WorldWideScience

Sample records for hygrothermal performance study

  1. Investigation of the Hygrothermal Performance of Alternative Insulation Materials

    DEFF Research Database (Denmark)

    Rode, Carsten; Kristiansen, Finn Harken; Rasmussen, Niels T.

    1999-01-01

    The paper gives an account of hygrothermal investigations carried out on some insulation products which are "alternative" to the ones that are traditionally used in Danish constructions. The alternative products are claimed to be friendly both to the environment and to the labour force. The mater......The paper gives an account of hygrothermal investigations carried out on some insulation products which are "alternative" to the ones that are traditionally used in Danish constructions. The alternative products are claimed to be friendly both to the environment and to the labour force...... is determined for the different materials with a guarded hot plate apparatus in which different vapour pressure conditions can be maintained over the specimens. The apparatus and some results are presented.2. Computational analysis of the hygrothermal performance of constructions with alternative insulation...... products.The hygrothermal performance of constructions with alternative insulation products is analysed with a computational model for combined heat and moisture transfer. The analysis concerns both traditional wall and roof constructions with the alternative insulation products, and some alternative...

  2. Building Enclosure Hygrothermal Performance Study, Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Karagiozis, A.N.

    2002-08-08

    The moisture performance of three different classes of wall systems has been investigated in the context of the preliminary hygrothermal analysis of walls in Seattle. The results reported in this phase specifically address the moisture performance of walls designed with loads that have some unintentional water penetration. The results have been developed in a manner to present the relative performance of the walls in the same climate with similar water penetration effects. The analysis was performed with the best available input data. Several limitations should be recognized within the context of this study. Results showed that selection of wooden sheathing boards on interior vapor-tight assemblies does not significantly influence the performance of stucco-clad walls. A larger effect was observed when the interior vapor control is made vapor open. When continuous cavity ventilation is employed, the effect of the selection of the type of sheathing board on the hygrothermal performance of the wall was found to be negligible. When comparing oriented strand board sheathing performance against the performance of exterior grade gypsum, the differences are very significant in terms of the amount of moisture content present in the walls. Moisture content alone does not indicate their respective durability as durability is directly related to the combination of relative humidity and temperature, mechanical, chemical, and biological properties of the substrates. This study did not investigate the durability performance of either sheathing. In terms of interior vapor control, inhabitant behavior must be considered during the wall hygrothermal design stage. If interior relative humidity is maintained below 60%, then a latex primer and paint may perform better than the use of PVA or even a polyethylene sheet. When the interior environment is maintained at a higher relative humidity, then stricter vapor control is needed. Multilayered building paper was experimentally shown to

  3. Experimental Study of the Hygrothermal Effect on Wear Behavior of Composite Materials

    Directory of Open Access Journals (Sweden)

    Fadhel Abbas. Abdulla

    2017-07-01

    Full Text Available The hygrothermal effect on the wear behavior of composite material (fiberglass and polyester resin vf=40% was investigated experimentally in this work. The study includes manufacturing of test device (pin on disc according to ASTM G 99. In order to study the hygrothermal effect on wear behavior of composite materials the hygrothermal chamber was manufactured. The experimental results show that the wear of glass fiber/polyester increased with increasing the load, sliding speed and sliding distance. The load and sliding distance were more effective on the wear of the composite rather than sliding speed. Also, it has been revealed that, the hygrothermal is considerable effect that, the wear rate of glass fiber/polyester without hygrothermal effect is lower than wear with hygrothermal effect. Applied load is the wear factor that has the highest physical influence on the wear of composites materials than other wear factors. Also, the wear of glass fiber/polyester without hygrothermal effect is lower than wear with hygrothermal effect.

  4. Hygrothermal performance of ventilated wooden cladding

    Energy Technology Data Exchange (ETDEWEB)

    Nore, Kristine

    2009-10-15

    This project contributes to more accurate design guidelines for high-performance building envelopes by analysis of hygrothermal performance of ventilated wooden cladding. Hygrothermal performance is defined by cladding temperature and moisture conditions, and subsequently by risk of degradation. Wood cladding is the most common facade material used in rural and residential areas in Norway. Historically, wooden cladding design varied in different regions in Norway. This was due to both climatic variations and the logistical distance to materials and craftspeople. The rebuilding of Norwegian houses in the 1950s followed central guidelines where local climate adaptation was often not evaluated. Nowadays we find some technical solutions that do not withstand all climate exposures. The demand for thermal comfort and also energy savings has changed hygrothermal condition of the building envelopes. In well-insulated wall assemblies, the cladding temperature is lower compared to traditional walls. Thus the drying out potential is smaller, and the risk of decay may be higher. The climate change scenario indicates a warmer and wetter future in Norway. Future buildings should be designed to endure harsher climate exposure than at present. Is there a need for refined climate differentiated design guidelines for building enclosures? As part of the Norwegian research programme 'Climate 2000', varieties of wooden claddings have been investigated on a test house in Trondheim. The aim of this investigation was to increase our understanding of the relation between microclimatic conditions and the responding hygrothermal performance of wooden cladding, according to orientation, design of ventilation gap, wood material quality and surface treatment. The two test facades, facing east and west have different climate exposure. Hourly measurements of in total 250 sensors provide meteorological data; temperature, radiation, wind properties, relative humidity, and test house data

  5. Hygrothermal Properties and Performance of Sea Grass Insulation

    DEFF Research Database (Denmark)

    Eriksen, Marlene Stenberg Hagen; Laursen, Theresa Back; Rode, Carsten

    2008-01-01

    In the attempt to obtain knowledge of the hygrothermal properties of sea grass as thermal insulation, experiments have been carried out in the laboratory to determine the thermal conductivity, sorption properties and the water vapour permeability of the material. In order to investigate the hygro......In the attempt to obtain knowledge of the hygrothermal properties of sea grass as thermal insulation, experiments have been carried out in the laboratory to determine the thermal conductivity, sorption properties and the water vapour permeability of the material. In order to investigate...

  6. Experimental Study of the Hygrothermal Effect on Wear Behavior of Composite Materials

    OpenAIRE

    Fadhel Abbas. Abdulla; Katea L. Hamid

    2017-01-01

    The hygrothermal effect on the wear behavior of composite material (fiberglass and polyester resin vf=40%) was investigated experimentally in this work. The study includes manufacturing of test device (pin on disc) according to ASTM G 99. In order to study the hygrothermal effect on wear behavior of composite materials the hygrothermal chamber was manufactured. The experimental results show that the wear of glass fiber/polyester increased with increasing the load, sliding speed and sliding di...

  7. Developing Innovative Wall Systems that Improve Hygrothermal Performance of Residential Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Robert Tichy; Chuck Murray

    2006-05-31

    This document serves as the Topical Report documenting work completed by Washington State University (WSU) under U.S. Department of Energy Grant, Developing Innovative Wall Systems that Improve Hygrothermal Performance of Residential Buildings. This project was conducted in collaboration with Oak Ridge National Laboratory (ORNL), and includes the participation of several industry partners including Weyerhaeuser, APA - The Engineered Wood Association, CertainTeed Corporation and Fortifiber. This document summarizes work completed by Washington State University August 2002 through June 2006. WSU's primary experimental role is the design and implementation of a field testing protocol that monitored long term changes in the hygrothermal response of wall systems. During the project period WSU constructed a test facility, developed a matrix of test wall designs, constructed and installed test walls in the test facility, installed instrumentation in the test walls and recorded data from the test wall specimens. Each year reports were published documenting the hygrothermal response of the test wall systems. Public presentation of the results was, and will continue to be, made available to the building industry at large by industry partners and the University.

  8. State-of-the-Art for Hygrothermal Simulation Tools

    Energy Technology Data Exchange (ETDEWEB)

    Boudreaux, Philip R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); New, Joshua Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Adams, Mark B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pallin, Simon B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    The hygrothermal (heat and moisture) performance of buildings can be assessed by utilizing simulation tools. There are currently a number of available hygrothermal calculation tools available which vary in their degree of sophistication and runtime requirements. This report investigates three of the most commonly used models (WUFI, HAMT, and EMPD) to assess their limitations and potential to generate physically realistic results to prioritize improvements for EnergyPlus (which uses HAMT and EMPD). The outcome of the study shows that, out of these three tools, WUFI has the greatest hygrothermal capabilities. Limitations of these tools were also assessed including: WUFI’s inability to properly account for air leakage and transfer at surface boundaries; HAMT’s inability to handle air leakage, precipitationrelated moisture problems, or condensation problems from high relative humidity; and multiple limitations for EMPD as a simplified method to estimate indoor temperature and humidity levels and generally not used to estimate the hygrothermal performance of the building envelope materials. In conclusion, out of the three investigated simulation tools, HAMT has the greatest modeling potential, is open source, and we have prioritized specific features that can enable EnergyPlus to model all relevant heat and moisture transfer mechanisms that impact the performance of building envelope components.

  9. Experimental Study on Bond Behavior of FRP-Concrete Interface in Hygrothermal Environment

    Directory of Open Access Journals (Sweden)

    X. H. Zheng

    2016-01-01

    Full Text Available As the technique of fiber-reinforced polymer (FRP composite material strengthened reinforced concrete structures is widely used in the field of civil engineering, durability of the strengthened structures has attracted more attention in recent years. Hygrothermal environment has an adverse effect on the bond behavior of the interface between FRP and concrete. This paper focuses on the bond durability of carbon fiber laminate- (CFL- concrete interface in hygrothermal condition which simulates the climate characteristic in South China. Twenty 100 mm × 100 mm × 720 mm specimens were divided into 6 groups based on different temperature and humidity. After pretreatment in hygrothermal environment, the specimens were tested using double shear method. Strain gauges bonded along the CFL surface and linear variation displacement transducers (LVDTs were used to measure longitudinal strains and slip of the interface. Failure mode, ultimate capacity, load-deflection relationship, and relative slip were analyzed. The bond behavior of FRP-concrete interface under hygrothermal environment was studied. Results show that the ultimate bearing capacity of the interface reduced after exposure to hygrothermal environments. The decreasing ranges were up to 27.9% after exposure at high temperature and humidity (60°C, 95% RH. The maximum strains (εmax of the specimens pretreated decreased obviously which indicated decay of the bond behavior after exposure to the hygrothermal environment.

  10. Study of Hygrothermal Processes in External Walls with Internal Insulation

    Directory of Open Access Journals (Sweden)

    Biseniece Edite

    2018-03-01

    Full Text Available Being an important contributor to the final energy consumption, historic buildings built before 1945 have high specific heating energy consumption compared to current energy standards and norms. However, they often cannot be insulated from the outside due to their heritage and culture value. Internal insulation is an alternative. However internal insulation faces challenges related to hygrothermal behaviour leading to mold growth, freezing, deterioration and other risks. The goal of this research is to link hygrothermal simulation results with experimental results for internally insulated historic brick masonry to assess correlation between simulated and measured data as well as the most influential parameters. The study is carried out by both a mathematical simulation tool and laboratory tests of historic masonry with internal insulation with four insulation materials (mineral wool, EPS, wood fiber and granulated aerogel in a cold climate (average 4000 heating degree days. We found disparity between measured and simulated hygrothermal performance of studied constructions due to differences in material parameters and initial conditions of materials. The latter plays a more important role than material parameters. Under a steady state of conditions, the condensate tolerating system varies between 72.7 % and 80.5 % relative humidity, but in condensate limiting systems relative humidity variates between 73.3 % and 82.3 %. The temperature between the masonry wall and all insulation materials has stabilized on average at +10 °C. Mold corresponding to Mold index 3 was discovered on wood fiber mat.

  11. Study of Hygrothermal Processes in External Walls with Internal Insulation

    Science.gov (United States)

    Biseniece, Edite; Freimanis, Ritvars; Purvins, Reinis; Gravelsins, Armands; Pumpurs, Aivars; Blumberga, Andra

    2018-03-01

    Being an important contributor to the final energy consumption, historic buildings built before 1945 have high specific heating energy consumption compared to current energy standards and norms. However, they often cannot be insulated from the outside due to their heritage and culture value. Internal insulation is an alternative. However internal insulation faces challenges related to hygrothermal behaviour leading to mold growth, freezing, deterioration and other risks. The goal of this research is to link hygrothermal simulation results with experimental results for internally insulated historic brick masonry to assess correlation between simulated and measured data as well as the most influential parameters. The study is carried out by both a mathematical simulation tool and laboratory tests of historic masonry with internal insulation with four insulation materials (mineral wool, EPS, wood fiber and granulated aerogel) in a cold climate (average 4000 heating degree days). We found disparity between measured and simulated hygrothermal performance of studied constructions due to differences in material parameters and initial conditions of materials. The latter plays a more important role than material parameters. Under a steady state of conditions, the condensate tolerating system varies between 72.7 % and 80.5 % relative humidity, but in condensate limiting systems relative humidity variates between 73.3 % and 82.3 %. The temperature between the masonry wall and all insulation materials has stabilized on average at +10 °C. Mold corresponding to Mold index 3 was discovered on wood fiber mat.

  12. Hygrothermal Simulation of Foundations: Part 1 - Soil Material Properties

    Energy Technology Data Exchange (ETDEWEB)

    Kehrer, Manfred [ORNL; Pallin, Simon B [ORNL

    2012-10-01

    The hygrothermal performance of soils coupled to buildings is a complicated process. A computational approach for heat transfer through the ground has been well defined (EN ISO 13370:2007, 2007), and simplified methods have been developed (Staszczuk, Radon, and Holm 2010). However, these approaches generally ignore the transfer of soil moisture, which is not negligible (Janssen, Carmeliet, and Hens 2004). This study is divided into several parts. The intention of the first part is to gather, comprehend and adapt soil properties from Soil Science. The obtained information must be applicable to related tasks in Building Science and validated with hygrothermal calculation tools. Future parts of this study will focus on the validation aspect of the soil properties to be implemented. Basic changes in the software code may be requested at this time. Different types of basement construction will be created with a hygrothermal calculation tool, WUFI. Simulations from WUFI will be compared with existing or ongoing measurements. The intentions of the first part of this study have been fulfilled. The soil properties of interest in Building Science have been defined for 12 different soil textures. These properties will serve as input parameters when performing hygrothermal calculations of building constructions coupled to soil materials. The reliability of the soil parameters will be further evaluated with measurements in Part 2.

  13. Cold Climate Foundation Retrofit Experimental Hygrothermal Performance. Cloquet Residential Research Facility Laboratory Results

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Harmon, Anna C. [NorthernSTAR, St. Paul, MN (United States)

    2015-04-09

    This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes. NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. These data currently span the period from November 10, 2012 through May 31, 2014 and are anticipated to be extended through November 2014. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.

  14. Hygrothermal behavior for a clay brick wall

    Science.gov (United States)

    Allam, R.; Issaadi, N.; Belarbi, R.; El-Meligy, M.; Altahrany, A.

    2018-06-01

    In Egypt, the clay brick is the common building materials which are used. By studying clay brick walls behavior for the heat and moisture transfer, the efficient use of the clay brick can be reached. So, this research studies the hygrothermal transfer in this material by measuring the hygrothermal properties and performing experimental tests for a constructed clay brick wall. We present the model for the hygrothermal transfer in the clay brick which takes the temperature and the vapor pressure as driving potentials. In addition, this research compares the presented model with previous models. By constructing the clay brick wall between two climates chambers with different boundary conditions, we can validate the numerical model and analyze the hygrothermal transfer in the wall. The temperature and relative humidity profiles within the material are measured experimentally and determined numerically. The numerical and experimental results have a good convergence with 3.5% difference. The surface boundary conditions, the ground effect, the infiltration from the closed chambers and the material heterogeneity affects the results. Thermal transfer of the clay brick walls reaches the steady state very rapidly than the moisture transfer. That means the effect of using only the external brick wall in the building in hot climate without increase the thermal resistance for the wall, will add more energy losses in the clay brick walls buildings. Also, the behavior of the wall at the heat and mass transfer calls the three-dimensional analysis for the whole building to reach the real behavior.

  15. Hygrothermal behavior for a clay brick wall

    Science.gov (United States)

    Allam, R.; Issaadi, N.; Belarbi, R.; El-Meligy, M.; Altahrany, A.

    2018-01-01

    In Egypt, the clay brick is the common building materials which are used. By studying clay brick walls behavior for the heat and moisture transfer, the efficient use of the clay brick can be reached. So, this research studies the hygrothermal transfer in this material by measuring the hygrothermal properties and performing experimental tests for a constructed clay brick wall. We present the model for the hygrothermal transfer in the clay brick which takes the temperature and the vapor pressure as driving potentials. In addition, this research compares the presented model with previous models. By constructing the clay brick wall between two climates chambers with different boundary conditions, we can validate the numerical model and analyze the hygrothermal transfer in the wall. The temperature and relative humidity profiles within the material are measured experimentally and determined numerically. The numerical and experimental results have a good convergence with 3.5% difference. The surface boundary conditions, the ground effect, the infiltration from the closed chambers and the material heterogeneity affects the results. Thermal transfer of the clay brick walls reaches the steady state very rapidly than the moisture transfer. That means the effect of using only the external brick wall in the building in hot climate without increase the thermal resistance for the wall, will add more energy losses in the clay brick walls buildings. Also, the behavior of the wall at the heat and mass transfer calls the three-dimensional analysis for the whole building to reach the real behavior.

  16. Cold Climate Foundation Retrofit Experimental Hygrothermal Performance: Cloquet Residential Research Facility Laboratory Results

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Harmon, Anna C. [NorthernSTAR, St. Paul, MN (United States)

    2015-04-01

    Thermal and moisture problems in existing basements create a unique challenge because the exterior face of the wall is not easily or inexpensively accessible. This approach addresses thermal and moisture management from the interior face of the wall without disturbing the exterior soil and landscaping. the interior and exterior environments. This approach has the potential for improving durability, comfort, and indoor air quality. This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes. NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.

  17. Whole-Building Hygrothermal Modeling in IEA Annex 41

    DEFF Research Database (Denmark)

    Rode, Carsten; Woloszyn, Monika

    2007-01-01

    . The IEA Annex 41 project runs from 2004–2007, coming to conclusion just before the Thermal Performance of the Exterior Envelopes of Whole Buildings X conference. The Annex 41 project and its Subtask 1 do not aim to produce one state-of-the-art hygrothermal simulation model for whole buildings, but rather...... the modeling, free scientific contributions have been invited from specific fields that need the most attention in order to better accomplish the integral building simulations. This paper will give an overview of the advances in whole-building hygrothermal simulation that have been accomplished and presented...

  18. Hygrothermal Material Properties for Soils in Building Science

    Energy Technology Data Exchange (ETDEWEB)

    Kehrer, Manfred [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pallin, Simon B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-01

    Hygrothermal performance of soils coupled to buildings is complicated because of the dearth of information on soil properties. However they are important when numerical simulation of coupled heat and moisture transport for below-grade building components are performed as their temperature and moisture content has an influence on the durability of the below-grade building component. Soils can be classified by soil texture. According to the Unified Soil Classification System (USCA), 12 different soils can be defined on the basis of three soil components: clay, sand, and silt. This study shows how existing material properties for typical American soils can be transferred and used for the calculation of the coupled heat and moisture transport of building components in contact with soil. Furthermore a thermal validation with field measurements under known boundary conditions is part of this study, too. Field measurements for soil temperature and moisture content for two specified soils are carried out right now under known boundary conditions. As these field measurements are not finished yet, the full hygrothermal validation is still missing

  19. Hygrothermal Behavior, Building Pathology and Durability

    CERN Document Server

    Delgado, JMPQ

    2013-01-01

    The main purpose of this book, Hygrothermal, Building Pathology and Durability, is to provide a collection of recent research works to contribute to the systematization and dissemination of knowledge related to construction pathology, hygrothermal behaviour of buildings, durability and diagnostic techniques and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of building physics and hygrothermal behaviour, durability approach for historical and old buildings and building pathology vs. durability. The book is divided in several chapters that are a resume of the current state of knowledge for benefit of professional colleagues, scientists, students, practitioners, lecturers and other interested parties to network.

  20. Hygrothermal Analysis and Failure Analysis of Composite Beams under Moving Loads

    Science.gov (United States)

    Hanif, Moiz

    Excellent combination of high structural stiffness and low weight are the qualities of composite material leading to the extensive work on such materials. In order to achieve the desired performance requirements, the designer has to take into consideration the structural requirements and the functional characteristics. Thus, in this study, the effect of hygrothermal conditions on fiber reinforced composite laminates with moving loads have been extensively studied and has been carried out that accompanies Classical Laminate Plate Theory (CLPT) as well as First Order Shear Deformation Theory (FSDT) on MATLAB. A glass/epoxy composite system has been chosen for study with which similar results may be expected for other laminated composites. The hygrothermal effect is incorporated by adjusting the stiffness coefficients of the laminate to its level of moisture concentration using empirical relations. The failure analysis is done using the maximum normal stress criterion and the factor of safety for the lamina calculated and compared with respect to the corresponding maximum stresses and strengths. Different fiber volume fraction with varying fiber orientation of the plies in the laminate were modeled and studied. The results presented show the effect of stresses and strains in dry conditions, whereas for hygrothermal analysis, they also indicate that not all the laminates behave in a similar fashion and so it is possible by selecting the proper laminate configuration, the effect of moisture can be reduced. Also deducing, that due to hygrothermal effects, changes in the stiffness coefficients of a laminate do not appear to affect the deflection results significantly.

  1. Hygrothermal analysis of surface layers of historical masonry

    Science.gov (United States)

    Kočí, Václav; Maděra, Jiří; Keppert, Martin; Černý, Robert

    2017-11-01

    The paper deals with the hygrothermal analysis of surface layers of historical masonry. Solid brick provided with a traditional and two modified lime-based plasters is studied. The heat and moisture transport in the envelope is induced by an exposure of the wall from the exterior side to dynamic climatic conditions of Olomouc, Czech Republic. The transport processes are described using diffusion type of mathematical model based on experimentally determined material properties. The computational results indicate that hygric transport and accumulation properties of exterior plasters affect the hygrothermal performance of the underlying solid brick in a very significant way, being able to regulate the amount of transported moisture. The modified lime plasters are not found generally superior to the traditional lime plasters in that respect. Therefore, their suitability for historical masonry should be assessed case by case, with a particular attention to the climatic conditions and to the properties of the load bearing structure.

  2. Hygrothermal Numerical Simulation Tools Applied to Building Physics

    CERN Document Server

    Delgado, João M P Q; Ramos, Nuno M M; Freitas, Vasco Peixoto

    2013-01-01

    This book presents a critical review on the development and application of hygrothermal analysis methods to simulate the coupled transport processes of Heat, Air, and Moisture (HAM) transfer for one or multidimensional cases. During the past few decades there has been relevant development in this field of study and an increase in the professional use of tools that simulate some of the physical phenomena that are involved in Heat, Air and Moisture conditions in building components or elements. Although there is a significant amount of hygrothermal models referred in the literature, the vast majority of them are not easily available to the public outside the institutions where they were developed, which restricts the analysis of this book to only 14 hygrothermal modelling tools. The special features of this book are (a) a state-of-the-art of numerical simulation tools applied to building physics, (b) the boundary conditions importance, (c) the material properties, namely, experimental methods for the measuremen...

  3. Experimental Study on the Hygrothermal Behavior of a Coated Sprayed Hemp Concrete Wall

    Directory of Open Access Journals (Sweden)

    Anthony Magueresse

    2013-01-01

    Full Text Available Hemp concrete is a sustainable lightweight concrete that became popular in the field of building construction because of its thermal and environmental properties. However; available experimental data on its hygrothermal behavior are rather scarce in the literature. This paper describes the design of a large-scale experiment developed to investigate the hygrothermal behavior of hemp concrete cast around a timber frame through a spraying process; and then coated with lime-based plaster. The equipment is composed of two climatic chambers surrounding the tested wall. The experiment consists of maintaining the indoor climate at constant values and applying incremental steps of temperature; relative humidity or vapor pressure in the outdoor chamber. Temperature and relative humidity of the room air and on various depths inside the wall are continuously registered during the experiments and evaporation phenomena are observed. The influence of the plaster on the hygrothermal behavior of hemp concrete is investigated. Moreover; a comparison of experimental temperatures with numerical results obtained from a purely conductive thermal model is proposed. Comparing the model with the measured data gave satisfactory agreement.

  4. Hygrothermal Simulation: A Tool for Building Envelope Design Analysis

    Science.gov (United States)

    Samuel V. Glass; Anton TenWolde; Samuel L. Zelinka

    2013-01-01

    Is it possible to gauge the risk of moisture problems while designing the building envelope? This article provides a brief introduction to computer-based hygrothermal (heat and moisture) simulation, shows how simulation can be useful as a design tool, and points out a number of im-portant considerations regarding model inputs and limita-tions. Hygrothermal simulation...

  5. Hygrothermal Effect on Mechanical and Fatigue Properties of laminated Lower Limb Socket and Bacteria Growth

    Directory of Open Access Journals (Sweden)

    Fadhel Abbas Abdullah

    2016-12-01

    Full Text Available In this work, hygrothermal effect on the mechanical and fatigue properties of prosthetic socket lamination and its effect on the bacteria growth were studied. Two laminations composite materials were used in manufacturing prosthetic socket by using vacuum device. The reinforced materials of these laminations were perlon and carbon nanopowder (CNP while the matrix material was polyurethane resin. Tests performed in this work were the moisture absorption properties test to calculate percent moisture content according to ASTM 5229, tensile and fatigue tests with and without the hygrothermal effect to find the mechanical and fatigue properties, and the bacteria growth test under the hygrothermal effect to calculate the number of bacteria on the laminations. The results showed that the lamination (10 perlon+1 wt % CNP has mechanical properties than lamination (10 perlon with and without hygrothermal effect. The mechanical and fatigue properties for the two laminations were decreasing with increasing temperature and moisture.. Adding carbon nanopowder to the lamination (10 perlon increased ultimate stress, modulus of elastic, and endurance limit by (1.36, 2.35, and2.72 time respectively. Finally, the results showed that the Staphylococcus aureus growth increases with increasing temperature and moisture on the two laminations used in manufacturing prosthetic socket, and adding carbon nanopowder also increased the Staphylococcus aureus growth on the lamination.

  6. Analytical investigation of the hygrothermal effects and parametric study of the Edge Crack Torsion (ECT) mode 3 test lay-ups

    Science.gov (United States)

    Li, Jian; Obrien, T. Kevin

    1995-01-01

    A shear deformation theory including residual thermal and moisture effects is developed for the analysis of either symmetric or unsymmetric laminates with mid-plane edge delamination under torsion loading. The theory is based on an assumed displacement field which includes shear deformation. The governing equations and boundary conditions are obtained from the principle of virtual work. The analysis of the (90/(+/- 45)(n)/(-/+ 45)(n)/90)(s) ECT mode 3 test lay-up indicates that there are no hygrothermal effects on the mode 3 strain energy release rate because the laminate, and both sublaminates above and below the delamination, are symmetric lay-ups. A further parametric study reveals that some other lay-ups can have negligible hygrothermal effects even when the sublaminates above and below the delamination are not symmetric about their own mid-planes. However, these lay-ups may suffer from distortion after the curing process. Another Interesting set of lay-ups investigated is a class of antisymmetric laminates with (+/-(theta/(theta -90)(2)/theta))(n) lay-ups. It is observed that when n takes on even numbers (2 and 4), both hygrothermal and mode 1 effects can be neglected. From this point of view, these lay-ups provide a way to determine the mode 3 toughness between two dissimilar layers. However, when n takes on odd numbers (1 and 3), both hygrothermal and mode 1 effects may be strong in these lay-ups. In particular, when theta equals 45 deg, the lay-ups are free from both hygrothermal and mode 1 effects irrespective of n.

  7. Optimizing the Physical, Mechanical and Hygrothermal Performance of Compressed Earth Bricks

    Directory of Open Access Journals (Sweden)

    Esther Obonyo

    2011-03-01

    Full Text Available The paper is based on findings from research that assesses the potential for enhancing the performance of compressed earth bricks. A set of experiments was carried out to assess the potential for enhancing the bricks’ physical, mechanical and hygrothermal performance through the design of an optimal stabilization strategy. Three different types of bricks were fabricated: soil-cement, soil-cement-lime, and soil-cement-fiber. The different types of bricks did not exhibit significant differences in performances when assessed on the basis of porosity, density, water absorption, and compressive strength. However, upon exposure to elevated moisture and temperature conditions, the soil-cement-fiber bricks had the highest residual strength (87%. The soil-cement and soil-cement-lime bricks had residual strength values of 48.19 and 46.20% respectively. These results suggest that, like any other cement-based material, compressed earth brick properties are affected by hydration-triggered chemical and structural changes occurring in the matrix that would be difficult to isolate using tests that focus on “bulk” changes. The discussion in this paper presents findings from a research effort directed at quantifying the specific changes through an analysis of the microstructure.

  8. Long-term monitoring of the Sedlec Ossuary - Analysis of hygrothermal conditions

    Science.gov (United States)

    Pavlík, Zbyšek; Balík, Lukáš; Maděra, Jiří; Černý, Robert

    2016-07-01

    The Sedlec Ossuary is one of the twelve UNESCO World Heritage Sites in the Czech Republic. Although the ossuary is listed among the most visited Czech tourist attractions, its technical state is almost critical and a radical renovation is necessary. On this account, hygrothermal performance of the ossuary is experimentally researched in the presented paper in order to get information on moisture sources and to get necessary data for optimized design of renovation treatments and reconstruction solutions that will allow preserve the historical significance of this attractive heritage site. Within the performed experimental analysis, the interior and exterior climatic conditions are monitored over an almost three year period together with relative humidity and temperature profiles measured in the most damage parts of the ossuary chapel. On the basis of measured data, the long-term hygrothermal state of the ossuary building is accessed and the periods of possible surface condensation are identified.

  9. Hygrothermal optimisation of museum storage spaces

    DEFF Research Database (Denmark)

    Janssen, Hans; Christensen, Jørgen Erik

    2013-01-01

    Despite the large economic and ecologic costs, museum storage spaces are often equipped with extensive air conditioning, to provide the desired stable interior climate. The new “passive conditioning” paradigm aims at resolving these costs: a high-hygrothermal-inertia building with a high-hygrothe......Despite the large economic and ecologic costs, museum storage spaces are often equipped with extensive air conditioning, to provide the desired stable interior climate. The new “passive conditioning” paradigm aims at resolving these costs: a high-hygrothermal-inertia building with a high...... and ecologic cost of conditioning, the paper finally assesses “concentrated dehumidification”: dehumidification during a part of the day only, while leaving the humidity free-running during the rest of the day. It is established that the hygric inertia of the interior air, building walls and stored objects...

  10. Characterization of fracture toughness of epoxy resin after hygrothermal aging

    KAUST Repository

    Quispe, Gustavo Q.

    2013-07-01

    Characterization of fracture toughness of epoxy resin after hygrothermal ageing Gustavo Quino Quispe The aim of this work is to characterize the e ects of hygrothermal aging in the plain strain fracture toughness of the epoxy system composed by cycloaliphatic epoxy resin and diglycidyl ether of bisphenol-A (DGEBA). For this, after having been under hygrothermal aging in a climatic chamber, epoxy samples were studied using ASTM D5045 fracture toughness test, and micrography and roughness measurements of the fracture surface. It is reported a rapid decrease of GIc and KIc during the rst 2 days. Moreover, a numerical model [13] was used to simulate and see with more detail the water absorption in the aged samples. From that, it was observed the heterogeneous distribution of water. Accordingly, it was proposed that the results should be correlated with the water content at the vicinity of the crack tip. Consequently, it was possible to obtain, by quasi-static simulations, the ideal load-displacement curves of crack propagation in the heterogeneous samples. Finally, another contribution of this work is the study of the fracture surface, that gives a clue of the relationship among the fracture energy, the appearance of microcracks in the fracture surface, and the roughness (Ra).

  11. Simulation of whole building coupled hygrothermal-airflow transfer in different climates

    International Nuclear Information System (INIS)

    Qin Menghao; Walton, George; Belarbi, Rafik; Allard, Francis

    2011-01-01

    The coupled heat, air and moisture transfer between building envelopes and indoor air is complicated, and has a significant influence on the indoor environment and the energy performance of buildings. In the paper, a model for predicting coupled multi-zone hygrothermal-airflow transfer is presented. Both heat and moisture transfer in the building envelope and multi-zone indoor airflow are simultaneously considered; their interactions are modeled. The coupled system model is implemented into Matlab-Simulink, and is validated by using a series of testing tools and experiments. The new program is applied to investigate the moisture transfer effect on indoor air humidity and building energy consumption in different climates (hot-humid, temperate and hot-dry climates). The results show that not accounting for hygrothermal effects in modeling will result in overestimation of energy costs for hot and humid climate situations and possible over sizing of plant leading to inefficient operation.

  12. Chapel of cemetery church of all saints in Sedlec - Long-term analysis of hygrothermal conditions

    Science.gov (United States)

    Pavlík, Zbyšek; Balík, Lukáš; Kudrnáčová, Lucie; Maděra, Jiří; Černý, Robert

    2017-07-01

    In this paper, long-term monitoring of hygrothermal conditions of the chapel of the cemetery church of All Saints in Sedlec, Czech Republic is presented as a practical tool for evaluation of functional problems of the researched structure. Within the performed experimental tests, interior and exterior climatic conditions were monitored over one year period. Herewith, surface temperature of the chapel wall was measured. Exterior climatic data were collected using weather station Vantage Pro2 placed in church tower. In interior, precise combined relative humidity/temperature sensors were installed. Based on the accessed hygrothermal state of the inspected chapel and identified periods of possible surface condensation, service conditions of the chapel will be optimized in order to prevent extensive damage of historically valuable finishing and furnishing materials, paintings, plasters, and architectural ornaments.

  13. Hygrothermal modelling of flooding events within historic buildings

    NARCIS (Netherlands)

    Huijbregts, Z.; Schellen, H.L.; Schijndel, van A.W.M.; Blades, N.

    2014-01-01

    Flooding events pose a high risk to valuable monumental buildings and their interiors. Due to higher river discharges and sea level rise, flooding events may occur more often in future. Hygrothermal building simulation models can be applied to investigate the impact of a flooding event on the

  14. Hygrothermal modelling of flooding events within historic buildings

    NARCIS (Netherlands)

    Huijbregts, Z.; Schijndel, van A.W.M.; Schellen, H.L.; Blades, N.; Mahdavi, A.; Mertens, B.

    2013-01-01

    Flooding events pose a high risk to valuable monumental buildings and their interiors. Due to higher river discharges and sea level rise, flooding events may occur more often in future. Hygrothermal building simulation models can be applied to investigate the impact of a flooding event on the

  15. Influence of Hygrothermal Aging on Poisson’s Ratio of Thin Injection-Molded Short Glass Fiber-Reinforced PA6

    OpenAIRE

    Thomas Illing; Heinrich Gotzig; Marcus Schoßig; Christian Bierögel; Wolfgang Grellmann

    2016-01-01

    The hygrothermal aging of short glass fiber-reinforced polyamide 6 materials (PA6 GF) represents a major problem, especially in thin-walled components, such as in the automotive sector. In this study, therefore, the thickness and the glass fiber content of PA6 GF materials were varied and the materials were exposed to hygrothermal aging. The temperature and relative humidity were selected in the range from −40 °C up to 85 °C, and from 10% up to 85% relative humidity (RH). In the dry-as-molded...

  16. Design of hygrothermal detection and control intelligent system based on AVR-MCU in radon chamber

    International Nuclear Information System (INIS)

    Zheng Yongming; Fang Fang; Zhou Wei; Zheng Meiyang; Xu Jianyi

    2006-01-01

    The design of a new hygrothermal detection and control system based on AVR-MCU, which is used in minitype and medium-sized radon chamber, is introduced. The kernel of the interface among ATmega128 MCU, hygrothermal sensor, refrigeration and desiccation components is described. In addition, with the calculation of the control capability in theory, it comes to the conclusion that the design is feasible, and this control system not only can work in independence, but also can cooperate with PC by RS232 communication. (authors)

  17. Development of the control algorithm of processes of intensive hygrothermal impact on capillary and porous materials in the conditions of the vacuum

    Directory of Open Access Journals (Sweden)

    Larina Ludmila

    2017-01-01

    Full Text Available Objective of this research is creation of an algorithm of a control system of the modes of the intensive hygrothermal influence (IGI in the conditions of a vacuum when performing the corresponding operations: moistening; the subsequent, if necessary, cyclic drying from within preparation of top of footwear; damp thermal treatment on universal installation with adjustable parameters of a working environment. For assessment of quality of the intensified hygrothermal impact on preparations of top of footwear the integrated criteria of efficiency of processes were used. Ensuring automatic control of parameters of processes of IGV on preparations of top of footwear in universal vacuum installation will allow to control quality of preparations upon transition from performance of one operation to another according to standard manufacturing techniques of footwear.

  18. ANALYSIS OF HYGROTHERMAL CONDITIONS OF EXTERNAL PARTITIONS IN AN UNDERGROUND FRUIT STORE

    Directory of Open Access Journals (Sweden)

    Grzegorz Nawalany

    2016-09-01

    Full Text Available The paper presents the analysis of hygrothermal conditions of external partitions in an underground fruit store. The results of measurements of temperature and humidity of the indoor and outdoor air as well as the surface surrounding temperature and the temperature of the air surrounding the store constituted the boundary conditions for the hygrothermal calculations. The paper presents the calculation of the distribution of the temperature and humidity on the ground floor, the wall contacting the ground, the wall contacting the outside air, and the ceiling above the storage chamber. The heat and moisture calculations have shown high risk of condensation submerged in non-insulated external walls. The condition of the adaptation of a traditional cold store to a simple and atmosphere controlled cold one is to increase the thermal resistance of the partitions. Such a solution will let cut the energy demand in those types of agricultural buildings.

  19. Variation of mechanical properties due to hygrothermal ageing and permanent changes upon redrying in clay/epoxy nanocomposites

    Science.gov (United States)

    Hamim, Salah Uddin Ahmed

    2011-12-01

    Epoxy polymers are an important class of material for use in various applications. Due to their hydrophilic nature, epoxy resins tend to absorb moisture. Absorption of moisture degrades the functional, structural and mechanical properties. For polymers, moisture absorption can lead to both reversible and irreversible changes. In this study, the combined effect of moisture and elevated temperature on the mechanical properties of Epon 862 and its nanocomposites were investigated. The extent of permanent damage on fracture toughness and flexural properties of epoxy, due to the aggressive degradation provided by hygrothermal ageing, was determined by drying the epoxy and their clay/epoxy nanocomposites after moisture absorption. From the investigation it was found out that, clay can help in reducing the negative effect of hygrothermal ageing. Significant permanent damage was observed for fracture toughness and modulus, while the extent of permanent damage was less significant for flexural strength. Failure mechanism of this nanocomposites were studied by using Scanning Electron Microscopy (SEM).

  20. Preparation and hygrothermal properties of composite phase change humidity control materials

    International Nuclear Information System (INIS)

    Chen, Zhi; Qin, Menghao

    2016-01-01

    Highlights: • A new kind of phase change humidity control material (PCHCM) was prepared. • The PCHCM can moderate both the indoor temperature and humidity. • The silicon dioxide shell can improve the thermal properties of the composite. • The PCM microcapsules can improve the moisture buffer ability of the composite. • The CPCM/vesuvianite composite has a better hygrothermal performance than pure hygroscopic material. - Abstract: A novel phase change humidity control material (PCHCM) was prepared by using PCM microcapsules and different hygroscopic porous materials. The PCHCM composite can regulate the indoor hygrothermal environment by absorbing or releasing both heat and moisture. The PCM microcapsules were synthesized with methyl triethoxysilane by the sol–gel method. The vesuvianite, sepiolite and zeolite were used as hygroscopic materials. The scanning electron microscopy (SEM) was used to measure the morphology profiles of the microcapsules and PCHCM. The differential scanning calorimetry (DSC) and the thermal gravimetric analysis (TGA) were used to determine the thermal properties and thermal stability. Both the moisture transfer coefficient and moisture buffer value (MBV) of different PCHCMs were measured by the improved cup method. The DSC results showed that the SiO 2 shell can reduce the super-cooling degree of PCM. The super-cooling degrees of microcapsules and PCHCM are lower than that of the pure PCM. The onset temperature of thermal degradation of the microcapsules and PCHCMs is higher than that of pure PCM. Both the moisture transfer coefficient and MBV of PCHCMs are higher than that of the pure hygroscopic materials. The results indicated the PCHCMs have better thermal properties and moisture buffer ability.

  1. Coupled hygrothermal, electrochemical, and mechanical modelling for deterioration prediction in reinforced cementitious materials

    DEFF Research Database (Denmark)

    Michel, Alexander; Geiker, Mette Rica; Lepech, M.

    2017-01-01

    In this paper a coupled hygrothermal, electrochemical, and mechanical modelling approach for the deterioration prediction in cementitious materials is briefly outlined. Deterioration prediction is thereby based on coupled modelling of (i) chemical processes including among others transport of hea......, i.e. information, such as such as corrosion current density, damage state of concrete cover, etc., are constantly exchanged between the models....... and matter as well as phase assemblage on the nano and micro scale, (ii) corrosion of steel including electrochemical processes at the reinforcement surface, and (iii) material performance including corrosion- and load-induced damages on the meso and macro scale. The individual FEM models are fully coupled...

  2. Hygrothermal effect of salt water environments on mechanical properties of carbon/epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Young Eun; Yoon, Sung Ho [Kumoh Nat' l Institute of Technology, Gumi (Korea, Republic of)

    2012-10-15

    In this study, salt water immersion tests were experimentally performed for up to 12 months to investigate the hygrothermal effect of salt water environments on the mechanical properties of carbon/epoxy composites. The composites were manufactured by laminating prepregs composed of carbon plain woven fabric and epoxy resin. The specimens were subjected to temperatures of 35, 55, and 75 .deg. C while being exposed to the salt water environments. Mechanical test results showed that the tensile modulus and tensile strength decreased at a small rate, and the compressive modulus and compressive strength decreased at a relatively larger rate, as the exposure temperature and time increased. The rate of decrease in compressive strength became larger as the exposure temperature became higher. This is because a higher environmental temperature accelerates the salt water uptake; this, in turn, reduces the compressive strength more rapidly.

  3. Hygrothermal effect of salt water environments on mechanical properties of carbon/epoxy composites

    International Nuclear Information System (INIS)

    Hwang, Young Eun; Yoon, Sung Ho

    2012-01-01

    In this study, salt water immersion tests were experimentally performed for up to 12 months to investigate the hygrothermal effect of salt water environments on the mechanical properties of carbon/epoxy composites. The composites were manufactured by laminating prepregs composed of carbon plain woven fabric and epoxy resin. The specimens were subjected to temperatures of 35, 55, and 75 .deg. C while being exposed to the salt water environments. Mechanical test results showed that the tensile modulus and tensile strength decreased at a small rate, and the compressive modulus and compressive strength decreased at a relatively larger rate, as the exposure temperature and time increased. The rate of decrease in compressive strength became larger as the exposure temperature became higher. This is because a higher environmental temperature accelerates the salt water uptake; this, in turn, reduces the compressive strength more rapidly

  4. Passive hygrothermal control of a museum storage building in Vejle

    DEFF Research Database (Denmark)

    Christensen, Jørgen Erik; Janssen, Hans

    2010-01-01

    and maintenance costs are currently motivating a paradigm change toward passive control. Passive control, via the thermal and hygric inertia of the building, is gaining a foothold in the museum conservation and building physical community. In this report we document the hygrothermal performance optimisation...... of a museum storage building, related to an existing storage centre in Vejle (Denmark). The current building design already incorporates passive control concepts: thermal inertia is provided by the thick walls, the ground floor and its underlying soil volume, while hygric inertia is provided by the thick...... with the thermal inertia of the ground and thus a higher temperature variation; For those reasons, more heavily insulated walls and roofs could be considered. Their effects on the interior climate and dehumidification load are however not that large. For the floor, no insulation should be added, and it could...

  5. Can crawl space temperature and moisture conditions be calculated with a whole-building hygrothermal simulation tool?

    DEFF Research Database (Denmark)

    Vanhoutteghem, Lies; Morelli, Martin; Sørensen, Lars Schiøtt

    2017-01-01

    of measurements was compared with simulations of temperature and moisture condition in the floor structure and crawl space. The measurements showed that the extra 50 mm insulation placed below the beams reduced moisture content in the beams below 20 weight% all year. A reasonable agreement between......The hygrothermal behaviour of an outdoor ventilated crawl space with two different designs of the floor structure was investigated. The first design had 250 mm insulation and visible wooden beams towards the crawl space. The second design had 300 mm insulation and no visible wooden beams. One year...... the measurements and simulations was found; however, the evaporation from the soil was a dominant parameter affecting the hygrothermal response in the crawl space and floor structure....

  6. A multiscale and multiphysics numerical framework for modelling of hygrothermal ageing in laminated composites

    NARCIS (Netherlands)

    Barcelos Carneiro M Rocha, Iuri; van der Meer, F.P.; Nijssen, RPL; Sluijs, Bert

    2017-01-01

    In this work, a numerical framework for modelling of hygrothermal ageing in laminated composites is proposed. The model consists of a macroscopic diffusion analysis based on Fick's second law coupled with a multiscale FE2 stress analysis in order to take microscopic degradation

  7. Hygromorphic characterization of softwood under high resolution X-ray tomography for hygrothermal simulation

    Science.gov (United States)

    El Hachem, Chady; Abahri, Kamilia; Vicente, Jérôme; Bennacer, Rachid; Belarbi, Rafik

    2018-03-01

    Because of their complex hygromorphic shape, microstructural study of wooden materials behavior has recently been the point of interest of researchers. The purpose of this study, in a first part, consists in characterizing by high resolution X-ray tomography the microstructural properties of spruce wood. In a second part, the subresulting geometrical parameters will be incorporated when evaluating the wooden hygrothermal transfers behavior. To do so, volume reconstructions of 3 Dimensional images (3D), obtained with a voxel size of 0.5 μm were achieved. The post-treatment of the corresponding volumes has given access to averages and standard deviations of lumens' diameters and cell walls' thicknesses. These results were performed for both early wood and latewood. Further, a segmentation approach for individualizing wood lumens was developed, which presents an important challenge in understanding localized physical properties. In this context, 3D heat and mass transfers within the real reconstructed geometries took place in order to highlight the effect of wood directions on the equivalent conductivity and moisture diffusion coefficients. Results confirm that the softwood cellular structure has a critical impact on the reliability of the studied physical parameters.

  8. Hygrothermal influence on delamination behavior of graphite/epoxy laminates

    Science.gov (United States)

    Garg, A.; Ishai, O.

    1985-01-01

    The hygrothermal effect on the fracture behavior of graphite-epoxy laminates was investigated to develop a methodology for damage tolerance predictions in advanced composite materials. Several T300/934 laminates were tested using a number of specimen configurations to evaluate the effects of temperature and humidity on delamination fracture toughness under mode 1 and mode 2 loading. It is indicated that moisture has a slightly beneficial influence on fracture toughness or critical strain energy release rate during mode 1 delamination, but has a slightly deleterious effect on mode 2 delamination, and mode 1 transverse cracking. The failed specimens are examined by SEM and topographical differences due to fracture modes are identified. It is concluded that the effect of moisture on fracture topography can not be distinguished.

  9. Effect of façade impregnation on feasibility of capillary active thermal internal insulation for a historic dormitory – A hygrothermal simulation study

    DEFF Research Database (Denmark)

    Finken, Gholam Reza; Bjarløv, Søren Peter; Peuhkuri, Ruut Hannele

    2016-01-01

    Internal insulation of external walls is known to create moisture performance challenges due to increased moisture levels and condensation risk on the cold side of the insulation. Capillary active/hydrophilic insulations have been introduced to solve these moisture problems, since they are able...... to transport liquid moisture to the inner surface and enable it to dry. Experience with this insulation type is rare in Denmark. In hygrothermal 1D computer simulations, several more or less capillary active insulation systems (AAC, calcium silicate, IQ-Therm) in various thicknesses (30–150 mm) have been....... A moisture safe construction was only achieved when exterior façade impregnation shielding against driving rain was added. The best system showed acceptable relative humidity values both behind the insulation and on the interior surface, a significant increase in minimum temperature on the interior surface...

  10. Experimental investigation of cyclic hygrothermal aging of hybrid composite

    KAUST Repository

    El Yagoubi, Jalal

    2013-04-05

    This work provides an experimental investigation of the cyclic hygrothermal aging of a hybrid composites. We aimed to propose a general framework in the view to further optimize polymer-based composites. It reports experimental data and relevant observations collected during an aging campaign (up to 2000 cycles) where anhydride-cured epoxy samples as well as composites samples are exposed to environmental conditions. The data gathered during the whole campaign reveals that (1) the polymer displays a non-classical sorption behavior (2) the volume change is correlated to the mass uptake (3) the elastic modulus is correlated to the glass transition temperature. Matrix and interface degradation of the hybrid composite is monitored by means of microstructural observations. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

  11. Experimental investigation of cyclic hygrothermal aging of hybrid composite

    KAUST Repository

    El Yagoubi, Jalal; Lubineau, Gilles; Saghir, Shahid; Selvakumaran, Lakshmi; Askari, Abe H.; Brown, Arlene M.

    2013-01-01

    This work provides an experimental investigation of the cyclic hygrothermal aging of a hybrid composites. We aimed to propose a general framework in the view to further optimize polymer-based composites. It reports experimental data and relevant observations collected during an aging campaign (up to 2000 cycles) where anhydride-cured epoxy samples as well as composites samples are exposed to environmental conditions. The data gathered during the whole campaign reveals that (1) the polymer displays a non-classical sorption behavior (2) the volume change is correlated to the mass uptake (3) the elastic modulus is correlated to the glass transition temperature. Matrix and interface degradation of the hybrid composite is monitored by means of microstructural observations. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

  12. Benchmarking of the advanced hygrothermal model-hygIRC with mid scale experiments

    Energy Technology Data Exchange (ETDEWEB)

    Maref, W.; Lacasse, M.; Kumaran, K.; Swinton, M.C. [National Research Council of Canada, Ottawa, ON (Canada). Inst. for Research in Construction

    2002-07-01

    An experimental study has been conducted to benchmark an advanced hygrothermal model entitled hygIRC which can be used to estimate the drying response of oriented strand board (OSB) used in timber-frame construction. Three specimens of OSB boards were immersed in water for 5 days and then allowed to stabilise in a sealed tank. A comparison of results from the computer model simulations to those obtained from experimental tests and laboratory measurements showed good agreement in terms of the shape of the drying curve and time taken to reach equilibrium moisture content. In general, it was determined that the drying process is controlled by the vapour permeability of the membrane. The higher the vapour permeability, the faster the rate of drying in a given condition. 11 refs., 1 tab., 9 figs.

  13. Experimental Study on Hygrothermal Deformation of External Thermal Insulation Cladding Systems with Glazed Hollow Bead

    Directory of Open Access Journals (Sweden)

    Houren Xiong

    2016-01-01

    Full Text Available This research analyzes the thermal and strain behavior of external thermal insulation cladding systems (ETICS with Glazed Hollow Beads (GHB thermal insulation mortar under hygrothermal cycles weather test in order to measure its durability under extreme weather (i.e., sunlight and rain. Thermometers and strain gauges are placed into different wall layers to gather thermal and strain data and another instrument measures the crack dimensions after every 4 cycles. The results showed that the finishing coat shrank at early stage (elastic deformation and then the finishing coat tends to expand and become damaged at later stage (plastic deformation. The deformation of insulation layer is similar to that of the finishing coat but its variation amplitude is smaller. Deformation of substrate expanded with heat and contracted with cold due to the small temperature variation. The length and width of cracks on the finishing coat grew as the experiment progressed but with a decreasing growth rate and the cracks stopped growing around 70 cycles.

  14. Actual measurement, hygrothermal response experiment and growth prediction analysis of microbial contamination of central air conditioning system in Dalian, China.

    Science.gov (United States)

    Lv, Yang; Hu, Guangyao; Wang, Chunyang; Yuan, Wenjie; Wei, Shanshan; Gao, Jiaoqi; Wang, Boyuan; Song, Fangchao

    2017-04-03

    The microbial contamination of central air conditioning system is one of the important factors that affect the indoor air quality. Actual measurement and analysis were carried out on microbial contamination in central air conditioning system at a venue in Dalian, China. Illumina miseq method was used and three fungal samples of two units were analysed by high throughput sequencing. Results showed that the predominant fungus in air conditioning unit A and B were Candida spp. and Cladosporium spp., and two fungus were further used in the hygrothermal response experiment. Based on the data of Cladosporium in hygrothermal response experiment, this paper used the logistic equation and the Gompertz equation to fit the growth predictive model of Cladosporium genera in different temperature and relative humidity conditions, and the square root model was fitted based on the two environmental factors. In addition, the models were carried on the analysis to verify the accuracy and feasibility of the established model equation.

  15. Interior insulation – Experimental investigation of hygrothermal conditions and damage evaluation of solid masonry façades in a listed building

    DEFF Research Database (Denmark)

    Odgaard, Tommy; Bjarløv, Søren Peter; Rode, Carsten

    2018-01-01

    Exterior walls in historic multi-storey buildings compared to walls in modern buildings have low thermal resistance, resulting in high energy loss and cold surfaces/floors in cold climates. When restrictions regarding alteration of the exterior appearance exist, interior insulation might be the o......Exterior walls in historic multi-storey buildings compared to walls in modern buildings have low thermal resistance, resulting in high energy loss and cold surfaces/floors in cold climates. When restrictions regarding alteration of the exterior appearance exist, interior insulation might...... be the only possibility to increase occupant comfort. This paper describes an investigation of the hygrothermal influence when applying 100 mm of diffusion open interior insulation to a historic multi-storey solid masonry spandrel. The dormitory room with the insulated spandrel had a normal indoor climate...... showed no risk of damage from the changed hygrothermal conditions when applying interior insulation to a solid masonry spandrel....

  16. Study on the energy performance of glazing surfaces

    Directory of Open Access Journals (Sweden)

    Ligia MOGA

    2014-12-01

    Full Text Available A proper thermal design of the building envelope represents an important factor for the energy economics. Glazing surfaces represent one of the important elements in the hygrothermal design activity of a building envelope. The window’s thermal performance has also a strong influence on the thermal performance of the opaque area of the wall. This fact imposed the research of the real interaction, of cooperation and of mutual influences of the characteristics between the two components of the wall of the building envelope, respectively the opaque and the glazing area. Optimal constructive details for the opaque and glazing area of the wall need to be properly designed in order to achieve the required thermal and energy performances imposed for new types of buildings, e.g. passive houses, zero energy buildings.

  17. Comparison of the corrosion of fasteners embedded in wood measured in outdoor exposure with the predictions from a combined hygrothermal-corrosion model

    Science.gov (United States)

    Samuel L. Zelinka; Samuel V. Glass; Charles R. Boardman; Dominique Derome

    2016-01-01

    This paper examines the accuracy of a recently developed hygrothermal-corrosion model which predictsthe corrosion of fasteners embedded in wood by comparing the results of the model to a one year fieldtest. Steel and galvanized steel fasteners were embedded into untreated and preservative treated woodand exposed outdoors while weather data were collected. Qualitatively...

  18. Accelerated hygrothermal stabilization of composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Gale, Jeffrey Alan [Univ. of California, Davis, CA (United States)

    1994-05-01

    Experimentation validated a simple moisture conditioning scheme to prepare Gr/Ep composite parts for precision applications by measuring dimensional changes over 90 days. It was shown that an elevated temperature moisture conditioning scheme produced a dimensionally stable part from which precision structures could be built/machined without significant moisture induced dimensional changes after fabrication. Conversely, that unconditioned Gr/Ep composite panels exhibited unacceptably large dimensional changes (i.e., greater than 125 ppM). It was also shown that time required to produce stable parts was shorter, by more than an order of magnitude, employing the conditioning scheme than using no conditioning scheme (46 days versus 1000+ days). Two final use environments were chosen for the experiments: 50% RH/21C and 0% RH/21C. Fiberite 3034K was chosen for its widespread use in aerospace applications. Two typical lay-ups were chosen, one with low sensitivity to hygrothermal distortions and the other high sensitivity: [0, ± 45, 90]s, [0, ± 15, 0]s. By employing an elevated temperature, constant humidity conditioning scheme, test panels achieved an equilibrium moisture content in less time, by more than an order of magnitude, than panels exposed to the same humidity environment and ambient temperature. Dimensional changes, over 90 days, were up to 4 times lower in the conditioned panels compared to unconditioned panels. Analysis of weight change versus time of test coupons concluded that the out-of-autoclave moisture content of Fiberite 3034K varied between 0.06 and 0.1%.

  19. When to stop drying fruit: Insights from hygrothermal modelling

    International Nuclear Information System (INIS)

    Defraeye, Thijs

    2017-01-01

    Highlights: • Partial dehydration reduces energy consumption and processing time and improves product quality. • This study gives a quantitative insight in when fruit drying should be stopped. • Decrease in dryer residence time of 2%, 24% and 70% are found for different stopping criteria. - Abstract: Stopping the drying process prior to complete dehydration reduces energy consumption and processing time but can also improve product quality. Using hygrothermal simulations, different stopping criteria are evaluated, which are based on the final water activity and residual moisture content in the fruit. Their impact on drying time and moisture redistribution kinetics inside fruit is quantified. One of the variants leads to a significant reduction in residence time in the dryer (24%), compared to full dehydration. For this variant, drying is stopped when the average moisture content in the sample reaches the value corresponding to an equilibrium water activity of 60% in the sample, as determined from the sorption isotherm. At the same time, this variant does not induce problems with fruit spoilage, as a sufficiently low water activity is reached after moisture redistribution during relaxation in the ambient environment. In addition, the relation of the drying time to the drying air temperature was quantified for all stopping criteria, as well as the impact of the humidity of the ambient environment in which the dried fruits are placed afterwards. This study gives a better quantitative insight in when fruit drying should be stopped, given specific drying conditions, without having to compromise food safety.

  20. External Thermal Insulation Composite Systems: Critical Parameters for Surface Hygrothermal Behaviour

    Directory of Open Access Journals (Sweden)

    Eva Barreira

    2014-01-01

    Full Text Available External Thermal Insulation Composite Systems (ETICS are often used in Europe. Despite its thermal advantages, low cost, and ease of application, this system has serious problems of biological growth causing the cladding defacement. Recent studies pointed that biological growth is due to high values of surface moisture content, which mostly results from the combined effect of exterior surface condensation, wind-driven rain, and drying process. Based on numerical simulation, this paper points the most critical parameters involved in hygrothermal behaviour of ETICS, considering the influence of thermal and hygric properties of the external rendering, the effect of the characteristics of the façade, and the consequences of the exterior and interior climate on exterior surface condensation, wind-driven rain, and drying process. The model used was previously validated by comparison with the results of an “in situ” campaign. The results of the sensitivity analyses show that relative humidity and temperature of the exterior air, atmospheric radiation, and emissivity of the exterior rendering are the parameters that most influence exterior surface condensation. Wind-driven rain depends mostly on horizontal rain, building’s height, wind velocity, and orientation. The drying capacity is influenced by short-wave absorbance, incident solar radiation, and orientation.

  1. Moisture condensation on building envelopes in differential ventilated spaces in the tropics: quantitative assessment of influencing factors

    Directory of Open Access Journals (Sweden)

    Ali Maisarah

    2016-01-01

    Full Text Available Ventilation systems play a significant role in maintaining the indoor thermal and hygric balance. Nevertheless, the systems had been implicated to result in many problems. In the tropical climate, especially for energy efficiency purposes, building spaces are operated with differential ventilation. Such spaces operate on 24-hrs basis, some on 8-hrs while others are either naturally ventilated or served with mechanical supply-exhaust fan systems with non-conditioned outdoor air. This practice had been found to result in condensation problems. This study involves a quantitative appraisal of the effect of operative conditions and hygrothermal quality of building envelopes on condensation risk. The in-situ experiment is combined with an analytical approach to assessing the hygrothermal quality of building envelopes in a tropical climate building under differential ventilation between adjacent spaces. The case-studied building is with a known history of condensation and associated damages including mould growth. The microclimate measurement and hygrothermal performance of the wall and floor against condensation and mould growth risks had been previously reported elsewhere. As a step further, the present study evaluates the effects of various envelope insulation types and configurations together with the HVAC cooling set-points on envelope hygrothermal performance. The results revealed that overcooling the air-conditioned side increases condensation risk on the non-air-conditioned side of the envelopes. The envelopes failed criteria for surface condensation at existing operative conditions irrespective of envelope hygrothermal quality improvements. However, the envelope performed well at improved cooling operative conditions even at existing envelope hygrothermal quality. It is, therefore, important to ascertain the envelope hygrothermal quality as well the cooling operative conditions while embarking on energy efficiency operations in mechanical

  2. Summary of the Effects of Two Years of Hygro-Thermal Cycling on a Carbon/Epoxy Composite Material

    Science.gov (United States)

    Kohlman, Lee W.; Binienda, Wieslaw K.; Roberts, Gary D.; Miller, Sandi G.; Pereira, J. Michael; Bail, Justin L.

    2011-01-01

    Composite materials are beginning to be used for structures in the fan section of commercial gas turbine engines. This paper explores the type of damage that could occur within one type of composite material after exposure to hygrothermal cycles (temperature/humidity cycles) that are representative of the environment in the fan section of an engine. The effect of this damage on composite material properties is measured. Chemical changes in the matrix material were limited to the exposed surface. Microcrack formation was identified in the composite material. This damage did not cause a significant reduction in tensile strength or impact penetration resistance of the composite material. Additional data is needed to assess the effect of damage on compressive strength.

  3. Isothermal and hygrothermal agings of hybrid glass fiber/carbon fiber composite

    Science.gov (United States)

    Barjasteh, Ehsan

    in the oxygen-transport properties (diffusivity and solubility of oxygen). The effect of thermal aging on mechanical properties of the aged composites was investigated. A relationship was derived relating TOL to tensile strength of the hybrid composite. The tensile strength remained essentially unchanged by thermal oxidation after 52 weeks of exposure. On the contrary, the oxidation resulted in a decrease in short-beam-shear (SBS) strength (a matrix-dominated property) due to degradation of matrix and fiber/matrix interface strength. However, the filled composites showed a lower reduction in SBS strength than that of the unfilled one for an identical duration of exposure. In addition, the effect of thermal aging on glass transition temperature (T g) was determined for isothermal exposures at 180ºC and 200ºC. The simultaneous effects of post-curing and thermal degradation resulted in the change in Tg during exposure. Another study on the composite rod was performed to investigate the sorption kinetics and the effects of moisture on mechanical and physical properties. Sorption curves were obtained for both hybrid and non-hybrid composite rods to determine characteristic parameters, including the diffusion coefficient (D) and the maximum moisture uptake (Minfinity ). The moisture uptake for the hybrid composites generally exhibited Fickian behavior (no hybridization effects), behaving much like non-hybrid composites. A two-dimensional diffusion model was employed to calculate moisture diffusivities in the longitudinal direction. Interfaces and thermally-induced residual stresses affected the moisture diffusion. In addition, the effect of hygrothermal aging on glass transition temperature (Tg), short beam shear strength (SBS), and tensile strength was determined for hygrothermal exposure at 60°C and 85% relative humidity (RH). Property retention and reversibility of property degradation was also measured. Microscopic inspection revealed no evidence of damage

  4. Introduction to Building Systems Performance: Houses That Work II; Period of Performance: January 2003--December 2003

    Energy Technology Data Exchange (ETDEWEB)

    2004-04-01

    Buildings should be suited to their environments. Design and construction must be responsive to varying seismic risks, wind loads, and snow loads, as well as soil conditions, frost depth, orientation, and solar radiation. In addition, building envelopes and mechanical systems should be designed for a specific hygro-thermal regions, rain exposure, and interior climate. The Building Science Consortium (BSC) design recommendations are based on the hygro-thermal regions with reference to the annual rainfall. Local climate must be addressed if it differs significantly from the climate described for a particular design.

  5. Nonlocal microstructure-dependent dynamic stability of refined porous FG nanoplates in hygro-thermal environments

    Science.gov (United States)

    Reza Barati, Mohammad

    2017-10-01

    Based on the generalized nonlocal strain gradient theory (NSGT), dynamic modeling and analysis of nanoporous inhomogeneous nanoplates is presented. Therefore, it is possible to capture both stiffness-softening and stiffness-hardening effects for a more accurate dynamic analysis of nanoplates. The nanoplate is in hygro-thermal environments and is subjected to an in-plane harmonic load. Porosities are incorporated to the model based on a modified rule of mixture. Modeling of the porous nanoplate is conducted according to a refined four-variable plate theory with fewer field variables than in the first-order plate theory. The governing equations and related classical and nonclassical boundary conditions are derived based on Hamilton's principle. These equations are solved for hinged nanoplates via Galerkin's method. It is shown that porosities, moisture rise, temperature rise, nonlocal parameter, strain gradient parameter, material gradation, elastic foundation and uniform dynamic load have a remarkable influence on the dynamic behavior of nanoscale plates.

  6. Evaluation of hygrothermal effects on the shear properties of Carall composites

    International Nuclear Information System (INIS)

    Botelho, E.C.; Pardini, L.C.; Rezende, M.C.

    2007-01-01

    Fiber metal laminates are the frontline materials for aeronautical and space structures. These composites consists of layers of 2024-T3-aluminum alloy and composite prepreg layers. When the composite layer is a carbon fiber prepreg, the fiber metal laminate, named Carall, offers significant improvements over current available materials for aircraft structures. While weight reduction and improved damage tolerance characteristics were the prime drivers to develop this new family of materials, it turns out that they have additional benefits, which become more and more important for today's designers, such as cost reduction and improved safety. The degradation of composites is due to environmental effects mainly on the chemical and/or physical properties of the polymer matrix leading to loss of adhesion of fiber/resin interface. Also, the reduction of fiber strength and stiffness are expected due to environmental degradation. Changes in interface/interphase properties leads to more pronounced changes in shear properties than any other mechanical properties. In this work, the influence of moisture in shear properties of carbon fiber/epoxy composites and Carall have been investigated by using interlaminar shear (ILSS) and Iosipescu tests. It was observed that hygrothermal conditioning reduces the Iosipescu shear strength of CF/E and Carall composites due to the moisture absorption in these materials

  7. Effect of hygrothermal conditioning on the mechanical and thermal properties of epoxy grouts for offshore pipeline rehabilitation

    Directory of Open Access Journals (Sweden)

    Allan Manalo

    2016-07-01

    Full Text Available Offshore oil and gas pipelines are susceptible to corrosion and need rehabilitation to keep them operating in-service conditions. Fibre composite filled with epoxy-based grout is emerging as an effective repair and rehabilitation system for offshore pipelines performing underwater. In such applications, the infill grout is often subjected to moisture and elevated temperature along with compressive, tensile and localised stresses at the defect. Current standards and practices for composite repairs suggest detailed investigation of the fibre reinforced sleeve, while the characterisation of the infill material is yet to be conducted for performance evaluation. The present work investigates the mechanical and thermal properties of three epoxy grouts as candidates for infill in a grouted sleeve repair for underwater pipeline. An understanding on the effect of hygrothermal ageing on the grout properties for defining the period of 1000 hours as “long-term” according to ISO/TS 24817, in comparison to their unconditioned state, is also presented. The compressive and tensile strength of the unconditioned grouts ranges from 100–120 MPa, and 19–32 MPa, respectively, which indicates that these grouts are suitable for structural rehabilitation of the pipelines. Moreover, the glass transition temperatures, Tg and Tt of the unconditioned grouts are found to be within the ranges of 50–60 °C, and 80–90 °C, respectively, which are reduced by about 20°C after conditioning.

  8. A Procedure to Measure the in-Situ Hygrothermal Behavior of Earth Walls

    Science.gov (United States)

    Chabriac, Pierre-Antoine; Fabbri, Antonin; Morel, Jean-Claude; Laurent, Jean-Paul; Blanc-Gonnet, Joachim

    2014-01-01

    Rammed earth is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities and its mechanical behavior. Both of these properties are known to strongly depend on the amount of water contained in wall pores and its evolution. Thus the aim of this paper is to present a procedure to measure this key parameter in rammed earth or cob walls by using two types of probes operating on the Time Domain Reflectometry (TDR) principle. A calibration procedure for the probes requiring solely four parameters is described. This calibration procedure is then used to monitor the hygrothermal behavior of a rammed earth wall (1.5 m × 1 m × 0.5 m), instrumented by six probes during its manufacture, and submitted to insulated, natural convection and forced convection conditions. These measurements underline the robustness of the calibration procedure over a large range of water content, even if the wall is submitted to quite important temperature variations. They also emphasize the importance of gravity on water content heterogeneity when the saturation is high, as well as the role of liquid-to-vapor phase change on the thermal behavior. PMID:28788603

  9. A Procedure to Measure the in-Situ Hygrothermal Behavior of Earth Walls

    Directory of Open Access Journals (Sweden)

    Pierre-Antoine Chabriac

    2014-04-01

    Full Text Available Rammed earth is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities and its mechanical behavior. Both of these properties are known to strongly depend on the amount of water contained in wall pores and its evolution. Thus the aim of this paper is to present a procedure to measure this key parameter in rammed earth or cob walls by using two types of probes operating on the Time Domain Reflectometry (TDR principle. A calibration procedure for the probes requiring solely four parameters is described. This calibration procedure is then used to monitor the hygrothermal behavior of a rammed earth wall (1.5 m × 1 m × 0.5 m, instrumented by six probes during its manufacture, and submitted to insulated, natural convection and forced convection conditions. These measurements underline the robustness of the calibration procedure over a large range of water content, even if the wall is submitted to quite important temperature variations. They also emphasize the importance of gravity on water content heterogeneity when the saturation is high, as well as the role of liquid-to-vapor phase change on the thermal behavior.

  10. An evaluation of highly insulated cold zinc roofs in a moderate humid region - Part II: Corrosion behavior of zinc sheeting

    NARCIS (Netherlands)

    Zheng, R.; Janssens, A.; Carmeliet, J.; Bogaerts, W.; Hens, H.

    2004-01-01

    In a previous paper [Zheng et al., Hygrothermal Performance, Part I; Const Building Mater, Vol. 18, Issue 1, pp. 49-59], the hygrothermal performances of four well-insulated cold zinc roofs were evaluated. This paper investigates the corrosion behavior of the zinc sheeting used in the roofs. The

  11. Effect of Hygrothermal Aging on the Mechanical Properties of Fluorinated and Nonfluorinated Clay-Epoxy Nanocomposites.

    Science.gov (United States)

    Hamim, Salah U; Singh, Raman P

    2014-01-01

    Hydrophilic nature of epoxy polymers can lead to both reversible and irreversible/permanent changes in epoxy upon moisture absorption. The permanent changes leading to the degradation of mechanical properties due to combined effect of moisture and elevated temperature on EPON 862, Nanomer I.28E, and Somasif MAE clay-epoxy nanocomposites are investigated in this study. The extent of permanent degradation on fracture and flexural properties due to the hygrothermal aging is determined by drying the epoxy and their clay-epoxy nanocomposites after moisture absorption. Significant permanent damage is observed for fracture toughness and flexural modulus, while the extent of permanent damage is less significant for flexural strength. It is also observed that permanent degradation in Somasif MAE clay-epoxy nanocomposites is higher compared to Nanomer I.28E clay-epoxy nanocomposites. Fourier transform infrared (FTIR) spectroscopy revealed that both clays retained their original chemical structure after the absorption-desorption cycle without undergoing significant changes. Scanning electron microscopy (SEM) images of the fracture surfaces provide evidence that Somasif MAE clay particles offered very little resistance to crack propagation in case of redried specimens when compared to Nanomer I.28E counterpart. The reason for the observed higher extent of permanent degradation in Somasif MAE clay-epoxy system has been attributed to the weakening of the filler-matrix interface.

  12. Material characterization models and test methods for historic building materials

    DEFF Research Database (Denmark)

    Hansen, Tessa Kvist; Peuhkuri, Ruut Hannele; Møller, Eva B.

    2017-01-01

    Predictions of long term hygrothermal performance can be assessed by dynamic hygrothermal simulations, in which material parameters are crucial input. Material parameters for especially historic materials are often unknown; therefore, there is a need to determine important parameters, and simple...

  13. Introduction to Building Systems Performance: Houses That Work II. Revised February 2005

    Energy Technology Data Exchange (ETDEWEB)

    2005-03-01

    Buildings should be suited to their environments. Design and construction must be responsive to varying seismic risks, wind loads, and snow loads, as well as soil conditions, frost depth, orientation, and solar radiation. In addition, building envelopes and mechanical systems should be designed for a specific hygro-thermal regions, rain exposure, and interior climate. The Building Science Consortium (BSC) design recommendations are based on the hygro-thermal regions with reference to the annual rainfall. Local climate must be addressed if it differs significantly from the climate described for a particular design.

  14. Análise do efeito higrotérmico no comportamento em fadiga de compósitos de PPS/fibras de carbono On the analysis of hygrothermal effect on fatigue behavior of PPS/carbon fiber composite

    Directory of Open Access Journals (Sweden)

    Maria C. M. de Faria

    2012-01-01

    Full Text Available O contínuo crescimento na utilização de compósitos termoplásticos em componentes estruturais na indústria aeroespacial deve-se, primordialmente, à flexibilidade de projeto, excelência de suas propriedades mecânicas e baixa massa específica, aliadas aos elevados valores de resistência mecânica e rigidez e baixa incidência de corrosão, atendendo aos severos requisitos de desempenho quando em serviço dessas estruturas. Componentes com exigências estruturais, quando expostos a ambientes agressivos como elevada temperatura e umidade, podem ter suas propriedades mecânicas sensibilizadas por esses fatores ambientais, e devem ser cuidadosamente avaliados antes de serem colocados em serviço. Em função do que foi exposto este trabalho tem como objetivo contribuir para a avaliação do efeito higrotérmico na resistência à fadiga do compósito termoplástico PPS/fibras de carbono. Os materiais estudados foram cedidos pela empresa holandesa TenCate, fornecedora de laminados da Airbus e EMBRAER. Os resultados obtidos neste trabalho mostram que compósitos de PPS/fibras de carbono apresentam um aumento nos valores de resistência à tração quando condicionados higrotermicamente, devido à plasticização desta matriz polimérica, aumentando, consecutivamente, sua tenacidade à fratura. Entretanto, a partir dos ensaios realizados, foi constatado que o condicionamento higrotérmico não alterou de forma significativa o comportamento de vida em fadiga dos laminados PPS-C.The continued growth in the use of polymer composites in structural components in the aerospace industry is due primarily to the design flexibility, excellent mechanical properties and low density, combined with the high values of mechanical strength and stiffness and low incidence of corrosion, with which these structures meet several performance requirements when in service. Components with structural requirements may have their mechanical properties affected when

  15. Beregnede fugtforhold i konstruktioner:Del af "Varme- og fugttekniske undersøgelser af alternative isoelringsmaterialer"

    OpenAIRE

    Rode, Carsten; Rasmussen, Niels T.

    1999-01-01

    Calculated Moisture Conditions in Building Constructions. Part of "Hygrothermal Properties of Alternative Insulation Materials".The hygrothermal performance of constructions with alternative insulation products has been analysed with the 1-dimensional computer model MATCH for combined heat and moisture transfer. The analysis concerns both traditional wall and roof constructions with the alternative insulation products, and some alternative designs prescribed by manufacturers of alternative in...

  16. Introduction to Building Systems Performance: Houses that Work II. Revised February 2005

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-03-01

    The Building Science Consortium (BSC) design recommendations are based on the hygrothermal regions with reference to the annual rainfall. Local climate must be addressed if it differs significantly from the climate described for a particular design.

  17. Effect of particle size and distribution of the sizing agent on the carbon fibers surface and interfacial shear strength (IFSS) of its composites

    International Nuclear Information System (INIS)

    Zhang, R.L.; Liu, Y.; Huang, Y.D.; Liu, L.

    2013-01-01

    Effect of particle size and distribution of the sizing agent on the performance of carbon fiber and carbon fiber composites has been investigated. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to characterize carbon fiber surface topographies. At the same time, the single fiber strength and Weibull distribution were also studied in order to investigate the effect of coatings on the fibers. The interfacial shear strength and hygrothermal aging of the carbon fiber/epoxy resin composites were also measured. The results indicated that the particle size and distribution is important for improving the surface of carbon fibers and its composites performance. Different particle size and distribution of sizing agent has different contribution to the wetting performance of carbon fibers. The fibers sized with P-2 had higher value of IFSS and better hygrothermal aging resistant properties.

  18. Interior thermal insulation systems for historical building envelopes

    Science.gov (United States)

    Jerman, Miloš; Solař, Miloš; Černý, Robert

    2017-11-01

    The design specifics of interior thermal insulation systems applied for historical building envelopes are described. The vapor-tight systems and systems based on capillary thermal insulation materials are taken into account as two basic options differing in building-physical considerations. The possibilities of hygrothermal analysis of renovated historical envelopes including laboratory methods, computer simulation techniques, and in-situ tests are discussed. It is concluded that the application of computational models for hygrothermal assessment of interior thermal insulation systems should always be performed with a particular care. On one hand, they present a very effective tool for both service life assessment and possible planning of subsequent reconstructions. On the other, the hygrothermal analysis of any historical building can involve quite a few potential uncertainties which may affect negatively the accuracy of obtained results.

  19. Impact of whole-building hygrothermal modelling on the assessment of indoor climate in a library building

    Energy Technology Data Exchange (ETDEWEB)

    Steeman, M.; Janssens, A. [Ghent University, Department of Architecture and Urban Planning, Jozef Plateaustraat 22, B-9000 Gent (Belgium); De Paepe, M. [Ghent University, Department of Flow, Heat and Combustion Mechanics, Sint-Pietersnieuwstraat 41, B-9000 Gent (Belgium)

    2010-07-15

    This paper focuses on the importance of accurately modelling the hygrothermal interaction between the building and its hygroscopic content for the assessment of the indoor climate. Libraries contain a large amount of stored books which require a stable relative humidity to guarantee their preservation. On the other hand, visitors and staff must be comfortable with the indoor climate. The indoor climate of a new library building is evaluated by means of measurements and simulations. Complaints of the staff are confirmed by measured data during the winter and summer of 2007-2008. For the evaluation of the indoor climate, a building simulation model is used in which the porous books are either described by a HAM model or by a simplified isothermal model. Calculations demonstrate that the HAM model predicts a more stable indoor climate regarding both temperature and relative humidity variations in comparison to the estimations by the simplified model. This is attributed to the ability of the HAM model to account for the effect of temperature variations on moisture storage. Moreover, by applying the HAM model, a good agreement with the measured indoor climate is found. As expected, a larger exposed book surface ameliorates the indoor climate because a more stable indoor relative humidity is obtained. Finally, the building simulation model is used to improve the indoor climate with respect to the preservation of valuable books. Results demonstrate that more stringent interventions on the air handling unit are expected when a simplified approach is used to model the hygroscopic books. (author)

  20. A CFD model for analysis of performance, water and thermal distribution, and mechanical related failure in PEM fuel cells

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2016-07-01

    Full Text Available This paper presents a comprehensive three–dimensional, multi–phase, non-isothermal model of a Proton Exchange Membrane (PEM fuel cell that incorporates significant physical processes and key parameters affecting the fuel cell performance. The model construction involves equations derivation, boundary conditions setting, and solution algorithm flow chart. Equations in gas flow channels, gas diffusion layers (GDLs, catalyst layers (CLs, and membrane as well as equations governing cell potential and hygro-thermal stresses are described. The algorithm flow chart starts from input of the desired cell current density, initialization, iteration of the equations solution, and finalizations by calculating the cell potential. In order to analyze performance, water and thermal distribution, and mechanical related failure in the cell, the equations are solved using a computational fluid dynamic (CFD code. Performance analysis includes a performance curve which plots the cell potential (Volt against nominal current density (A/cm2 as well as losses. Velocity vectors of gas and liquid water, liquid water saturation, and water content profile are calculated. Thermal distribution is then calculated together with hygro-thermal stresses and deformation. The CFD model was executed under boundary conditions of 20°C room temperature, 35% relative humidity, and 1 MPA pressure on the lower surface. Parameters values of membrane electrode assembly (MEA and other base conditions are selected. A cell with dimension of 1 mm x 1 mm x 50 mm is used as the object of analysis. The nominal current density of 1.4 A/cm2 is given as the input of the CFD calculation. The results show that the model represents well the performance curve obtained through experiment. Moreover, it can be concluded that the model can help in understanding complex process in the cell which is hard to be studied experimentally, and also provides computer aided tool for design and optimization of PEM

  1. Moisture performance of building materials: From material characterization to building simulation using the Moisture Buffer Value concept

    Energy Technology Data Exchange (ETDEWEB)

    Abadie, Marc Olivier [Mechanical Engineering Graduate Program, Pontifical Catholic University of Parana, PUC-PR/CCET, Curitiba, PR 80215-901 (Brazil); LEPTAB, University of La Rochelle, La Rochelle, 17042 Cedex 1 (France); Mendonca, Katia Cordeiro [Mechanical Engineering Graduate Program, Pontifical Catholic University of Parana, PUC-PR/CCET, Curitiba, PR 80215-901 (Brazil)

    2009-02-15

    Predicting the indoor air relative humidity evolution is of great importance to evaluate people thermal comfort, perceived air quality and energy consumption. In building environments, porous materials of the envelope and furniture act on the indoor air humidity by reducing its variations. Solving the physical processes involved inside the porous materials requires the knowledge of the material hygrothermal properties that needs multiple and, for some of them, time-consuming experimental procedures. Recently, both the NORDTEST Project and Japanese Industrial Standard described a new Moisture Buffer Capacity index that accounts for surrounding air vapor concentration variation. The Moisture Buffer Value (MBV) indicates the amount of water vapor that is transported in or out of a material, during a certain period of time, when the vapor concentration of the surrounding air varies. The MBV evaluation requires only one experimental procedure and its value permits a direct comparison of the building materials moisture performance. However, two limitations can be distinguished: first, no relation between the MBV and the usual material hygrothermal properties has been clearly identified and second, no model has been proposed to actually use the MBV in building simulation. The present study aims to solve these two problems. First, the MBV fundamentals are introduced and discussed; followed by its relation with the usual material properties. Then, a lumped model for building simulation, whose parameters can be determined from the MBV experimental procedure, is described. To finish, examples of the use of this MBV-based lumped model for moisture prediction in buildings are presented. (author)

  2. Moisture Durability Assessment of Selected Well-insulated Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Pallin, Simon B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boudreaux, Philip R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kehrer, Manfred [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    This report presents the results from studying the hygrothermal performance of two well-insulated wall assemblies, both complying with and exceeding international building codes (IECC 2015 2014, IRC 2015). The hygrothermal performance of walls is affected by a large number of influential parameters (e.g., outdoor and indoor climates, workmanship, material properties). This study was based on a probabilistic risk assessment in which a number of these influential parameters were simulated with their natural variability. The purpose of this approach was to generate simulation results based on laboratory chamber measurements that represent a variety of performances and thus better mimic realistic conditions. In total, laboratory measurements and 6,000 simulations were completed for five different US climate zones. A mold growth indicator (MGI) was used to estimate the risk of mold which potentially can cause moisture durability problems in the selected wall assemblies. Analyzing the possible impact on the indoor climate due to mold was not part of this study. The following conclusions can be reached from analyzing the simulation results. In a hot-humid climate, a higher R-value increases the importance of the airtightness because interior wall materials are at lower temperatures. In a cold climate, indoor humidity levels increase with increased airtightness. Air leakage must be considered in a hygrothermal risk assessment, since air efficiently brings moisture into buildings from either the interior or exterior environment. The sensitivity analysis of this study identifies mitigation strategies. Again, it is important to remark that MGI is an indicator of mold, not an indicator of indoor air quality and that mold is the most conservative indicator for moisture durability issues.

  3. Heat and Moisture Transport and Storage Parameters of Bricks Affected by the Environment

    Science.gov (United States)

    Kočí, Václav; Čáchová, Monika; Koňáková, Dana; Vejmelková, Eva; Jerman, Miloš; Keppert, Martin; Maděra, Jiří; Černý, Robert

    2018-05-01

    The effect of external environment on heat and moisture transport and storage properties of the traditional fired clay brick, sand-lime brick and highly perforated ceramic block commonly used in the Czech Republic and on their hygrothermal performance in building envelopes is analyzed by a combination of experimental and computational techniques. The experimental measurements of thermal, hygric and basic physical parameters are carried out in the reference state and after a 3-year exposure of the bricks to real climatic conditions of the city of Prague. The obtained results showed that after 3 years of weathering the porosity of the analyzed bricks increased up to five percentage points which led to an increase in liquid and gaseous moisture transport parameters and a decrease in thermal conductivity. Computational modeling of hygrothermal performance of building envelopes made of the studied bricks was done using both reference and weather-affected data. The simulated results indicated an improvement in the annual energy balances and a decrease in the time-of-wetness functions as a result of the use of data obtained after the 3-year exposure to the environment. The effects of weathering on both heat and moisture transport and storage parameters of the analyzed bricks and on their hygrothermal performance were found significant despite the occurrence of warm winters in the time period of 2012-2015 when the brick specimens were exposed to the environment.

  4. Prediction of deformation and hygro-thermal stresses distribution in PEM fuel cell vehicle using three-dimensional CFD model

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq Al-Baghdadi, Maher A.R. [Fuel Cell Research Center, International Energy & Environment Foundation, Al-Najaf, P.O.Box 39 (Iraq)

    2012-07-01

    Durability is one of the most critical remaining issues impeding successful commercialization of broad PEM fuel cell transportation energy applications. Automotive fuel cells are likely to operate with neat hydrogen under load-following or load-levelled modes and be expected to withstand variations in environmental conditions, particularly in the context of temperature and atmospheric composition. In addition, they are also required to survive over the course of their expected operational lifetimes i.e., around 5,500 hrs, while undergoing as many as 30,000 startup/shutdown cycles. The damage mechanisms in a PEM fuel cell are accelerated by mechanical stresses arising during fuel cell assembly (bolt assembling), and the stresses arise during fuel cell running, because it consists of the materials with different thermal expansion and swelling coefficients. Therefore, in order to acquire a complete understanding of the damage mechanisms in the membrane, mechanical response under steady-state hygro-thermal stresses should be studied under real cell operating conditions and in real cell geometry (three-dimensional). In this work, full three-dimensional, non-isothermal computational fluid dynamics model of a PEM fuel cell has been developed to simulate the stresses inside the PEM fuel cell, which are occurring during fuel cell assembly (bolt assembling), and the stresses arise during fuel cell running due to the changes of temperature and relative humidity. A unique feature of the present model is to incorporate the effect of hygro and thermal stresses into actual three-dimensional fuel cell model. In addition, the temperature and humidity dependent material properties are utilize in the simulation for the membrane. The model is shown to be able to understand the many interacting, complex electrochemical, transport phenomena, and stresses distribution that have limited experimental data. This model is used to study and analyse the effect of operating parameters on the

  5. A Review on Artificial Aging Behaviors of Fiber Reinforced Polymer-matrix Composites

    OpenAIRE

    Meng Jiangyan; Wang Yunying

    2016-01-01

    As is known, factors in climate environment such as hygrothermal effect and UV may have a negative effect on the mechanical properties of fiber reinforced polymer-matrix composites, resulting in their strength and stiffness degraded. In this review, we summarize all the recent studies on the artificial climate aging, hygrothermal aging, and thermal-oxidation aging of fiber reinforced polymer-matrix composites, as well as their artificial accelerated aging and natural aging. In addition, studi...

  6. Hygrothermal adaptability traditional housing in Tampico, Mexico / Adaptabilidad higrotérmica de la vivienda tradicional en Tampico, México

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Fuentes Pérez

    2014-09-01

    Full Text Available The annual increase in the concentration of CO2 in the air is on average 1.5 parts per million, is 0.5% per year, due to the anthropogony generating global climate change, estimates half a century predict a temperature rise of about 2.0°C. The human population is facing an environmental intramural and extramural change in housing. This research aims to determine the degree of hygrothermal adaptability into traditional housing during the year of 2013 in Tampico, Mexico. Depending on the level of scientific knowledge and observation the investigator arrives, makes that labour is diachronic first instance, made as a case study because it analyses the research problem in its genesis and historical conformation with an overview. The thermal behaviour is the thread, therefore, is the methodology to implement multimodal type and by triangulation, since different methods applied provide quantitative and qualitative research approach to the experimental oscillating applied to identify patterns of temperature and relative humidity only, not previously performed in this type of housing. El incremento anual de la concentración de CO2 en el aire es por término medio de 1.5 partes por millón, es decir un 0.5% por año, producto de la antropogenia que genera un cambio climático global, las estimaciones a medio siglo pronostican un aumento de temperatura de unos 2.0°C. La población humana está confrontando un cambio ambiental intramuros y extramuros en la vivienda.La presente investigación tiene como objetivo determinar el grado de adaptabilidad higrotérmica, al interior de la vivienda tradicional durante el año de 2013 en Tampico, México.Según el nivel de conocimiento científico y observación al que llega el investigador, formula que el trabajo es en primera instancia diacrónico, conformado como estudio de caso, porque analiza el problema de investigación en su génesis y conformación histórica con una visión de conjunto. El comportamiento

  7. National construction, Denmark. Flat roofs

    Energy Technology Data Exchange (ETDEWEB)

    Rode, C

    1995-04-01

    The Paris meeting of IEA Annex 24 (held in the spring of 1991) declared a set of typical building constructions, the Heat, Air and Moisture characteristics of which should be dealt with as part of the Annex work. Each type of construction was assigned to one or more countries as their National Construction, and it has been the responsibility of each country to prepare a report on what may be regarded as common knowledge in the country on the hygrothermal behaviour of their construction. This knowledge is in part due to experimental work carried out by research bodies in the countries, and due to experience form practice. This report has two main sections: Section 2 gives a general overview of the design of the most common variants of flat roofs and common knowledge reported for such roofs. Section 3 gives an account of research projects carried out in Denmark on flat roofs to analyze their hygrothermal performance. Whenever possible, an emphasis will be put on the hygrothermal consequences of thermally insulating such constructions. (EG) 19 refs.

  8. Microclimatic Parameters

    DEFF Research Database (Denmark)

    Kragh, Mikkel Kristian; Svendsen, Sv Aa Højgaard

    1996-01-01

    Review paper dealing with the outspoken need for models describing the microclimate at the exterior of the building envelope. In building physics, detailed hygrothermal calculations are performed on the basis of meteorological data, not considering the complex interaction with specific features o...... of the proposed building and its surroundings. KEYWORDS: Microclimate, moisture balance, driving rain, condensation, convection, recommendations for further studies....

  9. Influence of the convective surface transfer coefficients on the Heat, Air, and Moisture (HAM) building performance

    DEFF Research Database (Denmark)

    Steskens, Paul Wilhelmus Maria Hermanus; Janssen, Hans; Rode, Carsten

    2009-01-01

    Current models to predict heat, air and moisture (HAM) conditions in buildings assume constant boundary conditions for the temperature and relative humidity of the neighbouring air and for the surface heat and moisture transfer coefficients. These assumptions may introduce errors in the predicted...... influence on the predicted hygrothermal conditions at the surface of a building component and on the heat and vapour exchange with the indoor environment....

  10. Impact of wind-driven rain on historic brick wall buildings in a moderately cold and humid climate: Numerical analyses of mould growth risk, indoor climate and energy consumption

    DEFF Research Database (Denmark)

    Masaru, Abuku; Janssen, Hans; Roels, Staf

    2009-01-01

    This paper gives an onset to whole building hygrothermal modelling in which the interaction between interior and exterior climates via building enclosures is simulated under a moderately cold and humid climate. The focus is particularly on the impact of wind-driven rain (WDR) oil the hygrothermal...... response, mould growth at interior wall surfaces, indoor climate and energy consumption. First the WDR load oil the facades of a 4 m x 4 m x 10 m tower is determined. Then the hygrothermal behaviour of the brick walls is analysed oil a horizontal slice through the tower. The simulations demonstrate...

  11. Beregnede fugtforhold i konstruktioner

    DEFF Research Database (Denmark)

    Rode, Carsten; Rasmussen, Niels T.

    1999-01-01

    Calculated Moisture Conditions in Building Constructions. Part of "Hygrothermal Properties of Alternative Insulation Materials".The hygrothermal performance of constructions with alternative insulation products has been analysed with the 1-dimensional computer model MATCH for combined heat...... and moisture transfer. The analysis concerns both traditional wall and roof constructions with the alternative insulation products, and some alternative designs prescribed by manufacturers of alternative insulation materials. The choice of construction types originates both from an official direction on energy...... efficient building design, and from a catalogue of alternative construction layouts advised by a manufacturer of alternative insulation. The analysis comprises the use of flax, cellulose fibre, perlite, glass wool, and rock wool.The analysis has shown that alternative insulation materials can be used...

  12. A Systematic Method of Assessing the Durability of Wood-Frame Wall Assemblies

    DEFF Research Database (Denmark)

    Lacasse, Michael A.; Morelli, Martin

    2016-01-01

    The long-term performance in respect to moisture management within any wall assembly depends on the hygrothermal response of the wall. Critical factors in estimating the longevity of wood-frame structures include limiting the temperature range, wood moisture content, and time of exposure to condi......The long-term performance in respect to moisture management within any wall assembly depends on the hygrothermal response of the wall. Critical factors in estimating the longevity of wood-frame structures include limiting the temperature range, wood moisture content, and time of exposure...... to the effects of moisture accumulation in wall cavities. Several approaches to assessing the vulnerability of wood-frame structures to deterioration have been developed in recent years, some of which suggest applying a limit-states design approach to the performance assessment of the assembly. In this paper......, a limit-states design approach is described that forms the basis of a performance assessment method for wood-frame wall assemblies. The approach is based on the requirements set out in ISO 13823. The approach, developed for the Moisture Management of Exterior Wall Systems (MEWS) project, is described...

  13. Experimental characterization of thermal and hygric properties of hemp concrete with consideration of the material age evolution

    Science.gov (United States)

    Bennai, F.; Issaadi, N.; Abahri, K.; Belarbi, R.; Tahakourt, A.

    2018-04-01

    The incorporation of plant crops in construction materials offers very good hygrothermal performance to the building, ensuring substantial environmental and ecological benefits. This paper focuses on studying the evolution of hygrothermal properties of hemp concrete over age (7, 30 and 60 days). The analysis is done with respect to two main hygric and thermal properties, respectively: sorption isotherms, water vapor permeability, thermal conductivity and heat capacity. In fact, most of these parameters are very susceptible to change function of the age of the material. This influence of the aging is mainly due to the evolution of the microstructure with the binder hydration over time and the creation of new hydrates which can reduces the porosity of the material and consequently modify its properties. All the tested hemp concrete samples presented high moisture storage capacity and high-water vapor permeability whatever the age of such hygroscopic material. These hygric parameters increase significantly for high relative humidity requiring more consideration of such variability during the modeling of coupled heat and mass transfer within the material. By the same, the thermal conductivity and heat capacity tests highlighted the impact of the temperature and hygric state of the studied material.

  14. Selecting Eco-Friendly Thermal Systems for the “Vittoriale Degli Italiani” Historic Museum Building

    Directory of Open Access Journals (Sweden)

    Davide Astiaso Garcia

    2015-09-01

    Full Text Available Thermal systems installed in museums should guarantee the maintenance of the optimal hygrothermal parameters ranges for the conservation of their collection materials. Considering the preservation of historic buildings, according to their historical and landscaping constraints, not all the thermal system typologies could be installed in these buildings’ typologies. Therefore, the main aim of this paper is to present some indications for the choice of the best thermal system solutions for a considered historic museum building, called Vittoriale degli Italiani, in the north of Italy, taking into account their installation feasibility and their related environmental impacts. The methodology includes a monitoring of the current hygrothermal parameters as well as the assessment of design heat and cooling loads related to the maintenance of the optimal hygrothermal parameters ranges for the conservation of collection materials. In addition, a Life Cycle Assessment (LCA of each selected system typology is considered for highlighting the most eco-friendly solution among the suitable ones. The obtained results highlights the feasible thermal system solutions able to maintain the hygrothermal parameters between the optimal ranges with a lower environmental impact in the Vittoriale degli Italiani historic museum building.

  15. Integration of a Multizone Airflow Model into a Thermal simulation Program

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Sørensen, Karl Grau; Heiselberg, Per

    2007-01-01

    An existing computer model for dynamic hygrothermal analysis of buildings has been extended with a multizone airflow model based on loop equations to account for the coupled thermal and airflow in natural and hybrid ventilated buildings.......An existing computer model for dynamic hygrothermal analysis of buildings has been extended with a multizone airflow model based on loop equations to account for the coupled thermal and airflow in natural and hybrid ventilated buildings....

  16. Integrating a vented airspace into a spray-foam insulated solid masonry historic building in a cold climate: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Tzekova, Ekaterina; Pressnail, K.D.; Binkley, Clarissa [Department of Civil Engineering, University of Toronto (Canada); Pearson, Nastassja [Halsall Associates Limited (Canada); Pasqualini, Paul [Engineering Link Inc (Canada); Aikin, Craig [Halcrow Yolles (Canada)

    2011-07-01

    Thermal insulation was not included during the construction of historic brick buildings in Canada. Although thermal retrofits can improve building energy performance and occupant comfort, heritage requirements restrict the use of internal insulation. This paper presents an innovative Vented Masonry Retrofit (VMR), which consists of creating a vented airspace by incorporating Mortairvent between the insulation and the masonry. A numerical model and a field trial involving a three-storey heritage building were performed to compare the hygrothermal performance of the VMR with that of standard interior insulation. Temperature and relative humidity were collected during the winter months in foam-insulated, side-by-side wall assemblies along the east and south facing walls using both approaches. Modeling results predicted that using VMR assemblies would reduce the moisture content in both east and south elevations to below that obtained with standard insulation. However, the field trial showed improvement only along the south facade. Long term performance evaluation is required far a better evaluation of the VMR approach.

  17. Effects of Exterior Insulation on Moisture Performance of Wood-Frame Walls in the Pacific Northwest: Measurements and Hygrothermal Modeling

    Science.gov (United States)

    Samuel V. Glass; Borjen Yeh; Benjamin J. Herzog

    2016-01-01

    Continuous exterior insulation on above-grade walls is becoming more common in many parts of North America. It is generally accepted that exterior insulation provides advantages for energy performance, by reducing thermal bridging, and for moisture performance, by warming the wood structural members, thereby reducing the potential for wintertime moisture accumulation....

  18. Impact of coupled heat and moisture transfer effects on buildings energy consuption

    Directory of Open Access Journals (Sweden)

    Ferroukhi Mohammed Yacine

    2017-01-01

    Full Text Available Coupled heat, air, and moisture transfers through building envelope have an important effect on prediction of building energy requirements. Several works were conducted in order to integrate hygrothermal transfers in dynamic buildings simulations codes. However, the incorporation of multidirectional hygrothermal transfer analysis in the envelope into building simulation tools is rarely considered. In this work, coupled heat, air, and moisture (HAM transfer model in multilayer walls was established. Thereafter, the HAM model is coupled dynamically to a building behavior code (BES.The coupling concerns a co-simulation between COMSOL Multiphysics and TRNSYS software. Afterward, the HAM-BES co-simulation accuracy was verified. Then, HAM-BES co-simulation platform was applied to a case study with various types of climates (temperate, hot and humid, cold and humid. Three simulations cases were carried out. The first simulation case consists of the TRNSYS model without HAM transfer model. The second simulation case, 1-D HAM model for the envelope was integrated in TRNSYS code. For the third one, 1-D HAM model for the wall and 2-D HAM model for thermal bridges were coupled to the thermal building model of TRNSYS. Analysis of the results confirms the significant impact of 2-D envelope hygrothermal transfers on the indoor thermal and moisture behavior of building as well as on the energy building assessment. These conclusions are shown for different studied climates.

  19. Conditions for mould growth on typical interior surfaces

    DEFF Research Database (Denmark)

    Møller, Eva B.; Andersen, Birgitte; Rode, Carsten

    2017-01-01

    Prediction of the risk for mould growth is an important parameter for the analysis and design of the hygrothermal performance of building constructions. However, in practice the mould growth does not always follow the predicted behavior described by the mould growth models. This is often explained...... by uncertainty in the real conditions of exposure. In this study, laboratory experiments were designed to determine mould growth at controlled transient climate compared to growth at constant climate. The experiment included three building materials with four different surface treatments. The samples were...

  20. Moisture supply in Danish single-family houses – the influence of building style

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Møller, Eva B.

    2017-01-01

    According to ISO 13788 internal moisture supply in dwellings can be described by humidity classes defined by outdoor temperature, occupancy and ventilation. Hygrothermal measurements in 500 Danish single-family houses were made to investigate if building style and geographical location are import......According to ISO 13788 internal moisture supply in dwellings can be described by humidity classes defined by outdoor temperature, occupancy and ventilation. Hygrothermal measurements in 500 Danish single-family houses were made to investigate if building style and geographical location...

  1. Moisture Management for High R-Value Walls

    Energy Technology Data Exchange (ETDEWEB)

    Lepage, R.; Schumacher, C.; Lukachko, A.

    2013-11-01

    The following report explains the moisture-related concerns for High R-value wall assemblies and discusses past Building America research work that informs this study. Hygrothermal simulations were prepared for several common approaches to High R-value wall construction in six cities (Houston, Atlanta, Seattle, St. Louis, Chicago, and International Falls) representing a range of climate zones (2, 3, 4C, 4, 5A, and 7, respectively). The simulations are informed by experience gained from past research in this area and validated by field measurement and forensic experience. The modeling program was developed to assess the moisture durability of the wall assemblies based on three primary sources of moisture: construction moisture, air leakage condensation, and bulk water leakage. The peak annual moisture content of the wood based exterior sheathing was used to comparatively analyze the response to the moisture loads for each of the walls in each given city. Walls which experienced sheathing moisture contents between 20% and 28% were identified as risky, whereas those exceeding 28% were identified as very high risk. All of the wall assemblies perform well under idealized conditions. However, only the walls with exterior insulation, or cavity insulation which provides a hygrothermal function similar to exterior insulation, perform adequately when exposed to moisture loads. Walls with only cavity insulation are particularly susceptible to air leakage condensation. None of the walls performed well when a precipitation based bulk water leak was introduced to the backside of the sheathing, emphasizing the importance of proper flashing details.

  2. Mechanics of composite material subjected to eigenstress

    DEFF Research Database (Denmark)

    Fuglsang Nielsen, L.

    In this SBI Bulletin a theory is presented dealing with the mechanical behavior of composites subjected to hygro-thermal actions such as shrinkage caused by moisture variations and expansion caused by temperature variations of freezing of water in pore systems. Special attention is given to the t......In this SBI Bulletin a theory is presented dealing with the mechanical behavior of composites subjected to hygro-thermal actions such as shrinkage caused by moisture variations and expansion caused by temperature variations of freezing of water in pore systems. Special attention is given...

  3. Laboratorul de cercetare şi încercări higrotermice, instrument de verificare experimentală a calităţii construcţiilor, echipamentelor şi gestionării eficiente a energiei

    Directory of Open Access Journals (Sweden)

    Constantin Bogos

    2010-09-01

    Full Text Available This paper seeks to present the technical conditions and the main types of research and experimental verifications being conducted by the Laboratory of Research and Hygrothermal Testing for Materials, Building Elements and Parts at INCD URBAN-INCERC Iasi Branch. Another purpose of this paper is to describe the subjects of the research work done by the group of researchers within the Laboratory over the past 15 years. The main research papers, tests, expert studies, studies on the behavior of in-use buildings may be grouped in the following categories: verification of the quality of new products, products for the hygrothermal conservation and rehabilitation, for materials, elements, closing systems used in constructions and installations; homologation of the new building solutions or hygrothermal rehabilitation existing solutions; identification of the stationary regime specific thermal and physical parameters – resistance to thermal transfer, the condensation risk, the temperature range at the surface of closing elements, the global thermal transfer coefficient; determination of the behavior in case of water vapor diffusion; the accumulation of dew within the structure; determination of the behavior of thermally difficult areas: decks, joining areas, studs, areas with clamps, sashes, lintels etc; experimental determination of the behavior of non-stationary thermal regime closing elements – thermal inertia index, damping and dephasing of the thermal wave, phase displacement; technical agrementation of products, and climatic qualification of industrial equipments, under extreme climatic conditions.

  4. A model to predict moisture conditions in concrete reactor containments

    International Nuclear Information System (INIS)

    Ahs, M.; Nilsson, L.O.; Poyet, S.; L'Hostis, V.

    2015-01-01

    Moisture has an impact in many of the degradation mechanisms that appear in the structures of a nuclear power plant. Moisture conditions in a reactor containment wall have been simulated by using a hygro-thermal model of drying concrete. Methods to estimate the temperature dependency of the sorption isotherms and moisture transport properties is suggested and applied in the model. This temperature dependency is included as there is a temperature gradient present through the containment wall. The hygro-thermal model was applied on a full scale 3D model of a real reactor containment building and the concrete relative humidity has been computed at 4 different moments: 1, 10, 20 and 30 years. The results show that the major part of the concrete is not dried at all even after 30 years of operation. It is also clear that the temperature distribution inside the whole concrete volume is affected by the variable boundary conditions. It was concluded that the suggested hygro-thermal model was appropriate to use as a method to estimate the existing conditions in a PWR reactor containment wall

  5. Simulating non-isothermal water vapour transfer : an experimental validation on multi-layered building components

    NARCIS (Netherlands)

    Roels, S.; Depraetere, W.; Carmeliet, J.; Hens, H.

    1999-01-01

    The aim of this study is to validate different analytical relations used in hygrothermal simulations for the material properties. Therefore, a valida tion experiment on four types of flat roofs has been set up at the laboratory. All rele vant material properties of the individual material layers

  6. Characterization of a lime-pozzolan plaster containing phase change material

    International Nuclear Information System (INIS)

    Pavlíková, Milena; Pavlík, Zbyšek; Trník, Anton; Pokorný, Jaroslav; Černý, Robert

    2015-01-01

    A PCM (Phase Change Material) modified lime-pozzolan plaster for improvement of thermal energy storage of building envelopes is studied in the paper. The investigated plaster is composed of lime hydrate, pozzolan admixture based on metakaolin and mudstone, silica sand, water and paraffin wax encapsulated in polymer capsule. The reference plaster without PCM application is studied as well. The analyzed materials are characterized by bulk density, matrix density, total open porosity, compressive strength and pore size distribution. The temperature of phase change, heat of fusion and crystallization are studied using DSC (Difference Scanning Calorimetry) analysis performed in air atmosphere. In order to get information on materials hygrothermal performance, determination of thermal and hygric properties is done in laboratory conditions. Experimental data reveal a substantial improvement of heat storage capacity of PCM-modified plaster as compared to the reference material without PCM

  7. Degradation of cellulose at the wet-dry interface. II. Study of oxidation reactions and effect of antioxidants.

    Science.gov (United States)

    Jeong, Myung-Joon; Dupont, Anne-Laurence; de la Rie, E René

    2014-01-30

    To better understand the degradation of cellulose upon the formation of a tideline at the wet-dry interface when paper is suspended in water, the production of chemical species involved in oxidation reactions was studied. The quantitation of hydroperoxides and hydroxyl radicals was carried out in reverse phase chromatography using triphenylphosphine and terephthalic acid, respectively, as chemical probes. Both reactive oxygen species were found in the tideline immediately after its formation, in the range of micromoles and nanomoles per gram of paper, respectively. The results indicate that hydroxyl radicals form for the most part in paper before the tideline experiment, whereas hydroperoxides appear to be produced primarily during tideline formation. Iron sulfate impregnation of the paper raised the production of hydroperoxides. After hygrothermal aging in sealed vials the hydroxyl radical content in paper increased significantly. When aged together in the same vial, tideline samples strongly influenced the degradation of samples from other areas of the paper (multi-sample aging). Different types of antioxidants were added to the paper before the tideline experiment to investigate their effect on the oxidation reactions taking place. In samples treated with iron sulfate or artificially aged, the addition of Irgafos 168 (tris(2,4-ditert-butylphenyl) phosphate) and Tinuvin 292 (bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate) reduced the concentration of hydroperoxides and hydroxyl radicals, respectively. Tinuvin 292 was also found to considerably lower the rate of cellulose chain scission reactions during hygrothermal aging of the paper. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Experimental study on mass transfer of contaminants through an enthalpy recovery unit with polymer membrane foils

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Fang, Lei

    2014-01-01

    Laboratory experimental studies were conducted to investigate the mass transfer of contaminants through a total heat recovery unit with polymer membranes foils. The studies were conducted in twin climate chambers which simulated outdoor and indoor thermal climates. One manufacturd total heat...... chemical gases were used to simulate air contaminants. The concentrations of dosed contaminants in the supply and exhaust air upstream and downstream of the total heat recovery unit were measured with Multi-Gas Monitor Innova 1316 in real time. Experiment results showed that 5% to 9% of dosed contaminants...... could transfer from exhaust air to supply air through the enthalpy recovery unit. The mass transfer efficiency of contaminants was independent of the hygro-thermal differences between indoor and outdoor climate conditions. The mass transfer ratio of the chemical contaminants in the total heat recovery...

  9. Influence of rain water leakage on the hygrothermal performance of exterior insulation systems

    OpenAIRE

    Künzel, H.M.; Zirkelbach, D.

    2008-01-01

    This investigation shows that ETICS on light weight structures pose no moisture problem in cold and moderate climates when the detailing of joints and openings is well done, i.e. there is no rain water leakage. This holds for all locations investigated. However, if water leakage cannot be excluded completely and therefore the North-American Standard assumptions - penetration of 1% of the driving rain load - are applied this picture changes, making the drying potential an essential feature. Th...

  10. Integrated procedures and monitoring methodologies for thermographic investigations of architectural heritage: two applicative cases in Sicily, Italy

    International Nuclear Information System (INIS)

    Bianco, A.

    2013-01-01

    The paper explains some opportunities and limitations of thermographic investigations in terms of their capability to define the conservative conditions of architectural heritage and in terms of the historical recollection for a technical diagnosis. Different approaches are demonstrated in two case studies: the first integrates thermography with other investigative methods; the second combines thermographic monitoring with hygrothermal monitoring. (author)

  11. Moisture Performance of Energy-Efficient and Conventional Wood-Frame Wall Assemblies in a Mixed-Humid Climate

    Directory of Open Access Journals (Sweden)

    Samuel V. Glass

    2015-07-01

    Full Text Available Long-term moisture performance is a critical consideration for design and construction of building envelopes in energy-efficient buildings, yet field measurements of moisture characteristics for highly insulated wood-frame walls in mixed-humid climates are lacking. Temperature, relative humidity, and moisture content of wood framing and oriented strand board (OSB structural panel sheathing were measured over a period from mid-November 2011 through March 2013 in both north- and south-facing orientations in test structures near Washington, DC, USA. Wall configurations varied in exterior cladding, water-resistive barrier, level of cavity insulation, presence of exterior continuous insulation, and interior vapor retarder. The combination of high interior humidity and high vapor permeance of painted gypsum board led to significant moisture accumulation in OSB sheathing during winter in walls without a vapor retarder. In contrast, wintertime moisture accumulation was not significant with an interior kraft vapor retarder. Extruded polystyrene exterior insulation had a predictable effect on wall cavity temperature but a marginal impact on OSB moisture content in walls with vinyl siding and interior kraft vapor retarder. Hygrothermal simulations approximately captured the timing of seasonal changes in OSB moisture content, differences between north- and south-facing walls, and differences between walls with and without an interior kraft vapor retarder.

  12. Invention, design and performance of coconut agrowaste fiberboards for ecologically efficacious buildings

    Science.gov (United States)

    Lokko, Mae-ling Jovenes

    As global quantities of waste by-products from food production as well as the range of their applications increase, researchers are realizing critical opportunities to transform the burden of underutilized wastes into ecological profits. Within the tropical hot-humid region, where half the world's current and projected future population growth is concentrated, there is a dire demand for building materials to meet ambitious development schemes and rising housing deficits. However, the building sector has largely overlooked the potential of local agricultural wastes to serve as alternatives to energy-intensive, imported building technologies. Industrial ecologists have recently investigated the use of agrowaste biocomposites to replace conventional wood products that use harmful urea-formaldehyde, phenolic and isocyanate resins. Furthermore, developments in the performance of building material systems with respect to cost, energy, air quality management and construction innovation have evolved metrics about what constitutes material 'upcycling' within building life cycle. While these developments have largely been focused on technical and cost performance, much less attention has been paid to addressing deeply-seated social and cultural barriers to adoption that have sedimented over decades of importation. This dissertation evaluates the development coconut agricultural building material systems in four phases: (i) non-toxic, low-energy production of medium-high density boards (500-1200 kg/m3) from coconut fibers and emerging biobinders; (ii) characterization and evaluation of coconut agricultural building materials hygrothermal performance (iii) scaled-up design development of coconut modular building material systems and (iv) development of a value translation framework for the bottom-up distribution of value to stakeholders within the upcycling framework. This integrated design methodological approach is significant to develop ecological thinking around agrowaste

  13. Polymer Composite Rebars under Moisture and Mechanical Loading

    Science.gov (United States)

    Adam, Mohamed Ibrahim

    structural GFRP composites will, through their design life, be exposed to a range of hygrothermal and other environmental conditions. This study aims to investigate the durability of glass fiber reinforced vinyl ester rebars exposed to moisture at different temperatures and under mechanical loading. Rebars of 10 mm, 13 mm, and 16 mm diameter were immersed in deionized water until saturation for 220 days at three different temperatures 30°C, 70°C, and 100°C. The rebars were examined as-received and following exposure to moisture by scanning electron microscopy and CT scan for possible microvoids and for modes of failures after being tested in both compression as well as non-tested specimens. Diffusion parameters were calculated and the accelerated hygrothermal effect on the compressive strength, modulus, and porosity was investigated. Significant decrease in compressive modulus and a much less degree of degradation in strength was observed. Three modes of failure were noted: splitting, fiber microbuckling, and fiber kinking. Presence of microvoids on both as-received and exposed to moisture specimens was evident. Despite this degradation due to hygrothermal exposure, GFRP rebars were able to maintain their strength. This can be regarded as an edge in their performance compared to steel. However this advantage may not hold with prolonged exposure. It was also noted that the specimens exposed to moisture and temperature exhibited an increase in microvoids of approximately 33% and new distribution of microvoids sizes was recorded. The degradation of the mechanical properties of the GFRP rebars was attributed to the hygrothermal effect that was facilitated by the presence of microvoids which allow moisture to diffuse. Presence and growth of Microvoids due to exposure to moisture and temperature was deemed the primary reason causing the degradation of GFRP rebars. Presence of microvoids needs to be addressed in order to enhance the durability and performance of GFRP rebar.

  14. Moisture Dynamics in Building Envelopes

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele

    2003-01-01

    The overall scope of this Thesis "Moisture dynamics in building envelopes" has been to characterise how the various porous insulation materials investigated performed hygrothermally under conditions similar to those in a typical building envelope. As a result of the changing temperature...... part of the Thesis consists of a theory and literature review on the moisture storage and transport processes (Chapter 2), on the non-Fickian moisture transport (Chapter 3)and on the methods for determining the moisture properties (Chapter 4). In the second part, the conducted experimental work...

  15. Advanced Hygrothermal Performance of Building Component at Reconstruction of S. Radonezhskiy Temple in Volgograd

    Directory of Open Access Journals (Sweden)

    Korniyenko Sergey

    2016-01-01

    Full Text Available The paper presents new thermal design of external wall S. Radonezhskiy temple in Volgograd is developed according to author’s concept. The three-layer brick wall, including a thermal insulation layer from concrete with polystyrene aggregates, is considered. Calculation of interstitial condensation in building component is carried out according to simplified calculation method developed by the author and harmonized to ISO 13788. Analysis of calculation results shows that condensation occurs at one interface during some months but there is no accumulation over the year as all the condensate is predicted to evaporate again. Thus, there is no systematic moisture accumulation at the building component within a year. The risk of run-off from non-absorbent materials will be very low. Analysis of the evaporation rates at the interface shows that duration of drying wetted layer in external wall during initial stage does not exceed admissible values.

  16. A drying coefficient for building materials

    DEFF Research Database (Denmark)

    Scheffler, Gregor Albrecht; Plagge, Rudolf

    2009-01-01

    coefficient is defined which can be determined based on measured drying data. The correlation of this coefficient with the water absorption and the vapour diffusion coefficient is analyzed and its additional information content is critically challenged. As result, a drying coefficient has been derived......The drying experiment is an important element of the hygrothermal characterisation of building materials. Contrary to other moisture transport experiments as the vapour diffusion and the water absorption test, it is until now not possible to derive a simple coefficient for the drying. However......, in many cases such a coefficient would be highly appreciated, e.g. in interaction of industry and research or for the distinction and selection of suitable building materials throughout design and practise. This article first highlights the importance of drying experiments for hygrothermal...

  17. Caractérisation du comportement mécanique d'un composite (tissu ...

    African Journals Online (AJOL)

    epoxy resin) at different times during hygrothermal ageing. This paper considers the analysis of the mechanical behaviour of a laminate constituted of 12 layers of glass fiber fabric/epoxy resin conditioned at different relative humidities of 0, ...

  18. Comparing the Methodologies in ASTM G198 Using Combined Hygrothermal-Corrosion Modeling

    Science.gov (United States)

    Samuel L. Zelinka

    2013-01-01

    ASTM G198, “Standard test method for determining the relative corrosion performance of driven fasteners in contact with treated wood,” was accepted by consensus and published in 2011. The method has two different exposure conditions for determining fastener corrosion performance in treated wood. The first method places the wood and embedded fasteners in a...

  19. Study of the thermal behaviour of traditional wine cellars: the case of the area of ''Tierras Sorianas del Cid'' (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, I.C.; Ocana, S.M. [Universidad Politecnica de Madrid (Spain). Dpto. de Construccion y Vias Rurales

    2005-01-01

    This article studies the hygro-thermal behaviour of two traditional underground wine cellars from Morcuera (Soria, Spain). The differences between them are analyzed and our hypothesis is that one of these constructions is better than the other for the ageing of wines. The hypothesis takes into consideration the existence of a temperature difference of over 20{sup o}C between them as a basis for reaching the aforementioned conclusion. However, the relative humidity inside both of them is 100%, which could pose problems if the presence of mould is not controlled. This study is based on fieldwork for the inventory and cataloguing of traditional agrarian constructions in the ''Tierras Sorianas'' area. The objective of this investigation is to highlight some advantages of traditional building techniques over modern construction practices from the energy-saving viewpoint. (author)

  20. Case Study on Logistics Performance

    Directory of Open Access Journals (Sweden)

    Shahryar Sorooshian

    2013-05-01

    Full Text Available The paper presents research carried out at a medium‐size manufacturing organization in east Asia. The study tries to highlight the importance of supply chain management; specifically, our aim for this study is to understand logistics and performance measurement in the logistics and supply chain, and we include a theoretical discussion of online data collected and a case study of the logistic performance of a real organization. The study also examines the performance of the selected company, identifies the problems and provides recommendations for improvements. This study can be a guide for business advisers and those interested in analysing company performance, especially from a logistics viewpoint. We also suggest the methodology of this case study for those who want to have a better understanding of a business environment before starting their own business, or for benchmarking practice during strategic planning.

  1. LINEAR AND NONLINEAR VISCOELASTIC CHARACTERIZATION OF PROTON EXCHANGE MEMBRANES AND STRESS MODELING FOR FUEL CELL APPLICATIONS

    OpenAIRE

    Patankar, Kshitish A

    2009-01-01

    In this dissertation, the effect of temperature and humidity on the viscoelastic and fracture properties of proton exchange membranes (PEM) used in fuel cell applications was studied. Understanding and accurately modeling the linear and nonlinear viscoelastic constitutive properties of a PEM are important for making hygrothermal stress predictions in the cyclic temperature and humidity environment of operating fuel cells. In this study, Nafion® NRE 211, Gore-Select® 57, and Ion Power® N111...

  2. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  3. An investigation of the moisture sorption and permeability properties of mill-fabricated oriented strandboard

    Science.gov (United States)

    Timusk, Paul Christopher

    This thesis brings the disciplines of Building Science and Wood Science together in the study of the moisture-related properties of oriented strand board (OSB). Using controlled mill-manufactured panels specifically made for this project, this research reveals how the sorption and permeance properties of OSB are affected by several variables including production parameters and physical panel properties, moisture-history, and relative humidity exposure. Since OSB varies in composition through its thickness, this study isolated and tested various core and surface components. Permeability and sorption properties of individual OSB layers, intact panel sections, and panel sections that had undergone cyclic wetting and drying or relative humidity cycling prior to testing, were evaluated. After laboratory testing and analysis, a set of OSB permeance and sorption values were entered into the material database of a finite-element hygrothermal computer modeling program. Relying on this data, a series of hygrothermal wall simulations were carried out using standard wall sections exposed to various climate conditions found throughout North America. These simulations revealed that the results vary widely depending upon the permeance and sorption values used. Thus the common practice of characterizing a range of OSB products with various moisture histories by using a single permeance or sorption value may not be wise.

  4. Whole-building Hygrothermal Simulation Model

    DEFF Research Database (Denmark)

    Rode, Carsten; Grau, Karl

    2003-01-01

    An existing integrated simulation tool for dynamic thermal simulation of building was extended with a transient model for moisture release and uptake in building materials. Validation of the new model was begun with comparison against measurements in an outdoor test cell furnished with single...... materials. Almost quasi-steady, cyclic experiments were used to compare the indoor humidity variation and the numerical results of the integrated simulation tool with the new moisture model. Except for the case with chipboard as furnishing, the predictions of indoor humidity with the detailed model were...

  5. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  6. Influence of recycled polystyrene beads on cement paste properties

    Directory of Open Access Journals (Sweden)

    Maaroufi Maroua

    2018-01-01

    Full Text Available In order to keep up with the requirements of sustainable development, there is a growing interest towards reducing the energy consumption in the construction and rehabilitation of buildings and the promotion of recycling waste in building materials. The use of recycled polystyrene beads in cement-based materials composition constitutes a solution to improve the insulation in buildings. This allows also limiting landfill by reusing the polystyrene waste. The aim of this study is to compare some properties and performances of a cement paste containing polystyrene beads to a reference paste designed with only the same cement. An experimental campaign was conducted and the obtained results showed that adding recycled polystyrene beads to a cement paste improves its hygro-thermal properties. Further studies are however necessary to better understand the real role of the polystyrene beads in the heat and mass transfers.

  7. Evaluation of mechanical properties of four different carbon/epoxy composites used in aeronautical field

    Directory of Open Access Journals (Sweden)

    Jane Maria Faulstich de Paiva

    2005-03-01

    Full Text Available Four families of carbon fiber reinforced composites (CFRC used in aeronautical industry were evaluated by flexural and interlaminar shear tests. It is also characterized three families of non-conditioned and conditioned CFRC by compression test. The composites were obtained by hand lay-up process in autoclave by using prepregs based on epoxy matrices (F155 and F584 and carbon fiber fabric reinforcements (PW-"Plain Weave" and 8HS-"Eight Harness Satin". The F155-epoxy matrix was cured at 121 °C and the F584-epoxy type at 177 °C. After molding, the laminates were cut in specimens attending the ASTM D790 for the flexural test, the ASTM D2344 for the interlaminar shear test (ILSS and the ASTM D3410 for the compressive test. The compressive tests were performed for testing the specimens before and after hygrothermal conditioning. The results show that the F584-epoxy matrix laminates present higher mechanical properties when compared to the F155-epoxy ones. The shear-tested samples observed by scanning electron microscopy and that ones tested in flexural, analyzed by stereoscopy, revealed that the fractured surfaces present typical aspects. The compressive results show that the hygrothermal conditioning caused the decrease of the compressive strength in, approximately, 8-20% depending on the laminate type. The failure modes of the tested specimens were evaluated showing good agreement with the literature.

  8. Application of Spray Foam Insulation Under Plywood and Oriented Strand Board Roof Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Grin, A. [Building Science Corporation, Somerville, MA (United States); Smegal, J. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    2013-10-01

    Unvented roof strategies with open cell and closed cell spray polyurethane foam insulation sprayed to the underside of roof sheathing have been used since the mid-1990's to provide durable and efficient building enclosures. However, there have been isolated moisture related incidents reported anecdotally that raise potential concerns about the overall hygrothermal performance of these systems. This project involved hygrothermal modeling of a range of rainwater leakage and field evaluations of in-service residential roofs using spray foam insulation. All of the roof assemblies modeled exhibited drying capacity to handle minor rainwater leakage. All field evaluation locations of in-service residential roofs had moisture contents well within the safe range for wood-based sheathing. Explorations of eleven in-service roof systems were completed. The exploration involved taking a sample of spray foam from the underside of the roof sheathing, exposing the sheathing, then taking a moisture content reading. All locations had moisture contents well within the safe range for wood-based sheathing. One full-roof failure was reviewed, as an industry partner was involved with replacing structurally failed roof sheathing. In this case the manufacturer's investigation report concluded that the spray foam was installed on wet OSB based on the observation that the spray foam did not adhere well to the substrate and the pore structure of the closed cell spray foam at the ccSPF/OSB interface was indicative of a wet substrate.

  9. Analysis of coupled transport phenomena in concrete at elevated temperatures

    OpenAIRE

    Beneš, Michal; Štefan, Radek; Zeman, Jan

    2010-01-01

    In this paper, we study a non-linear numerical scheme arising from the implicit time discretization of the Ba\\v{z}ant-Thonguthai model for hygro-thermal behavior of concrete at high temperatures. Existence and uniqueness of the time-discrete solution in two dimensions is established using the theory of pseudomonotone operators in Banach spaces. Next, the spatial discretization is accomplished by the conforming finite element method. An illustrative numerical example shows that the numerical m...

  10. Diagnostic colonoscopy: performance measurement study.

    Science.gov (United States)

    Kuznets, Naomi

    2002-07-01

    This is the fifth of a series of best practices studies undertaken by the Performance Measurement Initiative (PMI), the centerpiece of the Institute for Quality Improvement (IQI), a not-for-profit quality improvement subsidiary of the Accreditation Association for Ambulatory Health Care (AAAHC) (Performance Measurement Initiative, 1999a, 1999b, 2000a, 2000b). The IQI was created to offer clinical performance measurement and improvement opportunities to ambulatory health care organizations and others interested in quality patient care. The purpose of the study was to provide opportunities to initiate clinical performance measurement on key processes and outcomes for this procedure and use this information for clinical quality improvement. This article provides performance measurement information on how organizations that have demonstrated and validated differences in clinical practice can have similar outcomes, but at a dramatically lower cost. The intent of the article is to provide organizations with alternatives in practice to provide a better value to their patients.

  11. Influence of Indoor Hygrothermal Conditions on Human Quality of Life in Social Housing.

    Science.gov (United States)

    Soares, Sara; Fraga, Silvia; Delgado, Joao M P Q; Ramos, Nuno M M

    2015-11-17

    Modern societies spend most of their time indoors, namely at home, and the indoor environment quality turns out to be a crucial factor to health, quality of life and well-being of the residents. The present study aims to understand how indoor environment relates with quality of life and how improving housing conditions impacts on individuals' health. This study case will rely on the following assessments in both rehabilitated and non-rehabilitated social housing: i) field measurements, in social dwellings (namely temperature, relative humidity, carbon dioxide concentration, air velocity, air change rate, level of mould spores and energy consumption); ii) residents' questionnaires on social, demogaphic, behavioural, health characteristics and quality of life. Also, iii) qualitative interviews performed with social housing residents from the rehabilitated houses, addressing the self-perception of living conditions and their influence in health status and quality of life. All the collected information will be combined and analysed in order to achieve the main objective. It is expected to define a Predicted Human Life Quality (PHLQ) index, that combines physical parameters describing the indoor environment measured through engineering techniques with residents' and neighbourhood quality of life characteristics assessed by health questionnaires. Improvement in social housing should be related with better health indicators and the new index might be an important tool contributing to enhance quality of life of the residents. Significance for public healthThis study will contribute to understand how indoor environment relates with quality of life and how improving housing conditions impacts on individuals' health, in social housing neighbourhoods. As so, it is important to share the undertaken methodology carried out by a multidisciplinary team, in order to allow other researchers following comparable studies to adopt a similar approach. The case study results will allow

  12. Predicting temperature and moisture distributions in conditioned spaces using the zonal approach

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, K.C. [Parana Pontifical Catholic Univ., Curitiba (Brazil); Wurtz, E.; Inard, C. [La Rochelle Univ., La Rochelle, Cedex (France). LEPTAB

    2005-07-01

    Moisture interacts with building elements in a number of different ways that impact upon building performance, causing deterioration of building materials, as well as contributing to poor indoor air quality. In humid climates, moisture represents one of the major loads in conditioned spaces. It is therefore important to understand and model moisture transport accurately. This paper discussed an intermediate zonal approach to building a library of data in order to predict whole hygrothermal behavior in conditioned rooms. The zonal library included 2 models in order to consider building envelope moisture buffering effects as well as taking into account the dynamic aspect of jet airflow in the zonal method. The zonal library was then applied to a case study to show the impact of external humidity on the whole hygrothermal performance of a room equipped with a vertical fan-coil unit. The proposed theory was structured into 3 groups representing 3 building domains: indoor air; envelope; and heating, ventilation and air conditioning (HVAC) systems. The indoor air sub-model related to indoor air space, where airflow speed was considered to be low. The envelope sub-model related to the radiation exchanges between the envelope and its environment as well as to the heat and mass transfers through the envelope material. The HVAC system sub-model referred to the whole system including equipment, control and specific airflow from the equipment. All the models were coupled into SPARK, where the resulting set of non-linear equations were solved simultaneously. A case study of a large office conditioned by a vertical fan-coil unit with a rectangular air supply diffuser was presented. Details of the building's external and internal environment were provided, as well as convective heat and mass transfer coefficients and temperature distributions versus time. Results of the study indicated that understanding building material moisture buffering effects is as important as

  13. Moisture Management for High R-Value Walls

    Energy Technology Data Exchange (ETDEWEB)

    Lepage, R. [Building Science Corporation, Somerville, MA (United States); Schumacher, C. [Building Science Corporation, Somerville, MA (United States); Lukachko, A. [Building Science Corporation, Somerville, MA (United States)

    2013-11-01

    This report explains the moisture-related concerns for high R-value wall assemblies and discusses past Building America research work that informs this study. In this project, hygrothermal simulations were prepared for several common approaches to High R-value wall construction in six cities (Houston, Atlanta, Seattle, St. Louis, Chicago, and International Falls) representing a range of climate zones. The modeling program assessed the moisture durability of the wall assemblies based on three primary sources of moisture: construction moisture, air leakage condensation, and bulk water leakage; the report presents results of the study.

  14. Hygrothermal effects on the mechanical behaviour of graphite fibre-reinforced epoxy laminates beyond initial failure

    Science.gov (United States)

    Ishai, O.; Garg, A.; Nelson, H. G.

    1986-01-01

    The critical load levels and associated cracking beyond which a multidirectional laminate can be considered as structurally failed has been determined by loading graphite fiber-reinforced epoxy laminates to different strain levels up to ultimate failure. Transverse matrix cracking was monitored by acoustic and optical methods. The residual stiffness and strength parallel and perpendicular to the cracks were determined and related to the environmental/loading history. Within the range of experimental conditions studied, it is concluded that the transverse cracking process does not have a crucial effect on the structural performance of multidirectional composite laminates.

  15. Class and Home Problems: Humidification, a True "Home" Problem for p. Chemical Engineer

    Science.gov (United States)

    Condoret, Jean-Stephane

    2012-01-01

    The problem of maintaining hygrothermal comfort in a house is addressed using the chemical engineer's toolbox. A simple dynamic modelling proved to give a good description of the humidification of the house in winter, using a domestic humidifier. Parameters of the model were identified from a simple experiment. Surprising results, especially…

  16. Influence of indoor hygrothermal conditions on human quality of life in social housing

    Directory of Open Access Journals (Sweden)

    Sara Soares

    2015-11-01

    Full Text Available Background: Modern societies spend most of their time indoors, namely at home, and the indoor environment quality turns out to be a crucial factor to health, quality of life and well-being of the residents. The present study aims to understand how indoor environment relates with quality of life and how improving housing conditions impacts on individuals’ health. Design and Methods: This study case will rely on the following assessments in both rehabilitated and non-rehabilitated social housing: i field measurements, in social dwellings (namely temperature, relative humidity, carbon dioxide concentration, air velocity, air change rate, level of mould spores and energy consumption; ii residents’ questionnaires on social, demogaphic, behavioural, health characteristics and quality of life. Also, iii qualitative interviews performed with social housing residents from the rehabilitated houses, addressing the self-perception of living conditions and their influence in health status and quality of life. All the collected information will be combined and analysed in order to achieve the main objective. Expected impact: It is expected to define a Predicted Human Life Quality (PHLQ index, that combines physical parameters describing the indoor environment measured through engineering techniques with residents’ and neighbourhood quality of life characteristics assessed by health questionnaires. Improvement in social housing should be related with better health indicators and the new index might be an important tool contributing to enhance quality of life of the residents.

  17. Can painted glass felt or glass fibre cloth be used as vapour barrier?

    DEFF Research Database (Denmark)

    El-Khattam, Amira; Andersen, Mie Them; Hansen, Kurt Kielsgaard

    2014-01-01

    In most Nordic homes the interior surfaces of walls and ceilings have some kind of surface treatment for aesthetical reasons. The treatments can for example be glass felt or glass fibre cloth which are painted afterwards. To evaluate the hygrothermal performance of walls and ceilings...... treatments. The surface treatments were glass felt or glass fibre cloth with different types of paints or just paint. The paint types were acrylic paint and silicate paint. The results show that the paint type has high influence on the water vapour resistance while the underlay i.e. glass felt or glass fibre...... acrylic paint on glass felt or glass fibre cloth cannot be used instead of a vapour barrier....

  18. Influence of temporal resolution and processing of exposure data on modeling of chloride ingress and reinforcement corrosion in concrete

    DEFF Research Database (Denmark)

    Flint, Madeleine; Michel, Alexander; Billington, Sarah L.

    2014-01-01

    a numerical heat and mass transport model that includes full coupling of heat, moisture and ion transport. Heat, moisture, and chloride concentration distributions were passed to a simplified reinforcement corrosion initiation and propagation model. The numerical study indicates that processing and temporal...... resolution of the exposure data has a considerable impact on long-term hygrothermal distribution, chloride ingress, and reinforcement section loss results. Use of time-averaged exposure data in the heat and mass transport model reduces the rate of chloride ingress in concrete and affects prediction...

  19. Improvements to water vapor transmission and capillary absorption measurements in porous materials

    Science.gov (United States)

    Samuel L. Zelinka; Samuel V. Glass; Charles R. Boardman

    2016-01-01

    The vapor permeability (or equivalently the vapor diffusion resistance factor) and the capillary absorption coefficient are frequently used as inputs to hygrothermal or heat, air, and moisture (HAM) models. However, it has been well documented that the methods used to determine these properties are sensitive to the operator, and wide variations in the properties have...

  20. Fastener Corrosion: A Result of Moisture Problems in the Building Envelope

    Science.gov (United States)

    Samuel L. Zelinka

    2013-01-01

    This paper reviews recent literature on the corrosion of metals embedded in wood and highlights the link be-tween moisture accumulation in wood and fastener cor-rosion. Mechanisms of fastener corrosion are described including dependence upon wood moisture content. These fundamental concepts are applied to practical examples by explaining how hygrothermal models can be...

  1. Excavationless Exterior Foundation Insulation Field Study

    Energy Technology Data Exchange (ETDEWEB)

    Schirber, T.; Mosiman, G.; Ojczyk, C.

    2014-10-01

    Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with a liquid insulating foam. The team was able to excavate a continuous 4" wide by 4' to 5' deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.

  2. Excavationless Exterior Foundation Insulation Field Study

    Energy Technology Data Exchange (ETDEWEB)

    Schirber, T. [NorthernSTAR, Minneaplolis, MN (United States); Mosiman, G. [NorthernSTAR, Minneaplolis, MN (United States); Ojczyk, C. [NorthernSTAR, Minneaplolis, MN (United States)

    2014-09-01

    Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with liquid insulating foam. The team was able to excavate a continuous 4 inches wide by 4 feet to 5 feet deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.

  3. High Performance Work System, HRD Climate and Organisational Performance: An Empirical Study

    Science.gov (United States)

    Muduli, Ashutosh

    2015-01-01

    Purpose: This paper aims to study the relationship between high-performance work system (HPWS) and organizational performance and to examine the role of human resource development (HRD) Climate in mediating the relationship between HPWS and the organizational performance in the context of the power sector of India. Design/methodology/approach: The…

  4. Impact de la fatigue et du vieillissement hygrothermique en eau ...

    African Journals Online (AJOL)

    composites, glass epoxy. Two sets of tests were conducted to distinguish the effects of fatigue and hygrothermal aging. During the first serie, the number of cycle of fatigue was set at 1000 cycles and we varied the materials times immersion from 100 to 1000 hours. For the second series, we varied the number of cycles of ...

  5. Mechanical properties and environmental effects of epoxy resins in the neat state and in composites

    International Nuclear Information System (INIS)

    Yang, C.M.P.

    1984-01-01

    The dynamic mechanical properties of graphite fiber reinforced, epoxy matrix composite laminates subjected to loading perpendicular to the plane of lamination and of neat epoxy resin are reported. The centrosymmetric deformation (CSD) test geometry provides an accurate and convenient test mode for the study of the viscoelastic behavior of very stiff graphite-epoxy laminates. It is found that the in-phase and out-of-phase stiffness superpose to form master curves covering a frequency range of 12 decades. By a suitable scaling procedure of the master curves, it is found that the in-phase stiffness has the same shape and the out-of-phase has the same dispersion for all laminates irrespective of the stacking sequence. The dispersion characteristics of in-situ and neat resin epoxy were nearly identical, but with the neat resin having a lower glass-transition temperature. The graphite/epoxy composites and neat resin epoxy have been shown to be sensitive to hygrothermal environment. For postcured specimens the plasticization and inhomogeneous swelling effects due to the moisture absorbed are found to be reversible, in the sense that the initially dry properties of the laminate are recovered after redrying the wet specimen. On the other hand, for as cured specimens, the plasticization and inhomogeneous swelling effects are found to be irreversible under the same hygrothermal environment

  6. Moisture supply in Danish single-family houses – the influence of occupant behaviour and type of room

    DEFF Research Database (Denmark)

    Møller, Eva B.; Hansen, Ernst Jan de Place

    2017-01-01

    According to ISO 13788, the internal moisture supply in dwellings can be described by humidity classes defined by outdoor temperature, occupancy and ventilation. Hygrothermal measurements in indoor air in 500 Danish single-family houses were made to investigate if this corresponds with reality....... The study focuses on the dependency of number and age of occupants, occupants’ time spent in the house, square meters living space, ventilation habits and type of room. Moisture supply depends on the type of room; bathroom, basement and living room have the highest values. None of the other parameters seems...

  7. Operator performance in non-destructive testing: A study of operator performance in a performance test

    Energy Technology Data Exchange (ETDEWEB)

    Enkvist, J.; Edland, A.; Svenson, Ola [Stockholm Univ. (Sweden). Dept. of Psychology

    2000-05-15

    In the process industries there is a need of inspecting the integrity of critical components without disrupting the process. Such in-service inspections are typically performed with non-destructive testing (NDT). In NDT the task of the operator is to (based on diagnostic information) decide if the component can remain in service or not. The present study looks at the performance in NDT. The aim is to improve performance, in the long run, by exploring the operators' decision strategies and other underlying factors and to this way find out what makes some operators more successful than others. Sixteen operators performed manual ultrasonic inspections of four test pieces with the aim to detect (implanted) cracks. In addition to these performance demonstration tests (PDT), the operators performed independent ability tests and filled out questionnaires. The results show that operators who trust their gut feeling more than the procedure (when the two come to different results) and that at the same time have a positive attitude towards the procedure have a higher PDT performance. These results indicate the need for operators to be motivated and confident when performing NDT. It was also found that the operators who performed better rated more decision criteria higher in the detection phase than the operators who performed worse. For characterizing it was the other way around. Also, the operators who performed better used more time, both detecting and characterizing, than the operators who performed worse.

  8. Operator performance in non-destructive testing: A study of operator performance in a performance test

    International Nuclear Information System (INIS)

    Enkvist, J.; Edland, A.; Svenson, Ola

    2000-05-01

    In the process industries there is a need of inspecting the integrity of critical components without disrupting the process. Such in-service inspections are typically performed with non-destructive testing (NDT). In NDT the task of the operator is to (based on diagnostic information) decide if the component can remain in service or not. The present study looks at the performance in NDT. The aim is to improve performance, in the long run, by exploring the operators' decision strategies and other underlying factors and to this way find out what makes some operators more successful than others. Sixteen operators performed manual ultrasonic inspections of four test pieces with the aim to detect (implanted) cracks. In addition to these performance demonstration tests (PDT), the operators performed independent ability tests and filled out questionnaires. The results show that operators who trust their gut feeling more than the procedure (when the two come to different results) and that at the same time have a positive attitude towards the procedure have a higher PDT performance. These results indicate the need for operators to be motivated and confident when performing NDT. It was also found that the operators who performed better rated more decision criteria higher in the detection phase than the operators who performed worse. For characterizing it was the other way around. Also, the operators who performed better used more time, both detecting and characterizing, than the operators who performed worse

  9. A Study of Vicon System Positioning Performance

    Directory of Open Access Journals (Sweden)

    Pierre Merriaux

    2017-07-01

    Full Text Available Motion capture setups are used in numerous fields. Studies based on motion capture data can be found in biomechanical, sport or animal science. Clinical science studies include gait analysis as well as balance, posture and motor control. Robotic applications encompass object tracking. Today’s life applications includes entertainment or augmented reality. Still, few studies investigate the positioning performance of motion capture setups. In this paper, we study the positioning performance of one player in the optoelectronic motion capture based on markers: Vicon system. Our protocol includes evaluations of static and dynamic performances. Mean error as well as positioning variabilities are studied with calibrated ground truth setups that are not based on other motion capture modalities. We introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments contrary to state-of-the art works that rely on inter-marker distances. The system performs well on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. Our dynamic experiments were carried out at speeds found in real applications. Our work suggests that the system error is less than 2 mm. We also found that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for our dynamic study.

  10. Application Performance Management Impact On Organizational Performance Local Company Studies In West Java - Indonesia

    Directory of Open Access Journals (Sweden)

    Teni Listiani

    2015-02-01

    Full Text Available Abstract This study aimed to analyze the effect on the performance of the companys performance management area. Management performance is measured through three dimensions performance planning performance assessment and feeding it behind. While organizational performance is measured through four dimensions financial perspective customer perspective internal business processes and learning and growth perspective. The unit of analysis in this research area comprising 30 companies from 23 taps 6 PD Market and 1 PD Health. Meanwhile the unit of observation is the top-middle-level managers-down of a total of 360 people. To determine the influence of the variables studied used Structural Equation Model SEM based on the model variant with Partial Least Square PLS. The results showed that in the enterprise area performance management affect the performance of the organization but the effect is not too large.

  11. Thermomechanical and hygroelastic properties of an epoxy system under humid and cold-warm cycling conditions

    KAUST Repository

    El Yagoubi, Jalal; Lubineau, Gilles; Saghir, Shahid; Verdu, Jacques; Askari, Abe H.

    2014-01-01

    In this paper, we study the hygrothermal aging of an anhydride-cured epoxy under temperature and hygrometry conditions simulating those experienced by an aircraft in wet tropical or subtropical regions. Gravimetric and dimensional measurements were performed and they indicate that there are three stages in this aging process: the first one, corresponding to the early cycles can be called the "induction stage". The second stage of about 1000 cycles duration, could be named the "swelling stage", during which the volume increase is almost equal to the volume of the (liquid) water absorbed. Both the first and second stages are accompanied by modifications of the mechanical properties and the glass transition temperature. During the third ("equilibrium") stage, up to 3000 cycles, there is no significant change in the physical properties despite the continuous increase of water uptake. This can be explained by the fact that only physically sorbed water can influence physical properties. © 2013 Elsevier Ltd. All rights reserved.

  12. The Study of the Relationship between Mother's Studies with Study Skills and Mathematics Performance of Students

    Directory of Open Access Journals (Sweden)

    Behnoush Taheri

    2015-07-01

    Full Text Available Certainly teaching study skills of mathematics has special importance and plays important role in mathematics performance of students. As mothers spend more times with self-children then they can be effect on study and their mathematics performance. Present research implements to study of the relationship between mothers' studies with study skills and mathematics performance of their children. Population of this research is all girl students of first grade in high school at zone one of Tehran and sample is 97 people. For collecting data of this research through standard questionnaire of mathematics studies skills is used for measuring of study skill of mathematics and questions for studying information related to mothers' studies and a math exam for getting information of mathematics performance of students are used. The results indicated that there is not significant relationship between mothers' studies and study skill of mathematics among students. Also, it is indicated that there is positive significant relationship between mothers' studies and mathematic performance of students.

  13. Choking vs. clutch performance: a study of sport performance under pressure.

    Science.gov (United States)

    Otten, Mark

    2009-10-01

    Choking research in sport has suggested that an athlete's tendency to choke, versus give a better than usual (i.e., "clutch") performance depends on his or her personality, as well as on situational influences, such as a reliance on explicit (versus implicit) knowledge when pressured. The current study integrated these hypotheses and tested a structural equation model (SEM) to predict sport performance under pressure. Two hundred and one participants attempted two sets of 15 basketball free throws, and were videotaped during their second set of shots as a manipulation of pressure. Results of the model suggest that "reinvesting" attention in the task leads to greater anxiety (cognitive and somatic), which then predicts a higher level of self-focus; self-focus, then, did not lead to improved performance under pressure, whereas feelings of self-reported "perceived control" did help performance. Implications for measurement of these constructs, and their relationships with performance, are discussed.

  14. The performative pleasure of imprecision: a diachronic study of entrainment in music performance

    Directory of Open Access Journals (Sweden)

    Andrew eGeeves

    2014-10-01

    Full Text Available This study focuses in on a moment of live performance in which the entrainment amongst a musical quartet is threatened. Entrainment is asymmetric in so far as there is an ensemble leader who improvises and expands the structure of a last chorus of a piece of music beyond the limits tacitly negotiated during prior rehearsals and performances. Despite the risk of entrainment being disturbed and performance interrupted, the other three musicians in the quartet follow the leading performer and smoothly transition into unprecedented performance territory. We use this moment of live performance to work back through the fieldwork data, building a diachronic study of the development and bases of entrainment in live music performance. We introduce the concept of entrainment and profile previous theory and research relevant to entrainment in music performance. After outlining our methodology, we trace the evolution of the structure of the piece of music from first rehearsal to final performance. Using video clip analysis, interviews and field notes we consider how entrainment shaped and was shaped by the moment of performance in focus. The sense of trust between quartet musicians is established through entrainment processes, is consolidated via smooth adaptation to the threats of disruption. Nonverbal communicative exchanges, via eye contact, gesture and spatial proximity, sustain entrainment through phase shifts occurring swiftly and on the fly in performance contexts. These exchanges permit smooth adaptation promoting trust. This frees the quartet members to play with the potential disturbance of equilibrium inherent in entrained relationships and to play with this tension in an improvisatory way that enhances audience engagement and the live quality of performance.

  15. Corporate Diversification and Firm Performance: an Empirical Study

    Directory of Open Access Journals (Sweden)

    Olu Ojo

    2009-05-01

    Full Text Available The importance of diversification and performance in then strategic management literature is widely accepted among academics and practitioners . However, the proxies for performance and diversification that have been employed in past strategy research has not been unanimously agreed upon. Given the current state of confusion that exists with regard to the impact of corporate diversification on firm performance in selected Nigerian companies. The reason for increased interest in diversification has always been on the possibility that diversification is related to corporate performance. However , while this topic is rich in studies, empirical evidence semerging from various studies about the effect of diversification on performance have so far yield mixed results that are inconclusive and contradictory. In addition , despite the existence of these studies, very litlle attention has been given to the companies in developing countries including Nigeria. This means that there is a major gap in the relevant literature on developing countries which has to be covered by research. This research attempts to fill this gap by studying the situation of the Nigeria companies and providing more empirical evidence on the effects of corporate diversification on firm performance based on individual company-level data. Survey research design was adopted in this study with the application of simple random sampling tehnique in selecting our case study companies as well as our respondents. Primary data were collected through questionnaire. Data were analysed through descriptive statistics and correlation and coefficient of determination were used to test our hypothese. It was discovered that diversification impacted performance of these companies posivitely and we recommend that these companies should engage in geographical diversification in addition to other forms of diversification they are currently involved in for maximum performance.

  16. An Empirical Study of a Solo Performance Assessment Model

    Science.gov (United States)

    Russell, Brian E.

    2015-01-01

    The purpose of this study was to test a hypothesized model of solo music performance assessment. Specifically, this study investigates the influence of technique and musical expression on perceptions of overall performance quality. The Aural Musical Performance Quality (AMPQ) measure was created to measure overall performance quality, technique,…

  17. Contribution of Portuguese Vernacular Building Strategies to Indoor Thermal Comfort and Occupants’ Perception

    Directory of Open Access Journals (Sweden)

    Jorge Fernandes

    2015-11-01

    Full Text Available Solar passive strategies that have been developed in vernacular architecture from different regions are a response to specific climate effects. These strategies are usually simple, low-tech and have low potential environmental impact. For this reason, several studies highlight them as having potential to reduce the demands of non-renewable energy for buildings operation. In this paper, the climatic contrast between northern and southern parts of mainland Portugal is presented, namely the regions of Beira Alta and Alentejo. Additionally, it discusses the contribution of different climate-responsive strategies developed in vernacular architecture from both regions to assure thermal comfort conditions. In Beira Alta, the use of glazed balconies as a strategy to capture solar gains is usual, while in Alentejo the focus is on passive cooling strategies. To understand the effectiveness of these strategies, thermal performances and comfort conditions of two case studies were evaluated based on the adaptive comfort model. Field tests included measurement of hygrothermal parameters and surveys on occupants’ thermal sensation. From the results, it has been found that the case studies have shown a good thermal performance by passive means alone and that the occupants feel comfortable, except during winter where there is the need to use simple heating systems.

  18. Thermal shock effect on Mechanical and Physical properties of pre-moisture treated GRE composite

    Science.gov (United States)

    Chakraverty, A. P.; Panda, A. B.; Mohanty, U. K.; Mishra, S. C.; Biswal, B. B.

    2018-03-01

    Many practical situations may be encountered under which a GFRP (Glass fibre reinforced polymer) composite, during its service life, is exposed to the severities of sudden temperature fluctuations. Moisture absorption of GRE (Glass fibre reinforced epoxy) composites followed by various gradients of temperature fluctuations may cause thermo- mechanical degradation. It is on this context, the hand layed GRE composite samples are exposed to up-thermal shock (-40°C to +50°C) and down-thermal shock (+50°C to -40°C) for various time interval after several periods of moisture (hydrothermal/hygrothermal) conditioning. The thermally shocked GRE specimens are put to 3-point bend test to divulge inter laminar shear strength (ILSS). Least ILSS values are recorded for the samples with maximum period of moisture treatments under with both up-thermal and down-thermal shock conditions. Lower glass transition temperature (Tg) values, as revealed through the low temperature DSC test, are exhibited at maximum durations of both up-thermal and down-thermal shock for the samples with higher periods of hygrothermal/hydrothermal treatments. SEM fractographs of representative GRE specimens after optimum period of moisture treatments and thermal shock show the various modes of failures.

  19. Sheep Wool as a Construction Material for Energy Efficiency Improvement

    Directory of Open Access Journals (Sweden)

    Azra Korjenic

    2015-06-01

    Full Text Available The building sector is responsible for 40% of the current CO2 emissions as well as energy consumption. Sustainability and energy efficiency of buildings are currently being evaluated, not only based on thermal insulation qualities and energy demands, but also based on primary energy demand, CO2 reductions and the ecological properties of the materials used. Therefore, in order to make buildings as sustainable as possible, it is crucial to maximize the use of ecological materials. This study explores alternative usage of sheep wool as a construction material beyond its traditional application in the textile industry. Another goal of this research was to study the feasibility of replacement of commonly used thermal insulations with natural and renewable materials which have better environmental and primary energy values. Building physics, energy and environmental characteristics were evaluated and compared based on hygrothermal simulation and ecological balance methods. The observations demonstrate that sheep wool, compared with mineral wool and calcium silicate, provides comparable thermal insulation characteristics, and in some applications even reveals better performance.

  20. Numerical analysis of passive strategies for energy retrofit of existing buildings in Mediterranean climate: thermal mass and natural ventilation combination

    Directory of Open Access Journals (Sweden)

    Calcerano Filippo

    2017-01-01

    Full Text Available The study investigates the potential of coupling natural ventilation and thermal storage systems to improve hygrothermal comfort and reduce energy consumption during summer season in an existing building in the Mediterranean. It aims at bridging the knowledge gap between designers, researchers and building scientists, fostering a multidisciplinary approach and promoting numerical simulation of the energy performance of buildings within architectural professional practice. The study analyses the interaction between six natural ventilation systems (single sided ventilation through facade openings; cross ventilation through facade openings, inlet wind tower, thermal chimney, evaporative cool tower, earth pipes and with two thermal storage typology (heavy and medium-light within four strategic Italian location (Rome, Naples, Messina and Catania. For each interaction we perform a numerical dynamic simulation of indoor comfort, indoor air quality and energy consumption during the summer period, on a reference building model corresponding to the most common Italian typology. Results show that the use of the chosen systems ensures significant reductions of discomfort hours and energy consumption in all configurations. The study also highlights the high efficiency of non invasive systems (single-sided and cross ventilation with automatic control present discomfort hours reduction and energy consumption reduction above 68% for all combinations and the significant influence of the daily thermal range value on the performance of systems without air pre-treatment.

  1. Paradigms of Communication in Performance and Dance Studies

    OpenAIRE

    Popa Blanariu, Nicoleta

    2015-01-01

    In her article "Paradigms of Communication in Performance and Dance Studies" Nicoleta Popa Blanariu approaches from an interdisciplinary perspective the measure in which performing arts (theater, music, ballet, Indian classical dance, folk dance, etc.), as well as ritual performance constitute a corpus that may be analysed by means of theoretical and conceptual tools in communication studies and semiotics. Popa Blanariu analyses the relation between signification and communication in performi...

  2. Organisational Learning and Performance--An Empirical Study

    Science.gov (United States)

    Jyothibabu, C.; Pradhan, Bibhuti Bhusan; Farooq, Ayesha

    2011-01-01

    This paper explores the important question "how the learning entities--individual, group or organisation--are affecting organisational performance". The answer is important for promoting learning and improving performance. This empirical study in the leading power utility in India found that there is a positive relation between…

  3. Performable Case Studies in Ethics Education.

    Science.gov (United States)

    Robeson, Richard; King, Nancy M P

    2017-09-12

    Bioethics education often includes the study of short stories, novels, plays, and films, because such materials present case examples that can highlight relevant issues and questions especially vividly for a wide range of students. In addition, creative writing is widely used in the education of health professional students and in continuing education settings for health professionals. There are very few academic or professional disciplines that do not use case studies, but the case study in dialogic form has not been standard practice for thousands of years. Dramatic arts casuistry-the creation and performance of short case studies designed specifically to raise bioethics issues for discussion-represents an application of literature and the medical humanities that is both unique and uniquely valuable. This essay describes the development and history of a course that has been successfully taught to medical students and graduate bioethics students, in which the class researches, writes, and performs a case study designed to elicit reflection and discussion about a topic and set of bioethics issues of current interest to both academic and general audiences. The model is also suited to the presentation and discussion of existing case studies, both live and via on-demand audio.

  4. EVA Health and Human Performance Benchmarking Study

    Science.gov (United States)

    Abercromby, A. F.; Norcross, J.; Jarvis, S. L.

    2016-01-01

    Multiple HRP Risks and Gaps require detailed characterization of human health and performance during exploration extravehicular activity (EVA) tasks; however, a rigorous and comprehensive methodology for characterizing and comparing the health and human performance implications of current and future EVA spacesuit designs does not exist. This study will identify and implement functional tasks and metrics, both objective and subjective, that are relevant to health and human performance, such as metabolic expenditure, suit fit, discomfort, suited postural stability, cognitive performance, and potentially biochemical responses for humans working inside different EVA suits doing functional tasks under the appropriate simulated reduced gravity environments. This study will provide health and human performance benchmark data for humans working in current EVA suits (EMU, Mark III, and Z2) as well as shirtsleeves using a standard set of tasks and metrics with quantified reliability. Results and methodologies developed during this test will provide benchmark data against which future EVA suits, and different suit configurations (eg, varied pressure, mass, CG) may be reliably compared in subsequent tests. Results will also inform fitness for duty standards as well as design requirements and operations concepts for future EVA suits and other exploration systems.

  5. Performance appraisal of coaches: Acomparative study | Surujlal ...

    African Journals Online (AJOL)

    Within the sport environment, the performance appraisal of coaches continues to be an issue. The performance appraisal of coaches is critical to sport organizations since major decisions like rewarding or terminating coaches is based on it. The purpose of this study was to examine whether any differences exist with regard ...

  6. Specification and time required for the application of a lime-based render inside historic buildings

    Directory of Open Access Journals (Sweden)

    Vasco Peixoto de Freitas

    2008-01-01

    Full Text Available Intervention in ancient buildings with historical and architectural value requires traditional techniques, such as the use of lime mortars for internal and external wall renderings. In order to ensure the desired performance, these rendering mortars must be rigorously specified and quality controls have to be performed during application. The choice of mortar composition should take account of factors such as compatibility with the substrate, mechanical requirements and water behaviour. The construction schedule, which used to be considered a second order variable, nowadays plays a decisive role in the selection of the rendering technique, given its effects upon costs. How should lime-based mortars be specified? How much time is required for the application and curing of a lime-based render? This paper reflects upon the feasibility of using traditional lime mortars in three-layer renders inside churches and monasteries under adverse hygrothermal conditions and when time is critical. A case study is presented in which internal lime mortar renderings were applied in a church in Northern Portugal, where the very high relative humidity meant that several months were necessary before the drying process was complete.

  7. The effects of water absorption on an ester vinyl resin system

    Directory of Open Access Journals (Sweden)

    Ledjane Lima Sobrinho

    2009-09-01

    Full Text Available Derakene is a vinyl ester resin largely employed as matrix for polymeric based composite systems. In this work, the performance of such polymeric system was evaluated considering the effect of hygrothermal aging. The mechanical and thermal properties were examined for the processed material before and after ageing in water at 60 ºC for a maximum period of 64 days. Both analyses indicated the occurrence of post cure of the system after 16 days due to exposition at 60 ºC in water, which was also confirmed by analyses in samples with post cure treatment. Moreover, it was observed plasticizing of resin after 36 and 64 days of ageing. Micro structural and fracture surface analyses were carried out in order to characterize the samples. The appearance of surface voids was also observed.

  8. A Comparative Study of Electronic Performance Support Systems

    Science.gov (United States)

    Nguyen, Frank; Klein, James D.; Sullivan, Howard

    2005-01-01

    Electronic performance support systems (EPSS) deliver relevant support information to users while they are performing tasks. The present study examined the effect of different types of EPSS on user performance, attitudes, system use and time on task. Employees at a manufacturing company were asked to complete a procedural software task and…

  9. Efeito higrotérmico em prepregs de fibra de vidro/epóxi por espectroscopia de luminescência Hygrothermal effect in glass fiber/epoxy by luminescence spectroscopy

    Directory of Open Access Journals (Sweden)

    Rita de Cássia M. Sales

    2008-03-01

    Full Text Available O objetivo deste trabalho é o estudo do efeito higrotérmico em pré-impregnados (prepreg não curados de fibra de vidro-resina epoxídica usando a técnica de espectroscopia eletrônica de luminescência em modo estacionário. O método de fluorescência extrínseca foi empregado utilizando-se a sonda 9- ácido antróico (9-AA, cujo comportamento fotofísico depende fortemente da polaridade do meio. As amostras foram submetidas a umidades relativas de 6 e 84% por meio da utilização de soluções aquosas saturadas de hidróxido de sódio a 34,5 °C e cloreto de potássio a 20,0 °C, em recipientes fechados, pelos períodos de tempo de 1 semana, 15 dias e 1 mês. As amostras submetidas à umidade relativa de 6% apresentaram aumento significativo das intensidades relativas dos espectros de fluorescência em relação à amostra referência. Este comportamento fotofísico foi atribuído à presença da forma protonada do 9-AA no meio devido à reticulação da matriz polimérica. Após 1 mês, o espectro de emissão apresenta uma diminuição da intensidade em seu máximo. Isto ocorreu provavelmente devido ao processo de plastificação da matriz polimérica promovido pela presença de água na matriz, confirmado pela análise gravimétrica. Os espectros de fluorescência extrínseca das amostras submetidas à umidade relativa de 84% apresentaram as seguintes modificações espectrais: a decaimento da intensidade de emissão das curvas b e d; b deslocamento da banda de emissão para a região do azul devido ao aumento do teor de água; e c aparecimento de um ombro na banda de emissão em 424 e 472 nm. Este comportamento fotofísico foi atribuído ao deslocamento do equilíbrio químico da forma protonada para a forma ionizada do 9-AA, promovido pela entrada de umidade no material.The work is aimed at studying hygrothermal effects on uncured glass-epoxy fiber prepreg (F-161 - Hexcel Co. using luminescence spectroscopy under steady

  10. US QCD computational performance studies with PERI

    International Nuclear Information System (INIS)

    Zhang, Y; Fowler, R; Huck, K; Malony, A; Porterfield, A; Reed, D; Shende, S; Taylor, V; Wu, X

    2007-01-01

    We report on some of the interactions between two SciDAC projects: The National Computational Infrastructure for Lattice Gauge Theory (USQCD), and the Performance Engineering Research Institute (PERI). Many modern scientific programs consistently report the need for faster computational resources to maintain global competitiveness. However, as the size and complexity of emerging high end computing (HEC) systems continue to rise, achieving good performance on such systems is becoming ever more challenging. In order to take full advantage of the resources, it is crucial to understand the characteristics of relevant scientific applications and the systems these applications are running on. Using tools developed under PERI and by other performance measurement researchers, we studied the performance of two applications, MILC and Chroma, on several high performance computing systems at DOE laboratories. In the case of Chroma, we discuss how the use of C++ and modern software engineering and programming methods are driving the evolution of performance tools

  11. Performance study for inlet installations

    Science.gov (United States)

    Bingaman, Donald C.

    1992-01-01

    A conceptual design trade study was conducted by McDonnell Aircraft Company (MCAIR) and NASA LARC PAB to determine the impact of inlet design features incorporated for reduced detectability on inlet performance, weight, and cost, for both fighter and attack-type aircraft. Quality Function Deployment (QFD) techniques were used to prioritize trade study issues, and select 'best' air induction system configurations for each of two notional aircraft, the Multi-Role Fighter (MRF) and the Advanced Medium Attack (AMA) bomber. Database deficiencies discovered in the trade study process were identified, and technology roadmaps were developed to address these deficiencies. Finally, two high speed inlet wind tunnel model concepts were developed for follow-on wind tunnel investigations.

  12. Environmental management and firm performance: a case study.

    Science.gov (United States)

    Claver, Enrique; López, María D; Molina, José F; Tarí, Juan J

    2007-09-01

    This study has as its aim to help to clarify the relationship between environmental management and economic performance by integrating it into a wider framework that includes the relationship between environmental strategy and firm performance, the latter being understood as the combination of environmental performance, competitive advantage and economic performance. A case study of the COATO farming cooperative showed us that its environmental management, focused on prevention logic, has had a positive net effect on its environmental performance. Besides, the order in which these practices were adopted favoured the development of new organisational capabilities that have contributed to the appearance of advantages derived from the greater accumulated experience of employees in creating new projects that are designed to reduce residues and pollution. COATO has also obtained a competitive advantage in differentiation thanks to an improved brand image and to its increased credibility in business relationships. Finally, a positive correlation exists between the pioneering proactive strategy adopted by this cooperative and the improvement of its firm performance with respect to the other firms in its sector.

  13. FINANCIAL PERFORMANCE VERSUS NON FINANCIAL PERFORMANCE. CASE STUDY AT ANTIBIOTICE TRADING COMPANY IASI

    Directory of Open Access Journals (Sweden)

    Beleneºi Mãrioara

    2012-07-01

    Full Text Available The actual economical conditions, the effect of global crisis and the efforts to pass this turning point, does force trading companies toward an extremely balanced management of performance. Now, when financial indicators are neither so spectacular nor so relevant, and when the principles of a durable development are mentioned over and over, the exigencies of companies’ external environment are higher and higher. This reality does force the companies to pay more attention to social responsibilities’ assuming and investment into green innovation, as well as to the field of information’s communication in a relevant way, which should gather financial, social and environment information. The absence of a normalized balance of financial and non-financial indicators used in measuring companies’ global performance, does allow them selecting of “agreed” indicators which should reflect the company under the light of high performance. But, the same reason urges the searcher for some research studies of the most adequate diagnostic model of global performance, which should faithfully reflect company’s current status. The purpose of this study is to measure the global performance of ANTIBIOTICE Trading Company, taking into account, both financial and non-financial indicators for a period of 5 years. For the financial years 2006 and 2008 company’s global performance is an acceptable one, while for the financial years 2007, 2009 and 2010 the global performance is a medium one. It should be highlighted the lack of involvement or transparency regarding social and environment responsibility in 2006 and weak financial performance in 2008, indicators which positioned the company to an acceptable level.

  14. Internal insulation applied in heritage multi-storey buildings with wooden beams embedded in solid masonry brick facades

    DEFF Research Database (Denmark)

    Harrestrup, Maria; Svendsen, Svend

    2016-01-01

    The use of internal insulation is investigated in a heritage building block with wooden beam construction and masonry brick walls as part of an energy renovation. Measurements were carried out and compared to results from a hygrothermal simulation model. The risk of mould growth in the wooden beams...... insulation on north-orientated walls, since the drying potential is reduced. Additionally, caution should be exercised also with west-orientated walls....

  15. Mechanical behaviour of PEM fuel cell catalyst layers during regular cell operation

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2010-01-01

    Damage mechanisms in a proton exchange membrane fuel cell are accelerated by mechanical stresses arising during fuel cell assembly (bolt assembling), and the stresses arise during fuel cell running, because it consists of the materials with different thermal expansion and swelling coefficients. Therefore, in order to acquire a complete understanding of the mechanical behaviour of the catalyst layers during regular cell operation, mechanical response under steady-state hygro-thermal stresses s...

  16. Malaria Laboratory Diagnostic Performance: Case studies of two ...

    African Journals Online (AJOL)

    Advantages of rapid diagnostic tests when compared with microscopy are simple to perform, fast, low ... The study was conducted to establish the performance of laboratory diagnosis of malaria in local Malawi .... Government of Malawi.

  17. Study habits as predictors of academic performance: a case study of ...

    African Journals Online (AJOL)

    The study assessed whether study habits predicted the academic performance of students at Zion Girls' Senior High School. One hundred and twelve students in form 2 were the respondents in the study. The Study Habit Survey questionnaire was used for data collection. The data was analyzed by the use of bivariate ...

  18. Carrier and symbol synchronization system performance study

    Science.gov (United States)

    Lindsey, W. C.

    1976-01-01

    Results pertinent to predicting the performance of convolutionally encoded binary phase-shift keyed communication links were presented. The details of the development are provided in four sections. These sections are concerned with developing the bit error probability performance degradations due to PN despreading by a time-shared delay locked loop, the Costas demodulation process, symbol synchronization effects and cycle slipping phenomena in the Costas loop. In addition, Costas cycle slipping probabilities are studied as functions of Doppler count time and signal-to-noise conditions. The effect of cycle slipping in the symbol synchronizer is also studied as a function of channel Doppler and other frequency uncertainties.

  19. Time preferences, study effort, and academic performance

    NARCIS (Netherlands)

    Non, J.A.; Tempelaar, D.T.

    2014-01-01

    We analyze the relation between time preferences, study effort, and academic performance among first-year Business and Economics students. Time preferences are measured by stated preferences for an immediate payment over larger delayed payments. Data on study efforts are derived from an electronic

  20. The relationship between study strategies and academic performance.

    Science.gov (United States)

    Zhou, Yuanyuan; Graham, Lori; West, Courtney

    2016-10-07

    To investigate if and to what extent the Learning and Study Strategy Inventory (LASSI) and the Self-Directed Learning Readiness Scale (SDLRS) yield academic performance predictors; To examine if LASSI findings are consistent with previous research. Medical school students completed the LASSI and SDLRS before their first and second years (n = 168). Correlational and regression analyses were used to determine the predictive value of the LASSI and the SDLRS. Paired t-tests were used to test if the two measurement points differed. Bivariate correlations and R 2 s were compared with five other relevant studies. The SDLRS was moderately correlated with all LASSI subscales in both measures (r (152) =.255, p=.001) to (r (152) =.592, p =.000). The first SDLRS, nor the first LASSI, were predictive of academic performance. The second LASSI measure was a significant predictor of academic performance (R 2 (138) = 0.188, p = .003). Six prior LASSI studies yielded a range of R 2 s from 10-49%. The SDLRS is moderately correlated with all LASSI subscales. However, the predictive value of the SDLRS and LASSI differ. The SDLRS does not appear to be directly related to academic performance, but LASSI subscales: Concentration, Motivation, Time Management, and Test Strategies tend to be correlated. The explained LASSI variance ranges from 10% to 49%, indicating a small to substantial effect. Utilizing the LASSI to provide medical school students with information about their strengths and weaknesses and implementing targeted support in specific study strategies may yield positive academic performance outcomes.

  1. Empirical Study on Annual Energy-Saving Performance of Energy Performance Contracting in China

    Directory of Open Access Journals (Sweden)

    Hongquan Ruan

    2018-05-01

    Full Text Available A lack of trust in Energy Service Company (ESCo is the most critical factor affecting the development of Energy Performance Contracting (EPC in China, compared with other constraints. One cannot easily estimate the energy-saving performance of an EPC project. Under that condition, lack of trust may cause the Energy-Consuming Unit (ECU to suspect the energy-saving performance promised by the ESCo, thus leaving potentially profitable projects without necessary funding. Currently, specific studies taking an across-projects viewpoint on annual energy-saving performance of EPC projects in multiple subsectors, objectively and quantitatively, are lacking. This paper studies the regression relationships of annual energy-saving quantity in terms of revamping cost and the regression relationships of annual cost saving in terms of revamping cost. The regression results show that there are statistically significant correlations in the above relationships in the nine subsectors investigated. This is significant for ESCos and ECUs, because knowledge on energy-saving performance could contribute to EPC investment decisions and trust relationships between ESCos and ECUs. Then, a multiple linear regression model of revamping cost is set up to analyze its influencing factors. The model indicates that the subsector the sample belongs to, financing, registered capital of the ESCo, and contract period have significant effects on revamping cost. Thus, policy implications regarding innovation of EE promotion technology, clarifying ESCos’ exit mechanism, innovation of financing mechanism, and improving the market credit environment for promoting investment in EPC projects, are provided.

  2. Impact of Moistened Bio-insulation on Whole Building Energy Use

    Directory of Open Access Journals (Sweden)

    Latif Eshrar

    2017-01-01

    Full Text Available One of the key properties of hemp insulation is its moisture adsorption capacity. Adsorption of moisture can increase both thermal conductivity and heat capacity of the insulation. The current study focuses on the effect of moisture induced thermal mass of installed hemp insulation on the whole building energy use. Hygrothermal and thermal simulations were performed using the CIBSE TRY weather data of Edinburgh and Birmingham with the aid of following simulation tools: WUFI and IES. Following simplified building types were considered: building-1 with dry hemp wall and loft insulations, building-2 with moistened hemp wall and loft insulation and building-3 with stone wool insulation. It was observed that the overall conditioning load of building-1 was 1.2 to 2.3% higher than building-2 and 3. However, during the summer season, the cooling load of building-2 was 3-7.5% lower than the other buildings. It implies that, moistened insulation can potentially mitigate the effect of increasing cooling degree days induced by global warming.

  3. A Study of the Journey from Training to Performance.

    Science.gov (United States)

    Rossett, Allison; Tobias, Catherine

    1999-01-01

    This study questioned progress in the shift from training to performance. A survey administered to 62 training and performance professionals queried respondents about concepts relevant to performance: analysis, solution systems, cross-functionality, customer and collegial expectations, and shared knowledge. Overall, results showed that…

  4. Deception studies manipulating centrally acting performance modifiers: a review.

    Science.gov (United States)

    Williams, Emily L; Jones, Hollie S; Sparks, Sandy; Marchant, David C; Micklewright, Dominic; McNaughton, Lars R

    2014-07-01

    Athletes anticipatorily set and continuously adjust pacing strategies before and during events to produce optimal performance. Self-regulation ensures maximal effort is exerted in correspondence with the end point of exercise, while preventing physiological changes that are detrimental and disruptive to homeostatic control. The integration of feedforward and feedback information, together with the proposed brain's performance modifiers is said to be fundamental to this anticipatory and continuous regulation of exercise. The manipulation of central, regulatory internal and external stimuli has been a key focus within deception research, attempting to influence the self-regulation of exercise and induce improvements in performance. Methods of manipulating performance modifiers such as unknown task end point, deceived duration or intensity feedback, self-belief, or previous experience create a challenge within research, as although they contextualize theoretical propositions, there are few ecological and practical approaches which integrate theory with practice. In addition, the different methods and measures demonstrated in manipulation studies have produced inconsistent results. This review examines and critically evaluates the current methods of how specific centrally controlled performance modifiers have been manipulated, within previous deception studies. From the 31 studies reviewed, 10 reported positive effects on performance, encouraging future investigations to explore the mechanisms responsible for influencing pacing and consequently how deceptive approaches can further facilitate performance. The review acts to discuss the use of expectation manipulation not only to examine which methods of deception are successful in facilitating performance but also to understand further the key components used in the regulation of exercise and performance.

  5. Psychological Determinants of University Students' Academic Performance: An Empirical Study

    Science.gov (United States)

    Gebka, Bartosz

    2014-01-01

    This study utilises an integrated conceptual model of academic performance which captures a series of psychological factors: cognitive style; self-theories such as self-esteem and self-efficacy; achievement goals such as mastery, performance, performance avoidance and work avoidance; study-processing strategies such as deep and surface learning;…

  6. Recent developments in building diagnosis techniques

    CERN Document Server

    2016-01-01

    This book presents a collection of recent research on building diagnosis techniques related to construction pathology, hygrothermal behavior and durability, and diagnostic techniques. It highlights recent advances and new developments in the field of building physics, building anomalies in materials and components, new techniques for improved energy efficiency analysis, and diagnosis techniques such as infrared thermography. This book will be of interest to a wide readership of professionals, scientists, students, practitioners, and lecturers.

  7. Modeling optimizes PEM fuel cell durability using three-dimensional multi-phase computational fluid dynamics model

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2010-01-01

    Damage mechanisms in a proton exchange membrane (PEM) fuel cell are accelerated by mechanical stresses arising during fuel cell assembly (bolt assembling), and the stresses arise during fuel cell running, because it consists of the materials with different thermal expansion and swelling coefficients. Therefore, in order to acquire a complete understanding of the damage mechanisms in the membrane and gas diffusion layers, mechanical response under steady-state hygro-thermal stresses should be ...

  8. High performance APCS conceptual design and evaluation scoping study

    International Nuclear Information System (INIS)

    Soelberg, N.; Liekhus, K.; Chambers, A.; Anderson, G.

    1998-02-01

    This Air Pollution Control System (APCS) Conceptual Design and Evaluation study was conducted to evaluate a high-performance (APC) system for minimizing air emissions from mixed waste thermal treatment systems. Seven variations of high-performance APCS designs were conceptualized using several design objectives. One of the system designs was selected for detailed process simulation using ASPEN PLUS to determine material and energy balances and evaluate performance. Installed system capital costs were also estimated. Sensitivity studies were conducted to evaluate the incremental cost and benefit of added carbon adsorber beds for mercury control, specific catalytic reduction for NO x control, and offgas retention tanks for holding the offgas until sample analysis is conducted to verify that the offgas meets emission limits. Results show that the high-performance dry-wet APCS can easily meet all expected emission limits except for possibly mercury. The capability to achieve high levels of mercury control (potentially necessary for thermally treating some DOE mixed streams) could not be validated using current performance data for mercury control technologies. The engineering approach and ASPEN PLUS modeling tool developed and used in this study identified APC equipment and system performance, size, cost, and other issues that are not yet resolved. These issues need to be addressed in feasibility studies and conceptual designs for new facilities or for determining how to modify existing facilities to meet expected emission limits. The ASPEN PLUS process simulation with current and refined input assumptions and calculations can be used to provide system performance information for decision-making, identifying best options, estimating costs, reducing the potential for emission violations, providing information needed for waste flow analysis, incorporating new APCS technologies in existing designs, or performing facility design and permitting activities

  9. Self-Esteem, Study Habits and Academic Performance Among University Students

    Directory of Open Access Journals (Sweden)

    Manuel L. Chilca Alva

    2017-04-01

    Full Text Available This study was intended to establish whether self-esteem and study habits correlate with academic performance among university students. Research conducted was descriptive observational, multivariate or cross-sectional factorial in nature. The study population consisted of 196 students enrolled in a Basic Mathematics 1 class at the School of Engineering of Universidad Tecnológica del Perú (Technical University of Peru, UTP in the third term of 2016, and the sample size numbered 86 students. The Coopersmith Self-Esteem Inventory, Luis Vicuña Peri’s Study Habits Inventory and the average grades obtained by students were used for research variable measurement. Results show that self-esteem does not significantly impact academic performance, but study habits do influence academic performance (p = .000 < α = .05. Hence students are expected to enhance academic performance as they refine study techniques.

  10. C++ and operating systems performance - A case study

    Science.gov (United States)

    Russo, Vincent F.; Madany, Peter W.; Campbell, Roy H.

    1990-01-01

    Object-oriented design and programming has many software engineering advantages. Its application to large systems, however, has previously been constrained by performance concerns. The Choices operating system, which has over 75,000 lines of code, is object-oriented and programmed in C++. This paper is a case study of the performance of Choices.

  11. Presence of bias in radiographer plain film reading performance studies

    International Nuclear Information System (INIS)

    Brealey, S.; Scally, A.J.; Thomas, N.B.

    2002-01-01

    Purpose To raise awareness of the frequency of bias that can affect the quality of radiographer plain film reading performance studies. Methods Studies that assessed radiographer(s) plain film reading performance were located by searching electronic databases and grey literature, hand-searching journals, personal communication and scanning reference lists. Thirty studies were judged eligible from all data sources. Results A one-way analysis of variance (ANOVA) demonstrates no statistically significant difference (P=0.25) in the mean proportion of biases present from diagnostic accuracy (0.37), performance (0.42) and outcome (0.44) study designs. Pearson's correlation coefficient showed no statistically significant linear association between the proportion of biases present for the three different study designs and the year that the study was performed. The frequency of biases in film and observer selection and application of the reference standard was quite low. In contrast, many biases were present concerning independence of film reporting and comparison of reports for concordance. Conclusions The findings indicate variation in the presence of bias in radiographer plain film reading performance studies. The careful consideration of bias is an essential component of study quality and hence the validity of the evidence-base used to underpin radiographic reporting policy

  12. Spent Fuel Transportation Package Performance Study - Experimental Design Challenges

    International Nuclear Information System (INIS)

    Snyder, A. M.; Murphy, A. J.; Sprung, J. L.; Ammerman, D. J.; Lopez, C.

    2003-01-01

    Numerous studies of spent nuclear fuel transportation accident risks have been performed since the late seventies that considered shipping container design and performance. Based in part on these studies, NRC has concluded that the level of protection provided by spent nuclear fuel transportation package designs under accident conditions is adequate. [1] Furthermore, actual spent nuclear fuel transport experience showcase a safety record that is exceptional and unparalleled when compared to other hazardous materials transportation shipments. There has never been a known or suspected release of the radioactive contents from an NRC-certified spent nuclear fuel cask as a result of a transportation accident. In 1999 the United States Nuclear Regulatory Commission (NRC) initiated a study, the Package Performance Study, to demonstrate the performance of spent fuel and spent fuel packages during severe transportation accidents. NRC is not studying or testing its current regulations, a s the rigorous regulatory accident conditions specified in 10 CFR Part 71 are adequate to ensure safe packaging and use. As part of this study, NRC currently plans on using detailed modeling followed by experimental testing to increase public confidence in the safety of spent nuclear fuel shipments. One of the aspects of this confirmatory research study is the commitment to solicit and consider public comment during the scoping phase and experimental design planning phase of this research

  13. Thermal conductivity of cement stabilized earth bricks reinforced with date palm fiber

    Science.gov (United States)

    Berrehail, Tahar; Zemmouri, Noureddine; Agoudjil, Boudjemaa

    2018-05-01

    Recently, some cheap materials are available and adaptable to climate seem to meet current requirements. This paper investigates the thermal and mechanical properties of cement stabilized earth bricks(CSEB) reinforced with date palm fibers (DPF). The main goal is to develop and expand the field of use of these materials in the construction sector, and investigate the possibility of new bio composite as renewable, insulating building material with low cost, made of earth and reinforced with palm wood waste. In this study, a particular interest is brought to the thermal and mechanical characteristics, which constitute a decisive character for the choice of a building material. A series of earthen samples stabilized at 5% and reinforced with DPF of various fiber weight fractions, (5%, 10%), were manufactured and compacted applying two levels compacting, (5MPa and 10MPa). Compressive strength and thermal conductivity were experimentally studied; heating capacity and diffusivity were indirectly calculated. It was found that the fibrous reinforcement proved thermal conductivity and compressive strength. it also enhanced thermal performances. Thus, the results found allow us to investigate hygrothermal behaviour and its impact on occupants comfort.

  14. Experimental study on performance of pulsed liquid jet pump

    International Nuclear Information System (INIS)

    Xu Weihui; Gao Chuanchang; Qin Haixia

    2010-01-01

    The device performance characteristics of transformer type pulsed liquid pump device were experimentally studied. The effects of the area ratio, work pressure and pulse parameters on the performance of the pulsed liquid jet pump device were performed in the tests. The potency of pulsed jet on improving the performance of the liquid jet pump device was also studied through the comparison with invariable jet pump at the same conditions. The results show that the pulsed jet can significantly improve the performance of transformer type jet pump devices. Area ratio and pulse parameters are the critical factors to the performance of the pulsed liquid jet pump device. The jet pump device performances are significantly improved by reducing the area ratio or by increasing the pulsed frequency. The flux characteristics of the pulsed liquid jet pump device presents the typical negative linear,the potency of pulsed jet in improving the performance of jet pump device with small area ratio can be more significant. The efficiency curve of pulsed liquid jet pump is similar to the parabola. At higher pulsed frequency, the top efficiency point of the pulsed jet pump moves to the higher flow ratio. The high efficiency area of the pulsed jet pump also is widened with the increase of the pulsed frequency. (authors)

  15. Review of research on the hygrothermal environmental durability of structural adhesively bonded joints

    Directory of Open Access Journals (Sweden)

    Xiao HAN

    2017-06-01

    Full Text Available In recent years, structural adhesive bonding technology has been widely used in many industrial fields, with many advantages over traditional mechanical connection methods, such as riveting, welding and bolt connection. Due to the adhesive characteristics of polymer materials, the environmental durability of adhesive joint becomes the key problems in engineering structure connection feasibility and long-term service reliability. On the basis of the review of the research of the hot-humid environmental durability of structural adhesive joints, the effects of temperature, moisture and coupled condition on the structural mechanical behaviour are discussed, introducing the published research progress and results both at home and abroad. The prospects are provided: the future research work can be combined with a variety of observation scales of environmental aging test and numerical simulation method, delve into sub hygroscopic, creep, thermal expansion and hygroscopic expansion aging behavior, such as the environment of model prediction method simulation in more than a variety of mechanical performance degradation behavior of coupling conditions, and provide more reliable theoretical modeling and experimental data for engineering design and application of cementing structure.

  16. Performances Study of a Hybrid Rocket Engine

    Directory of Open Access Journals (Sweden)

    Adrian-Nicolae BUTURACHE

    2018-06-01

    Full Text Available This paper presents a study which analyses the functioning and performances optimization of a hybrid rocket engine based on gaseous oxygen and polybutadiene polymer (HTPB. Calculations were performed with NASA CEA software in order to obtain the parameters resulted following the combustion process. Using these parameters, the main parameters of the hybrid rocket engine were optimized. Using the calculus previously stated, an experimental rocket engine producing 100 N of thrust was pre-dimensioned, followed by an optimization of the rocket engine as a function of several parameters. Having the geometry and the main parameters of the hybrid rocket engine combustion process, numerical simulations were performed in the CFX – ANSYS commercial software, which allowed visualizing the flow field and the jet expansion. Finally, the analytical calculus was validated through numerical simulations.

  17. Engineered Barrier System performance requirements systems study report. Revision 02

    International Nuclear Information System (INIS)

    Balady, M.A.

    1997-01-01

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken

  18. Engineered Barrier System performance requirements systems study report. Revision 02

    Energy Technology Data Exchange (ETDEWEB)

    Balady, M.A.

    1997-01-14

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken.

  19. Passive hygrothermal control of a museum storage building

    DEFF Research Database (Denmark)

    Christensen, Jørgen Erik; Janssen, Hans

    2011-01-01

    of C02 emission. The purpose for this paper is to show that it is possible to reach the goal of using renewable energy for museum storage buildings by rethinking the strategy for the dehumidification design and in this way contribute to a C02 neutral environment. The solution is to construct a very...

  20. Mould growth prediction by computational simulation on historic buildings

    OpenAIRE

    Krus, M.; Kilian, R.; Sedlbauer, K.

    2007-01-01

    Historical buildings are often renovated with a high expenditure of time and money without investigating and considering the causes of the damages. In many cases historic buildings can only be maintained by changing their usage. This change of use may influence the interior climate enormously. To assess the effect on the risk of mould growth on building parts or historic monuments a predictive model has been developed recently, describing the hygrothermal behaviour of the spore. It allows for...

  1. Global weak solutions for coupled transport processes in concrete walls at high temperatures

    OpenAIRE

    Beneš, Michal; Štefan, Radek

    2012-01-01

    We consider an initial-boundary value problem for a fully nonlinear coupled parabolic system with nonlinear boundary conditions modelling hygro-thermal behavior of concrete at high temperatures. We prove a global existence of a weak solution to this system on an arbitrary time interval. The main result is proved by an approximation procedure. This consists in proving the existence of solutions to mollified problems using the Leray-Schauder theorem, for which a priori estimates are obtained. T...

  2. Parametric study of closed wet cooling tower thermal performance

    Science.gov (United States)

    Qasim, S. M.; Hayder, M. J.

    2017-08-01

    The present study involves experimental and theoretical analysis to evaluate the thermal performance of modified Closed Wet Cooling Tower (CWCT). The experimental study includes: design, manufacture and testing prototype of a modified counter flow forced draft CWCT. The modification based on addition packing to the conventional CWCT. A series of experiments was carried out at different operational parameters. In view of energy analysis, the thermal performance parameters of the tower are: cooling range, tower approach, cooling capacity, thermal efficiency, heat and mass transfer coefficients. The theoretical study included develops Artificial Neural Network (ANN) models to predicting various thermal performance parameters of the tower. Utilizing experimental data for training and testing, the models simulated by multi-layer back propagation algorithm for varying all operational parameters stated in experimental test.

  3. Are study strategies related to medical licensing exam performance?

    Science.gov (United States)

    West, Courtney; Kurz, Terri; Smith, Sherry; Graham, Lori

    2014-11-02

    To examine the relationship between study strategies and performance on a high stakes medical licensing exam entitled the United States Medical Licensing Examination Step 1. The action research project included seventy nine student participants at the Texas A & M Health Science Center College of Medicine during their pre-clinical education. Data collection included pre-matriculation and matriculation academic performance data, standardized exam data, and the Learning and Study Strategies Instrument. Multiple regression analyses were conducted. For both models, the dependent variable was the Step 1 score, and the independent variables included Medical College Admission Test, Undergraduate Grade Point Average, Year 1 Average, Year 2 Average, Customized National Board of Medical Examiners Average, Comprehensive Basic Science Exam score, and Learning and Study Strategy Instrument sub-scores. Model 2 added Comprehensive Basic Science Self-Assessment average. Concentration (Model 1 - β = .264; Model 2 - β = .254) was the only study strategy correlated with Step 1 performance. The other statistically significant predictors were Customized National Board of Medical Examiners Average (β = .315) and Year 2 Average (β = .280) in Model 1 and Comprehensive Basic Science Self-Assessment Average (β = .338) in Model 2. There does appear to be a relationship between the study strategy concentration and Step 1 licensing exam performance. Teaching students to practice and utilize certain techniques to improve concentration skills when preparing for and taking exams may help improve licensing exam scores.

  4. Studying the impact of the organizational commitment on the job performance

    Directory of Open Access Journals (Sweden)

    Mojtaba Rafiei

    2014-08-01

    Full Text Available Success of any organization depends on the performance of its employees. Enhancing organizational commitment among employees is an important aspect to perform better. The purpose of this study is to examine the effect of three components of organizational commitment; namely Affective, Continuance and Normative commitment, on employee’s performance. The study is applied among 244 employees of Cooperatives, Labor and Social Welfare department of Markazi Province using a single-stage cluster sampling. The study uses a standard questionnaire for organizational commitment developed by Allen and Meyer and job performance questionnaire developed by Patterson were used to gather data. Structural equations modeling (SEM technique has been used for data analysis. The result of this analysis indicates that the organizational commitment had a positive significant effect on the job performance. In addition, the study also showed that all three dimensions of organizational commitment, Affective, continuance, and normative commitment, had a positive significant effect on the job performance. From the findings, it has been proved that job performance was strongly associated with employee's commitment.

  5. Application of data mining techniques in the analysis of indoor hygrothermal conditions

    CERN Document Server

    Ramos, Nuno M M; Almeida, Ricardo M S F; Simões, Maria L; Manuel, Sofia

    2016-01-01

    The main benefit of the book is that it explores available methodologies for both conducting in-situ measurements and adequately exploring the results, based on a case study that illustrates the benefits and difficulties of concurrent methodologies. The case study corresponds to a set of 25 social housing dwellings where an extensive in situ measurement campaign was conducted. The dwellings are located in the same quarter of a city. Measurements included indoor temperature and relative humidity, with continuous log in different rooms of each dwelling, blower-door tests and complete outdoor conditions provided by a nearby weather station. The book includes a variety of scientific and engineering disciplines, such as building physics, probability and statistics and civil engineering. It presents a synthesis of the current state of knowledge for benefit of professional engineers and scientists.

  6. Performance study of thermo-electric generator

    Science.gov (United States)

    Rohit, G.; Manaswini, D.; Kotebavi, Vinod; R, Nagaraja S.

    2017-07-01

    Devices like automobiles, stoves, ovens, boilers, kilns and heaters dissipate large amount of waste heat. Since most of this waste heat goes unused, the efficiency of these devices is drastically reduced. A lot of research is being conducted on the recovery of the waste heat, among which Thermoelectric Generators (TEG) is one of the popular method. TEG is a semiconductor device that produces electric potential difference when a thermal gradient develops on it. This paper deals with the study of performance of a TEG module for different hot surface temperatures. Performance characteristics used here are voltage, current and power developed by the TEG. One side of the TEG was kept on a hot plate where uniform heat flux was supplied to that. And the other side was cooled by supplying cold water. The results show that the output power increases significantly with increase in the temperature of the hot surface.

  7. The Consistency of Performance Management System Based on Attributes of the Performance Indicator: An Empirical Study

    Directory of Open Access Journals (Sweden)

    Jan Zavadsky

    2014-07-01

    Full Text Available Purpose: The performance management system (PMS is a metasystem over all business processes at the strategic and operational level. Effectiveness of the various management systems depends on many factors. One of them is the consistent definition of each system elements. The main purpose of this study is to explore if the performance management systems of the sample companies is consistent and how companies can create such a system. The consistency in this case is based on the homogenous definition of attributes relating to the performance indicator as a basic element of PMS.Methodology: At the beginning, we used an affinity diagram that helped us to clarify and to group various attributes of performance indicators. The main research results we achieved are through empirical study. The empirical study was carried out in a sample of Slovak companies. The criterion for selection was the existence of the certified management systems according to the ISO 9001. Representativeness of the sample companies was confirmed by application of Pearson´s chi-squared test (χ2 - test due to above standards. Findings: Coming from the review of various literature, we defined four groups of attributes relating to the performance indicator: formal attributes, attributes of target value, informational attributes and attributes of evaluation. The whole set contains 21 attributes. The consistency of PMS is based not on maximum or minimum number of attributes, but on the same type of attributes for each performance indicator used in PMS at both the operational and strategic level. The main findings are: companies use various financial and non-financial indicators at strategic or operational level; companies determine various attributes of performance indicator, but most of the performance indicators are otherwise determined; we identified the common attributes for the whole sample of companies. Practical implications: The research results have got an implication for

  8. CSR organisational taxonomy and job characteristics on performance: SME case studies

    Directory of Open Access Journals (Sweden)

    Thanalechumy Seeramulu

    2017-05-01

    Full Text Available This study examines the relationship between the CSR of organizational structure and job characteristics that influence employee job performance in the Malaysian context. Hence, it is important to study and analyze these two factors within the CSR taxonomy describing how these factors significantly influence employee job performance and to make recommendations how performance can be promoted among employees. This paper is based on a quantitative research approach where responses were gathered from the working population within Malaysia SMEs. The results from this study will help to point out the influence of these factors on the employee job performance and provide guidance to an organization for which these aspects should be emphasized in order to increase employees’ job performance to align performance with organizational goals. The analysis includes two dimensions of CSR taxonomy of organizational structure namely, centralization and formalization, as well as a set of five dimensions of job characteristics, such as task identity, task significance, skill variety, autonomy and feedback. The results of these findings show that job characteristics such as task significance, autonomy, feedback, and skill variety, positively influence job performance with autonomy having highest predictive power on job performance. The results of these findings reveal that the organizational structure does not contribute to the prediction of job performance even though a significant positive correlation exists between the structure and job performance in the Pearson correlation coefficient test. Therefore, this study will enrich the existing knowledge in the area of human resource management by focusing on job performance management.

  9. Study on institutionalization of risk-informed performance-based regulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. G.; Hong, S. Y.; Seo, M. R. [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    2003-02-15

    In this study, for the institutionalization of risk informed and performance based regulation in Korea, the latest technical movements of overseas countries are examined and reviewed. And the issues that was found when license change petition using risk information was submitted in Korean regulatory body are reviewed. Based on these review, the applicable areas to domestic situation will be found and proposed. This study can contribute to setting up the proper direction for the institutionalization of risk informed and performance based regulation.

  10. An Empirical Study on Low-Carbon: Human Resources Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Quan Chen

    2018-01-01

    Full Text Available Low-carbon logistics meets the requirements of a low-carbon economy and is the most effective operating model for logistic development to achieve sustainability by coping with severe energy consumption and global warming. Low-carbon logistics aims to reduce carbon intensity rather than simply reduce energy consumption and carbon emissions. Human resources are an important part of the great competition in the logistics market and significantly affect the operations of enterprises. Performance evaluations of human resources are particularly important for low-carbon logistics enterprises with scarce talents. Such evaluations in these enterprises are of great significance for their strategic development. This study constructed a human resource performance evaluation system to assess non-managerial employees’ low-carbon job capacity, job performance, and job attitude in the low-carbon logistics sector. The case study results revealed that the investigated company enjoyed initial success after having promoted low-carbon concepts and values to its non-managerial employees, and the success was demonstrated by excellent performance in its employees’ job attitude and knowledge. This study adopts the AHP method to reasonably determine an indicator system of performance evaluation and its weight to avoid certain human-caused bias. This study not only fills the gap in the related literature, but can also be applied to industrial practice.

  11. An Empirical Study on Low-Carbon: Human Resources Performance Evaluation

    Science.gov (United States)

    Chen, Quan; Tsai, Sang-Bing; Zhou, Jie; Yu, Jian; Chang, Li-Chung; Li, Guodong; Zheng, Yuxiang; Wang, Jiangtao

    2018-01-01

    Low-carbon logistics meets the requirements of a low-carbon economy and is the most effective operating model for logistic development to achieve sustainability by coping with severe energy consumption and global warming. Low-carbon logistics aims to reduce carbon intensity rather than simply reduce energy consumption and carbon emissions. Human resources are an important part of the great competition in the logistics market and significantly affect the operations of enterprises. Performance evaluations of human resources are particularly important for low-carbon logistics enterprises with scarce talents. Such evaluations in these enterprises are of great significance for their strategic development. This study constructed a human resource performance evaluation system to assess non-managerial employees’ low-carbon job capacity, job performance, and job attitude in the low-carbon logistics sector. The case study results revealed that the investigated company enjoyed initial success after having promoted low-carbon concepts and values to its non-managerial employees, and the success was demonstrated by excellent performance in its employees’ job attitude and knowledge. This study adopts the AHP method to reasonably determine an indicator system of performance evaluation and its weight to avoid certain human-caused bias. This study not only fills the gap in the related literature, but can also be applied to industrial practice. PMID:29301375

  12. An Empirical Study on Low-Carbon: Human Resources Performance Evaluation.

    Science.gov (United States)

    Chen, Quan; Tsai, Sang-Bing; Zhai, Yuming; Zhou, Jie; Yu, Jian; Chang, Li-Chung; Li, Guodong; Zheng, Yuxiang; Wang, Jiangtao

    2018-01-03

    Low-carbon logistics meets the requirements of a low-carbon economy and is the most effective operating model for logistic development to achieve sustainability by coping with severe energy consumption and global warming. Low-carbon logistics aims to reduce carbon intensity rather than simply reduce energy consumption and carbon emissions. Human resources are an important part of the great competition in the logistics market and significantly affect the operations of enterprises. Performance evaluations of human resources are particularly important for low-carbon logistics enterprises with scarce talents. Such evaluations in these enterprises are of great significance for their strategic development. This study constructed a human resource performance evaluation system to assess non-managerial employees' low-carbon job capacity, job performance, and job attitude in the low-carbon logistics sector. The case study results revealed that the investigated company enjoyed initial success after having promoted low-carbon concepts and values to its non-managerial employees, and the success was demonstrated by excellent performance in its employees' job attitude and knowledge. This study adopts the AHP method to reasonably determine an indicator system of performance evaluation and its weight to avoid certain human-caused bias. This study not only fills the gap in the related literature, but can also be applied to industrial practice.

  13. Study on dynamic performance of SOFC

    Science.gov (United States)

    Zhan, Haiyang; Liang, Qianchao; Wen, Qiang; Zhu, Runkai

    2017-05-01

    In order to solve the problem of real-time matching of load and fuel cell power, it is urgent to study the dynamic response process of SOFC in the case of load mutation. The mathematical model of SOFC is constructed, and its performance is simulated. The model consider the influence factors such as polarization effect, ohmic loss. It also takes the diffusion effect, thermal effect, energy exchange, mass conservation, momentum conservation. One dimensional dynamic mathematical model of SOFC is constructed by using distributed lumped parameter method. The simulation results show that the I-V characteristic curves are in good agreement with the experimental data, and the accuracy of the model is verified. The voltage response curve, power response curve and the efficiency curve are obtained by this way. It lays a solid foundation for the research of dynamic performance and optimal control in power generation system of high power fuel cell stack.

  14. Context Switching with Multiple Register Windows: A RISC Performance Study

    Science.gov (United States)

    Konsek, Marion B.; Reed, Daniel A.; Watcharawittayakul, Wittaya

    1987-01-01

    Although previous studies have shown that a large file of overlapping register windows can greatly reduce procedure call/return overhead, the effects of register windows in a multiprogramming environment are poorly understood. This paper investigates the performance of multiprogrammed, reduced instruction set computers (RISCs) as a function of window management strategy. Using an analytic model that reflects context switch and procedure call overheads, we analyze the performance of simple, linearly self-recursive programs. For more complex programs, we present the results of a simulation study. These studies show that a simple strategy that saves all windows prior to a context switch, but restores only a single window following a context switch, performs near optimally.

  15. Parametric Study for MOV Performance Improvement Using PPM Program

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seungho; Seon, Juhyoung; Han, Bongsub [SOOSAN INDUSTRIES, Seoul (Korea, Republic of)

    2016-10-15

    Nuclear power plants mainly use Air Operated Valve(hereinafter referred to as AOV) and Motor Operator Valve(hereinafter referred to as MOV) for protecting system, blocking and controlling flow. Field test(static, dynamic test) results and performance prediction program are used to evaluate if MOV currently installed on nuclear power plants has the operational performance. The improvement of operating performance for Flexible Gate valve was confirmed on changing input variables of performance program(PPM). here are several methods through reviewing design basis, changes operating procedures and maintenance work of stem(or packing, etc.) to improve operating performance of MOV generally installed in the nuclear power plants. This study verified the changes of the MOV operating performance through the improvement of stem and hydraulic parts(seat, guide etc.). Especially, MOV operating performance was much greater improved when the Disk Seat Angle was decreasing. Generally, improvement work to minimize friction of seat, disk and guide is limited and dynamic diagnostic testing has to be performed with change in valve factor for improvement of hydraulic parts.

  16. Reflector Performance Study in Ultra-long Cycle Fast Reactor

    International Nuclear Information System (INIS)

    Tak, Taewoo; Kong, Chidong; Choe, Jiwon; Lee, Deokjung

    2013-01-01

    There are reflector assemblies outside the fuel region, surrounding the fuel assemblies and axial reflector is located at the bottom of the core to control the neutron leakage fraction which is an important factor in fast reactor system. HT-9 was used as a reflector material as well as a structure material. In this study, alternative reflector materials were proposed and their reflection performance was tested and studied focused on its physics. ODS-MA957 and SiC were chosen from iron based alloy and ceramic respectively. The two materials were tested and compared with HT-9 in UCFR-1000 as a radial and an axial reflector and it was evaluated from the neutronics point of view with comparing the core life and the coolant void reactivity. The calculation and evaluation were performed by McCARD Monte Carlo code. The reflector materials for UCFR-1000 have been investigated in the aspect of neutronics. The reflection effect shows different performance corresponding to reflector material used. Also, the neutron energy spectrum is affected by changing materials which causes spectrum softening but it is not enough to influence the core life. With more reflector material candidates such as lead-based liquid metal, reflection performance and core parameter study will be investigated for next step

  17. An investigation on effective factors influencing employee performance: A case study

    Directory of Open Access Journals (Sweden)

    Hamid Reza Alavi

    2013-06-01

    Full Text Available Human resources are considered as one of the key components of any organization to reach its objectives. Human resources help organization performance doing organizational duties and making employees’ improvement. Because of this, employee performance appraisal has changed to one of the most important issues for top managers. Performance appraisal is necessary to select useful strategies for increasing productivity of human resource management along with productivity of employee to get strategic targets. In this study, we extract effective factors on increasing of employee performance and subsequently, present some suggestions to managers of academic organizations. The study was performed on some employees who worked for Islamic Azad University in 2013. Cronbach alpha was equal to 99.4% for employee performance appraisal, which confirmed the overall survey. To recognize key factors we used path analysis technique too. The results of the study revealed that in this school, employee performance in practical field was higher than expected, but in terms of operational and behavioral fields, they were in the middle stage.

  18. Marketing strategy and product performance: a study of selected ...

    African Journals Online (AJOL)

    Marketing strategy and product performance: a study of selected firms in Nigeria. ... Ethiopian Journal of Environmental Studies and Management ... This paper therefore recommends that business organisations should accord necessary ...

  19. Influência de diferentes condições higrotérmicas na resistência à tração de compósitos de fibra de carbono/epóxi modificada Influence of different hygrothermal conditions on the tensile strength of carbon/epoxy 8552 composites

    Directory of Open Access Journals (Sweden)

    José Antônio P. Cunha

    2006-01-01

    composites ([0/0]s were investigated. The longitudinal tensile strength results at room temperature was not significantly affected by exposing the samples to either the humidity-controlled chamber or the salt spray chamber. However, the specimens submitted to the humidity-controlled chamber and tested at elevated temperature (80 °C and 90% RH presented a decrease in the longitudinal tensile strength. A small decrease in the transversal tensile strength results was observed during room temperature tests in the samples submitted to salt spray chamber. A higher decrease in the transversal tensile strength was verified in the samples submitted to the humidity-chamber. Samples submitted to the salt spray chamber tested at elevated temperature showed a small decrease in the transversal tensile strength (11%. A drastic reduction in the strength (51% was observed in the samples submitted to the humidity-chamber and tested at high temperature. A fractograph study by scanning electronic microscopy (SEM was performed in every single sample involved in the tests. These results highlight that the elevated temperatures affect the polymeric matrix.

  20. Performance Measures of Academic Faculty--A Case Study

    Science.gov (United States)

    Davidovitch, Nitza; Soen, Dan; Sinuani-Stern, Zila

    2011-01-01

    This case study is the first to track the method used by an Israeli institution of higher education to assess and reward faculty members using a set of performance measures ("Excellence criteria"). The study profiles faculty members who received financial rewards for excellence during 2005-2007, based on the previous year's activities,…

  1. Principal elements of the Basalt Waste Isolation Project performance assessment studies

    International Nuclear Information System (INIS)

    Baca, R.G.; Wilde, R.T.

    1983-12-01

    In this paper, three of the principal elements of the Basalt Waste Isolation Project (BWIP) performance assessment studies are focused on: (1) development of a methodology for probabilistic risk assessment, (2) performance analyses of repository subsystems, and (3) selection and ranking of disruptive event scenarios. Other elements of the BWIP performance assessment studies are briefly outlined. 12 references, 5 figures

  2. SMEs’ Organizational Performance: Comparative Study between Cooperated and Uncooperated Companies

    Directory of Open Access Journals (Sweden)

    Ana Karla de Lucena Justino Gomes

    2017-12-01

    Full Text Available Faced with the need for survival and competitiveness, here called micro and small enterprises (MPE, they seek to develop competitive differentials, such as the insertion of the company into a cooperation network. Several researches seek to identify the benefits of cooperative strategies, but few studies seek to compare the organizational performance of cooperating companies with that of uncooperated companies. Thus, the present study has as general objective to verify if the MPE, when inserted in cooperation networks, present organizational performance superior to those that are not inserted in that context. The present research is of the survey type and involves 67 companies inserted in cooperation networks and 154 companies that do not participate in cooperation networks. To achieve the objective, the organizational performance was analyzed based on the managers' perception regarding aspects associated to the following performance measures: customer satisfaction, employee satisfaction, company growth, company profitability and overall performance. The results indicate that the companies included in cooperation networks presented superior performance when compared to the companies not included in cooperation networks

  3. Governing highly performing lean team behaviors : A mixed-methods longitudinal study

    NARCIS (Netherlands)

    Van Dun, Desirée H.; Wilderom, Celeste P.M.

    2015-01-01

    Work teams go through multiple performance cycles; initially highly performing teams may experience a decline in subsequent performance and vice-versa. This inductive study focuses on team-behavioral and contextual predictors of high lean team performance. Rooted in both the IMOI model and reviewing

  4. A Case Study of Teaching Musical Expression to Young Performers

    Science.gov (United States)

    Brenner, Brenda; Strand, Katherine

    2013-01-01

    What does it mean to teach musical expression to child performers? Is it teaching how to interpret a piece of music "correctly," or is there more involved? In this case study, we explored the beliefs and practices of five teachers who specialized in teaching children to perform in a variety of musical performance areas, including violin,…

  5. Effects of Performance-Based Financial Incentives on Work Performance: A Study of Technical-Level Employees in the Private Sector in Sri Lanka

    Science.gov (United States)

    Wickramasinghe, Vathsala; Dabere, Sampath

    2012-01-01

    The objective of the study is to investigate the effect of performance-based financial incentives on work performance. The study hypothesized that the design features of performance-based financial incentive schemes themselves may influence individuals' work performance. For the study, survey methodology was used and 93 technical-level employees…

  6. 42 CFR 456.245 - Number of studies required to be performed.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Number of studies required to be performed. 456.245 Section 456.245 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... Ur Plan: Medical Care Evaluation Studies § 456.245 Number of studies required to be performed. The...

  7. 42 CFR 456.145 - Number of studies required to be performed.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Number of studies required to be performed. 456.145 Section 456.145 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...: Medical Care Evaluation Studies § 456.145 Number of studies required to be performed. The hospital must...

  8. Problems of Clinical Nurse Performance Appraisal System: A Qualitative Study

    Directory of Open Access Journals (Sweden)

    Nasrin Nikpeyma

    2014-03-01

    Conclusion: The findings of this study reveal that the nurse performance appraisal system confronts with various problems. Some of these problems are related to organizational context while the others concerned structure, process and results of the performance appraisal system. In order to achieve high quality of patient care as the final goal of performance appraisal, changing and revision of this system is necessary.

  9. Lecture Attendance, Study Time, and Academic Performance: A Panel Data Study

    Science.gov (United States)

    Andrietti, Vincenzo; Velasco, Carlos

    2015-01-01

    The authors analyze matched administrative survey data on economics students enrolled in two econometrics courses offered in consecutive terms at a major public university in Spain to assess the impact of lecture attendance and study time on academic performance. Using proxy variables in a cross-sectional regression setting, they find a positive…

  10. Study habit skills as correlate of academic performance of ...

    African Journals Online (AJOL)

    Study habit is one of the major factors that could influence students' academic attainment. Thus, this study examined study habit skills as correlate of academic performance of undergraduates in Edo state, Nigeria. It employed a correlation research design, using multistage sampling technique. Two hundred and forty eight ...

  11. Conditional selectivity performance of Indian mutual fund schemes: An empirical study

    Directory of Open Access Journals (Sweden)

    Subrata Roy

    2015-06-01

    Full Text Available The present study seeks to examine the stock-selection performance of the sample open-ended equity mutual fund schemes of Birla Sun Life Mutual Fund Company based on traditional and conditional performance measures. It is generally expected that inclusion of some relevant predetermined public information variables in the conditional CAPM provides better performance estimates as compared to the traditional measures. The study reports that after inclusion of conditioning public information variables, the selectivity performances of the schemes have dramatically improved relative to the traditional measure and also found that conditional measure is superior to traditional measure in statistical test.

  12. Exceptional memory performance in the Long Life Family Study

    DEFF Research Database (Denmark)

    Barral, Sandra; Cosentino, Stephanie; Costa, Rosann

    2013-01-01

    Research to understand variability at the highest end of the cognitive performance distribution has been scarce. Our aim was to define a cognitive endophenotype based on exceptional episodic memory (EM) performance and to investigate familial aggregation of EM in families from the Long Life Family...... Study (LLFS). Using a sample of 1911 nondemented offspring of long-lived probands, we created a quantitative phenotype, EM (memory z ≥ 1.5), and classified LLFS families as EM and non-EM families based on the number of EM offspring. We then assessed differences in memory performance between LLFS...... = 1.4 × 10(-4)). We demonstrated that there is a familial correlation of the EM endophenotype, suggesting that genetic variants might influence memory performance in long-lived families....

  13. The Association between Meditation Practice and Job Performance: A Cross-Sectional Study.

    Science.gov (United States)

    Shiba, Koichiro; Nishimoto, Masahiro; Sugimoto, Minami; Ishikawa, Yoshiki

    2015-01-01

    Many previous studies have shown that meditation practice has a positive impact on cognitive and non-cognitive functioning, which are related to job performance. Thus, the aims of this study were to (1) estimate the prevalence of meditation practice, (2) identify the characteristics of individuals who practice meditation, and (3) examine the association between meditation practice and job performance. Two population-based, cross-sectional surveys were conducted. In study 1, we examined the prevalence of meditation practice and the characteristics of the persons practicing meditation; in Study 2, we examined the association between meditation practice and job performance. The outcome variables included work engagement, subjective job performance, and job satisfaction. The Utrecht Work Engagement Scale was used to assess work engagement, the World Health Organization Health and Work Performance Questionnaire (HPQ) was used to measure subjective job performance, and a scale developed by the Japanese government was used to assess job satisfaction. Hierarchical multiple regression analyses were used in Study 2. Demographic characteristics and behavioral risk factors were included as covariates in the analyses. The results of Study 1 indicated that 3.9% of persons surveyed (n = 30,665) practiced meditation; these individuals were younger and had a higher education, higher household income, higher stress level, and lower body mass index than those who did not practice meditation. The results of Study 2 (n = 1,470) indicated that meditation practice was significantly predictive of work engagement (β = 0.112, p meditation practice may positively influence job performance, including job satisfaction, subjective job performance, and work engagement.

  14. The study of the energetic performance in test cycles

    Science.gov (United States)

    Rentea, Cristian; Tuca, Alexandra; Oprean, Mircea; Marius, Bataus

    2017-10-01

    One of the most important subsystems of modern passenger cars is the transmission. This paper aims to investigate the global performances of a modern transmission in different test cycles including the newly introduced WLTC (Worldwide Harmonized Light Vehicles Test Cycle). The study is done using a complex model developed in a performant simulation environment. Transmission efficiency calculation is emphasized, the efficiency being considered variable depending on engine torque, engine speed and gear ratio. The main important parameters (vehicle speed fluctuation, overall transmission efficiency, fuel consumption ratio) needed to compare test cycles and the transmissions performance are determined.

  15. Flow and performance: a study among talented Dutch soccer players

    NARCIS (Netherlands)

    Bakker, A.B.; Oerlemans, Wido; Demerouti, E.; Bruins Slot, B.; Karamat Ali, D.

    2011-01-01

    Objective: The present study examines the relationship between environmental resources (autonomy,social support from the coach, and performance feedback), flow, and performance among young talented soccer players. Design: The design was non-experimental and involved both self- and coach-rated

  16. The Association between Meditation Practice and Job Performance: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Koichiro Shiba

    Full Text Available Many previous studies have shown that meditation practice has a positive impact on cognitive and non-cognitive functioning, which are related to job performance. Thus, the aims of this study were to (1 estimate the prevalence of meditation practice, (2 identify the characteristics of individuals who practice meditation, and (3 examine the association between meditation practice and job performance. Two population-based, cross-sectional surveys were conducted. In study 1, we examined the prevalence of meditation practice and the characteristics of the persons practicing meditation; in Study 2, we examined the association between meditation practice and job performance. The outcome variables included work engagement, subjective job performance, and job satisfaction. The Utrecht Work Engagement Scale was used to assess work engagement, the World Health Organization Health and Work Performance Questionnaire (HPQ was used to measure subjective job performance, and a scale developed by the Japanese government was used to assess job satisfaction. Hierarchical multiple regression analyses were used in Study 2. Demographic characteristics and behavioral risk factors were included as covariates in the analyses. The results of Study 1 indicated that 3.9% of persons surveyed (n = 30,665 practiced meditation; these individuals were younger and had a higher education, higher household income, higher stress level, and lower body mass index than those who did not practice meditation. The results of Study 2 (n = 1,470 indicated that meditation practice was significantly predictive of work engagement (β = 0.112, p < .001, subjective job performance (β = 0.116, p < .001, and job satisfaction (β = 0.079, p = .002, even after adjusting for covariates (β = 0.083, p < .001; β = 0.104, p < .001; β = 0.060, p = .015, respectively. The results indicate that meditation practice may positively influence job performance, including job satisfaction, subjective job

  17. Study on performance of centripetal fan, 1

    International Nuclear Information System (INIS)

    Ejiri, Eiji; Shirakura, Masaaki; Tagori, Tetsuo; Enomoto, Hisao.

    1984-01-01

    Centripetal fans are radial flow type fans which gather air from outer side into inner side. The construction is simple, and when heat exchangers are arranged around them, cooled air can be discharged upward only by connecting simple ducts, accordingly, centripetal fans are suitable to the ventilating fans for superlarge cooling towers of nuclear power plants. The static pressure rise is obtained only by the diffuser action of impellers, therefore, they are not suitable to pumps and compressors, and their use is limited only to fans. Centrifugal force exerts negative effect on static pressure rise, accordingly, the ratio of internal diameter/external diameter of impellers cannot be made very small. In this study, a small model with impeller diameter of 0.6 m was used, and its overall performance, the performance of moving blades in the range of stable operation, the rotating stall characteristics in the region of low flow rate, and the effect of side wind on the overall performance in outdoor use were examined. By changing the angle of inclination of entrance guide vanes, the range of stable operation was expanded, and the pressure coefficient and efficiency were increased. (Kako, I.)

  18. D0 central tracking chamber performance studies

    International Nuclear Information System (INIS)

    Pizzuto, D.

    1991-12-01

    The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an RΦ tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against γ → e + e - events

  19. Effect of humid-thermal environment on wave dispersion characteristics of single-layered graphene sheets

    Science.gov (United States)

    Ebrahimi, Farzad; Dabbagh, Ali

    2018-04-01

    In the present article, the hygro-thermal wave propagation properties of single-layered graphene sheets (SLGSs) are investigated for the first time employing a nonlocal strain gradient theory. A refined higher-order two-variable plate theory is utilized to derive the kinematic relations of graphene sheets. Here, nonlocal strain gradient theory is used to achieve a more precise analysis of small-scale plates. In the framework of the Hamilton's principle, the final governing equations are developed. Moreover, these obtained equations are deemed to be solved analytically and the wave frequency values are achieved. Some parametric studies are organized to investigate the influence of different variants such as nonlocal parameter, length scale parameter, wave number, temperature gradient and moisture concentration on the wave frequency of graphene sheets.

  20. Factors Influencing the Intention of Attending Theater Performances: Exploration Study

    Directory of Open Access Journals (Sweden)

    Sri Bramantoro Abdinagoro

    2017-09-01

    Full Text Available The phenomenon of theater goers who are not satisfied when watching but at the next show they were still watching, being the opposite of the concept of satisfaction. This research aimed to find the factors that caused people to intend to watch the theater again to answer the phenomenon. The researcher used an exploratory study that focused on exploring important features in the theater performing arts on those who had been watching and who had not watched. In this study, author constructed semi-structured interview questionnaires that were focused on; (1 reason for people watching the theater, (2 theatrical attributes, (3 audience expectation, and (4 audience development. The participants of the exploratory study in this study were; (1 a group of actors and performing arts workers, (2 people who watched the performing arts, and (3 people who did not watch the performing arts. The total participants were 15 persons. From the exploration results with at least 16 keywords or phrases obtained, the researcher analyzes and classifies the keywords and phrases with the same meaning and understanding that exist in each word. There are 8 (eight constructs formed based on these keyword groupings; theater play, theater reputation, goal achievement, theater atmosphere, satisfaction, flow, intention to watch again, and word of mouth. The results of this exploratory study at the next stage of the research will be the input of the research model.

  1. Barrier analogs: Long-term performance issues, preliminary studies, and recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W.J. [Rust Geotech, Inc., Grand Junction, CO (United States). Environmental Sciences Lab.; Chatters, J.C.; Last, G.V.; Bjornstad, B.N.; Link, S.O. [Pacific Northwest Lab., Richland, WA (United States); Hunter, C.R. [Cascade Earth Sciences, La Grande, OR (United States)

    1994-02-01

    The US Department of Energy`s Hanford Protective Barrier Development Program is funding studies of natural analogs of the long-term performance of waste site covers. Natural-analog studies examine past environments as evidence for projecting the future performance of engineered structures. The information generated by analog studies is needed to (1) evaluate the designs and results of short term experiments and demonstrations, (2) formulate performance-modeling problems that bound expected changes in waste site environments, and (3) understand emergent system attributes that cannot be evaluated with short-term experiments or computer models. Waste site covers will be part of dynamic environmental systems with attributes that transcend the traits of engineered components. This report discusses results of the previously unreported preliminary studies conducted in 1983 and 1984. These results indicate that analogs could play an important role in predicting the long-term behavior of engineered waste covers. Layered exposures of glacial-flood-deposited gravels mantled with silt or sand that resemble contemporary barrier designs were examined. Bergmounds, another anomaly left by cataclysmic glacial floods, were also examined as analogs of surface gravel.

  2. Package performance study: developments since PATRAM 13

    Energy Technology Data Exchange (ETDEWEB)

    Tegeler, B.; Snyder, A.; Lewis, R. [U.S. Nuclear Regulatory Commission, Washington, DC (United States); Sorenson, K. [Sandia National Labs., Albuquerque, NM (United States)

    2004-07-01

    The United States Nuclear Regulatory Commission (NRC) initiated a research program in 1999 to study the response of spent nuclear fuel transportation casks to extreme accident conditions. This confirmatory research program is called the Package Performance Study (PPS) and is founded on an enhanced public participatory process that is used to obtain public comments throughout all project phases. The study objectives are to: 1) assess the analysis tools and methods used to predict spent nuclear fuel transportation cask response to extreme mechanical and thermal environments, and 2) demonstrate the inherent safety in spent fuel cask design. Public outreach is a significant element in both of these objectives. The NRC Commission recently approved the full-scale testing of a single NRC certified spent nuclear fuel rail transportation cask. To satisfy Commission direction, NRC staff has developed, for Commission approval, detailed test plans for conducting a full-scale demonstration test on a spent fuel rail transportation cask. The staff proposes to perform a demonstration test involving the collision of a locomotive with a rail cask attached to a conveyance (i.e., railcar) and a subsequent fire test. Further, the staff plans to conduct detailed pre and post -test analysis to compare numerical calculations with data obtained from the test. This paper discusses the process for selection of this scenario and the uncertainties associated with demonstration testing and analysis predictions. The staff's proposal is currently under review by the Commission.

  3. Package performance study: developments since PATRAM 13

    International Nuclear Information System (INIS)

    Tegeler, B.; Snyder, A.; Lewis, R.; Sorenson, K.

    2004-01-01

    The United States Nuclear Regulatory Commission (NRC) initiated a research program in 1999 to study the response of spent nuclear fuel transportation casks to extreme accident conditions. This confirmatory research program is called the Package Performance Study (PPS) and is founded on an enhanced public participatory process that is used to obtain public comments throughout all project phases. The study objectives are to: 1) assess the analysis tools and methods used to predict spent nuclear fuel transportation cask response to extreme mechanical and thermal environments, and 2) demonstrate the inherent safety in spent fuel cask design. Public outreach is a significant element in both of these objectives. The NRC Commission recently approved the full-scale testing of a single NRC certified spent nuclear fuel rail transportation cask. To satisfy Commission direction, NRC staff has developed, for Commission approval, detailed test plans for conducting a full-scale demonstration test on a spent fuel rail transportation cask. The staff proposes to perform a demonstration test involving the collision of a locomotive with a rail cask attached to a conveyance (i.e., railcar) and a subsequent fire test. Further, the staff plans to conduct detailed pre and post -test analysis to compare numerical calculations with data obtained from the test. This paper discusses the process for selection of this scenario and the uncertainties associated with demonstration testing and analysis predictions. The staff's proposal is currently under review by the Commission

  4. Parametric study on the performance of automotive MR shock absorbers

    Science.gov (United States)

    Gołdasz, J.; Dzierżek, S.

    2016-09-01

    The paper contains the results of a parametric study to explore the influence of various quantities on the performance range of semi-active automotive shock absorbers using the magnetorheological (MR) fluid under steady-state and transient excitations. The analysis was performed with simulated data and using a standard single-tube shock absorber configuration with a single-gap MR valve. Additionally, the impact of material variables and valves geometry was examined as the parameters were varied and its dynamic range studied.

  5. The Qualitative Study of Key Performance Indicator on PT. Jiwasraya Manado

    OpenAIRE

    Rangian, Geby Melisa; Tumewu, Ferdinand

    2014-01-01

    Key Performance Indicator (KPI) is one of the most common tools used by the employees of companies to help manage more effectively and guide their progress. To perceive how far the achievement and the performance of the company, PT. Jiwasraya Manado use the Key Performance Indicator (KPI) to reveal the performance of the company. The objective of this study is to analyze the importance from the implementation of the key performance indicator for the insurance employee. There are several facts...

  6. IT-enabled dynamic capability on performance: An empirical study of BSC model

    Directory of Open Access Journals (Sweden)

    Adilson Carlos Yoshikuni

    2017-05-01

    Full Text Available ew studies have investigated the influence of “information capital,” through IT-enabled dynamic capability, on corporate performance, particularly in economic turbulence. Our study investigates the causal relationship between performance perspectives of the balanced scorecard using partial least squares path modeling. Using data on 845 Brazilian companies, we conduct a quantitative empirical study of firms during an economic crisis and observe the following interesting results. Operational and analytical IT-enabled dynamic capability had positive effects on business process improvement and corporate performance. Results pertaining to mediation (endogenous variables and moderation (control variables clarify IT’s role in and benefits for corporate performance.

  7. Monitoring and simulations of hydrolysis in epoxy matrix composites during hygrothermal aging

    KAUST Repository

    El Yagoubi, Jalal; Lubineau, Gilles; Traidia, Abderrazak; Verdu, Jacques

    2015-01-01

    In this paper, we studied the water transport in thermoset matrices. We used Fourier Transform Infrared analysis (FTIR) during sorption/desorption experiments to investigate the interaction between sorbed water and the epoxy network. Our results demonstrated that the polymer matrix undergoes hydrolysis. We found that the chemical species involved in the reaction process was the residual anhydride groups. These results support the physical basis of the three-dimensional (3D) diffusion/reaction model. We finally showed that this model is able to reproduce multi-cycle sorption/desorption experiment, as well as water uptake in hybrid metal/epoxy samples. We simulated the 3D distributions of the diffusing water and the reacted water.

  8. FORMATION OF HYGROTHERMAL CONDITIONS IN A DEEP-LITTER BARN IN A WINTER SEASON

    Directory of Open Access Journals (Sweden)

    Paweł Sokołowski

    2016-09-01

    Full Text Available In free stall, the maintenance of animals in the deep litter, the measurements of temperature and relative humidity of indoor air, temperature and relative humidity of the outside air were conducted. Observation also covered the thermal conditions of litter and its thickness. The study covered the winter period from 1st of December to 28th of February. The study showed that during the winter there is a slight risk of unfavorable thermal conditions for dairy cattle in the barn. The analysis of the obtained results showed a significant effect of the number of animals present in the barn on thermal conditions and humidity. The increase in stocking density in the barn affects the increase of the internal temperature and relative humidity.

  9. Explaining the Evolution of Performance Measures - A Dual Case-Study Approach

    Directory of Open Access Journals (Sweden)

    Mohammed Salloum

    2013-07-01

    Full Text Available Few empirical studies have examined how performance measures change in practice and the driving forces behind this change. The existing body of literature has taken a prescriptive approach to how managers and organisations ought to manage change in performance measures without any concern for studying the phenomenon itself and thus a theoretical gap exists. With this gap in mind, the purpose of this paper is to outline how and why the performance measures have changed at two case companies over the time period 2008-2011. In order to fulfil the purpose of this paper two case studies at two different case companies have been conducted. The choice of data collection method is justified by the ambition to attain an in-depth and holistic understanding of the phenomenon. For each case, the data collection was based on four components: an interview study, analysis of archived data, documentation and direct observations. In total, 28 interviews were conducted, 14 at each case company. The empirical findings exhibit that the performance measures are exposed to continuous and considerable change from several perspectives. The measurement scopes at both case companies are steadily expanding, the individual performance measures are constantly replaced and their characteristics are continuously altered. An array of change triggers has been identified in the empirical findings. In contrast to what is advocated in literature, the findings illustrate that the most frequent reason for change is the will to improve the performance measures, the measurement process and the overall performance rather than changing internal and external environments. There are several challenges that need to be addressed in the future research agenda.

  10. STUDY REGARDING THE PERFORMANCE OF THE ROMANIAN BANKING SYSTEM

    Directory of Open Access Journals (Sweden)

    Maria Daciana Rodean Cozma

    2014-09-01

    Full Text Available Bank performance is an indicator of the quality management and soundness of commercial banks. The systemic role of the commercial banks in the Romanian economy and their role of main creditor determine the supervisors to monitories their performance and their capacity to face the challenges. Taking into account that we are talking about a banking system which has not yet exceeded during turbulence generated by economic and financial crisis, the aim of this study is to identify and analyze the main determinants of bank performance, so any shocks that may impact on this indicator to be identified early and minimized. The financial authorities, in their attempt to avoid new bank failures, because of their negative impact on the entire financial system, have imposed new capital requirements in order to strengthen the banking system’ capacity to absorb shocks. The most used indicators in order to measure the performance of the banking system are return on assets and return on equity. Taking into accounts this consideration the main objective of this study is to analyze the determinants that have a major impact on the banking system performance in an empirical and theoretical manner. To achieve this goal we used a quantitative method, the Pearson’s coefficient. Into the model were involved datas recorded by Romanian banking system in the period 2008-2013, processed by the publications of National Bank, the International Monetary Fund and the National Institute of Statistics. In the model of the correlation coefficient, the regression involved the following indicators: solvency, nonperforming loans as a percentage of total loans, gross domestic product and inflation. The results demonstrated that the factor that have the greatest impact on banking performance is the solvency ratio, followed by the nonperforming loans, the inflation rate and by the gross domestic product. So it can be observe that internal determinants have a biggest impact on the

  11. Japanese University Athletes' Dilemma: Study, Sport Performance, or Both

    Science.gov (United States)

    Yamamoto, Yoshihiko

    2016-01-01

    The aims of this study were to investigate the Japanese university athletes' dilemma of managing both study and sport performance effectively, and to try to find answers to how they can effectively manage both their study and sport club activities. Questionnaires were used in order to collect the data (1st year, 2nd year, and 3rd year students). A…

  12. Cyclic hygrothermal aging of aircraft lightning protections: Phenomenological overview

    KAUST Repository

    Lubineau, Gilles

    2012-04-23

    The recent transition to full composite fuselages is a major breakthrough in aeronautical design. To ensure satisfactory lightning protection, the electrical properties of the primary composite structure need to be improved and a design solution lies on bonding a metallic fishnet to the fuselage. An important issue is the prediction of the aging behavior of this top layer when exposed to severe aging conditions representative of flight environment. Multiple aging mechanisms affect this top layer made of thermoset resin and metallic fishnet with complex geometry and a first modeling strategy is a necessary starting point to better understand its evolution. This paper describes the overall phenomenology and the different mechanisms that can be expected in such a structure.

  13. Cyclic hygrothermal aging of aircraft lightning protections: Phenomenological overview

    KAUST Repository

    Lubineau, Gilles; El Yagoubi, Jalal; Saghir, Shahid; Selvakumaran, Lakshmi; Askari, Abe H.

    2012-01-01

    The recent transition to full composite fuselages is a major breakthrough in aeronautical design. To ensure satisfactory lightning protection, the electrical properties of the primary composite structure need to be improved and a design solution lies on bonding a metallic fishnet to the fuselage. An important issue is the prediction of the aging behavior of this top layer when exposed to severe aging conditions representative of flight environment. Multiple aging mechanisms affect this top layer made of thermoset resin and metallic fishnet with complex geometry and a first modeling strategy is a necessary starting point to better understand its evolution. This paper describes the overall phenomenology and the different mechanisms that can be expected in such a structure.

  14. Hygrothermal response of a dwelling house. Thermal comfort criteria

    Directory of Open Access Journals (Sweden)

    Adrian IACOB

    2015-12-01

    Full Text Available The use of local natural materials in order to reduce the environmental negative impact of buildings has become common practice in recent years; such buildings are to be found in all regions of the planet. The high level of thermal protection provided by the envelope elements made from natural materials such as straw bale insulation, hemp insulation or sheep wool, and their lack of thermal massiveness require a more complex analysis on their ability to keep interior comfort without accentuated variations. This paper proposes a comparative analysis between different solutions for a residential building located near a Romanian city, Cluj-Napoca. The elements of the building envelope are designed in three alternative solutions, using as substitute to classical solutions (concrete and polystyrene, masonry and polystyrene, straw bales and rammed earth for enclosing elements. For this purpose there are conducted numerical simulations of heat and mass transfer, using a mathematical model that allows the analysis of indoor comfort, by comparing both objective factors (air temperature, operative temperature and relative humidity and subjective factors, which are needed to define interior thermal comfort indices PPD and PMV. Finally, a set of conclusions are presented and future research directions are drawn.

  15. Waste package performance allocation system study report

    International Nuclear Information System (INIS)

    Memory, R.D.

    1994-01-01

    The Waste Package Performance Allocation system study was performed in order to provide a technical basis for the selection of the waste package period of substantially complete containment and its resultant contribution to the overall total system performance. This study began with a reference case based on the current Mined Geologic Disposal System (MGDS) baseline design and added a number of alternative designs. The waste package designs were selected from the designs being considered in detail during Advanced Conceptual Design (ACD). The waste packages considered were multi-barrier packages with a 0.95 cm Alloy 825 inner barrier and a 10, 20, or 45 cm thick carbon steel outer barrier. The waste package capacities varied from 6 to 12 to 21 Pressurized Water Reactor (PWR) fuel assemblies. The vertical borehole and in-drift emplacement modes were also considered, as were thermal loadings of 25, 57, and 114 kW/acre. The repository cost analysis indicated that the 21 PWR in-drift emplacement mode option with the 10 cm and 20 cm outer barrier thicknesses are the least expensive and that the 12 PWR in-drift case has approximately the same cost as the 6 PWR vertical borehole. It was also found that the cost increase from the 10 cm outer barrier waste package to the 20 cm waste package was less per centimeter than the increase from the 20 cm outer barrier waste package to the 45 cm outer barrier waste package. However, the repository cost was nearly linear with the outer barrier thickness for the 21 PWR in-drift case. Finally, corrosion rate estimates are provided and the relationship of repository cost versus waste package lifetime is discussed as is cumulative radionuclide release from the waste package and to the accessible environment for time periods of 10,000 years and 100,000 years

  16. Performance management in a family business: a case study

    OpenAIRE

    Silva, Paulino; Silva, Rui

    2014-01-01

    This research, still at an early stage, and then presented in a poster format, intended to explain the management of organizational performance of a family business in the succession process using the case study method. The scripts for semi-structured interviews that will apply to managers, owners and other workers who are deemed suitable for the investigation, which include relatives of the owners of the company are being developed. For this work the model of organizational performance manag...

  17. Hygrothermal degradation of (3-glycidoxypropyl)trimethoxysilane films studied by neutron and X-ray reflectivity and attenuated total reflection infrared spectroscopy

    International Nuclear Information System (INIS)

    Tallant, David Robert; Garcia, Manuel Joseph; Majewski, Jaroslaw; Kent, Michael Stuart; Yim, Hyun

    2005-01-01

    Thin films of organosilanes have great technological importance in the areas of adhesion promotion, durability, and corrosion resistance. However, it is well-known that water can degrade organosilane films, particularly at elevated temperatures. In this work, X-ray and neutron reflectivity (XR and NR) were combined with attenuated total reflection infrared (ATR-IR) spectroscopy to study the chemical and structural changes within thin films of (3-glycidoxypropyl)trimethoxysilane (GPS) after exposure for various periods of time to air saturated with either D 2 O or H 2 O at 80 C. For NR and XR, ultrathin (∼100 (angstrom)) films were prepared by spin-coating. Both D 2 O and H 2 O provide neutron scattering contrast with GPS. Variations in the neutron scattering length density (SLD) profiles (a function of mass density and atomic composition) with conditioning time were measured after drying the samples out and also swelled with H 2 O or D 2 O vapor at room temperature. For samples that were dried out prior to measurement, little or no change was observed for H 2 O conditioning up to 3.5 days, but large changes were observed after 30 days of conditioning. The range of conditioning time for this structural change was narrowed to between 4 and 10 days with XR. The SLD profiles indicated that the top portion of the GPS film was transformed into a thick low-density layer after conditioning, but the bottom portion showed little structural change. A previous NR study of as-prepared GPS films involving swelling with deuterated nitrobenzene showed that the central portion of the film has much lower cross-link density than the region nearest the substrate. The present data show that the central portion also swells to a much greater extent with water and hydrolyzes more rapidly. The chemical degradation mechanism was identified by IR as hydrolysis of siloxane bonds. For ATR-IR, GPS films were prepared by dip-coating, which resulted in a greater and more variable thickness than

  18. Anthropometric and performance measures to study talent detection in youth volleyball.

    Science.gov (United States)

    Melchiorri, Giovanni; Viero, Valerio; Triossi, Tamara; Annino, Giuseppe; Padua, Elvira; Tancredi, Virginia

    2017-12-01

    The aim of this work was to study anthropometric and performance measurements in 60 young male volleyball players (YV) and 60 youth not active in the sport (YNA) to assess which of these would be more useful to study the characteristics of potential performers. Eight measures to assess anthropometric characteristics, six performance measures and two tests for joint mobility were used. Also relative age and level of maturation were assessed. The anthropometric variables, relative age and level of maturation measured did not show statistically significant differences between groups. The YV and YNA groups showed differences in the performance measures. YV group was characterized by a better performance of the ability to repeat short sprints, of the upper limbs, abdominal muscles and lower limbs, with a medium effect size (Shuttle Running Test: 0.6; Push-Up: 0.5; Sit-Up: 0.4; counter movement jump: 0.4). These performance variables were very sensitive and specific: the SRT measurement had the best positive likelihood ratio that indicates the utility of the test in identifying type of players (YV and YNA). In talent detection in youth volleyball, in the 11-13 age range, performance variables should be preferred to anthropometric ones.

  19. Bridging the Performance Gap with Ergonomics: A Case Study

    Science.gov (United States)

    Rethaber, James D.

    2011-01-01

    Faced with increased incidences of work-related strain and sprain injuries and OSHA-recordable injuries, the organization in this case study details how it resolved these performance-related issues. This case study also demonstrates the effectiveness of Thomas Gilbert's (1978) Behavior Engineering Model as a tool for analyzing, defining, and…

  20. THE STUDY OF RELATIONSHIP BETWEEN SOCIAL INTELLIGENCE AND ORGANIZATIONAL PERFORMANCE (CASE STUDY: ARDABIL REGIONAL WATER COMPANY'S MANAGERS

    Directory of Open Access Journals (Sweden)

    Habib Ebrahimpoor‎

    2013-06-01

    Full Text Available The aim of this study was to investigate the relationships among dimensions of social intelligence, social skills, social information processing, social awareness, social desirability of organizational performance. Methods: This research was a descriptive study. The population in this study comprised all experts, assistants and managers of regional water companies in Ardabil province, and was about 164 randomly selected people. And to gather data from field methods the means of questionnaires were used. Tromso questionnaire was chosen and designed to measure social intelligence and organizational performance by assessing specific questions about Balanced Scorecard as independent variable. To achieve the multiplier effect of each variable on the dependent variable, Pearson correlation test was performed. Results indicated that social skills, social information processing, social awareness and social desirability of improving organizational performance had the most important part in social information processing, and social awareness and social skills played a secondary role in improving performance.

  1. Deep geologic disposal. Lessons learnt from recent performance assessment studies

    International Nuclear Information System (INIS)

    Pescatore, C.; Andersson, J.

    1998-01-01

    Performance assessment (PA) studies are part of the decision basis for the siting, operation, and closure of deep repositories of long-lived nuclear wastes. In 1995 the NEA set up the Working Group on Integrated Performance Assessments of Deep Repositories (IPAG) with the goals to analyse existing PA studies, learn about what has been produced to date, and shed light on what could be done in future studies. Ten organisations submitted their most recent PA study for analysis and discussion, including written answers to over 70 questions. Waste management programmes, disposal concepts, geologies, and different types and amounts of waste offered a unique opportunity for exchanging information, assessing progress in PA since 1990, and identifying recent trends. A report was completed whose main lessons are overviewed. (author)

  2. Integration of a Multizone Airflow Model into a Thermalsimulation Program

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Sørensen, Karl Grau; Heiselberg, Per

    2007-01-01

    An existing computer model for dynamic hygrothermal analysis of buildings has been extended with a multizone airflow model based on loop equations to account for the coupled thermal and airflow in natural and hybrid ventilated buildings. In water distribution network and related fields loop...... a methodology adopted from water distribution network that automatically sets up the independent loops and is easy to implement into a computer program. Finally an example of verification of the model is given which demonstrates the ability of the models to accurately predict the airflow of a simple multizone...

  3. Moisture Buffer Effect and its Impact on Indoor Environment

    DEFF Research Database (Denmark)

    Zhang, Mingjie; Qin, Menghao; Chen, Zhi

    2017-01-01

    The moisture buffer effect of building materials may have great influence on indoor hygrothermal environment. In order to characterize the moisture buffering ability of materials, the basic concept of moisture buffer value (MBV) is adopted. Firstly, a theoretical correction factor is introduced...... in this paper. The moisture uptake/release by hygroscopic materials can be calculated with the factor and the basic MBV. Furthermore, the validation of the correction factor is carried out. The impact of moisture buffering on indoor environment is assessed by using numerical simulations. The results show...

  4. Concrete creep at transient temperature: constitutive law and mechanism

    International Nuclear Information System (INIS)

    Chern, J.C.; Bazant, Z.P.; Marchertas, A.H.

    1985-01-01

    A constitutive law which describes the transient thermal creep of concrete is presented. Moisture and temperature are two major parameters in this constitutive law. Aside from load, creep, cracking, and thermal (shrinkage) strains, stress-induced hygrothermal strains are also included in the analysis. The theory agrees with most types of test data which include basic creep, thermal expansion, shrinkage, swelling, creep at cyclic heating or drying, and creep at heating under compression or bending. Examples are given to demonstrate agreement between the theory and the experimental data. 15 refs., 6 figs

  5. Organic Insulation Materials, the Effect on Indoor Humidity, and the Necessity of a Vapor Barrier

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Examples of organic insulation products are cellulose fiber, other plant fiber, and animal wool. These materials, which are all very hygroscopic, are associated with certain assertions about their building physical behavior that need to be verified.Examples of such assertions are: "A vapor barrier...... is not needed when using organic insulation materials" and "Organic insulation materials have a stabilizing effect on the indoor humidity".The paper presents some numerical analyses of the hygrothermal behavior of wall constructions and the occupied spaces they surround when an organic insulation material...

  6. Moisture buffer value: A comprehensive analysis of essential parameters

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele; Rode, Carsten; Hansen, Kurt Kielsgaard

    2006-01-01

    There is an increasing focus on the possibilities of utilizing the absorptive ability of porous materials to create passive control of relative humidity (RH) variations in the indoor air.This has led to the need for determination of a newparameter that can be used for characterization of materials.......The dynamic nature of the buffering phenomena makes it difficult to use the standard hygrothermal material properties directly for this purpose. In this paper some experimental results on aerated cellular concrete are used for pointing out the methodological and experimental use of dynamic tests...

  7. Microsurgical Performance After Sleep Interruption: A NeuroTouch Simulator Study.

    Science.gov (United States)

    Micko, Alexander; Knopp, Karoline; Knosp, Engelbert; Wolfsberger, Stefan

    2017-10-01

    In times of the ubiquitous debate about doctors' working hour restrictions, it is still questionable if the physician's performance is impaired by high work load and long shifts. In this study, we evaluated the impact of sleep interruption on neurosurgical performance. Ten medical students and 10 neurosurgical residents were tested on the virtual-reality simulator NeuroTouch by performing an identical microsurgical task, well rested (baseline test), and after sleep interruption at night (stress test). Deviation of total score, timing, and excessive force on tissue were evaluated. In addition, vital parameters and self-assessment were analyzed. After sleep interruption, total performance score increased significantly (45.1 vs. 48.7, baseline vs. stress test, P = 0.048) while timing remained stable (10.1 vs. 10.4 minutes for baseline vs. stress test, P > 0.05) for both students and residents. Excessive force decreased in both groups during the stress test for the nondominant hand (P = 0.05). For the dominant hand, an increase of excessive force was encountered in the group of residents (P = 0.05). In contrast to their results, participants of both groups assessed their performance worse during the stress test. In our study, we found an increase of neurosurgical simulator performance in neurosurgical residents and medical students under simulated night shift conditions. Further, microsurgical dexterity remained unchanged. Based on our results and the data in the available literature, we cannot confirm that working hour restrictions will have a positive effect on neurosurgical performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. A study on relationship between quality of life and employee performance

    Directory of Open Access Journals (Sweden)

    Marziyeh Pourbagher

    2014-08-01

    Full Text Available This paper studies the relationship between quality of life and its eight components with employee performance in general directorate of youth and sport in province of Golestan, Iran. The study uses a questionnaire developed by Walton (1974 [Walton, R. E. (1974. Improving quality of work life. Harvard Business Review, 52(3, 12.] for quality of life and a standard questionnaire named ACHIEVE consists of 25 questions for measuring the performance. Using Spearman correlation test, the study has determined a positive and meaningful relationship between employee performance and eight components of Walton’s model including adequate and fair compensation, safe and healthy working conditions, development of human competencies, growth and security, social integration, constitutionalization and total life space and social reliance.

  9. Presence of Spotters Improves Bench Press Performance: A Deception Study.

    Science.gov (United States)

    Sheridan, Andrew; Marchant, David C; Williams, Emily L; Jones, Hollie S; Hewitt, Phil A; Sparks, S Andy

    2017-10-24

    Sheridan, A, Marchant, DC, Williams, EL, Jones, HS, Hewitt, PA, and Sparks, SA. Presence of spotters improves bench press performance: a deception study. J Strength Cond Res XX(X): 000-000, 2017-Resistance exercise is a widely used method of physical training in both recreational exercise and athletic populations. The use of training partners and spotters during resistance exercise is widespread, but little is known about the effect of the presence of these individuals on exercise performance. The purpose of the current study was to investigate the effect of spotter presence on bench press performance. Twelve recreationally trained participants (age, 21.3 ± 0.8 years, height, 1.82 ± 0.1 m, and weight, 84.8 ± 11.1 kg) performed 2 trials of 3 sets to failure at 60% of 1 repetition maximum on separate occasions. The 2 trials consisted of spotters being explicitly present or hidden from view (deception). During the trials, total repetitions (reps), total weight lifted, ratings of perceived exertion (RPE), and self-efficacy were measured. Total reps and weight lifted were significantly greater with spotters (difference = 4.5 reps, t = 5.68, p < 0.001 and difference = 209.6 kg, t = 5.65, p < 0.001, respectively). Although RPE and local RPE were significantly elevated in the deception trials (difference = 0.78, f = 6.16, p = 0.030 and difference = 0.81, f = 5.89, p = 0.034, respectively), self-efficacy was significantly reduced (difference = 1.58, f = 26.90, p < 0.001). This study demonstrates that resistance exercise is improved by the presence of spotters, which is facilitated by reduced RPE and increased self-efficacy. This has important implications for athletes and clients, who should perform resistance exercise in the proximity of others, to maximize total work performed.

  10. 38 CFR 1.929 - Reduction of debt through performance of work-study services.

    Science.gov (United States)

    2010-07-01

    ... performance of work-study services. 1.929 Section 1.929 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... performance of work-study services. (a) Scope. (1) Subject to the provisions of this section VA may allow an... becomes entitled by performance of work-study services under 38 U.S.C. 3485 and 3537 when the debt arose...

  11. A Collaborative Study of Sleep, Performance and Health Relationships

    National Research Council Canada - National Science Library

    Belenky, Gregory; Van Dongen, Hans

    2006-01-01

    .... These studies will provide the scientific basis for the effective management of sleep to sustain performance in the operational environment, including all 24x7 operations, extended work hours, and shiftwork...

  12. A Collaborative Study of Sleep, Performance and Health Relationships

    National Research Council Canada - National Science Library

    Belenky, Gregory; Van Dongen, Hans

    2005-01-01

    .... These studies will provide the scientific basis for the effective management of sleep to sustain performance in the operational environment, including all 24x7 operations, extended work hours, and shiftwork...

  13. Developing of Individual Instrument Performance Anxiety Scale: ValidityReliability Study

    Directory of Open Access Journals (Sweden)

    Esra DALKIRAN

    2016-07-01

    Full Text Available In this study, it is intended to develop a scale unique to our culture, concerning individual instrument performance anxiety of the students who are getting instrument training in the Department of Music Education. In the study, the descriptive research model is used and qualitative research techniques are utilized. The study population consists of the students attending the 23 universities which has Music Education Department. The sample of the study consists of 438 girls and 312 boys, totally 750 students who are studying in the Department of Music Education of randomly selected 10 universities. As a result of the explanatory and confirmatory factor analyses that were performed, a onedimensional structure consisting of 14 items was obtained. Also, t-scores and the coefficient scores of total item correlation concerning the distinguishing power of the items, the difference in the scores of the set of lower and upper 27% was calculated, and it was observed that the items are distinguishing as a result of both analyses. Of the scale, Cronbach's alpha coefficient of internal consistency was calculated as .94, and test-retest reliability coefficient was calculated as .93. As a result, a valid and reliable assessment and evaluation instrument that measures the exam performance anxiety of the students studying in the Department of Music Education, has been developed.

  14. Performance of engineering undergraduate students in mathematics: A case study in UniMAP

    Science.gov (United States)

    Saad, Syafawati Ab.; Azziz, Nor Hizamiyani Abdul; Zakaria, Siti Aisyah; Yazid, Nornadia Mohd

    2015-12-01

    The purpose of this paper is to study the trend performance of the first year engineering students at a public university in Mathematics course: Engineering Mathematics I. We analyze how ethnicity factor influenced students' performance in mathematics course over three years period. The performance of the undergraduate students in this study is measured by their cumulative grade point average (CGPA) in the first semester. Analysis of Variance (ANOVA) will be used to test the significance difference between three variables (Malay, Chinese and Indian). Method of simple linear regression (SLR) is used to test the relationship between the performances and to predict the future performance for this course. The findings of the study show that Chinese students perform better than Malay and Indian students.

  15. Study of functional-performance deficits in athletes with previous ankle sprains

    Directory of Open Access Journals (Sweden)

    hamid Babaee

    2008-04-01

    Full Text Available Abstract Background: Despite the importance of functional-performance deficits in athletes with history of ankle sprain few, studies have been carried out in this area. The aim of this research was to study relationship between previous ankle sprains and functional-performance deficits in athletes. Materials and methods: The subjects were 40 professional athletes selected through random sampling among volunteer participants in soccer, basketball, volleyball and handball teams of Lorestan province. The subjects were divided into 2 groups: Injured group (athletes with previous ankle sprains and healthy group (athletes without previous ankle sprains. In this descriptive study we used Functional-performance tests (figure 8 hop test and side hop test to determine ankle deficits and limitations. They participated in figure 8 hop test including hopping in 8 shape course with the length of 5 meters and side hop test including 10 side hop repetitions in course with the length of 30 centimeters. Time were recorded via stopwatch. Results: After data gathering and assessing information distributions, Pearson correlation was used to assess relationships, and independent T test to assess differences between variables. Finally the results showed that there is a significant relationship between previous ankle sprains and functional-performance deficits in the athletes. Conclusion: The athletes who had previous ankle sprains indicated functional-performance deficits more than healthy athletes in completion of mentioned functional-performance tests. The functional-performance tests (figure 8 hop test and side hop test are sensitive and suitable to assess and detect functional-performance deficits in athletes. Therefore we can use the figure 8 hop and side hop tests for goals such as prevention, assessment and rehabilitation of ankle sprains without spending too much money and time.

  16. What is global theater? or, What does new media studies have to do with performance studies?

    Directory of Open Access Journals (Sweden)

    Abigail De Kosnik

    2015-03-01

    Full Text Available This piece summarizes some key historical points of connection between new media studies and performance studies, beginning with Marshall McLuhan's concept of telecommunications networks as constitutive of a global theater. In combination with Kurt Lancaster's and Francesca Coppa's theories of fan works as performances, the global theater model can yield new insights into the nature and purpose of Internet fan fiction and fan fiction archives.

  17. Studies of the performance of the ATLAS detector using cosmic-ray muons

    CERN Document Server

    Aad, G.; Abdallah, J.; Abdelalim, A.A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; Acharya, B.S.; Adams, D.L.; Addy, T.N.; Adelman, J.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aharrouche, M.; Ahlen, S.P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Akdogan, T.; Akesson, T.P.A.; Akimoto, G.; Akimov, A.V.; Aktas, A.; Alam, M.S.; Alam, M.A.; Albrand, S.; Aleksa, M.; Aleksandrov, I.N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Aliyev, M.; Allport, P.P.; Allwood-Spiers, S.E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alviggi, M.G.; Amako, K.; Amelung, C.; Amoros, G.; Amram, N.; Anastopoulos, C.; Andeen, T.; Anders, C.F.; Anderson, K.J.; Andreazza, A.; Andrei, V.; Anduaga, X.S.; Angerami, A.; Anghinolfi, F.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonelli, S.; Antos, J.; Antunovic, B.; Anulli, F.; Aoun, S.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A.T.H.; Archambault, J.P.; Arguin, J-F.; Argyropoulos, T.; Arik, M.; Armbruster, A.J.; Arnaez, O.; Arnault, C.; Artamonov, A.; Arutinov, D.; Asai, M.; Asai, S.; Asfandiyarov, R.; Ask, S.; Asman, B.; Asner, D.; Asquith, L.; Assamagan, K.; Astvatsatourov, A.; Atoian, G.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Austin, N.; Avolio, G.; Avramidou, R.; Ay, C.; Azuma, Y.; Baak, M.A.; Bach, A.M.; Bachacou, H.; Bachas, K.; Backes, M.; Badescu, E.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J.T.; Baker, O.K.; Baker, M.D.; Baker, S.; Pedrosa, F.Baltasar Dos Santos; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Baranov, S.P.; Barashkou, A.; Barber, T.; Barberio, E.L.; Barberis, D.; Barbero, M.; Bardin, D.Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B.M.; Barnett, R.M.; Baroncelli, A.; Barr, A.J.; Barreiro, F.; Guimaraes da Costa, J.Barreiro; Barrillon, P.; Bartoldus, R.; Bartsch, D.; Bates, R.L.; Batkova, L.; Batley, J.R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H.S.; Beare, B.; Beau, T.; Beauchemin, P.H.; Beccherle, R.; Bechtle, P.; Beck, G.A.; Beck, H.P.; Beckingham, M.; Becks, K.H.; Beddall, A.J.; Beddall, A.; Bednyakov, V.A.; Bee, C.; Begel, M.; Harpaz, S.Behar; Behera, P.K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P.J.; Bell, W.H.; Bella, G.; Bellagamba, L.; Bellina, F.; Bellomo, M.; Belloni, A.; Belotskiy, K.; Beltramello, O.; Ami, S.Ben; Benary, O.; Benchekroun, D.; Bendel, M.; Benedict, B.H.; Benekos, N.; Benhammou, Y.; Benjamin, D.P.; Benoit, M.; Bensinger, J.R.; Benslama, K.; Bentvelsen, S.; Beretta, M.; Berge, D.; Kuutmann, E.Bergeaas; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertin, A.; Besana, M.I.; Besson, N.; Bethke, S.; Bianchi, R.M.; Bianco, M.; Biebel, O.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Bingul, A.; Bini, C.; Biscarat, C.; Bitenc, U.; Black, K.M.; Blair, R.E.; Blanchard, J-B.; Blanchot, G.; Blocker, C.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G.J.; Bocci, A.; Boehler, M.; Boek, J.; Boelaert, N.; Boser, S.; Bogaerts, J.A.; Bohm, C.; Boisvert, V.; Boldea, V.; Bondioli, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borroni, S.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E.V.; Boulahouache, C.; Bourdarios, C.; Boveia, A.; Boyd, J.; Boyko, I.R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Braem, A.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J.E.; Braun, H.M.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Britton, D.; Brochu, F.M.; Brock, I.; Brock, R.; Brodet, E.; Brooijmans, G.; Brooks, W.K.; Brown, G.; Bruckman de Renstrom, P.A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bucci, F.; Buchanan, J.; Buchholz, P.; Buckley, A.G.; Budagov, I.A.; Budick, B.; Buscher, V.; Bugge, L.; Bulekov, O.; Bunse, M.; Buran, T.; Burckhart, H.; Burdin, S.; Burgess, T.; Burke, S.; Busato, E.; Bussey, P.; Buszello, C.P.; Butin, F.; Butler, B.; Butler, J.M.; Buttar, C.M.; Butterworth, J.M.; Byatt, T.; Caballero, J.; Urban, S.Cabrera; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L.P.; Calvet, D.; Camarri, P.; Cameron, D.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Capasso, L.; Garrido, M.D.M.Capeans; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Caramarcu, C.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Montoya, G.D.Carrillo; Montero, S.Carron; Carter, A.A.; Carter, J.R.; Casadei, D.; Casado, M.P.; Cascella, M.; Castaneda Hernandez, A.M.; Castaneda-Miranda, E.; Castillo Gimenez, V.; Cataldi, G.; Catinaccio, A.; Catmore, J.R.; Cattai, A.; Cattani, G.; Caughron, S.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerqueira, A.S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cetin, S.A.; Chafaq, A.; Chakraborty, D.; Chan, K.; Chapman, J.D.; Chapman, J.W.; Chareyre, E.; Charlton, D.G.; Chavda, V.; Cheatham, S.; Chekanov, S.; Chekulaev, S.V.; Chelkov, G.A.; Chen, H.; Chen, S.; Chen, X.; Cheplakov, A.; Chepurnov, V.F.; El Moursli, R.Cherkaoui; Tcherniatine, V.; Chesneanu, D.; Cheu, E.; Cheung, S.L.; Chevalier, L.; Chevallier, F.; Chiefari, G.; Chikovani, L.; Childers, J.T.; Chilingarov, A.; Chiodini, G.; Chizhov, M.V.; Choudalakis, G.; Chouridou, S.; Christidi, I.A.; Christov, A.; Chromek-Burckhart, D.; Chu, M.L.; Chudoba, J.; Ciapetti, G.; Ciftci, A.K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciobotaru, M.D.; Ciocca, C.; Ciocio, A.; Clark, A.; Clark, P.J.; Cleland, W.; Clemens, J.C.; Clement, B.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coggeshall, J.; Cogneras, E.; Colijn, A.P.; Collard, C.; Collins, N.J.; Collins-Tooth, C.; Collot, J.; Colon, G.; Muino, P.Conde; Coniavitis, E.; Conidi, M.C.; Consonni, M.; Constantinescu, S.; Conta, C.; Cooke, M.; Cooper, B.D.; Cooper-Sarkar, A.M.; Cooper-Smith, N.J.; Copic, K.; Cornelissen, T.; 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Orlov, I.; Barrera, C.Oropeza; Orr, R.S.; Ortega, E.O.; Osculati, B.; Ospanov, R.; Osuna, C.; Otero y Garzon, G.; Ottersbach, J.P.; Ould-Saada, F.; Ouraou, A.; Ouyang, Q.; Owen, M.; Owen, S.; Oyarzun, A.; Ozcan, V.E.; Ozturk, N.; Pacheco Pages, A.; Aranda, C.Padilla; Paganis, E.; Paige, F.; Pajchel, K.; Palestini, S.; Pallin, D.; Palmer, J.D.; Pan, Y.B.; Panagiotopoulou, E.; Panes, B.; Panikashvili, N.; Panitkin, S.; Pantea, D.; Panuskova, M.; Paolone, V.; Papadopoulou, Th.D.; Park, S.J.; Parker, M.A.; Parodi, F.; Parsons, J.A.; Parzefall, U.; Pasqualucci, E.; Passeri, A.; Pastore, F.; Pastore, Fr.; Pataraia, S.; Patel, N.; Pater, J.R.; Patricelli, S.; Pauly, T.; Pecsy, M.; Pedraza Morales, M.I.; Peleganchuk, S.V.; Peng, H.; Penson, A.; Penwell, J.; Perantoni, M.; Perez Codina, E.; Perez Garcia-Estan, M.T.; Perez Reale, V.; Perini, L.; Pernegger, H.; Perrino, R.; Persembe, S.; Perus, P.; Peshekhonov, V.D.; Petersen, B.A.; Petersen, T.C.; Petit, E.; Petridou, C.; Petrolo, E.; Petrucci, F.; 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Quayle, W.B.; Quinonez, F.; Raas, M.; Radeka, V.; Radescu, V.; Radics, B.; Rador, T.; Ragusa, F.; Rahal, G.; Rahimi, A.M.; Rajagopalan, S.; Rammensee, M.; Rammes, M.; Rauscher, F.; Rauter, E.; Raymond, M.; Read, A.L.; Rebuzzi, D.M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Reinherz-Aronis, E.; Reinsch, A.; Reisinger, I.; Reljic, D.; Rembser, C.; Ren, Z.L.; Renkel, P.; Rescia, S.; Rescigno, M.; Resconi, S.; Resende, B.; Reznicek, P.; Rezvani, R.; Richards, A.; Richter, R.; Ridel, M.; Rijpstra, M.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Rios, R.R.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Romero, D.A.Roa; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J.E.M.; Robinson, M.; Robson, A.; Rocha de Lima, J.G.; Roda, C.; Santos, D.Roda Dos; Rodriguez, D.; Rodriguez Garcia, Y.; Roe, S.; Rohne, O.; Rojo, V.; Rolli, S.; Romaniouk, A.; Romanov, V.M.; Romeo, G.; Maltrana, D.Romero; Roos, L.; Ros, E.; Rosati, S.; Rosenbaum, G.A.; Rosselet, L.; Rossetti, V.; Rossi, L.P.; Rotaru, M.; Rothberg, J.; Rousseau, D.; Royon, C.R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Ruckert, B.; Ruckstuhl, N.; Rud, V.I.; Rudolph, G.; Ruhr, F.; Ruggieri, F.; Ruiz-Martinez, A.; Rumyantsev, L.; Rurikova, Z.; Rusakovich, N.A.; Rutherfoord, J.P.; Ruwiedel, C.; Ryabov, Y.F.; Ryan, P.; Rybkin, G.; Rzaeva, S.; Saavedra, A.F.; Sadrozinski, H.F-W.; Sadykov, R.; Tehrani, F.Safai; Sakamoto, H.; Salamanna, G.; Salamon, A.; Saleem, M.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvachua Ferrando, B.M.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Samset, B.H.; Sandaker, H.; Sander, H.G.; Sanders, M.P.; Sandhoff, M.; Sandhu, P.; Sandstroem, R.; Sandvoss, S.; Sankey, D.P.C.; Sansoni, A.; Rios, C.Santamarina; Santoni, C.; Santonico, R.; Sarangi, T.; Sarkisyan-Grinbaum, E.; Sarri, F.; Sasaki, O.; Sasao, N.; Satsounkevitch, I.; Sauvage, G.; Savine, A.Y.; Savinov, V.; Saxon, D.H.; Says, L.P.; Sbarra, C.; Sbrizzi, A.; Scannicchio, D.A.; Schaarschmidt, J.; Schacht, P.; Schafer, U.; Schaetzel, S.; Schaffer, A.C.; Schaile, D.; Schamberger, R.D.; Schamov, A.G.; Scharf, V.; Schegelsky, V.A.; Scheirich, D.; Schernau, M.; Scherzer, M.I.; Schiavi, C.; Schieck, J.; Schioppa, M.; Schlenker, S.; Schmidt, E.; Schmieden, K.; Schmitt, C.; Schmitz, M.; Schoning, A.; Schott, M.; Schouten, D.; Schovancova, J.; Schram, M.; Schreiner, A.; Schroeder, C.; Schroer, N.; Schroers, M.; Schultes, J.; Schultz-Coulon, H.C.; Schumacher, J.W.; Schumacher, M.; Schumm, B.A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwemling, Ph.; Schwienhorst, R.; Schwierz, R.; Schwindling, J.; Scott, W.G.; Searcy, J.; Sedykh, E.; Segura, E.; Seidel, S.C.; Seiden, A.; Seifert, F.; Seixas, J.M.; Sekhniaidze, G.; Seliverstov, D.M.; Sellden, B.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Seuster, R.; Severini, H.; Sevior, M.E.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L.Y.; Shank, J.T.; Shao, Q.T.; Shapiro, M.; Shatalov, P.B.; Shaw, K.; Sherman, D.; Sherwood, P.; Shibata, A.; Shimojima, M.; Shin, T.; Shmeleva, A.; Shochet, M.J.; Shupe, M.A.; Sicho, P.; Sidoti, A.; Siegert, F.; Siegrist, J.; Sijacki, Dj.; Silbert, O.; Silver, Y.; Silverstein, D.; Silverstein, S.B.; Simak, V.; Simic, Lj.; Simion, S.; Simmons, B.; Simonyan, M.; Sinervo, P.; Sinev, N.B.; Sipica, V.; Siragusa, G.; Sisakyan, A.N.; Sivoklokov, S.Yu.; Sjolin, J.; Sjursen, T.B.; Skovpen, K.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Sloper, J.; Smakhtin, V.; Smirnov, S.Yu.; Smirnov, Y.; Smirnova, L.N.; Smirnova, O.; Smith, B.C.; Smith, D.; Smith, K.M.; Smizanska, M.; Smolek, K.; Snesarev, A.A.; Snow, S.W.; Snow, J.; Snuverink, J.; Snyder, S.; Soares, M.; Sodomka, J.; Soffer, A.; Solans, C.A.; Solar, M.; Solc, J.; Camillocci, E.Solfaroli; Solodkov, A.A.; Solovyanov, O.V.; Sondericker, J.; Sopko, V.; Sopko, B.; Sosebee, M.; Soukharev, A.; Spagnolo, S.; Spano, F.; Spighi, R.; Spigo, G.; Spila, F.; Spiwoks, R.; Spousta, M.; Spurlock, B.; Denis, R.D.St.; Stahl, T.; Stahlman, J.; Stamen, R.; Stanecka, E.; Stanek, R.W.; Stanescu, C.; Stapnes, S.; Starchenko, E.A.; Stark, J.; Staroba, P.; Starovoitov, P.; Stavina, P.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H.J.; Stelzer-Chilton, O.; Stenzel, H.; Stevenson, K.; Stewart, G.A.; Stockton, M.C.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Strachota, P.; Stradling, A.R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strang, M.; Strauss, M.; Strizenec, P.; Strohmer, R.; Strom, D.M.; Stroynowski, R.; Strube, J.; Stugu, B.; Sturm, P.; Su, D.; Sugaya, Y.; Sugimoto, T.; Suhr, C.; Suita, K.; Suk, M.; Sulin, V.V.; Sultansoy, S.; Sumida, T.; Sun, X.; Sundermann, J.E.; Suruliz, K.; Sushkov, S.; Susinno, G.; Sutton, M.R.; Suzuki, Y.; Sykora, I.; Sykora, T.; Szymocha, T.; Sanchez, J.; Ta, D.; Tackmann, K.; Taffard, A.; Tafirout, R.; Taga, A.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Talby, M.; Talyshev, A.; Tamsett, M.C.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tani, K.; Tapprogge, S.; Tardif, D.; Tarem, S.; Tarrade, F.; Tartarelli, G.F.; Tas, P.; Tasevsky, M.; Tassi, E.; Tatarkhanov, M.; Taylor, C.; Taylor, F.E.; Taylor, G.N.; Taylor, W.; Castanheira, M.Teixeira Dias; Teixeira-Dias, P.; Kate, H.Ten; Teng, P.K.; Tennenbaum-Katan, Y.D.; Terada, S.; Terashi, K.; Terron, J.; Testa, M.; Therhaag, J.; Thioye, M.; Thoma, S.; Thomas, J.P.; Thompson, E.N.; Thompson, P.D.; Thompson, P.D.; Thompson, R.J.; Thompson, A.S.; Thomson, E.; Thun, R.P.; Tic, T.; Tikhomirov, V.O.; Tikhonov, Y.A.; Tipton, P.; Aires Viegas, F.J.Tique; Tisserant, S.; Toczek, B.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokar, S.; Tokunaga, K.; Tokushuku, K.; Tollefson, K.; Tomoto, M.; Tompkins, L.; Toms, K.; Tonoyan, A.; Topfel, C.; Topilin, N.D.; Torchiani, I.; Torrence, E.; Pastor, E.Torro; Touchard, F.; Tovey, D.R.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I.M.; Trincaz-Duvoid, S.; Trinh, T.N.; Tripiana, M.F.; Triplett, N.; Trischuk, W.; Trocme, B.; Troncon, C.; Trzupek, A.; Tsarouchas, C.; Tseng, J.C-L.; Tsiakiris, M.; Tsiareshka, P.V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, V.; Tskhadadze, E.G.; Tsukerman, I.I.; Tsulaia, V.; Tsung, J.W.; Tsuno, S.; Tsybychev, D.; Tuggle, J.M.; Turecek, D.; Cakir, I.Turk; Turlay, E.; Tuts, P.M.; Twomey, M.S.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ugland, M.; Uhlenbrock, M.; Uhrmacher, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Unno, Y.; Urbaniec, D.; Urkovsky, E.; Urrejola, P.; Usai, G.; Uslenghi, M.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valente, P.; Valentinetti, S.; Valkar, S.; Gallego, E.Valladolid; Vallecorsa, S.; Ferrer, J.A.Valls; van der Graaf, H.; van der Kraaij, E.; van der Poel, E.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vari, R.; Varnes, E.W.; Varouchas, D.; Vartapetian, A.; Varvell, K.E.; Vassilakopoulos, V.I.; Vazeille, F.; Vellidis, C.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J.C.; Vichou, I.; Vickey, T.; Viehhauser, G.H.A.; Villa, M.; Villani, E.G.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M.G.; Vinek, E.; Vinogradov, V.B.; Viret, S.; Virzi, J.; Vitale, A.; Vitells, O.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vlasak, M.; Vlasov, N.; Vogel, A.; Vokac, P.; Volpi, M.; von der Schmitt, H.; von Loeben, J.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorwerk, V.; Vos, M.; Voss, R.; Voss, T.T.; Vossebeld, J.H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Anh, T.Vu; Vudragovic, D.; Vuillermet, R.; Vukotic, I.; Wagner, P.; Walbersloh, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Wang, C.; Wang, H.; Wang, J.; Wang, S.M.; Warburton, A.; Ward, C.P.; Warsinsky, M.; Wastie, R.; Watkins, P.M.; Watson, A.T.; Watson, M.F.; Watts, G.; Watts, S.; Waugh, A.T.; Waugh, B.M.; Weber, M.D.; Weber, M.; Weber, M.S.; Weber, P.; Weidberg, A.R.; Weingarten, J.; Weiser, C.; Wellenstein, H.; Wells, P.S.; Wenaus, T.; Wendler, S.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Werth, M.; Werthenbach, U.; Wessels, M.; Whalen, K.; White, A.; White, M.J.; White, S.; Whitehead, S.R.; Whiteson, D.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F.J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik, L.A.M.; Wildauer, A.; Wilkens, H.G.; Williams, E.; Williams, H.H.; Willocq, S.; Wilson, J.A.; Wilson, M.G.; Wilson, A.; Wingerter-Seez, I.; Winklmeier, F.; Wittgen, M.; Wolter, M.W.; Wosiek, B.K.; Wotschack, J.; Woudstra, M.J.; Wraight, K.; Wright, C.; Wright, D.; Wrona, B.; Wu, S.L.; Wu, X.; Wulf, E.; Wynne, B.M.; Xaplanteris, L.; Xella, S.; Xie, S.; Xu, D.; Yamada, M.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamaoka, J.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, U.K.; Yang, Z.; Yao, W-M.; Yao, Y.; Yasu, Y.; Ye, J.; Ye, S.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Young, C.; Youssef, S.P.; Yu, D.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zaidan, R.; Zaitsev, A.M.; Zajacova, Z.; Zambrano, V.; Zanello, L.; Zaytsev, A.; Zeitnitz, C.; Zeller, M.; Zemla, A.; Zendler, C.; Zenin, O.; Zenis, T.; Zenonos, Z.; Zenz, S.; Zerwas, D.; della Porta, G.Zevi; Zhan, Z.; Zhang, H.; Zhang, J.; Zhang, Q.; Zhang, X.; Zhao, L.; Zhao, T.; Zhao, Z.; Zhemchugov, A.; Zhou, B.; Zhou, N.; Zhou, Y.; Zhu, C.G.; Zhu, H.; Zhu, Y.; Zhuang, X.; Zhuravlov, V.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Zivkovic, L.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.

    2011-01-01

    Muons from cosmic-ray interactions in the atmosphere provide a high-statistics source of particles that can be used to study the performance and calibration of the ATLAS detector. Cosmic-ray muons can penetrate to the cavern and deposit energy in all detector subsystems. Such events have played an important role in the commissioning of the detector since the start of the installation phase in 2005 and were particularly important for understanding the detector performance in the time prior to the arrival of the first LHC beams. Global cosmic-ray runs were undertaken in both 2008 and 2009 and these data have been used through to the early phases of collision data-taking as a tool for calibration, alignment and detector monitoring. These large datasets have also been used for detector performance studies, including investigations that rely on the combined performance of different subsystems. This paper presents the results of performance studies related to combined tracking, lepton identification and the reconst...

  18. AngularJS Performance: A Survey Study

    OpenAIRE

    Ramos, Miguel; Valente, Marco Tulio; Terra, Ricardo

    2017-01-01

    AngularJS is a popular JavaScript MVC-based framework to construct single-page web applications. In this paper, we report the results of a survey with 95 professional developers about performance issues of AngularJS applications. We report common practices followed by developers to avoid performance problems (e.g., use of third-party or custom components), the general causes of performance problems in AngularJS applications (e.g., inadequate architecture decisions taken by AngularJS users), a...

  19. Concept and performance study of turbocharged solid propellant ramjet

    Science.gov (United States)

    Li, Jiang; Liu, Kai; Liu, Yang; Liu, Shichang

    2018-06-01

    This study proposes a turbocharged solid propellant ramjet (TSPR) propulsion system that integrates a turbocharged system consisting of a solid propellant (SP) air turbo rocket (ATR) and the fuel-rich gas generator of a solid propellant ramjet (SPR). First, a suitable propellant scheme was determined for the TSPR. A solid hydrocarbon propellant is used to generate gas for driving the turbine, and a boron-based fuel-rich propellant is used to provide fuel-rich gas to the afterburner. An appropriate TSPR structure was also determined. The TSPR's thermodynamic cycle was analysed to prove its theoretical feasibility. The results showed that the TSPR's specific cycle power was larger than those of SP-ATR and SPR and thermal efficiency was slightly less than that of SP-ATR. Overall, TSPR showed optimal performance in a wide flight envelope. The specific impulses and specific thrusts of TSPR, SP-ATR, and SPR in the flight envelope were calculated and compared. TSPR's flight envelope roughly overlapped that of SP-ATR, its specific impulse was larger than that of SP-ATR, and its specific thrust was larger than those of SP-ATR and SPR. Attempts to improve the TSPR off-design performance prompted our proposal of a control plan for off-design codes in which both the turbocharger corrected speed and combustor excess gas coefficient are kept constant. An off-design performance model was established by analysing the TSPR working process. We concluded that TSPR with a constant corrected speed had wider flight envelope, higher thrust, and higher specific impulse than TSPR with a constant physical speed determined by calculating the performance of off-design TSPR codes under different control plans. The results of this study can provide a reference for further studies on TSPRs.

  20. User-friendly tools on handheld devices for observer performance study

    Science.gov (United States)

    Matsumoto, Takuya; Hara, Takeshi; Shiraishi, Junji; Fukuoka, Daisuke; Abe, Hiroyuki; Matsusako, Masaki; Yamada, Akira; Zhou, Xiangrong; Fujita, Hiroshi

    2012-02-01

    ROC studies require complex procedures to select cases from many data samples, and to set confidence levels in each selected case to generate ROC curves. In some observer performance studies, researchers have to develop software with specific graphical user interface (GUI) to obtain confidence levels from readers. Because ROC studies could be designed for various clinical situations, it is difficult task for preparing software corresponding to every ROC studies. In this work, we have developed software for recording confidence levels during observer studies on tiny personal handheld devices such as iPhone, iPod touch, and iPad. To confirm the functions of our software, three radiologists performed observer studies to detect lung nodules by using public database of chest radiograms published by Japan Society of Radiological Technology. The output in text format conformed to the format for the famous ROC kit from the University of Chicago. Times required for the reading each case was recorded very precisely.

  1. Neurocognitive performance in family-based and case-control studies of schizophrenia

    Science.gov (United States)

    Gur, Ruben C.; Braff, David L.; Calkins, Monica E.; Dobie, Dorcas J.; Freedman, Robert; Green, Michael F.; Greenwood, Tiffany A.; Lazzeroni, Laura C.; Light, Gregory A.; Nuechterlein, Keith H.; Olincy, Ann; Radant, Allen D.; Seidman, Larry J.; Siever, Larry J.; Silverman, Jeremy M.; Sprock, Joyce; Stone, William S.; Sugar, Catherine A.; Swerdlow, Neal R.; Tsuang, Debby W.; Tsuang, Ming T.; Turetsky, Bruce I.; Gur, Raquel E.

    2014-01-01

    Background Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. Methods The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Results Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Conclusions Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs. PMID:25432636

  2. Neurocognitive performance in family-based and case-control studies of schizophrenia.

    Science.gov (United States)

    Gur, Ruben C; Braff, David L; Calkins, Monica E; Dobie, Dorcas J; Freedman, Robert; Green, Michael F; Greenwood, Tiffany A; Lazzeroni, Laura C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Gur, Raquel E

    2015-04-01

    Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs.

  3. Self-Esteem, Study Habits and Academic Performance among University Students

    Science.gov (United States)

    Chilca Alva, Manuel L.

    2017-01-01

    This study was intended to establish whether self-esteem and study habits correlate with academic performance among university students. Research conducted was descriptive observational, multivariate or cross-sectional factorial in nature. The study population consisted of 196 students enrolled in a Basic Mathematics 1 class at the School of…

  4. 77 FR 30016 - Clinical Study Design and Performance of Hospital Glucose Sensors

    Science.gov (United States)

    2012-05-21

    ...] Clinical Study Design and Performance of Hospital Glucose Sensors AGENCY: Food and Drug Administration, HHS... Sensors.'' The purpose of this public meeting is to discuss clinical study design considerations and performance metrics for innovative glucose sensors intended to be used in hospital point of care settings...

  5. COMPETENCY, ENTREPRENEUR CHARACTERISTIC AND BUSINESS PERFORMANCE: STUDY OF THE PEMPEK BUSINESS IN PALEMBANG

    Directory of Open Access Journals (Sweden)

    Fransiska Soejono

    2015-01-01

    Full Text Available The purpose of this study was to examine empirically the effects of entrepreneurial compe-tencies and characteristics on business performance. Previous studies found that competencies and entrepreneurial characteristics significantly influenced business performance. A quantita-tive method was used and 122 respondents were involved as the sample in this study, who were pempek business owners in Palembang, South Sumatra. The results indicated an effect from entrepreneurial competencies on business performance. It was also found that the entrepre-neurs’ characteristics (owners’ ages significantly affected the businesses’ performance. This implication requires some sort of course or program for the entrepreneurs to improve their competence to direct the owners to gain better business performance. The growing age of the business owners requires equal insights to ensure age does not stop the owners from improving their business’ performance.

  6. DEVELOPING OF INDIVIDUAL INSTRUMENT PERFORMANCE ANXIETY SCALE: VALIDITY - RELIABILITY STUDY

    Directory of Open Access Journals (Sweden)

    Esra DALKIRAN

    2014-07-01

    Full Text Available The purpose of this study is to develop a scale unique to our culture, concerning  individual instrument performance anxiety of the students  who are getting instrument training  in the Department of Music Education. In the study, the descriptive research model is used and qualitative research techniques are utilized. The study population consists of the students attending the 23 universities which has Music Education Department. The sample of the study consists of 438 girls and 312 boys, totally 750 students  who are studying in the Department of Music Education of randomly selected 10 universities. As a result of the explanatory and confirmatory factor analyses that were performed, a one-dimensional structure consisting of 14 items was obtained. Also, t-scores and  the coefficient scores of total item correlation concerning the distinguishing power of the items, the difference in the scores of the set of lower and upper 27% was calculated, and it was observed that the items are distinguishing as a result of both analyses. Of the scale, Cronbach's alpha coefficient of internal consistency was calculated as .94, and test-retest reliability coefficient was calculated as .93. As a result, a valid and reliable assessment and evaluation instrument that measures the exam performance anxiety of the students studying in the Department of Music Education, has been developed.Extended AbstractsIntroductionAnxiety is a universal phenomenon which people experience once or a few times during lives. It was accepted as concern for the future or as an unpleasant emotional experience regarding probable hitches of the events (Di Tomasso & Gosch, 2002.In general, the occasions on which negative feelings are experienced cause anxiety to arise (Baltaş and Baltaş, 2000. People also feel anxious in dangerous situations. Anxiety may lead a person to be creative, while it may have hindering characteristics. Anxiety is that an individual considers him

  7. Performance Implications of Business Model Change: A Case Study

    Directory of Open Access Journals (Sweden)

    Jana Poláková

    2015-01-01

    Full Text Available The paper deals with changes in performance level introduced by the change of business model. The selected case is a small family business undergoing through substantial changes in reflection of structural changes of its markets. The authors used the concept of business model to describe value creation processes within the selected family business and by contrasting the differences between value creation processes before and after the change introduced they prove the role of business model as the performance differentiator. This is illustrated with the use of business model canvas constructed on the basis interviews, observations and document analysis. The two business model canvases allow for explanation of cause-and-effect relationships within the business leading to change in performance. The change in the performance is assessed by financial analysis of the business conducted over the period of 2006–2012 demonstrates changes in performance (comparing development of ROA, ROE and ROS having their lowest levels before the change of business model was introduced, growing after the introduction of the change, as well as the activity indicators with similar developments of the family business. The described case study contributes to the concept of business modeling with the arguments supporting its value as strategic tool facilitating decisions related to value creation within the business.

  8. Tack Coat Performance and Materials Study

    Science.gov (United States)

    2017-06-01

    A good bond provided by a tack coat can improve performance of asphalt overlays. The objectives of this research were: (1) develop a method for testing the bond between pavement layers; (2) evaluate the bond performance and predict long-term performa...

  9. Final waste forms project: Performance criteria for phase I treatability studies

    International Nuclear Information System (INIS)

    Gilliam, T.M.; Hutchins, D.A.; Chodak, P. III

    1994-06-01

    This document defines the product performance criteria to be used in Phase I of the Final Waste Forms Project. In Phase I, treatability studies will be performed to provide open-quotes proof-of-principleclose quotes data to establish the viability of stabilization/solidification (S/S) technologies. This information is required by March 1995. In Phase II, further treatability studies, some at the pilot scale, will be performed to provide sufficient data to allow treatment alternatives identified in Phase I to be more fully developed and evaluated, as well as to reduce performance uncertainties for those methods chosen to treat a specific waste. Three main factors influence the development and selection of an optimum waste form formulation and hence affect selection of performance criteria. These factors are regulatory, process-specific, and site-specific waste form standards or requirements. Clearly, the optimum waste form formulation will require consideration of performance criteria constraints from each of the three categories. Phase I will focus only on the regulatory criteria. These criteria may be considered the minimum criteria for an acceptable waste form. In other words, a S/S technology is considered viable only if it meet applicable regulatory criteria. The criteria to be utilized in the Phase I treatability studies were primarily taken from Environmental Protection Agency regulations addressed in 40 CFR 260 through 265 and 268; and Nuclear Regulatory Commission regulations addressed in 10 CFR 61. Thus the majority of the identified criteria are independent of waste form matrix composition (i.e., applicable to cement, glass, organic binders etc.)

  10. Final waste forms project: Performance criteria for phase I treatability studies

    Energy Technology Data Exchange (ETDEWEB)

    Gilliam, T.M. [Oak Ridge National Lab., TN (United States); Hutchins, D.A. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States); Chodak, P. III [Massachusetts Institute of Technology (United States)

    1994-06-01

    This document defines the product performance criteria to be used in Phase I of the Final Waste Forms Project. In Phase I, treatability studies will be performed to provide {open_quotes}proof-of-principle{close_quotes} data to establish the viability of stabilization/solidification (S/S) technologies. This information is required by March 1995. In Phase II, further treatability studies, some at the pilot scale, will be performed to provide sufficient data to allow treatment alternatives identified in Phase I to be more fully developed and evaluated, as well as to reduce performance uncertainties for those methods chosen to treat a specific waste. Three main factors influence the development and selection of an optimum waste form formulation and hence affect selection of performance criteria. These factors are regulatory, process-specific, and site-specific waste form standards or requirements. Clearly, the optimum waste form formulation will require consideration of performance criteria constraints from each of the three categories. Phase I will focus only on the regulatory criteria. These criteria may be considered the minimum criteria for an acceptable waste form. In other words, a S/S technology is considered viable only if it meet applicable regulatory criteria. The criteria to be utilized in the Phase I treatability studies were primarily taken from Environmental Protection Agency regulations addressed in 40 CFR 260 through 265 and 268; and Nuclear Regulatory Commission regulations addressed in 10 CFR 61. Thus the majority of the identified criteria are independent of waste form matrix composition (i.e., applicable to cement, glass, organic binders etc.).

  11. Commitment to Study as a Technique to Improve Exam Performance.

    Science.gov (United States)

    Leeming, Frank C.

    1997-01-01

    Reports on a technique that could increase study time by reducing procrastination. Randomly selected college students (N=197) made written commitments to study for an exam. Students in the commitment condition reported significantly more study time than did students in a control group; they also performed significantly better on the exam. (RJM)

  12. [A school-level longitudinal study of clinical performance examination scores].

    Science.gov (United States)

    Park, Jang Hee

    2015-06-01

    This school-level longitudinal study examined 7 years of clinical performance data to determine differences (effects) in students and annual changes within a school and between schools; examine how much their predictors (characteristics) influenced the variation in student performance; and calculate estimates of the schools' initial status and growth. A school-level longitudinal model was tested: level 1 (between students), level 2 (annual change within a school), and level 3 (between schools). The study sample comprised students who belonged to the CPX Consortium (n=5,283 for 2005~2008 and n=4,337 for 2009~2011). Despite a difference between evaluation domains, the performance outcomes were related to individual large-effect differences and small-effect school-level differences. Physical examination, clinical courtesy, and patient education were strongly influenced by the school effect, whereas patient-physician interaction was not affected much. Student scores are influenced by the school effect (differences), and the predictors explain the variation in differences, depending on the evaluation domain.

  13. A Case Study Based Analysis of Performance Metrics for Green Infrastructure

    Science.gov (United States)

    Gordon, B. L.; Ajami, N.; Quesnel, K.

    2017-12-01

    Aging infrastructure, population growth, and urbanization are demanding new approaches to management of all components of the urban water cycle, including stormwater. Traditionally, urban stormwater infrastructure was designed to capture and convey rainfall-induced runoff out of a city through a network of curbs, gutters, drains, and pipes, also known as grey infrastructure. These systems were planned with a single-purpose and designed under the assumption of hydrologic stationarity, a notion that no longer holds true in the face of a changing climate. One solution gaining momentum around the world is green infrastructure (GI). Beyond stormwater quality improvement and quantity reduction (or technical benefits), GI solutions offer many environmental, economic, and social benefits. Yet many practical barriers have prevented the widespread adoption of these systems worldwide. At the center of these challenges is the inability of stakeholders to know how to monitor, measure, and assess the multi-sector performance of GI systems. Traditional grey infrastructure projects require different monitoring strategies than natural systems; there are no overarching policies on how to best design GI monitoring and evaluation systems and measure performance. Previous studies have attempted to quantify the performance of GI, mostly using one evaluation method on a specific case study. We use a case study approach to address these knowledge gaps and develop a conceptual model of how to evaluate the performance of GI through the lens of financing. First, we examined many different case studies of successfully implemented GI around the world. Then we narrowed in on 10 exemplary case studies. For each case studies, we determined what performance method the project developer used such as LCA, TBL, Low Impact Design Assessment (LIDA) and others. Then, we determined which performance metrics were used to determine success and what data was needed to calculate those metrics. Finally, we

  14. Numerical study on tip clearance effect on performance of a centrifugal compressor

    International Nuclear Information System (INIS)

    Eum, Hark Jin; Kang, Shin Kyoung

    2003-01-01

    Effect of tip leakage flow on through flow and performance of a centrifugal compressor impeller was numerically studied using CFX-TASCflow. Seven different tip clearances were used to consider the influence of tip clearance on performance. Secondary flow and loss factor were evaluated to understand the loss mechanism inside the impeller due to tip leakage flow. The calculated results were circumferentially averaged along the passage and at the impeller exit for quantitative discussion. Tip clearance effect on performance could be decomposed into inviscid and viscous components using one dimensional equation. The inviscid component is related with the specific work reduction and the viscous component is related with the additional entropy generation. Two components affected performance equally, while efficiency drop was mainly influenced by viscous loss. Performance and efficiency drop due to tip clearance were proportional to the ratio of tip clearance to exit blade height. A simple model suggested in the present study predict performance and efficiency drop quite successfully

  15. Treatability studies performed in support of an engineering evaluation/cost analysis

    International Nuclear Information System (INIS)

    Myers, J.M.; Mueller, J.P.; Sundquist, J.A.; Moore, G.W.

    1995-01-01

    The Southern Shipbuilding Corporation (SSC) site is located on 54 acres of wooded land adjacent to Bayou Bonfouca, approximately 1.8 miles downstream of the Bayou Bonfouca National Priorities List (NPL) Superfund site in Slidell, St. Tammany Parish, Louisiana. Two one-acre, impoundments on the SSC site were used to store wastes generated from vessel cleaning. Wastes stored in the impoundments are migrating into Bayou Bonfouca, which empties into Lake Pontchartrain. In addition, the impoundments are frequently invaded by flood waters. The US EPA Emergency Response Branch (EPA-ERB) performed a site investigation which indicated that the majority of the contamination is petroleum-related and that the compounds of concern are polycyclic aromatic hydrocarbons (PARs). The wastes are generally contained with the two impoundments and surrounding soils. As part of an Engineering Evaluation/Cost Basis (EE/CA) of potential response action alternatives, four treatability studies were performed. A thermal treatment (incineration) study was performed at the EPA's Incineration Research Facility (IRF). Biodegradation remedy selection feasibility assessment was conducted on-site. A remedy screening soil washing study was also performed by TAT. A solidification/stabilization (S/S) study was conducted through EPA's Risk Reduction Engineering Laboratory (RREL) to ascertain if the PAHs could be immobilized within a solid matrix. Experimental objectives, dead methodology and conclusions for these studies are presented as they relate to potential response actions being evaluated at the SSC site

  16. An empirical study on performance management: A case study of national Iranian oil Production Distribution Company

    Directory of Open Access Journals (Sweden)

    Abolhassan Faghihi

    2012-10-01

    Full Text Available The primary goal of creating a culture of performance management is to improve processes based on the responsibility of individuals and groups for the continuous improvement of business processes, and to contribute to their skills. In this paper, we discuss all related issues and indentify the most important aspects and components of performance management. The proposed study of this paper is to find out which performance management works best for national Iranian oil products distribution company (NIOPDC. The proposed study uses analytical hierarchy process to prioritize all important factors based on pair-wise comparison. We use geometric mean to find the average of comparisons and all computations are performed using Expert Choice software package. In summary, stakeholders (0.262 are the most important components of our survey followed by employee management (0.247, social responsibility (0.190 comes in the third position and quality of services (0.166 and internal process (0.134 are two less important factors in this survey.

  17. Body Presence on Stage in Performance Studies and in Ethnoscenology

    Directory of Open Access Journals (Sweden)

    Armindo Jorge de Carvalho Bião

    2011-11-01

    Full Text Available This is a brief analysis on the titles of two related cross-disciplinary contemporary perspectives, in the university context, which seek to articulate theory and practice, arts and sciences, creation and criticism, cultural diversity and specific contexts, Ethnoscenology and Performance Studies, with emphasis on the explicit statement of their focus of interest, respectively performance and body presence on stage, and a statement about preferable choices.

  18. Motor performance as predictor of physical activity in children - The CHAMPS Study-DK

    DEFF Research Database (Denmark)

    Larsen, Lisbeth Runge; Kristensen, Peter Lund; Junge, Tina

    , health-related fitness and performance-related fitness were significantly associated to time spent at moderate to vigorous physical activity level at three years follow up. The clinical relevance of the results indicated cardiorespiratory fitness and shuttle run to be important skills to perceive......Background Physical activity is associated to several health benefits in children and has a tendency to track from childhood to adulthood. An adequate motor performance has been shown positively related to physical activity level in cross sectional studies and may be the foundation of a healthy...... lifestyle, but there is a lack of longitudinal studies. The objective of this study was to explore the longitudinal relationship between motor performance and physical activity in a three-year follow up study. Methods Longitudinal analyses were performed using data from the CHAMPS-Study DK, including 673...

  19. Systematic study on the performance of elliptic focusing neutron guides

    International Nuclear Information System (INIS)

    Martin Rodriguez, D.; DiJulio, D.D.; Bentley, P.M.

    2016-01-01

    In neutron scattering experiments there is an increasing trend towards the study of smaller volume samples, which make the use of focusing optics more important. Focusing guide geometries based on conic-sections, such as those with parabolic and elliptic shapes, have been extensively used in both recently built neutron instruments and upgrades of existing hardware. A large fraction of proposed instruments at the European Spallation Source feature the requirement of good performance when measuring on small samples. The optimised design of a focusing system comes after time consuming Monte-Carlo (MC) simulations. Therefore, in order to help reduce the time needed to design such focusing systems, it is necessary to study systematically the performance of focusing guides. In the present work, we perform a theoretical analysis of the focusing properties of neutron beams, and validate them using a combination of Monte-Carlo simulations and Particle Swarm Optimisations (PSOs), where there is a close correspondence between the maximum divergence of the beam and the shape of the guide. The analytical results show that two limits can be considered, which bound a range of conic section shapes that provide optimum performance. Finally, we analyse a more realistic guide example and we give an assessment of the importance of the contribution from multiple reflections in different systems.

  20. Depression and work performance: an ecological study using web-based screening.

    Science.gov (United States)

    Harvey, S B; Glozier, N; Henderson, M; Allaway, S; Litchfield, P; Holland-Elliott, K; Hotopf, M

    2011-05-01

    Depression is reported to be a major cause of illness-related sub-optimal work performance (presenteeism). However, the majority of studies examining presenteeism have relied on self-report measures of work performance. Furthermore, employers currently face a number of practical challenges in attempting to facilitate early identification of depression. To test whether a web-based screening tool for depression could be used successfully in the workplace and whether it was possible to detect an association between rates of depression and objective measures of impaired workgroup performance. All permanent employees of a telecommunications company with UK-based call centres were encouraged to complete a web-based psychological assessment using the Patient Health Questionnaire depression scale (PHQ-9). In addition to confidential individual level results, the tool was able to provide anonymized summary statistics for each workgroup. Four objective measures of work performance were collected for each workgroup. During the study period, 1161 web-based PHQ-9 questionnaires were completed. There was a negative linear relationship between rates of depressive symptoms and the overall performance of a workgroup (P balance, percent of temporary staff, employees' perceived level of engagement and satisfaction with their line manager (P work setting.

  1. Empirical study of self-configuring genetic programming algorithm performance and behaviour

    International Nuclear Information System (INIS)

    KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F. Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Semenkin, E; KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F. Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Semenkina, M

    2015-01-01

    The behaviour of the self-configuring genetic programming algorithm with a modified uniform crossover operator that implements a selective pressure on the recombination stage, is studied over symbolic programming problems. The operator's probabilistic rates interplay is studied and the role of operator variants on algorithm performance is investigated. Algorithm modifications based on the results of investigations are suggested. The performance improvement of the algorithm is demonstrated by the comparative analysis of suggested algorithms on the benchmark and real world problems

  2. Influence of job satisfaction on job performance: a study of teacher ...

    African Journals Online (AJOL)

    ... with their pay and promotion opportunities. However, they were found to be satisfied with the type of work they carry out daily. The study concludes that job satisfaction has a significant influence on job performance of teacher librarians. Keywords: job satisfaction, job performance, teacher librarians, employees satisfaction ...

  3. Facebook use, personality characteristics and academic performance: A correlational study

    OpenAIRE

    Sapsani, Georgia; Tselios, Nikolaos

    2017-01-01

    The present paper examines the relationship between the students personality, use of social media and their academic performance and engagement. In specific, the aim of this study is to examine the relationship of students facebook (fb) use and personality characteristics using the Big Five Personality Test with (a) student engagement, (b) time spent preparing for class, (c) time spent in co-curricular activities and (d) academic performance. Results illustrate that fb time was significantly ...

  4. Numerical study of hub taper angle on podded propeller performance

    International Nuclear Information System (INIS)

    Islam, M.F.; Veitch, B.; Bose, N.; Liu, P.

    2005-01-01

    Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

  5. The Study of Relationship between Organizational Learning and Organizational Performance

    Directory of Open Access Journals (Sweden)

    Bisotoon Azizi

    2017-01-01

    Full Text Available The aim of this study was to investigate the relationship between organizational learning and organizational performance among companies operating in the insurance industry of Tehran in Iran. The present study is a descriptive one in terms of the purpose and the method of data collection. The statistical population of the study was all insurance companies in the city of Tehran and 120 insurance companies were selected due to the lack of detailed statistical reference to their number. For this purpose, people were asked some questions who it was authorized to represent the name. The questionnaire is a tool for collecting data. The Gomez questionnaire et al. (2005 was used to measure organizational learning which includes four factors: management commitment, system perspective, openness and experimentation, transfer and integration of knowledge. To measure the organizational performance, the Yang et al. questionnaire (2004 is used. To determine the validity of data collection, the questionnaire was presented to six professors of management at various universities. The validity of questionnaire through the coordination of jury was about %100. The reliability of the questionnaire was conducted on thirty subjects, Cronbach alpha coefficient was calculated 0.91 and 0.85 for organizational learning and organizational performance, respectively. For data analysis, Pearson correlation coefficient and multiple regressions were used. The results showed that there is a positive relationship between organizational learning and its four dimensions (management commitment, vision systems, open space, and experimentation, transfer and integration of knowledge and organizational performance of Tehran insurance companies.

  6. A Study of Secondary School Students' Academic Performance at ...

    African Journals Online (AJOL)

    This study assessed and investigated the academic performance of secondary school students in two principal subjects (English Language and. Mathematics) at the Senior School Certificate Examinations (SSCE) in ten secondary schools typical of urban and rural locations in five randomised. Local Government Areas of ...

  7. Performance indicators for online secondary education: a case study

    NARCIS (Netherlands)

    van Diepen, P.; Bredeweg, B.; Bosse, T.; Bredeweg, B.

    2017-01-01

    There is little consensus about what variables extracted from learner data are the most reliable indicators of learning performance. The aim of this study is to determine such indicators by taking a wide range of variables into consideration concerning overall learning activity and content

  8. Performance-Based Service Quality Model: An Empirical Study on Japanese Universities

    Science.gov (United States)

    Sultan, Parves; Wong, Ho

    2010-01-01

    Purpose: This paper aims to develop and empirically test the performance-based higher education service quality model. Design/methodology/approach: The study develops 67-item instrument for measuring performance-based service quality with a particular focus on the higher education sector. Scale reliability is confirmed using the Cronbach's alpha.…

  9. Performance of Wild Fruit Marketing in Nigeria: A Case Study of ...

    African Journals Online (AJOL)

    Performance of Wild Fruit Marketing in Nigeria: A Case Study of African Star Apple ( Chrysophllum ... This study examined marketing of wild fruits in Nigeria using African Star Apple as a case study. ... EMAIL FULL TEXT EMAIL FULL TEXT

  10. Advanced analysis of finger-tapping performance: a preliminary study.

    Science.gov (United States)

    Barut, Cağatay; Kızıltan, Erhan; Gelir, Ethem; Köktürk, Fürüzan

    2013-06-01

    The finger-tapping test is a commonly employed quantitative assessment tool used to measure motor performance in the upper extremities. This task is a complex motion that is affected by external stimuli, mood and health status. The complexity of this task is difficult to explain with a single average intertap-interval value (time difference between successive tappings) which only provides general information and neglects the temporal effects of the aforementioned factors. This study evaluated the time course of average intertap-interval values and the patterns of variation in both the right and left hands of right-handed subjects using a computer-based finger-tapping system. Cross sectional study. Thirty eight male individuals aged between 20 and 28 years (Mean±SD = 22.24±1.65) participated in the study. Participants were asked to perform single-finger-tapping test for 10 seconds of test period. Only the results of right-handed (RH) 35 participants were considered in this study. The test records the time of tapping and saves data as the time difference between successive tappings for further analysis. The average number of tappings and the temporal fluctuation patterns of the intertap-intervals were calculated and compared. The variations in the intertap-interval were evaluated with the best curve fit method. An average tapping speed or tapping rate can reliably be defined for a single-finger tapping test by analysing the graphically presented data of the number of tappings within the test period. However, a different presentation of the same data, namely the intertap-interval values, shows temporal variation as the number of tapping increases. Curve fitting applications indicate that the variation has a biphasic nature. The measures obtained in this study reflect the complex nature of the finger-tapping task and are suggested to provide reliable information regarding hand performance. Moreover, the equation reflects both the variations in and the general

  11. Perceptions of Value: A Study of Worker Characteristics and Performance Interventions

    Science.gov (United States)

    Welch, Corey M.

    2013-01-01

    This study addressed the need of human performance technology (HPT) practitioners to make the most cost-effective performance intervention decisions, introducing a new instrument, the Intervention Value Survey, as a possible tool to provide a clearer profile of an audience's perceptions of what provides them value. Using a mixed methods…

  12. CAREER ANALYSIS AND BANK MANAGER???S PERFORMANCES (A Gender Study in Macassar)

    OpenAIRE

    Idayanti

    2012-01-01

    The purposes of this study are to analyze career and bank manager???s performances in Macassar. The study implemented t test among two groups of respondents. The results indicated that those two variables contributed differently based on types of sex perspectives. The result shown that women manager faced more obstacles in career development compare than men, however women manager have better performances.

  13. Attendance and exam performance at university: A case study

    OpenAIRE

    Allen, D. O.; Webber, D. J.

    2010-01-01

    The link between absenteeism and students’ academic performance at university is perpetually a hot topic for teaching academics. Most studies suggest the effect is negative, although the strength of this effect is in dispute. The issue is complicated further when researchers draw their inferences from different angles, such as the removal of a mandatory attendance policy or the implementation of a module-specific attendance policy. Although previous studies have suggested the effect on exam p...

  14. An analysis of alumni performance: A study of the quality of nursing education.

    Science.gov (United States)

    Altuntaş, Serap; Baykal, Ülkü

    2017-02-01

    The professional performance level of their alumni is one of the quality indicators of educational institutions. Nursing education institutions can use their alumni's performance analysis results to enhance their curricula, eliminate deficiencies, improve the quality of education and graduate more highly qualified nurses. This is a descriptive, cross-sectional and comparative study, which aimed to determine the professional performances of nurses who graduated from the same nursing faculty. The study sample included alumni of Turkey's first nursing faculty, part of the nation's first public university in Istanbul, and their administrative supervisors. The study data were collected using the self-assessment forms of 314 alumni who worked as bedside nurses in 36 Istanbul hospitals, and 314 evaluations by the 195 nurse managers who supervised them. The study's response rate was 82.6%. To collect the study data, the researchers created a performance evaluation form based on the relevant literature. The same form was administered both to the nurse managers and the alumni. The researchers obtained ethical board approval and official permissions from the relevant hospitals to conduct the study. The study data were analyzed by a statistics expert. According to the study results, the alumni's perceptions of themselves as well as the nurse managers' perceptions of the alumni were different from those of the other nurses with undergraduate degrees in terms of professional knowledge, expectations and ideals. The performance evaluation results showed that the alumni evaluated themselves more positively than their managers did. It was determined that there were highly significant differences (p=0.000) between the values provided by the five sub-dimensions of the scale and the total scale. In addition, the performance level was low in the sub-dimension focusing on research, and there was a significant difference in this sub-dimension (p=0.040). The study found that the alumni

  15. THE CONCEPT OF PERFORMANCE IN BUSINESS ORGANIZATIONS – CASE STUDY ON THE EMPLOYEE PERFORMANCE IN ROMANIAN BUSINESS ORGANIZATIONS

    OpenAIRE

    COSMIN OCTAVIAN DOBRIN; GHEORGHE N. POPESCU; VERONICA ADRIANA POPESCU; CRISTINA RALUCA POPESCU

    2012-01-01

    The general economic recession generated by the world financial crisis, with direct implications on funding, economic actors’ interactions, economic and social environment, technological progress and knowledge development, imposes the rethinking of the concept of performance in business organizations worldwide. Our study aims to present the importance held by performance at the level of business organizations in terms of a historical and multidisciplinary approach, in order to determine the b...

  16. Performance testing of extremity dosimeters, Study 2

    International Nuclear Information System (INIS)

    Harty, R.; Reece, W.D.; Hooker, C.D.

    1990-04-01

    The Health Physics Society Standards Committee (HPSSC) Working Group on Performance Testing of Extremity Dosimeters has issued a draft of a proposed standard for extremity dosimeters. The draft standard proposes methods to be used for testing dosimetry systems that determine occupational radiation dose to the extremities and the performance criterion used to determine compliance with the standard. Pacific Northwest Laboratory (PNL) has conducted two separate evaluations of the performance of extremity dosimeter processors to determine the appropriateness of the draft standard, as well as to obtain information regarding the performance of extremity dosimeters. Based on the information obtained during the facility visits and the results obtained from the performance testing, it was recommended that changes be made to ensure that the draft standard is appropriate for extremity dosimeters. The changes include: subdividing the mixture category and the beta particle category; eliminating the neutron category until appropriate flux-to-dose equivalent conversion factors are derived; and changing the tolerance level for the performance criterion to provide consistency with the performance criterion for whole body dosimeters, and to avoid making the draft standard overly difficult for processors of extremity dosimeters to pass. 20 refs., 10 figs., 6 tabs

  17. 78 FR 41926 - Proposed Information Collection Request; Comment Request; Performance Evaluation Studies on...

    Science.gov (United States)

    2013-07-12

    ... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OECA-2013-0413; FRL--9832-8] Proposed Information Collection Request; Comment Request; Performance Evaluation Studies on Wastewater Laboratories (Renewal); EPA... request (ICR), ``Performance Evaluation Studies on Wastewater Laboratories'' (EPA ICR No. 0234.11, OMB...

  18. Born to run. Studying the limits of human performance

    Directory of Open Access Journals (Sweden)

    Murray Andrew

    2012-07-01

    Full Text Available Abstract It is recognised that regular physical activity and a high level of fitness are powerful predictors of positive health outcomes. There is a long and rich history of significant feats of human endurance with some, for example, the death of the first marathon runner, Pheidippides, associated with negative health outcomes. Early studies on endurance running used X-ray and interview techniques to evaluate competitors and comment on performance. Since then, comparatively few studies have looked at runners competing in distances longer than a marathon. Those that have, tend to show significant musculoskeletal injuries and a remarkable level of adaptation to this endurance load. The TransEurope Footrace Project followed ultra-endurance runners aiming to complete 4,500 Km of running in 64 days across Europe. This pioneering study will assess the impact of extreme endurance on human physiology; analysing musculoskeletal and other tissue/organ injuries, and the body's potential ability to adapt to extreme physiological stress. The results will be of interest not only to endurance runners, but to anyone interested in the limits of human performance. Please see related article: http://www.biomedcentral.com/1741-7015/10/78

  19. Study on Biodiesel plants growth performance and tolerance to ...

    African Journals Online (AJOL)

    Abstract. In this research, we studied the growth performance and tolerance of three biodiesel plants namely; Jatropha curcas, Moringa oleifera and Ricinus communis to water stress. Research conducted on the three different soils from Kaita, Jibiya and Mai'adua in the semi-desert environments of Katsina State, Nigeria.

  20. Measurement of health system performance at district level: A study protocol

    Directory of Open Access Journals (Sweden)

    Atul Sharma

    2018-01-01

    Full Text Available Background: Limited efforts have been observed in low and middle income countries to undertake health system performance assessment at district level. Absence of a comprehensive data collection tool and lack of a standardised single summary measure defining overall performance are some of the main problems. Present study has been undertaken to develop a summary composite health system performance index at district level. Methods: A broad range of indicators covering all six domains as per building block framework were finalized by an expert panel. The domains were classified into twenty sub-domains, with 70 input and process indicators to measure performance. Seven sub-domains for assessing health system outputs and outcomes were identified, with a total of 28 indicators. Districts in Haryana state from north India were selected for the study. Primary and secondary data will be collected from 378 health facilities, district and state health directorate headquarters. Indicators will be normalized, aggregated to generate composite performance index at district level. Domain specific scores will present the quality of individual building block domains in the public health system. Robustness of the results will be checked using sensitivity analysis. Expected impact for public health: The study presents a methodology for comprehensive assessment of all health system domains on basis of input, process, output and outcome indicators which has never been reported from India. Generation of this index will help identify policy and implementation areas of concern and point towards potential solutions. Results may also help understand relationships between individual building blocks and their sub-components.

  1. Motor Performance as Predictor of Physical Activity in Children: The CHAMPS Study-DK.

    Science.gov (United States)

    Larsen, Lisbeth Runge; Kristensen, Peter Lund; Junge, Tina; Rexen, Christina Trifonov; Wedderkopp, Niels

    2015-09-01

    Physical activity (PA) is associated with several health benefits in children, and PA habits developed in childhood tend to persist into adulthood. PA may be the foundation of a healthy lifestyle, and motor performance has been shown to be positively associated with PA in cross-sectional studies. The purpose of this study was to explore the longitudinal relation between motor performance and PA in a 3-yr follow-up study. Longitudinal analyses were performed using data from 673 participants (44% boys, 6-12 yr old) who had been included in the Childhood Health Activity and Motor Performance School study-DK. Baseline motor performance tests consisted of vertical jump, shuttle run, hand grip strength, backward balance, precision throw, and cardiovascular fitness. Composite z-scores were generated to express health-related fitness and performance-related fitness. PA was measured by accelerometer at baseline and at 3-yr follow-up and was expressed as a percentage of time in moderate-to-vigorous PA. Cardiovascular fitness, vertical jump, health-related fitness, and performance-related fitness showed significant positive associations with 3-yr follow-up measures of PA in both sexes. Furthermore, shuttle run showed significant inverse associations with follow-up measures of PA for both sexes. Cardiorespiratory fitness, shuttle run, vertical jump, health-related fitness, and performance-related fitness were significantly associated with time spent in moderate-to-vigorous PA at 3-yr follow-up. The clinical relevance of the results indicates that cardiorespiratory fitness and shuttle run in childhood may be important determinants of PA in adolescence.

  2. Mood states and motor performance: a study with high performance voleybol athletes

    Directory of Open Access Journals (Sweden)

    Lenamar Fiorese Vieira

    2008-07-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n1p62 The objective of this research was to investigate the relationship between the sporting performance and mood states of high performance volleyball athletes. Twenty-three adult athletes of both sexes were assessed. The measurement instrument adopted was the POMS questionnaire. Data collection was carried out individually during the state championships. Dada were analyzed using descriptive statistics; the Friedman test for analysis of variance and the Mann-Whitney test for differences between means. The results demonstrated that both teams exhibited the mood state profi le corresponding to the “iceberg” profile. In the male team, vigor remained constant throughout all phases of the competition, while in the female team this element was unstable. The male team’s fatigue began low, during the training phase, with rates that rose as the competition progressed, with statistically significant differences between the fi rst and last matches the team played. In the female team, the confusion factor, which was at a high level during training, reduced progressively throughout the competition, with a difference that was signifi cant to p ≤ 0.05. With relation to performance and mood profi le, the female team exhibited statistically significant differences between the mean vigor and fatigue factors of high and low performance athletes. It is therefore concluded that the mood state profi le is a factor that impacts on the motor performance of these high performance teams.

  3. An Exploratory Study of Intrinsic & Extrinsic Motivators and Student Performance in an Auditing Course

    Science.gov (United States)

    Mo, Songtao

    2011-01-01

    The objective of this study is to investigate the association of intrinsic and extrinsic motivators and student performance. This study performs an exploratory analysis and presents evidence to demonstrate that intrinsic motivators affect the connection between external motivators and student performance. The empirical tests follow the framework…

  4. A study on improving the performance of a research reactor's equilibrium core

    Directory of Open Access Journals (Sweden)

    Muhammad Atta

    2013-01-01

    Full Text Available Utilizing low enriched uranium silicide fuel (U3Si2-Al of existing uranium density (3.285 g/cm3, different core configurations have been studied in search of an equilibrium core with an improved performance for the Pakistan Research Reactor-1. Furthermore, we have extended our analysis to the performance of higher density silicide fuels with a uranium density of 4.0 and 4.8 U g/cm3. The criterion used in selecting the best performing core was that of “unit flux time cycle length per 235U mass per cycle”. In order to analyze core performance by improving neutron moderation, utilizing higher-density fuel, the effect of the coolant channel width was also studied by reducing the number of plates in the standard/control fuel element. Calculations employing computer codes WIMSD/4 and CITATION were performed. A ten energy group structure for fission neutrons was used for the generation of microscopic cross-sections through WIMSD/4. To search the equilibrium core, two-dimensional core modelling was performed in CITATION. Performance indicators have shown that the higher-density uranium silicide-fuelled core (U density 4.8 g/cm3 without any changes in standard/control fuel elements, comprising of 15 standard and 4 control fuel elements, is the best performing of all analyzed cores.

  5. PRELATIONSHIP BETWEEN TRANSFORMATIONAL LEADERSHIP, EMPOWERMENT AND FOLLOWERS’ PERFORMANCE: A EMPIRICAL STUDY IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    Azman Ismail

    2009-07-01

    Full Text Available Further research reveals that the effect of transformational leadership on followers’ performance is indirectly affected by empowerment. The nature of this relationship is less emphasized in organizational leadership literature. Therefore, this study was conducted to examine the effect of transformational leadership on followers’ performance and investigate the mediating effect of empowerment in the relationship between transformational leadership and followers’ performance. Findings showed that the relationship between empowerment and transformational leadership had increased followers’ performance. This result confirms that empowerment acts as a full mediating role in the leadership model of the studied organization.

  6. The impact of manufacturing complexity drivers on performance-a preliminary study

    Science.gov (United States)

    Huah Leang, Suh; Mahmood, Wan Hasrulnizzam Wan; Rahman, Muhamad Arfauz A.

    2018-03-01

    Manufacturing systems, in pursuit of cost, time and flexibility optimisation are becoming more and more complex, exhibiting a dynamic and nonlinear behaviour. Unpredictability is a distinct characteristic of such behaviour and effects production planning significantly. Therefore, this study was undertaken to investigate the priority level and current achievement of manufacturing performance in Malaysia’s manufacturing industry and the complexity drivers on manufacturing productivity performance. The results showed that Malaysia’s manufacturing industry prioritised product quality and they managed to achieve a good on time delivery performance. However, for other manufacturing performance, there was a difference where the current achievement of manufacturing performances in Malaysia’s manufacturing industry is slightly lower than the priority given to them. The strong correlation of significant value for priority status was observed between efficient production levelling (finished goods) and finish product management while the strong correlation of significant value for current achievement was minimised the number of workstation and factory transportation system. This indicates that complexity drivers have an impact towards manufacturing performance. Consequently, it is necessary to identify complexity drivers to achieve well manufacturing performance.

  7. Strategic Orientation for Improving Financial Performance Case Study in Al-Qadissiya Governorate Banking

    Directory of Open Access Journals (Sweden)

    Basim Abbas Kraidy JASSMY

    2017-06-01

    Full Text Available This study investigated the relationships between market turbulence, competitive intensity, customer orientation, competitor orientation, inter-functional coordination, organizational commitment and financial performance in the banks of Al-Qadissya governorate. A survey questionnaire was conducted for investigation and data was collected from 170 mangers that work in these banks. To test these relationships, the authors examined all the variables under (SPSS V 20. In order to reveal the effects of the variables, the findings showed that market instability and competitive intensity have effect on strategic orientation, while market instability has no effect on organizational commitment and financial performance. At the same time, inter-functional coordination has no effect on organizational commitment. Furthermore, the study findings showed correlations between competitive intensity and organizational commitment, while there is no correlation between competitive intensity and financial performance. At last, organizational commitment influences financial performance. According to the study results could be improved by all types of strategic orientation and enhance organizational commitment that increase financial performance.

  8. An explorative study of school performance and antipsychotic medication.

    Science.gov (United States)

    van der Schans, J; Vardar, S; Çiçek, R; Bos, H J; Hoekstra, P J; de Vries, T W; Hak, E

    2016-09-21

    Antipsychotic therapy can reduce severe symptoms of psychiatric disorders, however, data on school performance among children on such treatment are lacking. The objective was to explore school performance among children using antipsychotic drugs at the end of primary education. A cross-sectional study was conducted using the University Groningen pharmacy database linked to academic achievement scores at the end of primary school (Dutch Cito-test) obtained from Statistics Netherlands. Mean Cito-test scores and standard deviations were obtained for children on antipsychotic therapy and reference children, and statistically compared using analyses of covariance. In addition, differences in subgroups as boys versus girls, ethnicity, household income, and late starters (start date within 12 months of the Cito-test) versus early starters (start date > 12 months before the Cito-test) were tested. In all, data from 7994 children could be linked to Cito-test scores. At the time of the Cito-test, 45 (0.6 %) were on treatment with antipsychotics. Children using antipsychotics scored on average 3.6 points lower than the reference peer group (534.5 ± 9.5). Scores were different across gender and levels of household income (p starters were significantly higher than starters within 12 months (533.7 ± 1.7 vs. 524.1 ± 2.6). This first exploration showed that children on antipsychotic treatment have lower school performance compared to the reference peer group at the end of primary school. This was most noticeable for girls, but early starters were less affected than later starters. Due to the observational cross-sectional nature of this study, no causality can be inferred, but the results indicate that school performance should be closely monitored and causes of underperformance despite treatment warrants more research.

  9. Undergraduate Student Happiness and Academic Performance: A Correlation Study

    Science.gov (United States)

    Langevin, Elizabeth L.

    2013-01-01

    The purpose of this study was to examine the relationship between undergraduate student happiness and academic performance (GPA), controlling for age, gender, and race/ethnicity for third and fourth year business students at University of Phoenix, Little Rock Campus. The eight-item Oxford Happiness Questionnaire (OHQ) was used to measure the…

  10. Cross-Validation of Numerical and Experimental Studies of Transitional Airfoil Performance

    DEFF Research Database (Denmark)

    Frere, Ariane; Hillewaert, Koen; Sarlak, Hamid

    2015-01-01

    The aerodynamic performance characteristic of airfoils are the main input for estimating wind turbine blade loading as well as annual energy production of wind farms. For transitional flow regimes these data are difficult to obtain, both experimentally as well as numerically, due to the very high...... sensitivity of the flow to perturbations, large scale separation and performance hysteresis. The objective of this work is to improve the understanding of the transitional airfoil flow performance by studying the S826 NREL airfoil at low Reynolds numbers (Re = 4:104 and 1:105) with two inherently different...

  11. Solid Polymer Fuel Cells. Electrode and membrane performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S.

    1996-12-31

    This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

  12. Solid Polymer Fuel Cells. Electrode and membrane performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S

    1997-12-31

    This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

  13. The Influence of Motivation on Employees' Performance: A Study of ...

    African Journals Online (AJOL)

    user

    motivation on employees' performance of selected manufacturing firms in Anambra State ..... Research Design: The survey research design method was used in this study. ... manager, the accountant, and the production manager). The sample.

  14. THE STUDY OF ORGANIZATIONAL BEHAVIOR ON FISHERY MANUFACTURE INDUSTRIES EMPLOYEES PERFORMANCES

    Directory of Open Access Journals (Sweden)

    Agung Wahyu Handaru

    2015-06-01

    Full Text Available The purpose of this study was to examine the employee performance of fish-based food processing industries in West Java, which driven by variables of organizational culture, job satisfaction and motivation. The fishing industry in Indonesia has resulted in huge foreign exchange. On the other hand, their products are still poor quality and do not meet export standard. This is likely due to low employee performance. The research object were employees of three fish-based food processing plants. The sample was selected by simple random sampling technique. This study revealed different results from previous studies, that only organizational culture has an effect on employee performance. While job satisfaction and motivation has no effect on performance. Tujuan penelitian ini adalah menguji kinerja karyawan industri pengolahan makanan berbasis ikan di wilayah Jawa Barat, yang dipengaruhi dari variabel budaya organisasi, kepuasan kerja dan motivasi. Industri perikanan di Indonesia telahmenghasilkan devisa negara besar. Disisi lain, hasil produknya masih banyak yang belum memenuhi standar ekspor dan bermutu rendah. Hal tersebut kemungkinan dikarenakan kinerja karyawan yang rendah. Objek penelitian ini adalah karyawan dari tiga pabrik pengolahan makanan berbasis ikan. Sampel dipilih dengan teknik simple random sampling. Penelitian ini mengungkapkan hasil yang berbeda dari penelitian sebelumnya. Dari ketiga variabel independen, hanya budaya organisasi yang berpengaruh pada kinerja karyawan. Sedangkan kepuasan kerja dan motivasi tidak berpengaruh.

  15. The Influence of Motivation on Employees' Performance: A Study of ...

    African Journals Online (AJOL)

    The study investigates the influence of Extrinsic and Intrinsic motivation on ... relationship between extrinsic motivation and the performance of employees while no ... should adopt extrinsic rewards in their various firms to increase productivity.

  16. Studies of natural analogues and geological systems. Their importance to performance assessment

    International Nuclear Information System (INIS)

    Brandberg, F.; Grundfelt, B.; Hoeglund, L.O.; Skagius, K.; Karlsson, Fred; Smellie, J.

    1992-04-01

    This review has involved studies of natural analogues and natural geological systems leading to the identification and quantification of processes and features of importance to the performance and safety of repositories for radioactive waste. The features and processes selected for the study comprise general geochemical issues related to the performance of the near- and of the far-field, the performance and durability of construction materials and the effects of glaciation. For each of these areas a number of potentially important processes for repository performance have been described, and evidence for their existence, as well as quantification of parameters of models describing the processes, have been sought from major natural analogue studies and site investigations. The review has aimed at covering a relatively broad range of issues at the expense of in-depth analysis. The quantitative data presented are in most cases compilations of data from the literature; in a few cases results of evaluations made within the current project are included. The results of the study show that studies of natural analogues and natural geological systems have provided significant information regarding many issues of importance to repository performance. In several cases the evidence from natural analogues has demonstrated that processes assumed to take place in repositories actually occur in natural systems or under conditions similar to those predicted to prevail in a future repository. One example of such a process is coprecipitation of fission products and ferric oxyhydroxides as an analogue to corrosion products from a steel canister. In addition, the study of concentration gradients of uranium and other trace substances in the rock surrounding groundwater conduits confirm that matrix diffusion occurs in nature and that the diffusivities in the rock matrix measured in the laboratory are consistent with the observations in nature

  17. Attendance and Exam Performance at University: A Case Study

    Science.gov (United States)

    Allen, David O.; Webber, Don J.

    2010-01-01

    The link between absenteeism and students' academic performance at university is perpetually a hot topic for teaching academics. Most studies suggest the effect is negative, although the strength of this effect is in dispute. The issue is complicated further when researchers draw their inferences from different angles, such as the removal of a…

  18. Assessing Vocal Performances Using Analytical Assessment: A Case Study

    Science.gov (United States)

    Gynnild, Vidar

    2016-01-01

    This study investigated ways to improve the appraisal of vocal performances within a national academy of music. Since a criterion-based assessment framework had already been adopted, the conceptual foundation of an assessment rubric was used as a guide in an action research project. The group of teachers involved wanted to explore thinking…

  19. An Empirical Study of the Relationship between Performance Appraisal Politics and Job Satisfaction

    Directory of Open Access Journals (Sweden)

    Azman Ismail

    2011-02-01

    Full Text Available Performance appraisal politics are viewed as a vital human resource management issuewhere it consists of two salient features: motivational motive and punishment motive. The ability ofappraisers (e.g., immediate bosses/managers to properly implement such appraisal politics inallocating performance ratings may have significant impact on job satisfaction. Although the nature ofthis relationship is important, little is known about the role of performance appraisal politics as apredicting variable in the performance appraisal models. Therefore, this study was conducted toexamine the effect of performance appraisal politics on job satisfaction using 150 usablequestionnaires gathered from employees who have worked in a national postal company in Sarawak,Malaysia. In initial data analysis, the results of exploratory factor analysis confirmed that themeasurement scales used in this study satisfactorily met the standards of validity and reliabilityanalyses. Further, in hypothesis testing, the outcomes of stepwise regression analysis showed thatperformance appraisal politics (i.e., motivational motive and punishment motive significantlycorrelated with job satisfaction. Statistically, this result confirms that performance appraisal politicsact as important predictors of job satisfaction in the studied organization. In addition, discussion,implications and conclusion are elaborated.

  20. Studies on denitrification performance of tricking filters

    International Nuclear Information System (INIS)

    Ruediger, A.

    1993-01-01

    Trickling filters are one of the oldest methods of biological waste water purification, widely used ever since they were first developed. These filters are mostly used for aerobic purification of water as highly polluted or lightly polluted reactors. While these systems are very useful for the elemination of organic pollution and the nitrification of the waste waters, denitrification of the whole plant poses considerable problems. The question is in how far trickling filters can be used as denitrification reactors. The conditions of successful denitrification in trickling filters is investigated, denitrification performance is established. Studies were conducted in laboratory, semi-industrial and industrial scale. (BBR) [de

  1. Study on electrohydrodynamic jetting performance of organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Hong; Nguyen, Xuan Hung; Gim, Yeong Hyeon; Ko, Han Seo [Sungkyunkwan University, Suwon (Korea, Republic of)

    2015-11-15

    The electrohydrodynamic (EHD) inkjet method is a printing technology using electricity. This technique allows for the printing of EML (Emission layer) materials, usually used for OLED devices, on a substrate. In this study, ejection experiments were performed with various solvents to verify which of them is properly ejected in the EHD method. The solvents employed were dielectric liquids with low viscosity and it was confirmed that among them two solvents, 1,2-Dichlorobenzene (DCB) and 1,2-Dichloroethane (DCE), produced the pulsating cone-Jet mode and stable cone-jet mode well. In addition, experiments were conducted to find out how the voltage and applied flux influence the ejection mode, in order to apply the result to the ejection control. It was found that the selected solvent was easily ejected and printed, due to the free surface charge and charge density determined by the dielectric constant. Finally, a patterning experiment was performed to verify proper printing.

  2. Heating Performance Study on a Passive Solar Heater

    Directory of Open Access Journals (Sweden)

    Naz Muhammad Y.

    2017-01-01

    Full Text Available A passive thermosyphon heating system was designed, fabricated and tested for its thermal performance in semi-arid and four-season climate of Pakistan. The heating system design was based on a two-stage storage and natural thermosyphon circulation of the water. The objective of the study was to enhance the heating performance of the thermosyphon systems by using a semicircular steel pot collector, water carrying copper coil cover, two step water storage, and side mirror reflectors. The experiments were conducted during April to July 2014 when ambient temperature was reported to vary between 32°C and 44°C. In continuous flow mode operation, the hot water temperature remained between 46°C and 78°C. Since water temperature in the range of 45°C to 50°C is considered suitable for the domestic use, the presented design can easily reach the temperatures even higher than those acceptable for the domestic use.

  3. Internally Heated Screw Pyrolysis Reactor (IHSPR) heat transfer performance study

    Science.gov (United States)

    Teo, S. H.; Gan, H. L.; Alias, A.; Gan, L. M.

    2018-04-01

    1.5 billion end-of-life tyres (ELT) were discarded globally each year and pyrolysis is considered the best solution to convert the ELT into valuable high energy-density products. Among all pyrolysis technologies, screw reactor is favourable. However, conventional screw reactor risks plugging issue due to its lacklustre heat transfer performance. An internally heated screw pyrolysis reactor (IHSPR) was developed by local renewable energy industry, which serves as the research subject for heat transfer performance study of this particular paper. Zero-load heating test (ZLHT) was first carried out to obtain the operational parameters of the reactor, followed by the one dimensional steady-state heat transfer analysis carried out using SolidWorks Flow Simulation 2016. Experiments with feed rate manipulations and pyrolysis products analyses were conducted last to conclude the study.

  4. Computational intelligence for the Balanced Scorecard: studying performance trends of hemodialysis clinics.

    Science.gov (United States)

    Cattinelli, Isabella; Bolzoni, Elena; Chermisi, Milena; Bellocchio, Francesco; Barbieri, Carlo; Mari, Flavio; Amato, Claudia; Menzer, Marcus; Stopper, Andrea; Gatti, Emanuele

    2013-07-01

    The Balanced Scorecard (BSC) is a general, widely employed instrument for enterprise performance monitoring based on the periodic assessment of strategic Key Performance Indicators that are scored against preset targets. The BSC is currently employed as an effective management support tool within Fresenius Medical Care (FME) and is routinely analyzed via standard statistical methods. More recently, the application of computational intelligence techniques (namely, self-organizing maps) to BSC data has been proposed as a way to enhance the quantity and quality of information that can be extracted from it. In this work, additional methods are presented to analyze the evolution of clinic performance over time. Performance evolution is studied at the single-clinic level by computing two complementary indexes that measure the proportion of time spent within performance clusters and improving/worsening trends. Self-organizing maps are used in conjunction with these indexes to identify the specific drivers of the observed performance. The performance evolution for groups of clinics is modeled under a probabilistic framework by resorting to Markov chain properties. These allow a study of the probability of transitioning between performance clusters as time progresses for the identification of the performance level that is expected to become dominant over time. We show the potential of the proposed methods through illustrative results derived from the analysis of BSC data of 109 FME clinics in three countries. We were able to identify the performance drivers for specific groups of clinics and to distinguish between countries whose performances are likely to improve from those where a decline in performance might be expected. According to the stationary distribution of the Markov chain, the expected trend is best in Turkey (where the highest performance cluster has the highest probability, P=0.46), followed by Portugal (where the second best performance cluster dominates

  5. Scientometric analyses of studies on the role of innate variation in athletic performance.

    Science.gov (United States)

    Lombardo, Michael P; Emiah, Shadie

    2014-01-01

    Historical events have produced an ideologically charged atmosphere in the USA surrounding the potential influences of innate variation on athletic performance. We tested the hypothesis that scientific studies of the role of innate variation in athletic performance were less likely to have authors with USA addresses than addresses elsewhere because of this cultural milieu. Using scientometric data collected from 290 scientific papers published in peer-reviewed journals from 2000-2012, we compared the proportions of authors with USA addresses with those that listed addresses elsewhere that studied the relationships between athletic performance and (a) prenatal exposure to androgens, as indicated by the ratio between digits 2 and 4, and (b) the genotypes for angiotensin converting enzyme, α-actinin-3, and myostatin; traits often associated with athletic performance. Authors with USA addresses were disproportionately underrepresented on papers about the role of innate variation in athletic performance. We searched NIH and NSF databases for grant proposals solicited or funded from 2000-2012 to determine if the proportion of authors that listed USA addresses was associated with funding patterns. NIH did not solicit grant proposals designed to examine these factors in the context of athletic performance and neither NIH nor NSF funded grants designed to study these topics. We think the combined effects of a lack of government funding and the avoidance of studying controversial or non-fundable topics by USA based scientists are responsible for the observation that authors with USA addresses were underrepresented on scientific papers examining the relationships between athletic performance and innate variation.

  6. Study for improvement of performance of the test and research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Fumio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    Current utilization needs for the test and research reactors become more advanced and diversified along with the advance of nuclear science and technology. Besides, the requested safety for the research and test reactors grows strictly every year as well as a case of the power reactors. Under this circumstance, every effort to improve reactor performance including its safety is necessary to be sustained for allowing more effective utilization of the test and research reactors as experimental apparatus for advanced researches. In this study, the following three themes i.e., JMTR high-performance fuel element, evaluation method of fast neutron irradiation dose in the JMTR, evaluation method of performance of siphon break valve as core covering system for water-cooled test and research reactors, were investigated respectively from the views of improvement of core performance as a neutron source, utilization performance as an experimental apparatus, and safety as a reactor plant. (author)

  7. Experimental Study on Fatigue Performance of Foamed Lightweight Soil

    Science.gov (United States)

    Qiu, Youqiang; Yang, Ping; Li, Yongliang; Zhang, Liujun

    2017-12-01

    In order to study fatigue performance of foamed lightweight soil and forecast its fatigue life in the supporting project, on the base of preliminary tests, beam fatigue tests on foamed lightweight soil is conducted by using UTM-100 test system. Based on Weibull distribution and lognormal distribution, using the mathematical statistics method, fatigue equations of foamed lightweight soil are obtained. At the same time, according to the traffic load on real road surface of the supporting project, fatigue life of formed lightweight soil is analyzed and compared with the cumulative equivalent axle loads during the design period of the pavement. The results show that even the fatigue life of foamed lightweight soil has discrete property, the linear relationship between logarithmic fatigue life and stress ratio still performs well. Especially, the fatigue life of Weibull distribution is more close to that derived from the lognormal distribution, in the instance of 50% guarantee ratio. In addition, the results demonstrated that foamed lightweight soil as subgrade filler has good anti-fatigue performance, which can be further adopted by other projects in the similar research domain.

  8. Multiscale modelling for better hygrothermal prediction of porous building materials

    Directory of Open Access Journals (Sweden)

    Belarbi Rafik

    2018-01-01

    Full Text Available The aim of this work is to understand the influence of the microstructuralgeometric parameters of porous building materials on the mechanisms of coupled heat, air and moisture transfers, in order to predict behavior of the building to control and improve it in its durability. For this a multi-scale approach is implemented. It consists of mastering the dominant physical phenomena and their interactions on the microscopic scale. Followed by a dual-scale modelling, microscopic-macroscopic, of coupled heat, air and moisture transfers that takes into account the intrinsic properties and microstructural topology of the material using X-ray tomography combined with the correlation of 3D images were undertaken. In fact, the hygromorphicbehavior under hydric solicitations was considered. In this context, a model of coupled heat, air and moisture transfer in porous building materials was developed using the periodic homogenization technique. These informations were subsequently implemented in a dynamic computation simulation that model the hygrothermalbehaviourof material at the scale of the envelopes and indoor air quality of building. Results reveals that is essential to consider the local behaviors of materials, but also to be able to measure and quantify the evolution of its properties on a macroscopic scale from the youngest age of the material. In addition, comparisons between experimental and numerical temperature and relative humidity profilesin multilayers wall and in building envelopes were undertaken. Good agreements were observed.

  9. Moisture buffering and its consequence in whole building hygrothermal modeling

    DEFF Research Database (Denmark)

    Rode, Carsten; Grau, Karl

    2008-01-01

    Moisture absorption and desorption of materials in contact with indoor air of buildings can be used as a passive, i.e., nonmechanical, way to moderate the variation of indoor humidity. This phenomenon, which is recognized as,moisture buffering', could potentially be used as an attractive feature...... for ventilation if indoor humidity is a parameter for controlling ventilation rate, 2. it is possible to improve the perceived acceptability of indoor air, as judged by the temperature and humidity of the air, by using moisture buffering to control the indoor humidity. The results of the whole building...

  10. Approaches to studying predict academic performance in undergraduate occupational therapy students: a cross-cultural study.

    Science.gov (United States)

    Bonsaksen, Tore; Brown, Ted; Lim, Hua Beng; Fong, Kenneth

    2017-05-02

    Learning outcomes may be a result of several factors including the learning environment, students' predispositions, study efforts, cultural factors and approaches towards studying. This study examined the influence of demographic variables, education-related factors, and approaches to studying on occupational therapy students' Grade Point Average (GPA). Undergraduate occupational therapy students (n = 712) from four countries completed the Approaches and Study Skills Inventory for Students (ASSIST). Demographic background, education-related factors, and ASSIST scores were used in a hierarchical linear regression analysis to predict the students' GPA. Being older, female and more time engaged in self-study activities were associated with higher GPA among the students. In addition, five ASSIST subscales predicted higher GPA: higher scores on 'seeking meaning', 'achieving', and 'lack of purpose', and lower scores on 'time management' and 'fear of failure'. The full model accounted for 9.6% of the variance related to the occupational therapy students' GPA. To improve academic performance among occupational therapy students, it appears important to increase their personal search for meaning and motivation for achievement, and to reduce their fear of failure. The results should be interpreted with caution due to small effect sizes and a modest amount of variance explained by the regression model, and further research on predictors of academic performance is required.

  11. Study on the relationship between Islamic leadership style, work ethics, job satisfaction, and employee performance

    OpenAIRE

    FEBRIANI RIZKI; THOYIB ARMANU; SURACHMAN S.; ROFIATY R.

    2017-01-01

    There are many studies to examine the relationship of Leadership Style, Work Ethic, Satisfaction and Employee Performance. However, these research more emphasis on study of non-Muslims. In addition, there is no study has comprehensively discussed the Leadership Style, Work Ethic, Satisfaction and Employee Performance. Therefore, this study will examine theoretically the relationship between Leadership Style, Work Ethic, Satisfaction and Employee Performance comprehensively and within Islamic ...

  12. Motor performance as predictor of physical activity in children - The CHAMPS Study-DK

    DEFF Research Database (Denmark)

    Larsen, Lisbeth Runge; Kristensen, Peter Lund; Junge, Tina

    2015-01-01

    Purpose Physical activity is associated with several health benefits in children, and physical activity habits developed in childhood tend to persist into adulthood. Physical activity may be the foundation of a healthy lifestyle and motor performance has been shown to be positively associated wit...... run in childhood may be important determinants of physical activity in adolescence.......Purpose Physical activity is associated with several health benefits in children, and physical activity habits developed in childhood tend to persist into adulthood. Physical activity may be the foundation of a healthy lifestyle and motor performance has been shown to be positively associated...... with physical activity in cross-sectional studies. The purpose of this study was to explore the longitudinal relationship between motor performance and physical activity in a three-year follow-up study. Methods Longitudinal analyses were performed using data from 673 participants (44% boys, 6-12 years old) who...

  13. Digital breast tomosynthesis versus digital mammography: a clinical performance study

    International Nuclear Information System (INIS)

    Gennaro, Gisella; Baldan, Enrica; Bezzon, Elisabetta; Polico, Ilaria; Proietti, Alessandro; Toffoli, Aida; Toledano, Alicia; Di Maggio, Cosimo; La Grassa, Manuela; Pescarini, Luigi; Muzzio, Pier Carlo

    2010-01-01

    To compare the clinical performance of digital breast tomosynthesis (DBT) with that of full-field digital mammography (FFDM) in a diagnostic population. The study enrolled 200 consenting women who had at least one breast lesion discovered by mammography and/or ultrasound classified as doubtful or suspicious or probably malignant. They underwent tomosynthesis in one view [mediolateral oblique (MLO)] of both breasts at a dose comparable to that of standard screen-film mammography in two views [craniocaudal (CC) and MLO]. Images were rated by six breast radiologists using the BIRADS score. Ratings were compared with the truth established according to the standard of care and a multiple-reader multiple-case (MRMC) receiver-operating characteristic (ROC) analysis was performed. Clinical performance of DBT compared with that of FFDM was evaluated in terms of the difference between areas under ROC curves (AUCs) for BIRADS scores. Overall clinical performance with DBT and FFDM for malignant versus all other cases was not significantly different (AUCs 0.851 vs 0.836, p = 0.645). The lower limit of the 95% CI or the difference between DBT and FFDM AUCs was -4.9%. Clinical performance of tomosynthesis in one view at the same total dose as standard screen-film mammography is not inferior to digital mammography in two views. (orig.)

  14. Studies of evolutionary temperature adaptation: muscle function and locomotor performance in Antarctic fish.

    Science.gov (United States)

    Franklin, C E

    1998-09-01

    1. Studies of evolutionary temperature adaptation of muscle and locomotor performance in fish are reviewed with a focus on the Antarctic fauna living at subzero temperatures. 2. Only limited data are available to compare the sustained and burst swimming kinematics and performance of Antarctic, temperate and tropical species. Available data indicate that low temperatures limit maximum swimming performance and this is especially evident in fish larvae. 3. In a recent study, muscle performance in the Antarctic rock cod Notothenia coriiceps at 0 degree C was found to be sufficient to produce maximum velocities during burst swimming that were similar to those seen in the sculpin Myoxocephalus scorpius at 10 degrees C, indicating temperature compensation of muscle and locomotor performance in the Antarctic fish. However, at 15 degrees C, sculpin produce maximum swimming velocities greater than N. coriiceps at 0 degree C. 4. It is recommended that strict hypothesis-driven investigations using ecologically relevant measures of performance are undertaken to study temperature adaptation in Antarctic fish. Recent detailed phylogenetic analyses of the Antarctic fish fauna and their temperate relatives will allow a stronger experimental approach by helping to separate what is due to adaptation to the cold and what is due to phylogeny alone.

  15. Performance study of hybrid photon detectors for the LHCb RICH

    CERN Document Server

    Kanaya, N; Gys, Thierry; Piedigrossi, D; Wyllie, K

    2005-01-01

    The LHCb experiment is designed to study CP violation and rare phenomena of B mesons with very high accuracy. The LHCb RICH detectors are essential for positive kaon identification, and several strict demands are required of its photon detectors to achieve excellent particle identification performance. In particular, they should have good single photon sensitivity for visible and UV wavelengths and large coverage with fine granularity. HPDs have been developed to meet these requirements in collaboration with industry. They have now been chosen as the photon detector for LHCb, and pre-series tubes are under test prior to mass production. At the same time, more detailed studies are on-going to understand more deeply their characteristics. The result of various performance tests of these tubes as well as the fraction of light reflection in the HPD are described in this paper.

  16. Examination performances of German and international medical students in the preclinical studying-term--a descriptive study.

    Science.gov (United States)

    Huhn, D; Resch, F; Duelli, R; Möltner, A; Huber, J; Karimian Jazi, K; Amr, A; Eckart, W; Herzog, W; Nikendei, C

    2014-01-01

    Medical students with a migration background face several specific problems during their studies. International surveys show first indications that this group of students performs worse in written, oral or practical exams. However, so far, nothing is known about the performance of international students in written pre-clinical tests as well as in pre-clinical State Examinations for German-speaking countries. A descriptive, retrospective analysis of the exam performances of medical students in the pre-clinical part of their studies was conducted at the Faculty of Medicine of Heidelberg in for the year 2012. Performance in written tests of the final exams in the second (N=276), third (N=292) and fourth semester (N=285) were compared between German students, students from EU countries and students from non-EU countries. Same comparison was drawn for the performance in the oral exam of the First State Examination in the period from 2009 - 2012 (N=1137). German students performed significantly better than students with a non-EU migration background both in all written exams and in the oral State Examination (all pstudents with an EU migration background was significantly better than that of students with a non-EU background in the written exam at the end of the third and fourth semester (pstudents completed the oral exam of the First State Examination significantly earlier than students with a non-EU migration background (students with a country of origin outside of the European Union has to be seen as a high-risk group among students with a migration background. For this group, there is an urgent need for early support to prepare for written and oral examinations.

  17. Advances in the study of far-field phenomena affecting repository performance

    International Nuclear Information System (INIS)

    Tsang, C.F.

    1991-01-01

    Studies of far-field phenomena affecting repository performance have focussed on the role of fractures and other heterogeneities in the potential transport of radioactive solutes from the repository to the biosphere. The present paper summarizes two recent advances in the subject: the channeling model for the understanding and analysis tracer transport in variable-aperture fractures and the modeling of coupled thermo-hydro-mechanical processes in geologic formation around a repository. The paper concludes with remarks on the need for duality in the approach to performance assessment. One line of the duality is fundamental studies and the other, goal-oriented assessment to satisfy regulatory requirements. 15 refs., 10 figs., 1 tab

  18. Tactile communication, cooperation, and performance: an ethological study of the NBA.

    Science.gov (United States)

    Kraus, Michael W; Huang, Cassey; Keltner, Dacher

    2010-10-01

    Tactile communication, or physical touch, promotes cooperation between people, communicates distinct emotions, soothes in times of stress, and is used to make inferences of warmth and trust. Based on this conceptual analysis, we predicted that in group competition, physical touch would predict increases in both individual and group performance. In an ethological study, we coded the touch behavior of players from the National Basketball Association (NBA) during the 2008-2009 regular season. Consistent with hypotheses, early season touch predicted greater performance for individuals as well as teams later in the season. Additional analyses confirmed that touch predicted improved performance even after accounting for player status, preseason expectations, and early season performance. Moreover, coded cooperative behaviors between teammates explained the association between touch and team performance. Discussion focused on the contributions touch makes to cooperative groups and the potential implications for other group settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  19. Gender Performativity through Musicking: Examples from a Norwegian Classroom Study

    OpenAIRE

    Onsrud, Silje Valde

    2015-01-01

    ABSTRACT This article is based on findings from the doctoral thesis Gender at Stake: A Study of Secondary School Pupils’ Musicking. The study explores how pupils stage and construct gender through the music they perform in the lower-secondary school music education in Norway. The observations and interviews of four music teaching practices in two urban lower-secondary schools that provided the qualitative data of the study are intended to highlight both the teachers’ and the pupils’ perspe...

  20. Self-Esteem, Study Habits and Academic Performance Among University Students

    OpenAIRE

    Chilca Alva, Manuel L.

    2017-01-01

    This study was intended to establish whether self-esteem and study habits correlate with academic performance among university students. Research conducted was descriptive observational, multivariate or cross-sectional factorial in nature. The study population consisted of 196 students enrolled in a Basic Mathematics 1 class at the School of Engineering of Universidad Tecnológica del Perú (Technical University of Peru, UTP) in the third term of 2016, and the sample size numbered 86 students. ...

  1. High performance computing system in the framework of the Higgs boson studies

    CERN Document Server

    Belyaev, Nikita; The ATLAS collaboration

    2017-01-01

    The Higgs boson physics is one of the most important and promising fields of study in modern High Energy Physics. To perform precision measurements of the Higgs boson properties, the use of fast and efficient instruments of Monte Carlo event simulation is required. Due to the increasing amount of data and to the growing complexity of the simulation software tools, the computing resources currently available for Monte Carlo simulation on the LHC GRID are not sufficient. One of the possibilities to address this shortfall of computing resources is the usage of institutes computer clusters, commercial computing resources and supercomputers. In this paper, a brief description of the Higgs boson physics, the Monte-Carlo generation and event simulation techniques are presented. A description of modern high performance computing systems and tests of their performance are also discussed. These studies have been performed on the Worldwide LHC Computing Grid and Kurchatov Institute Data Processing Center, including Tier...

  2. High performance computing system in the framework of the Higgs boson studies

    CERN Document Server

    Belyaev, Nikita; The ATLAS collaboration; Velikhov, Vasily; Konoplich, Rostislav

    2017-01-01

    The Higgs boson physics is one of the most important and promising fields of study in the modern high energy physics. It is important to notice, that GRID computing resources become strictly limited due to increasing amount of statistics, required for physics analyses and unprecedented LHC performance. One of the possibilities to address the shortfall of computing resources is the usage of computer institutes' clusters, commercial computing resources and supercomputers. To perform precision measurements of the Higgs boson properties in these realities, it is also highly required to have effective instruments to simulate kinematic distributions of signal events. In this talk we give a brief description of the modern distribution reconstruction method called Morphing and perform few efficiency tests to demonstrate its potential. These studies have been performed on the WLCG and Kurchatov Institute’s Data Processing Center, including Tier-1 GRID site and supercomputer as well. We also analyze the CPU efficienc...

  3. Calculation study of the WWER-440 fuel performance for extended burnup

    International Nuclear Information System (INIS)

    Kujal, J.; Pazdera, F.; Barta, O.

    1984-01-01

    The results of preliminary calculational study of extended burnup cycling schemes impact on WWER-440 fuel performance are presented. Two high burnup schemes were proposed with three and four cycles, resp. Comparison was made with three cycle reference case. The thermal mechanical analysis was performed with PIN and RELA codes. The values of rod internal pressure, fuel centerline temperatures and fuel-cladding gap are expressed as function of power history. (author)

  4. Increasing Performance of Professional Soccer Players and Elite Track and Field Athletes with Peak Performance Training and Biofeedback: A Pilot Study

    OpenAIRE

    Rijken, Noortje H.; Soer, Remko; de Maar, Ewold; Prins, Hilco; Teeuw, Wouter B.; Peuscher, Jan; Oosterveld, Frits G. J.

    2016-01-01

    The aim of this pilot study was to investigate the effects of an intervention consisting of mental coaching combined with either electro encephalogram (EEG) alpha power feedback or heart rate variability (HRV) feedback on HRV, EEG outcomes and self-reported factors related to stress, performance, recovery and sleep quality in elite athletes. A prospective pilot study was performed with two distinct cohorts. Soccer players were provided with four sessions of mental coaching combined with daily...

  5. Research studies performed using the Cairo Fourier Diffractometer Facility

    International Nuclear Information System (INIS)

    Maayouf, R.M.A.; Ridikas, D.

    2009-12-01

    This report represents the results of the research studies performed using the Cairo Fourier Diffractometer Facility (CFDF), within 10 years after it was installed and put into operation at the beginning of 1996. The main components of the CFDF were supplied by the IAEA according to the technical assistance project EGY/1/022 'Upgrading of Research Reactor Utilization'. The present report is the second published INDC report, while the first one, published at the beginning of 1997, was about the performance of the CFDF and its main characteristic parameters. Plenty of measurements were performed since then, yielding several publications both in local and international scientific periodicals and resulting in 8 M.Sc. and Ph.D. degrees from Egyptian Universities. In addition, a new approach for the analysis of the neutron spectra was implemented using the CFDF. Specially designed interface card with proper software program was applied instead of the reverse time of flight (RTOF) and Finnish made analyzer originally attached to the facility. It has been verified that the new approach can successfully replace the RTOF analyzer, significantly decreasing the time of measurement and saving the reactor's operation time. Besides, a special fault diagnostic system program was developed and tested for caring and handling the possible failures of the CFDF. Moreover, measurements were carried out for the diffraction spectra emitted at different points of one of the samples. The latter was scanned across the neutron beam of the CFDF, for studying the stress after welding; used in industrial applications. (author)

  6. Study on the micro direct ethanol fuel cell (Micro-DEFC) performance

    Science.gov (United States)

    Saisirirat, Penyarat; Joommanee, Bordindech

    2018-01-01

    The direct ethanol fuel cell (DEFC) is selected for this research. DEFC uses ethanol in the fuel cell instead of the more toxic methanol. Ethanol is more attractive than methanol by many reasons. Ethanol is a hydrogen-rich liquid and it has a higher specific energy (8.0 kWh/kg) compared to that of methanol (6.1 kWh/kg). Ethanol can be obtained in great quantity from biomass through a fermentation process from renewable resources such as sugar cane, wheat, corn, and even straw. The use of ethanol would also overcome both the storage and infrastructure challenge of hydrogen for fuel cell applications. The experimental apparatus on the micro direct ethanol fuel cell for measuring the cell performance has been set for this research. The objective is to study the micro direct ethanol fuel cell performance for applying with the portable electronic devices. The cell performance is specified in the terms of cell voltage, cell current and power of the cell at room operating temperature and 1 atm for the pressure and also includes the ethanol fuel consumption. The effect of operating temperature change on the electrical production performance is also studied. The steady-state time for collecting each data value is about 5-10 minutes. The results show that with the increase of concentrations of ethanol by volume, the reactant concentration at the reaction sites increases so the electrochemical rate also increases but when it reaches the saturated point the performance gradually drops.

  7. A review of studies performed to assess metal uptake by earthworms

    International Nuclear Information System (INIS)

    Nahmani, Johanne; Hodson, Mark E.; Black, Stuart

    2007-01-01

    Earthworms perform a number of essential functions in soil; the impacts of metals on earthworms are often investigated. In this review we consider the range of earthworm species, types of soil and forms of metal for which metal uptake and accumulation have been studied, the design of these experiments and the quantitative relationships that have been derived to predict earthworm metal body burden. We conclude that there is a need for more studies on earthworm species other than Eisenia fetida in order to apply the large existing database on this earthworm to other, soil dwelling species. To aid comparisons between studies agreement is needed on standard protocols that define exposure and depuration periods and the parameters, such as soil solution composition, soil chemical and physical properties to be measured. It is recommended that more field or terrestrial model ecosystem studies using real contaminated soil rather than metal-amended artificial soils are performed. - We review species, soil and experimental designs used to study metal uptake and accumulation by earthworms and suggest priorities for further studies

  8. A review of studies performed to assess metal uptake by earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Nahmani, Johanne [Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Berkshire, Reading RG6 6DW (United Kingdom)]. E-mail: j.y.nahmani@reading.ac.uk; Hodson, Mark E. [Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Berkshire, Reading RG6 6DW (United Kingdom)]. E-mail: m.e.hodson@reading.ac.uk; Black, Stuart [Department of Archaeology, School of Human and Environmental Sciences, Whiteknights, University of Reading, Reading RG6 6DW (United Kingdom)

    2007-01-15

    Earthworms perform a number of essential functions in soil; the impacts of metals on earthworms are often investigated. In this review we consider the range of earthworm species, types of soil and forms of metal for which metal uptake and accumulation have been studied, the design of these experiments and the quantitative relationships that have been derived to predict earthworm metal body burden. We conclude that there is a need for more studies on earthworm species other than Eisenia fetida in order to apply the large existing database on this earthworm to other, soil dwelling species. To aid comparisons between studies agreement is needed on standard protocols that define exposure and depuration periods and the parameters, such as soil solution composition, soil chemical and physical properties to be measured. It is recommended that more field or terrestrial model ecosystem studies using real contaminated soil rather than metal-amended artificial soils are performed. - We review species, soil and experimental designs used to study metal uptake and accumulation by earthworms and suggest priorities for further studies.

  9. Study findings on evaluation of integrated family planning programme performance.

    Science.gov (United States)

    1980-01-01

    In 1976 the United Nations's Economic and Social Commission for Asia and the Pacific launched a comparative study on integrated family planning programs in a number of countries in the region. In November 1979 the study directors from the participating countries meet in Bangkok to discuss the current status of the studies in their countries. The Korean and Malaysian studies were completed, the Bangladesh study was in the data collecting phase, and the Pakistani research design phase was completed. The meeting participants focused their attention on the findings and policy implications of the 2 completed studies and also discussed a number of theorectical and methodological issues which grew out of their research experience. The Malaysian study indicated that group structure, financial resources, and the frequency and quality of worker-client contact were the most significant variables determining program effectiveness. In the Korean Study, leadership, financial resources, and the frequency and quality of contact between agencies were the key variables in determining program effectiveness. In the Malaysian study there was a positive correlation between maternal and child health service performance measures and family planning service performance measures. This finding supported the contention that these 2 types of service provision are not in conflict with each other but instead serve to reinforce each other. Policy implications of the Korean study were 1) family planning should be an integral part of all community activities; 2) family planning workers should be adequately supported by financial and supply allocations; and 3) adequate record keeping and information exchange procedures should be incorporated in the programs.

  10. Academic performance study in young athletes from Playas de Castellón Athletics Club

    Directory of Open Access Journals (Sweden)

    Ana Capdevila Seder

    2014-03-01

    Full Text Available The study analyzed the possible relationship between academic performance of young athletes and some of the variables most used in this field. The sample consisted of 40 athletes Athletics Club Playas de Castellón, between 14 and 16 years, 22 boys and 18 girls. The main variables analyzed were academic performance, study habits, gender, sleep, sedentary leisure, socioeconomic status and dedication to sport. The instruments used were questionnaires CHTE (habits and study skills, PFYTL (physical practice and use of leisure time and the Questionnaire for parents. The results showed that academic performance was positively correlated with the dedication to sport and negatively with sleep. In addition, the female gender had a higher performance than male.

  11. Academic performance study in young athletes from Playas de Castellón Athletics Club

    Directory of Open Access Journals (Sweden)

    Ana Capdevila Seder

    2014-04-01

    Full Text Available The study analyzed the possible relationship between academic performance of young athletes and some of the variables most used in this field. The sample consisted of 40 athletes Athletics Club Playas de Castellón, between 14 and 16 years, 22 boys and 18 girls. The main variables analyzed were academic performance, study habits, gender, sleep, sedentary leisure, socioeconomic status and dedication to sport. The instruments used were questionnaires CHTE (habits and study skills, PFYTL (physical practice and use of leisure time and the Questionnaire for parents. The results showed that academic performance was positively correlated with the dedication to sport and negatively with sleep. In addition, the female gender had a higher performance than male.

  12. Dental Student Study Strategies: Are Self-Testing and Scheduling Related to Academic Performance?

    Science.gov (United States)

    McAndrew, Maureen; Morrow, Christina S; Atiyeh, Lindsey; Pierre, Gaëlle C

    2016-05-01

    Self-testing, a strategy wherein a student actively engages in creating questions and answers from study materials to assist with studying, has been found to be especially advantageous because it enhances future retrieval of information. Studies have found correlations among students' grade point averages (GPAs), self-testing, and rereading study strategies, as well as the spacing of study sessions over time. The aim of this study was to assess relationships among dental students' study strategies, scheduling of study time, and academic achievement. A 16-item survey requesting information on study habits, study schedules, and GPAs was distributed to 358 second-year dental students at New York University College of Dentistry. Additionally, the survey asked students to report the average number of hours per week they devoted to studying for didactic courses and preparing for hands-on preclinical courses. Of the 358 students, 94 (26%) responded to the survey. The vast majority of the respondents reported utilizing self-testing and rereading study strategies. High performers (with higher GPAs) were more likely to use self-testing, especially with flashcards, and to space their studying over multiple sessions. Lower performing students were more likely to highlight or underline their notes and to mass their study sessions or cram. Longer hours devoted to studying and practicing for simulation courses were associated with stronger performance; lower performers reported spending significantly fewer hours practicing for simulation courses. Half of the dental students surveyed said that they felt their studying would be more productive in the morning, although 84% reported doing most of their studying in the evening or late night. Sound study decisions depend on accurate regulation of ongoing learning and appropriate use and timing of evidence-based study strategies, so these results suggest that dental students may require guidance in these areas.

  13. Development of a polymeric matrix for composite material produced by the filament winding technique; Desenvolvimento de matriz polimerica visando a producao de material composito atraves da tecnica de enrolamento filamentar

    Energy Technology Data Exchange (ETDEWEB)

    Sobrinho, Ledjane Lima; Ferreira, Marisilvia; Bastian, Fernando Luiz [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    2005-07-01

    The study of the resin for composite materials to be produced by the filament winding technique is very important, since the good applicability of the technique is in part function of the characteristics of the resin. The objective of this work is the development of a polymeric matrix using vinyl ester resin for composite to be produced by the filament winding technique. Therefore, vinyl ester resin systems developed from Derakane 411-350 by varying the percentage of cure agent and activator. The system which presented the best behavior in tension (Yong's modulus 2,42 GPa, tensile strength = 47,67 MPa, elongation = 7,31 % and fracture toughness 2,67 J), adequate gel time and exothermic peak for the manufacture process was submitted to hygrothermal aging by immersion in water at 60 deg C for a maximum period of 64 days. (author)

  14. An analytical and experimental study of performance on jatropha biodiesel engine

    Directory of Open Access Journals (Sweden)

    Ganapathy Thirunavukkarasu

    2009-01-01

    Full Text Available Biodiesel plays a major role as one of the alternative fuel options in direct injection diesel engines for more than a decade. Though many feed stocks are employed for making biodiesel worldwide, biodiesel derived from domestically available non-edible feed stocks such as Jatropha curcas L. is the most promising alternative engine fuel option especially in developing countries. Since experimental analysis of the engine is pricey as well as more time consuming and laborious, a theoretical thermodynamic model is necessary to analyze the performance characteristics of jatropha biodiesel fueled diesel engine. There were many experimental studies of jatropha biodiesel fueled diesel engine reported in the literature, yet theoretical study of this biodiesel run diesel engine is scarce. This work presents a theoretical thermodynamic study of single cylinder four stroke direct injection diesel engine fueled with biodiesel derived from jatropha oil. The two zone thermodynamic model developed in the present study computes the in-cylinder pressure and temperature histories in addition to various performance parameters. The results of the model are validated with experimental values for a reasonable agreement. The variation of cylinder pressure with crank angle for various models are also compared and presented. The effects of injection timing, relative air fuel ratio and compression ratio on the engine performance characteristics for diesel and jatropha biodiesel fuels are then investigated and presented in the paper.

  15. The causal relation between commitment and performance: a study in research centers

    International Nuclear Information System (INIS)

    Tejos-Saldivia, Miguel Enrique

    2006-01-01

    In this work relation among leadership, motivation, organizational climate, teamwork, and the organizational and occupational commitment, were studied. The exploratory study was accomplished in three parts. In the first it was identified the more important performance factors in a larger relation resultant of the bibliographical research and in the second, it was undertaken a quantification the 4 performance factors together to the organizational and occupational commitments. In the first part, it was accomplished an exploratory research close to some experienced servants, with emphasis in the management area. In the second part it was interviewed 52 employees of the CCTM's at the Energy and Nuclear Research Institute - IPEN and 252 employees of the IAE at the Aerospace Technical Center - CTA. This research used 18 indicators of the organizational commitment and 18 indicators of the occupational commitment, all extracted from the instrument of Meyer, Allen and Smith. Beyond of these, it was used 7 demographic variables and 71 performance variables built from the theoretical revision. The results obtained with the exploratory research of the first part identified the 4 factors aforementioned performance factors. In the second part the obtained results in the two firsts places proved the hypothesis that the servants' locations or groups that show a higher degree of commitment tend to a higher degree of performance. In the third part of this study it was used the Structural Equations Modelling - SEM, from one theoretic model defined with the 12 more important variables from performance in both researched locals and with assistance of two statistical software SPSS and LISREL it was obtained a model of causal relations more strengthened to explain the relationship among the used variables. (author)

  16. A Study on Performance Requirements for Advanced Alarm System

    International Nuclear Information System (INIS)

    Seong, Duk Hyun; Jeong, Jae Hoon; Sim, Young Rok; Ko, Jong Hyun; Kim, Jung Seon; Jang, Gwi Sook; Park, Geun Ok

    2005-01-01

    A design goals of advanced alarm system is providing advanced alarm information to operator in main control room. To achive this, we applied computer based system to Alarm System. Because, It should apply data management and advanced alarm processing(ie. Data Base Mangegment System and S/W module for alarm processing). These are not impossible in analog based alarm system. And, preexitance research examples are made on digital computer. We have digital systems for test of advanced alarm system table and have tested and studied using by test equipment in the view point of the system performance, stability and security. In this paper, we discribed about general software architecture of preexitance research examples. Also, CPU performance and requirements of system software that served to accommodate it, stability and security

  17. The Halden Reactor Project Workshop on Studies of Operator Performance During Night Shift's

    International Nuclear Information System (INIS)

    Morisseau, Dolores S.; Braarud, Per Oeyvind; Collier, Steve; Droeivoldsmo, Asgeir; Larsen, Marit; Lirvall, Peter

    1996-01-01

    A workshop on Studies of Operator Performance during Nights Shifts was organised in Halden, February 27-28, 1996. The purpose of the workshop was to discuss and make recommendations on specific needs for the study of operator cognitive performance at night and identify the relevant research issues for which Halden could provide resolution. The workshop began with presentations by several invited speakers with expertise in studies of shift work and was then divided into three working groups that discussed the following issues in parallel: (1) Lines of Research to Be Pursued; (2) Methods and Measures to Be Used in Research on Cognitive Performance at Nights; and (3) Products of the Research on Operator Performance at Night. Each group produced specific recommendations that were summarised by the group's facilitator in a joint session of the workshop. This report summarises the presentation of the invited speakers, and the discussions and recommendations of the individual working groups. (author)

  18. Low Cost High Performance Generator Technology Program. Volume 2. Design study

    International Nuclear Information System (INIS)

    1975-06-01

    The systems studies directed towards up-rating the performance of an RTG using selenide thermoelectrics and a heat source with improved safety are reported. The resulting generator design, designated LCHPG, exhibits conversion efficiency of greater than 10 percent, a specific power of 3 W/lb., and a cost of $6,000/W(e). In the course of system analyses, the significant development activities required to achieve this performance by the 1980 time period are identified

  19. Financial performance after the Spanish banking reforms: A comparative study of 19 commercial banks

    Directory of Open Access Journals (Sweden)

    Pison F. Irene

    2014-06-01

    Full Text Available A diagnostic review of the Spanish financial system during the 2008 financial crisis reveals the emergency need for banking reform in the sector. In an attempt to evaluate the impact of the Spanish reform, the present study examines the bank´s performance before/after the reform was adopted, using data of 19 Spanish commercial banks extracted from the Global Vantage research database (Standard and Poor’s over the period 2006 to 2013. This study uses multivariable regression method to investigate the impact of the CAMELS rating system: capital adequacy, asset quality, management quality, liquidity and sensitivity to market risks on the bank´s performance such as earnings efficiency. The time-line of the study is essential because it helps us to determine the financial performance of Spanish commercial banks before the banking reforms during the financial crisis and an important set in terms of mergers and acquisition in the banking industry. The empirical results have found strong and positive evidence that Capital Adequacy, Management Capacity, Liquidity and Sensitivity to Market Risk are useful predictors of banks performance (earnings efficiency, thus, any reform pilot toward this banking indicators will eventually have a positive impact on banking performance. Base on the present study, the Spanish reform was so vital for better banking performance. Therefore, this study serves not only to academics but also to policy makers

  20. A Study of relationship between frailty and physical performance in elderly women

    OpenAIRE

    Jeoung, Bog Ja; Lee, Yang Chool

    2015-01-01

    Frailty is a disorder of multiple inter-related physiological systems. It is unclear whether the level of physical performance factors can serve as markers of frailty and a sign. The purpose of this study was to examine the relationship between frailty and physical performance in elderly women. One hundred fourteen elderly women participated in this study, their aged was from 65 to 80. We were measured 6-min walk test, grip-strength, 30-sec arm curl test, 30-sec chair stand test, 8 foot Up- a...

  1. Performance study of the paints for use in nuclear installations

    International Nuclear Information System (INIS)

    Yamashita, T.

    1978-01-01

    The performance of some Brazilian commercial paints under physical, chemical and radiation conditions typical of nuclear installations is studied. Resistance to gama rays in the range of 10 4 - 10 9 rad as well as the susceptibility to contamination, ease of decontamination and chemical resistance in 9 different types of paints are studied. Finally, suggestions are provided for the best choice of commercial paints according to their specific uses [pt

  2. Performance study of a GEM-TPC prototype using cosmic rays

    International Nuclear Information System (INIS)

    Li Yulan; Qi Huirong; Li Jin; Gao Yuanning; Li Yuanjing; Yang Zhenwei; Fujii, Keisuke; Matsuda, Takeshi

    2008-01-01

    Time projection chambers (TPCs) have been successfully used as the central tracking devices in a number of high-energy physics experiments. However, the performance requirements on TPCs for future high-energy physics experiments greatly exceed the abilities of traditional TPCs read out by multi-wire proportional chambers (MWPCs). Micro-pattern gas detectors (MPGDs), such as gas electron multipliers (GEMs) or micromegas, have great potential to improve TPC performance when used as readout detectors. In order to evaluate its feasibility, a GEM-based TPC prototype with a drift length up to 50 cm was designed. Measurements of the spatial resolution of cosmic-ray tracks without and with a magnetic field (B=1 T) are presented. A very good performance is achieved, matching the analytic formula for the spatial resolution of a MPGD-readout TPC. A dedicated study shows that the increase of GEM detector gain can improve the TPC's spatial resolution.

  3. Using physical models to study the gliding performance of extinct animals.

    Science.gov (United States)

    Koehl, M A R; Evangelista, Dennis; Yang, Karen

    2011-12-01

    Aerodynamic studies using physical models of fossil organisms can provide quantitative information about how performance of defined activities, such as gliding, depends on specific morphological features. Such analyses allow us to rule out hypotheses about the function of extinct organisms that are not physically plausible and to determine if and how specific morphological features and postures affect performance. The purpose of this article is to provide a practical guide for the design of dynamically scaled physical models to study the gliding of extinct animals using examples from our research on the theropod dinosaur, †Microraptor gui, which had flight feathers on its hind limbs as well as on its forelimbs. Analysis of the aerodynamics of †M. gui can shed light on the design of gliders with large surfaces posterior to the center of mass and provide functional information to evolutionary biologists trying to unravel the origins of flight in the dinosaurian ancestors and sister groups to birds. Measurements of lift, drag, side force, and moments in pitch, roll, and yaw on models in a wind tunnel can be used to calculate indices of gliding and parachuting performance, aerodynamic static stability, and control effectiveness in maneuvering. These indices permit the aerodynamic performance of bodies of different shape, size, stiffness, texture, and posture to be compared and thus can provide insights about the design of gliders, both biological and man-made. Our measurements of maximum lift-to-drag ratios of 2.5-3.1 for physical models of †M. gui suggest that its gliding performance was similar to that of flying squirrels and that the various leg postures that might have been used by †M. gui make little difference to that aspect of aerodynamic performance. We found that body orientation relative to the movement of air past the animal determines whether it is difficult or easy to maneuver.

  4. NEWLY-PACKAGED BALI TOURIST PERFORMING ARTS IN THE PERSPECTIVE OF CULTURAL STUDIES

    Directory of Open Access Journals (Sweden)

    Ni Made Ruastiti

    2012-11-01

    Full Text Available This research is focused on the newly packaged tourist performing arts; they are anew concept and seem to be different from the general tourist performing arts. They arepackaged from various components of Balinese arts and managed as large scale-touristperforming arts in terms of materials, space, and time of their performances. The researchercalls them new types of Bali tourist performing arts because how they are presented isnew and different from the traditional tourist performing arts which are simply performed.In this research, the newly-packaged performing arts are analyzed in the perspective ofcultural studies.The research was carried out at three palaces in Bali; they are Mengwi Palace inBadung regency, Anyar Palace at Kerambitan, Tabanan regency, and Banyuning Palace atBongkasa, Badung regency. There are three main problems to be discussed: firstly, how dothe tourist performing arts emerge in all the palaces? Secondly, are they related to thetourist industry developed in the palaces?, thirdly, what is the impact and meaning of themfor the sake of the palaces, society, and Balinese culture? The researcher uses a qualitativemethod and an interdisciplinary approach as characteristics of cultural studies. The theoriesused are hegemony, deconstruction, and structuration.The result shows that the tourism development at all the palaces has made the localsociety become more critical. The money-oriented economy based on the spirit of gettingbenefit has made the emergence of comodification in all sectors of life. The emergence oftourist industry at the palaces has led to the idea of showing all of the useful art and culturalpotentials which at the palaces and their surroundings. Theoretically, the palaces can bestated to have deconstructed the concept of presenting the Bali tourist performing arts into anew one, that is, “the newly packaged Bali tourist performing arts”.It has been observed that all the palaces have developed t

  5. A systematic literature search to identify performance measure outcomes used in clinical studies of racehorses.

    Science.gov (United States)

    Wylie, C E; Newton, J R

    2018-05-01

    Racing performance is often used as a measurable outcome variable in research studies investigating clinical diagnoses or interventions. However, the use of many different performance measures largely precludes conduct of meaningful comparative studies and, to date, those being used have not been collated. To systematically review the veterinary scientific literature for the use of racing performance as a measurable outcome variable in clinical studies of racehorses, collate and identify those most popular, and identify their advantages and disadvantages. Systematic literature search. The search criteria "((racing AND performance) AND (horses OR equidae))" were adapted for both MEDLINE and CAB Abstracts databases. Data were collected in standardised recording forms for binary, categorical and quantitative measures, and the use of performance indices. In total, 217 studies that described racing performance were identified, contributing 117 different performance measures. No one performance measure was used in all studies, despite 90.3% using more than one variable. Data regarding race starts and earnings were used most commonly, with 88.0% and 54.4% of studies including at least one measure of starts and earnings, respectively. Seventeen variables were used 10 times or more, with the top five comprising: 'return to racing', 'number of starts', 'days to first start', 'earnings per period of time' and 'earnings per start'. The search strategies may not have identified all relevant papers, introducing bias to the review. Performance indices have been developed to improve assessment of interventions; however, they are not widely adopted in the scientific literature. Use of the two most commonly identified measures, whether the horse returned to racing and number of starts over a defined period of time, would best facilitate future systematic reviews and meta-analyses in advance of the development of a gold-standard measure of race performance outcome. © 2017 EVJ Ltd.

  6. Cooperation, Technology, and Performance: A Case Study.

    Science.gov (United States)

    Cavanagh, Thomas; Dickenson, Sabrina; Brandt, Suzanne

    1999-01-01

    Describes the CTP (Cooperation, Technology, and Performance) model and explains how it is used by the Department of Veterans Affairs-Veteran's Benefit Administration (VBA) for training. Discusses task analysis; computer-based training; cooperative-based learning environments; technology-based learning; performance-assessment methods; courseware…

  7. Study of performance scaling of 22-nm epitaxial delta-doped channel MOS transistor

    Science.gov (United States)

    Sengupta, Sarmista; Pandit, Soumya

    2015-06-01

    Epitaxial delta-doped channel (EδDC) profile is a promising approach for extending the scalability of bulk metal oxide semiconductor (MOS) technology for low-power system-on-chip applications. A comparative study between EδDC bulk MOS transistor with gate length Lg = 22 nm and a conventional uniformly doped channel (UDC) bulk MOS transistor, with respect to various digital and analogue performances, is presented. The study has been performed using Silvaco technology computer-aided design device simulator, calibrated with experimental results. This study reveals that at smaller gate length, EδDC transistor outperforms the UDC transistor with respect to various studied performances. The reduced contribution of the lateral electric field in the channel plays the key role in this regard. Further, the carrier mobility in EδDC transistor is higher compared to UDC transistor. For moderate gate and drain bias, the impact ionisation rate of the carriers for EδDC MOS transistor is lower than that of the UDC transistor. In addition, at 22 nm, the performances of a EδDC transistor are competitive to that of an ultra-thin body silicon-on-insulator transistor.

  8. Intellectual capital and financial performance: A study of the Turkish Banking Sector

    Directory of Open Access Journals (Sweden)

    Nasif Ozkan

    2017-09-01

    Full Text Available The purpose of this study is to analyze the relationship between the intellectual capital performance and financial performance of 44 banks operating in Turkey between 2005 and 2014. The intellectual capital performance of banks is measured through the value added intellectual coefficient (VAIC methodology. The intellectual capital performance of the Turkish banking sector is generally affected by human capital efficiency (HCE. In terms of bank types, development and investment banks have the highest average VAIC. When VAIC is divided into its components, it can be observed that capital employed efficiency (CEE and human capital efficiency (HCE positively affect the financial performance of banks. However, CEE has more influence on the financial performance of banks compared to HCE. Therefore, banks operating in the Turkish banking sector should use their financial and physical capitals if they wish to reach a higher profitability level.

  9. Hygrothermal effects on the tensile strength of carbon/epoxy laminates with molded edges

    Directory of Open Access Journals (Sweden)

    Cândido Geraldo Maurício

    2000-01-01

    Full Text Available The interlaminar stresses are confined to a region near the free edge. Therefore, the laminate stacking sequence and the free edge finishing are some of the factors that affect the strength of the laminate and limit its life. The use of molded edges eliminates the need for trimming and machining the laminates edges thus improving productivity. However, this fabrication technique may have a detrimental effect on the laminate strength for certain stacking sequences. This effect in the presence of moisture has not been characterized. This work presents the results of a comparative study of the resistance to delamination of laminates with machined edges and molded edges. Additionally, two environmental conditions were considered: dry laminates and laminates saturated with moisture. The tensile strength of the laminates were measured and micrographs were used to analyze the microstructure of the laminates near the free edges. It is concluded that the mechanical properties of advanced composites depend on the environmental conditions and the fabrication techniques used to produce the laminates. Therefore, it is necessary to account for these factors when experimentally determining the design allowables.

  10. Study on behaviors and performances of universal N-glycopeptide enrichment methods.

    Science.gov (United States)

    Xue, Yu; Xie, Juanjuan; Fang, Pan; Yao, Jun; Yan, Guoquan; Shen, Huali; Yang, Pengyuan

    2018-04-16

    Glycosylation is a crucial process in protein biosynthesis. However, the analysis of glycopeptides through MS remains challenging due to the microheterogeneity and macroheterogeneity of the glycoprotein. Selective enrichment of glycopeptides from complex samples prior to MS analysis is essential for successful glycoproteome research. In this work, we systematically investigated the behaviors and performances of boronic acid chemistry, ZIC-HILIC, and PGC of glycopeptide enrichment to promote understanding of these methods. We also optimized boronic acid chemistry and ZIC-HILIC enrichment methods and applied them to enrich glycopeptides from mouse liver. The intact N-glycopeptides were interpreted using the in-house analysis software pGlyco 2.0. We found that boronic acid chemistry in this study preferred to capture glycopeptides with high mannose glycans, ZIC-HILIC enriched most N-glycopeptides and did not show significant preference during enrichment and PGC was not suitable for separating glycopeptides with a long amino acid sequence. We performed a detailed study on the behaviors and performances of boronic acid chemistry, ZIC-HILIC, and PGC enrichment methods and provide a better understanding of enrichment methods for further glycoproteomics research.

  11. Performance studies of the parallel VIM code

    International Nuclear Information System (INIS)

    Shi, B.; Blomquist, R.N.

    1996-01-01

    In this paper, the authors evaluate the performance of the parallel version of the VIM Monte Carlo code on the IBM SPx at the High Performance Computing Research Facility at ANL. Three test problems with contrasting computational characteristics were used to assess effects in performance. A statistical method for estimating the inefficiencies due to load imbalance and communication is also introduced. VIM is a large scale continuous energy Monte Carlo radiation transport program and was parallelized using history partitioning, the master/worker approach, and p4 message passing library. Dynamic load balancing is accomplished when the master processor assigns chunks of histories to workers that have completed a previously assigned task, accommodating variations in the lengths of histories, processor speeds, and worker loads. At the end of each batch (generation), the fission sites and tallies are sent from each worker to the master process, contributing to the parallel inefficiency. All communications are between master and workers, and are serial. The SPx is a scalable 128-node parallel supercomputer with high-performance Omega switches of 63 microsec latency and 35 MBytes/sec bandwidth. For uniform and reproducible performance, they used only the 120 identical regular processors (IBM RS/6000) and excluded the remaining eight planet nodes, which may be loaded by other's jobs

  12. An investigation on how TQM influences employee performance: A case study of banking industry

    Directory of Open Access Journals (Sweden)

    Saeed Hakami Nasab

    2014-01-01

    Full Text Available This paper presents an empirical investigation to study the relationship between employee performance and TQM. The proposed study of this paper designs two questionnaires for TQM and performance measurement and distributes them among some employees who worked for one of Iranian banks in city of Semnan, Iran. The result of Kolmogorov–Smirnov test confirms that all data are normally distributed and the study uses Pearson correlation to investigate the relationship between various components of the survey. The result of the implementation of Pearson correlation ratio indicates that there was a positive and meaningful relationship between employee performance and TQM components (r=4.6223, P-value=0.000. In addition, there are some positive and meaningful relationships between TQM components and employee performance. The highest correlation belongs to relationship between employee performance and feedback (r=4.6223, P-value=0.000 followed by training and development (r = 0.441, P-value = 0.000 and communication (r = 4.2861, P-value = 0.000.

  13. In-situ membrane hydration measurement of proton exchange membrane fuel cells

    Science.gov (United States)

    Lai, Yeh-Hung; Fly, Gerald W.; Clapham, Shawn

    2015-01-01

    Achieving proper membrane hydration control is one of the most critical aspects of PEM fuel cell development. This article describes the development and application of a novel 50 cm2 fuel cell device to study the in-situ membrane hydration by measuring the through-thickness membrane swelling via an array of linear variable differential transducers. Using this setup either as an air/air (dummy) cell or as a hydrogen/air (operating) cell, we performed a series of hydration and dehydration experiments by cycling the RH of the inlet gas streams at 80 °C. From the linear relationship between the under-the-land swelling and the over-the-channel water content, the mechanical constraint within the fuel cell assembly can suppress the membrane water uptake by 11%-18%. The results from the air/air humidity cycling test show that the membrane can equilibrate within 120 s for all RH conditions and that membrane can reach full hydration at a RH higher than 140% in spite of the use of a liquid water impermeable Carbel MP30Z microporous layer. This result confirms that the U.S. DOE's humidity cycling mechanical durability protocol induces sufficient humidity swings to maximize hygrothermal mechanical stresses. This study shows that the novel experimental technique can provide a robust and accurate means to study the in-situ hydration of thin membranes subject to a wide range of fuel cell conditions.

  14. Interlaboratory analytical performance studies; a way to estimate measurement uncertainty

    Directory of Open Access Journals (Sweden)

    El¿bieta £ysiak-Pastuszak

    2004-09-01

    Full Text Available Comparability of data collected within collaborative programmes became the key challenge of analytical chemistry in the 1990s, including monitoring of the marine environment. To obtain relevant and reliable data, the analytical process has to proceed under a well-established Quality Assurance (QA system with external analytical proficiency tests as an inherent component. A programme called Quality Assurance in Marine Monitoring in Europe (QUASIMEME was established in 1993 and evolved over the years as the major provider of QA proficiency tests for nutrients, trace metals and chlorinated organic compounds in marine environment studies. The article presents an evaluation of results obtained in QUASIMEME Laboratory Performance Studies by the monitoring laboratory of the Institute of Meteorology and Water Management (Gdynia, Poland in exercises on nutrient determination in seawater. The measurement uncertainty estimated from routine internal quality control measurements and from results of analytical performance exercises is also presented in the paper.

  15. Considering the use of polyethylene vapour barriers in temperate climates

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, M.D. [Morrison Hershfield Ltd., Vancouver, BC (Canada); Brown, W.C. [Morrison Hershfield Ltd., Ottawa, ON (Canada)

    2003-07-01

    Most building envelope assemblies in Canada must include a vapour barrier in order to comply with Canadian building codes. The installation of sheet polyethylene between the studs and the interior sheathing has been the most common method because it provides more diffusion resistance than necessary to control condensation within a building envelope assembly. It has been suggested that the presence of a polyethylene vapour barrier on the warm-in-winter side of the insulation may actually cause moisture problems because a very low permeance material increases average moisture levels. This paper examined the theory that a vapour barrier at this location restricts drying of moisture that enters the building from outside. Pacific coastal regions of Canada and the United States were presented as examples. Other ways that a polyethylene vapour barrier affects wall performance were also presented. The advanced hygrothermal model HygIRC, developed by Canada's National Research Council, was used to simulate the performance of a wall assembly. Results indicate that eliminating the low permeance polyethylene vapour barrier does not necessarily reduce the risk of moisture problems. Removal of the vapour barrier may have some negative effects, such as increased risk of periodic moisture accumulation and mold growth on paper-faced gypsum board. 7 refs., 2 tabs., 7 figs.

  16. Project Overcoat - An Exploration of Exterior Insulation Strategies for 1-1/2-Story Roof Applications in Cold Climates

    Energy Technology Data Exchange (ETDEWEB)

    Ojczyk, Cindy [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Mosiman, Garrett [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Huelman, Pat [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Schirber, Tom [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Yost, Peter [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Murry, Tessa [NorthernSTAR Building America Partnership, St. Paul, MN (United States)

    2013-04-01

    The development of an alternative method to interior-applied insulation strategies or exterior applied 'band-aids' such as heat tapes and ice belts may help reduce energy needs of millions of 1-1/2 story homes while reducing the risk of ice dam formation. A potential strategy for energy improvement of the roof is borrowed from new construction best practices: Here an 'overcoat' of a continuous air, moisture, and thermal barrier is applied on the outside of the roof structure for improved overall performance. The continuous insulation of this approach facilitates a reduction in thermal bridging which could further reduce energy consumption and bring existing homes closer to meeting the Building America goals for energy reduction. Research favors an exterior approach to deep energy retrofits and ice dam prevention in existing homes. The greatest amount of research focuses on whole house deep energy retrofits leaving a void in roof-only applications. The research is also void of data supporting the hygrothermal performance, durability, constructability, and cost of roof-only exterior overcoat strategies. Yet, contractors interviewed for this report indicate an understanding that exterior approaches are most promising for mitigating ice dams and energy loss and are able to sell these strategies to homeowners.

  17. STUDY OF THE METHODICAL ASPECTS OF THE PERFORMANCE BODYBUILDING PRECOMPETITIVE TRAINING

    Directory of Open Access Journals (Sweden)

    Potop Vladimir

    2009-12-01

    Full Text Available The goal of the work is to deal with the contents of the pre-competitive training in the performance classic bodybuilding. With this aim in view we have considered that the utilization of a correct training methodology during the pre-competitive stage will result in the loss of weight and will bring into reliefthe muscular groups in the performance classic bodybuilding.These problems determined us to organize a study of case within the School Sport Club (C.S.S. no.5 of Bucharest, MATRIX gym, having as subject the sportsman C.M, aged 26, with a bodybuilding experience of 10 years, double national champion at classic bodybuilding, 180 cm class.The results of the study emphasize a lowering and a decrease of the perimeters from one test to another, in parallel with the decrease of the pectoral musculature and lower limbs strength; in exchange, the strength of the back increases significantly.These results prove that the body was in a perfect pre-competitive training condition and that the utilization of the proposed methodology helped to loosing weight, maintaining and bringing the muscular groups into relief.We mention that this proposed methodology is recommended only to the performers who have the possibility to transform the bodybuilding into “a life style”, to devote all their energy and time to theachievement of the high performance during long periods of life.

  18. The mechanical and hygrothermal behavior of composite piping: Notes on the methodology of dimensioning and structural design

    International Nuclear Information System (INIS)

    Perreux, D.; Varchon, D.; Lebras, J.

    1995-01-01

    The production of electricity in power plants is directly linked to the duration and frequency of partial shutdowns. In order to be free of the problems of corrosion of the secondary metallic circuit which lead to lengthy shutdowns, Electricite de France (EDF) decided to substitute these circuits with those made from composite materials. In this paper the criteria of damage beginning for laminate pipes is discussed. The material is a glass-epoxy laminate manufactured by a winding filament process and is used for water pipelining. First of all a description of the damage is performed in order to define a damage variable. Thanks to the elastic energy an associated variable is defined. The damage criteria is written by using this last one. The parameter of the criteria is identified by mechanical and acoustical methods. The result is compared and exhibits good agreement

  19. Employee Job Satisfaction and Job Performance: A Case Study in a Franchised Retail-Chain Organization

    OpenAIRE

    Wong Yvonne; Rabeatul Husna Abdull Rahman; Choi Sang Long

    2014-01-01

    This study examines the relationship between job satisfaction and job performance among the employees. Job satisfaction is being discussed in term of its nine facets: pay, promotion, supervision, fringe benefits, contingent rewards, operating procedures, co-workers, nature of works and communication. On the other hand, job performance is being viewed in the aspects of contextual performance and task performance. The result of the study found that the two variables (job satisfaction and job pe...

  20. The Campaign: a case study in identity construction through performance

    Directory of Open Access Journals (Sweden)

    Matthew D. Riddle

    2009-12-01

    Full Text Available This article undertakes a detailed case study of The Campaign, a teaching and learning innovation in media and communications that uses an online educational role-play. The case study draws on the qualitative analysis of classroom observations, online communications and semi-structured interviews, employing an interpretive approach informed by models drawn from social theory and sociotechnical theory. Educational authors argue that online educational role-plays engage students in authentic learning, and represent an improvement over didactic teaching strategies. According to this literature, online role-play systems afford students the opportunity of acting and doing instead of only reading and listening. Literature in social theory and social studies of technology takes a different view of certain concepts such as performance, identity and reality. Models such as performative self constitution and actor network theory ask us to consider the constructed nature of identity and the roles of all of the actors, including the system itself. This article examines these concepts by addressing a series of research questions relating to identity formation and mediation, and suggests certain limitations of the situationist perspective in explaining the educational value of role-play systems.

  1. Do firm characteristics influence mutual fund performance? An empirical study for European mutual funds

    NARCIS (Netherlands)

    de Jong, F.C.J.M.; Wingens, L.

    2013-01-01

    This study investigates the influence of fund management firm characteristics on mutual fund performance. Using a sample of European domiciled open-end equity funds for the period 1998-2008, this study finds that the funds of private companies have performed better than the funds of public

  2. Overweight and school performance among primary school children: the PIAMA birth cohort study.

    Science.gov (United States)

    Veldwijk, Jorien; Fries, Marieke C E; Bemelmans, Wanda J E; Haveman-Nies, Annemien; Smit, Henriëtte A; Koppelman, Gerard H; Wijga, Alet H

    2012-03-01

    The aim of this study was to assess the association between overweight and school performance among primary school children prospectively and including a broad range of potential confounding factors. In addition it was investigated what factors mediate this association. For this purpose, data of 2,159 12-year-old children who participated in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study were used. Two indicators of school performance were parental reported when children were 12 years of age and included (i): the score on a standardized achievement test that Dutch children have to complete at the end of their primary education (Cito)-test and (ii): the teacher's advice regarding a child's potential performance level in secondary education. Children's height and weight were measured by a trained research assistant at the age of 8 and by their parents at the age of 12. Overweight was defined using age and gender specific cut-off points. Multivariate regression analyses were performed to assess the association between overweight and school performance. Besides, both confounder and mediation analyses were conducted. Results showed lower Cito-test scores and lower teacher's school-level advice among overweight children. These associations were no longer significant when adjusting for parental educational level, skipping breakfast, and screen time. This study found no independent association between overweight and school performance among primary school children. Results showed strong confounding by parental educational level.

  3. The evolution of CMS software performance studies

    CERN Document Server

    Kortelainen, Matti J

    2010-01-01

    CMS has had an ongoing and dedicated effort to optimize software performance for several years. Initially this effort focused primarily on the cleanup of many issues coming from basic C++ errors, namely reducing dynamic memory churn, unnecessary copies/temporaries and tools to routinely monitor these things. Over the past 1.5 years, however, the transition to 64bit, newer versions of the gcc compiler, newer tools and the enabling of techniques like vectorization have made possible more sophisticated improvements to the software performance. This presentation will cover this evolution and describe the current avenues being pursued for software performance, as well as the corresponding gains.

  4. The evolution of CMS software performance studies

    Science.gov (United States)

    Kortelainen, M. J.; Elmer, P.; Eulisse, G.; Innocente, V.; Jones, C. D.; Tuura, L.

    2011-12-01

    CMS has had an ongoing and dedicated effort to optimize software performance for several years. Initially this effort focused primarily on the cleanup of many issues coming from basic C++ errors, namely reducing dynamic memory churn, unnecessary copies/temporaries and tools to routinely monitor these things. Over the past 1.5 years, however, the transition to 64bit, newer versions of the gcc compiler, newer tools and the enabling of techniques like vectorization have made possible more sophisticated improvements to the software performance. This presentation will cover this evolution and describe the current avenues being pursued for software performance, as well as the corresponding gains.

  5. What effects do student jobs have on the study performance ...

    African Journals Online (AJOL)

    This research examines the effects student jobs have on the study performance, and the competency and career development of hospitality management students. A 13-item survey was administered to a sample of 82 hospitality management students to see how they think about their student job. Qualitative data was ...

  6. Organisational performance and business continuity management: a theoretical perspective and a case study.

    Science.gov (United States)

    Sawalha, Ihab Hanna Salman

    2013-01-01

    This paper seeks to extend the research relating to the strategic view of business continuity management (BCM) to the context of organisational performance (OP). It discusses potential performance consequences resulting from applying BCM aspects/elements within an organisation. The paper contributes to the understanding of the role of BCM in OP by discussing how deployment of BCM key aspects/elements can improve OP. Two main issues are discussed: first, background to performance and the elements of OP; and secondly, the role of BCM in achieving optimised OP. These issues are significant, as they go further than the extant literature relating to the significance of BCM and its potential influence on OP. The study focuses on Jordanian banks as a case study and as a way of illustrating how BCM helps improve OP for those organisations facing performance shortcomings or difficulties.

  7. Systems study on engineered barriers: barrier performance analysis

    International Nuclear Information System (INIS)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed

  8. Systems study on engineered barriers: barrier performance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed.

  9. A Study on the Relationship between Human Resource Management Practices and Organizational Performance

    OpenAIRE

    Özden AKIN; Hayat Ebru ERDOST ÇOLAK

    2012-01-01

    The main goal of this study is to investigate the relationship between organizational performance variables and Human Resource Management practices. Workforce planning, training and development, performance appraisal, rewarding, firm-employee relationship, and internal communication are used as human resource management practices. Employee turnover rate, employee productivity, and sales are used as organizational performance variables. The results are collected by survey from 108 companies wh...

  10. Need Satisfaction at Work, Job Strain, and Performance: A Diary Study.

    Science.gov (United States)

    De Gieter, Sara; Hofmans, Joeri; Bakker, Arnold B

    2017-08-24

    We performed a daily diary study to examine the mediating role of autonomy need satisfaction and competence need satisfaction in the relationships between job characteristics (i.e., job resources, challenge and hindrance demands) and strain and performance. For 10 consecutive working days, 194 employees reported on their daily job resources, challenge and hindrance demands, task performance, strain level, and satisfaction of the needs for competence and autonomy. Multilevel path modeling demonstrated that the within-person relationships between job resources, challenge and hindrance demands, and strain are mediated by autonomy need satisfaction, but not by competence need satisfaction. However, the relationships between job resources and hindrance demands, and performance are mediated by both competence and autonomy need satisfaction. Our findings show that organizations may benefit from designing jobs that provide employees with the opportunity to satisfy their basic needs for competence and autonomy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Experimental study for flow characteristics and performance evaluation of butterfly valves

    International Nuclear Information System (INIS)

    Kim, C K; Shin, M S; Yoon, J Y

    2010-01-01

    The industrial butterfly valves have been applied to transport a large of fluid with various fields of industry. Also, these are mainly used a control of fluid flux to the water and waste-water pipeline. Present, butterfly valves are manufacturing for multiplicity shape of bodies and discs with many producers. However, appropriate performance evaluation was not yet accomplished to compare about these valves through experiments. This study is performed the experiment of flow characteristics and performance of manufactured 400A butterfly valves for the water and waste pipeline, and compared experimental results. We performed experiments that were controlled fixed a differential pressure condition (1 psi) and the range of the flow rate conditions (500 m 3 /hr ∼ 2500 m 3 /hr), and also opened the disc of valves to a range of angle from 9 degree to 90 degree. We investigated and compared the valve flow coefficient and the valve loss coefficient of results through experiments with each butterfly valve.

  12. Designing a performance measurement system: A case study

    NARCIS (Netherlands)

    Lohman, Clemens; Fortuin, Leonard; Wouters, Marc

    2004-01-01

    Performance measurement (PM) by means of local performance indicators (PIs) is developing into performance management at a company-wide scale. But how should PIs at various levels in the organization be incorporated into one system that can help managers, working at levels that range from

  13. Designing a performance measurement system : a case study

    NARCIS (Netherlands)

    Lohman, C.T.M.; Fortuin, L.; Wouters, M.J.F.

    2004-01-01

    Performance measurement (PM) by means of local performance indicators (PIs) is developing into performance management at a company-wide scale. But how should PIs at various levels in the organization be incorporated into one system that can help managers, working at levels that range from

  14. Recent studies of tire braking performance. [for aircraft

    Science.gov (United States)

    Mccarty, J. L.; Leland, T. J. W.

    1973-01-01

    The results from recent studies of some factors affecting tire braking and cornering performance are presented together with a discussion of the possible application of these results to the design of aircraft braking systems. The first part of the paper is concerned with steady-state braking, that is, results from tests conducted at a constant slip ratio or steering angle or both. The second part deals with cyclic braking tests, both single cycle, where brakes are applied at a constant rate until wheel lockup is achieved, and rapid cycling of the brakes under control of a currently operational antiskid system.

  15. Ultrasonic inspection of composite hydrogen reservoirs using frequency diversity techniques

    International Nuclear Information System (INIS)

    Zellouf, D.; Goyette, J.; Massicotte, D.; Bose, T.K.

    2000-01-01

    During their service, cryogenic tanks are subjected to both hydrostatic and hygrothermic stresses. This can have as a consequence the initiation of the propagation of cracks within the structure of the material. Nevertheless, the analysis of ultrasonic signals collected during the inspection of composite materials must be dealt with carefully because of the presence of a strong background noise due to the reinforcement. This background noise results mostly from the interferences between the waves diffracted on the reinforcement. The target echo and the noise in which it is embedded both have the same frequency bandwidth. Thus we cannot use conventional linear filters to improve the signal-to-noise ratio

  16. Case study teaching method improves student performance and perceptions of learning gains.

    Science.gov (United States)

    Bonney, Kevin M

    2015-05-01

    Following years of widespread use in business and medical education, the case study teaching method is becoming an increasingly common teaching strategy in science education. However, the current body of research provides limited evidence that the use of published case studies effectively promotes the fulfillment of specific learning objectives integral to many biology courses. This study tested the hypothesis that case studies are more effective than classroom discussions and textbook reading at promoting learning of key biological concepts, development of written and oral communication skills, and comprehension of the relevance of biological concepts to everyday life. This study also tested the hypothesis that case studies produced by the instructor of a course are more effective at promoting learning than those produced by unaffiliated instructors. Additionally, performance on quantitative learning assessments and student perceptions of learning gains were analyzed to determine whether reported perceptions of learning gains accurately reflect academic performance. The results reported here suggest that case studies, regardless of the source, are significantly more effective than other methods of content delivery at increasing performance on examination questions related to chemical bonds, osmosis and diffusion, mitosis and meiosis, and DNA structure and replication. This finding was positively correlated to increased student perceptions of learning gains associated with oral and written communication skills and the ability to recognize connections between biological concepts and other aspects of life. Based on these findings, case studies should be considered as a preferred method for teaching about a variety of concepts in science courses.

  17. Case Study Teaching Method Improves Student Performance and Perceptions of Learning Gains

    Directory of Open Access Journals (Sweden)

    Kevin M. Bonney

    2015-02-01

    Full Text Available Following years of widespread use in business and medical education, the case study teaching method is becoming an increasingly common teaching strategy in science education. However, the current body of research provides limited evidence that the use of published case studies effectively promotes the fulfillment of specific learning objectives integral to many biology courses. This study tested the hypothesis that case studies are more effective than classroom discussions and textbook reading at promoting learning of key biological concepts, development of written and oral communication skills, and comprehension of the relevance of biological concepts to everyday life. This study also tested the hypothesis that case studies produced by the instructor of a course are more effective at promoting learning than those produced by unaffiliated instructors. Additionally, performance on quantitative learning assessments and student perceptions of learning gains were analyzed to determine whether reported perceptions of learning gains accurately reflect academic performance. The results reported here suggest that case studies, regardless of the source, are significantly more effective than other methods of content delivery at increasing performance on examination questions related to chemical bonds, osmosis and diffusion, mitosis and meiosis, and DNA structure and replication. This finding was positively correlated to increased student perceptions of learning gains associated with oral and written communication skills and the ability to recognize connections between biological concepts and other aspects of life. Based on these findings, case studies should be considered as a preferred method for teaching about a variety of concepts in science courses.

  18. Impact of job satisfaction on employees' performance: a case study ...

    African Journals Online (AJOL)

    This study investigated the effect of job satisfaction on employees' performance with specific focus on teachers in secondary schools in Yewa South Local Government Area, Ogun State, Nigeria. The survey research design was adopted while questionnaire was used as instrument of data collection. A total of 120 copies of ...

  19. Deep Energy Retrofit Performance Metric Comparison: Eight California Case Studies

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fisher, Jeremy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-06-01

    In this paper we will present the results of monitored annual energy use data from eight residential Deep Energy Retrofit (DER) case studies using a variety of performance metrics. For each home, the details of the retrofits were analyzed, diagnostic tests to characterize the home were performed and the homes were monitored for total and individual end-use energy consumption for approximately one year. Annual performance in site and source energy, as well as carbon dioxide equivalent (CO2e) emissions were determined on a per house, per person and per square foot basis to examine the sensitivity to these different metrics. All eight DERs showed consistent success in achieving substantial site energy and CO2e reductions, but some projects achieved very little, if any source energy reduction. This problem emerged in those homes that switched from natural gas to electricity for heating and hot water, resulting in energy consumption dominated by electricity use. This demonstrates the crucial importance of selecting an appropriate metric to be used in guiding retrofit decisions. Also, due to the dynamic nature of DERs, with changes in occupancy, size, layout, and comfort, several performance metrics might be necessary to understand a project’s success.

  20. The efficiency of SAP in improving the HR performance case study ...

    African Journals Online (AJOL)

    The efficiency of SAP in improving the HR performance case study: Masdar ... administrative and strategic levels, as well as identifying the contribution of ... Keywords: SAP, human resources management, Masdar Building Materials Company ...

  1. Experimental performance study of a proposed desiccant based air conditioning system.

    Science.gov (United States)

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

  2. Does an Environmental Marketing Strategy Influence Marketing and Financial Performance? A Study of Indonesian Exporting Firms

    Directory of Open Access Journals (Sweden)

    Kardison Lumban Batu

    2017-01-01

    Full Text Available Purpose – Broadly speaking, the implementation of green practice leads to higher performance in exporting firms. To test this concept empirically, this study proposes environmental marketing strategy as an antecedent of product differentiation and cost leadership as a means to promote marketing and financial performance. Design/Methodology/Approach – This study was conducted on 388 respondents serving as operational, production, and marketing managers of Indonesian exporting firms and used structural equation modelling (SEM with AMOS 18 as an analysis technique. Findings and implications – The findings revealed that environmental marketing strategy significantly influences product differentiation and cost leadership. More specifically, product differentiation simultaneously influences marketing and financial performance. However, cost leadership influences financial performance but not marketing performance. This study implies the importance of environmental orientation in setting a firm strategy and promoting the performance of international firms. Limitations – The measurement items proposed in this study were adopted from studies conducted in developed countries; they have not been proven appropriate for direct application in developing countries such as Indonesia. Originality – This study is original in that it explores the importance of environmental studies in setting a firm strategy and promoting the performance of international business.

  3. Examination performances of German and international medical students in the preclinical studying-term – A descriptive study

    Science.gov (United States)

    Huhn, D.; Resch, F.; Duelli, R.; Möltner, A.; Huber, J.; Karimian Jazi, K.; Amr, A.; Eckart, W.; Herzog, W.; Nikendei, C.

    2014-01-01

    Introduction: Medical students with a migration background face several specific problems during their studies. International surveys show first indications that this group of students performs worse in written, oral or practical exams. However, so far, nothing is known about the performance of international students in written pre-clinical tests as well as in pre-clinical State Examinations for German-speaking countries. Method: A descriptive, retrospective analysis of the exam performances of medical students in the pre-clinical part of their studies was conducted at the Faculty of Medicine of Heidelberg in for the year 2012. Performance in written tests of the final exams in the second (N=276), third (N=292) and fourth semester (N=285) were compared between German students, students from EU countries and students from non-EU countries. Same comparison was drawn for the performance in the oral exam of the First State Examination in the period from 2009 - 2012 (N=1137). Results: German students performed significantly better than students with a non-EU migration background both in all written exams and in the oral State Examination (all pstudents with an EU migration background was significantly better than that of students with a non-EU background in the written exam at the end of the third and fourth semester (pstudents completed the oral exam of the First State Examination significantly earlier than students with a non-EU migration background (students with a country of origin outside of the European Union has to be seen as a high-risk group among students with a migration background. For this group, there is an urgent need for early support to prepare for written and oral examinations. PMID:25228931

  4. Performance Study of Objective Speech Quality Measurement for Modern Wireless-VoIP Communications

    Directory of Open Access Journals (Sweden)

    Chan Wai-Yip

    2009-01-01

    Full Text Available Wireless-VoIP communications introduce perceptual degradations that are not present with traditional VoIP communications. This paper investigates the effects of such degradations on the performance of three state-of-the-art standard objective quality measurement algorithms—PESQ, P.563, and an "extended" E-model. The comparative study suggests that measurement performance is significantly affected by acoustic background noise type and level as well as speech codec and packet loss concealment strategy. On our data, PESQ attains superior overall performance and P.563 and E-model attain comparable performance figures.

  5. The effect of knowledge sharing behavior on organizational performance (Case Study: Iranian Space Agency

    Directory of Open Access Journals (Sweden)

    Maryam Philsoophian

    2017-06-01

    Full Text Available Purpose: One of the main activities in the field of knowledge management, is knowledge sharing, because employees can play an important role in organizational competitive advantages. Effective knowledge sharing  can improve the quality of R&D activities. On the other hand it seems that, knowledge sharing behavior improvs organizational performances and competitive advantages for the organization. The aim of this study is to investigate the effects of knowledge sharing (with regards to attitude, intention and behavior on organizational performances. Methodology: The research method is based on descriptive - survey and questionnaire methods that uses partial least squares by “SMARTPLS” software. Result and findings: Studying of 85 collected  questionnaire  showed that " attitude "  has positive and significant effect on " intention " and  " intention "has  a significant positive impact on "behavior". Also the knowledge sharing affects strongly on the performance of the Iranian Space Agency. Remarkably, the results indicate that all financial performance, processes performance and internal performance have positive impact on Iranian Space Agency performance.

  6. Digital breast tomosynthesis versus mammography and breast ultrasound: a multireader performance study

    International Nuclear Information System (INIS)

    Thibault, Fabienne; Malhaire, Caroline; Tardivon, Anne; Dromain, Clarisse; Balleyguier, Corinne S.; Breucq, Catherine; Steyaert, Luc; Baldan, Enrica; Drevon, Harir

    2013-01-01

    To compare the diagnostic performance of single-view breast tomosynthesis (BT) with that of dual-view mammography (MX); to assess the benefit of adding the craniocaudal (CC) mammographic view to BT, and of adding BT to MX plus breast ultrasound, considered to be the reference work-up. One hundred and fifty-five consenting patients with unresolved mammographic and/or ultrasound findings or breast symptoms underwent conventional work-up plus mediolateral oblique-view BT of the affected breast. The final study set in 130 patients resulted in 55 malignant and 76 benign and normal cases. Seven breast radiologists rated the cases through five sequential techniques using a BIRADS-based scale: MX, MX + ultrasound, MX + ultrasound + BT, BT, BT + MX(CC). Multireader, multicase receiver operating characteristic (ROC) analysis was performed and performance of the techniques was assessed from the areas under ROC curves. The performance of BT and of BT + MX(CC) was tested versus MX; the performance of MX + ultrasound + BT tested versus MX + ultrasound. Tomosynthesis was found to be non-inferior to mammography. BT + MX(CC) did not appear to be superior to MX, and MX + ultrasound + BT not superior to MX + ultrasound. Overall, none of the five techniques tested outperformed the others. Further clinical studies are needed to clarify the role of BT as a substitute for traditional work-up in the diagnostic environment. (orig.)

  7. Hospital readmission performance and patterns of readmission: retrospective cohort study of Medicare admissions

    Science.gov (United States)

    Hsieh, Angela F; Lin, Zhenqiu; Bueno, Héctor; Ross, Joseph S; Horwitz, Leora I; Barreto-Filho, José Augusto; Kim, Nancy; Suter, Lisa G; Bernheim, Susannah M; Drye, Elizabeth E; Krumholz, Harlan M

    2013-01-01

    Objectives To determine whether high performing hospitals with low 30 day risk standardized readmission rates have a lower proportion of readmissions from specific diagnoses and time periods after admission or instead have a similar distribution of readmission diagnoses and timing to lower performing institutions. Design Retrospective cohort study. Setting Medicare beneficiaries in the United States. Participants Patients aged 65 and older who were readmitted within 30 days after hospital admission for heart failure, acute myocardial infarction, or pneumonia in 2007-09. Main outcome measures Readmission diagnoses were classified with a modified version of the Centers for Medicare and Medicaid Services’ condition categories, and readmission timing was classified by day (0-30) after hospital discharge. Hospital 30 day risk standardized readmission rates over the three years of study were calculated with public reporting methods of the US federal government, and hospitals were categorized with bootstrap analysis as having high, average, or low readmission performance for each index condition. High and low performing hospitals had ≥95% probability of having an interval estimate respectively less than or greater than the national 30 day readmission rate over the three year period of study. All remaining hospitals were considered average performers. Results For readmissions in the 30 days after the index admission, there were 320 003 after 1 291 211 admissions for heart failure (4041 hospitals), 102 536 after 517 827 admissions for acute myocardial infarction (2378 hospitals), and 208 438 after 1 135 932 admissions for pneumonia (4283 hospitals). The distribution of readmissions by diagnosis was similar across categories of hospital performance for all three conditions. High performing hospitals had fewer readmissions for all common diagnoses. Median time to readmission was similar by hospital performance for heart failure and acute myocardial

  8. Building Energy and Cost Performance: An Analysis of Thirty Melbourne Case Studies

    Directory of Open Access Journals (Sweden)

    Yu Lay Langston

    2012-11-01

    Full Text Available This study investigates the energy and cost performance of thirty recent buildings in Melbourne, Australia. Commonly, building design decisions are based on issues pertaining to construction cost, and consideration of energy performance is made only within the context of the initial project budget. Even where energy is elevated to more importance, operating energy is seen as the focus and embodied energy is nearly always ignored. For the first time, a large sample of buildings has been assembled and analyzed to improve the understanding of both energy and cost performance over their full life cycle, which formed the basis of a wider doctoral study into the inherent relationship between energy and cost. The aim of this paper is to report on typical values for embodied energy, operating energy, capital cost and operating cost per square metre for a range of building functional types investigated in this research. The conclusion is that energy and cost have quite different profiles across projects, and yet the mean GJ/m2 or cost/m2 have relatively low coefficients of variation and therefore may be useful as benchmarks of typical building performance.  

  9. Impact of Smartphone Addiction on Business Students’ Academic Performance: A Case Study

    Directory of Open Access Journals (Sweden)

    Shamsul Arefin

    2017-09-01

    Full Text Available The development of telecom technology has a profound impact on the lives and activities of the people of the world. Smartphone usage became popular to young generation because of its educational and entertaining options by using the numerous apps. Among the young people, students are increasingly using Smartphone. But excessive Smartphone usage usually makes the students addicted to that subconsciously impacts on user’s academic performance, daily activities, physical and mental health and withdrawal tendency, and social relationships. This study aims at identifying the factors that affect the level of Smartphone addiction of the students and its impact on their academic performance. A structured questionnaire has been developed to gather data from the students. A total of 247 questionnaires were collected from the business students of a university of Bangladesh. Using Structural Equation Modeling (SEM the data were analyzed. Results revealed five Smartphone addiction factors such as, positive anticipation, impatience and tolerance, withdrawal, daily-life disturbance, and cyber friendship. Tolerance and daily-life disturbance have significant impact on students’ academic performance. This study suggests that the students should minimize the usage of Smartphone for achieving good academic performance.

  10. A study of self perception and academic performance of students ...

    African Journals Online (AJOL)

    The study investigated the influence of types of exceptionality on the self perception of students with special needs. It examined the influence of sex of students with special needs on their self perception. It also compared the academic performance of male and female students with special needs. One instrument named Self ...

  11. A Performative Approach to Teaching Care Ethics: A Case Study

    Science.gov (United States)

    Hamington, Maurice

    2012-01-01

    This article describes a unique experiment in reconceptualizing the teaching of ethics as an embodied, performative activity rather than a purely intellectual, scholarly study. Although the inclusion of corporeal dimensions in the teaching of ethics makes intuitive sense, because morality is all about how one acts in the world, ethics education in…

  12. Study on the BES Ⅲ offline software performance

    International Nuclear Information System (INIS)

    Zhang Xiaomei; Sun Gongxing

    2011-01-01

    Performance monitor and analysis on the BESⅢ offline software system is very useful for the software optimization and the improvement of CPU and memory usage. It presented a feasible performance monitoring service based on GAUDI, and carried out performance tests and analysis on the BESⅢ simulation and reconstruction with the service. (authors)

  13. DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?

    International Nuclear Information System (INIS)

    Camacho, V.; Estorch, M.; Tembl, A.; Mena, E.; Flotats, A.; Hernandez, Ma.; Fraga, G.; Carrio, I.

    2002-01-01

    DMSA study is an established method for the assessment of renal sequelae after acute pyelonephritis related to febrile urinary tract infection (UTI). However, at the moment is not established if the DMSA study performed during the acute UTI has any prognostic value for outcome assessment. Objectives: to assess the usefulness of DMSA study performed during febrile UTI as predictor of patient outcome. Methods: One hundred-fifty-two children (74 boys) with mean age 20 months (range 1m-12 y) with first febrile UTI were studied by DMSA planar scintigraphy during the acute illness period (first 5 days). All patients had positive grown bacillus in urine (78% E. coli, 8% P. mirabilis), and all followed the same antibiotic treatment. After acute UTI all patients were explored by voiding cysto urethrography for diagnosis of vesicoureteral reflux (VUR). Fifty-seven patients who had an abnormal DMSA study, VUR, or recurrent UTI underwent a DMSA control study (mean 8m after UTI). Results: DMSA study during febrile UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA studies were not performed due to a good clinical outcome (no VUR, no recurrent UTI). In the remaining 17 patients, follow-up DMSA studies were normal as well. Forty children (26%), who presented focal or diffuse cortical lesions during acute UTI, underwent a DMSA control study. Twenty-six of them presented a normal control DMSA, and 14 (9% of all patients) presented cortical lesions, 10 associated with a high-grade VUR. Fifty-seven children were followed by control DMSA, and no significant correlation between initial and follow-up study was found (κ= 0.250, p<0.007). Conclusion: These results indicate that DMSA study performed during febrile UTI may not be useful as predictor of patient outcome. Voiding cysto urethrography and control DMSA study seem to be more useful to select patients at risk of development of chronic cortical lesions

  14. Student performance of the general physical examination in internal medicine: an observational study

    Science.gov (United States)

    2014-01-01

    Background Many practicing physicians lack skills in physical examination. It is not known whether physical examination skills already show deficiencies after an early phase of clinical training. At the end of the internal medicine clerkship students are expected to be able to perform a general physical examination in every new patient encounter. In a previous study, the basic physical examination items that should standardly be performed were set by consensus. The aim of the current observational study was to assess whether medical students were able to correctly perform a general physical examination regarding completeness as well as technique at the end of the clerkship internal medicine. Methods One hundred students who had just finished their clerkship internal medicine were asked to perform a general physical examination on a standardized patient as they had learned during the clerkship. They were recorded on camera. Frequency of performance of each component of the physical examination was counted. Adequacy of performance was determined as either correct or incorrect or not assessable using a checklist of short descriptions of each physical examination component. A reliability analysis was performed by calculation of the intra class correlation coefficient for total scores of five physical examinations rated by three trained physicians and for their agreement on performance of all items. Results Approximately 40% of the agreed standard physical examination items were not performed by the students. Students put the most emphasis on examination of general parameters, heart, lungs and abdomen. Many components of the physical examination were not performed as was taught during precourses. Intra-class correlation was high for total scores of the physical examinations 0.91 (p internal medicine clerkship. Possible causes and suggestions for improvement are discussed. PMID:24712683

  15. Performance studies of four-dimensional cone beam computed tomography

    International Nuclear Information System (INIS)

    Qi Zhihua; Chen Guanghong

    2011-01-01

    Four-dimensional cone beam computed tomography (4DCBCT) has been proposed to characterize the breathing motion of tumors before radiotherapy treatment. However, when the acquired cone beam projection data are retrospectively gated into several respiratory phases, the available data to reconstruct each phase is under-sampled and thus causes streaking artifacts in the reconstructed images. To solve the under-sampling problem and improve image quality in 4DCBCT, various methods have been developed. This paper presents performance studies of three different 4DCBCT methods based on different reconstruction algorithms. The aims of this paper are to study (1) the relationship between the accuracy of the extracted motion trajectories and the data acquisition time of a 4DCBCT scan and (2) the relationship between the accuracy of the extracted motion trajectories and the number of phase bins used to sort projection data. These aims will be applied to three different 4DCBCT methods: conventional filtered backprojection reconstruction (FBP), FBP with McKinnon-Bates correction (MB) and prior image constrained compressed sensing (PICCS) reconstruction. A hybrid phantom consisting of realistic chest anatomy and a moving elliptical object with known 3D motion trajectories was constructed by superimposing the analytical projection data of the moving object to the simulated projection data from a chest CT volume dataset. CBCT scans with gantry rotation times from 1 to 4 min were simulated, and the generated projection data were sorted into 5, 10 and 20 phase bins before different methods were used to reconstruct 4D images. The motion trajectories of the moving object were extracted using a fast free-form deformable registration algorithm. The root mean square errors (RMSE) of the extracted motion trajectories were evaluated for all simulated cases to quantitatively study the performance. The results demonstrate (1) longer acquisition times result in more accurate motion delineation

  16. The relationship between organizational justice and quality performance among healthcare workers: a pilot study.

    Science.gov (United States)

    Mohamed, Salwa Attia

    2014-01-01

    Organization justice refers to the extent to which employees perceive workplace procedure, interactions, and outcomes to be fair in nature. So, this study aimed to investigate the relationship between organizational justice and quality performance among health care workers. The study was conducted at the Public Hospital in Fayoum, Egypt. The study included a convenience sample of 100 healthcare workers (60 nurses and 40 physicians) that were recruited. Tools used for data collection included (1) questionnaire sheet which is used to measure health workers' perception of organizational justices. It includes four types: distributive, procedural, interpersonal, and informational justice. (2) Quality performance questionnaire sheet: this tool was used to examine health workers' perception regarding their quality performance. It contained three types: information, value, and skill. The results revealed that a positive correlation was found between organizational justice components and quality performance among the various categories of health workers' perception (P ≤ 0.05). It has been recommended to replicate the study on a larger probability sample from different hospital settings to achieve more generalizable results and reinforce justice during organization of ministry centers in Egypt.

  17. Team Performance Pay and Motivation Theory: A Mixed Methods Study

    Science.gov (United States)

    Wells, Pamela; Combs, Julie P.; Bustamante, Rebecca M.

    2013-01-01

    This study was conducted to explore teachers' perceptions of a team performance pay program in a large suburban school district through the lens of motivation theories. Mixed data analysis was used to analyze teacher responses from two archival questionnaires (Year 1, n = 368; Year 2, n = 649). Responses from teachers who participated in the team…

  18. Study on explosives and their quality performance

    Energy Technology Data Exchange (ETDEWEB)

    Nabiullah, M.; Pingua, B.M.P.; Jagdish Khan, M.; Emranuzzaman [Central Mining Research Institute, Dhanbad (India)

    2005-07-01

    There are about forty suppliers of explosive and blasting accessories in India manufacturing site mixed emulsion, site mixed slurry, ANFO, HANFO, packed products, and blasting accessories of use in surface and underground mines. A field laboratory was set up to measure explosive properties of explosive samples, cast booster, detonating fuse, detonators, cord relay, MS connector, and shock tubes. Density, velocity of detonation, water percentage, water resistance, and energy output were considered as the important properties of explosives. A rating system was designed for selection of good explosive products. The delay interval and delay scattering in cord relay and shock tube was studied to improve blast performance. This paper describes in detail the method of measurement and vender rating system for explosive products as per marking system accepted by Coal India. 12 refs., 4 figs., 22 tabs.

  19. Studies on Steam Absorption Chillers Performance at a Cogeneration Plant

    Directory of Open Access Journals (Sweden)

    Abd Majid Mohd Amin

    2014-07-01

    Full Text Available Absorption chillers at cogeneration plants generate chilled water using steam supplied by heat recovery steam generators. The chillers can be of either single-effect or double effect configuration and the coefficient of performance (COP depends on the selection made. The COP varies from 0.7 to 1.2 depending on the types of chillers. Single effect chillers normally have COP in the range of 0.68 to 0.79. Double effect chillers COP are higher and can reach 1.2. However due to factors such as inappropriate operations and maintenance practices, COP could drop over a period of time. In this work the performances of double effect steam absorption chillers at a cogeneration plant were studied. The study revealed that during the period of eleven years of operation the COP of the chillers deteriorated from 1.25 to 0.6. Regression models on the operation data indicated that the state of deterioration was projected to persist. Hence, it would be recommended that the chillers be considered for replacement since they had already undergone a series of costly repairs.

  20. Study of the performance of Micromegas detectors in magnetic field

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00222923; The ATLAS collaboration

    2015-01-01

    Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes ($10 \\times 10 \\text{cm}^2$) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the cap...

  1. Study of the performance of Micromegas detectors in magnetic field

    CERN Document Server

    Sampsonidis, Dimos; The ATLAS collaboration

    2016-01-01

    Resistive Micromegas (Micro MEsh Gaseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade due to their capability to maintain full efficiency and high spatial resolution at high rates. Operation in the Inner Muon Station of the high-rapidity region, the so called New Small Wheel (NSW) requires also these performances to be maintened in magnetic fields up to about 0.3 T. The response of Micromegas chambers is affected by the magnetic field where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10x10cm2) in magnetic fields up to 1 T using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability to operate these chambers to get unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity ...

  2. Experimental Study on Shear Performance of Bolt in Roadway Supporting

    Directory of Open Access Journals (Sweden)

    D.J. Li

    2014-09-01

    Full Text Available The corner bolt is proved to be effective in the control of floor deformation of roadway, and the relevant studies on bolting mechanisms are of great significance in improving roadway stability. In this paper, two types of shear tests on six forms of bolts are performed by using self-designed shear test device, the electro-hydraulic servo triaxial testing system. The shear characteristics of different types of bolts are obtained. The results show that different bolt rods or different internal filling conditions result in large differences in shear resistance and different deformation adaptability. We find that the filling materials added can improve the shear performance of bolt significantly, and the bolt with steel not only can improve the strength of bolt body, but also has the bimodal characteristic that makes the bolt have the secondary bearing capacity and withstand larger deformation range during the process of shear, and shows a better support performance. Hoping to provide the experiment basis for support design and field application in the future.

  3. A Study on Relationships between Functional Performance and Task Performance Measure through Experiments in NPP MCR

    International Nuclear Information System (INIS)

    Jang, In Seok; Seong, Poong Hyun; Park, Jin Kyun

    2011-01-01

    Further improvements in levels of organization, management, man-machine interfaces, education, training, etc. are required, if high operating reliability of operators in huge and complex plants such as chemical plants and electrical power generating plants is to be maintained. Improvement requires good understanding of operators' behavior, including defining what is good performance for operators, especially in emergency situations. Human performance measures, therefore, are important to enhance performance and to reduce the probability of incidents and accidents in Nuclear Power Plants (NPPs). Operators' performance measures are used for multi-objectives such as control room design, human system interface evaluation, training, procedure and so on. There are two kinds of representative methods to measure operators' performance. These methods are now known as the functional performance measure and task performance measure. Functional performance measures are basically based on the plant process parameters. Functional performance measures indicate how well the operators controlled selected critical parameters. The parameters selected in this paper are derived from the four Critical Safety Functions (CSFs) identified in the emergency operating procedures such as achievement of subcriticality, maintenance of core cooling, maintenance of heat sink and maintenance of containment integrity. Task performance measures are based on the task analysis. Task analysis is to determine the tasks required and how operators are performed. In this paper, task analysis is done with ideal path for an accident completed by experts and Emergency Operation Procedure (EOP). However, most literatures related to operators' performance have been using one of these measures and there is no research to find out the relationships between two measures. In this paper, the relationships between functional performance measure and task performance measure are investigated using experiments. Shortly

  4. Performance-influencing factors in homogeneous groups of top athletes: a cross-sectional study

    NARCIS (Netherlands)

    van Ingen Schenau, G.J.; Bakker, F.C.; de Koning, J.J.; de Groot, G.

    1996-01-01

    Sport scientists have identified many factors as prerequisites for a good athletic performance in various sports. It is not clear whether these factors also influence the best performers in the homogeneous groups of top athletes selected for national teams. In this study, this issue is addressed

  5. Experimental study on mass transfer performances of cross flow dehumidifier using liquid desiccant

    International Nuclear Information System (INIS)

    Liu, X.H.; Zhang, Y.; Qu, K.Y.; Jiang, Y.

    2006-01-01

    The liquid desiccant air conditioning system is drawing more and more attention due to its advantages in energy saving and environmental friendliness. The dehumidifier is one of the essential parts of the system, which affects the whole system performance severely. This paper experimentally studies the performance of the cross flow dehumidifier, which has been less studied than the counter flow dehumidifier, although it is more applicable in practice. Celdek structured packings were used in the dehumidifier, and a LiBr aqueous solution was used as the liquid desiccant. The moisture removal rate and dehumidifier effectiveness were adopted as the dehumidifier performance indices. The effects of the dehumidifier inlet parameters, including air and desiccant flow rates, air inlet temperature and humidity ratio and desiccant inlet temperature and concentration, on the two indices were investigated. Correlations are proposed to predict the cross flow dehumidifier performance, which give results in good agreement with the present experimental findings

  6. Waste Disposal: Long-term Performance Studies for Radioactive Waste Disposal and Hydrogeological Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Marivoet, J

    2000-07-01

    The main objectives of SCK-CEN's R and D programme on long-term performance studies are: (1) to develop a methodology and associated tools for assessing the long-term safety of geological disposal of all types of radioactive waste in clay formations and of the shallow-land burial of low-level waste; (2) to assess the performance and to identify the most influential elements of integrated repository systems for the disposal of radioactive waste; (3) to collect geological, piezometric and hydraulic data required for studying the hydrogeological system in north-eastern Belgium; (4) to develop a regional aquifer model for north-easter Belgium and to apply it in the performance assessments for the Mol site; (5) to test, verify and improve computer codes used in the performance assessment calculations of waste disposal concepts and contaminated sites (the computer codes simulate water flow and transport of radionuclides in engineered barriers, aquifers and contaminated sites). The scientific programme and achievements in 1999 are described.

  7. Workplace bullying and task performance: A study on salespeople in retail industry

    Directory of Open Access Journals (Sweden)

    Shi Min Chia

    2018-06-01

    Full Text Available Occupational stress has been known as a major cause of safety and health issues among sales people in retail organizations. Despite this, numerous studies have indicated the importance of factors and outcomes of occupational stress in several occupations, a knowledge gap on occupational stress remains a hot topic of interest for academics and practitioners. This study aims to examine the workplace bullying as a factor and task performance as the outcome of occupational stress among salespeople in the retail industry in Malaysia. Questionnaires were distributed to salespeople in the large-scale retail organization. Data from 222 salespeople suggest that workplace bullying was positively related to occupational stress and in turn, it affects employee performance. These findings contribute to understanding how workplace bullying affects the occupational stress and how stress may affect the performance of salespeople. Implications were presented for employers and employees who should be viewed with caution, in turn, to reduce the occupational stress at the workplace.

  8. Primary care nurses' performance in motivational interviewing: a quantitative descriptive study.

    Science.gov (United States)

    Östlund, Ann-Sofi; Kristofferzon, Marja-Leena; Häggström, Elisabeth; Wadensten, Barbro

    2015-07-25

    Motivational interviewing is a collaborative conversational style intended to strengthen motivation to change. It has been shown to be effective in addressing many different lifestyle problems as well as in chronic disease management, and many disease prevention guidelines promote use of motivational interviewing. The aim of the present study was twofold: to assess to what extent the primary care nurses in the study perform motivational interviewing according to the Motivational Interviewing Treatment Integrity Code and to investigate how the participating primary care nurses rated their own performance in motivational interviewing. The study was based on twelve primary care nurses' audio-recorded motivational interviewing sessions with patients (total 32 sessions). After each session, the nurses completed a questionnaire regarding their experience of their own performance in motivational interviewing. The audio-recorded sessions were analyzed using Motivational Interviewing Integrity Code 3.1.1. None of the nurses achieved beginning proficiency in all parts of any motivational interviewing sessions and two nurses did not achieve beginning proficiency in any parts or sessions. Making more complex than simple reflections was the specific verbal behavior/summary score that most nurses achieved. Beginning proficiency/competency in "percent open questions" was the summary score that fewest achieved. Primary care nurses did not achieve beginning proficiency/competency in all aspects of motivational interviewing in their recorded sessions with patients, where lifestyle change was discussed. This indicates a need for improvement and thus additional training, feedback and supervision in clinical practice with motivational interviewing.

  9. Utilizing Lesson Study in Improving Year 12 Students' Learning and Performance in Mathematics

    Directory of Open Access Journals (Sweden)

    Jessie Siew Yin Chong

    2017-02-01

    Full Text Available This study investigated the use of Lesson Study to improve Year 12 students' performance in conditional probability through Inquiry-Based Learning (IBL lessons. In total, 66 students comprised of three Year 12 classes of similar abilities, and their three respective teachers from a government junior college participated in the study. The instruments used to collect the relevant data in this study were teachers' reflective journals and students' achievement tests. The collected data were then analyzed and interpreted quantitatively using the SPSS. The analysis of the students' pre- and post-tests concluded that as the lesson plans were gradually refined and enhanced, their performance in solving conditional probability questions steadily improved.

  10. Study of the Relationship Between Nurse Self-Concept and Clinical Performance Among Nursing Students

    Directory of Open Access Journals (Sweden)

    Badiyepeymaie Jahromi

    2015-09-01

    Full Text Available Background Scholars believe that if nursing students appreciate the value of their services, their sense of professionalism will increase and performance will improve. Nevertheless, little is known about the relationship between nursing students’ professional self-concept and clinical performance. Objectives This study examines the relationship between nurse self-concept and clinical performance among nursing students. Patients and Methods This cross-sectional analytical study employed the census method. The sample comprised 86 senior and junior nursing students at Jahrom university of medical sciences. Nurse self-concept and clinical performance were measured by using the nurses’ self-concept questionnaire (NSCQ, and the 6-dimension scale of nurse performance (6-DSNP, respectively. Results The mean and standard deviation of nurse self-concept and clinical performance scores were 5.46 ± 1.11 and 2.94 ± 1.45, respectively. Nurse self-concept was related to clinical performance (r = 0.24, P = 0.02. Total NSCQ scores were significantly related to four of the 6-DSNP dimensions: planning and evaluation, interpersonal relations and communication, critical care, and leadership. Conclusions Attempts should be made to enhance students’ nurse self-concept during their education. Counseling, improving public respect for nurses, and implementing measures to enhance students’ professional self-concept are essential for improving their performance.

  11. Study on functional relationships between ergonomics indexes of manual performance

    Science.gov (United States)

    Hu, Hui-Min; Ding, Li; Chen, Shou-Ping; Yang, Chun-Xin; Yuan, Xiu-Gan

    This paper investigates functional relationships between some of the key ergonomics indexes in manual performance, and attempts to condense the ergonomics appraisal indexes system and thus evaluate hand performance wearing EVA (extravehicular activity) glove, design and improve EVA glove's performance. Four types of ergonomics indexes were studied, i.e., dexterity, tactile sensibility (TS), strength and fatigue. Two test items of insert sticks into a holes-board (ISIHB) and nuts-bolts assembly task (NBAT) were used to measure dexterity, while shape discrimination (SD) was employed for TS, and grip force (GF) for strength and fatigue. The variables measured in this investigation included accomplishing time (AT) of ISIHB and NBAT, correct rate (CR) of SD, maximal grip force (MGF), instant grip force (IGF) and endurance time of grip force (ETGF). Experiments were conducted on 31 undergraduates (eight female and 23 male) with two experiment conditions of bare-hand group and gloved hand group. Results demonstrated that dexterity and TS performance of gloved hand group declined significantly compared with those of bare-hand group (pfatigue between two conditions (p>0.05). Four effective functional relationships were developed between four pairs of ergonomics indexes in bare-hand group. In gloved hand group, in addition to above-mentioned four pairs of relationships, another formula was found, which was y^=0.02061+0.01233x ( p<0.01, dexterity and TS).

  12. The Effect of IT Integration on Supply Chain Agility Towards Market Performance (A Proposed Study

    Directory of Open Access Journals (Sweden)

    Shaghayegh Maleki Far

    2017-06-01

    Full Text Available Aim/Purpose\t: An important objective of any firm is escalation of its performance and the achievement of competitive advantages. Supply chain agility plays a prominent role to enhance the level of firm’s performance. Moreover, information technology (IT plays a foundational role in supply chain management practices. Hence, this study proposes the relationship between IT integration as the competency of IT and firm’s market performance both directly and through mediating role of supply chain agility. Background:\tMany studies have been done to date on the impact of supply chain agility on overall firm’s performance. However, the effect of an agile supply chain on firm’s market performance per se needs to be studied. Furthermore, there is a gap in the literature about the effect of IT competency such as IT integration on firm’s market performance both directly and through mediating role of supply chain agility. Recommendation for Researchers: The first direction this study gives to researchers is to consider the different factors which have significant effect on the agility of supply chain, particularly the IT related ones. The second direction is about the study on the effect of IT competencies and supply chain agility on each category of firm’s performance separately instead of considering it as a one construct. Impact on Society\t: Although this is a conceptual study, it can highlight the importance of IT competency not only in our daily life, but also in our businesses and industries. Future Research:\tThis study only proposes some relationships based on theory and literature. Future researchers can test these proposed relationships in different contexts and compare the results. Furthermore, this study proposes the relationships for large manufacturing sector in developing countries. The model could be tested for SMEs as well. In addition, the proposed theoretical model in this study might be tested in both developing as well as

  13. The effect of klapskate hinge position on push-off performance: a simulation study

    NARCIS (Netherlands)

    Houdijk, J.H.P.; Bobbert, M.F.; de Koning, J.J.; de Groot, G.

    2003-01-01

    Purpose: The introduction of the klapskate in speed skating confronts skaters with the question of how to adjust the position of the hinge in order to maximize performance. The purpose of this study was to reveal the constraint that klapskate hinge position imposes on push-off performance in speed

  14. Methylphenidate use and school performance among primary school children: a descriptive study.

    Science.gov (United States)

    van der Schans, Jurjen; Çiçek, Rukiye; Vardar, Sefike; Bos, Jens Hj; de Vries, Tjalling W; Hoekstra, Pieter J; Hak, Eelko

    2017-03-29

    There is no conclusive evidence that stimulants have beneficial effects on major associated outcome parameters, particularly school performance. We assessed the differences in school performance among children using methylphenidate at the end of primary school in relation to various parameters of methylphenidate use. We linked children from a pharmacy prescription database with standardized achievement test results at the end of primary school. We explored differences in test scores between current methylphenidate users versus never users and methylphenidate users who stopped treatment at least 6 months before the test, early versus late starters, different dosage of methylphenidate, and concurrent antipsychotic or asthma treatment. Out of the 7736 children, 377 (4.9%) children were treated with methylphenidate at the time of the test. After adjusting for confounders the methylphenidate users (532.58 ± .48) performed significantly lower on the test than never users (534.72 ± .11). Compared with late starters of methylphenidate treatment (536.94 ± 1.51) we found significantly lower test scores for the early starters (532.33 ± .50). Our study indicates that children using methylphenidate still perform less at school compared to their peers. Our study also suggests that earlier start of methylphenidate treatment is associated with a lower school performance compared to children starting later with the treatment. This result could either indicate a limited effect of long term treatment or a more strongly affected group of early starters.

  15. A Study of relationship between frailty and physical performance in elderly women.

    Science.gov (United States)

    Jeoung, Bog Ja; Lee, Yang Chool

    2015-08-01

    Frailty is a disorder of multiple inter-related physiological systems. It is unclear whether the level of physical performance factors can serve as markers of frailty and a sign. The purpose of this study was to examine the relationship between frailty and physical performance in elderly women. One hundred fourteen elderly women participated in this study, their aged was from 65 to 80. We were measured 6-min walk test, grip-strength, 30-sec arm curl test, 30-sec chair stand test, 8 foot Up- and Go, Back scratch, chair sit and reach, unipedal stance, BMI, and the frailty with questionnaire. The collected data were analyzed by descriptive statistics, frequencies, correlation analysis, ANOVA, and simple liner regression using the IBM 21. SPSS program. In results, statistic tests showed that there were significant differences between frailty and 6-min walk test, 30-sec arm curl test, 30-sec chair stand test, grip-strength, Back scratch, and BMI. However, we did not find significant differences between frailty and 8 foot Up- and Go, unipedal stance. When the subjects were divided into five groups according to physical performance level, subjects with high 6-min walk, 30-sec arm curl test, chair sit and reach test, and high grip strength had low score frailty. Physical performance factors were strongly associated with decreased frailty, suggesting that physical performance improvements play an important role in preventing or reducing the frailty.

  16. The Study of the Relationship between Mothers' Anxiety with the Mathematical Performance and Students' Anxiety

    Directory of Open Access Journals (Sweden)

    Sepideh Moradpour

    2015-04-01

    Full Text Available Today mathematics stress have considered under interesting of many psychologists of mathematics education and cognitive psychologists too so that recognize emotion and mental stimulations of students in mathematics and to find scientific strategies for removing and controlling them. Anxiety is one of important and effective issues of 21th century. This study is done with aim of the study of relationship between mothers' anxiety with mathematics performance and anxiety of their children at first grade of high school at zone one of Tehran. Among population, 97 students and their mothers are chosen. Data of this research are collected by Cattell standard questionnaire for studying mothers' anxiety and standard questionnaire of mathematics anxiety for studying mathematics anxiety and a math exam for studying of students' performance. Research findings indicate that there is significant relationship between mothers' anxiety with mathematics anxiety and performance of students. Also it indicated that there is significant difference between students with high and low mathematics anxiety in term of mathematics performance.

  17. Insomnia and Its Temporal Association with Academic Performance among University Students: A Cross-Sectional Study.

    Science.gov (United States)

    Haile, Yohannes Gebreegziabhere; Alemu, Sisay Mulugeta; Habtewold, Tesfa Dejenie

    2017-01-01

    Studies show that 9.4% to 38.2% of university students are suffering from insomnia. However, research data in developing countries is limited. Thus, the aim of the study was to assess insomnia and its temporal association with academic performance. Institution based cross-sectional study was conducted with 388 students at Debre Berhan University. Data were collected at the nine colleges. Logistic and linear regression analysis was performed for modeling insomnia and academic performance with a p value threshold of 0.05, respectively. Data were entered using EPI-data version 3.1 and analyzed using SPSS version 20. The prevalence of insomnia was 61.6%. Field of study ( p value = 0.01), worshiping frequency ( p value = 0.048), marital status ( p value = 0.03), and common mental disorder ( p value academic performance ( p value = 0.53, β = -0.04). Insomnia explained 1.2% ( r 2 = 0.012) of the difference in academic performance between students. Nearly 3 out of 5 students had insomnia. We recommended that universities would endorse sleep quality and mental health illness screening programs for students.

  18. Distracting the mind improves performance: an ERP Study.

    Science.gov (United States)

    Wierda, Stefan M; van Rijn, Hedderik; Taatgen, Niels A; Martens, Sander

    2010-11-24

    When a second target (T2) is presented in close succession of a first target (T1), people often fail to identify T2, a phenomenon known as the attentional blink (AB). However, the AB can be reduced substantially when participants are distracted during the task, for instance by a concurrent task, without a cost for T1 performance. The goal of the current study was to investigate the electrophysiological correlates of this paradoxical effect. Participants successively performed three tasks, while EEG was recorded. The first task (standard AB) consisted of identifying two target letters in a sequential stream of distractor digits. The second task (grey dots task) was similar to the first task with the addition of an irrelevant grey dot moving in the periphery, concurrent with the central stimulus stream. The third task (red dot task) was similar to the second task, except that detection of an occasional brief color change in the moving grey dot was required. AB magnitude in the latter task was significantly smaller, whereas behavioral performance in the standard and grey dots tasks did not differ. Using mixed effects models, electrophysiological activity was compared during trials in the grey dots and red dot tasks that differed in task instruction but not in perceptual input. In the red dot task, both target-related parietal brain activity associated with working memory updating (P3) as well as distractor-related occipital activity was significantly reduced. The results support the idea that the AB might (at least partly) arise from an overinvestment of attentional resources or an overexertion of attentional control, which is reduced when a distracting secondary task is carried out. The present findings bring us a step closer in understanding why and how an AB occurs, and how these temporal restrictions in selective attention can be overcome.

  19. Distracting the mind improves performance: an ERP Study.

    Directory of Open Access Journals (Sweden)

    Stefan M Wierda

    2010-11-01

    Full Text Available When a second target (T2 is presented in close succession of a first target (T1, people often fail to identify T2, a phenomenon known as the attentional blink (AB. However, the AB can be reduced substantially when participants are distracted during the task, for instance by a concurrent task, without a cost for T1 performance. The goal of the current study was to investigate the electrophysiological correlates of this paradoxical effect.Participants successively performed three tasks, while EEG was recorded. The first task (standard AB consisted of identifying two target letters in a sequential stream of distractor digits. The second task (grey dots task was similar to the first task with the addition of an irrelevant grey dot moving in the periphery, concurrent with the central stimulus stream. The third task (red dot task was similar to the second task, except that detection of an occasional brief color change in the moving grey dot was required. AB magnitude in the latter task was significantly smaller, whereas behavioral performance in the standard and grey dots tasks did not differ. Using mixed effects models, electrophysiological activity was compared during trials in the grey dots and red dot tasks that differed in task instruction but not in perceptual input. In the red dot task, both target-related parietal brain activity associated with working memory updating (P3 as well as distractor-related occipital activity was significantly reduced.The results support the idea that the AB might (at least partly arise from an overinvestment of attentional resources or an overexertion of attentional control, which is reduced when a distracting secondary task is carried out. The present findings bring us a step closer in understanding why and how an AB occurs, and how these temporal restrictions in selective attention can be overcome.

  20. A Study of the Associations between Conditions of Performance and Characteristics of Performers and New York State Solo Performance Ratings

    Science.gov (United States)

    vonWurmb, Elizabeth C.

    2013-01-01

    This dissertation undertakes an analysis of 1,044 performance evaluations from New York State School Music Association (NYSSMA) Spring Festival solo adjudication ratings of student performers from a large suburban school district. It relies on results of evaluations of observed performances, and takes these evaluations as assessments of what the…

  1. Performance Based Islamic Performance Index (Study on the Bank Muamalat Indonesia and Bank Syariah Mandiri

    Directory of Open Access Journals (Sweden)

    Siti Aisjah

    2015-09-01

    Full Text Available The development of Islamic base banks in Indonesia in recent years show rapid growth. The main challenge for Islamic base banks is how to raise belief from the stakeholders. Stakeholder expectations of the Islamic banks is different from a conventional bank. Since, Islamic banks are built on basic principles of Islamic economics. Therefore, we need a tool to evaluate and measure the performance of Islamic base banks. Islamicity Performance Index is a method which can evaluate the performance of Islamic base banks not only their financial but also justice principles, halal (lawfulness, and tazkiyah (sanctification. There are six financial ratios which are measured from Islamicity Performance Index:profit sharing ratio, zakat performance ratio, equitable distribution ratio, directors-employees welfare ratio, Islamic investment versus non-Islamic investment ratio, Islamic income versus non-Islamic income. This research is intended to figure out the performance of Islamic base Bank in Indonesia based on Islamicity Performance Index. The samples are the Bank Muamalat Indonesia and Bank Syariah Mandiri. Sources of data are the financial reports of Bank Muamalat Indonesia and Bank Syariah Mandiri in 2009–2010 period.The results show that the financial performance of Islamic Base Bank in Indonesia during 2009-2010 period have ”quite satisfactory level of  valuation. However, there are two unsatisfactory ratios. They are zakat performance ratio and director-employee welfare contrast ratio. It shows that zakat issued by the Islamic base bank in Indonesia is still low and the contrast of the director-employee welfare is still huge.

  2. Performing masculinity, influencing health: a qualitative mixed-methods study of young Spanish men

    Science.gov (United States)

    Marcos, Jorge Marcos; Avilés, Nuria Romo; Lozano, María del Río; Cuadros, Juan Palomares; Calvente, María del Mar García

    2013-01-01

    Background The literature shows how gender mandates contribute to differences in exposure and vulnerability to certain health risk factors. This paper presents the results of a study developed in the south of Spain, where research aimed at understanding men from a gender perspective is still limited. Objective The aim of this paper is to explore the lay perceptions and meanings ascribed to the idea of masculinity, identifying ways in which gender displays are related to health. Design The study is based on a mixed-methods data collection strategy typical of qualitative research. We performed a qualitative content analysis focused on manifest and latent content. Results Our analysis showed that the relationship between masculinity and health was mainly defined with regard to behavioural explanations with an evident performative meaning. With regard to issues such as driving, the use of recreational drugs, aggressive behaviour, sexuality, and body image, important connections were established between manhood acts and health outcomes. Different ways of understanding and performing the male identity also emerged from the results. The findings revealed the implications of these aspects in the processes of change in the identity codes of men and women. Conclusions The study provides insights into how the category ‘man’ is highly dependent on collective practices and performative acts. Consideration of how males perform manhood acts might be required in guidance on the development of programmes and policies aimed at addressing gender inequalities in health in a particular local context. PMID:24044583

  3. Examination of mechanisms underlying enhanced memory performance in action video game players: a pilot study.

    Science.gov (United States)

    Li, Xianchun; Cheng, Xiaojun; Li, Jiaying; Pan, Yafeng; Hu, Yi; Ku, Yixuan

    2015-01-01

    Previous studies have shown enhanced memory performance resulting from extensive action video game playing. The mechanisms underlying the cognitive benefit were investigated in the current study. We presented two types of retro-cues, with variable intervals to memory array (Task 1) or test array (Task 2), during the retention interval in a change detection task. In Task 1, action video game players demonstrated steady performance while non-action video game players showed decreased performance as cues occurred later, indicating their performance difference increased as the cue-to-memory-array intervals became longer. In Task 2, both participant groups increased their performance at similar rates as cues presented later, implying the performance difference in two groups were irrespective of the test-array-to-cue intervals. These findings suggested that memory benefit from game plays is not attributable to the higher ability of overcoming interference from the test array, but to the interactions between the two processes of protection from decay and resistance from interference, or from alternative hypotheses. Implications for future studies were discussed.

  4. The Impact of Knowledge Management on Organizational Performance: An Empirical Study of Kuwait University

    Directory of Open Access Journals (Sweden)

    Mohammad Q. Ahmad Al-Qarioti

    2015-11-01

    Full Text Available Knowledge management (KM is a process that transforms individual knowledge into organizational institutionalized knowledge. The purpose of this paper is to shed light on KM infrastructure at Kuwait University to see how faculty members evaluate KM influence on organizational performance. Study findings provide insights into the infrastructure and process capabilities needed to provide knowledge support for organizational activities. The study was based on a stratified random sample consists of (355 faculty members from various colleges at Kuwait university. Study results show that faculty members evaluate knowledge management as “very good” with a (3.52 mean score at Likert five point scale, which indicates that Knowledge management components are highly related to organizational performance. Implications, imitations of the study, and recommendations regarding appropriate investments in knowledge management to enhance organizational performance are discussed.

  5. Performance study of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal system

    International Nuclear Information System (INIS)

    Li, Ming; Ji, Xu; Li, Guoliang; Wei, Shengxian; Li, YingFeng; Shi, Feng

    2011-01-01

    Highlights: → The performances of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal (TCPV/T) system have been studied. → The optimum concentration ratios for the single crystalline silicon cell, the Super cells and the GaAs cells were studied by experiments. → The influences between the solar cell's performance and the series resistances, the working temperature, solar irradiation intensity were explored. - Abstract: The performances of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal (TCPV/T) system have been studied via both experiment and theoretical calculation. The I-V characteristics of the solar cell arrays and the output performances of the TCPV/T system demonstrated that among the investigated four types of solar cell arrays, the triple junction GaAs cells possessed good performance characteristics and the polysilicon cells exhibited poor performance characteristics under concentrating conditions. The optimum concentration ratios for the single crystalline silicon cell, the Super cells and the GaAs cells were also studied by experiments. The optimum concentration ratios for the single crystalline silicon cells and Super cells were 4.23 and 8.46 respectively, and the triple junction GaAs cells could work well at higher concentration ratio. Besides, some theoretical calculations and experiments were performed to explore the influences of the series resistances and the working temperature. When the series resistances R s changed from 0 Ω to 1 Ω, the maximum power P m of the single crystalline silicon, the polycrystalline silicon, the Super cell and the GaAs cell arrays decreased by 67.78%, 74.93%, 77.30% and 58.07% respectively. When the cell temperature increased by 1 K, the short circuit current of the four types of solar cell arrays decreased by 0.11818 A, 0.05364 A, 0.01387 A and 0.00215 A respectively. The research results demonstrated that the output performance of the solar cell arrays with lower

  6. Academic performance study in young athletes from Playas de Castellón Athletics Club

    OpenAIRE

    Ana Capdevila Seder; Héctor Bellmunt Villalonga; Carlos Hernando Domingo

    2014-01-01

    The study analyzed the possible relationship between academic performance of young athletes and some of the variables most used in this field. The sample consisted of 40 athletes Athletics Club Playas de Castellón, between 14 and 16 years, 22 boys and 18 girls. The main variables analyzed were academic performance, study habits, gender, sleep, sedentary leisure, socioeconomic status and dedication to sport. The instruments used were questionnaires CHTE (habits and study skills), PFYTL (physic...

  7. Performation Metrics Development Analysis for Information and Communications Technology Outsourcing: A Case Study

    Science.gov (United States)

    Travis, James L., III

    2014-01-01

    This study investigated how and to what extent the development and use of the OV-5a operational architecture decomposition tree (OADT) from the Department of Defense (DoD) Architecture Framework (DoDAF) affects requirements analysis with respect to complete performance metrics for performance-based services acquisition of ICT under rigid…

  8. Physical Activity and School Performance: Evidence from a Danish Randomised School-Intervention Study

    Science.gov (United States)

    Quinto Romani, A.; Klausen, T. B.

    2017-01-01

    It has been claimed that physical activity has a positive effect on not only health but also on school performance. Using data from a randomised school-intervention study, this paper investigates whether different interventions promoting physical activity affect school performance in primary school children. The results indicate that on average,…

  9. Income Inequality or Performance Gap? A Multilevel Study of School Violence in 52 Countries.

    Science.gov (United States)

    Contreras, Dante; Elacqua, Gregory; Martinez, Matias; Miranda, Álvaro

    2015-11-01

    The purpose of the study was to examine the association between income inequality and school violence and between the performance inequality and school violence in two international samples. The study used data from Trends in International Mathematics and Science Study 2011 and from the Central Intelligence Agency of United States which combined information about academic performance and students' victimization (physical and social) for 269,456 fourth-grade students and 261,747 eighth-grade students, with gross domestic product and income inequality data in 52 countries. Ecological correlations tested associations between income inequality and victimization and between school performance inequality and victimization among countries. Multilevel ordinal regression and multilevel regression analyses tested the strength of these associations when controlling for socioeconomic and academic performance inequality at school level and family socioeconomic status and academic achievement at student level. Income inequality was associated with victimization rates in both fourth and eighth grade (r ≈ .60). Performance inequality shows stronger association with victimization among eighth graders (r ≈ .46) compared with fourth graders (r ≈ .30). Multilevel analyses indicate that both an increase in the income inequality in the country and school corresponds with more frequent physical and social victimization. On the other hand, an increase in the performance inequality at the system level shows no consistent association to victimization. However, school performance inequality seems related to an increase in both types of victimizations. Our results contribute to the finding that income inequality is a determinant of school violence. This result holds regardless of the national performance inequality between students. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  10. Correlation between MMI performance and OSCE performance – a pilot study

    Directory of Open Access Journals (Sweden)

    Adetokunbo Oluwasanjo

    2015-06-01

    Full Text Available Objective: The multiple mini-interview (MMI has been shown to have a positive correlation with early medical school performance, clerkship evaluations, and national licensing examinations. There is limited data on its predictive validity at the postgraduate level. Methods: Six hundred and nineteen internship candidates were interviewed using the MMI format by the internal medicine residency program of The Reading Health System, between September 2011 and February 2014. Fifty-two interns were recruited. Each intern participated in an objective structured clinical examination (OSCE 3–4 months after the start of the program. The OSCE score of each intern was used as the independent variable to test the relationship with both the MMI interpersonal score and the MMI overall score. Results: There was a moderate positive correlation between the average MMI interpersonal score and the communication score on the OSCE, r=0.384, n=52, p=0.005, and a negligible relationship between the average MMI overall score and the communication score on the OSCE, r=0.175, n=52, p=0.214. Conclusion: The MMI is a useful tool for residency programs to assess interpersonal and communication skills prior to matriculation into residency training. This study provides evidence for its validity in assessing these competencies.

  11. Psychophysical studies of the performance of an image database retrieval system

    Science.gov (United States)

    Papathomas, Thomas V.; Conway, Tiffany E.; Cox, Ingemar J.; Ghosn, Joumana; Miller, Matt L.; Minka, Thomas P.; Yianilos, Peter N.

    1998-07-01

    We describe psychophysical experiments conducted to study PicHunter, a content-based image retrieval (CBIR) system. Experiment 1 studies the importance of using (a) semantic information, (2) memory of earlier input and (3) relative, rather than absolute, judgements of image similarity. The target testing paradigm is used in which a user must search for an image identical to a target. We find that the best performance comes from a version of PicHunter that uses only semantic cues, with memory and relative similarity judgements. Second best is use of both pictorial and semantic cues, with memory and relative similarity judgements. Most reports of CBIR systems provide only qualitative measures of performance based on how similar retrieved images are to a target. Experiment 2 puts PicHunter into this context with a more rigorous test. We first establish a baseline for our database by measuring the time required to find an image that is similar to a target when the images are presented in random order. Although PicHunter's performance is measurably better than this, the test is weak because even random presentation of images yields reasonably short search times. This casts doubt on the strength of results given in other reports where no baseline is established.

  12. Experimental study on the seismic performance of new sandwich masonry walls

    Science.gov (United States)

    Xiao, Jianzhuang; Pu, Jie; Hu, Yongzhong

    2013-03-01

    Sandwich masonry walls are widely used as energy-saving panels since the interlayer between the outer leaves can act as an insulation layer. New types of sandwich walls are continually being introduced in research and applications, and due to their unique bond patterns, experimental studies have been performed to investigate their mechanical properties, especially with regard to their seismic performance. In this study, three new types of sandwich masonry wall have been designed, and cyclic lateral loading tests were carried out on five specimens. The results showed that the specimens failed mainly due to slippage along the bottom cracks or the development of diagonal cracks, and the failure patterns were considerably influenced by the aspect ratio. Analysis was undertaken on the seismic response of the new walls, which included ductility, stiffness degradation and energy dissipation capacity, and no obvious difference was observed between the seismic performance of the new walls and traditional walls. Comparisons were made between the experimental results and the calculated results of the shear capacity. It is concluded that the formulas in the two Chinese codes (GB 50011 and GB 50003) are suitable for the calculation of the shear capacity for the new types of walls, and the formula in GB 50011 tends to be more conservative.

  13. Study of the performance of Micromegas detectors in magnetic field

    Directory of Open Access Journals (Sweden)

    Dimitrios Sampsonidis

    2018-01-01

    Full Text Available Resistive Micromegas (MICRO MEsh GAseous Structure detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW, will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2 in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

  14. Parametric study of geohydrologic performance characteristics for geologic waste repositories

    International Nuclear Information System (INIS)

    Bailey, C.E.; Marine, I.W.

    1980-11-01

    One of the major objectives of the National Waste Terminal Storage Program is to identify potential geologic sites for storage and isolation of radioactive waste (and possibly irradiated fuel). Potential sites for the storage and isolation of radioactive waste or spent fuel in a geologic rock unit are being carefully evaluated to ensure that radionuclides from the stored waste or fuel will never appear in the biosphere in amounts that would constitute a hazard to the health and safety of the public. The objective of this report is to quantify and present in graphical form the effects of significant geohydrologic and other performance characteristics that would influence the movement of radionuclides from a storage site in a rock unit to the biosphere. The effort in this study was focused on transport by groundwater because that is the most likely method of radionuclide escape. Graphs of the major performance characteristics that influence the transport of radionuclides from a repository to the biosphere by groundwater are presented. The major characteristics addressed are radioactive decay, leach rate, hydraulic conductivity, porosity, groundwater gradient, hydrodynamic dispersion, ion exchange, and distance to the biosphere. These major performance characteristics are combind with each other and with the results of certain other combinations and presented in graphical form to provide the interrelationships of values measured during field studies. The graphical form of presentation should be useful in the screening process of site selection. An appendix illustrates the use of these graphs to assess the suitability of a site

  15. Study of the performance of Micromegas detectors in magnetic field

    Science.gov (United States)

    Dimitrios, Sampsonidis

    2018-02-01

    Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

  16. The Relationship between Organizational Justice and Quality Performance among Healthcare Workers: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Salwa Attia Mohamed

    2014-01-01

    Full Text Available Organization justice refers to the extent to which employees perceive workplace procedure, interactions, and outcomes to be fair in nature. So, this study aimed to investigate the relationship between organizational justice and quality performance among health care workers. The study was conducted at the Public Hospital in Fayoum, Egypt. The study included a convenience sample of 100 healthcare workers (60 nurses and 40 physicians that were recruited. Tools used for data collection included (1 questionnaire sheet which is used to measure health workers’ perception of organizational justices. It includes four types: distributive, procedural, interpersonal, and informational justice. (2 Quality performance questionnaire sheet: this tool was used to examine health workers’ perception regarding their quality performance. It contained three types: information, value, and skill. The results revealed that a positive correlation was found between organizational justice components and quality performance among the various categories of health workers’ perception (P≤0.05. It has been recommended to replicate the study on a larger probability sample from different hospital settings to achieve more generalizable results and reinforce justice during organization of ministry centers in Egypt.

  17. CFD Parametric Studies for Global Performance Improvement of Open Refrigerated Display Cabinets

    Directory of Open Access Journals (Sweden)

    Pedro Dinis Gaspar

    2012-01-01

    Full Text Available A detailed CFD modelling of an open refrigerated display cabinet has been formulated in a previous study. Some modifications are introduced in order to perform parametric studies dealing with low-cost geometrical and functional characteristics for improvement of the global performance and energy efficiency. The parametric studies are devoted to the analysis of the thermal response and behaviour inside the food conservation space influenced by (1 air flow rate through the evaporator heat exchanger; (2 air curtain behaviour; (3 hole dimensions and distribution of the back panel; (4 discharge and return grilles angles; and (5 flow deflectors inside the internal duct. The analysis of the numerical predictions from the parametric studies allows the development of an optimized model for the conception of an open refrigerated display cabinet with a more adequate configuration. The numerical predictions of the optimized model show lower product temperature and reduced electrical energy consumption, allowing the improvement of the food safety and the energy rationalization of the refrigeration equipment.

  18. A performance case study of energy pile foundation at Rosborg Gymnasium (Denmark)

    DEFF Research Database (Denmark)

    Pagola, Maria Alberdi; Jensen, Rasmus Lund; Poulsen, Søren Erbs

    2016-01-01

    The Rosborg Gymnasium building in Vejle (Denmark) is partially founded on 200 foundation pile heat exchangers (energy piles). The thermo-active foundation has supplemented the heating and free cooling needs of the building since 2011 (4,000 m2 living area). Operational data from the ground source...... ground heat extraction/injection activity , this paper provides a performance study of the energy pile-based ground source heat pump installation utilising operational data. The study demonstrates that the measured seasonal performance factors so far are lower than expected: 2.7 in heating mode and 4.......2 in cooling mode. Nevertheless, there is room for improvement if novel energy management strategies are applied. This highlights the relevance of considering the daily heating/cooling requirements of the building during the design phase of the heating and cooling system. Moreover, this study demonstrates...

  19. Working and learning with electronic performance support systems: An effectiveness study

    NARCIS (Netherlands)

    Bastiaens, T.J.; Nijhof, W.J.; Streumer, Jan; Abma, Harmen J.

    1997-01-01

    In this study the effectiveness of electronic performance support systems (EPSS) is reported. Some of the expected advantages of EPSS, such as an increase in productivity and improved learning are evaluated with insurance agents using laptop computers. Theoretical statements, research design and

  20. Study of Tungsten effect on CFETR performance

    Science.gov (United States)

    Shi, Shengyu; Xiang Gao Collaboration; Guoqiang Li Collaboration; Nan Shi Collaboration; Vincent Chan Collaboration; Xiang Jian Collaboration

    2017-10-01

    An integrated modeling workflow using OMFIT/TGYRO is constructed to evaluate W impurity effects on China Fusion Engineering Test Reactor (CFETR) performance. Self-consistent modeling of tungsten(W) core density profile, accounting for turbulence and neoclassical transport, is performed based on the CFETR steady-state scenario developed by D.Zhao (ZhaoDeng, APS, 2016). It's found that the fusion performance degraded in a limited level with increasing W concentration. The main challenge arises in sustainment of H-mode with significant W radiation. Assuming the power threshold of H-L back transition is approximately the same as that of L-H transition, using the scaling law of Takizuka (Takizuka etc, Plasma Phys. Control. Fusion, 2004), it is found that the fractional W concentration should not exceed 3e-5 to stay in H-mode for CFETR phase I. A future step is to connect this requirement to W wall erosion modeling. We are grateful to Dr. Emiliano Fable and Dr. Thomas Pütterich and Ms. Emily Belli for very helpful discussions and comments. We also would like to express our thanks to all the members of the CFETR Physics Group, and we appreciate the General Atomic Theory Group for permission to use the OMFIT framework and GA code suite, and for their valuable technical support. Numerical computations were performed on the ShenMa High Performance Computing Cluster in the Institute of Plasma Physics, Chinese Academy of Sciences. This work was mainly supported by the National Magnetic Confinement Fusion Research Program of China (Grant Nos. 2014GB110001, 2014GB110002, 2014GB110003) and supported in part by the National ITER Plans Program of China (Grant Nos. 2013GB106001, 2013GB111002, 2015GB110001).

  1. Design Methodology And Performance Studies Of A Flexible Electrotextile Surface

    Directory of Open Access Journals (Sweden)

    Kayacan Ozan

    2015-09-01

    Full Text Available ‘The smart textiles’ concept has to develop products based not only on design, fashion and comfort but also in terms of functions. The novel electro-textiles in the market open up new trends in smart and interactive gadgets. ‘Easy to care and durability’ properties are among the most important features of these products. On the other hand, wearable electronic knitwear has been gaining the attention of both researchers and industrial sectors. Combining knitting technology with electronics may become a dominant trend in the future because of the wide application possibilities. This research is concerned primarily with the design methodology of knitted fabrics containing electrically conductive textiles and especially in-use performance studies. The structural characteristics of the fabrics have been evaluated to enhance the performance properties.

  2. Increasing Performance of Professional Soccer Players and Elite Track and Field Athletes with Peak Performance Training and Biofeedback: A Pilot Study.

    Science.gov (United States)

    Rijken, Noortje H; Soer, Remko; de Maar, Ewold; Prins, Hilco; Teeuw, Wouter B; Peuscher, Jan; Oosterveld, Frits G J

    2016-12-01

    The aim of this pilot study was to investigate the effects of an intervention consisting of mental coaching combined with either electro encephalogram (EEG) alpha power feedback or heart rate variability (HRV) feedback on HRV, EEG outcomes and self-reported factors related to stress, performance, recovery and sleep quality in elite athletes. A prospective pilot study was performed with two distinct cohorts. Soccer players were provided with four sessions of mental coaching combined with daily HRV biofeedback (Group A); track and field athletes were provided with four sessions of mental coaching in combination with daily neurofeedback (Group B). Measurements were performed at baseline, post intervention and at 5 weeks follow-up. Objective measures: EEG and ECG. Subjective measures: Numeric Rating Scale for performance, Pittsburgh Sleep Quality Index, Rest and Stress Questionnaire and Sports Improvement-60. Group characteristics were too distinct to compare the interventions. Linear mixed models were used to analyze differences within groups over time. In Group A, significant changes over time were present in alpha power at 5 of 7 EEG locations (p HRV low frequency power and recovery scale of the REST-Q significantly increased (p = 0.02 and HRV or EEG alpha power feedback may increase HRV and alpha power and may lead to better performance-related outcomes and stress reduction. Further research is needed to elucidate the effects of either type of feedback and to compare effects with a control group.

  3. HDL-cholesterol and physical performance: results from the ageing and longevity study in the sirente geographic area (ilSIRENTE Study).

    Science.gov (United States)

    Landi, Francesco; Russo, Andrea; Cesari, Matteo; Pahor, Marco; Bernabei, Roberto; Onder, Graziano

    2007-09-01

    High-density lipoprotein (HDL) cholesterol has been hypothesised to be a reliable marker of frailty and poor prognosis among the oldest elderly. We evaluate the relationship of HDL-cholesterol with measures of physical performance, muscle strength, and functional status in older persons aged 80years or older. Data are from baseline evaluation of the ageing and longevity study in the Sirente geographic area (ilSIRENTE study) (n = 364). Physical performance was assessed using the physical performance battery score [short physical performance battery (SPPB)], which is based on three-timed tests: 4-m walking-speed, balance, and chair-stand tests. Muscle strength was measured by hand-grip strength. Analyses of covariance were performed to evaluate the relationship of different HDL-cholesterol levels with physical function. In the unadjusted analyses, physical function (as measured by the 4-m walking-speed, theSPPB score, the basic and instrumental activities of daily living scales scores), but not hand-grip strength, improved significantly as HDL-cholesterol tertiles increased. After adjustment for potential confounders, which included age, gender, living alone, alcohol abuse, physical activity, congestive heart failure, diabetes, cerebrovascular diseases, osteoarthritis, albumin, urea, C-reactive protein and LDL cholesterol, the association of HDL-cholesterol tertiles with the 4-m walking-speed and the SPPB score was still consistent. The present study suggests that among very old subjects living in the community the higher levels of HDL-cholesterol are associated with better functional performance.

  4. PERFORMANCE BASED PAY AS A DETERMINANT OF JOB SATISFACTION: A STUDY IN MALAYSIA GIATMARA CENTERS

    Directory of Open Access Journals (Sweden)

    Azman ISMAIL

    2011-01-01

    Full Text Available Compensation management literature highlights that performance based payhas two major characteristics: participation in pay systems and adequacy ofpay. The ability of management to properly implement such pay systems maylead to increased job satisfaction in organizations. Though, the nature of thisrelationship is interesting, little is known about the influence of performancebased pay on job satisfaction in compensation management literature.Therefore, this study was conducted to examine the relationship between payfor performance and job satisfaction in Malaysian GIATMARA centers. Theresults of exploratory factor analysis confirmed that measurement scalesused in this study satisfactorily met the standards of validity and reliabilityanalyses. An outcome of stepwise regression analysis shows thatdeterminant of job satisfaction is performance based pay. Further, this resultconfirms that pay for performance is an important antecedent for jobsatisfaction in the studied organizations.

  5. Human Resource Management Practice and Organizational Performance: Case Study from Hormuud Telecom in Mogadishu-Somalia

    Directory of Open Access Journals (Sweden)

    Abdulkadir Mohamud Dahie

    2017-06-01

    Full Text Available Organizational performance is getting more and more important, especially in a market with greater competition and dynamic. Organizational performance is measured through different indicators. It guarantees the continuity of the organization to be competitive in a global marketplace. Normally, the implementation of performance indicators achieved through human resources. Human resources are the key for keeping the organization in the market. These human resources need to be managed effectively to achieve the required performance of the organization. It is necessary to manage strategically the human resources and to adapt at its strategy with organizational strategy. The aim of this study is to investigate the influence of recruitment and selection on organizational performance, to examine the role of compensation and reward on organizational performance as well as the effect of performance appraisal management on organizational performance at Hormuud Telecom in Mogadishu-Somalia. The researcher utilized convenient sampling to collect 100 questionnaires from Hormuud Telecom in Mogadishu, Somalia. These respondents were provided a questionnaire with four main construct which measuring recruitment and selection, compensation and reward, performance appraisal management and organizational performance. However, using correlation coefficient, the study found that organizational performance (Dependent variable had significant positive influence with three dimensions of independent variable. The result of regression analysis found that three constructs had statistically significant, positive, and straight effects with organizational performance.

  6. A comparative study on dynamic mechanical performance of concrete and rock

    Directory of Open Access Journals (Sweden)

    Xia Zhengbing

    2015-10-01

    Full Text Available of underground cavities and field-leveling excavation. Dynamic mechanical performance of rocks has been gradually attached importance both in China and abroad. Concrete and rock are two kinds of the most frequently used engineering materials and also frequently used as experimental objects currently. To compare dynamic mechanical performance of these two materials, this study performed dynamic compression test with five different strain rates on concrete and rock using Split Hopkinson Pressure Bar (SHPB to obtain basic dynamic mechanical parameters of them and then summarized the relationship of dynamic compressive strength, peak strain and strain rate of two materials. Moreover, specific energy absorption is introduced to confirm dynamic damage mechanisms of concrete and rock materials. This work can not only help to improve working efficiency to the largest extent but also ensure the smooth development of engineering, providing rich theoretical guidance for development of related engineering in the future

  7. Health, safety and environmental unit performance assessment model under uncertainty (case study: steel industry).

    Science.gov (United States)

    Shamaii, Azin; Omidvari, Manouchehr; Lotfi, Farhad Hosseinzadeh

    2017-01-01

    Performance assessment is a critical objective of management systems. As a result of the non-deterministic and qualitative nature of performance indicators, assessments are likely to be influenced by evaluators' personal judgments. Furthermore, in developing countries, performance assessments by the Health, Safety and Environment (HSE) department are based solely on the number of accidents. A questionnaire is used to conduct the study in one of the largest steel production companies in Iran. With respect to health, safety, and environment, the results revealed that control of disease, fire hazards, and air pollution are of paramount importance, with coefficients of 0.057, 0.062, and 0.054, respectively. Furthermore, health and environment indicators were found to be the most common causes of poor performance. Finally, it was shown that HSE management systems can affect the majority of performance safety indicators in the short run, whereas health and environment indicators require longer periods of time. The objective of this study is to present an HSE-MS unit performance assessment model in steel industries. Moreover, we seek to answer the following question: what are the factors that affect HSE unit system in the steel industry? Also, for each factor, the extent of impact on the performance of the HSE management system in the organization is determined.

  8. Study Habits and Academic Performance of Secondary School Students in Mathematic: A Case Study of Selected Secondary Schools in Uyo Local Education Council

    Science.gov (United States)

    Sakirudeen, Abisola Oladeni; Sanni, Kudirat Bimbo

    2017-01-01

    The study examined study habits and academic performance of secondary school students in Mathematics. A case study of selected secondary schools in Uyo Local Education Council. The main purpose of the study was to investigate the relationship between study habits and academic performance of secondary school students in Mathematics. To carry out…

  9. STUDY OF WITHERS HEIGHT AVERAGE PERFORMANCES IN HUCUL HORSE BREED – HROBY BLOODLINE

    Directory of Open Access Journals (Sweden)

    M. MAFTEI

    2008-10-01

    Full Text Available Study of average performances in a population have a huge importance because, regarding a population, the average of phenotypic value is equal with average of genotypic value. So, the studies of the average value of characters offer us an idea about the population genetic level. The biological material is represented by 177 hucul horse from Hroby bloodline divided in 6 stallion families (tab. 1 analyzed at 18, 30 and 42 months old, owned by Lucina hucul stood farm. The average performances for withers height are presented in tab. 2. We can observe here that the average performances of the character are between characteristic limits of the breed. Both sexes have a small grade of variability with a decreasing tendency in the same time with ageing. We can observe a normal evolution in time for growth process with significant differences only at age of 42 months. We can say in this condition that the average performances for withers height have different values, influenced by the age, with a decreasing tendency.

  10. STUDY OF WITHERS HEIGHT AVERAGE PERFORMANCES IN HUCUL HORSE BREED –GORAL BLOODLINE

    Directory of Open Access Journals (Sweden)

    M. MAFTEI

    2008-10-01

    Full Text Available Study of average performances in a population have a huge importance because, regarding a population, the average of phenotypic value is equal with average of genotypic value. So, the studies of the average value of characters offer us an idea about the population genetic level. The biological material is represented by 87 hucul horse from Goral bloodline divided in 5 stallion families (tab. 1 analyzed at 18, 30 and 42 months old, owned by Lucina hucul stood farm. The average performances for withers height are presented in tab. 2. We can observe here that the average performances of the character are between characteristic limits of the breed. Both sexes have a small grade of variability with a decreasing tendency in the same time with ageing. We can observe a normal evolution in time for growth process with significant differences only at age of 42 months. We can say in this condition that the average performances for withers height have different values, influenced by the age, with a decreasing tendency.

  11. THE INFLUENCE OF PARENTS’ EDUCATIONAL BACKGROUND AND STUDY FACILITIES ON ACADEMIC PERFORMANCE AMONG SECONDARY SCHOOL STUDENTS

    OpenAIRE

    ALOKAN, FUNMILOLA BOSEDE; OSAKINLE, EUNICE OLUFUNMILAYO; ONIJINGIN, EMMANUEL OLUBU

    2013-01-01

    There has been an outcry against the poor performance of students in the Senior Secondary Certificate Examination in Nigeria. This study investigated the difference between the academic performance of students from parents with high educational background and students from parents with low educational background. It also investigated the influence of having study facilities at home on academic performance. The population for this study comprised all public secondary school students in Ondo St...

  12. A performance study of unmanned aerial vehicle-based sensor networks under cyber attack

    Science.gov (United States)

    Puchaty, Ethan M.

    In UAV-based sensor networks, an emerging area of interest is the performance of these networks under cyber attack. This study seeks to evaluate the performance trade-offs from a System-of-Systems (SoS) perspective between various UAV communications architecture options in the context two missions: tracking ballistic missiles and tracking insurgents. An agent-based discrete event simulation is used to model a sensor communication network consisting of UAVs, military communications satellites, ground relay stations, and a mission control center. Network susceptibility to cyber attack is modeled with probabilistic failures and induced data variability, with performance metrics focusing on information availability, latency, and trustworthiness. Results demonstrated that using UAVs as routers increased network availability with a minimal latency penalty and communications satellite networks were best for long distance operations. Redundancy in the number of links between communication nodes helped mitigate cyber-caused link failures and add robustness in cases of induced data variability by an adversary. However, when failures were not independent, redundancy and UAV routing were detrimental in some cases to network performance. Sensitivity studies indicated that long cyber-caused downtimes and increasing failure dependencies resulted in build-ups of failures and caused significant degradations in network performance.

  13. Numerical Study of Aeroacoustic Sound on Performance of Bladeless Fan

    Science.gov (United States)

    Jafari, Mohammad; Sojoudi, Atta; Hafezisefat, Parinaz

    2017-03-01

    Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study, effect of five geometric parameters was investigated on well performance of a Bladeless fan. Airflow through this fan was analyzed simulating a Bladeless fan within a 2 m×2 m×4 m room. Analysis of the flow field inside the fan and evaluating its performance were obtained by solving conservations of mass and momentum equations for aerodynamic investigations and FW-H noise equations for aeroacoustic analysis. In order to design Bladeless fan Eppler 473 airfoil profile was used as the cross section of this fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter and aspect ratio for circular and quadratic cross sections were considered. Validating acoustic code results, we compared numerical solution of FW-H noise equations for NACA0012 with experimental results. FW-H model was selected to predict the noise generated by the Bladeless fan as the numerical results indicated a good agreement with experimental ones for NACA0012. To validate 3-D numerical results, the experimental results of a round jet showed good agreement with those simulation data. In order to indicate the effect of each mentioned parameter on the fan performance, SPL and OASPL diagrams were illustrated.

  14. Meta-analysis of prediction model performance across multiple studies: Which scale helps ensure between-study normality for the C-statistic and calibration measures?

    Science.gov (United States)

    Snell, Kym Ie; Ensor, Joie; Debray, Thomas Pa; Moons, Karel Gm; Riley, Richard D

    2017-01-01

    If individual participant data are available from multiple studies or clusters, then a prediction model can be externally validated multiple times. This allows the model's discrimination and calibration performance to be examined across different settings. Random-effects meta-analysis can then be used to quantify overall (average) performance and heterogeneity in performance. This typically assumes a normal distribution of 'true' performance across studies. We conducted a simulation study to examine this normality assumption for various performance measures relating to a logistic regression prediction model. We simulated data across multiple studies with varying degrees of variability in baseline risk or predictor effects and then evaluated the shape of the between-study distribution in the C-statistic, calibration slope, calibration-in-the-large, and E/O statistic, and possible transformations thereof. We found that a normal between-study distribution was usually reasonable for the calibration slope and calibration-in-the-large; however, the distributions of the C-statistic and E/O were often skewed across studies, particularly in settings with large variability in the predictor effects. Normality was vastly improved when using the logit transformation for the C-statistic and the log transformation for E/O, and therefore we recommend these scales to be used for meta-analysis. An illustrated example is given using a random-effects meta-analysis of the performance of QRISK2 across 25 general practices.

  15. Performance Study of optical Modulator based on electrooptic effect

    International Nuclear Information System (INIS)

    Palodiya, V; Raghuwanshi, S K

    2016-01-01

    In this paper, we have studied and derive performance parameter of highly integrated Lithium Niobate optical modulator. This is a chirp free modulator having low switching voltage and large bandwidth. For an external modulator in which travelling-wave electrodes length L imposed the modulating switching voltage, the product of V_π and L is fixed for a given electro optic material Lithium Niobate. We investigate to achieve a low V_π by both magnitude of the electro-optic coefficient for a wide variety of electro-optic materials. A Sellmeier equation for the extraordinary index of congruent lithium niobate is derived. For phase-matching, predictions are accmate for temperature between room temperature 250°C and wavelength ranging from 0.4 to 5µm. The Sellmeier equations predict more accmately refractive indices at long wavelengths. Theoretical result is confirmed by simulated results. We have analysed the various parameters such as switching voltage, device performance index, time constant, transmittance, cut-off frequency, 3-dB bandwidth, power absorption coefficient and transmission bit rate of Lithium Niobate optical Modulator based on electro -optic effect. (paper)

  16. Strategies employed for LHC software performance studies

    CERN Document Server

    Nowak, A

    2010-01-01

    The objective of this work is to collect and assess the software performance related strategies employed by the major players in the LHC software arena: the four main experiments (ALICE, ATLAS, CMS and LHCb) and the two main software frameworks (Geant4 and ROOT). As the software used differs between the parties, so do the directions and methods in optimization, and their intensity. The common feeling shared by nearly all interviewed parties is that performance is not one of their top priorities and that maintaining it at a constant level is a satisfactory solution, given the resources at hand. In principle, despite some organized efforts, a less structured approach seems to be the dominant one, and opportunistic optimization prevails. Four out of six surveyed groups are investigating memory management related effects, deemed to be the primary cause of their performance issues. The most commonly used tools include Valgrind and homegrown software. All questioned groups expressed the desire for advanced tools, s...

  17. Operation window and part-load performance study of a syngas fired gas turbine

    International Nuclear Information System (INIS)

    He, Fen; Li, Zheng; Liu, Pei; Ma, Linwei; Pistikopoulos, Efstratios N.

    2012-01-01

    Integrated coal gasification combined cycle (IGCC) provides a great opportunity for clean utilization of coal while maintaining the advantage of high energy efficiency brought by gas turbines. A challenging problem arising from the integration of an existing gas turbine to an IGCC system is the performance change of the gas turbine due to the shift of fuel from natural gas to synthesis gas, or syngas, mainly consisting of carbon monoxide and hydrogen. Besides the change of base-load performance, which has been extensively studied, the change of part-load performance is also of great significance for the operation of a gas turbine and an IGCC plant. In this paper, a detailed mathematical model of a syngas fired gas turbine is developed to study its part-load performance. A baseline is firstly established using the part-load performance of a natural gas fired gas turbine, then the part-load performance of the gas turbine running with different compositions of syngas is investigated and compared with the baseline. Particularly, the impacts of the variable inlet guide vane, the degree of fuel dilution, and the degree of air bleed are investigated. Results indicate that insufficient cooling of turbine blades and a reduced compressor surge margin are the major factors that constrain the part-load performance of a syngas fired gas turbine. Results also show that air bleed from the compressor can greatly improve the working condition of a syngas fired gas turbine, especially for those fired with low lower heating value syngas. The regulating strategy of a syngas fired gas turbine should also be adjusted in accordance to the changes of part-load performance, and a reduced scope of constant TAT (turbine exhaust temperature) control mode is required.

  18. Sleep and academic performance in later adolescence: results from a large population-based study.

    Science.gov (United States)

    Hysing, Mari; Harvey, Allison G; Linton, Steven J; Askeland, Kristin G; Sivertsen, Børge

    2016-06-01

    The aim of the current study was to assess the association between sleep duration and sleep patterns and academic performance in 16-19 year-old adolescents using registry-based academic grades. A large population-based study from Norway conducted in 2012, the youth@hordaland-survey, surveyed 7798 adolescents aged 16-19 years (53.5% girls). The survey was linked with objective outcome data on school performance. Self-reported sleep measures provided information on sleep duration, sleep efficiency, sleep deficit and bedtime differences between weekday and weekend. School performance [grade point average (GPA)] was obtained from official administrative registries. Most sleep parameters were associated with increased risk for poor school performance. After adjusting for sociodemographic information, short sleep duration and sleep deficit were the sleep measures with the highest odds of poor GPA (lowest quartile). Weekday bedtime was associated significantly with GPA, with adolescents going to bed between 22:00 and 23:00 hours having the best GPA. Also, delayed sleep schedule during weekends was associated with poor academic performance. The associations were somewhat reduced after additional adjustment for non-attendance at school, but remained significant in the fully adjusted models. In conclusion, the demonstrated relationship between sleep problems and poor academic performance suggests that careful assessment of sleep is warranted when adolescents are underperforming at school. Future studies are needed on the association between impaired sleep in adolescence and later functioning in adulthood. © 2016 European Sleep Research Society.

  19. Financial Indicators of Reduced Impact Logging Performance in Brazil: Case Study Comparisons

    Science.gov (United States)

    Thomas P. Holmes; Frederick Boltz; Douglas R. Carter

    2001-01-01

    Indicators of financial performance are compared for three case studies in the Brazilian Amazon. Each case study presents parameters obtained from monitoring initial harvest entries into primary forests for reduced impact logging (RIL) and conventional logging (CL) operations. Differences in cost definitions and data collection protocols complicate the analysis, and...

  20. Ultra high performance concrete dematerialization study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-03-01

    Concrete is the most widely used building material in the world and its use is expected to grow. It is well recognized that the production of portland cement results in the release of large amounts of carbon dioxide, a greenhouse gas (GHG). The main challenge facing the industry is to produce concrete in an environmentally sustainable manner. Reclaimed industrial by-proudcts such as fly ash, silica fume and slag can reduce the amount of portland cement needed to make concrete, thereby reducing the amount of GHGs released to the atmosphere. The use of these supplementary cementing materials (SCM) can also enhance the long-term strength and durability of concrete. The intention of the EcoSmart{sup TM} Concrete Project is to develop sustainable concrete through innovation in supply, design and construction. In particular, the project focuses on finding a way to minimize the GHG signature of concrete by maximizing the replacement of portland cement in the concrete mix with SCM while improving the cost, performance and constructability. This paper describes the use of Ductal{sup R} Ultra High Performance Concrete (UHPC) for ramps in a condominium. It examined the relationship between the selection of UHPC and the overall environmental performance, cost, constructability maintenance and operational efficiency as it relates to the EcoSmart Program. The advantages and challenges of using UHPC were outlined. In addition to its very high strength, UHPC has been shown to have very good potential for GHG emission reduction due to the reduced material requirements, reduced transport costs and increased SCM content. refs., tabs., figs.