O2max) attainment in both protocols. Maximal cadence (CADmax), V[Combining Dot Above]O2 at VT2 and cadence at VT2 (CADVT2) were significantly higher during SS protocol, but maximal heart rate was significantly lower for the SS protocol. V[Combining Dot Above]O2max was significantly correlated with CADmax for the SS (r = 0.62) and LS protocols (r = 0.61). Strong correlations were found between CADmax and CADVT2 during the SS (r = 0.83) and LS protocols (r = 0.76). The results of the present study suggest that either SS or LS slide board incremental protocol can be used to evaluate skaters, since they elicited maximal physiological responses. Additionally, slide board incremental skating tests may be considered as a more specific and practical alternative than laboratory-based tests, especially when a large number of athletes need to be assessed.

  5. GREENER CHEMICAL PROCESS DESIGN ALTERNATIVES ARE REVEALED USING THE WASTE REDUCTION DECISION SUPPORT SYSTEM (WAR DSS)

    EPA Science Inventory

    The Waste Reduction Decision Support System (WAR DSS) is a Java-based software product providing comprehensive modeling of potential adverse environmental impacts (PEI) predicted to result from newly designed or redesigned chemical manufacturing processes. The purpose of this so...

  6. Sample size determination for alternate periods of use study designs with binary responses.

    PubMed

    Morel, Jorge G; Neerchal, Nagaraj K

    2012-01-01

    In this article, we consider several study designs that arise in practice, which are variations of standard crossover designs. Often, they may result from modifications made to a standard crossover design due to practical considerations. Characteristic features of the studies we are concerned with are (a) treatments consist of external use of products with little or no possibility of carry over effects, and (b) the periods of use are dictated by the subjects or by some specific event, such as diaper leakage or menstrual flow. We consider a number of such study designs for estimating the difference in the efficacy of two treatments or test products. We provide brief descriptions of studies to motivate the study design, the underlying data structure, and computations of the variances of the usual unbiased estimators of the difference in efficacy, and the sample size formulas. The situations considered here cover a number of popular crossover designs. The objective of our work is to provide guidance to members of a wide audience on how to answer the sample size question for their own nonstandard situations. We conclude the article with a brief report on a simulation study we conducted to investigate the impact of estimation on the sample size determination and consequently on the actual power realized in an effort to promote the "best practice" of checking whether the recommended sample sizes indeed achieve the desired level of power.

  7. Comparison of matching layers for automotive radome design

    NASA Astrophysics Data System (ADS)

    Fitzek, F.; Rasshofer, R. H.; Biebl, E. M.

    2010-09-01

    Hidden integration of 79 GHz sensors behind plastic and painted fascia represents a challenging task since both electromagnetic and car body design constraints have to be met. This paper compares different possibilities for low-cost integration of radar sensors. Based on a model for stratified media, a study of the most important parameters such as bandwidth, angle and tolerances is shown. Our results suggest that for plastic fascia, the requirements of future radar sensors can be met with low-cost matching. Even with metallic paints, the requirements imposed by modern 79 GHz radar sensors can be met under certain conditions.

  8. Comparison of Designer's Design Thinking Modes in Digital and Traditional Sketches

    ERIC Educational Resources Information Center

    Wu, Jun-Chieh; Chen, Cheng-Chi; Chen, Hsin-Chia

    2012-01-01

    The internal design thinking behaviour of designers in the concept development has been an important issue of cognitive psychology. In this study, the design thinking process designers have in applying digital media and traditional paper in the early concept development stage was explored. Special focus was made on the structure and procedure of…

  9. A Systems Biology Approach to Understanding the Mechanisms of Action of an Alternative Anticancer Compound in Comparison to Cisplatin

    PubMed Central

    Wright, Elise P.; Padula, Matthew P.; Higgins, Vincent J.; Aldrich-Wright, Janice R.; Coorssen, Jens R.

    2014-01-01

    Many clinically available anticancer compounds are designed to target DNA. This commonality of action often yields overlapping cellular response mechanisms and can thus detract from drug efficacy. New compounds are required to overcome resistance mechanisms that effectively neutralise compounds like cisplatin and those with similar chemical structures. Studies have shown that 56MESS is a novel compound which, unlike cisplatin, does not covalently bind to DNA, but is more toxic to many cell lines and active against cisplatin-resistant cells. Furthermore, a transcriptional study of 56MESS in yeast has implicated iron and copper metabolism as well as the general yeast stress response following challenge with 56MESS. Beyond this, the cytotoxicity of 56MESS remains largely uncharacterised. Here, yeast was used as a model system to facilitate a systems-level comparison between 56MESS and cisplatin. Preliminary experiments indicated that higher concentrations than seen in similar studies be used. Although a DNA interaction with 56MESS had been theorized, this work indicated that an effect on protein synthesis/ degradation was also implicated in the mechanism(s) of action of this novel anticancer compound. In contrast to cisplatin, the different mechanisms of action that are indicated for 56MESS suggest that this compound could overcome cisplatin resistance either as a stand-alone treatment or a synergistic component of therapeutics. PMID:28250393

  10. Comparison of visibility measurement techniques for forklift truck design factors.

    PubMed

    Choi, Chin-Bong; Park, Peom; Kim, Young-Ho; Susan Hallbeck, M; Jung, Myung-Chul

    2009-03-01

    This study applied the light bulb shadow test, a manikin vision assessment test, and an individual test to a forklift truck to identify forklift truck design factors influencing visibility. The light bulb shadow test followed the standard of ISO/DIS 13564-1 for traveling and maneuvering tests with four test paths (Test Nos. 1, 3, 4, and 6). Digital human and forklift truck models were developed for the manikin vision assessment test with CATIA V5R13 human modeling solutions. Six participants performed the individual tests. Both employed similar parameters to the light bulb shadow test. The individual test had better visibility with fewer numbers and a greater distribution of the shadowed grids than the other two tests due to eye movement and anthropometric differences. The design factors of load backrest extension, lift chain, hose, dashboard, and steering wheel should be the first factors considered to improve visibility, especially when a forklift truck mainly performs a forward traveling task in an open area.

  11. Comparison of Coil Designs for Transcranial Magnetic Stimulation on Mice

    NASA Astrophysics Data System (ADS)

    Rastogi, Priyam; Hadimani, Ravi; Jiles, David

    2015-03-01

    Transcranial magnetic stimulation (TMS) is a non-invasive treatment for neurological disorders using time varying magnetic field. The electric field generated by the time varying magnetic field is used to depolarize the brain neurons which can lead to measurable effects. TMS provides a surgical free method for the treatment of neurological brain disorders like depression, post-traumatic stress disorder, traumatic brain injury and Parkinson's disease. Before using TMS on human subjects, it is appropriate that its effects are verified on animals such as mice. The magnetic field intensity and stimulated region of the brain can be controlled by the shape, position and current in the coils. There are few reports on the designs of the coils for mice. In this paper, different types of coils are developed and compared using an anatomically realistic mouse model derived from MRI images. Parameters such as focality, depth of the stimulation, electric field strength on the scalp and in the deep brain regions, are taken into account. These parameters will help researchers to determine the most suitable coil design according to their need. This should result in improvements in treatment of specific disorders. Carver Charitable Trust.

  12. Study of alternate optical and fine guidance sensor designs for the space infrared telescope facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Wissinger, A.; Steir, M.; Mcfarlane, M.; Fuschetto, A.

    1984-01-01

    A unique optical design was developed that compensates for the coma degraded images caused by field chopping in SIRTF. The conic constants of a Cassegrain telescope were altered to compensate for the coma induced by the secondary mirror tilt. The modulation transfer function is essentially independent of secondary mirror tilt, and diffraction limited image quality is maintained over a several arcminute field during chopping. With an untilted secondary mirror, the coma compensated (CC) design has a smaller field than the unchopped Ritchey-Chretien design; but use of relay optics, such as the inverted Cassegrain design developed for the fine guidance sensor (FGS), can increase the CC telescope's field size. A reactionless secondary mirror chopper mechanism that uses superconducting magnets was studied. The heart producing elements are confined to a reaction plate that is not directly viewed by the IR focal plane. A design was also developed for a low moment of inertia, reticulated HIP beryllium secondary mirror consistent with blank fabrication technology and optical finishing requirements.

  13. Axiomatic design theory for the analysis, comparison, and redesign of curriculum for special education.

    PubMed

    Wettasinghe, C M; Koh, T H

    2008-11-01

    This paper explores a novel approach to instructional planning using the axiomatic design theory to create an optimized curriculum. First, an existing piece of curriculum is analyzed by axiomatic design approach and design matrices are made to check whether the independence axiom is satisfied or not. Second, functional requirements (FRs) are derived from the FRs of the existing curriculums developed through conventional methods. Constraints (Cs) are defined considering the time and subject. Design parameters (DPs) are conceived in physical domain to satisfy these specified FRs and Cs, and two alternative DPs for one FR are proposed. One of these alternatives having the least information content is selected by defining FRs as the minimization of the irrelevant subjects/topics and time. Also feasibility is estimated by comparing the information content of the redesigned curriculum with that of other curriculums in consideration of costs-involved, time, and subjects-relevance.

  14. QST-FST comparisons with unbalanced half-sib designs.

    PubMed

    Gilbert, Kimberly J; Whitlock, Michael C

    2015-03-01

    QST , a measure of quantitative genetic differentiation among populations, is an index that can suggest local adaptation if QST for a trait is sufficiently larger than the mean FST of neutral genetic markers. A previous method by Whitlock and Guillaume derived a simulation resampling approach to statistically test for a difference between QST and FST , but that method is limited to balanced data sets with offspring related as half-sibs through shared fathers. We extend this approach (i) to allow for a model more suitable for some plant populations or breeding designs in which offspring are related through mothers (assuming independent fathers for each offspring; half-sibs by dam); and (ii) by explicitly allowing for unbalanced data sets. The resulting approach is made available through the R package QstFstComp.

  15. Individually designed PALs vs. power optimized PALs adaptation comparison.

    PubMed

    Muždalo, Nataša Vujko; Mihelčič, Matjaž

    2015-03-01

    The practice shows that in everyday life we encounter ever-growing demand for better visual acuity at all viewing distances. The presbyopic population needs correction to far, near and intermediate distance with different dioptric powers. PAL lenses seem to be a comfortable solution. The object of the present study is the analysis of the factors determining adaptation to progressive addition lenses (PAL) of the first-time users. Only novice test persons were chosen in order to avoid the bias of previously worn particular lens design. For optimal results with this type of lens, several individual parameters must be considered: correct refraction, precise ocular and facial measures, and proper mounting of lenses into the frame. Nevertheless, first time wearers encounter various difficulties in the process of adapting to this type of glasses and adaptation time differs greatly between individual users. The question that arises is how much the individual parameters really affect the ease of adaptation and comfort when wearing progressive glasses. To clarify this, in the present study, the individual PAL lenses--Rodenstock's Impression FreeSign (with inclusion of all parameters related to the user's eye and spectacle frame: prescription, pupillary distance, fitting height, back vertex distance, pantoscopic angle and curvature of the frame) were compared to power optimized PAL--Rodenstock's Multigressiv MyView (respecting only prescription power and pupillary distance). Adaptation process was monitored over a period of four weeks. The collected results represent scores of user's subjective impressions, where the users themselves rated their adaptation to new progressive glasses and the degree of subjective visual impression. The results show that adaptation time to fully individually fit PAL is easier and quickly. The information obtained from users is valuable in everyday optometry practice because along with the manufacturer's specifications, the user's experience can

  16. Alternative methods of processing bio-feedstocks in formulated consumer product design

    PubMed Central

    Peremezhney, Nicolai; Jacob, Philipp-Maximilian; Lapkin, Alexei

    2014-01-01

    In this work new methods of processing bio-feedstocks in the formulated consumer products industry are discussed. Our current approach to formulated products design is based on heuristic knowledge of formulators that allows selecting individual compounds from a library of available materials with known properties. We speculate that most of the compounds (or functions) that make up the product to be designed can potentially be obtained from a few bio-sources. In this case, it may be possible to design a sequence of transformations required to convert feedstocks into products with desired properties, analogous to a metabolic pathway of a complex organism. We conceptualize some novel approaches to processing bio-feedstocks with the aim of bypassing the step of a fixed library of ingredients. Two approaches are brought forward: one making use of knowledge-based expert systems and the other making use of applications of metabolic engineering and dynamic combinatorial chemistry. PMID:24860803

  17. Evaluation of secondary coolant control design alternatives and their effects on heat removal performance

    SciTech Connect

    Khayat, M.I.; Anderson, J.; Battle, R.; March-Leuba, J.

    1994-03-01

    This report documents a series of calculations that evaluate the performance of the core-inlet temperature controller under different transient conditions and design options. The present analyses show that the core-inlet temperature can be controlled at {approx}45{degrees}C under all transient conditions analyzed using the controller design described in the conceptual design report, which includes variable-speed secondary coolant pumps and variable-speed cooling tower fans. This study also shows that a constant-speed secondary pump would be sufficient to maintain core-inlet temperature <45{degrees}C if this temperature is allowed to drop below the set point during some demanding transients, such as normal startup. The use of secondary loop hot coolant to warm the reactor building was also evaluated; however, optimization of the secondary hot-leg temperature can only be achieved by trading off control of the primary side core-inlet temperature.

  18. Alternative methods of processing bio-feedstocks in formulated consumer product design.

    PubMed

    Peremezhney, Nicolai; Jacob, Philipp-Maximilian; Lapkin, Alexei

    2014-01-01

    In this work new methods of processing bio-feedstocks in the formulated consumer products industry are discussed. Our current approach to formulated products design is based on heuristic knowledge of formulators that allows selecting individual compounds from a library of available materials with known properties. We speculate that most of the compounds (or functions) that make up the product to be designed can potentially be obtained from a few bio-sources. In this case, it may be possible to design a sequence of transformations required to convert feedstocks into products with desired properties, analogous to a metabolic pathway of a complex organism. We conceptualize some novel approaches to processing bio-feedstocks with the aim of bypassing the step of a fixed library of ingredients. Two approaches are brought forward: one making use of knowledge-based expert systems and the other making use of applications of metabolic engineering and dynamic combinatorial chemistry.

  19. Note: Circuit design for direct current and alternating current electrochemical etching of scanning probe microscopy tips

    NASA Astrophysics Data System (ADS)

    Jobbins, Matthew M.; Raigoza, Annette F.; Kandel, S. Alex

    2012-03-01

    We present control circuits designed for electrochemically etching, reproducibly sharp STM probes. The design uses an Arduino UNO microcontroller to allow for both ac and dc operation, as well as a comparator driven shut-off that allows for etching to be stopped in 0.5-1 μs. The Arduino allows the instrument to be customized to suit a wide variety of potential applications without significant changes to hardware. Data is presented for coarse chemical etching of 80:20 platinum-iridium, tungsten, and nickel tips.

  20. Comparison of Traditional Design Nonlinear Programming Optimization and Stochastic Methods for Structural Design

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Pai, Shantaram S.; Coroneos, Rula M.

    2010-01-01

    Structural design generated by traditional method, optimization method and the stochastic design concept are compared. In the traditional method, the constraints are manipulated to obtain the design and weight is back calculated. In design optimization, the weight of a structure becomes the merit function with constraints imposed on failure modes and an optimization algorithm is used to generate the solution. Stochastic design concept accounts for uncertainties in loads, material properties, and other parameters and solution is obtained by solving a design optimization problem for a specified reliability. Acceptable solutions were produced by all the three methods. The variation in the weight calculated by the methods was modest. Some variation was noticed in designs calculated by the methods. The variation may be attributed to structural indeterminacy. It is prudent to develop design by all three methods prior to its fabrication. The traditional design method can be improved when the simplified sensitivities of the behavior constraint is used. Such sensitivity can reduce design calculations and may have a potential to unify the traditional and optimization methods. Weight versus reliabilitytraced out an inverted-S-shaped graph. The center of the graph corresponded to mean valued design. A heavy design with weight approaching infinity could be produced for a near-zero rate of failure. Weight can be reduced to a small value for a most failure-prone design. Probabilistic modeling of load and material properties remained a challenge.

  1. An ROI Comparison of Initiatives Designed to Attract Diverse Students to Technology Careers

    ERIC Educational Resources Information Center

    Dillon, Thomas W.; Reif, Harry L.; Thomas, Daphyne S.

    2016-01-01

    This study examines two alternative interventions designed to attract diverse students to pursue information technology or, more generally, STEM (science, technology, engineering, and math) careers from a Return on Investment (ROI) perspective. More specifically, this study examines the effectiveness and efficiency of single-day and multi-day…

  2. Competency-Based Education: A Viable Alternative for Developmental Studies Program Design.

    ERIC Educational Resources Information Center

    Herrscher, Barton R.

    1980-01-01

    Advocates the use of both descriptive and prescriptive approaches to designing developmental studies programs in community colleges. Defines competency-based education (CBE) and examines five critical elements of CBE: educational framework, systematic structure, educational attainment, learning outcomes, and instructional processes. Discusses the…

  3. Discriminating effects of heterogeneity and matrix diffusion by alternative tracer designs

    SciTech Connect

    Tsang, Y.Y.W.

    1995-03-01

    Flow and transport calculations are carried out by numerical simulation for different tracer designs: single-well radially diverging/converging (huff-puff), single well radially converging, and two-well injection-withdrawal (doublet) in a 2D fracture zone. The fractured rocks are conceptualized as a dual-continuum: the well-connected fractures forming a heterogeneous continuum for advective transport, and the less permeable matrix forming a second continuum for tracer diffusion. Results show that the huff-puff design can be a good diagnostic test for matrix diffusion. The two-well doublet design averages over a large volume and corrects for the extreme sensitivity to spatial heterogeneities of the single well converging test, but requires prior knowledge of presence or absence of matrix diffusion to give reliable estimate of transport parameters. Results of this study demonstrate that using a suite of different tracer designs is important to reduce the uncertainty in association with solving the inverse problem of tracer test interpretation to characterize transport in fractured rocks.

  4. High Pressure Angle Gears: Comparison to Typical Gear Designs

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Zabrajsek, Andrew J.

    2010-01-01

    A preliminary study has been completed to determine the feasibility of using high-pressure angle gears in aeronautic and space applications. Tests were conducted in the NASA Glenn Research Center (GRC) Spur Gear Test Facility at speeds up to 10,000 rpm and 73 N*m (648 in.*lb) for 3.18, 2.12, and 1.59 module gears (8, 12, and 16 diametral pitch gears), all designed to operate in the same test facility. The 3.18 module (8-diametral pitch), 28 tooth, 20deg pressure angle gears are the GRC baseline test specimen. Also, 2.12 module (12-diametral pitch), 42 tooth, 25deg pressure angle gears were tested. Finally 1.59 module (16-diametral pitch), 56 tooth, 35deg pressure angle gears were tested. The high-pressure angle gears were the most efficient when operated in the high-speed aerospace mode (10,000 rpm, lubricated with a synthetic turbine engine oil), and produced the lowest wear rates when tested with a perfluoroether-based grease. The grease tests were conducted at 150 rpm and 71 N*m (630 in.*lb).

  5. Comparison of flanged and unflanged acetabular cup design

    PubMed Central

    2010-01-01

    Background and purpose Adequate depth of cement penetration and cement mantle thickness is important for the durability of cemented cups. A flanged cup, as opposed to unflanged, has been suggested to give a more uniform cement mantle and superior cement pressurization, thus improving the depth of cement penetration. This hypothesis was tested experimentally. Materials and methods The same cup design with and without flange (both without cement spacers) was investigated regarding intraacetabular pressure, cement mantle thickness, and depth of cement penetration. With machine control, the cups were inserted into open-pore ceramic acetabular models (10 flanged, 10 unflanged) and into paired cadaver acetabuli (10 flanged, 10 unflanged) with prior pressurization of the cement. Results No differences in intraacetabular pressures during cup insertion were found, but unflanged cups tended to migrate more towards the acetabular pole. Flanged cups resulted in thicker cement mantles because of less bottoming out, whereas no differences in cement penetration into the bone were observed. Interpretation Flanged cups do not generate higher cementation pressure or better cement penetration than unflanged cups. A possible advantage of the flange, however, may be to protect the cup from bottoming out, and there is possibly better closure of the periphery around the cup, sealing off the cement-bone interface. PMID:20860522

  6. Cat dissection and human cadaver prosection versus sculpting human structures from clay: A comparison of alternate approaches to human anatomy laboratory education

    NASA Astrophysics Data System (ADS)

    Waters, John R.

    Dissection and vivisection are traditional approaches to biology laboratory education. In the case of human anatomy teaching laboratories, there is a long tradition of using human and animal cadaver specimens in the classroom. In a review of the literature comparing traditional dissection and vivisection lessons to alternative lessons designed to reduce the time spent dissecting or the numbers of animals used, we conclude that it is difficult to come to any conclusion regarding the efficacy of different approaches. An analysis of the literature is confounded because many studies have very low statistical power or other methodological weaknesses, and investigators rely on a wide variety of testing instruments to measure an equally varied number of course objectives. Additional well designed studies are necessary before educators can reach any informed conclusions about the efficacy of traditional versus alternative approaches to laboratory education. In our experiments, we compared a traditional cat dissection based undergraduate human anatomy lesson to an alternative where students sculpted human muscles onto plastic human skeletons. Students in the alternative treatment performed significantly better than their peers in the traditional treatment when answering both lower and higher order human anatomy questions. In a subsequent experiment with a similar design, we concluded that the superior performance of the students in the alternative treatment on anatomy exams was likely due to the similarity between the human anatomy representation studied in lab, and the human anatomy questions asked on the exams. When the anatomy questions were presented in the context of a cat specimen, students in the traditional cat dissection treatment outperformed their peers in the alternative treatment. In a final experiment where student performance on a human anatomy exam was compared between a traditional prosected human cadaver treatment and the alternative clay sculpting

  7. Alternative cDEP Design to Facilitate Cell Isolation for Identification by Raman Spectroscopy

    PubMed Central

    Hanson, Cynthia; Vargis, Elizabeth

    2017-01-01

    Dielectrophoresis (DEP) uses non-uniform electric fields to cause motion in particles due to the particles’ intrinsic properties. As such, DEP is a well-suited label-free means for cell sorting. Of the various methods of implementing DEP, contactless dielectrophoresis (cDEP) is advantageous as it avoids common problems associated with DEP, such as electrode fouling and electrolysis. Unfortunately, cDEP devices can be difficult to fabricate, replicate, and reuse. In addition, the operating parameters are limited by the dielectric breakdown of polydimethylsiloxane (PDMS). This study presents an alternative way to fabricate a cDEP device allowing for higher operating voltages, improved replication, and the opportunity for analysis using Raman spectroscopy. In this device, channels were formed in fused silica rather than PDMS. The device successfully trapped 3.3 μm polystyrene spheres for analysis by Raman spectroscopy. The successful implementation indicates the potential to use cDEP to isolate and identify biological samples on a single device. PMID:28208767

  8. Crossover versus parallel designs: dose-escalation design comparisons for first-in-human studies.

    PubMed

    Yan, Zhiwu; Hosmane, Balakrishna; Locke, Charles

    2013-01-01

    We study the statistical efficiency for rising-dose designs in the context of first-in-human studies. Specifically, we identify a class of crossover designs that are appealing in terms of both subject safety and statistical efficiency and, for a three-period, two-panel design in such a class, we compare its A-efficiency relative to the corresponding parallel designs and optimal/efficient crossover designs, respectively, under various plausible models. In the meantime, we also evaluate the impact of inclusion of baseline measurements as a covariate in the statistical analysis, for both crossover and parallel studies.

  9. Nonparametric Statistical Tests for Single-Case Systematic and Randomized ABAB...AB and Alternating Treatment Intervention Designs: New Developments, New Directions

    ERIC Educational Resources Information Center

    Levin, Joel R.; Ferron, John M.; Kratochwill, Thomas R.

    2012-01-01

    In this four-investigation Monte Carlo simulation study, we examined the properties of nonparametric randomization and permutation statistical tests applied to single-case ABAB...AB and alternating treatment designs based on either systematically alternating or randomly determined phase assignments. Contrary to previous admonitions, when…

  10. An assessment of alternative fuel cell designs for residential and commercial cogeneration

    NASA Technical Reports Server (NTRS)

    Wakefield, R. A.

    1980-01-01

    A comparative assessment of three fuel cell systems for application in different buildings and geographic locations is presented. The study was performed at the NASA Lewis Center and comprised the fuel cell design, performance in different conditions, and the economic parameters. Applications in multifamily housing, stores and hospitals were considered, with a load of 10kW-1 MW. Designs were traced through system sizing, simulation/evaluation, and reliability analysis, and a computer simulation based on a fourth-order representation of a generalized system was performed. The cells were all phosphoric acid type cells, and were found to be incompatible with gas/electric systems and more favorable economically than the gas/electric systems in hospital uses. The methodology used provided an optimized energy-use pattern and minimized back-up system turn-on.

  11. Alternative approaches to fusion. [reactor design and reactor physics for Tokamak fusion reactors

    NASA Technical Reports Server (NTRS)

    Roth, R. J.

    1976-01-01

    The limitations of the Tokamak fusion reactor concept are discussed and various other fusion reactor concepts are considered that employ the containment of thermonuclear plasmas by magnetic fields (i.e., stellarators). Progress made in the containment of plasmas in toroidal devices is reported. Reactor design concepts are illustrated. The possibility of using fusion reactors as a power source in interplanetary space travel and electric power plants is briefly examined.

  12. The Pipe-Quadrupole, an Alternative for High Gradient Interaction Region Quadrupole Designs

    SciTech Connect

    Oort, J.M. van; Scanlan, R.M.

    1996-12-12

    In the design of interaction region (IR) quadrupoles for high luminosity colliders such as the LHC or a possible upgrade of the Tevatron, the radiation heating of the coil windings is an important issue. Two obvious solutions to this problem can be chosen. The first is to reduce the heat load by added shielding, increased cooling with fins or using Nb{sub 3}Sn to increase the temperature margin. The second solution eliminates the conductor from the areas with the highest radiation intensity, which are located on the symmetry-axes of the midplanes of the coils. A novel quadrupole design is presented, in which the conductor is wound on four half-moon shaped supports, forming elongated toroid sections. The assembly of the four shapes yields a quadrupole field with an active flux return path, and a void in the high radiation area. This void can be occupied by a liquid helium cooling pipe to lower the temperature of the windings from the inside. The coil layout, harmonic optimization and mechanical design are shown, together with the calculated temperature rise for the radiation load of the LHC interaction region quadrupoles.

  13. Alternate metal framework designs for the metal ceramic prosthesis to enhance the esthetics

    PubMed Central

    Vernekar, Naina Vilas; Jagadish, Prithviraj Kallahalla; Diwakar, Srinivasan; Nadgir, Ramesh

    2011-01-01

    PURPOSE The objective of the present study was to evaluate the effect of five different metal framework designs on the fracture resistance of the metal-ceramic restorations. MATERIALS AND METHODS For the purpose of this study, the central incisor tooth was prepared, and the metal analogue of it and a master die were fabricated. The counter die with the 0.5 mm clearance was used for fabricating the wax patterns for the metal copings. The metal copings with five different metal framework designs were designed from Group 1 to 5. Group 1 with the metal collar, Group 2, 3, 4 and 5 with 0 mm, 0.5 mm, 1 mm and 1.5 mm cervical metal reduction respectively were fabricated. Total of fifty metal ceramic crown samples were fabricated. The fracture resistance was evaluated with the Universal Testing Machine (Instron model No 1011, UK). The basic data was subjected to statistical analysis by ANOVA and Student's t-test. RESULTS Results revealed that the fracture resistance ranged from 651.2 to 993.6 N/m2. Group 1 showed the maximum and Group 5 showed the least value. CONCLUSION The maximum load required to fracture the test specimens even in the groups without the metal collar was found to be exceeding the occlusal forces. Therefore, the metal frameworks with 0.5 mm and 1 mm short of the finish line are recommended for anterior metal ceramic restoration having adequate fracture resistance. PMID:22053240

  14. Life Cycle Assessment of a Parabolic Trough Concentrating Solar Power Plant and Impacts of Key Design Alternatives: Preprint

    SciTech Connect

    Heath, G. A.; Burkhardt, J. J.; Turchi, C. S.

    2011-09-01

    Climate change and water scarcity are important issues for today's power sector. To inform capacity expansion decisions, hybrid life cycle assessment is used to evaluate a reference design of a parabolic trough concentrating solar power (CSP) facility located in Daggett, California, along four sustainability metrics: life cycle greenhouse gas (GHG) emissions, water consumption, cumulative energy demand (CED), and energy payback time (EPBT). This wet-cooled, 103 MW plant utilizes mined nitrate salts in its two-tank, thermal energy storage (TES) system. Design alternatives of dry-cooling, a thermocline TES, and synthetically-derived nitrate salt are evaluated. During its life cycle, the reference CSP plant is estimated to emit 26 g CO2eq per kWh, consume 4.7 L/kWh of water, and demand 0.40 MJeq/kWh of energy, resulting in an EPBT of approximately 1 year. The dry-cooled alternative is estimated to reduce life cycle water consumption by 77% but increase life cycle GHG emissions and CED by 8%. Synthetic nitrate salts may increase life cycle GHG emissions by 52% compared to mined. Switching from two-tank to thermocline TES configuration reduces life cycle GHG emissions, most significantly for plants using synthetically-derived nitrate salts. CSP can significantly reduce GHG emissions compared to fossil-fueled generation; however, dry-cooling may be required in many locations to minimize water consumption.

  15. Life cycle assessment of a parabolic trough concentrating solar power plant and the impacts of key design alternatives.

    PubMed

    Burkhardt, John J; Heath, Garvin A; Turchi, Craig S

    2011-03-15

    Climate change and water scarcity are important issues for today's power sector. To inform capacity expansion decisions, hybrid life cycle assessment is used to evaluate a reference design of a parabolic trough concentrating solar power (CSP) facility located in Daggett, CA, along four sustainability metrics: life cycle (LC) greenhouse gas (GHG) emissions, water consumption, cumulative energy demand (CED), and energy payback time (EPBT). This wet-cooled, 103 MW plant utilizes mined nitrates salts in its two-tank, thermal energy storage (TES) system. Design alternatives of dry-cooling, a thermocline TES, and synthetically derived nitrate salt are evaluated. During its LC, the reference CSP plant is estimated to emit 26 g of CO(2eq) per kWh, consume 4.7 L/kWh of water, and demand 0.40 MJ(eq)/kWh of energy, resulting in an EPBT of approximately 1 year. The dry-cooled alternative is estimated to reduce LC water consumption by 77% but increase LC GHG emissions and CED by 8%. Synthetic nitrate salts may increase LC GHG emissions by 52% compared to mined. Switching from two-tank to thermocline TES configuration reduces LC GHG emissions, most significantly for plants using synthetically derived nitrate salts. CSP can significantly reduce GHG emissions compared to fossil-fueled generation; however, dry-cooling may be required in many locations to minimize water consumption.

  16. Validating MCNP for LEU Fuel Design via Power Distribution Comparisons

    SciTech Connect

    Primm, Trent; Maldonado, G Ivan; Chandler, David

    2008-11-01

    The mission of the Reduced Enrichment for Research and Test Reactors (RERTR) Program is to minimize and, to the extent possible, eliminate the use of highly enriched uranium (HEU) in civilian nuclear applications by working to convert research and test reactors, as well as radioisotope production processes, to low enriched uranium (LEU) fuel and targets. Oak Ridge National Lab (ORNL) is reviewing the design bases and key operating criteria including fuel operating parameters, enrichment-related safety analyses, fuel performance, and fuel fabrication in regard to converting the fuel of the High Flux Isotope Reactor (HFIR) from HEU to LEU. The purpose of this study is to validate Monte Carlo methods currently in use for conversion analyses. The methods have been validated for the prediction of flux values in the reactor target, reflector, and beam tubes, but this study focuses on the prediction of the power density profile in the core. A current 3-D Monte Carlo N-Particle (MCNP) model was modified to replicate the HFIR Critical Experiment 3 (HFIRCE-3) core of 1965. In this experiment, the power profile was determined by counting the gamma activity at selected locations in the core. Foils (chunks of fuel meat and clad) were punched out of the fuel elements in HFIRCE-3 following irradiation and experimental relative power densities were obtained by measuring the activity of these foils and comparing each foil s activity to the activity of a normalizing foil. The current work consisted of calculating corresponding activities by inserting volume tallies into the modified MCNP model to represent the punchings. The average fission density was calculated for each foil location and then normalized to the normalizing foil. Power distributions were obtained for the clean core (no poison in moderator and symmetrical rod position at 17.5 inches) and fully poisoned-moderator (1.35 g B/liter in moderator and rods fully withdrawn) conditions. The observed deviations between the

  17. Snacks, beverages, vending machines, and school stores: a comparison of alternative and regular schools in Minnesota, 2002 to 2008.

    PubMed

    Kubik, Martha Y; Davey, Cynthia; MacLehose, Richard F; Coombes, Brandon; Nanney, Marilyn S

    2015-01-01

    In US secondary schools, vending machines and school stores are a common source of low-nutrient, energy-dense snacks and beverages, including sugar-sweetened beverages, high-fat salty snacks, and candy. However, little is known about the prevalence of these food practices in alternative schools, which are educational settings for students at risk of academic failure due to truancy, school expulsion, and behavior problems. Nationwide, more than 5,000 alternative schools enroll about one-half million students who are disproportionately minority and low-income youth. Principal survey data from a cross-sectional sample of alternative (n=104) and regular (n=339) schools collected biennially from 2002-2008 as part of the Centers for Disease Control and Prevention Minnesota School Health Profiles were used to assess and compare food practice prevalence over time. Generalized estimating equation models were used to estimate prevalence, adjusting for school demographics. Over time, food practice prevalence decreased significantly for both alternative and regular schools, although declines were mostly modest. However, the decrease in high-fat, salty snacks was significantly less for alternative than regular schools (-22.9% vs -42.2%; P<0.0001). Efforts to improve access to healthy food choices at school should reach all schools, including alternative schools. Study findings suggest high-fat salty snacks are more common in vending machines and school stores in alternative schools than regular schools, which may contribute to increased snacking behavior among students and extra consumption of salt, fat, and sugar. Study findings support the need to include alternative schools in future efforts that aim to reform the school food environment.

  18. Interplanetary Trajectory Design for the Asteroid Robotic Redirect Mission Alternate Approach Trade Study

    NASA Technical Reports Server (NTRS)

    Merrill, Raymond Gabriel; Qu, Min; Vavrina, Matthew A.; Englander, Jacob A.; Jones, Christopher A.

    2014-01-01

    This paper presents mission performance analysis methods and results for the Asteroid Robotic Redirect Mission (ARRM) option to capture a free standing boulder on the surface of a 100 m or larger NEA. It details the optimization and design of heliocentric low-thrust trajectories to asteroid targets for the ARRM solar electric propulsion spacecraft. Extensive searches were conducted to determine asteroid targets with large pick-up mass potential and potential observation opportunities. Interplanetary trajectory approximations were developed in method based tools for Itokawa, Bennu, 1999 JU3, and 2008 EV5 and were validated by end-to-end integrated trajectories.

  19. Building Low Carbon Cities: Framework to Design and Evaluate Alternative Technologies and Policies for Land Use Planning

    NASA Astrophysics Data System (ADS)

    Hashimoto, S.; Hamano, H.; Fujita, T.; Hori, H.

    2008-12-01

    Annex I parties of the Kyoto Protocol are facing even greater pressures to fulfill their commitment for GHG reduction as they enter the first commitment period of the Kyoto Protocol 2008-2012. In Japanese context, one such challenge is to reduce CO2 emissions from the household and business sectors because CO2 emissions from the both sectors has increased by 12% and 20% respectively since 1990 while the industry has achieved 21% of CO2 emissions reduction. Land use planning, which, either directly or indirectly, controls appropriate uses for land within jurisdictions, might play very important roles to deal with CO2 reductions from the household and business sectors. In this research, aiming at effective reductions of air- conditioning energy consumption and resultant CO2 emissions from the household and business sectors, the framework to design and evaluate land use planning was developed. The design and evaluation processes embraced in this framework consist of GIS database, technology and policy inventory for planning, one- dimensional urban canopy model which evaluate urban climate at neighborhood level and air-conditioning load calculation procedure. The GIS database provides spatial information of target areas such as land use, building use and road networks, which, then, helps design alternative land use plans. The technology and policy inventory includes various planning options ranging from those for land over control to those for building energy control, which, combined with the GIS database, serves for planning process. The urban canopy model derives vertical profiles of local climate, such as temperature and humidity, using the information of land use, building height and so on, aided by the GIS database. Vertical profiles of the urban climate are then utilized to derive air-conditioning load and associated CO2 emissions for each building located in target areas. The framework developed was applied to the coastal district of Kawasaki, Japan, with an

  20. Obtaining Paired Comparisons Data from Multiple Rank Orders Using Partially Balanced Incomplete Block Designs

    ERIC Educational Resources Information Center

    Straton, Ralph G.

    1975-01-01

    Complete paired comparisons data was obtained by use of multiple rank order (MRO) in the context of gathering rank order preferences of grade six students, their parents, and teachers for instructional objectives. Partially balanced incomplete block designs with two associate classes were used in the MRO instruments instead of the usual balanced…

  1. OSIRIS and SOMBRERO Inertial Fusion Power Plant Designs, Volume 2: Designs, Assessments, and Comparisons

    SciTech Connect

    Meier, W. R.; Bieri, R. L.; Monsler, M. J.; Hendricks, C. D.; Laybourne, P.; Shillito, K. R.

    1992-03-01

    This is a comprehensive design study of two Inertial Fusion Energy (IFE) electric power plants. Conceptual designs are presented for a fusion reactor (called Osiris) using an induction-linac heavy-ion beam driver, and another (called SOMBRERO) using a KrF laser driver. The designs covered all aspects of IFE power plants, including the chambers, heat transport and power conversion systems, balance-of-plant facilities, target fabrication, target injection and tracking, as well as the heavy-ion and KrF drivers. The point designs were assessed and compared in terms of their environmental & safety aspects, reliability and availability, economics, and technology development needs.

  2. Thermal Dissipation Modelling and Design of ITER PF Converter Alternating Current Busbar

    NASA Astrophysics Data System (ADS)

    Guo, Bin; Song, Zhiquan; Fu, Peng; Jiang, Li; Li, Jinchao; Wang, Min; Dong, Lin

    2016-10-01

    Because the larger metallic surrounds are heated by the eddy current, which is generated by the AC current flowing through the AC busbar in the International Thermonuclear Experimental Reactor (ITER) poloidal field (PF) converter system, shielding of the AC busbar is required to decrease the temperature rise of the surrounds to satisfy the design requirement. Three special types of AC busbar with natural cooling, air cooling and water cooling busbar structure have been proposed and investigated in this paper. For each cooling scheme, a 3D finite model based on the proposed structure has been developed to perform the electromagnetic and thermal analysis to predict their operation behavior. Comparing the analysis results of the three different cooling patterns, water cooling has more advantages than the other patterns and it is selected to be the thermal dissipation pattern for the AC busbar of ITER PF converter unit. The approach to qualify the suitable cooling scheme in this paper can be provided as a reference on the thermal dissipation design of AC busbar in the converter system. supported by National Natural Science Foundation of China (No. 51407179)

  3. Life cycle assessment of a power tower concentrating solar plant and the impacts of key design alternatives.

    PubMed

    Whitaker, Michael B; Heath, Garvin A; Burkhardt, John J; Turchi, Craig S

    2013-06-04

    A hybrid life cycle assessment (LCA) is used to evaluate four sustainability metrics over the life cycle of a power tower concentrating solar power (CSP) facility: greenhouse gas (GHG) emissions, water consumption, cumulative energy demand (CED), and energy payback time (EPBT). The reference design is for a dry-cooled, 106 MW(net) power tower facility located near Tucson, AZ that uses a mixture of mined nitrate salts as the heat transfer fluid and storage medium, a two-tank thermal energy storage system designed for six hours of full load-equivalent storage, and receives auxiliary power from the local electric grid. A thermocline-based storage system, synthetically derived salts, and natural gas auxiliary power are evaluated as design alternatives. Over its life cycle, the reference plant is estimated to have GHG emissions of 37 g CO2eq/kWh, consume 1.4 L/kWh of water and 0.49 MJ/kWh of energy, and have an EPBT of 15 months. Using synthetic salts is estimated to increase GHG emissions by 12%, CED by 7%, and water consumption by 4% compared to mined salts. Natural gas auxiliary power results in greater than 10% decreases in GHG emissions, water consumption, and CED. The thermocline design is most advantageous when coupled with the use of synthetic salts.

  4. Human-Centred Design Workshops in Collaborative Strategic Design Projects: An Educational and Professional Comparison

    ERIC Educational Resources Information Center

    Liem, Andre; Sanders, Elizabeth B.-N.

    2013-01-01

    It has been found that the implementation of Human-centred Design (HCD) methods in the Fuzzy Front-End is not likely to lead to diversification in educational product planning exercises, where time lines are short and executors lack experience. Companies, interested to collaborate with Master-level Industrial Design students on strategic design…

  5. Stated Choice design comparison in a developing country: recall and attribute nonattendance

    PubMed Central

    2014-01-01

    Background Experimental designs constitute a vital component of all Stated Choice (aka discrete choice experiment) studies. However, there exists limited empirical evaluation of the statistical benefits of Stated Choice (SC) experimental designs that employ non-zero prior estimates in constructing non-orthogonal constrained designs. This paper statistically compares the performance of contrasting SC experimental designs. In so doing, the effect of respondent literacy on patterns of Attribute non-Attendance (ANA) across fractional factorial orthogonal and efficient designs is also evaluated. The study uses a ‘real’ SC design to model consumer choice of primary health care providers in rural north India. A total of 623 respondents were sampled across four villages in Uttar Pradesh, India. Methods Comparison of orthogonal and efficient SC experimental designs is based on several measures. Appropriate comparison of each design’s respective efficiency measure is made using D-error results. Standardised Akaike Information Criteria are compared between designs and across recall periods. Comparisons control for stated and inferred ANA. Coefficient and standard error estimates are also compared. Results The added complexity of the efficient SC design, theorised elsewhere, is reflected in higher estimated amounts of ANA among illiterate respondents. However, controlling for ANA using stated and inferred methods consistently shows that the efficient design performs statistically better. Modelling SC data from the orthogonal and efficient design shows that model-fit of the efficient design outperform the orthogonal design when using a 14-day recall period. The performance of the orthogonal design, with respect to standardised AIC model-fit, is better when longer recall periods of 30-days, 6-months and 12-months are used. Conclusions The effect of the efficient design’s cognitive demand is apparent among literate and illiterate respondents, although, more pronounced

  6. Conceptual Design of Environmentally Friendly Rotorcraft - A Comparison of NASA and ONERA Approaches

    NASA Technical Reports Server (NTRS)

    Russell, Carl; Basset, Pierre-Marie

    2015-01-01

    In 2011, a task was initiated under the US-French Project Agreement on rotorcraft studies to collaborate on design methodologies for environmentally friendly rotorcraft. This paper summarizes the efforts of that collaboration. The French and US aerospace agencies, ONERA and NASA, have their own software toolsets and approaches to rotorcraft design. The first step of this research effort was to understand how rotorcraft impact the environment, with the initial focus on air pollution. Second, similar baseline helicopters were developed for a passenger transport mission, using NASA and ONERA rotorcraft design software tools. Comparisons were made between the designs generated by the two tools. Finally, rotorcraft designs were generated targeting reduced environmental impact. The results show that a rotorcraft design that targets reduced environmental impact can be significantly different than one that targets traditional cost drivers, such as fuel burn and empty weight.

  7. Alternative Evaluation Designs for Data-Centered Technology-Based Geoscience Education Projects

    NASA Astrophysics Data System (ADS)

    Zalles, D. R.

    2012-12-01

    This paper will present different strategies for how to evaluate contrasting K-12 geoscience classroom-based interventions with different goals, leveraging the first author's experiences as principal investigator of four NSF and NASA-funded geoscience education projects. Results will also be reported. Each project had its own distinctive features but all had in common the broad goal of bringing to high school classrooms uses of real place-based geospatial data to study the relationships of Earth system phenomena to climate change and sustainability. The first project's goal was to produce templates and exemplars for curriculum and assessment designs around studying contrasting geoscience topics with different data sets and forms of data representation. The project produced a near transfer performance assessment task in which students who studied climate trends in Phoenix turned their attention to climate in Chicago. The evaluation looked at the technical quality of the assessment instrument as measured by inter-rater reliability. It then analyzed the assessment results against student responses to the instructional tasks about Phoenix. The evaluation proved useful in pinpointing areas of student strength and weakness on different inquiry tasks, from simple map interpretation to analysis of contrasting claims about what the data indicate. The goal of the second project was to produce an exemplar curriculum unit that bridges Western science and traditional American Indian ecological knowledge for student learning and skill building about local environmental sustainability issues. The evaluation looked at the extent to which Western and traditional perspectives were incorporated into the design of the curriculum. The curriculum was not constructed with a separate assessment, yet evidence centered design was utilized to extrapolate from the exemplar unit templates for future instructional and assessment tasks around other places, other sustainability problems, and

  8. Optical design comparison of 60 eyepieces: one with a diffractive surface and one with aspherics

    NASA Astrophysics Data System (ADS)

    Knapp, Wayne; Blough, Gary; Khajurivala, Kumar; Michaels, Robert; Tatian, Berge; Volk, Brian

    1997-07-01

    An optical design comparison is made between two 60 field-of-view long-eye-relief eyepieces used for viewing a flat image-intensifier P-43 phosphor screen output. One eyepiece contains both spherical glass elements and plastic aspheric elements. The other eyepiece consists of spherical glass elements and a diffractive surface. Both optical designs were optimized by use of identical system constraints for size and weight. The eyepiece containing the diffractive surface provided an improved modulation transfer function performance and has been fabricated and tested. The fabricated lens characteristics and modulation transfer function performance closely matched the design expectations.

  9. Incorporating precision, accuracy and alternative sampling designs into a continental monitoring program for colonial waterbirds

    USGS Publications Warehouse

    Steinkamp, Melanie J.; Peterjohn, B.G.; Keisman, J.L.

    2003-01-01

    A comprehensive monitoring program for colonial waterbirds in North America has never existed. At smaller geographic scales, many states and provinces conduct surveys of colonial waterbird populations. Periodic regional surveys are conducted at varying times during the breeding season using a variety of survey methods, which complicates attempts to estimate population trends for most species. The US Geological Survey Patuxent Wildlife Research Center has recently started to coordinate colonial waterbird monitoring efforts throughout North America. A centralized database has been developed with an Internet-based data entry and retrieval page. The extent of existing colonial waterbird surveys has been defined, allowing gaps in coverage to be identified and basic inventories completed where desirable. To enable analyses of comparable data at regional or larger geographic scales, sampling populations through statistically sound sampling designs should supersede obtaining counts at every colony. Standardized breeding season survey techniques have been agreed upon and documented in a monitoring manual. Each survey in the manual has associated with it recommendations for bias estimation, and includes specific instructions on measuring detectability. The methods proposed in the manual are for developing reliable, comparable indices of population size to establish trend information at multiple spatial and temporal scales, but they will not result in robust estimates of total population numbers.

  10. Study of the liquid-film-forming apparatus as an alternative aeration system: design criteria and operating condition.

    PubMed

    Hongprasith, Narapong; Imai, Tsuyoshi; Painmanakul, Pisut

    2016-10-02

    Aeration is an important factor in aquaculture systems because it is a vital condition for all organisms that live in water and respire aerobically. Generally, mechanical surface aerators are widely used in Thailand due to their advantage for increasing dissolved oxygen (DO) and for their horizontal mixing of aquaculture ponds with large surface areas. However, these systems still have some drawbacks, primarily the low oxygen transfer efficiency (OTE) and energy. Regarding this issue, alternative aeration systems should be studied and applied. Therefore, this research aims to study the aeration mechanism obtained by the diffused-air aeration combined with a liquid-film-forming apparatus (LFFA). The effect of gas flow rates, types, and patterns of aerator installation were investigated in an aquaculture pond of 10 m × 10 m × 1.5 m. The analytical parameters were volumetric mass transfer coefficient (kLa), OTE, and aeration efficiency (AE). From the results, the '4-D' with partitions was proposed as the suitable pattern for the LFFA installation. The advantage could be obtained from high energy performance with 1.2 kg/kW h of AE. Then, the operation conditions can be applied as a design guideline for this alternative aeration system in the aquaculture ponds.

  11. Initial rollover effectiveness evaluation of an alternative seat belt design for agricultural tractors.

    PubMed

    Rains, G C

    2000-02-01

    A test program was conducted to determine the effectiveness of a seat belt restraint in preventing occupant movement in a rollover accident. A baseline type-2 seat belt (pelvic and torso restraint), and an improved type-2 seat belt restraint, both designed to restrict occupant motion in a rollover accident, were tested in a rollover restraints tester (RRT). Each seat belt was placed on a H-III 50th percentile male dummy and testing conducted at a single roll rate and two D-ring adjustment positions. Each test simulated what was approximately a 260 degrees per second rollover parallel to the longitudinal axis of the tractor with the top of the ROPS impacting the ground after 180 degrees of roll. Forces on the dummy's head and neck were measured, and video was taken to measure the head motion in the x-, y-, and z-axis of the dummy. The average vertical, forward, and lateral head movement in the baseline seat belt was 144, 222, and 184 mm, respectively, when the adjustable D-ring anchorage supporting the shoulder belt was in its lowest position. At the lowest D-ring height, the shoulder belt became ineffective and the seat belt performance became similar to a type-1 restraint (required for tractors with ROPS) resulting in increased vertical, forward, and lateral movement. The improved restraint reduced vertical head movement by as much as 75% without increasing head and neck loads above established injury criteria. Testing seat belts for rollover effectiveness will become increasingly important as seat belt usage on tractors with ROPS increases.

  12. Development of Lorentz force-type self-bearing motor for an alternative axial flow blood pump design.

    PubMed

    Lim, Tau Meng; Zhang, Dongsheng

    2006-05-01

    A Lorentz force-type self-bearing motor was developed to provide delivery of both motoring torque and levitation force for an alternative axial flow blood pump design with an enclosed impeller. The axial flow pumps currently available introduce electromagnetic coupling from the motor's stator to the impeller by means of permanent magnets (PMs) embedded in the tips of the pump's blades. This design has distinct disadvantages, for example, pumping efficiency and electromagnetic coupling transmission are compromised by the constrained or poor geometry of the blades and limited pole width of the PMs, respectively. In this research, a Lorentz force-type self-bearing motor was developed. It is composed of (i) an eight-pole PM hollow-cylindrical rotor assembly supposedly to house and enclose the impeller of an axial flow blood pump, and (ii) a six-pole stator with two sets of copper wire and different winding configurations to provide the motoring torque and levitating force for the rotor assembly. MATLAB's xPC Target interface hardware was used as the rapid prototyping tool for the development of the controller for the self-bearing motor. Experimental results on a free/simply supported rotor assembly validated the design feasibility and control algorithm effectiveness in providing both the motoring torque and levitation force for the rotor. When levitated, a maximum orbital displacement of 0.3 mm corresponding to 1050 rpm of the rotor was measured by two eddy current probes placed in the orthogonal direction. This design has the advantage of eliminating the trade-off between motoring torques, levitating force, and pumping efficiency of previous studies. It also indicated the benefits of enclosed-impeller design as having good dynamic response, linearity, and better reliability. The nonmechanical contact feature between rotating and stationary parts will further reduce hemolysis and thromboembolitic tendencies in a typical blood pump application.

  13. Non-CFC vacuum alternatives for the energy-efficient insulation of household refrigerators: Design and use

    SciTech Connect

    Potter, T.F.; Benson, D.K.

    1991-01-01

    Energy efficiency, environmental issues, and market incentives all encourage government and industry to continue work on thin-profile vacuum insulations for domestic refrigerators and freezers (R/Fs). Vacuum insulations promise significant improvement in thermal savings over current insulations; the technical objective of one design is an R-value of better than 10 (hr-ft{sup 2}-F/Btu) in 0.1 in. thickness. If performance is improved by a factor of 10 over that of CFC-blown insulating foams, the new insulations (made without CFCs or other potentially troublesome fill gases) will change the design and improve the efficiency of refrigerators. Such changes will meet the conservation, regulatory, and market drivers now strong in developed countries and likely to increase in developing countries. Prototypes of various designs have been tested in the laboratory and in factories, and results to date confirm the good thermal performance of these thin-profile alternatives. The next step is to resolve issues of reliability and cost effectiveness. 34 refs., 4 figs.

  14. The design and building of an alternating current scanning tunneling microscope for nanometer scale imaging of insulating surfaces

    NASA Astrophysics Data System (ADS)

    Schafer, Adam Jay David

    An alternating current scanning tunneling microscope (ACSTM) has been designed and built for the study of insulating surfaces on the nanometer scale. The instrument consists of an STM built within a microwave resonant cavity. This design allows for simultaneous operation for both DC and ACSTM. The instrument is housed in a nitrogen atmosphere glovebox for the observation and handling of air-sensitive samples. In order to achieve the detailed resolution of STM on insulating surfaces the ACSTM uses the application of a high frequency alternating current bias voltage across a tip-sample junction, the resulting alternating current can be measured. Specifically, the non-linearilty of the STM junction allows the third harmonic (TH) of the driving frequency to be used as the measured quantity for imaging and control. By using the third harmonic of the fundamental driving voltage as the measured quantity to control the tip-sample distance, STM quality images have been produced without the reliance on a conductive surface. The atomic scale resolution of a silicon dioxide surface and the growth of such layers appeared to provide an ideal system for imaging with the ACSTM. Through the use of DC STM we have shown how the H-Si(111) surface morphology is effected by the length of etch time and the kinetic effect of stirring the etchant solution. Several experimental results make use of the ACSTM employing the TH signal for measurement under both DC feedback control and under AC feedback control. We will address the experimental procedure, signal generation and sample dependence upon ACSTM image resolution. By comparing three sulfides (CuS, MoS2. and PbS) and H-Si(111), the TH signal generation and ultimate ACSTM resolution is explored. A more in depth analysis covers the application of the ACSTM to investigate the probe induced surface oxidation of natural PbS. With the ACSTM, the complete transformation from a semiconductive to an insulating surface is imaged in real-time for

  15. Alternatives to Standardized Tests. ERIC Digest.

    ERIC Educational Resources Information Center

    Wildemuth, Barbara M.

    Five alternatives to standardized testing of student achievement are described in this brief overview. The first, criterion-referenced tests, are designed to evaluate the accomplishment of specifically stated instructional objectives. Student performance is judged on the basis of the objectives, rather than in comparison to other students taking…

  16. Preliminary Design Feature Alternatives and Discussion of Their Feasibility for a National Education Practice File. Products 1.4. and 1.5. [Volume II].

    ERIC Educational Resources Information Center

    Benson, Gregory, Jr.

    This discussion of the alternative design features being considered for the National Education Practice File presents three design configurations for each feature, demonstrating how they differ and suggesting which is the most likely candidate for the pilot test based on utility benefits, technical feasibility, adherence to Federal Information…

  17. Strengthening the Regression Discontinuity Design Using Additional Design Elements: A Within-Study Comparison

    ERIC Educational Resources Information Center

    Wing, Coady; Cook, Thomas D.

    2013-01-01

    The sharp regression discontinuity design (RDD) has three key weaknesses compared to the randomized clinical trial (RCT). It has lower statistical power, it is more dependent on statistical modeling assumptions, and its treatment effect estimates are limited to the narrow subpopulation of cases immediately around the cutoff, which is rarely of…

  18. Observational Study Designs for Comparative Effectiveness Research: An Alternative Approach to Close Evidence Gaps in Head-and-Neck Cancer

    SciTech Connect

    Goulart, Bernardo H.L.; Ramsey, Scott D.; Parvathaneni, Upendra

    2014-01-01

    Comparative effectiveness research (CER) has emerged as an approach to improve quality of care and patient outcomes while reducing healthcare costs by providing evidence to guide healthcare decisions. Randomized controlled trials (RCTs) have represented the ideal study design to support treatment decisions in head-and-neck (H and N) cancers. In RCTs, formal chance (randomization) determines treatment allocation, which prevents selection bias from distorting the measure of treatment effects. Despite this advantage, only a minority of patients qualify for inclusion in H and N RCTs, which limits the validity of their results to the broader H and N cancer patient population seen in clinical practice. Randomized controlled trials often do not address other knowledge gaps in the management of H and N cancer, including treatment comparisons for rare types of H and N cancers, monitoring of rare or late toxicity events (eg, osteoradionecrosis), or in some instances an RCT is simply not feasible. Observational studies, or studies in which treatment allocation occurs independently of investigators' choice or randomization, may address several of these gaps in knowledge, thereby complementing the role of RCTs. This critical review discusses how observational CER studies complement RCTs in generating the evidence to inform healthcare decisions and improve the quality of care and outcomes of H and N cancer patients. Review topics include a balanced discussion about the strengths and limitations of both RCT and observational CER study designs; a brief description of design and analytic techniques to handle selection bias in observational studies; examples of observational studies that inform current clinical practices and management of H and N cancers; and suggestions for relevant CER questions that could be addressed by an observational study design.

  19. Sample size re-estimation and other mid-course adjustments with sequential parallel comparison design.

    PubMed

    Silverman, Rachel K; Ivanova, Anastasia

    2017-02-06

    Sequential parallel comparison design (SPCD) was proposed to reduce placebo response in a randomized trial with placebo comparator. Subjects are randomized between placebo and drug in stage 1 of the trial and then placebo non-responders are re-randomized in stage 2. Efficacy analysis includes all data from stage 1 and all placebo non-responding subjects from stage 2. This article investigates the possibility to re-estimate the sample size and adjust the design parameters, allocation proportion to placebo in stage 1 of SPCD and weight of stage 1 data in the overall efficacy test statistic, during an interim analysis.

  20. Dual-Frequency Alternating Current Designer Waveform for Reliable Voltammetric Determination of Electrode Kinetics Approaching the Reversible Limit.

    PubMed

    Li, Jiezhen; Bentley, Cameron L; Bond, Alan M; Zhang, Jie

    2016-02-16

    Alternating current (ac) voltammetry provides access to faster electrode kinetics than direct current (dc) methods. However, difficulties in ac and other methods arise when the heterogeneous electron-transfer rate constant (k(0)) approaches the reversible limit, because the voltammetric characteristics become insensitive to electrode kinetics. Thus, in this near-reversible regime, even small uncertainties associated with bulk concentration (C), diffusion coefficient (D), electrode area (A), and uncompensated resistance (Ru) can lead to significant systematic error in the determination of k(0). In this study, we have introduced a kinetically sensitive dual-frequency designer waveform into the Fourier-transformed large-amplitude alternating current (FTAC) voltammetric method that is made up of two sine waves having the same amplitude but with different frequencies (e.g., 37 and 615 Hz) superimposed onto a dc ramp to quantify the close-to-reversible Fc(0/+) process (Fc = ferrocene) in two nonhaloaluminate ionic liquids. The concept is that from a single experiment the lower-frequency data set, collected on a time scale where the target process is reversible, can be used as an internal reference to calibrate A, D, C, and Ru. These calibrated values are then used to calculate k(0) from analysis of the harmonics of the higher-frequency data set, where the target process is quasi-reversible. With this approach, k(0) values of 0.28 and 0.11 cm·s(-1) have been obtained at a 50 μm diameter platinum microdisk electrode for the close-to-diffusion-controlled Fc(0/+) process in two ionic liquids, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, respectively.

  1. Alternative Fleet Architecture Design

    DTIC Science & Technology

    2005-08-01

    times. The new competitive model is also an integral element of a broader strategic approach to cost. Since predicting the future is all but... approach does not model how these ships might be lost but is offered to show the consequences of losses. A fixed number of losses is typically...latter input parameter is directly related to the number of removal platforms the fleet employs in the given operation. When applying this model to

  2. Comparison of Heine-Abarenkov and alternative pseudopotentials for electron-phonon interaction in aluminium, lead, lithium and calcium

    NASA Astrophysics Data System (ADS)

    Zheng, X. H.; Walmsley, D. G.

    2017-01-01

    Applying the Heine-Abarenkov pseudopotential to aluminium and lead in both the superconducting and normal states, Carbotte and coworkers have set a challenging standard befitting the status of the classic BCS superconductor theory. Upholding the same standard and equipped with the technique of numerical inversion, we have extracted alternative pseudopotentials from experimental data with minimal prejudgement that might cloud the physics. The two potentials are broadly consistent in the superconducting state but distinctly different in the normal state. This is an urgent issue requiring confirmation or refutation in the context of the current search for high temperature conventional superconductivity.

  3. Comparison of STRUCTURAL-ACOUSTIC Control Designs on AN Active Composite Panel

    NASA Astrophysics Data System (ADS)

    BINGHAM, B.; ATALLA, M. J.; HAGOOD, N. W.

    2001-07-01

    This work presents a comparison of three technologies for structural-acoustic control that, while prevalent in the literature, had not been compared on a single structure. The comparison is generalizable because the techniques are implemented on a panel structure representative of a more complex structure (e.g., an aircraft fuselage, a submarine vehicle hull, a satellite payload shroud, etc.). The test-bed used for this comparison is a carbon-fiber composite panel manufactured with embedded active fiber composite actuators. Since such integrated structures constitute a continued avenue of research, the manufacturing and performance of this structure is illustrated. The design of the test-bed is guided by an effort to achieve a dynamic response similar to a single panel in a typical aircraft or rotorcraft fuselage.Existing active control architectures for broadband acoustic radiation reduction are compared both analytically and experimentally on a representative structure to quantify the capabilities and limitations of the existing control methodologies. Specifically, three broad categories of control are compared: classical feedback (rate feedback), optimal feedback (linear quadratic Gaussian), and adaptive feedforward control (x -filtered least mean square). The control architectures implemented during this study are all single-input/single-output in order to allow a fair comparison of the issues involved in the design, as well as the use and performance of each approach. Both the vibration and the acoustic performance are recorded for each experiment under equivalent conditions to allow a generalizable comparison. Experimental results lead to conclusions pertaining to the application of active structural-based control to improve the acoustic performance of more complex structures.

  4. A Non-scaling Fixed Field Alternating Gradient Accelerator for the Final Acceleration Stage of the International Design Study of the Neutrino Factory.

    SciTech Connect

    Berg, J.S.; Aslaninejad, M.; Pasternak, J.; Witte, H.; Bliss, N. Cordwell M.; Jones, T.; Muir, A., Kelliher, D.; Machida, S.

    2011-09-04

    The International Design Study of the Neutrino Factory (IDS-NF) has recently completed its Interim Design Report (IDR), which presents our current baseline design of the neutrino factory. To increase the efficiency and reduce the cost of acceleration, the IDR design uses a linear non-scaling fixed field alternating gradient accelerator (FFAG) for its final acceleration stage. We present the current lattice design of that FFAG, including the main ring plus its injection and extraction systems. We describe parameters for the main ring magnets, kickers, and septa, as well as the power supplies for the kickers. We present a first pass at an engineering layout for the ring and its subsystems.

  5. Comparison of biotyping methods as alternative identification tools to molecular typing of pathogenic Cryptococcus species in sub-Saharan Africa.

    PubMed

    Nyazika, Tinashe K; Robertson, Valerie J; Nherera, Brenda; Mapondera, Prichard T; Meis, Jacques F; Hagen, Ferry

    2016-03-01

    Cryptococcal meningitis is the leading fungal infection and AIDS defining opportunistic illness in patients with late stage HIV infection, particularly in South-East Asia and sub-Saharan Africa. Given the high mortality, clinical differences and the extensive ecological niche of Cryptococcus neoformans and Cryptococcus gattii species complexes, there is need for laboratories in sub-Sahara African countries to adopt new and alternative reliable diagnostic algorithms that rapidly identify and distinguish these species. We biotyped 74 and then amplified fragment length polymorphism (AFLP) genotyped 66 Cryptococcus isolates from a cohort of patients with HIV-associated cryptococcal meningitis. C. gattii sensu lato was isolated at a prevalence of 16.7% (n = 11/66) and C. neoformans sensu stricto was responsible for 83.3% (n = 55/66) of the infections. l-Canavanine glycine bromothymol blue, yeast-carbon-base-d-proline-d-tryptophan and creatinine dextrose bromothymol blue thymine were able to distinguish pathogenic C. gattii sensu lato from C. neoformans sensu stricto species when compared with AFLP genotyping. This study demonstrates high C. gattii sensu lato prevalence in Zimbabwe. In addition, biotyping methods can be used as alternative diagnostic tools to molecular typing in resource-limited areas for differentiating pathogenic Cryptococcus species.

  6. Comparison of biotyping methods as alternative identification tools to molecular typing of pathogenic Cryptococcus species in sub-Saharan Africa

    PubMed Central

    Nyazika, Tinashe K.; Robertson, Valerie J.; Nherera, Brenda; Mapondera, Prichard T.; Meis, Jacques F.; Hagen, Ferry

    2015-01-01

    Summary Cryptococcal meningitis is the leading fungal infection and AIDS defining opportunistic illness in patients with late stage HIV infection, particularly in South-East Asia and sub-Saharan Africa. Given the high mortality, clinical differences and the extensive ecological niche of Cryptococcus neoformans and Cryptococcus gattii species complexes, there is need for laboratories in sub-Sahara African countries to adopt new and alternative reliable diagnostic algorithms that rapidly identify and distinguish these species. We biotyped 74 and then amplified fragment length polymorphism (AFLP) genotyped 66 Cryptococcus isolates from a cohort of patients with HIV-associated cryptococcal meningitis. Cryptococcus gattii sensu lato was isolated at a prevalence of 16.7% (n = 11/66) and C. neoformans sensu stricto was responsible for 83.3% (n = 55/66) of the infections. l-Canavanine glycine bromothymol blue, yeast-carbon-base-d-proline-d-tryptophan and creatinine dextrose bromothymol blue thymine were able to distinguish pathogenic C. gattii sensu lato from C. neoformans sensu stricto species when compared with amplified fragment length polymorphism genotyping. This study demonstrates high C. gattii sensu lato prevalence in Zimbabwe. In addition, biotyping methods can be used as alternative diagnostic tools to molecular typing in resource-limited areas for differentiating pathogenic Cryptococcus species. PMID:26661484

  7. Moving virtuality into reality: A comparison study of the effectiveness of traditional and alternative assessments of learning in a multisensory, fully immersive physics program

    NASA Astrophysics Data System (ADS)

    Gamor, Keysha Ingram

    This paper contains a research study that investigated the relative efficacy of using both a traditional paper-and-pencil assessment instrument and an alternative, virtual reality (VR) assessment instrument to assist educators and/or instructional designers in measuring learning in a virtual reality learning environment. To this end, this research study investigated assessment in VR, with the goal of analyzing aspects of student learning in VR that are feasible to access or capture by traditional assessments and alternative assessments. The researcher also examined what additional types of learning alternative assessments may offer. More specifically, this study compared the effectiveness of a traditional method with an alternative (performance-based) method of assessment that was used to examine the ability of the tools to accurately evidence the levels of students' understanding and learning. The domain area was electrostatics, a complex, abstract multidimensional concept, with which students often experience difficulty. Outcomes of the study suggest that, in the evaluation of learning in an immersive VR learning environment, assessments would most accurately manifest student learning if the assessment measure matched the learning environment itself. In this study, learning and assessing in the VR environment yielded higher final test scores than learning in VR and testing with traditional paper-and-pencil. Being able to transfer knowledge from a VR environment to other situations is critical in demonstrating the overall level of understanding of a concept. For this reason, the researcher recommends a combination of testing measures to enhance understanding of complex, abstract concepts.

  8. Design study of a 15 kW free-piston Stirling engine-linear alternator for dispersed solar electric power systems

    NASA Technical Reports Server (NTRS)

    Dochat, G. R.; Chen, H. S.; Bhate, S.; Marusak, T.

    1979-01-01

    A conceptual design of a free piston solar Stirling engine-linear alternator which can be designed and developed to meet the requirements of a near-term solar test bed engine with minimum risks was developed. The conceptual design was calculated to have an overall system efficiency of 38% and provide 15kW electric output. The free piston engine design incorporates features such as gas bearings, close clearance seals, and gas springs. This design is hermetically sealed to provide long life, reliability, and maintenance free operation. An implementation assessment study performed indicates that the free piston solar Stirling engine-linear alternator can be manufactured at a reasonable price cost (direct labor plus material) of $2,500 per engine in production quantities of 25,000 units per year. Opportunity for significant reduction of cost was also identified.

  9. Thermal-hydraulics design comparisons for the tandem mirror hybrid reactor blanket

    SciTech Connect

    Wong, C.P.C.; Yang, Y.S.; Schultz, K.R.

    1980-09-01

    The Tandem Mirror Hybrid Reactor (TMHR) is a cylindrical reactor, and the fertile materials and tritium breeding fuel elements can be arranged with radial or axial orientation in the blanket module. Thermal-hydraulics performance comparisons were made between plate, axial rod and radial rod fuel geometrices. The three configurations result in different coolant/void fractions and different clad/structure fractions. The higher void fraction in the two rod designs means that these blankets will have to be thicker than the plate design blanket in order to achieve the same level of nuclear interactions. Their higher structural fractions will degrade the uranium breeding ratio and energy multiplication factor of the design. One difficulty in the thermal-hydraulics analysis of the plate design was caused by the varying energy multiplication of the blanket during the lifetime of the plate which forced the use of designs that operated in the transition flow regime at some point during life. To account for this, an approach was adopted from Gas Cooled Fast Reactor (GCFR) experience for the pressure drop calculation and the corresponding heat transfer coefficient that was used for the film drop thermal calculation. Because of the superior nuclear performance, the acceptable thermal-hydraulic characteristics and the mechanical design feasibility, the plate geometry concept was chosen for the reference gas-cooled TMHR blanket design.

  10. Spatial and stage-structured population model of the American crocodile for comparison of comprehensive Everglades Restoration Plan (CERP) alternatives

    USGS Publications Warehouse

    Green, Timothy W.; Slone, Daniel H.; Swain, Eric D.; Cherkiss, Michael S.; Lohmann, Melinda; Mazzotti, Frank J.; Rice, Kenneth G.

    2010-01-01

    the American crocodile. This modeling effort examines how CERP restoration alternatives will affect growth and survival rates of hatchling and juvenile crocodiles, hatchling dispersal to suitable nursery habitat, and relative abundance and distribution in response to changing salinity and water depth for all stage classes of crocodiles. The response of the American crocodile to restoration efforts will provide a quantifiable measure of restoration success. By applying the crocodile model to proposed restoration alternatives and predicting population responses, we can choose alternatives that approximate historical conditions, enhance habitat for multiple species, and identify future research needs.

  11. Comparison of an alternative and existing binning methods to reduce the acquisition duration of 4D PET/CT

    SciTech Connect

    Didierlaurent, David Ribes, Sophie; Caselles, Olivier; Jaudet, Cyril; Dierickx, Lawrence O.; Zerdoud, Slimane; Brillouet, Severine; Weits, Kathleen; Batatia, Hadj; Courbon, Frédéric

    2014-11-01

    Purpose: Respiratory motion is a source of artifacts that reduce image quality in PET. Four dimensional (4D) PET/CT is one approach to overcome this problem. Existing techniques to limiting the effects of respiratory motions are based on prospective phase binning which requires a long acquisition duration (15–25 min). This time is uncomfortable for the patients and limits the clinical exploitation of 4D PET/CT. In this work, the authors evaluated an existing method and an alternative retrospective binning method to reduce the acquisition duration of 4D PET/CT. Methods: The authors studied an existing mixed-amplitude binning (MAB) method and an alternative binning method by mixed-phases (MPhB). Before implementing MPhB, they analyzed the regularity of the breathing patterns in patients. They studied the breathing signal drift and missing CT slices that could be challenging for implementing MAB. They compared the performance of MAB and MPhB with current binning methods to measure the maximum uptake, internal volume, and maximal range of tumor motion. Results: MPhB can be implemented depending on an optimal phase (in average, the exhalation peak phase −4.1% of the entire breathing cycle duration). Signal drift of patients was in average 35% relative to the breathing amplitude. Even after correcting this drift, MAB was feasible in 4D CT for only 64% of patients. No significant differences appeared between the different binning methods to measure the maximum uptake, internal volume, and maximal range of tumor motion. The authors also determined the inaccuracies of MAB and MPhB to measure the maximum amplitude of tumor motion with three bins (less than 3 mm for movement inferior to 12 mm, up to 6.4 mm for a 21 mm movement). Conclusions: The authors proposed an alternative binning method by mixed-phase binning that halves the acquisition duration of 4D PET/CT. Mixed-amplitude binning was challenging because of signal drift and missing CT slices. They showed that more

  12. Alternatives to relational databases in precision medicine: Comparison of NoSQL approaches for big data storage using supercomputers

    NASA Astrophysics Data System (ADS)

    Velazquez, Enrique Israel

    Improvements in medical and genomic technologies have dramatically increased the production of electronic data over the last decade. As a result, data management is rapidly becoming a major determinant, and urgent challenge, for the development of Precision Medicine. Although successful data management is achievable using Relational Database Management Systems (RDBMS), exponential data growth is a significant contributor to failure scenarios. Growing amounts of data can also be observed in other sectors, such as economics and business, which, together with the previous facts, suggests that alternate database approaches (NoSQL) may soon be required for efficient storage and management of big databases. However, this hypothesis has been difficult to test in the Precision Medicine field since alternate database architectures are complex to assess and means to integrate heterogeneous electronic health records (EHR) with dynamic genomic data are not easily available. In this dissertation, we present a novel set of experiments for identifying NoSQL database approaches that enable effective data storage and management in Precision Medicine using patients' clinical and genomic information from the cancer genome atlas (TCGA). The first experiment draws on performance and scalability from biologically meaningful queries with differing complexity and database sizes. The second experiment measures performance and scalability in database updates without schema changes. The third experiment assesses performance and scalability in database updates with schema modifications due dynamic data. We have identified two NoSQL approach, based on Cassandra and Redis, which seems to be the ideal database management systems for our precision medicine queries in terms of performance and scalability. We present NoSQL approaches and show how they can be used to manage clinical and genomic big data. Our research is relevant to the public health since we are focusing on one of the main

  13. Alternatives for logistic regression in cross-sectional studies: an empirical comparison of models that directly estimate the prevalence ratio

    PubMed Central

    Barros, Aluísio JD; Hirakata, Vânia N

    2003-01-01

    Background Cross-sectional studies with binary outcomes analyzed by logistic regression are frequent in the epidemiological literature. However, the odds ratio can importantly overestimate the prevalence ratio, the measure of choice in these studies. Also, controlling for confounding is not equivalent for the two measures. In this paper we explore alternatives for modeling data of such studies with techniques that directly estimate the prevalence ratio. Methods We compared Cox regression with constant time at risk, Poisson regression and log-binomial regression against the standard Mantel-Haenszel estimators. Models with robust variance estimators in Cox and Poisson regressions and variance corrected by the scale parameter in Poisson regression were also evaluated. Results Three outcomes, from a cross-sectional study carried out in Pelotas, Brazil, with different levels of prevalence were explored: weight-for-age deficit (4%), asthma (31%) and mother in a paid job (52%). Unadjusted Cox/Poisson regression and Poisson regression with scale parameter adjusted by deviance performed worst in terms of interval estimates. Poisson regression with scale parameter adjusted by χ2 showed variable performance depending on the outcome prevalence. Cox/Poisson regression with robust variance, and log-binomial regression performed equally well when the model was correctly specified. Conclusions Cox or Poisson regression with robust variance and log-binomial regression provide correct estimates and are a better alternative for the analysis of cross-sectional studies with binary outcomes than logistic regression, since the prevalence ratio is more interpretable and easier to communicate to non-specialists than the odds ratio. However, precautions are needed to avoid estimation problems in specific situations. PMID:14567763

  14. Numerical simulation methodologies for design and development of Diffuser-Augmented Wind Turbines - analysis and comparison

    NASA Astrophysics Data System (ADS)

    Michał, Lipian; Maciej, Karczewski; Jakub, Molinski; Krzysztof, Jozwik

    2016-01-01

    Different numerical computation methods used to develop a methodology for fast, efficient, reliable design and comparison of Diffuser-Augmented Wind Turbine (DAWT) geometries are presented. The demand for such methods is evident, following the multitude of geometrical parameters that influence the flow character through ducted turbines. The results of the Actuator Disk Model (ADM) simulations will be confronted with a simulation method of higher order of accuracy, i.e. the 3D Fully-resolved Rotor Model (FRM) in the rotor design point. Both will be checked for consistency with the experimental results measured in the wind tunnel at the Institute of Turbo-machinery (IMP), Lodz University of Technology (TUL). An attempt to find an efficient method (with a compromise between accuracy and design time) for the flow analysis pertinent to the DAWT is a novel approach presented in this paper.

  15. Analysis of alternative push-pull-test-designs for determining in-situ trapping of CO2

    NASA Astrophysics Data System (ADS)

    Rasmusson, M.; Rasmusson, K.; Fagerlund, F.; Niemi, A.; Bensabat, J.; Shtivelman, V.

    2012-04-01

    Modeling results of different single-well push-pull (injection-withdrawal) test designs have been analyzed for their ability to determine residual and dissolution trapping of CO2 in-situ. The modeling aims to improve the design of a CO2 push-pull test that will be part of the field experiment conducted at the Heletz site, Israel, within the EU FP7 MUSTANG project. The injection will take place in a saline formation, where the target layer, an about 10 m thick sandstone layer composed of three layers, is located at a depth of 1600 m. Single-well experiments complement two-well injection-monitoring tests in that they offer a way of reducing heterogeneity effects on CO2 transport in comparison to two-well tests. The test scenarios simulated combine thermal, hydraulic and tracer tests in line with the work by Zhang et al (2011), where the test sequences have three main stages divided into (i) reference tests, (ii) creation of a zone of residual gas saturation and (iii) testing during residual gas saturation conditions. One of the main interests is to compare different ways of creating the residual zone, the two principal approaches being to push the mobile CO2 away by injecting CO2 saturated water, thus leaving the residual zone behind or by pumping the mobile CO2 back. Implications of the different designs on optimal use of tracers are also analyzed. Inverse modeling with the iTOUGH2/EOS17 and EOS7c simulators is used to analyze the ability of the competing test designs to accurately determine parameters of main interest during CO2 sequestration, in particular the residual gas saturation and dissolution. The inverse modeling approach uses results from e.g. sensitivity analysis and uncertainty propagation analysis to make design decisions leading to improvements in the test scenarios, choosing the optimum pumping and injection rates, heating effects, amount of CO2 used, tracer and method to create the zone of residual CO2 trapping, leading to a test design that will

  16. Conical scan impact study. Volume 1: General central data processing facility. [multispectral band scanner design alternatives for earth resources data

    NASA Technical Reports Server (NTRS)

    Ebert, D. H.; Eppes, T. A.; Thomas, D. J.

    1973-01-01

    The impact of a conical scan versus a linear scan multispectral scanner (MSS) instrument was studied in terms of: (1) design modifications required in framing and continuous image recording devices; and (2) changes in configurations of an all-digital precision image processor. A baseline system was defined to provide the framework for comparison, and included pertinent spacecraft parameters, a conical MSS, a linear MSS, an image recording system, and an all-digital precision processor. Lateral offset pointing of the sensors over a range of plus or minus 20 deg was considered. The study addressed the conical scan impact on geometric, radiometric, and aperture correction of MSS data in terms of hardware and software considerations, system complexity, quality of corrections, throughput, and cost of implementation. It was concluded that: (1) if the MSS data are to be only film recorded, then there is only a nomial concial scan impact on the ground data processing system; and (2) if digital data are to be provided to users on computer compatible tapes in rectilinear format, then there is a significant conical scan impact on the ground data processing system.

  17. Comparison of Resource Requirements for a Wind Tunnel Test Designed with Conventional vs. Modern Design of Experiments Methods

    NASA Technical Reports Server (NTRS)

    DeLoach, Richard; Micol, John R.

    2011-01-01

    The factors that determine data volume requirements in a typical wind tunnel test are identified. It is suggested that productivity in wind tunnel testing can be enhanced by managing the inference error risk associated with evaluating residuals in a response surface modeling experiment. The relationship between minimum data volume requirements and the factors upon which they depend is described and certain simplifications to this relationship are realized when specific model adequacy criteria are adopted. The question of response model residual evaluation is treated and certain practical aspects of response surface modeling are considered, including inference subspace truncation. A wind tunnel test plan developed by using the Modern Design of Experiments illustrates the advantages of an early estimate of data volume requirements. Comparisons are made with a representative One Factor At a Time (OFAT) wind tunnel test matrix developed to evaluate a surface to air missile.

  18. Comparison of proximal femur and vertebral body strength improvements in the FREEDOM trial using an alternative finite element methodology.

    PubMed

    Zysset, Philippe; Pahr, Dieter; Engelke, Klaus; Genant, Harry K; McClung, Michael R; Kendler, David L; Recknor, Christopher; Kinzl, Michael; Schwiedrzik, Jakob; Museyko, Oleg; Wang, Andrea; Libanati, Cesar

    2015-12-01

    Denosumab reduced the incidence of new fractures in postmenopausal women with osteoporosis by 68% at the spine and 40% at the hip over 36 months compared with placebo in the FREEDOM study. This efficacy was supported by improvements from baseline in vertebral (18.2%) strength in axial compression and femoral (8.6%) strength in sideways fall configuration at 36 months, estimated in Newtons by an established voxel-based finite element (FE) methodology. Since FE analyses rely on the choice of meshes, material properties, and boundary conditions, the aim of this study was to independently confirm and compare the effects of denosumab on vertebral and femoral strength during the FREEDOM trial using an alternative smooth FE methodology. Unlike the previous FE study, effects on femoral strength in physiological stance configuration were also examined. QCT data for the proximal femur and two lumbar vertebrae were analyzed by smooth FE methodology at baseline, 12, 24, and 36 months for 51 treated (denosumab) and 47 control (placebo) subjects. QCT images were segmented and converted into smooth FE models to compute bone strength. L1 and L2 vertebral bodies were virtually loaded in axial compression and the proximal femora in both fall and stance configurations. Denosumab increased vertebral body strength by 10.8%, 14.0%, and 17.4% from baseline at 12, 24, and 36 months, respectively (p<0.0001). Denosumab also increased femoral strength in the fall configuration by 4.3%, 5.1%, and 7.2% from baseline at 12, 24, and 36 months, respectively (p<0.0001). Similar improvements were observed in the stance configuration with increases of 4.2%, 5.2%, and 5.2% from baseline (p≤0.0007). Differences between the increasing strengths with denosumab and the decreasing strengths with placebo were significant starting at 12 months (vertebral and femoral fall) or 24 months (femoral stance). Using an alternative smooth FE methodology, we confirmed the significant improvements in vertebral body

  19. Comparison of Two Multidisciplinary Optimization Strategies for Launch-Vehicle Design

    NASA Technical Reports Server (NTRS)

    Braun, R. D.; Powell, R. W.; Lepsch, R. A.; Stanley, D. O.; Kroo, I. M.

    1995-01-01

    The investigation focuses on development of a rapid multidisciplinary analysis and optimization capability for launch-vehicle design. Two multidisciplinary optimization strategies in which the analyses are integrated in different manners are implemented and evaluated for solution of a single-stage-to-orbit launch-vehicle design problem. Weights and sizing, propulsion, and trajectory issues are directly addressed in each optimization process. Additionally, the need to maintain a consistent vehicle model across the disciplines is discussed. Both solution strategies were shown to obtain similar solutions from two different starting points. These solutions suggests that a dual-fuel, single-stage-to-orbit vehicle with a dry weight of approximately 1.927 x 10(exp 5)lb, gross liftoff weight of 2.165 x 10(exp 6)lb, and length of 181 ft is attainable. A comparison of the two approaches demonstrates that treatment or disciplinary coupling has a direct effect on optimization convergence and the required computational effort. In comparison with the first solution strategy, which is of the general form typically used within the launch vehicle design community at present, the second optimization approach is shown to he 3-4 times more computationally efficient.

  20. Design and validation of realistic breast models for use in multiple alternative forced choice virtual clinical trials

    NASA Astrophysics Data System (ADS)

    Elangovan, Premkumar; Mackenzie, Alistair; Dance, David R.; Young, Kenneth C.; Cooke, Victoria; Wilkinson, Louise; Given-Wilson, Rosalind M.; Wallis, Matthew G.; Wells, Kevin

    2017-04-01

    A novel method has been developed for generating quasi-realistic voxel phantoms which simulate the compressed breast in mammography and digital breast tomosynthesis (DBT). The models are suitable for use in virtual clinical trials requiring realistic anatomy which use the multiple alternative forced choice (AFC) paradigm and patches from the complete breast image. The breast models are produced by extracting features of breast tissue components from DBT clinical images including skin, adipose and fibro-glandular tissue, blood vessels and Cooper’s ligaments. A range of different breast models can then be generated by combining these components. Visual realism was validated using a receiver operating characteristic (ROC) study of patches from simulated images calculated using the breast models and from real patient images. Quantitative analysis was undertaken using fractal dimension and power spectrum analysis. The average areas under the ROC curves for 2D and DBT images were 0.51  ±  0.06 and 0.54  ±  0.09 demonstrating that simulated and real images were statistically indistinguishable by expert breast readers (7 observers); errors represented as one standard error of the mean. The average fractal dimensions (2D, DBT) for real and simulated images were (2.72  ±  0.01, 2.75  ±  0.01) and (2.77  ±  0.03, 2.82  ±  0.04) respectively; errors represented as one standard error of the mean. Excellent agreement was found between power spectrum curves of real and simulated images, with average β values (2D, DBT) of (3.10  ±  0.17, 3.21  ±  0.11) and (3.01  ±  0.32, 3.19  ±  0.07) respectively; errors represented as one standard error of the mean. These results demonstrate that radiological images of these breast models realistically represent the complexity of real breast structures and can be used to simulate patches from mammograms and DBT images that are indistinguishable from

  1. Alternating Current-Dielectrophoresis Collection and Chaining of Phytoplankton on Chip: Comparison of Individual Species and Artificial Communities

    PubMed Central

    Siebman, Coralie; Velev, Orlin D.; Slaveykova, Vera I.

    2017-01-01

    The capability of alternating current (AC) dielectrophoresis (DEP) for on-chip capture and chaining of the three species representative of freshwater phytoplankton was evaluated. The effects of the AC field intensity, frequency and duration on the chaining efficiency and chain lengths of green alga Chlamydomonas reinhardtii, cyanobacterium Synechocystis sp. and diatom Cyclotella meneghiniana were characterized systematically. C. reinhardtii showed an increase of the chaining efficiency from 100 Hz to 500 kHz at all field intensities; C. meneghiniana presented a decrease of chaining efficiency from 100 Hz to 1 kHz followed by a significant increase from 1 kHz to 500 kHz, while Synechocystis sp. exhibited low chaining tendency at all frequencies and all field intensities. The experimentally-determined DEP response and cell alignment of each microorganism were in agreement with their effective polarizability. Mixtures of cells in equal proportion or 10-times excess of Synechocystis sp. showed important differences in terms of chaining efficiency and length of the chains compared with the results obtained when the cells were alone in suspension. While a constant degree of chaining was observed with the mixture of C. reinhardtii and C. meneghiniana, the presence of Synechocystis sp. in each mixture suppressed the formation of chains for the two other phytoplankton species. All of these results prove the potential of DEP to discriminate different phytoplankton species depending on their effective polarizability and to enable their manipulation, such as specific collection or separation in freshwater. PMID:28067772

  2. Timing of peripheral blood stem cell yield: comparison of alternative methods with the classic method for CD34+ cell determination.

    PubMed

    Fatorova, I; Blaha, M; Lanska, M; Vokurkova, D; Rezacova, V; Zak, P

    2014-01-01

    Hematopoietic stem cells (HSCs), still represent a certain mystery in biology, have a unique property of dividing into equal cells and repopulating the hematopoietic tissue. This potential enables their use in transplantation treatments. The quality of the HSC grafts for transplantation is evaluated by flow cytometric determination of the CD34(+) cells, which enables optimal timing of the first apheresis and the acquisition of maximal yield of the peripheral blood stem cells (PBSCs). To identify a more efficient method for evaluating CD34(+) cells, we compared the following alternative methods with the reference method: hematopoietic progenitor cells (HPC) enumeration (using the Sysmex XE-2100 analyser), detection of CD133(+) cells, and quantification of aldehyde dehydrogenase activity in the PBSCs. 266 aphereses (84 patients) were evaluated. In the preapheretic blood, the new methods produced data that were in agreement with the reference method. The ROC curves have shown that for the first-day apheresis target, the optimal predictive cut-off value was 0.032 cells/mL for the HPC method (sensitivity 73.4%, specificity 69.3%). HPC method exhibited a definite practical superiority as compared to other methods tested. HPC enumeration could serve as a supplementary method for the optimal timing of the first apheresis; it is simple, rapid, and cheap.

  3. Comparison of Alternative Crop Phenology Detection Algorithms using MODIS NDVI Time Series Data in US Corn Belt Region

    NASA Astrophysics Data System (ADS)

    Lee, J.; Hong, S. Y.; Kang, S.

    2015-12-01

    Predicting crop phenology is important for understanding of crop development and growth processes and improving the accuracy of crop model. Remote sensing offers a feasible tool for monitoring spatio-temporal patterns of crop phenology in region and continental scales. Various methods have developed to determine the timing of crop phenological stages using spectral vegetation indices (i.e. NDVI and EVI) derived from satellite data. In our study, it was compared four alternative detection methods to identify crop phenological stages (i.e. the emergence and harvesting date) using high quality NDVI time series data derived from MODIS. In threshold method assumes the emergence and harvesting date when NDVI values exceed and decreases down to a given threshold, respectively. Two kind of threshold values were applied for NDVI and it increment for eight days. The other two methods use a logistic fitting model and inflection points on fitted curve, respectively. It was compared the four methods for corn and soybean, respectively. For validation, three kinds of datasets were utilized: AmeriFlux biological data of planting and harvest dates, and emergence date estimated from growing degree days (AGDDs) at flux tower sites, and state-level USDA Crop Progress Report (CPR). All methods showed substantial uncertainty but the threshold method showed relatively better agreement against with both site- and state-level data for soybean phenology. For better NDVI-based regional estimation of crop phenology, factors of uncertainty were examined and discussed in this study.

  4. Comparisons of intervention components within augmentative and alternative communication systems for individuals with developmental disabilities: a review of the literature.

    PubMed

    Gevarter, Cindy; O'Reilly, Mark F; Rojeski, Laura; Sammarco, Nicolette; Lang, Russell; Lancioni, Giulio E; Sigafoos, Jeff

    2013-12-01

    Decisions regarding augmentative and alternative communication (AAC) for individuals with developmental disabilities (e.g. what AAC to use and how to teach a person to use a specific AAC modality) should involve consideration of different intervention component options. In an effort to elucidate such decisions and options, this review synthesized 14 studies, published between 2004 and 2012, comparing different AAC intervention components including different symbol sets, instructional strategies, or speech output within aided AAC systems, and different verbal operants within unaided AAC. Evidence supported the following: (a) different instructional strategies such as building motivation, using errorless learning, or adding video models to picture exchange interventions may improve the acquisition or rate of acquisition of picture exchange mands, (b) limited data supports training mimetic (imitated) or mand signs over tacts and (c) differences in symbol sets and speech output levels appeared to have little effect on AAC-based mand acquisition, but listener-based differences should be considered. These findings have implications for future research and clinical practice.

  5. Alternating Current-Dielectrophoresis Collection and Chaining of Phytoplankton on Chip: Comparison of Individual Species and Artificial Communities.

    PubMed

    Siebman, Coralie; Velev, Orlin D; Slaveykova, Vera I

    2017-01-05

    The capability of alternating current (AC) dielectrophoresis (DEP) for on-chip capture and chaining of the three species representative of freshwater phytoplankton was evaluated. The effects of the AC field intensity, frequency and duration on the chaining efficiency and chain lengths of green alga Chlamydomonas reinhardtii, cyanobacterium Synechocystis sp. and diatom Cyclotella meneghiniana were characterized systematically. C. reinhardtii showed an increase of the chaining efficiency from 100 Hz to 500 kHz at all field intensities; C. meneghiniana presented a decrease of chaining efficiency from 100 Hz to 1 kHz followed by a significant increase from 1 kHz to 500 kHz, while Synechocystis sp. exhibited low chaining tendency at all frequencies and all field intensities. The experimentally-determined DEP response and cell alignment of each microorganism were in agreement with their effective polarizability. Mixtures of cells in equal proportion or 10-times excess of Synechocystis sp. showed important differences in terms of chaining efficiency and length of the chains compared with the results obtained when the cells were alone in suspension. While a constant degree of chaining was observed with the mixture of C. reinhardtii and C. meneghiniana, the presence of Synechocystis sp. in each mixture suppressed the formation of chains for the two other phytoplankton species. All of these results prove the potential of DEP to discriminate different phytoplankton species depending on their effective polarizability and to enable their manipulation, such as specific collection or separation in freshwater.

  6. Clean air program: Design guidelines for bus transit systems using compressed natural gas as an alternative fuel. Final report, July 1995-April 1996

    SciTech Connect

    Raj, P.K.; Hathaway, W.T.; Kangas, R.

    1996-06-01

    The guidelines document presents various facility and bus design issues that need to be considered to ensure safe operations when using CNG (Compressed Natural Gas) as the alternative fuel. Fueling facility, garaging facility, maintenance facility requirements and safety practices are indicated. Among the issues discussed are fuel properties, potential hazards, fuel requirements for specified level of service, applicable codes and standards, ventilation, and electrical classification. Critical fuel related safety issues in the design of the related systems on the bus are also discussed.

  7. The LIFE Laser Design in Context: A Comparison to the State-of-the-Art

    SciTech Connect

    Deri, R J; Bayramian, A J; Erlandson, A C

    2011-03-21

    The current point design for the LIFE laser leverages decades of solid-state laser development in order to achieve the performance and attributes required for inertial fusion energy. This document provides a brief comparison of the LIFE laser point design to other state-of-the-art solid-state lasers. Table I compares the attributes of the current LIFE laser point design to other systems. the state-of-the-art for single-shot performance at fusion-relevant beamline energies is exemplified by performance observed on the National Ignition Facility. The state-of-the-art for high average power is exemplified by the Northrup Grumman JHPSSL laser. Several items in Table I deal with the laser efficiency; a more detailed discussion of efficiency can be found in reference 5. The electrical-to-optical efficiency of the LIFE design exceeds that of reference 4 due to the availability of higher efficiency laser diode pumps (70% vs. {approx}50% used in reference 4). LIFE diode pumps are discussed in greater detail in reference 6. The 'beam steering' state of the art is represented by the deflection device that will be used in the LIFE laser, not a laser system. Inspection of Table I shows that most LIFE laser attributes have already been experimentally demonstrated. The two cases where the LIFE design is somewhat better than prior experimental work do not involve the development of new concepts: beamline power is increased simply by increasing aperture (as demonstrated by the power/aperture comparison in Table I), and efficiency increases are achieved by employing state-of-the-art diode pumps. In conclusion, the attributes anticipated for the LIFE laser are consistent with the demonstrated performance of existing solid-state lasers.

  8. An alternate side coupled structure for the Fermilab LINAC upgrade

    SciTech Connect

    Jurgens, T.G.; Kerns, Q.A.; Fritz, J.R.; May, M.A.

    1988-10-01

    An alternate side coupled structure (SCS) is being investigated. Comparisons are made to the traditional SCS. Mechanical comparisons include the relative cost and ease of fabrication. This discussion also addresses the use of CNC machining. Electrical comparisons include field distributions and coupling constants. Measured and numerical data are presented. The coupling constant of the alternate SCS is adjusted by independently changing either the separation of the coupling and accelerating cavity centers or the length of the slot. These two parameters are not independent in the traditional SCS design. 4 refs., 5 figs

  9. Elementary teachers' mental models of engineering design processes: A comparison of two communities of practice

    NASA Astrophysics Data System (ADS)

    McMahon, Ann P.

    understandings of the engineering process drive the social and emotional roles and skills used in that process. This comparison of mental models with the process that professional designers use defines a problem space for future studies that investigate how to incorporate engineering practices into elementary classrooms. Recommendations for engineering curriculum development and teacher professional development based on this study are presented.

  10. The Development of Mini Portable Digester Designs for Domestic and Restaurant Solid Waste Processing to be Clean Biogas as Energy's Alternative to Replace LPG

    NASA Astrophysics Data System (ADS)

    Mansur, A.; Janari dan, D.; Setiawan, N.

    2016-02-01

    Biofuel is developed as an alternative source of second generation energy that could be attained from organic waste. This research is purposed to create applicative and cheap Portable digester unit for society. The design concepts’ screening that was made under considerations of the experts is finally resumed. Design 1 with final weight score of 1, design 2 with final weight score of -1, design 3 with final weight score of 2, design 4 with final weight score 3, design 5 with final weight score of -1, design 6 with final weight score of 0. Accepted designs for further concept assessment are design 1, 2 and 6. The result of concept assessment applies weighting for the scoring. Design 1 resulting 2.67, design 2 results 2.15 while design 3 results 2.52. Design 1 is concluded as the design with biggest result, which is 2.67. Its specification is explained as follows: tank capacity of 60 liters, manual rotating crank pivot, tank's material is plastic with symbol 1, material of axle swivel arm is grey cast iron, 2 mm rotary blades with hole. The experiment 1 contained 23.78% methane and 13.65 carbon dioxide that resulted from content test.

  11. A comparison of the effect of doxorubicin and phenol on the skeletal muscle. May doxorubicin be a new alternative treatment agent for spasticity?

    PubMed

    Cullu, Emre; Ozkan, Ilhan; Culhaci, Nil; Alparslan, Bulent

    2005-03-01

    Since spasticity is still an unsolved problem for orthopaedic surgeons, different chemical agents are tried before surgery. Phenol is a chemical agent which has been used for spasticity treatment for a long time. Doxorubicin is an antitumoral agent that has recently been used for chemomyectomy. The intramuscular effects of phenol and two different dose of doxorubicin were compared in that experimental study. In the first group 0.5 mg/0.5 cm3 doxorubicin, in the second group 1 mg/0.5 doxorubicin and in the third group 5% aqueous solution of fenol/0.5 injection were applied into left quadriceps muscle of rats. Degeneration areas were wider in the high dose doxorubicin group (29.9%; 8.5-61), in comparison with the low dose doxorubicin group (6.4%; 3.1-12) and phenol group (4%; 0-14) after 6 weeks. Differences in degeneration area among three groups were statistically significant (P<0.001). The difference was significant between the high dose doxorubicin group and the phenol group (P=0.001) and also between the high dose doxorubicin group and the low dose doxorubicin group (P<0.001). The results of this study suggested that doxorubicin could provide an alternative treatment modality for neuromuscular disease causing spasticity and it has a dose-dependent effect. Further studies are needed for long-term comparison and clinical use of doxorubicin for spasticity treatment.

  12. Complementary and Alternative Medicine: Comparison of Current Knowledge, Attitudes and Interest among German Medical Students and Doctors

    PubMed Central

    Münstedt, Karsten; Harren, Hildegard; von Georgi, Richard; Hackethal, Andreas

    2011-01-01

    Although it has been agreed that complementary and alternative medicine (CAM) should be included in the German medical curriculum, there is no consensus on which methods and how it should be taught. This study aimed to assess needs for CAM education by evaluating current knowledge, attitudes and interests of medical students, general physicians and gynecologists. Two instruments based on established and validated questionnaires were developed. One was given to seventh semester medical students and the other to office-based doctors. Data were analyzed by bivariate correlation and cross-tabulation. Altogether 550 questionnaires were distributed—280 to doctors and 270 to medical students. Completed questionnaires were returned by 80.4% of students and 78.2% of doctors. Although 73.8% (160/219) of doctors and 40% (87/217) of students had already informed themselves about CAM, neither group felt that they knew much about CAM. Doctors believed that CAM was most useful in general medicine, supportive oncology, pediatrics, dermatology and gynecology, while students believed that dermatology, general medicine, psychiatry and rheumatology offered opportunities; both recommended that CAM should be taught in these areas. Both groups believed that CAM should be included in medical education; however, they believed that CAM needed more investigation and should be taught “critically". German doctors and students would like to be better informed about CAM. An approach which teaches fundamental competences to students, chooses specific content based on evidence, demographics and medical conditions and provides students with the skills they need for future learning should be adopted. PMID:19098296

  13. A comparison of single oxidants versus advanced oxidation processes as chlorine-alternatives for wild blueberry processing (Vaccinium angustifolium).

    PubMed

    Crowe, Kristi M; Bushway, Alfred A; Bushway, Rodney J; Davis-Dentici, Katherine; Hazen, Russell A

    2007-05-01

    Advanced oxidation processes and single chemical oxidants were evaluated for their antimicrobial efficacy against common spoilage bacteria isolated from lowbush blueberries. Predominant bacterial flora were identified using biochemical testing with the assessment of relative abundance using non-selective and differential media. Single chemical oxidants evaluated for postharvest processing of lowbush blueberries included 1% hydrogen peroxide, 100 ppm chlorine, and 1 ppm aqueous ozone while advanced oxidation processes (AOPs) included combinations of 1% hydrogen peroxide/UV, 100 ppm chlorine/UV, and 1 ppm ozone/1% hydrogen peroxide/UV. Enterobacter agglomerans and Pseudomonas fluorescens were found to comprise 90-95% of the bacterial flora on lowbush blueberries. Results of inoculation studies reveal significant log reductions (p< or 5) in populations of E. agglomerans and P. fluorescens on all samples receiving treatment with 1% hydrogen peroxide, 1% hydrogen peroxide/UV, 1 ppm ozone, or a combined ozone/hydrogen peroxide/UV treatment as compared to chlorine treatments and unwashed control berries. Although population reductions approached 2.5 log CFU/g, microbial reductions among these treatments were not found to be significantly different (p< or 5) from each other despite the synergistic potential that should result from AOPs; furthermore, as a single oxidant, UV inactivation of inoculated bacteria was minimal and did not prove effective as a non-aqueous bactericidal process for fresh pack blueberries. Overall, results indicate that hydrogen peroxide and ozone, as single chemical oxidants, are as effective as AOPs and could be considered as chlorine-alternatives in improving the microbiological quality of lowbush blueberries.

  14. Comparison of the microbiological and chemical characterization of harvested rainwater and reservoir water as alternative water resources.

    PubMed

    Lee, Ju Young; Yang, Jung-Seok; Han, Mooyoung; Choi, Jaeyoung

    2010-01-15

    Rainwater harvesting (RWH) offers considerable potential as an alternative water supply. In this study, all of the harvested rainwater samples met the requirements for grey water but not for drinking water. In terms of microbiological parameters, total coliform (TC) and Escherichia coli (EC) were measured in 91.6% and 72%, respectively, of harvested rainwater samples at levels exceeding the guidelines for drinking water, consistent with rainfall events. In the case of the reservoir water samples, TC and EC were detected in 94.4% and 85.2%, respectively, of the samples at levels exceeding the guidelines for drinking water. Both indicators gradually increased in summer and fall. The highest median values of both TC and EC were detected during the fall. Chemical parameters such as common anions and major cations as well as metal ions in harvested rainwater were within the acceptable ranges for drinking water. By contrast, Al shows a notable increase to over 200mugL(-1) in the spring due to the intense periodic dust storms that can pass over the Gobi Desert in northern China. In terms of statistical analysis, the harvested rainwater quality showed that TC and EC exhibit high positive correlations with NO(3)(-) (rho(TC)=0.786 and rho(EC)=0.42) and PO(4)(-) (rho(TC)=0.646 and rho(EC)=0.653), which originally derive from catchment contamination, but strong negative correlations with Cl(-) (rho(TC)=-0.688 and rho(EC)=-0.484) and Na(+) (rho(TC)=-0.469 and rho(EC)=-0.418), which originate from seawater.

  15. Multivariate classification of animal communication signals: a simulation-based comparison of alternative signal processing procedures using electric fishes.

    PubMed

    Crampton, William G R; Davis, Justin K; Lovejoy, Nathan R; Pensky, Marianna

    2008-01-01

    Evolutionary studies of communication can benefit from classification procedures that allow individual animals to be assigned to groups (e.g. species) on the basis of high-dimension data representing their signals. Prior to classification, signals are usually transformed by a signal processing procedure into structural features. Applications of these signal processing procedures to animal communication have been largely restricted to the manual or semi-automated identification of landmark features from graphical representations of signals. Nonetheless, theory predicts that automated time-frequency-based digital signal processing (DSP) procedures can represent signals more efficiently (using fewer features) than can landmark procedures or frequency-based DSP - allowing more accurate classification. Moreover, DSP procedures are objective in that they require little previous knowledge of signal diversity, and are relatively free from potentially ungrounded assumptions of cross-taxon homology. Using a model data set of electric organ discharge waveforms from five sympatric species of the electric fish Gymnotus, we adopted an exhaustive simulation approach to investigate the classificatory performance of different signal processing procedures. We considered a landmark procedure, a frequency-based DSP procedure (the fast Fourier transform), and two kinds of time-frequency-based DSP procedures (a short-time Fourier transform, and several implementations of the discrete wavelet transform -DWT). The features derived from each of these signal processing procedures were then subjected to dimension reduction procedures to separate those features which permit the most effective discrimination among groups of signalers. We considered four alternative dimension reduction methods. Finally, each combination of reduced data was submitted to classification by linear discriminant analysis. Our results support theoretical predictions that time-frequency DSP procedures (especially DWT

  16. Design of magnetic molecularly imprinted polymer nanoparticles for controlled release of doxorubicin under an alternative magnetic field in athermal conditions

    NASA Astrophysics Data System (ADS)

    Griffete, N.; Fresnais, J.; Espinosa, A.; Wilhelm, C.; Bée, A.; Ménager, C.

    2015-11-01

    An innovative magnetic delivery nanomaterial for triggered cancer therapy showing active control over drug release by using an alternative magnetic field is proposed. In vitro and In vivo release of doxorubicin (DOX) were investigated and showed a massive DOX release under an alternative magnetic field without temperature elevation of the medium.An innovative magnetic delivery nanomaterial for triggered cancer therapy showing active control over drug release by using an alternative magnetic field is proposed. In vitro and In vivo release of doxorubicin (DOX) were investigated and showed a massive DOX release under an alternative magnetic field without temperature elevation of the medium. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06133d

  17. Clean air program: Design guidelines for bus transit systems using liquefied petroleum gas (LPG) as an alternative fuel. Final report, July 1995-April 1996

    SciTech Connect

    Raj, P.K.; Hathaway, W.T.; Kangas, R.

    1996-09-01

    The Federal Transit Administration (FTA) has initiated the development of `Design Guidelines for Bus Transit Systems Using Alternative Fuels.` This report provides design guidelines for the safe uses of Liquefied Petroleum Gas (LPG). It forms a part of the series of individual monographs being published by the FTA on (the guidelines for the safe use of) Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG), Liquefied Petroleum Gas (LPG) and alcohol fuels (Methanol and Ethanol). Each report in this series describes for the subject fuel the important fuel properties, guidelines for the design and operation of bus fueling, storage and maintenance facilities, issues on personnel training and emergency preparedness.

  18. Energy conversion alternatives study

    NASA Technical Reports Server (NTRS)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  19. Aerodynamic optimization, comparison, and trim design of canard and conventional high performance general aviation configurations

    NASA Technical Reports Server (NTRS)

    Keith, M. W.; Selberg, B. P.

    1983-01-01

    A design study has been conducted to optimize trim cruise flight of high performance general aviation canard aircraft which achieve minimum drag. In order to investigate the advantages and disadvantages of canard configured aircraft, corresponding conventional tail-aft 'baseline' aircraft were designed and used for comparison. Two-dimensional predictions were obtained by coupling inviscid results from a vortex panel multi-element program to a momentum integral boundary layer analysis. Using the results of the two-dimensional vortex panel analysis, a vortex lattice method was employed to predict the finite wing results. The analysis utilized a turbulent airfoil and a natural laminar airfoil which are two NASA state-of-the-art airfoil sections. The canard aircraft designs give quantitative results of wing and canard loadings, wing-to-canard moment arm ratios, and aspect ratio effects for trim cruise flight for a wide range of wing-to-canard area ratios. Both canard and baseline aircraft achieved a 25 to 30 percent improvement in performance over typical current technology aircraft, but high canard loading necessary for trim resulted in slightly poorer performance of the canard aircraft as compared to the baseline designs.

  20. A Comparison of Golf Shoe Designs Highlights Greater Ground Reaction Forces with Shorter Irons

    PubMed Central

    Worsfold, Paul; Smith, Neal A.; Dyson, Rosemary J.

    2007-01-01

    In an effort to reduce golf turf damage the traditional metal spike golf shoe has been redesigned, but shoe-ground biomechanical evaluations have utilised artificial grass surfaces. Twenty-four golfers wore three different golf shoe traction designs (traditional metal spikes, alternative spikes, and a flat-soled shoe with no additional traction) when performing shots with a driver, 3 iron and 7 iron. Ground action forces were measured beneath the feet by two natural grass covered force platforms. The maximum vertical force recorded at the back foot with the 3 iron and 7 iron was 0.82 BW (body weight) and at the front foot 1.1 BW approximately in both the metal spike and alternative spike golf shoe designs. When using the driver these maximal vertical values were 0.49 BW at the back foot and 0.84 BW at the front foot. Furthermore, as performance of the backswing and then downswing necessitates a change in movement direction the range of force generated during the complete swing was calculated. In the metal spike shoe the vertical force generated at the back foot with both irons was 0.67 BW and at the front foot 0.96 BW with the 3 iron and 0.92 BW with the 7 iron. The back foot vertical force generated with the driver was 0.33 BW and at the front foot 0.83 BW wearing the metal spike shoe. Results indicated the greater force generation with the irons. When using the driver the more horizontal swing plane associated with the longer club reduced vertical forces at the back and front foot. However, the mediolateral force generated across each foot in the metal and alternative spike shoes when using the driver was greater than when the irons were used. The coefficient of friction was 0. 62 at the back and front foot whichever shoe was worn or club used. Key pointsDuring the golf swing ground reaction forces at the golf shoe to natural grass turf interface were greater with irons than with the longer driver.In the golf swing maximal vertical forces were greater at the

  1. Comparison of alternative spatial resolutions in the application of a spatially distributed biogeochemical model over complex terrain

    USGS Publications Warehouse

    Turner, D.P.; Dodson, R.; Marks, D.

    1996-01-01

    Spatially distributed biogeochemical models may be applied over grids at a range of spatial resolutions, however, evaluation of potential errors and loss of information at relatively coarse resolutions is rare. In this study, a georeferenced database at the 1-km spatial resolution was developed to initialize and drive a process-based model (Forest-BGC) of water and carbon balance over a gridded 54976 km2 area covering two river basins in mountainous western Oregon. Corresponding data sets were also prepared at 10-km and 50-km spatial resolutions using commonly employed aggregation schemes. Estimates were made at each grid cell for climate variables including daily solar radiation, air temperature, humidity, and precipitation. The topographic structure, water holding capacity, vegetation type and leaf area index were likewise estimated for initial conditions. The daily time series for the climatic drivers was developed from interpolations of meteorological station data for the water year 1990 (1 October 1989-30 September 1990). Model outputs at the 1-km resolution showed good agreement with observed patterns in runoff and productivity. The ranges for model inputs at the 10-km and 50-km resolutions tended to contract because of the smoothed topography. Estimates for mean evapotranspiration and runoff were relatively insensitive to changing the spatial resolution of the grid whereas estimates of mean annual net primary production varied by 11%. The designation of a vegetation type and leaf area at the 50-km resolution often subsumed significant heterogeneity in vegetation, and this factor accounted for much of the difference in the mean values for the carbon flux variables. Although area wide means for model outputs were generally similar across resolutions, difference maps often revealed large areas of disagreement. Relatively high spatial resolution analyses of biogeochemical cycling are desirable from several perspectives and may be particularly important in the

  2. Alternative security

    SciTech Connect

    Weston, B.H. )

    1990-01-01

    This book contains the following chapters: The Military and Alternative Security: New Missions for Stable Conventional Security; Technology and Alternative Security: A Cherished Myth Expires; Law and Alternative Security: Toward a Just World Peace; Politics and Alternative Security: Toward a More Democratic, Therefore More Peaceful, World; Economics and Alternative Security: Toward a Peacekeeping International Economy; Psychology and Alternative Security: Needs, Perceptions, and Misperceptions; Religion and Alternative Security: A Prophetic Vision; and Toward Post-Nuclear Global Security: An Overview.

  3. Northern Power Systems WindPACT Drive Train Alternative Design Study Report; Period of Performance: April 12, 2001 to January 31, 2005

    SciTech Connect

    Bywaters, G.; John, V.; Lynch, J.; Mattila, P.; Norton, G.; Stowell, J.; Salata, M.; Labath, O.; Chertok, A.; Hablanian, D.

    2004-10-01

    The National Renewable Energy Laboratory (NREL) Wind Partnerships for Advanced Component Technologies (WindPACT) project seeks to advance wind turbine technology by exploring innovative concepts in drivetrain design. A team led by Northern Power Systems (Northern) of Waitsfield, Vermont, was chosen to perform this work. Conducted under subcontract YCX-1-30209-02, project objectives are to identify, design, and test a megawatt (MW)-scale drivetrain with the lowest overall life cycle cost. The project entails three phases: preliminary study of alternative drivetrain designs (Phase I), detailed design development (Phase II), and proof of concept fabrication and test (Phase III). This report summarizes the results of the preliminary design study (Phase I).

  4. International Space Station USOS Crew Quarters On-orbit vs Design Performance Comparison

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.; Borrego, Melissa Ann; Bahr, Juergen F.

    2008-01-01

    The International Space Station (ISS) United States Operational Segment (USOS) received the first two permanent ISS Crew Quarters (CQ) on Utility Logistics Flight Two (ULF2) in November 2008. Up to four CQs can be installed into the Node 2 element to increase the ISS crewmember size to six. The CQs provide private crewmember space with enhanced acoustic noise mitigation, integrated radiation reduction material, communication equipment, redundant electrical systems, and redundant caution and warning systems. The racksized CQ is a system with multiple crewmember restraints, adjustable lighting, controllable ventilation, and interfaces that allow each crewmember to personalize their CQ workspace. The deployment and initial operational checkout during integration of the ISS CQ to the Node is described. Additionally, the comparison of on-orbit to original design performance is outlined for the following key operational parameters: interior acoustic performance, air flow rate, temperature rise, and crewmember feedback on provisioning and restraint layout.

  5. Target selection and comparison of mission design for space debris removal by DLR's advanced study group

    NASA Astrophysics Data System (ADS)

    van der Pas, Niels; Lousada, Joao; Terhes, Claudia; Bernabeu, Marc; Bauer, Waldemar

    2014-09-01

    Space debris is a growing problem. Models show that the Kessler syndrome, the exponential growth of debris due to collisions, has become unavoidable unless an active debris removal program is initiated. The debris population in LEO with inclination between 60° and 95° is considered as the most critical zone. In order to stabilize the debris population in orbit, especially in LEO, 5 to 10 objects will need to be removed every year. The unique circumstances of such a mission could require that several objects are removed with a single launch. This will require a mission to rendezvous with a multitude of objects orbiting on different altitudes, inclinations and planes. Removal models have assumed that the top priority targets will be removed first. However this will lead to a suboptimal mission design and increase the ΔV-budget. Since there is a multitude of targets to choose from, the targets can be selected for an optimal mission design. In order to select a group of targets for a removal mission the orbital parameters and political constraints should also be taken into account. Within this paper a number of the target selection criteria are presented. The possible mission targets and their order of retrieval is dependent on the mission architecture. A comparison between several global mission architectures is given. Under consideration are 3 global missions of which a number of parameters are varied. The first mission launches multiple separate deorbit kits. The second launches a mother craft with deorbit kits. The third launches an orbital tug which pulls the debris in a lower orbit, after which a deorbit kit performs the final deorbit burn. A RoM mass and cost comparison is presented. The research described in this paper has been conducted as part of an active debris removal study by the Advanced Study Group (ASG). The ASG is an interdisciplinary student group working at the DLR, analyzing existing technologies and developing new ideas into preliminary

  6. Ponce de Leon Inlet, FL: An Integrated Hydrodynamic and Morphologic Assessment of Design Alternatives using the U.S. Army Corps of Engineers’ Coastal Modeling System

    DTIC Science & Technology

    2009-07-01

    since stabilization of the inlet in 1972 by a dual-jetty weir system and eventual closure of the weir in 1984. This study utilized the Coastal Modeling...and shoaling of the south spit. Fifteen alternate designs were developed based on an extension of the south jetty and included reopening the weir , an...hazardous navigation conditions since stabilization of the inlet in 1972 by a dual-jetty weir system, and eventual closure of the weir in 1984. In 1993

  7. ECONOMIC AND ENVIRONMENTAL IMPLICATIONS OF ALTERNATIVE LANDSCAPE DESIGNS IN THE WALNUT CREEK WATERSHED OF IOWA. (R825335)

    EPA Science Inventory

    This paper evaluates the economic and environmental impacts of three alternative landscape scenarios created by a team of landscape architects, following input from an interdisciplinary team of researchers. In the first scenario, the main objective was to increase production a...

  8. Comparison of classical methods for blade design and the influence of tip correction on rotor performance

    NASA Astrophysics Data System (ADS)

    Sørensen, J. N.; Okulov, V. L.; Mikkelsen, R. F.; Naumov, I. V.; Litvinov, I. V.

    2016-09-01

    The classical blade-element/momentum (BE/M) method, which is used together with different types of corrections (e.g. the Prandtl or Glauert tip correction), is today the most basic tool in the design of wind turbine rotors. However, there are other classical techniques based on a combination of the blade-element approach and lifting-line (BE/LL) methods, which are less used by the wind turbine community. The BE/LL method involves different interpretations for rotors with finite or infinite numbers of blades and different assumptions with respect to the optimum circulation distribution. In the present study we compare the performance and the resulting design of the BE/M method by Glauert [1] and the BE/LL method by Betz [2] for finite as well as for infinite-bladed rotors, corrected for finiteness through the tip correction. In the first part of the paper, expressions are given for the optimum design, including blade plan forms and local pitch distributions. The comparison shows that the resulting geometry of the rotor depends on the method used, but that the differences mainly exist in the inner part of the blade and at relatively small tip speed ratios (TSR<5). An important conclusion is that an infinite-bladed approach combined with a tip correction results in a geometry which is nearly identical to a geometry generated from a finite-bladed approach. Next, the results from an experimental investigation on the influence on rotor performances of the tip correction on two different rotors are presented. Employing BE/M without the tip correction (“Glauert rotor”) and BE/LL with the Goldstein's circulation (“Betz rotor”) two different 3-bladed rotors were designed and manufactured. The two rotors were investigated experimentally in a water flume to compare their performance at different tip speed ratios and pitch angles. As a result of the comparison it was found that the Betz rotor had the best performance.

  9. Clean air program: Design guidelines for bus transit systems using hydrogen as an alternative fuel. Final report, September 1997--May 1998

    SciTech Connect

    Raj, P.K.; Hathaway, W.T.; Kangas, R.A.

    1998-10-01

    Alternative fuels such as Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG), Liquified Petroleum Gas (LPG), and alcohol fuels (methanol and ethanol) are already being used in commercial vehicles and transit buses in revenue service. Hydrogen, which has better air quality characteristics as a vehicle fuel, is being used in research demonstration projects in fuel cell powered buses, as well as in internal combustion engines in automobiles and small trucks. At present, there are no facility guidelines to assist transit agencies (and others) contemplating the use of hydrogen as an alternative fuel. This document addresses the various issues involved. Hydrogen fuel properties, potential hazards, fuel requirements for specified levels of bus service, applicable codes and standards, ventilation, and electrical classification are indicated in this document. These guidelines also present various facility and bus design issues that need to be considered by a transit agency to ensure safe operations when using hydrogen as an alternative fuel. Fueling facility, garaging facility, maintenance facility requirements and safety practices are discussed. Critical fuel-related safety issues in the design of the related system on the bus are also identified. A system safety assessment and hazard resolution process is also presented. This approach may be used to select design strategies which are economical, yet ensure a specified level of safety.

  10. Electric field depth–focality tradeoff in transcranial magnetic stimulation: simulation comparison of 50 coil designs

    PubMed Central

    Deng, Zhi-De; Lisanby, Sarah H.; Peterchev, Angel V.

    2012-01-01

    Background Various transcranial magnetic stimulation (TMS) coil designs are available or have been proposed. However, key coil characteristics such as electric field focality and attenuation in depth have not been adequately compared. Knowledge of the coil focality and depth characteristics can help TMS researchers and clinicians with coil selection and interpretation of TMS studies. Objective To quantify the electric field focality and depth of penetration of various TMS coils. Methods The electric field distributions induced by 50 TMS coils were simulated in a spherical human head model using the finite element method. For each coil design, we quantified the electric field penetration by the half-value depth, d1/2, and focality by the tangential spread, S1/2, defined as the half-value volume (V1/2) divided by the half-value depth, S1/2 = V1/2/d1/2. Results The 50 TMS coils exhibit a wide range of electric field focality and depth, but all followed a depth–focality tradeoff: coils with larger half-value depth cannot be as focal as more superficial coils. The ranges of achievable d1/2 are similar between coils producing circular and figure-8 electric field patterns, ranging 1.0–3.5 cm and 0.9–3.4 cm, respectively. However, figure-8 field coils are more focal, having S1/2 as low as 5 cm2 compared to 34 cm2 for circular field coils. Conclusions For any coil design, the ability to directly stimulate deeper brain structures is obtained at the expense of inducing wider electrical field spread. Novel coil designs should be benchmarked against comparison coils with consistent metrics such as d1/2 and S1/2. PMID:22483681

  11. Economic comparison of CAES designs employing hardrock, salt and aquifer storage reservoirs

    NASA Astrophysics Data System (ADS)

    Reilly, R. W.; Schainker, R. B.

    The economic performance of three compressed air energy storage (CAES) designs is briefly examined. Each design was developed under different assumptions and constraints, and each employed a different ytpe of air storage facility: a hardrock-mined cavity, a solution mined salt deposit, and an aquifer. The results indicate that aquifer and salt storage facilities cost roughly 60 to 70% of the equivalent hardrock mined cavern. In this comparison the aquifer storage facility was somewhat less expensive than the salt cavity, but this difference could be reversed with different salt and/or aquifer characteristics. For instance, if the aquifer was less permeable, then more wells would be required for the same power level, and total storage cost would be higher. The major difference between the plant cost estimates lies not in the cost of storage facilities, but rather in vendor estimates of turbomachinery cost. And, since turbomachinery contributes about half of total plant cost, this difference could be critical to the decision to build a CAES plant.

  12. Economic comparison of CAES designs employing hardrock, salt, and aquifer storage reservoirs

    SciTech Connect

    Reilly, R.W.; Schainker, R.B.

    1981-01-01

    The economic performance of three CAES designs is briefly examined. Each design was developed by a different A and E under different assumptions and constraints, and each employed a different type of air storage facility: a hardrock-mined cavity, a solution-mined salt deposit, and an aquifer. The results indicate that aquifer and salt storage facilities cost roughly 60 to 70% of the equivalent hardrock-mined cavern. In this comparison the aquifer storage facility was somewhat less expensive than the salt cavity, but this difference could be reversed with different salt and/or aquifer characteristics. For instance, if the aquifer had been less permeable, then more wells would have been required for the same power level, and total storage cost would have been higher. The major difference between the plant cost estimates lies not in the cost of storage facilities, but rather in vendor estimates of turbomachinery cost. And, since turbomachinery contributes about half of total plant cost, this difference could be critical to the decision to build a CAES plant.

  13. Comparison of differential pulse and alternating current polarography in the soft-modelling study of the complexation of Cd(II) by the fragment Cys-Gly and by the phytochelatin (gamma-Glu-Cys)2Gly.

    PubMed

    Garrigosa, Anna Maria; Ariño, Cristina; Díaz-Cruz, José Manuel; Esteban, Miquel

    2008-07-01

    A comparison of a differential pulse polarographic with a phase sensitive alternating current polarographic study of the Cd-Cys-Gly and Cd-PC(2) systems [PC(2) being a phytochelatin of general structure (gamma-Glu-Cys)(n)-Gly, with n = 2] has been performed. The chemometric multivariate curve resolution method with alternating least squares was applied in the experimental data analysis. The results obtained by both polarographic techniques have made it possible to find out the formation sequences of the complexes and their final stoichiometries. The alternating current polarograms compared with the differential pulse ones show some differences (a new signal and an important shift of peak potentials), which anyway are consistent with some of the conclusions obtained by differential pulse polarography. This fact implies that although the alternating current polarography results need some corrections before data treatment, they provide extra information that complements the conclusions achieved by differential pulse polarography.

  14. A Design Comparison of Atmospheric Flight Vehicles for the Exploration of Titan

    NASA Technical Reports Server (NTRS)

    Gasbarre, Joseph F.; Wright, Henry S.; Lewis, Mark J.

    2005-01-01

    Titan, the largest moon of Saturn, is one of the most scientifically interesting locations in the Solar System. With a very cold atmosphere that is five times as dense as Earth s, and one and a half times the surface pressure, it also provides one of the most aeronautically fascinating environments known to humankind. While this may seem the ideal place to attempt atmospheric flight, many challenges await any vehicle attempting to navigate through it. In addition to these physical challenges, any scientific exploration mission to Titan will most likely have several operational constraints. One difficult constraint is the desire for a global survey of the planet and thus, a long duration flight within the atmosphere. Since many of the scientific measurements that would be unique to a vehicle flying through the atmosphere (as opposed to an orbiting spacecraft) desire near-surface positioning of their associated instruments, the vehicle must also be able to fly within the first scale height of the atmosphere. Another difficult constraint is that interaction with the surface, whether by landing or dropped probe, is also highly desirable from a scientific perspective. Two common atmospheric flight platforms that might be used for this mission are the airplane and airship. Under the assumption of a mission architecture that would involve an orbiting relay spacecraft delivered via aerocapture and an atmospheric flight vehicle delivered via direct entry, designs were developed for both platforms that are unique to Titan. Consequently, after a viable design was achieved for each platform, their advantages and disadvantages were compared. This comparison included such factors as deployment risk, surface interaction capability, mass, and design heritage. When considering all factors, the preferred candidate platform for a global survey of Titan is an airship.

  15. Model comparison in ANOVA.

    PubMed

    Rouder, Jeffrey N; Engelhardt, Christopher R; McCabe, Simon; Morey, Richard D

    2016-12-01

    Analysis of variance (ANOVA), the workhorse analysis of experimental designs, consists of F-tests of main effects and interactions. Yet, testing, including traditional ANOVA, has been recently critiqued on a number of theoretical and practical grounds. In light of these critiques, model comparison and model selection serve as an attractive alternative. Model comparison differs from testing in that one can support a null or nested model vis-a-vis a more general alternative by penalizing more flexible models. We argue this ability to support more simple models allows for more nuanced theoretical conclusions than provided by traditional ANOVA F-tests. We provide a model comparison strategy and show how ANOVA models may be reparameterized to better address substantive questions in data analysis.

  16. Design, cost and performance comparisons of several solar thermal systems for process heat. Volume 4: Energy centralization

    NASA Astrophysics Data System (ADS)

    Iannucci, J. J.; Hostetler, L. D.

    1981-03-01

    A large matrix of self-consistent piping systems for dishes, troughs, and central receivers are designed, costed, and analyzed for performance. The solar installations collect thermal energy at temperatures ranging from 2000 to 20000 F, at sizes of 3, 30, 300, and 1500 megawatts thermal. First order design differences and similaies are highlighted, with emphasis on the comparison of dish and trough piping. Dishes are found to inefficient piping networks due to the large length of piping required.

  17. Exploration of a Capability-Focused Aerospace System of Systems Architecture Alternative with Bilayer Design Space, Based on RST-SOM Algorithmic Methods

    PubMed Central

    Li, Zhifei; Qin, Dongliang

    2014-01-01

    In defense related programs, the use of capability-based analysis, design, and acquisition has been significant. In order to confront one of the most challenging features of a huge design space in capability based analysis (CBA), a literature review of design space exploration was first examined. Then, in the process of an aerospace system of systems design space exploration, a bilayer mapping method was put forward, based on the existing experimental and operating data. Finally, the feasibility of the foregoing approach was demonstrated with an illustrative example. With the data mining RST (rough sets theory) and SOM (self-organized mapping) techniques, the alternative to the aerospace system of systems architecture was mapping from P-space (performance space) to C-space (configuration space), and then from C-space to D-space (design space), respectively. Ultimately, the performance space was mapped to the design space, which completed the exploration and preliminary reduction of the entire design space. This method provides a computational analysis and implementation scheme for large-scale simulation. PMID:24790572

  18. Exploration of a capability-focused aerospace system of systems architecture alternative with bilayer design space, based on RST-SOM algorithmic methods.

    PubMed

    Li, Zhifei; Qin, Dongliang; Yang, Feng

    2014-01-01

    In defense related programs, the use of capability-based analysis, design, and acquisition has been significant. In order to confront one of the most challenging features of a huge design space in capability based analysis (CBA), a literature review of design space exploration was first examined. Then, in the process of an aerospace system of systems design space exploration, a bilayer mapping method was put forward, based on the existing experimental and operating data. Finally, the feasibility of the foregoing approach was demonstrated with an illustrative example. With the data mining RST (rough sets theory) and SOM (self-organized mapping) techniques, the alternative to the aerospace system of systems architecture was mapping from P-space (performance space) to C-space (configuration space), and then from C-space to D-space (design space), respectively. Ultimately, the performance space was mapped to the design space, which completed the exploration and preliminary reduction of the entire design space. This method provides a computational analysis and implementation scheme for large-scale simulation.

  19. M-X Environmental Technical Report. Environmental Characteristics of Alternative Designated Deployment Areas, Aquatic Habitats and Biota.

    DTIC Science & Technology

    1980-12-22

    AD-A095 789 HNNINGSON DURHAM AND RICHARDSON SANTA BARBARA CA F/6 16/1 M! X ENVIRONMENT L TECHN AL REPORT. ENVIRONMENTAL CHARACTERISTD-ETCIU: DEC 80...F04704-78-C-0029 UNCLASSIFIED MXETR-16 AFSCTR81I1SIJ ~EE~~E LL fllllllllfffff AFSC-TR-81-31 ’-" o LEVEL - two M- X ENVIRONMENTAL TECHNICAL REPORT DTIC...and Subtitle) 5. TYPE OF REPORT a PERIOD COVERED M- X Environmental Technical Report-Enviror- Final Report mental Characteristics of Alternative

  20. Comparison of the Performances of APEX and SWAT Models in Simulating the Impacts of Alternate Grazing Management Practices on Hydrology and Water Quality

    NASA Astrophysics Data System (ADS)

    Ale, S.; Park, J.; Teague, W. R.

    2015-12-01

    Comparison of hydrologic and water quality models is useful to contrast merits and demerits of each model and enable user to select an appropriate model for an intended purpose. In this study, the performances of APEX and SWAT models in evaluating the effects of alternate grazing management practices on water balances, and sediment and nutrient losses in a rangeland-dominated Clear Creek watershed (763 km2) located in north central Texas, were compared. Three grazing management practices including the light continuous (LC), heavy continuous (HC) and planned multi-paddock (MP) grazing were simulated. Measured data on vegetation, soil physical and hydrological properties, and grazing management at four study ranches within the study watershed (two under planned MP and one each under LC and HC grazing management), was used to parameterize both APEX and SWAT models. Both models were calibrated and validated using the measured streamflow (1980-2013), sediment (1994-2009), total nitrogen (TN) and total phosphorous (TP) (1986-2009) load data at the watershed outlet. Preliminary results indicated that in general, both models performed equally well in terms of hydrology, but the APEX model performed better in predicting sediment and nutrient losses. At the watershed level, shifting grazing management from the baseline HC scenario to planned MP grazing decreased annual streamflow by 29% and 27%, and TN load by 47% and 35%, according to the APEX and SWAT models, respectively. The simulated reduction in sediment load with the change in grazing management from the baseline HC to the planned MP grazing was about the same (40%) according to both models.

  1. Conceptual design and comparison of aramid and polyester taut leg spread moorings for deepwater applications

    SciTech Connect

    Wilde, B.; Kelly, P.; Librino, F.; Whitehill, A.S.

    1996-12-31

    As the offshore industry looks beyond water depths of 3,000 ft for future oil and gas production, the industry standard steel catenary spread mooring (CSM) system used on all floating production systems installed to date becomes increasingly inefficient and costly. An alternative to the CSM is the Taut Leg Spread Mooring (TLSM) system with its characteristic short scope legs and vertically loaded anchors. In water depths greater than 3,000 ft, it has been shown that TLSMs comprised of synthetic mooring lines have performance advantages over systems utilizing steel wire rope and demonstrated potential for significant cost reductions. Early studies investigated the use of aramid fiber rope due to its high strength, lower in-water weight and lower axial stiffness as compared to ropes made from steel. Later studies indicated that the material properties of polyester fiber, primarily its lower Young`s modulus, made polyester mooring lines more suitable for use in TLSMs. As the TLSM knowledge base expanded, aramid rope construction evolved. Earlier efforts to match the characteristics of steel wire rope have given way to new generation soft aramid constructions. This paper compares the mooring performance and total installed cost of a soft aramid TLSM to a typical polyester configuration. Both systems were designed for use in the Gulf of Mexico (GOM) with an FPS based on the Aker P45.

  2. Design and Development of a Technology Enhanced Hybrid Instruction Based on MOLTA Model: Its Effectiveness in Comparison to Traditional Instruction

    ERIC Educational Resources Information Center

    Delialioglu, Omer; Yildirim, Zahide

    2008-01-01

    Using the model for learning and teaching activities (MOLTA), a new technology enhanced hybrid instruction was designed, developed and implemented. The effectiveness of the hybrid instruction in regard to students' achievement, knowledge retention, attitudes towards the subject, and course satisfaction was evaluated in comparison to traditional…

  3. Helical Tomotherapy for Whole-Brain Irradiation With Integrated Boost to Multiple Brain Metastases: Evaluation of Dose Distribution Characteristics and Comparison With Alternative Techniques

    SciTech Connect

    Levegrün, Sabine; Pöttgen, Christoph; Wittig, Andrea; Lübcke, Wolfgang; Abu Jawad, Jehad; Stuschke, Martin

    2013-07-15

    Purpose: To quantitatively evaluate dose distribution characteristics achieved with helical tomotherapy (HT) for whole-brain irradiation (WBRT) with integrated boost (IB) to multiple brain metastases in comparison with alternative techniques. Methods and Materials: Dose distributions for 23 patients with 81 metastases treated with WBRT (30 Gy/10 fractions) and IB (50 Gy) were analyzed. The median number of metastases per patient (N{sub mets}) was 3 (range, 2-8). Mean values of the composite planning target volume of all metastases per patient (PTV{sub mets}) and of the individual metastasis planning target volume (PTV{sub ind} {sub met}) were 8.7 ± 8.9 cm{sup 3} (range, 1.3-35.5 cm{sup 3}) and 2.5 ± 4.5 cm{sup 3} (range, 0.19-24.7 cm{sup 3}), respectively. Dose distributions in PTV{sub mets} and PTV{sub ind} {sub met} were evaluated with respect to dose conformity (conformation number [CN], RTOG conformity index [PITV]), target coverage (TC), and homogeneity (homogeneity index [HI], ratio of maximum dose to prescription dose [MDPD]). The dependence of dose conformity on target size and N{sub mets} was investigated. The dose distribution characteristics were benchmarked against alternative irradiation techniques identified in a systematic literature review. Results: Mean ± standard deviation of dose distribution characteristics derived for PTV{sub mets} amounted to CN = 0.790 ± 0.101, PITV = 1.161 ± 0.154, TC = 0.95 ± 0.01, HI = 0.142 ± 0.022, and MDPD = 1.147 ± 0.029, respectively, demonstrating high dose conformity with acceptable homogeneity. Corresponding numbers for PTV{sub ind} {sub met} were CN = 0.708 ± 0.128, PITV = 1.174 ± 0.237, TC = 0.90 ± 0.10, HI = 0.140 ± 0.027, and MDPD = 1.129 ± 0.030, respectively. The target size had a statistically significant influence on dose conformity to PTV{sub mets} (CN = 0.737 for PTV{sub mets} ≤4.32 cm{sup 3} vs CN = 0.848 for PTV{sub mets} >4.32 cm{sup 3}, P=.006), in contrast to N{sub mets}. The achieved

  4. Simulated performance of CIEE's 'Alternatives to Compressive Cooling' prototype house under design conditions in various California climates

    SciTech Connect

    Huang, Yu Joe

    1999-12-01

    To support the design development of a compressorless house that does not rely on mechanical air-conditioning, the author carried out detailed computer analysis of a prototypical house design to determine the indoor thermal conditions during peak cooling periods for over 170 California locations. The peak cooling periods are five-day sequences at 2{percent} frequency determined through statistical analysis of long-term historical weather data. The DOE-2 program was used to simulate the indoor temperatures of the house under four operating options: windows closed, with mechanical ventilation, evaporatively-cooled mechanical ventilation, or a conventional 1 1/2-ton air conditioner. The study found that with a 1500 CFM mechanical ventilation system, the house design would maintain comfort under peak conditions in the San Francisco Bay Area out to Walnut Creek, but not beyond. In southern California, the same system and house design would maintain adequate comfort only along the coast. With the evaporatively-cooled ventilation system, the applicability of the house design can be extended to Fairfield and Livermore in northern California, but in southern California a larger 3000 CFM system would be needed to maintain comfort conditions over half of the greater Los Angeles area, the southern half of the Inland Empire, and most of San Diego county. With the 1 1/2-ton air conditioner, the proposed house design would perform satisfactorily through most of the state, except in the upper areas of the Central Valley and the hot desert areas in southern California. In terms of energy savings, the simulations showed that the prototypical house design would save from 0.20 to 0.43 in northern California, 0.20 to 0.53 in southern California, and 0.16 to 0.35 in the Central Valley, the energy used by the same house design built to Title-24 requirements.

  5. Alternation of Generations and Experimental Design: A Guided-Inquiry Lab Exploring the Nature of the her1 Developmental Mutant of Ceratopteris richardii (C-Fern)

    PubMed Central

    Knisely, Karin I.

    2008-01-01

    Inquiry-based labs have been shown to greatly increase student participation and learning within the biological sciences. One challenge is to develop effective lab exercises within the constraints of large introductory labs. We have designed a lab for first-year biology majors to address two primary goals: to provide effective learning of the unique aspects of the plant life cycle and to gain a practical knowledge of experimental design. An additional goal was to engage students regardless of their biology background. In our experience, plant biology, and the plant life cycle in particular, present a pedagogical challenge because of negative student attitudes and lack of experience with this topic. This lab uses the fern Ceratopteris richardii (C-Fern), a model system for teaching and research that is particularly useful for illustrating alternation of generations. This lab does not simply present the stages of the life cycle; it also uses knowledge of alternation of generations as a starting point for characterizing the her1 mutation that affects gametophyte sexual development. Students develop hypotheses, arrive at an appropriate experimental design, and carry out a guided inquiry on the mechanism underlying the her1 mutation. Quantitative assessment of student learning and attitudes demonstrate that this lab achieves the desired goals. PMID:18316811

  6. Comparison of simulated quenching algorithms for design of diffractive optical elements.

    PubMed

    Liu, J S; Caley, A J; Waddie, A J; Taghizadeh, M R

    2008-02-20

    We compare the performance of very fast simulated quenching; generalized simulated quenching, which unifies classical Boltzmann simulated quenching and Cauchy fast simulated quenching; and variable step size simulated quenching. The comparison is carried out by applying these algorithms to the design of diffractive optical elements for beam shaping of monochromatic, spatially incoherent light to a tightly focused image spot, whose central lobe should be smaller than the geometrical-optics limit. For generalized simulated quenching we choose values of visiting and acceptance shape parameters recommended by other investigators and use both a one-dimensional and a multidimensional Tsallis random number generator. We find that, under our test conditions, variable step size simulated quenching, which generates each parameter's new states based on the acceptance ratio instead of a certain theoretical probability distribution, produces the best results. Finally, we demonstrate experimentally a tightly focused image spot, with a central lobe 0.22-0.68 times the geometrical-optics limit and a relative sidelobe intensity 55%-60% that of the central maximum intensity.

  7. Developing an efficient modelling and data presentation strategy for ATDEM system comparison and survey design

    NASA Astrophysics Data System (ADS)

    Combrinck, Magdel

    2015-10-01

    Forward modelling of airborne time-domain electromagnetic (ATDEM) responses is frequently used to compare systems and design surveys for optimum detection of expected mineral exploration targets. It is a challenging exercise to display and analyse the forward modelled responses due to the large amount of data generated for three dimensional models as well as the system dependent nature of the data. I propose simplifying the display of ATDEM responses through using the dimensionless quantity of signal-to-noise ratios (signal:noise) instead of respective system units. I also introduce the concept of a three-dimensional signal:noise nomo-volume as an efficient tool to visually present and analyse large amounts of data. The signal:noise nomo-volume is a logical extension of the two-dimensional conductance nomogram. It contains the signal:noise values of all system time channels and components for various target depths and conductances integrated into a single interactive three-dimensional image. Responses are calculated over a complete survey grid and therefore include effects of system and target geometries. The user can interactively select signal:noise cut-off values on the nomo-volume and is able to perform visual comparisons between various system and target responses. The process is easy to apply and geophysicists with access to forward modelling airborne electromagnetic (AEM) and three-dimensional imaging software already possess the tools required to produce and analyse signal:noise nomo-volumes.

  8. Is the linear modeling technique good enough for optimal form design? A comparison of quantitative analysis models.

    PubMed

    Lin, Yang-Cheng; Yeh, Chung-Hsing; Wang, Chen-Cheng; Wei, Chun-Chun

    2012-01-01

    How to design highly reputable and hot-selling products is an essential issue in product design. Whether consumers choose a product depends largely on their perception of the product image. A consumer-oriented design approach presented in this paper helps product designers incorporate consumers' perceptions of product forms in the design process. The consumer-oriented design approach uses quantification theory type I, grey prediction (the linear modeling technique), and neural networks (the nonlinear modeling technique) to determine the optimal form combination of product design for matching a given product image. An experimental study based on the concept of Kansei Engineering is conducted to collect numerical data for examining the relationship between consumers' perception of product image and product form elements of personal digital assistants (PDAs). The result of performance comparison shows that the QTTI model is good enough to help product designers determine the optimal form combination of product design. Although the PDA form design is used as a case study, the approach is applicable to other consumer products with various design elements and product images. The approach provides an effective mechanism for facilitating the consumer-oriented product design process.

  9. Is the Linear Modeling Technique Good Enough for Optimal Form Design? A Comparison of Quantitative Analysis Models

    PubMed Central

    Lin, Yang-Cheng; Yeh, Chung-Hsing; Wang, Chen-Cheng; Wei, Chun-Chun

    2012-01-01

    How to design highly reputable and hot-selling products is an essential issue in product design. Whether consumers choose a product depends largely on their perception of the product image. A consumer-oriented design approach presented in this paper helps product designers incorporate consumers' perceptions of product forms in the design process. The consumer-oriented design approach uses quantification theory type I, grey prediction (the linear modeling technique), and neural networks (the nonlinear modeling technique) to determine the optimal form combination of product design for matching a given product image. An experimental study based on the concept of Kansei Engineering is conducted to collect numerical data for examining the relationship between consumers' perception of product image and product form elements of personal digital assistants (PDAs). The result of performance comparison shows that the QTTI model is good enough to help product designers determine the optimal form combination of product design. Although the PDA form design is used as a case study, the approach is applicable to other consumer products with various design elements and product images. The approach provides an effective mechanism for facilitating the consumer-oriented product design process. PMID:23258961

  10. Design of a high-gain laser diode-array pumped Nd:YAG alternating precessive slab amplifier (APS amplifier)

    NASA Technical Reports Server (NTRS)

    Coyle, D. B.

    1991-01-01

    In the design of space-qualifiable laser systems for ranging and altimetry, such as NASA's Geodynamic Laser Ranging System (GLRS), the transmitter must be kept small, powerful yet efficient, and must consist of as few components as possible. A novel preamplifier design is examined which requires no external beam steering optics, yielding a compact component with simple alignment procedures. The gains achieved are comparable to multipass zigzag amplifiers using two or more sets of external optics for extra passes through the amplifying medium.

  11. Alternative Fuels

    EPA Pesticide Factsheets

    Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

  12. Alternative Therapies

    MedlinePlus

    ... Late Effects of Poliomyelitis for Physicians and Survivors © Alternative Therapies Alternative therapies, also called complementary, can support ... of motion, pain, and fatigue are often reported. Energy work includes acupuncture and acupressure, traditional Chinese medicine ...

  13. Solving Real World Problems with Alternate Reality Gaming: Student Experiences in the Global Village Playground Capstone Course Design

    ERIC Educational Resources Information Center

    Dondlinger, Mary Jo; McLeod, Julie K.

    2015-01-01

    The Global Village Playground (GVP) was a capstone learning experience designed to address institutional assessment needs while providing an integrated and authentic learning experience for students aimed at fostering complex problem solving, as well as critical and creative thinking. In the GVP, students work on simulated and real-world problems…

  14. Use of nonlinear design optimization techniques in the comparison of battery discharger topologies for the space platform

    NASA Technical Reports Server (NTRS)

    Sable, Dan M.; Cho, Bo H.; Lee, Fred C.

    1990-01-01

    A detailed comparison of a boost converter, a voltage-fed, autotransformer converter, and a multimodule boost converter, designed specifically for the space platform battery discharger, is performed. Computer-based nonlinear optimization techniques are used to facilitate an objective comparison. The multimodule boost converter is shown to be the optimum topology at all efficiencies. The margin is greatest at 97 percent efficiency. The multimodule, multiphase boost converter combines the advantages of high efficiency, light weight, and ample margin on the component stresses, thus ensuring high reliability.

  15. A large volume striped bass egg incubation chamber: design and comparison with a traditional method

    USGS Publications Warehouse

    Harper, C.J.

    2009-01-01

    I conducted a comparative study of a new jar design (experimental chamber) with a standard egg incubation vessel (McDonald jar). Experimental chambers measured 0.4 m in diameter by 1.3 m in height and had a volume of 200 L. McDonald hatching jars measured 16 cm in diameter by 45 cm in height and had a volume of 6 L. Post-hatch survival was estimated at 48, 96 and 144 h. Stocking rates resulted in an average egg density of 21.9 eggs ml-1 (range = 21.6 – 22.1) for McDonald jars and 10.9 eggs ml-1 (range = 7.0 – 16.8) for experimental chambers. I was unable to detect an effect of container type on survival to 48, 96 or 144 h. At 144 h striped bass fry survival averaged 37.3% for McDonald jars and 34.2% for experimental chambers. Survival among replicates was significantly different. Survival of striped bass significantly decreased between 96 and 144 h. Mean survival among replicates ranged from 12.4 to 57.3%. I was unable to detect an effect of initial stocking density on survival. Experimental jars allow for incubation of a larger number of eggs in a much smaller space. As hatchery production is often limited by space or water supply, experimental chambers offer an alternative to extending spawning activities, thereby reducing manpower and cost. However, the increase in the number of eggs per rearing container does increase the risk associated with catastrophic loss of a production unit. I conclude the experimental chamber is suitable for striped bass egg incubation.

  16. Comparison of 45-degree Kelman and 45-degree balanced phaco tip designs in torsional microcoaxial phacoemulsification

    PubMed Central

    Demircan, Süleyman; Ataş, Mustafa; Göktaş, Emre; Başkan, Burhan

    2015-01-01

    AIM To compare the intraoperative performance and postoperative outcome after microcoaxial torsional phacoemulsification using either a Kelman or balanced phaco tip. METHODS Cataracts were treated using 2.2 mm microcoaxial torsional phacoemulsification using either a 45-degree mini-flared Kelman® or a 45-degree Intrepid® Balanced phaco tip. Intraoperative measurements included total ultrasound (US) time, cumulative dissipated energy (CDE), torsional US time, and balanced salt solution (BSS) use. The central endothelial cell density (ECD) and central corneal thickness (CCT) were evaluated preoperatively and postoperatively 1, 7, and 30d after surgery using noncontact specular microscopy. RESULTS The 116 enrolled eyes (116 patients) were divided equally between the Kelman and balanced tip groups. Intraoperative measurements showed significantly less total US time, torsional US time, CDE, and BSS use in the balanced group than in Kelman group (P<0.05). The total US time, torsional US time, CDE, and BSS use were 17.45±14.53s, 16.63±13.97s, 6.38±5.26, and 48.21±17.21 mL in the Kelman group and 11.39 ± 9.60s, 10.90 ± 9.25s, 4.04 ± 3.42, and 41.36 ± 12.70 mL in the balanced group, respectively. CONCLUSION Torsional phacoemulsification performed with a balanced tip provided more effective lens removal with less total US time, torsional time, CDE, and BSS use, as well as similar changes in ECD with a Kelman tip in all cataract grades. This special designed phaco tip for torsional phacoemulsification provides an alternative phaco tip for many surgeons' preference with straight phaco tip. PMID:26682167

  17. Applying visual attention theory to transportation safety research and design: evaluation of alternative automobile rear lighting systems.

    PubMed

    McIntyre, Scott E; Gugerty, Leo

    2014-06-01

    This field experiment takes a novel approach in applying methodologies and theories of visual search to the subject of conspicuity in automobile rear lighting. Traditional rear lighting research has not used the visual search paradigm in experimental design. It is our claim that the visual search design uniquely uncovers visual attention processes operating when drivers search the visual field that current designs fail to capture. This experiment is a validation and extension of previous simulator research on this same topic and demonstrates that detection of red automobile brake lamps will be improved if tail lamps are another color (in this test, amber) rather than the currently mandated red. Results indicate that when drivers miss brake lamp onset in low ambient light, RT and error are reduced in detecting the presence and absence of red brake lamps with multiple lead vehicles when tail lamps are not red compared to current rear lighting which mandates red tail lamps. This performance improvement is attributed to efficient visual processing that automatically segregates tail (amber) and brake (red) lamp colors into distractors and targets respectively.

  18. An alternative strategy for targeted gene replacement in plants using a dual-sgRNA/Cas9 design.

    PubMed

    Zhao, Yongping; Zhang, Congsheng; Liu, Wenwen; Gao, Wei; Liu, Changlin; Song, Gaoyuan; Li, Wen-Xue; Mao, Long; Chen, Beijiu; Xu, Yunbi; Li, Xinhai; Xie, Chuanxiao

    2016-04-01

    Precision DNA/gene replacement is a promising genome-editing tool that is highly desirable for molecular engineering and breeding by design. Although the CRISPR/Cas9 system works well as a tool for gene knockout in plants, gene replacement has rarely been reported. Towards this end, we first designed a combinatory dual-sgRNA/Cas9 vector (construct #1) that successfully deleted miRNA gene regions (MIR169a and MIR827a). The deletions were confirmed by PCR and subsequent sequencing, yielding deletion efficiencies of 20% and 24% on MIR169a and MIR827a loci, respectively. We designed a second structure (construct #2) that contains sites homologous to Arabidopsis TERMINAL FLOWER 1 (TFL1) for homology-directed repair (HDR) with regions corresponding to the two sgRNAs on the modified construct #1. The two constructs were co-transformed into Arabidopsis plants to provide both targeted deletion and donor repair for targeted gene replacement by HDR. Four of 500 stably transformed T0 transgenic plants (0.8%) contained replaced fragments. The presence of the expected recombination sites was further confirmed by sequencing. Therefore, we successfully established a gene deletion/replacement system in stably transformed plants that can potentially be utilized to introduce genes of interest for targeted crop improvement.

  19. Investigation, comparison and design of chambers used in centrifugal partition chromatography on the basis of flow pattern and separation experiments.

    PubMed

    Schwienheer, C; Merz, J; Schembecker, G

    2015-04-17

    In centrifugal partition chromatography (CPC) the separation efficiency is mainly influenced by the hydrodynamic of mobile and stationary phase in the chambers. Thus, the hydrodynamic has to be investigated and understood in order to enhance a CPC separation run. Different chamber geometries have been developed in the past and the influence of several phase systems and CPC operating conditions were investigated for these chambers. However, a direct comparison between the different chamber types has not been performed yet. In order to investigate the direct influence of the chamber design on the hydrodynamic, several chamber designs - partially similar in geometry to commercial available designs - are investigated under standardized conditions in the present study. The results show the influence of geometrical aspects of the chamber design on the hydrodynamic and therewith, on the separation efficiency. As a conclusion of the present study, some ideas for an optimal chamber design for laboratory and industrial purpose are proposed.

  20. Large-Scale Assessment Systems: Design Principles Drawn from International Comparisons

    ERIC Educational Resources Information Center

    Black, P.; Wiliam, D.

    2007-01-01

    In recent years, a number of analyses assessments used in different countries have appeared. Analyses emerging from international comparisons such as Trends in International Mathematics and Science Study (TIMSS) and Programme for International Student Assessment (PISA) have focused on what might be termed "cross-sectional" comparisons;…

  1. Alternatives for Jet Engine Control

    NASA Technical Reports Server (NTRS)

    Leake, R. J.; Sain, M. K.

    1976-01-01

    Approaches are developed as alternatives to current design methods which rely heavily on linear quadratic and Riccati equation methods. The main alternatives are discussed in two broad categories, local multivariable frequency domain methods and global nonlinear optimal methods.

  2. Using Behavioral Science to Design a Peer Comparison Intervention for Postabortion Family Planning in Nepal

    PubMed Central

    Spring, Hannah; Datta, Saugato; Sapkota, Sabitri

    2016-01-01

    Despite the provision of free and subsidized family planning services and clients’ demonstrated intentions to delay pregnancies, family planning uptake among women who receive abortion and postabortion services at Sunaulo Parivar Nepal (SPN), one of Nepal’s largest non-governmental sexual and reproductive health (SRH) providers, remains low. Through meetings, interviews, and observations with SPN’s stakeholders, service providers, and clients at its 36 SRH centers, we developed hypotheses about client- and provider-side barriers that may inhibit postabortion family planning (PAFP) uptake. On the provider side, we found that the lack of benchmarks (such as the performance of other facilities) against which providers could compare their own performance and the lack of feedback on the performance were important barriers to PAFP uptake. We designed several variants of three interventions to address these barriers. Through conversations with team members at SPN’s centralized support office and service providers at SPN centers, we prioritized a peer-comparison tool that allows providers at one center to compare their performance with that of other similar centers. We used feedback from the community of providers on the tools’ usability and features to select a variant of the tool that also leverages and reinforces providers’ strong intrinsic motivation to provide quality PAFP services. In this paper, we detail the process of identifying barriers and creating an intervention to overcome those barriers. The intervention’s effectiveness will be tested with a center-level, stepped-wedge randomized control trial in which SPN’s 36 centers will be randomly assigned to receive the intervention at 1-month intervals over a 6-month period. Existing medical record data will be used to monitor family planning uptake. PMID:27446891

  3. Evaluation of simulation alternatives for the brute-force ray-tracing approach used in backlight design

    NASA Astrophysics Data System (ADS)

    Desnijder, Karel; Hanselaer, Peter; Meuret, Youri

    2016-04-01

    A key requirement to obtain a uniform luminance for a side-lit LED backlight is the optimised spatial pattern of structures on the light guide that extract the light. The generation of such a scatter pattern is usually performed by applying an iterative approach. In each iteration, the luminance distribution of the backlight with a particular scatter pattern is analysed. This is typically performed with a brute-force ray-tracing algorithm, although this approach results in a time-consuming optimisation process. In this study, the Adding-Doubling method is explored as an alternative way for evaluating the luminance of a backlight. Due to the similarities between light propagating in a backlight with extraction structures and light scattering in a cloud of light scatterers, the Adding-Doubling method which is used to model the latter could also be used to model the light distribution in a backlight. The backlight problem is translated to a form upon which the Adding-Doubling method is directly applicable. The calculated luminance for a simple uniform extraction pattern with the Adding-Doubling method matches the luminance generated by a commercial raytracer very well. Although successful, no clear computational advantage over ray tracers is realised. However, the dynamics of light propagation in a light guide as used the Adding-Doubling method, also allow to enhance the efficiency of brute-force ray-tracing algorithms. The performance of this enhanced ray-tracing approach for the simulation of backlights is also evaluated against a typical brute-force ray-tracing approach.

  4. Preliminary Structural Design Using Topology Optimization with a Comparison of Results from Gradient and Genetic Algorithm Methods

    NASA Technical Reports Server (NTRS)

    Burt, Adam O.; Tinker, Michael L.

    2014-01-01

    In this paper, genetic algorithm based and gradient-based topology optimization is presented in application to a real hardware design problem. Preliminary design of a planetary lander mockup structure is accomplished using these methods that prove to provide major weight savings by addressing the structural efficiency during the design cycle. This paper presents two alternative formulations of the topology optimization problem. The first is the widely-used gradient-based implementation using commercially available algorithms. The second is formulated using genetic algorithms and internally developed capabilities. These two approaches are applied to a practical design problem for hardware that has been built, tested and proven to be functional. Both formulations converged on similar solutions and therefore were proven to be equally valid implementations of the process. This paper discusses both of these formulations at a high level.

  5. Development and field testing of an alternative latrine design utilizing basic oxygen furnace slag as a treatment media for pathogen removal

    NASA Astrophysics Data System (ADS)

    Stimson, J.; Suhogusoff, A. V.; Blowes, D. W.; Hirata, R. A.; Ptacek, C. J.; Robertson, W. D.; Emelko, M. B.

    2009-05-01

    In densely-populated communities in developing countries, appropriate setback distances for pit latrines often cannot be met. An alternative latrine was designed that incorporates two permeable reactive media to treat pathogens and nitrate from effluent. Basic oxygen furnace (BOF) slag in contact with wastewater effluent elevates pH to levels (> 11) that inactivate pathogens. Saturated woodchip creates reducing conditions that encourage the growth of denitrifying bacteria which remove NO3-. The field application was constructed in Santo Antônio, a peri-urban community located 25 km south of the city of São Paulo, Brazil. A 2-m diameter pit was excavated to a depth of 4 m into the sandy-clay unsaturated zone. A geotextile liner was emplaced to create saturated conditions in the 0.5-m thick woodchip barrier. Above the woodchip barrier, a 1-m thick layer of BOF slag mixed with pea gravel and sand was emplaced. A series of filter layers, grading upward from coarse sand to fine gravel, where placed above the BOF layer, and gravel was also infilled around the outer perimeter of the excavation, to ensure O2 diffusion into the design, the formation of biofilm, and degradation of organic material. A control latrine, constructed with similar hydraulic characteristics and nonreactive materials, was constructed at a locality 100 m away, in the same geological materials. Total coliform, thermotolerant coliform, and E. coli are removed by approximately 4-5 log concentration units in less than one meter of vertical transport through the BOF slag media. In the control latrine, comparable reductions in these pathogenic indicators are observed over three meters of vertical transport. Removal of sulphur-reducing Clostridia, Clostridium perfrigens and somatic coliphage are also achieved in the alternative design, but initial concentrations in effluent are low. Some measurable concentrations of pathogen indicators are measured in lysimeters below the BOF layer, but are associated

  6. Problem Decomposition and Recomposition in Engineering Design: A Comparison of Design Behavior between Professional Engineers, Engineering Seniors, and Engineering Freshmen

    ERIC Educational Resources Information Center

    Song, Ting; Becker, Kurt; Gero, John; DeBerard, Scott; DeBerard, Oenardi; Reeve, Edward

    2016-01-01

    The authors investigated the differences in using problem decomposition and problem recomposition between dyads of engineering experts, engineering seniors, and engineering freshmen. Participants worked in dyads to complete an engineering design challenge within 1 hour. The entire design process was video and audio recorded. After the design…

  7. MRS Action Plan Task B report: Analyses of alternative designs and operating approaches for a Monitored Retrievable Storage Facility

    SciTech Connect

    Woods, W.D.; Jowdy, A.K.; Keehn, C.H.; Gale, R.M.; Smith, R.I.

    1988-12-01

    The Nuclear Waste Policy Amendments Act (NWPAA) instituted a number of changes in the DOE commercial nuclear waste management system. After passage of the Act, the DOE initiated a number of systems studies to reevaluate the role of Monitored Retrievable Storage (MRS) within the federal waste management system. This report summarizes the results of a study to determine the schedules and costs of developing those MRS facilities needed under a number of scenarios, with differing functions allocated to the MRS and/or different spent fuel acceptance schedules. Nine cases were defined for the system study, seven of which included an MRS Facility. The study cases or scenarios evaluated varied relative to the specific functions to be performed at the MRS. The scenarios ranged in magnitude from storage and shipment of bare, intact spent fuel to consolidating the spent fuel into repository emplacement containers prior to storage and shipment. Each scenario required specific modifications to be made to the design developed for the MRS proposal to Congress (the Conceptual Design Report). 41 figs., 326 tabs.

  8. Differential Item Functioning Comparisons on a Performance-Based Alternate Assessment for Students with Severe Cognitive Impairments, Autism and Orthopedic Impairments

    ERIC Educational Resources Information Center

    Laitusis, Cara Cahalan; Maneckshana, Behroz; Monfils, Lora; Ahlgrim-Delzell, Lynn

    2009-01-01

    The purpose of this study was to examine Differential Item Functioning (DIF) by disability groups on an on-demand performance assessment for students with severe cognitive impairments. Researchers examined the presence of DIF for two comparisons. One comparison involved students with severe cognitive impairments who served as the reference group…

  9. Osiris and SOMBRERO inertial confinement fusion power plant designs. Volume 2, Designs, assessments, and comparisons, Final report

    SciTech Connect

    Meier, W.R.; Bieri, R.L.; Monsler, M.J.

    1992-03-01

    The primary objective of the of the IFE Reactor Design Studies was to provide the Office of Fusion Energy with an evaluation of the potential of inertial fusion for electric power production. The term reactor studies is somewhat of a misnomer since these studies included the conceptual design and analysis of all aspects of the IFE power plants: the chambers, heat transport and power conversion systems, other balance of plant facilities, target systems (including the target production, injection, and tracking systems), and the two drivers. The scope of the IFE Reactor Design Studies was quite ambitious. The majority of our effort was spent on the conceptual design of two IFE electric power plants, one using an induction linac heavy ion beam (HIB) driver and the other using a Krypton Fluoride (KrF) laser driver. After the two point designs were developed, they were assessed in terms of their (1) environmental and safety aspects; (2) reliability, availability, and maintainability; (3) technical issues and technology development requirements; and (4) economics. Finally, we compared the design features and the results of the assessments for the two designs.

  10. An Alternative Approach to "Identification of Unknowns": Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria.

    PubMed

    Martinez-Vaz, Betsy M; Denny, Roxanne; Young, Nevin D; Sadowsky, Michael J

    2015-12-01

    Microbiology courses often include a laboratory activity on the identification of unknown microbes. This activity consists of providing students with microbial cultures and running biochemical assays to identify the organisms. This approach lacks molecular techniques such as sequencing of genes encoding 16S rRNA, which is currently the method of choice for identification of unknown bacteria. A laboratory activity was developed to teach students how to identify microorganisms using 16S rRNA polymerase chain reaction (PCR) and validate microbial identities using biochemical techniques. We hypothesized that designing an experimental protocol to confirm the identity of a bacterium would improve students' knowledge of microbial identification techniques and the physiological characteristics of bacterial species. Nitrogen-fixing bacteria were isolated from the root nodules of Medicago truncatula and prepared for 16S rRNA PCR analysis. Once DNA sequencing revealed the identity of the organisms, the students designed experimental protocols to verify the identity of rhizobia. An assessment was conducted by analyzing pre- and posttest scores and by grading students' verification protocols and presentations. Posttest scores were higher than pretest scores at or below p = 0.001. Normalized learning gains (G) showed an improvement of students' knowledge of microbial identification methods (LO4, G = 0.46), biochemical properties of nitrogen-fixing bacteria (LO3, G = 0.45), and the events leading to the establishment of nitrogen-fixing symbioses (LO1&2, G = 0.51, G = 0.37). An evaluation of verification protocols also showed significant improvement with a p value of less than 0.001.

  11. An Alternative Approach to “Identification of Unknowns”: Designing a Protocol to Verify the Identities of Nitrogen Fixing Bacteria†

    PubMed Central

    Martinez-Vaz, Betsy M.; Denny, Roxanne; Young, Nevin D.; Sadowsky, Michael J.

    2015-01-01

    Microbiology courses often include a laboratory activity on the identification of unknown microbes. This activity consists of providing students with microbial cultures and running biochemical assays to identify the organisms. This approach lacks molecular techniques such as sequencing of genes encoding 16S rRNA, which is currently the method of choice for identification of unknown bacteria. A laboratory activity was developed to teach students how to identify microorganisms using 16S rRNA polymerase chain reaction (PCR) and validate microbial identities using biochemical techniques. We hypothesized that designing an experimental protocol to confirm the identity of a bacterium would improve students’ knowledge of microbial identification techniques and the physiological characteristics of bacterial species. Nitrogen-fixing bacteria were isolated from the root nodules of Medicago truncatula and prepared for 16S rRNA PCR analysis. Once DNA sequencing revealed the identity of the organisms, the students designed experimental protocols to verify the identity of rhizobia. An assessment was conducted by analyzing pre- and posttest scores and by grading students’ verification protocols and presentations. Posttest scores were higher than pretest scores at or below p = 0.001. Normalized learning gains (G) showed an improvement of students’ knowledge of microbial identification methods (LO4, G = 0.46), biochemical properties of nitrogen-fixing bacteria (LO3, G = 0.45), and the events leading to the establishment of nitrogen-fixing symbioses (LO1&2, G = 0.51, G = 0.37). An evaluation of verification protocols also showed significant improvement with a p value of less than 0.001. PMID:26753033

  12. Nanoemulsions containing a synthetic chalcone as an alternative for treating cutaneous leshmaniasis: optimization using a full factorial design

    PubMed Central

    de Mattos, Cristiane Bastos; Argenta, Débora Fretes; Melchiades, Gabriela de Lima; Sechini Cordeiro, Marlon Norberto; Tonini, Maiko Luis; Moraes, Milene Hoehr; Weber, Tanara Beatriz; Roman, Silvane Souza; Nunes, Ricardo José; Teixeira, Helder Ferreira; Steindel, Mário; Koester, Letícia Scherer

    2015-01-01

    Nanoemulsions are drug delivery systems that may increase the penetration of lipophilic compounds through the skin, enhancing their topical effect. Chalcones are compounds of low water solubility that have been described as promising molecules for the treatment of cutaneous leishmaniasis (CL). In this context, the aim of this work was to optimize the development of a nanoemulsion containing a synthetic chalcone for CL treatment using a 22 full factorial design. The formulations were prepared by spontaneous emulsification and the experimental design studied the influence of two independent variables (type of surfactant – soybean lecithin or sorbitan monooleate and type of co-surfactants – polysorbate 20 or polysorbate 80) on the physicochemical characteristics of the nanoemulsions, as well as on the skin permeation/retention of the synthetic chalcone in porcine skin. In order to evaluate the stability of the systems, the antileishmanial assay was performed against Leishmania amazonensis 24 hours and 60 days after the preparation of the nanoemulsions. The formulation composed of soybean lecithin and polysorbate 20 presented suitable physicochemical characteristics (droplet size 171.9 nm; polydispersity index 0.14; zeta potential −39.43 mV; pH 5.16; and viscosity 2.00 cP), drug content (91.09%) and the highest retention in dermis (3.03 µg·g−1) – the main response of interest – confirmed by confocal microscopy. This formulation also presented better stability of leishmanicidal activity in vitro against L. amazonensis amastigote forms (half maximal inhibitory concentration value 0.32±0.05 µM), which confirmed the potential of the nanoemulsion soybean lecithin and polysorbate 20 for CL treatment. PMID:26366075

  13. Comparison of Teaching Attitudes, Teacher Efficacy, and Teacher Performance of First Year Teachers Prepared by Alternative and Traditional Teacher Education Programs.

    ERIC Educational Resources Information Center

    Guyton, Edith; And Others

    1991-01-01

    The findings from this study of Georgia teachers generally support the contention that condensed pedagogical preparation and a supervised internship are a reasonable alternative to traditional teacher preparation programs for persons with degrees in the subject they will teach. (IAH)

  14. Alternative fuels

    SciTech Connect

    Not Available

    1991-07-01

    This paper presents the preliminary results of a review, of the experiences of Brazil, Canada, and New Zealand, which have implemented programs to encourage the use of alternative motor fuels. It will also discuss the results of a separate completed review of the Department of Energy's (DOE) progress in implementing the Alternative Motor Fuels Act of 1988. The act calls for, among other things, the federal government to use alternative-fueled vehicles in its fleet. The Persian Gulf War, environmental concerns, and the administration's National Energy Strategy have greatly heightened interest in the use of alternative fuels in this country.

  15. Comparison of the experimental aerodynamic characteristics of theoretically and experimentally designed supercritical airfoils

    NASA Technical Reports Server (NTRS)

    Harris, C. D.

    1974-01-01

    A lifting airfoil theoretically designed for shockless supercritical flow utilizing a complex hodograph method has been evaluated in the Langley 8-foot transonic pressure tunnel at design and off-design conditions. The experimental results are presented and compared with those of an experimentally designed supercritical airfoil which were obtained in the same tunnel.

  16. Design of disulfide bridge as an alternative mechanism for color shift in firefly luciferase and development of secreted luciferase.

    PubMed

    Nazari, Mahboobeh; Hosseinkhani, Saman

    2011-07-01

    The bioluminescence reaction, which uses luciferin, Mg(2+)-ATP and molecular oxygen to yield an electronically excited oxyluciferin, is carried out by luciferase and emits visible light. The bioluminescence color of firefly luciferases is determined by the luciferase structure and assay conditions. It is proposed that the stability of a protein can be increased by introduction of disulfide bridge that decreases the configurational entropy of unfolding. A disulfide bridge is introduced into Photinus pyralis firefly luciferase to make three separate mutant enzymes with a single bridge. Moreover, C(81)-A(105)C mutant luciferase was modified and successfully secreted to the extracellular medium. By introduction of disulfide bridges using site-directed mutagenesis in Photinus pyralis luciferase the color of emitted light was changed to red and the optimum temperature of activity was also increased (up to 10 °C more than wild type). Amongst mutants with a disulfide bridge, P(451)C-V(469)C and L(306)C-L(309)C mutants exhibit a single peak in the red region of the spectrum at pH 7.8. It is worthwhile to note that with the design of a secreted luciferase, the increased optimum temperature, thermostability and emission of red light might make mutant luciferase suitable reporters for the study of gene expression in high through-put screening.

  17. Comparison of High Aspect Ratio Cooling Channel Designs for a Rocket Combustion Chamber with Development of an Optimized Design

    NASA Technical Reports Server (NTRS)

    Wadel, Mary F.

    1998-01-01

    An analytical investigation on the effect of high aspect ratio (height/width) cooling channels, considering different coolant channel designs, on hot-gas-side wall temperature and coolant pressure drop for a liquid hydrogen cooled rocket combustion chamber, was performed. Coolant channel design elements considered were: length of combustion chamber in which high aspect ratio cooling was applied, number of coolant channels, and coolant channel shape. Seven coolant channel designs were investigated using a coupling of the Rocket Thermal Evaluation code and the Two-Dimensional Kinetics code. Initially, each coolant channel design was developed, without consideration for fabrication, to reduce the hot-gas-side wall temperature from a given conventional cooling channel baseline. These designs produced hot-gas-side wall temperature reductions up to 22 percent, with coolant pressure drop increases as low as 7.5 percent from the baseline. Fabrication constraints for milled channels were applied to the seven designs. These produced hot-gas-side wall temperature reductions of up to 20 percent, with coolant pressure drop increases as low as 2 percent. Using high aspect ratio cooling channels for the entire length of the combustion chamber had no additional benefit on hot-gas-side wall temperature over using high aspect ratio cooling channels only in the throat region, but increased coolant pressure drop 33 percent. Independent of coolant channel shape, high aspect ratio cooling was able to reduce the hot-gas-side wall temperature by at least 8 percent, with as low as a 2 percent increase in coolant pressure drop. ne design with the highest overall benefit to hot-gas-side wall temperature and minimal coolant pressure drop increase was the design which used bifurcated cooling channels and high aspect ratio cooling in the throat region. An optimized bifurcated high aspect ratio cooling channel design was developed which reduced the hot-gas-side wall temperature by 18 percent and

  18. Pleasant Alternatives.

    ERIC Educational Resources Information Center

    Unks, Gerald

    1981-01-01

    The author feels that the current wave of political conservatism may prove beneficial to education if the national mood of decentralization and decontrol leads to a resurgence of community involvement and locally-developed alternatives. He cites several examples of successful urban alternative schools. (SJL)

  19. Alternative Schools.

    ERIC Educational Resources Information Center

    Annett, Larry D.

    A model is presented for the categorizing of alternative schools, then the nature of the free school, which represents the essence of the alternative school movement, is examined. Strengths and weaknesses of court, legislative, and administrative approaches to resolve governance issues are set forth. This is followed by an analysis of three…

  20. Alternative Assessment.

    ERIC Educational Resources Information Center

    Stefonek, Tom; And Others

    1991-01-01

    This special double issue focuses on the issue of alternative assessment and its place in educational reform. "Alternative Assessment: A National Perspective" (T. Stefonek) emphasizes that the fundamental purposes of new assessment methods are grounded in educational goals, meaningful outcomes, and curricular and instructional programs…

  1. Systematic comparison of tissue fixation with alternative fixatives to conventional tissue fixation with buffered formalin in a xenograft-based model.

    PubMed

    Nietner, Thorben; Jarutat, Tiantom; Mertens, Alfred

    2012-09-01

    In our study we systematically compared the alternative fixatives acidified formal alcohol (AFA), PAXgene®, HOPE®, and combinations of AFA or formalin with ultrasound treatment to standard (buffered) formalin fixation. We examined general morphology and detectability of protein structures by immunohistochemistry of the membrane receptors epidermal growth factor receptor (EGFR), insulin-like growth factor 1 receptor (IGF-1R), and phosphorylated human epidermal growth factor receptor 2 (phospho-HER2). In order to allow for stringent comparability of different fixation techniques, we used matched mouse xenograft tumor samples from three different human cancer cell lines (colon, ovarian, and non-small cell lung cancer), either fixed conventionally with formalin or an alternative fixative. Tissue morphology after fixation with AFA and PAXgene® was comparable to formalin-fixed paraffin-embedded tissue (FFPET) morphology. Ultrasound fixations resulted in slightly inferior morphology and HOPE® fixation preserved morphology only poorly compared to FFPET in this system. None of the tested alternative fixatives enabled immunohistochemical detectability of all three targets in the same manner as FFPET. Pronounced staining was possible for EGFR and IGF-1R with all alternative fixatives but HOPE®, and phospho-HER2 staining was only noteworthy with formalin-ultrasound-fixed tissue. Therefore, the use of alternative fixatives comes with the need for careful validation of obtained IHC results individually for each target.

  2. Comparing solar energy alternatives

    NASA Astrophysics Data System (ADS)

    White, J. R.

    1984-03-01

    This paper outlines a computational procedure for comparing the merits of alternative processes to convert solar radiation to heat, electrical power, or chemical energy. The procedure uses the ratio of equipment investment to useful work as an index. Comparisons with conversion counterparts based on conventional fuels are also facilitated by examining this index. The procedure is illustrated by comparisons of (1) photovoltaic converters of differing efficiencies; (2) photovoltaic converters with and without focusing concentrators; (3) photovoltaic conversion plus electrolysis vs photocatalysis for the production of hydrogen; (4) photovoltaic conversion plus plasma arcs vs photocatalysis for nitrogen fixation. Estimates for conventionally-fuelled processes are included for comparison. The reasons why solar-based concepts fare poorly in such comparisons are traced to the low energy density of solar radiation and its low stream time factor resulting from the limited number of daylight hours available and clouds obscuring the sun.

  3. A comparison of the dynamic stiffness of the Goldcrown GC-500 grinding machine for three slide designs

    SciTech Connect

    Bennett, J.G.; Goldman, P.; Williams, D.C.; Farrar, C.R.

    1994-01-01

    This report provides a summary of the results obtained from the calculations that compare the dynamic stiffness of three slide design systems for the Goldcrown GC-500 centerless grinder; it also describes the models and procedures used to develop the calculations, the assumptions made, and the details that went into performing this work. The authors developed analytical models of the three Goldcrown slide designs and performed several computational studies to determine the dynamic stiffness of the designs. The three slide systems are hereafter referred to as the plane slide, the INA slide, and the polymer-coated slide. The plane slide is the dovetail slide and way traditionally used in machine tool designs. The INA slide is a design created by Goldcrown using INA Bearing Company recirculating roller bearings, and dampers on a rail guideway. The polymer-coated slide is a design using a low friction polymer coating for a modified plane slide system. A study of the drawings indicated that a comparison could be made, within a reasonable amount of time and effort, that would be indicative of the dynamic stiffness of the three designs if the machine was modeled as being composed of the following seven structural components: (1) the base, (2) the swivel plate, (3) the lower slide, (4) the upper housing, (5) the regulating wheel housing, (6) the ball screw, and (7) the in-feed body.

  4. Flight Test Validation of Optimal Input Design and Comparison to Conventional Inputs

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    1997-01-01

    A technique for designing optimal inputs for aerodynamic parameter estimation was flight tested on the F-18 High Angle of Attack Research Vehicle (HARV). Model parameter accuracies calculated from flight test data were compared on an equal basis for optimal input designs and conventional inputs at the same flight condition. In spite of errors in the a priori input design models and distortions of the input form by the feedback control system, the optimal inputs increased estimated parameter accuracies compared to conventional 3-2-1-1 and doublet inputs. In addition, the tests using optimal input designs demonstrated enhanced design flexibility, allowing the optimal input design technique to use a larger input amplitude to achieve further increases in estimated parameter accuracy without departing from the desired flight test condition. This work validated the analysis used to develop the optimal input designs, and demonstrated the feasibility and practical utility of the optimal input design technique.

  5. A Comparison between Mechanisms of Multi-Alternative Perceptual Decision Making: Ability to Explain Human Behavior, Predictions for Neurophysiology, and Relationship with Decision Theory.

    PubMed

    Ditterich, Jochen

    2010-01-01

    While there seems to be relatively wide agreement about perceptual decision making relying on integration-to-threshold mechanisms, proposed models differ in a variety of details. This study compares a range of mechanisms for multi-alternative perceptual decision making, including integration with and without leakage, feedforward and feedback inhibition for mediating the competition between integrators, as well as linear and non-linear mechanisms for combining signals across alternatives. It is shown that a number of mechanisms make very similar predictions for the decision behavior and are therefore able to explain previously published data from a multi-alternative perceptual decision task. However, it is also demonstrated that the mechanisms differ in their internal dynamics and therefore make different predictions for neuorphysiological experiments. The study further addresses the relationship of these mechanisms with decision theory and statistical testing and analyzes their optimality.

  6. A Comparison Study of Second-Order Screening Designs and Their Extension

    DTIC Science & Technology

    2013-12-01

    40 vii Page III. Effect of Heredity and Sparsity on Second-Order Screening Design Performance...second- order screening designs with respect to the assumptions of both sparsity (factor or effect) and heredity (strong or weak). To date, evaluation of...screening design per- formance has assumed both factor sparsity and strong effect heredity . The article is currently under review for publication in

  7. Alternative fuel transit buses

    SciTech Connect

    Motta, R.; Norton, P.; Kelly, K.

    1996-10-01

    The National Renewable Energy Laboratory (NREL) is a U.S. Department of Energy (DOE) national laboratory; this project was funded by DOE. One of NREL`s missions is to objectively evaluate the performance, emissions, and operating costs of alternative fuel vehicles so fleet managers can make informed decisions when purchasing them. Alternative fuels have made greater inroads into the transit bus market than into any other. Each year, the American Public Transit Association (APTA) surveys its members on their inventory and buying plans. The latest APTA data show that about 4% of the 50,000 transit buses in its survey run on an alternative fuel. Furthermore, 1 in 5 of the new transit buses that members have on order are alternative fuel buses. This program was designed to comprehensively and objectively evaluate the alternative fuels in use in the industry.

  8. Dosimetric comparison of four new design {sup 103}Pd brachytherapy sources: Optimal design using silver and copper rod cores

    SciTech Connect

    Hosseini, S. Hamed; Sadeghi, Mahdi; Ataeinia, Vahideh

    2009-07-15

    Four new brachytherapy sources, IRA1-{sup 103}Pd, IRA2-{sup 103}Pd, IRA3-{sup 103}Pd, and IRA4-{sup 103}Pd, have been developed at Agricultural, Medical, and Industrial Research School and are designed for permanent implant application. With the goal of determining an optimal design for a {sup 103}Pd source, this article compares the dosimetric properties of these sources with reference to the authors' earlier IRA-{sup 103}Pd source. The four new sources differ in end cap configuration and thickness and in the core material, silver or copper, that carries the adsorbed {sup 103}Pd. Dosimetric data derived from the authors' Monte Carlo simulation results are reported in accordance with the updated AAPM Task Group No. 43 report (TG-43U1). For each source, the authors obtained detailed results for the dose rate constant {Lambda}, the radial dose function g(r), the anisotropy function F(r,{theta}), and the anisotropy factor {phi}{sub an}(r). In this study, the optimal source IRA3-{sup 103}Pd provides the most isotropic dose distribution in water with the dose rate constant of 0.678({+-}0.1%) cGy h{sup -1} U{sup -1}. The IRA3-{sup 103}Pd design has a silver rod core combined with thin-wall, concave end caps. Finally, the authors compared the results for their optimal source with published results for those of other source manufacturers.

  9. Assessing Vocational Interests in the Basque Country Using Paired Comparison Design

    ERIC Educational Resources Information Center

    Elosua, Paula

    2007-01-01

    This article proposes the Thurstonian paired comparison model to assess vocational preferences and uses this approach to evaluate the Realistic, Investigative, Artistic, Social, Enterprise, and Conventional (RIASEC) model in the Basque Country (Spain). First, one unrestricted model is estimated in the Structural Equation Modelling framework using…

  10. Questionnaire Design in Broad-Based Evaluation Studies: Letting Someone Else Collect Comparison Group Data.

    ERIC Educational Resources Information Center

    Clark, Sheldon B.; Boser, Judith A.

    A context in which existing items may provide a convenient source of questions for questionnaires was explored through a case study making use of existing comparison groups. Two programs at Oak Ridge Associated Universities (ORAU), the Science and Engineering Research Semester (SERS) and the Laboratory Graduate Research Participation (Lab Grad)…

  11. A Comparison of the Success of Community College Graduates Who Entered College with a GED, a High School Diploma, or an Alternative Diploma

    ERIC Educational Resources Information Center

    Miles, April Danielle

    2014-01-01

    In this study, the researcher compared the success of community college graduates who entered college with a GED, a high school diploma, or an alternative diploma. The researcher used a quantitative analysis method with the existing data of students for three years within a single community college system to answer research questions to determine…

  12. Operational Design and Convergent Threats: A Comparison Case Study of Plan Colombia and Afghanistan Aimed to Enhance the Fight Against Narcotic-Funded Insurgencies

    DTIC Science & Technology

    2012-05-17

    Monograph JUN 2011- MAY 2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Operational Design and Convergent Threats: A Comparison Case Study of...in the strength government that enforces the law , provides services, and uphold the social contract established by people and their government. The...Operational Design and Convergent Threats: A Comparison Case Study of Plan Colombia and Afghanistan Aimed to Enhance the Fight against Narcotic

  13. Design and Development Comparison of Rapid Cycle Amine 1.0, 2.0, and 3.0

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Campbell, Colin; Papale, William; Murray, Sean; Wichowski, Robert; Conger, Bruce; McMillin, Summer

    2016-01-01

    The development of the Rapid Cycle Amine (RCA) swing-bed technology for carbon dioxide (CO2) removal has been in progress since favorable results were published in 1996. Shortly thereafter, a prototype was designed, developed, and tested successfully and delivered to Johnson Space Center in 1999. An improved prototype was delivered to NASA in 2006 and was notated as RCA 1.0 and sized for the extravehicular activity (EVA). The new RCA swing-bed technology is a regenerative system which employs two alternating solid-amine sorbent beds to remove CO2 and water. The two- bed design employs a chemisorption process whereby the beds alternate between adsorbtion and desorbsion. This process provides for an efficient operation of the RCA so that while one bed is in adsorb (uptake) mode, the other is in the desorb (regeneration) mode. The RCA has now progressed through several iterations of technology readiness levels. Test articles have now been designed, developed, and tested for the advanced space suit portable life support system (PLSS) including RCA 1.0, RCA 2.0, and RCA 3.0. The RCA 3.0 was the most recent RCA fabrication and was delivered to NASA-JSC in June 2015. The RCA 1.0 test article was designed with a pneumatically actuated linear motion spool valve. The RCA 2.0 and 3.0 test articles were designed with a valve assembly which allows for switching between uptake and regeneration modes while minimizing gas volume losses to the vacuum source. RCA 2.0 and 3.0 also include an embedded controller design to control RCA operation and provide the capability of interfacing with various sensors and other ventilation loop components. The RCA technology is low power, small, and has fulfilled all test requirements levied upon the technology during development testing thus far. This paper will provide an overreview of the design and development of RCA 1.0, 2.0 and 3.0 including detail differences between the design specifications of each.

  14. Design and Development Comparison of Rapid Cycle Amine 1.0, 2.0, and 3.0

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Campbell, Colin; Papale, William; Murray, Sean; Wichowski, Robert; Conger, Bruce; McMillin, Summer

    2016-01-01

    The development of the Rapid Cycle Amine (RCA) swing-bed technology for carbon dioxide (CO2) removal has been in progress since favorable results were published in 1996. Shortly thereafter, a prototype was designed, developed, and tested successfully and delivered to Johnson Space Center in 1999. An improved prototype (RCA 1.0) was delivered to NASA in 2006 and sized for the extravehicular activity (EVA). The RCA swing-bed technology is a regenerative system which employs two alternating solid-amine sorbent beds to remove CO2 and water. The two-bed design employs a chemisorption process whereby the beds alternate between adsorption and desorption. This process provides for an efficient RCA operation that enables one bed to be in adsorb (uptake) mode, while the other is in the desorb (regeneration) mode. The RCA has progressed through several iterations of technology readiness levels. Test articles have now been designed, developed, and tested for the advanced space suit portable life support system (PLSS) including RCA 1.0, RCA 2.0, and RCA 3.0. The RCA 3.0 was the most recent RCA fabrication and was delivered to NASA-JSC in June 2015. The RCA 1.0 test article was designed with a pneumatically actuated linear motion spool valve. The RCA 2.0 and 3.0 test articles were designed with a valve assembly which allows for switching between uptake and regeneration modes while minimizing gas volume losses to the vacuum source. RCA 2.0 and 3.0 also include an embedded controller design to control RCA operation and provide the capability of interfacing with various sensors and other ventilation loop components. The RCA technology is low power, small, and has fulfilled all test requirements levied upon the technology during development testing thus far. This paper will provide an overview of the design and development of RCA 1.0, 2.0 and 3.0 including detail differences between the design specifications of each. Nomenclature.

  15. The conceptual Design of a hybrid Life Support System based on the Evaluation and Comparison of Terrestrial Testbeds

    NASA Astrophysics Data System (ADS)

    Czupalla, M.; Horneck, G.; Blome, H. J.

    This report summarizes a trade study which was conducted at the DLR in Cologne as part of an Aerospace Engineering Thesis for the University of Applied Sciences at Aachen. The goal of this study was the evaluation of bioregenerative options of a Life Support System (LSS) and a subsequent conceptual design of a hybrid LSS. This concept is supported by previous work on P/C LSS. Baseline for the evaluation of bioregenerative options were the terrestrial experiments in the LSS area. The experiments considered for the study were as follows. MELISSA (ESA's Microbial LSS Approach) BIOS (Russia experiments on CELSS) ALS Project (American practical and theoretical work on LSS) Computer models including mass flows were established for each of the systems with the goal of closing system loops to the extent possible. The terrestrial test initiatives achieved different levels of maturity as of supported crew size and the provided nutrition. For comparison, all systems were scaled for supporting a crew of six as given in the NASA Design Reference Mission Scenario (DRM). In addition one uniform nutritional baseline, as of calories, was applied to all models. Equivalent System Mass analysis was used to compare the scaled terrestrial designs against each other. Following the comparison of the terrestrial systems, the system specific subsystem options for Food Supply, Waste Processing, Water Management and Atmosphere Revitalization were evaluated separately in a trade study. Resulting technologies were integrated into an overall design solution based on mass flow relationships. The bioregenerative part of the LSS was hereby supplemented with P/C LSS technologies in order to enhance system performance and to minimize re-supply requirements. Eventually an iterated conceptual hybrid LSS for DRM type mission was designed and will be presented.

  16. A Comparison of Functional Models for Use in the Function-Failure Design Method

    NASA Technical Reports Server (NTRS)

    Stock, Michael E.; Stone, Robert B.; Tumer, Irem Y.

    2006-01-01

    When failure analysis and prevention, guided by historical design knowledge, are coupled with product design at its conception, shorter design cycles are possible. By decreasing the design time of a product in this manner, design costs are reduced and the product will better suit the customer s needs. Prior work indicates that similar failure modes occur with products (or components) with similar functionality. To capitalize on this finding, a knowledge base of historical failure information linked to functionality is assembled for use by designers. One possible use for this knowledge base is within the Elemental Function-Failure Design Method (EFDM). This design methodology and failure analysis tool begins at conceptual design and keeps the designer cognizant of failures that are likely to occur based on the product s functionality. The EFDM offers potential improvement over current failure analysis methods, such as FMEA, FMECA, and Fault Tree Analysis, because it can be implemented hand in hand with other conceptual design steps and carried throughout a product s design cycle. These other failure analysis methods can only truly be effective after a physical design has been completed. The EFDM however is only as good as the knowledge base that it draws from, and therefore it is of utmost importance to develop a knowledge base that will be suitable for use across a wide spectrum of products. One fundamental question that arises in using the EFDM is: At what level of detail should functional descriptions of components be encoded? This paper explores two approaches to populating a knowledge base with actual failure occurrence information from Bell 206 helicopters. Functional models expressed at various levels of detail are investigated to determine the necessary detail for an applicable knowledge base that can be used by designers in both new designs as well as redesigns. High level and more detailed functional descriptions are derived for each failed component based

  17. A comparison of two sampling designs for fish assemblage assessment in a large river

    USGS Publications Warehouse

    Kiraly, Ian A.; Coghlan Jr., Stephen M.; Zydlewski, Joseph; Hayes, Daniel

    2014-01-01

    We compared the efficiency of stratified random and fixed-station sampling designs to characterize fish assemblages in anticipation of dam removal on the Penobscot River, the largest river in Maine. We used boat electrofishing methods in both sampling designs. Multiple 500-m transects were selected randomly and electrofished in each of nine strata within the stratified random sampling design. Within the fixed-station design, up to 11 transects (1,000 m) were electrofished, all of which had been sampled previously. In total, 88 km of shoreline were electrofished during summer and fall in 2010 and 2011, and 45,874 individuals of 34 fish species were captured. Species-accumulation and dissimilarity curve analyses indicated that all sampling effort, other than fall 2011 under the fixed-station design, provided repeatable estimates of total species richness and proportional abundances. Overall, our sampling designs were similar in precision and efficiency for sampling fish assemblages. The fixed-station design was negatively biased for estimating the abundance of species such as Common Shiner Luxilus cornutus and Fallfish Semotilus corporalis and was positively biased for estimating biomass for species such as White Sucker Catostomus commersonii and Atlantic Salmon Salmo salar. However, we found no significant differences between the designs for proportional catch and biomass per unit effort, except in fall 2011. The difference observed in fall 2011 was due to limitations on the number and location of fixed sites that could be sampled, rather than an inherent bias within the design. Given the results from sampling in the Penobscot River, application of the stratified random design is preferable to the fixed-station design due to less potential for bias caused by varying sampling effort, such as what occurred in the fall 2011 fixed-station sample or due to purposeful site selection.

  18. Homeostasis of Complementary Pair Theory: Ecological Comparisons in Diverse Universal Design for Learning Environments

    ERIC Educational Resources Information Center

    Ianneo, Brittany

    2014-01-01

    Accommodation~assimilation relations were theorized by Kelso and Engstrom (2006) as independent and dependent complementary pairs. This study defined relationships between organisms that experienced complementary interactions of accommodation~assimilation in diverse ecologies designed with universal design for learning environments (UDLE) compared…

  19. A Comparison of Diary Method Variations for Enlightening Form Generation in the Design Process

    ERIC Educational Resources Information Center

    Babapour, Maral; Rehammar, Bjorn; Rahe, Ulrike

    2012-01-01

    This paper presents two studies in which an empirical approach was taken to understand and explain form generation and decisions taken in the design process. In particular, the activities addressing aesthetic aspects when exteriorising form ideas in the design process have been the focus of the present study. Diary methods were the starting point…

  20. An Empirical Comparison of Five Linear Equating Methods for the NEAT Design

    ERIC Educational Resources Information Center

    Suh, Youngsuk; Mroch, Andrew A.; Kane, Michael T.; Ripkey, Douglas R.

    2009-01-01

    In this study, a data base containing the responses of 40,000 candidates to 90 multiple-choice questions was used to mimic data sets for 50-item tests under the "nonequivalent groups with anchor test" (NEAT) design. Using these smaller data sets, we evaluated the performance of five linear equating methods for the NEAT design with five levels of…

  1. A Comparison of Parallelism in Interface Designs for Computer-Based Learning Environments

    ERIC Educational Resources Information Center

    Min, Rik; Yu, Tao; Spenkelink, Gerd; Vos, Hans

    2004-01-01

    In this paper we discuss an experiment that was carried out with a prototype, designed in conformity with the concept of parallelism and the Parallel Instruction theory (the PI theory). We designed this prototype with five different interfaces, and ran an empirical study in which 18 participants completed an abstract task. The five basic designs…

  2. Causal Inference and the Comparative Interrupted Time Series Design: Findings from Within-Study Comparisons

    ERIC Educational Resources Information Center

    St. Clair, Travis; Hallberg, Kelly; Cook, Thomas D.

    2014-01-01

    Researchers are increasingly using comparative interrupted time series (CITS) designs to estimate the effects of programs and policies when randomized controlled trials are not feasible. In a simple interrupted time series design, researchers compare the pre-treatment values of a treatment group time series to post-treatment values in order to…

  3. Designing Online Interaction to Address Disciplinary Competencies: A Cross-Country Comparison of Faculty Perspectives

    ERIC Educational Resources Information Center

    Barberà, Elena; Layne, Ludmila; Gunawardena, Charlotte N.

    2014-01-01

    This study was conducted at colleges in three countries (United States, Venezuela, and Spain) and across three academic disciplines (engineering, education, and business), to examine how experienced faculty define competencies for their discipline, and design instructional interaction for online courses. A qualitative research design employing…

  4. Motivating Students through Positive Learning Experiences: A Comparison of Three Learning Designs for Computer Programming Courses

    ERIC Educational Resources Information Center

    Lykke, Marianne; Coto, Mayela; Jantzen, Christian; Mora, Sonia; Vandel, Niels

    2015-01-01

    Based on the assumption that wellbeing, positive emotions and engagement influence motivation for learning, the aim of this paper is to provide insight into students' emotional responses to and engagement in different learning designs. By comparing students' reports on the experiential qualities of three different learning designs, their…

  5. A comparison of design variables for control theory based airfoil optimization

    NASA Technical Reports Server (NTRS)

    Reuther, James; Jameson, Antony

    1995-01-01

    This paper describes the implementation of optimization techniques based on control theory for airfoil design. In our previous work in the area it was shown that control theory could be employed to devise effective optimization procedures for two-dimensional profiles by using either the potential flow or the Euler equations with either a conformal mapping or a general coordinate system. We have also explored three-dimensional extensions of these formulations recently. The goal of our present work is to demonstrate the versatility of the control theory approach by designing airfoils using both Hicks-Henne functions and B-spline control points as design variables. The research also demonstrates that the parameterization of the design space is an open question in aerodynamic design.

  6. A Comparison of Multivariable Control Design Techniques for a Turbofan Engine Control

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Watts, Stephen R.

    1995-01-01

    This paper compares two previously published design procedures for two different multivariable control design techniques for application to a linear engine model of a jet engine. The two multivariable control design techniques compared were the Linear Quadratic Gaussian with Loop Transfer Recovery (LQG/LTR) and the H-Infinity synthesis. The two control design techniques were used with specific previously published design procedures to synthesize controls which would provide equivalent closed loop frequency response for the primary control loops while assuring adequate loop decoupling. The resulting controllers were then reduced in order to minimize the programming and data storage requirements for a typical implementation. The reduced order linear controllers designed by each method were combined with the linear model of an advanced turbofan engine and the system performance was evaluated for the continuous linear system. Included in the performance analysis are the resulting frequency and transient responses as well as actuator usage and rate capability for each design method. The controls were also analyzed for robustness with respect to structured uncertainties in the unmodeled system dynamics. The two controls were then compared for performance capability and hardware implementation issues.

  7. Escherichia coli removal in waste stabilization ponds: a comparison of modern and classical designs.

    PubMed

    Banda, C G; Sleigh, P A; Mara, D D

    2005-01-01

    Two PC-based waste stabilization pond design procedures, based on parameter uncertainty and 10,000-trial Monte Carlo simulations, were developed for a series of anaerobic, facultative and maturation ponds to produce < or = 1000 E. coli per 100 ml for both 50% and 95% compliance. One procedure was based on the classical Marais equations and the other on the modern von Sperling equations. For the range of parameter variations selected the classical design procedure required less land area and had a shorter hydraulic retention time than the modern design procedure. For both procedures the design for 90% compliance required substantially more land and a longer retention time than the design for 50% compliance. Regulators and designers should seek a balance between system reliability (as set by the percentage compliance specified or adopted) and system costs, especially (but not only) in developing countries. It is recommended that new waste stabilization pond (WSP) systems be designed for compliance with a given E. coli effluent requirement by the classical procedure and that existing overloaded WSP systems be upgraded using the modern procedure.

  8. Comparison of sampling designs for estimating deforestation from landsat TM and MODIS imagery: a case study in Mato Grosso, Brazil.

    PubMed

    Zhu, Shanyou; Zhang, Hailong; Liu, Ronggao; Cao, Yun; Zhang, Guixin

    2014-01-01

    Sampling designs are commonly used to estimate deforestation over large areas, but comparisons between different sampling strategies are required. Using PRODES deforestation data as a reference, deforestation in the state of Mato Grosso in Brazil from 2005 to 2006 is evaluated using Landsat imagery and a nearly synchronous MODIS dataset. The MODIS-derived deforestation is used to assist in sampling and extrapolation. Three sampling designs are compared according to the estimated deforestation of the entire study area based on simple extrapolation and linear regression models. The results show that stratified sampling for strata construction and sample allocation using the MODIS-derived deforestation hotspots provided more precise estimations than simple random and systematic sampling. Moreover, the relationship between the MODIS-derived and TM-derived deforestation provides a precise estimate of the total deforestation area as well as the distribution of deforestation in each block.

  9. Comparison of Sampling Designs for Estimating Deforestation from Landsat TM and MODIS Imagery: A Case Study in Mato Grosso, Brazil

    PubMed Central

    Zhu, Shanyou; Zhang, Hailong; Liu, Ronggao; Cao, Yun; Zhang, Guixin

    2014-01-01

    Sampling designs are commonly used to estimate deforestation over large areas, but comparisons between different sampling strategies are required. Using PRODES deforestation data as a reference, deforestation in the state of Mato Grosso in Brazil from 2005 to 2006 is evaluated using Landsat imagery and a nearly synchronous MODIS dataset. The MODIS-derived deforestation is used to assist in sampling and extrapolation. Three sampling designs are compared according to the estimated deforestation of the entire study area based on simple extrapolation and linear regression models. The results show that stratified sampling for strata construction and sample allocation using the MODIS-derived deforestation hotspots provided more precise estimations than simple random and systematic sampling. Moreover, the relationship between the MODIS-derived and TM-derived deforestation provides a precise estimate of the total deforestation area as well as the distribution of deforestation in each block. PMID:25258742

  10. Low-cost floating emergence net and bottle trap: Comparison of two designs

    USGS Publications Warehouse

    Cadmus, Pete; Pomeranz, Justin; Kraus, Johanna M.

    2016-01-01

    Sampling emergent aquatic insects is of interest to many freshwater ecologists. Many quantitative emergence traps require the use of aspiration for collection. However, aspiration is infeasible in studies with large amounts of replication that is often required in large biomonitoring projects. We designed an economic, collapsible pyramid-shaped floating emergence trap with an external collection bottle that avoids the need for aspiration. This design was compared experimentally to a design of similar dimensions that relied on aspiration to ensure comparable results. The pyramid-shaped design captured twice as many total emerging insects. When a preservative was used in bottle collectors, >95% of the emergent abundance was collected in the bottle. When no preservative was used, >81% of the total insects were collected from the bottle. In addition to capturing fewer emergent insects, the traps that required aspiration took significantly longer to sample. Large studies and studies sampling remote locations could benefit from the economical construction, speed of sampling, and capture efficiency.

  11. The comparison of laser surface designing and pigment printing methods for the product quality

    NASA Astrophysics Data System (ADS)

    Ozguney, Arif Taner

    2007-07-01

    Developing new designs by using the computer and transferring the designs that are obtained to textile surfaces will not only increase and facilitate the production in a more practical manner, but also help you create identical designs. This means serial manufacturing of the products at standard quality and increasing their added values. Moreover, creating textile designs using the laser will also contribute to the value of the product as far as the consumer is concerned because it will not cause any wearing off and deformation in the texture of the fabric unlike the other methods. In the system that has been designed, the laser beam at selected wavelength and intensity was directed onto a selected textile surface and a computer-controlled laser beam source was used to change the colour substances on the textile surface. Pigment printing is also used for designing in textile and apparel sector. In this method, designs are transferred to the fabric manually by using dyestuff. In this study, the denim fabric used for the surfacing trial was 100% cotton, with a weft count per centimeter of 20 and a warp count per centimeter of 27, with fabric weight of 458 g/m 2. The first step was to prepare 40 pieces of denim samples, half of which were prepared manually pigment printing and the other half by using the laser beam. After this, some test applications were done. The tensile strength, tensile extension and some fastness values of designed pieces with two methods were compared according to the international standards.

  12. Computer-aided design comparisons of monolithic and hybrid MEM-tunable VCSELs

    NASA Astrophysics Data System (ADS)

    Ochoa, Edward M.; Nelson, Thomas R., Jr.; Blum-Spahn, Olga; Lott, James A.

    2003-07-01

    We report and use our micro-electro-mechanically tunable vertical cavity surface emitting laser (MEM-TVCSEL) computer-aided design methodology to investigate the resonant frequency design space for monolithic and hybrid MEM-TVCSELs. For various initial optical air gap thickness, we examine the sensitivity of monolithic or hybrid MEM-TVCSEL resonant frequency by simulating zero, two, and four percent variations in III-V material growth thickness. As expected, as initial optical airgap increases, tuning range decreases due to less coupling between the active region and the tuning mirror. However, each design has different resonant frequency sensitivity to variations in III-V growth parameters. In particular, since the monolithic design is comprised of III-V material, the shift in all growth thicknesses significantly shifts the resonant frequency response. However, for hybrid MEMTVCSELs, less shift results, since the lower reflector is an Au mirror with reflectivity independent of III-V growth variations. Finally, since the hybrid design is comprised of a MUMPS polysilicon mechanical actuator, pull-in voltage remains independent of the initial optical airgap between the tuning reflector and the III-V material. Conversely, as the initial airgap increases in the monolithic design, the pull-in voltage significantly increases.

  13. Design comparison of single phase outer and inner-rotor hybrid excitation flux switching motor for hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Mazlan, Mohamed Mubin Aizat; Sulaiman, Erwan; Husin, Zhafir Aizat; Othman, Syed Muhammad Naufal Syed; Khan, Faisal

    2015-05-01

    In hybrid excitation machines (HEMs), there are two main flux sources which are permanent magnet (PM) and field excitation coil (FEC). These HEMs have better features when compared with the interior permanent magnet synchronous machines (IPMSM) used in conventional hybrid electric vehicles (HEVs). Since all flux sources including PM, FEC and armature coils are located on the stator core, the rotor becomes a single piece structure similar with switch reluctance machine (SRM). The combined flux generated by PM and FEC established more excitation fluxes that are required to produce much higher torque of the motor. In addition, variable DC FEC can control the flux capabilities of the motor, thus the machine can be applied for high-speed motor drive system. In this paper, the comparisons of single-phase 8S-4P outer and inner rotor hybrid excitation flux switching machine (HEFSM) are presented. Initially, design procedures of the HEFSM including parts drawing, materials and conditions setting, and properties setting are explained. Flux comparisons analysis is performed to investigate the flux capabilities at various current densities. Then the flux linkages of PM with DC FEC of various DC FEC current densities are examined. Finally torque performances are analyzed at various armature and FEC current densities for both designs. As a result, the outer-rotor HEFSM has higher flux linkage of PM with DC FEC and higher average torque of approximately 10% when compared with inner-rotor HEFSM.

  14. Disposal of post-consumer polyethylene terephthalate (PET) bottles: comparison of five disposal alternatives in the small island state of Mauritius using a life cycle assessment tool.

    PubMed

    Foolmaun, Rajendra Kumar; Ramjeeawon, Toolseeram

    2012-01-01

    Used polyethylene terephthalate bottles (PET) dumped indiscriminately onto bare lands and water bodies constitute an eyesore. This problem is viewed as a serious impediment to the flourishing tourism industry in Mauritius. Currently, over 100 million PET bottles are generated annually and the only fully operational disposal route is through the sole sanitary landfill. There is no formal segregation of waste and therefore used PET bottles are disposed of commingled with domestic waste. Despite a satisfactory waste collection system, a considerable amount of used PET bottles unfortunately end up in water bodies and on bare lands. An appreciable amount of PET bottles is now being collected separately for flake production prior to export to South Africa. This paper investigated the environmental impact of five waste management scenarios (100% landfill; 100% incineration with energy recovery; 50% incineration and 50% landfill; 34% flake production and 66% landfill; 100% flake production) for used PET bottles in Mauritius. Comparison of the five scenarios was based on the life cycle assessment (LCA) methodology described in ISO 14040 and ISO 14044. SimaPro 7.1 software was used to analyse the data. Comparison of the five scenarios showed that the highest environmental impacts occurred when 100% of used PET bottles were sent to the landfill. The comparison also indicated that there were least impacts on the environment when all used PET bottles were incinerated with energy recovery.

  15. Endogenous and exogenous electric fields as modifiers of brain activity: rational design of noninvasive brain stimulation with transcranial alternating current stimulation.

    PubMed

    Fröhlich, Flavio

    2014-03-01

    Synchronized neuronal activity in the cortex generates weak electric fields that are routinely measured in humans and animal models by electroencephalography and local field potential recordings. Traditionally, these endogenous electric fields have been considered to be an epiphenomenon of brain activity. Recent work has demonstrated that active cortical networks are surprisingly susceptible to weak perturbations of the membrane voltage of a large number of neurons by electric fields. Simultaneously, noninvasive brain stimulation with weak, exogenous electric fields (transcranial current stimulation, TCS) has undergone a renaissance due to the broad scope of its possible applications in modulating brain activity for cognitive enhancement and treatment of brain disorders. This review aims to interface the recent developments in the study of both endogenous and exogenous electric fields, with a particular focus on rhythmic stimulation for the modulation of cortical oscillations. The main goal is to provide a starting point for the use of rational design for the development of novel mechanism-based TCS therapeutics based on transcranial alternating current stimulation, for the treatment of psychiatric illnesses.

  16. Endogenous and exogenous electric fields as modifiers of brain activity: rational design of noninvasive brain stimulation with transcranial alternating current stimulation

    PubMed Central

    Fröhlich, Flavio

    2014-01-01

    Synchronized neuronal activity in the cortex generates weak electric fields that are routinely measured in humans and animal models by electroencephalography and local field potential recordings. Traditionally, these endogenous electric fields have been considered to be an epiphenomenon of brain activity. Recent work has demonstrated that active cortical networks are surprisingly susceptible to weak perturbations of the membrane voltage of a large number of neurons by electric fields. Simultaneously, noninvasive brain stimulation with weak, exogenous electric fields (transcranial current stimulation, TCS) has undergone a renaissance due to the broad scope of its possible applications in modulating brain activity for cognitive enhancement and treatment of brain disorders. This review aims to interface the recent developments in the study of both endogenous and exogenous electric fields, with a particular focus on rhythmic stimulation for the modulation of cortical oscillations. The main goal is to provide a starting point for the use of rational design for the development of novel mechanism-based TCS therapeutics based on transcranial alternating current stimulation, for the treatment of psychiatric illnesses. PMID:24733974

  17. Further comparison of wind tunnel and airplane acoustic data for advanced design high speed propeller models

    NASA Astrophysics Data System (ADS)

    Dittmar, J. H.

    Comparisons were made between the SR-2 and SR-3 model propeller noise data taken in the NASA 8-by-6 wind tunnel, in the United Technologies Research Center (UTRC) anechoic tunnel, and with boom and fuselage microphones on the NASA Jetstar airplane. Plots of peak blade passage tone noise versus helical tip Mach number generally showed good agreement. The levels of the airplane fuselage data were somewhat lower than the boom data by an approximately uniform value. The curve shapes were similar except for the UTRC data which was flatter than the other sets. This was attributed to the UTRC data being taken at constant power while the other data were taken at constant advance ratio. General curves of the peak blade passage tone versus helical tip Mach number fit through all the data are also presented. Directivity shape comparisons at the cruise condition were similar for the airplane and 8-by-6 tunnel data. The UTRC data peaked farther forward but, when an angle correction was made for the different axial Mach number used in the UTRC tests, the shape was similar to the others. The general agreement of the data from the four configurations enables the formation of a good consensus of the noise from these propellers.

  18. Further comparison of wind tunnel and airplane acoustic data for advanced design high speed propeller models

    NASA Technical Reports Server (NTRS)

    Dittmar, J. H.

    1985-01-01

    Comparisons were made between the SR-2 and SR-3 model propeller noise data taken in the NASA 8-by-6 wind tunnel, in the United Technologies Research Center (UTRC) anechoic tunnel, and with boom and fuselage microphones on the NASA Jetstar airplane. Plots of peak blade passage tone noise versus helical tip Mach number generally showed good agreement. The levels of the airplane fuselage data were somewhat lower than the boom data by an approximately uniform value. The curve shapes were similar except for the UTRC data which was flatter than the other sets. This was attributed to the UTRC data being taken at constant power while the other data were taken at constant advance ratio. General curves of the peak blade passage tone versus helical tip Mach number fit through all the data are also presented. Directivity shape comparisons at the cruise condition were similar for the airplane and 8-by-6 tunnel data. The UTRC data peaked farther forward but, when an angle correction was made for the different axial Mach number used in the UTRC tests, the shape was similar to the others. The general agreement of the data from the four configurations enables the formation of a good consensus of the noise from these propellers.

  19. Comparison of High Aspect Ratio Cooling Channel Designs for a Rocket Combustion Chamber

    NASA Technical Reports Server (NTRS)

    Wadel, Mary F.

    1997-01-01

    An analytical investigation on the effect of high aspect ratio (height/width) cooling channels, considering different coolant channel designs, on hot-gas-side wall temperature and coolant pressure drop for a liquid hydrogen cooled rocket combustion chamber, was performed. Coolant channel design elements considered were: length of combustion chamber in which high aspect ratio cooling was applied, number of coolant channels, and coolant channel shape. Seven coolant channel designs were investigated using a coupling of the Rocket Thermal Evaluation code and the Two-Dimensional Kinetics code. Initially, each coolant channel design was developed, without consideration for fabrication, to reduce the hot-gas-side wall temperature from a given conventional cooling channel baseline. These designs produced hot-gas-side wall temperature reductions up to 22 percent, with coolant pressure drop increases as low as 7.5 percent from the baseline. Fabrication constraints for milled channels were applied to the seven designs. These produced hot-gas-side wall temperature reductions of up to 20 percent, with coolant pressure drop increases as low as 2 percent. Using high aspect ratio cooling channels for the entire length of the combustion chamber had no additional benefit on hot-gas-side wall temperature over using high aspect ratio cooling channels only in the throat region, but increased coolant pressure drop 33 percent. Independent of coolant channel shape, high aspect ratio cooling was able to reduce the hot-gas-side wall temperature by at least 8 percent, with as low as a 2 percent increase in coolant pressure drop. The design with the highest overall benefit to hot-gas-side wall temperature and minimal coolant pressure drop cooling can now be done in relatively short periods of time with multiple iterations.

  20. International comparison of criteria for evaluating sensitization of PRTR-designated chemical substances.

    PubMed

    Murakami, Tomoe; Oyama, Tsunehiro; Isse, Toyohi; Ogawa, Masanori; Sugie, Takuya; Kawamoto, Toshihiro

    2007-03-01

    In this study, we aim to compare the criteria for sensitizers among national organizations in various countries and international organizations, and to specify whether each Pollutant Release and Transfer Register (PRTR)-designated chemical substance is a sensitizer by each organization. The definition of sensitizing chemicals and the designation of respective sensitizers according to the PRTR law, Japan Society for Occupational Health (JSOH), American Conference of Governmental Industrial Hygienists (ACGIH), European Union (EU), and Deutsche Forschungsgemeinshaft (DFG) were studied. Of the 435 PRTR-designated chemical substances, 15 are listed as sensitizers according to the PRTR law, 16 as sensitizers of the airway and 21 as sensitizers of the skin by JSOH, 12 as sensitizers (no discrimination) by ACGIH, 19 (airway) and 85 (skin) by EU, and 15 (airway) and 43 (skin) by DFG. Only 9 substances were designated as sensitizers by all these organizations. The variation in the designation of sensitizers is accounted for by the differences in the classification criteria and grouping of chemical substances. JSOH limits the definition of sensitizers to substances that induce allergic reactions in humans and uses only human data. Other organizations utilize not only human evidence but also appropriate animal tests. In addition, EU designates an isocyanate as a sensitizer except those for which there is evidence showing that they do not cause respiratory sensitivity. The worldwide enforcement of the globally harmonized system (GHS) of classification and labeling of chemicals could promote not only the consistent designation of sensitizers among national and international organizations, but also the development of testing guidelines and classification criteria for mixtures.